drm/tilcdc: Add drm bridge support for attaching drm bridge drivers

Adds drm bride support for attaching drm bridge drivers to tilcdc. The
decision whether a video port leads to an external encoder or bridge
is made simply based on remote device's compatible string. The code
has been tested with BeagleBone-Black with and without BeagleBone
DVI-D Cape Rev A3 using ti-tfp410 driver.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

4 files changed, 207 insertions, 74 deletions

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 3d2cea090d6f..7f4d3bc7152f 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -209,7 +209,7 @@ static void tilcdc_fini(struct drm_device *dev)
 
         drm_irq_uninstall(dev);
         drm_mode_config_cleanup(dev);
-        tilcdc_remove_external_encoders(dev);
+        tilcdc_remove_external_device(dev);
 
 #ifdef CONFIG_CPU_FREQ
         if (priv->freq_transition.notifier_call)
@@ -381,12 +381,17 @@ static int tilcdc_init(struct drm_driver *ddrv, struct device *dev)
                 if (ret < 0)
                         goto init_failed;
 
-                ret = tilcdc_add_external_encoders(ddev);
+                ret = tilcdc_add_component_encoder(ddev);
                 if (ret < 0)
                         goto init_failed;
+        } else {
+                ret = tilcdc_attach_external_device(ddev);
+                if (ret)
+                        goto init_failed;
         }
 
-        if ((priv->num_encoders == 0) || (priv->num_connectors == 0)) {
+        if (!priv->external_connector &&
+            ((priv->num_encoders == 0) || (priv->num_connectors == 0))) {
                 dev_err(dev, "no encoders/connectors found\n");
                 ret = -ENXIO;
                 goto init_failed;
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
index d31fe5d8ab9d..411f8a8d8158 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
@@ -88,7 +88,10 @@ struct tilcdc_drm_private {
 
         unsigned int num_connectors;
         struct drm_connector *connectors[8];
-        const struct drm_connector_helper_funcs *connector_funcs[8];
+
+        struct drm_encoder *external_encoder;
+        struct drm_connector *external_connector;
+        const struct drm_connector_helper_funcs *connector_funcs;
 
         bool is_registered;
         bool is_componentized;
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.c b/drivers/gpu/drm/tilcdc/tilcdc_external.c
index 06a4c584f3cb..c67d7cd7d57e 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_external.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_external.c
@@ -28,44 +28,50 @@ static const struct tilcdc_panel_info panel_info_tda998x = {
                 .raster_order           = 0,
 };
 
+static const struct tilcdc_panel_info panel_info_default = {
+                .ac_bias                = 255,
+                .ac_bias_intrpt         = 0,
+                .dma_burst_sz           = 16,
+                .bpp                    = 16,
+                .fdd                    = 0x80,
+                .tft_alt_mode           = 0,
+                .sync_edge              = 0,
+                .sync_ctrl              = 1,
+                .raster_order           = 0,
+};
+
 static int tilcdc_external_mode_valid(struct drm_connector *connector,
                                       struct drm_display_mode *mode)
 {
         struct tilcdc_drm_private *priv = connector->dev->dev_private;
-        int ret, i;
+        int ret;
 
         ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
         if (ret != MODE_OK)
                 return ret;
 
-        for (i = 0; i < priv->num_connectors &&
-                     priv->connectors[i] != connector; i++)
-                ;
-
-        BUG_ON(priv->connectors[i] != connector);
-        BUG_ON(!priv->connector_funcs[i]);
+        BUG_ON(priv->external_connector != connector);
+        BUG_ON(!priv->connector_funcs);
 
         /* If the connector has its own mode_valid call it. */
-        if (!IS_ERR(priv->connector_funcs[i]) &&
-            priv->connector_funcs[i]->mode_valid)
-                return priv->connector_funcs[i]->mode_valid(connector, mode);
+        if (!IS_ERR(priv->connector_funcs) &&
+            priv->connector_funcs->mode_valid)
+                return priv->connector_funcs->mode_valid(connector, mode);
 
         return MODE_OK;
 }
 
-static int tilcdc_add_external_encoder(struct drm_device *dev,
-                                       struct drm_connector *connector)
+static int tilcdc_add_external_connector(struct drm_device *dev,
+                                         struct drm_connector *connector)
 {
         struct tilcdc_drm_private *priv = dev->dev_private;
         struct drm_connector_helper_funcs *connector_funcs;
 
-        priv->connectors[priv->num_connectors] = connector;
-        priv->encoders[priv->num_encoders++] = connector->encoder;
-
-        /* Only tda998x is supported at the moment. */
-        tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
-        tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
+        /* There should never be more than one connector */
+        if (WARN_ON(priv->external_connector))
+                return -EINVAL;
 
+        priv->external_connector = connector;
         connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
                                        GFP_KERNEL);
         if (!connector_funcs)
@@ -78,56 +84,177 @@ static int tilcdc_add_external_encoder(struct drm_device *dev,
          * everything else but use our own mode_valid() (above).
          */
         if (connector->helper_private) {
-                priv->connector_funcs[priv->num_connectors] =
-                        connector->helper_private;
-                *connector_funcs = *priv->connector_funcs[priv->num_connectors];
+                priv->connector_funcs = connector->helper_private;
+                *connector_funcs = *priv->connector_funcs;
         } else {
-                priv->connector_funcs[priv->num_connectors] = ERR_PTR(-ENOENT);
+                priv->connector_funcs = ERR_PTR(-ENOENT);
         }
         connector_funcs->mode_valid = tilcdc_external_mode_valid;
         drm_connector_helper_add(connector, connector_funcs);
-        priv->num_connectors++;
 
-        dev_dbg(dev->dev, "External encoder '%s' connected\n",
-                connector->encoder->name);
+        dev_dbg(dev->dev, "External connector '%s' connected\n",
+                connector->name);
 
         return 0;
 }
 
-int tilcdc_add_external_encoders(struct drm_device *dev)
+static
+struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev,
+                                                    struct drm_encoder *encoder)
 {
-        struct tilcdc_drm_private *priv = dev->dev_private;
         struct drm_connector *connector;
-        int num_internal_connectors = priv->num_connectors;
-
-        list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-                bool found = false;
-                int i, ret;
-
-                for (i = 0; i < num_internal_connectors; i++)
-                        if (connector == priv->connectors[i])
-                                found = true;
-                if (!found) {
-                        ret = tilcdc_add_external_encoder(dev, connector);
-                        if (ret)
-                                return ret;
-                }
+        int i;
+
+        list_for_each_entry(connector, &ddev->mode_config.connector_list, head)
+                for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
+                        if (connector->encoder_ids[i] == encoder->base.id)
+                                return connector;
+
+        dev_err(ddev->dev, "No connector found for %s encoder (id %d)\n",
+                encoder->name, encoder->base.id);
+
+        return NULL;
+}
+
+int tilcdc_add_component_encoder(struct drm_device *ddev)
+{
+        struct tilcdc_drm_private *priv = ddev->dev_private;
+        struct drm_connector *connector;
+        struct drm_encoder *encoder;
+
+        list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head)
+                if (encoder->possible_crtcs & (1 << priv->crtc->index))
+                        break;
+
+        if (!encoder) {
+                dev_err(ddev->dev, "%s: No suitable encoder found\n", __func__);
+                return -ENODEV;
         }
-        return 0;
+
+        connector = tilcdc_encoder_find_connector(ddev, encoder);
+
+        if (!connector)
+                return -ENODEV;
+
+        /* Only tda998x is supported at the moment. */
+        tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
+        tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
+
+        return tilcdc_add_external_connector(ddev, connector);
 }
 
-void tilcdc_remove_external_encoders(struct drm_device *dev)
+void tilcdc_remove_external_device(struct drm_device *dev)
 {
         struct tilcdc_drm_private *priv = dev->dev_private;
-        int i;
 
         /* Restore the original helper functions, if any. */
-        for (i = 0; i < priv->num_connectors; i++)
-                if (IS_ERR(priv->connector_funcs[i]))
-                        drm_connector_helper_add(priv->connectors[i], NULL);
-                else if (priv->connector_funcs[i])
-                        drm_connector_helper_add(priv->connectors[i],
-                                                 priv->connector_funcs[i]);
+        if (IS_ERR(priv->connector_funcs))
+                drm_connector_helper_add(priv->external_connector, NULL);
+        else if (priv->connector_funcs)
+                drm_connector_helper_add(priv->external_connector,
+                                         priv->connector_funcs);
+}
+
+static const struct drm_encoder_funcs tilcdc_external_encoder_funcs = {
+        .destroy        = drm_encoder_cleanup,
+};
+
+static
+int tilcdc_attach_bridge(struct drm_device *ddev, struct drm_bridge *bridge)
+{
+        struct tilcdc_drm_private *priv = ddev->dev_private;
+        struct drm_connector *connector;
+        int ret;
+
+        priv->external_encoder->possible_crtcs = BIT(0);
+        priv->external_encoder->bridge = bridge;
+        bridge->encoder = priv->external_encoder;
+
+        ret = drm_bridge_attach(ddev, bridge);
+        if (ret) {
+                dev_err(ddev->dev, "drm_bridge_attach() failed %d\n", ret);
+                return ret;
+        }
+
+        tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_default);
+
+        connector = tilcdc_encoder_find_connector(ddev, priv->external_encoder);
+        if (!connector)
+                return -ENODEV;
+
+        ret = tilcdc_add_external_connector(ddev, connector);
+
+        return ret;
+}
+
+static int tilcdc_node_has_port(struct device_node *dev_node)
+{
+        struct device_node *node;
+
+        node = of_get_child_by_name(dev_node, "ports");
+        if (!node)
+                node = of_get_child_by_name(dev_node, "port");
+        if (!node)
+                return 0;
+        of_node_put(node);
+
+        return 1;
+}
+
+static
+struct device_node *tilcdc_get_remote_node(struct device_node *node)
+{
+        struct device_node *ep;
+        struct device_node *parent;
+
+        if (!tilcdc_node_has_port(node))
+                return NULL;
+
+        ep = of_graph_get_next_endpoint(node, NULL);
+        if (!ep)
+                return NULL;
+
+        parent = of_graph_get_remote_port_parent(ep);
+        of_node_put(ep);
+
+        return parent;
+}
+
+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;
+        int ret;
+
+        remote_node = tilcdc_get_remote_node(ddev->dev->of_node);
+        if (!remote_node)
+                return 0;
+
+        bridge = of_drm_find_bridge(remote_node);
+        of_node_put(remote_node);
+        if (!bridge)
+                return -EPROBE_DEFER;
+
+        priv->external_encoder = devm_kzalloc(ddev->dev,
+                                              sizeof(*priv->external_encoder),
+                                              GFP_KERNEL);
+        if (!priv->external_encoder)
+                return -ENOMEM;
+
+        ret = drm_encoder_init(ddev, priv->external_encoder,
+                               &tilcdc_external_encoder_funcs,
+                               DRM_MODE_ENCODER_NONE, NULL);
+        if (ret) {
+                dev_err(ddev->dev, "drm_encoder_init() failed %d\n", ret);
+                return ret;
+        }
+
+        ret = tilcdc_attach_bridge(ddev, bridge);
+        if (ret)
+                drm_encoder_cleanup(priv->external_encoder);
+
+        return ret;
 }
 
 static int dev_match_of(struct device *dev, void *data)
@@ -141,16 +268,10 @@ int tilcdc_get_external_components(struct device *dev,
         struct device_node *node;
         struct device_node *ep = NULL;
         int count = 0;
+        int ret = 0;
 
-        /* Avoid error print by of_graph_get_next_endpoint() if there
-         * is no ports present.
-         */
-        node = of_get_child_by_name(dev->of_node, "ports");
-        if (!node)
-                node = of_get_child_by_name(dev->of_node, "port");
-        if (!node)
+        if (!tilcdc_node_has_port(dev->of_node))
                 return 0;
-        of_node_put(node);
 
         while ((ep = of_graph_get_next_endpoint(dev->of_node, ep))) {
                 node = of_graph_get_remote_port_parent(ep);
@@ -160,17 +281,20 @@ int tilcdc_get_external_components(struct device *dev,
                 }
 
                 dev_dbg(dev, "Subdevice node '%s' found\n", node->name);
-                if (match)
-                        drm_of_component_match_add(dev, match, dev_match_of,
-                                                   node);
-                of_node_put(node);
-                count++;
-        }
 
-        if (count > 1) {
-                dev_err(dev, "Only one external encoder is supported\n");
-                return -EINVAL;
+                if (of_device_is_compatible(node, "nxp,tda998x")) {
+                        if (match)
+                                drm_of_component_match_add(dev, match,
+                                                           dev_match_of, node);
+                        ret = 1;
+                }
+
+                of_node_put(node);
+                if (count++ > 1) {
+                        dev_err(dev, "Only one port is supported\n");
+                        return -EINVAL;
+                }
         }
 
-        return count;
+        return ret;
 }
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.h b/drivers/gpu/drm/tilcdc/tilcdc_external.h
index c700e0c1623e..763d18f006c7 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_external.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_external.h
@@ -18,8 +18,9 @@
 #ifndef __TILCDC_EXTERNAL_H__
 #define __TILCDC_EXTERNAL_H__
 
-int tilcdc_add_external_encoders(struct drm_device *dev);
-void tilcdc_remove_external_encoders(struct drm_device *dev);
+int tilcdc_add_component_encoder(struct drm_device *dev);
+void tilcdc_remove_external_device(struct drm_device *dev);
 int tilcdc_get_external_components(struct device *dev,
                                    struct component_match **match);
+int tilcdc_attach_external_device(struct drm_device *ddev);
 #endif /* __TILCDC_SLAVE_H__ */