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Date:   Mon, 16 Oct 2023 12:32:14 +0800
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From:   Jacky Huang <ychuang570808@gmail.com>
Subject: Re: [PATCH 2/4] dt-bindings: pinctrl: Document nuvoton ma35d1 pin
 control
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>
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Dear Krzysztof,

Thank you for the review.


On 2023/10/13 上午 03:41, Krzysztof Kozlowski wrote:
> On 11/10/2023 11:05, Jacky Huang wrote:
>> From: Jacky Huang<ychuang3@nuvoton.com>
>>
>> Add the dt-bindings header for nuvoton ma35d1 pinctrl, that gets shared
>> between the pin control driver and pin configuration in the dts.
>>
>> Add documentation to describe nuvoton ma35d1 pin control and GPIO.
>>
>> Signed-off-by: Jacky Huang<ychuang3@nuvoton.com>
>> ---
>>   .../pinctrl/nuvoton,ma35d1-pinctrl.yaml       | 180 ++++++++++++++++++
>>   include/dt-bindings/pinctrl/ma35d1-pinfunc.h  |  38 ++++
>>   2 files changed, 218 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/pinctrl/nuvoton,ma35d1-pinctrl.yaml
>>   create mode 100644 include/dt-bindings/pinctrl/ma35d1-pinfunc.h
>>
>> diff --git a/Documentation/devicetree/bindings/pinctrl/nuvoton,ma35d1-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/nuvoton,ma35d1-pinctrl.yaml
>> new file mode 100644
>> index 000000000000..0ddedbad4b78
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pinctrl/nuvoton,ma35d1-pinctrl.yaml
>> @@ -0,0 +1,180 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id:http://devicetree.org/schemas/pinctrl/nuvoton,ma35d1-pinctrl.yaml#
>> +$schema:http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Nuvoton MA35D1 pin control and GPIO
>> +
>> +maintainers:
>> +  - Shan-Chun Hung<schung@nuvoton.com>
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - nuvoton,ma35d1-pinctrl
>> +
>> +  '#address-cells':
>> +    const: 1
>> +
>> +  '#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.
>
>
>> +    $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:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
       Help pinctrl driver to access system registers by means 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.


>> +    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.

>> +
>> +      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.

>> +        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.'
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?


>> +
>> +additionalProperties:
>> +  type: object
>> +  additionalProperties:
>> +    type: object
> Wait, what? What are you describing here?

I will fix it as:

   "-grp[0-9]$":
     type: object
     description:
       Pinctrl node's client devices use subnodes for desired pin 
configuration.
       Client device subnodes use below standard properties.
     properties:
       nuvoton,pins:
       ....

and fix the example dts also.

>> +    properties:
>> +      nuvoton,pin:
>> +        description:
>> +          Each entry consists of 4 parameters and represents the mux and config
>> +          setting for one pin.
>> +        $ref: /schemas/types.yaml#/definitions/uint32-matrix
>> +        minItems: 1
>> +        items:
>> +          items:
>> +            - minimum: 0x80
>> +              maximum: 0xec
>> +              description:
>> +                The pinctrl register offset in syscon registers.
>> +            - minimum: 0
>> +              maximum: 30
>> +              description:
>> +                The bit offset in the pinctrl register.
>> +            - minimum: 0
>> +              maximum: 15
>> +              description:
>> +                The multi-function pin value.
>> +            - description:
>> +                The phandle of a node contains the generic pinconfig options
>> +                to use as described in pinctrl-bindings.txt.
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/gpio/gpio.h>
>> +    #include <dt-bindings/clock/nuvoton,ma35d1-clk.h>
>> +    #include <dt-bindings/pinctrl/ma35d1-pinfunc.h>
>> +
>> +    pinctrl@40040000 {
>> +        compatible = "nuvoton,ma35d1-pinctrl";
>> +        #address-cells = <1>;
>> +        #size-cells = <1>;
>> +        nuvoton,sys = <&sys>;
>> +        ranges = <0 0x40040000 0xc00>;
>> +
>> +        gpioa@40040000 {
>> +                reg = <0x0 0x40>;
>> +                interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
>> +                clocks = <&clk GPA_GATE>;
>> +                gpio-controller;
>> +                #gpio-cells = <2>;
>> +                interrupt-controller;
>> +                #interrupt-cells = <2>;
>> +        };
>> +
>> +        pcfg_default: pcfg-default {
>> +                slew-rate = <0>;
>> +                input-schmitt-disable;
>> +                bias-disable;
>> +                power-source = <3300>;
>> +                drive-strength = <0>;
> Really 0 mA?
>
> Why this is so incomplete?

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.

>> +        };
>> +    };
>> +
>> +    pinctrl {> +        uart13 {
>> +                pinctrl_uart13: uart13grp {
> According to your bindings this does not belong here.

I will fix.

>> +                        nuvoton,pins =
>> +                                <MA35_SYS_REG_GPH_H 24 2 &pcfg_default>,
>> +                                <MA35_SYS_REG_GPH_H 28 2 &pcfg_default>;
>> +                };
>> +        };
>> +    };
>> +
>> +    serial@407d0000 {
> Drop node, not related at all.

Okay, I will drop this node.

>> +        compatible = "nuvoton,ma35d1-uart";
>> +        reg = <0x407d0000 0x100>;
>> +        interrupts = <GIC_SPI 119 IRQ_TYPE_LEVEL_HIGH>;
>> +        clocks = <&clk UART13_GATE>;
>> +        pinctrl-0 = <&pinctrl_uart13>;
>> +    };
>> diff --git a/include/dt-bindings/pinctrl/ma35d1-pinfunc.h b/include/dt-bindings/pinctrl/ma35d1-pinfunc.h
>> new file mode 100644
>> index 000000000000..a2609d466dc9
>> --- /dev/null
>> +++ b/include/dt-bindings/pinctrl/ma35d1-pinfunc.h
> Filename matching bindings. The same name.
>
>> @@ -0,0 +1,38 @@
>> +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) */
>> +/*
>> + * Copyright (C) 2023 Nuvoton Technologies.
>> + */
>> +
>> +#ifndef __DT_BINDINGS_PINCTRL_NUVOTON_MA35D1_H
>> +#define __DT_BINDINGS_PINCTRL_NUVOTON_MA35D1_H
>> +
>> +#define MA35_SYS_REG_GPA_L	0x80
> Registry addresses are not suitable for bindings. There is also no need
> to have REG address in the binding. Drop entire file.
>
> Best regards,
> Krzysztof
>

I will remove 'ma35d1-pinfunc.h' as it will be useless after the 
'nuvoton,pin' definition changed. Best Regards, Jacky Huang