#!/bin/bash
# BrainCraft HAT audio (HANDOFF package 1): our WM8960 overlay (pi/overlays/hermes-wm8960.dts: the
# stock wm8960-soundcard plus the clock on the codec node, which Ubuntu's driver needs), with the
# Pi's own headphone audio off (it shares PWM hardware with the servos). Run as root. Re-runnable.
# Needs a reboot afterwards.
set -euo pipefail
cd "$(dirname "$0")"

command -v dtc >/dev/null || apt-get -y install device-tree-compiler
dtc -@ -I dts -O dtb -o /boot/firmware/overlays/hermes-wm8960.dtbo overlays/hermes-wm8960.dts

cfg=/boot/firmware/config.txt
[ -e "$cfg.bak-audio" ] || cp "$cfg" "$cfg.bak-audio"
sed -i 's/^dtparam=audio=on$/dtparam=audio=off/' "$cfg"
sed -i '/^dtoverlay=wm8960-soundcard$/d' "$cfg"
if ! grep -qx 'dtoverlay=hermes-wm8960' "$cfg"; then
  # dtparam lines must come before the first dtoverlay, so put this right after vc4-kms-v3d
  sed -i '0,/^dtoverlay=vc4-kms-v3d$/s//dtoverlay=vc4-kms-v3d\ndtoverlay=hermes-wm8960/' "$cfg"
fi
grep -nE '^dtparam=audio|^dtoverlay=(hermes-)?wm8960' "$cfg"
echo "done; reboot to apply"