1==================== 2Kernel driver lp855x 3==================== 4 5Backlight driver for LP855x ICs 6 7Supported chips: 8 9 Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8555, LP8556 and 10 LP8557 11 12Author: Milo(Woogyom) Kim <milo.kim@ti.com> 13 14Description 15----------- 16 17* Brightness control 18 19 Brightness can be controlled by the pwm input or the i2c command. 20 The lp855x driver supports both cases. 21 22* Device attributes 23 24 1) bl_ctl_mode 25 26 Backlight control mode. 27 28 Value: pwm based or register based 29 30 2) chip_id 31 32 The lp855x chip id. 33 34 Value: lp8550/lp8551/lp8552/lp8553/lp8555/lp8556/lp8557 35 36Platform data for lp855x 37------------------------ 38 39For supporting platform specific data, the lp855x platform data can be used. 40 41* name: 42 Backlight driver name. If it is not defined, default name is set. 43* device_control: 44 Value of DEVICE CONTROL register. 45* initial_brightness: 46 Initial value of backlight brightness. 47* period_ns: 48 Platform specific PWM period value. unit is nano. 49 Only valid when brightness is pwm input mode. 50* size_program: 51 Total size of lp855x_rom_data. 52* rom_data: 53 List of new eeprom/eprom registers. 54 55Examples 56======== 57 581) lp8552 platform data: i2c register mode with new eeprom data:: 59 60 #define EEPROM_A5_ADDR 0xA5 61 #define EEPROM_A5_VAL 0x4f /* EN_VSYNC=0 */ 62 63 static struct lp855x_rom_data lp8552_eeprom_arr[] = { 64 {EEPROM_A5_ADDR, EEPROM_A5_VAL}, 65 }; 66 67 static struct lp855x_platform_data lp8552_pdata = { 68 .name = "lcd-bl", 69 .device_control = I2C_CONFIG(LP8552), 70 .initial_brightness = INITIAL_BRT, 71 .size_program = ARRAY_SIZE(lp8552_eeprom_arr), 72 .rom_data = lp8552_eeprom_arr, 73 }; 74 752) lp8556 platform data: pwm input mode with default rom data:: 76 77 static struct lp855x_platform_data lp8556_pdata = { 78 .device_control = PWM_CONFIG(LP8556), 79 .initial_brightness = INITIAL_BRT, 80 .period_ns = 1000000, 81 }; 82