u-boot/board/esd/cpci750/i2c.c
2004-12-16 21:44:03 +00:00

488 lines
10 KiB
C

/*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.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
*
* Hacked for the DB64360 board by Ingo.Assmus@keymile.com
* extra improvments by Brain Waite
* for cpci750 by reinhard.arlt@esd-electronics.com
*/
#include <common.h>
#include <mpc8xx.h>
#include <malloc.h>
#include "../../Marvell/include/mv_gen_reg.h"
#include "../../Marvell/include/core.h"
#define I2C_DELAY 100
#undef DEBUG_I2C
#ifdef DEBUG_I2C
#define DP(x) x
#else
#define DP(x)
#endif
/* Assuming that there is only one master on the bus (us) */
static void i2c_init (int speed, int slaveaddr)
{
unsigned int n, m, freq, margin, power;
unsigned int actualN = 0, actualM = 0;
unsigned int minMargin = 0xffffffff;
unsigned int tclk = CFG_TCLK;
unsigned int i2cFreq = speed; /* 100000 max. Fast mode not supported */
DP (puts ("i2c_init\n"));
/* gtI2cMasterInit */
for (n = 0; n < 8; n++) {
for (m = 0; m < 16; m++) {
power = 2 << n; /* power = 2^(n+1) */
freq = tclk / (10 * (m + 1) * power);
if (i2cFreq > freq)
margin = i2cFreq - freq;
else
margin = freq - i2cFreq;
if (margin < minMargin) {
minMargin = margin;
actualN = n;
actualM = m;
}
}
}
DP (puts ("setup i2c bus\n"));
/* Setup bus */
/* gtI2cReset */
GT_REG_WRITE (I2C_SOFT_RESET, 0);
asm(" sync");
GT_REG_WRITE (I2C_CONTROL, 0);
asm(" sync");
DP (puts ("set baudrate\n"));
GT_REG_WRITE (I2C_STATUS_BAUDE_RATE, (actualM << 3) | actualN);
asm(" sync");
DP (puts ("udelay...\n"));
udelay (I2C_DELAY);
GT_REG_WRITE (I2C_CONTROL, (0x1 << 2) | (0x1 << 6));
asm(" sync");
}
static uchar i2c_select_device (uchar dev_addr, uchar read, int ten_bit)
{
unsigned int status, data, bits = 7;
unsigned int control;
int count = 0;
DP (puts ("i2c_select_device\n"));
/* Output slave address */
if (ten_bit) {
bits = 10;
}
GT_REG_READ (I2C_CONTROL, &control);
control |= (0x1 << 2);
GT_REG_WRITE (I2C_CONTROL, control);
asm(" sync");
GT_REG_READ (I2C_CONTROL, &control);
control |= (0x1 << 5); /* generate the I2C_START_BIT */
GT_REG_WRITE (I2C_CONTROL, control);
asm(" sync");
RESET_REG_BITS (I2C_CONTROL, (0x01 << 3));
asm(" sync");
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
count = 0;
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
while (((status & 0xff) != 0x08) && ((status & 0xff) != 0x10)){
if (count > 200) {
#ifdef DEBUG_I2C
printf ("Failed to set startbit: 0x%02x\n", status);
#endif
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
asm(" sync");
return (status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
}
DP (puts ("i2c_select_device:write addr byte\n"));
/* assert the address */
data = (dev_addr << 1);
/* set the read bit */
data |= read;
GT_REG_WRITE (I2C_DATA, data);
asm(" sync");
RESET_REG_BITS (I2C_CONTROL, BIT3);
asm(" sync");
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count = 0;
while (((status & 0xff) != 0x40) && ((status & 0xff) != 0x18)) {
if (count > 200) {
#ifdef DEBUG_I2C
printf ("Failed to write address: 0x%02x\n", status);
#endif
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
return (status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
asm(" sync");
count++;
}
if (bits == 10) {
printf ("10 bit I2C addressing not yet implemented\n");
return (0xff);
}
return (0);
}
static uchar i2c_get_data (uchar * return_data, int len)
{
unsigned int data, status;
int count = 0;
DP (puts ("i2c_get_data\n"));
while (len) {
RESET_REG_BITS (I2C_CONTROL, BIT3);
asm(" sync");
/* Get and return the data */
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
while ((status & 0xff) != 0x50) {
if (count > 20) {
#ifdef DEBUG_I2C
printf ("Failed to get data len status: 0x%02x\n", status);
#endif
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
asm(" sync");
return 0;
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
}
GT_REG_READ (I2C_DATA, &data);
len--;
*return_data = (uchar) data;
return_data++;
}
RESET_REG_BITS (I2C_CONTROL, BIT2 | BIT3);
asm(" sync");
count = 0;
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
while ((status & 0xff) != 0x58) {
if (count > 2000) {
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
return (status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
}
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /* stop */
asm(" sync");
RESET_REG_BITS (I2C_CONTROL, (0x1 << 3));
asm(" sync");
return (0);
}
static uchar i2c_write_data (unsigned int *data, int len)
{
unsigned int status;
int count;
unsigned int temp;
unsigned int *temp_ptr = data;
DP (puts ("i2c_write_data\n"));
while (len) {
count = 0;
temp = (unsigned int) (*temp_ptr);
GT_REG_WRITE (I2C_DATA, temp);
asm(" sync");
RESET_REG_BITS (I2C_CONTROL, (0x1 << 3));
asm(" sync");
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
while ((status & 0xff) != 0x28) {
if (count > 200) {
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
asm(" sync");
return (status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
}
len--;
temp_ptr++;
}
return (0);
}
static uchar i2c_write_byte (unsigned char *data, int len)
{
unsigned int status;
int count;
unsigned int temp;
unsigned char *temp_ptr = data;
DP (puts ("i2c_write_byte\n"));
while (len) {
count = 0;
/* Set and assert the data */
temp = *temp_ptr;
GT_REG_WRITE (I2C_DATA, temp);
asm(" sync");
RESET_REG_BITS (I2C_CONTROL, (0x1 << 3));
asm(" sync");
GT_REG_READ (I2C_CONTROL, &status);
while ((status & 0x08) != 0x08) {
GT_REG_READ (I2C_CONTROL, &status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
while ((status & 0xff) != 0x28) {
if (count > 200) {
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4)); /*stop */
asm(" sync");
return (status);
}
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &status);
count++;
}
len--;
temp_ptr++;
}
return (0);
}
static uchar
i2c_set_dev_offset (uchar dev_addr, unsigned int offset, int ten_bit,
int alen)
{
uchar status;
unsigned int table[2];
table[1] = (offset ) & 0x0ff; /* low byte */
table[0] = (offset >> 8) & 0x0ff; /* high byte */
DP (puts ("i2c_set_dev_offset\n"));
status = i2c_select_device (dev_addr, 0, ten_bit);
if (status) {
#ifdef DEBUG_I2C
22 printf ("Failed to select device setting offset: 0x%02x\n",
status);
#endif
return status;
}
/* check the address offset length */
if (alen == 0)
/* no address offset */
return (0);
else if (alen == 1) {
/* 1 byte address offset */
status = i2c_write_data (&offset, 1);
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to write data: 0x%02x\n", status);
#endif
return status;
}
} else if (alen == 2) {
/* 2 bytes address offset */
status = i2c_write_data (table, 2);
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to write data: 0x%02x\n", status);
#endif
return status;
}
} else {
/* address offset unknown or not supported */
printf ("Address length offset %d is not supported\n", alen);
return 1;
}
return 0; /* sucessful completion */
}
uchar
i2c_read (uchar dev_addr, unsigned int offset, int alen, uchar * data,
int len)
{
uchar status = 0;
unsigned int i2cFreq = CFG_I2C_SPEED;
DP (puts ("i2c_read\n"));
i2c_init (i2cFreq, 0); /* set the i2c frequency */
status = i2c_set_dev_offset (dev_addr, offset, 0, alen); /* send the slave address + offset */
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to set slave address & offset: 0x%02x\n",
status);
#endif
return status;
}
status = i2c_select_device (dev_addr, 1, 0);
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to select device for data read: 0x%02x\n",
status);
#endif
return status;
}
status = i2c_get_data (data, len);
if (status) {
#ifdef DEBUG_I2C
printf ("Data not read: 0x%02x\n", status);
#endif
return status;
}
return 0;
}
void i2c_stop (void)
{
GT_REG_WRITE (I2C_CONTROL, (0x1 << 4));
asm(" sync");
}
uchar
i2c_write (uchar dev_addr, unsigned int offset, int alen, uchar * data,
int len)
{
uchar status = 0;
unsigned int i2cFreq = CFG_I2C_SPEED;
DP (puts ("i2c_write\n"));
i2c_init (i2cFreq, 0); /* set the i2c frequency */
status = i2c_set_dev_offset (dev_addr, offset, 0, alen); /* send the slave address + offset */
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to set slave address & offset: 0x%02x\n",
status);
#endif
return status;
}
status = i2c_write_byte (data, len); /* write the data */
if (status) {
#ifdef DEBUG_I2C
printf ("Data not written: 0x%02x\n", status);
#endif
return status;
}
/* issue a stop bit */
i2c_stop ();
return 0;
}
int i2c_probe (uchar chip)
{
#ifdef DEBUG_I2C
unsigned int i2c_status;
#endif
uchar status = 0;
unsigned int i2cFreq = CFG_I2C_SPEED;
DP (puts ("i2c_probe\n"));
i2c_init (i2cFreq, 0); /* set the i2c frequency */
status = i2c_set_dev_offset (chip, 0, 0, 0); /* send the slave address + no offset */
if (status) {
#ifdef DEBUG_I2C
printf ("Failed to set slave address: 0x%02x\n", status);
#endif
return (int) status;
}
#ifdef DEBUG_I2C
GT_REG_READ (I2C_STATUS_BAUDE_RATE, &i2c_status);
printf ("address %#x returned %#x\n", chip, i2c_status);
#endif
/* issue a stop bit */
i2c_stop ();
return 0; /* successful completion */
}