LCD 亮度相关(背光)
\kernel\msm-3.18\drivers\video\msm\mdss\mdss_fb.c
调用led_classdev_register();注册lcd-backlight
/sys/class/leds/lcd-backlight
dtsi:dsi-panel-BOE-NT51021-1200p-video.dtsi中:
qcom,mdss-dsi-bl-min-level = <1>; 最小等级
qcom,mdss-dsi-bl-max-level = <100>; 最大等级
qcom,mdss-brightness-max-level = <255>; 最大亮度