drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
/*
|
|
|
|
|
* Core driver for the pin muxing portions of the pin control subsystem
|
|
|
|
|
*
|
2012-02-09 13:23:28 +07:00
|
|
|
* Copyright (C) 2011-2012 ST-Ericsson SA
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
* Written on behalf of Linaro for ST-Ericsson
|
|
|
|
|
* Based on bits of regulator core, gpio core and clk core
|
|
|
|
|
*
|
|
|
|
|
* Author: Linus Walleij <linus.walleij@linaro.org>
|
|
|
|
|
*
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
|
|
|
|
|
*
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
* License terms: GNU General Public License (GPL) version 2
|
|
|
|
|
*/
|
|
|
|
|
#define pr_fmt(fmt) "pinmux core: " fmt
|
|
|
|
|
|
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
|
#include <linux/init.h>
|
|
|
|
|
#include <linux/device.h>
|
|
|
|
|
#include <linux/slab.h>
|
|
|
|
|
#include <linux/radix-tree.h>
|
|
|
|
|
#include <linux/err.h>
|
|
|
|
|
#include <linux/list.h>
|
2011-11-29 18:52:39 +07:00
|
|
|
#include <linux/string.h>
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
#include <linux/sysfs.h>
|
|
|
|
|
#include <linux/debugfs.h>
|
|
|
|
|
#include <linux/seq_file.h>
|
|
|
|
|
#include <linux/pinctrl/machine.h>
|
|
|
|
|
#include <linux/pinctrl/pinmux.h>
|
|
|
|
|
#include "core.h"
|
2012-02-10 01:47:48 +07:00
|
|
|
#include "pinmux.h"
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2012-02-20 13:45:45 +07:00
|
|
|
int pinmux_check_ops(struct pinctrl_dev *pctldev)
|
|
|
|
|
{
|
|
|
|
|
const struct pinmux_ops *ops = pctldev->desc->pmxops;
|
2012-04-06 19:18:09 +07:00
|
|
|
unsigned nfuncs;
|
2012-02-20 13:45:45 +07:00
|
|
|
unsigned selector = 0;
|
|
|
|
|
|
|
|
|
|
/* Check that we implement required operations */
|
2012-04-06 19:18:09 +07:00
|
|
|
if (!ops ||
|
|
|
|
|
!ops->get_functions_count ||
|
2012-02-20 13:45:45 +07:00
|
|
|
!ops->get_function_name ||
|
|
|
|
|
!ops->get_function_groups ||
|
2014-09-03 18:02:56 +07:00
|
|
|
!ops->set_mux) {
|
2012-04-26 21:47:11 +07:00
|
|
|
dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
|
2012-02-20 13:45:45 +07:00
|
|
|
return -EINVAL;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
2012-02-20 13:45:45 +07:00
|
|
|
/* Check that all functions registered have names */
|
2012-04-06 19:18:09 +07:00
|
|
|
nfuncs = ops->get_functions_count(pctldev);
|
2012-03-30 12:55:40 +07:00
|
|
|
while (selector < nfuncs) {
|
2012-02-20 13:45:45 +07:00
|
|
|
const char *fname = ops->get_function_name(pctldev,
|
|
|
|
|
selector);
|
|
|
|
|
if (!fname) {
|
2012-04-06 19:18:09 +07:00
|
|
|
dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
|
2012-02-20 13:45:45 +07:00
|
|
|
selector);
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
selector++;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2012-03-03 03:05:48 +07:00
|
|
|
int pinmux_validate_map(struct pinctrl_map const *map, int i)
|
|
|
|
|
{
|
|
|
|
|
if (!map->data.mux.function) {
|
|
|
|
|
pr_err("failed to register map %s (%d): no function given\n",
|
|
|
|
|
map->name, i);
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
/**
|
|
|
|
|
* pin_request() - request a single pin to be muxed in, typically for GPIO
|
|
|
|
|
* @pin: the pin number in the global pin space
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
* @owner: a representation of the owner of this pin; typically the device
|
|
|
|
|
* name that controls its mux function, or the requested GPIO name
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
* @gpio_range: the range matching the GPIO pin if this is a request for a
|
|
|
|
|
* single GPIO pin
|
|
|
|
|
*/
|
|
|
|
|
static int pin_request(struct pinctrl_dev *pctldev,
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
int pin, const char *owner,
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
struct pinctrl_gpio_range *gpio_range)
|
|
|
|
|
{
|
|
|
|
|
struct pin_desc *desc;
|
|
|
|
|
const struct pinmux_ops *ops = pctldev->desc->pmxops;
|
|
|
|
|
int status = -EINVAL;
|
|
|
|
|
|
|
|
|
|
desc = pin_desc_get(pctldev, pin);
|
|
|
|
|
if (desc == NULL) {
|
2011-12-10 06:59:05 +07:00
|
|
|
dev_err(pctldev->dev,
|
2012-05-02 00:14:15 +07:00
|
|
|
"pin %d is not registered so it cannot be requested\n",
|
|
|
|
|
pin);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2012-04-17 14:00:45 +07:00
|
|
|
dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
|
|
|
|
|
pin, desc->name, owner);
|
|
|
|
|
|
2016-12-25 07:59:28 +07:00
|
|
|
if ((!gpio_range || ops->strict) &&
|
|
|
|
|
desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
|
|
|
|
|
dev_err(pctldev->dev,
|
|
|
|
|
"pin %s already requested by %s; cannot claim for %s\n",
|
|
|
|
|
desc->name, desc->mux_owner, owner);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((gpio_range || ops->strict) && desc->gpio_owner) {
|
|
|
|
|
dev_err(pctldev->dev,
|
|
|
|
|
"pin %s already requested by %s; cannot claim for %s\n",
|
|
|
|
|
desc->name, desc->gpio_owner, owner);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2012-03-03 03:05:46 +07:00
|
|
|
|
2016-12-25 07:59:28 +07:00
|
|
|
if (gpio_range) {
|
2012-03-06 07:22:15 +07:00
|
|
|
desc->gpio_owner = owner;
|
|
|
|
|
} else {
|
|
|
|
|
desc->mux_usecount++;
|
|
|
|
|
if (desc->mux_usecount > 1)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
desc->mux_owner = owner;
|
|
|
|
|
}
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
/* Let each pin increase references to this module */
|
|
|
|
|
if (!try_module_get(pctldev->owner)) {
|
2011-12-10 06:59:05 +07:00
|
|
|
dev_err(pctldev->dev,
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
"could not increase module refcount for pin %d\n",
|
|
|
|
|
pin);
|
|
|
|
|
status = -EINVAL;
|
|
|
|
|
goto out_free_pin;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If there is no kind of request function for the pin we just assume
|
|
|
|
|
* we got it by default and proceed.
|
|
|
|
|
*/
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
if (gpio_range && ops->gpio_request_enable)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
/* This requests and enables a single GPIO pin */
|
|
|
|
|
status = ops->gpio_request_enable(pctldev, gpio_range, pin);
|
|
|
|
|
else if (ops->request)
|
|
|
|
|
status = ops->request(pctldev, pin);
|
|
|
|
|
else
|
|
|
|
|
status = 0;
|
|
|
|
|
|
2012-03-03 03:05:46 +07:00
|
|
|
if (status) {
|
2012-05-02 00:14:15 +07:00
|
|
|
dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
|
2012-03-03 03:05:46 +07:00
|
|
|
module_put(pctldev->owner);
|
|
|
|
|
}
|
|
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
out_free_pin:
|
2012-03-03 03:05:46 +07:00
|
|
|
if (status) {
|
2012-03-06 07:22:15 +07:00
|
|
|
if (gpio_range) {
|
|
|
|
|
desc->gpio_owner = NULL;
|
|
|
|
|
} else {
|
|
|
|
|
desc->mux_usecount--;
|
|
|
|
|
if (!desc->mux_usecount)
|
|
|
|
|
desc->mux_owner = NULL;
|
|
|
|
|
}
|
2012-03-03 03:05:46 +07:00
|
|
|
}
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
out:
|
|
|
|
|
if (status)
|
2011-12-10 06:59:05 +07:00
|
|
|
dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
|
2012-05-02 00:14:15 +07:00
|
|
|
pin, owner, status);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
return status;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pin_free() - release a single muxed in pin so something else can be muxed
|
|
|
|
|
* @pctldev: pin controller device handling this pin
|
|
|
|
|
* @pin: the pin to free
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
* @gpio_range: the range matching the GPIO pin if this is a request for a
|
|
|
|
|
* single GPIO pin
|
2011-11-10 15:27:41 +07:00
|
|
|
*
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
* This function returns a pointer to the previous owner. This is used
|
|
|
|
|
* for callers that dynamically allocate an owner name so it can be freed
|
2011-11-10 15:27:41 +07:00
|
|
|
* once the pin is free. This is done for GPIO request functions.
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
*/
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
|
|
|
|
|
struct pinctrl_gpio_range *gpio_range)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
|
|
|
|
const struct pinmux_ops *ops = pctldev->desc->pmxops;
|
|
|
|
|
struct pin_desc *desc;
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
const char *owner;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
desc = pin_desc_get(pctldev, pin);
|
|
|
|
|
if (desc == NULL) {
|
2011-12-10 06:59:05 +07:00
|
|
|
dev_err(pctldev->dev,
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
"pin is not registered so it cannot be freed\n");
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
return NULL;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
2012-03-06 07:22:15 +07:00
|
|
|
if (!gpio_range) {
|
2013-03-21 18:21:47 +07:00
|
|
|
/*
|
|
|
|
|
* A pin should not be freed more times than allocated.
|
|
|
|
|
*/
|
|
|
|
|
if (WARN_ON(!desc->mux_usecount))
|
|
|
|
|
return NULL;
|
2012-03-06 07:22:15 +07:00
|
|
|
desc->mux_usecount--;
|
|
|
|
|
if (desc->mux_usecount)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
2012-03-03 03:05:46 +07:00
|
|
|
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
/*
|
|
|
|
|
* If there is no kind of request function for the pin we just assume
|
|
|
|
|
* we got it by default and proceed.
|
|
|
|
|
*/
|
|
|
|
|
if (gpio_range && ops->gpio_disable_free)
|
|
|
|
|
ops->gpio_disable_free(pctldev, gpio_range, pin);
|
|
|
|
|
else if (ops->free)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
ops->free(pctldev, pin);
|
|
|
|
|
|
2012-03-06 07:22:15 +07:00
|
|
|
if (gpio_range) {
|
|
|
|
|
owner = desc->gpio_owner;
|
|
|
|
|
desc->gpio_owner = NULL;
|
|
|
|
|
} else {
|
|
|
|
|
owner = desc->mux_owner;
|
|
|
|
|
desc->mux_owner = NULL;
|
|
|
|
|
desc->mux_setting = NULL;
|
|
|
|
|
}
|
|
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
module_put(pctldev->owner);
|
pinctrl: add explicit gpio_disable_free pinmux_op
Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a
completely different manner than they select which function to mux out of
that pin. In order to support a single "free" pinmux_op, the driver would
need to maintain a per-pin state of requested-for-gpio vs. requested-for-
function. However, that's a lot of work when the core already has explicit
separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free()
call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and
when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming
special case, so instead, I reworked pin_free() to always return the pin's
previously requested function, and now pinmux_free_gpio() calls
kfree(function). This is much more balanced with the allocation having
been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-22 01:25:53 +07:00
|
|
|
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
return owner;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
2012-02-10 01:47:48 +07:00
|
|
|
* pinmux_request_gpio() - request pinmuxing for a GPIO pin
|
|
|
|
|
* @pctldev: pin controller device affected
|
|
|
|
|
* @pin: the pin to mux in for GPIO
|
|
|
|
|
* @range: the applicable GPIO range
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
*/
|
2012-02-10 01:47:48 +07:00
|
|
|
int pinmux_request_gpio(struct pinctrl_dev *pctldev,
|
|
|
|
|
struct pinctrl_gpio_range *range,
|
|
|
|
|
unsigned pin, unsigned gpio)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
const char *owner;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
/* Conjure some name stating what chip and pin this is taken by */
|
2012-09-14 02:48:14 +07:00
|
|
|
owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
if (!owner)
|
2016-05-25 18:14:13 +07:00
|
|
|
return -ENOMEM;
|
2011-10-20 05:19:28 +07:00
|
|
|
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
ret = pin_request(pctldev, pin, owner, range);
|
2011-10-20 05:19:28 +07:00
|
|
|
if (ret < 0)
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
kfree(owner);
|
2011-10-20 05:19:28 +07:00
|
|
|
|
|
|
|
|
return ret;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
2012-02-10 01:47:48 +07:00
|
|
|
* pinmux_free_gpio() - release a pin from GPIO muxing
|
|
|
|
|
* @pctldev: the pin controller device for the pin
|
|
|
|
|
* @pin: the affected currently GPIO-muxed in pin
|
|
|
|
|
* @range: applicable GPIO range
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
*/
|
2012-02-10 01:47:48 +07:00
|
|
|
void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
|
|
|
|
|
struct pinctrl_gpio_range *range)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
const char *owner;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
pinctrl: record a pin owner, not mux function, when requesting pins
When pins are requested/acquired/got, some device becomes the owner of
their mux setting. At this point, it isn't certain which mux function
will be selected for the pin, since this may vary between each of the
device's states in the pinctrl mapping table. As such, we should record
the owning device, not what we think the initial mux setting will be,
when requesting pins.
This doesn't make a lot of difference right now since pinctrl_get gets
only one single device/state combination, but this will make a difference
when pinctrl_get gets all states, and pinctrl_select_state can switch
between states.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-20 13:45:44 +07:00
|
|
|
owner = pin_free(pctldev, pin, range);
|
|
|
|
|
kfree(owner);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
2012-02-10 01:47:48 +07:00
|
|
|
/**
|
|
|
|
|
* pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
|
|
|
|
|
* @pctldev: the pin controller handling this pin
|
|
|
|
|
* @range: applicable GPIO range
|
|
|
|
|
* @pin: the affected GPIO pin in this controller
|
|
|
|
|
* @input: true if we set the pin as input, false for output
|
|
|
|
|
*/
|
|
|
|
|
int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
|
|
|
|
|
struct pinctrl_gpio_range *range,
|
|
|
|
|
unsigned pin, bool input)
|
2011-11-14 16:06:22 +07:00
|
|
|
{
|
|
|
|
|
const struct pinmux_ops *ops;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ops = pctldev->desc->pmxops;
|
|
|
|
|
|
|
|
|
|
if (ops->gpio_set_direction)
|
|
|
|
|
ret = ops->gpio_set_direction(pctldev, range, pin, input);
|
|
|
|
|
else
|
|
|
|
|
ret = 0;
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
|
|
|
|
|
const char *function)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
|
|
|
|
const struct pinmux_ops *ops = pctldev->desc->pmxops;
|
2012-03-30 12:55:40 +07:00
|
|
|
unsigned nfuncs = ops->get_functions_count(pctldev);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
unsigned selector = 0;
|
|
|
|
|
|
|
|
|
|
/* See if this pctldev has this function */
|
2012-03-30 12:55:40 +07:00
|
|
|
while (selector < nfuncs) {
|
2015-08-01 11:22:38 +07:00
|
|
|
const char *fname = ops->get_function_name(pctldev, selector);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
if (!strcmp(function, fname))
|
|
|
|
|
return selector;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
selector++;
|
|
|
|
|
}
|
|
|
|
|
|
2015-07-21 13:25:27 +07:00
|
|
|
dev_err(pctldev->dev, "function '%s' not supported\n", function);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
int pinmux_map_to_setting(struct pinctrl_map const *map,
|
|
|
|
|
struct pinctrl_setting *setting)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
struct pinctrl_dev *pctldev = setting->pctldev;
|
|
|
|
|
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
|
|
|
|
|
char const * const *groups;
|
|
|
|
|
unsigned num_groups;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
int ret;
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
const char *group;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2012-04-10 11:41:34 +07:00
|
|
|
if (!pmxops) {
|
|
|
|
|
dev_err(pctldev->dev, "does not support mux function\n");
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
2012-04-24 00:01:58 +07:00
|
|
|
ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
|
2012-04-26 21:47:11 +07:00
|
|
|
if (ret < 0) {
|
|
|
|
|
dev_err(pctldev->dev, "invalid function %s in map table\n",
|
|
|
|
|
map->data.mux.function);
|
2012-04-24 00:01:58 +07:00
|
|
|
return ret;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
2012-04-24 00:01:58 +07:00
|
|
|
setting->data.mux.func = ret;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2012-03-03 03:05:48 +07:00
|
|
|
ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
&groups, &num_groups);
|
2012-04-26 21:47:11 +07:00
|
|
|
if (ret < 0) {
|
|
|
|
|
dev_err(pctldev->dev, "can't query groups for function %s\n",
|
|
|
|
|
map->data.mux.function);
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
return ret;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
|
|
|
|
if (!num_groups) {
|
|
|
|
|
dev_err(pctldev->dev,
|
|
|
|
|
"function %s can't be selected on any group\n",
|
|
|
|
|
map->data.mux.function);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
return -EINVAL;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
2012-03-03 03:05:48 +07:00
|
|
|
if (map->data.mux.group) {
|
|
|
|
|
group = map->data.mux.group;
|
2016-03-18 04:22:20 +07:00
|
|
|
ret = match_string(groups, num_groups, group);
|
|
|
|
|
if (ret < 0) {
|
2012-04-26 21:47:11 +07:00
|
|
|
dev_err(pctldev->dev,
|
|
|
|
|
"invalid group \"%s\" for function \"%s\"\n",
|
|
|
|
|
group, map->data.mux.function);
|
2016-03-18 04:22:20 +07:00
|
|
|
return ret;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
} else {
|
|
|
|
|
group = groups[0];
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
2012-04-24 00:01:58 +07:00
|
|
|
ret = pinctrl_get_group_selector(pctldev, group);
|
2012-04-26 21:47:11 +07:00
|
|
|
if (ret < 0) {
|
|
|
|
|
dev_err(pctldev->dev, "invalid group %s in map table\n",
|
|
|
|
|
map->data.mux.group);
|
2012-04-24 00:01:58 +07:00
|
|
|
return ret;
|
2012-04-26 21:47:11 +07:00
|
|
|
}
|
2012-04-24 00:01:58 +07:00
|
|
|
setting->data.mux.group = ret;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
void pinmux_free_setting(struct pinctrl_setting const *setting)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
2012-10-18 01:51:54 +07:00
|
|
|
/* This function is currently unused */
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
int pinmux_enable_setting(struct pinctrl_setting const *setting)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
struct pinctrl_dev *pctldev = setting->pctldev;
|
2012-03-03 03:05:49 +07:00
|
|
|
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
|
2012-02-10 01:47:48 +07:00
|
|
|
const struct pinmux_ops *ops = pctldev->desc->pmxops;
|
2014-04-10 20:07:50 +07:00
|
|
|
int ret = 0;
|
|
|
|
|
const unsigned *pins = NULL;
|
|
|
|
|
unsigned num_pins = 0;
|
2012-03-03 03:05:49 +07:00
|
|
|
int i;
|
|
|
|
|
struct pin_desc *desc;
|
|
|
|
|
|
2014-04-10 20:07:50 +07:00
|
|
|
if (pctlops->get_group_pins)
|
|
|
|
|
ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
|
|
|
|
|
&pins, &num_pins);
|
|
|
|
|
|
2012-03-03 03:05:49 +07:00
|
|
|
if (ret) {
|
2013-08-14 23:23:33 +07:00
|
|
|
const char *gname;
|
|
|
|
|
|
2012-03-03 03:05:49 +07:00
|
|
|
/* errors only affect debug data, so just warn */
|
2013-08-14 23:23:33 +07:00
|
|
|
gname = pctlops->get_group_name(pctldev,
|
|
|
|
|
setting->data.mux.group);
|
2012-03-03 03:05:49 +07:00
|
|
|
dev_warn(pctldev->dev,
|
2013-08-14 23:23:33 +07:00
|
|
|
"could not get pins for group %s\n",
|
|
|
|
|
gname);
|
2012-03-03 03:05:49 +07:00
|
|
|
num_pins = 0;
|
|
|
|
|
}
|
|
|
|
|
|
2012-10-18 01:51:54 +07:00
|
|
|
/* Try to allocate all pins in this group, one by one */
|
|
|
|
|
for (i = 0; i < num_pins; i++) {
|
|
|
|
|
ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
|
|
|
|
|
if (ret) {
|
2013-08-14 23:23:33 +07:00
|
|
|
const char *gname;
|
|
|
|
|
const char *pname;
|
|
|
|
|
|
|
|
|
|
desc = pin_desc_get(pctldev, pins[i]);
|
|
|
|
|
pname = desc ? desc->name : "non-existing";
|
|
|
|
|
gname = pctlops->get_group_name(pctldev,
|
|
|
|
|
setting->data.mux.group);
|
2012-10-18 01:51:54 +07:00
|
|
|
dev_err(pctldev->dev,
|
2013-08-14 23:23:33 +07:00
|
|
|
"could not request pin %d (%s) from group %s "
|
|
|
|
|
" on device %s\n",
|
|
|
|
|
pins[i], pname, gname,
|
|
|
|
|
pinctrl_dev_get_name(pctldev));
|
2012-11-10 20:53:20 +07:00
|
|
|
goto err_pin_request;
|
2012-10-18 01:51:54 +07:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Now that we have acquired the pins, encode the mux setting */
|
2012-03-03 03:05:49 +07:00
|
|
|
for (i = 0; i < num_pins; i++) {
|
|
|
|
|
desc = pin_desc_get(pctldev, pins[i]);
|
|
|
|
|
if (desc == NULL) {
|
|
|
|
|
dev_warn(pctldev->dev,
|
|
|
|
|
"could not get pin desc for pin %d\n",
|
|
|
|
|
pins[i]);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
desc->mux_setting = &(setting->data.mux);
|
|
|
|
|
}
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2014-09-03 18:02:56 +07:00
|
|
|
ret = ops->set_mux(pctldev, setting->data.mux.func,
|
|
|
|
|
setting->data.mux.group);
|
2012-11-10 20:53:20 +07:00
|
|
|
|
|
|
|
|
if (ret)
|
2014-09-03 18:02:56 +07:00
|
|
|
goto err_set_mux;
|
2012-11-10 20:53:20 +07:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
|
2014-09-03 18:02:56 +07:00
|
|
|
err_set_mux:
|
2012-11-10 20:53:20 +07:00
|
|
|
for (i = 0; i < num_pins; i++) {
|
|
|
|
|
desc = pin_desc_get(pctldev, pins[i]);
|
|
|
|
|
if (desc)
|
|
|
|
|
desc->mux_setting = NULL;
|
|
|
|
|
}
|
|
|
|
|
err_pin_request:
|
|
|
|
|
/* On error release all taken pins */
|
|
|
|
|
while (--i >= 0)
|
|
|
|
|
pin_free(pctldev, pins[i], NULL);
|
|
|
|
|
|
|
|
|
|
return ret;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
void pinmux_disable_setting(struct pinctrl_setting const *setting)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
struct pinctrl_dev *pctldev = setting->pctldev;
|
2012-03-03 03:05:49 +07:00
|
|
|
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
|
2014-04-10 20:07:50 +07:00
|
|
|
int ret = 0;
|
|
|
|
|
const unsigned *pins = NULL;
|
|
|
|
|
unsigned num_pins = 0;
|
2012-03-03 03:05:49 +07:00
|
|
|
int i;
|
|
|
|
|
struct pin_desc *desc;
|
|
|
|
|
|
2014-04-10 20:07:50 +07:00
|
|
|
if (pctlops->get_group_pins)
|
|
|
|
|
ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
|
|
|
|
|
&pins, &num_pins);
|
2012-03-03 03:05:49 +07:00
|
|
|
if (ret) {
|
2013-08-14 23:23:33 +07:00
|
|
|
const char *gname;
|
|
|
|
|
|
2012-03-03 03:05:49 +07:00
|
|
|
/* errors only affect debug data, so just warn */
|
2013-08-14 23:23:33 +07:00
|
|
|
gname = pctlops->get_group_name(pctldev,
|
|
|
|
|
setting->data.mux.group);
|
2012-03-03 03:05:49 +07:00
|
|
|
dev_warn(pctldev->dev,
|
2013-08-14 23:23:33 +07:00
|
|
|
"could not get pins for group %s\n",
|
|
|
|
|
gname);
|
2012-03-03 03:05:49 +07:00
|
|
|
num_pins = 0;
|
|
|
|
|
}
|
|
|
|
|
|
2012-10-18 01:51:54 +07:00
|
|
|
/* Flag the descs that no setting is active */
|
2012-03-03 03:05:49 +07:00
|
|
|
for (i = 0; i < num_pins; i++) {
|
|
|
|
|
desc = pin_desc_get(pctldev, pins[i]);
|
|
|
|
|
if (desc == NULL) {
|
|
|
|
|
dev_warn(pctldev->dev,
|
|
|
|
|
"could not get pin desc for pin %d\n",
|
|
|
|
|
pins[i]);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
2013-08-14 12:26:43 +07:00
|
|
|
if (desc->mux_setting == &(setting->data.mux)) {
|
|
|
|
|
desc->mux_setting = NULL;
|
|
|
|
|
/* And release the pin */
|
|
|
|
|
pin_free(pctldev, pins[i], NULL);
|
2013-08-14 23:23:33 +07:00
|
|
|
} else {
|
|
|
|
|
const char *gname;
|
|
|
|
|
|
|
|
|
|
gname = pctlops->get_group_name(pctldev,
|
|
|
|
|
setting->data.mux.group);
|
|
|
|
|
dev_warn(pctldev->dev,
|
|
|
|
|
"not freeing pin %d (%s) as part of "
|
|
|
|
|
"deactivating group %s - it is already "
|
|
|
|
|
"used for some other setting",
|
2013-10-29 10:50:45 +07:00
|
|
|
pins[i], desc->name, gname);
|
2013-08-14 12:26:43 +07:00
|
|
|
}
|
2012-03-03 03:05:49 +07:00
|
|
|
}
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
|
|
|
|
|
|
/* Called from pincontrol core */
|
|
|
|
|
static int pinmux_functions_show(struct seq_file *s, void *what)
|
|
|
|
|
{
|
|
|
|
|
struct pinctrl_dev *pctldev = s->private;
|
|
|
|
|
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
|
2012-04-10 11:41:34 +07:00
|
|
|
unsigned nfuncs;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
unsigned func_selector = 0;
|
|
|
|
|
|
2012-04-10 11:41:34 +07:00
|
|
|
if (!pmxops)
|
|
|
|
|
return 0;
|
pinctrl: fix and simplify locking
There are many problems with the current pinctrl locking:
struct pinctrl_dev's gpio_ranges_lock isn't effective;
pinctrl_match_gpio_range() only holds this lock while searching for a gpio
range, but the found range is return and manipulated after releading the
lock. This could allow pinctrl_remove_gpio_range() for that range while it
is in use, and the caller may very well delete the range after removing it,
causing pinctrl code to touch the now-free range object.
Solving this requires the introduction of a higher-level lock, at least
a lock per pin controller, which both gpio range registration and
pinctrl_get()/put() will acquire.
There is missing locking on HW programming; pin controllers may pack the
configuration for different pins/groups/config options/... into one
register, and hence have to read-modify-write the register. This needs to
be protected, but currently isn't. Related, a future change will add a
"complete" op to the pin controller drivers, the idea being that each
state's programming will be programmed into the pinctrl driver followed
by the "complete" call, which may e.g. flush a register cache to HW. For
this to work, it must not be possible to interleave the pinctrl driver
calls for different devices.
As above, solving this requires the introduction of a higher-level lock,
at least a lock per pin controller, which will be held for the duration
of any pinctrl_enable()/disable() call.
However, each pinctrl mapping table entry may affect a different pin
controller if necessary. Hence, with a per-pin-controller lock, almost
any pinctrl API may need to acquire multiple locks, one per controller.
To avoid deadlock, these would need to be acquired in the same order in
all cases. This is extremely difficult to implement in the case of
pinctrl_get(), which doesn't know which pin controllers to lock until it
has parsed the entire mapping table, since it contains somewhat arbitrary
data.
The simplest solution here is to introduce a single lock that covers all
pin controllers at once. This will be acquired by all pinctrl APIs.
This then makes struct pinctrl's mutex irrelevant, since that single lock
will always be held whenever this mutex is currently held.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:44 +07:00
|
|
|
|
pinctrl: move subsystem mutex to pinctrl_dev struct
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.
Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().
For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
- pinctrl_get()/pinctrl_put()
- pinctrl_register_maps()
So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.
Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.
Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().
Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
is located inside pinctrl_select_state(). When parsing
the state->setting list, take the per-pin-controller driver
lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
in all functions which parse or modify pictrldev_list.
(Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
pinctrl/core.c in order to protect pinctrldev_list.
(Patrice).
- Sink mutex:es into some functions and remove some _locked
variants down to where the lists are actually accessed to
make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
and pinctrl_select_state() - no relevant mutex was taken
and it was unclear what this was protecting against. (Linus)
Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-11 16:01:27 +07:00
|
|
|
mutex_lock(&pctldev->mutex);
|
2012-04-10 11:41:34 +07:00
|
|
|
nfuncs = pmxops->get_functions_count(pctldev);
|
2012-03-30 12:55:40 +07:00
|
|
|
while (func_selector < nfuncs) {
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
const char *func = pmxops->get_function_name(pctldev,
|
|
|
|
|
func_selector);
|
|
|
|
|
const char * const *groups;
|
|
|
|
|
unsigned num_groups;
|
|
|
|
|
int ret;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
ret = pmxops->get_function_groups(pctldev, func_selector,
|
|
|
|
|
&groups, &num_groups);
|
2015-06-08 22:16:37 +07:00
|
|
|
if (ret) {
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
|
|
|
|
|
func);
|
2015-06-08 22:16:37 +07:00
|
|
|
func_selector++;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
|
|
|
|
seq_printf(s, "function: %s, groups = [ ", func);
|
|
|
|
|
for (i = 0; i < num_groups; i++)
|
|
|
|
|
seq_printf(s, "%s ", groups[i]);
|
|
|
|
|
seq_puts(s, "]\n");
|
|
|
|
|
|
|
|
|
|
func_selector++;
|
|
|
|
|
}
|
|
|
|
|
|
pinctrl: move subsystem mutex to pinctrl_dev struct
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.
Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().
For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
- pinctrl_get()/pinctrl_put()
- pinctrl_register_maps()
So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.
Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.
Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().
Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
is located inside pinctrl_select_state(). When parsing
the state->setting list, take the per-pin-controller driver
lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
in all functions which parse or modify pictrldev_list.
(Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
pinctrl/core.c in order to protect pinctrldev_list.
(Patrice).
- Sink mutex:es into some functions and remove some _locked
variants down to where the lists are actually accessed to
make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
and pinctrl_select_state() - no relevant mutex was taken
and it was unclear what this was protecting against. (Linus)
Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-11 16:01:27 +07:00
|
|
|
mutex_unlock(&pctldev->mutex);
|
pinctrl: fix and simplify locking
There are many problems with the current pinctrl locking:
struct pinctrl_dev's gpio_ranges_lock isn't effective;
pinctrl_match_gpio_range() only holds this lock while searching for a gpio
range, but the found range is return and manipulated after releading the
lock. This could allow pinctrl_remove_gpio_range() for that range while it
is in use, and the caller may very well delete the range after removing it,
causing pinctrl code to touch the now-free range object.
Solving this requires the introduction of a higher-level lock, at least
a lock per pin controller, which both gpio range registration and
pinctrl_get()/put() will acquire.
There is missing locking on HW programming; pin controllers may pack the
configuration for different pins/groups/config options/... into one
register, and hence have to read-modify-write the register. This needs to
be protected, but currently isn't. Related, a future change will add a
"complete" op to the pin controller drivers, the idea being that each
state's programming will be programmed into the pinctrl driver followed
by the "complete" call, which may e.g. flush a register cache to HW. For
this to work, it must not be possible to interleave the pinctrl driver
calls for different devices.
As above, solving this requires the introduction of a higher-level lock,
at least a lock per pin controller, which will be held for the duration
of any pinctrl_enable()/disable() call.
However, each pinctrl mapping table entry may affect a different pin
controller if necessary. Hence, with a per-pin-controller lock, almost
any pinctrl API may need to acquire multiple locks, one per controller.
To avoid deadlock, these would need to be acquired in the same order in
all cases. This is extremely difficult to implement in the case of
pinctrl_get(), which doesn't know which pin controllers to lock until it
has parsed the entire mapping table, since it contains somewhat arbitrary
data.
The simplest solution here is to introduce a single lock that covers all
pin controllers at once. This will be acquired by all pinctrl APIs.
This then makes struct pinctrl's mutex irrelevant, since that single lock
will always be held whenever this mutex is currently held.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:44 +07:00
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int pinmux_pins_show(struct seq_file *s, void *what)
|
|
|
|
|
{
|
|
|
|
|
struct pinctrl_dev *pctldev = s->private;
|
2012-03-03 03:05:49 +07:00
|
|
|
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
|
|
|
|
|
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
|
2012-01-03 14:47:50 +07:00
|
|
|
unsigned i, pin;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2012-04-10 11:41:34 +07:00
|
|
|
if (!pmxops)
|
|
|
|
|
return 0;
|
|
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
seq_puts(s, "Pinmux settings per pin\n");
|
2015-05-28 15:11:19 +07:00
|
|
|
if (pmxops->strict)
|
|
|
|
|
seq_puts(s,
|
|
|
|
|
"Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
|
|
|
|
|
else
|
|
|
|
|
seq_puts(s,
|
|
|
|
|
"Format: pin (name): mux_owner gpio_owner hog?\n");
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
pinctrl: move subsystem mutex to pinctrl_dev struct
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.
Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().
For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
- pinctrl_get()/pinctrl_put()
- pinctrl_register_maps()
So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.
Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.
Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().
Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
is located inside pinctrl_select_state(). When parsing
the state->setting list, take the per-pin-controller driver
lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
in all functions which parse or modify pictrldev_list.
(Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
pinctrl/core.c in order to protect pinctrldev_list.
(Patrice).
- Sink mutex:es into some functions and remove some _locked
variants down to where the lists are actually accessed to
make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
and pinctrl_select_state() - no relevant mutex was taken
and it was unclear what this was protecting against. (Linus)
Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-11 16:01:27 +07:00
|
|
|
mutex_lock(&pctldev->mutex);
|
pinctrl: fix and simplify locking
There are many problems with the current pinctrl locking:
struct pinctrl_dev's gpio_ranges_lock isn't effective;
pinctrl_match_gpio_range() only holds this lock while searching for a gpio
range, but the found range is return and manipulated after releading the
lock. This could allow pinctrl_remove_gpio_range() for that range while it
is in use, and the caller may very well delete the range after removing it,
causing pinctrl code to touch the now-free range object.
Solving this requires the introduction of a higher-level lock, at least
a lock per pin controller, which both gpio range registration and
pinctrl_get()/put() will acquire.
There is missing locking on HW programming; pin controllers may pack the
configuration for different pins/groups/config options/... into one
register, and hence have to read-modify-write the register. This needs to
be protected, but currently isn't. Related, a future change will add a
"complete" op to the pin controller drivers, the idea being that each
state's programming will be programmed into the pinctrl driver followed
by the "complete" call, which may e.g. flush a register cache to HW. For
this to work, it must not be possible to interleave the pinctrl driver
calls for different devices.
As above, solving this requires the introduction of a higher-level lock,
at least a lock per pin controller, which will be held for the duration
of any pinctrl_enable()/disable() call.
However, each pinctrl mapping table entry may affect a different pin
controller if necessary. Hence, with a per-pin-controller lock, almost
any pinctrl API may need to acquire multiple locks, one per controller.
To avoid deadlock, these would need to be acquired in the same order in
all cases. This is extremely difficult to implement in the case of
pinctrl_get(), which doesn't know which pin controllers to lock until it
has parsed the entire mapping table, since it contains somewhat arbitrary
data.
The simplest solution here is to introduce a single lock that covers all
pin controllers at once. This will be acquired by all pinctrl APIs.
This then makes struct pinctrl's mutex irrelevant, since that single lock
will always be held whenever this mutex is currently held.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:44 +07:00
|
|
|
|
2012-01-03 14:47:50 +07:00
|
|
|
/* The pin number can be retrived from the pin controller descriptor */
|
|
|
|
|
for (i = 0; i < pctldev->desc->npins; i++) {
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
struct pin_desc *desc;
|
2012-02-24 12:53:04 +07:00
|
|
|
bool is_hog = false;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
|
2012-01-03 14:47:50 +07:00
|
|
|
pin = pctldev->desc->pins[i].number;
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
desc = pin_desc_get(pctldev, pin);
|
2012-01-03 14:47:50 +07:00
|
|
|
/* Skip if we cannot search the pin */
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
if (desc == NULL)
|
|
|
|
|
continue;
|
|
|
|
|
|
2012-03-06 07:22:15 +07:00
|
|
|
if (desc->mux_owner &&
|
|
|
|
|
!strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
|
2012-02-24 12:53:04 +07:00
|
|
|
is_hog = true;
|
|
|
|
|
|
2015-05-28 15:11:19 +07:00
|
|
|
if (pmxops->strict) {
|
|
|
|
|
if (desc->mux_owner)
|
|
|
|
|
seq_printf(s, "pin %d (%s): device %s%s",
|
2016-05-24 12:26:26 +07:00
|
|
|
pin, desc->name, desc->mux_owner,
|
2015-05-28 15:11:19 +07:00
|
|
|
is_hog ? " (HOG)" : "");
|
|
|
|
|
else if (desc->gpio_owner)
|
|
|
|
|
seq_printf(s, "pin %d (%s): GPIO %s",
|
2016-05-24 12:26:26 +07:00
|
|
|
pin, desc->name, desc->gpio_owner);
|
2015-05-28 15:11:19 +07:00
|
|
|
else
|
|
|
|
|
seq_printf(s, "pin %d (%s): UNCLAIMED",
|
2016-05-24 12:26:26 +07:00
|
|
|
pin, desc->name);
|
2015-05-28 15:11:19 +07:00
|
|
|
} else {
|
|
|
|
|
/* For non-strict controllers */
|
2016-05-24 12:26:26 +07:00
|
|
|
seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
|
2015-05-28 15:11:19 +07:00
|
|
|
desc->mux_owner ? desc->mux_owner
|
|
|
|
|
: "(MUX UNCLAIMED)",
|
|
|
|
|
desc->gpio_owner ? desc->gpio_owner
|
|
|
|
|
: "(GPIO UNCLAIMED)",
|
|
|
|
|
is_hog ? " (HOG)" : "");
|
|
|
|
|
}
|
2012-03-03 03:05:49 +07:00
|
|
|
|
2015-05-28 15:11:19 +07:00
|
|
|
/* If mux: print function+group claiming the pin */
|
2012-03-03 03:05:49 +07:00
|
|
|
if (desc->mux_setting)
|
|
|
|
|
seq_printf(s, " function %s group %s\n",
|
|
|
|
|
pmxops->get_function_name(pctldev,
|
|
|
|
|
desc->mux_setting->func),
|
|
|
|
|
pctlops->get_group_name(pctldev,
|
|
|
|
|
desc->mux_setting->group));
|
|
|
|
|
else
|
|
|
|
|
seq_printf(s, "\n");
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
pinctrl: move subsystem mutex to pinctrl_dev struct
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.
Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().
For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
- pinctrl_get()/pinctrl_put()
- pinctrl_register_maps()
So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.
Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.
Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().
Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
is located inside pinctrl_select_state(). When parsing
the state->setting list, take the per-pin-controller driver
lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
in all functions which parse or modify pictrldev_list.
(Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
pinctrl/core.c in order to protect pinctrldev_list.
(Patrice).
- Sink mutex:es into some functions and remove some _locked
variants down to where the lists are actually accessed to
make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
and pinctrl_select_state() - no relevant mutex was taken
and it was unclear what this was protecting against. (Linus)
Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-11 16:01:27 +07:00
|
|
|
mutex_unlock(&pctldev->mutex);
|
pinctrl: fix and simplify locking
There are many problems with the current pinctrl locking:
struct pinctrl_dev's gpio_ranges_lock isn't effective;
pinctrl_match_gpio_range() only holds this lock while searching for a gpio
range, but the found range is return and manipulated after releading the
lock. This could allow pinctrl_remove_gpio_range() for that range while it
is in use, and the caller may very well delete the range after removing it,
causing pinctrl code to touch the now-free range object.
Solving this requires the introduction of a higher-level lock, at least
a lock per pin controller, which both gpio range registration and
pinctrl_get()/put() will acquire.
There is missing locking on HW programming; pin controllers may pack the
configuration for different pins/groups/config options/... into one
register, and hence have to read-modify-write the register. This needs to
be protected, but currently isn't. Related, a future change will add a
"complete" op to the pin controller drivers, the idea being that each
state's programming will be programmed into the pinctrl driver followed
by the "complete" call, which may e.g. flush a register cache to HW. For
this to work, it must not be possible to interleave the pinctrl driver
calls for different devices.
As above, solving this requires the introduction of a higher-level lock,
at least a lock per pin controller, which will be held for the duration
of any pinctrl_enable()/disable() call.
However, each pinctrl mapping table entry may affect a different pin
controller if necessary. Hence, with a per-pin-controller lock, almost
any pinctrl API may need to acquire multiple locks, one per controller.
To avoid deadlock, these would need to be acquired in the same order in
all cases. This is extremely difficult to implement in the case of
pinctrl_get(), which doesn't know which pin controllers to lock until it
has parsed the entire mapping table, since it contains somewhat arbitrary
data.
The simplest solution here is to introduce a single lock that covers all
pin controllers at once. This will be acquired by all pinctrl APIs.
This then makes struct pinctrl's mutex irrelevant, since that single lock
will always be held whenever this mutex is currently held.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:44 +07:00
|
|
|
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2012-03-03 03:05:48 +07:00
|
|
|
void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
|
|
|
|
|
{
|
|
|
|
|
seq_printf(s, "group %s\nfunction %s\n",
|
|
|
|
|
map->data.mux.group ? map->data.mux.group : "(default)",
|
|
|
|
|
map->data.mux.function);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void pinmux_show_setting(struct seq_file *s,
|
|
|
|
|
struct pinctrl_setting const *setting)
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
{
|
pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:
a) The data representation of the parsed mapping table, into:
1) The top-level struct pinctrl object, a single entity returned
by pinctrl_get().
2) The parsed version of each mapping table entry, struct
pinctrl_setting, of which there is one per mapping table entry.
b) The code that handles this; the code for (1) above is in core.c, and
the code to parse/execute each entry in (2) above is in pinmux.c, while
the iteration over multiple settings is lifted to core.c.
This will allow the following future changes:
1) pinctrl_get() API rework, so that struct pinctrl represents all states
for the device, and the device can select between them without calling
put()/get() again.
2) To support that, a struct pinctrl_state object will be inserted into
the data model between the struct pinctrl and struct pinctrl_setting.
3) The mapping table will be extended to allow specification of pin config
settings too. To support this, struct pinctrl_setting will be enhanced
to store either mux settings or config settings, and functions will be
added to pinconf.c to parse/execute pin configuration settings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-03 03:05:45 +07:00
|
|
|
struct pinctrl_dev *pctldev = setting->pctldev;
|
|
|
|
|
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
|
|
|
|
|
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
|
|
|
|
|
|
2012-03-03 03:05:48 +07:00
|
|
|
seq_printf(s, "group: %s (%u) function: %s (%u)\n",
|
|
|
|
|
pctlops->get_group_name(pctldev, setting->data.mux.group),
|
|
|
|
|
setting->data.mux.group,
|
|
|
|
|
pmxops->get_function_name(pctldev, setting->data.mux.func),
|
|
|
|
|
setting->data.mux.func);
|
drivers: create a pin control subsystem
This creates a subsystem for handling of pin control devices.
These are devices that control different aspects of package
pins.
Currently it handles pinmuxing, i.e. assigning electronic
functions to groups of pins on primarily PGA and BGA type of
chip packages which are common in embedded systems.
The plan is to also handle other I/O pin control aspects
such as biasing, driving, input properties such as
schmitt-triggering, load capacitance etc within this
subsystem, to remove a lot of ARM arch code as well as
feature-creepy GPIO drivers which are implementing the same
thing over and over again.
This is being done to depopulate the arch/arm/* directory
of such custom drivers and try to abstract the infrastructure
they all need. See the Documentation/pinctrl.txt file that is
part of this patch for more details.
ChangeLog v1->v2:
- Various minor fixes from Joe's and Stephens review comments
- Added a pinmux_config() that can invoke custom configuration
with arbitrary data passed in or out to/from the pinmux driver
ChangeLog v2->v3:
- Renamed subsystem folder to "pinctrl" since we will likely
want to keep other pin control such as biasing in this
subsystem too, so let us keep to something generic even though
we're mainly doing pinmux now.
- As a consequence, register pins as an abstract entity separate
from the pinmux. The muxing functions will claim pins out of the
pin pool and make sure they do not collide. Pins can now be
named by the pinctrl core.
- Converted the pin lookup from a static array into a radix tree,
I agreed with Grant Likely to try to avoid any static allocation
(which is crap for device tree stuff) so I just rewrote this
to be dynamic, just like irq number descriptors. The
platform-wide definition of number of pins goes away - this is
now just the sum total of the pins registered to the subsystem.
- Make sure mappings with only a function name and no device
works properly.
ChangeLog v3->v4:
- Define a number space per controller instead of globally,
Stephen and Grant requested the same thing so now maps need to
define target controller, and the radix tree of pin descriptors
is a property on each pin controller device.
- Add a compulsory pinctrl device entry to the pinctrl mapping
table. This must match the pinctrl device, like "pinctrl.0"
- Split the file core.c in two: core.c and pinmux.c where the
latter carry all pinmux stuff, the core is for generic pin
control, and use local headers to access functionality between
files. It is now possible to implement a "blank" pin controller
without pinmux capabilities. This split will make new additions
like pindrive.c, pinbias.c etc possible for combined drivers
and chunks of functionality which is a GoodThing(TM).
- Rewrite the interaction with the GPIO subsystem - the pin
controller descriptor now handles this by defining an offset
into the GPIO numberspace for its handled pin range. This is
used to look up the apropriate pin controller for a GPIO pin.
Then that specific GPIO range is matched 1-1 for the target
controller instance.
- Fixed a number of review comments from Joe Perches.
- Broke out a header file pinctrl.h for the core pin handling
stuff that will be reused by other stuff than pinmux.
- Fixed some erroneous EXPORT() stuff.
- Remove mispatched U300 Kconfig and Makefile entries
- Fixed a number of review comments from Stephen Warren, not all
of them - still WIP. But I think the new mapping that will
specify which function goes to which pin mux controller address
50% of your concerns (else beat me up).
ChangeLog v4->v5:
- Defined a "position" for each function, so the pin controller now
tracks a function in a certain position, and the pinmux maps define
what position you want the function in. (Feedback from Stephen
Warren and Sascha Hauer).
- Since we now need to request a combined function+position from
the machine mapping table that connect mux settings to drivers,
it was extended with a position field and a name field. The
name field is now used if you e.g. need to switch between two
mux map settings at runtime.
- Switched from a class device to using struct bus_type for this
subsystem. Verified sysfs functionality: seems to work fine.
(Feedback from Arnd Bergmann and Greg Kroah-Hartman)
- Define a per pincontroller list of GPIO ranges from the GPIO
pin space that can be handled by the pin controller. These can
be added one by one at runtime. (Feedback from Barry Song)
- Expanded documentation of regulator_[get|enable|disable|put]
semantics.
- Fixed a number of review comments from Barry Song. (Thanks!)
ChangeLog v5->v6:
- Create an abstract pin group concept that can sort pins into
named and enumerated groups no matter what the use of these
groups may be, one possible usecase is a group of pins being
muxed in or so. The intention is however to also use these
groups for other pin control activities.
- Make it compulsory for pinmux functions to associate with
at least one group, so the abstract pin group concept is used
to define the groups of pins affected by a pinmux function.
The pinmux driver interface has been altered so as to enforce
a function to list applicable groups per function.
- Provide an optional .group entry in the pinmux machine map
so the map can select beteween different available groups
to be used with a certain function.
- Consequent changes all over the place so that e.g. debugfs
present reasonable information about the world.
- Drop the per-pin mux (*config) function in the pinmux_ops
struct - I was afraid that this would start to be used for
things totally unrelated to muxing, we can introduce that to
the generic struct pinctrl_ops if needed. I want to keep
muxing orthogonal to other pin control subjects and not mix
these things up.
ChangeLog v6->v7:
- Make it possible to have several map entries matching the
same device, pin controller and function, but using
a different group, and alter the semantics so that
pinmux_get() will pick all matching map entries, and
store the associated groups in a list. The list will
then be iterated over at pinmux_enable()/pinmux_disable()
and corresponding driver functions called for each
defined group. Notice that you're only allowed to map
multiple *groups* to the same
{ device, pin controller, function } triplet, attempts
to map the same device to multiple pin controllers will
for example fail. This is hopefully the crucial feature
requested by Stephen Warren.
- Add a pinmux hogging field to the pinmux mapping entries,
and enable the pinmux core to hog pinmux map entries.
This currently only works for pinmuxes without assigned
devices as it looks now, but with device trees we can
look up the corresponding struct device * entries when
we register the pinmux driver, and have it hog each
pinmux map in turn, for a simple approach to
non-dynamic pin muxing. This addresses an issue from
Grant Likely that the machine should take care of as
much of the pinmux setup as possible, not the devices.
By supplying a list of hogs, it can now instruct the
core to take care of any static mappings.
- Switch pinmux group retrieveal function to grab an
array of strings representing the groups rather than an
array of unsigned and rewrite accordingly.
- Alter debugfs to show the grouplist handled by each
pinmux. Also add a list of hogs.
- Dynamically allocate a struct pinmux at pinmux_get() and
free it at pinmux_put(), then add these to the global
list of pinmuxes active as we go along.
- Go over the list of pinmux maps at pinmux_get() time
and repeatedly apply matches.
- Retrieve applicable groups per function from the driver
as a string array rather than a unsigned array, then
lookup the enumerators.
- Make the device to pinmux map a singleton - only allow the
mapping table to be registered once and even tag the
registration function with __init so it surely won't be
abused.
- Create a separate debugfs file to view the pinmux map at
runtime.
- Introduce a spin lock to the pin descriptor struct, lock it
when modifying pin status entries. Reported by Stijn Devriendt.
- Fix up the documentation after review from Stephen Warren.
- Let the GPIO ranges give names as const char * instead of some
fixed-length string.
- add a function to unregister GPIO ranges to mirror the
registration function.
- Privatized the struct pinctrl_device and removed it from the
<linux/pinctrl/pinctrl.h> API, the drivers do not need to know
the members of this struct. It is now in the local header
"core.h".
- Rename the concept of "anonymous" mux maps to "system" muxes
and add convenience macros and documentation.
ChangeLog v7->v8:
- Delete the leftover pinmux_config() function from the
<linux/pinctrl/pinmux.h> header.
- Fix a race condition found by Stijn Devriendt in pin_request()
ChangeLog v8->v9:
- Drop the bus_type and the sysfs attributes and all, we're not on
the clear about how this should be used for e.g. userspace
interfaces so let us save this for the future.
- Use the right name in MAINTAINERS, PIN CONTROL rather than
PINMUX
- Don't kfree() the device state holder, let the .remove() callback
handle this.
- Fix up numerous kerneldoc headers to have one line for the function
description and more verbose documentation below the parameters
ChangeLog v9->v10:
- pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
from Steven Rothwell
- fix pinctrl_register error handling, folded in a patch from
Axel Lin
- Various fixes to documentation text so that it's consistent.
- Removed pointless comment from drivers/Kconfig
- Removed dependency on SYSFS since we removed the bus in
v9.
- Renamed hopelessly abbreviated pctldev_* functions to the
more verbose pinctrl_dev_*
- Drop mutex properly when looking up GPIO ranges
- Return NULL instead of ERR_PTR() errors on registration of
pin controllers, using cast pointers is fragile. We can
live without the detailed error codes for sure.
Cc: Stijn Devriendt <highguy@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 01:50:54 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int pinmux_functions_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
return single_open(file, pinmux_functions_show, inode->i_private);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int pinmux_pins_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
return single_open(file, pinmux_pins_show, inode->i_private);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct file_operations pinmux_functions_ops = {
|
|
|
|
|
.open = pinmux_functions_open,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = single_release,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static const struct file_operations pinmux_pins_ops = {
|
|
|
|
|
.open = pinmux_pins_open,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = single_release,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
void pinmux_init_device_debugfs(struct dentry *devroot,
|
|
|
|
|
struct pinctrl_dev *pctldev)
|
|
|
|
|
{
|
|
|
|
|
debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
|
|
|
|
|
devroot, pctldev, &pinmux_functions_ops);
|
|
|
|
|
debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
|
|
|
|
|
devroot, pctldev, &pinmux_pins_ops);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* CONFIG_DEBUG_FS */
|
2016-12-28 00:20:01 +07:00
|
|
|
|
|
|
|
|
#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_get_function_count() - returns number of functions
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
*/
|
|
|
|
|
int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
|
|
|
|
|
{
|
|
|
|
|
return pctldev->num_functions;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_get_function_name() - returns the function name
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
* @selector: function number
|
|
|
|
|
*/
|
|
|
|
|
const char *
|
|
|
|
|
pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
|
|
|
|
|
unsigned int selector)
|
|
|
|
|
{
|
|
|
|
|
struct function_desc *function;
|
|
|
|
|
|
|
|
|
|
function = radix_tree_lookup(&pctldev->pin_function_tree,
|
|
|
|
|
selector);
|
|
|
|
|
if (!function)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
return function->name;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_get_function_groups() - gets the function groups
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
* @selector: function number
|
|
|
|
|
* @groups: array of pin groups
|
|
|
|
|
* @num_groups: number of pin groups
|
|
|
|
|
*/
|
|
|
|
|
int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
|
|
|
|
|
unsigned int selector,
|
|
|
|
|
const char * const **groups,
|
|
|
|
|
unsigned * const num_groups)
|
|
|
|
|
{
|
|
|
|
|
struct function_desc *function;
|
|
|
|
|
|
|
|
|
|
function = radix_tree_lookup(&pctldev->pin_function_tree,
|
|
|
|
|
selector);
|
|
|
|
|
if (!function) {
|
|
|
|
|
dev_err(pctldev->dev, "%s could not find function%i\n",
|
|
|
|
|
__func__, selector);
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
*groups = function->group_names;
|
|
|
|
|
*num_groups = function->num_group_names;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_get_function() - returns a function based on the number
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
* @group_selector: function number
|
|
|
|
|
*/
|
|
|
|
|
struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
|
|
|
|
|
unsigned int selector)
|
|
|
|
|
{
|
|
|
|
|
struct function_desc *function;
|
|
|
|
|
|
|
|
|
|
function = radix_tree_lookup(&pctldev->pin_function_tree,
|
|
|
|
|
selector);
|
|
|
|
|
if (!function)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
return function;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
|
|
|
|
|
|
|
|
|
|
/**
|
2017-04-03 15:32:42 +07:00
|
|
|
* pinmux_generic_add_function() - adds a function group
|
2016-12-28 00:20:01 +07:00
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
* @name: name of the function
|
|
|
|
|
* @groups: array of pin groups
|
|
|
|
|
* @num_groups: number of pin groups
|
|
|
|
|
* @data: pin controller driver specific data
|
|
|
|
|
*/
|
|
|
|
|
int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
|
|
|
|
|
const char *name,
|
|
|
|
|
const char **groups,
|
|
|
|
|
const unsigned int num_groups,
|
|
|
|
|
void *data)
|
|
|
|
|
{
|
|
|
|
|
struct function_desc *function;
|
|
|
|
|
|
|
|
|
|
function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
|
|
|
|
|
if (!function)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
function->name = name;
|
|
|
|
|
function->group_names = groups;
|
|
|
|
|
function->num_group_names = num_groups;
|
|
|
|
|
function->data = data;
|
|
|
|
|
|
|
|
|
|
radix_tree_insert(&pctldev->pin_function_tree, pctldev->num_functions,
|
|
|
|
|
function);
|
|
|
|
|
|
|
|
|
|
pctldev->num_functions++;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_remove_function() - removes a numbered function
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
* @selector: function number
|
|
|
|
|
*
|
|
|
|
|
* Note that the caller must take care of locking.
|
|
|
|
|
*/
|
|
|
|
|
int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
|
|
|
|
|
unsigned int selector)
|
|
|
|
|
{
|
|
|
|
|
struct function_desc *function;
|
|
|
|
|
|
|
|
|
|
function = radix_tree_lookup(&pctldev->pin_function_tree,
|
|
|
|
|
selector);
|
|
|
|
|
if (!function)
|
|
|
|
|
return -ENOENT;
|
|
|
|
|
|
|
|
|
|
radix_tree_delete(&pctldev->pin_function_tree, selector);
|
|
|
|
|
devm_kfree(pctldev->dev, function);
|
|
|
|
|
|
|
|
|
|
pctldev->num_functions--;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* pinmux_generic_free_functions() - removes all functions
|
|
|
|
|
* @pctldev: pin controller device
|
|
|
|
|
*
|
2017-05-12 22:47:57 +07:00
|
|
|
* Note that the caller must take care of locking. The pinctrl
|
|
|
|
|
* functions are allocated with devm_kzalloc() so no need to free
|
|
|
|
|
* them here.
|
2016-12-28 00:20:01 +07:00
|
|
|
*/
|
|
|
|
|
void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
|
|
|
|
|
{
|
|
|
|
|
struct radix_tree_iter iter;
|
|
|
|
|
void **slot;
|
|
|
|
|
|
|
|
|
|
radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
|
2017-05-12 22:47:57 +07:00
|
|
|
radix_tree_delete(&pctldev->pin_function_tree, iter.index);
|
2016-12-28 00:20:01 +07:00
|
|
|
|
|
|
|
|
pctldev->num_functions = 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */
|