ALSA: core, oxygen, virtuoso: add an enum control info helper

Introduce the helper function snd_ctl_enum_info() to fill out the
elem_info fields for an enumerated control.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/control.h

@@ -160,12 +160,14 @@ static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id
 }
 
 /*
- * Frequently used control callbacks
+ * Frequently used control callbacks/helpers
  */
 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 			      struct snd_ctl_elem_info *uinfo);
 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_info *uinfo);
+int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
+		      unsigned int items, const char *const names[]);
 
 /*
  * virtual master control

sound/core/control.c

@@ -1488,7 +1488,7 @@ int snd_ctl_create(struct snd_card *card)
 }
 
 /*
- * Frequently used control callbacks
+ * Frequently used control callbacks/helpers
  */
 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 			      struct snd_ctl_elem_info *uinfo)
@@ -1513,3 +1513,29 @@ int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 }
 
 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
+
+/**
+ * snd_ctl_enum_info - fills the info structure for an enumerated control
+ * @info: the structure to be filled
+ * @channels: the number of the control's channels; often one
+ * @items: the number of control values; also the size of @names
+ * @names: an array containing the names of all control values
+ *
+ * Sets all required fields in @info to their appropriate values.
+ * If the control's accessibility is not the default (readable and writable),
+ * the caller has to fill @info->access.
+ */
+int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
+		      unsigned int items, const char *const names[])
+{
+	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
+	info->count = channels;
+	info->value.enumerated.items = items;
+	if (info->value.enumerated.item >= items)
+		info->value.enumerated.item = items - 1;
+	strlcpy(info->value.enumerated.name,
+		names[info->value.enumerated.item],
+		sizeof(info->value.enumerated.name));
+	return 0;
+}
+EXPORT_SYMBOL(snd_ctl_enum_info);

sound/pci/oxygen/oxygen.c

@@ -415,13 +415,7 @@ static int rolloff_info(struct snd_kcontrol *ctl,
 		"Sharp Roll-off", "Slow Roll-off"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	if (info->value.enumerated.item >= 2)
-		info->value.enumerated.item = 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int rolloff_get(struct snd_kcontrol *ctl,
@@ -473,13 +467,7 @@ static int hpf_info(struct snd_kcontrol *ctl, struct snd_ctl_elem_info *info)
 		"None", "High-pass Filter"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	if (info->value.enumerated.item >= 2)
-		info->value.enumerated.item = 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int hpf_get(struct snd_kcontrol *ctl, struct snd_ctl_elem_value *value)

sound/pci/oxygen/oxygen_mixer.c

@@ -119,13 +119,7 @@ static int upmix_info(struct snd_kcontrol *ctl, struct snd_ctl_elem_info *info)
 	struct oxygen *chip = ctl->private_data;
 	unsigned int count = upmix_item_count(chip);
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = count;
-	if (info->value.enumerated.item >= count)
-		info->value.enumerated.item = count - 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, count, names);
 }
 
 static int upmix_get(struct snd_kcontrol *ctl, struct snd_ctl_elem_value *value)
@@ -659,12 +653,7 @@ static int mic_fmic_source_info(struct snd_kcontrol *ctl,
 {
 	static const char *const names[] = { "Mic Jack", "Front Panel" };
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	info->value.enumerated.item &= 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int mic_fmic_source_get(struct snd_kcontrol *ctl,

sound/pci/oxygen/xonar_cs43xx.c

@@ -298,13 +298,7 @@ static int rolloff_info(struct snd_kcontrol *ctl,
 		"Fast Roll-off", "Slow Roll-off"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	if (info->value.enumerated.item >= 2)
-		info->value.enumerated.item = 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int rolloff_get(struct snd_kcontrol *ctl,

sound/pci/oxygen/xonar_dg.c

@@ -213,13 +213,7 @@ static int output_switch_info(struct snd_kcontrol *ctl,
 		"Speakers", "Headphones", "FP Headphones"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 3;
-	if (info->value.enumerated.item >= 3)
-		info->value.enumerated.item = 2;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 3, names);
 }
 
 static int output_switch_get(struct snd_kcontrol *ctl,
@@ -276,13 +270,7 @@ static int hp_volume_offset_info(struct snd_kcontrol *ctl,
 		"< 64 ohms", "64-150 ohms", "150-300 ohms"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 3;
-	if (info->value.enumerated.item >= 3)
-		info->value.enumerated.item = 2;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 3, names);
 }
 
 static int hp_volume_offset_get(struct snd_kcontrol *ctl,
@@ -390,12 +378,7 @@ static int input_sel_info(struct snd_kcontrol *ctl,
 		"Mic", "Aux", "Front Mic", "Line"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 4;
-	info->value.enumerated.item &= 3;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 4, names);
 }
 
 static int input_sel_get(struct snd_kcontrol *ctl,
@@ -453,12 +436,7 @@ static int hpf_info(struct snd_kcontrol *ctl, struct snd_ctl_elem_info *info)
 {
 	static const char *const names[2] = { "Active", "Frozen" };
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	info->value.enumerated.item &= 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int hpf_get(struct snd_kcontrol *ctl, struct snd_ctl_elem_value *value)

sound/pci/oxygen/xonar_pcm179x.c

@@ -678,13 +678,7 @@ static int rolloff_info(struct snd_kcontrol *ctl,
 		"Sharp Roll-off", "Slow Roll-off"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	if (info->value.enumerated.item >= 2)
-		info->value.enumerated.item = 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int rolloff_get(struct snd_kcontrol *ctl,
@@ -748,13 +742,7 @@ static int st_output_switch_info(struct snd_kcontrol *ctl,
 		"Speakers", "Headphones", "FP Headphones"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 3;
-	if (info->value.enumerated.item >= 3)
-		info->value.enumerated.item = 2;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 3, names);
 }
 
 static int st_output_switch_get(struct snd_kcontrol *ctl,
@@ -809,13 +797,7 @@ static int st_hp_volume_offset_info(struct snd_kcontrol *ctl,
 		"< 64 ohms", "64-300 ohms", "300-600 ohms"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 3;
-	if (info->value.enumerated.item > 2)
-		info->value.enumerated.item = 2;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 3, names);
 }
 
 static int st_hp_volume_offset_get(struct snd_kcontrol *ctl,

sound/pci/oxygen/xonar_wm87x6.c

@@ -577,11 +577,6 @@ static int wm8776_field_enum_info(struct snd_kcontrol *ctl,
 	const char *const *names;
 
 	max = (ctl->private_value >> 12) & 0xf;
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = max + 1;
-	if (info->value.enumerated.item > max)
-		info->value.enumerated.item = max;
 	switch ((ctl->private_value >> 24) & 0x1f) {
 	case WM8776_ALCCTRL2:
 		names = hld;
@@ -605,8 +600,7 @@ static int wm8776_field_enum_info(struct snd_kcontrol *ctl,
 	default:
 		return -ENXIO;
 	}
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, max + 1, names);
 }
 
 static int wm8776_field_volume_info(struct snd_kcontrol *ctl,
@@ -863,13 +857,8 @@ static int wm8776_level_control_info(struct snd_kcontrol *ctl,
 	static const char *const names[3] = {
 		"None", "Peak Limiter", "Automatic Level Control"
 	};
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 3;
-	if (info->value.enumerated.item >= 3)
-		info->value.enumerated.item = 2;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+
+	return snd_ctl_enum_info(info, 1, 3, names);
 }
 
 static int wm8776_level_control_get(struct snd_kcontrol *ctl,
@@ -955,13 +944,7 @@ static int hpf_info(struct snd_kcontrol *ctl, struct snd_ctl_elem_info *info)
 		"None", "High-pass Filter"
 	};
 
-	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	info->count = 1;
-	info->value.enumerated.items = 2;
-	if (info->value.enumerated.item >= 2)
-		info->value.enumerated.item = 1;
-	strcpy(info->value.enumerated.name, names[info->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(info, 1, 2, names);
 }
 
 static int hpf_get(struct snd_kcontrol *ctl, struct snd_ctl_elem_value *value)