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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 F22B3C3F68F for ; Fri, 7 Feb 2020 11:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4C1622464 for ; Fri, 7 Feb 2020 11:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726951AbgBGLck (ORCPT ); Fri, 7 Feb 2020 06:32:40 -0500 Received: from foss.arm.com ([217.140.110.172]:39266 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbgBGLck (ORCPT ); Fri, 7 Feb 2020 06:32:40 -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 4F3AA328; Fri, 7 Feb 2020 03:32:39 -0800 (PST) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B3CFA3F68E; Fri, 7 Feb 2020 03:32:37 -0800 (PST) Date: Fri, 7 Feb 2020 11:32:35 +0000 From: Sudeep Holla To: Marc Zyngier Cc: Peng Fan , robh+dt@kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, f.fainelli@gmail.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, dl-linux-imx , andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org, Sudeep Holla Subject: Re: [PATCH 1/2] dt-bindings: arm: arm,scmi: add smc/hvc transports Message-ID: <20200207113235.GC40103@bogus> References: <1580994086-17850-1-git-send-email-peng.fan@nxp.com> <1580994086-17850-2-git-send-email-peng.fan@nxp.com> <7875e2533c4ba23b8ca0a2a296699497@kernel.org> <20200207104736.GB36345@bogus> <5a073c37e877d23977e440de52dba6e0@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 07, 2020 at 11:09:48AM +0000, Marc Zyngier wrote: > On 2020-02-07 11:00, Peng Fan wrote: > > > Subject: Re: [PATCH 1/2] dt-bindings: arm: arm,scmi: add smc/hvc > > > transports > > > > > > On 2020-02-07 10:47, Sudeep Holla wrote: > > > > On Fri, Feb 07, 2020 at 10:08:36AM +0000, Marc Zyngier wrote: > > > >> On 2020-02-06 13:01, peng.fan@nxp.com wrote: > > > >> > From: Peng Fan > > > >> > > > > >> > SCMI could use SMC/HVC as tranports, so add into devicetree binding > > > >> > doc. > > > >> > > > > >> > Signed-off-by: Peng Fan > > > >> > --- > > > >> > Documentation/devicetree/bindings/arm/arm,scmi.txt | 4 +++- > > > >> > 1 file changed, 3 insertions(+), 1 deletion(-) > > > >> > > > > >> > diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt > > > >> > b/Documentation/devicetree/bindings/arm/arm,scmi.txt > > > >> > index f493d69e6194..03cff8b55a93 100644 > > > >> > --- a/Documentation/devicetree/bindings/arm/arm,scmi.txt > > > >> > +++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt > > > >> > @@ -14,7 +14,7 @@ Required properties: > > > >> > > > > >> > The scmi node with the following properties shall be under the > > > >> > /firmware/ node. > > > >> > > > > >> > -- compatible : shall be "arm,scmi" > > > >> > +- compatible : shall be "arm,scmi" or "arm,scmi-smc" > > > >> > - mboxes: List of phandle and mailbox channel specifiers. It > > > >> > should contain > > > >> > exactly one or two mailboxes, one for transmitting messages("tx") > > > >> > and another optional for receiving the notifications("rx") if > > > >> > @@ -25,6 +25,8 @@ The scmi node with the following properties shall > > > >> > be under the /firmware/ node. > > > >> > protocol identifier for a given sub-node. > > > >> > - #size-cells : should be '0' as 'reg' property doesn't have any size > > > >> > associated with it. > > > >> > +- arm,smc-id : SMC id required when using smc transports > > > >> > +- arm,hvc-id : HVC id required when using hvc transports > > > >> > > > > >> > Optional properties: > > > >> > > > >> Not directly related to DT: Why do we need to distinguish between SMC > > > >> and HVC? > > > > > > > > IIUC you want just one property to get the function ID ? Does that > > > > align with what you are saying ? I wanted to ask the same question and > > > > I see no need for 2 different properties. > > > > > > Exactly. Using SMC or HVC should come from the context, and there is > > > zero > > > value in having different different IDs, depending on the conduit. > > > > > > We *really* want SMC and HVC to behave the same way. Any attempt to > > > make them different should just be NAKed. > > > > ok. Then just like psci node, > > Add a "method" property for each protocol, and add "arm,func-id" to > > indicate the ID. > > > > How about this? > > Or rather just a function ID, full stop. the conduit *MUST* be inherited > from the PSCI context. Absolutely, this is what I was expecting. Peng, You have already introduced a compatible for smc/hvc transport instead of default mailbox, why do you need anything more ? Just use SMC or HVC conduit from PSCI/SMCCC. I don't think you need anything more than the function ID. -- Regards, Sudeep