On some QOCM platforms BAM control registers are managed remotely hence can not be accessed by application processor for writes. Pass a DT property qcom,bam_ctrl_remote to declare the same to skip bam_init. Move the pipe number initialisation from bam_init to probe functiom as it should be done for all platforms. Signed-off-by: Pramod Gurav <gpramod@xxxxxxxxxxxxxx> --- Documentation/devicetree/bindings/dma/qcom_bam_dma.txt | 3 +++ drivers/dma/qcom/bam_dma.c | 18 +++++++++++------- 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt index 1c9d48e..46e33ae 100644 --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt @@ -13,6 +13,8 @@ Required properties: - clock-names: must contain "bam_clk" entry - qcom,ee : indicates the active Execution Environment identifier (0-7) used in the secure world. +- qcom,bam_ctrl_remote: Use when BAM global device control is managed remotely + and not locally by the application processor. Example: @@ -24,6 +26,7 @@ Example: clock-names = "bam_clk"; #dma-cells = <1>; qcom,ee = <0>; + qcom,bam_ctrl_remote; }; DMA clients must use the format described in the dma.txt file, using a two cell diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 0880345..04dd446 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -384,6 +384,7 @@ struct bam_device { struct device_dma_parameters dma_parms; struct bam_chan *channels; u32 num_channels; + bool bam_ctrl_remote; /* execution environment ID, from DT */ u32 ee; @@ -1036,9 +1037,6 @@ static int bam_init(struct bam_device *bdev) if (bdev->ee >= val) return -EINVAL; - val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES)); - bdev->num_channels = val & BAM_NUM_PIPES_MASK; - /* s/w reset bam */ /* after reset all pipes are disabled and idle */ val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL)); @@ -1095,7 +1093,7 @@ static int bam_dma_probe(struct platform_device *pdev) struct bam_device *bdev; const struct of_device_id *match; struct resource *iores; - int ret, i; + int ret, i, val; bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL); if (!bdev) @@ -1136,9 +1134,15 @@ static int bam_dma_probe(struct platform_device *pdev) return ret; } - ret = bam_init(bdev); - if (ret) - goto err_disable_clk; + val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES)); + bdev->num_channels = val & BAM_NUM_PIPES_MASK; + + bdev->bam_ctrl_remote = of_property_read_bool(pdev->dev.of_node, + "qcom,bam_ctrl_remote"); + if (bdev->bam_ctrl_remote != true) + ret = bam_init(bdev); + if (ret) + goto err_disable_clk; tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev); -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html