/* *  i2c Support for Atmel's AT91RM9200 Two-Wire Interface * *  (c) Rick Bronson * *  Borrowed heavily from original work by: *  Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> * *  Modified to work with u-boot by (C) 2004 Gary Jennejohn garyj@denx.de * *  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., 675 Mass Ave, Cambridge, MA 02139, USA. **/#include <common.h>#ifdef CONFIG_HARD_I2C#include <i2c.h>#include <asm/io.h>#include <asm/arch/hardware.h>#include <at91rm9200_i2c.h>/* define DEBUG *//* * Poll the i2c status register until the specified bit is set. * Returns 0 if timed out (100 msec) */static short at91_poll_status(AT91PS_TWI twi, unsigned long bit) {	int loop_cntr = 10000;	do {		udelay(10);	} while (!(twi->TWI_SR & bit) && (--loop_cntr > 0));	return (loop_cntr > 0);}/* * Generic i2c master transfer entrypoint * * rw == 1 means that this is a read */static intat91_xfer(unsigned char chip, unsigned int addr, int alen,						unsigned char *buffer, int len, int rw){	AT91PS_TWI twi = (AT91PS_TWI) AT91_TWI_BASE;	int length;	unsigned char *buf;	/* Set the TWI Master Mode Register */	twi->TWI_MMR = (chip << 16) | (alen << 8)		| ((rw == 1) ? AT91C_TWI_MREAD : 0);	/* Set TWI Internal Address Register with first messages data field */	if (alen > 0)		twi->TWI_IADR = addr;	length = len;	buf = buffer;	if (length && buf) {	/* sanity check */		if (rw) {			twi->TWI_CR = AT91C_TWI_START;			while (length--) {				if (!length)					twi->TWI_CR = AT91C_TWI_STOP;				/* Wait until transfer is finished */				if (!at91_poll_status(twi, AT91C_TWI_RXRDY)) {					debug ("at91_i2c: timeout 1\n");					return 1;				}				*buf++ = twi->TWI_RHR;			}			if (!at91_poll_status(twi, AT91C_TWI_TXCOMP)) {				debug ("at91_i2c: timeout 2\n");				return 1;			}		} else {			twi->TWI_CR = AT91C_TWI_START;			while (length--) {				twi->TWI_THR = *buf++;				if (!length)					twi->TWI_CR = AT91C_TWI_STOP;				if (!at91_poll_status(twi, AT91C_TWI_TXRDY)) {					debug ("at91_i2c: timeout 3\n");					return 1;				}			}			/* Wait until transfer is finished */			if (!at91_poll_status(twi, AT91C_TWI_TXCOMP)) {				debug ("at91_i2c: timeout 4\n");				return 1;			}		}	}	return 0;}inti2c_probe(unsigned char chip){	char buffer[1];	return at91_xfer(chip, 0, 0, buffer, 1, 1);}inti2c_read (unsigned char chip, unsigned int addr, int alen,	  unsigned char *buffer, int len){#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW	/* we only allow one address byte */	if (alen > 1)		return 1;	/* XXX assume an ATMEL AT24C16 */	if (alen == 1) {#if 0 /* EEPROM code already sets this correctly */		chip |= (addr >> 8) & 0xff;#endif		addr = addr & 0xff;	}#endif	return at91_xfer(chip, addr, alen, buffer, len, 1);}inti2c_write(unsigned char chip, unsigned int addr, int alen,	  unsigned char *buffer, int len){#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW	int i;	unsigned char *buf;	/* we only allow one address byte */	if (alen > 1)		return 1;	/* XXX assume an ATMEL AT24C16 */	if (alen == 1) {		buf = buffer;		/* do single byte writes */		for (i = 0; i < len; i++) {#if 0 /* EEPROM code already sets this correctly */			chip |= (addr >> 8) & 0xff;#endif			addr = addr & 0xff;			if (at91_xfer(chip, addr, alen, buf++, 1, 0))				return 1;			addr++;		}		return 0;	}#endif	return at91_xfer(chip, addr, alen, buffer, len, 0);}/* * Main initialization routine */voidi2c_init(int speed, int slaveaddr){	AT91PS_TWI twi = (AT91PS_TWI) AT91_TWI_BASE;	*AT91C_PIOA_PDR = AT91C_PA25_TWD | AT91C_PA26_TWCK;	*AT91C_PIOA_ASR = AT91C_PA25_TWD | AT91C_PA26_TWCK;	*AT91C_PIOA_MDER = AT91C_PA25_TWD | AT91C_PA26_TWCK;	*AT91C_PMC_PCER = 1 << AT91C_ID_TWI;		/* enable peripheral clock */	twi->TWI_IDR = 0x3ff;				/* Disable all interrupts */	twi->TWI_CR = AT91C_TWI_SWRST;			/* Reset peripheral */	twi->TWI_CR = AT91C_TWI_MSEN | AT91C_TWI_SVDIS;	/* Set Master mode */	/* Here, CKDIV = 1 and CHDIV=CLDIV  ==> CLDIV = CHDIV = 1/4*((Fmclk/FTWI) -6) */	twi->TWI_CWGR = AT91C_TWI_CKDIV1 | AT91C_TWI_CLDIV3 | (AT91C_TWI_CLDIV3 << 8);	debug ("Found AT91 i2c\n");	return;}uchar i2c_reg_read(uchar i2c_addr, uchar reg){	char buf;	i2c_read(i2c_addr, reg, 1, &buf, 1);	return(buf);}void i2c_reg_write(uchar i2c_addr, uchar reg, uchar val){	i2c_write(i2c_addr, reg, 1, &val, 1);}#endif /* CONFIG_HARD_I2C */