On Friday 14 February 2014 04:49 AM, Tony Lindgren wrote: > * Lokesh Vutla <lokeshvutla@xxxxxx> [140207 02:24]: >> From: Rajendra Nayak <rnayak@xxxxxx> >> >> The SyncTimer in AM43x is clocked using the following two sources: >> 1) An inaccuarte 32k clock (CLK_32KHZ) derived from PER DPLL, causing system >> time to go slowly (~10% deviation). >> 2) external 32KHz RTC clock, which may not always be available on board like >> in the case of ePOS EVM >> >> Use gptimer as clocksource instead, as is done in the case of AM335x >> (which does not have a SyncTimer). With this, system time keeping works >> accurately. > > Hmm doesn't this also mean that PM for any deeper idle states won't > work properly? Thats true. This would mean we cannot put the peripheral/core domain down in idle. Suspend however can still work if suspend/resume callbacks are added to the clockevent and clocksource code to shut the non-wakeup domain timer. regards, Rajendra > > Regards, > > Tony > >> Signed-off-by: Rajendra Nayak <rnayak@xxxxxx> >> Signed-off-by: Lokesh Vutla <lokeshvutla@xxxxxx> >> --- >> arch/arm/mach-omap2/board-generic.c | 2 +- >> arch/arm/mach-omap2/timer.c | 3 ++- >> 2 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c >> index 8e3daa1..5679464a 100644 >> --- a/arch/arm/mach-omap2/board-generic.c >> +++ b/arch/arm/mach-omap2/board-generic.c >> @@ -229,7 +229,7 @@ DT_MACHINE_START(AM43_DT, "Generic AM43 (Flattened Device Tree)") >> .init_late = am43xx_init_late, >> .init_irq = omap_gic_of_init, >> .init_machine = omap_generic_init, >> - .init_time = omap3_sync32k_timer_init, >> + .init_time = omap3_gptimer_timer_init, >> .dt_compat = am43_boards_compat, >> MACHINE_END >> #endif >> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c >> index 74044aa..b62de9f 100644 >> --- a/arch/arm/mach-omap2/timer.c >> +++ b/arch/arm/mach-omap2/timer.c >> @@ -604,7 +604,8 @@ OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure", >> 2, "timer_sys_ck", NULL); >> #endif /* CONFIG_ARCH_OMAP3 */ >> >> -#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) >> +#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \ >> + defined(CONFIG_SOC_AM43XX) >> OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL, >> 1, "timer_sys_ck", "ti,timer-alwon"); >> #endif >> -- >> 1.7.9.5 >> -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
