Re: [PATCH v2 1/5] dt-bindings: Add compatible string opencores,gpio to gpio-mmio

Hi Stafford,

On Wed, 17 Dec 2025 at 09:15, Stafford Horne <[email protected]> wrote:
> In FPGA Development boards with GPIOs we use the opencores gpio verilog
> rtl.  This is compatible with the gpio-mmio.  Add the compatible string
> to allow as below.
>
> Example:
>
>         gpio0: gpio@91000000 {
>                 compatible = "opencores,gpio", "brcm,bcm6345-gpio";
>                 reg = <0x91000000 0x1>, <0x91000001 0x1>;
>                 reg-names = "dat", "dirout";
>                 gpio-controller;
>                 #gpio-cells = <2>;
>                 status = "okay";
>         };
>
> Link: https://opencores.org/projects/gpio
> Signed-off-by: Stafford Horne <[email protected]>

Thanks for your patch, which is now commit f48b5e8bc2e1344f
("dt-bindings: gpio-mmio: Add compatible string for opencores,gpio")
in gpio/gpio/for-next.

> --- a/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml
> +++ b/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml
> @@ -18,11 +18,16 @@ description:
>
>  properties:
>    compatible:
> -    enum:
> -      - brcm,bcm6345-gpio
> -      - ni,169445-nand-gpio
> -      - wd,mbl-gpio # Western Digital MyBook Live memory-mapped GPIO controller
> -      - intel,ixp4xx-expansion-bus-mmio-gpio
> +    oneOf:
> +      - enum:
> +          - brcm,bcm6345-gpio
> +          - ni,169445-nand-gpio
> +          - wd,mbl-gpio # Western Digital MyBook Live memory-mapped GPIO controller
> +          - intel,ixp4xx-expansion-bus-mmio-gpio
> +      - items:
> +          - enum:
> +              - opencores,gpio
> +          - const: brcm,bcm6345-gpio

What is the rationale behind using brcm,bcm6345-gpio?
Given brcm,bcm6345-gpio has 32-bit registers, while opencores,gpio
has 8-bit registers, I doubt the latter is compatible with the former...

>
>    big-endian: true
>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds