drm/fsl-dcu: rework codes to support of_graph dt binding for panel

This patch rework the output code to add of_graph dt binding support
for panel device and also keeps the backward compatibility

Signed-off-by: Meng Yi <meng.yi@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stefan Agner <stefan@agner.ch>

3 files changed, 50 insertions, 23 deletions

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
index a6e4cd591960..d9d6cc1c8e39 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_kms.c
@@ -43,7 +43,7 @@ int fsl_dcu_drm_modeset_init(struct fsl_dcu_drm_device *fsl_dev)
         if (ret)
                 goto err;
 
-        ret = fsl_dcu_drm_connector_create(fsl_dev, &fsl_dev->encoder);
+        ret = fsl_dcu_create_outputs(fsl_dev);
         if (ret)
                 goto err;
 
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
index 7093109fbc21..5a7b88e19e44 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_output.h
@@ -25,9 +25,8 @@ to_fsl_dcu_connector(struct drm_connector *con)
                      : NULL;
 }
 
-int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
-                                 struct drm_encoder *encoder);
 int fsl_dcu_drm_encoder_create(struct fsl_dcu_drm_device *fsl_dev,
                                struct drm_crtc *crtc);
+int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev);
 
 #endif /* __FSL_DCU_DRM_CONNECTOR_H__ */
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
index 0b0989e503ea..32eff990d199 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/backlight.h>
+#include <linux/of_graph.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
@@ -132,12 +133,12 @@ static const struct drm_connector_helper_funcs connector_helper_funcs = {
         .mode_valid = fsl_dcu_drm_connector_mode_valid,
 };
 
-int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
-                                 struct drm_encoder *encoder)
+static int fsl_dcu_attach_panel(struct fsl_dcu_drm_device *fsl_dev,
+                                 struct drm_panel *panel)
 {
+        struct drm_encoder *encoder = &fsl_dev->encoder;
         struct drm_connector *connector = &fsl_dev->connector.base;
         struct drm_mode_config *mode_config = &fsl_dev->drm->mode_config;
-        struct device_node *panel_node;
         int ret;
 
         fsl_dev->connector.encoder = encoder;
@@ -161,21 +162,7 @@ int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
                                       mode_config->dpms_property,
                                       DRM_MODE_DPMS_OFF);
 
-        panel_node = of_parse_phandle(fsl_dev->np, "fsl,panel", 0);
-        if (!panel_node) {
-                dev_err(fsl_dev->dev, "fsl,panel property not found\n");
-                ret = -ENODEV;
-                goto err_sysfs;
-        }
-
-        fsl_dev->connector.panel = of_drm_find_panel(panel_node);
-        if (!fsl_dev->connector.panel) {
-                ret = -EPROBE_DEFER;
-                goto err_panel;
-        }
-        of_node_put(panel_node);
-
-        ret = drm_panel_attach(fsl_dev->connector.panel, connector);
+        ret = drm_panel_attach(panel, connector);
         if (ret) {
                 dev_err(fsl_dev->dev, "failed to attach panel\n");
                 goto err_sysfs;
@@ -183,11 +170,52 @@ int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
 
         return 0;
 
-err_panel:
-        of_node_put(panel_node);
 err_sysfs:
         drm_connector_unregister(connector);
 err_cleanup:
         drm_connector_cleanup(connector);
         return ret;
 }
+
+static int fsl_dcu_attach_endpoint(struct fsl_dcu_drm_device *fsl_dev,
+                                   const struct of_endpoint *ep)
+{
+        struct device_node *np;
+
+        np = of_graph_get_remote_port_parent(ep->local_node);
+
+        fsl_dev->connector.panel = of_drm_find_panel(np);
+        of_node_put(np);
+        if (fsl_dev->connector.panel)
+                return fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel);
+
+        return -ENODEV;
+}
+
+int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
+{
+        struct of_endpoint ep;
+        struct device_node *ep_node, *panel_node;
+        int ret;
+
+        /* This is for backward compatibility */
+        panel_node = of_parse_phandle(fsl_dev->np, "fsl,panel", 0);
+        if (panel_node) {
+                fsl_dev->connector.panel = of_drm_find_panel(panel_node);
+                of_node_put(panel_node);
+                if (!fsl_dev->connector.panel)
+                        return -EPROBE_DEFER;
+                return fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel);
+        }
+
+        ep_node = of_graph_get_next_endpoint(fsl_dev->np, NULL);
+        if (!ep_node)
+                return -ENODEV;
+
+        ret = of_graph_parse_endpoint(ep_node, &ep);
+        of_node_put(ep_node);
+        if (ret)
+                return -ENODEV;
+
+        return fsl_dcu_attach_endpoint(fsl_dev, &ep);
+}