| Kernel driver lp855x |
| ==================== |
| |
| Backlight driver for LP855x ICs |
| |
| Supported chips: |
| Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8556 and LP8557 |
| |
| Author: Milo(Woogyom) Kim <milo.kim@ti.com> |
| |
| Description |
| ----------- |
| |
| * Brightness control |
| |
| 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 |
| |
| 2) chip_id |
| The lp855x chip id. |
| Value : lp8550/lp8551/lp8552/lp8553/lp8556/lp8557 |
| |
| Platform data for lp855x |
| ------------------------ |
| |
| For supporting platform specific data, the lp855x platform data can be used. |
| |
| * 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. |
| |
| example 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 = { |
| .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 |
| |
| static struct lp855x_platform_data lp8556_pdata = { |
| .device_control = PWM_CONFIG(LP8556), |
| .initial_brightness = INITIAL_BRT, |
| .period_ns = 1000000, |
| }; |