Re: [PATCH 2/3] dt-bindings: remoteproc: add Versal-NET platform

[Krzysztof Kozlowski]

On 20/03/2024 16:14, Tanmay Shah wrote:
> 
> 
> On 3/20/24 2:40 AM, Krzysztof Kozlowski wrote:
>> On 19/03/2024 15:42, Tanmay Shah wrote:
>>>
>>>
>>> On 3/19/24 12:30 AM, Krzysztof Kozlowski wrote:
>>>> On 19/03/2024 01:51, Tanmay Shah wrote:
>>>>> Hello Krzysztof,
>>>>>
>>>>> Thanks for reviews. Please find my comments below.
>>>>>
>>>>> On 3/17/24 1:53 PM, Krzysztof Kozlowski wrote:
>>>>>> On 15/03/2024 22:15, Tanmay Shah wrote:
>>>>>>> AMD-Xilinx Versal-NET platform is successor of Versal platform. It
>>>>>>> contains multiple clusters of cortex-R52 real-time processing units.
>>>>>>> Each cluster contains two cores of cortex-R52 processors. Each cluster
>>>>>>> can be configured in lockstep mode or split mode.
>>>>>>>
>>>>>>> Each R52 core is assigned 128KB of TCM memory. ATCM memory is 64KB, BTCM
>>>>>>> and CTCM memoreis are 32KB each. Each TCM memory has its own dedicated
>>>>>>> power-domain that needs to be requested before using it.
>>>>>>>
>>>>>>> Signed-off-by: Tanmay Shah <tanmay.shah@xxxxxxx>
>>>>>>> ---
>>>>>>>  .../remoteproc/xlnx,zynqmp-r5fss.yaml         | 220 +++++++++++++++---
>>>>>>>  1 file changed, 184 insertions(+), 36 deletions(-)
>>>>>>>
>>>>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/xlnx,zynqmp-r5fss.yaml b/Documentation/devicetree/bindings/remoteproc/xlnx,zynqmp-r5fss.yaml
>>>>>>> index 711da0272250..55654ee02eef 100644
>>>>>>> --- a/Documentation/devicetree/bindings/remoteproc/xlnx,zynqmp-r5fss.yaml
>>>>>>> +++ b/Documentation/devicetree/bindings/remoteproc/xlnx,zynqmp-r5fss.yaml
>>>>>>> @@ -18,7 +18,9 @@ description: |
>>>>>>>  
>>>>>>>  properties:
>>>>>>>    compatible:
>>>>>>> -    const: xlnx,zynqmp-r5fss
>>>>>>> +    enum:
>>>>>>> +      - xlnx,zynqmp-r5fss
>>>>>>> +      - xlnx,versal-net-r52fss
>>>>>>>  
>>>>>>>    "#address-cells":
>>>>>>>      const: 2
>>>>>>> @@ -64,7 +66,9 @@ patternProperties:
>>>>>>>  
>>>>>>>      properties:
>>>>>>>        compatible:
>>>>>>> -        const: xlnx,zynqmp-r5f
>>>>>>> +        enum:
>>>>>>> +          - xlnx,zynqmp-r5f
>>>>>>> +          - xlnx,versal-net-r52f
>>>>>>>  
>>>>>>>        reg:
>>>>>>>          minItems: 1
>>>>>>> @@ -135,9 +139,11 @@ required:
>>>>>>>  allOf:
>>>>>>>    - if:
>>>>>>>        properties:
>>>>>>> -        xlnx,cluster-mode:
>>>>>>> -          enum:
>>>>>>> -            - 1
>>>>>>> +        compatible:
>>>>>>> +          contains:
>>>>>>> +            enum:
>>>>>>> +              - xlnx,versal-net-r52fss
>>>>>>
>>>>>> Why do you touch these lines?
>>>>>>
>>>>>>> +
>>>>>>>      then:
>>>>>>>        patternProperties:
>>>>>>>          "^r5f@[0-9a-f]+$":
>>>>>>> @@ -149,16 +155,14 @@ allOf:
>>>>>>>                items:
>>>>>>>                  - description: ATCM internal memory
>>>>>>>                  - description: BTCM internal memory
>>>>>>> -                - description: extra ATCM memory in lockstep mode
>>>>>>> -                - description: extra BTCM memory in lockstep mode
>>>>>>> +                - description: CTCM internal memory
>>>>>>>  
>>>>>>>              reg-names:
>>>>>>>                minItems: 1
>>>>>>>                items:
>>>>>>> -                - const: atcm0
>>>>>>> -                - const: btcm0
>>>>>>> -                - const: atcm1
>>>>>>> -                - const: btcm1
>>>>>>> +                - const: atcm
>>>>>>> +                - const: btcm
>>>>>>> +                - const: ctcm
>>>>>>>  
>>>>>>>              power-domains:
>>>>>>>                minItems: 2
>>>>>>> @@ -166,33 +170,70 @@ allOf:
>>>>>>>                  - description: RPU core power domain
>>>>>>>                  - description: ATCM power domain
>>>>>>>                  - description: BTCM power domain
>>>>>>> -                - description: second ATCM power domain
>>>>>>> -                - description: second BTCM power domain
>>>>>>> +                - description: CTCM power domain
>>>>>>>  
>>>>>>>      else:
>>>>>>> -      patternProperties:
>>>>>>> -        "^r5f@[0-9a-f]+$":
>>>>>>> -          type: object
>>>>>>> -
>>>>>>> -          properties:
>>>>>>> -            reg:
>>>>>>> -              minItems: 1
>>>>>>> -              items:
>>>>>>> -                - description: ATCM internal memory
>>>>>>> -                - description: BTCM internal memory
>>>>>>> -
>>>>>>> -            reg-names:
>>>>>>> -              minItems: 1
>>>>>>> -              items:
>>>>>>> -                - const: atcm0
>>>>>>> -                - const: btcm0
>>>>>>> -
>>>>>>> -            power-domains:
>>>>>>> -              minItems: 2
>>>>>>> -              items:
>>>>>>> -                - description: RPU core power domain
>>>>>>> -                - description: ATCM power domain
>>>>>>> -                - description: BTCM power domain
>>>>>>> +      allOf:
>>>>>>> +        - if:
>>>>>>> +            properties:
>>>>>>> +              xlnx,cluster-mode:
>>>>>>> +                enum:
>>>>>>> +                  - 1
>>>>>>
>>>>>> Whatever you did here, is not really readable. You have now multiple
>>>>>> if:then:if:then embedded.
>>>>>
>>>>> For ZynqMP platform, TCM can be configured differently in lockstep mode
>>>>> and split mode.
>>>>>
>>>>> For Versal-NET no such configuration is available, but new CTCM memory
>>>>> is added.
>>>>>
>>>>> So, I am trying to achieve following representation of TCM for both:
>>>>>
>>>>> if: versal-net compatible
>>>>> then:
>>>>>   ATCM - 64KB
>>>>>   BTCM - 32KB
>>>>>   CTCM - 32KB
>>>>>
>>>>> else: (ZynqMP compatible)
>>>>>   if:
>>>>>     xlnx,cluster-mode (lockstep mode)
>>>>>   then:
>>>>>     ATCM0 - 64KB
>>>>>     BTCM0 - 64KB
>>>>>     ATCM1 - 64KB
>>>>>     BTCM1 - 64KB
>>>>>   else: (split mode)
>>>>>     ATCM0 - 64KB
>>>>>     BTCM0 - 64KB
>>>>>
>>>>>
>>>>> If bindings are getting complicated, does it make sense to introduce
>>>>> new file for Versal-NET bindings? Let me know how you would like me
>>>>> to proceed.
>>>>
>>>> All this is broken in your previous patchset, but now we nicely see.
>>>>
>>>> No, this does not work like this. You do not have entirely different
>>>> programming models in one device, don't you?
>>>>
>>>
>>> I don't understand what do you mean? Programming model is same. Only number
>>> of TCMs are changing based on configuration and platform. I can certainly
>>> list different compatible for different platforms as requested. But other than
>>> that not sure what needs to be fixed.
>>
>> You cannot have same programming model with different memory mappings.
>> Anyway, please follow writing bindings rules: all of your different
>> devices must have dedicated compatible. I really though we talked about
>> two IPs on same SoC...
> 
> I agree that Versal compatible should be added, I will do that in next revision.
> 
> For ZynqMP case, it is two IPs on same SOC. In lockstep mode and split mode,
> same SOC is configuring TCM differently.
> 
> How this should be resolved for Versal-NET ? Driver avoids such TCM configuration
> for Versal-NET.

Binding should describe the hardware, not what driver is doing
currently, so the question is: does your device have such properties or
not? Anyway, you need compatible per each variant and each SoC
implementation.

Best regards,
Krzysztof