jackingoff-sof.sh

#!/bin/bash

# written & tested on Acer Nitro 5 AN515-56 only; use at your own risk
# run after recording (or arecord | aplay monitoring) is started

# hwC1D0 for me
ALC295_CLASS_PATH=$(grep -l "ALC295" /sys/class/sound/hwC*/chip_name 2>/dev/null | sed 's/\/chip_name//')
CODEC="/dev/snd/$(basename $ALC295_CLASS_PATH)"

# Acer Nitro 5 has three SOF channels normally: one is silent (ALC295), and two hold webcam sound (48kHz/16kHz)
# this looks up for the first one (normally 0x10 if active). checked here to be sure that the channel is opened at all
CONV=$(hda-verb $CODEC 0x07 GET_CONV 0x00 | grep -i -o '0x[0-9a-f]*' | tail -n 1)
if [ -z "$CONV" ] || [ "$CONV" = "0x0" ] || [ "$CONV" = "0x00" ]; then
    echo "Error: no channels are currently opened" >&2
    exit 1
fi

hda-verb $CODEC 0x21 SET_PIN_WIDGET_CONTROL 0x00

hda-verb $CODEC 0x20 SET_COEF_INDEX 0x4a
hda-verb $CODEC 0x20 SET_PROC_COEF 0x20e0
hda-verb $CODEC 0x57 SET_COEF_INDEX 0x05
hda-verb $CODEC 0x57 SET_PROC_COEF 0x7680

hda-verb $CODEC 0x1b SET_POWER_STATE 0x00
hda-verb $CODEC 0x1b SET_PIN_WIDGET_CONTROL 0x21
hda-verb $CODEC 0x1b SET_AMP_GAIN_MUTE 0x7000

hda-verb $CODEC 0x23 SET_POWER_STATE 0x00
hda-verb $CODEC 0x23 SET_CONNECT_SEL 0x02
hda-verb $CODEC 0x23 SET_AMP_GAIN_MUTE 0x7200

hda-verb $CODEC 0x08 SET_POWER_STATE 0x00

# the 2nd byte represents the gain. 0x17 usually leaves enough headroom for my usage
hda-verb $CODEC 0x08 SET_AMP_GAIN_MUTE 0x7017

hda-verb $CODEC 0x07 SET_CHANNEL_STREAMID 0x00
hda-verb $CODEC 0x08 SET_CHANNEL_STREAMID $CONV

echo "Done for $CONV"