linux/drivers/leds
David Brownell de5c9edee7 PWM LED driver
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>
2008-02-08 09:22:38 -08:00
..
Kconfig PWM LED driver 2008-02-08 09:22:38 -08:00
led-class.c leds: add possibility to remove leds classdevs during suspend/resume 2008-02-05 09:44:23 -08:00
led-core.c leds: Fix leds_list_lock locking issues 2007-12-31 23:09:44 +00:00
led-triggers.c leds: Fix leds_list_lock locking issues 2007-12-31 23:09:44 +00:00
leds-ams-delta.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-atmel-pwm.c PWM LED driver 2008-02-08 09:22:38 -08:00
leds-clevo-mail.c leds: hw acceleration for Clevo mail LED driver 2008-02-07 09:52:02 +00:00
leds-cm-x270.c [ARM] 4576/1: CM-X270 machine support 2007-10-15 18:53:57 +01:00
leds-cobalt-qube.c leds: Update Cobalt Qube series front LED support 2007-10-11 22:24:00 +01:00
leds-cobalt-raq.c leds: Add Cobalt Raq series LEDs support 2007-10-11 22:24:00 +01:00
leds-corgi.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-gpio.c leds: Fix led-gpio active_low default brightness 2008-02-07 09:52:02 +00:00
leds-h1940.c fix file specification in comments 2007-05-09 08:58:16 +02:00
leds-hp6xx.c leds: Add HP Jornada 6xx driver 2008-02-07 10:10:28 +00:00
leds-locomo.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-net48xx.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-s3c24xx.c fix typo "sort" -> "short" 2007-10-20 01:55:58 +02:00
leds-spitz.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-tosa.c leds: Standardise LED naming scheme 2008-02-07 09:47:00 +00:00
leds-wrap.c leds: Add power LED to the wrap driver 2008-02-07 09:52:03 +00:00
leds.h leds: Fix leds_list_lock locking issues 2007-12-31 23:09:44 +00:00
ledtrig-heartbeat.c [PATCH] LED: add LED heartbeat trigger 2006-06-25 10:01:23 -07:00
ledtrig-ide-disk.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
ledtrig-timer.c leds: Add support for hardware accelerated LED flashing 2008-02-07 09:49:38 +00:00
Makefile PWM LED driver 2008-02-08 09:22:38 -08:00