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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 D6335C83000 for ; Wed, 29 Apr 2020 14:55:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE725206F0 for ; Wed, 29 Apr 2020 14:55:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588172113; bh=o5+qieYC1jNSQz5eJwHFnRMubO1WO57oPgy4ZnZ6/80=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=d6JuhtNX0tHQzy9ZAVjhewmiPfDDOjP/iC3b1O4lhU6MyUn8vrNObUCZdF8kLDjBF var5XttiYDAHn2uQIapKeJuCcJPmoE8f2xkckErjKcfgkMzby9sawJW/60AvOHiwq6 RAtF4+58jZaipvh0OMDoohHefaQhB0jFIg6ncBGE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726476AbgD2OzN (ORCPT ); Wed, 29 Apr 2020 10:55:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:45426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726456AbgD2OzN (ORCPT ); Wed, 29 Apr 2020 10:55:13 -0400 Received: from mail-ot1-f53.google.com (mail-ot1-f53.google.com [209.85.210.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B15A920B80 for ; Wed, 29 Apr 2020 14:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588172112; bh=o5+qieYC1jNSQz5eJwHFnRMubO1WO57oPgy4ZnZ6/80=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=FsaDwm/RJkBJHqMIroJ+44p/jNXijYy79P0wF5b12jLM1EExMUyz2iyseDNJjx9Et ov2K5u49q77X7k7Cq2mgVmn1J9TlP2mjQvKZLvBr7uCkwuMFZY2hAp/15IQD2zO5fA DqzO8FFeBwlhBwAWAgYwzp+eXyQxoWuKQeoRLV9k= Received: by mail-ot1-f53.google.com with SMTP id g14so1887760otg.10 for ; Wed, 29 Apr 2020 07:55:12 -0700 (PDT) X-Gm-Message-State: AGi0PuaQsGb0kq1n9dC5/lCOaddkA331mkz8Fmt1+43C288YrfOykv7X CAXYbjNnDytgPjyag7LCwF60C6ZoIPb7oAlrDQ== X-Google-Smtp-Source: APiQypJSfmto6bzeis9z5KUnimUNVl97fompNnDgnZX8cq19V3OO58z1uxH0xGL3xXnRejbdArofpQJuDy5QTPVWK4s= X-Received: by 2002:a9d:7d85:: with SMTP id j5mr25331065otn.107.1588172111959; Wed, 29 Apr 2020 07:55:11 -0700 (PDT) MIME-Version: 1.0 References: <6cdf20c3-7b74-679c-0e6f-4d385d12f9fe@xilinx.com> <845e6a12-ca33-957f-debb-4a1fcec70742@xilinx.com> In-Reply-To: <845e6a12-ca33-957f-debb-4a1fcec70742@xilinx.com> From: Rob Herring Date: Wed, 29 Apr 2020 09:55:00 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: u-boot DT configuration node To: Michal Simek Cc: "devicetree@vger.kernel.org" , "u-boot@lists.denx.de" , Tom Rini , Loic Poulain Content-Type: text/plain; charset="UTF-8" Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Apr 28, 2020 at 8:51 AM Michal Simek wrote: > > On 28. 04. 20 15:23, Rob Herring wrote: > > On Wed, Apr 1, 2020 at 4:23 AM Michal Simek wrote: > >> > >> Hi Rob and others, > >> > >> for couple of years already u-boot is using config node in root DT for > >> u-boot configuration. > >> > >> Here is one example in u-boot source code. > >> https://gitlab.denx.de/u-boot/u-boot/-/blob/master/arch/arm/dts/exynos5250-spring.dts#L47 > >> > >> And here is dt binding description > >> https://gitlab.denx.de/u-boot/u-boot/-/blob/master/doc/device-tree-bindings/config.txt > >> > >> I was checking dt binding specification and there no such a thing > >> described there. It means I expect this is more adhoc u-boot solution. > >> We have reached the point where could be beneficial to put some u-boot > >> specific configurations to DT. > >> > >> Actually I have done similar thing some time ago too by using chosen > >> node and add xilinx specific property there to point to eeprom. > >> https://gitlab.denx.de/u-boot/u-boot/-/blob/master/arch/arm/dts/zynqmp-zcu102-revA.dts#L39 > > > > In this case, I think an alias should be used as it's more of just a > > shortcut to finding a specific node. > > What alias name do you suggest to use? > We have systems where one i2c eeprom described based board and another > i2c eeprom describe bootable module. And I need to have shotcuts to both > of them. > > dt specification doesn't list any keywords for aliases but there is > generic name recommendation. I do want make aliases a registered list of names. > Based on keywords it should look like this. > eeprom0 = ...; > eeprom1 = ...; That was my initial thought, but maybe "nvmemX" to be a bit more generic. > >> I think it is a time to discuss it and do it properly. > >> > >> First of all my question is where we could list SW prefixes to make sure > >> that they are listed and everybody is aware about it. We have > >> vendor-prefixes and we should have a way to record also prefixes for sw > >> projects. U-Boot is using u-boot. Xen has file in the kernel with using > >> xen prefix. At least these two should be listed. > > > > Documentation/devicetree/bindings/vendor-prefixes.yaml. > > thx > > > > >> Next my question is what is the recommended way to pass sw specific > >> parameters via DT? I think using chosen node is more appropriate then > >> adhoc config node. Or is there a better way how this should be done? > > > > /chosen > > > > For vendor specific things though I would be cautious. If they are > > settings for a specific device, then they probably belong in the > > device's node. Second, are they really vendor specific? What we don't > > want is each vendor doing the same thing in slightly different ways. > > For u-boot specific setting like - offsets it should be generic for > everybody. I was already talking to Loic that for saving u-boot > variables to QSPI we should be using MTD partition map and put there > maybe a flag to say that this is the location for storing them. I'd standardize on the partition name. Rob