Re: [PATCH v3 1/3] dt-bindings: watchdog: sunxi: Add compatibles for R329

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Sep 02, 2021 at 05:57:48PM -0500, Samuel Holland wrote:
> On existing SoCs, the watchdog has a single clock input: HOSC (OSC24M)
> divided by 750.  However, starting with R329, LOSC (OSC32k) is added as
> an alternative clock source, with a bit to switch between them.
> 
> Since 24 MHz / 750 == 32 kHz, not 32.768 kHz, the hardware adjusts the
> cycle counts to keep the timeouts independent of the clock source. This
> keeps the programming interface backward-compatible.
> 
> Furthermore, the R329 has two watchdogs: one for use by the ARM CPUs
> at 0x20000a0, and a second one for use by the DSPs at 0x7020400. The
> first of these adds two more new registers, to allow software to
> immediately assert the SoC reset signal. Add an additional "-reset"
> suffix to signify the presence of this feature.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> Acked-by: Maxime Ripard <maxime@cerno.tech>
> Reviewed-by: Rob Herring <robh@kernel.org>

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
> Changes v2 to v3:
>  - Add else case
>  - Add additional allwinner,sun50i-r329-wdt-reset compatible
> Changes v1 to v2:
>  - Switch clock-names from enum to const
>  - Add descriptions to "clocks" items
> 
>  .../watchdog/allwinner,sun4i-a10-wdt.yaml     | 42 ++++++++++++++++++-
>  1 file changed, 41 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
> index 9aa3c313c49f..877f47759814 100644
> --- a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
> @@ -24,6 +24,8 @@ properties:
>                - allwinner,sun50i-a100-wdt
>                - allwinner,sun50i-h6-wdt
>                - allwinner,sun50i-h616-wdt
> +              - allwinner,sun50i-r329-wdt
> +              - allwinner,sun50i-r329-wdt-reset
>            - const: allwinner,sun6i-a31-wdt
>        - items:
>            - const: allwinner,suniv-f1c100s-wdt
> @@ -33,7 +35,18 @@ properties:
>      maxItems: 1
>  
>    clocks:
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
> +    items:
> +      - description: High-frequency oscillator input, divided internally
> +      - description: Low-frequency oscillator input, only found on some variants
> +
> +  clock-names:
> +    minItems: 1
> +    maxItems: 2
> +    items:
> +      - const: hosc
> +      - const: losc
>  
>    interrupts:
>      maxItems: 1
> @@ -44,6 +57,33 @@ required:
>    - clocks
>    - interrupts
>  
> +if:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - allwinner,sun50i-r329-wdt
> +          - allwinner,sun50i-r329-wdt-reset
> +
> +then:
> +  properties:
> +    clocks:
> +      minItems: 2
> +
> +    clock-names:
> +      minItems: 2
> +
> +  required:
> +    - clock-names
> +
> +else:
> +  properties:
> +    clocks:
> +      maxItems: 1
> +
> +    clock-names:
> +      maxItems: 1
> +
>  unevaluatedProperties: false
>  
>  examples: