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authorMathias Tausen <mta@satlab.com>2022-07-26 16:02:12 +0200
committerVinod Koul <vkoul@kernel.org>2022-07-26 22:05:20 +0530
commit9327c7e7539371c6f202303d5539afbae006ec72 (patch)
tree431f1fbeffc3554b998c0f743da39ba8a3adaea2 /drivers/dma
parent7d3a3aaaa9cc8ec53e9ef4f3e1711827107f76c5 (diff)
dmaengine: axi-dmac: check cache coherency register
Marking the DMA as cache coherent (dma-coherent in devicetree) is only safe with versions of axi_dmac that have this feature enabled. Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Vinod Koul <vkoul@kernel.org> Acked-by: Nuno Sá <nuno.sa@analog.com> Signed-off-by: Mathias Tausen <mta@satlab.com> Link: https://lore.kernel.org/r/20220726140213.786939-1-mta@satlab.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/dma-axi-dmac.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
index 5161b73c30c4..f30dabc99795 100644
--- a/drivers/dma/dma-axi-dmac.c
+++ b/drivers/dma/dma-axi-dmac.c
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
+#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
@@ -55,6 +56,9 @@
#define AXI_DMAC_DMA_DST_TYPE_GET(x) FIELD_GET(AXI_DMAC_DMA_DST_TYPE_MSK, x)
#define AXI_DMAC_DMA_DST_WIDTH_MSK GENMASK(3, 0)
#define AXI_DMAC_DMA_DST_WIDTH_GET(x) FIELD_GET(AXI_DMAC_DMA_DST_WIDTH_MSK, x)
+#define AXI_DMAC_REG_COHERENCY_DESC 0x14
+#define AXI_DMAC_DST_COHERENT_MSK BIT(0)
+#define AXI_DMAC_DST_COHERENT_GET(x) FIELD_GET(AXI_DMAC_DST_COHERENT_MSK, x)
#define AXI_DMAC_REG_IRQ_MASK 0x80
#define AXI_DMAC_REG_IRQ_PENDING 0x84
@@ -979,6 +983,18 @@ static int axi_dmac_probe(struct platform_device *pdev)
axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00);
+ if (of_dma_is_coherent(pdev->dev.of_node)) {
+ ret = axi_dmac_read(dmac, AXI_DMAC_REG_COHERENCY_DESC);
+
+ if (version < ADI_AXI_PCORE_VER(4, 4, 'a') ||
+ !AXI_DMAC_DST_COHERENT_GET(ret)) {
+ dev_err(dmac->dma_dev.dev,
+ "Coherent DMA not supported in hardware");
+ ret = -EINVAL;
+ goto err_clk_disable;
+ }
+ }
+
ret = dma_async_device_register(dma_dev);
if (ret)
goto err_clk_disable;