From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755009AbcKVDRZ (ORCPT ); Mon, 21 Nov 2016 22:17:25 -0500 Received: from mail-pg0-f50.google.com ([74.125.83.50]:35061 "EHLO mail-pg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754815AbcKVDRX (ORCPT ); Mon, 21 Nov 2016 22:17:23 -0500 Date: Tue, 22 Nov 2016 08:47:17 +0530 From: Viresh Kumar To: Rob Herring Cc: Rafael Wysocki , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Rutland , Kevin Hilman , Ulf Hansson , Vincent Guittot , Lina Iyer , devicetree@vger.kernel.org, Stephen Boyd , Nayak Rajendra Subject: Re: [PATCH 1/2] PM / Domains: Introduce domain-performance-state binding Message-ID: <20161122031717.GE10014@vireshk-i7> References: <20161121150708.j4gosfr2uetc7mwp@rob-hp-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161121150708.j4gosfr2uetc7mwp@rob-hp-laptop> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21-11-16, 09:07, Rob Herring wrote: > On Fri, Nov 18, 2016 at 02:53:12PM +0530, Viresh Kumar wrote: > > Some platforms have the capability to configure the performance state of > > their Power Domains. The performance levels are represented by positive > > integer values, a lower value represents lower performance state. > > > > The power-domains until now were only concentrating on the idle state > > management of the device and this needs to change in order to reuse the > > infrastructure of power domains for active state management. > > > > This patch introduces a new optional property for the consumers of the > > power-domains: domain-performance-state. > > > > If the consumers don't need the capability of switching to different > > domain performance states at runtime, then they can simply define their > > required domain performance state in their node directly. Otherwise the > > consumers can define their requirements with help of other > > infrastructure, for example the OPP table. > > > > Signed-off-by: Viresh Kumar > > --- > > Documentation/devicetree/bindings/power/power_domain.txt | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt > > index e1650364b296..db42eacf8b5c 100644 > > --- a/Documentation/devicetree/bindings/power/power_domain.txt > > +++ b/Documentation/devicetree/bindings/power/power_domain.txt > > @@ -106,6 +106,12 @@ domain provided by the 'parent' power controller. > > - power-domains : A phandle and PM domain specifier as defined by bindings of > > the power controller specified by phandle. > > > > +Optional properties: > > +- domain-performance-state: A positive integer value representing the minimum > > + performance level (of the parent domain) required by the consumer for its > > + working. The integer value '1' represents the lowest performance level and the > > + highest value represents the highest performance level. > > How does one come up with the range of values? Why would we need a range here? The value here represents the minimum 'state' and the assumption is that everything above that level would be fine. So the range is automatically: domain-performance-state -> MAX. > It seems like you are > just making up numbers. Couldn't the domain performance level be an OPP > in the sense that it is a collection of clock frequencies and voltage > settings? The clock is going to be handled by the device itself (at least for the case we have today) and the performance-state lies with the power-domain which is configured separately. If the performance level includes both clk and voltage, then why would we need to show the clock rates in the DT ? Wouldn't a performance level be enough in such cases? -- viresh