From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH V1 Resend 2/3] cpufreq: dt: Add generic platform-device creation support Date: Fri, 1 Apr 2016 18:22:14 +0530 Message-ID: <20160401125214.GE2987@vireshk-i7> References: <12972545.Mi9sHiNJpR@wuerfel> <20160330032240.GB8773@vireshk-i7> <7250220.227umpmTug@wuerfel> <20160401102350.GA5532@vireshk-i7> <56FE69E0.1080800@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:34325 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758311AbcDAMwS (ORCPT ); Fri, 1 Apr 2016 08:52:18 -0400 Received: by mail-pf0-f176.google.com with SMTP id x3so93850990pfb.1 for ; Fri, 01 Apr 2016 05:52:18 -0700 (PDT) Content-Disposition: inline In-Reply-To: <56FE69E0.1080800@free.fr> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Mason Cc: Arnd Bergmann , 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 On 01-04-16, 14:30, Mason wrote: > 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? DT is all about expressing hardware in a file. The same bindings should be usable across any operating system, not just Linux. And so we shouldn't have any OS or software-implementation specific properties here. > 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? Its not about just making it work, otherwise we would have done it long time back by creating a DT node for cpufreq-dt driver. > > @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? That compatible property will describe how to parse/describe operating-points for a CPU. Any driver, which has the ability to parse those bindings can do things base on such a compatibility string. I hope you got the idea. -- viresh