Commit 48d163b1 authored by Srinivas Kandagatla's avatar Srinivas Kandagatla Committed by Vinod Koul
Browse files

dmaengine: qcom: bam_dma: get num-channels and num-ees from dt 



When Linux is master of BAM, it can directly read registers to know number
of supported channels, however when its remotely controlled reading these
registers would trigger a crash if the BAM is not yet initialized or
powered up on the remote side.

This patch allows driver to read num-channels and num-ees from Device Tree
for remotely controlled BAM.

Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent d545afc9

drivers/dma/qcom/bam_dma.c

+22 −5
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ struct bam_device { 
	struct device_dma_parameters dma_parms;

	struct bam_chan *channels;

	u32 num_channels;

	u32 num_ees;



	/* execution environment ID, from DT */

	u32 ee;
@@ -1128,15 +1129,19 @@ static int bam_init(struct bam_device *bdev) 
	u32 val;



	/* read revision and configuration information */

	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;

	val &= NUM_EES_MASK;

	if (!bdev->num_ees) {

		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));

		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;

	}



	/* check that configured EE is within range */

	if (bdev->ee >= val)

	if (bdev->ee >= bdev->num_ees)

		return -EINVAL;



	if (!bdev->num_channels) {

		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));

		bdev->num_channels = val & BAM_NUM_PIPES_MASK;

	}



	if (bdev->controlled_remotely)

		return 0;
@@ -1232,6 +1237,18 @@ static int bam_dma_probe(struct platform_device *pdev) 
	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,

						"qcom,controlled-remotely");



	if (bdev->controlled_remotely) {

		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",

					   &bdev->num_channels);

		if (ret)

			dev_err(bdev->dev, "num-channels unspecified in dt\n");



		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",

					   &bdev->num_ees);

		if (ret)

			dev_err(bdev->dev, "num-ees unspecified in dt\n");

	}



	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");

	if (IS_ERR(bdev->bamclk)) {

		if (!bdev->controlled_remotely)

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