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| author | Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com> | 2018-11-20 16:31:48 +0100 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-01-07 09:53:11 +0530 |
| commit | ae809690b46a71dc56cda5b3b8884c8c41a0df15 (patch) | |
| tree | bedeeefafb4c153660382cab7f730b48a96af886 /drivers/dma/xilinx | |
| parent | 7df54dbeb055229f6689161aa90bf00bf4af077e (diff) | |
| download | lwn-ae809690b46a71dc56cda5b3b8884c8c41a0df15.tar.gz lwn-ae809690b46a71dc56cda5b3b8884c8c41a0df15.zip | |
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>
Diffstat (limited to 'drivers/dma/xilinx')
| -rw-r--r-- | drivers/dma/xilinx/xilinx_dma.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index 93435f7002ab..d59af2b33a99 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -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", |