[4/4] dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely controlled

[4/4] dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely controlled

[Srinivas Kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

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

This patch adds new binding num-ees to specify supported number of
Execution Environments when BAM is remotely controlled.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 Documentation/devicetree/bindings/dma/qcom_bam_dma.txt |  2 ++
 drivers/dma/qcom/bam_dma.c                             | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
index aa6822cbb230..f0d10c2b393e 100644
--- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
+++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
@@ -17,6 +17,8 @@ Required properties:
   remote proccessor i.e. execution environment.
 - num-channels : optional, indicates supported number of DMA channels in a
   remotely controlled bam.
+- num-ees : optional, indicates supported number of Execution Environments in a
+  remotely controlled bam.
 
 Example:
 
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index bbbb755d7549..7a8727271d60 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -387,6 +387,7 @@ 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;
@@ -1079,11 +1080,14 @@ 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)) >> NUM_EES_SHIFT;
+		val &= NUM_EES_MASK;
+		bdev->num_ees = val;
+	}
 
 	/* check that configured EE is within range */
-	if (bdev->ee >= val)
+	if (bdev->ee >= bdev->num_ees)
 		return -EINVAL;
 
 	if (!bdev->num_channels) {
@@ -1189,6 +1193,11 @@ static int bam_dma_probe(struct platform_device *pdev)
 					   &bdev->num_channels);
 		if (ret)
 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
+
+		ret = of_property_read_u32(pdev->dev.of_node, "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");

[4/4] dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely controlled

[Rob Herring]

On Tue, Jan 16, 2018 at 07:02:36PM +0000, srinivas.kandagatla@linaro.org wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> When Linux is master of BAM, it can directly read registers to know number
> of supported execution enviroments, however when its remotely controlled
> reading these registers would trigger a crash if the BAM is not yet
> intialized/powered up on the remote side.
> 
> This patch adds new binding num-ees to specify supported number of
> Execution Environments when BAM is remotely controlled.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  Documentation/devicetree/bindings/dma/qcom_bam_dma.txt |  2 ++
>  drivers/dma/qcom/bam_dma.c                             | 15 ++++++++++++---
>  2 files changed, 14 insertions(+), 3 deletions(-)

The correct split is the binding changes in 1 patch. Driver changes 
separate.

> 
> diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
> index aa6822cbb230..f0d10c2b393e 100644
> --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
> +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
> @@ -17,6 +17,8 @@ Required properties:
>    remote proccessor i.e. execution environment.
>  - num-channels : optional, indicates supported number of DMA channels in a
>    remotely controlled bam.
> +- num-ees : optional, indicates supported number of Execution Environments in a
> +  remotely controlled bam.

This one needs a vendor prefix as it is not a common property.

>  
>  Example:
>
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[4/4] dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely controlled

[Srinivas Kandagatla]

Thanks for the review,

On 29/01/18 16:21, Rob Herring wrote:
> On Tue, Jan 16, 2018 at 07:02:36PM +0000, srinivas.kandagatla@linaro.org wrote:
>> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>>
>> When Linux is master of BAM, it can directly read registers to know number
>> of supported execution enviroments, however when its remotely controlled
>> reading these registers would trigger a crash if the BAM is not yet
>> intialized/powered up on the remote side.
>>
>> This patch adds new binding num-ees to specify supported number of
>> Execution Environments when BAM is remotely controlled.
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   Documentation/devicetree/bindings/dma/qcom_bam_dma.txt |  2 ++
>>   drivers/dma/qcom/bam_dma.c                             | 15 ++++++++++++---
>>   2 files changed, 14 insertions(+), 3 deletions(-)
> 
> The correct split is the binding changes in 1 patch. Driver changes
> separate.
> 
Sure, Will Split it in next version.
>>
>> diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
>> index aa6822cbb230..f0d10c2b393e 100644
>> --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
>> +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
>> @@ -17,6 +17,8 @@ Required properties:
>>     remote proccessor i.e. execution environment.
>>   - num-channels : optional, indicates supported number of DMA channels in a
>>     remotely controlled bam.
>> +- num-ees : optional, indicates supported number of Execution Environments in a
>> +  remotely controlled bam.
> 
> This one needs a vendor prefix as it is not a common property.
> 
Make sense, I will change it in next version.

Thanks,
Srini
>>   
>>   Example:
>>
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