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/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6b2e1e4f..04cb8c8 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -50,6 +50,19 @@
 	  controlled manually or using PWM input or using ambient
 	  light automatically.
 
+config LEDS_LM3533
+	tristate "LED support for LM3533"
+	depends on LEDS_CLASS
+	depends on MFD_LM3533
+	help
+	  This option enables support for the LEDs on National Semiconductor /
+	  TI LM3533 Lighting Power chips.
+
+	  The LEDs can be controlled directly, through PWM input, or by the
+	  ambient-light-sensor interface. The chip supports
+	  hardware-accelerated blinking with maximum on and off periods of 9.8
+	  and 77 seconds respectively.
+
 config LEDS_LOCOMO
 	tristate "LED Support for Locomo device"
 	depends on LEDS_CLASS