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dmaengine: xilinx_dma: program hardware supported buffer length 

AXI-DMA IP supports configurable (c_sg_length_width) buffer length
register width, hence read buffer length (xlnx,sg-length-width) DT
property and ensure that driver doesn't program buffer length
exceeding the supported limit. For VDMA and CDMA there is no change.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com> [rebase, reword]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Radhey Shyam Pandey 2018-11-20 16:31:48 +01:00 committed by Vinod Koul
parent 7df54dbeb0
commit ae809690b4
1 changed files with 20 additions and 4 deletions
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24
drivers/dma/xilinx/xilinx_dma.c
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@ -161,7 +161,9 @@
#define XILINX_DMA_REG_BTT 0x28
/* AXI DMA Specific Masks/Bit fields */
#define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0)
#define XILINX_DMA_MAX_TRANS_LEN_MIN 8
#define XILINX_DMA_MAX_TRANS_LEN_MAX 23
#define XILINX_DMA_V2_MAX_TRANS_LEN_MAX 26
#define XILINX_DMA_CR_COALESCE_MAX GENMASK(23, 16)
#define XILINX_DMA_CR_CYCLIC_BD_EN_MASK BIT(4)
#define XILINX_DMA_CR_COALESCE_SHIFT 16
@ -2626,7 +2628,7 @@ 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, len_width;
int i, err;
/* Allocate and initialize the DMA engine structure */
@ -2658,10 +2660,24 @@ static int xilinx_dma_probe(struct platform_device *pdev)
/* Retrieve the DMA engine properties from the device tree */
xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
xdev->max_buffer_len = XILINX_DMA_MAX_TRANS_LEN;
xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
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");
if (!of_property_read_u32(node, "xlnx,sg-length-width",
&len_width)) {
if (len_width < XILINX_DMA_MAX_TRANS_LEN_MIN ||
len_width > XILINX_DMA_V2_MAX_TRANS_LEN_MAX) {
dev_warn(xdev->dev,
"invalid xlnx,sg-length-width property value. Using default width\n");
} else {
if (len_width > XILINX_DMA_MAX_TRANS_LEN_MAX)
dev_warn(xdev->dev, "Please ensure that IP supports buffer length > 23 bits\n");
xdev->max_buffer_len =
GENMASK(len_width - 1, 0);
}
}
}
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
err = of_property_read_u32(node, "xlnx,num-fstores",