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Commit 464aa6f5 authored by Stefan Brüns's avatar Stefan Brüns Committed by Vinod Koul
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dmaengine: sun6i: Retrieve channel count/max request from devicetree 



To avoid introduction of a new compatible for each small SoC/DMA controller
variation, move the definition of the channel count to the devicetree.

The number of vchans is no longer explicit, but limited by the highest
port/DMA request number. The result is a slight overallocation for SoCs
with a sparse port mapping.

Signed-off-by: default avatarStefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 12e01770

drivers/dma/sun6i-dma.c

+26 −1
Original line number Diff line number Diff line
@@ -42,6 +42,9 @@ 


#define DMA_STAT		0x30



/* Offset between DMA_IRQ_EN and DMA_IRQ_STAT limits number of channels */

#define DMA_MAX_CHANNELS	(DMA_IRQ_CHAN_NR * 0x10 / 4)



/*

 * sun8i specific registers

 */
@@ -65,7 +68,8 @@ 
#define DMA_CHAN_LLI_ADDR	0x08



#define DMA_CHAN_CUR_CFG	0x0c

#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & 0x1f)

#define DMA_CHAN_MAX_DRQ		0x1f

#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & DMA_CHAN_MAX_DRQ)

#define DMA_CHAN_CFG_SRC_IO_MODE	BIT(5)

#define DMA_CHAN_CFG_SRC_LINEAR_MODE	(0 << 5)

#define DMA_CHAN_CFG_SRC_BURST_A31(x)	(((x) & 0x3) << 7)
@@ -1174,6 +1178,7 @@ MODULE_DEVICE_TABLE(of, sun6i_dma_match); 


static int sun6i_dma_probe(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	struct sun6i_dma_dev *sdc;

	struct resource *res;

	int ret, i;
@@ -1248,6 +1253,26 @@ static int sun6i_dma_probe(struct platform_device *pdev) 
	sdc->num_vchans = sdc->cfg->nr_max_vchans;

	sdc->max_request = sdc->cfg->nr_max_requests;



	ret = of_property_read_u32(np, "dma-channels", &sdc->num_pchans);

	if (ret && !sdc->num_pchans) {

		dev_err(&pdev->dev, "Can't get dma-channels.\n");

		return ret;

	}



	ret = of_property_read_u32(np, "dma-requests", &sdc->max_request);

	if (ret && !sdc->max_request) {

		dev_info(&pdev->dev, "Missing dma-requests, using %u.\n",

			 DMA_CHAN_MAX_DRQ);

		sdc->max_request = DMA_CHAN_MAX_DRQ;

	}



	/*

	 * If the number of vchans is not specified, derive it from the

	 * highest port number, at most one channel per port and direction.

	 */

	if (!sdc->num_vchans)

		sdc->num_vchans = 2 * (sdc->max_request + 1);



	sdc->pchans = devm_kcalloc(&pdev->dev, sdc->num_pchans,

				   sizeof(struct sun6i_pchan), GFP_KERNEL);

	if (!sdc->pchans)