From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5927C3526A for ; Wed, 16 Dec 2020 12:25:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FE0D2339F for ; Wed, 16 Dec 2020 12:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725974AbgLPMY7 (ORCPT ); Wed, 16 Dec 2020 07:24:59 -0500 Received: from foss.arm.com ([217.140.110.172]:49834 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbgLPMY7 (ORCPT ); Wed, 16 Dec 2020 07:24:59 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A3AA01FB; Wed, 16 Dec 2020 04:24:13 -0800 (PST) Received: from bogus (unknown [10.57.54.168]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 08A113F66E; Wed, 16 Dec 2020 04:24:10 -0800 (PST) Date: Wed, 16 Dec 2020 12:24:08 +0000 From: Sudeep Holla To: Rob Herring Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Trilok Soni , arve@android.com, Andrew Walbran , David Hartley , Achin Gupta , Sudeep Holla , Jens Wiklander , Arunachalam Ganapathy Subject: Re: [PATCH v3 1/7] dt-bindings: Arm: Add Firmware Framework for Armv8-A (FF-A) binding Message-ID: <20201216122408.2fhubdyqm2ofpgc3@bogus> References: <20201204121137.2966778-1-sudeep.holla@arm.com> <20201204121137.2966778-2-sudeep.holla@arm.com> <20201214220107.GA2430387@robh.at.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20201214220107.GA2430387@robh.at.kernel.org> User-Agent: NeoMutt/20171215 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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 > > --- > > .../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 > > + > > +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