PWM_ASPEED_DUTY_CYCLE_FALLING_POINT
duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val);
PWM_ASPEED_DUTY_CYCLE_FALLING_POINT);
val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt);