Re: [PATCH 2/4] dt-bindings: pinctrl: Document nuvoton ma35d1 pin control

Krzysztof Kozlowski
2023-10-16T19:52:45Z

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.

>>
>>
>>> + $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.

>     $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.

>
>
>
>>> +
>>> + 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?

>
>
>>> + 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.

>
>>> +
>>> + 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?

>
>>> + 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".

Rob, Linus, any ideas for generic property replacing register-specific
power-source?

Best regards,
Krzysztof