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Message-ID: <8e983479-709f-4ec8-85e2-c46a5256a2ec@gmail.com>
Date:   Wed, 18 Oct 2023 11:26:21 +0800
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Subject: Re: [PATCH 2/4] dt-bindings: pinctrl: Document nuvoton ma35d1 pin
 control
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        linus.walleij@linaro.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        p.zabel@pengutronix.de, j.neuschaefer@gmx.net
Cc:     linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        schung@nuvoton.com, Jacky Huang <ychuang3@nuvoton.com>
References: <20231011090510.114476-1-ychuang570808@gmail.com>
 <20231011090510.114476-3-ychuang570808@gmail.com>
 <7800b2d6-33c4-4c4f-8d0c-c11ff0e47535@linaro.org>
 <17a80031-98bf-48bf-8cea-c0ca4400f142@gmail.com>
 <254837e5-a0fa-4796-8928-277db4b98bf1@linaro.org>
From:   Jacky Huang <ychuang570808@gmail.com>
In-Reply-To: <254837e5-a0fa-4796-8928-277db4b98bf1@linaro.org>
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Dear Krzysztof,

Thank you for the review.


On 2023/10/17 上午 03:52, Krzysztof Kozlowski wrote:
> On 16/10/2023 06:32, Jacky Huang wrote:
>>>> +  '#size-cells':
>>>> +    const: 1
>>>> +
>>>> +  nuvoton,sys:
>>>> +    description:
>>>> +      phandle to the syscon node
>>> sys is quite generic. Description explains nothing except duplicating
>>> known information. Drop duplicated info and instead explain to what this
>>> phandle points and how it is going to be used.
> Read comments carefully.


I will update the description of 'nuvoton,sys'.

>
>>>
>>>> +    $ref: /schemas/types.yaml#/definitions/phandle-array
>>>> +    items:
>>>> +      maxItems: 1
>>> So just phandle, not phandle-array, unless it is defined like this in
>>> some other binding.
>> I would like to update this as:
>>
>>     nuvoton,sys:
> Nothing improved.

Here just fix  the 'phandle-array' to 'phandle' and remove 'maxItems'.

>>       $ref: /schemas/types.yaml#/definitions/phandle
>>       description:
>>         Help pinctrl driver to access system registers by means of regmap.
> Driver is not relevant here. Say which part of syscon are necessary for
> pinctrl operation.
>

I will update description as:

   nuvoton,sys:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
       The pin function control registers are located in the system
       control register space. This phandle provides pinctrl the
       ability to access the pin function control registers through
       the use of regmap.


>>
>>
>>>> +
>>>> +  ranges: true
>>>> +
>>>> +allOf:
>>>> +  - $ref: pinctrl.yaml#
>>> allOf: goes after required: block.
>> I will fix it.
>>
>>>> +
>>>> +patternProperties:
>>>> +  "gpio[a-n]@[0-9a-f]+$":
>>> ^gpio@[0-9a-f]+$":
>> I will fix this, and also fix the dtsi.
>>
>>>> +    type: object
>>>> +    additionalProperties: false
>>>> +    properties:
>>>> +
>>> Drop blank line
>> I will fix it.
>>
>>>> +      gpio-controller: true
>>>> +
>>>> +      '#gpio-cells':
>>>> +        const: 2
>>>> +
>>>> +      reg:
>>>> +        maxItems: 1
>>>> +
>>>> +      clocks:
>>>> +        maxItems: 1
>>>> +
>>>> +      interrupt-controller: true
>>>> +
>>>> +      '#interrupt-cells':
>>>> +        const: 2
>>>> +
>>>> +      interrupts:
>>>> +        description:
>>>> +          The interrupt outputs to sysirq.
>>>> +        maxItems: 1
>>>> +
>>>> +    required:
>>>> +      - reg
>>>> +      - interrupts
>>>> +      - interrupt-controller
>>>> +      - '#interrupt-cells'
>>>> +      - gpio-controller
>>>> +      - '#gpio-cells'
>>> Keep the same order as in list of properties.
>> I will fix the order.
>>
>>>> +
>>>> +  "pcfg-[a-z0-9-.]+$":
>>> Why using different naming than other Nuvoton SoCs? You also accept
>>> "foobarpcfg-1", which does not look intentional.
>>>
>> I will use '"^pin-[a-z0-9-.]+$" instead.
> [.] is redundant... What exactly do you want to match?

I want to match the name like "-1.8v" or "-3.3v".
However, this should be specified in the property, so I will drop the "-.".


>>
>>>> +    type: object
>>>> +    description:
>>>> +      A pinctrl node should contain at least one subnodes representing the
>>>> +      pinctrl groups available on the machine. Each subnode will list the
>>>> +      pins it needs, and how they should be configured, with regard to muxer
>>>> +      configuration, pullups, drive strength, input enable/disable and input
>>>> +      schmitt.
>>>> +
>>>> +    allOf:
>>>> +      - $ref: pincfg-node.yaml#
>>> missing additional/unevaluatedProperties: false.
>> I will add unevaluatedProperties: false.
>>
>>>> +
>>>> +    properties:
>>>> +      bias-disable: true
>>> Why do you need this and other ones?
>> We expect the pin configuration to select one of ==>
>> bias-disable;
>> bias-pull-down;
>> bias-pull-up;
>>
>> This is the same as rockchip,pinctrl.yaml and renesas,rzv2m-pinctrl.yaml.
> OK, then go with nuvoton approach. List the properties (:true) and use
> additionalProperties: false.

I got it.

>>>> +
>>>> +      bias-pull-down: true
>>>> +
>>>> +      bias-pull-up: true
>>>> +
>>>> +      drive-strength:
>>>> +        minimum: 0
>>> 0 mA? Is it really valid? Are you sure you used correct property?
>> We treat this value as the value to be written to the control register,
>> not as
>> a current value in mA. I will correct this mistake.
> Instead treat it as mA. Is this possible?

I will update it as:

       drive-strength-microamp:
         oneOf:
           - enum: [ 2900, 4400, 5800, 7300, 8600, 10100, 11500, 13000 ]
             description: 1.8V I/O driving strength
           - enum: [ 17100, 25600, 34100, 42800, 48000, 56000, 77000, 
82000 ]
             description: 3.3V I/O driving strength

And use a lookup table in the pinctrl driver to translate it into 
register value.


>>>> +        maximum: 7
>>>> +
>>>> +      input-enable: true
>>>> +
>>>> +      input-schmitt-enable: true
>>>> +
>>>> +      power-source:
>>>> +        description:
>>>> +          I/O voltage in millivolt.
>>>> +        enum: [ 1800, 3300 ]
>>> Missing units in property name. power-source also does not really
>>> describe the property.
>>
>> The output voltage level of GPIO can be configured as 1.8V or 3.3V,
>> but I cannot find any suitable output properties in 'pincfg-node.yaml.'
> There is actually power-source, but treated as actual choice of power
> supplies.
>
>> I noticed that 'xlnx,zynq-pinctrl.yaml' and 'xlnx,zynq-pinctrl.yaml' use
>> 'power source' to specify the output voltage.  Should I follow their
>> approach or define a vendor-specific one?
> Maybe Rob or Linus have here some recommendation, but I would suggest to
> go either with rtd1319d-pinctrl.yaml approach or add a generic property
> to pincfg-node expressed in real units like "io-microvolt".

OK, I will update it as:

       power-source:
         description: |
           Valid arguments are described as below:
           0: power supply of 1.8V
           1: power supply of 3.3V
         enum: [0, 1]


> Rob, Linus, any ideas for generic property replacing register-specific
> power-source?
>
>
> Best regards,
> Krzysztof
>

Best Regards,
Jacky Huang