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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
..
acorn/char
acpi ACPI: fix build warning 2008-02-07 04:24:01 -05:00
amba
ata ata_piix.c:piix_init_one() must be __devinit 2008-02-06 07:01:56 -05:00
atm
auxdisplay
base Driver core: Revert "Fix Firmware class name collision" 2008-02-07 11:31:46 -08:00
block aoe: statically initialise devlist_lock 2008-02-08 09:22:32 -08:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2008-02-05 10:09:07 -08:00
cdrom Merge branch 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2008-02-07 09:02:26 -08:00
char tty_ioctl: drag screaming into compliance with the coding style 2008-02-08 09:22:25 -08:00
clocksource
connector
cpufreq [CPUFREQ] fix configuration help message 2008-02-06 22:57:58 -05:00
cpuidle Revert "cpuidle: build fix for non-x86" 2008-02-07 04:16:34 -05:00
crypto
dca
dio dio: ARRAY_SIZE() cleanup 2008-02-05 09:44:23 -08:00
dma async_tx: replace 'int_en' with operation preparation flags 2008-02-06 10:12:18 -07:00
edac drivers/edac/i3000: document type promotion 2008-02-07 08:42:23 -08:00
eisa
firewire
firmware SMBIOS/DMI: add type 41 = Onboard Devices Extended Information 2008-02-08 09:22:37 -08:00
gpio gpio: handle pca953{4,5,6,7,8} too 2008-02-06 10:41:15 -08:00
hid
hwmon hwmon: (lm80) Add individual alarm files 2008-02-07 20:39:45 -05:00
i2c hwmon: Discard useless I2C driver IDs 2008-02-07 20:39:44 -05:00
ide aout: remove unnecessary inclusions of {asm, linux}/a.out.h 2008-02-08 09:22:30 -08:00
ieee1394 ieee1394: sbp2: fix bogus s/g access change 2008-02-02 13:48:16 +01:00
infiniband RDMA/nes: Add a driver for NetEffect RNICs 2008-02-04 20:20:45 -08:00
input mn10300: add the MN10300/AM33 architecture to the kernel 2008-02-08 09:22:30 -08:00
isdn drivers/isdn/hardware/eicon/debug.c: fix uninitialized var warning 2008-02-06 10:41:12 -08:00
leds PWM LED driver 2008-02-08 09:22:38 -08:00
lguest Fix container_of() usage 2008-02-08 09:22:32 -08:00
macintosh ppc: fix #ifdef-s in mediabay driver (take 2) 2008-02-06 02:57:50 +01:00
mca
md dm raid1: report fault status 2008-02-08 02:11:39 +00:00
media Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2008-02-07 12:57:44 -08:00
message drivers/message/: Spelling fixes 2008-02-03 17:21:01 +02:00
mfd ASIC3 driver 2008-02-07 08:42:23 -08:00
misc Basic PWM driver for AVR32 and AT91 2008-02-08 09:22:38 -08:00
mmc
mtd Merge git://git.infradead.org/mtd-2.6 2008-02-07 10:20:31 -08:00
net mn10300: add the MN10300/AM33 architecture to the kernel 2008-02-08 09:22:30 -08:00
nubus nubus: kill drivers/nubus/nubus_syms.c 2008-02-05 09:44:23 -08:00
of [POWERPC] Create and hook up of_platform_device_shutdown 2008-02-06 16:29:59 +11:00
oprofile
parisc iommu sg merging: parisc: make iommu respect the segment size limits 2008-02-05 09:44:10 -08:00
parport parport: fix ieee1284_epp_read_addr 2008-02-08 09:22:36 -08:00
pci mn10300: add the MN10300/AM33 architecture to the kernel 2008-02-08 09:22:30 -08:00
pcmcia drivers/pcmcia: add missing pci_dev_get 2008-02-05 09:44:09 -08:00
pnp Merge branches 'release', 'bugzilla-6217', 'bugzilla-6629', 'bugzilla-6933', 'bugzilla-7186', 'bugzilla-8269', 'bugzilla-8570', 'bugzilla-9139', 'bugzilla-9277', 'bugzilla-9341', 'bugzilla-9444', 'bugzilla-9614', 'bugzilla-9643' and 'bugzilla-9644' into release 2008-02-07 03:09:43 -05:00
power Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2008-02-07 09:45:58 -08:00
ps3 ps3: use symbolic names for video modes 2008-02-06 10:41:17 -08:00
rapidio
rtc rtc: at91sam9 RTC support (RTT and/or RTC) 2008-02-06 10:41:14 -08:00
s390 calibrate_delay() must be __cpuinit 2008-02-06 10:41:08 -08:00
sbus
scsi Convert SG from nopage to fault. 2008-02-07 19:09:22 -08:00
serial atmel_serial: show tty name in /proc/interrupts 2008-02-08 09:22:37 -08:00
sh
sn
spi spi: remove more dev->power.power_state usage 2008-02-06 10:41:11 -08:00
ssb drivers/ssb/: Spelling fixes 2008-02-03 17:30:25 +02:00
tc
telephony
thermal the generic thermal sysfs driver 2008-02-01 23:12:19 -05:00
uio uio: nopage 2008-02-06 10:41:07 -08:00
usb usb: net2280 can't have a function called show_registers() 2008-02-08 09:22:30 -08:00
video mn10300: add the MN10300/AM33 architecture to the kernel 2008-02-08 09:22:30 -08:00
virtio virtio: add missing #include <linux/delay.h> 2008-02-06 10:41:21 -08:00
w1 DS1WM: decouple host IRQ and INTR active state settings 2008-02-07 08:42:06 -08:00
watchdog drivers/watchdog/: Spelling fixes 2008-02-03 17:32:52 +02:00
xen
zorro
Kconfig Merge branches 'release' and 'menlo' into release 2008-02-07 03:18:04 -05:00
Makefile Merge branches 'release' and 'menlo' into release 2008-02-07 03:18:04 -05:00