function find_gpio_keys_dt ()
{
    for NEXT in $(find -L /proc/device-tree -name "compatible" | sort);
    do
        cat ${NEXT} | grep -xz "gpio-keys" > /dev/null && {
            KEYS_DIRNAME="$(dirname ${NEXT})";
            KEYS_COMPATIBLE="$(cat ${KEYS_DIRNAME}/compatible)";
            echo "${KEYS_DIRNAME}";
            echo -e "\tcompatible = '${KEYS_COMPATIBLE}'";
            for NEXT_KEY in $(find -L "${KEYS_DIRNAME}" -name "gpios" | sort);
            do
                NEXT_KEY_DIR="$(dirname ${NEXT_KEY})";
                echo "${NEXT_KEY_DIR}";
                KEYS_GPIOS="$(hexdump -v -e '"0x" 4/1 "%02x" " "' "${NEXT_KEY}")";
                CONTROLLER_PHANDLE_HEX=$(echo ${KEYS_GPIOS} | cut -d ' ' -f 1);
                GPIO_BIT_HEX=$(echo ${KEYS_GPIOS} | cut -d ' ' -f 2);
                INVERTED_FLAG_HEX=$(echo ${KEYS_GPIOS} | cut -d ' ' -f 3);
                printf "             gpios = ('%d', '%d', '%d') : ('%s', '%s', '%s')\n" "${CONTROLLER_PHANDLE_HEX}" "${GPIO_BIT_HEX}" "${INVERTED_FLAG_HEX}" "controller" "bit" "flag";
                KEYS_CODE="$(hexdump -v -e '"0x" 4/1 "%02x"' "${NEXT_KEY_DIR}/linux,code")";
                printf "              code = '%d'\n" "${KEYS_CODE}";
                GPIO_CONTROLLER="unknown";
                CONTROLLER_PHANDLE_DEC="$(printf "%d" "${CONTROLLER_PHANDLE_HEX}")";
                for NEXT in $(find -L /proc/device-tree -name "phandle" | sort);
                do
                    PHANDLE_HEX="$(hexdump -v -e '"0x" 4/1 "%02x"' "${NEXT}")";
                    PHANDLE_DEC="$(printf "%d" "${PHANDLE_HEX}")";
                    [ "${PHANDLE_DEC}" -eq "${CONTROLLER_PHANDLE_DEC}" ] && {
                        GPIO_CONTROLLER="$(dirname ${NEXT})"
                    };
                done;
                printf "        controller = '%s'\n" "${GPIO_CONTROLLER}";
            done
        };
    done
}