This is a LED driver using the PWM on newer SOCs from Atmel; brightness is
controlled by changing the PWM duty cycle. So for example if you've set up
two leds labeled "pwm0" and "pwm1":
echo 0 > /sys/class/leds/pwm2/brightness # off (0%)
echo 80 > /sys/class/leds/pwm2/brightness
echo 255 > /sys/class/leds/pwm2/brightness # on (100%)
Note that "brightness" here isn't linear; maybe that should change. Going
from 4 to 8 probably doubles perceived brightness, while 244 to 248 is
imperceptible.
This is mostly intended to be a simple example of PWM, although it's
realistic since LCD backlights are often driven with PWM to conserve
battery power (and offer brightness options).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for the LEDs on the HP Jornada 620/660/680/690 devices.
Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
All boards using the IXP4XX-GPIO-LED driver have been updated to use
the generic leds-gpio driver instead.
Signed-off-by: Rod Whitby <rod@whitby.id.au>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
The 3rd LED on this board is something like a power-led, it is on all the
time. With this change to the leds-wrap driver it is possible to use this
LED too.
Signed-off-by: Michael Loeffler <zvpunry@zvpunry.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
When gpio_direction_output() is called, led_dat->active_low is used
as default value. This means that the led will always be off by
default. cdev.brightness should really have been set to LED_OFF
unconditionally to reflect this behavior.
Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Add support for hardware accelerated LED blinking for the mail LED
commonly found on Clevo notebooks.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
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>
As discussed on LKML some notion of 'function' is needed in
LED naming. This patch adds this to the documentation and
standardises existing LED drivers.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
The driver supports the mail LED commonly found on different Clevo notebooks.
The driver access the LED through the i8042 hardware which is handled by
the input subsystem.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Covert leds_list_lock to a rw_sempahore to match previous LED trigger
locking fixes, fixing lock ordering.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
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>
Three bugfixes to the leds-gpio driver, plus minor whitespace tweaks:
- Do the INIT_WORK() before registering each LED, so if its trigger
becomes immediately active it can schedule work without oopsing..
- Use normal registration, not platform_driver_probe(), so that
devices appearing "late" (hotplug type) can still be bound.
- Mark the driver remove code as "__devexit", preventing oopses
when the underlying device is removed.
These issues came up when using this driver with some GPIO expanders
living on serial busses, which act unlike "normal" platform devices:
they can appear and vanish along with the serial bus driver.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (40 commits)
kbuild: introduce ccflags-y, asflags-y and ldflags-y
kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP
kbuild: enable use of AFLAGS and CFLAGS on commandline
kbuild: enable 'make AFLAGS=...' to add additional options to AS
kbuild: fix AFLAGS use in h8300 and m68knommu
kbuild: check for wrong use of CFLAGS
kbuild: enable 'make CFLAGS=...' to add additional options to CC
kbuild: fix up CFLAGS usage
kbuild: make modpost detect unterminated device id lists
kbuild: call export_report from the Makefile
kbuild: move Kai Germaschewski to CREDITS
kconfig/menuconfig: distinguish between selected-by-another options and comments
kconfig: tristate choices with mixed tristate and boolean values
include/linux/Kbuild: remove duplicate entries
kbuild: kill backward compatibility checks
kbuild: kill EXTRA_ARFLAGS
kbuild: fix documentation in makefiles.txt
kbuild: call make once for all targets when O=.. is used
kbuild: pass -g to assembler under CONFIG_DEBUG_INFO
kbuild: update _shipped files for kconfig syntax cleanup
...
Fix up conflicts in arch/um/sys-{x86_64,i386}/Makefile manually.
The leds-cobalt driver only supports the Coable Qube series
(not included in Cobalt Raq series).
Rename the driver and update Kconfig/Makefile.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Acked-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
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>
Fix led_trigger_unregister_simple to handle the case where
led_trigger_register_simple fails, avoiding a NULL pointer
dereference.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Change Kconfig objects from "menu, config" into "menuconfig" so
that the user can disable the whole feature without having to
enter the menu first.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
