net/cadence/macb: add support for dt phy definition

The macb driver only handle PHY description through platform_data
(macb_platform_data).
Thus, when using dt you cannot define phy properties like phy address or
phy irq pin.

This patch makes use of the of_mdiobus_register to add support for
phy device definition using dt.
A fallback to the autoscan procedure is added in case there is no phy
devices defined in dt.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.c

@@ -27,6 +27,7 @@
 #include <linux/phy.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_mdio.h>
 #include <linux/of_net.h>
 #include <linux/pinctrl/consumer.h>
 
@@ -314,6 +315,7 @@ static int macb_mii_probe(struct net_device *dev)
 int macb_mii_init(struct macb *bp)
 {
 	struct macb_platform_data *pdata;
+	struct device_node *np;
 	int err = -ENXIO, i;
 
 	/* Enable management port */
@@ -335,21 +337,46 @@ int macb_mii_init(struct macb *bp)
 	bp->mii_bus->parent = &bp->dev->dev;
 	pdata = bp->pdev->dev.platform_data;
 
-	if (pdata)
-		bp->mii_bus->phy_mask = pdata->phy_mask;
-
 	bp->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
 	if (!bp->mii_bus->irq) {
 		err = -ENOMEM;
 		goto err_out_free_mdiobus;
 	}
 
+	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
+
+	np = bp->pdev->dev.of_node;
+	if (np) {
+		/* try dt phy registration */
+		err = of_mdiobus_register(bp->mii_bus, np);
+
+		/* fallback to standard phy registration if no phy were
+		   found during dt phy registration */
+		if (!err && !phy_find_first(bp->mii_bus)) {
+			for (i = 0; i < PHY_MAX_ADDR; i++) {
+				struct phy_device *phydev;
+
+				phydev = mdiobus_scan(bp->mii_bus, i);
+				if (IS_ERR(phydev)) {
+					err = PTR_ERR(phydev);
+					break;
+				}
+			}
+
+			if (err)
+				goto err_out_unregister_bus;
+		}
+	} else {
 		for (i = 0; i < PHY_MAX_ADDR; i++)
 			bp->mii_bus->irq[i] = PHY_POLL;
 
-	dev_set_drvdata(&bp->dev->dev, bp->mii_bus);
+		if (pdata)
+			bp->mii_bus->phy_mask = pdata->phy_mask;
 
-	if (mdiobus_register(bp->mii_bus))
+		err = mdiobus_register(bp->mii_bus);
+	}
+
+	if (err)
 		goto err_out_free_mdio_irq;
 
 	if (macb_mii_probe(bp->dev) != 0) {