/*

   * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)

   * Licensed under the GPL
   */

  #include <linux/clockchips.h>

  #include <linux/init.h>

  #include <linux/interrupt.h>
  #include <linux/jiffies.h>
  #include <linux/threads.h>
  #include <asm/irq.h>
  #include <asm/param.h>

  #include "kern_util.h"

  #include "os.h"

  void timer_handler(int sig, struct uml_pt_regs *regs)

  {

  	unsigned long flags;

  
  	local_irq_save(flags);

  	do_IRQ(TIMER_IRQ, regs);

  	local_irq_restore(flags);

  }

  static void itimer_set_mode(enum clock_event_mode mode,
  			    struct clock_event_device *evt)

  {

  	switch (mode) {

  	case CLOCK_EVT_MODE_PERIODIC:
  		set_interval();
  		break;
  
  	case CLOCK_EVT_MODE_SHUTDOWN:
  	case CLOCK_EVT_MODE_UNUSED:

  	case CLOCK_EVT_MODE_ONESHOT:

  		disable_timer();

  		break;
  
  	case CLOCK_EVT_MODE_RESUME:
  		break;
  	}

  }

  static int itimer_next_event(unsigned long delta,
  			     struct clock_event_device *evt)
  {
  	return timer_one_shot(delta + 1);
  }

  static struct clock_event_device itimer_clockevent = {
  	.name		= "itimer",
  	.rating		= 250,

  	.cpumask	= cpu_all_mask,

  	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,

  	.set_mode	= itimer_set_mode,

  	.set_next_event = itimer_next_event,

  	.shift		= 32,
  	.irq		= 0,
  };
  
  static irqreturn_t um_timer(int irq, void *dev)

  {

  	(*itimer_clockevent.event_handler)(&itimer_clockevent);

  	return IRQ_HANDLED;

  }

  static cycle_t itimer_read(struct clocksource *cs)

  {

  	return os_nsecs() / 1000;

  }
  
  static struct clocksource itimer_clocksource = {
  	.name		= "itimer",
  	.rating		= 300,
  	.read		= itimer_read,
  	.mask		= CLOCKSOURCE_MASK(64),

  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
  };

  static void __init setup_itimer(void)

  {
  	int err;
  
  	err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);

  	if (err != 0)

  		printk(KERN_ERR "register_timer : request_irq failed - "

  		       "errno = %d
  ", -err);

  	itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32);
  	itimer_clockevent.max_delta_ns =
  		clockevent_delta2ns(60 * HZ, &itimer_clockevent);
  	itimer_clockevent.min_delta_ns =
  		clockevent_delta2ns(1, &itimer_clockevent);

  	err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);

  	if (err) {

  		printk(KERN_ERR "clocksource_register_hz returned %d
  ", err);

  		return;
  	}

  	clockevents_register_device(&itimer_clockevent);

  }

  void read_persistent_clock(struct timespec *ts)
  {

  	long long nsecs = os_nsecs();

  	set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
  				nsecs % NSEC_PER_SEC);
  }

  void __init time_init(void)

  {

  	timer_init();

  	late_time_init = setup_itimer;

  }