Date:   Tue, 27 Dec 2022 15:08:23 +0530
From:   Devarsh Thakkar <devarsht@...com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        <andersson@...nel.org>, <devicetree@...r.kernel.org>,
        <mathieu.poirier@...aro.org>, <linux-remoteproc@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <s-anna@...com>,
        Rob Herring <robh+dt@...nel.org>
CC:     <hnagalla@...com>, <praneeth@...com>, <nm@...com>,
        <vigneshr@...com>, <a-bhatia1@...com>, <j-luthra@...com>
Subject: Re: [PATCH v3 1/2] dt-bindings: remoteproc: ti: Add new compatible
 for AM62 SoC family



On 26/12/22 17:48, Krzysztof Kozlowski wrote:
> On 23/12/2022 12:56, Devarsh Thakkar wrote:
>> AM62 family of devices don't have a R5F cluster, instead
>> they have single core DM R5F.
>> Add new compatible string ti,am62-r5fss to support this scenario.
>>
>> When this new compatible is used don't allow cluster-mode
>> property usage in device-tree as this implies that there
>> is no R5F cluster available and only single R5F core
>> is present.
>>
>> Signed-off-by: Devarsh Thakkar <devarsht@...com>
>> ---
>> V2: Avoid acronyms, use "Device Manager" instead of "DM"
>> V3:
>> - Use separate if block for each compatible for ti,cluster-mode property
>> - Rearrange compatibles as per alphabatical order
>> ---
>>  .../bindings/remoteproc/ti,k3-r5f-rproc.yaml  | 68 +++++++++++++------
>>  1 file changed, 47 insertions(+), 21 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> index fb9605f0655b..e8a861179bd9 100644
>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>> @@ -21,6 +21,9 @@ description: |
>>    called "Single-CPU" mode, where only Core0 is used, but with ability to use
>>    Core1's TCMs as well.
>>  
>> +  AM62 SoC family support a single R5F core only which runs Device Manager
>> +  firmware and can also be used as a remote processor with IPC communication.
>> +
>>    Each Dual-Core R5F sub-system is represented as a single DTS node
>>    representing the cluster, with a pair of child DT nodes representing
>>    the individual R5F cores. Each node has a number of required or optional
>> @@ -28,16 +31,20 @@ description: |
>>    the device management of the remote processor and to communicate with the
>>    remote processor.
>>  
>> +  Since AM62 SoC family only support a single core, there is no cluster-mode
>> +  property setting required for it.
>> +
>>  properties:
>>    $nodename:
>>      pattern: "^r5fss(@.*)?"
>>  
>>    compatible:
>>      enum:
>> +      - ti,am62-r5fss
>> +      - ti,am64-r5fss
>>        - ti,am654-r5fss
>> -      - ti,j721e-r5fss
>>        - ti,j7200-r5fss
>> -      - ti,am64-r5fss
>> +      - ti,j721e-r5fss
>>        - ti,j721s2-r5fss
>>  
>>    power-domains:
>> @@ -80,7 +87,9 @@ patternProperties:
>>        node representing a TI instantiation of the Arm Cortex R5F core. There
>>        are some specific integration differences for the IP like the usage of
>>        a Region Address Translator (RAT) for translating the larger SoC bus
>> -      addresses into a 32-bit address space for the processor.
>> +      addresses into a 32-bit address space for the processor. For AM62x,
>> +      the R5F Sub-System device node should only define one R5F child node
>> +      as it has only one core available.
>>  
>>        Each R5F core has an associated 64 KB of Tightly-Coupled Memory (TCM)
>>        internal memories split between two banks - TCMA and TCMB (further
>> @@ -100,11 +109,12 @@ patternProperties:
>>      properties:
>>        compatible:
>>          enum:
>> -          - ti,am654-r5f
>> -          - ti,j721e-r5f
>> -          - ti,j7200-r5f
>> -          - ti,am64-r5f
>> -          - ti,j721s2-r5f
>> +          - ti,am62-r5fss
>> +          - ti,am64-r5fss
>> +          - ti,am654-r5fss
>> +          - ti,j7200-r5fss
>> +          - ti,j721e-r5fss
>> +          - ti,j721s2-r5fss
>>  
There is a problem here, the compatibles still need to be "-r5f" I will
correct it in V4.
>>        reg:
>>          items:
>> @@ -208,19 +218,35 @@ patternProperties:
>>  
>>      unevaluatedProperties: false
>>  
>> -if:
>> -  properties:
>> -    compatible:
>> -      enum:
>> -        - ti,am64-r5fss
>> -then:
>> -  properties:
>> -    ti,cluster-mode:
>> -      enum: [0, 2]
>> -else:
>> -  properties:
>> -    ti,cluster-mode:
>> -      enum: [0, 1]
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          enum:
>> +            - ti,am64-r5fss
>> +    then:
>> +      properties:
>> +        ti,cluster-mode:
>> +          enum: [0, 2]
>> +
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          enum: ["ti,am654-r5fss", "ti,j7200-r5fss", "ti,j721e-r5fss",  "ti,j721s2-r5fss"]
> 
> That's not how enums are spelled for such cases. Git grep for examples -
> this should be a enum with each item in new entry, no quotes.
Yeah, that was my initial thought but then I looked at section 4.9.3 of
https://json-schema.org/understanding-json-schema/UnderstandingJSONSchema.pdf
which had below example and based on that did this change thus avoiding
separate entries for each enum.

Example:
{
"enum": ["red", "amber", "green", null, 42]
}

To confirm whether the change works fine, I deliberately modified cluster-mode
values for each of the SoC's beyond acceptable ranges as seen in
https://gist.github.com/devarsht/1956063c8e39f1bdbad3574ea96b95a3
and then ran "make dtbs_check" and it was able to catch the inappropriate
values of cluster-mode as seen in below logs :

https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L392
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L500
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L712
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L741
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L750
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L766
https://gist.github.com/devarsht/bc8cfb82c55b75d85649585d3fd536a0#file-gistfile1-txt-L773

Kindly let me know if you see some issues with this approach.

Best Regards,
Devarsh

> 
> Best regards,
> Krzysztof
> 

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