LED屏幕背光调试

1. 指令直接设置

cd /sys/devices/platform/backlight/backlight/backlight
echo 40 > brightness  //设置亮度为40
cat brightness       //查看当前设置的亮度

2. framework层配置

/frameworks/base/core/res/res/values/config.xml  //position
config_screenBrightnessSettingMinimum     
config_screenBrightnessSettingMaximum
config_screenBrightnessSettingDefault

3. framework层代码

frameworks\base\packages\SystemUI\src\com\android\systemui\settings\BrightnessDialog.java
packages/apps/Settings/res/xml/display_settings.xml
frameworks/base/packages/SystemUI/AndroidManifest.xml

ref: https://www.cnblogs.com/crushgirl/p/15474247.html

4. 驱动层代码和配置

drivers/video/backlight/pwm_bl.c
kernel/arch/arm64/boot/dts/rockchip/rk3399-evb-ind-mipi-CLCMSZ4900.dtsi

5. framework层动态调试

待补充

6. 通过hook方式动态修改代码避免重新编译系统

待补充