ipq807x gpio prober and destroyer

ipq807x-probe-gpio.sh

#! /bin/ash

qpic_gpios="443 445 446 447 448 449 451 452 453 454 455 456 457 458 459"
uart_gpios="465 466"
mdio_pins="510 511"
stay_the_fuck_away="$qpic_gpios $uart_gpios $mdio_pins"

is_forbidden() {
	local gpio_num="$1"

	for forbidden in $stay_the_fuck_away; do
		if [ "$gpio_num" = "$forbidden" ]; then
			true
			return
		fi
	done

	false
}

for gpio_num in $(seq 442 511); do
	gpio="/sys/class/gpio/gpio$gpio_num"

	if is_forbidden $gpio_num; then
		echo "Skipping $gpio_num"
		continue
	fi

	if [ ! -d "$gpio" ]; then
		echo "$gpio_num" > /sys/class/gpio/export
	fi

	if [ ! -d "$gpio" ]; then
		continue
	fi

	echo "GPIO$gpio_num = out (hi) -- in 1 sec"
	sleep 1

	echo out > "$gpio/direction"
	echo 1 > "$gpio/value"
done

for gpio_num in $(seq 442 511); do
	gpio="/sys/class/gpio/gpio$gpio_num"

	if [ ! -d "$gpio" ]; then
		continue
	fi

	echo 0 > "$gpio/value"
	echo "GPIO$gpio_num = 0"
	sleep 1
done