Rework routing system

- Add 'route' to snd_avirt_stream, remove from audio path
- Add route checking - ensure that source ap and ink ap have
compatible hw params
- Add private data support for both source and sink Audio
Paths, to ensure that the PCM can hold multiple private data(s).
- Add ability to use copy_kernel and exttriggers from AVIRT instead of from Audio Paths
- Reintroduce pcm_trigger and pcm_prepare, so that 
they may be called appropriately from AVIRT, rather
than child Audio Paths.

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

1 files changed, 201 insertions, 12 deletions

diff --git a/core.c b/core.c
index f7e7978..41d6b40 100644
--- a/core.c
+++ b/core.c
@@ -51,7 +51,7 @@ static void pcm_private_free(struct snd_pcm *pcm)
 	/* Free Audio Path private data */
 	avirt_private_data = (struct snd_avirt_private_data *)pcm->private_data;
 	if (avirt_private_data) {
-		if (avirt_private_data->ap_private_data &&
+		if (avirt_private_data->ap_private_data[0] &&
 		    avirt_private_data->ap_private_free)
 			avirt_private_data->ap_private_free(pcm);
 	}
@@ -94,7 +94,7 @@ static struct snd_pcm *snd_avirt_pcm_create(struct snd_avirt_stream *stream)
 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, stream->pcm_ops);
 
 	pcm->info_flags = 0;
-	strcpy(pcm->name, stream->name);
+	strncpy(pcm->name, stream->name, MAX_NAME_LEN);
 
 	avirt_private_data = kzalloc(sizeof(*avirt_private_data), GFP_KERNEL);
 	pcm->private_data = avirt_private_data;
@@ -106,6 +106,22 @@ static struct snd_pcm *snd_avirt_pcm_create(struct snd_avirt_stream *stream)
 	return pcm;
 }
 
+static struct snd_avirt_route *snd_avirt_route_get(const char *uid)
+{
+	struct list_head *entry;
+	struct config_item *item;
+	struct snd_avirt_route *route;
+
+	list_for_each (entry, &core.route_group->cg_children) {
+		item = container_of(entry, struct config_item, ci_entry);
+		route = snd_avirt_route_from_config_item(item);
+		if (!strcmp(route->uid, uid))
+			return route;
+	}
+
+	return NULL;
+}
+
 int snd_avirt_stream_set_map(struct snd_avirt_stream *stream, const char *map)
 {
 	struct snd_avirt_audiopath *audiopath;
@@ -127,6 +143,10 @@ int snd_avirt_stream_set_map(struct snd_avirt_stream *stream, const char *map)
 		return -EFAULT;
 	}
 
+	/* Check for any routes that have been created for this stream */
+	stream->route = snd_avirt_route_get(stream->name);
+
+	/* Set up PCM ops */
 	if (!stream->direction)
 		pcm_ops_ap = (struct snd_pcm_ops *)audiopath->pcm_playback_ops;
 	else
@@ -140,8 +160,6 @@ int snd_avirt_stream_set_map(struct snd_avirt_stream *stream, const char *map)
 	}
 
 	/* Set PCM ops for the Audio Path*/
-	PCM_OPS_SET(pcm_ops_ap, &stream->pcm_ops, prepare);
-	PCM_OPS_SET(pcm_ops_ap, &stream->pcm_ops, trigger);
 	PCM_OPS_SET(pcm_ops_ap, &stream->pcm_ops, pointer);
 	PCM_OPS_SET(pcm_ops_ap, &stream->pcm_ops, get_time_info);
 	PCM_OPS_SET(pcm_ops_ap, &stream->pcm_ops, fill_silence);
@@ -185,9 +203,124 @@ static int snd_avirt_streams_get(const char *map,
 }
 
 /**
- * snd_avirt_audiopath_get - retrieves the Audio Path by its UID
- * @uid: Unique ID for the Audio Path
- * @return: Corresponding Audio Path
+ * snd_avirt_route_endpoint_pos - get route endpoint position for Audio Path
+ * @pcm: The PCM whose route to inspect.
+ * @ap_uid: The Audio Path UID to get
+ * @endpoint: The route position (SND_AVIRT_ROUTE_SOURCE or SND_AVIRT_ROUTE_SINK)
+ *            of the Audio Path in it's route (if any).
+ * @return: 0 if an Audio Path is found in the route, -1 if there is no route,
+ *          or -2 otherwise.
+ */
+int snd_avirt_route_endpoint_pos(struct snd_pcm *pcm, const char *ap_uid,
+				 snd_avirt_route_endpoint *endpoint)
+{
+	struct snd_avirt_audiopath *endpoint_ap;
+	struct snd_avirt_stream *stream;
+	int i;
+
+	stream = snd_avirt_stream_find_by_device(pcm->device);
+	if (IS_ERR_VALUE(stream) || !stream)
+		goto exit_err;
+
+	if (!stream->route)
+		return -1;
+
+	for (i = 0; i < 2; i++) {
+		endpoint_ap = stream->route->endpoint_ap[i];
+		if (endpoint_ap)
+			if (!strcmp(endpoint_ap->uid, ap_uid)) {
+				*endpoint = i;
+				return 0;
+			}
+	}
+
+exit_err:
+	D_ERRORK("Could not find Audio Path '%s' in route '%s'", ap_uid,
+		 stream->route->uid);
+	return -2;
+}
+
+/**
+ * snd_avirt_route_endpoint_copy - get endpoint copy function for a given
+ *                                 Audio Path's source/sink.
+ * @ap: The Audio Path whose endpoint copy function to find.
+ * @endpoint: The endpoint (SND_AVIRT_ROUTE_SOURCE or SND_AVIRT_ROUTE_SINK).
+ * @return: A snd_pcm_copy_kernel function pointer that can be used to either:
+ *          1. Source PCM data into the Audio Path, or,
+ *          2. Sink PCM data out of the Audio Path.
+ *          If no Audio Path endpoint is routed for 'endpoint', NULL is returned.
+ */
+snd_pcm_copy_kernel
+snd_avirt_route_endpoint_copy(struct snd_pcm_substream *substream,
+			      snd_avirt_route_endpoint endpoint)
+{
+	struct snd_avirt_audiopath *endpoint_ap;
+	struct snd_avirt_stream *stream;
+
+	if (endpoint < 0 || endpoint > 1) {
+		D_ERRORK("Route endpoint must be 0 or 1");
+		return NULL;
+	}
+
+	stream = snd_avirt_stream_find_by_device(substream->pcm->device);
+	if (IS_ERR_VALUE(stream) || !stream)
+		return NULL;
+
+	if (!stream->route)
+		return NULL;
+	endpoint_ap = stream->route->endpoint_ap[endpoint];
+	if (!endpoint_ap)
+		return NULL;
+
+	switch (endpoint) {
+	case SND_AVIRT_ROUTE_SOURCE:
+		return endpoint_ap->pcm_capture_ops->copy_kernel;
+	case SND_AVIRT_ROUTE_SINK:
+		return endpoint_ap->pcm_playback_ops->copy_kernel;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(snd_avirt_route_endpoint_copy);
+
+/**
+ * snd_avirt_route_endpoint_trigger - Trigger an Audio Path's endpoint
+ *                                    (sink/source).
+ * @uid: The Audio Path whose endpoint trigger function to call.
+ * @endpoint: The endpoint (SND_AVIRT_ROUTE_SOURCE or SND_AVIRT_ROUTE_SINK).
+ * @return: 0 on success or -1 on failure.
+ */
+int snd_avirt_route_endpoint_trigger(struct snd_pcm_substream *substream,
+				     snd_avirt_route_endpoint endpoint)
+{
+	struct snd_avirt_audiopath *endpoint_ap;
+	struct snd_avirt_stream *stream;
+
+	if (endpoint < 0 || endpoint > 1) {
+		D_ERRORK("Route endpoint must be 0 or 1");
+		return -1;
+	}
+
+	stream = snd_avirt_stream_find_by_device(substream->pcm->device);
+	if (IS_ERR_VALUE(stream) || !stream)
+		return -1;
+
+	if (!stream->route)
+		return -1;
+	endpoint_ap = stream->route->endpoint_ap[endpoint];
+	if (!endpoint_ap)
+		return -1;
+
+	endpoint_ap->pcm_exttrigger();
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_avirt_route_endpoint_trigger);
+
+/**
+ * snd_avirt_audiopath_get - get Audio Path by it's UID
+ * @uid: The Audio Path UID to get
+ * @return: The Audio Path if it exists, NULL otherwise.
  */
 struct snd_avirt_audiopath *snd_avirt_audiopath_get(const char *uid)
 {
@@ -202,6 +335,62 @@ struct snd_avirt_audiopath *snd_avirt_audiopath_get(const char *uid)
 }
 EXPORT_SYMBOL_GPL(snd_avirt_audiopath_get);
 
+/*
+ * snd_avirt_audiopath_set_private_data - set PCM private data for an Audio Path
+ * @ap: The Audio Path whose private data to set.
+ * @pcm: The PCM where the private data is stored.
+ * @ap_private_data: The value to set to the private data.
+ * @return: 0 on success, -1 on failure.
+ */
+int snd_avirt_audiopath_set_private_data(struct snd_avirt_audiopath *ap,
+					 struct snd_pcm *pcm,
+					 void *ap_private_data)
+{
+	int err = 0;
+	snd_avirt_route_endpoint endpoint = SND_AVIRT_ROUTE_SOURCE;
+	struct snd_avirt_private_data *avirt_private_data = pcm->private_data;
+
+	err = snd_avirt_route_endpoint_pos(pcm, ap->uid, &endpoint);
+	if (err == -2)
+		goto exit_err;
+	if (!avirt_private_data)
+		goto exit_err;
+
+	avirt_private_data->ap_private_data[endpoint] = ap_private_data;
+
+	return 0;
+
+exit_err:
+	return -1;
+}
+EXPORT_SYMBOL_GPL(snd_avirt_audiopath_set_private_data);
+
+/*
+ * snd_avirt_audiopath_get_private_data - get PCM private data for an Audio Path
+ * @ap: The Audio Path whose private data to get.
+ * @pcm: The PCM where the private data is stored.
+ * @return: The value assigned to the private data.
+ */
+void *snd_avirt_audiopath_get_private_data(struct snd_avirt_audiopath *ap,
+					   struct snd_pcm *pcm)
+{
+	int err = 0;
+	snd_avirt_route_endpoint endpoint = SND_AVIRT_ROUTE_SOURCE;
+	struct snd_avirt_private_data *avirt_private_data = pcm->private_data;
+
+	err = snd_avirt_route_endpoint_pos(pcm, ap->uid, &endpoint);
+	if (err == -2)
+		goto exit_err;
+	if (!avirt_private_data)
+		goto exit_err;
+
+	return avirt_private_data->ap_private_data[endpoint];
+
+exit_err:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(snd_avirt_audiopath_get_private_data);
+
 /**
  * snd_avirt_audiopath_register - register Audio Path with AVIRT
  * @audiopath: Audio Path to be registered
@@ -271,12 +460,12 @@ EXPORT_SYMBOL_GPL(snd_avirt_audiopath_deregister);
 
 /**
  * snd_avirt_route_create - Create audio route
- * @name: The name designated to the audio route
+ * @uid: The unique ID designated to the audio route.
  * @direction: The PCM direction (SNDRV_PCM_STREAM_PLAYBACK or
  *             SNDRV_PCM_STREAM_CAPTURE)
  * @return: The newly created audio route if successful, or an error pointer
  */
-struct snd_avirt_route *snd_avirt_route_create(const char *name, int direction)
+struct snd_avirt_route *snd_avirt_route_create(const char *uid, int direction)
 {
 	struct snd_avirt_route *route;
 
@@ -284,7 +473,7 @@ struct snd_avirt_route *snd_avirt_route_create(const char *name, int direction)
 	if (!route)
 		return ERR_PTR(-ENOMEM);
 
-	strcpy(route->name, name);
+	strncpy(route->uid, uid, MAX_NAME_LEN);
 	route->channels = 0;
 	route->direction = direction;
 
@@ -312,8 +501,8 @@ struct snd_avirt_stream *snd_avirt_stream_create(const char *name,
 	if (!stream)
 		return ERR_PTR(-ENOMEM);
 
-	strcpy(stream->name, name);
-	strcpy(stream->map, "none");
+	strncpy(stream->name, name, MAX_NAME_LEN);
+	strncpy(stream->map, "none", MAX_NAME_LEN);
 	stream->channels = 0;
 	stream->direction = direction;
 	stream->device = core.stream_count++;