From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Date: Wed, 3 May 2017 12:29:21 +0100 Message-ID: References: <025acedb263eaa6089d354d9630214ada8013990.1493203884.git.viresh.kumar@linaro.org> <20170428204803.plu467okibtxga4d@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170428204803.plu467okibtxga4d@rob-hp-laptop> Sender: linux-pm-owner@vger.kernel.org To: Rob Herring , Viresh Kumar Cc: Sudeep Holla , Rafael Wysocki , ulf.hansson@linaro.org, Kevin Hilman , 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 List-Id: devicetree@vger.kernel.org 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] -- Regards, Sudeep [0] http://www.spinics.net/lists/devicetree/msg174725.html [1] http://www.spinics.net/lists/devicetree/msg175113.html