drm/panel: lvds: Read panel orientation

The panel orientation needs to parsed from a device-tree and assigned to
the panel's connector in order to make orientation property available to
userspace. That's what this patch does for the generic LVDS panel.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200813215609.28643-4-digetx@gmail.com

drivers/gpu/drm/panel/panel-lvds.c

@@ -37,6 +37,8 @@ struct panel_lvds {
 
 	struct gpio_desc *enable_gpio;
 	struct gpio_desc *reset_gpio;
+
+	enum drm_panel_orientation orientation;
 };
 
 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
@@ -99,6 +101,7 @@ static int panel_lvds_get_modes(struct drm_panel *panel,
 	connector->display_info.bus_flags = lvds->data_mirror
 					  ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
 					  : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
+	drm_connector_set_panel_orientation(connector, lvds->orientation);
 
 	return 1;
 }
@@ -116,6 +119,12 @@ static int panel_lvds_parse_dt(struct panel_lvds *lvds)
 	const char *mapping;
 	int ret;
 
+	ret = of_drm_get_panel_orientation(np, &lvds->orientation);
+	if (ret < 0) {
+		dev_err(lvds->dev, "%pOF: failed to get orientation %d\n", np, ret);
+		return ret;
+	}
+
 	ret = of_get_display_timing(np, "panel-timing", &timing);
 	if (ret < 0) {
 		dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",