Re: [PATCH v2 1/2] dt-bindings: wkup-m3-ipc: Add vtt toggle gpio pin property

[Rob Herring]

On Sat, Apr 09, 2022 at 02:12:14PM -0700, Drew Fustini wrote:
> Document Wakeup M3 IPC property that indicates a GPIO pin is connected
> to the enable pin on DDR VTT regulator and can be toggled during low
> power mode transitions.
> 
> Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
> [dfustini: converted to YAML, removed unnecessary "ti,needs-vtt-toggle"]
> Signed-off-by: Drew Fustini <dfustini@xxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/soc/ti/wkup-m3-ipc.yaml     | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> index d855c01ce61c..7f4a75c5fcaa 100644
> --- a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> +++ b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> @@ -24,6 +24,14 @@ description: |+
>    A wkup_m3_ipc device node is used to represent the IPC registers within an
>    SoC.
>  
> +  Support for VTT Toggle
> +  ==================================
> +  On some boards like the AM335x EVM-SK and the AM437x GP EVM, a GPIO pin is
> +  connected to the enable pin on the DDR VTT regulator. This allows the
> +  regulator to be disabled upon suspend and enabled upon resume. Please note
> +  that the GPIO pin must be part of the GPIO0 module as only this GPIO module
> +  is in the wakeup power domain.
> +
>  properties:
>    compatible:
>      enum:
> @@ -51,6 +59,10 @@ properties:
>        mbox_wkupm3 child node.
>      maxItems: 1
>  
> +  ti,vtt-gpio-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: GPIO pin connected to enable pin on VTT regulator

Looking at the driver, can't you add 'maximum: 31' here? If so, I can 
add it when applying.

Rob