On Tue, 18 Dec 2018 18:59:39 +0100, shuah@xxxxxxxxxx wrote: > > From: Shuah Khan <shuah@xxxxxxxxxx> > > Media Device Allocator API to allows multiple drivers share a media device. > This API solves a very common use-case for media devices where one physical > device (an USB stick) provides both audio and video. When such media device > exposes a standard USB Audio class, a proprietary Video class, two or more > independent drivers will share a single physical USB bridge. In such cases, > it is necessary to coordinate access to the shared resource. > > Using this API, drivers can allocate a media device with the shared struct > device as the key. Once the media device is allocated by a driver, other > drivers can get a reference to it. The media device is released when all > the references are released. > > Change the ALSA driver to use the Media Controller API to share media > resources with DVB, and V4L2 drivers on a AU0828 media device. > > The 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 > returned. > > Media specific cleanup is done in usb_audio_disconnect(). > > Signed-off-by: Shuah Khan <shuah@xxxxxxxxxx> Feel free to take my ack regarding the sound stuff: Reviewed-by: Takashi Iwai <tiwai@xxxxxxx> Thanks! Takashi
