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,URIBL_BLOCKED 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 F179BC4321D for ; Tue, 21 Aug 2018 09:56:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B132F214DA for ; Tue, 21 Aug 2018 09:56:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B132F214DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com 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 S1727049AbeHUNQN (ORCPT ); Tue, 21 Aug 2018 09:16:13 -0400 Received: from mail.bootlin.com ([62.4.15.54]:37457 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726709AbeHUNQN (ORCPT ); Tue, 21 Aug 2018 09:16:13 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 37DB820799; Tue, 21 Aug 2018 11:56:41 +0200 (CEST) Received: from bbrezillon (91-160-177-164.subs.proxad.net [91.160.177.164]) by mail.bootlin.com (Postfix) with ESMTPSA id 68FD120618; Tue, 21 Aug 2018 11:56:40 +0200 (CEST) Date: Tue, 21 Aug 2018 11:56:39 +0200 From: Boris Brezillon To: Srinivas Kandagatla Cc: Alban , Bartosz Golaszewski , Jonathan Corbet , Sekhar Nori , Kevin Hilman , Russell King , Arnd Bergmann , Greg Kroah-Hartman , David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Grygorii Strashko , "David S . Miller" , Naren , Mauro Carvalho Chehab , Andrew Morton , Lukas Wunner , Dan Carpenter , Florian Fainelli , Ivan Khoronzhuk , Sven Van Asbroeck , Paolo Abeni , Rob Herring , David Lechner , Andrew Lunn , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, netdev@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH v2 06/29] mtd: Add support for reading MTD devices via the nvmem API Message-ID: <20180821115639.4894c1c9@bbrezillon> In-Reply-To: References: <20180810080526.27207-1-brgl@bgdev.pl> <20180810080526.27207-7-brgl@bgdev.pl> <20180817182720.6a6e5e8e@bbrezillon> <20180819133106.0420df5f@tock> <20180819184609.6dcdbb9a@bbrezillon> <5b8c30b8-41e1-d59e-542b-fef6c6469ff0@linaro.org> <20180820202038.5d3dc195@bbrezillon> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 21 Aug 2018 10:50:07 +0100 Srinivas Kandagatla wrote: > On 20/08/18 19:20, Boris Brezillon wrote: > > On Mon, 20 Aug 2018 11:43:34 +0100 > > Srinivas Kandagatla wrote: > > > >> > >> Overall am still not able to clear visualize on how MTD bindings with > >> nvmem cells would look in both partition and un-partition usecases? > >> An example DT would be nice here!! > > > > Something along those lines: > > > This looks good to me. > > mtdnode { > > nvmem-cells { > > #address-cells = <1>; > > #size-cells = <1>; > > > > cell@0 { > > reg = <0x0 0x14>; > > }; > > }; > > > > partitions { > > compatible = "fixed-partitions"; > > #address-cells = <1>; > > #size-cells = <1>; > > > > partition@0 { > > reg = <0x0 0x20000>; > > > > nvmem-cells { > > #address-cells = <1>; > > #size-cells = <1>; > > > > cell@0 { > > reg = <0x0 0x10>; > > }; > > }; > > }; > > }; > > }; > > > Just curious...Is there a reason why we can't do it like this?: > Is this because of issue of #address-cells and #size-cells Or mtd > bindings always prefer subnodes? > > mtdnode { > reg = <0x0123000 0x40000>; > #address-cells = <1>; > #size-cells = <1>; > cell@0 { > compatible = "nvmem-cell"; > reg = <0x0 0x14>; > }; > > partitions { > compatible = "fixed-partitions"; > #address-cells = <1>; > #size-cells = <1>; > > partition@0 { > reg = <0x0 0x20000>; > cell@0 { > compatible = "nvmem-cell"; > reg = <0x0 0x10>; > }; > }; > }; > }; It's because partitions were initially directly defined under the mtd node, so, if you have an old DT you might have something like: mtdnode { reg = <0x0123000 0x40000>; #address-cells = <1>; #size-cells = <1>; partition@0 { reg = <0x0 0x20000>; ... }; ... }; If we use such a DT with this patch applied, the NVMEM framework will consider MTD partitions as nvmem cells, which is not what we want.