/*
* 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...
*
* 1994-07-02 Alan Modra
* fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
* 1998-12-20 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.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 <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/leds.h>
#include <asm/thread_info.h>
#include <asm/mach/time.h>
u64 jiffies_64 = INITIAL_JIFFIES;
EXPORT_SYMBOL(jiffies_64);
/*
* Our system timer.
*/
struct sys_timer *system_timer;
extern unsigned long wall_jiffies;
/* this needs a better home */
DEFINE_SPINLOCK(rtc_lock);
#ifdef CONFIG_SA1100_RTC_MODULE
EXPORT_SYMBOL(rtc_lock);
#endif
/* 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)
{
unsigned long fp, pc = instruction_pointer(regs);
if (in_lock_functions(pc)) {
fp = regs->ARM_fp;
pc = pc_pointer(((unsigned long *)fp)[-1]);
}
return pc;
}
EXPORT_SYMBOL(profile_pc);
#endif
/*
* hook for setting the RTC's idea of the current time.
*/
int (*set_rtc)(void);
static unsigned long dummy_gettimeoffset(void)
{
return 0;
}
/*
* Scheduler clock - returns current time in nanosec units.
* This is the default implementation. Sub-architecture
* implementations can override this.
*/
unsigned long long __attribute__((weak)) sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
static unsigned long next_rtc_update;
/*
* If we have an externally synchronized linux clock, then update
* CMOS clock accordingly every ~11 minutes. set_rtc() has to be
* called as close as possible to 500 ms before the new second
* starts.
*/
static inline void do_set_rtc(void)
{
if (time_status & STA_UNSYNC || set_rtc == NULL)
return;
if (next_rtc_update &&
time_before((unsigned long)xtime.tv_sec, next_rtc_update))
return;
if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
return;
if (set_rtc())
/*
* rtc update failed. Try again in 60s
*/
next_rtc_update = xtime.tv_sec + 60;
else
next_rtc_update = xtime.tv_sec + 660;
}
#ifdef CONFIG_LEDS
static void dummy_leds_event(led_event_t evt)
{
}
void (*leds_event)(led_event_t) = dummy_leds_event;
struct leds_evt_name {
const char name[8];
int on;
int off;
};
static const struct leds_evt_name evt_names[] = {
{ "amber", led_amber_on, led_amber_off },
{ "blue", led_blue_on, led_blue_off },
{ "green", led_green_on, led_green_off },
{ "red", led_red_on, led_red_off },
};
static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size)
{
int ret = -EINVAL, len = strcspn(buf, " ");
if (len > 0 && buf[len] == '\0')
len--;
if (strncmp(buf, "claim", len) == 0) {
leds_event(led_claim);
ret = size;
} else if (strncmp(buf, "release", len) == 0) {
leds_event(led_release);
ret = size;
} else {
int i;
for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
if (strlen(evt_names[i].name) != len ||
strncmp(buf, evt_names[i].name, len) != 0)
continue;
if (strncmp(buf+len, " on", 3) == 0) {
leds_event(evt_names[i].on);
ret = size;
} else if (strncmp(buf+len, " off", 4) == 0) {
leds_event(evt_names[i].off);
ret = size;
}
break;
}
}
return ret;
}
static SYSDEV_ATTR(event, 0200, NULL, leds_store);
static int leds_suspend(struct sys_device *dev, pm_message_t state)
{
leds_event(led_stop);
return 0;
}
static int leds_resume(struct sys_device *dev)
{
leds_event(led_start);
return 0;
}
static int leds_shutdown(struct sys_device *dev)
{
leds_event(led_halted);
return 0;
}
static struct sysdev_class leds_sysclass = {
set_kset_name("leds"),
.shutdown = leds_shutdown,
.suspend = leds_suspend,
.resume = leds_resume,
};
static struct sys_device leds_device = {
.id = 0,
.cls = &leds_sysclass,
};
static int __init leds_init(void)
{
int ret;
ret = sysdev_class_register(&leds_sysclass);
if (ret == 0)
ret = sysdev_register(&leds_device);
if (ret == 0)
ret = sysdev_create_file(&leds_device, &attr_event);
return ret;
}
device_initcall(leds_init);
EXPORT_SYMBOL(leds_event);
#endif
#ifdef CONFIG_LEDS_TIMER
static inline void do_leds(void)
{
static unsigned int count = 50;
if (--count == 0) {
count = 50;
leds_event(led_timer);
}
}
#else
#define do_leds()
#endif
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec, lost;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = system_timer->offset();
lost = jiffies - wall_jiffies;
if (lost)
usec += lost * USECS_PER_JIFFY;
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;
nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
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);
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
/**
* save_time_delta - Save the offset between system time and RTC time
* @delta: pointer to timespec to store delta
* @rtc: pointer to timespec for current RTC time
*
* Return a delta between the system time and the RTC time, such
* that system time can be restored later with restore_time_delta()
*/
void save_time_delta(struct timespec *delta, struct timespec *rtc)
{
set_normalized_timespec(delta,
xtime.tv_sec - rtc->tv_sec,
xtime.tv_nsec - rtc->tv_nsec);
}
EXPORT_SYMBOL(save_time_delta);
/**
* restore_time_delta - Restore the current system time
* @delta: delta returned by save_time_delta()
* @rtc: pointer to timespec for current RTC time
*/
void restore_time_delta(struct timespec *delta, struct timespec *rtc)
{
struct timespec ts;
set_normalized_timespec(&ts,
delta->tv_sec + rtc->tv_sec,
delta->tv_nsec + rtc->tv_nsec);
do_settimeofday(&ts);
}
EXPORT_SYMBOL(restore_time_delta);
/*
* Kernel system timer support.
*/
void timer_tick(struct pt_regs *regs)
{
profile_tick(CPU_PROFILING, regs);
do_leds();
do_set_rtc();
do_timer(regs);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
}
#ifdef CONFIG_PM
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 = {
set_kset_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)
{
if (system_timer->offset == NULL)
system_timer->offset = dummy_gettimeoffset;
system_timer->init();
}
