drm/bridge: panel: Infer connector type from panel by default

The drm panel bridge creates a connector using a connector type
explicitly passed by the display controller or bridge driver that
instantiates the panel bridge. Now that drm_panel reports its connector
type, we can use it to avoid passing an explicit (and often incorrect)
connector type to drm_panel_bridge_add() and
devm_drm_panel_bridge_add().

Several drivers report incorrect or unknown connector types to
userspace. Reporting a different type may result in a breakage. For that
reason, rename (devm_)drm_panel_bridge_add() to
(devm_)drm_panel_bridge_add_typed(), and add new
(devm_)drm_panel_bridge_add() functions that use the panel connector
type. Update all callers of (devm_)drm_panel_bridge_add() to the _typed
function, they will be converted one by one after testing.

The panel drivers have been updated with the following Coccinelle
semantic patch, with manual inspection and fixes to indentation.

@@
expression bridge;
expression dev;
expression panel;
identifier type;
@@
(
-bridge = drm_panel_bridge_add(panel, type);
+bridge = drm_panel_bridge_add_typed(panel, type);
|
-bridge = devm_drm_panel_bridge_add(dev, panel, type);
+bridge = devm_drm_panel_bridge_add_typed(dev, panel, type);
)

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904132804.29680-3-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c

@@ -107,7 +107,8 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
 	output->encoder.possible_crtcs = 0x1;
 
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown);
+		bridge = drm_panel_bridge_add_typed(panel,
+						    DRM_MODE_CONNECTOR_Unknown);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 	}

drivers/gpu/drm/bridge/cdns-dsi.c

@@ -956,7 +956,8 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host,
 
 	panel = of_drm_find_panel(np);
 	if (!IS_ERR(panel)) {
-		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
+		bridge = drm_panel_bridge_add_typed(panel,
+						    DRM_MODE_CONNECTOR_DSI);
 	} else {
 		bridge = of_drm_find_bridge(dev->dev.of_node);
 		if (!bridge)

drivers/gpu/drm/bridge/lvds-encoder.c

@@ -106,7 +106,8 @@ static int lvds_encoder_probe(struct platform_device *pdev)
 	}
 
 	lvds_encoder->panel_bridge =
-		devm_drm_panel_bridge_add(dev, panel, DRM_MODE_CONNECTOR_LVDS);
+		devm_drm_panel_bridge_add_typed(dev, panel,
+						DRM_MODE_CONNECTOR_LVDS);
 	if (IS_ERR(lvds_encoder->panel_bridge))
 		return PTR_ERR(lvds_encoder->panel_bridge);
 

drivers/gpu/drm/bridge/panel.c

@@ -134,8 +134,6 @@ static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
  * just calls the appropriate functions from &drm_panel.
  *
  * @panel: The drm_panel being wrapped.  Must be non-NULL.
- * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
- * created.
  *
  * For drivers converting from directly using drm_panel: The expected
  * usage pattern is that during either encoder module probe or DSI
@@ -149,11 +147,37 @@ static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
  * drm_mode_config_cleanup() if the bridge has already been attached), then
  * drm_panel_bridge_remove() to free it.
  *
+ * The connector type is set to @panel->connector_type, which must be set to a
+ * known type. Calling this function with a panel whose connector type is
+ * DRM_MODE_CONNECTOR_Unknown will return NULL.
+ *
  * See devm_drm_panel_bridge_add() for an automatically manged version of this
  * function.
  */
-struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
+struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
-					u32 connector_type)
+{
+	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
+		return NULL;
+
+	return drm_panel_bridge_add_typed(panel, panel->connector_type);
+}
+EXPORT_SYMBOL(drm_panel_bridge_add);
+
+/**
+ * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
+ * an explicit connector type.
+ * @panel: The drm_panel being wrapped.  Must be non-NULL.
+ * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
+ *
+ * This is just like drm_panel_bridge_add(), but forces the connector type to
+ * @connector_type instead of infering it from the panel.
+ *
+ * This function is deprecated and should not be used in new drivers. Use
+ * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
+ * don't report a connector type.
+ */
+struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
+					      u32 connector_type)
 {
 	struct panel_bridge *panel_bridge;
 
@@ -177,7 +201,7 @@ struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
 
 	return &panel_bridge->bridge;
 }
-EXPORT_SYMBOL(drm_panel_bridge_add);
+EXPORT_SYMBOL(drm_panel_bridge_add_typed);
 
 /**
  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
@@ -214,15 +238,38 @@ static void devm_drm_panel_bridge_release(struct device *dev, void *res)
  * that just calls the appropriate functions from &drm_panel.
  * @dev: device to tie the bridge lifetime to
  * @panel: The drm_panel being wrapped.  Must be non-NULL.
- * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
- * created.
  *
  * This is the managed version of drm_panel_bridge_add() which automatically
  * calls drm_panel_bridge_remove() when @dev is unbound.
  */
 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
-					     struct drm_panel *panel,
+					     struct drm_panel *panel)
-					     u32 connector_type)
+{
+	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
+		return NULL;
+
+	return devm_drm_panel_bridge_add_typed(dev, panel,
+					       panel->connector_type);
+}
+EXPORT_SYMBOL(devm_drm_panel_bridge_add);
+
+/**
+ * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
+ * &drm_connector with an explicit connector type.
+ * @dev: device to tie the bridge lifetime to
+ * @panel: The drm_panel being wrapped.  Must be non-NULL.
+ * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
+ *
+ * This is just like devm_drm_panel_bridge_add(), but forces the connector type
+ * to @connector_type instead of infering it from the panel.
+ *
+ * This function is deprecated and should not be used in new drivers. Use
+ * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
+ * they don't report a connector type.
+ */
+struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
+						   struct drm_panel *panel,
+						   u32 connector_type)
 {
 	struct drm_bridge **ptr, *bridge;
 
@@ -231,7 +278,7 @@ struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-	bridge = drm_panel_bridge_add(panel, connector_type);
+	bridge = drm_panel_bridge_add_typed(panel, connector_type);
 	if (!IS_ERR(bridge)) {
 		*ptr = bridge;
 		devres_add(dev, ptr);
@@ -241,4 +288,4 @@ struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
 
 	return bridge;
 }
-EXPORT_SYMBOL(devm_drm_panel_bridge_add);
+EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -316,7 +316,8 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
 		return ret;
 
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
+		bridge = drm_panel_bridge_add_typed(panel,
+						    DRM_MODE_CONNECTOR_DSI);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 	}

drivers/gpu/drm/ingenic/ingenic-drm.c

@@ -677,8 +677,8 @@ static int ingenic_drm_probe(struct platform_device *pdev)
 	}
 
 	if (panel)
-		bridge = devm_drm_panel_bridge_add(dev, panel,
+		bridge = devm_drm_panel_bridge_add_typed(dev, panel,
-						   DRM_MODE_CONNECTOR_DPI);
+							 DRM_MODE_CONNECTOR_DPI);
 
 	priv->dma_hwdesc = dma_alloc_coherent(dev, sizeof(*priv->dma_hwdesc),
 					      &priv->dma_hwdesc_phys,

drivers/gpu/drm/mcde/mcde_dsi.c

@@ -922,8 +922,8 @@ static int mcde_dsi_bind(struct device *dev, struct device *master,
 		}
 	}
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel,
+		bridge = drm_panel_bridge_add_typed(panel,
-					      DRM_MODE_CONNECTOR_DSI);
+						    DRM_MODE_CONNECTOR_DSI);
 		if (IS_ERR(bridge)) {
 			dev_err(dev, "error adding panel bridge\n");
 			return PTR_ERR(bridge);

drivers/gpu/drm/pl111/pl111_drv.c

@@ -150,8 +150,8 @@ static int pl111_modeset_init(struct drm_device *dev)
 		return -EPROBE_DEFER;
 
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel,
+		bridge = drm_panel_bridge_add_typed(panel,
-					      DRM_MODE_CONNECTOR_Unknown);
+						    DRM_MODE_CONNECTOR_Unknown);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto out_config;

drivers/gpu/drm/rcar-du/rcar_du_encoder.c

@@ -85,8 +85,8 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 			goto done;
 		}
 
-		bridge = devm_drm_panel_bridge_add(rcdu->dev, panel,
+		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
-						   DRM_MODE_CONNECTOR_DPI);
+							 DRM_MODE_CONNECTOR_DPI);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto done;

drivers/gpu/drm/rockchip/rockchip_rgb.c

@@ -136,7 +136,8 @@ struct rockchip_rgb *rockchip_rgb_init(struct device *dev,
 	drm_encoder_helper_add(encoder, &rockchip_rgb_encoder_helper_funcs);
 
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
+		bridge = drm_panel_bridge_add_typed(panel,
+						    DRM_MODE_CONNECTOR_LVDS);
 		if (IS_ERR(bridge))
 			return ERR_CAST(bridge);
 	}

drivers/gpu/drm/stm/ltdc.c

@@ -1236,8 +1236,8 @@ int ltdc_load(struct drm_device *ddev)
 	/* Add endpoints panels or bridges if any */
 	for (i = 0; i < MAX_ENDPOINTS; i++) {
 		if (panel[i]) {
-			bridge[i] = drm_panel_bridge_add(panel[i],
+			bridge[i] = drm_panel_bridge_add_typed(panel[i],
-							DRM_MODE_CONNECTOR_DPI);
+							       DRM_MODE_CONNECTOR_DPI);
 			if (IS_ERR(bridge[i])) {
 				DRM_ERROR("panel-bridge endpoint %d\n", i);
 				ret = PTR_ERR(bridge[i]);

drivers/gpu/drm/tilcdc/tilcdc_external.c

@@ -140,8 +140,8 @@ int tilcdc_attach_external_device(struct drm_device *ddev)
 	}
 
 	if (panel) {
-		bridge = devm_drm_panel_bridge_add(ddev->dev, panel,
+		bridge = devm_drm_panel_bridge_add_typed(ddev->dev, panel,
-						   DRM_MODE_CONNECTOR_DPI);
+							 DRM_MODE_CONNECTOR_DPI);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto err_encoder_cleanup;

drivers/gpu/drm/tve200/tve200_drv.c

@@ -80,8 +80,8 @@ static int tve200_modeset_init(struct drm_device *dev)
 	if (ret && ret != -ENODEV)
 		return ret;
 	if (panel) {
-		bridge = drm_panel_bridge_add(panel,
+		bridge = drm_panel_bridge_add_typed(panel,
-					      DRM_MODE_CONNECTOR_Unknown);
+						    DRM_MODE_CONNECTOR_Unknown);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto out_bridge;

drivers/gpu/drm/vc4/vc4_dpi.c

@@ -249,7 +249,8 @@ static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 	}
 
 	if (panel)
-		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
+		bridge = drm_panel_bridge_add_typed(panel,
+						    DRM_MODE_CONNECTOR_DPI);
 
 	return drm_bridge_attach(dpi->encoder, bridge, NULL);
 }

drivers/gpu/drm/vc4/vc4_dsi.c

@@ -1576,8 +1576,8 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	}
 
 	if (panel) {
-		dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
+		dsi->bridge = devm_drm_panel_bridge_add_typed(dev, panel,
-							DRM_MODE_CONNECTOR_DSI);
+							      DRM_MODE_CONNECTOR_DSI);
 		if (IS_ERR(dsi->bridge))
 			return PTR_ERR(dsi->bridge);
 	}

include/drm/drm_bridge.h

@@ -429,12 +429,15 @@ void drm_atomic_bridge_enable(struct drm_bridge *bridge,
 			      struct drm_atomic_state *state);
 
 #ifdef CONFIG_DRM_PANEL_BRIDGE
-struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
+struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
-					u32 connector_type);
+struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
+					      u32 connector_type);
 void drm_panel_bridge_remove(struct drm_bridge *bridge);
 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
-					     struct drm_panel *panel,
+					     struct drm_panel *panel);
-					     u32 connector_type);
+struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
+						   struct drm_panel *panel,
+						   u32 connector_type);
 #endif
 
 #endif