Dectmngr-3.6.6: replace access to GPIO sysfs with command line tools from libgpiod

The reason of this changes is that GPIO sysfs has been deprecated from Linux 4.8 so the
DECT chip cannot be started/restarted by sysfs any longer with the errors like below.

/etc/rc.common: line 115: can't create /sys/class/gpio/gpio50/value: nonexistent directory

dectmngr/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dectmngr
 PKG_RELEASE:=3
-PKG_VERSION:=3.6.5
+PKG_VERSION:=3.6.6
 
 LOCAL_DEV=0
 ifneq ($(LOCAL_DEV),1)

dectmngr/files/etc/init.d/dectmngr

@@ -11,7 +11,8 @@ LOG_PATH=/var/log/dectmngr
 DB_PATH=/etc/dect
 DCX81_UART_DT_ALIAS=/proc/device-tree/aliases/dcx81-uart
 
-DECT_GPIO="$(gpiofind DCX81_RSTN | cut -d ' ' -f 2 2>/dev/null)"
+DECT_GPIO_CHIP="$(gpiofind DCX81_RSTN | cut -d ' ' -f 1 2>/dev/null)"
+DECT_GPIO_LINE="$(gpiofind DCX81_RSTN | cut -d ' ' -f 2 2>/dev/null)"
 
 # Ask dectmngr to exit nicely and wait for it to clean up, which is a slow process.
 stop_and_wait_dectmngr() {
@@ -52,6 +53,7 @@ start_service() {
 	local rfpi=
 	local model_id=
 	local rxtun=
+	local gpioset_pid=
 
 	if ! has_dect; then
 		logger -t "$PROG" "Not starting because no DECT hardware is available."
@@ -64,7 +66,12 @@ start_service() {
 		dcx81_uart_device=/dev/ttyH0
 	fi
 
-	[ -n "$DECT_GPIO" ] && echo 1 > /sys/class/gpio/gpio${DECT_GPIO}/value
+	[ -n  "$DECT_GPIO_CHIP" -a -n "$DECT_GPIO_LINE" ] && {
+		gpioset_pid="$(ps | grep gpioset | grep "$DECT_GPIO_CHIP $DECT_GPIO_LINE" | cut -d $USER -f 1 2>/dev/null)"
+		[ -n "$gpioset_pid" ] && kill $gpioset_pid
+		gpioset --mode=signal --background $DECT_GPIO_CHIP $DECT_GPIO_LINE=1
+		echo "debug_tmp: set GPIO $DECT_GPIO_LINE to 1"
+	}
 
 	rfpi=$(db -q get hw.board.dect_rfpi)
 	[ -n "$rfpi" -a ${#rfpi} -eq 14 ] && opt_ext="$opt_ext -rfpi $rfpi"
@@ -110,9 +117,17 @@ start_service() {
 }
 
 stop_service() {
+	local gpioset_pid=
+
 	has_dect || return 0
 
-	[ -n "$DECT_GPIO" ] && echo 0 > /sys/class/gpio/gpio${DECT_GPIO}/value
+	[ -n  "$DECT_GPIO_CHIP" -a -n "$DECT_GPIO_LINE" ] && {
+		gpioset_pid="$(ps | grep gpioset | grep "$DECT_GPIO_CHIP $DECT_GPIO_LINE" | cut -d $USER -f 1 2>/dev/null)"
+		[ -n "$gpioset_pid" ] && kill $gpioset_pid
+		gpioset --mode=signal --background $DECT_GPIO_CHIP $DECT_GPIO_LINE=0
+		echo "debug_tmp: set GPIO $DECT_GPIO_LINE to 0"
+	}
+
 	stop_and_wait_dectmngr
 }
 
@@ -126,11 +141,6 @@ service_triggers() {
 }
 
 boot() {
-	[ -n "$DECT_GPIO" ] && {
-		echo ${DECT_GPIO} > /sys/class/gpio/export
-		echo out > /sys/class/gpio/gpio${DECT_GPIO}/direction
-	}
-
 	[ ! -d $LOG_PATH ] && mkdir -p $LOG_PATH
 	[ ! -d $DB_PATH ] && mkdir -p $DB_PATH
 	start