From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [PATCH v2 2/2] Documentation: devicetree: Add boost-frequency binding to list boost mode frequency Date: Fri, 7 Feb 2014 10:43:39 -0600 Message-ID: References: <1391786342-11812-1-git-send-email-thomas.ab@samsung.com> <1391786342-11812-3-git-send-email-thomas.ab@samsung.com> <52F50698.4060305@arm.com> <52F509BD.70903@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <52F509BD.70903@arm.com> Sender: linux-pm-owner@vger.kernel.org To: Sudeep Holla Cc: Thomas Abraham , "linux-pm@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "rjw@rjwysocki.net" , "linux-samsung-soc@vger.kernel.org" , "kgene.kim@samsung.com" , "t.figa@samsung.com" , "l.majewski@samsung.com" , "viresh.kumar@linaro.org" , "thomas.ab@samsung.com" , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org On Fri, Feb 7, 2014 at 10:28 AM, Sudeep Holla wrote: > On 07/02/14 16:15, Sudeep Holla wrote: >> On 07/02/14 15:19, 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 >>> --- >>> Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> 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. >>> >> >> Won't single entry for boost frequency suffice which would be the starting >> frequency in the boost range. IOW will there be OPP list with frequencies: >> A > B > C > D, but only B and C are boost frequency. That seems little odd, >> unless it's some configuration chosen purely on software basis rather than >> hardware. For me B marks the beginning of over-clocking. >> > Ah, I meant A < B < C < D in the above example. Should'nt we let the SoC dts define that - traditionally, yes, but consider the following: A, B, C uses clk_parent X which describes B, C as overclocked. and say D uses clk_parent Y which is not "over clocked", then you have the scenario that on the first look seems counter-intutive. Regards, Nishanth Menon