da850evm: read mac address from I2C EEPROM on AM18x EVM

add support to read mac address for AM18x EVM manufactured from
Spectrum digital which have mac address stored in I2C EEPROM manufactured
by WINBOND. This patch reads mac address from I2C EEPROM and sets the
environment variable if not set, If mac address is already present in
environment compare it with the mac address in EEPROM and warn on
mismatch.Introduced a config option CONFIG_MAC_ADDR_IN_EEPROM to where
to look for the mac address.

Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Cc: Tom Rini <trini@ti.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Wolfgang Denk <wd@denx.de>
diff --git a/board/davinci/da8xxevm/da850evm.c b/board/davinci/da8xxevm/da850evm.c
index beb5657..004d5ad 100644
--- a/board/davinci/da8xxevm/da850evm.c
+++ b/board/davinci/da8xxevm/da850evm.c
@@ -132,13 +132,17 @@
 {
 	dspwake();
 
-#ifdef CONFIG_MAC_ADDR_IN_SPIFLASH
+#if defined(CONFIG_MAC_ADDR_IN_SPIFLASH) || defined(CONFIG_MAC_ADDR_IN_EEPROM)
+
 	uchar env_enetaddr[6];
 	int enetaddr_found;
+
+	enetaddr_found = eth_getenv_enetaddr("ethaddr", env_enetaddr);
+
+#ifdef CONFIG_MAC_ADDR_IN_SPIFLASH
 	int spi_mac_read;
 	uchar buff[6];
 
-	enetaddr_found = eth_getenv_enetaddr("ethaddr", env_enetaddr);
 	spi_mac_read = get_mac_addr(buff);
 
 	/*
@@ -170,6 +174,33 @@
 			printf("Default using MAC address from environment\n");
 	}
 #endif
+	uint8_t enetaddr[8];
+	int eeprom_mac_read;
+
+	/* Read Ethernet MAC address from EEPROM */
+	eeprom_mac_read = dvevm_read_mac_address(enetaddr);
+
+	/*
+	 * MAC address not present in the environment
+	 * try and read the MAC address from EEPROM flash
+	 * and set it.
+	 */
+	if (!enetaddr_found) {
+		if (eeprom_mac_read)
+			/* Set Ethernet MAC address from EEPROM */
+			davinci_sync_env_enetaddr(enetaddr);
+	} else {
+		/*
+		 * MAC address present in environment compare it with
+		 * the MAC address in EEPROM and warn on mismatch
+		 */
+		if (eeprom_mac_read && memcmp(enetaddr, env_enetaddr, 6))
+			printf("Warning: MAC address in EEPROM don't match "
+					"with the MAC address in the environment\n");
+			printf("Default using MAC address from environment\n");
+	}
+
+#endif
 	return 0;
 }