garage-door-gpio

#!/bin/bash 
PATH=/sbin:/bin:/usr/sbin:/usr/bin
DESC="Enable GPIO for the Garage Door Module"
NAME="garage-door-gpio"
SCRIPTNAME=/etc/init.d/$NAME

. /lib/lsb/init-functions

function export_pin {
  if [ ! -e /sys/class/gpio/gpio${1} ] ; then
    echo $1 > /sys/class/gpio/export
    if [ "$3" == "low" ] ; then
      echo 1 > /sys/class/gpio/gpio${1}/active_low
    else
      echo 0 > /sys/class/gpio/gpio${1}/active_low
    fi
    echo $2 > /sys/class/gpio/gpio${1}/direction
    if [ "$2" == "out" ] ; then
      echo $4 > /sys/class/gpio/gpio${1}/value
    fi
  fi
}

function unexport_pin {
  if [ -e /sys/class/gpio/gpio${1} ] ; then
    echo $1 > /sys/class/gpio/unexport
  fi
}

if [ "$1" == "start" ] ; then
  log_daemon_msg "Enabling Garage Door GPIO pins for door 0"
  export_pin 5 out low 0 
  export_pin 20 in high 0
  log_end_msg 0

  log_daemon_msg "Enabling Garage Door GPIO pins for door 1"
  export_pin 6 out low 0
  export_pin 21 in high 0
  log_end_msg 0
else [ "$1" == "stop" ]  
  log_daemon_msg "Disabling Garage Door GPIO pins for door 0"
  unexport_pin 5
  unexport_pin 20

  log_daemon_msg "Disabling Garage Door GPIO pins for door 1"
  unexport_pin 6
  unexport_pin 21
fi