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[2620:137:e000::1:20]) by mx.google.com with ESMTP id 4-20020a630104000000b0050f9b910fa1si20299724pgb.368.2023.05.17.01.59.29; Wed, 17 May 2023 01:59:43 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20221208 header.b=fN7P3xoz; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 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 S230302AbjEQI0c (ORCPT + 99 others); Wed, 17 May 2023 04:26:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230156AbjEQI0Z (ORCPT ); Wed, 17 May 2023 04:26:25 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6412D3AB0; Wed, 17 May 2023 01:26:19 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id 98e67ed59e1d1-24e0c29733fso554840a91.2; Wed, 17 May 2023 01:26:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684311979; x=1686903979; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=KTc75nBooVuD86e3sizZpv99O1kaziV5RzesGn9lJ30=; b=fN7P3xozEcsdZ4tKVtucSdhKOuWQ/7nxXF++xcFuu9tZMOCdXRPPK29xCPtANLYhw3 L1xJlALCPenPxQeO6DFFYCvvaak4kjFAMGJiniyPGzO2WIN5i+jEERe0QQmMr0EquT9x IFlLbuGe3SEu4WtHB1MbPEBglsjbPoP4EQF5VcP40O37Mct922mgznPv9TmSdkPwQXZJ vmkjadqcPkQ3/K7ubFULfg0Fsxv4Gykav5nopIE5b0J+KYbFMEImZRI4C2zJCHePcC4n n4kXPIz1s6OEIRrQYAt+Xp5Z2gomExmQZ+MrV1QfwCORNM/DglZ3Q7KOgYzJ7vuz65Fb Wk+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684311979; x=1686903979; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=KTc75nBooVuD86e3sizZpv99O1kaziV5RzesGn9lJ30=; b=FUjy4CsQMyOAXqbALrfeFWSUOw6fKZhceps8aHb1QtrXlHPbXCq25ZMhOKpB/T4dAx htQj5NlpvXwmfKwME9XWA/WQJCmk0QZO7DCte2hD0FJOZZpxruvQ1MscjDi0n0ouLrGL d2dBB/vwF5q9Lsq/EgSwf2MXOTndVU+1HavB8EbZe8uZVvHfx+k5ddFXeIY/JaEePz4D Z0w9bf4frMbKjQDjN4kjGEnkhLQyErdXuTQGl17LeLLfYULaqF68bNkwx+OMuUDlXc4X 9mWzENYtXoJTeXdkC5Zz8PIx/zU3y+uNTLsu5a0CxqVnyz1qb9GUfif4q4FDrxJvJtad YAoA== X-Gm-Message-State: AC+VfDxyyQ/wIfTh1nJi3F89u6LFQXUwAmcHcmb53Wded1jIRFm/cDrH tWijPdXIU7yMSHUF0CK32JzOxhsL7Hlf3zqjAyg= X-Received: by 2002:a17:90b:3a8e:b0:247:6ead:d0ed with SMTP id om14-20020a17090b3a8e00b002476eadd0edmr40836957pjb.28.1684311978781; Wed, 17 May 2023 01:26:18 -0700 (PDT) MIME-Version: 1.0 References: <20230511135632.78344-1-bstruempfel@ultratronik.de> <20230511231317.158214-1-bstruempfel@ultratronik.de> <20230511231317.158214-2-bstruempfel@ultratronik.de> In-Reply-To: From: =?UTF-8?B?QsO2cmdlIFN0csO8bXBmZWw=?= Date: Wed, 17 May 2023 10:26:07 +0200 Message-ID: Subject: Re: [PATCH v2 1/4] spi: dt-bindings: Introduce spi-mosi-idle-low flag To: Mark Brown Cc: bstruempfel@ultratronik.de, andy.shevchenko@gmail.com, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thank you for your feedback Am Mo., 15. Mai 2023 um 02:34 Uhr schrieb Mark Brown : > > On Fri, May 12, 2023 at 08:54:19AM +0200, B=C3=B6rge Str=C3=BCmpfel wrote= : > > Am Fr., 12. Mai 2023 um 05:30 Uhr schrieb Mark Brown : > > > > If this is always required for a given device (which I'd expect to be > > > the case) why configure it through DT? I know we've got some legacy > > > stuff like that but not all legacy DT choices were good and no need t= o > > > continue the pattern. > > > Yes this will always be the case for specific spi-device, spi-controlle= r > > combinations. Just to make sure, that I understand your suggestion > > correctly: You propose to check from the specific spi-device-driver, if > > the spi-controller supports this particular mode-bit, and then set it i= f > > it does and thereby loose the need for the DT entry completely? > > Yes, we shouldn't need DT here. Though the device should just be > setting this unconditionally if it's always required. I agree with you, that we should not need DT here. I will remove the dt-binding in the next patch version. However I am not so sure about setting it unconditionally, since this is dependent on the spi-controller. Not all spi-controller show this behavior, that they use a high mosi line in idle mode and have the ability to change this. As far as I know, another common behavior is that the mosi just keeps the last state which it transmitted. In this case, devices like Neopixel would still work without this mode bit.