Test a range of pin, a single pin or all pins of either a specific GPIO controller or on all GPIO controller

gpio_output_test.sh

#!/bin/sh

# Copyright (C) 2017 Mathias Kresin
#
# This is free software, licensed under the GNU General Public License v2.
#
# Test a range of pin, a single pin or all pins of either a specific GPIO
# controller or on all GPIO controller
#
# Usage:
#
#  Test a range of pins:
#    gpio_output_test.sh --start=<pin> --end=<pin>
#
#  Test a single pin
#    gpio_output_test.sh --pin=<pin>
#
#  Test a range of pins/single pin only on specific controller
#    gpio_output_test.sh --controller=<nr> --pin=<pin>
#
#  Test all pins on all controller
#    gpio_output_test.sh
#

GPIOSYSFS="/sys/class/gpio"

for i in "$@"; do
	case $i in
		--controller*)
			CONTROLLER="${i#*=}"
			shift
			;;
		--start*|--pin=*)
			START="${i#*=}"
			shift
			;;
		--end*)
			END="${i#*=}"
			shift
			;;
	esac
done

echo "Found the following GPIO controller:"
CURCONTROLLER=0
for GPIOCHIP in ${GPIOSYSFS}/gpiochip*;do
	echo "  ${CURCONTROLLER}: $GPIOCHIP"
	CURCONTROLLER=$((CURCONTROLLER + 1))
done

CURCONTROLLER=0
for GPIOCHIP in ${GPIOSYSFS}/gpiochip*;do
	GPIOBASE=$(cat "${GPIOCHIP}/base")
	GPIOSTARTPIN=${START}
	GPIOENDPIN=${END}
	GPIOPINCOUNT=$(cat "${GPIOCHIP}/ngpio")

	[ -n "${CONTROLLER}" ] && [ "${CURCONTROLLER}" -ne "${CONTROLLER}" ] && {
		CURCONTROLLER=$((CURCONTROLLER + 1))
		continue
	}

	echo ""
	echo "Testing ${GPIOCHIP} (controller nr: ${CURCONTROLLER}, nr. of GPIOs: ${GPIOPINCOUNT})"

	[ -z "$GPIOSTARTPIN" ] && [ -z "$GPIOENDPIN" ] && {
		GPIOSTARTPIN=0
		GPIOENDPIN=$((GPIOPINCOUNT - 1))
	}

	[ -z "$GPIOENDPIN" ] && GPIOENDPIN="${GPIOSTARTPIN}"

	for i in $(seq $GPIOSTARTPIN $GPIOENDPIN); do
		GPIOPIN=$((i + GPIOBASE))

		[ "$i" -ge "$GPIOPINCOUNT" ] && {
			echo "  This gpio controller doesn't have a Pin ${i} (${GPIOPIN}). Skipping."
			continue
		}

		echo "  ${GPIOCHIP} - Pin ${i} (${GPIOPIN})"

		echo "${GPIOPIN}" > "${GPIOSYSFS}/export" 2> /dev/null || {
			echo "    Pin in use. Skipping."
			continue
		}

		echo out > "${GPIOSYSFS}/gpio${GPIOPIN}/direction"

		ITERATIONS=0
		while [ $ITERATIONS -lt 5 ]; do
			echo 0 > "${GPIOSYSFS}/gpio${GPIOPIN}/value"
			sleep 1
			echo 1 > "${GPIOSYSFS}/gpio${GPIOPIN}/value"
			sleep 1
			ITERATIONS=$((ITERATIONS + 1))
		done

		echo "${GPIOPIN}" > "${GPIOSYSFS}/unexport"
	done

	CURCONTROLLER=$((CURCONTROLLER + 1))
done