66 lines
1.7 KiB
Plaintext
66 lines
1.7 KiB
Plaintext
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,
|
|
};
|