mcd_dmaapi.c

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				     contextSaveSpace)[CURRBD + CSAVE_OFFSET];
		/* See if they match: */
		if (prevRep.lastSrcAddr != progRep->lastSrcAddr
		    || prevRep.lastDestAddr != progRep->lastDestAddr
		    || prevRep.dmaSize != progRep->dmaSize
		    || prevRep.currBufDesc != progRep->currBufDesc) {
			/* If they don't match, remember previous values and
			   try again: */
			prevRep.lastSrcAddr = progRep->lastSrcAddr;
			prevRep.lastDestAddr = progRep->lastDestAddr;
			prevRep.dmaSize = progRep->dmaSize;
			prevRep.currBufDesc = progRep->currBufDesc;
			again = MCD_TRUE;
		} else
			again = MCD_FALSE;
	} while (again == MCD_TRUE);

	/* Update the dCount, srcAddr and destAddr */
	/* To calculate dmaCount, we consider destination address. C
	   overs M1,P1,Z for destination */
	switch (MCD_remVariants.remDestRsdIncr[channel]) {
	case MINUS1:
		subModVal =
		    ((int)progRep->
		     lastDestAddr) & ((MCD_remVariants.remXferSize[channel]) -
				      1);
		addModVal =
		    ((int)progRep->currBufDesc->
		     destAddr) & ((MCD_remVariants.remXferSize[channel]) - 1);
		LWAlignedInitDestAddr =
		    (progRep->currBufDesc->destAddr) - addModVal;
		LWAlignedCurrDestAddr = (progRep->lastDestAddr) - subModVal;
		destDiffBytes = LWAlignedInitDestAddr - LWAlignedCurrDestAddr;
		bytesNotXfered =
		    (destDiffBytes / MCD_remVariants.remDestIncr[channel]) *
		    (MCD_remVariants.remDestIncr[channel]
		     + MCD_remVariants.remXferSize[channel]);
		progRep->dmaSize =
		    destDiffBytes - bytesNotXfered + addModVal - subModVal;
		break;
	case ZERO:
		progRep->lastDestAddr = progRep->currBufDesc->destAddr;
		break;
	case PLUS1:
		/* This value has to be subtracted from the final
		   calculated dCount. */
		subModVal =
		    ((int)progRep->currBufDesc->
		     destAddr) & ((MCD_remVariants.remXferSize[channel]) - 1);
		/* These bytes are already in lastDestAddr. */
		addModVal =
		    ((int)progRep->
		     lastDestAddr) & ((MCD_remVariants.remXferSize[channel]) -
				      1);
		LWAlignedInitDestAddr =
		    (progRep->currBufDesc->destAddr) - subModVal;
		LWAlignedCurrDestAddr = (progRep->lastDestAddr) - addModVal;
		destDiffBytes = (progRep->lastDestAddr - LWAlignedInitDestAddr);
		numIterations =
		    (LWAlignedCurrDestAddr -
		     LWAlignedInitDestAddr) /
		    MCD_remVariants.remDestIncr[channel];
		bytesNotXfered =
		    numIterations * (MCD_remVariants.remDestIncr[channel]
				     - MCD_remVariants.remXferSize[channel]);
		progRep->dmaSize = destDiffBytes - bytesNotXfered - subModVal;
		break;
	default:
		break;
	}

	/* This covers M1,P1,Z for source */
	switch (MCD_remVariants.remSrcRsdIncr[channel]) {
	case MINUS1:
		progRep->lastSrcAddr =
		    progRep->currBufDesc->srcAddr +
		    (MCD_remVariants.remSrcIncr[channel] *
		     (progRep->dmaSize / MCD_remVariants.remXferSize[channel]));
		break;
	case ZERO:
		progRep->lastSrcAddr = progRep->currBufDesc->srcAddr;
		break;
	case PLUS1:
		progRep->lastSrcAddr =
		    progRep->currBufDesc->srcAddr +
		    (MCD_remVariants.remSrcIncr[channel] *
		     (progRep->dmaSize / MCD_remVariants.remXferSize[channel]));
		break;
	default:
		break;
	}

	return (MCD_OK);
}

/******************* End of MCD_XferProgrQuery() ********************/

/********************************************************************/
/* MCD_resmActions() does the majority of the actions of a DMA resume.
 * It is called from MCD_killDma() and MCD_resumeDma().  It has to be
 * a separate function because the kill function has to negate the task
 * enable before resuming it, but the resume function has to do nothing
 * if there is no DMA on that channel (i.e., if the enable bit is 0).
 */
static void MCD_resmActions(int channel)
{
	MCD_dmaBar->debugControl = DBG_CTL_DISABLE;
	MCD_dmaBar->debugStatus = MCD_dmaBar->debugStatus;
	/* This register is selected to know which initiator is
	   actually asserted. */
	MCD_dmaBar->ptdDebug = PTD_DBG_TSK_VLD_INIT;

	if ((MCD_dmaBar->ptdDebug >> channel) & 0x1)
		MCD_chStatus[channel] = MCD_RUNNING;
	else
		MCD_chStatus[channel] = MCD_IDLE;
}

/********************* End of MCD_resmActions() *********************/

/********************************************************************/
/* Function:    MCD_killDma
 * Purpose:     Halt the DMA on the requested channel, without any
 *              intention of resuming the DMA.
 * Arguments:   channel - requested channel
 * Returns:     MCD_CHANNEL_INVALID if channel is invalid, else MCD_OK
 *
 * Notes:
 *  A DMA may be killed from any state, including paused state, and it
 *  always goes to the MCD_HALTED state even if it is killed while in
 *  the MCD_NO_DMA or MCD_IDLE states.
 */
int MCD_killDma(int channel)
{
	/* MCD_XferProg progRep; */

	if ((channel < 0) || (channel >= NCHANNELS))
		return (MCD_CHANNEL_INVALID);

	MCD_dmaBar->taskControl[channel] = 0x0;
	MCD_resumeDma(channel);
	/*
	 * This must be after the write to the TCR so that the task doesn't
	 * start up again momentarily, and before the status assignment so
	 * as to override whatever MCD_resumeDma() may do to the channel
	 * status.
	 */
	MCD_chStatus[channel] = MCD_HALTED;

	/*
	 * Update the current buffer descriptor's lastDestAddr field
	 *
	 * MCD_XferProgrQuery (channel, &progRep);
	 * progRep.currBufDesc->lastDestAddr = progRep.lastDestAddr;
	 */
	return (MCD_OK);
}

/************************ End of MCD_killDma() **********************/

/********************************************************************/
/* Function:    MCD_continDma
 * Purpose:     Continue a DMA which as stopped due to encountering an
 *              unready buffer descriptor.
 * Arguments:   channel - channel to continue the DMA on
 * Returns:     MCD_CHANNEL_INVALID if channel is invalid, else MCD_OK
 *
 * Notes:
 *  This routine does not check to see if there is a task which can
 *  be continued. Also this routine should not be used with single DMAs.
 */
int MCD_continDma(int channel)
{
	if ((channel < 0) || (channel >= NCHANNELS))
		return (MCD_CHANNEL_INVALID);

	MCD_dmaBar->taskControl[channel] |= TASK_CTL_EN;
	MCD_chStatus[channel] = MCD_RUNNING;

	return (MCD_OK);
}

/********************** End of MCD_continDma() **********************/

/*********************************************************************
 * MCD_pauseDma() and MCD_resumeDma() below use the DMA's debug unit
 * to freeze a task and resume it.  We freeze a task by breakpointing
 * on the stated task.  That is, not any specific place in the task,
 * but any time that task executes.  In particular, when that task
 * executes, we want to freeze that task and only that task.
 *
 * The bits of the debug control register influence interrupts vs.
 * breakpoints as follows:
 * - Bits 14 and 0 enable or disable debug functions.  If enabled, you
 *   will get the interrupt but you may or may not get a breakpoint.
 * - Bits 2 and 1 decide whether you also get a breakpoint in addition
 *   to an interrupt.
 *
 * The debug unit can do these actions in response to either internally
 * detected breakpoint conditions from the comparators, or in response
 * to the external breakpoint pin, or both.
 * - Bits 14 and 1 perform the above-described functions for
 *   internally-generated conditions, i.e., the debug comparators.
 * - Bits 0 and 2 perform the above-described functions for external
 *   conditions, i.e., the breakpoint external pin.
 *
 * Note that, although you "always" get the interrupt when you turn
 * the debug functions, the interrupt can nevertheless, if desired, be
 * masked by the corresponding bit in the PTD's IMR. Note also that
 * this means that bits 14 and 0 must enable debug functions before
 * bits 1 and 2, respectively, have any effect.
 *
 * NOTE: It's extremely important to not pause more than one DMA channel
 *  at a time.
 ********************************************************************/

/********************************************************************/
/* Function:    MCD_pauseDma
 * Purpose:     Pauses the DMA on a given channel (if any DMA is running
 *              on that channel).
 * Arguments:   channel
 * Returns:     MCD_CHANNEL_INVALID if channel is invalid, else MCD_OK
 */
int MCD_pauseDma(int channel)
{
	/* MCD_XferProg progRep; */

	if ((channel < 0) || (channel >= NCHANNELS))
		return (MCD_CHANNEL_INVALID);

	if (MCD_dmaBar->taskControl[channel] & TASK_CTL_EN) {
		MCD_dmaBar->debugComp1 = channel;
		MCD_dmaBar->debugControl =
		    DBG_CTL_ENABLE | (1 << (channel + 16));
		MCD_chStatus[channel] = MCD_PAUSED;

		/*
		 * Update the current buffer descriptor's lastDestAddr field
		 *
		 * MCD_XferProgrQuery (channel, &progRep);
		 * progRep.currBufDesc->lastDestAddr = progRep.lastDestAddr;
		 */
	}
	return (MCD_OK);
}

/************************* End of MCD_pauseDma() ********************/

/********************************************************************/
/* Function:    MCD_resumeDma
 * Purpose:     Resumes the DMA on a given channel (if any DMA is
 *              running on that channel).
 * Arguments:   channel - channel on which to resume DMA
 * Returns:     MCD_CHANNEL_INVALID if channel is invalid, else MCD_OK
 */
int MCD_resumeDma(int channel)
{
	if ((channel < 0) || (channel >= NCHANNELS))
		return (MCD_CHANNEL_INVALID);

	if (MCD_dmaBar->taskControl[channel] & TASK_CTL_EN)
		MCD_resmActions(channel);

	return (MCD_OK);
}

/************************ End of MCD_resumeDma() ********************/

/********************************************************************/
/* Function:    MCD_csumQuery
 * Purpose:     Provide the checksum after performing a non-chained DMA
 * Arguments:   channel - channel to report on
 *              csum - pointer to where to write the checksum/CRC
 * Returns:     MCD_ERROR if the channel is invalid, else MCD_OK
 *
 * Notes:
 *
 */
int MCD_csumQuery(int channel, u32 * csum)
{
#ifdef MCD_INCLUDE_EU
	if ((channel < 0) || (channel >= NCHANNELS))
		return (MCD_CHANNEL_INVALID);

	*csum = MCD_relocBuffDesc[channel].csumResult;
	return (MCD_OK);
#else
	return (MCD_ERROR);
#endif
}

/*********************** End of MCD_resumeDma() *********************/

/********************************************************************/
/* Function:    MCD_getCodeSize
 * Purpose:     Provide the size requirements of the microcoded tasks
 * Returns:     Size in bytes
 */
int MCD_getCodeSize(void)
{
#ifdef MCD_INCLUDE_EU
	return (0x2b5c);
#else
	return (0x173c);
#endif
}

/********************** End of MCD_getCodeSize() ********************/

/********************************************************************/
/* Function:    MCD_getVersion
 * Purpose:     Provide the version string and number
 * Arguments:   longVersion - user supplied pointer to a pointer to a char
 *                    which points to the version string
 * Returns:     Version number and version string (by reference)
 */
char MCD_versionString[] = "Multi-channel DMA API Alpha v0.3 (2004-04-26)";
#define MCD_REV_MAJOR   0x00
#define MCD_REV_MINOR   0x03

int MCD_getVersion(char **longVersion)
{
	*longVersion = MCD_versionString;
	return ((MCD_REV_MAJOR << 8) | MCD_REV_MINOR);
}

/********************** End of MCD_getVersion() *********************/

/********************************************************************/
/* Private version of memcpy()
 * Note that everything this is used for is longword-aligned.
 */
static void MCD_memcpy(int *dest, int *src, u32 size)
{
	u32 i;

	for (i = 0; i < size; i += sizeof(int), dest++, src++)
		*dest = *src;
}
#endif				/* CONFIG_FSLDMAFEC */