diff options
| author |   Srinivas Kandagatla <srinivas.kandagatla@linaro.org> | 2018-02-15 12:25:09 +0000 |
|---|---|---|
| committer |   Vinod Koul <vinod.koul@intel.com> | 2018-03-01 14:14:27 +0530 |
| commit | 48d163b1aa6e7f650c0b7a4f9c61c387a6def868 (patch) | |
| tree | edf269c9b0227b919038365530d754a8ef1cc232 /drivers/dma/qcom | |
| parent | dt-bindings: dmaengine: bam_dma: add remote controlled bindings (diff) | |
| download | linux-dev-48d163b1aa6e7f650c0b7a4f9c61c387a6def868.tar.xz linux-dev-48d163b1aa6e7f650c0b7a4f9c61c387a6def868.zip | |
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: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/qcom')
| -rw-r--r-- | drivers/dma/qcom/bam_dma.c | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index b79691fcc82d..139e9f5e47a9 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -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; - 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; @@ -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) |