Re: [PATCH] dt-bindings: access-controllers: add controller configuration property

[Gatien CHEVALLIER <gatien.chevallier@foss.st.com>]

On 7/16/24 18:14, Gatien Chevallier wrote:
> Add a pattern property that allows to define several controller
> configuration in the device tree. It allows run-time controller
> reconfiguration for an authorized entity as in OP-TEE OS [1].
> 
> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
> Link: https://github.com/OP-TEE/optee_os/pull/6946 [1]
> ---
>   .../access-controllers/access-controllers.yaml | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml b/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
> index 99e2865f0e46..88824719bb73 100644
> --- a/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
> +++ b/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
> @@ -58,6 +58,13 @@ properties:
>         A list of access controller specifiers, as defined by the
>         bindings of the access-controllers provider.
>   
> +patternProperties:
> +  ".*(?<=)-access-conf$":
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    description:
> +      Contains a list of inseparable access controller specifiers that forms
> +      an access controller configuration.
> +
>   additionalProperties: true
>   
>   examples:
> @@ -81,4 +88,15 @@ examples:
>                                    <&bus_controller 1 3 5>;
>               access-controller-names = "clock", "bus";
>           };
> +
> +        uart5: serial@60200 {
> +          reg = <0x60200 0x400>;
> +          clocks = <&clk_serial2>;
> +          access-controllers = <&bus_controller 0 0 0>, <&bus_controller 1 0 0>,
> +                               <&clock_controller 2 3>;
> +          default-access-conf = <&bus_controller 0 10 0>,
> +                                <&bus_controller 1 10 0>;
> +          shared-access-conf = <&bus_controller 0 256 4>,
> +                               <&bus_controller 1 256 4>;
> +        };
>       };

Hi,

Looking back at this, I think it would be coherent to declare a
dedicated cell definition for this property. It makes little sense
to base it on the #access-controllers-cells as there could be
different arguments. Maybe #access-conf-cells.

Then, I should change the description as this property should describe
a list of access controller configuration entries. This list can contain
references to one or more controller.

What are your thoughts?

Best regards,
Gatien