Add 'internal' streams for routing, revamp stream finalisation

Uses the ALSA internal PCM API to create streams purely used for internal
routing purposes.
Adds the 'try_complete' functions for both streams and routes in an
attempt to standardize the finalization of a stream or route object.

Signed-off-by: Mark Farrugia <mark.farrugia@fiberdyne.com.au>

4 files changed, 140 insertions, 29 deletions

diff --git a/configfs.c b/configfs.c
index bc10efb..2751d66 100644
--- a/configfs.c
+++ b/configfs.c
@@ -59,6 +59,7 @@
 		if ((tmp > INT_MAX) || (tmp == 0))                             \
 			return -ERANGE;                                        \
 		s->channels = tmp;                                             \
+		snd_avirt_##type##_try_complete(s);                            \
 		return count;                                                  \
 	}                                                                      \
 	CONFIGFS_ATTR(cfg_snd_avirt_##type##_, channels);
@@ -140,12 +141,30 @@ static ssize_t cfg_snd_avirt_stream_map_show(struct config_item *item,
 static ssize_t cfg_snd_avirt_stream_map_store(struct config_item *item,
 					      const char *page, size_t count)
 {
-	char *split;
+	char *map;
+	struct snd_avirt_audiopath *audiopath;
 	struct snd_avirt_stream *stream =
 		snd_avirt_stream_from_config_item(item);
 
-	split = strsep((char **)&page, "\n");
-	snd_avirt_stream_set_map(stream, split);
+	map = strsep((char **)&page, "\n");
+
+	/* If already sealed, we cannot create the stream */
+	if (snd_avirt_streams_sealed()) {
+		D_ERRORK("Streams already sealed. Cannot set map: '%s'", map);
+		return -EPERM;
+	}
+
+	if (!strcmp(stream->map, map))
+		return -1;
+
+	audiopath = snd_avirt_audiopath_get(map);
+	if (!audiopath) {
+		D_ERRORK("Cannot find Audio Path uid: '%s'!", stream->map);
+	}
+
+	memcpy(stream->map, (char *)map, strlen(map));
+
+	snd_avirt_stream_try_complete(stream);
 
 	return count;
 }
@@ -304,7 +323,8 @@ static struct config_item_type cfg_snd_avirt_route_type = {
 static struct config_item *
 cfg_snd_avirt_stream_make_item(struct config_group *group, const char *name)
 {
-	char *split;
+	char *split, *stream_name;
+	bool internal = false;
 	int direction;
 	struct snd_avirt_stream *stream;
 
@@ -326,16 +346,23 @@ cfg_snd_avirt_stream_make_item(struct config_group *group, const char *name)
 	}
 
 	// Get stream name, and create PCM for stream
-	split = strsep((char **)&name, "\n");
-	stream = snd_avirt_stream_create(split, direction);
+	stream_name = strsep((char **)&name, "\n");
+
+	// If internal, get internal
+	split = strstr(stream_name, "__internal");
+	if (split) {
+		stream_name = strsep((char **)&stream_name, "__");
+		internal = true;
+	}
+
+	// Finally, create stream
+	stream = snd_avirt_stream_create(stream_name, direction, internal);
 	if (IS_ERR(stream))
 		return ERR_PTR(PTR_ERR(stream));
 
 	config_item_init_type_name(&stream->item, name,
 				   &cfg_snd_avirt_stream_type);
 
-	D_INFOK("Make stream: %s", stream->name);
-
 	return &stream->item;
 }
 
diff --git a/core.c b/core.c
index 41d6b40..d66ee2a 100644
--- a/core.c
+++ b/core.c
@@ -77,8 +77,14 @@ static struct snd_pcm *snd_avirt_pcm_create(struct snd_avirt_stream *stream)
 		capture = true;
 	}
 
-	err = snd_pcm_new(core.card, stream->name, stream->device, playback,
-			  capture, &pcm);
+	if (stream->internal) {
+		err = snd_pcm_new_internal(core.card, stream->name,
+					   stream->device, playback, capture,
+					   &pcm);
+	} else {
+		err = snd_pcm_new(core.card, stream->name, stream->device,
+				  playback, capture, &pcm);
+	}
 
 	if (err < 0) {
 		D_ERRORK("Failed to create PCM device for stream: '%s'",
@@ -122,29 +128,56 @@ static struct snd_avirt_route *snd_avirt_route_get(const char *uid)
 	return NULL;
 }
 
-int snd_avirt_stream_set_map(struct snd_avirt_stream *stream, const char *map)
+/**
+ * int snd_avirt_route_try_complete - Set up remaining parameters for a route.
+ *                                    Channels, sink, and source Audio Paths
+ *                                    should be set when calling this function.
+ * @stream: The route to attempt to finalize parameters for.
+ * @return: 0 on success, negative ERRNO on failure
+ */
+int snd_avirt_route_try_complete(struct snd_avirt_route *route)
+{
+	return 0;
+}
+
+/**
+ * int snd_avirt_stream_try_complete - Set up remaining parameters for a stream.
+ *                                     Channels and map should be set when
+ *                                     calling this function.
+ * @stream: The stream to attempt to finalize parameters for.
+ * @return: 0 on success, negative ERRNO on failure
+ */
+int snd_avirt_stream_try_complete(struct snd_avirt_stream *stream)
 {
 	struct snd_avirt_audiopath *audiopath;
+	struct snd_avirt_route *route;
 	struct snd_pcm_ops *pcm_ops_ap;
 
-	/* If already sealed, we cannot create the stream */
-	if (snd_avirt_streams_sealed()) {
-		D_ERRORK("Streams already sealed. Cannot set map: '%s'", map);
+	if (snd_avirt_streams_sealed())
 		return -EPERM;
-	}
 
-	if (!strcmp(stream->map, map))
-		return -1;
+	if ((stream->channels == 0) || (!strcmp(stream->map, "none")))
+		return -EPERM;
 
-	memcpy(stream->map, (char *)map, strlen(map));
-	audiopath = snd_avirt_audiopath_get(map);
+	audiopath = snd_avirt_audiopath_get(stream->map);
 	if (!audiopath) {
 		D_ERRORK("Cannot find Audio Path uid: '%s'!", stream->map);
-		return -EFAULT;
 	}
 
 	/* Check for any routes that have been created for this stream */
-	stream->route = snd_avirt_route_get(stream->name);
+	route = snd_avirt_route_get(stream->name);
+	if (route) {
+		if (audiopath == route->endpoint_ap[SND_AVIRT_ROUTE_SOURCE])
+			route->endpoint_stream[SND_AVIRT_ROUTE_SOURCE] = stream;
+		else if (audiopath == route->endpoint_ap[SND_AVIRT_ROUTE_SINK])
+			route->endpoint_stream[SND_AVIRT_ROUTE_SINK] = stream;
+		else {
+			D_INFOK("Cannot set route. Audio Path not compatible");
+			return -EPERM;
+		}
+
+		stream->route = route;
+	}
 
 	/* Set up PCM ops */
 	if (!stream->direction)
@@ -348,11 +381,21 @@ int snd_avirt_audiopath_set_private_data(struct snd_avirt_audiopath *ap,
 {
 	int err = 0;
 	snd_avirt_route_endpoint endpoint = SND_AVIRT_ROUTE_SOURCE;
-	struct snd_avirt_private_data *avirt_private_data = pcm->private_data;
+	struct snd_avirt_stream *stream;
+	struct snd_avirt_private_data *avirt_private_data;
+
+	stream = snd_avirt_stream_find_by_device(pcm->device);
+	if (IS_ERR_VALUE(stream) || !stream)
+		goto exit_err;
 
 	err = snd_avirt_route_endpoint_pos(pcm, ap->uid, &endpoint);
 	if (err == -2)
 		goto exit_err;
+
+	if (stream->internal && stream->route)
+		pcm = stream->route->endpoint_stream[!endpoint]->pcm;
+
+	avirt_private_data = pcm->private_data;
 	if (!avirt_private_data)
 		goto exit_err;
 
@@ -361,6 +404,8 @@ int snd_avirt_audiopath_set_private_data(struct snd_avirt_audiopath *ap,
 	return 0;
 
 exit_err:
+	D_ERRORK("Error setting private data for ap:%s, stream:%s, endpoint:%d",
+		 ap->uid, pcm->name, endpoint);
 	return -1;
 }
 EXPORT_SYMBOL_GPL(snd_avirt_audiopath_set_private_data);
@@ -376,17 +421,29 @@ void *snd_avirt_audiopath_get_private_data(struct snd_avirt_audiopath *ap,
 {
 	int err = 0;
 	snd_avirt_route_endpoint endpoint = SND_AVIRT_ROUTE_SOURCE;
-	struct snd_avirt_private_data *avirt_private_data = pcm->private_data;
+	struct snd_avirt_stream *stream;
+	struct snd_avirt_private_data *avirt_private_data;
+
+	stream = snd_avirt_stream_find_by_device(pcm->device);
+	if (IS_ERR_VALUE(stream) || !stream)
+		return NULL;
 
 	err = snd_avirt_route_endpoint_pos(pcm, ap->uid, &endpoint);
 	if (err == -2)
 		goto exit_err;
+
+	if (stream->internal && stream->route)
+		pcm = stream->route->endpoint_stream[!endpoint]->pcm;
+
+	avirt_private_data = pcm->private_data;
 	if (!avirt_private_data)
 		goto exit_err;
 
 	return avirt_private_data->ap_private_data[endpoint];
 
 exit_err:
+	D_ERRORK("Error getting private data for ap:%s, stream:%s, endpoint:%d",
+		 ap->uid, pcm->name, endpoint);
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(snd_avirt_audiopath_get_private_data);
@@ -485,10 +542,11 @@ struct snd_avirt_route *snd_avirt_route_create(const char *uid, int direction)
  * @name: The name designated to the audio stream
  * @direction: The PCM direction (SNDRV_PCM_STREAM_PLAYBACK or
  *             SNDRV_PCM_STREAM_CAPTURE)
+ * @internal: Whether the PCM should be internal or not
  * @return: The newly created audio stream if successful, or an error pointer
  */
 struct snd_avirt_stream *snd_avirt_stream_create(const char *name,
-						 int direction)
+						 int direction, bool internal)
 {
 	struct snd_avirt_stream *stream;
 
@@ -505,6 +563,7 @@ struct snd_avirt_stream *snd_avirt_stream_create(const char *name,
 	strncpy(stream->map, "none", MAX_NAME_LEN);
 	stream->channels = 0;
 	stream->direction = direction;
+	stream->internal = internal;
 	stream->device = core.stream_count++;
 
 	/* Initialize PCM ops table for this stream.
@@ -516,7 +575,12 @@ struct snd_avirt_stream *snd_avirt_stream_create(const char *name,
 	}
 	memcpy(stream->pcm_ops, &pcm_ops_avirt, sizeof(struct snd_pcm_ops));
 
-	D_INFOK("name:%s device:%d", name, stream->device);
+	if (stream->internal) {
+		D_INFOK("name:%s device:%d internal:%d", name, stream->device,
+			stream->internal);
+	} else {
+		D_INFOK("name:%s device:%d", name, stream->device);
+	}
 
 	return stream;
 }
@@ -540,9 +604,8 @@ int snd_avirt_streams_seal(void)
 		    0)
 			continue;
 
-		D_INFOK("Do configure for AP: %s streams:%d cb:%p",
-			ap_obj->path->uid, stream_array.count,
-			ap_obj->path->configure);
+		D_INFOK("Do configure for AP: %s streams:%d", ap_obj->path->uid,
+			stream_array.count);
 		ap_obj->path->configure(core.card, &stream_array);
 	}
 
diff --git a/core.h b/core.h
index f915c04..38fee35 100644
--- a/core.h
+++ b/core.h
@@ -99,10 +99,29 @@ struct snd_avirt_stream *snd_avirt_stream_find_by_device(unsigned int device);
  * @name: The name designated to the audio stream
  * @direction: The PCM direction (SNDRV_PCM_STREAM_PLAYBACK or
  *             SNDRV_PCM_STREAM_CAPTURE)
+ * @internal: Whether the PCM should be internal or not
  * @return: The newly created audio stream if successful, or an error pointer
  */
 struct snd_avirt_stream *snd_avirt_stream_create(const char *name,
-						 int direction);
+						 int direction, bool internal);
+
+/**
+ * int snd_avirt_route_try_complete - Set up remaining parameters for a route.
+ *                                    Channels, sink, and source Audio Paths
+ *                                    should be set when calling this function.
+ * @stream: The route to attempt to finalize parameters for.
+ * @return: 0 on success, negative ERRNO on failure
+ */
+int snd_avirt_route_try_complete(struct snd_avirt_route *route);
+
+/**
+ * int snd_avirt_stream_try_complete - Set up remaining parameters for a stream.
+ *                                     Channels and map should be set when
+ *                                     calling this function.
+ * @stream: The stream to attempt to finalize parameters for.
+ * @return: 0 on success, negative ERRNO on failure
+ */
+int snd_avirt_stream_try_complete(struct snd_avirt_stream *stream);
 /**
  * snd_avirt_stream_set_map - Set Audio Path mapping for a given stream
  * @stream: The stream to assign the mapping to.
diff --git a/sound/avirt.h b/sound/avirt.h
index ecb0a21..9259d83 100644
--- a/sound/avirt.h
+++ b/sound/avirt.h
@@ -63,6 +63,7 @@ struct snd_avirt_route {
 	unsigned int channels; /* Route stream channel count */
 	unsigned int direction; /* Route stream direction */
 	struct snd_avirt_audiopath *endpoint_ap[2]; /* Source/sink */
+	struct snd_avirt_stream *endpoint_stream[2]; /* Router PCM */
 	struct config_item item; /* configfs item reference */
 };
 
@@ -91,6 +92,7 @@ struct snd_avirt_stream {
 	unsigned int channels; /* Stream channel count */
 	unsigned int device; /* Stream PCM device no. */
 	unsigned int direction; /* Stream direction */
+	bool internal; /* Stream is internal only? */
 	struct snd_pcm *pcm; /* ALSA PCM  */
 	struct snd_pcm_ops *pcm_ops; /* ALSA PCM ops */
 	struct snd_avirt_route *route; /* Associated route, if any */