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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 76ACDC433E9 for ; Wed, 10 Mar 2021 08:59:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FEA864FF1 for ; Wed, 10 Mar 2021 08:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232460AbhCJI63 (ORCPT ); Wed, 10 Mar 2021 03:58:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232414AbhCJI6N (ORCPT ); Wed, 10 Mar 2021 03:58:13 -0500 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F02AC061760 for ; Wed, 10 Mar 2021 00:58:13 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id n22so6551875wmc.2 for ; Wed, 10 Mar 2021 00:58:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=14jUD9KR757Xt0m9lZ7BZTdoTxbSvdhfDsuNoCK1Gws=; b=S5vlGFlGizRIezNjHHZSjocQgxeL5UoFO7634X+FQ0uNQiW8tzKmR+4Y2CbrApd9Sa Q8OZVineJAjvzQakJ9JDj8QY/RdEMPErhkB08dUaEx+d4l1EJzhao/WrrAscbotxFyPw IuuFgJw3+fE6hNj5hVsb4JzRGVjqX+tVxW+Kbu0sFFDUwejZ04U0wArZgDMpfkXUxnwl LASYLKgCa99RC+JkNd9EVcWZ+MUGFoV96svCpqkjZtyOI6fYhKTdLKH+WI/7E5LH1c9D P3yPuDF9nT70gUbH7fFDwRAOLtRsnmeMlPMOaN/b6yz8uYzHEDLbpTUhzSU8mrOQHlyX aMsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=14jUD9KR757Xt0m9lZ7BZTdoTxbSvdhfDsuNoCK1Gws=; b=unTZTtweVnE6lFnu0K//Z35duY6MY6+oshcxUh+ti+vwP3iUYc0MxyXjsUQNmHVchL zM2MTf9jQU6l8sBYRulmgr6AmsC5XSi8gUNgOwqlwcV6JkKrsKvG/pBl1iPi6UGLgOLu 3HPuzBoFKMg2QZRsedMmooRTfwxJFSS58hQI1V7s34QV6WwIMQCpQZ5NTmpYvDGNdyxQ sLPQnyeYNqPONp5twi5xEBFwwtW2golEYfOX4RSmpH/obpNqaF4mv+jZ617HHzWHzrB9 bDm7Mk1//9DcIZMivKZLmfXmIEQASgJoOA3zc6MqXkFj2GFKndlu7dcigPq5edzqNJwU E14w== X-Gm-Message-State: AOAM530urg4MiUCq4B/8C9eCIQ6oInnFfitiadIk0zvum6o+U1vdq5Uw lD3SffEsB9fObsjcbGJOZEcNRA== X-Google-Smtp-Source: ABdhPJyFp09UmbR/M/toEClX4xNfONENLYumn7IGLRVc+t9NZc46CFDo+qm5vYkbvQfTX7myWzJbFg== X-Received: by 2002:a1c:21c3:: with SMTP id h186mr2215391wmh.32.1615366691731; Wed, 10 Mar 2021 00:58:11 -0800 (PST) Received: from dell ([91.110.221.204]) by smtp.gmail.com with ESMTPSA id v2sm13747943wmj.1.2021.03.10.00.58.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 00:58:11 -0800 (PST) Date: Wed, 10 Mar 2021 08:58:09 +0000 From: Lee Jones To: Adam Ward Cc: Mark Jonas , Mark Jonas , Support Opensource , "linux-kernel@vger.kernel.org" , "linux-i2c@vger.kernel.org" , Adam Thomson , Steve Twiss , "marek.vasut@gmail.com" , "RUAN Tingquan (BT-FIR/ENG1-Zhu)" , "Streidl Hubert (BT-FIR/ENG1-Grb)" , Wolfram Sang Subject: Re: [PATCH v4] mfd: da9063: Support SMBus and I2C mode Message-ID: <20210310085809.GE4931@dell> References: <20210208152758.13093-1-mark.jonas@de.bosch.com> <20210308144211.GK4931@dell> <20210309094211.GN4931@dell> 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: linux-i2c@vger.kernel.org On Tue, 09 Mar 2021, Adam Ward wrote: > Hi Lee, > > Tidy, but I've noticed the logic got inverted along the way: > > > On Tue 09 Mar 2021, Lee Jones wrote: > > On Tue, 09 Mar 2021, Mark Jonas wrote: > > This is my suggestion: > > > > /* If SMBus Mode is not available, enter Two-Wire Mode */ > > if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) { > > Determine bus *is* I2C, so assume SMBus timings not supported... > if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) { > > > ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONFIG_J, > > DA9063_TWOWIRE_TO, DA9063_TWOWIRE_TO); > > ...and *clear* the (currently set by default) timeout bit: > DA9063_TWOWIRE_TO, 0); Thanks for checking this. You're right. The example was provided as a back-of-a-fag-packet design, not a fully tested (or even compiled) solution. It took me 2 mins to type out. > > if (ret < 0) { > > dev_err(da9063->dev, "Failed to set Two-Wire Bus > > Mode\n"); > > return -EIO; > > } > > } > > I think you're right to exclude a case; vendor motivation to > override the TO default seems inherently trustworthy. A default value is a default value. :) -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog