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 C3D77C433EF for ; Mon, 28 Mar 2022 20:37:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345259AbiC1Uji (ORCPT ); Mon, 28 Mar 2022 16:39:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343781AbiC1Ujf (ORCPT ); Mon, 28 Mar 2022 16:39:35 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D639D66AE5 for ; Mon, 28 Mar 2022 13:37:53 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id w8so15714450pll.10 for ; Mon, 28 Mar 2022 13:37:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=ftOkaLxffUNn0UIvFFh85pkRel4UoC8QUOBNdj53Afs=; b=CMKKR3lFgackfgTVVWESREwEUx3E+WL7J+TqfQNMRECiHz71yj/VeH6JyZYk0NyDhB vToP+xlnxA+ZmPYrusmxo9mH+CT2sh54WumswxVGETHc5hOC70yn6vIL+tl34Pla5K9J UN73/vaQJ3lQBFWlX45mH1p1lBRPThJeb2Lp9ZTteOUkLjj591CSWSNdmuU+LnB5lCmU 4ELWEWErqKVc4wX3Jl1eaa7VO8RIMfZLO1+r6SZA875hDgJTQIsCtExjdExUlVgi3Qtf oIn5Hbb5LqIrQPOfcznXNOuCZcEMeSRhuAopNt3mAZR1y9YhzlR8HpVqNBncZSoNoeJD 9szw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=ftOkaLxffUNn0UIvFFh85pkRel4UoC8QUOBNdj53Afs=; b=c5MIHQ68M5ivmI7Qgp7kRArLhYuJMcKNgz4RB8GtR3WtbchsQooBBeak6tQmRT4svS DBT0bMOtmgOx1UUtak9j8TOShIQxPdytuy8/6aHOEGVct8KueyQr6v7nUBoUOakyB51g TojbLp0pfMnoFGCCC6OSZFszCo20ifqQsp2PE3+/oFZ4o83Z8E3qKE1o9VLCvjSAhKlG ziODuL6Q8F21GWaWPu4qaGUag7+ftyf+6lyCq5dWKXhkiFK15N5eti0KsvuBsyUw8oRQ p7/tmXQ3eCUudydPzx8gPuENXmh+a3Up0+DCynp9rNIuBKNPE/b7QPpz3CHaKG6iAa35 Tzrw== X-Gm-Message-State: AOAM5321ogrNBm5gjXkPBdPFSJCeo7M6wDg+D5xvYDieeLAlSkSCuEXw qFFkTRA6C35DkpX38rkYzgFNZ+U8YAYNXA== X-Google-Smtp-Source: ABdhPJzbfjVSjIhRJrOwAxFCzWkGeHwmUnsNPA04svo6SzEJbPLyKsboopfOVOQ9GMFz58BrWkcXQw== X-Received: by 2002:a17:90b:1d0e:b0:1c9:b74e:494 with SMTP id on14-20020a17090b1d0e00b001c9b74e0494mr921905pjb.238.1648499873342; Mon, 28 Mar 2022 13:37:53 -0700 (PDT) Received: from localhost (c-71-197-186-152.hsd1.wa.comcast.net. [71.197.186.152]) by smtp.gmail.com with ESMTPSA id k137-20020a633d8f000000b0039800918b00sm10033798pga.77.2022.03.28.13.37.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Mar 2022 13:37:52 -0700 (PDT) From: Kevin Hilman To: Lucas Tanure , Neil Armstrong , Jerome Brunet , Martin Blumenstingl Cc: linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, Lucas Tanure Subject: Re: [PATCH 0/3] Ensure Low period of SCL is correct In-Reply-To: <20220326102229.421718-1-tanure@linux.com> References: <20220326102229.421718-1-tanure@linux.com> Date: Mon, 28 Mar 2022 13:37:52 -0700 Message-ID: <7hee2lu82n.fsf@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lucas, Lucas Tanure writes: > The default duty cycle of 33% is less than the required > by the I2C specs for the LOW period of the SCL clock. > > So, for 100Khz or less, use 50%H/50%L duty cycle, and > for the clock above 100Khz, use 40%H/60%L duty cycle. > That ensures the low period of SCL is always more than > the minimum required by the specs at any given frequency. Thanks for the fixes! This is going to affect all SoCs, so ould you please summarize how your changes were tested, and on which SoCs & boards? Thanks, Kevin