Hi All,
This weekend I've created a modified ucm config based on:
https://github.com/plbossart/UCM/tree/master/chtrt5645
For a board which has a single speaker connected to the left channel (standard mono speaker setup) and a stereo headphone jack with working jack detection.
I've been unable to come up with a ucm file which allows selecting between a "Stereo Speaker + Headphone" vs "Mono Speaker + Headphone" output profile.
https://github.com/plbossart/UCM/tree/master/byt-rt5640 has "Mono Speaker", "Stereo Speaker" and "Headphone" profiles but does not auto-switch between Headphone and speaker based on jack detection, I've been unable to allow selecting either stereo or mono speaker while keeping auto-switching to/from the headphones.
But thinking more about this I don't think that having "Stereo Speaker + Headphone" and "Mono Speaker + Headphone" profiles is the answer. Profiles make sense on machines with a bunch of outputs where we don't no what the user is going to plug in, but in this case the stereo vs mono speaker distinction is a clear property of the device, which we should IMHO autodetect based on the device-model.
So I think we need a way to have different ucm files per board, so instead of loading /usr/share/ucm/chtrt5645/*.conf on my device, alsa should try to load /usr/share/ucm/chtrt5645-<boardname>/*.conf
Specifically I'm thinking about using udev + hwdb (dmi string) matching to set an ALSA_UCM_NAME udev property.
If the consensus is that this is a good idea I can take a shot at writing patches for this (in my spare time mostly), the downside of this approach is it would cause a dependency on libudev for the alsa ucm code.
Regards,
Hans