1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
|
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* arch/sh64/kernel/time.c
*
* Copyright (C) 2000, 2001 Paolo Alberelli
* Copyright (C) 2003, 2004 Paul Mundt
* Copyright (C) 2003 Richard Curnow
*
* Original TMU/RTC code taken from sh version.
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Some code taken from i386 version.
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*/
#include <linux/errno.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/smp.h>
#include <linux/module.h>
#include <linux/bcd.h>
#include <asm/registers.h> /* required by inline __asm__ stmt. */
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <linux/timex.h>
#include <linux/irq.h>
#include <asm/hardware.h>
#define TMU_TOCR_INIT 0x00
#define TMU0_TCR_INIT 0x0020
#define TMU_TSTR_INIT 1
#define TMU_TSTR_OFF 0
/* RCR1 Bits */
#define RCR1_CF 0x80 /* Carry Flag */
#define RCR1_CIE 0x10 /* Carry Interrupt Enable */
#define RCR1_AIE 0x08 /* Alarm Interrupt Enable */
#define RCR1_AF 0x01 /* Alarm Flag */
/* RCR2 Bits */
#define RCR2_PEF 0x80 /* PEriodic interrupt Flag */
#define RCR2_PESMASK 0x70 /* Periodic interrupt Set */
#define RCR2_RTCEN 0x08 /* ENable RTC */
#define RCR2_ADJ 0x04 /* ADJustment (30-second) */
#define RCR2_RESET 0x02 /* Reset bit */
#define RCR2_START 0x01 /* Start bit */
/* Clock, Power and Reset Controller */
#define CPRC_BLOCK_OFF 0x01010000
#define CPRC_BASE PHYS_PERIPHERAL_BLOCK + CPRC_BLOCK_OFF
#define FRQCR (cprc_base+0x0)
#define WTCSR (cprc_base+0x0018)
#define STBCR (cprc_base+0x0030)
/* Time Management Unit */
#define TMU_BLOCK_OFF 0x01020000
#define TMU_BASE PHYS_PERIPHERAL_BLOCK + TMU_BLOCK_OFF
#define TMU0_BASE tmu_base + 0x8 + (0xc * 0x0)
#define TMU1_BASE tmu_base + 0x8 + (0xc * 0x1)
#define TMU2_BASE tmu_base + 0x8 + (0xc * 0x2)
#define TMU_TOCR tmu_base+0x0 /* Byte access */
#define TMU_TSTR tmu_base+0x4 /* Byte access */
#define TMU0_TCOR TMU0_BASE+0x0 /* Long access */
#define TMU0_TCNT TMU0_BASE+0x4 /* Long access */
#define TMU0_TCR TMU0_BASE+0x8 /* Word access */
/* Real Time Clock */
#define RTC_BLOCK_OFF 0x01040000
#define RTC_BASE PHYS_PERIPHERAL_BLOCK + RTC_BLOCK_OFF
#define R64CNT rtc_base+0x00
#define RSECCNT rtc_base+0x04
#define RMINCNT rtc_base+0x08
#define RHRCNT rtc_base+0x0c
#define RWKCNT rtc_base+0x10
#define RDAYCNT rtc_base+0x14
#define RMONCNT rtc_base+0x18
#define RYRCNT rtc_base+0x1c /* 16bit */
#define RSECAR rtc_base+0x20
#define RMINAR rtc_base+0x24
#define RHRAR rtc_base+0x28
#define RWKAR rtc_base+0x2c
#define RDAYAR rtc_base+0x30
#define RMONAR rtc_base+0x34
#define RCR1 rtc_base+0x38
#define RCR2 rtc_base+0x3c
#define TICK_SIZE (tick_nsec / 1000)
static unsigned long tmu_base, rtc_base;
unsigned long cprc_base;
/* Variables to allow interpolation of time of day to resolution better than a
* jiffy. */
/* This is effectively protected by xtime_lock */
static unsigned long ctc_last_interrupt;
static unsigned long long usecs_per_jiffy = 1000000/HZ; /* Approximation */
#define CTC_JIFFY_SCALE_SHIFT 40
/* 2**CTC_JIFFY_SCALE_SHIFT / ctc_ticks_per_jiffy */
static unsigned long long scaled_recip_ctc_ticks_per_jiffy;
/* Estimate number of microseconds that have elapsed since the last timer tick,
by scaling the delta that has occured in the CTC register.
WARNING WARNING WARNING : This algorithm relies on the CTC decrementing at
the CPU clock rate. If the CPU sleeps, the CTC stops counting. Bear this
in mind if enabling SLEEP_WORKS in process.c. In that case, this algorithm
probably needs to use TMU.TCNT0 instead. This will work even if the CPU is
sleeping, though will be coarser.
FIXME : What if usecs_per_tick is moving around too much, e.g. if an adjtime
is running or if the freq or tick arguments of adjtimex are modified after
we have calibrated the scaling factor? This will result in either a jump at
the end of a tick period, or a wrap backwards at the start of the next one,
if the application is reading the time of day often enough. I think we
ought to do better than this. For this reason, usecs_per_jiffy is left
separated out in the calculation below. This allows some future hook into
the adjtime-related stuff in kernel/timer.c to remove this hazard.
*/
static unsigned long usecs_since_tick(void)
{
unsigned long long current_ctc;
long ctc_ticks_since_interrupt;
unsigned long long ull_ctc_ticks_since_interrupt;
unsigned long result;
unsigned long long mul1_out;
unsigned long long mul1_out_high;
unsigned long long mul2_out_low, mul2_out_high;
/* Read CTC register */
asm ("getcon cr62, %0" : "=r" (current_ctc));
/* Note, the CTC counts down on each CPU clock, not up.
Note(2), use long type to get correct wraparound arithmetic when
the counter crosses zero. */
ctc_ticks_since_interrupt = (long) ctc_last_interrupt - (long) current_ctc;
ull_ctc_ticks_since_interrupt = (unsigned long long) ctc_ticks_since_interrupt;
/* Inline assembly to do 32x32x32->64 multiplier */
asm volatile ("mulu.l %1, %2, %0" :
"=r" (mul1_out) :
"r" (ull_ctc_ticks_since_interrupt), "r" (usecs_per_jiffy));
mul1_out_high = mul1_out >> 32;
asm volatile ("mulu.l %1, %2, %0" :
"=r" (mul2_out_low) :
"r" (mul1_out), "r" (scaled_recip_ctc_ticks_per_jiffy));
#if 1
asm volatile ("mulu.l %1, %2, %0" :
"=r" (mul2_out_high) :
"r" (mul1_out_high), "r" (scaled_recip_ctc_ticks_per_jiffy));
#endif
result = (unsigned long) (((mul2_out_high << 32) + mul2_out_low) >> CTC_JIFFY_SCALE_SHIFT);
return result;
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = usecs_since_tick();
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;
}
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* made, and then undo it!
*/
nsec -= 1000 * usecs_since_tick();
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
static int set_rtc_time(unsigned long nowtime)
{
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
ctrl_outb(RCR2_RESET, RCR2); /* Reset pre-scaler & stop RTC */
cmos_minutes = ctrl_inb(RMINCNT);
BCD_TO_BIN(cmos_minutes);
/*
* since we're only adjusting minutes and seconds,
* don't interfere with hour overflow. This avoids
* messing with unknown time zones but requires your
* RTC not to be off by more than 15 minutes
*/
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
if (abs(real_minutes - cmos_minutes) < 30) {
BIN_TO_BCD(real_seconds);
BIN_TO_BCD(real_minutes);
ctrl_outb(real_seconds, RSECCNT);
ctrl_outb(real_minutes, RMINCNT);
} else {
printk(KERN_WARNING
"set_rtc_time: can't update from %d to %d\n",
cmos_minutes, real_minutes);
retval = -1;
}
ctrl_outb(RCR2_RTCEN|RCR2_START, RCR2); /* Start RTC */
return retval;
}
/* last time the RTC clock got updated */
static long last_rtc_update = 0;
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static inline void do_timer_interrupt(int irq, struct pt_regs *regs)
{
unsigned long long current_ctc;
asm ("getcon cr62, %0" : "=r" (current_ctc));
ctc_last_interrupt = (unsigned long) current_ctc;
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
profile_tick(CPU_PROFILING, regs);
#ifdef CONFIG_HEARTBEAT
{
extern void heartbeat(void);
heartbeat();
}
#endif
/*
* If we have an externally synchronized Linux clock, then update
* RTC 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 (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >=
|