/* *  linux/drivers/clocksource/dummy_timer.c * *  Copyright (C) 2013 ARM Ltd. *  All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */#include <linux/clockchips.h>#include <linux/cpu.h>#include <linux/init.h>#include <linux/percpu.h>#include <linux/cpumask.h> static DEFINE_PER_CPU(struct clock_event_device, dummy_timer_evt); static void dummy_timer_set_mode(enum clock_event_mode mode,			   struct clock_event_device *evt){	/*	 * Core clockevents code will call this when exchanging timer devices.	 * We don't need to do anything here.	 */} static void dummy_timer_setup(void){	int cpu = smp_processor_id();	struct clock_event_device *evt = __this_cpu_ptr(&dummy_timer_evt); 	evt->name	= "dummy_timer";	evt->features	= CLOCK_EVT_FEAT_PERIODIC |			  CLOCK_EVT_FEAT_ONESHOT |			  CLOCK_EVT_FEAT_DUMMY;	evt->rating	= 100;	evt->set_mode	= dummy_timer_set_mode;	evt->cpumask	= cpumask_of(cpu); 	clockevents_register_device(evt);} static int dummy_timer_cpu_notify(struct notifier_block *self,				      unsigned long action, void *hcpu){	if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING)		dummy_timer_setup(); 	return NOTIFY_OK;} static struct notifier_block dummy_timer_cpu_nb = {	.notifier_call = dummy_timer_cpu_notify,}; static int __init dummy_timer_register(void){	int err = register_cpu_notifier(&dummy_timer_cpu_nb);	if (err)		return err; 	/* We won't get a call on the boot CPU, so register immediately */	if (num_possible_cpus() > 1)		dummy_timer_setup(); 	return 0;}early_initcall(dummy_timer_register);