Drivers for the Google AIY Voice HAT ported to mainline kernel. The card can only accept S32_LE and has no hardware volume control, so a sample asoundrc is provided with dmix and softvol set up to make your life easier.
Tested on a Raspberry Pi 3B with Linux 5.8.9. The speaker that comes with the kit is pretty meh, but the sound is passable for a voice assistant I guess 🤷♂️
Build manually or with DKMS, and use the device tree overlay from the Raspberry Pi foundation repo.