diff options
Diffstat (limited to 'arch/v850/kernel/time.c')
| -rw-r--r-- | arch/v850/kernel/time.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/v850/kernel/time.c b/arch/v850/kernel/time.c new file mode 100644 index 000000000000..f722a268238a --- /dev/null +++ b/arch/v850/kernel/time.c @@ -0,0 +1,198 @@ +/* + * linux/arch/v850/kernel/time.c -- Arch-dependent timer functions + * + * Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds + * + * This file contains the v850-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/config.h> /* CONFIG_HEARTBEAT */ +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/param.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/timex.h> +#include <linux/profile.h> + +#include <asm/io.h> + +#include "mach.h" + +u64 jiffies_64 = INITIAL_JIFFIES; + +EXPORT_SYMBOL(jiffies_64); + +#define TICK_SIZE (tick_nsec / 1000) + +/* + * Scheduler clock - returns current time in nanosec units. + */ +unsigned long long sched_clock(void) +{ + return (unsigned long long)jiffies * (1000000000 / HZ); +} + +/* + * 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, struct pt_regs *regs) +{ +#if 0 + /* last time the cmos clock got updated */ + static long last_rtc_update=0; +#endif + + /* may need to kick the hardware timer */ + if (mach_tick) + mach_tick (); + + do_timer (regs); +#ifndef CONFIG_SMP + update_process_times(user_mode(regs)); +#endif + profile_tick(CPU_PROFILING, regs); +#if 0 + /* + * If we have an externally synchronized Linux clock, then update + * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be + * called as close as possible to 500 ms before the new second starts. + */ + if ((time_status & STA_UNSYNC) == 0 && + xtime.tv_sec > last_rtc_update + 660 && + (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && + (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { + if (set_rtc_mmss (xtime.tv_sec) == 0) + last_rtc_update = xtime.tv_sec; + else + last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ + } +#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 */ +#endif /* 0 */ + + return IRQ_HANDLED; +} + +/* + * This version of gettimeofday has near microsecond resolution. + */ +void do_gettimeofday (struct timeval *tv) +{ +#if 0 /* DAVIDM later if possible */ + extern volatile unsigned long lost_ticks; + unsigned long lost; +#endif + unsigned long flags; + unsigned long usec, sec; + unsigned long seq; + + do { + seq = read_seqbegin_irqsave(&xtime_lock, flags); + +#if 0 + usec = mach_gettimeoffset ? mach_gettimeoffset () : 0; +#else + usec = 0; +#endif +#if 0 /* DAVIDM later if possible */ + lost = lost_ticks; + if (lost) + usec += lost * (1000000/HZ); +#endif + 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) +{ + 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! + */ +#if 0 + tv->tv_nsec -= mach_gettimeoffset() * 1000; +#endif + + while (tv->tv_nsec < 0) { + tv->tv_nsec += NSEC_PER_SEC; + tv->tv_sec--; + } + + xtime.tv_sec = tv->tv_sec; + xtime.tv_nsec = tv->tv_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); + +static int timer_dev_id; +static struct irqaction timer_irqaction = { + timer_interrupt, + SA_INTERRUPT, + CPU_MASK_NONE, + "timer", + &timer_dev_id, + NULL +}; + +void time_init (void) +{ + mach_gettimeofday (&xtime); + mach_sched_init (&timer_irqaction); +} |