From 730c1fad0ee22a170d2ee76a904709ee304931c0 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Wed, 27 Oct 2010 17:28:57 +0100 Subject: MN10300: Generic time support Implement generic time support for MN10300. Signed-off-by: Mark Salter Signed-off-by: David Howells --- arch/mn10300/kernel/time.c | 79 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 61 insertions(+), 18 deletions(-) (limited to 'arch/mn10300/kernel/time.c') diff --git a/arch/mn10300/kernel/time.c b/arch/mn10300/kernel/time.c index 0cb9bdb3b6bd..f860a340acc9 100644 --- a/arch/mn10300/kernel/time.c +++ b/arch/mn10300/kernel/time.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include #include #include #include @@ -27,14 +29,6 @@ static unsigned long mn10300_last_tsc; /* time-stamp counter at last time * interrupt occurred */ -static irqreturn_t timer_interrupt(int irq, void *dev_id); - -static struct irqaction timer_irq = { - .handler = timer_interrupt, - .flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER, - .name = "timer", -}; - static unsigned long sched_clock_multiplier; /* @@ -54,7 +48,7 @@ unsigned long long sched_clock(void) /* read the TSC value */ - tsc = 0 - get_cycles(); /* get_cycles() counts down */ + tsc = get_cycles(); /* expand to 64-bits. * - sched_clock() must be called once a minute or better or the @@ -103,6 +97,7 @@ irqreturn_t local_timer_interrupt(void) return IRQ_HANDLED; } +#ifndef CONFIG_GENERIC_TIME /* * advance the kernel's time keeping clocks (xtime and jiffies) * - we use Timer 0 & 1 cascaded as a clock to nudge us the next time @@ -116,11 +111,11 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) write_seqlock(&xtime_lock); while (tsc = get_cycles(), - elapse = mn10300_last_tsc - tsc, /* time elapsed since last + elapse = tsc - mn10300_last_tsc, /* time elapsed since last * tick */ elapse > MN10300_TSC_PER_HZ ) { - mn10300_last_tsc -= MN10300_TSC_PER_HZ; + mn10300_last_tsc += MN10300_TSC_PER_HZ; /* advance the kernel's time tracking system */ do_timer(1); @@ -135,6 +130,50 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) return ret; } +static struct irqaction timer_irq = { + .handler = timer_interrupt, + .flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER, + .name = "timer", +}; +#endif /* CONFIG_GENERIC_TIME */ + +#ifdef CONFIG_CSRC_MN10300 +void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock) +{ + u64 temp; + u32 shift; + + /* Find a shift value */ + for (shift = 32; shift > 0; shift--) { + temp = (u64) NSEC_PER_SEC << shift; + do_div(temp, clock); + if ((temp >> 32) == 0) + break; + } + cs->shift = shift; + cs->mult = (u32) temp; +} +#endif + +#if CONFIG_CEVT_MN10300 +void __cpuinit clockevent_set_clock(struct clock_event_device *cd, + unsigned int clock) +{ + u64 temp; + u32 shift; + + /* Find a shift value */ + for (shift = 32; shift > 0; shift--) { + temp = (u64) clock << shift; + do_div(temp, NSEC_PER_SEC); + if ((temp >> 32) == 0) + break; + } + cd->shift = shift; + cd->mult = (u32) temp; +} +#endif + /* * initialise the various timers used by the main part of the kernel */ @@ -146,21 +185,25 @@ void __init time_init(void) */ TMPSCNT |= TMPSCNT_ENABLE; +#ifdef CONFIG_GENERIC_TIME + init_clocksource(); +#else startup_timestamp_counter(); +#endif printk(KERN_INFO "timestamp counter I/O clock running at %lu.%02lu" " (calibrated against RTC)\n", MN10300_TSCCLK / 1000000, (MN10300_TSCCLK / 10000) % 100); - mn10300_last_tsc = TMTSCBC; + mn10300_last_tsc = read_timestamp_counter(); - /* use timer 0 & 1 cascaded to tick at as close to HZ as possible */ - setup_irq(TMJCIRQ, &timer_irq); - - set_intr_level(TMJCIRQ, NUM2GxICR_LEVEL(CONFIG_TIMER_IRQ_LEVEL)); - - startup_jiffies_counter(); +#ifdef CONFIG_GENERIC_CLOCKEVENTS + init_clockevents(); +#else + reload_jiffies_counter(MN10300_JC_PER_HZ - 1); + setup_jiffies_interrupt(TMJCIRQ, &timer_irq, CONFIG_TIMER_IRQ_LEVEL); +#endif #ifdef CONFIG_MN10300_WD_TIMER /* start the watchdog timer */ -- cgit v1.2.3