On Mon, Dec 14, 2020 at 04:01:07PM -0600, Rob Herring wrote: > On Fri, Dec 04, 2020 at 12:11:31PM +0000, Sudeep Holla wrote: > > Since the FF-A v1.0 specification doesn't list the UUID of all the > > partitions in the discovery API, we need to specify the UUID of the > > partitions that need to be accessed by drivers within the kernel. > > > > This binding to provide the list of partitions that kernel drivers > > may need to access. > > > > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> > > --- > > .../devicetree/bindings/arm/arm,ffa.yaml | 58 +++++++++++++++++++ > > 1 file changed, 58 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml > > > > diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml > > new file mode 100644 > > index 000000000000..a014a5801c34 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml > > @@ -0,0 +1,58 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Arm Firmware Framework for Arm v8-A (in-kernel users) > > + > > +maintainers: > > + - Sudeep Holla <sudeep.holla@xxxxxxx> > > + > > +description: | > > + Firmware frameworks implementing partition according to the FF-A > > + specification defined by ARM document number ARM DEN 0077A ("Arm Firmware > > + Framework for Arm v8-A") [0], providing services to be used by other > > + partitions. > > + > > + [0] https://developer.arm.com/docs/den0077/latest > > + > > +properties: > > + $nodename: > > + const: ffa > > + > > + compatible: > > + oneOf: > > + - const: arm,ffa-1.0 > > + > > +patternProperties: > > + "^ffa_partition[0-9]+$": > > + type: object > > + description: One or more child nodes, each describing an FFA partition. > > + properties: > > + $nodename: > > + const: ffa_partition > > + > > + compatible: > > + oneOf: > > + - const: arm,ffa-1.0-partition > > + > > + uuid: > > + $ref: '/schemas/types.yaml#definitions/string' > > + description: | > > + The 128-bit UUID [2] of the service implemented by this partition. > > + > > + [2] https://tools.ietf.org/html/rfc4122 > > UUIDs are actually a known thing in json-schema with 'format: uuid'. > The meta-schema will probably reject that, so we'll need to add support > to dtschema. Maybe it should be a new definition to reference. > Ah OK, I will try that and ask for help if I am stuck as I am still trying to learn these, not there yet 😄 > > + > > +additionalProperties: false > > + > > +examples: > > + - | > > + ffa { > > + compatible = "arm,ffa-1.0"; > > + > > + ffa_partition0 { > > + compatible = "arm,ffa-1.0-partition"; > > + uuid = "12345678-9abc-def0-1234-56789abcdef0"; > > + }; > > + }; > > This could all be simplified down to just a single property: > Thanks for the suggestion, I would love this to force spec authors to stop relying on DT and add whatever needed in future to the spec as part of discovery APIs. > arm,ffa-partitions = "12345678-9abc-def0-1234-56789abcdef0", > "12345678-9abc-def0-1234-56789abcdef1" > "12345678-9abc-def0-1234-56789abcdef2"; > > Obviously, that's not extensible, but do we need it to be? > I prefer if we don't, but I will run this through spec authors so that they are aware of what we will do in DT which means they *have* to incorporate any future needs into the spec discovery apis. Ah I forgot the spec author is cc-ed. @Achin please shout if you see issues with this approach. -- Regards, Sudeep
