The HW can be either direct-access or scatter-gather version. These are
SW incompatible.
The driver can handle both version: a DT propriety was used to
tell the driver whether to assume the HW is is scatter-gather mode.
This patch makes the driver to autodetect this information. The DT
propriety is not required anymore.
Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx>
---
Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt | 3 ---
drivers/dma/xilinx/xilinx_dma.c | 12 ++++++++----
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfa..2897e6d 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -37,9 +37,6 @@ Required properties:
Required properties for VDMA:
- xlnx,num-fstores: Should be the number of framebuffers as configured in h/w.
-Optional properties:
-- xlnx,include-sg: Tells configured for Scatter-mode in
- the hardware.
Optional properties for AXI DMA:
- xlnx,mcdma: Tells whether configured for multi-channel mode in the hardware.
Optional properties for VDMA:
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 8288fe4..b99094c 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -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)
@@ -377,7 +378,6 @@ 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
@@ -396,7 +396,6 @@ 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;
@@ -2324,7 +2323,6 @@ 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;
@@ -2404,6 +2402,13 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
else
chan->start_transfer = xilinx_vdma_start_transfer;
+ /* check if SG is enabled */
+ 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);
@@ -2541,7 +2546,6 @@ 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");
if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
--
2.7.4
--
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