Re: [PATCH v2 2/6] dt-bindings: interconnect: Add property to set BCM TCS wait behavior

Mike Tipton
2020-07-18T00:41:06Z

On 7/10/2020 9:31 AM, Rob Herring wrote:
> On Thu, Jul 09, 2020 at 06:56:48PM -0700, Mike Tipton wrote:
>> Add "qcom,tcs-wait" property to set which TCS should wait for completion
>> when triggering.
>>
>> Signed-off-by: Mike Tipton <mdtipton@codeaurora.org>
>> ---
>> .../bindings/interconnect/qcom,bcm-voter.yaml | 13 +++++++++++++
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.yaml b/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.yaml
>> index 5971fc1df08d..f0c3d6b01831 100644
>> --- a/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.yaml
>> +++ b/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.yaml
>> @@ -21,6 +21,16 @@ properties:
>> enum:
>> - qcom,bcm-voter
>>
>> + qcom,tcs-wait:
>> + description: |
>> + Optional mask of which TCSs (Triggered Command Sets) wait for completion
>> + upon triggering. In most cases, it's necessary to wait in both the AMC
>> + and WAKE sets to ensure resources are available before use. If a specific
>> + RSC and its use cases can ensure sufficient delay by other means, then
>> + this can be overridden to reduce latencies.
>
> I have no idea what any of this means to provide any meaningful comment.
>
>> + $ref: /schemas/types.yaml#/definitions/uint32
>> + default: QCOM_ICC_TAG_ACTIVE_ONLY
>
> Can't use defines here.

What's the recommended alternative? The meaning isn't obvious as a raw
number (3). We expect the defines to be used in the dt files themselves
(see example below). Is this just a restriction for the `default`
documentation specifically? I could just mention the default behavior in
the description I suppose, but that seems to defeat the purpose of
having a separate `default` key.

>
>> +
>> required:
>> - compatible
>>
>> @@ -39,7 +49,10 @@ examples:
>> # as defined in Documentation/devicetree/bindings/soc/qcom/rpmh-rsc.txt
>> - |
>>
>> + #include <dt-bindings/interconnect/qcom,icc.h>
>> +
>> disp_bcm_voter: bcm_voter {
>> compatible = "qcom,bcm-voter";
>> + qcom,tcs-wait = <QCOM_ICC_TAG_AMC>;
>> };
>> ...
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project
>>