mirror of https://gitee.com/openkylin/linux.git
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/*
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* linux/arch/v850/kernel/time.c -- Arch-dependent timer functions
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*
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* Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds
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*
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* This file contains the v850-specific time handling details.
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* Most of the stuff is located in the machine specific files.
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*
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* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
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* "A Kernel Model for Precision Timekeeping" by Dave Mills
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*/
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/timex.h>
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#include <linux/profile.h>
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#include <asm/io.h>
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#include "mach.h"
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#define TICK_SIZE (tick_nsec / 1000)
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/*
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* timer_interrupt() needs to keep up the real-time clock,
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* as well as call the "do_timer()" routine every clocktick
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*/
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static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
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{
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#if 0
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/* last time the cmos clock got updated */
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static long last_rtc_update=0;
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#endif
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/* may need to kick the hardware timer */
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if (mach_tick)
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mach_tick ();
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do_timer (1);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(regs));
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#endif
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profile_tick(CPU_PROFILING, regs);
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#if 0
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/*
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* If we have an externally synchronized Linux clock, then update
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* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
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* called as close as possible to 500 ms before the new second starts.
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*/
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if (ntp_synced() &&
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xtime.tv_sec > last_rtc_update + 660 &&
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(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
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(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
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if (set_rtc_mmss (xtime.tv_sec) == 0)
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last_rtc_update = xtime.tv_sec;
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else
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last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
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}
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#ifdef CONFIG_HEARTBEAT
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/* use power LED as a heartbeat instead -- much more useful
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for debugging -- based on the version for PReP by Cort */
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/* acts like an actual heart beat -- ie thump-thump-pause... */
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if (mach_heartbeat) {
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static unsigned cnt = 0, period = 0, dist = 0;
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if (cnt == 0 || cnt == dist)
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mach_heartbeat ( 1 );
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else if (cnt == 7 || cnt == dist+7)
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mach_heartbeat ( 0 );
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if (++cnt > period) {
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cnt = 0;
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/* The hyperbolic function below modifies the heartbeat period
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* length in dependency of the current (5min) load. It goes
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* through the points f(0)=126, f(1)=86, f(5)=51,
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* f(inf)->30. */
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period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
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dist = period / 4;
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}
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}
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#endif /* CONFIG_HEARTBEAT */
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#endif /* 0 */
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return IRQ_HANDLED;
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}
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static int timer_dev_id;
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static struct irqaction timer_irqaction = {
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.handler = timer_interrupt,
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.flags = IRQF_DISABLED,
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.mask = CPU_MASK_NONE,
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.name = "timer",
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.dev_id = &timer_dev_id,
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};
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void time_init (void)
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{
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mach_gettimeofday (&xtime);
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mach_sched_init (&timer_irqaction);
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}
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