drm/bridge: migrate bridge_chains to per-encoder file

Instead of having a single file with all bridge chains, list bridges
under a corresponding per-encoder debugfs directory.

While we are at it, also slightly improve the formatting of the bridge
data: split a single line entry into multiple lines, include the symbol
name of the bridge funcs and add the textual representation of the
bridge ops.

Example of the listing:

$ cat /sys/kernel/debug/dri/0/encoder-0/bridges
bridge[0]: dsi_mgr_bridge_funcs
	type: [0] Unknown
	ops: [0]
bridge[1]: lt9611uxc_bridge_funcs
	type: [11] HDMI-A
	OF: /soc@0/geniqup@9c0000/i2c@994000/hdmi-bridge@2b:lontium,lt9611uxc
	ops: [7] detect edid hpd

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231203115315.1306124-3-dmitry.baryshkov@linaro.org

drivers/gpu/drm/drm_bridge.c

@@ -1347,50 +1347,6 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
 EXPORT_SYMBOL(of_drm_find_bridge);
 #endif
 
-#ifdef CONFIG_DEBUG_FS
-static int drm_bridge_chains_info(struct seq_file *m, void *data)
-{
-	struct drm_debugfs_entry *entry = m->private;
-	struct drm_device *dev = entry->dev;
-	struct drm_printer p = drm_seq_file_printer(m);
-	struct drm_mode_config *config = &dev->mode_config;
-	struct drm_encoder *encoder;
-	unsigned int bridge_idx = 0;
-
-	list_for_each_entry(encoder, &config->encoder_list, head) {
-		struct drm_bridge *bridge;
-
-		drm_printf(&p, "encoder[%u]\n", encoder->base.id);
-
-		drm_for_each_bridge_in_chain(encoder, bridge) {
-			drm_printf(&p, "\tbridge[%u] type: %u, ops: %#x",
-				   bridge_idx, bridge->type, bridge->ops);
-
-#ifdef CONFIG_OF
-			if (bridge->of_node)
-				drm_printf(&p, ", OF: %pOFfc", bridge->of_node);
-#endif
-
-			drm_printf(&p, "\n");
-
-			bridge_idx++;
-		}
-	}
-
-	return 0;
-}
-
-static const struct drm_debugfs_info drm_bridge_debugfs_list[] = {
-	{ "bridge_chains", drm_bridge_chains_info, 0 },
-};
-
-void drm_bridge_debugfs_init(struct drm_device *dev)
-{
-	drm_debugfs_add_files(dev, drm_bridge_debugfs_list,
-			      ARRAY_SIZE(drm_bridge_debugfs_list));
-}
-#endif
-
 MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
 MODULE_DESCRIPTION("DRM bridge infrastructure");
 MODULE_LICENSE("GPL and additional rights");

drivers/gpu/drm/drm_debugfs.c

@@ -314,10 +314,8 @@ void drm_debugfs_dev_register(struct drm_device *dev)
 		drm_framebuffer_debugfs_init(dev);
 		drm_client_debugfs_init(dev);
 	}
-	if (drm_drv_uses_atomic_modeset(dev)) {
+	if (drm_drv_uses_atomic_modeset(dev))
 		drm_atomic_debugfs_init(dev);
-		drm_bridge_debugfs_init(dev);
-	}
 }
 
 int drm_debugfs_register(struct drm_minor *minor, int minor_id,
@@ -589,6 +587,38 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc)
 	crtc->debugfs_entry = NULL;
 }
 
+static int bridges_show(struct seq_file *m, void *data)
+{
+	struct drm_encoder *encoder = m->private;
+	struct drm_printer p = drm_seq_file_printer(m);
+	struct drm_bridge *bridge;
+	unsigned int idx = 0;
+
+	drm_for_each_bridge_in_chain(encoder, bridge) {
+		drm_printf(&p, "bridge[%d]: %ps\n", idx++, bridge->funcs);
+		drm_printf(&p, "\ttype: [%d] %s\n",
+			   bridge->type,
+			   drm_get_connector_type_name(bridge->type));
+#ifdef CONFIG_OF
+		if (bridge->of_node)
+			drm_printf(&p, "\tOF: %pOFfc\n", bridge->of_node);
+#endif
+		drm_printf(&p, "\tops: [0x%x]", bridge->ops);
+		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
+			drm_puts(&p, " detect");
+		if (bridge->ops & DRM_BRIDGE_OP_EDID)
+			drm_puts(&p, " edid");
+		if (bridge->ops & DRM_BRIDGE_OP_HPD)
+			drm_puts(&p, " hpd");
+		if (bridge->ops & DRM_BRIDGE_OP_MODES)
+			drm_puts(&p, " modes");
+		drm_puts(&p, "\n");
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(bridges);
+
 void drm_debugfs_encoder_add(struct drm_encoder *encoder)
 {
 	struct drm_minor *minor = encoder->dev->primary;
@@ -604,6 +634,10 @@ void drm_debugfs_encoder_add(struct drm_encoder *encoder)
 
 	encoder->debugfs_entry = root;
 
+	/* bridges list */
+	debugfs_create_file("bridges", 0444, root, encoder,
+			    &bridges_fops);
+
 	if (encoder->funcs->debugfs_init)
 		encoder->funcs->debugfs_init(encoder, root);
 }

include/drm/drm_bridge.h

@@ -950,6 +950,4 @@ static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
 }
 #endif
 
-void drm_bridge_debugfs_init(struct drm_device *dev);
-
 #endif