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: Thu, 7 Apr 2016 14:00:36 +0530 Message-ID: <20160407083036.GB3201@vireshk-i7> References: <12972545.Mi9sHiNJpR@wuerfel> <20160330032240.GB8773@vireshk-i7> <7250220.227umpmTug@wuerfel> <20160401102350.GA5532@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f180.google.com ([209.85.192.180]:34335 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbcDGIak (ORCPT ); Thu, 7 Apr 2016 04:30:40 -0400 Received: by mail-pf0-f180.google.com with SMTP id c20so51597260pfc.1 for ; Thu, 07 Apr 2016 01:30:40 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Rob Herring Cc: Arnd Bergmann , Rob Herring , Krzysztof =?utf-8?Q?Koz=C5=82owski?= , Kukjin Kim , Heiko =?iso-8859-1?Q?St=FCbner?= , "linux-pm@vger.kernel.org" , Matthew McClintock , xf@rock-chips.com, Rafael Wysocki , "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" , Mason On 01-04-16, 09:15, Rob Herring wrote: > On Fri, Apr 1, 2016 at 5:23 AM, Viresh Kumar wrote: > > So you mean for future DT files we can have something like this: > > > > cpus { > > compatible = "operation-points-v2"; > > #address-cells = <1>; > > #size-cells = <0>; > > > > cpu@0 { > > compatible = "arm,cortex-a9"; > > reg = <0>; > > next-level-cache = <&L2>; > > operating-points-v2 = <&cpu0_opp_table>; > > }; > > }; > > > > cpu0_opp_table: opp_table0 { > > opp@1000000000 { > > opp-hz = /bits/ 64 <1000000000>; > > opp-microvolt = <970000 975000 985000>; > > opp-microamp = <70000>; > > clock-latency-ns = <300000>; > > opp-suspend; > > }; > > opp@1100000000 { > > opp-hz = /bits/ 64 <1100000000>; > > opp-microvolt = <980000 1000000 1010000>; > > opp-microamp = <80000>; > > clock-latency-ns = <310000>; > > }; > > }; > > }; > > > > > > And the cpufreq-dt driver can match /cpus node's compatible string against > > "operating-points-v2" and create a device at runtime ? > > > > @Rob: Will that be acceptable to you? We are discussing (again) about how to > > probe cpufreq-dt driver automatically for platforms :) > > No, I don't think that belongs in /cpus. > > Part of the problem is this requires a DT change if you switch between > a platform-specific driver and generic driver. Right. > I don't understand the issue having a little bit of code to parse the > DT and create the device. I am fine with that, we were just re-evaluating our options :) > If you are worried about having a long list > of platforms, At least I am not. > you could instead check the tree for operating-points-v2 > property in the cpu node and create the device unless the platform is > black-listed. I don't really like the black-list idea much. It forces a Non cpufreq-dt platform to edit cpufreq-dt related file, just to make its own cpufreq driver work. I find that ugly somehow :) -- viresh