docs: lp855x-driver.txt: convert to ReST and move to kernel-api

This small file seems to be an attempt to start documenting
backlight drivers.

It contains descriptions of the controls for the driver
with could sound as an somewhat user-faced description, but
it's main focus is to describe, instead, the data that should
be passed via platform data and some driver-specific stuff.

While this is not part of the driver-api book, mark it as
:orphan:, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/backlight/lp855x-driver.txt → Documentation/backlight/lp855x-driver.rst

+:orphan:
+
+====================
 Kernel driver lp855x
 ====================
 
 Backlight driver for LP855x ICs
 
 Supported chips:
+
 	Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8555, LP8556 and
 	LP8557
 
@@ -14,53 +18,66 @@ Description
 
 * Brightness control
 
-Brightness can be controlled by the pwm input or the i2c command.
-The lp855x driver supports both cases.
+  Brightness can be controlled by the pwm input or the i2c command.
+  The lp855x driver supports both cases.
 
 * Device attributes
 
-1) bl_ctl_mode
-Backlight control mode.
-Value : pwm based or register based
+  1) bl_ctl_mode
 
-2) chip_id
-The lp855x chip id.
-Value : lp8550/lp8551/lp8552/lp8553/lp8555/lp8556/lp8557
+  Backlight control mode.
 
-Platform data for lp855x
-------------------------
+  Value: pwm based or register based
 
-For supporting platform specific data, the lp855x platform data can be used.
+  2) chip_id
 
-* name : Backlight driver name. If it is not defined, default name is set.
-* device_control : Value of DEVICE CONTROL register.
-* initial_brightness : Initial value of backlight brightness.
-* period_ns : Platform specific PWM period value. unit is nano.
-	     Only valid when brightness is pwm input mode.
-* size_program : Total size of lp855x_rom_data.
-* rom_data : List of new eeprom/eprom registers.
+  The lp855x chip id.
 
-example 1) lp8552 platform data : i2c register mode with new eeprom data
+  Value: lp8550/lp8551/lp8552/lp8553/lp8555/lp8556/lp8557
 
-#define EEPROM_A5_ADDR	0xA5
-#define EEPROM_A5_VAL	0x4f	/* EN_VSYNC=0 */
+Platform data for lp855x
+------------------------
+
+For supporting platform specific data, the lp855x platform data can be used.
 
-static struct lp855x_rom_data lp8552_eeprom_arr[] = {
+* name:
+	Backlight driver name. If it is not defined, default name is set.
+* device_control:
+	Value of DEVICE CONTROL register.
+* initial_brightness:
+	Initial value of backlight brightness.
+* period_ns:
+	Platform specific PWM period value. unit is nano.
+	Only valid when brightness is pwm input mode.
+* size_program:
+	Total size of lp855x_rom_data.
+* rom_data:
+	List of new eeprom/eprom registers.
+
+Examples
+========
+
+1) lp8552 platform data: i2c register mode with new eeprom data::
+
+    #define EEPROM_A5_ADDR	0xA5
+    #define EEPROM_A5_VAL	0x4f	/* EN_VSYNC=0 */
+
+    static struct lp855x_rom_data lp8552_eeprom_arr[] = {
 	{EEPROM_A5_ADDR, EEPROM_A5_VAL},
-};
+    };
 
-static struct lp855x_platform_data lp8552_pdata = {
+    static struct lp855x_platform_data lp8552_pdata = {
 	.name = "lcd-bl",
 	.device_control = I2C_CONFIG(LP8552),
 	.initial_brightness = INITIAL_BRT,
 	.size_program = ARRAY_SIZE(lp8552_eeprom_arr),
 	.rom_data = lp8552_eeprom_arr,
-};
+    };
 
-example 2) lp8556 platform data : pwm input mode with default rom data
+2) lp8556 platform data: pwm input mode with default rom data::
 
-static struct lp855x_platform_data lp8556_pdata = {
+    static struct lp855x_platform_data lp8556_pdata = {
 	.device_control = PWM_CONFIG(LP8556),
 	.initial_brightness = INITIAL_BRT,
 	.period_ns = 1000000,
-};
+    };

MAINTAINERS

@@ -15964,7 +15964,7 @@ F:	sound/soc/codecs/isabelle*
 TI LP855x BACKLIGHT DRIVER
 M:	Milo Kim <milo.kim@ti.com>
 S:	Maintained
-F:	Documentation/backlight/lp855x-driver.txt
+F:	Documentation/backlight/lp855x-driver.rst
 F:	drivers/video/backlight/lp855x_bl.c
 F:	include/linux/platform_data/lp855x.h