net: fec_mpc52xx: Read MAC address from device-tree

Until now, the MPC5200 FEC ethernet driver relied upon the bootloader
(U-Boot) to write the MAC address into the ethernet controller
registers. The Linux driver should not rely on such a thing. So
lets read the MAC address from the DT as it should be done here.

The following priority is now used to read the MAC address:

1) First, try OF node MAC address, if not present or invalid, then:

2) Read from MAC address registers, if invalid, then:

3) Log a warning message, and choose a random MAC address.

This fixes a problem with a MPC5200 board that uses the SPL U-Boot
version without FEC initialization before Linux booting for
boot speedup.

Additionally a status line is now be printed upon successful
driver probing, also displaying this MAC address.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_mpc52xx.c

@@ -29,6 +29,7 @@
 #include <linux/delay.h>
 #include <linux/of_device.h>
 #include <linux/of_mdio.h>
+#include <linux/of_net.h>
 #include <linux/of_platform.h>
 
 #include <linux/netdevice.h>
@@ -76,10 +77,6 @@ static void mpc52xx_fec_stop(struct net_device *dev);
 static void mpc52xx_fec_start(struct net_device *dev);
 static void mpc52xx_fec_reset(struct net_device *dev);
 
-static u8 mpc52xx_fec_mac_addr[6];
-module_param_array_named(mac, mpc52xx_fec_mac_addr, byte, NULL, 0);
-MODULE_PARM_DESC(mac, "six hex digits, ie. 0x1,0x2,0xc0,0x01,0xba,0xbe");
-
 #define MPC52xx_MESSAGES_DEFAULT ( NETIF_MSG_DRV | NETIF_MSG_PROBE | \
 		NETIF_MSG_LINK | NETIF_MSG_IFDOWN | NETIF_MSG_IFUP)
 static int debug = -1;	/* the above default */
@@ -110,15 +107,6 @@ static void mpc52xx_fec_set_paddr(struct net_device *dev, u8 *mac)
 	out_be32(&fec->paddr2, (*(u16 *)(&mac[4]) << 16) | FEC_PADDR2_TYPE);
 }
 
-static void mpc52xx_fec_get_paddr(struct net_device *dev, u8 *mac)
-{
-	struct mpc52xx_fec_priv *priv = netdev_priv(dev);
-	struct mpc52xx_fec __iomem *fec = priv->fec;
-
-	*(u32 *)(&mac[0]) = in_be32(&fec->paddr1);
-	*(u16 *)(&mac[4]) = in_be32(&fec->paddr2) >> 16;
-}
-
 static int mpc52xx_fec_set_mac_address(struct net_device *dev, void *addr)
 {
 	struct sockaddr *sock = addr;
@@ -853,6 +841,8 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 	struct resource mem;
 	const u32 *prop;
 	int prop_size;
+	struct device_node *np = op->dev.of_node;
+	const char *mac_addr;
 
 	phys_addr_t rx_fifo;
 	phys_addr_t tx_fifo;
@@ -866,7 +856,7 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 	priv->ndev = ndev;
 
 	/* Reserve FEC control zone */
-	rv = of_address_to_resource(op->dev.of_node, 0, &mem);
+	rv = of_address_to_resource(np, 0, &mem);
 	if (rv) {
 		printk(KERN_ERR DRIVER_NAME ": "
 				"Error while parsing device node resource\n" );
@@ -919,7 +909,7 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 
 	/* Get the IRQ we need one by one */
 		/* Control */
-	ndev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
+	ndev->irq = irq_of_parse_and_map(np, 0);
 
 		/* RX */
 	priv->r_irq = bcom_get_task_irq(priv->rx_dmatsk);
@@ -927,11 +917,33 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 		/* TX */
 	priv->t_irq = bcom_get_task_irq(priv->tx_dmatsk);
 
-	/* MAC address init */
-	if (!is_zero_ether_addr(mpc52xx_fec_mac_addr))
-		memcpy(ndev->dev_addr, mpc52xx_fec_mac_addr, 6);
-	else
-		mpc52xx_fec_get_paddr(ndev, ndev->dev_addr);
+	/*
+	 * MAC address init:
+	 *
+	 * First try to read MAC address from DT
+	 */
+	mac_addr = of_get_mac_address(np);
+	if (mac_addr) {
+		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
+	} else {
+		struct mpc52xx_fec __iomem *fec = priv->fec;
+
+		/*
+		 * If the MAC addresse is not provided via DT then read
+		 * it back from the controller regs
+		 */
+		*(u32 *)(&ndev->dev_addr[0]) = in_be32(&fec->paddr1);
+		*(u16 *)(&ndev->dev_addr[4]) = in_be32(&fec->paddr2) >> 16;
+	}
+
+	/*
+	 * Check if the MAC address is valid, if not get a random one
+	 */
+	if (!is_valid_ether_addr(ndev->dev_addr)) {
+		eth_hw_addr_random(ndev);
+		dev_warn(&ndev->dev, "using random MAC address %pM\n",
+			 ndev->dev_addr);
+	}
 
 	priv->msg_enable = netif_msg_init(debug, MPC52xx_MESSAGES_DEFAULT);
 
@@ -942,20 +954,20 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 	/* Start with safe defaults for link connection */
 	priv->speed = 100;
 	priv->duplex = DUPLEX_HALF;
-	priv->mdio_speed = ((mpc5xxx_get_bus_frequency(op->dev.of_node) >> 20) / 5) << 1;
+	priv->mdio_speed = ((mpc5xxx_get_bus_frequency(np) >> 20) / 5) << 1;
 
 	/* The current speed preconfigures the speed of the MII link */
-	prop = of_get_property(op->dev.of_node, "current-speed", &prop_size);
+	prop = of_get_property(np, "current-speed", &prop_size);
 	if (prop && (prop_size >= sizeof(u32) * 2)) {
 		priv->speed = prop[0];
 		priv->duplex = prop[1] ? DUPLEX_FULL : DUPLEX_HALF;
 	}
 
 	/* If there is a phy handle, then get the PHY node */
-	priv->phy_node = of_parse_phandle(op->dev.of_node, "phy-handle", 0);
+	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);
 
 	/* the 7-wire property means don't use MII mode */
-	if (of_find_property(op->dev.of_node, "fsl,7-wire-mode", NULL)) {
+	if (of_find_property(np, "fsl,7-wire-mode", NULL)) {
 		priv->seven_wire_mode = 1;
 		dev_info(&ndev->dev, "using 7-wire PHY mode\n");
 	}
@@ -970,6 +982,8 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 
 	/* We're done ! */
 	dev_set_drvdata(&op->dev, ndev);
+	printk(KERN_INFO "%s: %s MAC %pM\n",
+	       ndev->name, op->dev.of_node->full_name, ndev->dev_addr);
 
 	return 0;