uchar
i2c_read (uchar dev_addr, unsigned int offset, int alen, uchar * data,
int len)
{
uchar status = 0;
unsigned int i2cFreq = CONFIG_SYS_I2C_SPEED;
DP (puts ("i2c_read\n"));
i2c_init (i2cFreq, 0); /* set the i2c frequency */
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, 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;
}
i2c_init (i2cFreq, 0); /* set the i2c frequency again */
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, 0); /* send the slave address */
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;
}
/*!
* \brief Write to an I<sup>2</sup>C device.
*
* The i2c_write() primitive writes data to a device at the given address
* on the given I<sup>2</sup>C Bus.
*
* \param [in,out] i2c Pointer to I<sup>2</sup>C Bus handle.
* \param addr I<sup>2</sup>C device's 7/10-bit address.
* \param buf Pointer to the buffer that will be written.
* \param len Number of bytes to write.
*
* \return
* On success, returns \h_ge 0 number of bytes written.\n
* Else errno is set appropriately and -1 is returned.
*/
int i2c_write(i2c_t *i2c, i2c_addr_t addr, const byte_t *buf, uint_t len)
{
int rc;
if( (rc = i2c_select_device(i2c , addr)) != -1 )
{
rc = (int)write(i2c->fd , buf, (size_t)len);
}
return rc;
}
static uchar
i2c_set_dev_offset (uchar dev_addr, unsigned int offset, int ten_bit,
int alen)
{
uchar status;
unsigned int table[2];
/* initialize the table of address offset bytes */
/* utilized for 2 byte address offsets */
/* NOTE: the order is high byte first! */
table[1] = offset & 0xff; /* low byte */
table[0] = offset / 0x100; /* high byte */
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;
}
/* 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 */
}
/* Send data from SVC to switch */
inline int i2c_switch_send_msg(uint8_t *buf, unsigned int size)
{
int ret;
dbg_verbose("%s()\n", __func__);
dbg_print_buf(DBG_VERBOSE, buf, size);
i2c_select_device(I2C_ADDR_SWITCH);
ret = I2C_WRITE(sw_exp_dev, buf, size);
if (ret) {
dbg_error("%s(): Error %d\n", __func__, ret);
return ERROR;
}
return 0;
}
/* Write data to the IO Expander */
int i2c_ioexp_write(uint8_t *msg, int size, uint8_t addr)
{
int ret;
i2c_select_device(addr);
ret = I2C_WRITE(sw_exp_dev, msg, size);
if (ret) {
dbg_error("%s(): Error %d\n", __func__, ret);
return ERROR;
}
dbg_verbose("%s()\n", __func__);
dbg_print_buf(DBG_VERBOSE, msg, size);
return ret;
}
/* Read data from the IO Expander */
int i2c_ioexp_read(uint8_t *msg, int size, uint8_t addr)
{
int ret;
dbg_verbose("%s()\n", __func__);
dbg_print_buf(DBG_VERBOSE, msg, size);
i2c_select_device(addr);
/* We need 2 messages (cf. datasheet) */
struct i2c_msg_s msgv[2] = {
/* Write the command byte, no restart */
{
.addr = addr,
.flags = 0,
.buffer = msg,
.length = 1
},
/* Read the bytes */
{
.addr = addr,
bool read_l3g4200d(int& fd,short& x, short& y, short& z) {
if(!i2c_select_device(fd,L3G4200D,"L3G4200D")) {
return false;
}
char buf[7];
buf[0] = 0x28; // This is the register we wish to read from
if(!i2c_write(fd,buf,2)) {
return false;
}
if (i2c_read(fd, buf, 6) != 6) { // Read back data into buf[]
printf("Unable to read from slave\n");
return false;
} else {
x = (buf[1]<<8) | buf[0];
y = (buf[3]<<8) | buf[2];
z = (buf[5]<<8) | buf[4];
}
return true;
}
