Hi, just reading through this thread.
The WM8960 codec is already supported on the Linux kernel that BalenaOS is using. The only missing pieces that are provided by the manufacturer are the asound.conf and asound.state files.
Could you try to copy them into the host OS and verify the playback and recording?
To copy them, log into the hostOS and type the following:
mount -o remount,rw /
And then, from your workstation clone the project and copy the files to the device:
cd /tmp
git clone https://github.com/waveshare/WM8960-Audio-HAT.git
scp -P 22222 /tmp/WM8960-Audio-HAT/asound.conf root@<ip address>:/etc/asound.conf
scp -P 22222 /tmp/WM8960-Audio-HAT/wm8960_asound.state root@<ip address>:/var/lib/alsa/asound.state
If scp is not working for you (depends on your client version), you can try using rsync.
Once that is done, reboot the device, and try to play and record with:
aplay -l
arecord -l