drm/panel: rocktech-jh057n00900: use drm_panel backlight support

Use the backlight support in drm_panel to simplify the driver.
While touching the include files sort them
and divide them up in blocks.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: "Guido Günther" <agx@sigxcpu.org>
Cc: Purism Kernel Team <kernel@puri.sm>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191207140353.23967-18-sam@ravnborg.org

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c

@@ -5,20 +5,22 @@
  * Copyright (C) Purism SPC 2019
  */
 
-#include <drm/drm_mipi_dsi.h>
-#include <drm/drm_modes.h>
-#include <drm/drm_panel.h>
-#include <drm/drm_print.h>
-#include <linux/backlight.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/media-bus-format.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
+
 #include <video/display_timing.h>
 #include <video/mipi_display.h>
 
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
 #define DRV_NAME "panel-rocktech-jh057n00900"
 
 /* Manufacturer specific Commands send via DSI */
@@ -47,7 +49,6 @@ struct jh057n {
 	struct device *dev;
 	struct drm_panel panel;
 	struct gpio_desc *reset_gpio;
-	struct backlight_device *backlight;
 	struct regulator *vcc;
 	struct regulator *iovcc;
 	bool prepared;
@@ -152,7 +153,7 @@ static int jh057n_enable(struct drm_panel *panel)
 		return ret;
 	}
 
-	return backlight_enable(ctx->backlight);
+	return 0;
 }
 
 static int jh057n_disable(struct drm_panel *panel)
@@ -160,7 +161,6 @@ static int jh057n_disable(struct drm_panel *panel)
 	struct jh057n *ctx = panel_to_jh057n(panel);
 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
 
-	backlight_disable(ctx->backlight);
 	return mipi_dsi_dcs_set_display_off(dsi);
 }
 
@@ -321,10 +321,6 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
 		MIPI_DSI_MODE_VIDEO_BURST | MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
 
-	ctx->backlight = devm_of_find_backlight(dev);
-	if (IS_ERR(ctx->backlight))
-		return PTR_ERR(ctx->backlight);
-
 	ctx->vcc = devm_regulator_get(dev, "vcc");
 	if (IS_ERR(ctx->vcc)) {
 		ret = PTR_ERR(ctx->vcc);
@@ -347,6 +343,10 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 	drm_panel_init(&ctx->panel, dev, &jh057n_drm_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
 
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
 	drm_panel_add(&ctx->panel);
 
 	ret = mipi_dsi_attach(dsi);