cros_ec_hwmon_read_pwm_enable
ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, channel,
ret = cros_ec_hwmon_read_pwm_enable(cros_ec, index, &control_method);
ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, i, &control_method);