From 8cc3e30bea9a90f9ab7a1bc4612792c40ad7ae95 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Fri, 18 Apr 2014 21:50:33 -0500 Subject: 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: Joel Fernandes Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'drivers/dma') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index ea04b2192822..43f56a7d9d61 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -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); -- cgit v1.2.3