From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754162AbdEFVol (ORCPT ); Sat, 6 May 2017 17:44:41 -0400 Received: from mail-pg0-f41.google.com ([74.125.83.41]:32978 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341AbdEFVod (ORCPT ); Sat, 6 May 2017 17:44:33 -0400 From: Kevin Hilman To: Sudeep Holla Cc: Rob Herring , Viresh Kumar , Rafael Wysocki , ulf.hansson@linaro.org, Viresh Kumar , Nishanth Menon , Stephen Boyd , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Guittot , lina.iyer@linaro.org, rnayak@codeaurora.org, devicetree@vger.kernel.org Subject: Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Organization: BayLibre References: <025acedb263eaa6089d354d9630214ada8013990.1493203884.git.viresh.kumar@linaro.org> <20170428204803.plu467okibtxga4d@rob-hp-laptop> Date: Sat, 06 May 2017 11:39:08 +0200 In-Reply-To: (Sudeep Holla's message of "Wed, 3 May 2017 12:29:21 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (darwin) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sudeep Holla writes: > On 28/04/17 21:48, Rob Herring wrote: >> On Wed, Apr 26, 2017 at 04:27:05PM +0530, Viresh Kumar wrote: >>> Power-domains need to express their active states in DT and the devices >>> within the power-domain need to express their dependency on those active >>> states. The power-domains can use the OPP tables without any >>> modifications to the bindings. >>> >>> Add a new property "power-domain-opp", which will contain phandle to the >>> OPP node of the parent power domain. This is required for devices which >>> have dependency on the configured active state of the power domain for >>> their working. >>> >>> For some platforms the actual frequency and voltages of the power >>> domains are managed by the firmware and are so hidden from the high >>> level operating system. The "opp-hz" property is relaxed a bit to >>> contain indexes instead of actual frequency values to support such >>> platforms. >>> >>> Signed-off-by: Viresh Kumar >>> --- >>> Documentation/devicetree/bindings/opp/opp.txt | 74 ++++++++++++++++++++++++++- >>> 1 file changed, 73 insertions(+), 1 deletion(-) >>> >>> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt >>> index 63725498bd20..6e30cae2a936 100644 >>> --- a/Documentation/devicetree/bindings/opp/opp.txt >>> +++ b/Documentation/devicetree/bindings/opp/opp.txt >>> @@ -77,7 +77,10 @@ This defines voltage-current-frequency combinations along with other related >>> properties. >>> >>> Required properties: >>> -- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer. >>> +- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer. In some >>> + cases the exact frequency in Hz may be hidden from the OS by the firmware and >>> + this field may contain values that represent the frequency in a firmware >>> + dependent way, for example an index of an array in the firmware. >> >> Not really sure OPP binding makes sense here. What about all the other >> properties. We expose voltage, but not freq? >> > > I completely agree with that and I have been pushing this to be > represented as just regulators[0]. Mark B seem to dislike that > idea [1] And Mark is right, because what's being described is not (simply) a voltage regultor. While it might be "just" voltage on some SoCs (for now), it is clearly about performance (a.k.a. OPP) on others. Kevin