ALSA: virtuoso: add one more headphone impedance setting

Add one more option to the "Headphones Impedance" control to synchronize
with recent versions of the Windows driver.
Tested-by: Nfugazzi® <fugazzi99@gmail.com>
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/oxygen/xonar_pcm179x.c

@@ -795,11 +795,11 @@ static int st_output_switch_put(struct snd_kcontrol *ctl,
 static int st_hp_volume_offset_info(struct snd_kcontrol *ctl,
 				    struct snd_ctl_elem_info *info)
 {
-	static const char *const names[3] = {
-		"< 64 ohms", "64-300 ohms", "300-600 ohms"
+	static const char *const names[4] = {
+		"< 32 ohms", "32-64 ohms", "64-300 ohms", "300-600 ohms"
 	};
 
-	return snd_ctl_enum_info(info, 1, 3, names);
+	return snd_ctl_enum_info(info, 1, 4, names);
 }
 
 static int st_hp_volume_offset_get(struct snd_kcontrol *ctl,
@@ -809,12 +809,14 @@ static int st_hp_volume_offset_get(struct snd_kcontrol *ctl,
 	struct xonar_pcm179x *data = chip->model_data;
 
 	mutex_lock(&chip->mutex);
-	if (data->hp_gain_offset < 2*-6)
+	if (data->hp_gain_offset < 2*-12)
 		value->value.enumerated.item[0] = 0;
-	else if (data->hp_gain_offset < 0)
+	else if (data->hp_gain_offset < 2*-6)
 		value->value.enumerated.item[0] = 1;
-	else
+	else if (data->hp_gain_offset < 0)
 		value->value.enumerated.item[0] = 2;
+	else
+		value->value.enumerated.item[0] = 3;
 	mutex_unlock(&chip->mutex);
 	return 0;
 }
@@ -823,13 +825,13 @@ static int st_hp_volume_offset_get(struct snd_kcontrol *ctl,
 static int st_hp_volume_offset_put(struct snd_kcontrol *ctl,
 				   struct snd_ctl_elem_value *value)
 {
-	static const s8 offsets[] = { 2*-18, 2*-6, 0 };
+	static const s8 offsets[] = { 2*-18, 2*-12, 2*-6, 0 };
 	struct oxygen *chip = ctl->private_data;
 	struct xonar_pcm179x *data = chip->model_data;
 	s8 offset;
 	int changed;
 
-	if (value->value.enumerated.item[0] > 2)
+	if (value->value.enumerated.item[0] > 3)
 		return -EINVAL;
 	offset = offsets[value->value.enumerated.item[0]];
 	mutex_lock(&chip->mutex);