Re: [PATCH 1/4] dt-bindings: pinctrl: mediatek: Document MT6878 pin controller bindings

["Igor Belwon" <igor.belwon@mentallysanemainliners.org>]

On Tue Sep 9, 2025 at 9:37 AM CEST, Krzysztof Kozlowski wrote:
> On Mon, Sep 08, 2025 at 09:17:55PM +0200, Igor Belwon wrote:
>> Add device-tree bindings for the pin controller and the EINT controller
>> found in the MediaTek MT6878 SoC.
>> 
>> Signed-off-by: Igor Belwon <igor.belwon@mentallysanemainliners.org>
>> ---
>>  .../bindings/pinctrl/mediatek,mt6878-pinctrl.yaml  |  209 ++++
>>  include/dt-bindings/pinctrl/mt6878-pinfunc.h       | 1201 ++++++++++++++++++++
>>  2 files changed, 1410 insertions(+)
>> 
>> diff --git a/Documentation/devicetree/bindings/pinctrl/mediatek,mt6878-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6878-pinctrl.yaml
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..ecd24ab23a0c41810828ddb8827ab39c4cd3d2fc
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6878-pinctrl.yaml
>> @@ -0,0 +1,209 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/pinctrl/mediatek,mt6878-pinctrl.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: MediaTek MT6878 Pin Controller
>> +
>> +maintainers:
>> +  - Igor Belwon <igor.belwon@mentallysanemainliners.org>
>> +
>> +description:
>> +  The MediaTek MT6878 Pin controller is used to control SoC pins.
>> +
>> +properties:
>> +  compatible:
>> +    const: mediatek,mt6878-pinctrl
>> +
>> +  reg:
>> +    items:
>> +      - description: pin controller base
>> +      - description: bl group IO
>> +      - description: bm group IO
>> +      - description: br group IO
>> +      - description: bl1 group IO
>> +      - description: br1 group IO
>> +      - description: lm group IO
>> +      - description: lt group IO
>> +      - description: rm group IO
>> +      - description: rt group IO
>> +      - description: EINT controller E block
>> +      - description: EINT controller S block
>> +      - description: EINT controller W block
>> +      - description: EINT controller C block
>> +
>> +  reg-names:
>> +    items:
>> +      - const: base
>> +      - const: bl
>> +      - const: bm
>> +      - const: br
>> +      - const: bl1
>> +      - const: br1
>> +      - const: lm
>> +      - const: lt
>> +      - const: rm
>> +      - const: rt
>> +      - const: eint-e
>> +      - const: eint-s
>> +      - const: eint-w
>> +      - const: eint-c
>> +
>> +  gpio-controller: true
>> +
>> +  '#gpio-cells':
>> +    description:
>> +      Number of cells in GPIO specifier. Since the generic GPIO binding is used,
>> +      the amount of cells must be specified as 2. See the below mentioned gpio
>> +      binding representation for description of particular cells.
>> +    const: 2
>> +
>> +  gpio-ranges:
>> +    maxItems: 1
>> +
>> +  gpio-line-names: true
>
> How many GPIOs do you have? No limit?
>

How shall I limit the GPIOs?
The maximum amount that this SoC supports is 216, looking into
dt-bindings for pinctrl, I haven't seen a SoC that limits them in
bindings. Maybe I missed it though...

>> +
>> +  interrupts:
>> +    description: The interrupt outputs to sysirq
>> +    maxItems: 1
>> +
>> +  interrupt-controller: true
>> +
>> +  '#interrupt-cells':
>> +    const: 2
>> +
>> +# PIN CONFIGURATION NODES
>> +patternProperties:
>> +  '-pins$':
>> +    type: object
>> +    additionalProperties: false
>> +
>> +    patternProperties:
>> +      '^pins':
>> +        type: object
>> +        allOf:
>> +          - $ref: /schemas/pinctrl/pincfg-node.yaml
>> +          - $ref: /schemas/pinctrl/pinmux-node.yaml
>> +        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.
>> +
>> +        properties:
>> +          pinmux:
>> +            description:
>> +              Integer array, represents gpio pin number and mux setting.
>> +              Supported pin number and mux are defined as macros in
>> +              arch/arm64/boot/dts/mediatek/mt8196-pinfunc.h for this SoC.
>> +
>> +          drive-strength:
>> +            enum: [2, 4, 6, 8, 10, 12, 14, 16]
>> +
>> +          drive-strength-microamp:
>> +            enum: [125, 250, 500, 1000]
>> +
>> +          bias-pull-down:
>> +            oneOf:
>> +              - type: boolean
>> +              - enum: [75000, 5000]
>> +                description: Pull down RSEL type resistance values (in ohms)
>> +            description:
>> +              For normal pull down type there is no need to specify a resistance
>> +              value, hence this can be specified as a boolean property.
>> +              For RSEL pull down type a resistance value (in ohms) can be added.
>> +
>> +          bias-pull-up:
>> +            oneOf:
>> +              - type: boolean
>> +              - enum: [10000, 5000, 4000, 3000]
>> +                description: Pull up RSEL type resistance values (in ohms)
>> +            description:
>> +              For normal pull up type there is no need to specify a resistance
>> +              value, hence this can be specified as a boolean property.
>> +              For RSEL pull up type a resistance value (in ohms) can be added.
>> +
>> +          bias-disable: true
>> +
>> +          output-high: true
>> +
>> +          output-low: true
>> +
>> +          input-enable: true
>> +
>> +          input-disable: true
>> +
>> +          input-schmitt-enable: true
>> +
>> +          input-schmitt-disable: true
>> +
>> +        required:
>> +          - pinmux
>> +
>> +        additionalProperties: false
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - interrupts
>> +  - interrupt-controller
>> +  - '#interrupt-cells'
>> +  - gpio-controller
>> +  - '#gpio-cells'
>> +  - gpio-ranges
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/pinctrl/mt65xx.h>
>
> Why including mt65xx?
>
>> +    #define PINMUX_GPIO0__FUNC_GPIO0 (MTK_PIN_NO(0) | 0)
>
> I don't understand why do you need it? Didn't you have header for that?
> Or you prepared for header removal (see my further comment), but then it
> is just confusing.
>

Will use the new header in V2.

>> +    #define PINMUX_GPIO99__FUNC_SCL0 (MTK_PIN_NO(99) | 1)
>> +    #define PINMUX_GPIO100__FUNC_SDA0 (MTK_PIN_NO(100) | 1)
>> +
>> +    pio: pinctrl@10005000 {
>> +        compatible = "mediatek,mt6878-pinctrl";
>> +        reg = <0x10005000 0x1000>,
>> +              <0x11d10000 0x1000>,
>> +              <0x11d30000 0x1000>,
>> +              <0x11d40000 0x1000>,
>> +              <0x11d50000 0x1000>,
>> +              <0x11d60000 0x1000>,
>> +              <0x11e20000 0x1000>,
>> +              <0x11e30000 0x1000>,
>> +              <0x11eb0000 0x1000>,
>> +              <0x11ec0000 0x1000>,
>> +              <0x11ce0000 0x1000>,
>> +              <0x11de0000 0x1000>,
>> +              <0x11e60000 0x1000>,
>> +              <0x1c01e000 0x1000>;
>> +        reg-names = "base", "bl", "bm", "br", "bl1", "br1",
>> +                    "lm", "lt", "rm", "rt", "eint-e", "eint-s",
>> +                    "eint-w", "eint-c";
>> +        gpio-controller;
>> +        #gpio-cells = <2>;
>> +        gpio-ranges = <&pio 0 0 220>;
>> +        interrupt-controller;
>> +        interrupts = <GIC_SPI 239 IRQ_TYPE_LEVEL_HIGH 0>;
>> +        #interrupt-cells = <2>;
>> +
>> +        gpio-pins {
>> +            pins {
>> +                pinmux = <PINMUX_GPIO0__FUNC_GPIO0>;
>> +                bias-pull-up = <4000>;
>> +                drive-strength = <6>;
>> +            };
>> +        };
>> +
>> +        i2c0-pins {
>> +            pins-bus {
>> +                pinmux = <PINMUX_GPIO99__FUNC_SCL0>,
>> +                         <PINMUX_GPIO100__FUNC_SDA0>;
>> +                bias-pull-down = <75000>;
>> +                drive-strength-microamp = <1000>;
>> +            };
>> +        };
>> +    };
>> diff --git a/include/dt-bindings/pinctrl/mt6878-pinfunc.h b/include/dt-bindings/pinctrl/mt6878-pinfunc.h
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..4e8e475a74549b513ac7075ac2ef0fe6f7f1d097
>> --- /dev/null
>> +++ b/include/dt-bindings/pinctrl/mt6878-pinfunc.h
>
> This is now in DTS.

Will move over in V2.

>
>> @@ -0,0 +1,1201 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>
> Otherwise wrong license and wrong filename (vendor prefix, filename
> matching binding).
>
> Best regards,
> Krzysztof

Thanks,
Igor