On 13/11/2015 13:48, Grygorii Strashko wrote: > On 11/12/2015 08:06 PM, Felipe Balbi wrote: >> Make sure to tell the kernel that AM437x has >> TWD and global timers. >> >> Signed-off-by: Felipe Balbi <ba...@ti.com> >> --- >> >> Hi Tony, >> >> now that all dependencies are in place, we can >> finally enable twd and global_timer for AM437x. >> > > I'd appreciated if someone can clarify if all described below is valid. > (may be some questions are dummy - sorry). > > After all last changes related to TI OMAP clock source/clock event/sched > clock's > devices configuration we will have the following for am437x case: > > clockevents: > "timer1", clockevent_gpt, .rating = 300, CLOCK_EVT_FEAT_PERIODIC | > CLOCK_EVT_FEAT_ONESHOT, ti,timer-alwon, > "arm,twd-timer", twd_evt,.rating = 350, CLOCK_EVT_FEAT_PERIODIC | > CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP > "arm_global_timer", gt_evt, rating = 300, CLOCK_EVT_FEAT_PERIODIC | > CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERCPU
NB: AFAIU/IIUC the global timer ticks at cpuclk/N but the driver does not deal with frequency updates (unlike smp_twd.c) I'm not sure global timer can be used reliably together with cpufreq. > clocksources: > "jiffies", clocksource_jiffies, rating = 1 > if use_gptimer_clksrc > "timer2", clocksource_gpt, .rating = 300, CLOCK_SOURCE_IS_CONTINUOUS, > |-sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate); > else > "ti,omap-counter32k", ti_32k_timer, .rating = 250, > CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP, > |-sched_clock_register(omap_32k_read_sched_clock, 32, 32768); > > "arm,global-timer", gt_clocksource, .rating = 300, CLOCK_SOURCE_IS_CONTINUOUS If using cpufreq, I don't think the global timer can be used as a clock source. Again AFAIU and IIUC and I may be wrong. Regards. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
