Index: linux-3.10.49/drivers/net/phy/mdio_bus.c
===================================================================
--- linux-3.10.49.orig/drivers/net/phy/mdio_bus.c
+++ linux-3.10.49/drivers/net/phy/mdio_bus.c
@@ -36,6 +36,7 @@
 #include <linux/mii.h>
 #include <linux/ethtool.h>
 #include <linux/phy.h>
+#include <linux/debugfs.h>
 
 #include <asm/io.h>
 #include <asm/irq.h>
@@ -127,6 +128,82 @@ struct mii_bus *of_mdio_find_bus(struct
 EXPORT_SYMBOL(of_mdio_find_bus);
 #endif
 
+struct dentry *mdiobus_debug_root;
+EXPORT_SYMBOL_GPL(mdiobus_debug_root);
+
+static int mdiobus_debugfs_init(void)
+{
+	mdiobus_debug_root = debugfs_create_dir("mdio_bus", NULL);
+	if (!mdiobus_debug_root)
+		return -ENOENT;
+	return 0;
+}
+
+static void mdiobus_debugfs_cleanup(void)
+{
+	debugfs_remove(mdiobus_debug_root);
+}
+
+
+static void mdiobus_debugfs_del(struct mii_bus *bus)
+{
+	debugfs_remove_recursive(bus->debugfs_dir);
+	bus->debugfs_dir = NULL;
+}
+
+static int mdiobus_debugfs_add(struct mii_bus *bus)
+{
+	bus->debugfs_dir = debugfs_create_dir(bus->name, mdiobus_debug_root);
+	if (!bus->debugfs_dir)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int phy_dump_show(struct seq_file *seq, void *v)
+{
+	int ret = 0, i;
+	u16 *buffer = NULL;
+	struct phy_device *phy = seq->private;
+
+	buffer = kzalloc(32 * sizeof(u16), GFP_KERNEL);
+	if (!buffer) {
+		return -ENOMEM;
+	}
+
+	for (i=0; i<32; i++) {
+		buffer[i] = mdiobus_read(phy->bus, phy->addr, i) & 0xffff;
+	}
+	ret = seq_write(seq, buffer, 32 * sizeof(*buffer));
+
+	kfree(buffer);
+	return ret;
+}
+
+static int phy_dump_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, phy_dump_show, inode->i_private);
+}
+
+static const struct file_operations phy_dump_debugfs_fops = {
+	.owner   = THIS_MODULE,
+	.open    = phy_dump_open,
+	.release = single_release,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+};
+
+
+void mdiobus_debugfs_add_phy(struct mii_bus *bus, struct phy_device *phydev)
+{
+	struct dentry *parent = debugfs_create_dir(dev_name(&phydev->dev), bus->debugfs_dir);
+	if (!parent)
+		return;
+
+	debugfs_create_file("regdump", S_IRUSR, parent,
+			(void *)phydev, &phy_dump_debugfs_fops);
+}
+
 /**
  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  * @bus: target mii_bus
@@ -159,6 +236,8 @@ int mdiobus_register(struct mii_bus *bus
 		return -EINVAL;
 	}
 
+	mdiobus_debugfs_add(bus);
+
 	mutex_init(&bus->mdio_lock);
 
 	if (bus->reset)
@@ -173,6 +252,8 @@ int mdiobus_register(struct mii_bus *bus
 				err = PTR_ERR(phydev);
 				goto error;
 			}
+			if (phydev)
+				mdiobus_debugfs_add_phy(bus, phydev);
 		}
 	}
 
@@ -185,6 +266,7 @@ error:
 		if (bus->phy_map[i])
 			device_unregister(&bus->phy_map[i]->dev);
 	}
+	mdiobus_debugfs_del(bus);
 	device_del(&bus->dev);
 	return err;
 }
@@ -476,11 +558,14 @@ int __init mdio_bus_init(void)
 {
 	int ret;
 
+	mdiobus_debugfs_init();
 	ret = class_register(&mdio_bus_class);
 	if (!ret) {
 		ret = bus_register(&mdio_bus_type);
-		if (ret)
+		if (ret) {
 			class_unregister(&mdio_bus_class);
+			mdiobus_debugfs_cleanup();
+		}
 	}
 
 	return ret;
@@ -488,6 +573,7 @@ int __init mdio_bus_init(void)
 
 void mdio_bus_exit(void)
 {
+	mdiobus_debugfs_cleanup();
 	class_unregister(&mdio_bus_class);
 	bus_unregister(&mdio_bus_type);
 }
Index: linux-3.10.49/include/linux/phy.h
===================================================================
--- linux-3.10.49.orig/include/linux/phy.h
+++ linux-3.10.49/include/linux/phy.h
@@ -128,6 +128,10 @@ struct mii_bus {
 	 * interrupt at the index matching its address
 	 */
 	int *irq;
+#ifdef CONFIG_DEBUG_FS
+	/* debugfs directory node */
+	struct dentry *debugfs_dir;
+#endif
 };
 #define to_mii_bus(d) container_of(d, struct mii_bus, dev)