text: /*
   * (C) Copyright 2000, 2001, 2002
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * (C) Copyright 2005
   * Martin Krause, TQ-Systems GmbH, martin.krause@tqs.de
   *
   * See file CREDITS for list of people who contributed to this
   * project.
   *
   * 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., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  /* #define DEBUG */
  
  #include <common.h>
  
  #define I2C_CHIP	0x50	/* I2C bus address of onboard EEPROM */
  #define I2C_ALEN	1	/* length of EEPROM addresses in bytes */
  #define I2C_OFFSET	0x0	/* start address of manufacturere data block
  				 * in EEPROM */
  
  /* 64 Byte manufacturer data block in EEPROM */
  struct manufacturer_data {
  	unsigned int	serial_number;	/* serial number (0...999999) */
  	unsigned short	hardware;	/* hardware version (e.g. V1.02) */
  	unsigned short	manuf_date;	/* manufacture date (e.g. 25/02) */
  	unsigned char	name[20];	/* device name (in CHIP.INI) */
  	unsigned char	macadr[6];	/* MAC address */
  	signed char	a_kal[4];	/* calibration value for U */
  	signed char	i_kal[4];	/* calibration value for I */
  	unsigned char	reserve[18];	/* reserved */
  	unsigned short	save_nr;	/* save count */
  	unsigned short	chksum;		/* checksum */
  };
  
  
  int i2c_read (unsigned char chip, unsigned int addr, int alen,
  	      unsigned char *buffer, int len);
  
  /*-----------------------------------------------------------------------
   * Process manufacturer data block in EEPROM:
   *
   * If we boot on a system fresh from factory, check if the manufacturer data
   * in the EEPROM is valid and save some information it contains.
   *
   * CMC manufacturer data is defined as follows:
   *
   * - located in the onboard EEPROM
   * - starts at offset 0x0
   * - size 0x00000040
   *
   * Internal structure: see struct definition
   */
  
  void load_sernum_ethaddr (void)
  {
  	struct manufacturer_data data;
  	char  ethaddr[18];
  	char  serial [9];
  	unsigned short chksum;
  	unsigned char *p;
  	unsigned short i, is, id;
  
  #if !defined(CONFIG_HARD_I2C) && !defined(CONFIG_SOFT_I2C)
  #error you must define some I2C support (CONFIG_HARD_I2C or CONFIG_SOFT_I2C)
  #endif
  	if (i2c_read(I2C_CHIP, I2C_OFFSET, I2C_ALEN, (unsigned char *)&data,
  		     sizeof(data)) != 0) {
  		puts ("Error reading manufacturer data from EEPROM\n");
  		return;
  	}
  
  	/* check if manufacturer data block is valid  */
  	p = (unsigned char *)&data;
  	chksum = 0;
  	for (i = 0; i < (sizeof(data) - sizeof(data.chksum)); i++)
  		chksum += *p++;
  
  	debug ("checksum of manufacturer data block: %#.4x\n", chksum);
  
  	if (chksum != data.chksum) {
  		puts ("Error: manufacturer data block has invalid checksum\n");
  		return;
  	}
  
  	/* copy MAC address */
  	is = 0;
  	id = 0;
  	for (i = 0; i < 6; i++) {
  		sprintf (&ethaddr[id], "%02x", data.macadr[is++]);
  		id += 2;
  		if (is < 6)
  			ethaddr[id++] = ':';
  	}
  	ethaddr[id] = '\0';	/* just to be sure */
  
  	/* copy serial number */
  	sprintf (serial, "%d", data.serial_number);
  
  	/* set serial# and ethaddr if not yet defined */
  	if (getenv("serial#") == NULL) {
  		setenv ("serial#", serial);
  	}
  
  	if (getenv("ethaddr") == NULL) {
  		setenv ("ethaddr", ethaddr);
  	}
  }
  