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dmaengine: xilinx_dma: autodetect whether the HW supports scatter-gather 

The AXIDMA and CDMA HW can be either direct-access or scatter-gather
version. These are SW incompatible.

The driver can handle both versions: a DT property was used to
tell the driver whether to assume the HW is in scatter-gather mode.

This patch makes the driver to autodetect this information. The DT
property is not required anymore.

No changes for VDMA.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Andrea Merello 2018-11-20 16:31:49 +01:00 committed by Vinod Koul
parent ae809690b4
commit 05f7ea7f6e
1 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/dma/xilinx/xilinx_dma.c
View File

@ -86,6 +86,7 @@
#define XILINX_DMA_DMASR_DMA_DEC_ERR BIT(6)
#define XILINX_DMA_DMASR_DMA_SLAVE_ERR BIT(5)
#define XILINX_DMA_DMASR_DMA_INT_ERR BIT(4)
#define XILINX_DMA_DMASR_SG_MASK BIT(3)
#define XILINX_DMA_DMASR_IDLE BIT(1)
#define XILINX_DMA_DMASR_HALTED BIT(0)
#define XILINX_DMA_DMASR_DELAY_MASK GENMASK(31, 24)
@ -414,7 +415,6 @@ struct xilinx_dma_config {
* @dev: Device Structure
* @common: DMA device structure
* @chan: Driver specific DMA channel
* @has_sg: Specifies whether Scatter-Gather is present or not
* @mcdma: Specifies whether Multi-Channel is present or not
* @flush_on_fsync: Flush on frame sync
* @ext_addr: Indicates 64 bit addressing is supported by dma device
@ -434,7 +434,6 @@ struct xilinx_dma_device {
struct device *dev;
struct dma_device common;
struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE];
bool has_sg;
bool mcdma;
u32 flush_on_fsync;
bool ext_addr;
@ -2421,7 +2420,6 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->dev = xdev->dev;
chan->xdev = xdev;
chan->has_sg = xdev->has_sg;
chan->desc_pendingcount = 0x0;
chan->ext_addr = xdev->ext_addr;
/* This variable ensures that descriptors are not
@ -2521,6 +2519,15 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->stop_transfer = xilinx_dma_stop_transfer;
}
/* check if SG is enabled (only for AXIDMA and CDMA) */
if (xdev->dma_config->dmatype != XDMA_TYPE_VDMA) {
if (dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
XILINX_DMA_DMASR_SG_MASK)
chan->has_sg = true;
dev_dbg(chan->dev, "ch %d: SG %s\n", chan->id,
chan->has_sg ? "enabled" : "disabled");
}
/* Initialize the tasklet */
tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet,
(unsigned long)chan);
@ -2659,7 +2666,6 @@ static int xilinx_dma_probe(struct platform_device *pdev)
return PTR_ERR(xdev->regs);
/* Retrieve the DMA engine properties from the device tree */
xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {