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