1234567891011121314151617181920212223242526272829303132333435363738 |
- // 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);
|