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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 821CEECDE4B for ; Thu, 8 Nov 2018 13:40:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B10920825 for ; Thu, 8 Nov 2018 13:40:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B10920825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbeKHXPu (ORCPT ); Thu, 8 Nov 2018 18:15:50 -0500 Received: from mail-qk1-f196.google.com ([209.85.222.196]:36908 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726417AbeKHXPt (ORCPT ); Thu, 8 Nov 2018 18:15:49 -0500 Received: by mail-qk1-f196.google.com with SMTP id 131so26441412qkd.4; Thu, 08 Nov 2018 05:40:17 -0800 (PST) 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=+WH+TBA+ttso5qoOGbz9K70Y5upwqCAShyaOWEC2UDY=; b=bXf2Tn2uth43+HStR3ENeRsyt7WgtPAimt6qa5aKkGVe5X140pc11OU++Pr9lxqhvF QZmk2BnXhwOSVQeM6J1aQ1HursmvADf52SDRKsERfvUUR0BdE5t62DN0QbNLJDEPaVyq yKqkOGvCwtRI5PtfOIuSs9ml0qxAKYY7god5qqD+q+HZ1XCtoqbV0UdA+UmgHlGfk0XT dmUGtK52sE/IGupJe8ZPW9c1Pt8ewKEKh14RGIjaQiOpJ2cqQ47h2erHol9gf6qUFPPa WZHRFTeah2w+SfReN7zuHdqHOz1+7Sh37r/Kz6yJexjY1SZMrfeuFHAwJeDMIUa4VLOO y/jQ== X-Gm-Message-State: AGRZ1gJ3WQSm6ZqUODU3l+VQ9PmoJ4EltApkN57/PXbe1jx8umykyMRJ 0dcOHgwiDysWrl2vkquj8cuos81Qi+b+SfjmDNY= X-Google-Smtp-Source: AJdET5e/xfc1OPYep6gFh0BGqgWkJXtEQsyL8k0Cq44tNYu2qCTFVbRgCS/m60qi//qUIE4QAWruhPPB3NS4MN4H7Y4= X-Received: by 2002:a37:4116:: with SMTP id o22-v6mr3927693qka.107.1541684416887; Thu, 08 Nov 2018 05:40:16 -0800 (PST) MIME-Version: 1.0 References: <20181104155501.14767-1-TheSven73@googlemail.com> <20181104155501.14767-2-TheSven73@googlemail.com> <20181105212049.GA320@bogus> In-Reply-To: From: Arnd Bergmann Date: Thu, 8 Nov 2018 14:40:00 +0100 Message-ID: Subject: Re: [PATCH anybus v3 1/6] misc: support the Arcx anybus bridge To: thesven73@gmail.com Cc: Rob Herring , svendev@arcx.com, Linus Walleij , Lee Jones , Mark Rutland , =?UTF-8?Q?Andreas_F=C3=A4rber?= , Thierry Reding , David Lechner , noralf@tronnes.org, Johan Hovold , Michal Simek , michal.vokac@ysoft.com, gregkh , John Garry , Geert Uytterhoeven , Robin Murphy , Paul Gortmaker , Sebastien Bourdelin , Icenowy Zheng , Stuart Yoder , Maxime Ripard , Linux Kernel Mailing List , DTML 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 On Tue, Nov 6, 2018 at 9:05 PM Sven Van Asbroeck wrote: > On Tue, Nov 6, 2018 at 1:31 PM Rob Herring wrote: > > > If the host is not a h/w component, but just a s/w protocol then it > > doesn't belong in DT. Perhaps it could be a library which the bridge > > driver can call into. > > Anybus cards have an id register, which identifies what they are, so > that the appropriate client driver may be instantiated. > In that sense anybus is very suited to the bus/client abstraction of > pci/usb/etc. > > > What are the resets connected to? The slots? Maybe you should model > > the slots in DT. > > > > Yes, the resets are ultimately connected to the slots. > I'm happy to model the slots in DT. It makes sense, they are physical, > hardware components. It may also be necessary to have a way to add more DT properties to a device in the slot that can not be probed by looking at the ID register. Ideally it should not be needed, but we have added this to most buses anyway: USB, PCI, MMC and others can all be probed automatically for many devices, but there are some devices that need a place where extra information can be stored, e.g. an ethernet MAC address (in the absence of a PROM), an external clock or reset line that is not part of the normal protocol, or a more specific identification when two devices accidentally have the same ID. Arnd