/*
* This function reads the slave device's register
*
* Parameters:
* deviceAddress - i2c Slave device address which register
* to be read from
* registerIndex - Slave device's register to be read
*
* Return Value:
* Register value
*/
unsigned char hwI2CReadReg(
unsigned char deviceAddress,
unsigned char registerIndex
)
{
unsigned char value = (0xFF);
if (hwI2CWriteData(deviceAddress, 1, ®isterIndex) == 1)
hwI2CReadData(deviceAddress, 1, &value);
return value;
}
/*
* This function writes a value to the i2c device register.
*
* Input: deviceAddress - I2C Device Address
* registerIndex - Register index to be read
*
* Output:
* The value of the register being read.
*/
long hwI2CWriteRegMultiple(
unsigned char deviceAddress,
unsigned char registerIndex,
unsigned long length,
unsigned char *pBuffer
)
{
unsigned char value[MAX_HWI2C_FIFO], index, count, start = 1;
unsigned long totalData = 0;
/* The length is limited to 256 since register index is limited to unsigned char. */
if ((registerIndex + length) > 256)
length = 256 - registerIndex;
#if 1
/* Temporary use this one */
for (index = 0; index < (unsigned char)length; index++)
{
if (hwI2CWriteReg(deviceAddress, registerIndex + index, *pBuffer++) != 0)
return (-1);
}
#else
/* Does not work here. Need to find out how to write multiple data at once. */
while (length > 0)
{
if (length < MAX_HWI2C_FIFO)
count = length + 1; /* Add one for the register Index. */
else
count = MAX_HWI2C_FIFO;
/* Write the starting register index */
value[0] = registerIndex;
/* Write the data */
for (index = 1; index < count; index++)
value[index] = *pBuffer++;
if (hwI2CWriteData(deviceAddress, count, &value[0]) != count)
return (-1);
/* Update the length */
length -= (count - 1);
/* Update the registerIndex */
registerIndex += (count - 1);
}
#endif
return 0;
}
/*
* This function writes a value to the slave device's register
*
* Parameters:
* deviceAddress - i2c Slave device address which register
* to be written
* registerIndex - Slave device's register to be written
* data - Data to be written to the register
*
* Result:
* 0 - Success
* -1 - Fail
*/
int hwI2CWriteReg(
unsigned char deviceAddress,
unsigned char registerIndex,
unsigned char data
)
{
unsigned char value[2];
value[0] = registerIndex;
value[1] = data;
if (hwI2CWriteData(deviceAddress, 2, value) == 2)
return 0;
return (-1);
}
/*
* This function read the i2c device register value
*
* Input: deviceAddress - I2C Device Address
* registerIndex - Register index to be read
*
* Output:
* The value of the register being read.
*/
unsigned long hwI2CReadRegMultiple(
unsigned char deviceAddress,
unsigned char registerIndex,
unsigned long length,
unsigned char *pBuffer
)
{
unsigned long totalData = 0;
/* The length is limited to 256 since register index is limited to unsigned char. */
if ((registerIndex + length) > 256)
length = 256 - registerIndex;
/* Read from the slave device */
if (hwI2CWriteData(deviceAddress, 1, ®isterIndex) == 1)
totalData = hwI2CReadData(deviceAddress, length, pBuffer);
/* Return the total number of read data */
return totalData;
}
