Commit Graph

264 Commits

Author SHA1 Message Date
Linus Walleij
df4878e969 gpio: store reflect the label to userspace
The gpio_chip label is useful for userspace to understand what
kind of GPIO chip it is dealing with. Let's store a copy of this
label in the gpio_device, add it to the struct passed to userspace
for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:48:41 +01:00
Josh Cartwright
969f07b445 gpio: use kzalloc to allocate gpio_device
The use of kmalloc() to allocate the gpio_device leaves the contained struct
device object in an unknown state.  Calling dev_set_name() on a struct device
of unknown state can trigger the free() of an invalid pointer, as seen in the
following backtrace (collected by Tony Lindgren):

  kfree
  kobject_set_name_vargs
  dev_set_name
  gpiochip_add_data
  omap_gpio_probe
  platform_drv_probe
  ...

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Michael Welling <mwelling@ieee.org>
Reported-by: Tony Lindgren <tony@atomide.com>
Tested-by: Michael Welling <mwelling@ieee.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Josh Cartwright <joshc@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-18 20:45:25 +01:00
Linus Walleij
143b65d677 gpio: create an API to detect open drain/source on lines
My left hand merges code to privatize the descriptor handling
while my right hand merges drivers that poke around and
disrespect with the same gpiolib internals.

So let's expose the proper APIs for drivers to ask the gpiolib
core if a line is marked as open drain or open source and
get some order around things so this driver compiles again.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 15:41:42 +01:00
Linus Walleij
43c54ecade gpio: move the subdriver data pointer into gpio_device
We move to manage this pointer under gpiolib control rather than
leave it in the subdevice's gpio_chip. We can not NULL it after
gpiochip_remove so at to keep things tight.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:02 +01:00
Linus Walleij
20ec3e39fc gpio: move the pin ranges into gpio_device
Instead of keeping this reference to the pin ranges in the
client driver-supplied gpio_chip, move it to the internal
gpio_device as the drivers have no need to inspect this.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:02 +01:00
Linus Walleij
33a68e86fd gpio: reference count the gpio device for each desc
Every time a descriptor is retrieved from the gpiolib, we issue
module_get() to reference count the module supplying the GPIOs.
We also need to call device_get() and device_put() as we also
reference the backing gpio_device when doing this.

Since the sysfs GPIO interface is using gpiod_get() this will
also reference count the sysfs requests until all GPIOs are
unexported.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:46 +01:00
Linus Walleij
fdeb8e1547 gpio: reflect base and ngpio into gpio_device
Some information about the GPIO chip need to stay around also
after the gpio_chip has been removed and only the gpio_device
persist. The base and ngpio are such things, for example we
don't want a new chip arriving to overlap the number space
of a dangling gpio_device, and the chardev may still query
the device for the number of lines etc.

Note that the code that assigns base and insert gpio_device
into the global list no longer check for a missing gpio_chip:
we respect the number space allocated by any other gpio_device.

As a consequence of the gdev being referenced directly from
the gpio_desc, we need to verify it differently from all
in-kernel API calls that fall through to direct queries to
the gpio_chip vtable: we first check that desc is !NULL, then
that desc->gdev is !NULL, then, if desc->gdev->chip is NULL,
we *BAIL OUT* without any error, so as to manage the case
where operations are requested on a device that is gone.

These checks were non-uniform and partly missing in the past:
so to simplify: create the macros VALIDATE_DESC() that will
return -EINVAL if the desc or desc->gdev is missing and just
0 if the chip is gone, and conversely VALIDATE_DESC_VOID()
for the case where the function does not return an error.
By using these macros, we get warning messages about missing
gdev with reference to the right function in the kernel log.

Despite the macro business this simplifies the code and make
it more readable than if we copy/paste the same descriptor
checking code into all code ABI call sites (IMHO).

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:46 +01:00
Linus Walleij
6cee3821e4 gpio/pinctrl: sunxi: stop poking around in private vars
This kind of hacks disturbs the refactoring of the gpiolib.

The descriptor table belongs to the gpiolib, if we want to know
something about something in it, use or define the proper accessor
functions. Let's add this gpiochip_lins_is_irq() to do what the
sunxi driver is trying at so we can privatize the descriptors
properly.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:45 +01:00
Linus Walleij
1c3cdb1861 gpio: move descriptors into gpio_device
We need gpio_device to hold the descriptors so that they can
be lifecycled with the struct gpio_device held from userspace.
Move the descriptor array into gpio_device. Also rename it from
"desc" (singularis) to "descs" (pluralis) to reflect the fact
that it is an array.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 20:29:45 +01:00
Linus Walleij
afbc4f312b gpio: move sysfs mock device to the gpio_device
Since gpio_device is the struct that survives if the backing
gpio_chip is removed, move the sysfs mock device to this state
container so it becomes part of the dangling state of the
GPIO device on removal.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 18:16:54 +01:00
Linus Walleij
9efd9e6956 gpio: remember to finally free gpio_device
When the device core reference count for the device goes to
0 and it calls .release() we free resources and so can also
finally free up the GPIO state container, struct gpio_device.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11 18:16:53 +01:00
Linus Walleij
3c702e9987 gpio: add a userspace chardev ABI for GPIOs
A new chardev that is to be used for userspace GPIO access is
added in this patch. It is intended to gradually replace the
horribly broken sysfs ABI.

Using a chardev has many upsides:

- All operations are per-gpiochip, which is the actual
  device underlying the GPIOs, making us tie in to the
  kernel device model properly.

- Hotpluggable GPIO controllers can come and go, as this
  kind of problem has been know to userspace for character
  devices since ages, and if a gpiochip handle is held in
  userspace we know we will break something, whereas the
  sysfs is stateless.

- The one-value-per-file rule of sysfs is really hard to
  maintain when you want to twist more than one knob at a time,
  for example have in-kernel APIs to switch several GPIO
  lines at the same time, and this will be possible to do
  with a single ioctl() from userspace, saving a lot of
  context switching.

We also need to add a new bus type for GPIO. This is
necessary for example for userspace coldplug, where sysfs is
traversed to find the boot-time device nodes and create the
character devices in /dev.

This new chardev ABI is *non* *optional* and can be counted
on to be present in the future, emphasizing the preference
of this ABI.

The ABI only implements one single ioctl() to get the name
and number of GPIO lines of a chip. Even this is debatable:
see it as a minimal example for review. This ABI shall be
ruthlessly reviewed and etched in stone.

The old /sys/class/gpio is still optional to compile in,
but will be deprecated.

Unique device IDs are created using IDR, which is overkill
and insanely scalable, but also well tested.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:09:35 +01:00
Linus Walleij
34ffd85d9c gpio: refer to gpio device in prints and debugfs
We use the new struct device inside gpio_chip to related debug
prints and warnings, and we also add it to the debugfs dump.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:09:30 +01:00
Linus Walleij
ff2b135922 gpio: make the gpiochip a real device
GPIO chips have been around for years, but were never real devices,
instead they were piggy-backing on a parent device (such as a
platform_device or amba_device) but this was always optional.
GPIO chips could also exist without any device at all, with its
struct device *parent (ex *dev) pointer being set to null.

When sysfs was in use, a mock device would be created, with the
optional parent assigned, or just floating orphaned with NULL
as parent.

If sysfs is active, it will use this device as parent.

We now create a gpio_device struct containing a real
struct device and move the subsystem over to using that. The
list of struct gpio_chip:s is augmented to hold struct
gpio_device:s and we find gpio_chips:s by first looking up
the struct gpio_device.

The struct gpio_device is designed to stay around even if the
gpio_chip is removed, so as to satisfy users in userspace
that need a backing data structure to hold the state of the
session initiated with e.g. a character device even if there is
no physical chip anymore.

From this point on, gpiochips are devices.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09 11:03:53 +01:00
Linus Torvalds
58cf279aca GPIO bulk updates for the v4.5 kernel cycle:
Infrastructural changes:
 
 - In struct gpio_chip, rename the .dev node to .parent to better reflect
   the fact that this is not the GPIO struct device abstraction. We will
   add that soon so this would be totallt confusing.
 
 - It was noted that the driver .get_value() callbacks was
   sometimes reporting negative -ERR values to the gpiolib core, expecting
   them to be propagated to consumer gpiod_get_value() and gpio_get_value()
   calls. This was not happening, so as there was a mess of drivers
   returning negative errors and some returning "anything else than zero"
   to indicate that a line was active. As some would have bit 31 set to
   indicate "line active" it clashed with negative error codes. This is
   fixed by the largeish series clamping values in all drivers with
   !!value to [0,1] and then augmenting the code to propagate error codes
   to consumers. (Includes some ACKed patches in other subsystems.)
 
 - Add a void *data pointer to struct gpio_chip. The container_of() design
   pattern is indeed very nice, but we want to reform the struct gpio_chip
   to be a non-volative, stateless business, and keep states internal to
   the gpiolib to be able to hold on to the state when adding a proper
   userspace ABI (character device) further down the road. To achieve this,
   drivers need a handle at the internal state that is not dependent on
   their struct gpio_chip() so we add gpiochip_add_data() and
   gpiochip_get_data() following the pattern of many other subsystems.
   All the "use gpiochip data pointer" patches transforms drivers to this
   scheme.
 
 - The Generic GPIO chip header has been merged into the general
   <linux/gpio/driver.h> header, and the custom header for that removed.
   Instead of having a separate mm_gpio_chip struct for these generic
   drivers, merge that into struct gpio_chip, simplifying the code and
   removing the need for separate and confusing includes.
 
 Misc improvements:
 
 - Stabilize the way GPIOs are looked up from the ACPI legacy
   specification.
 
 - Incremental driver features for PXA, PCA953X, Lantiq (patches from the
   OpenWRT community), RCAR, Zynq, PL061, 104-idi-48
 
 New drivers:
 
 - Add a GPIO chip to the ALSA SoC AC97 driver.
 
 - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir, but
   the branch is merged here too to account for infrastructural changes).
 
 - The sx150x driver now supports the sx1502.
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Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "Here is the bulk of GPIO changes for v4.5.

  Notably there are big refactorings mostly by myself, aimed at getting
  the gpio_chip into a shape that makes me believe I can proceed to
  preserve state for a proper userspace ABI (character device) that has
  already been proposed once, but resulted in the feedback that I need
  to go back and restructure stuff.  So I've been restructuring stuff.
  On the way I ran into brokenness (return code from the get_value()
  callback) and had to fix it.  Also, refactored generic GPIO to be
  simpler.

  Some of that is still waiting to trickle down from the subsystems all
  over the kernel that provide random gpio_chips, I've touched every
  single GPIO driver in the kernel now, oh man I didn't know I was
  responsible for so much...

  Apart from that we're churning along as usual.

  I took some effort to test and retest so it should merge nicely and we
  shook out a couple of bugs in -next.

  Infrastructural changes:

   - In struct gpio_chip, rename the .dev node to .parent to better
     reflect the fact that this is not the GPIO struct device
     abstraction.  We will add that soon so this would be totallt
     confusing.

   - It was noted that the driver .get_value() callbacks was sometimes
     reporting negative -ERR values to the gpiolib core, expecting them
     to be propagated to consumer gpiod_get_value() and gpio_get_value()
     calls.  This was not happening, so as there was a mess of drivers
     returning negative errors and some returning "anything else than
     zero" to indicate that a line was active.  As some would have bit
     31 set to indicate "line active" it clashed with negative error
     codes.  This is fixed by the largeish series clamping values in all
     drivers with !!value to [0,1] and then augmenting the code to
     propagate error codes to consumers.  (Includes some ACKed patches
     in other subsystems.)

   - Add a void *data pointer to struct gpio_chip.  The container_of()
     design pattern is indeed very nice, but we want to reform the
     struct gpio_chip to be a non-volative, stateless business, and keep
     states internal to the gpiolib to be able to hold on to the state
     when adding a proper userspace ABI (character device) further down
     the road.  To achieve this, drivers need a handle at the internal
     state that is not dependent on their struct gpio_chip() so we add
     gpiochip_add_data() and gpiochip_get_data() following the pattern
     of many other subsystems.  All the "use gpiochip data pointer"
     patches transforms drivers to this scheme.

   - The Generic GPIO chip header has been merged into the general
     <linux/gpio/driver.h> header, and the custom header for that
     removed.  Instead of having a separate mm_gpio_chip struct for
     these generic drivers, merge that into struct gpio_chip,
     simplifying the code and removing the need for separate and
     confusing includes.

  Misc improvements:

   - Stabilize the way GPIOs are looked up from the ACPI legacy
     specification.

   - Incremental driver features for PXA, PCA953X, Lantiq (patches from
     the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48

  New drivers:

   - Add a GPIO chip to the ALSA SoC AC97 driver.

   - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
     but the branch is merged here too to account for infrastructural
     changes).

   - The sx150x driver now supports the sx1502"

* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
  gpio: generic: make bgpio_pdata always visible
  gpiolib: fix chip order in gpio list
  gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
  gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
  gpio: brcmstb: Allow building driver for BMIPS_GENERIC
  gpio: brcmstb: Set endian flags for big-endian MIPS
  gpio: moxart: fix build regression
  gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
  leds: pca9532: use gpiochip data pointer
  leds: tca6507: use gpiochip data pointer
  hid: cp2112: use gpiochip data pointer
  bcma: gpio: use gpiochip data pointer
  avr32: gpio: use gpiochip data pointer
  video: fbdev: via: use gpiochip data pointer
  gpio: pch: Optimize pch_gpio_get()
  Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
  pinctrl: nsp-gpio: use gpiochip data pointer
  pinctrl: vt8500-wmt: use gpiochip data pointer
  pinctrl: exynos5440: use gpiochip data pointer
  pinctrl: at91-pio4: use gpiochip data pointer
  ...
2016-01-17 12:32:01 -08:00
Linus Torvalds
1c5ff2ab7b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
 - new driver for eGalaxTouch serial touchscreen
 - new driver for TS-4800 touchscreen
 - an update for Goodix touchscreen driver
 - PS/2 mouse module was reworked to limit number of protocols we try on
   pass-through ports to speed up their detection time
 - wacom_w8001 touchscreen driver now reports pen and touch via separate
   instances of input devices
 - other driver changes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (42 commits)
  Input: elantech - mark protocols v2 and v3 as semi-mt
  Input: wacom_w8001 - drop use of ABS_MT_TOOL_TYPE
  Input: gpio-keys - fix check for disabling unsupported keys
  Input: omap-keypad - remove dead check
  Input: ti_am335x_tsc - fix HWPEN interrupt handling
  Input: omap-keypad - set tasklet data earlier
  Input: rohm_bu21023 - fix handling of retrying firmware update
  Input: ALPS - report v3 pinnacle trackstick device only if is present
  Input: ALPS - detect trackstick presence for v7 protocol
  Input: pcap_ts - use to_delayed_work
  Input: bma150 - constify bma150_cfg structure
  Input: i8042 - add Fujitsu Lifebook U745 to the nomux list
  Input: egalax_ts_serial - fix potential NULL dereference on error
  Input: uinput - sanity check on ff_effects_max and EV_FF
  Input: uinput - rework ABS validation
  Input: uinput - add new UINPUT_DEV_SETUP and UI_ABS_SETUP ioctl
  Input: goodix - use "inverted_[xy]" flags instead of "rotated_screen"
  Input: goodix - add axis swapping and axis inversion support
  Input: goodix - use goodix_i2c_write_u8 instead of i2c_master_send
  Input: goodix - add power management support
  ...
2016-01-13 11:14:05 -08:00
Julien Grossholtz
96098df125 gpiolib: fix chip order in gpio list
In some situations the gpio_list order is not correct.
As a consequence gpiochip_find_base returns the same
base number twice. This happens when a first ship is added
with manual base number, then other ships are added using
automatic base number.

To prevent this behaviour, this patch add the new chip after
the last element of the gpio list.

Signed-off-by: Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-13 10:57:49 +01:00
Linus Walleij
09dd5f9e24 gpio: fix misleading comment
We are not relying on container_of() now that we have
gpiochip_get_data().

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-05 11:21:20 +01:00
Linus Walleij
b08ea35a32 gpio: add a data pointer to gpio_chip
This adds a void * pointer to gpio_chip so that driver can
assign and retrieve some states. This is done to get rid of
container_of() calls for gpio_chips embedded inside state
containers, so we can remove the need to have the gpio_chip
or later (planned) struct gpio_device be dynamically allocated
at registration time, so that its struct device can be properly
reference counted and not bound to its parent device (e.g.
a platform_device) but instead live on after unregistration
if it is opened by e.g. a char device or sysfs.

The data is added with the new function gpiochip_add_data()
and for compatibility we add static inline wrapper function
gpiochip_add() that will call gpiochip_add_data() with
NULL as argument. The latter will be removed once we have
exorcised gpiochip_add() from the kernel.

gpiochip_get_data() is added as a static inline accessor
for drivers to quickly get their data out.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-05 11:20:12 +01:00
Christophe RICARD
52044723cd ACPI / gpio: Add irq_type when a GPIO is used as an interrupt
When a GPIO is used as an interrupt in ACPI, the irq_type was not
available for device driver.

Make available polarity and triggering information in acpi_find_gpio by
renaming acpi_gpio_info field active_low  to polarity and adding triggering
field (edge/level).

For sanity, in gpiolib.c replace info.active_low by
"info.polarity == GPIO_ACTIVE_LOW".

Set the irq_type if necessary in acpi_dev_gpio_irq_get.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-01 03:20:25 +01:00
Sudip Mukherjee
e28ecca6ea gpio: fix warning about iterator
We were getting build warning about "iterator" being used uninitialized.
Use iterator properly to fix the build warning and in the process remove
the variable "pos" which is not required now.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-27 23:51:21 +01:00
Linus Walleij
723a63034e Revert "gpio: revert get() to non-errorprogating behaviour"
This reverts commit 45ad7db90b.

We have fixed all the drivers that were returning ambious values
not clamped to [0,1] or an error code, so return the error
propagating behaviour of the API.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-26 22:28:42 +01:00
Linus Walleij
0529357f10 Linux 4.4-rc6
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Merge tag 'v4.4-rc6' into devel

Linux 4.4-rc6
2015-12-21 09:36:21 +01:00
Linus Walleij
45ad7db90b gpio: revert get() to non-errorprogating behaviour
commit e20538b82f
("gpio: Propagate errors from chip->get()")
started to propagate errors from the .get() functions since
we can get errors from the infrastructure of e.g. slowbus
GPIO expanders.

However it turns out a bunch of drivers relied on the core
to clamp the value, so we need to revert to the old behaviour
and go over all drivers and fix them to conform to the
expectations of the core before we go back to propagating
the error code.

Cc: stable@vger.kernel.org # 4.3+
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Fixes: e20538b82f ("gpio: Propagate errors from chip->get()")
Reported-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-17 15:48:29 +01:00
Dmitry Torokhov
7f0ad5396a Merge branch 'for-dmitry' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio into goodix
Bring in changes to ACPI GPIOLIB to better handle legacy ACPI mappings
needed for subsequent Goodix driver changes.
2015-12-15 10:23:43 -08:00
Dmitry Torokhov
10cf4899f8 gpiolib: tighten up ACPI legacy gpio lookups
We should not fall back to the legacy unnamed gpio lookup style if the
driver requests gpios with different names, because we'll give out the same
gpio twice. Let's keep track of the names that were used for the device and
only do the fallback for the first name used.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-13 17:36:02 +01:00
Bamvor Jian Zhang
c88402c2e6 gpiolib: make comment consistent with code
Commit f4d566a8a0e6 ("gpio: change member .dev to .parent") changes
member of gpiochip from .dev to .parent. Update the corresponding
comment.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-29 22:37:10 +01:00
Vladimir Zapolskiy
d06165b329 gpiolib: fix oops, if gpio name is NULL
Commit c0017ed719 ("gpio: Introduce gpio descriptor 'name'") causes
OOPS on boot on LPC32xx boards:

    Unable to handle kernel NULL pointer dereference at virtual address 00000000
    CPU: 0 PID: 1 Comm: swapper Not tainted 4.3.0+ #707
    Hardware name: LPC32XX SoC (Flattened Device Tree)
    task: c381baa0 ti: c381e000 task.ti: c381e000
    PC is at strcmp+0x10/0x40
    LR is at gpiochip_add+0x3d0/0x4d4
    pc : [<>]    lr : [<>]    psr: a0000093
    sp : c381fd60  ip : c381fd70  fp : c381fd6c

    [snip]

    Backtrace:
    [<>] (strcmp) from [<>] (gpiochip_add+0x3d0/0x4d4)
    [<>] (gpiochip_add) from [<>] (lpc32xx_gpio_probe+0x44/0x60)
    [<>] (lpc32xx_gpio_probe) from [<>] (platform_drv_probe+0x40/0x8c)
    [<>] (platform_drv_probe) from [<>] (driver_probe_device+0x110/0x294)
    [<>] (driver_probe_device) from [<>] (__driver_attach+0x70/0x94)
    [<>] (__driver_attach) from [<>] (bus_for_each_dev+0x74/0x98)
    [<>] (bus_for_each_dev) from [<>] (driver_attach+0x20/0x28)
    [<>] (driver_attach) from [<>] (bus_add_driver+0xd4/0x1f0)
    [<>] (bus_add_driver) from [<>] (driver_register+0xa4/0xe8)
    [<>] (driver_register) from [<>] (__platform_driver_register+0x38/0x4c)
    [<>] (__platform_driver_register) from [<>] (lpc32xx_gpio_driver_init+0x18/0x20)
    [<>] (lpc32xx_gpio_driver_init) from [<>] (do_one_initcall+0x108/0x1c8)
    [<>] (do_one_initcall) from [<>] (kernel_init_freeable+0x10c/0x1d4)
    [<>] (kernel_init_freeable) from [<>] (kernel_init+0x10/0xec)
    [<>] (kernel_init) from [<>] (ret_from_fork+0x14/0x24)

This is caused by the fact that at the moment some GPIO names are set
to NULL, there is a hole in linear representation of one GPI bank, see
drivers/gpio/gpio-lpc32xx.c / gpi_p3_names[] for details.

The same problem most probably affects also gpio-cs5535.c, see
cs5535_gpio_names[].

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-29 22:17:40 +01:00
Bamvor Jian Zhang
5ed41cc4ba gpiolib: do not allow to insert an empty gpiochip
We need to check if number of gpio is positive if there is no
such check in devicetree or acpi or whatever called before
gpiochip_add.

I suppose that devicetree and acpi do not allow insert gpiochip
with zero number but I do not know if it is enough to ignore
this check in gpiochip_add.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:40 +01:00
Bamvor Jian Zhang
ef7c755303 gpiolib: improve overlap check of range of gpio
There are limitations for the current checker:
1.  Could not check the overlap if the new gpiochip is the secondly
    gpiochip.
2.  Could not check the overlap if the new gpiochip is overlap
    with the left of gpiochip. E.g. if we insert [c, d] between
    [a,b] and [e, f], and e >= c + d, it will successful even if
    c < a + b.
3.  Allow overlap of base of different gpiochip.

This patch fix these issues by checking the overlap of both right and
left gpiochip in the same loop statement.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
[Tweaked to remove unnecessary ret variable]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:40 +01:00
Bamvor Jian Zhang
ed37915cb1 gpiolib: keep comment consistent with code
The commit f881bab038 ("gpio: keep the GPIO line names internal")
change the error to warning in gpiochip_set_desc_names. Update the
comment accordingly.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:39 +01:00
Dmitry Torokhov
9c3c9bc9cc gpiolib: tighten up ACPI legacy gpio lookups
We should not fall back to the legacy unnamed gpio lookup style if the
driver requests gpios with different names, because we'll give out the same
gpio twice. Let's keep track of the names that were used for the device and
only do the fallback for the first name used.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:37 +01:00
Linus Walleij
58383c7842 gpio: change member .dev to .parent
The name .dev in a struct is normally reserved for a struct device
that is let us say a superclass to the thing described by the struct.
struct gpio_chip stands out by confusingly using a struct device *dev
to point to the parent device (such as a platform_device) that
represents the hardware. As we want to give gpio_chip:s real devices,
this is not working. We need to rename this member to parent.

This was done by two coccinelle scripts, I guess it is possible to
combine them into one, but I don't know such stuff. They look like
this:

@@
struct gpio_chip *var;
@@
-var->dev
+var->parent

and:

@@
struct gpio_chip var;
@@
-var.dev
+var.parent

and:

@@
struct bgpio_chip *var;
@@
-var->gc.dev
+var->gc.parent

Plus a few instances of bgpio that I couldn't figure out how
to teach Coccinelle to rewrite.

This patch hits all over the place, but I *strongly* prefer this
solution to any piecemal approaches that just exercise patch
mechanics all over the place. It mainly hits drivers/gpio and
drivers/pinctrl which is my own backyard anyway.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-19 09:24:35 +01:00
Linus Torvalds
0d51ce9ca1 Power management and ACPI updates for v4.4-rc1
- ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).
 
    The most significant change is to allow the AML debugger to be
    built into the kernel.  On top of that there is an update related
    to the NFIT table (the ACPI persistent memory interface)
    and a few fixes and cleanups.
 
  - ACPI CPPC2 (Collaborative Processor Performance Control v2)
    support along with a cpufreq frontend (Ashwin Chaugule).
 
    This can only be enabled on ARM64 at this point.
 
  - New ACPI infrastructure for the early probing of IRQ chips and
    clock sources (Marc Zyngier).
 
  - Support for a new hierarchical properties extension of the ACPI
    _DSD (Device Specific Data) device configuration object allowing
    the kernel to handle hierarchical properties (provided by the
    platform firmware this way) automatically and make them available
    to device drivers via the generic device properties interface
    (Rafael Wysocki).
 
  - Generic device properties API extension to obtain an index of
    certain string value in an array of strings, along the lines of
    of_property_match_string(), but working for all of the supported
    firmware node types, and support for the "dma-names" device
    property based on it (Mika Westerberg).
 
  - ACPI core fix to parse the MADT (Multiple APIC Description Table)
    entries in the order expected by platform firmware (and mandated
    by the specification) to avoid confusion on systems with more than
    255 logical CPUs (Lukasz Anaczkowski).
 
  - Consolidation of the ACPI-based handling of PCI host bridges
    on x86 and ia64 (Jiang Liu).
 
  - ACPI core fixes to ensure that the correct IRQ number is used to
    represent the SCI (System Control Interrupt) in the cases when
    it has been re-mapped (Chen Yu).
 
  - New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).
 
  - ACPI EC driver fixes (Lv Zheng).
 
  - Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
    Kosina, Rami Rosen, Rasmus Villemoes).
 
  - New mechanism in the PM core allowing drivers to check if the
    platform firmware is going to be involved in the upcoming system
    suspend or if it has been involved in the suspend the system is
    resuming from at the moment (Rafael Wysocki).
 
    This should allow drivers to optimize their suspend/resume
    handling in some cases and the changes include a couple of users
    of it (the i8042 input driver, PCI PM).
 
  - PCI PM fix to prevent runtime-suspended devices with PME enabled
    from being resumed during system suspend even if they aren't
    configured to wake up the system from sleep (Rafael Wysocki).
 
  - New mechanism to report the number of a wakeup IRQ that woke up
    the system from sleep last time (Alexandra Yates).
 
  - Removal of unused interfaces from the generic power domains
    framework and fixes related to latency measurements in that
    code (Ulf Hansson, Daniel Lezcano).
 
  - cpufreq core sysfs interface rework to make it handle CPUs that
    share performance scaling settings (represented by a common
    cpufreq policy object) more symmetrically (Viresh Kumar).
 
    This should help to simplify the CPU offline/online handling among
    other things.
 
  - cpufreq core fixes and cleanups (Viresh Kumar).
 
  - intel_pstate fixes related to the Turbo Activation Ratio (TAR)
    mechanism on client platforms which causes the turbo P-states
    range to vary depending on platform firmware settings (Srinivas
    Pandruvada).
 
  - intel_pstate sysfs interface fix (Prarit Bhargava).
 
  - Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
    and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
    Bhat, Luis de Bethencourt).
 
  - cpuidle mvebu driver cleanups (Russell King).
 
  - OPP (Operating Performance Points) framework code reorganization
    to make it more maintainable (Viresh Kumar).
 
  - Intel Broxton support for the RAPL (Running Average Power Limits)
    power capping driver (Amy Wiles).
 
  - Assorted power management code fixes and cleanups (Dan Carpenter,
    Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
    Villemoes).
 
 /
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Merge tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "Quite a new features are included this time.

  First off, the Collaborative Processor Performance Control interface
  (version 2) defined by ACPI will now be supported on ARM64 along with
  a cpufreq frontend for CPU performance scaling.

  Second, ACPI gets a new infrastructure for the early probing of IRQ
  chips and clock sources (along the lines of the existing similar
  mechanism for DT).

  Next, the ACPI core and the generic device properties API will now
  support a recently introduced hierarchical properties extension of the
  _DSD (Device Specific Data) ACPI device configuration object.  If the
  ACPI platform firmware uses that extension to organize device
  properties in a hierarchical way, the kernel will automatically handle
  it and make those properties available to device drivers via the
  generic device properties API.

  It also will be possible to build the ACPICA's AML interpreter
  debugger into the kernel now and use that to diagnose AML-related
  problems more efficiently.  In the future, this should make it
  possible to single-step AML execution and do similar things.
  Interesting stuff, although somewhat experimental at this point.

  Finally, the PM core gets a new mechanism that can be used by device
  drivers to distinguish between suspend-to-RAM (based on platform
  firmware support) and suspend-to-idle (or other variants of system
  suspend the platform firmware is not involved in) and possibly
  optimize their device suspend/resume handling accordingly.

  In addition to that, some existing features are re-organized quite
  substantially.

  First, the ACPI-based handling of PCI host bridges on x86 and ia64 is
  unified and the common code goes into the ACPI core (so as to reduce
  code duplication and eliminate non-essential differences between the
  two architectures in that area).

  Second, the Operating Performance Points (OPP) framework is
  reorganized to make the code easier to find and follow.

  Next, the cpufreq core's sysfs interface is reorganized to get rid of
  the "primary CPU" concept for configurations in which the same
  performance scaling settings are shared between multiple CPUs.

  Finally, some interfaces that aren't necessary any more are dropped
  from the generic power domains framework.

  On top of the above we have some minor extensions, cleanups and bug
  fixes in multiple places, as usual.

  Specifics:

   - ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).

     The most significant change is to allow the AML debugger to be
     built into the kernel.  On top of that there is an update related
     to the NFIT table (the ACPI persistent memory interface) and a few
     fixes and cleanups.

   - ACPI CPPC2 (Collaborative Processor Performance Control v2) support
     along with a cpufreq frontend (Ashwin Chaugule).

     This can only be enabled on ARM64 at this point.

   - New ACPI infrastructure for the early probing of IRQ chips and
     clock sources (Marc Zyngier).

   - Support for a new hierarchical properties extension of the ACPI
     _DSD (Device Specific Data) device configuration object allowing
     the kernel to handle hierarchical properties (provided by the
     platform firmware this way) automatically and make them available
     to device drivers via the generic device properties interface
     (Rafael Wysocki).

   - Generic device properties API extension to obtain an index of
     certain string value in an array of strings, along the lines of
     of_property_match_string(), but working for all of the supported
     firmware node types, and support for the "dma-names" device
     property based on it (Mika Westerberg).

   - ACPI core fix to parse the MADT (Multiple APIC Description Table)
     entries in the order expected by platform firmware (and mandated by
     the specification) to avoid confusion on systems with more than 255
     logical CPUs (Lukasz Anaczkowski).

   - Consolidation of the ACPI-based handling of PCI host bridges on x86
     and ia64 (Jiang Liu).

   - ACPI core fixes to ensure that the correct IRQ number is used to
     represent the SCI (System Control Interrupt) in the cases when it
     has been re-mapped (Chen Yu).

   - New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).

   - ACPI EC driver fixes (Lv Zheng).

   - Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
     Kosina, Rami Rosen, Rasmus Villemoes).

   - New mechanism in the PM core allowing drivers to check if the
     platform firmware is going to be involved in the upcoming system
     suspend or if it has been involved in the suspend the system is
     resuming from at the moment (Rafael Wysocki).

     This should allow drivers to optimize their suspend/resume handling
     in some cases and the changes include a couple of users of it (the
     i8042 input driver, PCI PM).

   - PCI PM fix to prevent runtime-suspended devices with PME enabled
     from being resumed during system suspend even if they aren't
     configured to wake up the system from sleep (Rafael Wysocki).

   - New mechanism to report the number of a wakeup IRQ that woke up the
     system from sleep last time (Alexandra Yates).

   - Removal of unused interfaces from the generic power domains
     framework and fixes related to latency measurements in that code
     (Ulf Hansson, Daniel Lezcano).

   - cpufreq core sysfs interface rework to make it handle CPUs that
     share performance scaling settings (represented by a common cpufreq
     policy object) more symmetrically (Viresh Kumar).

     This should help to simplify the CPU offline/online handling among
     other things.

   - cpufreq core fixes and cleanups (Viresh Kumar).

   - intel_pstate fixes related to the Turbo Activation Ratio (TAR)
     mechanism on client platforms which causes the turbo P-states range
     to vary depending on platform firmware settings (Srinivas
     Pandruvada).

   - intel_pstate sysfs interface fix (Prarit Bhargava).

   - Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
     and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
     Bhat, Luis de Bethencourt).

   - cpuidle mvebu driver cleanups (Russell King).

   - OPP (Operating Performance Points) framework code reorganization to
     make it more maintainable (Viresh Kumar).

   - Intel Broxton support for the RAPL (Running Average Power Limits)
     power capping driver (Amy Wiles).

   - Assorted power management code fixes and cleanups (Dan Carpenter,
     Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
     Villemoes)"

* tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (108 commits)
  cpufreq: postfix policy directory with the first CPU in related_cpus
  cpufreq: create cpu/cpufreq/policyX directories
  cpufreq: remove cpufreq_sysfs_{create|remove}_file()
  cpufreq: create cpu/cpufreq at boot time
  cpufreq: Use cpumask_copy instead of cpumask_or to copy a mask
  cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate()
  PM / Domains: Merge measurements for PM QoS device latencies
  PM / Domains: Don't measure ->start|stop() latency in system PM callbacks
  PM / clk: Fix broken build due to non-matching code and header #ifdefs
  ACPI / Documentation: add copy_dsdt to ACPI format options
  ACPI / sysfs: correctly check failing memory allocation
  ACPI / video: Add a quirk to force native backlight on Lenovo IdeaPad S405
  ACPI / CPPC: Fix potential memory leak
  ACPI / CPPC: signedness bug in register_pcc_channel()
  ACPI / PAD: power_saving_thread() is not freezable
  ACPI / PM: Fix incorrect wakeup IRQ setting during suspend-to-idle
  ACPI: Using correct irq when waiting for events
  ACPI: Use correct IRQ when uninstalling ACPI interrupt handler
  cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver
  cpuidle: mvebu: clean up multiple platform drivers
  ...
2015-11-04 18:10:13 -08:00
Rafael J. Wysocki
ab736d7dc1 Merge branch 'device-properties'
* device-properties:
  ACPI / property: Fix subnode lookup scope for data-only subnodes
  acpi-dma: Add support for "dma-names" device property
  device property: Add fwnode_property_match_string()
  ACPI / property: Extend device_get_next_child_node() to data-only nodes
  ACPI / gpio: Split acpi_get_gpiod_by_index()
  ACPI / property: Extend fwnode_property_* to data-only subnodes
  ACPI / property: Expose data-only subnodes via sysfs
  ACPI / property: Add support for data-only subnodes
  ACPI / property: Add routine for extraction of _DSD properties
2015-10-25 22:51:48 +01:00
Laurent Pinchart
90b665f627 gpiolib: Add and use OF_GPIO_SINGLE_ENDED flag
The flag matches the DT GPIO_SINGLE_ENDED flag and allows drivers to
parse and use the DT flag to handle single-ended (open-drain or
open-source) GPIOs.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-16 22:49:26 +02:00
Laurent Pinchart
923b93e451 gpiolib: Split GPIO flags parsing and GPIO configuration
When requesting a GPIO through the legacy or the gpiod_* API the
gpiochip request operation is first called and then the GPIO flags are
parsed and the GPIO is configured. This prevents the gpiochip from
rejecting the request if the flags are not supported by the device.

To fix this split the parse-and-configure operation in two and parse
flags before requesting the GPIO.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-16 22:46:46 +02:00
Jonas Gorski
c771c2f484 gpiolib: provide generic request/free implementations
Provide generic request/free implementations that pinctrl aware gpio
drivers can use instead of open coding if they use a 1:1 pin to gpio
signal mapping.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-16 22:11:16 +02:00
Dirk Behme
48b5953ed8 gpio: gpiolib: don't compare an unsigned for >= 0
The parameter offset is an unsigned, so it makes no sense to compare
it for >= 0. Fix the compiler warning regarding this by removing this
comparison.

As the macro GPIO_OFFSET_VALID is only used at this single place, simplify
the code by dropping the macro completely and dropping the invert, too.

No functional change.

Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-02 04:19:35 -07:00
Linus Walleij
f881bab038 gpio: keep the GPIO line names internal
This refactors the changes to the GPIO line naming mechanism to
not have so widespread effects, instead we conclude the patch series
by having created a name attribute in the GPIO descriptor, that need
not be globally unique, and it will be initialized from the old
.names array in struct gpio_chip if it exists, then used in the legacy
sysfs code like the array was used previously.

The associated changes to name lines from the device tree are
controversial and need to stand alone from this. Resulting changes:

1. Remove the export and the header for the gpio_name_to_desc() as so
far the only use is inside gpiolib.c. Staticize gpio_name_to_desc()
and move it above the only function using it.

2. Only print a warning if there are two GPIO lines with the same name.
The reason is to preserve current behaviour: before the previous
changes to the naming mechanism this would not reject probing the
driver, instead the error would occur when trying to export the line
in sysfs, so restore this behaviour, but print a friendly warning
if names collide.

Cc: Johan Hovold <johan@kernel.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24 10:48:53 -07:00
Markus Pargmann
ced433e2a4 gpiolib: Add gpio name information to /sys/kernel/debug/gpio
Add some information about gpio names to the debugfs gpio file. name and
label of a GPIO are then displayed next to each other. This way it is
easy to see what the real name of GPIO is and what the driver requested
it for.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
[Dropped unsolicited sysfs ABI patch hunk]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24 10:48:53 -07:00
Markus Pargmann
5f3ca7329b gpiolib: Use GPIO name from names array for gpio descriptor
This patch adds GPIO names to the GPIO descriptors when initializing the
gpiochip. It also introduces a check whether any of the new names will
conflict with an existing GPIO name.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24 10:48:52 -07:00
Markus Pargmann
c0017ed719 gpio: Introduce gpio descriptor 'name'
The latest gpio hogging mechanism assigns each gpio a 'line-name' in the
devicetree. The 'name' field is different from the 'label' field.
'label' is only used for requested GPIOs to describe its current use by
driver or userspace.

The 'name' field describes the GPIO itself, not the use. This is most
likely identical to the label in the schematic on the GPIO line and
should help to find this particular GPIO.

This is equivalent to the gpiochip->names array. However names should be
stored in the GPIO descriptor. We will use gpiochip->names in the future
only as initializer for the GPIO descriptors for drivers that assign
GPIO names hardcoded. All other GPIO names will be parsed from DT and
directly assigned to the GPIO descriptor.

This patch adds a helper function to find gpio descriptors by name
instead of gpio number.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24 10:48:51 -07:00
Rafael J. Wysocki
504a337499 ACPI / property: Extend device_get_next_child_node() to data-only nodes
Make device_get_next_child_node() work with ACPI data-only subnodes
introduced previously.

Namely, replace acpi_get_next_child() with acpi_get_next_subnode()
that can handle (and return) child device objects as well as child
data-only subnodes of the given device and modify the ACPI part
of the GPIO subsystem to handle data-only subnodes returned by it.

To that end, introduce acpi_node_get_gpiod() taking a struct
fwnode_handle pointer as the first argument.  That argument may
point to an ACPI device object as well as to a data-only subnode
and the function should do the right thing (ie. look for the matching
GPIO descriptor correctly) in either case.

Next, modify fwnode_get_named_gpiod() to use acpi_node_get_gpiod()
instead of acpi_get_gpiod_by_index() which automatically causes
devm_get_gpiod_from_child() to work with ACPI data-only subnodes
that may be returned by device_get_next_child_node() which in turn
is required by the users of that function (the gpio_keys_polled
and gpio-leds drivers).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-15 01:47:34 +02:00
Rafael J. Wysocki
3a7a2ab839 ACPI / property: Extend fwnode_property_* to data-only subnodes
Modify is_acpi_node() to return "true" for ACPI data-only subnodes as
well as for ACPI device objects and change the name of to_acpi_node()
to to_acpi_device_node() so it is clear that it covers ACPI device
objects only.  Accordingly, introduce to_acpi_data_node() to cover
data-only subnodes in an analogous way.

With that, make the fwnode_property_* family of functions work with
ACPI data-only subnodes introduced previously.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2015-09-15 01:47:34 +02:00
Bjorn Andersson
e20538b82f gpio: Propagate errors from chip->get()
It's possible to have gpio chips hanging off unreliable remote buses
where the get() operation will fail to acquire a readout of the current
gpio state. Propagate these errors to the consumer so that they can
act on, retry or ignore these failing reads, instead of treating them as
the line being held high.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-14 09:12:03 +02:00
Linus Torvalds
f377ea88b8 Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
 "This is the main pull request for the drm for 4.3.  Nouveau is
  probably the biggest amount of changes in here, since it missed 4.2.
  Highlights below, along with the usual bunch of fixes.

  All stuff outside drm should have applicable acks.

  Highlights:

   - new drivers:
        freescale dcu kms driver

   - core:
        more atomic fixes
        disable some dri1 interfaces on kms drivers
        drop fb panic handling, this was just getting more broken, as more locking was required.
        new core fbdev Kconfig support - instead of each driver enable/disabling it
        struct_mutex cleanups

   - panel:
        more new panels
        cleanup Kconfig

   - i915:
        Skylake support enabled by default
        legacy modesetting using atomic infrastructure
        Skylake fixes
        GEN9 workarounds

   - amdgpu:
        Fiji support
        CGS support for amdgpu
        Initial GPU scheduler - off by default
        Lots of bug fixes and optimisations.

   - radeon:
        DP fixes
        misc fixes

   - amdkfd:
        Add Carrizo support for amdkfd using amdgpu.

   - nouveau:
        long pending cleanup to complete driver,
        fully bisectable which makes it larger,
        perfmon work
        more reclocking improvements
        maxwell displayport fixes

   - vmwgfx:
        new DX device support, supports OpenGL 3.3
        screen targets support

   - mgag200:
        G200eW support
        G200e new revision support

   - msm:
        dragonboard 410c support, msm8x94 support, msm8x74v1 support
        yuv format support
        dma plane support
        mdp5 rotation
        initial hdcp

   - sti:
        atomic support

   - exynos:
        lots of cleanups
        atomic modesetting/pageflipping support
        render node support

   - tegra:
        tegra210 support (dc, dsi, dp/hdmi)
        dpms with atomic modesetting support

   - atmel:
        support for 3 more atmel SoCs
        new input formats, PRIME support.

   - dwhdmi:
        preparing to add audio support

   - rockchip:
        yuv plane support"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (1369 commits)
  drm/amdgpu: rename gmc_v8_0_init_compute_vmid
  drm/amdgpu: fix vce3 instance handling
  drm/amdgpu: remove ib test for the second VCE Ring
  drm/amdgpu: properly enable VM fault interrupts
  drm/amdgpu: fix warning in scheduler
  drm/amdgpu: fix buffer placement under memory pressure
  drm/amdgpu/cz: fix cz_dpm_update_low_memory_pstate logic
  drm/amdgpu: fix typo in dce11 watermark setup
  drm/amdgpu: fix typo in dce10 watermark setup
  drm/amdgpu: use top down allocation for non-CPU accessible vram
  drm/amdgpu: be explicit about cpu vram access for driver BOs (v2)
  drm/amdgpu: set MEC doorbell range for Fiji
  drm/amdgpu: implement burst NOP for SDMA
  drm/amdgpu: add insert_nop ring func and default implementation
  drm/amdgpu: add amdgpu_get_sdma_instance helper function
  drm/amdgpu: add AMDGPU_MAX_SDMA_INSTANCES
  drm/amdgpu: add burst_nop flag for sdma
  drm/amdgpu: add count field for the SDMA NOP packet v2
  drm/amdgpu: use PT for VM sync on unmap
  drm/amdgpu: make wait_event uninterruptible in push_job
  ...
2015-09-04 15:49:32 -07:00
Grygorii Strashko
a0a8bcf467 gpiolib: irqchip: use different lockdep class for each gpio irqchip
Since IRQ chip helpers were introduced drivers lose ability to
register separate lockdep classes for each registered GPIO IRQ
chip and the gpiolib now is using shared lockdep class for
all GPIO IRQ chips (gpiochip_irq_lock_class).
As result, lockdep will produce warning when there are min two
stacked GPIO chips and all of them are interrupt controllers.

HW configuration which generates lockdep warning (TI dra7-evm):

[SOC GPIO bankA.gpioX]
  <- irq - [pcf875x.gpioY]
            <- irq - DevZ.enable_irq_wake(pcf_gpioY_irq);
The issue was reported in [1] and discussed [2].

=============================================
[ INFO: possible recursive locking detected ]
4.2.0-rc6-00013-g5d050ed-dirty #55 Not tainted
---------------------------------------------
sh/63 is trying to acquire lock:
 (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

but task is already holding lock:
 (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(class);
  lock(class);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

7 locks held by sh/63:
 #0:  (sb_writers#4){.+.+.+}, at: [<c016bbb8>] vfs_write+0x13c/0x164
 #1:  (&of->mutex){+.+.+.}, at: [<c01debf4>] kernfs_fop_write+0x4c/0x1a0
 #2:  (s_active#36){.+.+.+}, at: [<c01debfc>] kernfs_fop_write+0x54/0x1a0
 #3:  (pm_mutex){+.+.+.}, at: [<c009758c>] pm_suspend+0xec/0x4c4
 #4:  (&dev->mutex){......}, at: [<c03f77f8>] __device_suspend+0xd4/0x398
 #5:  (&gpio->lock){+.+.+.}, at: [<c009b940>] __irq_get_desc_lock+0x74/0x94
 #6:  (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94

stack backtrace:
CPU: 0 PID: 63 Comm: sh Not tainted 4.2.0-rc6-00013-g5d050ed-dirty #55
Hardware name: Generic DRA74X (Flattened Device Tree)
[<c0016e24>] (unwind_backtrace) from [<c0013338>] (show_stack+0x10/0x14)
[<c0013338>] (show_stack) from [<c05f6b24>] (dump_stack+0x84/0x9c)
[<c05f6b24>] (dump_stack) from [<c00903f4>] (__lock_acquire+0x19c0/0x1e20)
[<c00903f4>] (__lock_acquire) from [<c0091098>] (lock_acquire+0xa8/0x128)
[<c0091098>] (lock_acquire) from [<c05fd61c>] (_raw_spin_lock_irqsave+0x38/0x4c)
[<c05fd61c>] (_raw_spin_lock_irqsave) from [<c009b91c>] (__irq_get_desc_lock+0x50/0x94)
[<c009b91c>] (__irq_get_desc_lock) from [<c009c4f4>] (irq_set_irq_wake+0x20/0xfc)
[<c009c4f4>] (irq_set_irq_wake) from [<c0393ac4>] (pcf857x_irq_set_wake+0x24/0x54)
[<c0393ac4>] (pcf857x_irq_set_wake) from [<c009c560>] (irq_set_irq_wake+0x8c/0xfc)
[<c009c560>] (irq_set_irq_wake) from [<c04a02ac>] (gpio_keys_suspend+0x70/0xd4)
[<c04a02ac>] (gpio_keys_suspend) from [<c03f6a00>] (dpm_run_callback+0x50/0x124)
[<c03f6a00>] (dpm_run_callback) from [<c03f7830>] (__device_suspend+0x10c/0x398)
[<c03f7830>] (__device_suspend) from [<c03f90f0>] (dpm_suspend+0x134/0x2f4)
[<c03f90f0>] (dpm_suspend) from [<c0096e20>] (suspend_devices_and_enter+0xa8/0x728)
[<c0096e20>] (suspend_devices_and_enter) from [<c00977cc>] (pm_suspend+0x32c/0x4c4)
[<c00977cc>] (pm_suspend) from [<c0096060>] (state_store+0x64/0xb8)
[<c0096060>] (state_store) from [<c01dec64>] (kernfs_fop_write+0xbc/0x1a0)
[<c01dec64>] (kernfs_fop_write) from [<c016b280>] (__vfs_write+0x20/0xd8)
[<c016b280>] (__vfs_write) from [<c016bb0c>] (vfs_write+0x90/0x164)
[<c016bb0c>] (vfs_write) from [<c016c330>] (SyS_write+0x44/0x9c)
[<c016c330>] (SyS_write) from [<c000f500>] (ret_fast_syscall+0x0/0x54)

Lets fix it by using separate lockdep class for each registered GPIO
IRQ Chip. This is done by wrapping gpiochip_irqchip_add call into macros.

The implementation of this patch inspired by solution done by Nicolas
Boichat for regmap [3]

[1] http://www.spinics.net/lists/linux-gpio/msg05844.html
[2] http://www.spinics.net/lists/linux-gpio/msg06021.html
[3] http://www.spinics.net/lists/arm-kernel/msg429834.html

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roger Quadros <rogerq@ti.com>
Reported-by: Roger Quadros <rogerq@ti.com>
Tested-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-17 15:32:03 +02:00
Rabin Vincent
8b67a1f0ad gpio: don't override irq_*_resources() callbacks
If the driver has specified its own irq_{request/release}_resources()
functions, don't override them.  The gpio-etraxfs driver will use this.

Signed-off-by: Rabin Vincent <rabin@rab.in>
[Added a small comment blurb]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-03 10:52:02 +02:00
Tomeu Vizoso
28355f8196 gpio: defer probe if pinctrl cannot be found
When an OF node has a pin range for its GPIOs, return -EPROBE_DEFER if
the pin controller isn't available.

Otherwise, the GPIO range wouldn't be set at all unless the pin
controller probed always before the GPIO chip.

With this change, the probe of the GPIO chip will be deferred and will
be retried at a later point, hopefully once the pin controller has been
registered and probed already.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-28 13:55:36 +02:00