Commit Graph

28 Commits

Author SHA1 Message Date
Masahiro Yamada
13fba8ef50 reset: remove reset_control_get(_optional)
No more users of these two.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-27 09:16:40 +01:00
Masahiro Yamada
dfc1d9b247 reset: minimize the number of headers included from <linux/reset.h>
Commit 62e24c5775 ("reset: add exported __reset_control_get, return
NULL if optional") moved the dev->of_node reference to core.c, so
<linux/reset.h> does not need to know the members of struct device.
Declaring device and device_node as structure is enough.

<linux/types.h> is necessary for bool, true, and false.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-27 09:16:40 +01:00
Masahiro Yamada
bb6c776838 reset: remove remaining WARN_ON() in <linux/reset.h>
Commit bb475230b8 ("reset: make optional functions really optional")
gave a new meaning to _get_optional variants.

The differentiation by WARN_ON() is not needed any more.  We already
have inconsistency about this; (devm_)reset_control_get_exclusive()
has WARN_ON() check, but of_reset_control_get_exclusive() does not.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-27 09:16:39 +01:00
Masahiro Yamada
1554bbd4ad reset: make device_reset_optional() really optional
Commit bb475230b8 ("reset: make optional functions really optional")
converted *_get_optional* functions, but device_reset_optional() was
left behind.  Convert it in the same way.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-27 09:16:39 +01:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Vivek Gautam
17c82e206d reset: Add APIs to manage array of resets
Many devices may want to request a bunch of resets and control them. So
it's better to manage them as an array. Add APIs to _get() an array of
reset_control, reusing the _assert(), _deassert(), and _reset() APIs for
single reset controls. Since reset controls already may control multiple
reset lines with a single hardware bit, from the user perspective, reset
control arrays are not at all different from single reset controls.
Note that these APIs don't guarantee that the reset lines managed in the
array are handled in any particular order.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
[p.zabel@pengutronix.de: changed API to hide reset control arrays behind
 struct reset_control]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-07-19 10:28:12 +02:00
Philipp Zabel
62e24c5775 reset: add exported __reset_control_get, return NULL if optional
Rename the internal __reset_control_get/put functions to
__reset_control_get/put_internal and add an exported
__reset_control_get equivalent to __of_reset_control_get
that takes a struct device parameter.
This avoids the confusing call to __of_reset_control_get in
the non-DT case and fixes the devm_reset_control_get_optional
function to return NULL if RESET_CONTROLLER is enabled but
dev->of_node == NULL.

Fixes: bb475230b8 ("reset: make optional functions really optional")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-04-04 17:36:10 +02:00
Philipp Zabel
0ca10b60ce reset: fix optional reset_control_get stubs to return NULL
When RESET_CONTROLLER is not enabled, the optional reset_control_get
stubs should now also return NULL.

Since it is now valid for reset_control_assert/deassert/reset/status/put
to be called unconditionally, with NULL as an argument for optional
resets, the stubs are not allowed to warn anymore.

Fixes: bb475230b8 ("reset: make optional functions really optional")
Reported-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-21 18:19:43 +01:00
Ramiro Oliveira
bb475230b8 reset: make optional functions really optional
The *_get_optional_* functions weren't really optional so this patch
makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.

Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-01-20 10:36:15 +01:00
Ramiro Oliveira
ee48c726d0 reset: Change shared flag from int to bool
Since the new parameter being added is going to be a bool this patch
changes the shared flag from int to bool to match the new parameter.

Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-01-20 10:36:14 +01:00
Philipp Zabel
af3e1629c8 Merge branch 'reset/explicit-api' into reset/next 2016-06-29 23:39:52 +02:00
Lee Jones
0bcc0eab36 reset: TRIVIAL: Add line break at same place for similar APIs
Standardise the way inline functions:

  devm_reset_control_get_shared_by_index
  devm_reset_control_get_exclusive_by_index

... are formatted.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-29 21:24:53 +02:00
Lee Jones
c33d61a0c4 reset: Supply *_shared variant calls when using *_optional APIs
Consumers need to be able to specify whether they are requesting an
'exclusive' or 'shared' reset line no matter which API (of_*, devm_*,
etc) they are using.  This change allows users of the optional_* API
in particular to specify that their request is for a 'shared' line.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-29 21:24:53 +02:00
Lee Jones
40faee8ee4 reset: Supply *_shared variant calls when using of_* API
Consumers need to be able to specify whether they are requesting an
'exclusive' or 'shared' reset line no matter which API (of_*, devm_*,
etc) they are using.  This change allows users of the of_* API in
particular to specify that their request is for a 'shared' line.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-29 21:24:52 +02:00
Lee Jones
a53e35db70 reset: Ensure drivers are explicit when requesting reset lines
Phasing out generic reset line requests enables us to make some better
decisions on when and how to (de)assert said lines.  If an 'exclusive'
line is requested, we know a device *requires* a reset and that it's
preferable to act upon a request right away.  However, if a 'shared'
reset line is requested, we can reasonably assume sure that placing a
device into reset isn't a hard requirement, but probably a measure to
save power and is thus able to cope with not being asserted if another
device is still in use.

In order allow gentle adoption and not to forcing all consumers to
move to the API immediately, causing administration headache between
subsystems, this patch adds some temporary stand-in shim-calls.  This
will ease the burden at merge time and allow subsystems to migrate over
to the new API in a more realistic time-frame.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-29 21:24:52 +02:00
Lee Jones
3c35f6edc0 reset: Reorder inline reset_control_get*() wrappers
We're about to split the current API into two, where consumers will
be forced to be explicit when requesting reset lines.  The choice
will be to either the call the *_exclusive or *_shared variant
depending on whether they can actually tolorate not being asserted
when that request is made.

The new API will look like this once reorded and complete:

  reset_control_get_exclusive()
  reset_control_get_shared()
  reset_control_get_optional_exclusive()
  reset_control_get_optional_shared()
  of_reset_control_get_exclusive()
  of_reset_control_get_shared()
  of_reset_control_get_exclusive_by_index()
  of_reset_control_get_shared_by_index()
  devm_reset_control_get_exclusive()
  devm_reset_control_get_shared()
  devm_reset_control_get_optional_exclusive()
  devm_reset_control_get_optional_shared()
  devm_reset_control_get_exclusive_by_index()
  devm_reset_control_get_shared_by_index()

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-29 21:24:52 +02:00
John Youn
168d7c4e8b reset: Return -ENOTSUPP when not configured
Prior to commit 6c96f05c8b ("reset: Make [of_]reset_control_get[_foo]
functions wrappers"), the "optional" functions returned -ENOTSUPP when
CONFIG_RESET_CONTROLLER was not set.

Revert back to the old behavior by changing the new
__devm_reset_control_get() and __of_reset_control_get() functions to
return ERR_PTR(-ENOTSUPP) when compiled without CONFIG_RESET_CONTROLLER.

Otherwise they will return -EINVAL causing users to think that an error
occurred when CONFIG_RESET_CONTROLLER is not set.

Fixes: 6c96f05c8b ("reset: Make [of_]reset_control_get[_foo] functions wrappers")
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-06-01 08:21:08 +02:00
Daniel Lezcano
4113652252 reset: Add missing function stub for device_reset
The Mediatek's thermal driver fails to compile when the RESET_CONTROLLER
option is not set. Logically, as the driver depends on this option to compile,
the Kconfig should select it but actually that is not correct because the
Kconfig provides also the COMPILE_TEST to increase the compile test coverage.

By providing the missing 'device_reset' stub for the driver in reset.h, that
let the kernel to compile on different platforms with the Mediatek thermal
driver enabled with the COMPILE_TEST option.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-04-04 18:15:23 +02:00
Hans de Goede
0b52297f22 reset: Add support for shared reset controls
In some SoCs some hw-blocks share a reset control. Add support for this
setup by adding new:

reset_control_get_shared()
devm_reset_control_get_shared()
devm_reset_control_get_shared_by_index()

methods to get a reset_control. Note that this patch omits adding of_
variants, if these are needed later they can be easily added.

This patch also changes the behavior of the existing exclusive
reset_control_get() variants, if these are now called more then once
for the same reset_control they will return -EBUSY. To catch existing
drivers triggering this error (there should not be any) a WARN_ON(1)
is added in this path.

When a reset_control is shared, the behavior of reset_control_assert /
deassert is changed, for shared reset_controls these will work like the
clock-enable/disable and regulator-on/off functions. They will keep a
deassert_count, and only (re-)assert the reset after reset_control_assert
has been called as many times as reset_control_deassert was called.

Calling reset_control_assert without first calling reset_control_deassert
is not allowed on a shared reset control. Calling reset_control_reset is
also not allowed on a shared reset control.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-03-30 15:42:05 +02:00
Hans de Goede
6c96f05c8b reset: Make [of_]reset_control_get[_foo] functions wrappers
With both the regular, _by_index and _optional variants we already have
quite a few variants of [of_]reset_control_get[_foo], the upcoming
addition of shared reset lines support makes this worse.

This commit changes all the variants into wrappers around common core
functions. For completeness sake this commit also adds a new
devm_get_reset_control_by_index wrapper.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-03-30 15:42:01 +02:00
Philipp Zabel
39b4da71ca reset: use ENOTSUPP instead of ENOSYS
ENOSYS is reserved to report invalid syscalls to userspace.
Consistently return ENOTSUPP to indicate that the driver doesn't support
the functionality or the reset framework is not enabled at all.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2015-11-16 09:23:47 +01:00
Vince Hsu
c0a13aa6da reset: add of_reset_control_get_by_index()
Add of_reset_control_get_by_index() to allow the drivers to get reset
device without knowing its name.

Signed-off-by: Vince Hsu <vinceh@nvidia.com>
[jonathanh@nvidia.com: Updated stub function to return -ENOTSUPP instead
 of -ENOSYS which should only be used for system calls.]
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2015-11-16 09:23:47 +01:00
Axel Lin
5bcd0b7f3c reset: Add (devm_)reset_control_get stub functions
So the drivers can be compiled with CONFIG_RESET_CONTROLLER disabled.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2015-09-01 09:56:58 +02:00
Dinh Nguyen
729de41baf reset: add reset_control_status helper function
There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the
reset controller API.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2014-10-20 10:11:29 +02:00
Hans de Goede
e3ec0a8c6e reset: Add of_reset_control_get to reset.h
of_reset_control_get is not declared static in drivers/reset/core.c, which
is correct as we want to use it elsewhere too. But it does not have a
protype declared anywhere under include/linux. Add a prototype / stub for it
to linux/reset.h to fix this.

Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2014-04-14 16:47:28 +02:00
Philipp Zabel
b424080a9e reset: Add optional resets and stubs
This patch adds device_reset_optional and (devm_)reset_control_get_optional
variants that drivers can use to indicate they can function without control
over the reset line. For those functions, stubs are added so the drivers can
be compiled with CONFIG_RESET_CONTROLLER disabled.
Also, device_reset is annotated with __must_check. Drivers ignoring the return
value should use device_reset_optional instead.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-09 19:53:45 +01:00
Maxime Ripard
fc0a592156 reset: Add of_reset_control_get
In some cases, you might need to deassert from reset an hardware block that
doesn't associated to a struct device (CPUs, timers, etc.).

Add a small helper to retrieve the reset controller from the device tree
without the need to pass a struct device.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2014-02-03 10:19:40 +01:00
Philipp Zabel
61fc413176 reset: Add reset controller API
This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
2013-04-12 10:26:23 +02:00