Re: [PATCH v5 02/12] dt-bindings: soc/microchip: add services as children of sys ctrlr

[Rob Herring <robh@kernel.org>]

On Mon, Jan 31, 2022 at 11:47:17AM +0000, conor.dooley@microchip.com wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> Add mpfs-rng and mpfs-generic-services as children of the system
> controller.
> 
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
>  .../microchip,mpfs-sys-controller.yaml        | 41 ++++++++++++++++++-
>  1 file changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-sys-controller.yaml b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-sys-controller.yaml
> index f699772fedf3..5e9977bc114e 100644
> --- a/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-sys-controller.yaml
> +++ b/Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-sys-controller.yaml
> @@ -13,7 +13,6 @@ description: |
>    The PolarFire SoC system controller is communicated with via a mailbox.
>    This document describes the bindings for the client portion of that mailbox.
>  
> -
>  properties:
>    mboxes:
>      maxItems: 1
> @@ -21,6 +20,38 @@ properties:
>    compatible:
>      const: microchip,mpfs-sys-controller
>  
> +  rng:
> +    type: object
> +
> +    description: |
> +      The hardware random number generator on the Polarfire SoC is
> +      accessed via the mailbox interface provided by the system controller
> +
> +    properties:
> +      compatible:
> +        const: microchip,mpfs-rng
> +
> +    required:
> +      - compatible
> +
> +  sysserv:
> +    type: object
> +
> +    description: |
> +      The PolarFire SoC system controller is communicated with via a mailbox.
> +      This binding represents several of the functions provided by the system
> +      controller which do not belong in a specific subsystem, such as reading
> +      the fpga device certificate, all of which follow the same format:
> +        - a command + optional payload sent to the sys controller
> +        - a status + a payload returned to Linux
> +
> +    properties:
> +      compatible:
> +        const: microchip,mpfs-generic-service
> +
> +    required:
> +      - compatible
> +
>  required:
>    - compatible
>    - mboxes
> @@ -29,7 +60,13 @@ additionalProperties: false
>  
>  examples:
>    - |
> -    syscontroller: syscontroller {
> +    syscontroller {
>        compatible = "microchip,mpfs-sys-controller";
>        mboxes = <&mbox 0>;
> +      rng: rng {
> +        compatible = "microchip,mpfs-rng";
> +      };
> +      sysserv: sysserv {
> +        compatible = "microchip,mpfs-generic-service";
> +      };

You don't have any resources for the child nodes, so they don't need to 
be in DT. Just have the driver for "microchip,mpfs-sys-controller" 
create the sub devices you need.

Rob