drm/panel: lvds: 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/20191207140353.23967-13-sam@ravnborg.org

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

@@ -8,7 +8,6 @@
  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
  */
 
-#include <linux/backlight.h>
 #include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
@@ -34,7 +33,6 @@ struct panel_lvds {
 	unsigned int bus_format;
 	bool data_mirror;
 
-	struct backlight_device *backlight;
 	struct regulator *supply;
 
 	struct gpio_desc *enable_gpio;
@@ -46,19 +44,6 @@ static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
 	return container_of(panel, struct panel_lvds, panel);
 }
 
-static int panel_lvds_disable(struct drm_panel *panel)
-{
-	struct panel_lvds *lvds = to_panel_lvds(panel);
-
-	if (lvds->backlight) {
-		lvds->backlight->props.power = FB_BLANK_POWERDOWN;
-		lvds->backlight->props.state |= BL_CORE_FBBLANK;
-		backlight_update_status(lvds->backlight);
-	}
-
-	return 0;
-}
-
 static int panel_lvds_unprepare(struct drm_panel *panel)
 {
 	struct panel_lvds *lvds = to_panel_lvds(panel);
@@ -93,19 +78,6 @@ static int panel_lvds_prepare(struct drm_panel *panel)
 	return 0;
 }
 
-static int panel_lvds_enable(struct drm_panel *panel)
-{
-	struct panel_lvds *lvds = to_panel_lvds(panel);
-
-	if (lvds->backlight) {
-		lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
-		lvds->backlight->props.power = FB_BLANK_UNBLANK;
-		backlight_update_status(lvds->backlight);
-	}
-
-	return 0;
-}
-
 static int panel_lvds_get_modes(struct drm_panel *panel,
 				struct drm_connector *connector)
 {
@@ -132,10 +104,8 @@ static int panel_lvds_get_modes(struct drm_panel *panel,
 }
 
 static const struct drm_panel_funcs panel_lvds_funcs = {
-	.disable = panel_lvds_disable,
 	.unprepare = panel_lvds_unprepare,
 	.prepare = panel_lvds_prepare,
-	.enable = panel_lvds_enable,
 	.get_modes = panel_lvds_get_modes,
 };
 
@@ -242,10 +212,6 @@ static int panel_lvds_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	lvds->backlight = devm_of_find_backlight(lvds->dev);
-	if (IS_ERR(lvds->backlight))
-		return PTR_ERR(lvds->backlight);
-
 	/*
 	 * TODO: Handle all power supplies specified in the DT node in a generic
 	 * way for panels that don't care about power supply ordering. LVDS
@@ -257,6 +223,10 @@ static int panel_lvds_probe(struct platform_device *pdev)
 	drm_panel_init(&lvds->panel, lvds->dev, &panel_lvds_funcs,
 		       DRM_MODE_CONNECTOR_LVDS);
 
+	ret = drm_panel_of_backlight(&lvds->panel);
+	if (ret)
+		return ret;
+
 	ret = drm_panel_add(&lvds->panel);
 	if (ret < 0)
 		return ret;
@@ -271,7 +241,7 @@ static int panel_lvds_remove(struct platform_device *pdev)
 
 	drm_panel_remove(&lvds->panel);
 
-	panel_lvds_disable(&lvds->panel);
+	drm_panel_disable(&lvds->panel);
 
 	return 0;
 }