// 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\usbcsc\usbcsc_bil.cpp

// 

//

#include <e32std.h>

#include <e32std_private.h>

#include <d32usbcsc.h>

#include <e32debug.h>

/** @file usbcsc_bil.cpp

	Buffer Interface Layer for USB Client Device driver stack, using shared chunks.

	@internalTechnology

*/

EXPORT_C TInt RDevUsbcScClient::FinalizeInterface()

	{

	TInt errorOrhandle = DoControl(EControlRealizeInterface); //returns a error value or chunk handle

	TInt r = iSharedChunk.SetReturnedHandle(errorOrhandle);

	iEndpointStatus = 0x00; //all endpoints are closed at the moment

	iAlternateSetting = 0;

	iNewAltSetting = 0;

	iAltSettingSeq = 0;

	return r;

	}

EXPORT_C TInt RDevUsbcScClient::FinalizeInterface(RChunk*& aChunk)

	{

	TInt errorOrhandle = DoControl(EControlRealizeInterface);

	iSharedChunk.SetReturnedHandle(errorOrhandle);

	iEndpointStatus = 0x00; //all endpoints are closed at the moment

	iAlternateSetting = 0;

	return aChunk->SetReturnedHandle(errorOrhandle);

	}

EXPORT_C TInt RDevUsbcScClient::OpenEndpoint(TEndpointBuffer& aEpB, TInt aEpI)

	{

	TUsbcScHdrEndpointRecord* endpointInf = NULL;

	TBuf8<KUsbDescSize_Endpoint> descriptor;

	TUsbcScChunkHeader chunkHeader(iSharedChunk);

	//Do some validity checks

	if((aEpB.iInState != TEndpointBuffer::ENotValid) && (aEpB.iOutState != TEndpointBuffer::ENotValid))

		return KErrArgument;

	TInt nEndpoints = chunkHeader.GetNumberOfEndpoints(iAlternateSetting);	

	if ((aEpI < KEp0Number) && (aEpI > nEndpoints)) // Check endpoint number range 

		return KErrNotFound;

	if(iEndpointStatus & (1 << aEpI)) // Check that endpoint isn't already opene

		return KErrInUse;

	if(aEpI == KEp0Number) //endpoint 0

		{

		TUsbcScHdrEndpointRecord ep0=  TUsbcScHdrEndpointRecord(KUsbcScEndpointZero, KUsbScHdrEpDirectionBiDir | KUsbScHdrEpTypeControl);

		aEpB.Construct(this,iSharedChunk.Base(), &ep0 ,aEpI, 

		(SUsbcScBufferHeader*) ((TUint)iSharedChunk.Base() + (chunkHeader.iBuffers)->Ep0Out()->Offset()));

		aEpB.iBufferStartAddr = (TUint8*) ((TUint)iSharedChunk.Base() + (chunkHeader.iBuffers)->Ep0In()->Offset());

		aEpB.iSize = chunkHeader.iBuffers->Ep0In()->Size();

		}

	else  // If normal endpoint (!ep0)

		{

		TUsbcScBufferRecord* buf = 	chunkHeader.GetBuffer(iAlternateSetting,aEpI,endpointInf);

		if (!buf)

			return KErrGeneral;

		// Set up endpoint members

		aEpB.iBufferStartAddr = (TUint8*)  (buf->Offset() + (TUint)iSharedChunk.Base());

		aEpB.iSize = buf->Size();

		TInt r = GetEndpointDescriptor(iAlternateSetting, aEpI, descriptor);

		if(r != KErrNone) // We need this to be able to calculate alignment

			{

			return r;

			}

		if (endpointInf->Direction()&KUsbScHdrEpDirectionIn)

			{  							//in case of IN endpoints, first endpoint buffer location points to end offset

			aEpB.Construct(this,iSharedChunk.Base(),endpointInf,aEpI);

			if (iInAltSetting==KErrEof)

			aEpB.iInState=TEndpointBuffer::EEOF;

			}

		else

			{

			SUsbcScBufferHeader *endpointHdr = (SUsbcScBufferHeader *) aEpB.iBufferStartAddr;

			//In this case,SUsbcScBufferHeader points to full OUT endpoint header 

			aEpB.Construct(this,iSharedChunk.Base(),endpointInf,aEpI, endpointHdr);

			}

		}

	iEndpointStatus |= (1 << aEpI);	

#ifdef _DEBUG

	aEpB.Dump();

	RDebug::Printf("iEndpointStatus: %x \n",iEndpointStatus);

#endif

	return KErrNone;

	}

//Internal, used by RDevUsbcScClient::StartNextOutAlternateSetting(...)

//This drains any old data from an OUT buffer, and gets it ready for reading an ep.

//aBufferOffset - The offset, into the chunk, that the buffer in question, may be found.

TInt RDevUsbcScClient::Drain(TUint aBufferOffset)

{

	TUint8* base = iSharedChunk.Base();

	SUsbcScBufferHeader* endpointHdr = (SUsbcScBufferHeader*) (aBufferOffset+base);

	TUint localTail = endpointHdr->iBilTail;

	TUsbcScTransferHeader* currentTransfer;

	TUint16 next = (iAltSettingSeq+1)&0xFFFF;

	TInt err=KErrNone;

	while (ETrue)

		{

		if (localTail == (TUint) endpointHdr->iHead)

			{

			err = KErrNotReady;

			break;

			}

		currentTransfer = (TUsbcScTransferHeader*) (base + localTail);

		if (currentTransfer->iAltSettingSeq == next)

			{

			iNewAltSetting=currentTransfer->iAltSetting; // record new alt setting

			break;

			}

		else

			{

			localTail = currentTransfer->iNext;

			}

		} // end while

	endpointHdr->iBilTail = localTail;

	endpointHdr->iTail = localTail;

	return err;

}

//Internal, used by RDevUsbcScClient::StartNextOutAlternateSetting(...)

//This method checks that the OUT buffer is ready for reading an ep.

//aBufferOffset - The offset, into the chunk, that the buffer in question, may be found.

TInt RDevUsbcScClient::Peek(TUint aBufferOffset)

{

	TUint8* base = iSharedChunk.Base();

	SUsbcScBufferHeader* endpointHdr = (SUsbcScBufferHeader*) (aBufferOffset+base);

	TUint localTail = endpointHdr->iBilTail;

	TUsbcScTransferHeader* currentTransfer = (TUsbcScTransferHeader*) (base + localTail);

	if ((localTail == (TUint)endpointHdr->iHead) || (currentTransfer->iAltSettingSeq != (iAltSettingSeq+1)&0xFFFF))

		// if alternate setting has not changed

		return KErrNotReady;

	else

		{

		iNewAltSetting=currentTransfer->iAltSetting;

		return KErrNone;

		}

}

//Internal, used by RDevUsbcScClient::StartNextOutAlternateSetting(...)

//This method is called if an alternate setting change happens from a set of ONLY IN endpoints.

//Used to find the least possible alternate setting it can return to the user, stored in iNewAltSetting

//Returns the sequence number of the 'latest' alternate setting it can switch to

TInt RDevUsbcScClient::FindNextAlternateSetting()

	{

	TUsbcScChunkHeader chunkHeader(iSharedChunk);

	TUsbcScHdrEndpointRecord* endpointInf = NULL;

	TUint bufOff;

	TInt altSet;

	TInt ep;

	TInt bufNum;

	RArray <TInt> bufferOffset;	// Array to contain all OUT enpoint buffer offsets

	// Populate array

	for (altSet = 0; altSet < chunkHeader.iAltSettings->iNumOfAltSettings ; altSet++)

		{

		TInt numEndpoints = chunkHeader.GetNumberOfEndpoints(altSet);

		for (ep =  1; ep  <= numEndpoints ; ep ++)

			{

			bufOff = chunkHeader.GetBuffer(altSet, ep, endpointInf)->Offset();	

			if ((endpointInf->Direction() & KUsbScHdrEpDirectionOut) && (bufferOffset.Find(bufOff) == KErrNotFound))

				{

				bufferOffset.Append(bufOff);

				}

			}

		}

	TInt err = KErrNotFound;

	TUint16 altSetSeqDelta = 0;

	TUint16 currentaltSetSeqDelta = 0;

	TBool noNewSettingFound = ETrue;

	TInt altSetSeq = iAltSettingSeq;

	TUint8* base = iSharedChunk.Base();

	for (bufNum = 0; bufNum < bufferOffset.Count(); bufNum++) // Scan all OUT buffers

		{	

		SUsbcScBufferHeader* endpointHdr = (SUsbcScBufferHeader*) (bufferOffset[bufNum] + base);

		TUint localTail = endpointHdr->iBilTail;

		TUsbcScTransferHeader* currentTransfer;

		TUint16 next = (iAltSettingSeq+1)&0xFFFF;

		while (ETrue)

			{

			if (localTail == (TUint) endpointHdr->iHead)

				{

				break;	// This OUT endpoint buffer has no data, proceed checking with other OUT endpoint buffers

				}

			currentTransfer = (TUsbcScTransferHeader*) (base + localTail);

			if (currentTransfer->iAltSettingSeq != iAltSettingSeq) 

				{

				if (currentTransfer->iAltSettingSeq == next)

					{

					altSetSeq = currentTransfer->iAltSettingSeq;

					iNewAltSetting = currentTransfer->iAltSetting; // record new alt setting

					err = KErrNone;

					break;

					}

				if (noNewSettingFound)

					{

					altSetSeqDelta = Abs(iAltSettingSeq - currentTransfer->iAltSettingSeq);

					altSetSeq = currentTransfer->iAltSettingSeq;

					iNewAltSetting = currentTransfer->iAltSetting; // record new alt setting

					noNewSettingFound = EFalse;

					}

				else

					{

					currentaltSetSeqDelta = Abs(iAltSettingSeq - currentTransfer->iAltSettingSeq);

					if (currentaltSetSeqDelta < altSetSeqDelta)

						{

						altSetSeqDelta = currentaltSetSeqDelta;

						altSetSeq = currentTransfer->iAltSettingSeq;

						iNewAltSetting = currentTransfer->iAltSetting;

						}

					}

				break;

				}

			localTail = currentTransfer->iNext;

			} // end while

		if (!err) // Found an alt set sequence one after iAltSettingSeq

			{

			break; // found 'the next' alternate setting, exit for loop

			}

		}// for loop

	return altSetSeq;

	}

EXPORT_C TInt RDevUsbcScClient::StartNextOutAlternateSetting(TBool aFlush)

	{

	TUsbcScChunkHeader chunkHeader(iSharedChunk);

	//if endpoints are still open, return KErrInUse 

	if((iEndpointStatus&~1) != 0)

		{

		return KErrInUse;

		}

	TInt r;

	TInt ep;

	TInt noEp;

	TUint bufOff;

	TBool inEndpointSet = ETrue;

	TUsbcScHdrEndpointRecord* endpointInf = NULL;

	// check if alternate setting contains all IN endpoints

	noEp = chunkHeader.GetNumberOfEndpoints(iAlternateSetting);

	// for each used buffer. 

	for (ep=1;ep<=noEp;ep++)

		{

		bufOff = chunkHeader.GetBuffer(iAlternateSetting,ep,endpointInf)->Offset();	

		if (endpointInf->Direction() & KUsbScHdrEpDirectionOut) 

			{

			inEndpointSet = EFalse;

			if (aFlush)

				r = Drain(bufOff); // we need to remove anythng in the way, and get it ready for reading.

			else

				r = Peek(bufOff); // we need to check it is ready for reading!

			if (r) 

				return r;

			}

		}

	TInt altSeq = 0;

	if (inEndpointSet)	// If all endpoints in the current alternate setting are IN endpoints

		{	// go through all OUT buffers for alternate setting change

		altSeq = FindNextAlternateSetting();

		}

	if((iNewAltSetting == iAlternateSetting) && (!inEndpointSet))

			{

			return KErrNotReady;

			}

	// Find/Set IN alternate setting

	TInt ret = StartNextInAlternateSetting();

	SUsbcScAlternateSetting* altrec = ((SUsbcScAlternateSetting*) (&ret));

	if (altrec->iSequence==iAltSettingSeq+1)

		{

		if (altrec->iSetting!=iNewAltSetting)

			return KErrGeneral;

		iInAltSetting=iNewAltSetting;

		}

	else

		{

		if (inEndpointSet)

			{

			if ((altSeq == iAltSettingSeq) || (iAltSettingSeq == altrec->iSequence))

				{

				return KErrNotReady;

				}

			else if (altSeq != altrec->iSequence)

				{

				iInAltSetting=KErrEof;

				}

			}

		iInAltSetting=KErrEof;

		}

	iAlternateSetting = iNewAltSetting;

	iAltSettingSeq += 1;

	return iAlternateSetting;

	}

EXPORT_C TInt RDevUsbcScClient::GetDataTransferChunk(RChunk* & aChunk)

	{

	aChunk = &iSharedChunk;

	return KErrNone;

	}

// Constructor

EXPORT_C TEndpointBuffer::TEndpointBuffer()

		:iInState(ENotValid),

		iOutState(ENotValid),

		iEndpointNumber(-1),

		iBufferNum(-1),

		iBufferStartAddr(0),

		iSize(0)

	{

	}

// Internal, called by RDevUsbcScClient::OpenEndpoint.

void TEndpointBuffer::Construct(RDevUsbcScClient* aClient, TUint8* aBaseAddr, const TUsbcScHdrEndpointRecord* aEpType , TInt aEndpointNumber,SUsbcScBufferHeader* aEndpointHdr)

	{

	iClient		= aClient;

	iBaseAddr	= (TUint) aBaseAddr;

	iInState 	= (((aEpType->Direction())&KUsbScHdrEpDirectionIn) ? EValid :  ENotValid);

	iOutState	= (((aEpType->Direction())&KUsbScHdrEpDirectionOut) ? EValid :  ENotValid);

	iBufferNum	= (aEpType->iBufferNo==(KUsbcScEndpointZero&0xFF))?KUsbcScEndpointZero:aEpType->iBufferNo;

	iEndpointNumber = aEndpointNumber;

	iEndpointHdr = aEndpointHdr;

	};

EXPORT_C TInt TEndpointBuffer::GetInBufferRange(TAny*& aStart, TUint& aSize)

	{

	if ((iInState))

		{

		return iInState;

		}

	aStart= iBufferStartAddr;

	aSize= iSize;

	return KErrNone;

	};

EXPORT_C TInt TEndpointBuffer::GetInBufferRange(TUint& aStart, TUint& aSize)

	{

	if ((iInState))

		return iInState;

	aStart=	(TUint) iBufferStartAddr - iBaseAddr;

	aSize= iSize;

	return KErrNone;

	}

EXPORT_C TInt TEndpointBuffer::GetBuffer(TAny*& aBuffer,TUint& aSize,TBool& aZLP,TRequestStatus& aStatus,TUint aLength)

	{

	if (iOutState)

		return iOutState;

	TUsbcScTransferHeader* currentTransfer;

	TInt r;

	do // until we have a transfer with data.

		{

		iEndpointHdr->iTail = iEndpointHdr->iBilTail; 

		if(iEndpointHdr->iBilTail == iEndpointHdr->iHead)  //If no new data, create request

			{

			r = iClient->ReadDataNotify(iBufferNum,aStatus);

			if (r!=KErrCompletion)  // Data could arrive since we checked.

				return r;

			}

		currentTransfer = (TUsbcScTransferHeader*) (iBaseAddr + iEndpointHdr->iBilTail);

		iEndpointHdr->iBilTail = currentTransfer->iNext;

		aZLP = (currentTransfer->iFlags & KUsbcScShortPacket)!=EFalse;

		if(currentTransfer->iAltSettingSeq != (iClient->iAltSettingSeq))  // if alternate setting has changed

			{

			if (currentTransfer->iAltSettingSeq == (iClient->iAltSettingSeq+1))	   //Note- KIS ATM, if multiple alternate setting changes happen

				iClient->iNewAltSetting = currentTransfer->iAltSetting; //before StartNextOutAlternateSetting is called, 		   

																	   //this variable will reflect the latest requested AlternateSetting

			if (iEndpointNumber != KEp0Number)

				{

//				iOutState =  EEOF;	

				return KErrEof;

				}

			else if ((currentTransfer->iBytes==0) && (!aZLP)) 

				{

				return KErrAlternateSettingChanged;

				}

			}						

		}

	while ((currentTransfer->iBytes==0) && (!aZLP)); // ignore empty transfers

	aBuffer = currentTransfer->iData.i;

	aSize = currentTransfer->iBytes;	

	return (currentTransfer->iFlags & KUsbcScStateChange)?KStateChange:KErrCompletion;	

	}

EXPORT_C TInt TEndpointBuffer::TakeBuffer(TAny*& aBuffer,TUint& aSize,TBool& aZLP,TRequestStatus& aStatus,TUint aLength)

	{

	if (iOutState)

		return iOutState;

	TUsbcScTransferHeader* currentTransfer;

	TInt r;

	do // until we have a transfer with data.

		{

		if(iEndpointHdr->iBilTail == iEndpointHdr->iHead)  //If no new data, create request

			{

			r = iClient->ReadDataNotify(iBufferNum,aStatus);

			if (r!=KErrCompletion)  // Data could arrive since we checked.

				{

				return r;

				}

			}

		currentTransfer = (TUsbcScTransferHeader*) (iBaseAddr + iEndpointHdr->iBilTail);

		iEndpointHdr->iBilTail = currentTransfer->iNext;

		aZLP = (currentTransfer->iFlags & KUsbcScShortPacket)!=EFalse; // True if short packet else false 

		if(currentTransfer->iAltSettingSeq != (iClient->iAltSettingSeq))  // if alternate setting has changed

			{

			if (currentTransfer->iAltSettingSeq == (iClient->iAltSettingSeq+1))	   //Note- KIS ATM, if multiple alternate setting changes happen

				iClient->iNewAltSetting = currentTransfer->iAltSetting; //before StartNextOutAlternateSetting is called, 		   

																	   //this variable will reflect the latest requested AlternateSetting

			Expire(currentTransfer->iData.i);

			if (iEndpointNumber != KEp0Number)

				{

//				iOutState = EEOF;

				return KErrEof;

				}

			else if ((currentTransfer->iBytes==0) && (!aZLP)) 

				{

				return KErrAlternateSettingChanged;

				}

			}	

		if ((currentTransfer->iBytes==0) && (!aZLP)) // here , if empty transfer with alt setting information, Call expire 

			{

			Expire(currentTransfer->iData.i);

			}

		}

	while ((currentTransfer->iBytes==0) && (!aZLP)); // ignore empty transfers

	aBuffer = currentTransfer->iData.i;

	aSize = currentTransfer->iBytes;

	return (currentTransfer->iFlags & KUsbcScStateChange)?KStateChange:KErrCompletion;	

	}

EXPORT_C TInt TEndpointBuffer::Expire()

	{

	if (!(iOutState != ENotValid))

		return iOutState;

	if (iEndpointHdr->iTail != iEndpointHdr->iBilTail)

		{

		TUsbcScTransferHeader* currentTransfer = (TUsbcScTransferHeader*) (iBaseAddr + iEndpointHdr->iTail);

		iEndpointHdr->iTail = currentTransfer->iNext;

		}

	return KErrNone;

	}

EXPORT_C TInt TEndpointBuffer::Expire(TAny* aAddress)

	{

	if (!(iOutState != ENotValid))

		return iOutState;

	TUint headerSize = sizeof(TUsbcScTransferHeader)-4; // TransferHeader includes 4 bytes of data.

	TInt transferToExpire = ((TUint) aAddress - headerSize);

	TInt offsetToExpire = transferToExpire - iBaseAddr; 

	TInt currentTail = iEndpointHdr->iTail;

	TInt prevTail = NULL;

	TBool found = EFalse;

	while (currentTail != iEndpointHdr->iBilTail)

		{