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/*
* 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/module.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/sysdev.h>
#include <linux/timer.h>
#include <linux/irq.h>
#include <linux/mc146818rtc.h>
#include <asm/leds.h>
#include <asm/thread_info.h>
#include <asm/stacktrace.h>
#include <asm/mach/time.h>
/*
* Our system timer.
*/
struct sys_timer *system_timer;
#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
/* this needs a better home */
DEFINE_SPINLOCK(rtc_lock);
#ifdef CONFIG_RTC_DRV_CMOS_MODULE
EXPORT_SYMBOL(rtc_lock);
#endif
#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
#ifndef CONFIG_GENERIC_TIME
static unsigned long dummy_gettimeoffset(void)
{
return 0;
}
#endif
#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_TIME
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = system_timer->offset();
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
/* usec may have gone up a lot: be safe */
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* done, and then undo it!
*/
nsec -= system_timer->offset() * NSEC_PER_USEC;
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
#endif /* !CONFIG_GENERIC_TIME */
#ifndef CONFIG_GENERIC_CLOCKEVENTS
/*
* Kernel system timer support.
*/
void timer_tick(void)
{
profile_tick(CPU_PROFILING);
do_leds();
write_seqlock(&xtime_lock);
do_timer(1);
write_sequnlock(&xtime_lock);
#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(struct sys_device *dev, pm_message_t state)
{
struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
if (timer->suspend != NULL)
timer->suspend();
return 0;
}
static int timer_resume(struct sys_device *dev)
{
struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
if (timer->resume != NULL)
timer->resume();
return 0;
}
#else
#define timer_suspend NULL
#define timer_resume NULL
#endif
static struct sysdev_class timer_sysclass = {
.name = "timer",
.suspend = timer_suspend,
.resume = timer_resume,
};
static int __init timer_init_sysfs(void)
{
int ret = sysdev_class_register(&timer_sysclass);
if (ret == 0) {
system_timer->dev.cls = &timer_sysclass;
ret = sysdev_register(&system_timer->dev);
}
return ret;
}
device_initcall(timer_init_sysfs);
void __init time_init(void)
{
#ifndef CONFIG_GENERIC_TIME
if (system_timer->offset == NULL)
system_timer->offset = dummy_gettimeoffset;
#endif
system_timer->init();
}
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