From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jon Medhurst (Tixy)" Subject: Re: [PATCH 4/4] cpufreq: arm_big_little: add SCPI interface driver Date: Fri, 01 May 2015 14:19:38 +0100 Message-ID: <1430486378.3045.56.camel@linaro.org> References: <1430134846-24320-1-git-send-email-sudeep.holla@arm.com> <1430134846-24320-5-git-send-email-sudeep.holla@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1430134846-24320-5-git-send-email-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Sudeep Holla Cc: linux-kernel@vger.kernel.org, Liviu Dudau , Lorenzo Pieralisi , Viresh Kumar , "Rafael J. Wysocki" , linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org On Mon, 2015-04-27 at 12:40 +0100, Sudeep Holla wrote: > On some ARM based systems, a separate Cortex-M based System Control > Processor(SCP) provides the overall power, clock, reset and system > control including CPU DVFS. SCPI Message Protocol is used to > communicate with the SCPI. > > This patch adds a interface driver for adding OPPs and registering > the arm_big_little cpufreq driver for such systems. > > Signed-off-by: Sudeep Holla > Cc: Viresh Kumar > Cc: "Rafael J. Wysocki" > Cc: linux-pm@vger.kernel.org > --- > drivers/cpufreq/Kconfig.arm | 9 ++++ > drivers/cpufreq/Makefile | 1 + > drivers/cpufreq/scpi-cpufreq.c | 103 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 113 insertions(+) > create mode 100644 drivers/cpufreq/scpi-cpufreq.c > > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > index 4f3dbc8cf729..9e678bf1687c 100644 > --- a/drivers/cpufreq/Kconfig.arm > +++ b/drivers/cpufreq/Kconfig.arm > @@ -24,6 +24,15 @@ config ARM_VEXPRESS_SPC_CPUFREQ > This add the CPUfreq driver support for Versatile Express > big.LITTLE platforms using SPC for power management. > > +config ARM_SCPI_CPUFREQ > + tristate "SCPI based CPUfreq driver" > + depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL And ARM_BIG_LITTLE_CPUFREQ depends on CONFIG_ARM, so we can't build this for arm64, which is the only platform (Juno) we have to run these patches on. Unless you're prepared for a horrid hack... https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e or a pair of less horrid ones... http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa Any reason why the above two aren't suitable for mainline Linux? The second was actually committed then reverted because it broke arm64 builds, but the other patch fixes that. -- Tixy