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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 0DFF8C433E2 for ; Tue, 23 Jun 2020 06:05:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD72420656 for ; Tue, 23 Jun 2020 06:05:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="qCtbnkfa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730619AbgFWGFh (ORCPT ); Tue, 23 Jun 2020 02:05:37 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:1393 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730149AbgFWGFh (ORCPT ); Tue, 23 Jun 2020 02:05:37 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 22 Jun 2020 23:04:51 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 22 Jun 2020 23:05:36 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 22 Jun 2020 23:05:36 -0700 Received: from [10.24.37.103] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 23 Jun 2020 06:05:30 +0000 Subject: Re: [TEGRA194_CPUFREQ Patch v3 1/4] dt-bindings: arm: Add t194 ccplex compatible and bpmp property To: Viresh Kumar CC: , , , , , , , , , , , , , , Sumit Gupta References: <1592775274-27513-1-git-send-email-sumitg@nvidia.com> <1592775274-27513-2-git-send-email-sumitg@nvidia.com> <20200622072247.agrvmw6sl3jwgjkz@vireshk-i7> From: Sumit Gupta Message-ID: <3ef570ec-1a55-5449-58fb-4e0039350299@nvidia.com> Date: Tue, 23 Jun 2020 11:35:27 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200622072247.agrvmw6sl3jwgjkz@vireshk-i7> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1592892291; bh=x7pllGVCRVcZl/z7oNpDAAgML8RbNEkRhkrXs3sdRss=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=qCtbnkfaHgvl3zipzaZafhR7lVvhAKG8qv/fMpHfK859kAvg4dPHxQeojQOW9d6b3 cTeJr3AN+fK98HqEPlFq6ZzbBEKm5xSA2lgMtePQ/6shHf4t6UYdPKkW0100JQLSzR 6EdgrcydReThwiJX9TAlcsKZSRmBaEyHVWqilL+wJYYIt0mxQMAohe4xD1gO6LSghc 5bjDaPzrcL8iCe4+gl94JXUAP98cUiTPOKeyOHd9gnTAdoHxZBvqsazNBgWNOWAhWD jT18qyd5C7ZJvS0GLrR2YM17NJ24DxUJy2KRBp5Ht+qffE2wEEb2tA3cEtSy18ZI// U7mMuO8NceS9w== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/06/20 12:52 PM, Viresh Kumar wrote: > External email: Use caution opening links or attachments > > > On 22-06-20, 03:04, Sumit Gupta wrote: >> To do frequency scaling on all CPUs within T194 CPU Complex, we need >> to query BPMP for data on valid operating points. Document a compatible >> string under 'cpus' node to represent the CPU Complex for binding drivers >> like cpufreq which don't have their node or CPU Complex node to bind to. >> Also, document a property to point to the BPMP device that can be queried >> for all CPUs. > > You shouldn't be putting how linux is going to use this information and entries > shouldn't be made just so cpufreq can bind to a driver. > > Though I see that this is a real hardware register which you can use to interact > with the firmware ? And so it makes sense to have it, maybe in different form > though. > CPUFREQ driver doesn't communicate directly with BPMP firmware. It uses BPMP node's reference to call api's exported by BPMP driver which communicates with BPMP firmware. > I will let Rob explain what would be the right way of doing this though. > This is already discussed by Thierry with Rob. Please refer https://marc.info/?l=linux-arm-kernel&m=158999171528418&w=2 >> >> Signed-off-by: Sumit Gupta >> --- >> Documentation/devicetree/bindings/arm/cpus.yaml | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/arm/cpus.yaml b/Documentation/devicetree/bindings/arm/cpus.yaml >> index a018147..737b55e 100644 >> --- a/Documentation/devicetree/bindings/arm/cpus.yaml >> +++ b/Documentation/devicetree/bindings/arm/cpus.yaml >> @@ -162,6 +162,7 @@ properties: >> - nvidia,tegra132-denver >> - nvidia,tegra186-denver >> - nvidia,tegra194-carmel >> + - nvidia,tegra194-ccplex >> - qcom,krait >> - qcom,kryo >> - qcom,kryo260 >> @@ -255,6 +256,14 @@ properties: >> >> where voltage is in V, frequency is in MHz. >> >> + nvidia,bpmp: >> + $ref: '/schemas/types.yaml#/definitions/phandle' >> + descrption: | >> + Specifies the bpmp node that needs to be queried to get >> + operating point data for all CPUs. >> + >> + Optional for NVIDIA Tegra194 Carmel CPUs >> + >> power-domains: >> $ref: '/schemas/types.yaml#/definitions/phandle-array' >> description: >> -- >> 2.7.4 > > -- > viresh >