1Kernel driver lp855x
2====================
3
4Backlight driver for LP855x ICs
5
6Supported chips:
7	Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8555, LP8556 and
8	LP8557
9
10Author: Milo(Woogyom) Kim <milo.kim@ti.com>
11
12Description
13-----------
14
15* Brightness control
16
17Brightness can be controlled by the pwm input or the i2c command.
18The lp855x driver supports both cases.
19
20* Device attributes
21
221) bl_ctl_mode
23Backlight control mode.
24Value : pwm based or register based
25
262) chip_id
27The lp855x chip id.
28Value : lp8550/lp8551/lp8552/lp8553/lp8555/lp8556/lp8557
29
30Platform data for lp855x
31------------------------
32
33For supporting platform specific data, the lp855x platform data can be used.
34
35* name : Backlight driver name. If it is not defined, default name is set.
36* device_control : Value of DEVICE CONTROL register.
37* initial_brightness : Initial value of backlight brightness.
38* period_ns : Platform specific PWM period value. unit is nano.
39	     Only valid when brightness is pwm input mode.
40* size_program : Total size of lp855x_rom_data.
41* rom_data : List of new eeprom/eprom registers.
42
43example 1) lp8552 platform data : i2c register mode with new eeprom data
44
45#define EEPROM_A5_ADDR	0xA5
46#define EEPROM_A5_VAL	0x4f	/* EN_VSYNC=0 */
47
48static struct lp855x_rom_data lp8552_eeprom_arr[] = {
49	{EEPROM_A5_ADDR, EEPROM_A5_VAL},
50};
51
52static struct lp855x_platform_data lp8552_pdata = {
53	.name = "lcd-bl",
54	.device_control = I2C_CONFIG(LP8552),
55	.initial_brightness = INITIAL_BRT,
56	.size_program = ARRAY_SIZE(lp8552_eeprom_arr),
57	.rom_data = lp8552_eeprom_arr,
58};
59
60example 2) lp8556 platform data : pwm input mode with default rom data
61
62static struct lp855x_platform_data lp8556_pdata = {
63	.device_control = PWM_CONFIG(LP8556),
64	.initial_brightness = INITIAL_BRT,
65	.period_ns = 1000000,
66};
67