The maximumum trasfer length is currently hardcoded in the driver, but
it depends by how the soft-IP is actually configuried.
This seems to affect also max possible length for SG transfers.
This patch introduce a new DT property in order to operate with proper
maximum trasfer length.
Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx>
---
drivers/dma/xilinx/xilinx_dma.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 33c0949..cbd8d8c 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -409,6 +409,7 @@ struct xilinx_dma_device {
struct clk *rxs_clk;
u32 nr_channels;
u32 chan_id;
+ int max_transfer;
};
/* Macros */
@@ -1764,8 +1765,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
* the next chuck start address is aligned
*/
copy = sg_dma_len(sg) - sg_used;
- if (copy > XILINX_DMA_MAX_TRANS_LEN)
- copy = XILINX_DMA_MAX_TRANS_LEN &
+ if (copy > chan->xdev->max_transfer)
+ copy = chan->xdev->max_transfer &
chan->copy_mask;
hw = &segment->hw;
@@ -1875,8 +1876,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
* the next chuck start address is aligned
*/
copy = period_len - sg_used;
- if (copy > XILINX_DMA_MAX_TRANS_LEN)
- copy = XILINX_DMA_MAX_TRANS_LEN &
+ if (copy > chan->xdev->max_transfer)
+ copy = chan->xdev->max_transfer &
chan->copy_mask;
hw = &segment->hw;
@@ -2534,7 +2535,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
struct xilinx_dma_device *xdev;
struct device_node *child, *np = pdev->dev.of_node;
struct resource *io;
- u32 num_frames, addr_width;
+ u32 num_frames, addr_width, lenreg_width;
int i, err;
/* Allocate and initialize the DMA engine structure */
@@ -2565,8 +2566,17 @@ static int xilinx_dma_probe(struct platform_device *pdev)
return PTR_ERR(xdev->regs);
/* Retrieve the DMA engine properties from the device tree */
- if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
+ err = of_property_read_u32(node, "xlnx,lengthregwidth",
+ &lenreg_width);
+ if (err < 0) {
+ dev_err(xdev->dev,
+ "missing xlnx,lengthregwidth property\n");
+ return err;
+ }
+ xdev->max_transfer = GENMASK(lenreg_width, 0);
+ }
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
err = of_property_read_u32(node, "xlnx,num-fstores",
--
2.7.4
--
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