u-boot/board/cm_t35/eeprom.c

/*
 * (C) Copyright 2011 CompuLab, Ltd. <www.compulab.co.il>
 *
 * Authors: Nikita Kiryanov <nikita@compulab.co.il>
 *	    Igor Grinberg <grinberg@compulab.co.il>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc.
 */

#include <common.h>
#include <i2c.h>

#define EEPROM_LAYOUT_VER_OFFSET	44
#define BOARD_SERIAL_OFFSET		20
#define BOARD_SERIAL_OFFSET_LEGACY	8
#define BOARD_REV_OFFSET		0
#define BOARD_REV_OFFSET_LEGACY		6
#define BOARD_REV_SIZE			2
#define MAC_ADDR_OFFSET			4
#define MAC_ADDR_OFFSET_LEGACY		0

#define LAYOUT_INVALID	0
#define LAYOUT_LEGACY	0xff

static int eeprom_layout; /* Implicitly LAYOUT_INVALID */

static int cm_t3x_eeprom_read(uint offset, uchar *buf, int len)
{
	return i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
			CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
}

static int eeprom_setup_layout(void)
{
	int res;

	if (eeprom_layout != LAYOUT_INVALID)
		return 0;

	res = cm_t3x_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
						(uchar *)&eeprom_layout, 1);
	if (res) {
		eeprom_layout = LAYOUT_INVALID;
		return res;
	}

	if (eeprom_layout == 0 || eeprom_layout >= 0x20)
		eeprom_layout = LAYOUT_LEGACY;

	return 0;
}

void get_board_serial(struct tag_serialnr *serialnr)
{
	u32 serial[2];
	uint offset;

	memset(serialnr, 0, sizeof(*serialnr));
	if (eeprom_setup_layout())
		return;

	offset = (eeprom_layout != LAYOUT_LEGACY) ?
			BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
	if (cm_t3x_eeprom_read(offset, (uchar *)serial, 8))
		return;

	if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
		serialnr->low = serial[0];
		serialnr->high = serial[1];
	}
}

/*
 * Routine: cm_t3x_eeprom_read_mac_addr
 * Description: read mac address and store it in buf.
 */
int cm_t3x_eeprom_read_mac_addr(uchar *buf)
{
	uint offset;

	if (eeprom_setup_layout())
		return 0;

	offset = (eeprom_layout != LAYOUT_LEGACY) ?
			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
	return cm_t3x_eeprom_read(offset, buf, 6);
}

/*
 * Routine: cm_t3x_eeprom_get_board_rev
 * Description: read system revision from eeprom
 */
u32 cm_t3x_eeprom_get_board_rev(void)
{
	u32 rev = 0;
	char str[5]; /* Legacy representation can contain at most 4 digits */
	uint offset = BOARD_REV_OFFSET_LEGACY;

	if (eeprom_setup_layout())
		return 0;

	if (eeprom_layout != LAYOUT_LEGACY)
		offset = BOARD_REV_OFFSET;

	if (cm_t3x_eeprom_read(offset, (uchar *)&rev, BOARD_REV_SIZE))
		return 0;

	/*
	 * Convert legacy syntactic representation to semantic
	 * representation. i.e. for rev 1.00: 0x100 --> 0x64
	 */
	if (eeprom_layout == LAYOUT_LEGACY) {
		sprintf(str, "%x", rev);
		rev = simple_strtoul(str, NULL, 10);
	}

	return rev;
};