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Date:   Mon, 21 Feb 2022 22:01:43 +0100
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Subject: Re: [RFC PATCH 0/1] dt-bindings: arm: Add scmi_devid paramter for
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To:     Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>
Cc:     "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Cristian Marussi <cristian.marussi@arm.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <cover.1645460043.git.oleksii_moisieiev@epam.com>
From:   Krzysztof Kozlowski <krzk@kernel.org>
In-Reply-To: <cover.1645460043.git.oleksii_moisieiev@epam.com>
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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