1/* $Id: time.c,v 1.1.1.1 2007/08/03 18:51:42 Exp $
2 *
3 *  linux/arch/cris/kernel/time.c
4 *
5 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
6 *  Copyright (C) 1999, 2000, 2001 Axis Communications AB
7 *
8 * 1994-07-02    Alan Modra
9 *	fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
10 * 1995-03-26    Markus Kuhn
11 *      fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887
12 *      precision CMOS clock update
13 * 1996-05-03    Ingo Molnar
14 *      fixed time warps in do_[slow|fast]_gettimeoffset()
15 * 1997-09-10	Updated NTP code according to technical memorandum Jan '96
16 *		"A Kernel Model for Precision Timekeeping" by Dave Mills
17 *
18 * Linux/CRIS specific code:
19 *
20 * Authors:    Bjorn Wesen
21 *             Johan Adolfsson
22 *
23 */
24
25#include <asm/rtc.h>
26#include <linux/errno.h>
27#include <linux/module.h>
28#include <linux/param.h>
29#include <linux/jiffies.h>
30#include <linux/bcd.h>
31#include <linux/timex.h>
32#include <linux/init.h>
33#include <linux/profile.h>
34#include <linux/sched.h>	/* just for sched_clock() - funny that */
35
36int have_rtc;  /* used to remember if we have an RTC or not */;
37
38#define TICK_SIZE tick
39
40extern unsigned long loops_per_jiffy; /* init/main.c */
41unsigned long loops_per_usec;
42
43extern unsigned long do_slow_gettimeoffset(void);
44static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
45
46/*
47 * This version of gettimeofday has near microsecond resolution.
48 *
49 * Note: Division is quite slow on CRIS and do_gettimeofday is called
50 *       rather often. Maybe we should do some kind of approximation here
51 *       (a naive approximation would be to divide by 1024).
52 */
53void do_gettimeofday(struct timeval *tv)
54{
55	unsigned long flags;
56	signed long usec, sec;
57	local_irq_save(flags);
58	usec = do_gettimeoffset();
59
60        /*
61	 * If time_adjust is negative then NTP is slowing the clock
62	 * so make sure not to go into next possible interval.
63	 * Better to lose some accuracy than have time go backwards..
64	 */
65	if (unlikely(time_adjust < 0) && usec > tickadj)
66		usec = tickadj;
67
68	sec = xtime.tv_sec;
69	usec += xtime.tv_nsec / 1000;
70	local_irq_restore(flags);
71
72	while (usec >= 1000000) {
73		usec -= 1000000;
74		sec++;
75	}
76
77	tv->tv_sec = sec;
78	tv->tv_usec = usec;
79}
80
81EXPORT_SYMBOL(do_gettimeofday);
82
83int do_settimeofday(struct timespec *tv)
84{
85	time_t wtm_sec, sec = tv->tv_sec;
86	long wtm_nsec, nsec = tv->tv_nsec;
87
88	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
89		return -EINVAL;
90
91	write_seqlock_irq(&xtime_lock);
92	/*
93	 * This is revolting. We need to set "xtime" correctly. However, the
94	 * value in this location is the value at the most recent update of
95	 * wall time.  Discover what correction gettimeofday() would have
96	 * made, and then undo it!
97	 */
98	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
99
100	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
101	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
102
103	set_normalized_timespec(&xtime, sec, nsec);
104	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
105
106	ntp_clear();
107	write_sequnlock_irq(&xtime_lock);
108	clock_was_set();
109	return 0;
110}
111
112EXPORT_SYMBOL(do_settimeofday);
113
114
115/*
116 * BUG: This routine does not handle hour overflow properly; it just
117 *      sets the minutes. Usually you'll only notice that after reboot!
118 */
119
120int set_rtc_mmss(unsigned long nowtime)
121{
122	int retval = 0;
123	int real_seconds, real_minutes, cmos_minutes;
124
125	printk(KERN_DEBUG "set_rtc_mmss(%lu)\n", nowtime);
126
127	if(!have_rtc)
128		return 0;
129
130	cmos_minutes = CMOS_READ(RTC_MINUTES);
131	BCD_TO_BIN(cmos_minutes);
132
133	/*
134	 * since we're only adjusting minutes and seconds,
135	 * don't interfere with hour overflow. This avoids
136	 * messing with unknown time zones but requires your
137	 * RTC not to be off by more than 15 minutes
138	 */
139	real_seconds = nowtime % 60;
140	real_minutes = nowtime / 60;
141	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
142		real_minutes += 30;		/* correct for half hour time zone */
143	real_minutes %= 60;
144
145	if (abs(real_minutes - cmos_minutes) < 30) {
146		BIN_TO_BCD(real_seconds);
147		BIN_TO_BCD(real_minutes);
148		CMOS_WRITE(real_seconds,RTC_SECONDS);
149		CMOS_WRITE(real_minutes,RTC_MINUTES);
150	} else {
151		printk(KERN_WARNING
152		       "set_rtc_mmss: can't update from %d to %d\n",
153		       cmos_minutes, real_minutes);
154		retval = -1;
155	}
156
157	return retval;
158}
159
160/* grab the time from the RTC chip */
161
162unsigned long
163get_cmos_time(void)
164{
165	unsigned int year, mon, day, hour, min, sec;
166
167	sec = CMOS_READ(RTC_SECONDS);
168	min = CMOS_READ(RTC_MINUTES);
169	hour = CMOS_READ(RTC_HOURS);
170	day = CMOS_READ(RTC_DAY_OF_MONTH);
171	mon = CMOS_READ(RTC_MONTH);
172	year = CMOS_READ(RTC_YEAR);
173
174	printk(KERN_DEBUG
175	       "rtc: sec 0x%x min 0x%x hour 0x%x day 0x%x mon 0x%x year 0x%x\n",
176	       sec, min, hour, day, mon, year);
177
178	BCD_TO_BIN(sec);
179	BCD_TO_BIN(min);
180	BCD_TO_BIN(hour);
181	BCD_TO_BIN(day);
182	BCD_TO_BIN(mon);
183	BCD_TO_BIN(year);
184
185	if ((year += 1900) < 1970)
186		year += 100;
187
188	return mktime(year, mon, day, hour, min, sec);
189}
190
191/* update xtime from the CMOS settings. used when /dev/rtc gets a SET_TIME.
192 * TODO: this doesn't reset the fancy NTP phase stuff as do_settimeofday does.
193 */
194
195void
196update_xtime_from_cmos(void)
197{
198	if(have_rtc) {
199		xtime.tv_sec = get_cmos_time();
200		xtime.tv_nsec = 0;
201	}
202}
203
204extern void cris_profile_sample(struct pt_regs* regs);
205
206void
207cris_do_profile(struct pt_regs* regs)
208{
209
210#if CONFIG_SYSTEM_PROFILER
211        cris_profile_sample(regs);
212#endif
213
214#if CONFIG_PROFILING
215        profile_tick(CPU_PROFILING, regs);
216#endif
217}
218
219static int
220__init init_udelay(void)
221{
222	loops_per_usec = (loops_per_jiffy * HZ) / 1000000;
223	return 0;
224}
225
226__initcall(init_udelay);
227