int snd_find_minor(int type, int card_num, int dev)
{
if (snd_BUG_ON(card_num < 0 || card_num >= SNDRV_CARDS))
return -EINVAL;
return find_snd_minor(type, snd_cards[card_num], dev);
}
int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
struct device_attribute *attr)
{
int minor, ret = -EINVAL;
struct device *d;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
ret = device_create_file(d, attr);
mutex_unlock(&sound_mutex);
return ret;
}
/* get the assigned device to the given type and device number;
* the caller needs to release it via put_device() after using it
*/
struct device *snd_get_device(int type, struct snd_card *card, int dev)
{
int minor;
struct device *d = NULL;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
if (minor >= 0) {
d = snd_minors[minor]->dev;
if (d)
get_device(d);
}
mutex_unlock(&sound_mutex);
return d;
}
/**
* snd_unregister_device - unregister the device on the given card
* @type: the device type, SNDRV_DEVICE_TYPE_XXX
* @card: the card instance
* @dev: the device index
*
* Unregisters the device file already registered via
* snd_register_device().
*
* Returns zero if sucecessful, or a negative error code on failure
*/
int snd_unregister_device(int type, struct snd_card *card, int dev)
{
int minor;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
if (minor < 0) {
mutex_unlock(&sound_mutex);
return -EINVAL;
}
device_destroy(sound_class, MKDEV(major, minor));
kfree(snd_minors[minor]);
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
return 0;
}