On 8/1/24 03:17, Wesley Cheng wrote: > The QC ADSP is able to support USB playback endpoints, so that the main > application processor can be placed into lower CPU power modes. This adds > the required AFE port configurations and port start command to start an > audio session. > > Specifically, the QC ADSP can support all potential endpoints that are > exposed by the audio data interface. This includes, feedback endpoints > (both implicit and explicit) as well as the isochronous (data) endpoints. > The size of audio samples sent per USB frame (microframe) will be adjusted > based on information received on the feedback endpoint. > > Some pre-requisites are needed before issuing the AFE port start command, > such as setting the USB AFE dev_token. This carries information about the > available USB SND cards and PCM devices that have been discovered on the > USB bus. The dev_token field is used by the audio DSP to notify the USB > offload driver of which card and PCM index to enable playback on. It's just fine if the AFE stuff relies on the 'port' definition/concept, but I don't think it needs to pop-up at the ASoC/USB level.
