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Date:   Thu, 2 Jun 2022 18:19:00 -0700 (PDT)
From:   Stefano Stabellini <sstabellini@kernel.org>
To:     Rob Herring <robh@kernel.org>
cc:     Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>,
        "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>
Subject: Re: [PATCH v3 0/1] dt-bindings: Add device-perms property
 description
In-Reply-To: <20220601193956.GA234900-robh@kernel.org>
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References: <cover.1651749565.git.oleksii_moisieiev@epam.com> <20220601193956.GA234900-robh@kernel.org>
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On Wed, 1 Jun 2022, Rob Herring wrote:
> On Thu, May 05, 2022 at 11:23:50AM +0000, Oleksii Moisieiev wrote:
> > Introduce 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]).
> 
> Is that an exhaustive list of controls? Seems like there would be a 
> GET_DEVICE_PERMISSIONS.
> 
> > Device permissions management described in DEN 0056, Section 4.2.2.10 [0].
> > Given parameter should set the device_id, needed to set device
> > permissions in the Firmware.
> > This property is used by trusted Agent to set permissions for the devices,
> > passed-through to the non-trusted Agents. Trusted Agent will use device-perms 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].
> 
> As I said on the call discussing this, this looks very similar to other 
> proposals wanting to control or check permissions on devices handled by 
> some provider. While the consumer of the binding is different in various 
> proposals, that doesn't really matter from a DT perspective. DT is just 
> describing some type of connection between nodes. So I'm looking for 
> collaboration here with folks that have made prior proposals. To put it 
> another way, for a new common binding like this, I want to see more than 
> one user. 

Do you have a pointer to another similar proposal or the name of someone
that might be interested and might be having a second use-case for this?