/* * (C) Copyright 2002 ELTEC Elektronik AG * Frank Gottschling <fgottschling@eltec.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 */#include <common.h>#include "srom.h"/*----------------------------------------------------------------------------*//* *  START sequence *        _ _________ *  SCLK  _>         \____ *        _ ____ *  SDIO  _>    \_________ *         :    :    : */static void eepStart (void){    out8(I2C_BUS_DAT, 0x60);     /* SCLK = high  SDIO = high */    out8(I2C_BUS_DIR, 0x60);     /* set output direction for SCLK/SDIO */    udelay(10);    out8(I2C_BUS_DAT, 0x40);     /* SCLK = high  SDIO = low */    udelay(10);    out8(I2C_BUS_DAT, 0x00);     /* SCLK = low   SDIO = low */    udelay(10);}/*----------------------------------------------------------------------------*//* *  STOP sequence *              _______ *  SCLK  _____/ *        _         ___ *  SDIO  _>_______/ *         :   :   : */static void eepStop (void){    out8(I2C_BUS_DAT, 0x00);      /* SCLK = low   SDIO = low */    out8(I2C_BUS_DIR, 0x60);      /* set output direction for SCLK/SDIO */    udelay(10);    out8(I2C_BUS_DAT, 0x40);      /* SCLK = high  SDIO = low */    udelay(10);    out8(I2C_BUS_DAT, 0x60);      /* SCLK = high  SDIO = high */    udelay(10);    out8(I2C_BUS_DIR, 0x00);      /* reset to input direction */}/*----------------------------------------------------------------------------*//* *  Read one byte from EEPROM *            ___     ___     ___     ___     ___     ___     ___     ___ *  SCLK  ___/   \___/   \___/   \___/   \___/   \___/   \___/   \___/   \ *        _________________________________________________________________ *  SDIO  >     ^       ^       ^       ^       ^       ^       ^       ^ *        :  :   :   :   :   :   :   :   :   :   :   :   :   :   :   :   : */static unsigned char eepReadByte (void){    register unsigned char buf = 0x00;    register int i;    out8(I2C_BUS_DIR, 0x40);    for (i = 0; i < 8; i++)    {	out8(I2C_BUS_DAT, 0x00);    /* SCLK = low   SDIO = high */	udelay(10);	out8(I2C_BUS_DAT, 0x40);    /* SCLK = high  SDIO = high */	udelay(15);	buf <<= 1;	buf = (in8(I2C_BUS_DAT) & 0x20) ? (buf | 0x01) : (buf & 0xFE);	out8(I2C_BUS_DAT, 0x00);    /* SCLK = low   SDIO = high */	udelay(10);    }    return(buf);}/*----------------------------------------------------------------------------*//* *  Write one byte to EEPROM *           ___     ___     ___     ___     ___     ___     ___     ___ *  SCLK  __/   \___/   \___/   \___/   \___/   \___/   \___/   \___/   \__ *         _______ _______ _______ _______ _______ _______ _______ ________ *  SDIO  X_______X_______X_______X_______X_______X_______X_______X________ *      :   7   :   6   :   5   :   4   :   3   :   2   :   1   :   0 */static void eepWriteByte (register unsigned char buf){    register int    i;    (buf & 0x80) ? out8(I2C_BUS_DAT, 0x20) : out8(I2C_BUS_DAT, 0x00);     /* SCLK = low   SDIO = data */    out8(I2C_BUS_DIR, 0x60);    for (i = 7; i >= 0; i--)    {	(buf & 0x80) ? out8(I2C_BUS_DAT, 0x20) : out8(I2C_BUS_DAT, 0x00); /* SCLK=low  SDIO=data */	udelay(10);	(buf & 0x80) ? out8(I2C_BUS_DAT, 0x60) : out8(I2C_BUS_DAT, 0x40); /* SCLK=high SDIO=data */	udelay(15);	(buf & 0x80) ? out8(I2C_BUS_DAT, 0x20) : out8(I2C_BUS_DAT, 0x00); /* SCLK=low  SDIO=data */	udelay(10);	buf <<= 1;    }}/*----------------------------------------------------------------------------*//* *  Read data acknowledge of EEPROM *             _______ *  SCLK  ____/       \___ *         _______________ *  SDIO  > *        :   :   ^   : */static int eepReadAck (void){    int retval;    out8(I2C_BUS_DIR, 0x40);    out8(I2C_BUS_DAT, 0x00);            /* SCLK = low   SDIO = high */    udelay(10);    out8(I2C_BUS_DAT, 0x40);            /* SCLK = high  SDIO = high */    udelay(10);    retval = (in8(I2C_BUS_DAT) & 0x20) ? ERROR : 0;    udelay(10);    out8(I2C_BUS_DAT, 0x00);            /* SCLK = low   SDIO = high */    udelay(10);    return(retval);}/*----------------------------------------------------------------------------*//* *  Write data acknowledge to EEPROM *             _______ *  SCLK  ____/       \___ * *  SDIO  >_______________ *        :   :       : */static void eepWriteAck (unsigned char ack){    ack ? out8(I2C_BUS_DAT, 0x20) : out8(I2C_BUS_DAT, 0x00); /* SCLK = low   SDIO = ack */    out8(I2C_BUS_DIR, 0x60);    udelay(10);    ack ? out8(I2C_BUS_DAT, 0x60) : out8(I2C_BUS_DAT, 0x40); /* SCLK = high  SDIO = ack */    udelay(15);    ack ? out8(I2C_BUS_DAT, 0x20) : out8(I2C_BUS_DAT, 0x00); /* SCLK = low   SDIO = ack */    udelay(10);}/*----------------------------------------------------------------------------*//* * Read bytes from EEPROM */int el_srom_load (addr, buf, cnt, device, block)unsigned char addr;unsigned char *buf;int cnt;unsigned char device;unsigned char block;{    register int i;    for (i=0;i<cnt;i++)    {	eepStart();	eepWriteByte(0xA0 | device | block);	if (eepReadAck() == ERROR)	{	   eepStop();	    return(ERROR);	}	eepWriteByte(addr++);	if (eepReadAck() == ERROR)	{	    eepStop();	    return(ERROR);	}	eepStart();	eepWriteByte(0xA1 | device | block);	if (eepReadAck() == ERROR)	{	    eepStop();	    return(ERROR);	}	*buf++ = eepReadByte();	eepWriteAck(1);	eepStop();	if ((addr == 0) && (i != (cnt-1)))    /* is it the same block ? */	{	    if (block == FIRST_BLOCK)		block = SECOND_BLOCK;	    else		return(ERROR);	}    }    return(cnt);}/*----------------------------------------------------------------------------*//* * * Write bytes to EEPROM * */int el_srom_store (addr, buf, cnt, device, block)unsigned char    addr, *buf, device, block;int        cnt;{    register int i, retVal;    for (i=0;i<cnt;i++)    {	retVal = ERROR;	do	{	    eepStart();	    eepWriteByte(0xA0 | device | block);	    if ((retVal = eepReadAck()) == ERROR)		eepStop();	} while (retVal == ERROR);	eepWriteByte(addr++);	if (eepReadAck() == ERROR)  return(ERROR);	if ((addr == 0) && (i != (cnt-1)))    /* is it the same block ? */	{	    if (block == FIRST_BLOCK)		block = SECOND_BLOCK;	    else	    return(ERROR);	}	eepWriteByte(*buf++);	if (eepReadAck() == ERROR)	    return(ERROR);	eepStop();    }    return(cnt);}/*----------------------------------------------------------------------------*//* * calculate checksum for ELTEC revision srom */unsigned long el_srom_checksum (ptr, size)register unsigned char *ptr;unsigned long size;{    u_long f, accu = 0;    u_int  i;    u_char byte;    for (; size; size--)    {	byte = *ptr++;	for (i = 8; i; i--)	{	    f =  ((byte & 1) ^ (accu & 1)) ? 0x84083001 : 0;	    accu >>= 1; accu ^= f;	    byte >>= 1;	}    }    return(accu);}/*----------------------------------------------------------------------------*/