| Message ID | 1391768486-2134-5-git-send-email-lokeshvutla@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Lokesh Vutla <lokeshvutla@ti.com> [140207 02:24]: > From: Rajendra Nayak <rnayak@ti.com> > > 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? Regards, Tony > Signed-off-by: Rajendra Nayak <rnayak@ti.com> > Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> > --- > 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 >
On Friday 14 February 2014 04:49 AM, Tony Lindgren wrote: > * Lokesh Vutla <lokeshvutla@ti.com> [140207 02:24]: >> From: Rajendra Nayak <rnayak@ti.com> >> >> 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@ti.com> >> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> >> --- >> 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 >>
Hi Tony, On Friday 14 February 2014 02:16 PM, Rajendra Nayak wrote: > On Friday 14 February 2014 04:49 AM, Tony Lindgren wrote: >> * Lokesh Vutla <lokeshvutla@ti.com> [140207 02:24]: >>> From: Rajendra Nayak <rnayak@ti.com> >>> >>> 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. This is a platform level limitation that only MPU domain can be put down in idle, just like AM335x. Thanks and regards, Lokesh > > regards, > Rajendra > >> >> Regards, >> >> Tony >> >>> Signed-off-by: Rajendra Nayak <rnayak@ti.com> >>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> >>> --- >>> 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 >>> >
* Lokesh Vutla <lokeshvutla@ti.com> [140224 05:08]: > Hi Tony, > On Friday 14 February 2014 02:16 PM, Rajendra Nayak wrote: > > On Friday 14 February 2014 04:49 AM, Tony Lindgren wrote: > >> * Lokesh Vutla <lokeshvutla@ti.com> [140207 02:24]: > >>> From: Rajendra Nayak <rnayak@ti.com> > >>> > >>> 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. > This is a platform level limitation that only MPU domain can be put down in idle, just like AM335x. OK applying all four into omap-for-v3.15/soc thanks. Tony
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