da850evm: add support to read mac address from SPI flash

add support to read mac address for da850/L138 evm manufactured by
Logic PD which store mac address in SPI flash manufactured by ST
Microelectronics. This patch adds support to read mac address from
SPI flash and set the mac address if it hasn't been set in environment,
If it has been set in the environment it compares the value one with
SPI flash and warns on mismatch. Introduced a config option
CONFIG_MAC_ADDR_IN_SPIFLASH indicating where to look mac address for.

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 34ef53d..beb5657 100644
--- a/board/davinci/da8xxevm/da850evm.c
+++ b/board/davinci/da8xxevm/da850evm.c
@@ -25,12 +25,15 @@
 #include <i2c.h>
 #include <net.h>
 #include <netdev.h>
+#include <spi.h>
+#include <spi_flash.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/emif_defs.h>
 #include <asm/arch/emac_defs.h>
 #include <asm/arch/pinmux_defs.h>
 #include <asm/io.h>
 #include <asm/arch/davinci_misc.h>
+#include <asm/errno.h>
 #include <hwconfig.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -43,6 +46,36 @@
 #endif
 #endif /* CONFIG_DRIVER_TI_EMAC */
 
+#define CFG_MAC_ADDR_SPI_BUS	0
+#define CFG_MAC_ADDR_SPI_CS	0
+#define CFG_MAC_ADDR_SPI_MAX_HZ	CONFIG_SF_DEFAULT_SPEED
+#define CFG_MAC_ADDR_SPI_MODE	SPI_MODE_3
+
+#define CFG_MAC_ADDR_OFFSET	(flash->size - SZ_64K)
+
+#ifdef CONFIG_MAC_ADDR_IN_SPIFLASH
+static int get_mac_addr(u8 *addr)
+{
+	struct spi_flash *flash;
+	int ret;
+
+	flash = spi_flash_probe(CFG_MAC_ADDR_SPI_BUS, CFG_MAC_ADDR_SPI_CS,
+			CFG_MAC_ADDR_SPI_MAX_HZ, CFG_MAC_ADDR_SPI_MODE);
+	if (!flash) {
+		printf("Error - unable to probe SPI flash.\n");
+		return -1;
+	}
+
+	ret = spi_flash_read(flash, CFG_MAC_ADDR_OFFSET, 6, addr);
+	if (ret) {
+		printf("Error - unable to read MAC address from SPI flash.\n");
+		return -1;
+	}
+
+	return ret;
+}
+#endif
+
 void dsp_lpsc_on(unsigned domain, unsigned int id)
 {
 	dv_reg_p mdstat, mdctl, ptstat, ptcmd;
@@ -98,6 +131,45 @@
 int misc_init_r(void)
 {
 	dspwake();
+
+#ifdef CONFIG_MAC_ADDR_IN_SPIFLASH
+	uchar env_enetaddr[6];
+	int enetaddr_found;
+	int spi_mac_read;
+	uchar buff[6];
+
+	enetaddr_found = eth_getenv_enetaddr("ethaddr", env_enetaddr);
+	spi_mac_read = get_mac_addr(buff);
+
+	/*
+	 * MAC address not present in the environment
+	 * try and read the MAC address from SPI flash
+	 * and set it.
+	 */
+	if (!enetaddr_found) {
+		if (!spi_mac_read) {
+			if (is_valid_ether_addr(buff)) {
+				if (eth_setenv_enetaddr("ethaddr", buff)) {
+					printf("Warning: Failed to "
+					"set MAC address from SPI flash\n");
+				}
+			} else {
+					printf("Warning: Invalid "
+					"MAC address read from SPI flash\n");
+			}
+		}
+	} else {
+		/*
+		 * MAC address present in environment compare it with
+		 * the MAC address in SPI flash and warn on mismatch
+		 */
+		if (!spi_mac_read && is_valid_ether_addr(buff) &&
+						memcmp(env_enetaddr, buff, 6))
+			printf("Warning: MAC address in SPI flash don't match "
+					"with the MAC address in the environment\n");
+			printf("Default using MAC address from environment\n");
+	}
+#endif
 	return 0;
 }