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Commit 8cc3e30b authored by Joel Fernandes's avatar Joel Fernandes Committed by Vinod Koul
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dmaengine: edma: Add DMA memcpy support 



We add DMA memcpy support to EDMA driver. Successful tests performed using
dmatest kernel module. Copy alignment is set to DMA_SLAVE_BUSWIDTH_4_BYTES and
users must ensure length is aligned so that copy is performed fully.

Signed-off-by: default avatarJoel Fernandes <joelf@ti.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent e6fad592

drivers/dma/edma.c

+51 −0
Original line number Diff line number Diff line
@@ -379,6 +379,11 @@ static int edma_config_pset(struct dma_chan *chan, struct edmacc_param *pset, 
		src_cidx = 0;

		dst_bidx = acnt;

		dst_cidx = cidx;

	} else if (direction == DMA_MEM_TO_MEM)  {

		src_bidx = acnt;

		src_cidx = cidx;

		dst_bidx = acnt;

		dst_cidx = cidx;

	} else {

		dev_err(dev, "%s: direction not implemented yet\n", __func__);

		return -EINVAL;
@@ -499,6 +504,44 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( 
	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);

}



struct dma_async_tx_descriptor *edma_prep_dma_memcpy(

	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,

	size_t len, unsigned long tx_flags)

{

	int ret;

	struct edma_desc *edesc;

	struct device *dev = chan->device->dev;

	struct edma_chan *echan = to_edma_chan(chan);



	if (unlikely(!echan || !len))

		return NULL;



	edesc = kzalloc(sizeof(*edesc) + sizeof(edesc->pset[0]), GFP_ATOMIC);

	if (!edesc) {

		dev_dbg(dev, "Failed to allocate a descriptor\n");

		return NULL;

	}



	edesc->pset_nr = 1;



	ret = edma_config_pset(chan, &edesc->pset[0], src, dest, 1,

			       DMA_SLAVE_BUSWIDTH_4_BYTES, len, DMA_MEM_TO_MEM);

	if (ret < 0)

		return NULL;



	edesc->absync = ret;



	/*

	 * Enable intermediate transfer chaining to re-trigger channel

	 * on completion of every TR, and enable transfer-completion

	 * interrupt on completion of the whole transfer.

	 */

	edesc->pset[0].opt |= ITCCHEN;

	edesc->pset[0].opt |= TCINTEN;



	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);

}



static struct dma_async_tx_descriptor *edma_prep_dma_cyclic(

	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,

	size_t period_len, enum dma_transfer_direction direction,
@@ -877,6 +920,7 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma, 
{

	dma->device_prep_slave_sg = edma_prep_slave_sg;

	dma->device_prep_dma_cyclic = edma_prep_dma_cyclic;

	dma->device_prep_dma_memcpy = edma_prep_dma_memcpy;

	dma->device_alloc_chan_resources = edma_alloc_chan_resources;

	dma->device_free_chan_resources = edma_free_chan_resources;

	dma->device_issue_pending = edma_issue_pending;
@@ -885,6 +929,12 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma, 
	dma->device_slave_caps = edma_dma_device_slave_caps;

	dma->dev = dev;



	/*

	 * code using dma memcpy must make sure alignment of

	 * length is at dma->copy_align boundary.

	 */

	dma->copy_align = DMA_SLAVE_BUSWIDTH_4_BYTES;



	INIT_LIST_HEAD(&dma->channels);

}
@@ -913,6 +963,7 @@ static int edma_probe(struct platform_device *pdev) 
	dma_cap_zero(ecc->dma_slave.cap_mask);

	dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask);

	dma_cap_set(DMA_CYCLIC, ecc->dma_slave.cap_mask);

	dma_cap_set(DMA_MEMCPY, ecc->dma_slave.cap_mask);



	edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev);