Add ability to route audio between audio paths

Configfs interface for adding 'routes' is added, and allows two audio paths to chain together particular inputs/outputs, allowing for multistage audio driver handling.

A particular use-case is that of an ADSP driver. We can feed in audio to it, and capture the processed, and/or mixed, audio at it's output, and direct to another audio path driver, such as the UNICENS audio driver.

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

1 files changed, 21 insertions, 0 deletions

diff --git a/core.h b/core.h
index e83631f..e4fb7a4 100644
--- a/core.h
+++ b/core.h
@@ -23,6 +23,7 @@ struct snd_avirt_core {
 	struct class *class;
 	struct platform_device *plat_dev;
 	struct config_group *stream_group;
+	struct config_group *route_group;
 	unsigned int stream_count;
 	bool streams_sealed;
 };
@@ -118,6 +119,15 @@ int snd_avirt_stream_set_map(struct snd_avirt_stream *stream, const char *map);
 struct snd_avirt_audiopath *snd_avirt_audiopath_get(const char *uid);
 
 /**
+ * snd_avirt_route_create - Create audio route
+ * @name: The name 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);
+
+/**
  * snd_avirt_stream_from_config_item - Convert config_item to a snd_avirt_stream
  * @item: The config_item to convert from
  * @return: The item's snd_avirt_stream if successful, NULL otherwise
@@ -128,4 +138,15 @@ snd_avirt_stream_from_config_item(struct config_item *item)
 	return item ? container_of(item, struct snd_avirt_stream, item) : NULL;
 }
 
+/**
+ * snd_avirt_route_from_config_item - Convert config_item to a snd_avirt_route
+ * @item: The config_item to convert from
+ * @return: The item's snd_avirt_stream if successful, NULL otherwise
+ */
+static inline struct snd_avirt_route *
+snd_avirt_route_from_config_item(struct config_item *item)
+{
+	return item ? container_of(item, struct snd_avirt_route, item) : NULL;
+}
+
 #endif /* __SOUND_AVIRT_CORE_H */