A shell script for testing (iManager) GPIO-LED

test-led.sh

#!/bin/bash
################################################################################
# test-led.sh - Shell script to test GPIOs through sysfs
#
# Copyright (c) 2016 Richard Vidal-Dorsch
#
# 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.
#
################################################################################

VERSION=v1.0.0.20160613

DRVNAME=gpio-imanager
GPIO_SYSFS_PATH=/sys/class/gpio

print_banner()
{
	echo "GPIO LED Test Script ${VERSION}"
	echo "Richard Vidal-Dorsch <[email protected]>"
	echo "Copyright (c) 2016 Richard Vidal-Dorsch"
	echo
}

# Returns path to gpiochip<base number> of the matching GPIO chip
find_gpiochip()
{
	local drvname=${1}

	for i in ${GPIO_SYSFS_PATH}/gpiochip*; do
		[[ ! -e ${i} ]] && return
		if [ "$(cat ${i}/label)" == "${drvname}" ]; then
			echo ${i}
			break
		fi
	done
}

check_requirements()
{
	[ -d "$GPIO_SYSFS_PATH/" ] || { \
		echo "Error: Directory '$GPIO_SYSFS_PATH/' does not exist.";\
		echo "Please enable GPIO sysfs support in your kernel";
		return 1; }

	if [ -z "$(find_gpiochip ${DRVNAME})" ]; then
		echo "Error: GPIO driver '${DRVNAME}' does not seem to be loaded."
		return 1
	fi
}

create_gpio_files()
{
	local arr=(${1})
	for i in ${arr[*]}; do
		[ ! -e  $GPIO_SYSFS_PATH/gpio${i} ] && \
			echo "$i" > $GPIO_SYSFS_PATH/export
	done
	sleep 0.5; # Give enough time to create those nodes
}

remove_gpio_files()
{
	local arr=(${1})
	for i in ${arr[*]};do
		echo "$i" > $GPIO_SYSFS_PATH/unexport || return 1
	done
}

set_gpio_direction()
{
	local num=$1
	local dir=$2 # "in" or "out"
	echo $dir > $GPIO_SYSFS_PATH/gpio${num}/direction || return 1
}

set_gpio_state()
{
	local num=$1
	local state=$2 # "0" or "1"
	echo $state > $GPIO_SYSFS_PATH/gpio${num}/value || return 1
}

gpio_set_dirs2out()
{
	local arr=(${1})

	for i in ${arr[*]}; do
		set_gpio_direction $i "out"
	done
}

gpio_restore_direction()
{
	local arr=(${1})

	# Set all GPIO direction to input
	for i in ${arr[*]}; do
		set_gpio_direction $i "in"
	done
}

# --- main ---

print_banner

check_requirements || exit 1

sysfs_path_chip=$(find_gpiochip "${DRVNAME}")

base=$(cat ${sysfs_path_chip}/base)
ngpio=$(cat ${sysfs_path_chip}/ngpio)
max=$(echo $[${base} + ${ngpio} - 1])

range=($(seq $base $max))

# Export GPIO to user space
create_gpio_files "${range[*]}"

gpio_set_dirs2out "${range[*]}"

for i in ${range[*]}; do set_gpio_state $i 0;done

for i in ${range[*]}; do
	for j in $(seq 1 5); do
		printf "\rSet GPO %d to '1'" $(echo $[${i} - ${base}])
		set_gpio_state $i 1
		sleep 0.2
		printf "\rSet GPO %d to '0'" $(echo $[${i} - ${base}])
		set_gpio_state $i 0
		sleep 0.2
	done
	printf "\r"
done

# Remove GPIO from user space
remove_gpio_files "${range[*]}"