Re: [PATCH v3 1/1] dt-bindings: Add device-perms property description

[Oleksii Moisieiev]

Hello Rob,

Did you have a chance to take a look on the patch?

--
Oleksii.

On Thu, May 05, 2022 at 11:23:50AM +0000, Oleksii Moisieiev wrote:
> Document device-perms property which is intended to set the device
> permissions for the System Management interfaces.
> An example of this interface is SCMI (System Control and Management
> Interface) which controls clocks/power-domains/resets etc from the
> Firmware. This property sets the device_id to set the device permissions
> for the Fimware using BASE_SET_DEVICE_PERMISSIONS message (see 4.2.2.10 of [0]).
> Device permissions management described in DEN 0056, Section 4.2.2.10 [0].
> 
> For SCMI this property is used by Trusted Agent to set the device permissions
> for the Non-Trusted Agents.
> Trusted and non-trusted Agent terms described in Section 4.1.1 [0].
> 
> [0] https://developer.arm.com/documentation/den0056/latest
> 
> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> ---
> Changes V1 -> V2:
>    - update parameter name, made it xen-specific
>    - add xen vendor bindings
> 
> Changes V2 -> V3:
>    - update parameter name, make it generic
>    - update parameter format, add link to controller
>    - do not include xen vendor bindings as already upstreamed
> ---
>  .../bindings/firmware/device-perms.yaml       | 43 +++++++++++++++++++
>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/firmware/device-perms.yaml
> 
> diff --git a/Documentation/devicetree/bindings/firmware/device-perms.yaml b/Documentation/devicetree/bindings/firmware/device-perms.yaml
> new file mode 100644
> index 000000000000..5cf45f7f26d3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/firmware/device-perms.yaml
> @@ -0,0 +1,43 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2022 EPAM Systems.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/firmware/device-perms.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Device Permission settings for the Firmware
> +
> +maintainers:
> +  - Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> +
> +select: true
> +
> +description: |
> +  The provided property is intendend to set the device permissions for the
> +  System Management interfaces.
> +  An expample of such interface is SCMI (System Control and Management
> +  Interface) which manages the device permissions via SCMI protocol in the
> +  Firmware. Binding provides ID for each related device which should match
> +  device ids, defined in the Firmware so the device permissions
> +  can be requested by sending BASE_SET_DEVICE_PERMISSIONS (see 4.2.2.10 of [0]).
> +
> +  For SCMI this property is used by Trusted Agent to set the device permissions
> +  for the Non-Trusted Agents.
> +
> +  [0] https://developer.arm.com/documentation/den0056/latest
> +
> +properties:
> +  device-perms:
> +    description: Link to DT node, which should set the device permissions,
> +        device unique identifier should be set as the parameter.
> +
> +additionalProperties: true
> +
> +examples:
> +  - |
> +    ohci1: usb@ee0a0000 {
> +        /* ... */
> +        reg = <0xee0a0000 0x100>;
> +        device-perms = <&scmi 11>;
> +        clocks = <&scmi_clock 4>;
> +    };
> -- 
> 2.27.0