-> backlight_update_status //注册完成后，更新背光 -> bd->ops->update_status //通过backlight...
上节提到的设置回调函数的结构体变量定义如下,其中有update_status成员变量,通过后续的backlight分析可知,在更新背光亮度和开关状态时,会调用此函数: static const struct backlight_ops pwm_backlight_ops = { .update_status = pwm_backlight_update_status, .check_fb = pwm_backlight_check_fb, }; 1. 2....
backlight_update_status(bl); } devm_backlight_device_register是backlight class提供的接口函数,将设备注册到backlight class上,属性文件向文件系统注册,读写操作的实现均在backlight中实现,最终的gpio和pwm控制通过在pwm_backlight_ops中设置的回调实现。 2.2 为backlight class注册设置回调 上节提到的设置回调函数...
58 int (*update_status)(struct backlight_device *); //更新背光设备亮度等属性 61 int (*get_brightness)(struct backlight_device *); //获取背光设备亮度 64 int (*check_fb)(struct backlight_device *, struct fb_info *); 65 }; 继续看backlight类属性中写的函数,例如设置当前背光值函...
52 struct backlight_ops { 53 unsigned int options; 58 int (*update_status)(struct backlight_device *); //更新背光设备亮度等属性 61 int (*get_brightness)(struct backlight_device *); //获取背光设备亮度 64 int (*check_fb)(struct backlight_device *, struct fb_info *); ...
pwm_backlight_update_status -> compute_duty_cycle //计算占空比,下面会分析. compute_duty_cycle //计算占空比 pwm_config //配置pwm pwm_backlight_power_on //enable背光 platform_set_drvdata platform_set_drvdata //可以将 pdev 保存成平台总线设备的私有数据,以后再要使用它时只需调用 platform_get...
pwm_backlight_power_on(pb); } else { @@ -120,7 +120,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) * inactive output. */ state.enabled = !pb->power_supply && !pb->enable_gpio; pwm_apply_state(pb->pwm, &state); pwm_apply_might_sleep(pb->pwm, &...
static void SetBackLight(uint8_t _bright) { /* 背光口线是 PB1, 复用功能选择 TIM3_CH4 当关闭背光时,将CPU IO设置为浮动输入模式(推荐设置为推挽输出,并驱动到低电平) 将TIM3关闭以节约功耗 */ GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCI...
An example of the use of the RESTART bit would be the restoring of a customer’s laptop LCD backlight intensity coming out of Standby to the level it was before going into Standby. 1. Two methods can be used to do an orderly shutdown. The fastest is to write a logic 1 to bit 4 ...
status = "okay"; }; &ldb { ipu_id = <0>; disp_id = <0>; ext_ref = <1>; mode = "sin0"; sec_ipu_id = <1>; sec_disp_id = <0>; status = "okay"; }; backlight { compatible = "pwm-backlight"; pwms = <&pwm1 0 10000000>; brightness-levels = <0 4 8 16 32 64...