Input: gpio-keys - add system suspend support for dedicated wakeirqs

Some SoCs have a separate dedicated wake-up interrupt controller that can
be used to wake up the system from deeper idle states. We already support
configuring a separate interrupt for a gpio-keys button to be used with a
gpio line. However, we are lacking support system suspend for cases where
a separate interrupt needs to be used in deeper sleep modes.

Because of it's nature, gpio-keys does not know about the runtime PM state
of the button gpios, and may have several gpio buttons configured for each
gpio-keys device instance. Implementing runtime PM support for gpio-keys
does not help, and we cannot use drivers/base/power/wakeirq.c support. We
need to implement custom wakeirq support for gpio-keys.

For handling a dedicated wakeirq for system suspend, we enable and disable
it with gpio_keys_enable_wakeup() and gpio_keys_disable_wakeup() that we
already use based on device_may_wakeup().

Some systems may have a dedicated wakeirq that can also be used as the
main interrupt, this is already working for gpio-keys. Let's add some
wakeirq related comments while at it as the usage with a gpio line and
separate interrupt line may not be obvious.

Tested-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231129110618.27551-2-tony@atomide.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: gpio_keys - add missing include to gpio_keys.h

gpio_keys.h uses 'bool' - type which is defined in linux/types.h.
Include this header.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: gpio-keys - add support for wakeup event action

Add support for specifying event actions to trigger wakeup when using
the gpio-keys input device as a wakeup source.

This would allow the device to configure when to wakeup the system. For
example a gpio-keys input device for pen insert, may only want to wakeup
the system when ejecting the pen.

Suggested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

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>

Input: gpio_keys_polled - keep button data constant

Commit 633a21d80b4a ("input: gpio_keys_polled: Add support for GPIO
descriptors") placed gpio descriptor into gpio_keys_button structure, which
is supposed to be part of platform data and not modifiable by the driver.
To keep the data constant, let's move the descriptor to
gpio_keys_button_data structure instead.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

input: gpio_keys_polled: Add support for GPIO descriptors

GPIO descriptors are the preferred way over legacy GPIO numbers
nowadays. Convert the driver to use GPIO descriptors internally but
still allow passing legacy GPIO numbers from platform data to support
existing platforms.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Input: gpio_keys - convert struct descriptions to kernel-doc

This patch converts descriptions of the structures defined in
linux/gpio_keys.h to follow kernel-doc format.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: gpio_keys - add support for interrupt only keys

Some of buttons, like power-on key or onkey, may only generate interrupts
when pressed and not actually be mapped as gpio in the system. Allow
setting gpio to invalid value and specify IRQ instead to support such
keys. The debounce timer is used not to debounce but to ignore new IRQs
coming while button is kept pressed.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio_keys - fix struct device declared inside parameter list

A struct device parameter is used in the enable and disable callbacks to
distinguish between different gpio_keys devices.

Platforms that don't use these callbacks may not include struct device
at all, as seen on arch/arm/mach-s3c2410/mach-n30.c

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio-keys - add support for setting device name

This patch allows to set a device name which helps distinguishing several
gpio-keys devices.

Signed-off-by: Alexander Stein <alexander.stein@informatik.tu-chemnitz.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio_keys - add support for EV_ABS

With this patch you can setup a group of GPIOs representing a specific
position on an EV_ABS axis.

Signed-off-by: Alexander Stein <alexander.stein@informatik.tu-chemnitz.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: add input driver for polled GPIO buttons

The existing gpio-keys driver can be usable only for GPIO lines with
interrupt support. Several devices have buttons connected to a GPIO
line which is not capable to generate interrupts. This patch adds a
new input driver using the generic GPIO layer and the input-polldev
to support such buttons.

[Ben Gardiner <bengardiner@nanometrics.ca: fold code to use more
of the original gpio_keys infrastructure; cleanups and other
improvements.]

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio_keys - add hooks to enable/disable device

Allow platform code to specify callbcks that will be invoked when
input device is opened or closed, allowing, for example, to enable
the device.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio-keys - add support for disabling gpios through sysfs

Now gpio-keys input driver exports 4 new attributes to userland through
sysfs:
/sys/devices/platform/gpio-keys/keys [ro]
/sys/devices/platform/gpio-keys/switches [ro]
/sys/devices/platform/gpio-keys/disabled_keys [rw]
/sys/devices/platform/gpio-keys/disables_switches [rw]

With these attributes, userland program can read which keys and
switches can be disabled and then disable/enable them as needed.
Keys and switches are exported as stringified bitmap of codes
(keycodes or switch codes). For example keys 15, 89, 100, 101,
102 are exported as: '15,89,100-102'.

Description of the attributes:
keys - bitmap of keys which can be disabled
switches - bitmap of switches which can be disabled
disabled_keys - bitmap of currently disabled keys
(bit 1 means disabled, 0 enabled)
disabled_switches - bitmap of currently disabled switches
(bit 1 means disabled, 0 enabled)

Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio-keys - add flag to allow auto repeat

This patch adds a flag to gpio-key driver to turn on the input subsystems
auto repeat feature if needed.

Signed-off-by: Dominic Curran <dcurran@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio-keys debouncing support

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio-keys - add suspend/resume support

This patch adds suspend/resume support and enables wakeup from
gpio_keys buttons.

Signed-off-by: Anti Sullin <anti.sullin@artecdesign.ee>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: gpio_keys - add support for switches (EV_SW)

Signed-off-by: Roman Moravcik <roman.moravcik@gmail.com>
Signed-off-by: Paul Sokolovsky <pmiscml@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

[PATCH] gpio_keys driver shouldn't be ARM-specific

The gpio_keys driver is wrongly ARM-specific; it can't build on
other platforms with GPIO suport. This fixes that problem.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: pHilipp Zabel <philipp.zabel@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Ben Nizette <ben.nizette@iinet.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>