projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 06470651 MR |
1 | /* |
| 2 | * linux/drivers/clocksource/dummy_timer.c | |
| 3 | * | |
| 4 | * Copyright (C) 2013 ARM Ltd. | |
| 5 | * All Rights Reserved | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | #include <linux/clockchips.h> | |
| 12 | #include <linux/cpu.h> | |
| 13 | #include <linux/init.h> | |
| 14 | #include <linux/percpu.h> | |
| 15 | #include <linux/cpumask.h> | |
| 16 | ||
| 17 | static DEFINE_PER_CPU(struct clock_event_device, dummy_timer_evt); | |
| 18 | ||
| 19 | static void dummy_timer_set_mode(enum clock_event_mode mode, | |
| 20 | struct clock_event_device *evt) | |
| 21 | { | |
| 22 | /* | |
| 23 | * Core clockevents code will call this when exchanging timer devices. | |
| 24 | * We don't need to do anything here. | |
| 25 | */ | |
| 26 | } | |
| 27 | ||
| 8c37bb3a | 28 | static void dummy_timer_setup(void) |
| 06470651 MR |
29 | { |
| 30 | int cpu = smp_processor_id(); | |
| 31 | struct clock_event_device *evt = __this_cpu_ptr(&dummy_timer_evt); | |
| 32 | ||
| 33 | evt->name = "dummy_timer"; | |
| 34 | evt->features = CLOCK_EVT_FEAT_PERIODIC | | |
| 35 | CLOCK_EVT_FEAT_ONESHOT | | |
| 36 | CLOCK_EVT_FEAT_DUMMY; | |
| 37 | evt->rating = 100; | |
| 38 | evt->set_mode = dummy_timer_set_mode; | |
| 39 | evt->cpumask = cpumask_of(cpu); | |
| 40 | ||
| 41 | clockevents_register_device(evt); | |
| 42 | } | |
| 43 | ||
| 8c37bb3a | 44 | static int dummy_timer_cpu_notify(struct notifier_block *self, |
| 06470651 MR |
45 | unsigned long action, void *hcpu) |
| 46 | { | |
| 47 | if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING) | |
| 48 | dummy_timer_setup(); | |
| 49 | ||
| 50 | return NOTIFY_OK; | |
| 51 | } | |
| 52 | ||
| 8c37bb3a | 53 | static struct notifier_block dummy_timer_cpu_nb = { |
| 06470651 MR |
54 | .notifier_call = dummy_timer_cpu_notify, |
| 55 | }; | |
| 56 | ||
| 57 | static int __init dummy_timer_register(void) | |
| 58 | { | |
| 59 | int err = register_cpu_notifier(&dummy_timer_cpu_nb); | |
| 60 | if (err) | |
| 61 | return err; | |
| 62 | ||
| 63 | /* We won't get a call on the boot CPU, so register immediately */ | |
| 64 | if (num_possible_cpus() > 1) | |
| 65 | dummy_timer_setup(); | |
| 66 | ||
| 67 | return 0; | |
| 68 | } | |
| 69 | early_initcall(dummy_timer_register); |