sound/usb: Use Media Controller API to share media resources

Change ALSA driver to use Media Controller API to share media resources
with DVB, and V4L2 drivers on a AU0828 media device.

Media Controller specific initialization is done after sound card is
registered.  ALSA creates Media interface and entity function graph
nodes for Control, Mixer, PCM Playback, and PCM Capture devices.

snd_usb_hw_params() will call Media Controller enable source handler
interface to request the media resource. If resource request is granted,
it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is

Media specific cleanup is done in usb_audio_disconnect().

Signed-off-by: Shuah Khan <>
11 files changed