hardware bug in the revision of the Samsung SC2440
				CPU this driver was developed on.  See the header
				at the top of this file for details.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
BOOL HardwareContext::StartInputDMA()
{
	//------ On platforms with the revsion of the Samsung SC2440 CPU with the IIS SLAVE bug fix, this -----
	//		 code can be used to configure DMA channel 1 for input.

	AC97MSG(1,(TEXT("+++StartInputDMA\n")));

	if(!m_InputDMARunning)
    {
        //----- 1. Initialize our buffer counters -----
        m_InputDMARunning=TRUE;
		Codec_channel();        // Turn On Input channel
        m_InBytes[IN_BUFFER_A]=m_InBytes[IN_BUFFER_B]=0;

        //----- 2. Prime the output buffer with sound data -----
		m_InputDMAStatus = (DMA_DONEA | DMA_DONEB) & ~DMA_BIU;	

		//----- 3. Configure the DMA channel for record -----
		if(!InitInputDMA())
		{
			DEBUGMSG(ZONE_ERROR, (TEXT("HardwareContext::StartInputDMA() - Unable to initialize input DMA channel!\r\n")));
			goto START_ERROR;
		}

#if	DMA_FLAG
		v_pAC97regs->rAC_GLBCTRL = (v_pAC97regs->rAC_GLBCTRL & ~(0x3<<8)) | (0x2<<8);	// 0x2 = DMA
#else
		v_pAC97regs->rAC_GLBCTRL = (v_pAC97regs->rAC_GLBCTRL & ~(0x3<<8)) | (0x1<<8);	// 0x1 = PIO
#endif	
	
		//----- 4. Make sure the audio isn't muted -----
		AudioMute(DMA_CH_MIC, FALSE);					

		//----- 5. Start the input DMA -----
		AUDIO_RESET_RECORD_POINTER();
		SELECT_AUDIO_DMA_INPUT_BUFFER_A();

		Codec_channel();        // Turn On Input channel
		v_pDMAregs->rDMASKTRIG2 = ENABLE_DMA_CHANNEL;		
		
#if DMA_FLAG			
        // wait for DMA to start.
        delay_count = 0;
        while((v_pDMAregs->rDSTAT2&0xfffff)==0){
        	RETAILMSG(1,(_T("2")));

#if WAIT_DMA_END
			Sleep(1);
#else
        	if( delay_count++ > DELAY_COUNT )	break;
#endif
        } 
        // change the buffer pointer
        SELECT_AUDIO_DMA_INPUT_BUFFER_B();
#endif	        
				
    }
    AC97MSG(1,(TEXT("---StartInputDMA\n")));
	return TRUE;

START_ERROR:
	return FALSE;
}

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		StopInputDMA()

Description:	Stops any DMA activity on the input channel.

Notes:			***** NOT IMPLEMENTED *****

				The following routine is not implemented due to a
				hardware bug in the revision of the Samsung SC2440
				CPU this driver was developed on.  See the header
				at the top of this file for details.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
void HardwareContext::StopInputDMA()
{

	//------ On platforms with the revsion of the Samsung SC2440 CPU with the IIS SLAVE bug fix, this -----
	//		 code can be used to configure DMA channel 1 for input.

	//----- 1. If the output DMA is running, stop it -----
    if (m_InputDMARunning)
	{
		AUDIO_IN_DMA_DISABLE(); // jylee
		AUDIO_IN_CLEAR_INTERRUPTS();

		m_InputDMAStatus = DMA_CLEAR;				

		v_pAC97regs->rAC_GLBCTRL = (v_pAC97regs->rAC_GLBCTRL & ~(0x3<<8)) | (0x0<<8);	// 0x0 = OFF
		
		AudioMute(DMA_CH_MIC, TRUE);		
    }

	m_InputDMARunning = FALSE;
	Codec_channel();
}


DWORD HardwareContext::GetInterruptThreadPriority()
{
    HKEY hDevKey;
    DWORD dwValType;
    DWORD dwValLen;
    DWORD dwPrio = 249; // Default priority

    hDevKey = OpenDeviceKey((LPWSTR)m_DriverIndex);
    if (hDevKey)
    {
        dwValLen = sizeof(DWORD);
        RegQueryValueEx(
            hDevKey,
            TEXT("Priority256"),
            NULL,
            &dwValType,
            (PUCHAR)&dwPrio,
            &dwValLen);
        RegCloseKey(hDevKey);
    }

    return dwPrio;
}

/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
// SetForceSpeaker is called from the device context to update the state of the
// m_bForceSpeaker variable.
/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8

DWORD HardwareContext::ForceSpeaker( BOOL bForceSpeaker )
{
    // If m_NumForcedSpeaker is non-zero, audio should be routed to an
    // external speaker (if hw permits).
    if (bForceSpeaker)
    {
        m_NumForcedSpeaker++;
        if (m_NumForcedSpeaker==1)
        {
            RecalcSpeakerEnable();
        }
    }
    else
    {
        m_NumForcedSpeaker--;
        if (m_NumForcedSpeaker==0)
        {
            RecalcSpeakerEnable();
        }
    }

    return MMSYSERR_NOERROR;
}

// Control the hardware speaker enable
void HardwareContext::SetSpeakerEnable(BOOL bEnable)
{
    // Code to turn speaker on/off here
    return;
}

/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
// RecalcSpeakerEnable decides whether to enable the speaker or not.
// For now, it only looks at the m_bForceSpeaker variable, but it could
// also look at whether the headset is plugged in
// and/or whether we're in a voice call. Some mechanism would
// need to be implemented to inform the wave driver of changes in the state of
// these variables however.
/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8

void HardwareContext::RecalcSpeakerEnable()
{
    SetSpeakerEnable(m_NumForcedSpeaker);
}

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		InitInterruptThread()

Description:	Initializes the IST for handling DMA interrupts.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
BOOL HardwareContext::InitInterruptThread()
{
    BOOL bSuccess;
    
    m_hAudioInterrupt = CreateEvent( NULL, FALSE, FALSE, NULL);

    if (!m_hAudioInterrupt)
    {
        return FALSE;
    }

    bSuccess = InterruptInitialize(m_IntrAudio, m_hAudioInterrupt, NULL, 0);

    m_hAudioInterruptThread  = CreateThread((LPSECURITY_ATTRIBUTES)NULL,
                                            0,
                                            (LPTHREAD_START_ROUTINE)CallInterruptThread,
                                            this,
                                            0,
                                            NULL);
    if (!m_hAudioInterruptThread)
    {
        return FALSE;
    }

    // Bump up the priority since the interrupt must be serviced immediately.
	CeSetThreadPriority(m_hAudioInterruptThread, GetInterruptThreadPriority());

    return TRUE;
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		PowerUp()

Description:	Powers up the audio codec chip.

Notes:			Currently, this function is unimplemented because
				the audio codec chip is ONLY powered up when the 
				user wishes to play or record.  The AudioMute() function
				handles the powerup sequence.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
void HardwareContext::PowerUp()
{
    RETAILMSG(1,(_T("AC97:PowerUP()\r\n")));

    AC97_Init();
    //AC97_GPIO_Init();
    
    InitCodec();
    
    //AudioMute(DMA_CH_OUT, FALSE);		// 030711

    // setup DMA output
    //InitOutputDMA();

    //AudioMute((DMA_CH_OUT | DMA_CH_MIC), FALSE);
    AudioMute(DMA_CH_OUT, FALSE);
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		PowerDown()

Description:	Powers down the audio codec chip.

Notes:			Even if the input/output channels are muted, this
				function powers down the audio codec chip in order
				to conserve battery power.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
void HardwareContext::PowerDown()
{
    RETAILMSG(1,(_T("AC97:PowerDown()\r\n")));
    //StopOutputDMA();

	m_OutputDMAStatus = DMA_CLEAR;				
	AUDIO_OUT_DMA_DISABLE();
	AUDIO_OUT_CLEAR_INTERRUPTS();

	v_pAC97regs->rAC_GLBCTRL = (v_pAC97regs->rAC_GLBCTRL & ~(0x3<<12)) | (0x0<<12);	// 0x0 = OFF

	//AudioMute(DMA_CH_OUT, TRUE);		


	m_OutputDMARunning = FALSE;
	m_InputDMARunning = FALSE;

	AudioMute((DMA_CH_OUT | DMA_CH_MIC), TRUE);
}


//############################################ Helper Functions #############################################

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		TransferOutputBuffer()

Description:	Retrieves the next "mixed" audio buffer of data to
				DMA into the output channel.

Returns:		Number of bytes needing to be transferred.
-------------------------------------------------------------------*/
ULONG HardwareContext::TransferOutputBuffer(ULONG NumBuf)
{
    ULONG BytesTransferred = 0;

    PBYTE pBufferStart = m_Output_pbDMA_PAGES[NumBuf];
    PBYTE pBufferEnd = pBufferStart + AUDIO_DMA_PAGE_SIZE;
    PBYTE pBufferLast;

	__try
	{
		pBufferLast = m_OutputDeviceContext.TransferBuffer(pBufferStart, pBufferEnd,NULL);
		BytesTransferred = m_OutBytes[NumBuf] = pBufferLast-pBufferStart;

		// Enable if you need to clear the rest of the DMA buffer
		StreamContext::ClearBuffer(pBufferLast,pBufferEnd);
		//memset(pBufferStart, 0, AUDIO_DMA_PAGE_SIZE);
		
		if(NumBuf == OUT_BUFFER_A)			// Output Buffer A
		{
			m_OutputDMAStatus &= ~DMA_DONEA;
			m_OutputDMAStatus |= DMA_STRTA;
		}
		else								// Output Buffer B
		{
			m_OutputDMAStatus &= ~DMA_DONEB;
			m_OutputDMAStatus |= DMA_STRTB;
		}
	}
	__except(EXCEPTION_EXECUTE_HANDLER) 
	{
		DEBUGMSG(ZONE_ERROR, (TEXT("WAVDEV2.DLL:TransferOutputBuffer() - EXCEPTION: %d"), GetExceptionCode()));
	}

    return BytesTransferred;
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		TransferOutputBuffers()

Description:	Determines which output buffer (A or B) needs to 
				be filled with sound data.  The correct buffer is
				then populated with data and ready to DMA to the 
				output channel.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
ULONG HardwareContext::TransferOutputBuffers(DWORD dwDCSR)
{
    ULONG BytesTransferred = 0;

    ULONG BytesTotal;
    DWORD Bits = dwDCSR & (DMA_DONEA|DMA_DONEB|DMA_BIU);

	switch (Bits)
    {
    case 0:
    case DMA_BIU:
        // No done bits set- must not be my interrupt
        return 0;
    case DMA_DONEA|DMA_DONEB|DMA_BIU:
        // Load B, then A
        BytesTransferred = TransferOutputBuffer(OUT_BUFFER_B);
        // fall through
    case DMA_DONEA: // This should never happen!
    case DMA_DONEA|DMA_BIU:
		BytesTransferred += TransferOutputBuffer(OUT_BUFFER_A);		// charlie, A => B
        break;
    case DMA_DONEA|DMA_DONEB:
        // Load A, then B
        BytesTransferred = TransferOutputBuffer(OUT_BUFFER_A);
#if DMA_FLAG        
        // charlie
        BytesTransferred += TransferOutputBuffer(OUT_BUFFER_B);
        break;		// charlie
#endif        
        // fall through
    case DMA_DONEB|DMA_BIU: // This should never happen!
    case DMA_DONEB:
        // Load B
        BytesTransferred += TransferOutputBuffer(OUT_BUFFER_B);		// charlie, B => A
        break;
    }

    // If it was our interrupt, but we weren't able to transfer any bytes
    // (e.g. no full buffers ready to be emptied)
    // and all the output DMA buffers are now empty, then stop the output DMA
    BytesTotal = m_OutBytes[OUT_BUFFER_A]+m_OutBytes[OUT_BUFFER_B];

	if (BytesTotal==0)
    {
		StopOutputDMA();
    }
    return BytesTransferred;
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		TransferInputBuffer()

Description:	Retrieves the chunk of recorded sound data and inputs
				it into an audio buffer for potential "mixing".

Returns:		Number of bytes needing to be transferred.
-------------------------------------------------------------------*/
ULONG HardwareContext::TransferInputBuffer(ULONG NumBuf)
{
    ULONG BytesTransferred = 0;

    PBYTE pBufferStart = m_Input_pbDMA_PAGES[NumBuf];
    PBYTE pBufferEnd = pBufferStart + AUDIO_DMA_PAGE_SIZE;
    PBYTE pBufferLast;

	__try
	{
		pBufferLast = m_InputDeviceContext.TransferBuffer(pBufferStart, pBufferEnd,NULL);
		BytesTransferred = m_InBytes[NumBuf] = pBufferLast-pBufferStart;

		if(NumBuf == IN_BUFFER_A)			// Input Buffer A
		{
			m_InputDMAStatus &= ~DMA_DONEA;
			m_InputDMAStatus |= DMA_STRTA;
		}
		else								// Input Buffer B
		{
			m_InputDMAStatus &= ~DMA_DONEB;
			m_InputDMAStatus |= DMA_STRTB;
		}

	}
	__except(EXCEPTION_EXECUTE_HANDLER) 
	{
		DEBUGMSG(ZONE_ERROR, (TEXT("WAVDEV2.DLL:TransferInputBuffer() - EXCEPTION: %d"), GetExceptionCode()));
	}

    return BytesTransferred;
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		TransferInputBuffers()

Description:	Determines which input buffer (A or B) needs to 
				be filled with recorded sound data.  The correct 
				buffer is then populated with recorded sound data
				from the input channel.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
ULONG HardwareContext::TransferInputBuffers(DWORD dwDCSR)
{
    ULONG BytesTransferred=0;