diff options
Diffstat (limited to 'arch/arm/mach-sa1100/time.c')
| -rw-r--r-- | arch/arm/mach-sa1100/time.c | 159 |
1 files changed, 65 insertions, 94 deletions
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c index c2677368d6a..a9799cb35b7 100644 --- a/arch/arm/mach-sa1100/time.c +++ b/arch/arm/mach-sa1100/time.c @@ -13,67 +13,69 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/timex.h> -#include <linux/signal.h> -#include <linux/clocksource.h> +#include <linux/clockchips.h> #include <asm/mach/time.h> #include <asm/hardware.h> -#define RTC_DEF_DIVIDER (32768 - 1) -#define RTC_DEF_TRIM 0 +#define MIN_OSCR_DELTA 2 -static int sa1100_set_rtc(void) +static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id) { - unsigned long current_time = xtime.tv_sec; + struct clock_event_device *c = dev_id; - if (RTSR & RTSR_ALE) { - /* make sure not to forward the clock over an alarm */ - unsigned long alarm = RTAR; - if (current_time >= alarm && alarm >= RCNR) - return -ERESTARTSYS; - } - RCNR = current_time; - return 0; -} + /* Disarm the compare/match, signal the event. */ + OIER &= ~OIER_E0; + OSSR = OSSR_M0; + c->event_handler(c); -#ifdef CONFIG_NO_IDLE_HZ -static unsigned long initial_match; -static int match_posponed; -#endif + return IRQ_HANDLED; +} -static irqreturn_t -sa1100_timer_interrupt(int irq, void *dev_id) +static int +sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c) { - unsigned int next_match; + unsigned long flags, next, oscr; -#ifdef CONFIG_NO_IDLE_HZ - if (match_posponed) { - match_posponed = 0; - OSMR0 = initial_match; - } -#endif + raw_local_irq_save(flags); + OIER |= OIER_E0; + next = OSCR + delta; + OSMR0 = next; + oscr = OSCR; + raw_local_irq_restore(flags); - /* - * Loop until we get ahead of the free running timer. - * This ensures an exact clock tick count and time accuracy. - * Since IRQs are disabled at this point, coherence between - * lost_ticks(updated in do_timer()) and the match reg value is - * ensured, hence we can use do_gettimeofday() from interrupt - * handlers. - */ - do { - timer_tick(); - OSSR = OSSR_M0; /* Clear match on timer 0 */ - next_match = (OSMR0 += LATCH); - } while ((signed long)(next_match - OSCR) <= 0); + return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0; +} - return IRQ_HANDLED; +static void +sa1100_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c) +{ + unsigned long flags; + + switch (mode) { + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + raw_local_irq_save(flags); + OIER &= ~OIER_E0; + OSSR = OSSR_M0; + raw_local_irq_restore(flags); + break; + + case CLOCK_EVT_MODE_RESUME: + case CLOCK_EVT_MODE_PERIODIC: + break; + } } -static struct irqaction sa1100_timer_irq = { - .name = "SA11xx Timer Tick", - .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, - .handler = sa1100_timer_interrupt, +static struct clock_event_device ckevt_sa1100_osmr0 = { + .name = "osmr0", + .features = CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .rating = 200, + .cpumask = CPU_MASK_CPU0, + .set_next_event = sa1100_osmr0_set_next_event, + .set_mode = sa1100_osmr0_set_mode, }; static cycle_t sa1100_read_oscr(void) @@ -90,62 +92,34 @@ static struct clocksource cksrc_sa1100_oscr = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static struct irqaction sa1100_timer_irq = { + .name = "ost0", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = sa1100_ost0_interrupt, + .dev_id = &ckevt_sa1100_osmr0, +}; + static void __init sa1100_timer_init(void) { - unsigned long flags; - - set_rtc = sa1100_set_rtc; - OIER = 0; /* disable any timer interrupts */ OSSR = 0xf; /* clear status on all timers */ - setup_irq(IRQ_OST0, &sa1100_timer_irq); - local_irq_save(flags); - OIER = OIER_E0; /* enable match on timer 0 to cause interrupts */ - OSMR0 = OSCR + LATCH; /* set initial match */ - local_irq_restore(flags); + + ckevt_sa1100_osmr0.mult = + div_sc(3686400, NSEC_PER_SEC, ckevt_sa1100_osmr0.shift); + ckevt_sa1100_osmr0.max_delta_ns = + clockevent_delta2ns(0x7fffffff, &ckevt_sa1100_osmr0); + ckevt_sa1100_osmr0.min_delta_ns = + clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_sa1100_osmr0) + 1; cksrc_sa1100_oscr.mult = clocksource_hz2mult(CLOCK_TICK_RATE, cksrc_sa1100_oscr.shift); - clocksource_register(&cksrc_sa1100_oscr); -} - -#ifdef CONFIG_NO_IDLE_HZ -static int sa1100_dyn_tick_enable_disable(void) -{ - /* nothing to do */ - return 0; -} - -static void sa1100_dyn_tick_reprogram(unsigned long ticks) -{ - if (ticks > 1) { - initial_match = OSMR0; - OSMR0 = initial_match + ticks * LATCH; - match_posponed = 1; - } -} + setup_irq(IRQ_OST0, &sa1100_timer_irq); -static irqreturn_t -sa1100_dyn_tick_handler(int irq, void *dev_id) -{ - if (match_posponed) { - match_posponed = 0; - OSMR0 = initial_match; - if ((signed long)(initial_match - OSCR) <= 0) - return sa1100_timer_interrupt(irq, dev_id); - } - return IRQ_NONE; + clocksource_register(&cksrc_sa1100_oscr); + clockevents_register_device(&ckevt_sa1100_osmr0); } -static struct dyn_tick_timer sa1100_dyn_tick = { - .enable = sa1100_dyn_tick_enable_disable, - .disable = sa1100_dyn_tick_enable_disable, - .reprogram = sa1100_dyn_tick_reprogram, - .handler = sa1100_dyn_tick_handler, -}; -#endif - #ifdef CONFIG_PM unsigned long osmr[4], oier; @@ -181,7 +155,4 @@ struct sys_timer sa1100_timer = { .init = sa1100_timer_init, .suspend = sa1100_timer_suspend, .resume = sa1100_timer_resume, -#ifdef CONFIG_NO_IDLE_HZ - .dyn_tick = &sa1100_dyn_tick, -#endif }; |