From patchwork Sun Jan 15 10:10:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiner Kallweit X-Patchwork-Id: 642995 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 A6476C3DA78 for ; Sun, 15 Jan 2023 10:11:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230088AbjAOKLl (ORCPT ); Sun, 15 Jan 2023 05:11:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229988AbjAOKLk (ORCPT ); Sun, 15 Jan 2023 05:11:40 -0500 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B01807296; Sun, 15 Jan 2023 02:11:38 -0800 (PST) Received: by mail-wm1-x333.google.com with SMTP id k22-20020a05600c1c9600b003d1ee3a6289so20159590wms.2; Sun, 15 Jan 2023 02:11:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:subject:content-language:cc:to:from :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=jaUFFdfJUDeyRNl7j9nd9AfJouyEYiFU0X0Hysi4jPM=; b=aw3tZQ5B+fzfQzUZ6d8Kjk8Cr+w3jTNM5QHBp3GLXvX40bRz7LoDvxldSYSzykxtBK AzFen/LghFG8yPHjPUf2lKqkKRA0RX19ewZhM9qA9vdHmNaWv/+qQuVlNgg/TlsUEPNT wFcsiyNBb/FMIOB13HnGE48fVVBqsn0esD+QfOVpmK5Sr1MrHaDALEFFkHAchweOAkc/ +r/QHWBAzm4c0Z6+3m/WIv4iClU3aX9AOMRod8A8IOkNPwJ/YVSAzATTiFykZ+sCmi+Y sQso4AqpTwe6jUc5h3pKqNAFd6LFoPGz0vmOyHGyvbXfm2w4Uv0Gg+0LAn4zR6fd13N5 pWKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:subject:content-language:cc:to:from :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=jaUFFdfJUDeyRNl7j9nd9AfJouyEYiFU0X0Hysi4jPM=; b=tu6uUFd5QTiVpEjYorEov8Km54atBw54x7Z2mLtQ/6gjuHRvml5OEoe64bNx3RyJ8R 2IuNoSg238vz8ZA2wCYjaGJpGuIQKh0rqWQyDwJ5a8MwZNqdIDWZkTpP3gyEN3a9m9uQ IdZUllEvXdW7ebTdNN4jrakjxGq5CL8hk4zBG0D2B5diCW4HXJ2xA+d6zvuyOcygKRCh uhak2y5CqdqQE8haE9jDiP8lVX7JIgCQu8iIXtSlVcjzWJP/48dfooJMQYiQNkSnzwO1 gzoPnCAXKmUetH30DCPf/mzWWVXZpuuSRml+j5gMEQX6pSxT1cLa4aVwH3cLEGaEjn67 r+5w== X-Gm-Message-State: AFqh2kr99pdXbbpqYipLophM9wJbxG7TbfjNzrJ3sZzhf2RcyLbBD8Cq POyahcINB7KnMFuYV9Cm5PY= X-Google-Smtp-Source: AMrXdXvZ7oWzX87ba3J2EJM0a1X45/noT5Wui8evIy+AzfXgIx1nIJwwiasLTg/8DiCbYuuyYPrCdg== X-Received: by 2002:a1c:cc11:0:b0:3da:1d52:26b5 with SMTP id h17-20020a1ccc11000000b003da1d5226b5mr4882343wmb.14.1673777496996; Sun, 15 Jan 2023 02:11:36 -0800 (PST) Received: from ?IPV6:2a01:c22:6e61:8c00:154f:326e:8d45:8ce7? (dynamic-2a01-0c22-6e61-8c00-154f-326e-8d45-8ce7.c22.pool.telefonica.de. [2a01:c22:6e61:8c00:154f:326e:8d45:8ce7]) by smtp.googlemail.com with ESMTPSA id l24-20020a05600c1d1800b003daf6e3bc2fsm2058405wms.1.2023.01.15.02.11.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 15 Jan 2023 02:11:36 -0800 (PST) Message-ID: <3a5545f3-f858-2c80-8bd4-2e0d401a1dc0@gmail.com> Date: Sun, 15 Jan 2023 11:10:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 From: Heiner Kallweit To: Rob Herring , Krzysztof Kozlowski , Wolfram Sang Cc: "linux-i2c@vger.kernel.org" , "devicetree@vger.kernel.org" Content-Language: en-US Subject: [PATCH v3 0/3] i2c: gpio: support write-only sda Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org There are slave devices that understand I2C but have read-only SDA and SCL. Examples are FD650 7-segment LED controller and its derivatives. Typical board designs don't even have a pull-up for both pins. This patch makes i2c-gpio usable with such devices, based on new DT property i2c-gpio,sda-output-only. v2: - improve commit message for patch 1 v3: - patch 2: check for adap->getsda in readbytes() - patch 2: align warning message level for info on missing getscl/getsda - patch 3: improve description of attribute sda_is_output_only Heiner Kallweit (3): dt-bindings: i2c-gpio: Add property i2c-gpio,sda-output-only i2c: algo: bit: allow getsda to be NULL i2c: gpio: support write-only sda .../devicetree/bindings/i2c/i2c-gpio.yaml | 4 ++++ drivers/i2c/algos/i2c-algo-bit.c | 16 ++++++++++++++-- drivers/i2c/busses/i2c-gpio.c | 14 +++++++++++--- include/linux/platform_data/i2c-gpio.h | 3 +++ 4 files changed, 32 insertions(+), 5 deletions(-)