From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH v3 2/2] Documentation: devicetree: Add boost-frequency binding to list boost mode frequency Date: Wed, 14 May 2014 16:06:03 +0100 Message-ID: <5373865B.2040205@arm.com> References: <1400029380-5372-1-git-send-email-thomas.ab@samsung.com> <1400029380-5372-3-git-send-email-thomas.ab@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: 8BIT Return-path: Received: from service87.mimecast.com ([91.220.42.44]:53301 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753082AbaENPGF convert rfc822-to-8bit (ORCPT ); Wed, 14 May 2014 11:06:05 -0400 In-Reply-To: <1400029380-5372-3-git-send-email-thomas.ab@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Thomas Abraham , "linux-samsung-soc@vger.kernel.org" , "linux-pm@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Cc: Sudeep Holla , "rjw@rjwysocki.net" , "kgene.kim@samsung.com" , "t.figa@samsung.com" , "l.majewski@samsung.com" , "viresh.kumar@linaro.org" , "thomas.ab@samsung.com" , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala On 14/05/14 02:03, Thomas Abraham wrote: > From: Thomas Abraham > > Add a new optional boost-frequency binding for specifying the frequencies > usable in boost mode. > > Cc: Nishanth Menon > Cc: Lukasz Majewski > Cc: Rob Herring > Cc: Pawel Moll > Cc: Mark Rutland > Cc: Ian Campbell > Cc: Kumar Gala > Signed-off-by: Thomas Abraham > --- > .../devicetree/bindings/cpufreq/cpufreq-boost.txt | 11 +++++++++++ > 1 files changed, 11 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt > > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt > new file mode 100644 > index 0000000..d925e38 > --- /dev/null > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt > @@ -0,0 +1,11 @@ > +* Device tree binding for CPU boost frequency (aka over-clocking) > + > +Certain CPU's can be operated in optional 'boost' mode (or sometimes referred as > +overclocking) in which the CPU can operate in frequencies beyond the normal > +operating conditions. > + > +Optional Properties: > +- boost-frequency: list of frequencies in KHz to be used only in boost mode. > + This list should be a subset of frequencies listed in "operating-points" > + property. Refer to Documentation/devicetree/bindings/power/opp.txt for > + details about "operating-points" property. > Though I understand the need of it, I think the binding is designed to suffice the need of the boost frequency support in cpufreq. Typically SoC would provide characteristics like under-drive(hits performance but most energy efficient), nominal(highest sustained performance w/o any external constraint like power, thermal) and over-drive(maximum performance but not sustainable for long periods) IMO the binding could represent these unique points on the curve instead. Regards, Sudeep