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);
--
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