[ALSA] alsa core: add struct device pointer to struct snd_pcm

This patch adds a struct device pointer to struct snd_pcm in order to be
able to give it a different device than the card. It defaults to the card's
device, however, so it should behave identically for drivers not touching
the field.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

2 files changed, 14 insertions, 5 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 2f645dfd7f70..016c41893b06 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -427,6 +427,7 @@ struct snd_pcm {
         wait_queue_head_t open_wait;
         void *private_data;
         void (*private_free) (struct snd_pcm *pcm);
+        struct device *dev; /* actual hw device this belongs to */
 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
         struct snd_pcm_oss oss;
 #endif
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 8e0189885516..4701f07ee0ae 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -944,6 +944,7 @@ static int snd_pcm_dev_register(struct snd_device *device)
         struct list_head *list;
         char str[16];
         struct snd_pcm *pcm = device->device_data;
+        struct device *dev;
 
         snd_assert(pcm != NULL && device != NULL, return -ENXIO);
         mutex_lock(&register_mutex);
@@ -966,11 +967,18 @@ static int snd_pcm_dev_register(struct snd_device *device)
                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
                         break;
                 }
-                if ((err = snd_register_device(devtype, pcm->card,
-                                               pcm->device,
-                                               &snd_pcm_f_ops[cidx],
-                                               pcm, str)) < 0)
-                {
+                /* device pointer to use, pcm->dev takes precedence if
+                 * it is assigned, otherwise fall back to card's device
+                 * if possible */
+                dev = pcm->dev;
+                if (!dev)
+                        dev = pcm->card ? pcm->card->dev : NULL;
+                /* register pcm */
+                err = snd_register_device_for_dev(devtype, pcm->card,
+                                                  pcm->device,
+                                                  &snd_pcm_f_ops[cidx],
+                                                  pcm, str, dev);
+                if (err < 0) {
                         list_del(&pcm->list);
                         mutex_unlock(&register_mutex);
                         return err;