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/*
* (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);
}
/*----------------------------------------------------------------------------*/
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