net: ks8851: Support DT-provided MAC address

Allow the boot loader to specify the MAC address in the device tree
to override the EEPROM, or in case no EEPROM is present.

Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Tristram Ha <tristram.ha@micrel.com>
Cc: David J. Choi <david.choi@micrel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/micrel/ks8851.c

@@ -28,6 +28,7 @@
 #include <linux/spi/spi.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
+#include <linux/of_net.h>
 
 #include "ks8851.h"
 
@@ -407,15 +408,23 @@ static void ks8851_read_mac_addr(struct net_device *dev)
  * @ks: The device structure
  *
  * Get or create the initial mac address for the device and then set that
- * into the station address register. If there is an EEPROM present, then
+ * into the station address register. A mac address supplied in the device
+ * tree takes precedence. Otherwise, if there is an EEPROM present, then
  * we try that. If no valid mac address is found we use eth_random_addr()
  * to create a new one.
  */
 static void ks8851_init_mac(struct ks8851_net *ks)
 {
 	struct net_device *dev = ks->netdev;
+	const u8 *mac_addr;
+
+	mac_addr = of_get_mac_address(ks->spidev->dev.of_node);
+	if (mac_addr) {
+		memcpy(dev->dev_addr, mac_addr, ETH_ALEN);
+		ks8851_write_mac_addr(dev);
+		return;
+	}
 
-	/* first, try reading what we've got already */
 	if (ks->rc_ccr & CCR_EEPROM) {
 		ks8851_read_mac_addr(dev);
 		if (is_valid_ether_addr(dev->dev_addr))