Messages in this thread | | | Date | Wed, 14 Jan 2015 17:02:03 +0100 | From | Daniel Lezcano <> | Subject | Re: [RESEND PATCH v3] clocksource: exynos_mct: Add the support for Exynos 64bit SoC |
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On 01/14/2015 04:51 PM, Kukjin Kim wrote: > On 01/14/15 14:33, Chanwoo Choi wrote: > > Hi, > > + Doug, Olof > >> This patch adds the support for Exynos 64bit SoC. The delay_timer is only used >> for Exynos 32bit SoC. >> > Yes, the Exynos MCT(Multi-Core Timer) is 64bit timer and it is available > on 64bit exynos SoC such as exynos7. But basically ARMv8 architecture is > including ARM ARCH timer (ARM Generic Timer) and exynos7 also has > implemented it and additionally its access is faster than using memory > mapped register called SFR for MCT...so Doug submitted patch to use MCT > on 32bit exynos SoCs before. > > I know using MCT on 64bit exynos is usefulness for Power Management and > I need to talk to relevant guys in office again. If anything, I'll let > you know.
I will wait for your answer before digging more the patch.
Thanks -- Daniel
>> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Kukjin Kim <kgene.kim@samsung.com> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> >> --- >> This patch set is tested on 64-bit Exynos SoC. I send only this patch from >> following patchst[1]. >> [1] https://lkml.org/lkml/2014/12/2/134 >> >> Changes from v2: >> - None >> Changes from v1: >> - Use CONFIG_ARM instead of CONFIG_ARM64 >> >> drivers/clocksource/Kconfig | 1 - >> drivers/clocksource/exynos_mct.c | 4 ++++ >> 2 files changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >> index fc01ec2..be38119 100644 >> --- a/drivers/clocksource/Kconfig >> +++ b/drivers/clocksource/Kconfig >> @@ -135,7 +135,6 @@ config CLKSRC_METAG_GENERIC >> >> config CLKSRC_EXYNOS_MCT >> def_bool y if ARCH_EXYNOS >> - depends on !ARM64 >> help >> Support for Multi Core Timer controller on Exynos SoCs. >> >> diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c >> index 9403061..b840ea1 100644 >> --- a/drivers/clocksource/exynos_mct.c >> +++ b/drivers/clocksource/exynos_mct.c >> @@ -223,6 +223,7 @@ static u64 notrace exynos4_read_sched_clock(void) >> return exynos4_read_count_32(); >> } >> >> +#if defined(CONFIG_ARM) >> static struct delay_timer exynos4_delay_timer; >> >> static cycles_t exynos4_read_current_timer(void) >> @@ -231,14 +232,17 @@ static cycles_t exynos4_read_current_timer(void) >> "cycles_t needs to move to 32-bit for ARM64 usage"); >> return exynos4_read_count_32(); >> } >> +#endif >> >> static void __init exynos4_clocksource_init(void) >> { >> exynos4_mct_frc_start(); >> >> +#if defined(CONFIG_ARM) >> exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; >> exynos4_delay_timer.freq = clk_rate; >> register_current_timer_delay(&exynos4_delay_timer); >> +#endif >> >> if (clocksource_register_hz(&mct_frc, clk_rate)) >> panic("%s: can't register clocksource\n", mct_frc.name);
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