net: e1000: implement eth_write_hwaddr

Implement programming MAC address to the hardware, i.e. external flash
seen as EEPROM.

MAC address is only written if it differs from what is already stored in
flash or if reading the current MAC address fails.

Signed-off-by: Hannu Lounento <hannu.lounento@ge.com>
CC: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/net/e1000.c

@@ -5649,6 +5649,45 @@ e1000_poll(struct eth_device *nic)
 	return len ? 1 : 0;
 }
 
+static int e1000_write_hwaddr(struct eth_device *dev)
+{
+#ifndef CONFIG_E1000_NO_NVM
+	unsigned char *mac = dev->enetaddr;
+	unsigned char current_mac[6];
+	struct e1000_hw *hw = dev->priv;
+	uint16_t data[3];
+	int ret_val, i;
+
+	DEBUGOUT("%s: mac=%pM\n", __func__, mac);
+
+	memset(current_mac, 0, 6);
+
+	/* Read from EEPROM, not from registers, to make sure
+	 * the address is persistently configured
+	 */
+	ret_val = e1000_read_mac_addr_from_eeprom(hw, current_mac);
+	DEBUGOUT("%s: current mac=%pM\n", __func__, current_mac);
+
+	/* Only write to EEPROM if the given address is different or
+	 * reading the current address failed
+	 */
+	if (!ret_val && memcmp(current_mac, mac, 6) == 0)
+		return 0;
+
+	for (i = 0; i < 3; ++i)
+		data[i] = mac[i * 2 + 1] << 8 | mac[i * 2];
+
+	ret_val = e1000_write_eeprom_srwr(hw, 0x0, 3, data);
+
+	if (!ret_val)
+		ret_val = e1000_update_eeprom_checksum_i210(hw);
+
+	return ret_val;
+#else
+	return 0;
+#endif
+}
+
 /**************************************************************************
 PROBE - Look for an adapter, this routine's visible to the outside
 You should omit the last argument struct pci_device * for a non-PCI NIC
@@ -5698,6 +5737,7 @@ e1000_initialize(bd_t * bis)
 		nic->recv = e1000_poll;
 		nic->send = e1000_transmit;
 		nic->halt = e1000_disable;
+		nic->write_hwaddr = e1000_write_hwaddr;
 		eth_register(nic);
 	}