execute all as root

sudo su

(first time only) install required packages

apt-get install raspberrypi-kernel-headers gcc make device-tree-compiler git

(first time only) download Hermes-RPi driver sources

git clone https://github.com/miero/tpa-hermes-rpi-dev.git

enter driver directory

cd tpa-hermes-rpi-dev

(upgrade only) download current Hermes-RPi driver sources

git pull

build and install modules and overlay file from the tpa-hermes-rpi-dev directory

make clean
make install
depmod -A

(first time only on most RPi distros) append loading tpa-hermes-rpi overlay into config.txt

echo "dtoverlay=tpa-hermes-rpi" >> /boot/config.txt

(first time only on DietPi) append loading tpa-hermes-rpi overlay into config.txt

echo "dtoverlay=tpa-hermes-rpi" >> /DietPi/config.txt
/DietPi/dietpi/func/dietpi-set_hardware soundcard hw:sndtpahermesrpi,0

reboot

reboot

verify that the driver is loaded

aplay -l

output of aplay command should contain sndtpahermesrpi device

**** List of PLAYBACK Hardware Devices ****
...
card 1: sndtpahermesrpi [snd_tpa_hermes_rpi], device 0: TPA-Hermes-RPi HiFi tpa-hermes-rpi-dai-0 []
 Subdevices: 1/1
 Subdevice #0: subdevice #0