hwctxt.cpp

基于WINCE 的音频驱动源码

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		StartOutputDMA()

Description:	Starts outputting the sound data to the audio codec
				chip via DMA.

Notes:			Currently, both playback and record share the same
				DMA channel.  Consequently, we can only start this
				operation if the input channel isn't using DMA.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
BOOL HardwareContext::StartOutputDMA()
{
	DEBUGMSG(ZONE_FUNCTION,(TEXT("+++StartOutputDMA\n")));
	
    if(!m_OutputDMARunning)
    {
        //----- 1. Initialize our buffer counters -----
        m_OutputDMARunning=TRUE;
        m_OutBytes[OUT_BUFFER_A]=m_OutBytes[OUT_BUFFER_B]=0;

        //----- 2. Prime the output buffer with sound data -----
		m_OutputDMAStatus = (DMA_DONEA | DMA_DONEB) & ~DMA_BIU;	
		ULONG OutputTransferred = TransferOutputBuffers(m_OutputDMAStatus);
        
		//----- 3. If we did transfer any data to the DMA buffers, go ahead and enable DMA -----
		if(OutputTransferred)
        {
			//----- 4. Configure the DMA channel for playback -----
			if(!InitOutputDMA())
			{
				DEBUGMSG(ZONE_ERROR, (TEXT("HardwareContext::StartOutputDMA() - Unable to initialize output DMA channel!\r\n")));
				goto START_ERROR;
			}
			////////////////////////////////////////////////////////////////////////////////
			// To correct left/right channel on ouput stream,
			// You should reset IISCON[0] bit.
			Lock();
			g_pIISregs->IISCON  &= ~IIS_INTERFACE_ENABLE;
			g_pIISregs->IISCON |= TRANSMIT_DMA_REQUEST_ENABLE;
			g_pIISregs->IISCON &= ~TRANSMIT_IDLE_CMD;
			g_pIISregs->IISFCON |= (  TRANSMIT_FIFO_ACCESS_DMA | TRANSMIT_FIFO_ENABLE  );
			g_pIISregs->IISMOD  |= IIS_TRANSMIT_MODE;
			//----- 5. Make sure the audio isn't muted -----
			AudioMute(DMA_CH_OUT, FALSE);					

			//----- 6. Start the DMA controller -----
			AUDIO_RESET_PLAYBACK_POINTER();
			SELECT_AUDIO_DMA_OUTPUT_BUFFER_A();
			Codec_channel();								// Turn ON output channel
			// charlie, start A buffer
			AUDIO_OUT_DMA_ENABLE();
	        // wait for DMA to start.
	        while((g_pDMAregs->DSTAT2&0xfffff)==0);        
			// check if tx fifo data is ready
			while ( !(g_pIISregs->IISCON & (1<<7)) ) ;

			g_pIISregs->IISCON  |= IIS_INTERFACE_ENABLE;
			Unlock();
			////////////////////////////////////////////////////////////////////////////////
	        // change the buffer pointer
	        SELECT_AUDIO_DMA_OUTPUT_BUFFER_B();
	        // Set DMA for B Buffer
        }
        else    // We didn't transfer any data, so DMA wasn't enabled
        {
            m_OutputDMARunning=FALSE;
        }
    }
    
    DEBUGMSG(ZONE_FUNCTION,(TEXT("---StartOutputDMA\n")));

	return TRUE;

START_ERROR:
	return FALSE;
}

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		StopOutputDMA()

Description:	Stops any DMA activity on the output channel.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
void HardwareContext::StopOutputDMA()
{
	//----- 1. If the output DMA is running, stop it -----
    if (m_OutputDMARunning)
	{
		m_OutputDMAStatus = DMA_CLEAR;				
		AUDIO_OUT_DMA_DISABLE();
		AUDIO_OUT_CLEAR_INTERRUPTS();
		while(g_pIISregs->IISCON & (1<<7)); // wait for tx fifo empty
		g_pIISregs->IISCON &= ~TRANSMIT_DMA_REQUEST_ENABLE;
		g_pIISregs->IISCON |= TRANSMIT_IDLE_CMD;
		g_pIISregs->IISFCON &= ~(  TRANSMIT_FIFO_ACCESS_DMA | TRANSMIT_FIFO_ENABLE  );
		g_pIISregs->IISMOD  &= ~IIS_TRANSMIT_MODE;
		AudioMute(DMA_CH_OUT, TRUE);		
    }

	m_OutputDMARunning = FALSE;
	Codec_channel();
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		InitInputDMA()

Description:	Initializes the DMA channel for input.

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
-------------------------------------------------------------------*/
BOOL HardwareContext::InitInputDMA()
{

	DEBUGMSG(ZONE_FUNCTION,(TEXT("+++InitInputDMA\n")));

    if (!g_PhysDMABufferAddr.LowPart)
    {
        DEBUGMSG(TRUE, (TEXT("ERROR:HardwareContext::InitInputDMA: Invalid DMA buffer physical address.\r\n")));
        return(FALSE);
    }

	//============================ Configure DMA Channel 1 ===========================
	//------ 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. Initialize the DMA channel for input mode and use the first input DMA buffer -----
	g_pDMAregs->DISRC1	= (int)(S3C2440A_BASE_REG_PA_IISBUS+0x10);
	g_pDMAregs->DISRCC1 = (SOURCE_PERIPHERAL_BUS | FIXED_SOURCE_ADDRESS);				// Source is periperal bus, fixed addr
    
    //----- 2. Initialize the DMA channel to receive data over the I2S bus -----
    g_pDMAregs->DIDST1	= (int)(g_PhysDMABufferAddr.LowPart); 
    g_pDMAregs->DIDSTC1 &= ~(DESTINATION_PERIPHERAL_BUS | FIXED_DESTINATION_ADDRESS);	// Destination is system bus, increment addr

	//----- 3. Configure the DMA channel's transfer characteristics: handshake, sync PCLK, interrupt, -----
	//		   single tx, single service, I2SSDI, I2S request, no auto-reload, half-word, tx count
	g_pDMAregs->DCON1	= (  HANDSHAKE_MODE | GENERATE_INTERRUPT | I2SSDI_DMA1 | DMA_TRIGGERED_BY_HARDWARE 
                           | TRANSFER_HALF_WORD | (AUDIO_DMA_PAGE_SIZE / 2)
                            );
	return(TRUE);
}


/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Function:		StartInputDMA()

Description:	Starts inputting the recorded sound data from the 
				audio codec chip via DMA.

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
-------------------------------------------------------------------*/
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.

	DEBUGMSG(ZONE_FUNCTION,(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;
		}
		g_pIISregs->IISFCON |= (RECEIVE_FIFO_ACCESS_DMA  | RECEIVE_FIFO_ENABLE);
		g_pIISregs->IISCON  |= RECEIVE_DMA_REQUEST_ENABLE;	 
		g_pIISregs->IISMOD  |= IIS_RECEIVE_MODE;
	
		//----- 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
		g_pDMAregs->DMASKTRIG1 = ENABLE_DMA_CHANNEL;		
		
        // wait for DMA to start.
        while((g_pDMAregs->DSTAT1&0xfffff)==0);        
        // change the buffer pointer
        SELECT_AUDIO_DMA_INPUT_BUFFER_B();
				
    }
    DEBUGMSG(ZONE_FUNCTION,(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)
	{
		m_InputDMAStatus = DMA_CLEAR;				
		
		g_pIISregs->IISCON &= ~RECEIVE_DMA_REQUEST_ENABLE;
		g_pIISregs->IISFCON &= ~(RECEIVE_FIFO_ACCESS_DMA  | RECEIVE_FIFO_ENABLE);
		g_pDMAregs->DMASKTRIG1 |= STOP_DMA_TRANSFER;
		g_pDMAregs->DMASKTRIG1 &= ~ENABLE_DMA_CHANNEL;
		g_pIISregs->IISMOD  &= ~IIS_RECEIVE_MODE;
		AUDIO_IN_CLEAR_INTERRUPTS();
		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;
}



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

Description:	Initializes the IST for handling DMA interrupts.

Returns:		Boolean indicating success
-------------------------------------------------------------------*/
BOOL HardwareContext::InitInterruptThread()
{
    m_hAudioInterrupt = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (!m_hAudioInterrupt)
    {
        ERRMSG("Unable to create interrupt event");
        return(FALSE);
    }

    if (! InterruptInitialize(m_dwSysintrOutput, m_hAudioInterrupt, NULL, 0)) {
        ERRMSG("Unable to initialize output interrupt");
        return FALSE;
    }
    if (! InterruptInitialize(m_dwSysintrInput, m_hAudioInterrupt, NULL, 0)) {
        ERRMSG("Unable to initialize input interrupt");
        return FALSE;
    }

    m_hAudioInterruptThread  = CreateThread((LPSECURITY_ATTRIBUTES)NULL,
                                            0,
                                            (LPTHREAD_START_ROUTINE)CallInterruptThread,
                                            this,
                                            0,
                                            NULL);
    if (!m_hAudioInterruptThread)
    {
        ERRMSG("Unable to create interrupt thread");
        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()
{
//    SPI_Init();
    I2S_Init();
}

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++