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-rw-r--r--arch/v850/kernel/time.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/v850/kernel/time.c b/arch/v850/kernel/time.c
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1/*
2 * linux/arch/v850/kernel/time.c -- Arch-dependent timer functions
3 *
4 * Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds
5 *
6 * This file contains the v850-specific time handling details.
7 * Most of the stuff is located in the machine specific files.
8 *
9 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
10 * "A Kernel Model for Precision Timekeeping" by Dave Mills
11 */
12
13#include <linux/config.h> /* CONFIG_HEARTBEAT */
14#include <linux/errno.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/param.h>
18#include <linux/string.h>
19#include <linux/mm.h>
20#include <linux/interrupt.h>
21#include <linux/time.h>
22#include <linux/timex.h>
23#include <linux/profile.h>
24
25#include <asm/io.h>
26
27#include "mach.h"
28
29u64 jiffies_64 = INITIAL_JIFFIES;
30
31EXPORT_SYMBOL(jiffies_64);
32
33#define TICK_SIZE (tick_nsec / 1000)
34
35/*
36 * Scheduler clock - returns current time in nanosec units.
37 */
38unsigned long long sched_clock(void)
39{
40 return (unsigned long long)jiffies * (1000000000 / HZ);
41}
42
43/*
44 * timer_interrupt() needs to keep up the real-time clock,
45 * as well as call the "do_timer()" routine every clocktick
46 */
47static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
48{
49#if 0
50 /* last time the cmos clock got updated */
51 static long last_rtc_update=0;
52#endif
53
54 /* may need to kick the hardware timer */
55 if (mach_tick)
56 mach_tick ();
57
58 do_timer (regs);
59#ifndef CONFIG_SMP
60 update_process_times(user_mode(regs));
61#endif
62 profile_tick(CPU_PROFILING, regs);
63#if 0
64 /*
65 * If we have an externally synchronized Linux clock, then update
66 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
67 * called as close as possible to 500 ms before the new second starts.
68 */
69 if ((time_status & STA_UNSYNC) == 0 &&
70 xtime.tv_sec > last_rtc_update + 660 &&
71 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
72 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
73 if (set_rtc_mmss (xtime.tv_sec) == 0)
74 last_rtc_update = xtime.tv_sec;
75 else
76 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
77 }
78#ifdef CONFIG_HEARTBEAT
79 /* use power LED as a heartbeat instead -- much more useful
80 for debugging -- based on the version for PReP by Cort */
81 /* acts like an actual heart beat -- ie thump-thump-pause... */
82 if (mach_heartbeat) {
83 static unsigned cnt = 0, period = 0, dist = 0;
84
85 if (cnt == 0 || cnt == dist)
86 mach_heartbeat ( 1 );
87 else if (cnt == 7 || cnt == dist+7)
88 mach_heartbeat ( 0 );
89
90 if (++cnt > period) {
91 cnt = 0;
92 /* The hyperbolic function below modifies the heartbeat period
93 * length in dependency of the current (5min) load. It goes
94 * through the points f(0)=126, f(1)=86, f(5)=51,
95 * f(inf)->30. */
96 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
97 dist = period / 4;
98 }
99 }
100#endif /* CONFIG_HEARTBEAT */
101#endif /* 0 */
102
103 return IRQ_HANDLED;
104}
105
106/*
107 * This version of gettimeofday has near microsecond resolution.
108 */
109void do_gettimeofday (struct timeval *tv)
110{
111#if 0 /* DAVIDM later if possible */
112 extern volatile unsigned long lost_ticks;
113 unsigned long lost;
114#endif
115 unsigned long flags;
116 unsigned long usec, sec;
117 unsigned long seq;
118
119 do {
120 seq = read_seqbegin_irqsave(&xtime_lock, flags);
121
122#if 0
123 usec = mach_gettimeoffset ? mach_gettimeoffset () : 0;
124#else
125 usec = 0;
126#endif
127#if 0 /* DAVIDM later if possible */
128 lost = lost_ticks;
129 if (lost)
130 usec += lost * (1000000/HZ);
131#endif
132 sec = xtime.tv_sec;
133 usec += xtime.tv_nsec / 1000;
134 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
135
136 while (usec >= 1000000) {
137 usec -= 1000000;
138 sec++;
139 }
140
141 tv->tv_sec = sec;
142 tv->tv_usec = usec;
143}
144
145EXPORT_SYMBOL(do_gettimeofday);
146
147int do_settimeofday(struct timespec *tv)
148{
149 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
150 return -EINVAL;
151
152 write_seqlock_irq (&xtime_lock);
153
154 /* This is revolting. We need to set the xtime.tv_nsec
155 * correctly. However, the value in this location is
156 * is value at the last tick.
157 * Discover what correction gettimeofday
158 * would have done, and then undo it!
159 */
160#if 0
161 tv->tv_nsec -= mach_gettimeoffset() * 1000;
162#endif
163
164 while (tv->tv_nsec < 0) {
165 tv->tv_nsec += NSEC_PER_SEC;
166 tv->tv_sec--;
167 }
168
169 xtime.tv_sec = tv->tv_sec;
170 xtime.tv_nsec = tv->tv_nsec;
171
172 time_adjust = 0; /* stop active adjtime () */
173 time_status |= STA_UNSYNC;
174 time_maxerror = NTP_PHASE_LIMIT;
175 time_esterror = NTP_PHASE_LIMIT;
176
177 write_sequnlock_irq (&xtime_lock);
178 clock_was_set();
179 return 0;
180}
181
182EXPORT_SYMBOL(do_settimeofday);
183
184static int timer_dev_id;
185static struct irqaction timer_irqaction = {
186 timer_interrupt,
187 SA_INTERRUPT,
188 CPU_MASK_NONE,
189 "timer",
190 &timer_dev_id,
191 NULL
192};
193
194void time_init (void)
195{
196 mach_gettimeofday (&xtime);
197 mach_sched_init (&timer_irqaction);
198}