[PATCH v6 2/6] dmaengine: dma-axi-dmac: Implement device_prep_slave_dma_vec

[Paul Cercueil <paul@crapouillou.net>]

Add implementation of the .device_prep_slave_dma_vec() callback.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>

---
v3: New patch

v5: Implement .device_prep_slave_dma_vec() instead of v3's
    .device_prep_slave_dma_array().

v6: Use new prototype for axi_dmac_alloc_desc() as it changed upstream.
---
 drivers/dma/dma-axi-dmac.c | 40 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
index 4e339c04fc1e..276856a1742d 100644
--- a/drivers/dma/dma-axi-dmac.c
+++ b/drivers/dma/dma-axi-dmac.c
@@ -620,6 +620,45 @@ static struct axi_dmac_sg *axi_dmac_fill_linear_sg(struct axi_dmac_chan *chan,
 	return sg;
 }
 
+static struct dma_async_tx_descriptor *
+axi_dmac_prep_slave_dma_vec(struct dma_chan *c, const struct dma_vec *vecs,
+			    size_t nb, enum dma_transfer_direction direction,
+			    unsigned long flags)
+{
+	struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
+	struct axi_dmac_desc *desc;
+	unsigned int num_sgs = 0;
+	struct axi_dmac_sg *dsg;
+	size_t i;
+
+	if (direction != chan->direction)
+		return NULL;
+
+	for (i = 0; i < nb; i++)
+		num_sgs += DIV_ROUND_UP(vecs[i].len, chan->max_length);
+
+	desc = axi_dmac_alloc_desc(chan, num_sgs);
+	if (!desc)
+		return NULL;
+
+	dsg = desc->sg;
+
+	for (i = 0; i < nb; i++) {
+		if (!axi_dmac_check_addr(chan, vecs[i].addr) ||
+		    !axi_dmac_check_len(chan, vecs[i].len)) {
+			kfree(desc);
+			return NULL;
+		}
+
+		dsg = axi_dmac_fill_linear_sg(chan, direction, vecs[i].addr, 1,
+					      vecs[i].len, dsg);
+	}
+
+	desc->cyclic = false;
+
+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
 static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
 	struct dma_chan *c, struct scatterlist *sgl,
 	unsigned int sg_len, enum dma_transfer_direction direction,
@@ -1055,6 +1094,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
 	dma_dev->device_tx_status = dma_cookie_status;
 	dma_dev->device_issue_pending = axi_dmac_issue_pending;
 	dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;
+	dma_dev->device_prep_slave_dma_vec = axi_dmac_prep_slave_dma_vec;
 	dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
 	dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
 	dma_dev->device_terminate_all = axi_dmac_terminate_all;
-- 
2.43.0