From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S944185AbdDTJvf (ORCPT ); Thu, 20 Apr 2017 05:51:35 -0400 Received: from foss.arm.com ([217.140.101.70]:51864 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S944119AbdDTJvd (ORCPT ); Thu, 20 Apr 2017 05:51:33 -0400 Subject: Re: [PATCH V4 1/9] PM / OPP: Allow OPP table to be used for power-domains To: Ulf Hansson , Viresh Kumar References: <0a7146f9-72f1-317c-3aab-770a72462968@arm.com> <20170413053736.GM5910@vireshk-i7> <3adbef6a-7b43-528f-e88f-c2121d30a5d3@arm.com> <20170417052758.GF28191@vireshk-i7> <95aa4b97-4e1a-13bb-f4d8-982b778012ba@arm.com> <20170419114740.GD5436@vireshk-i7> <9dee7c0d-e5f4-9fcd-3c92-bf7ec9d43a3b@arm.com> <20170420052533.GF5436@vireshk-i7> Cc: Sudeep Holla , Rafael Wysocki , Kevin Hilman , Viresh Kumar , Nishanth Menon , Stephen Boyd , linaro-kernel , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Vincent Guittot , Rob Herring , Lina Iyer , Rajendra Nayak , "devicetree@vger.kernel.org" From: Sudeep Holla Organization: ARM Message-ID: Date: Thu, 20 Apr 2017 10:51:27 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/04/17 09:23, Ulf Hansson wrote: > Viresh, Sudeep, > > Sorry for jumping in late. > > [...] > >>> On the contrary(playing devil's advocate here), we can treat all >>> existing regulators alone as OPP then if you strip the voltages and >>> treat it as abstract number. >> >> But then we are going to have lots of platform specific code which >> will program the actual hardware, etc. Which is all handled by the >> regulator framework. Also note that the regulator core selects the >> common voltage selected by all the children, while we want to select >> the highest performance point here. > > If I understand correctly, Sudeep is not convinced that this is about > PM domain regulator(s), right? > No, I am saying that it has to be modeled as regulators or some kind of advanced regulators. I am against modeling it as some new feature and using similar terminology that are quite close to OPP/CPPC in which case it's quite hard not to misunderstand the concepts and eventually use these bindings incorrectly. > To me there is no doubt, these regulators is exactly the definition of > PM domain regulators. > +1 > That said, long time ago we have decided PM domain regulator shall be > modeled as exactly that. From DT point of view, this means the handle > to the PM domain regulator belongs in the node of the PM domain > controller - and not in each device's node of those belonging to the > PM domain. > > Isn't that what this discussion really boils down to? Or maybe I am > not getting it. > I completely agree with you on all the above points. I am against the performance state terminology. Since the regulators and OPP are already defined in the bindings, all we need to explicitly state(if not already) is that there are hierarchical. -- Regards, Sudeep