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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6C1CC433FE for ; Fri, 28 Jan 2022 23:09:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245061AbiA1XJe (ORCPT ); Fri, 28 Jan 2022 18:09:34 -0500 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]:10080 "EHLO alexa-out-sd-02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243573AbiA1XJe (ORCPT ); Fri, 28 Jan 2022 18:09:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1643411374; x=1674947374; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=/WErSQ5riLjTn9G82iWYYkqLnkTM7a6hv6C1CsU4/Wc=; b=U04MmxlRcwoYYqlGGmwnFCId4ynwzyuk1vC+YhBdrqnqMSPaG+1h6BzC oMKQpeQleFOIrNtflnGlZVKtfpViJR+KVSpB95LtCu9qmKph1c5xBvAiA sR/DjUQJC0o+9iaYIYwbxB5ZwdGg9OQpTlDEf+5z1nNZVAmFvHhqUOiTM s=; Received: from unknown (HELO ironmsg05-sd.qualcomm.com) ([10.53.140.145]) by alexa-out-sd-02.qualcomm.com with ESMTP; 28 Jan 2022 15:09:33 -0800 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg05-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2022 15:09:33 -0800 Received: from [10.46.160.247] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Fri, 28 Jan 2022 15:09:31 -0800 Subject: Re: [RESEND PATCH 1/2] dt-bindings: firmware: arm,scmi: define support for name based regulators To: Mark Brown CC: Rob Herring , Sudeep Holla , , Liam Girdwood , "Cristian Marussi" , , , , "Subbaraman Narayanamurthy" References: From: David Collins Message-ID: <8355035c-6d90-adfd-c4e1-7bb37a2d8055@quicinc.com> Date: Fri, 28 Jan 2022 15:09:30 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01b.na.qualcomm.com (10.46.141.250) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 1/28/22 11:32 AM, Mark Brown wrote: > On Mon, Jan 24, 2022 at 04:27:35PM -0800, David Collins wrote: > >> Name based SCMI regulator specification helps ensure that an SCMI >> agent doesn't need to be aware of the numbering scheme used for > > What is a "SCMI agent" in this context? This is changing how the DT > bindings are specified, at some point things are going to need to be > hard coded. An SCMI agent is the entity that issues SCMI commands (i.e. the consumer). An SCMI platform is the entity that receives the SCMI commands and performs the necessary operations (i.e. the provider). This is the terminology used in the ARM SCMI spec [1]. A typical system layout could have an agent that is the application processor (running Linux) and a platform that is an embedded controller. The system layout that this patch is targeted for consists of an SCMI platform implemented in software in the primary Linux OS on the application processor and an SCMI agent in a guest VM (also running Linux). This provides paravirtualized regulator control to the guest VM where full virtualization is not supported. During the course of development of these software images, it may be necessary to add or reorder the set of SCMI voltage domains (regulators) implemented on the platform side. If the voltage domains are only identified and matched based on the ID number, then it is easy for the platform and agent to get out of sync. Using the voltage domain name instead of ID number for identification and matching provides robust assurance of correct regulator usage in the face of domains being added, removed, or reordered on the platform side. >> + regulator-name: true >> + >> + anyOf: >> + - required: >> + - reg >> + - required: >> + - regulator-name > > This is abusing the existing regulator-name property which is there to > allow a human readable descriptive string to be attached to a regulator. > It should have no effect other than being included in diagnostic output. Would you be ok with a new DT property being added in place of "regulator-name" in this patch which serves the same matching purpose (perhaps "arm,scmi-domain-name")? Thanks, David [1]: https://developer.arm.com/documentation/den0056/latest 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D9A34C433F5 for ; Fri, 28 Jan 2022 23:11:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=dCfEdQKGvIWCe1y2vuLcXoP4liyGhDRHx5kx+wX4BZc=; b=kdZu5E+CR8EQ731yjONOQMhq82 /Za6GLUQc4YUXgrCNu00EBBlQqTAXIuKBswVYGf//a0xIp7Kav8IFDp7lc/l0WgUwFFZIVZYSGvZP oWfEgc21pFqUJAaKCOj16etum8+5MYQnrYLkTLmDN+0TK5N/dN/sFa/WFv2xuw/OgMHFuKCHgx0/1 FbJn2IXlyyPZlXHfJtnKB5DySJvkfx04Zn6o4LUgvDDXwjyYfPCd4CdySGiYbD72SEjbl3BbTU9NH EKXjr5jEIk4JaLBNYk3WUa9Xjz1el99AvcMvkrxmTbEo72h05nR6tydj53pRzTjPyBPeubn0POGjG cSbRtDZw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDaNC-003kbc-F1; Fri, 28 Jan 2022 23:09:42 +0000 Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDaN7-003kae-Sp for linux-arm-kernel@lists.infradead.org; Fri, 28 Jan 2022 23:09:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1643411377; x=1674947377; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=/WErSQ5riLjTn9G82iWYYkqLnkTM7a6hv6C1CsU4/Wc=; b=siGvksHU4ihJBT9xdtag2Iy6sGCEkvwmrwhqFZYQN2rmHH2kDTvr1Lh0 BLWNPCb8D3yGDMvr/0M1ZYBcvhsw7if+GTKWByYKJ8Io3/czfsbTqAb0D cShrHIqp8mHx5H3Edo33kN1MnXE5wGm/th/3deXGv0b8m8nuWKO0MgOo+ 4=; Received: from unknown (HELO ironmsg05-sd.qualcomm.com) ([10.53.140.145]) by alexa-out-sd-01.qualcomm.com with ESMTP; 28 Jan 2022 15:09:33 -0800 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg05-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2022 15:09:33 -0800 Received: from [10.46.160.247] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Fri, 28 Jan 2022 15:09:31 -0800 Subject: Re: [RESEND PATCH 1/2] dt-bindings: firmware: arm,scmi: define support for name based regulators To: Mark Brown CC: Rob Herring , Sudeep Holla , , Liam Girdwood , "Cristian Marussi" , , , , "Subbaraman Narayanamurthy" References: From: David Collins Message-ID: <8355035c-6d90-adfd-c4e1-7bb37a2d8055@quicinc.com> Date: Fri, 28 Jan 2022 15:09:30 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01b.na.qualcomm.com (10.46.141.250) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220128_150938_016114_3237F14E X-CRM114-Status: GOOD ( 21.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 1/28/22 11:32 AM, Mark Brown wrote: > On Mon, Jan 24, 2022 at 04:27:35PM -0800, David Collins wrote: > >> Name based SCMI regulator specification helps ensure that an SCMI >> agent doesn't need to be aware of the numbering scheme used for > > What is a "SCMI agent" in this context? This is changing how the DT > bindings are specified, at some point things are going to need to be > hard coded. An SCMI agent is the entity that issues SCMI commands (i.e. the consumer). An SCMI platform is the entity that receives the SCMI commands and performs the necessary operations (i.e. the provider). This is the terminology used in the ARM SCMI spec [1]. A typical system layout could have an agent that is the application processor (running Linux) and a platform that is an embedded controller. The system layout that this patch is targeted for consists of an SCMI platform implemented in software in the primary Linux OS on the application processor and an SCMI agent in a guest VM (also running Linux). This provides paravirtualized regulator control to the guest VM where full virtualization is not supported. During the course of development of these software images, it may be necessary to add or reorder the set of SCMI voltage domains (regulators) implemented on the platform side. If the voltage domains are only identified and matched based on the ID number, then it is easy for the platform and agent to get out of sync. Using the voltage domain name instead of ID number for identification and matching provides robust assurance of correct regulator usage in the face of domains being added, removed, or reordered on the platform side. >> + regulator-name: true >> + >> + anyOf: >> + - required: >> + - reg >> + - required: >> + - regulator-name > > This is abusing the existing regulator-name property which is there to > allow a human readable descriptive string to be attached to a regulator. > It should have no effect other than being included in diagnostic output. Would you be ok with a new DT property being added in place of "regulator-name" in this patch which serves the same matching purpose (perhaps "arm,scmi-domain-name")? Thanks, David [1]: https://developer.arm.com/documentation/den0056/latest _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel