Re: [PATCH v8 1/2] dt-bindings: clock: gpio-gate-clock: Add a new compatible string

[Jerome Brunet <jbrunet@baylibre.com>]

On Sun 27 Sep 2026 at 14:59, Vyacheslav Yurkov via B4 Relay <devnull+V.Yurkov.EXT.bruker.com@kernel.org> wrote:

> From: Vyacheslav Yurkov <V.Yurkov.EXT@bruker.com>
>
> Extend the binding to be used also for gpio-locked-fixed-clock.
> A GPIO-locked fixed clock provider exposes a fixed-rate clock whose
> availability depends on one or more GPIO lock-status signals.
>
> Some hardware designs provide fixed-frequency clocks generated outside
> software control, such as by FPGA-resident PLLs. While the clock rate is
> fixed, a separate GPIO signal indicates whether the clock source is
> locked and producing a valid output.
>
> Signed-off-by: Vyacheslav Yurkov <V.Yurkov.EXT@bruker.com>
> ---
>  .../devicetree/bindings/clock/gpio-gate-clock.yaml | 32 ++++++++++++++++++++--
>  1 file changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/clock/gpio-gate-clock.yaml b/Documentation/devicetree/bindings/clock/gpio-gate-clock.yaml
> index d09d0e3f0c6e..1ad87c8b36b9 100644
> --- a/Documentation/devicetree/bindings/clock/gpio-gate-clock.yaml
> +++ b/Documentation/devicetree/bindings/clock/gpio-gate-clock.yaml
> @@ -11,7 +11,9 @@ maintainers:
>  
>  properties:
>    compatible:
> -    const: gpio-gate-clock
> +    enum:
> +      - gpio-gate-clock
> +      - gpio-locked-clock

I think this name does not illustrate well what your driver does
anymore. As I noted before, locked if very much PLL centric. enabled ?

While the driver sits in the same C file (clk-gpio), I don't the binding doc
should. I'll defer to the DT folks on this but I think it would more
approriate with a different yaml. clk-gpio-gate and clk-gpio-mux have
their own binding doc

>  
>    clocks:
>      maxItems: 1
> @@ -23,10 +25,29 @@ properties:
>      description: GPIO reference for enabling and disabling the clock.
>      maxItems: 1
>  
> +  enabled-gpios:
> +    description: GPIO that indicates whether the clock is enabled or disabled.
> +    maxItems: 1
> +
>  required:
>    - compatible
>    - '#clock-cells'
> -  - enable-gpios
> +
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          const: gpio-gate-clock
> +    then:
> +      required:
> +        - enable-gpios
> +  - if:
> +      properties:
> +        compatible:
> +          const: gpio-locked-clock

I think there should be a property in here to express how long you are
willing to wait for the clock to be enabled. IOW the lock timeout.

> +    then:
> +      required:
> +        - enabled-gpios
>  
>  additionalProperties: false
>  
> @@ -40,3 +61,10 @@ examples:
>          #clock-cells = <0>;
>          enable-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
>      };
> +
> +    clk_gpio_locked {
> +        compatible = "gpio-locked-clock";
> +        #clock-cells = <0>;
> +        clocks = <&pll>;
> +        enabled-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
> +    };
>
> -- 
> 2.34.1
>
>

-- 
Jerome