1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/arm/mach-footbridge/isa-timer.c 4 * 5 * Copyright (C) 1998 Russell King. 6 * Copyright (C) 1998 Phil Blundell 7 */ 8 #include <linux/clockchips.h> 9 #include <linux/i8253.h> 10 #include <linux/init.h> 11 #include <linux/interrupt.h> 12 #include <linux/irq.h> 13 #include <linux/spinlock.h> 14 #include <linux/timex.h> 15 16 #include <asm/irq.h> 17 #include <asm/mach/time.h> 18 19 #include "common.h" 20 21 static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) 22 { 23 struct clock_event_device *ce = dev_id; 24 ce->event_handler(ce); 25 return IRQ_HANDLED; 26 } 27 28 void __init isa_timer_init(void) 29 { 30 clocksource_i8253_init(); 31 32 if (request_irq(i8253_clockevent.irq, pit_timer_interrupt, 33 IRQF_TIMER | IRQF_IRQPOLL, "pit", &i8253_clockevent)) 34 pr_err("Failed to request irq %d(pit)\n", i8253_clockevent.irq); 35 clockevent_i8253_init(false); 36 } 37