my_setup.bridge.sh

#!/bin/bash
# Copyright 2013
# Charles Steinkuehler <charles@steinkuehler.net>
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

dtbo_err () {
	echo "Error loading device tree overlay file: $DTBO" >&2
	exit 1
}

pin_err () {
	echo "Error exporting pin:$PIN" >&2
	exit 1
}

dir_err () {
	echo "Error setting direction:$DIR on pin:$PIN" >&2
	exit 1
}

SLOTS=/sys/devices/bone_capemgr.*/slots

# Export GPIO pins
export_gpio () {
	while read PIN DIR JUNK ; do
	        case "$PIN" in
	        ""|\#*)	
			continue ;;
	        *)
			[ -r /sys/class/gpio/gpio$PIN ] && continue
	                sudo -A su -c "echo $PIN > /sys/class/gpio/export" || pin_err
			sudo -A su -c "echo $DIR > /sys/class/gpio/gpio$PIN/direction" || dir_err
	                ;;
	        esac

	done
}

# Identify if a particular cape or overlay is actually loaded
# $1 = cape to look for
cape_loaded() {
	grep ,$1\$ $SLOTS | { 
		# Default to cape not loaded
		RET=1 

		# Check for cape
		while read SLOT STATUS CAPE JUNK ; do
			case $STATUS in
			*L )	RET=0 ; break ;;	# Cape is loaded
			*- )	RET=2 ;;		# Cape is present, but not loaded
			* )	RET=3 ;;		# Unknown status
			esac
		done

		return $RET
	}
}

# Load a cape
# $1 = cape to load
# $2 = revision (optional)
load_cape () {
	echo Loading $1 overlay
	sudo -A bash -c "echo $1${2:+:$2} > $SLOTS" || dtbo_err
	sleep 1
}

# Make sure required device tree overlay(s) are loaded
DTBO=cape-my-mill
REV=00A0
if cape_loaded $DTBO ; then
	echo $DTBO overlay found
else
	load_cape $DTBO $REV
fi

#if [ ! -r /sys/devices/ocp.*/44e0d000.tscadc/tiadc/iio:device0/in_voltage5_raw ] ; then
#	echo "Analog input files not found in /sys/devices/ocp.*/44e0d000.tscadc/tiadc/iio:device0/" >&2
#	exit 1;
#fi

if [ ! -r /sys/class/uio/uio0 ] ; then
	echo PRU control files not found in /sys/class/uio/uio0 >&2
	exit 1;
fi

# Using Official overlay, setup pin muxing to match what the HAL file expects

# Setup PWM outputs to use GPIO pins
#for FILE in /sys/devices/ocp.*/bebopr_pwm_J[234]_pinmux.*/state ; do
#	if [ -f $FILE ] ; then
#		sudo -A su -c "echo gpio > $FILE" || bebopr_err pwm: $FILE
#	fi
#done

# Setup LED with no trigger, so we can drive it with the GPIO pin
# Change this if you want the LED tied to something else (like heartbeat)
#FILE=/sys/devices/ocp.*/bebopr_leds.*/leds/bebopr\:status_led/trigger
#if [ -f $FILE ] ; then
#	sudo -A su -c "echo none > $FILE" || bebopr_err led: $FILE
#fi

# Export PWM GPIO pins which are not exported by the overlay
#export_gpio <<- EOF
#	23	low	# P8.13		gpio0.23	PWM0
#	22	low	# P8.19		gpio0.22	PWM1
#	50	low	# p9.14		gpio1.18	PWM2
#EOF