When debugging the display, after the Android system is started, the display brightness is very dark, and the brightness needs to be adjusted so that the default brightness is sufficient. The modification points are as follows:
File path:frameworks/base/packages/SettingsProvider/res/values/defaults.xml
The def_screen_brightness value is as above, and the maximum brightness value of the system screen is 255. If you want to modify it, the default is 80%; therefore 255 * 80% = 204. Modify def_screen_brightness_automatic_mode to true, and the software will not be able to manually adjust the screen brightness.
2. Modify the maximum value, minimum value, and default value of screen brightness
File path:frameworks/base/core/res/res/values/config.xml
config_screenBrightnessSettingMinimum: brightness minimum value
config_screenBrightnessSettingMaximum: brightness maximum value
config_screenBrightnessSettingDefault: Brightness default value
The maximum brightness value of the system screen is 255. If you want to modify it, the default is 80%; therefore 255 * 80% = 204
3. Modify the default value of pwm duty cycle in the device tree
