net: bcmgenet: Fetch MAC address from the adapter

ARM/ACPI machines should utilize self describing hardware
when possible. The MAC address on the BCMGENET can be
read from the adapter if a full featured firmware has already
programmed it. Lets try using the address already programmed,
if it appears to be valid.

It should be noted that while we move the macaddr logic below
the clock and power logic in the driver, none of that code will
ever be active in an ACPI environment as the device will be
attached to the acpi power domain, and brought to full power
with all clocks enabled immediately before the device probe
routine is called.

One side effect of the above tweak is that while its now
possible to read the MAC address via _DSD properties, it should
be avoided.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -2772,6 +2772,21 @@ static void bcmgenet_set_hw_addr(struct bcmgenet_priv *priv,
 	bcmgenet_umac_writel(priv, (addr[4] << 8) | addr[5], UMAC_MAC1);
 }
 
+static void bcmgenet_get_hw_addr(struct bcmgenet_priv *priv,
+				 unsigned char *addr)
+{
+	u32 addr_tmp;
+
+	addr_tmp = bcmgenet_umac_readl(priv, UMAC_MAC0);
+	addr[0] = addr_tmp >> 24;
+	addr[1] = (addr_tmp >> 16) & 0xff;
+	addr[2] = (addr_tmp >>	8) & 0xff;
+	addr[3] = addr_tmp & 0xff;
+	addr_tmp = bcmgenet_umac_readl(priv, UMAC_MAC1);
+	addr[4] = (addr_tmp >> 8) & 0xff;
+	addr[5] = addr_tmp & 0xff;
+}
+
 /* Returns a reusable dma control register value */
 static u32 bcmgenet_dma_disable(struct bcmgenet_priv *priv)
 {
@@ -3467,7 +3482,6 @@ static int bcmgenet_probe(struct platform_device *pdev)
 	const struct bcmgenet_plat_data *pdata;
 	struct bcmgenet_priv *priv;
 	struct net_device *dev;
-	const void *macaddr = NULL;
 	unsigned int i;
 	int err = -EIO;
 
@@ -3498,11 +3512,6 @@ static int bcmgenet_probe(struct platform_device *pdev)
 	}
 	priv->wol_irq = platform_get_irq_optional(pdev, 2);
 
-	if (dn)
-		macaddr = of_get_mac_address(dn);
-	else if (pd)
-		macaddr = pd->mac_address;
-
 	priv->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->base)) {
 		err = PTR_ERR(priv->base);
@@ -3513,12 +3522,6 @@ static int bcmgenet_probe(struct platform_device *pdev)
 
 	SET_NETDEV_DEV(dev, &pdev->dev);
 	dev_set_drvdata(&pdev->dev, dev);
-	if (IS_ERR_OR_NULL(macaddr) || !is_valid_ether_addr(macaddr)) {
-		dev_warn(&pdev->dev, "using random Ethernet MAC\n");
-		eth_hw_addr_random(dev);
-	} else {
-		ether_addr_copy(dev->dev_addr, macaddr);
-	}
 	dev->watchdog_timeo = 2 * HZ;
 	dev->ethtool_ops = &bcmgenet_ethtool_ops;
 	dev->netdev_ops = &bcmgenet_netdev_ops;
@@ -3599,6 +3602,18 @@ static int bcmgenet_probe(struct platform_device *pdev)
 	if (device_get_phy_mode(&pdev->dev) == PHY_INTERFACE_MODE_INTERNAL)
 		bcmgenet_power_up(priv, GENET_POWER_PASSIVE);
 
+	if ((pd) && (!IS_ERR_OR_NULL(pd->mac_address)))
+		ether_addr_copy(dev->dev_addr, pd->mac_address);
+	else
+		if (!device_get_mac_address(&pdev->dev, dev->dev_addr, ETH_ALEN))
+			if (has_acpi_companion(&pdev->dev))
+				bcmgenet_get_hw_addr(priv, dev->dev_addr);
+
+	if (!is_valid_ether_addr(dev->dev_addr)) {
+		dev_warn(&pdev->dev, "using random Ethernet MAC\n");
+		eth_hw_addr_random(dev);
+	}
+
 	reset_umac(priv);
 
 	err = bcmgenet_mii_init(dev);