blob: cada3ba4b9902f23bb13620e726a2625897e5d8a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/m32r/kernel/time.c
3 *
4 * Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata,
5 * Hitoshi Yamamoto
6 * Taken from i386 version.
7 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
8 * Copyright (C) 1996, 1997, 1998 Ralf Baechle
9 *
10 * This file contains the time handling details for PC-style clocks as
11 * found in some MIPS systems.
12 *
13 * Some code taken from sh version.
14 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
15 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
16 */
17
18#undef DEBUG_TIMER
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/errno.h>
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/sched.h>
24#include <linux/kernel.h>
25#include <linux/param.h>
26#include <linux/string.h>
27#include <linux/mm.h>
28#include <linux/interrupt.h>
29#include <linux/profile.h>
30
31#include <asm/io.h>
32#include <asm/m32r.h>
33
34#include <asm/hw_irq.h>
35
36#ifdef CONFIG_SMP
Al Viro9c8e7f52006-10-07 16:29:18 +010037extern void smp_local_timer_interrupt(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#endif
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#define TICK_SIZE (tick_nsec / 1000)
41
42/*
43 * Change this if you have some constant time drift
44 */
45
46/* This is for machines which generate the exact clock. */
47#define USECS_PER_JIFFY (1000000/HZ)
48
49static unsigned long latch;
50
51static unsigned long do_gettimeoffset(void)
52{
53 unsigned long elapsed_time = 0; /* [us] */
54
55#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
56 || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
Hirokazu Takata9287d952006-01-06 00:18:41 -080057 || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#ifndef CONFIG_SMP
59
60 unsigned long count;
61
62 /* timer count may underflow right here */
63 count = inl(M32R_MFT2CUT_PORTL);
64
65 if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */
66 count = 0;
67
68 count = (latch - count) * TICK_SIZE;
69 elapsed_time = (count + latch / 2) / latch;
70 /* NOTE: LATCH is equal to the "interval" value (= reload count). */
71
72#else /* CONFIG_SMP */
73 unsigned long count;
74 static unsigned long p_jiffies = -1;
75 static unsigned long p_count = 0;
76
77 /* timer count may underflow right here */
78 count = inl(M32R_MFT2CUT_PORTL);
79
80 if (jiffies == p_jiffies && count > p_count)
81 count = 0;
82
83 p_jiffies = jiffies;
84 p_count = count;
85
86 count = (latch - count) * TICK_SIZE;
87 elapsed_time = (count + latch / 2) / latch;
88 /* NOTE: LATCH is equal to the "interval" value (= reload count). */
89#endif /* CONFIG_SMP */
90#elif defined(CONFIG_CHIP_M32310)
91#warning do_gettimeoffse not implemented
92#else
93#error no chip configuration
94#endif
95
96 return elapsed_time;
97}
98
99/*
100 * This version of gettimeofday has near microsecond resolution.
101 */
102void do_gettimeofday(struct timeval *tv)
103{
104 unsigned long seq;
105 unsigned long usec, sec;
106 unsigned long max_ntp_tick = tick_usec - tickadj;
107
108 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 seq = read_seqbegin(&xtime_lock);
110
111 usec = do_gettimeoffset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113 /*
114 * If time_adjust is negative then NTP is slowing the clock
115 * so make sure not to go into next possible interval.
116 * Better to lose some accuracy than have time go backwards..
117 */
Atsushi Nemoto8ef38602006-09-30 23:28:31 -0700118 if (unlikely(time_adjust < 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 usec = min(usec, max_ntp_tick);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
121 sec = xtime.tv_sec;
122 usec += (xtime.tv_nsec / 1000);
123 } while (read_seqretry(&xtime_lock, seq));
124
125 while (usec >= 1000000) {
126 usec -= 1000000;
127 sec++;
128 }
129
130 tv->tv_sec = sec;
131 tv->tv_usec = usec;
132}
133
134EXPORT_SYMBOL(do_gettimeofday);
135
136int do_settimeofday(struct timespec *tv)
137{
138 time_t wtm_sec, sec = tv->tv_sec;
139 long wtm_nsec, nsec = tv->tv_nsec;
140
141 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
142 return -EINVAL;
143
144 write_seqlock_irq(&xtime_lock);
145 /*
146 * This is revolting. We need to set "xtime" correctly. However, the
147 * value in this location is the value at the most recent update of
148 * wall time. Discover what correction gettimeofday() would have
149 * made, and then undo it!
150 */
151 nsec -= do_gettimeoffset() * NSEC_PER_USEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
154 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
155
156 set_normalized_timespec(&xtime, sec, nsec);
157 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
158
john stultzb149ee22005-09-06 15:17:46 -0700159 ntp_clear();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 write_sequnlock_irq(&xtime_lock);
161 clock_was_set();
162
163 return 0;
164}
165
166EXPORT_SYMBOL(do_settimeofday);
167
168/*
169 * In order to set the CMOS clock precisely, set_rtc_mmss has to be
170 * called 500 ms after the second nowtime has started, because when
171 * nowtime is written into the registers of the CMOS clock, it will
172 * jump to the next second precisely 500 ms later. Check the Motorola
173 * MC146818A or Dallas DS12887 data sheet for details.
174 *
175 * BUG: This routine does not handle hour overflow properly; it just
176 * sets the minutes. Usually you won't notice until after reboot!
177 */
178static inline int set_rtc_mmss(unsigned long nowtime)
179{
180 return 0;
181}
182
183/* last time the cmos clock got updated */
184static long last_rtc_update = 0;
185
186/*
187 * timer_interrupt() needs to keep up the real-time clock,
188 * as well as call the "do_timer()" routine every clocktick
189 */
Adrian Bunk81e48072008-09-24 15:01:47 +0900190static irqreturn_t timer_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
192#ifndef CONFIG_SMP
Al Viro9c8e7f52006-10-07 16:29:18 +0100193 profile_tick(CPU_PROFILING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194#endif
Atsushi Nemoto3171a032006-09-29 02:00:32 -0700195 do_timer(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197#ifndef CONFIG_SMP
Al Viro9c8e7f52006-10-07 16:29:18 +0100198 update_process_times(user_mode(get_irq_regs()));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199#endif
200 /*
201 * If we have an externally synchronized Linux clock, then update
202 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
203 * called as close as possible to 500 ms before the new second starts.
204 */
Hirokazu Takata2757a712005-08-01 21:11:35 -0700205 write_seqlock(&xtime_lock);
john stultzb149ee22005-09-06 15:17:46 -0700206 if (ntp_synced()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 && xtime.tv_sec > last_rtc_update + 660
208 && (xtime.tv_nsec / 1000) >= 500000 - ((unsigned)TICK_SIZE) / 2
209 && (xtime.tv_nsec / 1000) <= 500000 + ((unsigned)TICK_SIZE) / 2)
210 {
211 if (set_rtc_mmss(xtime.tv_sec) == 0)
212 last_rtc_update = xtime.tv_sec;
213 else /* do it again in 60 s */
214 last_rtc_update = xtime.tv_sec - 600;
215 }
Hirokazu Takata2757a712005-08-01 21:11:35 -0700216 write_sequnlock(&xtime_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 /* As we return to user mode fire off the other CPU schedulers..
218 this is basically because we don't yet share IRQ's around.
219 This message is rigged to be safe on the 386 - basically it's
220 a hack, so don't look closely for now.. */
221
222#ifdef CONFIG_SMP
Al Viro9c8e7f52006-10-07 16:29:18 +0100223 smp_local_timer_interrupt();
Hirokazu Takata2757a712005-08-01 21:11:35 -0700224 smp_send_timer();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 return IRQ_HANDLED;
228}
229
Adrian Bunk81e48072008-09-24 15:01:47 +0900230static struct irqaction irq0 = {
Thomas Gleixner977676a2007-10-16 01:26:36 -0700231 .handler = timer_interrupt,
232 .flags = IRQF_DISABLED,
Thomas Gleixner977676a2007-10-16 01:26:36 -0700233 .name = "MFT2",
234};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
236void __init time_init(void)
237{
238 unsigned int epoch, year, mon, day, hour, min, sec;
239
240 sec = min = hour = day = mon = year = 0;
241 epoch = 0;
242
243 year = 23;
244 mon = 4;
245 day = 17;
246
247 /* Attempt to guess the epoch. This is the same heuristic as in rtc.c
248 so no stupid things will happen to timekeeping. Who knows, maybe
249 Ultrix also uses 1952 as epoch ... */
250 if (year > 10 && year < 44)
251 epoch = 1980;
252 else if (year < 96)
253 epoch = 1952;
254 year += epoch;
255
256 xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
257 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
258 set_normalized_timespec(&wall_to_monotonic,
259 -xtime.tv_sec, -xtime.tv_nsec);
260
261#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
262 || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
Hirokazu Takata9287d952006-01-06 00:18:41 -0800263 || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265 /* M32102 MFT setup */
266 setup_irq(M32R_IRQ_MFT2, &irq0);
267 {
268 unsigned long bus_clock;
269 unsigned short divide;
270
271 bus_clock = boot_cpu_data.bus_clock;
272 divide = boot_cpu_data.timer_divide;
273 latch = (bus_clock/divide + HZ / 2) / HZ;
274
275 printk("Timer start : latch = %ld\n", latch);
276
277 outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
278 |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
279 outl(latch, M32R_MFT2RLD_PORTL);
280 outl(latch, M32R_MFT2CUT_PORTL);
281 outl(0, M32R_MFT2CMPRLD_PORTL);
282 outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
283 }
284
285#elif defined(CONFIG_CHIP_M32310)
286#warning time_init not implemented
287#else
288#error no chip configuration
289#endif
290}