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 <joelf@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 51 insertions, 0 deletions

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);