diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/dummy_timer.c | 69 |
2 files changed, 70 insertions, 0 deletions
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 4853ea0f8fd5..9ba8b4d867e3 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -31,3 +31,4 @@ obj-$(CONFIG_VF_PIT_TIMER) += vf_pit_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o +obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o diff --git a/drivers/clocksource/dummy_timer.c b/drivers/clocksource/dummy_timer.c new file mode 100644 index 000000000000..1f55f9620338 --- /dev/null +++ b/drivers/clocksource/dummy_timer.c @@ -0,0 +1,69 @@ +/* + * 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 __cpuinit 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 __cpuinit 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 __cpuinitdata = { + .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); |