ALSA: compress: Drop unused functions

snd_compress_register() and snd_compress_deregister() API functions
have been never used by in-tree drivers.
Let's clean up the dead code.

Acked-by: Vinod Koul <[e-mail]>
Reviewed-by: Peter Ujfalusi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Takashi Iwai <[e-mail]>

include/sound/compress_driver.h

···
 };
 
 /* compress device register APIs */
-int snd_compress_register(struct snd_compr *device);
-int snd_compress_deregister(struct snd_compr *device);
 int snd_compress_new(struct snd_card *card, int device,
 			int type, const char *id, struct snd_compr *compr);
 

sound/core/compress_offload.c

···
  *	driver should be able to register multiple nodes
  */
 
-static DEFINE_MUTEX(device_mutex);
-
 struct snd_compr_file {
 	unsigned long caps;
 	struct snd_compr_stream stream;
···
 	return ret;
 }
 EXPORT_SYMBOL_GPL(snd_compress_new);
-
-static int snd_compress_add_device(struct snd_compr *device)
-{
-	int ret;
-
-	if (!device->card)
-		return -EINVAL;
-
-	/* register the card */
-	ret = snd_card_register(device->card);
-	if (ret)
-		goto out;
-	return 0;
-
-out:
-	pr_err("failed with %d\n", ret);
-	return ret;
-
-}
-
-static int snd_compress_remove_device(struct snd_compr *device)
-{
-	return snd_card_free(device->card);
-}
-
-/**
- * snd_compress_register - register compressed device
- *
- * @device: compressed device to register
- */
-int snd_compress_register(struct snd_compr *device)
-{
-	int retval;
-
-	if (device->name == NULL || device->ops == NULL)
-		return -EINVAL;
-
-	pr_debug("Registering compressed device %s\n", device->name);
-	if (snd_BUG_ON(!device->ops->open))
-		return -EINVAL;
-	if (snd_BUG_ON(!device->ops->free))
-		return -EINVAL;
-	if (snd_BUG_ON(!device->ops->set_params))
-		return -EINVAL;
-	if (snd_BUG_ON(!device->ops->trigger))
-		return -EINVAL;
-
-	mutex_init(&device->lock);
-
-	/* register a compressed card */
-	mutex_lock(&device_mutex);
-	retval = snd_compress_add_device(device);
-	mutex_unlock(&device_mutex);
-	return retval;
-}
-EXPORT_SYMBOL_GPL(snd_compress_register);
-
-int snd_compress_deregister(struct snd_compr *device)
-{
-	pr_debug("Removing compressed device %s\n", device->name);
-	mutex_lock(&device_mutex);
-	snd_compress_remove_device(device);
-	mutex_unlock(&device_mutex);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(snd_compress_deregister);
 
 MODULE_DESCRIPTION("ALSA Compressed offload framework");
 MODULE_AUTHOR("Vinod Koul <[e-mail]>");