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#include <common.h>
#include <mpc8xx.h>
#include <malloc.h>
#include <galileo/gt64260R.h>
#include <galileo/core.h>
#define MAX_I2C_RETRYS 10
#define I2C_DELAY 1000 /* Should be at least the # of MHz of Tclk */
#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 actualFreq, actualN = 0, actualM = 0;
unsigned int control, status;
unsigned int minMargin = 0xffffffff;
unsigned int tclk = 125000000;
DP(puts("i2c_init\n"));
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 (speed > freq)
margin = speed - freq;
else
margin = freq - speed;
if (margin < minMargin) {
minMargin = margin;
actualFreq = freq;
actualN = n;
actualM = m;
}
}
}
DP(puts("setup i2c bus\n"));
/* Setup bus */
GT_REG_WRITE(I2C_SOFT_RESET, 0);
DP(puts("udelay...\n"));
udelay(I2C_DELAY);
DP(puts("set baudrate\n"));
GT_REG_WRITE(I2C_STATUS_BAUDE_RATE, (actualM << 3) | actualN);
GT_REG_WRITE(I2C_CONTROL, (0x1 << 2) | (0x1 << 6));
udelay(I2C_DELAY * 10);
DP(puts("read control, baudrate\n"));
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
GT_REG_READ(I2C_CONTROL, &control);
}
static uchar
i2c_start(void)
{
unsigned int control, status;
int count = 0;
DP(puts("i2c_start\n"));
/* Set the start bit */
GT_REG_READ(I2C_CONTROL, &control);
control |= (0x1 << 5);
GT_REG_WRITE(I2C_CONTROL, control);
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count = 0;
while ((status & 0xff) != 0x08) {
udelay(I2C_DELAY);
if (count > 20) {
GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
return status;
}
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count++;
}
return 0;
}
static uchar
i2c_select_device(uchar dev_addr, uchar read, int ten_bit)
{
unsigned int status, data, bits = 7;
int count = 0;
DP(puts("i2c_select_device\n"));
/* Output slave address */
if (ten_bit)
bits = 10;
data = (dev_addr << 1);
/* set the read bit */
data |= read;
GT_REG_WRITE(I2C_DATA, data);
/* assert the address */
RESET_REG_BITS(I2C_CONTROL, BIT3);
udelay(I2C_DELAY);
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count = 0;
while (((status & 0xff) != 0x40) && ((status & 0xff) != 0x18)) {
udelay(I2C_DELAY);
if (count > 20) {
GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
return status;
}
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
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 = 0;
int count = 0;
DP(puts("i2c_get_data\n"));
while (len) {
/* Get and return the data */
RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
udelay(I2C_DELAY * 5);
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count++;
while ((status & 0xff) != 0x50) {
udelay(I2C_DELAY);
if (count > 2) {
GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
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);
while ((status & 0xff) != 0x58) {
udelay(I2C_DELAY);
if (count > 200) {
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 */
return 0;
}
static uchar
i2c_write_data(unsigned int data, int len)
{
unsigned int status;
int count = 0;
DP(puts("i2c_write_data\n"));
if (len > 4)
return -1;
while (len) {
/* Set and assert the data */
GT_REG_WRITE(I2C_DATA, (unsigned int)data);
RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
udelay(I2C_DELAY);
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count++;
while ((status & 0xff) != 0x28) {
udelay(I2C_DELAY);
if (count > 20) {
GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
return status;
}
GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
count++;
}
len--;
}
GT_REG_WRITE(I2C_CONTROL, (0x1 << 3) | (0x1 << 4));
GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
udelay(I2C_DELAY * 10);
return 0;
}
static uchar
i2c_set_dev_offset(uchar dev_addr, unsigned int offset, int ten_bit)
{
uchar status;
DP(puts("i2c_set_dev_offset\n"));
status = i2c_select_device(dev_addr, 0, ten_bit);
if (status) {
#ifdef DEBUG_I2C
printf("Failed to select device setting offset: 0x%02x\n",
status);
#endif
return status;
}
status = i2c_write_data(offset, 1);
if (status) {
#ifdef DEBUG_I2C
printf("Failed to write data: 0x%02x\n", status);
#endif
return status;
}
return 0;
}
uchar
i2c_read(uchar dev_addr, unsigned int offset, int len, uchar *data,
int ten_bit)
{
uchar status = 0;
unsigned int i2cFreq = 400000;
DP(puts("i2c_read\n"));
i2c_init(i2cFreq, 0);
status = i2c_start();
if (status) {
#ifdef DEBUG_I2C
printf("Transaction start failed: 0x%02x\n", status);
#endif
return status;
}
status = i2c_set_dev_offset(dev_addr, 0, 0);
if (status) {
#ifdef DEBUG_I2C
printf("Failed to set offset: 0x%02x\n", status);
#endif
return status;
}
i2c_init(i2cFreq, 0);
status = i2c_start();
if (status) {
#ifdef DEBUG_I2C
printf("Transaction restart failed: 0x%02x\n", status);
#endif
return status;
}
status = i2c_select_device(dev_addr, 1, ten_bit);
if (status) {
#ifdef DEBUG_I2C
printf("Address not acknowledged: 0x%02x\n", status);
#endif
return status;
}
status = i2c_get_data(data, len);
if (status) {
#ifdef DEBUG_I2C
printf("Data not received: 0x%02x\n", status);
#endif
return status;
}
return 0;
}
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