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

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 21/03/2024 16:13, Tanmay Shah wrote:
> 
> 
> On 3/21/24 2:39 AM, Krzysztof Kozlowski wrote:
>> 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@amd.com>
>>>>>>>>> ---
>>>>>>>>>  .../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.
> 
> Thanks for reviews.
> 
> Okay in that case I believe I should add one more property to current bindings for TCM
> configuration.
> 

I am not sure if you understand how IRC works... You sent me message on
IRC about this topic and shortly after you quit. So how am I supposed to
send reply? IRC does not work like that...

> From our discussion I conclude to following next steps:
> 
> 1) I will send Versal and Versal-NET support as part of previous series (v14) so we get
> bigger picture in the first place.
> 
> 2) Add separate compatible for versal platform.
> Use device compatible string to maintain
> backward compatibility and not machine (root node) compatible string.
> 
> 3) Add tcm,mode property in bindings and each device must configure TCM based on that
> property only and not based on compatible string.
> 
> 4) Versal-NET will disallow tcm,mode property in bindings as no such configuration is
> possible for that platform.

I really don't know your SoCs. What about Zynq? You keep using here
names all over the place, but I am not Xilinx maintainer.


Best regards,
Krzysztof