net: macb: Add remove callback

To avoid the failure of mdio_register(), add the remove callback
to unregister the mii_dev when removing the ethernet device.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Fixed up unused variable warning, e.g. for gurnard:
Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/net/macb.c

@@ -111,6 +111,9 @@ struct macb_device {
 #endif
 	unsigned short		phy_addr;
 	struct mii_dev		*bus;
+#ifdef CONFIG_PHYLIB
+	struct phy_device	*phydev;
+#endif
 
 #ifdef CONFIG_DM_ETH
 #ifdef CONFIG_CLK
@@ -478,9 +481,6 @@ static int macb_phy_init(struct macb_device *macb, const char *name)
 {
 #ifdef CONFIG_DM_ETH
 	struct macb_device *macb = dev_get_priv(dev);
-#endif
-#ifdef CONFIG_PHYLIB
-	struct phy_device *phydev;
 #endif
 	u32 ncfgr;
 	u16 phy_id, status, adv, lpa;
@@ -503,19 +503,19 @@ static int macb_phy_init(struct macb_device *macb, const char *name)
 
 #ifdef CONFIG_PHYLIB
 #ifdef CONFIG_DM_ETH
-	phydev = phy_connect(macb->bus, macb->phy_addr, dev,
+	macb->phydev = phy_connect(macb->bus, macb->phy_addr, dev,
 			     macb->phy_interface);
 #else
 	/* need to consider other phy interface mode */
-	phydev = phy_connect(macb->bus, macb->phy_addr, &macb->netdev,
+	macb->phydev = phy_connect(macb->bus, macb->phy_addr, &macb->netdev,
 			     PHY_INTERFACE_MODE_RGMII);
 #endif
-	if (!phydev) {
+	if (!macb->phydev) {
 		printf("phy_connect failed\n");
 		return -ENODEV;
 	}
 
-	phy_config(phydev);
+	phy_config(macb->phydev);
 #endif
 
 	status = macb_mdio_read(macb, MII_BMSR);
@@ -1035,6 +1035,7 @@ static int macb_eth_probe(struct udevice *dev)
 	struct eth_pdata *pdata = dev_get_platdata(dev);
 	struct macb_device *macb = dev_get_priv(dev);
 	const char *phy_mode;
+	__maybe_unused int ret;
 
 	phy_mode = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "phy-mode",
 			       NULL);
@@ -1048,7 +1049,7 @@ static int macb_eth_probe(struct udevice *dev)
 	macb->regs = (void *)pdata->iobase;
 
 #ifdef CONFIG_CLK
-	int ret = macb_enable_clk(dev);
+	ret = macb_enable_clk(dev);
 	if (ret)
 		return ret;
 #endif
@@ -1056,23 +1057,35 @@ static int macb_eth_probe(struct udevice *dev)
 	_macb_eth_initialize(macb);
 
 #if defined(CONFIG_CMD_MII) || defined(CONFIG_PHYLIB)
-	int retval;
-	struct mii_dev *mdiodev = mdio_alloc();
-	if (!mdiodev)
+	macb->bus = mdio_alloc();
+	if (!macb->bus)
 		return -ENOMEM;
-	strncpy(mdiodev->name, dev->name, MDIO_NAME_LEN);
-	mdiodev->read = macb_miiphy_read;
-	mdiodev->write = macb_miiphy_write;
+	strncpy(macb->bus->name, dev->name, MDIO_NAME_LEN);
+	macb->bus->read = macb_miiphy_read;
+	macb->bus->write = macb_miiphy_write;
 
-	retval = mdio_register(mdiodev);
-	if (retval < 0)
-		return retval;
+	ret = mdio_register(macb->bus);
+	if (ret < 0)
+		return ret;
 	macb->bus = miiphy_get_dev_by_name(dev->name);
 #endif
 
 	return 0;
 }
 
+static int macb_eth_remove(struct udevice *dev)
+{
+	struct macb_device *macb = dev_get_priv(dev);
+
+#ifdef CONFIG_PHYLIB
+	free(macb->phydev);
+#endif
+	mdio_unregister(macb->bus);
+	mdio_free(macb->bus);
+
+	return 0;
+}
+
 static int macb_eth_ofdata_to_platdata(struct udevice *dev)
 {
 	struct eth_pdata *pdata = dev_get_platdata(dev);
@@ -1092,6 +1105,7 @@ U_BOOT_DRIVER(eth_macb) = {
 	.of_match = macb_eth_ids,
 	.ofdata_to_platdata = macb_eth_ofdata_to_platdata,
 	.probe	= macb_eth_probe,
+	.remove	= macb_eth_remove,
 	.ops	= &macb_eth_ops,
 	.priv_auto_alloc_size = sizeof(struct macb_device),
 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),