#!/bin/sh -e
############################################################################
# Copyright (c) 2006 O.S. Systems
#
# Author: Otavio Salvador <otavio@ossystems.com.br>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful, but
#  WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#  General Public License for more details.
############################################################################

# This utility serialize parallel requests

if [ "$1" = on ]; then
	OPTION=-o
else
	OPTION=-f
fi

LOCK=$STATE_DIR/serial

if [ -z "$SERIAL_POWER_PIN" ]; then
	echo "SERIAL_POWER_PIN required for serial control" >&2
	exit 1
fi

sigout () {
	lockfile-remove $LOCK
}

trap sigout INT QUIT

lockfile-create $LOCK
lockfile-touch --oneshot $LOCK

serial-control $OPTION $SERIAL_POWER_PIN

lockfile-remove $LOCK