Commit 9327c7e7 authored by Mathias Tausen's avatar Mathias Tausen Committed by Vinod Koul
Browse files

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: default avatarNuno Sá <nuno.sa@analog.com>
Signed-off-by: default avatarMathias Tausen <mta@satlab.com>
Link: https://lore.kernel.org/r/20220726140213.786939-1-mta@satlab.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 7d3a3aaa

drivers/dma/dma-axi-dmac.c

+16 −0
Original line number Diff line number Diff line
@@ -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;