Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Phil Elwell <phil@raspberrypi.org>
To:     Woojung Huh <woojung.huh@microchip.com>,
        Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        "David S. Miller" <davem@davemloft.net>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Randy Dunlap <rdunlap@infradead.org>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org
Cc:     Phil Elwell <phil@raspberrypi.org>
Subject: [PATCH 1/4] lan78xx: Read MAC address from DT if present
Date:   Thu, 12 Apr 2018 14:55:33 +0100
Message-Id: <1523541336-145953-2-git-send-email-phil@raspberrypi.org>
In-Reply-To: <1523541336-145953-1-git-send-email-phil@raspberrypi.org>
References: <1523541336-145953-1-git-send-email-phil@raspberrypi.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>
---
 drivers/net/usb/lan78xx.c | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 55a78eb..d2727b5 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -37,6 +37,7 @@
 #include <linux/irqchip/chained_irq.h>
 #include <linux/microchipphy.h>
 #include <linux/phy.h>
+#include <linux/of_net.h>
 #include "lan78xx.h"
 
 #define DRIVER_AUTHOR	"WOOJUNG HUH <woojung.huh@microchip.com>"
@@ -1651,34 +1652,35 @@ 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");
-			}
+		const u8 *mac_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);
+		mac_addr = of_get_mac_address(dev->udev->dev.of_node);
+		if (mac_addr) {
+			/* valid address present in Device Tree */
+			ether_addr_copy(addr, mac_addr);
+			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);
-- 
2.7.4