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, 22 insertions, 0 deletions

diff --git a/core.c b/core.c
index fd74b08..e1b056e 100644
--- a/core.c
+++ b/core.c
@@ -266,6 +266,28 @@ int snd_avirt_audiopath_deregister(struct snd_avirt_audiopath *audiopath)
 EXPORT_SYMBOL_GPL(snd_avirt_audiopath_deregister);
 
 /**
+ * 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)
+{
+	struct snd_avirt_route *route;
+
+	route = kzalloc(sizeof(*route), GFP_KERNEL);
+	if (!route)
+		return ERR_PTR(-ENOMEM);
+
+	strcpy(route->name, name);
+	route->channels = 0;
+	route->direction = direction;
+
+	return route;
+}
+
+/**
  * snd_avirt_stream_create - Create audio stream, including it's ALSA PCM device
  * @name: The name designated to the audio stream
  * @direction: The PCM direction (SNDRV_PCM_STREAM_PLAYBACK or