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A little more DMA logic

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2559 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2010-03-28 16:25:48 +00:00
parent 9ae2468586
commit 8d8305d76c
1 changed files with 55 additions and 1 deletions
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56
arch/arm/src/sam3u/sam3u_dmac.c
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@ -76,6 +76,7 @@ struct sam3u_dma_s
void *arg; /* Argument passed to callback function */
uint16_t bufsize; /* Transfer buffer size in bytes */
volatile uint16_t remaining; /* Total number of bytes remaining to be transferred */
int result; /* Transfer result (OK or negated errno) */
};
/****************************************************************************
@ -364,7 +365,60 @@ static inline void sam3u_flowcontrol(struct sam3u_dma_s *dmach, uint32_t setting
static int sam3u_dmainterrupt(int irq, void *context)
{
# warning "Missing logic"
struct sam3u_dma_s *dmach;
unsigned int chndx;
uint32_t regval;
/* Get the DMAC status register value */
regval = getreg32(SAM3U_DMAC_EBCISR);
/* Check if the any buffer transfer has completed */
if (regval & DMAC_EBC_BTC_MASK)
{
/* Check each channel status */
for (chndx = 0; chndx < DMA_CHANNEL_NUM; chndx++)
{
/* Are interrupts enabled for this channel? */
if ((regval & DMAC_EBC_BTC(chndx)) != 0)
{
/* Subtract the number of bytes transferred so far */
dmach->remaining -= dmach->bufsize;
/* Is the transfer finished? */
if (dmach->remaining == 0)
{
/* Disable Buffer Transfer Complete interrupts */
dmach = &g_dma[chndx];
putreg32(DMAC_EBC_BTC(dmach->chan), SAM3U_DMAC_EBCIDR);
/* Disable the DMA channel */
putreg32(DMAC_CHDR_DIS(dmach->chan), SAM3U_DMAC_CHDR);
/* Perform the DMA complete callback */
if (dmach->callback)
{
dmach->callback(dmach->arg);
}
}
else
{
/* Write the KEEPON field to clear the STALL states */
putreg32(DMAC_CHER_KEEP(dmach->chan), SAM3U_DMAC_CHER);
}
}
}
}
return OK;
}
/****************************************************************************