diff options
Diffstat (limited to 'board/eltec/bab7xx/el_srom.c')
-rw-r--r-- | board/eltec/bab7xx/el_srom.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/board/eltec/bab7xx/el_srom.c b/board/eltec/bab7xx/el_srom.c new file mode 100644 index 0000000000..56abdc7c26 --- /dev/null +++ b/board/eltec/bab7xx/el_srom.c @@ -0,0 +1,292 @@ +/* + * (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); +} + +/*----------------------------------------------------------------------------*/ |