I don't know about examples with Debian as you know the supported image is Yocto, and there are some examples in the Shield Tests Report. Also there is the possibility to use ALSA in your project with USB.
What are you using right now (node, python, IoT.. ) to develop your project?
I will try to find more useful information related to your situation.
I read Analog GPIO through Linux Sysfs interface (Source)
I'm doing the project with java, but i know that it introduces much delays (VM,GC...), so i can change language if necessary (c,c++).
If it is an hardware constraint, i can only do with ALSA. How i can test if ALSA is supported in my distro?