distribution/packages/sysutils/system-utils/sources/devices/RK3399/headphone_sense

#!/bin/bash

# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2023-present BrooksyTech (https://github.com/brooksytech)

. /etc/profile

# Check headphone gpio at boot and set the correct output device
HP_GPIO=$(cat /sys/class/gpio/gpio${DEVICE_JACK}/value)
  case ${HP_GPIO} in
    "1")
      amixer cset name='Speaker Switch' ${DEVICE_PLAYBACK_PATH_HP}
      amixer set 'Headphone' '67%'
      amixer set 'Playback Polarity' Normal
      set_setting "audio.device" "headphone"
    ;;
    *)
      amixer cset name='Speaker Switch' ${DEVICE_PLAYBACK_PATH_SPK}
      amixer set 'Headphone' '100%'
      amixer set 'Playback Polarity' 'R Invert'
      set_setting "audio.device" "speakers"
    ;;
  esac

# Headphone sensing
DEVICE="${DEVICE_HEADPHONE_DEV}"

HP_OFF='*(SW_HEADPHONE_INSERT), value 0*'
HP_ON='*(SW_HEADPHONE_INSERT), value 1*'

evtest "${DEVICE}" | while read line; do
    case $line in
    (${HP_ON})
      amixer cset name='Speaker Switch' ${DEVICE_PLAYBACK_PATH_HP}
      amixer set 'Headphone' '67%'
      amixer set 'Playback Polarity' Normal
      set_setting "audio.device" "headphone"
    ;;
    (${HP_OFF})
      amixer cset name='Speaker Switch' ${DEVICE_PLAYBACK_PATH_SPK}
      amixer set 'Headphone' '100%'
      amixer set 'Playback Polarity' 'R Invert'
      set_setting "audio.device" "speakers"
    ;;
    esac
done