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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 CF93DC43141 for ; Thu, 14 Nov 2019 10:47:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACC672070E for ; Thu, 14 Nov 2019 10:47:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="QmKQUDdo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726505AbfKNKrD (ORCPT ); Thu, 14 Nov 2019 05:47:03 -0500 Received: from mail-ua1-f65.google.com ([209.85.222.65]:35443 "EHLO mail-ua1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726002AbfKNKrD (ORCPT ); Thu, 14 Nov 2019 05:47:03 -0500 Received: by mail-ua1-f65.google.com with SMTP id s14so1722918uad.2 for ; Thu, 14 Nov 2019 02:47:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+Z7zzjF1yR5HW1GmAitGOf39HmOM3mJTrajNy5woG3s=; b=QmKQUDdoeOMyx6GoduNvAB+A6ByZBHDCd+m44cbjKkLycBOCHODSVbwGUtmtZnFncI jBSatmf+RWZClV7+/BbAdYlKRMyyAijZM/mTIM/4AIh3nL2mbNlizGws7XFqqjSyznmX Dn0gEK8v15SByp0mIgAuXm4ACcaG+8wlLEZZIjr9uDr4PeVGEzM043Uj4wVOg+qktF6d PE94zBhSofxflwJqnIoljIpQNv0gzelfMX/0QBMZNpLbhBsuR9WUPo8TdZDTUPrI9b4H HFDaB0Obzgblcc6SmVLw2/kbduFDbXerQRneC2C3GZMrJz5OvaV7L/qCpremwSvgrsIl +o0Q== 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=+Z7zzjF1yR5HW1GmAitGOf39HmOM3mJTrajNy5woG3s=; b=cuZSnPB7hzyjD6lSHga5ehiLsyCA5HkyuE7PYCo6EFYR3P3lFDjiOhiF+GBTbhorBr rYAKawTdpvsLIoPoQsYC9Kl6qP911wIPR7lVcZ8f3aPnklvSSfR+VuEq7X27vyswYr1C jAFcPUV1fW13bmy24rBkfgOdXgrfQLlIA1DQPJv0wGFqYVdyt3UUI+2wyBJ3BDOIXmaG Wg+DBlQnha6v6x18x+Vo9i9CbUpeFqpn2RmfDnLv1+jfWchEjxhRYsbECXGIiqoXEXue uF8swltykLTBeiqOGkYLTAx9WL1ubK4NeVJQ7CWfm9j/QnKgtur5CHmvosLLiTY778IE dfow== X-Gm-Message-State: APjAAAVqAHFfnicFxyPIKwL2/5egHUm1CXmI1N/fk8Xvu2Sxm/IoUu/p +6ptswMoU09uwWZId3Xcd+CUaRQAYY28kY4V683AhxIY X-Google-Smtp-Source: APXvYqzs2hzCHGhzo4MLkvjZ4GdlPj6hUM6/5I/OJ+TEn23Lr7XxbNQB98pkh3DLyHV1zrutRRH8jaIY8J3D/SKfoY0= X-Received: by 2002:ab0:2042:: with SMTP id g2mr4940760ual.19.1573728422241; Thu, 14 Nov 2019 02:47:02 -0800 (PST) MIME-Version: 1.0 References: <20191105055015.23656-1-erosca@de.adit-jv.com> <20191105062223.GB1048@kunai> <20191105083213.GA24603@vmlxhi-102.adit-jv.com> <20191107003907.GA22634@bogus> <20191112211950.GB3402@kunai> In-Reply-To: <20191112211950.GB3402@kunai> From: Ulf Hansson Date: Thu, 14 Nov 2019 11:46:26 +0100 Message-ID: Subject: Re: [PATCH 1/3] dt-bindings: mmc: Add 'fixed-emmc-driver-type-hs{200,400}' To: Wolfram Sang Cc: Rob Herring , Eugeniu Rosca , Adrian Hunter , Wolfram Sang , "linux-mmc@vger.kernel.org" , Linus Walleij , Mathieu Malaterre , Pavel Machek , DTML , Linux Kernel Mailing List , Eugeniu Rosca Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [...] > > > > > > One option to achieve a similar degree of flexibility by using an array > > > OF property (instead of several u32 properties) would be to agree on a > > > convention based on magic values, i.e. below DT one-liner could be an > > > example of providing solely the "fixed-emmc-driver-type-hs200" value > > > (based on the agreement that 0xFF values are discarded by the driver): > > > > > > fixed-emmc-driver-type = <0xFF 0x1 0xFF>; > > > > I don't understand why you have 3 values instead of 2. > > Because he sketches maximum flexibility here. Have a non-HS (default) > value, one for HS200, and one for HS400: > > fixed-emmc-driver-type = <[default] [HS200] [HS400]>; > > > I would just use -1 if you want to ignore an entry. If that's the common > > '-1' sounds good to me, too. > > > case, then I'd stick with what you originally proposed. If rare, then I > > think an array is the better route. > > What I have seen so far: setting drive strength alone is more on the > rare side. Setting specific values for default and HS200/400 seems even > more rare to me. With this patchset, it is the first time I hear about > it. > > Yet, my experience might be a bit limited, maybe others (Hi Ulf! ;)) can add > their views, too? My experience in this field is quite limited. No input from me, sorry. Kind regards Uffe