From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758561AbcDAMas (ORCPT ); Fri, 1 Apr 2016 08:30:48 -0400 Received: from smtp2-g21.free.fr ([212.27.42.2]:7705 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752761AbcDAMap (ORCPT ); Fri, 1 Apr 2016 08:30:45 -0400 Subject: Re: [PATCH V1 Resend 2/3] cpufreq: dt: Add generic platform-device creation support To: Viresh Kumar , Arnd Bergmann Cc: linaro-kernel@lists.linaro.org, k.kozlowski@samsung.com, kgene.kim@samsung.com, heiko@sntech.de, linux-pm@vger.kernel.org, mmcclint@codeaurora.org, xf@rock-chips.com, Rafael Wysocki , linux-kernel@vger.kernel.org, rob.herring@linaro.org, Sebastian Frias References: <12972545.Mi9sHiNJpR@wuerfel> <20160330032240.GB8773@vireshk-i7> <7250220.227umpmTug@wuerfel> <20160401102350.GA5532@vireshk-i7> From: Mason Message-ID: <56FE69E0.1080800@free.fr> Date: Fri, 1 Apr 2016 14:30:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:42.0) Gecko/20100101 Firefox/42.0 SeaMonkey/2.39 MIME-Version: 1.0 In-Reply-To: <20160401102350.GA5532@vireshk-i7> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/04/2016 12:23, Viresh Kumar wrote: > Cc'ing Rob and Mason. > > On 30-03-16, 09:53, Arnd Bergmann wrote: > >> I think it should be something in the /cpus or the /opp_table hierarchy, >> not the root of the device tree, but other than that I don't care much >> whether it's a variation of the oppv2 compatible string or an additional >> property in any of the nodes. > > So you mean for future DT files we can have something like this: > > cpus { > compatible = "operation-points-v2"; > [...] > > And the cpufreq-dt driver can match /cpus node's compatible string against > "operating-points-v2" and create a device at runtime ? Hmmm... I'm using the older operating-points prop in my platform's DT. Why can't we define a new property (e.g. "enable-generic-cpufreq") which registers the "cpufreq-dt" pseudo-device? And platforms that manually register "cpufreq-dt" would be automatically white-listed, even if they don't have the new property, to maintain backward-compat? > @Rob: Will that be acceptable to you? We are discussing (again) about how to > probe cpufreq-dt driver automatically for platforms :) > > The cpus node doesn't have any 'compatible' property today, and I will be > required to add that in this case. Why does it need a compatible prop? Why isn't a bool prop enough? Regards.