Greetings,
I've got an HDMI receiver chip I'm working on a driver for which provides the audio signal from the HDMI source. An HDMI source can be a variety of sample-rates, channels, widths, and formats. If I understand correctly I need to register the device as supporting all the possible rates/channels/formats then constrain these to what is actually available at the time in the startup callback with snd_pcm_hw_contstraint_minmax and snd_pcm_hw_constraint_mask.
How do I notify userspace when the chip tells me that the HDMI audio source rate/channels/format has changed?
I know on the Video side the driver sends a V4L2_EVENT_SOURCE_CHANGE event to userspace when input format/resolution has changed so that userspace can stop streaming, call VIDIOC_QUERY_DV_TIMINGS and then VIDIOC_S_DV_TIMINGS with new timings.
Regards,
Tim