drm: of: move drm_of_find_panel_or_bridge() from drm_of.c to drm_panel.c

We want to move drm_panel.o from the main drm module to a new drm_panel
module, but there is one function in the drm module that calls into
drm_panel.c code:

  drm_of_find_panel_or_bridge() (drm_of.c, drm module)
     -> calls of_drm_find_panel (drm_panel.c, future drm_panel module)

Avoid this issue by moving drm_of_find_panel_or_bridge() to drm_panel.c.

Update Kconfig symbols of drivers calling drm_of_find_panel_or_bridge() to
select DRM_PANEL when this is not done already.

No functional changes, just moving code around.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patch.msgid.link/20260916-drm-bridge-every-panel-v3-1-83afb4f1a707@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

drivers/gpu/drm/bridge/Kconfig

@@ -151,6 +151,7 @@ config DRM_LONTIUM_LT8912B
 config DRM_LONTIUM_LT9211
 	tristate "Lontium LT9211 DSI/LVDS/DPI bridge"
 	depends on OF
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
 	select DRM_MIPI_DSI
@@ -498,6 +499,7 @@ config DRM_WAVESHARE_BRIDGE
 	tristate "Waveshare DSI bridge"
 	depends on OF
 	depends on BACKLIGHT_CLASS_DEVICE
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
 	select DRM_MIPI_DSI

drivers/gpu/drm/bridge/analogix/Kconfig

@@ -6,6 +6,7 @@ config DRM_ANALOGIX_ANX6345
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER
 	select DRM_KMS_HELPER
+	select DRM_PANEL
 	select REGMAP_I2C
 	help
 	  ANX6345 is an ultra-low power Full-HD DisplayPort/eDP
@@ -32,6 +33,7 @@ config DRM_ANALOGIX_DP
 	depends on DRM
 	depends on OF
 	select DRM_DISPLAY_DP_AUX_BUS
+	select DRM_PANEL
 
 config DRM_ANALOGIX_ANX7625
 	tristate "Analogix Anx7625 MIPI to DP interface support"

drivers/gpu/drm/drm_of.c

@@ -264,69 +264,6 @@ int drm_of_get_panel_orientation(const struct device_node *np,
 }
 EXPORT_SYMBOL_GPL(drm_of_get_panel_orientation);
 
-/**
- * drm_of_find_panel_or_bridge - return connected panel or bridge device
- * @np: device tree node containing encoder output ports
- * @port: port in the device tree node
- * @endpoint: endpoint in the device tree node
- * @panel: pointer to hold returned drm_panel, must not be NULL. On success
- *         the caller must call drm_panel_put() when done with the panel
- * @bridge: pointer to hold returned drm_bridge
- *
- * Given a DT node's port and endpoint number, find the connected node and
- * return either the associated struct drm_panel or drm_bridge device.
- *
- * This function is deprecated and should not be used in new drivers. Use
- * of_drm_get_bridge_by_endpoint() instead when not looking for a panel, or
- * devm_drm_of_get_bridge() otherwise.
- *
- * Returns zero if successful, or one of the standard error codes if it fails.
- */
-int drm_of_find_panel_or_bridge(const struct device_node *np,
-				int port, int endpoint,
-				struct drm_panel **panel,
-				struct drm_bridge **bridge)
-{
-	if (WARN_ON(!panel))
-		return -EINVAL;
-
-	*panel = NULL;
-	if (bridge)
-		*bridge = NULL;
-
-	/*
-	 * of_graph_get_remote_node() produces a noisy error message if port
-	 * node isn't found and the absence of the port is a legit case here,
-	 * so at first we silently check whether a graph is present in the
-	 * device-tree node.
-	 */
-	if (!of_graph_is_present(np))
-		return -ENODEV;
-
-	struct device_node *remote __free(device_node) =
-		of_graph_get_remote_node(np, port, endpoint);
-	if (!remote)
-		return -ENODEV;
-
-	*panel = of_drm_find_panel(remote);
-	if (!IS_ERR(*panel))
-		return 0;
-
-	*panel = NULL;
-
-	if (bridge) {
-		/* No panel found yet, check for a bridge next. */
-		*bridge = of_drm_find_bridge(remote);
-		if (*bridge)
-			return 0;
-
-		*bridge = NULL;
-	}
-
-	return -EPROBE_DEFER;
-}
-EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
-
 enum drm_of_lvds_pixels {
 	DRM_OF_LVDS_EVEN = BIT(0),
 	DRM_OF_LVDS_ODD = BIT(1),

drivers/gpu/drm/drm_panel.c

@@ -498,6 +498,69 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
 	return ERR_PTR(-EPROBE_DEFER);
 }
 EXPORT_SYMBOL(of_drm_find_panel);
+
+/**
+ * drm_of_find_panel_or_bridge - return connected panel or bridge device
+ * @np: device tree node containing encoder output ports
+ * @port: port in the device tree node
+ * @endpoint: endpoint in the device tree node
+ * @panel: pointer to hold returned drm_panel, must not be NULL. On success
+ *         the caller must call drm_panel_put() when done with the panel
+ * @bridge: pointer to hold returned drm_bridge
+ *
+ * Given a DT node's port and endpoint number, find the connected node and
+ * return either the associated struct drm_panel or drm_bridge device.
+ *
+ * This function is deprecated and should not be used in new drivers. Use
+ * of_drm_get_bridge_by_endpoint() instead when not looking for a panel, or
+ * devm_drm_of_get_bridge() otherwise.
+ *
+ * Returns zero if successful, or one of the standard error codes if it fails.
+ */
+int drm_of_find_panel_or_bridge(const struct device_node *np,
+				int port, int endpoint,
+				struct drm_panel **panel,
+				struct drm_bridge **bridge)
+{
+	if (WARN_ON(!panel))
+		return -EINVAL;
+
+	*panel = NULL;
+	if (bridge)
+		*bridge = NULL;
+
+	/*
+	 * of_graph_get_remote_node() produces a noisy error message if port
+	 * node isn't found and the absence of the port is a legit case here,
+	 * so at first we silently check whether a graph is present in the
+	 * device-tree node.
+	 */
+	if (!of_graph_is_present(np))
+		return -ENODEV;
+
+	struct device_node *remote __free(device_node) =
+		of_graph_get_remote_node(np, port, endpoint);
+	if (!remote)
+		return -ENODEV;
+
+	*panel = of_drm_find_panel(remote);
+	if (!IS_ERR(*panel))
+		return 0;
+
+	*panel = NULL;
+
+	if (bridge) {
+		/* No panel found yet, check for a bridge next. */
+		*bridge = of_drm_find_bridge(remote);
+		if (*bridge)
+			return 0;
+
+		*bridge = NULL;
+	}
+
+	return -EPROBE_DEFER;
+}
+EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
 #endif
 
 /*

drivers/gpu/drm/imx/dcss/Kconfig

@@ -6,6 +6,7 @@ config DRM_IMX_DCSS
 	select DRM_DISPLAY_HELPER
 	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
+	select DRM_PANEL
 	select VIDEOMODE_HELPERS
 	depends on DRM && ((ARCH_MXC && ARM64) || COMPILE_TEST)
 	help

drivers/gpu/drm/ingenic/Kconfig

@@ -7,6 +7,7 @@ config DRM_INGENIC
 	depends on COMMON_CLK
 	select DRM_BRIDGE
 	select DRM_CLIENT_SELECTION
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
 	select DRM_DISPLAY_HELPER

drivers/gpu/drm/logicvc/Kconfig

@@ -5,6 +5,7 @@ config DRM_LOGICVC
 	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
+	select DRM_PANEL
 	select REGMAP
 	select REGMAP_MMIO
 	help

drivers/gpu/drm/mcde/Kconfig

@@ -9,6 +9,7 @@ config DRM_MCDE
 	select DRM_CLIENT_SELECTION
 	select DRM_MIPI_DSI
 	select DRM_BRIDGE
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER

drivers/gpu/drm/pl111/Kconfig

@@ -9,6 +9,7 @@ config DRM_PL111
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
 	select DRM_BRIDGE
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	help
 	  Choose this option for DRM support for the PL111 CLCD controller.

drivers/gpu/drm/rockchip/Kconfig

@@ -125,6 +125,7 @@ config ROCKCHIP_LVDS
 	depends on PINCTRL && OF
 	select DRM_DISPLAY_HELPER
 	select DRM_BRIDGE_CONNECTOR
+	select DRM_PANEL
 	help
 	  Choose this option to enable support for Rockchip LVDS controllers.
 	  Rockchip rk3288 SoC has LVDS TX Controller can be used, and it
@@ -137,6 +138,7 @@ config ROCKCHIP_RGB
 	depends on PINCTRL
 	select DRM_DISPLAY_HELPER
 	select DRM_BRIDGE_CONNECTOR
+	select DRM_PANEL
 	help
 	  Choose this option to enable support for Rockchip RGB output.
 	  Some Rockchip CRTCs, like rv1108, can directly output parallel

drivers/gpu/drm/stm/Kconfig

@@ -6,6 +6,7 @@ config DRM_STM
 	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select VIDEOMODE_HELPERS
 	select FB_PROVIDE_GET_FB_UNMAPPED_AREA if FB

drivers/gpu/drm/tidss/Kconfig

@@ -7,6 +7,7 @@ config DRM_TIDSS
 	select DRM_DISPLAY_HELPER
 	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
+	select DRM_PANEL
 	help
 	  The TI Keystone family SoCs introduced a new generation of
 	  Display SubSystem. There is currently three Keystone family

drivers/gpu/drm/tve200/Kconfig

@@ -7,6 +7,7 @@ config DRM_TVE200
 	depends on OF
 	select DRM_BRIDGE
 	select DRM_CLIENT_SELECTION
+	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER

include/drm/drm_of.h

@@ -51,10 +51,6 @@ int drm_of_encoder_active_endpoint(struct device_node *node,
 				   struct of_endpoint *endpoint);
 int drm_of_get_panel_orientation(const struct device_node *np,
 				 enum drm_panel_orientation *orientation);
-int drm_of_find_panel_or_bridge(const struct device_node *np,
-				int port, int endpoint,
-				struct drm_panel **panel,
-				struct drm_bridge **bridge);
 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
 					  const struct device_node *port2);
 int drm_of_lvds_get_dual_link_pixel_order_sink(struct device_node *port1,
@@ -112,14 +108,6 @@ static inline int drm_of_get_panel_orientation(const struct device_node *np,
 	return -EINVAL;
 }
 
-static inline int drm_of_find_panel_or_bridge(const struct device_node *np,
-					      int port, int endpoint,
-					      struct drm_panel **panel,
-					      struct drm_bridge **bridge)
-{
-	return -EINVAL;
-}
-
 static inline int
 drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
 				      const struct device_node *port2)

include/drm/drm_panel.h

@@ -33,6 +33,7 @@
 struct backlight_device;
 struct dentry;
 struct device_node;
+struct drm_bridge;
 struct drm_connector;
 struct drm_panel_follower;
 struct drm_panel;
@@ -337,11 +338,23 @@ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector
 
 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 struct drm_panel *of_drm_find_panel(const struct device_node *np);
+int drm_of_find_panel_or_bridge(const struct device_node *np,
+				int port, int endpoint,
+				struct drm_panel **panel,
+				struct drm_bridge **bridge);
 #else
 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 {
 	return ERR_PTR(-ENODEV);
 }
+
+static inline int drm_of_find_panel_or_bridge(const struct device_node *np,
+					      int port, int endpoint,
+					      struct drm_panel **panel,
+					      struct drm_bridge **bridge)
+{
+	return -EINVAL;
+}
 #endif
 
 #if defined(CONFIG_DRM_PANEL)