net: smsc95xx: fix DM MAC address reading

eth-uclass.c expects DM-capable Ethernet adapters to implement ops->
read_rom_hwaddr(), or for some other mechanism to set pdata->enetaddr, or
for the user to set environment variable $usbethaddr. Without any of
these, it will refuse to initialize the device since no valid MAC address
is known. Implement this function for the smsc95xx driver.

With this feature implemented, there is no point smsc95xx_init_common()
re-reading the MAC address from ROM, so ifdef out this code when DM_ETH
is enabled.

This allows (at least) the built-in Ethernet on the NVIDIA Harmony board
to operate again.

Fixes: 0990fcb772 ("net: smsc95xx: Add driver-model support")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/usb/eth/smsc95xx.c

@@ -519,9 +519,11 @@ static int smsc95xx_init_common(struct usb_device *udev, struct ueth_data *dev,
 		debug("timeout waiting for PHY Reset\n");
 		return -ETIMEDOUT;
 	}
+#ifndef CONFIG_DM_ETH
 	if (!priv->have_hwaddr && smsc95xx_init_mac_address(enetaddr, udev) ==
 			0)
 		priv->have_hwaddr = 1;
+#endif
 	if (!priv->have_hwaddr) {
 		puts("Error: SMSC95xx: No MAC address set - set usbethaddr\n");
 		return -EADDRNOTAVAIL;
@@ -1022,6 +1024,19 @@ int smsc95xx_write_hwaddr(struct udevice *dev)
 	return smsc95xx_write_hwaddr_common(udev, priv, pdata->enetaddr);
 }
 
+int smsc95xx_read_rom_hwaddr(struct udevice *dev)
+{
+	struct usb_device *udev = dev_get_parent_priv(dev);
+	struct eth_pdata *pdata = dev_get_platdata(dev);
+	int ret;
+
+	ret = smsc95xx_init_mac_address(pdata->enetaddr, udev);
+	if (ret)
+		memset(pdata->enetaddr, 0, 6);
+
+	return 0;
+}
+
 static int smsc95xx_eth_probe(struct udevice *dev)
 {
 	struct smsc95xx_private *priv = dev_get_priv(dev);
@@ -1037,6 +1052,7 @@ static const struct eth_ops smsc95xx_eth_ops = {
 	.free_pkt = smsc95xx_free_pkt,
 	.stop	= smsc95xx_eth_stop,
 	.write_hwaddr = smsc95xx_write_hwaddr,
+	.read_rom_hwaddr = smsc95xx_read_rom_hwaddr,
 };
 
 U_BOOT_DRIVER(smsc95xx_eth) = {