leds: Add new LED driver for lm355x chips

This driver is a general version for LM355x,lm3554 and lm3556,led chips of TI.

LM3554 :
The LM3554 is a 2 MHz fixed-frequency synchronous boost
converter with 1.2A dual high side led drivers.
Datasheet: www.ti.com/lit/ds/symlink/lm3554.pdf

LM3556 :
The LM3556 is a 4 MHz fixed-frequency synchronous boost
converter plus 1.5A constant current driver for a high-current white LED.
Datasheet: www.national.com/ds/LM/LM3556.pdf

(bryan.wu@canonical.com: use flush_work() to replace flush_work_sync() which is
deprecated)

Signed-off-by: G.Shark Jeong <gshark.jeong@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

drivers/leds/Kconfig

@@ -423,13 +423,13 @@ config LEDS_MAX8997
 	  This option enables support for on-chip LED drivers on
 	  MAXIM MAX8997 PMIC.
 
-config LEDS_LM3556
-	tristate "LED support for LM3556 Chip"
+config LEDS_LM355x
+	tristate "LED support for LM355x Chips, LM3554 and LM3556"
 	depends on LEDS_CLASS && I2C
 	select REGMAP_I2C
 	help
-	  This option enables support for LEDs connected to LM3556.
-	  LM3556 includes Torch, Flash and Indicator functions.
+	  This option enables support for LEDs connected to LM355x.
+	  LM355x includes Torch, Flash and Indicator functions.
 
 config LEDS_OT200
 	tristate "LED support for the Bachmann OT200"

drivers/leds/Makefile

@@ -48,7 +48,7 @@ obj-$(CONFIG_LEDS_NETXBIG)		+= leds-netxbig.o
 obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_RENESAS_TPU)		+= leds-renesas-tpu.o
 obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
-obj-$(CONFIG_LEDS_LM3556)		+= leds-lm3556.o
+obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 
 # LED SPI Drivers