180 строки
4.2 KiB
C
180 строки
4.2 KiB
C
/*
|
|
* linux/arch/m68k/kernel/time.c
|
|
*
|
|
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
|
|
*
|
|
* This file contains the m68k-specific time handling details.
|
|
* Most of the stuff is located in the machine specific files.
|
|
*
|
|
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
|
|
* "A Kernel Model for Precision Timekeeping" by Dave Mills
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/param.h>
|
|
#include <linux/string.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include <asm/machdep.h>
|
|
#include <asm/io.h>
|
|
#include <asm/irq_regs.h>
|
|
|
|
#include <linux/time.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/profile.h>
|
|
|
|
static inline int set_rtc_mmss(unsigned long nowtime)
|
|
{
|
|
if (mach_set_clock_mmss)
|
|
return mach_set_clock_mmss (nowtime);
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* timer_interrupt() needs to keep up the real-time clock,
|
|
* as well as call the "do_timer()" routine every clocktick
|
|
*/
|
|
static irqreturn_t timer_interrupt(int irq, void *dummy)
|
|
{
|
|
do_timer(1);
|
|
#ifndef CONFIG_SMP
|
|
update_process_times(user_mode(get_irq_regs()));
|
|
#endif
|
|
profile_tick(CPU_PROFILING);
|
|
|
|
#ifdef CONFIG_HEARTBEAT
|
|
/* use power LED as a heartbeat instead -- much more useful
|
|
for debugging -- based on the version for PReP by Cort */
|
|
/* acts like an actual heart beat -- ie thump-thump-pause... */
|
|
if (mach_heartbeat) {
|
|
static unsigned cnt = 0, period = 0, dist = 0;
|
|
|
|
if (cnt == 0 || cnt == dist)
|
|
mach_heartbeat( 1 );
|
|
else if (cnt == 7 || cnt == dist+7)
|
|
mach_heartbeat( 0 );
|
|
|
|
if (++cnt > period) {
|
|
cnt = 0;
|
|
/* The hyperbolic function below modifies the heartbeat period
|
|
* length in dependency of the current (5min) load. It goes
|
|
* through the points f(0)=126, f(1)=86, f(5)=51,
|
|
* f(inf)->30. */
|
|
period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
|
|
dist = period / 4;
|
|
}
|
|
}
|
|
#endif /* CONFIG_HEARTBEAT */
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
void __init time_init(void)
|
|
{
|
|
struct rtc_time time;
|
|
|
|
if (mach_hwclk) {
|
|
mach_hwclk(0, &time);
|
|
|
|
if ((time.tm_year += 1900) < 1970)
|
|
time.tm_year += 100;
|
|
xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
|
|
time.tm_hour, time.tm_min, time.tm_sec);
|
|
xtime.tv_nsec = 0;
|
|
}
|
|
wall_to_monotonic.tv_sec = -xtime.tv_sec;
|
|
|
|
mach_sched_init(timer_interrupt);
|
|
}
|
|
|
|
/*
|
|
* This version of gettimeofday has near microsecond resolution.
|
|
*/
|
|
void do_gettimeofday(struct timeval *tv)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long seq;
|
|
unsigned long usec, sec;
|
|
unsigned long max_ntp_tick = tick_usec - tickadj;
|
|
|
|
do {
|
|
seq = read_seqbegin_irqsave(&xtime_lock, flags);
|
|
|
|
usec = mach_gettimeoffset();
|
|
|
|
/*
|
|
* If time_adjust is negative then NTP is slowing the clock
|
|
* so make sure not to go into next possible interval.
|
|
* Better to lose some accuracy than have time go backwards..
|
|
*/
|
|
if (unlikely(time_adjust < 0))
|
|
usec = min(usec, max_ntp_tick);
|
|
|
|
sec = xtime.tv_sec;
|
|
usec += xtime.tv_nsec/1000;
|
|
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
|
|
|
|
|
|
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 the xtime.tv_nsec
|
|
* correctly. However, the value in this location is
|
|
* is value at the last tick.
|
|
* Discover what correction gettimeofday
|
|
* would have done, and then undo it!
|
|
*/
|
|
nsec -= 1000 * mach_gettimeoffset();
|
|
|
|
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);
|
|
|
|
|
|
static int __init rtc_init(void)
|
|
{
|
|
struct platform_device *pdev;
|
|
|
|
if (!mach_hwclk)
|
|
return -ENODEV;
|
|
|
|
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
|
|
if (IS_ERR(pdev))
|
|
return PTR_ERR(pdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
module_init(rtc_init);
|