118 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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|  * Licensed under the GPL
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|  */
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| 
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| #include <linux/clockchips.h>
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| #include <linux/init.h>
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| #include <linux/interrupt.h>
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| #include <linux/jiffies.h>
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| #include <linux/threads.h>
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| #include <asm/irq.h>
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| #include <asm/param.h>
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| #include "kern_util.h"
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| #include "os.h"
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| 
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| void timer_handler(int sig, struct uml_pt_regs *regs)
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| {
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| 	unsigned long flags;
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| 
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| 	local_irq_save(flags);
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| 	do_IRQ(TIMER_IRQ, regs);
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| 	local_irq_restore(flags);
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| }
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| 
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| static void itimer_set_mode(enum clock_event_mode mode,
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| 			    struct clock_event_device *evt)
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| {
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| 	switch (mode) {
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| 	case CLOCK_EVT_MODE_PERIODIC:
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| 		set_interval();
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| 		break;
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| 
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| 	case CLOCK_EVT_MODE_SHUTDOWN:
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| 	case CLOCK_EVT_MODE_UNUSED:
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| 	case CLOCK_EVT_MODE_ONESHOT:
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| 		disable_timer();
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| 		break;
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| 
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| 	case CLOCK_EVT_MODE_RESUME:
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| 		break;
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| 	}
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| }
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| 
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| static int itimer_next_event(unsigned long delta,
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| 			     struct clock_event_device *evt)
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| {
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| 	return timer_one_shot(delta + 1);
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| }
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| 
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| static struct clock_event_device itimer_clockevent = {
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| 	.name		= "itimer",
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| 	.rating		= 250,
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| 	.cpumask	= cpu_all_mask,
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| 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
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| 	.set_mode	= itimer_set_mode,
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| 	.set_next_event = itimer_next_event,
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| 	.shift		= 32,
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| 	.irq		= 0,
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| };
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| 
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| static irqreturn_t um_timer(int irq, void *dev)
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| {
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| 	(*itimer_clockevent.event_handler)(&itimer_clockevent);
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static cycle_t itimer_read(struct clocksource *cs)
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| {
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| 	return os_nsecs() / 1000;
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| }
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| 
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| static struct clocksource itimer_clocksource = {
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| 	.name		= "itimer",
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| 	.rating		= 300,
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| 	.read		= itimer_read,
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| 	.mask		= CLOCKSOURCE_MASK(64),
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| 	.mult		= 1000,
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| 	.shift		= 0,
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| 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
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| };
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| 
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| static void __init setup_itimer(void)
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| {
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| 	int err;
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| 
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| 	err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
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| 	if (err != 0)
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| 		printk(KERN_ERR "register_timer : request_irq failed - "
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| 		       "errno = %d\n", -err);
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| 
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| 	itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32);
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| 	itimer_clockevent.max_delta_ns =
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| 		clockevent_delta2ns(60 * HZ, &itimer_clockevent);
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| 	itimer_clockevent.min_delta_ns =
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| 		clockevent_delta2ns(1, &itimer_clockevent);
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| 	err = clocksource_register(&itimer_clocksource);
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| 	if (err) {
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| 		printk(KERN_ERR "clocksource_register returned %d\n", err);
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| 		return;
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| 	}
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| 	clockevents_register_device(&itimer_clockevent);
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| }
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| 
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| void __init time_init(void)
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| {
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| 	long long nsecs;
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| 
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| 	timer_init();
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| 
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| 	nsecs = os_nsecs();
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| 	set_normalized_timespec(&wall_to_monotonic, -nsecs / NSEC_PER_SEC,
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| 				-nsecs % NSEC_PER_SEC);
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| 	set_normalized_timespec(&xtime, nsecs / NSEC_PER_SEC,
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| 				nsecs % NSEC_PER_SEC);
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| 	late_time_init = setup_itimer;
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| }
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