Revert "lvgl-demo: remove vestigial Wayland logic"

We're going to be adding support for LVGL's wayland backend in the following
commits, so recover the initscript logic that ties in with said backend

This reverts commit 21d9c4f17b.

https://onedigi.atlassian.net/browse/DEL-9925

Signed-off-by: Gabriel Valcazar <gabriel.valcazar@digi.com>

meta-digi-dey/recipes-graphics/lvgl/files/lvgl-demo-init

@@ -16,6 +16,8 @@
 readonly DEMO_NAME="lvgl-demo"
 readonly DEMO_PATH="/usr/bin/${DEMO_NAME}"
 readonly DEMO_TITLE="LVGL Demo Application"
+readonly DEMO_DISPLAY="##LVGL_DEMO_DISPLAY##"
+readonly DEMO_ENV="##LVGL_DEMO_ENV##"
 readonly PID_FILE="/run/${DEMO_NAME}.pid"
 
 log() {
@@ -52,6 +54,21 @@ check_is_running() {
 	return 1
 }
 
+wait_for_wayland() {
+	local count=20
+	local wayland_socket="/run/user/0/${DEMO_DISPLAY}"
+
+	while [ ! -S "${wayland_socket}" ]; do
+		sleep 1
+		count=$((count-1))
+		if [ "${count}" = 0 ]; then
+			return 1
+		fi
+	done
+	sleep 1
+	return 0
+}
+
 stop() {
 	check_is_running || return
 
@@ -72,11 +89,15 @@ stop() {
 start() {
 	check_is_running && { log warning "start: ${DEMO_NAME} ALREADY running"; exit 0; }
 
-	# Disable the cursor when displaying at full screen on fbdev
-	echo "0" > /sys/class/graphics/fbcon/cursor_blink
+	if [ -d "/usr/share/wayland" ]; then
+		wait_for_wayland
+	else
+		# Disable the cursor when displaying at full screen on fbdev
+		echo "0" > /sys/class/graphics/fbcon/cursor_blink
+	fi
 
 	# Launch demo
-	env ${DEMO_PATH} >/dev/null 2>&1 &
+	env ${DEMO_ENV} ${DEMO_PATH} >/dev/null 2>&1 &
 
 	if [ $? -eq 0 ]; then
 		echo $! > ${PID_FILE}

meta-digi-dey/recipes-graphics/lvgl/lvgl-demo_9.3.0.bb

@@ -44,6 +44,9 @@ inherit cmake systemd update-rc.d
 
 S = "${WORKDIR}/git"
 
+LVGL_DEMO_ENV ?= "DISPLAY=:0.0 XDG_RUNTIME_DIR=/run/user/0 WAYLAND_DISPLAY=\$\{DEMO_DISPLAY\}"
+LVGL_DEMO_ENV:ccimx6ul ?= ""
+
 do_configure:prepend() {
 	if [ "${LVGL_CONFIG_USE_SDL}" -eq 1 ] ; then
 		# Add libsdl build dependency, SDL2_image has no cmake file
@@ -68,6 +71,9 @@ do_install:append() {
 	sed -i -e 's,##LVGL_CONFIG_DRM_CARD##,${LVGL_CONFIG_DRM_CARD},g' \
 	    -i -e 's,##LVGL_CONFIG_FBDEV_DEVICE##,${LVGL_CONFIG_FBDEV_DEVICE},g' \
 	    -i ${D}${sysconfdir}/lvgl-demo-init
+	sed -i -e "s@##LVGL_DEMO_DISPLAY##@${WAYLAND_DISPLAY}@g" \
+                   -e "s@##LVGL_DEMO_ENV##@${LVGL_DEMO_ENV}@g" \
+                   "${D}${sysconfdir}/lvgl-demo-init"
 	ln -sf ${sysconfdir}/lvgl-demo-init ${D}${sysconfdir}/init.d/lvgl-demo-init
 }