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[23.128.96.18]) by mx.google.com with ESMTP id g3si803328ejf.612.2021.01.06.04.15.11; Wed, 06 Jan 2021 04:15:35 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=vQVMe4am; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725944AbhAFMNU (ORCPT + 99 others); Wed, 6 Jan 2021 07:13:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725789AbhAFMNT (ORCPT ); Wed, 6 Jan 2021 07:13:19 -0500 Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67C9FC06134C; Wed, 6 Jan 2021 04:12:39 -0800 (PST) Received: by mail-yb1-xb34.google.com with SMTP id f6so2547862ybq.13; Wed, 06 Jan 2021 04:12:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IbmnpdtDMofYt9r9PreFEY+jECTRLDnRGKyuIas7p/U=; b=vQVMe4amxBe4sHm26L0WZFx8mDPo8zrOczpKhC1CSm/mYNkqOGqltMXFrEigDKfURG HItAnVB/gFV3jRcbg83Nc3wbvrL+GlAY9sZ3wYtga5Av6YsmZQE3DurYcleziZQ6PQ8h +HwzpCbP4x8lL7VkIc3Et5KqROwuQBoPyjsJVJKwtbnC6ahvJS8EwMlXqngH1xe+qafb hKiyOo9olaQxi2Fv5/ZKKeT0u1LhucTaPnAFsiSlHnYI1JTr0XcKx1HlIK8fQQSRcQ6m 3581kDKGWADFkWEe6cDL2bhYqX9bqxU/HbNYT0I8WVru5idDW3i3mOLwpZFHCVm2jq/n Zr4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=IbmnpdtDMofYt9r9PreFEY+jECTRLDnRGKyuIas7p/U=; b=Lc4GGNBGyROaaATF6NafNKs1nDbm7AHoGt/SQmD9/X652ejt5xP7hGiNblQe0OgaQ4 IuyeymJHlh3Ng8Ww/8bocF/MBrfCwfrW0YlIDL8vsPcC6RF6305SDDTWt+TAnX/wkbwN L1i7eO6+o9+ezGkrKOyaVNDen6f1Px7C2kVffmNwOOXczhDJaUNJZG+YSj6pa5KzPHit BI7/B/9KVgOR+Quag9G/al6SaSPOIqyLEZfEahHjrSLlcw6EYeM+n4+7VSvwN0MtpUfO 0IvCd78KKPf/LB2MgCbFqOKrnLtwJhDbDxVuWML7dwVzOBtUJQFWEzSRfUedb9/piTfV ZD1g== X-Gm-Message-State: AOAM5331EZYg0FZbW6GqC2cm0HJr0xlJfrsIYW0hAHZhoa5pZEYTskdo VxiasVAakE7BoYuUx7juRzTGdz71nBSI9PCaHs4= X-Received: by 2002:a25:538a:: with SMTP id h132mr5393839ybb.247.1609935158689; Wed, 06 Jan 2021 04:12:38 -0800 (PST) MIME-Version: 1.0 References: <20210106113730.k5qveshjgcd57kgx@runtux.com> In-Reply-To: <20210106113730.k5qveshjgcd57kgx@runtux.com> From: Miguel Ojeda Date: Wed, 6 Jan 2021 13:12:28 +0100 Message-ID: Subject: Re: [PATCH 0/1] auxdisplay: Add I2C gpio expander example To: Ralf Schlatterbeck Cc: linux-kernel , Willy Tarreau , Lars Poeschel , Linus Walleij , Geert Uytterhoeven , devicetree@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 6, 2021 at 12:37 PM Ralf Schlatterbeck wrote: > > The Hitachi HD44780 is often used together with a PCF8574 based I2C > I/O expander. It was non-obvious to me that the existing parallel > connected version of the auxdisplay driver can already handle this > configuration with appropriate device tree magic. This patch documents > the necessary incantations in an example. > > That this is not only non-obvious to me is documented by at least two > I2C kernel implementations for the display out there. > > Thanks to Geert Uytterhoeven for pointing out how this is done. > Thanks to Miguel Ojeda for extensively commenting on my previous patch. You're welcome! A couple tips: - Normally, you will want to use scripts/get_maintainer.pl to know to whom send a given change. In this case, I am Cc'ing Rob, Geert and the devicetree mailing list which were missing. - Also, for single patches, typically you would want to send the patch without a cover letter. If you want to put comments that shouldn't go into the commit, you can write them just below the "---" line. Thank you for contributing to the kernel and welcome! Cheers, Miguel