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

[ Upstream commit 48d163b1aa ]

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: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Srinivas Kandagatla 2018-02-15 12:25:09 +00:00 committed by Greg Kroah-Hartman
parent 7efeaf6d51
commit 909474cd38
1 changed files with 22 additions and 5 deletions
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27
drivers/dma/qcom/bam_dma.c
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@ -388,6 +388,7 @@ 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;
@ -1080,15 +1081,19 @@ 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;
val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
bdev->num_channels = val & BAM_NUM_PIPES_MASK;
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;
@ -1183,6 +1188,18 @@ 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))
return PTR_ERR(bdev->bamclk);