[PATCH v2 01/13] dt-bindings: gpio: add common schema for GPIO controllers

[Rob Herring]

On Thu, Sep 17, 2020 at 10:53 AM Krzysztof Kozlowski <krzk at kernel.org> wrote:
>
> Convert parts of gpio.txt bindings into common dtschema file for GPIO
> controllers.  The schema enforces proper naming of GPIO controller nodes
> and GPIO hogs.

Did you not see my previous reply about a common schema? We already
have a common GPIO and hog schema in dtschema. Please add to it
whatever is missing.

My goal is all common schema end up in dtschema, but I haven't pushed
folks to do that yet. Ones I've done are there though. One issue is
what's in dtschema should be GPL/BSD and the existing text bindings
are default GPL, so there's a relicensing exercise. In some cases, the
schema is there but I haven't copied over the descriptions.

Rob


> +    description:
> +      Indicates the start and size of the GPIOs that can't be used.
> +
> +  ngpios:
> +    description: |
> +      Optionally, a GPIO controller may have a "ngpios" property. This property
> +      indicates the number of in-use slots of available slots for GPIOs. The
> +      typical example is something like this: the hardware register is 32 bits
> +      wide, but only 18 of the bits have a physical counterpart. The driver is
> +      generally written so that all 32 bits can be used, but the IP block is
> +      reused in a lot of designs, some using all 32 bits, some using 18 and
> +      some using 12. In this case, setting "ngpios = <18>;" informs the driver
> +      that only the first 18 GPIOs, at local offset 0 .. 17, are in use.
> +
> +      If these GPIOs do not happen to be the first N GPIOs at offset 0...N-1,
> +      an additional set of tuples is needed to specify which GPIOs are
> +      unusable, with the gpio-reserved-ranges binding.
> +
> +patternProperties:
> +  "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$":
> +    type: object
> +    description:
> +      The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism
> +      providing automatic GPIO request and configuration as part of the
> +      gpio-controller's driver probe function.
> +      Each GPIO hog definition is represented as a child node of the GPIO controller.
> +
> +    properties:
> +      gpio-hog: true
> +      gpios: true
> +      input: true
> +      output-high: true
> +      output-low: true
> +      line-name:
> +        description:
> +          The GPIO label name. If not present the node name is used.
> +
> +    required:
> +      - gpio-hog
> +      - gpios
> +
> +    oneOf:
> +      - required:
> +          - input
> +      - required:
> +          - output-high
> +      - required:
> +          - output-low
> +
> +    additionalProperties: false
> +
> +required:
> +  - "#gpio-cells"
> +  - gpio-controller
> +
> +examples:
> +  - |
> +    gpio-controller at 15000000 {
> +        compatible = "foo";
> +        reg = <0x15000000 0x1000>;
> +        gpio-controller;
> +        #gpio-cells = <2>;
> +        ngpios = <18>;
> +        gpio-reserved-ranges = <0 4>, <12 2>;
> +        gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R",
> +                          "LED G", "LED B", "Col A", "Col B", "Col C", "Col D",
> +                          "Row A", "Row B", "Row C", "Row D", "NMI button",
> +                          "poweroff", "reset";
> +    };
> +
> +  - |
> +    gpio-controller at 1400 {
> +        compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
> +        reg = <0x1400 0x18>;
> +        gpio-controller;
> +        #gpio-cells = <2>;
> +
> +        line-b-hog {
> +            gpio-hog;
> +            gpios = <6 0>;
> +            input;
> +            line-name = "foo-bar-gpio";
> +        };
> +    };
> --
> 2.17.1
>