[PATCH v3 02/11] dmaengine: dma-axi-dmac: Implement device_prep_slave_dma_array

[Paul Cercueil <paul@crapouillou.net>]

Add implementation of the .device_prep_slave_dma_array() callback.

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

---
v3: New patch
---
 drivers/dma/dma-axi-dmac.c | 41 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
index a812b9b00e6b..61a796aca631 100644
--- a/drivers/dma/dma-axi-dmac.c
+++ b/drivers/dma/dma-axi-dmac.c
@@ -536,6 +536,46 @@ 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_array(struct dma_chan *c, dma_addr_t *addrs,
+			      size_t *lengths, 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(lengths[i], chan->max_length);
+
+	desc = axi_dmac_alloc_desc(num_sgs);
+	if (!desc)
+		return NULL;
+
+	dsg = desc->sg;
+
+	for (i = 0; i < nb; i++) {
+		if (!axi_dmac_check_addr(chan, addrs[i]) ||
+		    !axi_dmac_check_len(chan, lengths[i])) {
+			kfree(desc);
+			return NULL;
+		}
+
+		dsg = axi_dmac_fill_linear_sg(chan, direction, addrs[i], 1,
+					      lengths[i], 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,
@@ -958,6 +998,7 @@ 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_array = axi_dmac_prep_slave_dma_array;
 	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;
-- 
2.39.2