leds: triggers: default-on: Add module alias for module auto-loading

A bigger number of board device tree files, plus few drivers, set
default-on as default trigger for LED's. Therefore add an alias for
module auto-loading.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/7e94d26b-d772-4a07-b0f6-bb3111b9ff75@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

leds: default-on trigger: make use of module_led_trigger()

This removes some boilerplate from the driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: let struct led_trigger::activate() return an error code

Given that activating a trigger can fail, let the callback return an
indication. This prevents to have a trigger active according to the
"trigger" sysfs attribute but not functional.

All users are changed accordingly to return 0 for now. There is no intended
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: make the MODULE_LICENSE string match the actual license

These files are licensed under GPL version 2 only. So use "GPL v2"
instead of "GPL" (which means v2 or later).

Also remove an empty (but commented) line at the end of the license
header which nicely proves in the context that the drivers are really v2
only :-)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: core: Add led_set_brightness_nosleep{nopm} functions

This patch adds led_set_brightness_nosleep() and led_set_brightness_nopm()
functions, that guarantee setting LED brightness in a non-blocking way.
The latter is used from pm_ops context and doesn't modify the brightness
cached in the struct led_classdev. Its execution always ends up with
a call to brightness setting op - either directly or through
a set_brightness_work, regardless of LED_SUSPENDED flag state.

The patch also replaces led_set_brightness_async() with
led_set_brightness_nosleep() in all places where the most vital was setting
brightness in a non sleeping way but not necessarily asynchronously, which
is not needed for non-blocking drivers.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

leds: Add support for setting brightness in a synchronous way

There are use cases when setting a LED brightness has to
have immediate effect (e.g. setting a torch LED brightness).
This patch extends LED subsystem to support such operations.
The LED subsystem internal API __led_set_brightness is changed
to led_set_brightness_async and new led_set_brightness_sync API
is added.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: move LED trigger drivers into new subdirectory

For better driver management, new subdirectory, 'trigger' is created.
All LED trigger drivers are moved into this directory.

Internal header, 'leds.h' is included in each LED trigger drivers.
Fix the location of header file, "leds.h" -> "../leds.h" in driver files.
One exception is here, 'ledtrig-timer.c'.
There is no need to include 'leds.h'. so '#include "leds.h"' line was removed.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>