On Tue, Nov 10, 2026 at 03:02:30PM +0800, Rong Zhang wrote:
> The Loongson-7A has a watchdog, which is similar to Loongson 2K0300,
> except that it has no clock controller.

I find this hard to believe, the device seems to be getting a clock from
somewhere that the clock-frequency property is providing the rate of.

Why is that clock not represented in devicetree?

Confused,
Conor.

> 
> Add "loongson,ls7a-wdt" compatible as well as a conditionally required
> field clock-frequency.
> 
> Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
> ---
>  .../bindings/watchdog/loongson,ls1x-wdt.yaml       | 31 +++++++++++++++++++++-
>  1 file changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/loongson,ls1x-wdt.yaml b/Documentation/devicetree/bindings/watchdog/loongson,ls1x-wdt.yaml
> index 50a9b468c4a3..cb93e9578f82 100644
> --- a/Documentation/devicetree/bindings/watchdog/loongson,ls1x-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/loongson,ls1x-wdt.yaml
> @@ -18,6 +18,7 @@ properties:
>        - loongson,ls1b-wdt
>        - loongson,ls1c-wdt
>        - loongson,ls2k0300-wdt
> +      - loongson,ls7a-wdt
>  
>    reg:
>      maxItems: 1
> @@ -25,13 +26,34 @@ properties:
>    clocks:
>      maxItems: 1
>  
> +  clock-frequency:
> +    description: Frequency of clock in Hz
> +
>  required:
>    - compatible
>    - reg
> -  - clocks
>  
>  unevaluatedProperties: false
>  
> +if:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - loongson,ls7a-wdt
> +
> +then:
> +  properties:
> +    clocks: false
> +  required:
> +    - clock-frequency
> +
> +else:
> +  properties:
> +    clock-frequency: false
> +  required:
> +    - clocks
> +
>  examples:
>    - |
>      #include <dt-bindings/clock/loongson,ls1x-clk.h>
> @@ -41,3 +63,10 @@ examples:
>  
>          clocks = <&clkc LS1X_CLKID_APB>;
>      };
> +
> +  - |
> +    watchdog@100d0030 {
> +        compatible = "loongson,ls7a-wdt";
> +        reg = <0x100d0030 0xc>;
> +        clock-frequency = <50000000>;
> +    };
> 
> -- 
> 2.55.0