MT6370_ITORCH_STEP_uA
s->step = MT6370_ITORCH_STEP_uA;
val = mt6370_clamp(val, MT6370_ITORCH_MIN_uA, max_ua, MT6370_ITORCH_STEP_uA);
lcdev->max_brightness = (val - MT6370_ITORCH_MIN_uA) / MT6370_ITORCH_STEP_uA + 1;