pwm_to_reg
data->pwm_duty[nr] == pwm_to_reg(data, 0xff))
data->pwm_duty[nr] = pwm_to_reg(data, 0xff);
data->pwm_duty[nr] = pwm_to_reg(data, val);
data->pwm_duty[nr] = pwm_to_reg(data, val);
data->auto_pwm[nr][point] = pwm_to_reg(data, val);