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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 2618CC04A6B for ; Wed, 8 May 2019 13:27:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9455205ED for ; Wed, 8 May 2019 13:27:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mqtxi/yi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727161AbfEHN1s (ORCPT ); Wed, 8 May 2019 09:27:48 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:43283 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbfEHN1s (ORCPT ); Wed, 8 May 2019 09:27:48 -0400 Received: by mail-lj1-f196.google.com with SMTP id z5so12371482lji.10; Wed, 08 May 2019 06:27:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=2D3RG8pXMm+z0HEk76Tz92evizs+d/UqhmcHqQu6yA0=; b=mqtxi/yiwaglx8Z9kcnVjlPEnzlHFKooyG01vtm3OqueUr2ldpmOi4OBCKZs+Rj8u3 +sAqgF6ISrNjlM9QBob5MH1hwcKQ06mehu7RYf0pQKZJOylx3aaT/lPL1emAUeoffZME Rk0IujZXNYkIDdbB3TBKQ7x2ZKV/66bwKgJw9WD1q0IfPpUf/8wjzMSXe5uECl1axvtD wcGZN6zdfvs3I7PFVoL8456rTrOLaVvFey+2Ka/MoTp2dyiTVwfyzt6bSegArSCpmpbF CemykKpi41MiWm1ig+/ppg2Suf6OuURWnx7AVnIK5OGw/yjTOMtNAxnjVEtFuGhZVOSe 3B7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=2D3RG8pXMm+z0HEk76Tz92evizs+d/UqhmcHqQu6yA0=; b=rK/O0SBtcaD5tKpcY7oMRUaMEE5SMmLXQFLVz+Yr5XZF5ZF4hdTuEBEzlKEuj/KYGJ +TtTB4iky5tacUHRuaOBp/wekZPd7ZT7R1BewRnkerX6bQLguYcCe+J+bpY8zRRHZC6f zAg4Maua1sgkElb/yuDT9brMjRfToqqJ8w8SxSbaVyoUYzM6CzXkYoaNO9RI/9vvjEfT u8gHK9V+H6v+dyEgEuZwyN3hyB2XylogVdLg+bPfgE0cftZOQqvB5dlmfWNtF02zKsc5 MB8fTpb+rhHxIrxePq3jPQsiJwbrnMSp4obTQ90IU1y7vS6vZ1w7kheZSgj2a4NCp3cX KLTA== X-Gm-Message-State: APjAAAXMrG9AzCAgoTzA8VLqE2asn4eJJ1MtbaOmkwI+t94yo3p7vrEd lIQ3kgsmWXSSxJDhExAAz7URBUGt X-Google-Smtp-Source: APXvYqwJNhl/SS47KTmlnE23qhbggTKV/WCPJsEnQkPRfSj07XNZ+x7u4WiOR3Qys8r6RGxkKXg8XA== X-Received: by 2002:a2e:9a58:: with SMTP id k24mr14366245ljj.90.1557322065507; Wed, 08 May 2019 06:27:45 -0700 (PDT) Received: from [192.168.2.145] (ppp94-29-35-107.pppoe.spdop.ru. [94.29.35.107]) by smtp.googlemail.com with ESMTPSA id p14sm1019184lfk.24.2019.05.08.06.27.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 May 2019 06:27:43 -0700 (PDT) Subject: Re: [RFC PATCH v1 6/6] soc/tegra: regulators: Add regulators coupler for Tegra30 To: Mark Brown Cc: Liam Girdwood , Thierry Reding , Jonathan Hunter , Peter De Schrijver , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190414175939.12368-1-digetx@gmail.com> <20190414175939.12368-7-digetx@gmail.com> <20190508075848.GX14916@sirena.org.uk> From: Dmitry Osipenko Message-ID: Date: Wed, 8 May 2019 16:27:42 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508075848.GX14916@sirena.org.uk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 08.05.2019 10:58, Mark Brown пишет: > On Sun, Apr 14, 2019 at 08:59:39PM +0300, Dmitry Osipenko wrote: >> Add regulators coupler for Tegra30 SoC's that performs voltage balancing >> of a coupled regulators and thus provides voltage scaling functionality. > > Same here, what are the requirements this is implementing? > There are two coupled regulators: CPU and CORE. Constraints: 1) The max-spread voltage is 300mV. 2) CORE voltage must be higher than the CPU by at least N mV, where N varies depending on the CPU voltage. 3) There is a constraint on the maximum CORE voltage depending on hardware model/revision (cpu_speedo_id) where a higher voltages apparently may cause physical damage, so it's better to hardcode the limitation in the code rather than to rely on a board's device-tree description. This constraint is quite vaguely defined in the downstream kernel, I'm not really sure if it's solely about the hardware safety.