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