On Fri, 2015-05-01 at 14:32 +0100, Sudeep Holla wrote: > > On 01/05/15 14:19, Jon Medhurst (Tixy) wrote: > > 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 <sudeep.ho...@arm.com> > >> Cc: Viresh Kumar <viresh.ku...@linaro.org> > >> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net> > >> Cc: linux...@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. > > Yes I know > > > Unless you're prepared for a horrid hack... > > https://github.com/ARM-software/linux/commit/b9ceaa0cbd7c57d57ee7e69146cc627697570f6e > > I need to check if it can be improved before I post on the list and > hence dropped it in the first version of this patch-set. > > > or a pair of less horrid ones... > > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/4b5dd8ff98613b7e90c8f3214522a00ab6900fe9 > > No not this one, this was already discussed long back I believe. > It doesn't make sense to add bl-switcher for ARM64 IMO. > > > http://git.linaro.org/kernel/linux-linaro-tracking.git/commit/8641dbfe253f6a9061742ca11f769fc1d82c2aaa > > > > Yes the Kconfig changes looks better than what I have now. > > > 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. > > > Yes IMO since arm-big-little also supports multi-cluster cpufreq(yes I > know it can be merged into cpufreq-dt once we have OPPv2 bindings, but > until then), it should handle the config where CONFIG_BL_SWITCHER=n and > that's what I have attempted in my patch above.
OK, that all makes sense, just wanted to make sure things didn't get overlooked, because having code that has no users in mainline seemed a bit odd. -- Tixy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
