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Diffstat (limited to 'arch/arm/kernel/time.c')
| -rw-r--r-- | arch/arm/kernel/time.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c new file mode 100644 index 00000000..fe31b22f --- /dev/null +++ b/arch/arm/kernel/time.c @@ -0,0 +1,152 @@ +/* + * linux/arch/arm/kernel/time.c + * + * Copyright (C) 1991, 1992, 1995 Linus Torvalds + * Modifications for ARM (C) 1994-2001 Russell King + * + * 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. + * + * This file contains the ARM-specific time handling details: + * reading the RTC at bootup, etc... + */ +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/timex.h> +#include <linux/errno.h> +#include <linux/profile.h> +#include <linux/syscore_ops.h> +#include <linux/timer.h> +#include <linux/irq.h> + +#include <asm/leds.h> +#include <asm/thread_info.h> +#include <asm/sched_clock.h> +#include <asm/stacktrace.h> +#include <asm/mach/arch.h> +#include <asm/mach/time.h> + +/* + * Our system timer. + */ +static struct sys_timer *system_timer; + +#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \ + defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE) +/* this needs a better home */ +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL(rtc_lock); +#endif /* pc-style 'CMOS' RTC support */ + +/* change this if you have some constant time drift */ +#define USECS_PER_JIFFY (1000000/HZ) + +#ifdef CONFIG_SMP +unsigned long profile_pc(struct pt_regs *regs) +{ + struct stackframe frame; + + if (!in_lock_functions(regs->ARM_pc)) + return regs->ARM_pc; + + frame.fp = regs->ARM_fp; + frame.sp = regs->ARM_sp; + frame.lr = regs->ARM_lr; + frame.pc = regs->ARM_pc; + do { + int ret = unwind_frame(&frame); + if (ret < 0) + return 0; + } while (in_lock_functions(frame.pc)); + + return frame.pc; +} +EXPORT_SYMBOL(profile_pc); +#endif + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET +u32 arch_gettimeoffset(void) +{ + if (system_timer->offset != NULL) + return system_timer->offset() * 1000; + + return 0; +} +#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */ + +#ifdef CONFIG_LEDS_TIMER +static inline void do_leds(void) +{ + static unsigned int count = HZ/2; + + if (--count == 0) { + count = HZ/2; + leds_event(led_timer); + } +} +#else +#define do_leds() +#endif + + +#ifndef CONFIG_GENERIC_CLOCKEVENTS +/* + * Kernel system timer support. + */ +void timer_tick(void) +{ + profile_tick(CPU_PROFILING); + do_leds(); + xtime_update(1); +#ifndef CONFIG_SMP + update_process_times(user_mode(get_irq_regs())); +#endif +} +#endif + +#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) +static int timer_suspend(void) +{ + if (system_timer->suspend) + system_timer->suspend(); + + return 0; +} + +static void timer_resume(void) +{ + if (system_timer->resume) + system_timer->resume(); +} +#else +#define timer_suspend NULL +#define timer_resume NULL +#endif + +static struct syscore_ops timer_syscore_ops = { + .suspend = timer_suspend, + .resume = timer_resume, +}; + +static int __init timer_init_syscore_ops(void) +{ + register_syscore_ops(&timer_syscore_ops); + + return 0; +} + +device_initcall(timer_init_syscore_ops); + +void __init time_init(void) +{ + system_timer = machine_desc->timer; + system_timer->init(); + sched_clock_postinit(); +} + |