xllp_dmac.c

PXA270硬件测试源代码

  Function Name: XllpDmacDetachDesc

  Description: XllpDmacDetachDesc detaches the specified descriptor to the 
  			   chained/linked descriptors.  Users who want to detach a 
  			   descriptor on the fly can use this function.  Note that if 
  			   DMA transfers are already in session for the specified channel,
  			   this transfer will be stopped, detach the descriptor, and then
  			   restarted.  Users can use XllpDmacGetChannelStatus to request 
  			   status of the channel, ensure that the current transfer completes
  			   before detaching descriptors. 
  			   
  Global Registers Modified: 
	DCSRx, and DDADRx registers, where x indicate the channel number  
  
  Input Arguments:
	pDesc:  Holds the pointer to the descriptor to be detached.  The pointer
			cannot be null.
	pPrevDesc:  Holds the pointer to the descriptor in the chain that had the 
				"to be detached" descriptor pDesc as the next descriptor.  That
				is, pPrevDesc had pDesc as the next descriptor, but will now 
				have pNextDesc as its next descriptor in the chain.  Before 
				executing the primitive pPrevDesc pointed to pDesc and pDesc 
				pointed to pNextDesc, after executing this function pPrevDesc 
				will be pointer to pNextDesc.  Neither pointers can have a null.
	pNextDesc:  Holds the pointer to the descriptor in the chain that will be 
				the next descriptor to pPrevDesc. See description of pPrevDesc 
				for more details.  The pointer cannot be null
	pStartDesc: Descriptor to re-start DMA transfer from			
	aChannel:  Specifies the DMA channel this chained descriptors are utilizing 
			   for the transfer process.  Valid values are 0-31.
  
  Output Arguments:
  	None
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacDetachDesc(
			    		P_XLLP_DMAC_DESCRIPTOR_T  pDesc,
			    		P_XLLP_DMAC_DESCRIPTOR_T  pPrevDesc,
			    		P_XLLP_DMAC_DESCRIPTOR_T  pNextDesc,
			    		P_XLLP_DMAC_DESCRIPTOR_T  pStartDesc,
						XLLP_DMAC_CHANNEL_T       aChannel
					   )
{
	XLLP_VUINT32_T aTargetValue; 
	XLLP_BOOL_T    aChannelRunStatus = XLLP_FALSE;

	/* Read Control & Status register,   */
	/* verify if transfer is in process. */
	/* If so, stop the channel           */
	aTargetValue  = pDmacHandle->DCSR[aChannel];
	if((aTargetValue & (XLLP_VUINT32_T)XLLP_DMAC_DCSR_RUN) == (XLLP_VUINT32_T)XLLP_DMAC_DCSR_RUN)
	{
		aTargetValue &= ~XLLP_DMAC_DCSR_RUN;
		pDmacHandle->DCSR[aChannel] = aTargetValue;
	  	aChannelRunStatus = XLLP_TRUE;  
	}

	/* Detach descriptor                 */
	pPrevDesc->DDADR = (XLLP_VUINT32_T)pNextDesc;

	pDmacHandle->DDG[aChannel].DDADR = (XLLP_VUINT32_T)pStartDesc;

	/* If channel was running, restart it*/
	if (aChannelRunStatus == XLLP_TRUE)
	{
		aTargetValue |= XLLP_DMAC_DCSR_RUN;
		pDmacHandle->DCSR[aChannel] = aTargetValue;
	}
}

/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmacGetChannelStatus

  Description: XllpDmacGetChannelStatus returns the status of the DMA transfer 
  			   process for the specified channel.  The function can return a 
  			   status or multiple status for a particular DMA channel.
  			   
  Global Registers Modified: 
	None
		  
  Input Arguments:
	aChannel:  Specifies the DMA channel whose status to return.  Valid values 
			   are 0-31.
	aStatus:  Specifies the DMA channel status the caller is requesting.  aStatus
			  could be an element of type XLLP_DMAC_CHANNEL_STATUS_T or multiple 
			  elements of the said type.
  
  Output Arguments:
	pStatus: Holds the DMA channel status requested by the caller.  pStatus may
			 contain one or multiple statuses depending on aStatus.  
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacGetChannelStatus(
							 XLLP_DMAC_CHANNEL_T          aChannel,
							 XLLP_DMAC_CHANNEL_STATUS_T   aStatus,
							 P_XLLP_DMAC_CHANNEL_STATUS_T pStatus
							 )
{
 /* IMPLEMENTION IS EXCLUDED BECAUSE IT IS A WRAPPER FUNCTION   */

 /* WILL BE ADDED IF THERE ARE USERS WHO WILL LIKE TO USE IT*/
}

/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmacClearChannelStatus

  Description: XllpDmacClearChannelStatus clears the status of the DMA transfer 
  			   process for the specified channel.  The function can clear one or
  			   multiple statuses for a particular DMA channel.
  			   
  Global Registers Modified: 
	DCSRx register, where x denotes the channel number.		  
  
  Input Arguments:
	aChannel:  Specifies the DMA channel whose status to clear.  Valid values 
			   are 0-31.
	aStatus:  Specifies the DMA channel status(s) to clear.  aStatus could be an
	 		  element of type XLLP_DMAC_CHANNEL_STATUS_T or multiple elements of
	 		  the said type.
  
  Output Arguments:
	None
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacClearChannelStatus(
							   XLLP_DMAC_CHANNEL_T        aChannel,
							   XLLP_DMAC_CHANNEL_STATUS_T aStatus 
					           )
{
 /* IMPLEMENTION IS EXCLUDED BECAUSE IT IS A WRAPPER FUNCTION   */

 /* WILL BE ADDED IF THERE ARE USERS WHO WILL LIKE TO USE IT*/
}

/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmacMapDeviceToChannel

  Description: XllpDmacMapDeviceToChannel is used to map the specified device
  			   to the specified DMA channel. 
  			   
  Global Registers Modified: 
	DRCMRx register, where x denotes the channel number.  
  
  Input Arguments:
	aDeviceDrcmr:  Specifies the device to be mapped to the DMA channel.  Valid 
			  parameters are values of type  XLLP_DMAC_DRCMR_T, otherwise
			  invalid.
	aChannel: Specifies the DMA channel to map the specified device to.  Valid 
			  channel values range from 0-31.
  
  Output Arguments:
	None
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacMapDeviceToChannel(
							   XLLP_DMAC_DRCMR_T   aDeviceDrcmr,
							   XLLP_DMAC_CHANNEL_T aChannel
						       )
{
	if (aDeviceDrcmr < XLLP_DMAC_DRCMR1_NUM)
	{
		/* Enable device-to-channel mapping */
		pDmacHandle->DRCMR1[aDeviceDrcmr] = (XLLP_DMAC_DRCMR_ENABLE + aChannel);
	}
	else
	{
		/* Enable device-to-channel mapping */
		pDmacHandle->DRCMR2[aDeviceDrcmr-XLLP_DMAC_DRCMR1_NUM] = (XLLP_DMAC_DRCMR_ENABLE + aChannel);
	}	
}

/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmacUnMapDeviceToChannel

  Description: XllpDmacUnMapDeviceToChannel is used to unmap the specified 
  			   device from the specified DMA channel.  
  			   
  Global Registers Modified: 
	DRCMRx register, where x denotes the channel number.  
  
  Input Arguments:
	aDeviceDrcmr:  Specifies the device to be unmapped from the DMA channel.  Valid
			  parameters are values of type XLLP_DMAC_DRCMR_T, otherwise invalid.
	aChannel: Specifies the DMA channel to unmap the specified device from.  
			  Valid channel values range from 0-31.

  Output Arguments:
	None
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacUnMapDeviceToChannel(
								 XLLP_DMAC_DRCMR_T   aDeviceDrcmr,
								 XLLP_DMAC_CHANNEL_T aChannel
								 )
{
	if (aDeviceDrcmr < XLLP_DMAC_DRCMR1_NUM)
	{
		/* Disable device-to-channel mapping */
		pDmacHandle->DRCMR1[aDeviceDrcmr] = (XLLP_DMAC_DRCMR_DISABLE + aChannel);
	}
	else
	{
		/* Disable device-to-channel mapping */
		pDmacHandle->DRCMR2[aDeviceDrcmr-XLLP_DMAC_DRCMR1_NUM] = (XLLP_DMAC_DRCMR_DISABLE + aChannel);
	}	
}


/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmacSetEor

  Description: XllpDmacSetEor sets the stop on EOR functionality for the specified channel
  			   
  Global Registers Modified: 
	DCSRx register, where x indicate the channel number
  
  Input Arguments:
	aChannel:  Specifies the channel for which to set the stop on EOR functionality   
  
  Output Arguments:
  	None
  Return Value: 
	None 

XLLP_DOC_HDR_END
*******************************************************************************/
void XllpDmacSetEor( XLLP_DMAC_CHANNEL_T aChannel )
{
	XLLP_VUINT32_T aTargetData;     

	aTargetData  = pDmacHandle->DCSR[aChannel];	
    aTargetData |= XLLP_DMAC_DCSR_EOR_STOP_EN;	
	pDmacHandle->DCSR[aChannel]  = aTargetData;
}


/******************************************************************************
XLLP_DOC_HDR_BEGIN

  Function Name: XllpDmaAllocOneChannel

  Description: XllpDmacAllocOneChannel is used to allocate a specific DMA channel in 
  			   the system.  The channel that is allocated must then be used to
  			   bind a service routine to the operating system such that all 
  			   interrupts that occur on the channel will be routed to the bound
  			   service routine.  Once the channel is done transferring data, it
  			   can be freed by using XllpDmacFreeChannel.
  
  Global Registers Modified: None 

  Input Arguments:
    aChannel: Specifies the DMA channel to be assigned to the calling device 
	          DMA channels range is from 0-31.   
		                 
  Output Arguments:
	
  Return Value: 
	XLLP_STATUS_SUCCESS: Returned when specified channel is available and assigned to caller
	XLLP_NO_DMA_CHANNELS_AVAILABLE: Returned when the specified channel is not available

XLLP_DOC_HDR_END
*******************************************************************************/
XLLP_STATUS_T XllpDmacAllocOneChannel(
			   		 			  XLLP_DMAC_CHANNEL_T        aChannel			     	 			  
			     	 			  )
{
	if (aChannel < XLLP_DMAC_CHANNEL_NUM)
	{
		if (pArrayChannel[aChannel] == 0)
		{
			pArrayChannel[aChannel] = 1;
			return (XLLP_STATUS_SUCCESS);   
		}
	}	
	return XLLP_STATUS_NO_DMA_CHANNEL_AVAILABLE;
}