Re: [RFC PATCH 0/1] dt-bindings: arm: Add scmi_devid paramter for

From: Krzysztof Kozlowski
Date: Mon Feb 21 2022 - 16:01:51 EST


On 21/02/2022 18:26, Oleksii Moisieiev wrote:
> Introducing new parameter called scmi_devid to the device-tree bindings.
> This parameter should be set for the device nodes, which has
> clocks/power-domains/resets working through SCMI.
> Given parameter should set the device_id, needed to set device
> permissions in the Firmware. This feature will be extremely useful for
> the virtualized systems, which has more that one Guests running on the
> system at the same time or for the syestems, which require several
> agents with different permissions. Trusted agent will use scmi_devid to
> set the Device permissions for the Firmware (See Section 4.2.2.10 [0]
> for details).
> Agents concept is described in Section 4.2.1 [0].
>
> scmi_devid in Device-tree node example:
> usb@e6590000
> {
> scmi_devid = <19>;
> clocks = <&scmi_clock 3>, <&scmi_clock 2>;
> resets = <&scmi_reset 10>, <&scmi_reset 9>;
> power-domains = <&scmi_power 0>;
> };

And how do you prevent DT overlay adding such devid to any other node
thus allowing any other device to send requests with given devid?

Plus few technicalities:
1. Hyphen, not underscore in property name, so scmi-devid.
2. Your schema does is not selected by anything. How is it intended to
be used? Nothing is including it, either...

Best regards,
Krzysztof