From: Jyri Sarha <jsarha@ti.com>
Date: Sun, 18 Feb 2018 19:48:32 +0200
Subject: drm/tilcdc: Add support for drm panels
Git-commit: 544f7377d92c9dcd7578e5e376bbc2ec96478b37
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Add support for drm panels to tilcdc. Adding the support on top of the
existing bridge support needs only couple of lines of code when using
using the drm panel bridge helpers.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/tilcdc/Kconfig           |    2 ++
 drivers/gpu/drm/tilcdc/tilcdc_external.c |   29 ++++++++++++++++++++---------
 2 files changed, 22 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/tilcdc/Kconfig
+++ b/drivers/gpu/drm/tilcdc/Kconfig
@@ -4,6 +4,8 @@ config DRM_TILCDC
 	select DRM_KMS_HELPER
 	select DRM_KMS_CMA_HELPER
 	select DRM_GEM_CMA_HELPER
+	select DRM_BRIDGE
+	select DRM_PANEL_BRIDGE
 	select VIDEOMODE_HELPERS
 	select BACKLIGHT_CLASS_DEVICE
 	select BACKLIGHT_LCD_SUPPORT
--- a/drivers/gpu/drm/tilcdc/tilcdc_external.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_external.c
@@ -188,18 +188,16 @@ int tilcdc_attach_bridge(struct drm_devi
 int tilcdc_attach_external_device(struct drm_device *ddev)
 {
 	struct tilcdc_drm_private *priv = ddev->dev_private;
-	struct device_node *remote_node;
 	struct drm_bridge *bridge;
+	struct drm_panel *panel;
 	int ret;
 
-	remote_node = of_graph_get_remote_node(ddev->dev->of_node, 0, 0);
-	if (!remote_node)
+	ret = drm_of_find_panel_or_bridge(ddev->dev->of_node, 0, 0,
+					  &panel, &bridge);
+	if (ret == -ENODEV)
 		return 0;
-
-	bridge = of_drm_find_bridge(remote_node);
-	of_node_put(remote_node);
-	if (!bridge)
-		return -EPROBE_DEFER;
+	else if (ret)
+		return ret;
 
 	priv->external_encoder = devm_kzalloc(ddev->dev,
 					      sizeof(*priv->external_encoder),
@@ -215,10 +213,23 @@ int tilcdc_attach_external_device(struct
 		return ret;
 	}
 
+	if (panel) {
+		bridge = devm_drm_panel_bridge_add(ddev->dev, panel,
+						   DRM_MODE_CONNECTOR_DPI);
+		if (IS_ERR(bridge)) {
+			ret = PTR_ERR(bridge);
+			goto err_encoder_cleanup;
+		}
+	}
+
 	ret = tilcdc_attach_bridge(ddev, bridge);
 	if (ret)
-		drm_encoder_cleanup(priv->external_encoder);
+		goto err_encoder_cleanup;
+
+	return 0;
 
+err_encoder_cleanup:
+	drm_encoder_cleanup(priv->external_encoder);
 	return ret;
 }