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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 F384FC433F5 for ; Wed, 22 Sep 2021 12:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5A6560555 for ; Wed, 22 Sep 2021 12:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235917AbhIVMk7 (ORCPT ); Wed, 22 Sep 2021 08:40:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235834AbhIVMk6 (ORCPT ); Wed, 22 Sep 2021 08:40:58 -0400 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB63EC061574; Wed, 22 Sep 2021 05:39:28 -0700 (PDT) Received: by mail-oi1-x234.google.com with SMTP id z11so4248580oih.1; Wed, 22 Sep 2021 05:39:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=ATJeqTXclVnaTU6OlYKqpRsa99iDhu9c6SozT+medwI=; b=G8q/gUm8xQW7IedlOjatTLgy3ls1E5RNm5KOrpb+goJ5Xk4YX3jkWnwEk4/BE8d9lI yW03lXGwYnQoHw6o0m+s4teSD61iHXyio6vEgigWbFqLOIdWVVhxh9wIn/+N200eN8HT D7CsHjnCrj4VXekkDBBAiz8Oec1IwNpDFxG+rTqJUSLhmaEvnfjUUWboK+HojPew/Rgl kraWFLWYMp97bZhz0VOrxbhkiDmVPBj+Rh+wTlTPEZWvIvZqCXOCeE6E91wB2YjRPr/I NqLuigF3/aO0juptgrjV4lL/pd+DtDJQAnTagZHWwiKcSpBv2Y7YWVQ3vHpLKI4KxyJp x+3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition :content-transfer-encoding:in-reply-to; bh=ATJeqTXclVnaTU6OlYKqpRsa99iDhu9c6SozT+medwI=; b=QaQF7quJ7zFJjjK5mLjgXXGxY4USMWKKEPgAIwLYUT2NOh0RHqpU9/gmQBoGclCJ2d F5dI+pTBNA/vZ+WlRknEphdpnfNeuCA06U+eqf1Z7kd7hMhIlxKfqvy+tHaaWr0AwU/o aiwC8mYqyDEEikMtTS4CUwrhgzCKDRMGqPpp522JPIFGzhSp8wpvh6nNGlUWoosMnA5O 2AzZg41landaDKX32NRfO7V8B92XRLibq0AbenoJk1cM4Rp4Wlfpumbbfitabkntdf/X tplRX79RI/R7cU/VE1pQDBBOV4Co0Fer4OCwsiFke6Xc8chwGOVOYDg4LPl9JF48WAVJ V6vA== X-Gm-Message-State: AOAM531EmlyjwOnDtTMHP5KIDuF+HDlScd9+RAkk+8J/uH8BCrZ1yHo5 dkhyek9vqTN4Tq9b8PUXATM= X-Google-Smtp-Source: ABdhPJxCm2PqeuEockuno6TIwl4nNORCwKB5Nnok6mZwsib7VZKpW+7JgEb2Rf3DGhiK8ufUgZWvAg== X-Received: by 2002:a05:6808:169f:: with SMTP id bb31mr8193671oib.18.1632314368122; Wed, 22 Sep 2021 05:39:28 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id l4sm456926oth.4.2021.09.22.05.39.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Sep 2021 05:39:27 -0700 (PDT) Sender: Guenter Roeck Date: Wed, 22 Sep 2021 05:39:26 -0700 From: Guenter Roeck To: Krzysztof Adamski Cc: Rob Herring , Jean Delvare , linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, Oskar Senft Subject: Re: [PATCH 8/8] dt-bindings: hwmon: allow specifying channels for tmp421 Message-ID: <20210922123926.GB3201379@roeck-us.net> References: <12984255aac11a3edfc0e6278e1a1cac70ce97ec.1631021349.git.krzysztof.adamski@nokia.com> <20210921125831.GB1864238@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Sep 22, 2021 at 09:22:33AM +0200, Krzysztof Adamski wrote: > Dnia Tue, Sep 21, 2021 at 05:58:31AM -0700, Guenter Roeck napisał(a): > > > > > > ti,n-factor > > > > n-factor isn't just supported by TI sensors, though it isn't always called > > n-factor. Maxim (eg MAX6581) uses the term "ideality factor", though they > > also refer to the factor as "N" in the datasheet. > > > > So question is if we make this ti,n-factor and maxim,n-factor, or if we make > > it generic and define some kind of generic units. Thoughts ? My personal > > preference would be a generic definition, but is not a strong preference. > > That was exactly my way of thinking here - many sensors have n-factor > parameter and this is the name I see most often. > > That being said, maybe it should be "nfactor" instead of "n-factor", as > this is what tmp513 is using? > > > In regard to units, the n-factor is, as the name says, a factor. Default > > value is 1.008. The value range for MAX6581 is 0.999 to 1.030. For TMP421 > > it is 0.706542 to 1.747977. So the scondary question is if the value > > written should be the register value (as proposed here) or the absolute > > factor (eg in micro-units). > > Since expressing the fractional values in DT isn't well supported and > (at least here) hardware guys like to think in terms of register values > so this is what I proposed. Also, I just noticed that, for example, > TMP531 is using register values as well. > I never see "someone else does that" as valid argument. Also, DT does support fractional values, via units. It is perfectly valid to describe a voltage as micro-volt, for example. If the agreement is to use raw register values, I think the property name should be prefixed with the vendor name, since it won't be a standard property. I'll defer on Rob for that, though. Thanks, Guenter