#!/bin/sh

#RPi v1: BUS=0
#RPi v2: BUS=1
#Auto: BUS=-1
BUS=-1

#BATTERY=0: trickle charger for supercap enabled
#BATTERY=1: trickle charger for supercap disabled
BATTERY=0

if [ "`id -u`" != "0" ]; then
	exec sudo "${0}" "${@}"
fi

if [ "${BUS}" = "-1" ]; then
	rev="0x`awk '{if ($1 == "Revision") {print $NF};}' /proc/cpuinfo`"
	rev=$((rev & 0xffff))
	if [ "${rev}" -ge "4" ]; then
		echo "RPi version 2 detected"
		BUS=1
	else
		echo "RPi version 1 detected"
		BUS=0
	fi
fi

if [ ! -e "/dev/i2c-${BUS}" ]; then
	modprobe i2c-dev
fi

if [ ! -e "/sys/bus/i2c/devices/${BUS}-0068" ]; then
	echo "enabling RTC"
	modprobe rtc-ds1307
	
	tcharger="0xa5"
	tchargertext="enabling"
	if [ "${BATTERY}" = "1" ]; then
		tcharger="0x00"
		tchargertext="disabling"
	fi

	if [ "`i2cget -y "${BUS}" 0x68 0x10`" != "${tcharger}" ]; then
		echo "${tchargertext} trickle-charger for supercap"
		i2cset -y "${BUS}" 0x68 0x10 "${tcharger}"
	fi
	echo "ds1339 0x68" >"/sys/class/i2c-adapter/i2c-${BUS}/new_device"
fi

if [ ! -e "/sys/bus/i2c/devices/${BUS}-0018" ]; then
	echo "enabling 1wire"
	modprobe ds2482
	echo "ds2482 0x18" >"/sys/class/i2c-adapter/i2c-${BUS}/new_device"
fi

echo "resetting 868MHz extension..."
if test ! -d /sys/class/gpio/gpio17; then echo 17 > /sys/class/gpio/export; fi
if test ! -d /sys/class/gpio/gpio18; then echo 18 > /sys/class/gpio/export; fi
echo out > /sys/class/gpio/gpio17/direction
echo out > /sys/class/gpio/gpio18/direction
echo 1 > /sys/class/gpio/gpio18/value
echo 0 > /sys/class/gpio/gpio17/value
sleep 1
echo 1 > /sys/class/gpio/gpio17/value
sleep 1