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Date:   Tue, 6 Sep 2022 10:32:49 +0530
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Subject: Re: [PATCH v4 1/2] dt-bindings: phy: ti: phy-gmii-sel: Add bindings
 for J7200
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        <krzysztof.kozlowski+dt@linaro.org>
References: <20220901085506.138633-1-s-vadapalli@ti.com>
 <20220901085506.138633-2-s-vadapalli@ti.com>
 <4b681c03-7f5a-0234-2276-316e0bad1de5@linaro.org>
 <44339382-c4e2-26db-de5d-263ae5a585b8@ti.com>
 <4e61b63b-74ac-1682-968f-17e5d8db7ce6@linaro.org>
From:   Siddharth Vadapalli <s-vadapalli@ti.com>
In-Reply-To: <4e61b63b-74ac-1682-968f-17e5d8db7ce6@linaro.org>
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Hello Krzysztof,

On 05/09/22 18:39, Krzysztof Kozlowski wrote:
> On 02/09/2022 08:09, Siddharth Vadapalli wrote:
>> Hello Krzysztof,
>>
>> On 01/09/22 20:51, Krzysztof Kozlowski wrote:
>>> On 01/09/2022 11:55, Siddharth Vadapalli wrote:
>>>> TI's J7200 SoC supports additional PHY modes like QSGMII and SGMII
>>>> that are not supported on earlier SoCs. Add a compatible for it.
>>>>
>>>> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
>>>> ---
>>>>  .../mfd/ti,j721e-system-controller.yaml       |  6 ++++
>>>>  .../bindings/phy/ti,phy-gmii-sel.yaml         | 30 ++++++++++++++++++-
>>>>  2 files changed, 35 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/mfd/ti,j721e-system-controller.yaml b/Documentation/devicetree/bindings/mfd/ti,j721e-system-controller.yaml
>>>> index 1aeac43cad92..802374e7645f 100644
>>>> --- a/Documentation/devicetree/bindings/mfd/ti,j721e-system-controller.yaml
>>>> +++ b/Documentation/devicetree/bindings/mfd/ti,j721e-system-controller.yaml
>>>> @@ -54,6 +54,12 @@ patternProperties:
>>>>      description:
>>>>        Clock provider for TI EHRPWM nodes.
>>>>  
>>>> +  "phy@[0-9a-f]+$":
>>>> +    type: object
>>>> +    $ref: /schemas/phy/phy-provider.yaml
>>>
>>> You need instead ref to specific device bindings/schema. Probably to
>>> /schemas/phy/ti,phy-gmii-sel.yaml#
>>
>> Thank you for the clarification. I will update $ref to
>> "/schemas/phy/ti,phy-gmii-sel.yaml#" in the v5 series.
>>
>>>
>>> This was entirely different in v3, so your change is very confusing.
>>
>> I had misunderstood Rob's comment in the v3 patch. I had initially
>> provided the relative path to the bindings file ti,phy-gmii-sel.yaml in
>> the v3 patch. When Rob commented "/schemas/phy/..", I misunderstood and
>> thought that I had to point $ref to a generic phy-provider schema
>> present in the dt-schema repo and thus, in this v4 patch, I had updated
>> $ref accordingly.
>>
>>>
>>>> +    description:
>>>> +      This is the register to set phy mode through phy-gmii-sel driver.
>>>
>>> I don't understand the description. Please focus on the hardware not
>>> some drivers - what is here? Phy for something?
>>
>> I will fix the description, updating it to the following:
>> "Address of the CTRLMMR_ENETx_CTRL registers which are used to configure
>> the phy-mode of the CPSW MAC ports."
>>
>> Please let me know if the above description is fine.
> 
> Hm, but that's a phy node, not address of register... Isn't this a phy
> node representing the phy of the CPSW MAC ports?

Despite it being a phy node, the phy-gmii-sel driver actually uses this
node to obtain the address of the CTRLMMR_ENETx_CTRL registers which
correspond to the CPSW MAC configuration and are therefore unrelated to
the PHY. Please let me know if my suggested description would be fine.

> 
>>
>>>
>>>> +
>>>>  required:
>>>>    - compatible
>>>>    - reg
>>>> diff --git a/Documentation/devicetree/bindings/phy/ti,phy-gmii-sel.yaml b/Documentation/devicetree/bindings/phy/ti,phy-gmii-sel.yaml
>>>> index ff8a6d9eb153..0ffb97f1a77c 100644
>>>> --- a/Documentation/devicetree/bindings/phy/ti,phy-gmii-sel.yaml
>>>> +++ b/Documentation/devicetree/bindings/phy/ti,phy-gmii-sel.yaml
>>>> @@ -53,12 +53,24 @@ properties:
>>>>        - ti,am43xx-phy-gmii-sel
>>>>        - ti,dm814-phy-gmii-sel
>>>>        - ti,am654-phy-gmii-sel
>>>> +      - ti,j7200-cpsw5g-phy-gmii-sel
>>>>  
>>>>    reg:
>>>>      maxItems: 1
>>>>  
>>>>    '#phy-cells': true
>>>>  
>>>> +  ti,qsgmii-main-ports:
>>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>>> +    description: |
>>>> +      Required only for QSGMII mode. Array to select the port for
>>>> +      QSGMII main mode. Rest of the ports are selected as QSGMII_SUB
>>>> +      ports automatically. Any one of the 4 CPSW5G ports can act as the
>>>> +      main port with the rest of them being the QSGMII_SUB ports.
>>>> +    items:
>>>> +      minimum: 1
>>>> +      maximum: 4
>>>> +
>>>>  allOf:
>>>>    - if:
>>>>        properties:
>>>> @@ -73,6 +85,22 @@ allOf:
>>>>          '#phy-cells':
>>>>            const: 1
>>>>            description: CPSW port number (starting from 1)
>>>
>>> Blank line
>>
>> I will fix this in the v5 series.
>>
>>>
>>>
>>>> +  - if:
>>>> +      properties:
>>>> +        compatible:
>>>> +          contains:
>>>> +            enum:
>>>> +              - ti,j7200-cpsw5g-phy-gmii-sel
>>>> +    then:
>>>> +      properties:
>>>> +        '#phy-cells':
>>>> +          const: 1
>>>> +          description: CPSW port number (starting from 1)
>>>> +        ti,qsgmii-main-ports:
>>>> +          maxItems: 1
>>>
>>> It does not really make sense to limit items here, in the context of
>>> this patch. You got a comment for it already. Your patch should make
>>> sense on its own.
>>
>> I had defined the property as an array because there are more than one
>> QSGMII main ports for other devices for which I will be posting the
>> patches. I had planned to reuse this property, with "maxItems: 2" in the
>> future patches for other compatibles. However, as suggested by you, I
>> will change the property to a uint32 instead of uint32-array in this
>> series. Later, in my future patches for other devices, I will change it
>> back to a uint32-array when I reuse the property.
> 
> Wait, no. You should not change the property. This should be
> uint32-array, because you will extend it soon, just maxItems must be
> defined in top-level place.

Thank you for clarifying. I will move "maxItems: 1" to the top where
"ti,qsgmii-main-ports" property is first defined, and continue using the
property as a uint32-array.

Regards,
Siddharth.