YB_KBD_BL_MAX
if ((value < 0) || (value > YB_KBD_BL_MAX))
data->kbd_bl_led.max_brightness = YB_KBD_BL_MAX;
param.integer.value = YB_KBD_BL_MAX - level;
.duty_cycle = YB_KBD_BL_PWM_PERIOD * level / YB_KBD_BL_MAX,