1/*
2 * i8253.c  8253/PIT functions
3 *
4 */
5#include <linux/clockchips.h>
6#include <linux/i8253.h>
7#include <linux/export.h>
8#include <linux/smp.h>
9#include <linux/irq.h>
10
11#include <asm/time.h>
12
13static irqreturn_t timer_interrupt(int irq, void *dev_id)
14{
15	i8253_clockevent.event_handler(&i8253_clockevent);
16
17	return IRQ_HANDLED;
18}
19
20static struct irqaction irq0  = {
21	.handler = timer_interrupt,
22	.flags = IRQF_NOBALANCING | IRQF_TIMER,
23	.name = "timer"
24};
25
26void __init setup_pit_timer(void)
27{
28	clockevent_i8253_init(true);
29	setup_irq(0, &irq0);
30}
31
32static int __init init_pit_clocksource(void)
33{
34	if (num_possible_cpus() > 1) /* PIT does not scale! */
35		return 0;
36
37	return clocksource_i8253_init();
38}
39arch_initcall(init_pit_clocksource);
40