/* * i8253.c 8253/PIT functions * */ #include <linux/clockchips.h> #include <linux/i8253.h> #include <linux/export.h> #include <linux/smp.h> #include <linux/irq.h> #include <asm/time.h> static irqreturn_t timer_interrupt(int irq, void *dev_id) { i8253_clockevent.event_handler(&i8253_clockevent); return IRQ_HANDLED; } static struct irqaction irq0 = { .handler = timer_interrupt, .flags = IRQF_NOBALANCING | IRQF_TIMER, .name = "timer" }; void __init setup_pit_timer(void) { clockevent_i8253_init(true); setup_irq(0, &irq0); } static int __init init_pit_clocksource(void) { if (num_possible_cpus() > 1) /* PIT does not scale! */ return 0; return clocksource_i8253_init(); } arch_initcall(init_pit_clocksource);