mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 05:57:08 +07:00
7be865ab86
THis driver supports TI LP8550/LP8551/LP8552/LP8553/LP8556 backlight devices. The brightness can be controlled by the I2C or PWM input. The lp855x driver provides both modes. For the PWM control, pwm-specific functions can be defined in the platform data. And some information can be read via the sysfs(lp855x device attributes). For details, please refer to Documentation/backlight/lp855x-driver.txt. [axel.lin@gmail.com: add missing mutex_unlock in lp855x_read_byte() error path] [axel.lin@gmail.com: check platform data in lp855x_probe()] [axel.lin@gmail.com: small cleanups] [dan.carpenter@oracle.com: silence a compiler warning] [axel.lin@gmail.com: use id->driver_data to differentiate lp855x chips] [akpm@linux-foundation.org: simplify boolean return expression] Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
79 lines
2.2 KiB
Plaintext
79 lines
2.2 KiB
Plaintext
Kernel driver lp855x
|
|
====================
|
|
|
|
Backlight driver for LP855x ICs
|
|
|
|
Supported chips:
|
|
Texas Instruments LP8550, LP8551, LP8552, LP8553 and LP8556
|
|
|
|
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
|
|
|
|
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.
|
|
* mode : Brightness control mode. PWM or register based.
|
|
* device_control : Value of DEVICE CONTROL register.
|
|
* initial_brightness : Initial value of backlight brightness.
|
|
* pwm_data : Platform specific pwm generation functions.
|
|
Only valid when brightness is pwm input mode.
|
|
Functions should be implemented by PWM driver.
|
|
- pwm_set_intensity() : set duty of PWM
|
|
- pwm_get_intensity() : get current duty of PWM
|
|
* load_new_rom_data :
|
|
0 : use default configuration data
|
|
1 : update values of eeprom or eprom registers on loading driver
|
|
* 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",
|
|
.mode = REGISTER_BASED,
|
|
.device_control = I2C_CONFIG(LP8552),
|
|
.initial_brightness = INITIAL_BRT,
|
|
.load_new_rom_data = 1,
|
|
.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 = {
|
|
.mode = PWM_BASED,
|
|
.device_control = PWM_CONFIG(LP8556),
|
|
.initial_brightness = INITIAL_BRT,
|
|
.pwm_data = {
|
|
.pwm_set_intensity = platform_pwm_set_intensity,
|
|
.pwm_get_intensity = platform_pwm_get_intensity,
|
|
},
|
|
};
|