From a1b53b1b06be2e46f17d6330cc1721d0752042df Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Thu, 19 Apr 2018 17:59:38 +0100
Subject: [PATCH] lan78xx: Read MAC address from DT if present

commit 760db29bdc97b73ff60b091315ad787b1deb5cf5 upstream.

There is a standard mechanism for locating and using a MAC address from
the Device Tree. Use this facility in the lan78xx driver to support
applications without programmed EEPROM or OTP. At the same time,
regularise the handling of the different address sources.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/usb/lan78xx.c | 42 +++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 22 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 0cbcd3f77341c..6b4e38105b725 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -31,6 +31,7 @@
 #include <linux/mdio.h>
 #include <net/ip6_checksum.h>
 #include <linux/microchipphy.h>
+#include <linux/of_net.h>
 #include "lan78xx.h"
 
 #define DRIVER_AUTHOR	"WOOJUNG HUH <woojung.huh@microchip.com>"
@@ -1644,34 +1645,31 @@ static void lan78xx_init_mac_address(struct lan78xx_net *dev)
 	addr[5] = (addr_hi >> 8) & 0xFF;
 
 	if (!is_valid_ether_addr(addr)) {
-		/* reading mac address from EEPROM or OTP */
-		if ((lan78xx_read_eeprom(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
-					 addr) == 0) ||
-		    (lan78xx_read_otp(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
-				      addr) == 0)) {
-			if (is_valid_ether_addr(addr)) {
-				/* eeprom values are valid so use them */
-				netif_dbg(dev, ifup, dev->net,
-					  "MAC address read from EEPROM");
-			} else {
-				/* generate random MAC */
-				random_ether_addr(addr);
-				netif_dbg(dev, ifup, dev->net,
-					  "MAC address set to random addr");
-			}
-
-			addr_lo = addr[0] | (addr[1] << 8) |
-				  (addr[2] << 16) | (addr[3] << 24);
-			addr_hi = addr[4] | (addr[5] << 8);
-
-			ret = lan78xx_write_reg(dev, RX_ADDRL, addr_lo);
-			ret = lan78xx_write_reg(dev, RX_ADDRH, addr_hi);
+		if (!eth_platform_get_mac_address(&dev->udev->dev, addr)) {
+			/* valid address present in Device Tree */
+			netif_dbg(dev, ifup, dev->net,
+				  "MAC address read from Device Tree");
+		} else if (((lan78xx_read_eeprom(dev, EEPROM_MAC_OFFSET,
+						 ETH_ALEN, addr) == 0) ||
+			    (lan78xx_read_otp(dev, EEPROM_MAC_OFFSET,
+					      ETH_ALEN, addr) == 0)) &&
+			   is_valid_ether_addr(addr)) {
+			/* eeprom values are valid so use them */
+			netif_dbg(dev, ifup, dev->net,
+				  "MAC address read from EEPROM");
 		} else {
 			/* generate random MAC */
 			random_ether_addr(addr);
 			netif_dbg(dev, ifup, dev->net,
 				  "MAC address set to random addr");
 		}
+
+		addr_lo = addr[0] | (addr[1] << 8) |
+			  (addr[2] << 16) | (addr[3] << 24);
+		addr_hi = addr[4] | (addr[5] << 8);
+
+		ret = lan78xx_write_reg(dev, RX_ADDRL, addr_lo);
+		ret = lan78xx_write_reg(dev, RX_ADDRH, addr_hi);
 	}
 
 	ret = lan78xx_write_reg(dev, MAF_LO(0), addr_lo);