ARM: DaVinci: Read MAC address from I2C EEPROM

Adds support for AT24 I2C EEPROM on DM646X
Signed-off-by: Chaithrika U.S <chaithrika@ti.com>

arch/arm/mach-davinci/board-dm646x-evm.c

@@ -40,6 +40,12 @@
 #include <mach/serial.h>
 #include <mach/i2c.h>
 
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/i2c/at24.h>
+#include <linux/etherdevice.h>
+#include <mach/emac.h>
+
 static struct davinci_uart_config davinci_evm_uart_config __initdata = {
 	.enabled_uarts = (1 << 0),
 };
@@ -48,6 +54,58 @@ static struct davinci_board_config_kernel davinci_evm_config[] __initdata = {
 	{ DAVINCI_TAG_UART,     &davinci_evm_uart_config },
 };
 
+/* Most of this EEPROM is unused, but U-Boot uses some data:
+ *  - 0x7f00, 6 bytes Ethernet Address
+ *  - ... newer boards may have more
+ */
+static struct at24_iface *at24_if;
+
+static int at24_setup(struct at24_iface *iface, void *context)
+{
+	DECLARE_MAC_BUF(mac_str);
+	char mac_addr[6];
+
+	at24_if = iface;
+
+	/* Read MAC addr from EEPROM */
+	if (at24_if->read(at24_if, mac_addr, 0x7f00, 6) == 6) {
+		printk(KERN_INFO "Read MAC addr from EEPROM: %s\n",
+		print_mac(mac_str, mac_addr));
+
+		davinci_init_emac(mac_addr);
+	}
+	return 0;
+}
+static struct at24_platform_data eeprom_info = {
+	.byte_len       = (256*1024) / 8,
+	.page_size      = 64,
+	.flags          = AT24_FLAG_ADDR16,
+	.setup          = at24_setup,
+};
+
+int dm646xevm_eeprom_read(void *buf, off_t off, size_t count)
+{
+	if (at24_if)
+		return at24_if->read(at24_if, buf, off, count);
+	return -ENODEV;
+}
+EXPORT_SYMBOL(dm646xevm_eeprom_read);
+
+int dm646xevm_eeprom_write(void *buf, off_t off, size_t count)
+{
+	if (at24_if)
+		return at24_if->write(at24_if, buf, off, count);
+	return -ENODEV;
+}
+EXPORT_SYMBOL(dm646xevm_eeprom_write);
+
+static struct i2c_board_info __initdata i2c_info[] =  {
+	{
+		I2C_BOARD_INFO("24c256", 0x50),
+		.platform_data  = &eeprom_info,
+	},
+};
+
 static struct davinci_i2c_platform_data i2c_pdata = {
 	.bus_freq       = 100 /* kHz */,
 	.bus_delay      = 0 /* usec */,
@@ -56,6 +114,7 @@ static struct davinci_i2c_platform_data i2c_pdata = {
 static void __init evm_init_i2c(void)
 {
 	davinci_init_i2c(&i2c_pdata);
+	i2c_register_board_info(1, i2c_info, ARRAY_SIZE(i2c_info));
 }
 
 #define UART_DM646X_SCR         (DAVINCI_UART0_BASE + 0x40)