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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 90743C433ED for ; Thu, 8 Apr 2021 17:57:20 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3337361105 for ; Thu, 8 Apr 2021 17:57:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3337361105 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BL4Yvf6ac6LVBhsvvo61qKeImapqtuQrIK7xk89bGAA=; b=ZtQmZ8HPgzfLd4QyMNL8R4Qxx mC2GMpg9TnVuF4WK1AIdi6ufnNyfuYhpyewji5OOFdO/uVtt5trKSbwjOST7Fjx9OTCXBH/NNC02Z Pg7hnu5uDKH0MX4GTGuSRnILyurFqwU5hggq1xV0G+ZVOOomET4wcYn5yCuE6rdpuF1QnW1A08dRn gZsRrmj+gZUuX89fB3NygGkzdGr1jFe6MZFypIOSnh45DAp7JLzTBPDOLsMQI4+nCjw5mN7xv+LGs CKcKxr3X+rgpkvxflStveJPngaUeXPT9u35/lrDyQE+nmoEuP3ZXhR15Zaqel2yAgjDJHaOdWQm61 QjWW/35wA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lUYsc-008qMX-11; Thu, 08 Apr 2021 17:55:46 +0000 Received: from mail-ot1-f43.google.com ([209.85.210.43]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lUYsW-008qLI-RQ; Thu, 08 Apr 2021 17:55:42 +0000 Received: by mail-ot1-f43.google.com with SMTP id 91-20020a9d08640000b0290237d9c40382so3104238oty.12; Thu, 08 Apr 2021 10:55:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=3TOQkf6y0+tFgPWi7wzwRS6LltZgb6boVG0kZSOaui4=; b=ZbtVDrViCTlDhom7HTcUsNBnKUUg7Vib4pU4As3zQIDbmOjUeerQjhil0ZvK7CSqfF gs0lfV0z6pMgfabz/LOAi6CrQyapaLlX4BqO2XVhWs+K9Lq4iZyXnKVeX8PCvJ6C19BL ignH/8/4XvUFF3CWFndr6YcdLhIBI6jita2YpNuVlCFMgVSt4QvSIgRqtDQaMDtHP65v uVGBnvnzh55+U1FrokoEkrlKIAc/wZVyEJkMnd0L+crnaiLfX/ktfabM65J2jGLkhjcj 5H4LOPvdMJ3SjnsvOYSdV1Bujh0xmUF6HE4aZc+QhE5F6W4LMfZZs1SvztUoY49qX5ds tGyQ== X-Gm-Message-State: AOAM530AO2dxurvM/pW7glSqzD5Wx3M/XTnZozqhYgsypXz4NNVdEl8n dYARFFYv4yyqaz2A+JRu7A== X-Google-Smtp-Source: ABdhPJyTErOlUI7ErNldOV1VbI5u50JYPHqEBsBBiIsIzHTTwtqaeKL04S8AQSgLdnIEjy+UfHL9fg== X-Received: by 2002:a9d:3423:: with SMTP id v32mr8860415otb.168.1617904539749; Thu, 08 Apr 2021 10:55:39 -0700 (PDT) Received: from robh.at.kernel.org (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id j10sm29616oos.27.2021.04.08.10.55.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Apr 2021 10:55:39 -0700 (PDT) Received: (nullmailer pid 1706321 invoked by uid 1000); Thu, 08 Apr 2021 17:55:38 -0000 Date: Thu, 8 Apr 2021 12:55:38 -0500 From: Rob Herring To: Jim Quinlan Cc: Mark Brown , linux-pci , Nicolas Saenz Julienne , bcm-kernel-feedback-list , Jim Quinlan , Florian Fainelli , Bjorn Helgaas , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Subject: Re: [PATCH v4 2/6] dt-bindings: PCI: Add bindings for Brcmstb endpoint device voltage regulators Message-ID: <20210408175538.GA1688320@robh.at.kernel.org> References: <20210401212148.47033-1-jim2101024@gmail.com> <20210401212148.47033-3-jim2101024@gmail.com> <20210406164708.GM6443@sirena.org.uk> <20210406173211.GP6443@sirena.org.uk> <20210408162016.GA1556444@robh.at.kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210408_185540_939005_4E2DA311 X-CRM114-Status: GOOD ( 32.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 08, 2021 at 12:58:05PM -0400, Jim Quinlan wrote: > On Thu, Apr 8, 2021 at 12:20 PM Rob Herring wrote: > > > > On Tue, Apr 06, 2021 at 02:25:49PM -0400, Jim Quinlan wrote: > > > On Tue, Apr 6, 2021 at 1:32 PM Mark Brown wrote: > > > > > > > > On Tue, Apr 06, 2021 at 01:26:51PM -0400, Jim Quinlan wrote: > > > > > On Tue, Apr 6, 2021 at 12:47 PM Mark Brown wrote: > > > > > > > > > > No great problem with having these in the controller node (assming it > > > > > > accurately describes the hardware) but I do think we ought to also be > > > > > > able to describe these per slot. > > > > PCIe is effectively point to point, so there's only 1 slot unless > > there's a PCIe switch in the middle. If that's the case, then it's all > > more complicated. > > > > > > > Can you explain what you think that would look like in the DT? > > > > > > > > I *think* that's just some properties on the nodes for the endpoints, > > > > note that the driver could just ignore them for now. Not sure where or > > > > if we document any extensions but child nodes are in section 4 of the > > > > v2.1 PCI bus binding. > > > > > > Hi Mark, > > > > > > I'm a little confused -- here is how I remember the chronology of the > > > "DT bindings" commit reviews, please correct me if I'm wrong: > > > > > > o JimQ submitted a pullreq for using voltage regulators in the same > > > style as the existing "rockport" PCIe driver. > > > o After some deliberation, RobH preferred that the voltage regulators > > > should go into the PCIe subnode device's DT node. > > > > IIRC, that's because you said there isn't a standard slot. > Admittedly, I'm not exactly sure what you mean by a "standard slot". > Our PCIIe HW does not support hotplug or have a presence bit or > anything like that. Our root complex has one port; it can only > directly connect to a single switch or endpoint. This connection shows > up as slot0. The voltage regulator(s) involved depend on a GPIO that > turns the power on/off for the connected device/chip. The gpio pin > can vary from board to board but this is easily handled in our DT. > Some boards have regulators that are always on and not associated with > a GPIO pin -- these have no representation in our DT. By standard slot, I mean you have standard voltage rails 12V and 3.3V (or 1.5 and 3.3 for mini PCIe) and PERST# signal, no other extra things to make a device discoverable, and the timing for those rails and PERST# follow what the spec defines. There's also CLKREQ, WAKE, and hotplug detect signals, but I think those are all optional and could be tied off. I think most PCI h/w is not hotplug capable. Rob _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel