From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH v7 5/8] CPPC: Add a CPUFreq driver for use with CPPC Date: Mon, 20 Jul 2015 15:22:09 +0100 Message-ID: <55AD0411.4000603@arm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Ashwin Chaugule Cc: "rjw@rjwysocki.net" , "jaswinder.singh@linaro.org" , Sudeep Holla , "linux-pm@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "linaro-acpi@lists.linaro.org" , "patches@linaro.org" , "viresh.kumar@linaro.org" List-Id: linux-acpi@vger.kernel.org On 09/07/15 19:04, Ashwin Chaugule wrote: > This driver utilizes the methods introduced in the previous > patch - "ACPI: Introduce CPU performance controls using CPPC" > and enables usage with existing CPUFreq governors. > > Signed-off-by: Ashwin Chaugule > Reviewed-by: Al Stone > --- > drivers/cpufreq/Kconfig.arm | 16 ++++ > drivers/cpufreq/Makefile | 2 + > drivers/cpufreq/cppc_cpufreq.c | 197 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 215 insertions(+) > create mode 100644 drivers/cpufreq/cppc_cpufreq.c > > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > index 4f3dbc8..578384d 100644 > --- a/drivers/cpufreq/Kconfig.arm > +++ b/drivers/cpufreq/Kconfig.arm > @@ -272,3 +272,19 @@ config ARM_PXA2xx_CPUFREQ > This add the CPUFreq driver support for Intel PXA2xx SOCs. > > If in doubt, say N. > + > +config ACPI_CPPC_CPUFREQ > + tristate "CPUFreq driver based on the ACPI CPPC spec" > + depends on ACPI_CPPC_LIB > + default n > + help > + This adds a CPUFreq driver which uses CPPC methods > + as described in the ACPIv5.1 spec. CPPC stands for > + Collaborative Processor Performance Controls. It > + is based on an abstract continuous scale of CPU > + performance values which allows the remote power > + processor to flexibly optimize for power and > + performance. CPPC relies on power management firmware > + for its operation. Why is this ARM specific ? It might be used only on ARM but doesn't mean it should be visible only on ARM ACPI systems. Regards, Sudeep