EXPORT_SYMBOL(snd_ctl_free_one);
-static unsigned int snd_ctl_hole_check(struct snd_card *card,
- unsigned int count)
+static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
+ unsigned int count)
{
struct snd_kcontrol *kctl;
list_for_each_entry(kctl, &card->controls, list) {
- if ((kctl->id.numid <= card->last_numid &&
- kctl->id.numid + kctl->count > card->last_numid) ||
- (kctl->id.numid <= card->last_numid + count - 1 &&
- kctl->id.numid + kctl->count > card->last_numid + count - 1))
- return card->last_numid = kctl->id.numid + kctl->count - 1;
+ if (kctl->id.numid < card->last_numid + 1 + count &&
+ kctl->id.numid + kctl->count > card->last_numid + 1) {
+ card->last_numid = kctl->id.numid + kctl->count - 1;
+ return true;
+ }
}
- return card->last_numid;
+ return false;
}
static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
{
- unsigned int last_numid, iter = 100000;
+ unsigned int iter = 100000;
- last_numid = card->last_numid;
- while (last_numid != snd_ctl_hole_check(card, count)) {
+ while (snd_ctl_remove_numid_conflict(card, count)) {
if (--iter == 0) {
/* this situation is very unlikely */
snd_printk(KERN_ERR "unable to allocate new control numid\n");
return -ENOMEM;
}
- last_numid = card->last_numid;
}
return 0;
}
EXPORT_SYMBOL(snd_ctl_add);
+/**
+ * snd_ctl_replace - replace the control instance of the card
+ * @card: the card instance
+ * @kcontrol: the control instance to replace
+ * @add_on_replace: add the control if not already added
+ *
+ * Replaces the given control. If the given control does not exist
+ * and the add_on_replace flag is set, the control is added. If the
+ * control exists, it is destroyed first.
+ *
+ * Returns zero if successful, or a negative error code on failure.
+ *
+ * It frees automatically the control which cannot be added or replaced.
+ */
+int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
+ bool add_on_replace)
+{
+ struct snd_ctl_elem_id id;
+ unsigned int idx;
+ struct snd_kcontrol *old;
+ int ret;
+
+ if (!kcontrol)
+ return -EINVAL;
+ if (snd_BUG_ON(!card || !kcontrol->info)) {
+ ret = -EINVAL;
+ goto error;
+ }
+ id = kcontrol->id;
+ down_write(&card->controls_rwsem);
+ old = snd_ctl_find_id(card, &id);
+ if (!old) {
+ if (add_on_replace)
+ goto add;
+ up_write(&card->controls_rwsem);
+ ret = -EINVAL;
+ goto error;
+ }
+ ret = snd_ctl_remove(card, old);
+ if (ret < 0) {
+ up_write(&card->controls_rwsem);
+ goto error;
+ }
+add:
+ if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
+ up_write(&card->controls_rwsem);
+ ret = -ENOMEM;
+ goto error;
+ }
+ list_add_tail(&kcontrol->list, &card->controls);
+ card->controls_count += kcontrol->count;
+ kcontrol->id.numid = card->last_numid + 1;
+ card->last_numid += kcontrol->count;
+ up_write(&card->controls_rwsem);
+ for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
+ snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
+ return 0;
+
+error:
+ snd_ctl_free_one(kcontrol);
+ return ret;
+}
+EXPORT_SYMBOL(snd_ctl_replace);
+
/**
* snd_ctl_remove - remove the control from the card and release it
* @card: the card instance
return ret;
}
+/**
+ * snd_ctl_activate_id - activate/inactivate the control of the given id
+ * @card: the card instance
+ * @id: the control id to activate/inactivate
+ * @active: non-zero to activate
+ *
+ * Finds the control instance with the given id, and activate or
+ * inactivate the control together with notification, if changed.
+ *
+ * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
+ */
+int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
+ int active)
+{
+ struct snd_kcontrol *kctl;
+ struct snd_kcontrol_volatile *vd;
+ unsigned int index_offset;
+ int ret;
+
+ down_write(&card->controls_rwsem);
+ kctl = snd_ctl_find_id(card, id);
+ if (kctl == NULL) {
+ ret = -ENOENT;
+ goto unlock;
+ }
+ index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
+ vd = &kctl->vd[index_offset];
+ ret = 0;
+ if (active) {
+ if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
+ goto unlock;
+ vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+ } else {
+ if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
+ goto unlock;
+ vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+ }
+ ret = 1;
+ unlock:
+ up_write(&card->controls_rwsem);
+ if (ret > 0)
+ snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
+
/**
* snd_ctl_rename_id - replace the id of a control on the card
* @card: the card instance
struct snd_ctl_elem_list list;
struct snd_kcontrol *kctl;
struct snd_ctl_elem_id *dst, *id;
- unsigned int offset, space, first, jidx;
+ unsigned int offset, space, jidx;
if (copy_from_user(&list, _list, sizeof(list)))
return -EFAULT;
offset = list.offset;
space = list.space;
- first = 0;
/* try limit maximum space */
if (space > 16384)
return -ENOMEM;
}
/*
- * 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)
}
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);