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// SPDX-License-Identifier: GPL-2.0
/*
* 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;
}
void __init setup_pit_timer(void)
{
unsigned long flags = IRQF_NOBALANCING | IRQF_TIMER;
clockevent_i8253_init(true);
if (request_irq(0, timer_interrupt, flags, "timer", NULL))
pr_err("Failed to request irq 0 (timer)\n");
}
static int __init init_pit_clocksource(void)
{
if (num_possible_cpus() > 1 || /* PIT does not scale! */
!clockevent_state_periodic(&i8253_clockevent))
return 0;
return clocksource_i8253_init();
}
arch_initcall(init_pit_clocksource);
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