mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-05 02:51:00 +00:00
315 lines
5.8 KiB
C
315 lines
5.8 KiB
C
#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 recieved: 0x%02x\n", status);
|
|
#endif
|
|
return status;
|
|
}
|
|
|
|
return 0;
|
|
}
|