// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// e32\drivers\iic_channel.cpp

// IIC Channel Platform Independent Layer (PIL)

//

#include <drivers/iic_channel.h>

#ifdef IIC_INSTRUMENTATION_MACRO

#include <drivers/iic_trace.h>

#endif

// The timer call back function which calls the PSL's HandleSlaveTimeout()

// Note that this assumes that the channel thread has been unblocked - if this

// is not the case, the callback will never get to run

TInt DIicBusChannelMaster::DoCreate()

    {return KErrNone;}

void DIicBusChannelMaster::Lock()

    {NKern::FMWait(&iTransactionQLock);}

void DIicBusChannelMaster::Unlock()

    {NKern::FMSignal(&iTransactionQLock);}

TIicBusTransaction* DIicBusChannelMaster::NextTrans(TIicBusTransaction* aTrans)

    {

    // call multi-transaction call back function to get next transaction

    if((aTrans->iFlags&KTransactionWithPreamble)&&(aTrans->iFlags&KTransactionWithMultiTransc))

        return ((TIicBusTransactionPreambleExt*)aTrans)->iMultiTransc(aTrans, ((TIicBusTransactionPreambleExt*)aTrans)->iMultiTranscArg);

    else if(aTrans->iFlags&KTransactionWithMultiTransc)

        return ((TIicBusTransactionMultiTransc*)aTrans)->iMultiTransc(aTrans, ((TIicBusTransactionMultiTransc*)aTrans)->iMultiTranscArg);

    else

        return NULL;

    }

void DIicBusChannelMaster::UnlockAndKick()

    {iTransQDfc.Enque(&iTransactionQLock);}

void DIicBusChannelMaster::SlaveTimeoutCallback(TAny* aPtr)

	{

	DIicBusChannelMaster* aChanMaster=(DIicBusChannelMaster* )aPtr;

	TInt r = aChanMaster->HandleSlaveTimeout();

	aChanMaster->CompleteRequest(r);

	}

TInt DIicBusChannelMaster::TransFlow(TIicBusTransaction* aTransaction)

    {

    if(aTransaction->iHalfDuplexTrans == NULL)

        return KErrArgument;

    else if(aTransaction->iFullDuplexTrans == NULL)

        return DIicBusChannel::EHalfDuplex;

    else return DIicBusChannel::EFullDuplex;

    }

TInt8 DIicBusChannelMaster::IsMasterBusy()

    {

    if((iTransCount&~KTransCountMsBit) == 0)

        return 0;

    else return 1;

    }

DIicBusChannelMaster::DIicBusChannelMaster(TBusType aBusType, TChannelDuplex aChanDuplex)

		: DIicBusChannel(DIicBusChannel::EMaster, aBusType, aChanDuplex),

		iTransQDfc(DIicBusChannelMaster::MsgQFunc, this, NULL, 1), iChannelReady(EFalse)

	{

	new(&iTimeoutTimer) NTimer(SlaveTimeoutCallback,this);

	}

DIicBusChannelMaster::~DIicBusChannelMaster()

	{

	delete iSlaveTimeoutDfc;

	}

TInt DIicBusChannelMaster::Init()

	{

	iSlaveTimeoutDfc = new TDfc(SlaveTimeoutCallback,(TAny*)this, 7);	// Highest Dfc priority

	if(!iSlaveTimeoutDfc)

		return KErrNoMemory;

	else

		return KErrNone;

	}

// Function to used to indicate if the Slave response has exceeded

// an expected time

TInt DIicBusChannelMaster::StartSlaveTimeOutTimer(TInt aTime)

	{

	TInt r = iTimeoutTimer.OneShot(NKern::TimerTicks(aTime),(*iSlaveTimeoutDfc));

	return r;

	}

void DIicBusChannelMaster::SetDfcQ(TDfcQue* aDfcQue)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::SetDfcQ 0x%x\n",aDfcQue));

	__ASSERT_DEBUG(aDfcQue!=NULL, Kern::Fault(KIicChannelPanic,__LINE__));

	iDfcQ=aDfcQue;

	iTransQDfc.SetDfcQ(iDfcQ);

	iSlaveTimeoutDfc->SetDfcQ(iDfcQ);

	Lock();

	__ASSERT_DEBUG(!iChannelReady, Kern::Fault(KIicChannelPanic,__LINE__));

	if (!iTransactionQ.IsEmpty())

		{

		iTransaction=(TIicBusTransaction*)(iTransactionQ.First()->Deque());

		__KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::SetDfcQ got %08x",iTransaction));

		iTransaction->iState=TIicBusTransaction::EAccepted;

		iCurrentTransaction = iTransaction;

		UnlockAndKick();

		}

	else

		{

		__KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::SetDfcQ"));

		iChannelReady=ETrue;

		iTransaction=NULL;

		iCurrentTransaction = NULL;

		Unlock();

		}

	}

void DIicBusChannelMaster::CompleteRequest(TInt aResult)

	{

	TIicBusTransaction* nextTrans=NextTrans(iCurrentTransaction);

	if((aResult != KErrNone)||(nextTrans == NULL))

		EndTransaction(iTransaction,aResult,iTransaction->iCallback);

	else

		{

		nextTrans->iBusId = iCurrentTransaction->iBusId; // Pass the bus configuration info to the PSL

		iCurrentTransaction = nextTrans;

		DoRequest(nextTrans);

		}

	}

#ifdef MASTER_MODE

/*

For Master-side transaction queuing APIs

the Channel implementation sends the transaction as a message to the Channel's message queue,

optionally blocking the client thread on the message's semaphore (synchronous APIs).

*/

TInt DIicBusChannelMaster::QueueTransaction(TIicBusTransaction* aTransaction)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::QueueTransaction, aTransaction=0x%x\n",aTransaction));

	// Send the transaction as a message to the Channel's message queue

	// Synchronous API, so block the calling thread during the processing

	TInt r = QueueTransaction(aTransaction, NULL);

	if(r!=KErrNone)

		return r;	// Transaction was not queued - so don't wait for a notification that it completed.

	__KTRACE_OPT(KIIC, Kern::Printf("<DIicBusChannelMaster::QueueTransaction ret %d",aTransaction->iResult));

	return aTransaction->iResult;

	}

TInt DIicBusChannelMaster::QueueTransaction(TIicBusTransaction* aTransaction, TIicBusCallback* aCallback)

	{

	__KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::QueueTransaction, aTransaction=0x%x, aCallback=0x%x\n",aTransaction,aCallback));

	// Check aTransaction is non-NULL (aCallback may be NULL if the synchronous operation is required).

	if(aTransaction == NULL)

		{

		return KErrArgument;

		}

	// Send the transaction as a message to the Channel's message queue and return

	aTransaction->iCallback = aCallback;

	if(aCallback != NULL)

		{

		aCallback->iTransaction = aTransaction;

		}

	// Call the PSL implementation to check that the header is valid for this channel

	TInt r = CheckHdr(aTransaction->iHeader);

	if(r!=KErrNone)

		{

		return r;

		}

	// Duplex operation is indicated in the transaction object

	if((TransFlow((TIicBusTransaction*)aTransaction) == DIicBusChannel::EFullDuplex) &&

	   (ChannelDuplex()                              != DIicBusChannel::EFullDuplex))

		{

		return KErrNotSupported;

		}

	DThread* pC =& Kern::CurrentThread();

	Lock();

	__ASSERT_DEBUG(aTransaction->iState == TIicBusTransaction::EFree, Kern::Fault(KIicChannelPanic,__LINE__));

	if(!(iTransCount & KTransCountMsBit))

		{

		if(iTransCount < ~KTransCountMsBit)

			{

			++iTransCount;

			}

		else

			{

			Unlock();

			return KErrOverflow;

			}

		}

	aTransaction->iSyncNotification.iCount = 0;

	aTransaction->iSyncNotification.iOwningThread = &pC->iNThread;

	pC->Open();

	if (iChannelReady)

		{

		aTransaction->iState = TIicBusTransaction::EAccepted;

		iTransaction = aTransaction;

		iCurrentTransaction = aTransaction;

		iChannelReady = EFalse;

		UnlockAndKick();

		}

	else

		{

		iTransactionQ.Add(aTransaction);

		aTransaction->iState = TIicBusTransaction::EDelivered;

		Unlock();

		}

	// Wait on a semaphore if called from synchronous version

	if(aCallback == NULL)

		{

		NKern::FSWait(&aTransaction->iSyncNotification);

		}

	return KErrNone;

	}

TInt DIicBusChannelMaster::CancelTransaction(TIicBusTransaction* aTransaction)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::CancelTransaction, aTransaction=0x%x\n",aTransaction));

	// Check aTransaction is non-NULL

	if(aTransaction == NULL)

		{

		return KErrArgument;

		}

	// If the method is called on a synchronous transaction return KErrNotSupported

	if(aTransaction->iCallback == NULL)

		{

		return KErrNotSupported;

		}

	DThread* pT = NULL;

	Lock();

	TInt r = KErrNone;

	switch(aTransaction->iState)

		{

		case TIicBusTransaction::EDelivered:

			{

			aTransaction->Deque();

			pT=_LOFF(aTransaction->iSyncNotification.iOwningThread,DThread,iNThread);

			aTransaction->iState=TIicBusTransaction::EFree;

			--iTransCount; // Count must be greater than zero if the transaction is in this state

			r = KErrCancel;

			break;

			}

		case TIicBusTransaction::EAccepted:

			{

			r = KErrInUse;

			break;

			}

		case TIicBusTransaction::EFree:

			{

			r = KErrCancel;

			break;

			}

		}

	Unlock();

	if (pT)

		{

		pT->AsyncClose();

		}

	return r;

	}

#else /*MASTER_MODE*/

TInt DIicBusChannelMaster::QueueTransaction(TIicBusTransaction* /*aTransaction*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::QueueTransaction invoked when not in MASTER_MODE!\n"));

	return KErrNotSupported;

	}

TInt DIicBusChannelMaster::QueueTransaction(TIicBusTransaction* /*aTransaction*/, TIicBusCallback* /*aCallback*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::QueueTransaction invoked when not in MASTER_MODE!\n"));

	return KErrNotSupported;

	}

TInt DIicBusChannelMaster::CancelTransaction(TIicBusTransaction* /*aTransaction*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::CancelTransaction invoked when not in MASTER_MODE!\n"));

	return KErrNotSupported;

	}

#endif/*MASTER_MODE*/

// Invoked in response to receiving a message

// Function argument is a pointer to the required channel object

// Invoke the channel's PSL implementation of the DoRequest method with a pointer to the transaction object

//

void DIicBusChannelMaster::MsgQFunc(TAny* aPtr)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc, aPtr=0x%x\n",aPtr));

	DIicBusChannelMaster* channel=(DIicBusChannelMaster*)aPtr;

	TIicBusTransaction* trans = channel->iTransaction;

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_MPROCESSTRANS_START_PIL_TRACE;

#endif

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc trans->iHeader=0x%x\n",trans->iHeader));

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc trans->iHalfDuplexTrans=0x%x\n",trans->iHalfDuplexTrans));

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc trans->iFullDuplexTrans=0x%x\n",trans->iFullDuplexTrans));

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc trans->iCallback=0x%x\n",trans->iCallback));

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelMaster::MsgQFunc trans->iFlags=0x%x\n",trans->iFlags));

	TInt r = KErrNone;

	// invoke the preamble callback function supplied by the client of the IIC if there is any

	if(GetTransFlags(trans) & KTransactionWithPreamble)

		{

		TIicBusTransactionPreamble* transPreamble = (TIicBusTransactionPreamble*)trans;

		TIicBusPreamble funcPtr=NULL;

		funcPtr=(GetPreambleFuncPtr(transPreamble));

		funcPtr(transPreamble,GetPreambleFuncArg(transPreamble));

		}

	r = channel->DoRequest(trans);	// Instigate processing in the PSL

	if(r!=KErrNone)

		channel->EndTransaction(trans, r, trans->iCallback);

	}

void DIicBusChannelMaster::EndTransaction(TIicBusTransaction* aTrans, TInt aResult, TIicBusCallback* aCb)

	{

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_MPROCESSTRANS_END_PIL_TRACE;

#endif

	Complete(aResult,aTrans);

	if(aCb != NULL)

		{

		aCb->iResult = aResult;

		aCb->Enque();

		}

	}

void DIicBusChannelMaster::CancelTimeOut()

	{

	iTimeoutTimer.Cancel();

	}

void DIicBusChannelMaster::Complete(TInt aResult, TIicBusTransaction* aTransaction) //Completes a kernel message and receive the next one

	{

	__KTRACE_OPT(KIIC, Kern::Printf("MsgB::Complete %08x, %d",this,aResult));

	Lock();

	__ASSERT_DEBUG(aTransaction->iState == TIicBusTransaction::EAccepted, Kern::Fault(KIicChannelPanic,__LINE__));

	aTransaction->iResult=aResult;

	aTransaction->iState=TIicBusTransaction::EFree;

	--iTransCount;

	DThread* pT=_LOFF(aTransaction->iSyncNotification.iOwningThread,DThread,iNThread);

	__ASSERT_DEBUG(!iChannelReady, Kern::Fault(KIicChannelPanic,__LINE__));

	if (!iTransactionQ.IsEmpty())

		{

		TIicBusTransaction* pM=(TIicBusTransaction*)iTransactionQ.First()->Deque();

		__KTRACE_OPT(KIIC, Kern::Printf("rxnext: got %08x",pM));

		pM->iState=TIicBusTransaction::EAccepted;

		iTransaction = pM;

		iCurrentTransaction = pM;

		iTransQDfc.Enque();

		}

	else

		{

		__KTRACE_OPT(KIIC, Kern::Printf("rxnext"));

		iChannelReady=ETrue;

		iTransaction=NULL;

		iCurrentTransaction = NULL;

		}

	NKern::FSSignal(&aTransaction->iSyncNotification,&iTransactionQLock);

	pT->AsyncClose();

	}

TInt DIicBusChannelMaster::StaticExtension(TUint /*aFunction*/, TAny* /*aParam1*/, TAny* /*aParam*/)

 	{

 	return KErrNotSupported;

 	}

TInt DIicBusChannelMaster::Spare1(TInt /*aVal*/, TAny* /*aPtr1*/, TAny* /*aPtr2*/)

	{

	return KErrNotSupported;

	}

#ifdef SLAVE_MODE

TInt DIicBusChannelSlave::CaptureChannel(TDes8* aConfigHdr, TIicBusSlaveCallback* aCallback, TInt& aChannelId, TBool aAsynch)

	{

	// Only one client can have access to the Slave channel at any one time. Any subsequent attempts to capture the

	// same channel should return an error.

	//

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::CaptureChannel\n"));

	if((aConfigHdr == NULL) || (aCallback == NULL))

		{

	    __KTRACE_OPT(KIIC, Kern::Printf("ERROR: non-NULL argument aConfigHdr=0x%x, aCallback=0x%x\n",aConfigHdr,aCallback));

		return KErrArgument;

		}

	//

	// Check the header is valid for the channel

	TInt r = CheckHdr(aConfigHdr);

	if(r == KErrNone)

		{

		// Check Slave channel is available for capture

		// If iChannelInUse is not set, capture should succeed

		// If this Slave channel is part of a MasterSlave channel iChannelInUse will already be set

		// but iClient will still be NULL. In this case, the capture should succeed.

		TInt intState=__SPIN_LOCK_IRQSAVE(iSpinLock);

		DThread* pT=&(Kern::CurrentThread());

		if((iChannelInUse)&&(iClient!=NULL))

			r=KErrInUse;

		else

			{

			iChannelInUse=1;

			iClient=pT;

			}

		__SPIN_UNLOCK_IRQRESTORE(iSpinLock,intState);

		if(r == KErrNone)

			{

			iClient->Open();

			aCallback->iChannel=this;

			iNotif = aCallback;

			iConfigHeader=aConfigHdr;	// Header alread checked, so just assign it

			// Invoke the PSL processing

			if(aAsynch)

				{

				aChannelId = 0; // the client should read iChannelId from the callback object.

				r=DoRequest(EAsyncConfigPwrUp);

				}

			else

				r=DoRequest(ESyncConfigPwrUp);

			if(r == KErrNone)

				{

				if(!aAsynch)	// For asynchronous version there is nothing more to do until the callback is invoked

					{

					SetChannelId(aChannelId);

					iClientTimeoutDfc->SetDfcQ(iNotif->iDfcQ);

					}

				}

			else

				{

				// PSL encountered an error

				ReleaseChannel();

				if(aAsynch)

					CompleteAsynchCapture(r);	// Queue the client callback for execution

				}

			}

		}

	return r;

	}

TInt DIicBusChannelSlave::ReleaseChannel()

	{

	__KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::ReleaseChannel\n"));

	 // Release a previously-captured channel.

	TInt r=KErrNone;;

	// Ensure that only the channel's client may release the channel

	DThread* pT=&(Kern::CurrentThread());

	if(iClient!=pT)			// Direct access since iClient can't be modified while channel is still captured

		return KErrAccessDenied;

	r=SetNotificationTrigger(0);			// Attempt to clear notification requests

	if((r!=KErrNone)&&(r!=KErrTimedOut))	// KErrTimedOut refers to an earlier transaction, and is for information only

		return r;

	iTimeoutTimer.Cancel();

	r=DoRequest(EPowerDown);

	if(r == KErrNone)

		{

		TInt intState=__SPIN_LOCK_IRQSAVE(iSpinLock);

		iClient=NULL;

		iChannelInUse=0;	// Channel now available for capture by other clients

		__SPIN_UNLOCK_IRQRESTORE(iSpinLock,intState);

		pT->AsyncClose();	// Allow Client thread to close now channel has been released

		}

	else

		{

		// PSL error when releasing the channel - have to assume the hardware has a problem.

		// The channel is no longer considered "captured" by the controller, i.e. will not accept commands

		// But not having cleared the busy flag means that it can not be used for master channel

		// operations if it is part of a MasterSlave channel

		// Must Fault the Kernel.

		__KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::ReleaseChannel - PSL returned error code %d\n",r));

		__ASSERT_ALWAYS(EFalse, Kern::Fault(KIicChannelPanic,__LINE__));

		}

	return r;

	}

TInt DIicBusChannelSlave::RegisterRxBuffer(TPtr8 aRxBuffer, TInt8 aBufGranularity, TInt8 aNumWords, TInt8 aOffset)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::RegisterRxBuffer\n"));

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_SREGRXBUF_START_PIL_TRACE;

#endif

	TInt r=KErrNone;

	// Ensure that only the channel's client may perform this operation

	DThread* pT=&(Kern::CurrentThread());

	if(iClient!=pT)			// Direct access since iClient can't be modified while channel is still captured

		return KErrAccessDenied;

	//If the buffer pointer is NULL, return KErrArgument

	if(aRxBuffer.Ptr() == NULL)

		return KErrArgument;

	// If a buffer is already registered, a subsequent request to do the same should return KErrAlreadyExists

	// This will be the case if SetNotificationTrigger has been invoked with any of ERxAllBytes, ERxUnderrun or ERxOverrun

	if(iReqTrig&(ERxAllBytes|ERxUnderrun|ERxOverrun))

		r=KErrAlreadyExists;

	else

		{

		iRxBuf=(TInt8*)(aRxBuffer.Ptr());

		iRxGranularity=aBufGranularity;

		iNumRxWords=aNumWords;

		iRxOffset=aOffset;

		}

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_SREGRXBUF_END_PIL_TRACE;

#endif

	 return r;

	}

TInt DIicBusChannelSlave::RegisterTxBuffer(TPtr8 aTxBuffer, TInt8 aBufGranularity, TInt8 aNumWords, TInt8 aOffset)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::RegisterTxBuffer	- default implementation\n"));

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_SREGTXBUF_START_PIL_TRACE;

#endif

	TInt r=KErrNone;

	// Ensure that only the channel's client may perform this operation

	DThread* pT=&(Kern::CurrentThread());

	if(iClient!=pT)			// Direct access since iClient can't be modified while channel is still captured

		return KErrAccessDenied;

	//If the buffer pointer is NULL, return KErrArgument

	if(aTxBuffer.Ptr() == NULL)

		return KErrArgument;

	// If a buffer is already registered and a request is pending, a subsequent request to register a buffer should return

	// KErrAlreadyExists

	// This will be the case if SetNotificationTrigger has been invoked with any of ETxAllBytes, ETxUnderrun or ETxOverrun

	if(iReqTrig&(ETxAllBytes|ETxUnderrun|ETxOverrun))

		r=KErrAlreadyExists;

	else

		{

		iTxBuf=(TInt8*)(aTxBuffer.Ptr());

		iTxGranularity=aBufGranularity;

		iNumTxWords=aNumWords;

		iTxOffset=aOffset;

		}

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_SREGTXBUF_END_PIL_TRACE;

#endif

	return r;

	}

TInt DIicBusChannelSlave::SetNotificationTrigger(TInt aTrigger)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::SetNotificationTrigger invoked with aTrigger=0x%x\n",aTrigger));

	// Ensure that only the channel's client may perform this operation

	DThread* pT=&(Kern::CurrentThread());

	if(iClient!=pT)			// Direct access since iClient can't be modified while channel is still captured

		return KErrAccessDenied;

	TInt retVal = KErrNone;

	TInt trigger = aTrigger;

	switch (iTimerState)	// Handle existing timer conditions

		{

		case DIicBusChannelSlave::EInactive:

			{

			// In this state no timers have been started - so no action required

			break;

			}

		case DIicBusChannelSlave::EWaitForClient:

			{

			// Client has responded within the given time period, so stop the timer.

			StopTimer();

			break;

			}

		case DIicBusChannelSlave::EWaitForMaster:

			{

			// If both Rx and Tx events had been requested, and if ERxOverrun had occurred, the Client

			// may have called this function with new requests for Rx notifications, in order to

			// continue reading data sent by the Master. At this point, all Rx request flags in iReqTrig

			// will have been cleared.

			// If both Rx and Tx events had been requested, and if ETxUnderrun had occurred, the Client

			// may have called this function with new requests for Tx notifications, in order to

			// continue sending data to the Master. At this point, all Tx request flags in iReqTrig will

			// have been cleared.

			//

			// To handle the ERxOverrun situation, aTrigger may specify only the new Rx trigger settings,

			// or it may also re-specify the exisiting Tx settings. Similarly for the ETxUnderrun, aTrigger

			// may specify only the new Tx triggers, or both the new Tx triggers and the existing Rx triggers.

			//

			// However, if Rx flags are still set in iReqTrig, a request to change the Rx settings

			// will be rejected (similarly, for Tx).

			//

			// If the requested notification is zero, which would represent an attempt to clear all triggers

			// while the Master may have commenced a transfer, the request will be rejected.

			__ASSERT_DEBUG(iReqTrig != 0, Kern::Fault(KIicChannelPanic,__LINE__));

			if(trigger == 0)

				{

				return KErrInUse;

				}

			TInt allRxFlags = ERxAllBytes | ERxOverrun | ERxUnderrun;

			TInt allTxFlags = ETxAllBytes | ETxOverrun | ETxUnderrun;

			// Check the Rx flags

			TInt rxTrig = iReqTrig & allRxFlags;

			TInt reqRxTrig = trigger & allRxFlags;

			if(rxTrig == 0)

				{

				rxTrig = reqRxTrig;

				}

			else if(reqRxTrig != 0)

				{

				// New Rx triggers specified - check that Client is not attempting to modify the existing

				// settings

				if(rxTrig ^ reqRxTrig)

					{

					// Attempting to change the trigger settings - so reject the request

					return KErrInUse;

					}

				}

			// Check the Tx flags

			TInt txTrig = iReqTrig & allTxFlags;

			TInt reqTxTrig = trigger & allTxFlags;

			if(txTrig == 0)

				{

				txTrig = reqTxTrig;

				}

			else if(reqTxTrig != 0)

				{

				// New Tx triggers specified - check that Client is not attempting to modify the existing

				// settings

				if(txTrig ^ reqTxTrig)

					{

					// Attempting to change the trigger settings - so reject the request

					return KErrInUse;

					}

				}

			// Udate iReqTrig for the new requested trigger

			// and cancel the timer - since we are now starting a new transfer, we should

			// allow the Master the time to perform it

			trigger = rxTrig | txTrig;

			StopTimer();

			break;

			}

		case DIicBusChannelSlave::EClientTimeout:

			{

			// The Client did not respond within the expected time for the previous transfer. As a result,

			// the transaction will have been terminated for the Client.

			// Set the return value to inform the Client that it previously exceeded the expected response time

			retVal = KErrTimedOut;

			break;

			}

		default:

			{

			__ASSERT_DEBUG(0, Kern::Fault(KIicChannelPanic,__LINE__));

			break;

			}

		}

	// Ensure that requests for notification of asynchronous capture of channel is removed, since this

	// is not a valid event to request (the channel will already have been captured to get this far).

	// Also ensure that requests for EGeneralBusError are removed, since they are redundant (a notification

	// for a bus error is unconditional) and just represent overhead.

	trigger &= ~(EAsyncCaptChan | EGeneralBusError);

	iReqTrig = (TInt8)trigger; 				// Not atomic access since only client thread modifies iReqTrig

	iAccumTrig = 0;						// New transfer, so initialise accumulated event record

	TInt reqFlags=0;

	// Overrun and/or underrun may be requested if Client is unsure how much data is to follow,

	// so need to instigate Rx/Tx operation for any such request

	if(iReqTrig & (ERxOverrun|ERxUnderrun|ERxAllBytes))

		{

		reqFlags |= EReceive;

		}

	if(iReqTrig & (ETxOverrun|ETxUnderrun|ETxAllBytes))

		{

		reqFlags |= ETransmit;

		}

	TInt r = DoRequest(reqFlags);

	if(r != KErrNone)

		{

		// PSL encountered an error in intiating the requested trigger. Set the return value accordingly.

		// Assume triggers have been cancelled - if they have not, the client-provided callback will still

		// be invoked, but it will have been warned to expecte erroneous behaviour by the value assigned to retVal.

		iReqTrig = 0;

		retVal = KErrGeneral;

		}

	else	// PSL accepted the request, so update timer and state information

		{

		switch (iTimerState)

			{

			case DIicBusChannelSlave::EInactive:

				{

				// Do not start the timer. Must wait for the Master to access a Slave buffer before considering

				// a transaction as started.

				break;

				}

			case DIicBusChannelSlave::EWaitForClient:

				{

				// Client has responded within the given time period. The next state is

				// dependent on the requested trigger - if set to zero, the Client is explicitly

				// ending the transaction, so the next state is EInactive; otherwise, the

				// Client has indicated the next action expected from the Master and so the

				// timer is started and next state is EWaitForMaster

				if(iReqTrig == 0)

					{

					iTimerState = DIicBusChannelSlave::EInactive;

					}

				else

					{

					iTimerState = DIicBusChannelSlave::EWaitForMaster;

					StartTimerByState();

					}

				break;

				}

			case DIicBusChannelSlave::EClientTimeout:

				{

				// For the previous transfer, the Client failed to respond within the required time - and

				// the PSL will have been instructed to indicate a bus error (so the Master

				// will have been informed). The error code returned by this function will be KErrTimedOut

				// so the Client will be informed of what has happened.

				// A transaction is considered to start when the Slave is addressed by the Master

				// (as indicated by the PSL invoking NotifyClient) - which has not yet happened -

				// so the next state is EInactive.

				iTimerState=DIicBusChannelSlave::EInactive;

				break;

				}

			case DIicBusChannelSlave::EWaitForMaster:

				{

				// In this case we are handling a new requested trigger from the client to handle ERxOverrun or

				// ETxUnderrun. The PSL has accepted the new trigger, so must allow the Master sufficient time

				// to perform the newly-requested transfer; the timer has already been stopped, so just start it again..

				StartTimerByState();

				break;

				}

			default:

				{

				__ASSERT_DEBUG(0, Kern::Fault(KIicChannelPanic,__LINE__));

				break;

				}

			}

		}

	return retVal;

	}

#else /*SLAVE_MODE*/

TInt DIicBusChannelSlave::CaptureChannel(TDes8* /*aConfigHdr*/, TIicBusSlaveCallback* /*aCallback*/, TInt& /*aChannelId*/, TBool /*aAsynch*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::CaptureChannel invoked when not in SLAVE_MODE!\n"));

	 return KErrNotSupported;

	}

TInt DIicBusChannelSlave::ReleaseChannel()

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::ReleaseChannel invoked when not in SLAVE_MODE!\n"));

	 return KErrNotSupported;

	}

TInt DIicBusChannelSlave::RegisterRxBuffer(TPtr8 /*aRxBuffer*/, TInt8 /*aBufGranularity*/, TInt8 /*aNumWords*/, TInt8 /*aOffset*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::RegisterRxBuffer invoked when not in SLAVE_MODE!\n"));

	 return KErrNotSupported;

	}

TInt DIicBusChannelSlave::RegisterTxBuffer(TPtr8 /*aTxBuffer*/, TInt8 /*aBufGranularity*/, TInt8 /*aNumWords*/, TInt8 /*aOffset*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::RegisterTxBuffer invoked when not in SLAVE_MODE!\n"));

	 return KErrNotSupported;

	}

TInt DIicBusChannelSlave::SetNotificationTrigger(TInt /*aTrigger*/)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("DIicBusChannelSlave::SetNotificationTrigger invoked when not in SLAVE_MODE!\n"));

	 return KErrNotSupported;

	}

#endif/*SLAVE_MODE*/

DIicBusChannelSlave::DIicBusChannelSlave(TBusType aBusType, TChannelDuplex aChanDuplex, TInt16 aChannelId)

	: DIicBusChannel(DIicBusChannel::ESlave, aBusType, aChanDuplex),

	iChannelId(aChannelId), iTimerState(EInactive),

	iMasterWaitTime(KSlaveDefMWaitTime), iClientWaitTime(KSlaveDefCWaitTime),

	iSpinLock(TSpinLock::EOrderGenericIrqLow2)  // Semi-arbitrary, low priority value

	{

#ifndef STANDALONE_CHANNEL

	iController = NULL;

#endif

	}

DIicBusChannelSlave::~DIicBusChannelSlave()

    {

    delete iClientTimeoutDfc;

    }

void DIicBusChannelSlave::SlaveStaticCB(TAny* aPtr)

	{

	DIicBusChannelSlave* chan = (DIicBusChannelSlave*)aPtr;

	chan->SlaveTimerCallBack();

	return;

	}

TInt DIicBusChannelSlave::Init()

	{

	iClientTimeoutDfc = new TDfc(SlaveStaticCB,(TAny*)this, 7);	// Highest Dfc priority

	if(!iClientTimeoutDfc)

		return KErrNoMemory;

	else

		return KErrNone;

	}

void DIicBusChannelSlave::ChanCaptureCallback(TInt aResult)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("ChanCaptureCallback: aChannel=0x%x, aResult=%d\n",this,aResult));

	TInt r=aResult;

	TInt channelId = 0;

	if(aResult == KErrNone)

		{

		SetChannelId(channelId);

#ifndef STANDALONE_CHANNEL

		__ASSERT_DEBUG(iController, Kern::Fault(KIicChannelPanic,__LINE__));

		iController->InstallCapturedChannel(channelId, this);

#endif

		iClientTimeoutDfc->SetDfcQ(iNotif->iDfcQ);

		r=KErrCompletion;

		}

	else

		ReleaseChannel();

#ifdef IIC_INSTRUMENTATION_MACRO

	IIC_SCAPTCHANASYNC_END_PIL_TRACE;

#endif

	CompleteAsynchCapture(r);	// Queue the client callback for execution

	}

void DIicBusChannelSlave::SlaveTimerCallBack()

	{

    __KTRACE_OPT(KIIC, Kern::Printf("SlaveTimerCallBack"));

	if(iTimerState == DIicBusChannelSlave::EWaitForMaster)

		{

		// Master timeout. Consider the transaction terminated - call NotifyClient

		// to inform both the Client and the PSL, and update the state machine

		NotifyClient(EGeneralBusError);

		}

	else if(iTimerState == DIicBusChannelSlave::EWaitForClient)

		{

		// Client timeout. Instigate the PSL-specific bus error indication

		iTimerState=DIicBusChannelSlave::EClientTimeout;

		SendBusErrorAndReturn();

		}

	else

		{

		__ASSERT_DEBUG(0, Kern::Fault(KIicChannelPanic,__LINE__));

		}

	}

void DIicBusChannelSlave::StartTimerByState()

	{

	if(iTimerState == DIicBusChannelSlave::EWaitForMaster)

		{

		iTimeoutTimer.OneShot(NKern::TimerTicks(iMasterWaitTime),(*iClientTimeoutDfc));

		}

	else if(iTimerState == DIicBusChannelSlave::EWaitForClient)

		{

		iTimeoutTimer.OneShot(NKern::TimerTicks(iClientWaitTime),(*iClientTimeoutDfc));

		}

	else

		{

		__ASSERT_DEBUG(NULL, Kern::Fault(KIicChannelPanic,__LINE__));

		}

	}

void DIicBusChannelSlave::StopTimer()

	{

	iTimeoutTimer.Cancel();

	}

TInt DIicBusChannelSlave::UpdateReqTrig(TInt8& aCbTrigVal, TInt& aCallbackRet)

	{

    __KTRACE_OPT(KIIC, Kern::Printf("UpdateReqTrig"));

	TInt nextSteps = 0;

	iAccumTrig |= iNotif->iTrigger;	// Update the accumulated event history, regardless of if the trigger was requested

	if(iNotif->iTrigger & EGeneralBusError)

		{

		// In the event of a bus error, always cancel the timer and call the Client callback

		nextSteps |= (EStopTimer | EInvokeCb);

		iTimerState = EInactive;

		aCallbackRet = KErrGeneral;

		}

	else if(iNotif->iTrigger == EAsyncCaptChan)

		{

		// For asynchronous channel capture, no timers are involved - just call the Client callback

		nextSteps |= EInvokeCb;

		aCallbackRet = KErrCompletion;

		}

	else if((iNotif->iTrigger & iReqTrig) != 0)

		{

		// If a requested Rx event has occurred, clear all Rx flags from the requested triggers (similarly for Tx)

		if(iNotif->iTrigger & (ERxAllBytes | ERxUnderrun | ERxOverrun))

			{

			iReqTrig &= ~(ERxAllBytes | ERxUnderrun | ERxOverrun);

			}

		if(iNotif->iTrigger & (ETxAllBytes | ETxUnderrun | ETxOverrun))

			{

			iReqTrig &= ~(ETxAllBytes | ETxUnderrun | ETxOverrun);

			}

		if(iTimerState == EInactive)

			{

			nextSteps |= (EStartTimer | EInvokeCb);

			// The next state in the state machine depends on if all the requested events have occurred

			if(iReqTrig == 0)

				{

				// All triggers required have occurred, so transition to state EWaitForClient

				iTimerState = EWaitForClient;

				}

			else

				{

				// The Client can request both Rx an Tx triggers; if only one has occurred, must wait for

				// the Master to generate the other

				iTimerState = EWaitForMaster;

				}

			aCallbackRet = KErrNone;

			}

		else if(iTimerState == EWaitForMaster)

			{

			// The next state in the state machine depends on if all the requested events have occurred

			if(iReqTrig == 0)

				{

				// All triggers required have occurred, so transition to state EWaitForClient

				iTimerState = EWaitForClient;

				nextSteps |= (EStopTimer | EInvokeCb | EStartTimer);

				}

			else

				{

				// The Client can request both Rx an Tx triggers; if only one has occurred, must wait for

				// the Master to generate the other - so remain in this state, do not cancel the timer or

				// re-start it with a new timeout period. Still invoke the callback to notify the client

				// that at least one of the requested triggers has occurred.

				nextSteps |= EInvokeCb;

				}

			aCallbackRet = KErrNone;

			}

		else if((iTimerState == EWaitForClient) || (iTimerState == EClientTimeout))

			{

			// No triggers are expected in these states (iReqTrig==0).

			__ASSERT_DEBUG(NULL, Kern::Fault(KIicChannelPanic,__LINE__));

			}

		}

	aCbTrigVal = iAccumTrig;

	return nextSteps;

	}

void DIicBusChannelSlave::NotifyClient(TInt aTrigger)

	{

	TIicBusSlaveCallback* notif = iNotif;

	notif->iTrigger = aTrigger;	// Ensure ProcessData is provided with the trigger

	if(NKern::CurrentContext() == NKern::EThread && &(Kern::CurrentThread()) == iClient)

		{

		// PSL will update notif to represent the events that have occurred

		ProcessData(aTrigger, notif);

		// Only invoke the client's callback (and update the state machine) if one of the requested triggers has

		// occurred or if a bus error has been witnessed

		TInt8 callbackTrig=0;

		TInt callbackRet=0;

		TInt nextSteps = UpdateReqTrig(callbackTrig, callbackRet);

		if(nextSteps & EStopTimer)

			{

			iTimeoutTimer.Cancel();

			}

		if(nextSteps & EInvokeCb)

			{

			(notif->iCallback)(notif->iChannelId, (TInt)callbackRet, callbackTrig, notif->iRxWords, notif->iTxWords, notif->iParam);

			// Callback now processed, so re-initialise callback object members