On 04/04/2025, Youngmin Nam wrote:
> On Wed, Apr 02, 2025 at 04:33:51PM -0700, Will McVicker wrote:
> > This series adds support to build the Arm64 Exynos MCT driver as a module. This
> > is only possible on Arm64 SoCs since they can use the Arm architected timer as
> > the clocksource. Once the Exynos MCT module is loaded and the device probes,
> > the MCT is used as the wakeup source for the arch_timer to ensure the device
> > can wakeup from the "c2" idle state.
> >
> > These patches are originally from the downstream Pixel 6 (gs101) kernel found
> > at [1] and have been adapted for upstream. Not only has the Exynos MCT driver
> > been shipping as a module in the field with Android, but I've also tested this
> > seris with the upstream kernel on my Pixel 6 Pro.
> >
> > Thanks,
> > Will
> >
> > Note1, instructions to build and flash a Pixel 6 device with the upstream kernel
> > can be found at [2].
> >
> > Note2, this series is based off of linux-next/master commit 405e2241def8 ("Add
> > linux-next specific files for 20250331").
> >
> > [1] https://android.googlesource.com/kernel/gs/+log/refs/heads/android-gs-raviole-5.10-android12-d1
> > [2] https://protect2.fireeye.com/v1/url?k=d287bb1b-b30cae21-d2863054-74fe4860008a-f0cb7ae29f3b1b85&q=1&e=4e8467a4-13da-4dd4-a8fd-4ddfc38e89b4&u=https%3A%2F%2Fgit.codelinaro.org%2Flinaro%2Fgooglelt%2Fpixelscripts%2F-%2Fblob%2Fclo%2Fmain%2FREADME.md%3Fref_type%3Dheads
> >
> > Cc: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> > Cc: Donghoon Yu <hoony.yu@xxxxxxxxxxx>
> > Cc: Hosung Kim <hosung0.kim@xxxxxxxxxxx>
> > Cc: kernel-team@xxxxxxxxxxx
> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: Rob Herring <robh@xxxxxxxxxx>
> > Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Youngmin Nam <youngmin.nam@xxxxxxxxxxx>
> > Cc: Peter Griffin <peter.griffin@xxxxxxxxxx>
> > Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
> > Cc: André Draszik <andre.draszik@xxxxxxxxxx>
> > Cc: Will Deacon <will@xxxxxxxxxx>
> > Cc: Conor Dooley <conor+dt@xxxxxxxxxx>
> > Cc: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > Cc: linux-samsung-soc@xxxxxxxxxxxxxxx
> >
> > ---
> > Changes in v2:
> > - Re-worked patch v1 5 based on Rob Herring's review to use the compatible data
> > for retrieving the mct_init function pointer.
> > - Updated the Kconfig logic to disallow building the Exynos MCT driver as
> > a module for ARM32 configurations based on Krzysztof Kozlowski's findings.
> > - Added comments and clarified commit messages in patches 1 and 2 based on
> > reviews from John Stultz and Youngmin Nam.
> > - Fixed an issue found during testing that resulted in the device getting
> > stuck on boot. This is included in v2 as patch 5.
> > - Collected *-by tags
> > - Rebased to the latest linux-next/master.
> >
> > ---
> > Donghoon Yu (1):
> > clocksource/drivers/exynos_mct: Add module support
> >
> > Hosung Kim (1):
> > clocksource/drivers/exynos_mct: Set local timer interrupts as percpu
> >
> > Will Deacon (1):
> > arm64: dts: exynos: gs101: Add 'local-timer-stop' to cpuidle nodes
> >
> > Will McVicker (4):
> > of/irq: Export of_irq_count for modules
> > clocksource/drivers/exynos_mct: Don't register as a sched_clock on
> > arm64
> > clocksource/drivers/exynos_mct: Fix uninitialized irq name warning
> > arm64: exynos: Drop select CLKSRC_EXYNOS_MCT
> >
> > arch/arm64/Kconfig.platforms | 1 -
> > arch/arm64/boot/dts/exynos/google/gs101.dtsi | 3 +
> > drivers/clocksource/Kconfig | 3 +-
> > drivers/clocksource/exynos_mct.c | 73 ++++++++++++++++----
> > drivers/of/irq.c | 1 +
> > 5 files changed, 67 insertions(+), 14 deletions(-)
> >
> > --
> > 2.49.0.472.ge94155a9ec-goog
> >
> >
>
> Hi Will.
>
> I tested this series on a E850-96(Exynos3830 based) board and it's working as a moudle.
>
> # dmesg | grep mct
> [7.376224] clocksource: mct-frc: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 73510017198 ns
>
> # lsmod | grep exynos_mct
> exynos_mct 12288 0
>
> # cat /sys/devices/system/clocksource/clocksource0/current_clocksource
> arch_sys_counter
> # cat /sys/devices/system/clockevents/clockevent0/current_device
> arch_sys_timer
>
> # cat /proc/interrupts
> CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
> 12: 2566 2752 2467 4026 3372 2822 2115 3227 GIC-0 27 Level arch_timer
> ...
> 77: 0 0 0 0 0 0 0 0 GIC-0 235 Level mct_comp_irq
> 78: 0 0 0 0 0 0 0 0 GIC-0 239 Level mct_tick0
> 79: 0 0 0 0 0 0 0 0 GIC-0 240 Level mct_tick1
> 80: 0 0 0 0 0 0 0 0 GIC-0 241 Level mct_tick2
> 81: 0 0 0 0 0 0 0 0 GIC-0 242 Level mct_tick3
> 82: 0 0 0 0 0 0 0 0 GIC-0 243 Level mct_tick4
> 83: 0 0 0 0 0 0 0 0 GIC-0 244 Level mct_tick5
> 84: 0 0 0 0 0 0 0 0 GIC-0 245 Level mct_tick6
> 85: 0 0 0 0 0 0 0 0 GIC-0 246 Level mct_tick7
>
> Reviewed-by: Youngmin Nam <youngmin.nam@xxxxxxxxxxx>
> Tested-by: Youngmin Nam <youngmin.nam@xxxxxxxxxxx>
>
> Thanks,
> Youngmin
Thanks Youngmin for the reviews and testing!
Regards,
Will
