From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759202Ab3BTL2n (ORCPT ); Wed, 20 Feb 2013 06:28:43 -0500 Received: from mail-qa0-f53.google.com ([209.85.216.53]:50585 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826Ab3BTL2m (ORCPT ); Wed, 20 Feb 2013 06:28:42 -0500 MIME-Version: 1.0 In-Reply-To: <201302201114.49304.arnd@arndb.de> References: <1361198522-23789-1-git-send-email-shc_work@mail.ru> <201302201006.41287.arnd@arndb.de> <201302201114.49304.arnd@arndb.de> Date: Wed, 20 Feb 2013 19:28:40 +0800 Message-ID: Subject: Re: Re[8]: [PATCH v3] mfd: syscon: Add non-DT support From: Dong Aisheng To: Arnd Bergmann Cc: Alexander Shiyan , linux-kernel@vger.kernel.org, Samuel Ortiz , Mark Brown Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20 February 2013 19:14, Arnd Bergmann wrote: > On Wednesday 20 February 2013, Dong Aisheng wrote: >> On 20 February 2013 18:06, Arnd Bergmann wrote: >> > I would first like to get an answer to the question I asked in my first mail, >> > which is what the use case of non-DT support in this driver is. If this >> > is used only by a new platform that has to use DT anyway, or by an existing >> > platform that is easy enough to convert, we probably shouldn't do all this >> > at all. >> > >> >> If the platform can convert to dt, then we do not have such issue. >> The question is do we allow the existing non-dt platforms to use it >> before converting? > > I think the answer to that is "it depends". It's basically a question of > how much work it would be to convert the platforms that need it over to > DT, and how much of the interface it actually needs. E.g. if there is > only one in-tree platform that needs to use syscon but can't easily be > moved over to DT, but that platform can only have a single syscon device, > then we don't need any of the matching support but could simply return > the first regmap area we have in the list. > > Of course, if the platform in question is out of tree, I would argue > that the whatever patches are needed by that platform should also > remain out of tree. > Basically i agree with your point. Alexander seems to be the first non-dt user of syscon driver. He may answer whether they could choose to convert to dt first. But one question i wonder is that it may be hard to know how many poteintial non-dt platforms may use syscon. Regards Dong Aisheng