/******************************************************************************
*
* This function fills the FIFO using the occupancy register to determine the
* available space to be filled. When the repeated start option is on, the last
* byte is withheld to allow the control register to be properly set on the last
* byte.
*
* @param InstancePtr is a pointer to the XIic instance to be worked on.
*
* @param Role indicates the role of this IIC device, a slave or a master,
* on the IIC bus (XIIC_SLAVE_ROLE or XIIC_MASTER_ROLE).
*
* @return None.
*
* @note None.
*
******************************************************************************/
void XIic_TransmitFifoFill(XIic *InstancePtr, int Role)
{
u8 AvailBytes;
int LoopCnt;
int NumBytesToSend;
/*
* Determine number of bytes to write to FIFO. Number of bytes that
* can be put into the FIFO is (FIFO depth) - (current occupancy + 1)
* When more room in FIFO than msg bytes put all of message in the FIFO.
*/
AvailBytes = IIC_TX_FIFO_DEPTH -
(u8) (XIic_ReadReg(InstancePtr->BaseAddress,
XIIC_TFO_REG_OFFSET) + 1);
if (InstancePtr->SendByteCount > AvailBytes) {
NumBytesToSend = AvailBytes;
} else {
/*
* More space in FIFO than bytes in message.
*/
if ((InstancePtr->Options & XII_REPEATED_START_OPTION) ||
(Role == XIIC_SLAVE_ROLE)) {
NumBytesToSend = InstancePtr->SendByteCount;
} else {
NumBytesToSend = InstancePtr->SendByteCount - 1;
}
}
/*
* Fill FIFO with amount determined above.
*/
for (LoopCnt = 0; LoopCnt < NumBytesToSend; LoopCnt++) {
XIic_WriteSendByte(InstancePtr);
}
}
/******************************************************************************
*
* When the IIC Tx FIFO/register goes empty, this routine is called by the
* interrupt service routine to fill the transmit FIFO with data to be sent.
*
* This function also is called by the Tx ½ empty interrupt as the data handling
* is identical when you don't assume the FIFO is empty but use the Tx_FIFO_OCY
* register to indicate the available free FIFO bytes.
*
* @param InstancePtr is a pointer to the XIic instance to be worked on.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void SendMasterData(XIic *InstancePtr)
{
u32 CntlReg;
/*
* The device is a master on the bus. If there is still more address
* bytes to send when in master receive operation and the slave device
* is 10 bit addressed.
* This requires the lower 7 bits of address to be resent when the mode
* switches to Read instead of write (while sending addresses).
*/
if (InstancePtr->TxAddrMode & XIIC_TX_ADDR_MSTR_RECV_MASK) {
/*
* Send the 1st byte of the slave address in the read operation
* and change the state to indicate this has been done
*/
SendSlaveAddr(InstancePtr);
InstancePtr->TxAddrMode = XIIC_TX_ADDR_SENT;
}
/*
* In between 1st and last byte of message, fill the FIFO with more data
* to send, disable the 1/2 empty interrupt based upon data left to
* send.
*/
else if (InstancePtr->SendByteCount > 1) {
XIic_TransmitFifoFill(InstancePtr, XIIC_MASTER_ROLE);
if (InstancePtr->SendByteCount < 2) {
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_INTR_TX_HALF_MASK);
}
}
/*
* If there is only one byte left to send, processing differs between
* repeated start and normal messages.
*/
else if (InstancePtr->SendByteCount == 1) {
/*
* When using repeated start, another interrupt is expected
* after the last byte has been sent, so the message is not
* done yet.
*/
if (InstancePtr->Options & XII_REPEATED_START_OPTION) {
XIic_WriteSendByte(InstancePtr);
}
/*
* When not using repeated start, the stop condition must be
* generated after the last byte is written. The bus is
* throttled waiting for the last byte.
*/
else {
/*
* Set the stop condition before sending the last byte
* of data so that the stop condition will be generated
* immediately following the data another transmit
* interrupt is not expected so the message is done.
*/
CntlReg = XIic_ReadReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET);
CntlReg &= ~XIIC_CR_MSMS_MASK;
XIic_WriteReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET,
CntlReg);
XIic_WriteSendByte(InstancePtr);
/*
* Wait for bus to not be busy before declaring message
* has been sent for the no repeated start operation.
* The callback will be called from the BusNotBusy part
* of the Interrupt handler to ensure that the message
* is completely sent.
* Disable the Tx interrupts and enable the BNB
* interrupt.
*/
InstancePtr->BNBOnly = FALSE;
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_TX_INTERRUPTS);
XIic_EnableIntr(InstancePtr->BaseAddress,
XIIC_INTR_BNB_MASK);
}
} else {
if (InstancePtr->Options & XII_REPEATED_START_OPTION) {
/*
* The message being sent has completed. When using
* repeated start with no more bytes to send repeated
* start needs to be set in the control register so
* that the bus will still be held by this master.
*/
CntlReg = XIic_ReadReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET);
CntlReg |= XIIC_CR_REPEATED_START_MASK;
XIic_WriteReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET, CntlReg);
/*
* If the message that was being sent has finished,
* disable all transmit interrupts and call the callback
* that was setup to indicate the message was sent,
* with 0 bytes remaining.
*/
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_TX_INTERRUPTS);
InstancePtr->SendHandler(InstancePtr->SendCallBackRef,
0);
}
}
return;
}
/******************************************************************************
*
* When the IIC Tx FIFO/register goes empty, this routine is called by the
* interrupt service routine to fill the transmit FIFO with data to be sent.
*
* This function also is called by the Tx ½ empty interrupt as the data handling
* is identical when you don't assume the FIFO is empty but use the Tx_FIFO_OCY
* register to indicate the available free FIFO bytes.
*
* @param InstancePtr is a pointer to the XIic instance to be worked on.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void DynSendMasterData(XIic *InstancePtr)
{
u32 CntlReg;
/*
* In between 1st and last byte of message, fill the FIFO with more data
* to send, disable the 1/2 empty interrupt based upon data left to
* send.
*/
if (InstancePtr->SendByteCount > 1) {
XIic_TransmitFifoFill(InstancePtr, XIIC_MASTER_ROLE);
if (InstancePtr->SendByteCount < 2) {
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_INTR_TX_HALF_MASK);
}
}
/*
* If there is only one byte left to send, processing differs between
* repeated start and normal messages.
*/
else if (InstancePtr->SendByteCount == 1) {
/*
* When using repeated start, another interrupt is expected
* after the last byte has been sent, so the message is not
* done yet.
*/
if (InstancePtr->Options & XII_REPEATED_START_OPTION) {
XIic_WriteSendByte(InstancePtr);
} else {
XIic_DynSendStop(InstancePtr->BaseAddress,
*InstancePtr->SendBufferPtr);
/*
* Wait for bus to not be busy before declaring message
* has been sent for the no repeated start operation.
* The callback will be called from the BusNotBusy part
* of the Interrupt handler to ensure that the message
* is completely sent. Disable the Tx interrupts and
* enable the BNB interrupt.
*/
InstancePtr->BNBOnly = FALSE;
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_TX_INTERRUPTS);
XIic_EnableIntr(InstancePtr->BaseAddress,
XIIC_INTR_BNB_MASK);
}
} else {
if (InstancePtr->Options & XII_REPEATED_START_OPTION) {
/*
* The message being sent has completed. When using
* repeated start with no more bytes to send repeated
* start needs to be set in the control register so
* that the bus will still be held by this master.
*/
CntlReg = XIic_ReadReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET);
CntlReg |= XIIC_CR_REPEATED_START_MASK;
XIic_WriteReg(InstancePtr->BaseAddress,
XIIC_CR_REG_OFFSET, CntlReg);
/*
* If the message that was being sent has finished,
* disable all transmit interrupts and call the callback
* that was setup to indicate the message was sent,
* with 0 bytes remaining.
*/
XIic_DisableIntr(InstancePtr->BaseAddress,
XIIC_TX_INTERRUPTS);
InstancePtr->SendHandler(InstancePtr->SendCallBackRef,
0);
}
}
return;
}
