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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 BB03DC433F5 for ; Mon, 20 Sep 2021 12:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A28F560F58 for ; Mon, 20 Sep 2021 12:25:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235098AbhITM0t (ORCPT ); Mon, 20 Sep 2021 08:26:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235204AbhITM0t (ORCPT ); Mon, 20 Sep 2021 08:26:49 -0400 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 744F1C061574; Mon, 20 Sep 2021 05:25:22 -0700 (PDT) Received: by mail-ed1-x529.google.com with SMTP id bx4so15864875edb.4; Mon, 20 Sep 2021 05:25:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=sjxm2CPGEqNmN39+wQosQN0k3TqmDMi00hAHGOM6RNE=; b=fVgTfxy4xKbk244lemHrnob7suMDKO7pI6DrClcXKn/xNCwgQT3gWmyOzkkvzYV84E AhYt4SN5X7I9A5sAJRyfR4BrK34wxWfMfzUHEVGYO7hlLfUuf1aMeFQT9ujpqcSe5B25 34OPBbaNv3PHYaniRwckL6kFDy4qwABgx/h3io4aH358kkARlHiH9SMFqAzuH0x6Vtp/ T+BfRPdlOLQ6bD5/VbTTsENc0oaEhkaJjzLi2+B8YsyJQVW9QrdA7syjyskREc/+H0ry 6G4PynCZDUQct3N5QLELbAekJVZ1vojOmRTKG0dIKoB+1kTyDx6KErA0wepmaEJNpJ7u IhSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=sjxm2CPGEqNmN39+wQosQN0k3TqmDMi00hAHGOM6RNE=; b=2Zj9l89wwk0yVUnM2SIsAgBd+dfVEeS4pMff2ZAbcTljXb94KNeESmrPleM7ppR35g URbmrLABq5wKqkBHGt1QOchDFe3+2rsUOaAxHo3btP/QmGsez9qvDMvqfoQR+ltv7iRf osznc8RNx8bVwImM25YsVJrBzf2dX06bAscyakHJVdkTc3KgQpZABSM+Y1pJF/+JNGlq vqj6TU6zehi5mJKMpkYZ0VciIQVoctE9TCSrL1igttXBC4y3TWpFBWh99a8hmtDrsydN 8CNrsOGmavt9A2bcGktUDWZqgktvN9T9qVrJLcHX2tO9Rf1y1mATa+GKJu8tM9Hbztq4 n+QQ== X-Gm-Message-State: AOAM531a4LjVs3UDZqSKPYnvJIhnFm6u2DsEXDEvH+ytQMKrD6aCh1m9 f5fYvr7bekMvJP1p8aFdVHZrjcbG0Ymam3IEjrvyzVMH X-Google-Smtp-Source: ABdhPJx5S6Yi9grI/kQVIAeFYNM7Y4/Re5oTX9gacZcOz39l62sjKv4qHUYWr3UN4tNOJMLi+sJTQkOEVApQrHMBAow= X-Received: by 2002:a17:906:e82:: with SMTP id p2mr27932667ejf.50.1632140720891; Mon, 20 Sep 2021 05:25:20 -0700 (PDT) MIME-Version: 1.0 References: <20210825122757.91133-1-aford173@gmail.com> In-Reply-To: From: Adam Ford Date: Mon, 20 Sep 2021 07:25:09 -0500 Message-ID: Subject: Re: [PATCH] arm64: dts: renesas: beacon: Fix i2c2 speed calcuation To: Wolfram Sang , Geert Uytterhoeven , Adam Ford , Linux-Renesas , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Sep 14, 2021 at 5:41 AM Wolfram Sang wrote: > > On Wed, Aug 25, 2021 at 02:47:21PM +0200, Geert Uytterhoeven wrote: > > CC Wolfram > > > > On Wed, Aug 25, 2021 at 2:28 PM Adam Ford wrote: > > > The desired i2c2 speed is 400KHz, but when measured on a scope, it > > > is incorrect. The driver can use the i2c-scl-rising-time-ns to help > > > calculate the proper setting to get exactly 400KHz. > > The question for me is: Has it been measured that SCL rising time is > really 50ns or has it been measured that the bus clock is now exactly > 400kHz? The person who originally reported this to me moved on, so I don't know if he measured both the rise time or just the clock speed. I know originally, the clock speed was measured to be 426KHz instead of 400KHz, and with the change to the rise time, the measured clock speed was exactly 400KHz. I do not know if the measured rise time is really 50ns or not. adam >