/**
* Send data as a master on the IIC bus. This function sends the data using
* polled I/O and blocks until the data has been sent. It only supports 7 bit
* addressing. The user is responsible for ensuring the bus is not busy if
* multiple masters are present on the bus.
*
* @param BaseAddress contains the base address of the IIC Device.
* @param Address contains the 7 bit IIC address of the device to send the
* specified data to.
* @param BufferPtr points to the data to be sent.
* @param ByteCount is the number of bytes to be sent.
* @param Option: XIIC_STOP = end with STOP condition,
* XIIC_REPEATED_START = don't end with STOP condition.
*
* @return The number of bytes sent.
*
* @note None.
*
******************************************************************************/
unsigned XIic_DynSend(u32 BaseAddress, u16 Address, u8 *BufferPtr,
u8 ByteCount, u8 Option)
{
unsigned RemainingByteCount;
u32 StatusRegister;
/*
* Clear the latched interrupt status so that it will be updated with
* the new state when it changes, this must be done after the address
* is put in the FIFO
*/
XIic_ClearIisr(BaseAddress, XIIC_INTR_TX_EMPTY_MASK |
XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_ARB_LOST_MASK);
/*
* Put the address into the Fifo to be sent and indicate that the
* operation to be performed on the bus is a write operation. Upon
* writing the address, a start condition is initiated. MSMS is
* automatically set to master when the address is written to the Fifo.
* If MSMS was already set, then a re-start is sent prior to the
* address.
*/
if(!(Address & XIIC_TX_DYN_STOP_MASK)) {
XIic_DynSend7BitAddress(BaseAddress, Address,
XIIC_WRITE_OPERATION);
} else {
XIic_DynSendStartStopAddress(BaseAddress, Address,
XIIC_WRITE_OPERATION);
}
/*
* Wait for the bus to go busy.
*/
StatusRegister = XIic_ReadReg(BaseAddress, XIIC_SR_REG_OFFSET);
while (( StatusRegister & XIIC_SR_BUS_BUSY_MASK) !=
XIIC_SR_BUS_BUSY_MASK) {
StatusRegister = XIic_ReadReg(BaseAddress,
XIIC_SR_REG_OFFSET);
}
/*
* Clear the latched interrupt status for the bus not busy bit which
* must be done while the bus is busy.
*/
XIic_ClearIisr(BaseAddress, XIIC_INTR_BNB_MASK);
/*
* Send the specified data to the device on the IIC bus specified by the
* the address.
*/
RemainingByteCount = DynSendData(BaseAddress, BufferPtr, ByteCount,
Option);
/*
* The send is complete return the number of bytes that was sent.
*/
return ByteCount - RemainingByteCount;
}
/**
* Receive data as a master on the IIC bus. This function receives the data
* using polled I/O and blocks until the data has been received. It only
* supports 7 bit addressing. The user is responsible for ensuring the bus is
* not busy if multiple masters are present on the bus.
*
* @param BaseAddress contains the base address of the IIC Device.
* @param Address contains the 7 bit IIC Device address of the device to
* send the specified data to.
* @param BufferPtr points to the data to be sent.
* @param ByteCount is the number of bytes to be sent. This value can't be
* greater than 255 and needs to be greater than 0.
*
* @return The number of bytes received.
*
* @note Upon entry to this function, the IIC interface needs to be
* already enabled in the CR register.
*
******************************************************************************/
unsigned XIic_DynRecv(u32 BaseAddress, u8 Address, u8 *BufferPtr, u8 ByteCount)
{
unsigned RemainingByteCount;
u32 StatusRegister;
/*
* Clear the latched interrupt status so that it will be updated with
* the new state when it changes.
*/
XIic_ClearIisr(BaseAddress, XIIC_INTR_TX_EMPTY_MASK |
XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_ARB_LOST_MASK);
/*
* Send the 7 bit slave address for a read operation and set the state
* to indicate the address has been sent. Upon writing the address, a
* start condition is initiated. MSMS is automatically set to master
* when the address is written to the Fifo. If MSMS was already set,
* then a re-start is sent prior to the address.
*/
XIic_DynSend7BitAddress(BaseAddress, Address, XIIC_READ_OPERATION);
/*
* Wait for the bus to go busy.
*/
StatusRegister = XIic_ReadReg(BaseAddress, XIIC_SR_REG_OFFSET);
while (( StatusRegister & XIIC_SR_BUS_BUSY_MASK)
!= XIIC_SR_BUS_BUSY_MASK) {
StatusRegister = XIic_ReadReg(BaseAddress,
XIIC_SR_REG_OFFSET);
}
/*
* Clear the latched interrupt status for the bus not busy bit which
* must be done while the bus is busy.
*/
XIic_ClearIisr(BaseAddress, XIIC_INTR_BNB_MASK);
/*
* Write to the Tx Fifo the dynamic stop control bit with the number of
* bytes that are to be read over the IIC interface from the presently
* addressed device.
*/
XIic_DynSendStop(BaseAddress, ByteCount);
/*
* Receive the data from the IIC bus.
*/
RemainingByteCount = DynRecvData(BaseAddress, BufferPtr, ByteCount);
/*
* The receive is complete. Return the number of bytes that were
* received.
*/
return ByteCount - RemainingByteCount;
}
/**
* This function receives data as a master from a slave device on the IIC bus.
* If the bus is busy, it will indicate so and then enable an interrupt such
* that the status handler will be called when the bus is no longer busy. The
* slave address which has been set with the XIic_SetAddress() function is the
* address from which data is received. Receiving data on the bus performs a
* read operation.
*
* @param InstancePtr is a pointer to the Iic instance to be worked on.
* @param RxMsgPtr is a pointer to the data to be transmitted.
* @param ByteCount is the number of message bytes to be sent.
*
* @return - XST_SUCCESS indicates the message reception processes has been
* initiated.
* - XST_IIC_BUS_BUSY indicates the bus was in use and that the
* BusNotBusy interrupt is enabled which will update the
* EventStatus when the bus is no longer busy.
* - XST_IIC_GENERAL_CALL_ADDRESS indicates the slave address is
* set to the general call address. This is not allowed for Master
* receive mode.
*
* @note The receive FIFO threshold is a zero based count such that 1
* must be subtracted from the desired count to get the correct
* value. When receiving data it is also necessary to not receive
* the last byte with the prior bytes because the acknowledge must
* be setup before the last byte is received.
*
******************************************************************************/
int XIic_DynMasterRecv(XIic *InstancePtr, u8 *RxMsgPtr, u8 ByteCount)
{
u32 CntlReg;
u32 RxFifoOccy;
/*
* If the slave address is zero (general call) the master can't perform
* receive operations, indicate an error.
*/
if (InstancePtr->AddrOfSlave == 0) {
return XST_IIC_GENERAL_CALL_ADDRESS;
}
/*
* Disable the Interrupts.
*/
XIic_IntrGlobalDisable(InstancePtr->BaseAddress);
/*
* Ensure that the master processing has been included such that events
* will be properly handled.
*/
XIIC_DYN_MASTER_INCLUDE;
InstancePtr->IsDynamic = TRUE;
/*
* If the busy is busy, then exit the critical region and wait for the
* bus to not be busy, the function enables the bus not busy interrupt.
*/
if (IsBusBusy(InstancePtr)) {
XIic_IntrGlobalEnable(InstancePtr->BaseAddress);
return XST_IIC_BUS_BUSY;
}
/*
* Save message state for event driven processing.
*/
InstancePtr->RecvByteCount = ByteCount;
InstancePtr->RecvBufferPtr = RxMsgPtr;
/*
* Clear and enable Rx full interrupt.
*/
XIic_ClearEnableIntr(InstancePtr->BaseAddress, XIIC_INTR_RX_FULL_MASK);
/*
* If already a master on the bus, the direction was set by Rx Interrupt
* routine to Tx which is throttling bus because during Rxing, Tx reg is
* empty = throttle. CR needs setting before putting data or the address
* written will go out as Tx instead of receive. Start Master Rx by
* setting CR Bits MSMS to Master and msg direction.
*/
CntlReg = XIic_ReadReg(InstancePtr->BaseAddress, XIIC_CR_REG_OFFSET);
if (CntlReg & XIIC_CR_MSMS_MASK) {
/*
* Set the Repeated Start bit in CR.
*/
CntlReg |= XIIC_CR_REPEATED_START_MASK;
XIic_SetControlRegister(InstancePtr, CntlReg, ByteCount);
/*
* Increment stats counts.
*/
InstancePtr->Stats.RepeatedStarts++;
XIic_WriteReg(InstancePtr->BaseAddress, XIIC_CR_REG_OFFSET,
CntlReg);
}
/*
* Set receive FIFO occupancy depth which must be done prior to writing
* the address in the FIFO because the transmitter will immediately
* start when in repeated start mode followed by the receiver such
* that the number of bytes to receive should be set 1st.
*/
if (ByteCount == 1) {
RxFifoOccy = 0;
}
else {
if (ByteCount <= IIC_RX_FIFO_DEPTH) {
RxFifoOccy = ByteCount - 2;
} else {
RxFifoOccy = IIC_RX_FIFO_DEPTH - 1;
}
}
XIic_WriteReg(InstancePtr->BaseAddress, XIIC_RFD_REG_OFFSET,
RxFifoOccy);
/*
* Send the Seven Bit address. Only 7 bit addressing is supported in
* Dynamic mode and mark that the address has been sent.
*/
XIic_DynSend7BitAddress(InstancePtr->BaseAddress,
InstancePtr->AddrOfSlave, XIIC_READ_OPERATION);
InstancePtr->TxAddrMode = XIIC_TX_ADDR_SENT;
/*
* Send the bytecount to be received and set the stop bit.
*/
XIic_DynSendStop(InstancePtr->BaseAddress, ByteCount);
/*
* Tx error is enabled incase the address has no device to answer
* with Ack. When only one byte of data, must set NO ACK before address
* goes out therefore Tx error must not be enabled as it will go off
* immediately and the Rx full interrupt will be checked. If full, then
* the one byte was received and the Tx error will be disabled without
* sending an error callback msg.
*/
XIic_ClearEnableIntr(InstancePtr->BaseAddress,
XIIC_INTR_TX_ERROR_MASK);
/*
* Enable the Interrupts.
*/
XIic_IntrGlobalEnable(InstancePtr->BaseAddress);
return XST_SUCCESS;
}
/**
* This function sends data as a Dynamic master on the IIC bus. If the bus is
* busy, it will indicate so and then enable an interrupt such that the status
* handler will be called when the bus is no longer busy. The slave address is
* sent by using XIic_DynSend7BitAddress().
*
* @param InstancePtr points to the Iic instance to be worked on.
* @param TxMsgPtr points to the data to be transmitted.
* @param ByteCount is the number of message bytes to be sent.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int XIic_DynMasterSend(XIic *InstancePtr, u8 *TxMsgPtr, u8 ByteCount)
{
u32 CntlReg;
XIic_IntrGlobalDisable(InstancePtr->BaseAddress);
/*
* Ensure that the Dynamic master processing has been included such that
* events will be properly handled.
*/
XIIC_DYN_MASTER_INCLUDE;
InstancePtr->IsDynamic = TRUE;
/*
* If the busy is busy, then exit the critical region and wait for the
* bus not to be busy. The function enables the BusNotBusy interrupt.
*/
if (IsBusBusy(InstancePtr)) {
XIic_IntrGlobalEnable(InstancePtr->BaseAddress);
return XST_FAILURE;
}
/*
* If it is already a master on the bus (repeated start), the direction
* was set to Tx which is throttling bus. The control register needs to
* be set before putting data into the FIFO.
*/
CntlReg = XIic_ReadReg(InstancePtr->BaseAddress, XIIC_CR_REG_OFFSET);
if (CntlReg & XIIC_CR_MSMS_MASK) {
CntlReg &= ~XIIC_CR_NO_ACK_MASK;
CntlReg |= XIIC_CR_DIR_IS_TX_MASK;
XIic_WriteReg(InstancePtr->BaseAddress, XIIC_CR_REG_OFFSET,
CntlReg);
InstancePtr->Stats.RepeatedStarts++;
}
/*
* Save message state.
*/
InstancePtr->SendByteCount = ByteCount;
InstancePtr->SendBufferPtr = TxMsgPtr;
/*
* Send the Seven Bit address. Only 7 bit addressing is supported in
* Dynamic mode.
*/
XIic_DynSend7BitAddress(InstancePtr->BaseAddress,
InstancePtr->AddrOfSlave,
XIIC_WRITE_OPERATION);
/*
* Set the transmit address state to indicate the address has been sent
* for communication with event driven processing.
*/
InstancePtr->TxAddrMode = XIIC_TX_ADDR_SENT;
/*
* Fill the Tx FIFO.
*/
if (InstancePtr->SendByteCount > 1) {
XIic_TransmitFifoFill(InstancePtr, XIIC_MASTER_ROLE);
}
/*
* After filling fifo, if data yet to send > 1, enable Tx ½ empty
* interrupt.
*/
if (InstancePtr->SendByteCount > 1) {
XIic_ClearEnableIntr(InstancePtr->BaseAddress,
XIIC_INTR_TX_HALF_MASK);
}
/*
* Clear any pending Tx empty, Tx Error and then enable them.
*/
XIic_ClearEnableIntr(InstancePtr->BaseAddress,
XIIC_INTR_TX_ERROR_MASK |
XIIC_INTR_TX_EMPTY_MASK);
/*
* Enable the Interrupts.
*/
XIic_IntrGlobalEnable(InstancePtr->BaseAddress);
return XST_SUCCESS;
}
