drm/panel: panasonic-vvx10f034n00: use drm_panel backlight support

Use the backlight support in drm_panel to simplify the driver
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191207140353.23967-16-sam@ravnborg.org

drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c

@@ -7,7 +7,6 @@
  * Based on AUO panel driver by Rob Clark <robdclark@gmail.com>
  */
 
-#include <linux/backlight.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -31,7 +30,6 @@ struct wuxga_nt_panel {
 	struct drm_panel base;
 	struct mipi_dsi_device *dsi;
 
-	struct backlight_device *backlight;
 	struct regulator *supply;
 
 	bool prepared;
@@ -62,12 +60,6 @@ static int wuxga_nt_panel_disable(struct drm_panel *panel)
 
 	mipi_ret = mipi_dsi_shutdown_peripheral(wuxga_nt->dsi);
 
-	if (wuxga_nt->backlight) {
-		wuxga_nt->backlight->props.power = FB_BLANK_POWERDOWN;
-		wuxga_nt->backlight->props.state |= BL_CORE_FBBLANK;
-		bl_ret = backlight_update_status(wuxga_nt->backlight);
-	}
-
 	wuxga_nt->enabled = false;
 
 	return mipi_ret ? mipi_ret : bl_ret;
@@ -142,12 +134,6 @@ static int wuxga_nt_panel_enable(struct drm_panel *panel)
 	if (wuxga_nt->enabled)
 		return 0;
 
-	if (wuxga_nt->backlight) {
-		wuxga_nt->backlight->props.power = FB_BLANK_UNBLANK;
-		wuxga_nt->backlight->props.state &= ~BL_CORE_FBBLANK;
-		backlight_update_status(wuxga_nt->backlight);
-	}
-
 	wuxga_nt->enabled = true;
 
 	return 0;
@@ -206,7 +192,6 @@ MODULE_DEVICE_TABLE(of, wuxga_nt_of_match);
 static int wuxga_nt_panel_add(struct wuxga_nt_panel *wuxga_nt)
 {
 	struct device *dev = &wuxga_nt->dsi->dev;
-	struct device_node *np;
 	int ret;
 
 	wuxga_nt->mode = &default_mode;
@@ -215,38 +200,20 @@ static int wuxga_nt_panel_add(struct wuxga_nt_panel *wuxga_nt)
 	if (IS_ERR(wuxga_nt->supply))
 		return PTR_ERR(wuxga_nt->supply);
 
-	np = of_parse_phandle(dev->of_node, "backlight", 0);
-	if (np) {
-		wuxga_nt->backlight = of_find_backlight_by_node(np);
-		of_node_put(np);
-
-		if (!wuxga_nt->backlight)
-			return -EPROBE_DEFER;
-	}
-
 	drm_panel_init(&wuxga_nt->base, &wuxga_nt->dsi->dev,
 		       &wuxga_nt_panel_funcs, DRM_MODE_CONNECTOR_DSI);
 
-	ret = drm_panel_add(&wuxga_nt->base);
-	if (ret < 0)
-		goto put_backlight;
-
-	return 0;
-
-put_backlight:
-	if (wuxga_nt->backlight)
-		put_device(&wuxga_nt->backlight->dev);
-
+	ret = drm_panel_of_backlight(&wuxga_nt->base);
+	if (ret)
 		return ret;
+
+	return drm_panel_add(&wuxga_nt->base);
 }
 
 static void wuxga_nt_panel_del(struct wuxga_nt_panel *wuxga_nt)
 {
 	if (wuxga_nt->base.dev)
 		drm_panel_remove(&wuxga_nt->base);
-
-	if (wuxga_nt->backlight)
-		put_device(&wuxga_nt->backlight->dev);
 }
 
 static int wuxga_nt_panel_probe(struct mipi_dsi_device *dsi)
@@ -281,7 +248,7 @@ static int wuxga_nt_panel_remove(struct mipi_dsi_device *dsi)
 	struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
 	int ret;
 
-	ret = wuxga_nt_panel_disable(&wuxga_nt->base);
+	ret = drm_panel_disable(&wuxga_nt->base);
 	if (ret < 0)
 		dev_err(&dsi->dev, "failed to disable panel: %d\n", ret);
 
@@ -298,7 +265,7 @@ static void wuxga_nt_panel_shutdown(struct mipi_dsi_device *dsi)
 {
 	struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
 
-	wuxga_nt_panel_disable(&wuxga_nt->base);
+	drm_panel_disable(&wuxga_nt->base);
 }
 
 static struct mipi_dsi_driver wuxga_nt_panel_driver = {