leds: add LM3533 LED driver

Add sub-driver for the LEDs on National Semiconductor / TI LM3533 lighting
power chips.

The chip provides 256 brightness levels, hardware accelerated blinking as
well as ambient-light-sensor and pwm input control.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Rob Landley <rob@landley.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
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>
diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-lm3533 b/Documentation/ABI/testing/sysfs-class-led-driver-lm3533
new file mode 100644
index 0000000..620ebb3
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-driver-lm3533
@@ -0,0 +1,65 @@
+What:		/sys/class/leds/<led>/als_channel
+Date:		May 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Set the ALS output channel to use as input in
+		ALS-current-control mode (1, 2), where
+
+		1 - out_current1
+		2 - out_current2
+
+What:		/sys/class/leds/<led>/als_en
+Date:		May 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Enable ALS-current-control mode (0, 1).
+
+What:		/sys/class/leds/<led>/falltime
+What:		/sys/class/leds/<led>/risetime
+Date:		April 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Set the pattern generator fall and rise times (0..7), where
+
+		0 - 2048 us
+		1 - 262 ms
+		2 - 524 ms
+		3 - 1.049 s
+		4 - 2.097 s
+		5 - 4.194 s
+		6 - 8.389 s
+		7 - 16.78 s
+
+What:		/sys/class/leds/<led>/id
+Date:		April 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Get the id of this led (0..3).
+
+What:		/sys/class/leds/<led>/linear
+Date:		April 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Set the brightness-mapping mode (0, 1), where
+
+		0 - exponential mode
+		1 - linear mode
+
+What:		/sys/class/leds/<led>/pwm
+Date:		April 2012
+KernelVersion:	3.5
+Contact:	Johan Hovold <jhovold@gmail.com>
+Description:
+		Set the PWM-input control mask (5 bits), where
+
+		bit 5 - PWM-input enabled in Zone 4
+		bit 4 - PWM-input enabled in Zone 3
+		bit 3 - PWM-input enabled in Zone 2
+		bit 2 - PWM-input enabled in Zone 1
+		bit 1 - PWM-input enabled in Zone 0
+		bit 0 - PWM-input enabled