Some LED devices support flash/torch functionality through the LED subsystem.
This patch enables direct LED trigger controls by the driver.
Flash on/off and torch on/off can be done simply by other driver space.
Two trigger APIs are added, ledtrig_flash_ctrl() and ledtrig_torch_ctrl().
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Macros are used in case that an inline function doesn't work.
Otherwise, use an empty inline function.
(a) Case of !CONFIG_LEDS_TRIGGERS
Following macros are replaced with inline functions.
led_trigger_register_simple()
led_trigger_unregister_simple()
led_trigger_event()
To make inline types, the structure, 'led_trigger' should be defined.
This structure has no member at all.
(b) Case of !CONFIG_LEDS_TRIGGER_IDE_DISK
ledtrig_ide_activity() macro is replaced with an inline function as well.
(c) DEFINE_LED_TRIGGER() and DEFINE_LED_TRIGGER_GLOBAL()
Struct 'led_trigger' is defined both cases, with CONFIG_LEDS_TRIGGERS and
without CONFIG_LEDS_TRIGGERS.
Those macros are moved out of CONFIG_LED_TRIGGERS because of no-dependency
on CONFIG_LEDS_TRIGGERS.
(d) Fix build errors in mmc-core driver
After replacing macros with inline functions, following build errors occur.
(condition: CONFIG_LEDS_TRIGGERS is not set)
drivers/mmc/core/core.c: In function 'mmc_request_done':
drivers/mmc/core/core.c:164:25: error: 'struct mmc_host' has no member named 'led'
drivers/mmc/core/core.c: In function 'mmc_start_request':
drivers/mmc/core/core.c:254:24: error: 'struct mmc_host' has no member named 'led'
make[3]: *** [drivers/mmc/core/core.o] Error 1
The reason of these errors is non-existent member variable, 'led'.
It is only valid when CONFIG_LEDS_TRIGGERS is set.
But now, it can be used without this dependency.
To fix build errors, member 'led' is always used without its config option in
'include/linux/mmc/host.h'.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
This patch fixes build warnings when CONFIG_LEDS_TRIGGERS is
disabled as below:
include/linux/leds.h:158:18: warning: 'struct led_trigger' declared inside parameter list [enabled by default]
include/linux/leds.h:158:18: warning: its scope is only this definition or declaration, which is probably not what you want [enabled
by default]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Implements a "led_trigger_rename" function to rename a trigger with
proper locking.
This assumes that led name was originally allocated in non-constant
storage.
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Pull LED subsystem update from Bryan Wu.
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (24 commits)
leds: add output driver configuration for pca9633 led driver
leds: lm3642: Use regmap_update_bits() in lm3642_chip_init()
leds: Add new LED driver for lm3642 chips
leds-lp5523: Fix riskiness of the page fault
leds-lp5523: turn off the LED engines on unloading the driver
leds-lm3530: Fix smatch warnings
leds-lm3530: Use devm_regulator_get function
leds: leds-gpio: adopt pinctrl support
leds: Add new LED driver for lm355x chips
leds-lp5523: use the i2c device id rather than fixed name
leds-lp5523: add new device id for LP55231
leds-lp5523: support new LP55231 device
leds: triggers: send uevent when changing triggers
leds-lp5523: minor code style fixes
leds-lp5523: change the return type of lp5523_set_mode()
leds-lp5523: set the brightness to 0 forcely on removing the driver
leds-lp5523: add channel name in the platform data
leds: leds-gpio: Use of_get_child_count() helper
leds: leds-gpio: Use platform_{get,set}_drvdata
leds: leds-gpio: use of_match_ptr()
...
Delay execution of led_set_brightness() if need to stop soft-blink
timer.
This allows led_set_brightness to be called in hard-irq context even if
soft-blink was activated on that LED.
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
From Bryan Wu <bryan.wu@canonical.com>:
Based on Linus Walleij's ARM LED consolidation work, this patchset introduce a
new generic led trigger for CPU not only for ARM but also for others.
For enabling CPU idle event, CPU arch code should call ledtrig_cpu() stub to
trigger idle start or idle end event.
These patches convert old style LED driver in arch/arm to gpio_led or new led
driver interface. Against 3.5 release and build successfully for all the machines.
Test ledtrig-cpu driver on OMAP4 Panda board.
v9 --> v10
* fix compiling issue on versatile_defconfig reported by Russell King
* rebase to 3.5 kernel and move patches to new git tree
v8 --> v9:
* use mutex to replace rw_sema pointed out by Tim Gardner
* add a new struct led_trigger_cpu
* add lock_is_inited to record mutex lock initialization
v6 --> v7:
* add a patch to unify the led-trigger name
* fix some typo pointed
* use BUG_ON to detect CPU numbers during building stage
v5 --> v6:
* replace __get_cpu_var() to per_cpu()
* remove smp_processor_id() which is wrong with for_each_possible_cpu()
* test on real OMAP4 Panda board
* add comments about CPU hotplug in the CPU LED trigger driver
v4 --> v5:
* rebase all the patches on top of latest linux-next
* replace on_each_cpu() with for_each_possible_cpu()
* add some description of ledtrig_cpu() API
* remove old leds code from driver nwflash.c, which should use a new led trigger then
* this trigger driver can be built as module now
v3 --> v4:
* fix a typo pointed by Jochen Friedrich
* fix some building errors
* add Reviewed-by and Tested-by into patch log
v2 --> v3:
* almost rewrote the whole ledtrig-cpu driver, which is more simple
* every CPU will have a per-CPU trigger
* cpu trigger can be assigned to any leds
* fix a lockdep issue in led-trigger common code
* other fix according to review
v1 --> v2:
* remove select operations in Kconfig of every machines
* add back supporting of led in core module of mach-integrator
* solidate name scheme in ledtrig-cpu.c
* add comments of CPU_LED_* cpu led events
* fold patches of RealView and Versatile together
* add machine_is_ check during assabet led driver init
* add some Acked-by in patch logs
* remove code for simpad machine in machine-sa11000, since Jochen Friedrich
introduced gpiolib and gpio-led driver for simpad
* on Assabet and Netwinder machine, LED operations is reversed like:
setting bit means turn off leds
clearing bit means turn on leds
* add a new function to read CM_CTRL register for led driver
* 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
ARM: use new LEDS CPU trigger stub to replace old one
ARM: mach-sa1100: retire custom LED code
ARM: mach-omap1: retire custom LED code
ARM: mach-pnx4008: remove including old leds event API header file
ARM: plat-samsung: remove including old leds event API header file
ARM: mach-pxa: retire custom LED code
char: nwflash: remove old led event code
ARM: mach-footbridge: retire custom LED code
ARM: mach-ebsa110: retire custom LED code
ARM: mach-clps711x: retire custom LED code of P720T machine
ARM: mach-integrator: retire custom LED code
ARM: mach-integrator: move CM_CTRL to header file for accessing by other functions
ARM: mach-orion5x: convert custom LED code to gpio_led and LED CPU trigger
ARM: mach-shark: retire custom LED code
ARM: mach-ks8695: remove leds driver, since nobody use it
ARM: mach-realview and mach-versatile: retire custom LED code
ARM: at91: convert old leds drivers to gpio_led and led_trigger drivers
led-triggers: create a trigger for CPU activity
Conflicts:
arch/arm/mach-clps711x/p720t.c
arch/arm/mach-sa1100/leds-cerf.c
arch/arm/mach-sa1100/leds-lart.c
Let's hope this is the last time we pull this and it doesn't cause
more trouble. I have verified that version 10 causes no build
warnings or errors any more, and the patches still look good.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Attempting to consolidate the ARM LED code, this removes the
custom RealView LED trigger code to turn LEDs on and off in
response to CPU activity and replace it with a standard trigger.
(bryan.wu@canonical.com:
It introduces several syscore stubs into this trigger.
It also provides ledtrig_cpu trigger event stub in <linux/leds.h>.
Although it was inspired by ARM work, it can be used in other arch.)
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Jochen Friedrich <jochen@scram.de>
Rename leds external interface led_brightness_set() to led_set_brightness().
This is the second phase of the change to reduce confusion between the
leds internal and external interfaces that set brightness. With this change,
now the external interface is led_set_brightness(). The first phase renamed
the internal interface led_set_brightness() to __led_set_brightness().
There are no changes to the interface implementations.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Add two new functions, led_blink_set_oneshot and
led_trigger_blink_oneshot, to be used by triggers for one-shot blink of
led devices.
This is implemented extending the existing software-blink code, and uses
the same timer and handler function.
The behavior of the code is to do a blink-on, blink-off sequence when
the function is called, ignoring other calls until the sequence is
completed so that the leds keep blinking at constant rate if the
functions are called repeatedly.
This is meant to be used by drivers which needs to trigger on sporadic
event, but doesn't have clear busy/idle trigger points.
After the blink sequence the led remains off. This behavior can be
inverted setting the "invert" argument, which blink the led off, than on
and leave the led on after the sequence.
(bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking
when writing the same value to delay_on or delay_off')
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Add a new field to led_classdev to save activattion state after activate
routine is successful. This saved state is used in deactivate routine to
do cleanup such as removing device files, and free memory allocated during
activation. Currently trigger_data not being null is used for this
purpose.
Existing triggers will need changes to use this new field.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function makes a deep copy of the platform data to allow it to live
in init memory. For a kernel that supports several machines and so
includes the definition for several leds-gpio devices this saves quite
some memory because all but one definition can be free'd after boot.
As the function is used by arch code it must be builtin and so cannot go
into leds-gpio.c.
[akpm@linux-foundation.org: s/CONFIG_LED_REGISTER_GPIO/CONFIG_LEDS_REGISTER_GPIO/]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: H Hartley Sweeten <hartleys@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.infradead.org/battery-2.6: (30 commits)
bq20z75: Fix time and temp units
bq20z75: Fix issues with present and suspend
z2_battery: Fix count of properties
s3c_adc_battery: Fix method names when PM not set
z2_battery: Add MODULE_DEVICE_TABLE
ds2782_battery: Add MODULE_DEVICE_TABLE
bq20z75: Add MODULE_DEVICE_TABLE
power_supply: Update power_supply_is_watt_property
bq20z75: Add i2c retry mechanism
bq20z75: Add optional battery detect gpio
twl4030_charger: Make the driver atomic notifier safe
bq27x00: Use single i2c_transfer call for property read
bq27x00: Cleanup bq27x00_i2c_read
bq27x00: Minor cleanups
bq27x00: Give more specific reports on battery status
bq27x00: Add MODULE_DEVICE_TABLE
bq27x00: Add new properties
bq27x00: Poll battery state
bq27x00: Cache battery registers
bq27x00: Add bq27000 support
...
As blink API is now available, it's possible to add ability to blink via
simple trigger.
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Currently, blinking LEDs can be awkward because it is not guaranteed that
all LEDs implement blinking. The trigger that wants it to blink then
needs to implement its own timer solution.
Rather than require that, add led_blink_set() API that triggers can use.
This function will attempt to use hw blinking, but if that fails
implements a timer for it. To stop blinking again, brightness_set() also
needs to be wrapped into API that will stop the software blink.
As a result of this, the timer trigger becomes a very trivial one, and
hopefully we can finally see triggers using blinking as well because it's
always easy to use.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The leds-gpio blink_set() callback follows the same prototype as the
main leds subsystem blink_set() one.
The problem is that to stop blink, normally, a leds driver does it
in the brightness_set() callback when asked to set a new fixed value.
However, with leds-gpio, the platform has no hook to do so, as this
later callback results in a standard GPIO manipulation.
This changes the leds-gpio specific callback to take a new argument
that indicates whether the LED should be blinking or not and in what
state it should be set if not. We also update the dns323 platform
which seems to be the only user of this so far.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
The documentation for the parameters of blink_set() was a bit hard
to find so put some where I'd expected to find it.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Add an option to preserve LED state when suspending/resuming to the LED
gpio driver. Based on a suggestion from Robert Jarzmik.
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
This patch allows drivers to override the default maximum brightness value
of 255. We take care to preserve backwards-compatibility as much as
possible, so that user-space ABI doesn't change for existing drivers.
LED trigger code has also been updated to use the per-LED maximum.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Add suspend/resume to the core class and remove all the now unneeded
code from various drivers. Originally the class code couldn't support
suspend/resume but since class_device can there is no reason for
each driver doing its own suspend/resume anymore.
There is one place where the struct led_classdev as the function
argument is named differently. Fix it.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
The default_trigger fields of struct gpio_led and thus struct
led_classdev are pretty much always assigned from a string literal,
which means the string can't be modified. Which is fine, since there is
no reason to modify the string and in fact it never is.
But they should be marked const to prevent such code from being added,
to prevent warnings if -Wwrite-strings is used, when assigned from a
constant string other than a string literal (which produces a warning
under current kernel compiler flags), and for general good coding
practices.
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
This driver supports the PCA9550, PCA9551, PCA9552, and PCA9553
LED driver chips.
Signed-off-by: Nate Case <ncase@xes-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
LED classdev core doesn't modify memory pointed by the default_trigger,
so mark it as const and we'll able to pass const char *s without getting
compiler warnings.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Make sure there is no confusion about the contexts brightness_set
can be called under by documenting it.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Some led hardware allows drivers to query the led state, and this patch
adds a hook to let the led class take advantage of that information when
available.
Without this functionality, when access to the led hardware is not
exclusive (i.e. firmware or hardware might change its state behind the
kernel's back), reality goes out of sync with the led class' idea of what
the led is doing, which is annoying at best.
Behaviour for drivers that do not or cannot read the led status is
unchanged.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Enhance leds-gpio to provide hardware-based led flashing by passing
through the blink_set() call to a optionally set platform-specific
function pointer.
Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
After 2.6.24 there was a plan to make the PM core acquire all device
semaphores during a suspend/hibernation to protect itself from
concurrent operations involving device objects. That proved to be
too heavy-handed and we found a better way to achieve the goal, but
before it happened, we had introduced the functions
device_pm_schedule_removal() and destroy_suspended_device() to allow
drivers to "safely" destroy a suspended device and we had adapted some
drivers to use them. Now that these functions are no longer necessary,
it seems reasonable to remove them and modify their users to use the
normal device unregistration instead.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Extends the leds subsystem with a blink_set() callback function which can
be optionally implemented by a LED driver. If implemented, the driver can use
the hardware acceleration for blinking a LED.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Make it possible to unregister a led classdev object in a safe way during a
suspend/resume cycle.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert part of the led trigger core from rw spinlocks to rw
semaphores. We're calling functions which can sleep from invalid
contexts otherwise. Fixes bug #9264.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
This patch has added #include <linux/spinlock.h> to include/linux/leds.h
for rwlock_t.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds:
leds: Convert from struct class_device to struct device
leds: leds-gpio for ngw100
leds: Add warning printks in error paths
leds: Fix trigger unregister_simple if register_simple fails
leds: Use menuconfig objects II - LED
leds: Teach leds-gpio to handle timer-unsafe GPIOs
leds: Add generic GPIO LED driver
Remove the obviously unnecessary includes of <linux/spinlock.h> under the
include/linux/ directory, and fix the couple errors that are introduced as
a result of that.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the LEDs class from struct class_device to struct device
since class_device is scheduled for removal.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds support for GPIO connected leds via the new GPIO framework.
Information about leds (gpio, polarity, name, default trigger) is passed
to the driver via platform_data.
Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Make it possible to include linux/leds.h without first including list.h and
spinlock.h.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Lay out the structure definitions in include/linux/leds.h to be aligned as
much as possible. Also minor updates to the comments to make them more
concise.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add an LED trigger for IDE disk activity to the ide-disk driver.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add support for LED triggers to the LED subsystem. "Triggers" are events
which change the state of an LED. Two kinds of trigger are available, simple
ones which can be added to exising code with minimum disruption and complex
ones for implementing new or more complex functionality.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add the foundations of a new LEDs subsystem. This patch adds a class which
presents LED devices within sysfs and allows their brightness to be
controlled.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
