connect wwan modems i2s lines to notebook for voice calls

[chri2]

I'm looking for a way to connect a m.2 wwan modem to a notebook in such a way that I could use its voice call functions.

My idea has been so far that I'd put the m.2 card into an adapter that gives me an usb connection for data and control.

That's the easy part. The hard part seems to connect the modems i2s lines to the notebook. I didn't find an m.2-usb adapter providing i2s audio to a linux computer. As far as I fond out I'd need to solder the i2s lines to the m.2 socket in the usb-m.2 adapter. There doesn't seem to be an easy way to connect i2s to a notebook via available ports like usb directly.

This is when I stumbled over the i2s micropython implementation. My idea has been to use an esp32, Teensy 4(.1) or STM32F469I-DISCO with micropython to communicate with the i2s lines of the modem.

If this'd work eletrically (modem provides 1.8V level i2s) I could talk to the modem using micropython if I understood these very helpful examples correctly.

On the notebook I'd need a sound device for input/output. If the rest of the idea could work out - what would be a good solution to make the audio available to alsa/pulse on a linux computer?

Any suggestions and comments helpful to an absolute beginner would be very much appreciated!