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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/time.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds | |
5 | * Modifications for ARM (C) 1994-2001 Russell King | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This file contains the ARM-specific time handling details: | |
12 | * reading the RTC at bootup, etc... | |
13 | * | |
14 | * 1994-07-02 Alan Modra | |
15 | * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime | |
16 | * 1998-12-20 Updated NTP code according to technical memorandum Jan '96 | |
17 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
18 | */ | |
1da177e4 LT |
19 | #include <linux/module.h> |
20 | #include <linux/kernel.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/time.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/smp.h> | |
25 | #include <linux/timex.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/profile.h> | |
28 | #include <linux/sysdev.h> | |
29 | #include <linux/timer.h> | |
e317c8cc | 30 | #include <linux/irq.h> |
1da177e4 | 31 | |
1da177e4 LT |
32 | #include <asm/leds.h> |
33 | #include <asm/thread_info.h> | |
34 | #include <asm/mach/time.h> | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * Our system timer. | |
38 | */ | |
39 | struct sys_timer *system_timer; | |
40 | ||
1da177e4 LT |
41 | /* this needs a better home */ |
42 | DEFINE_SPINLOCK(rtc_lock); | |
43 | ||
44 | #ifdef CONFIG_SA1100_RTC_MODULE | |
45 | EXPORT_SYMBOL(rtc_lock); | |
46 | #endif | |
47 | ||
48 | /* change this if you have some constant time drift */ | |
49 | #define USECS_PER_JIFFY (1000000/HZ) | |
50 | ||
51 | #ifdef CONFIG_SMP | |
52 | unsigned long profile_pc(struct pt_regs *regs) | |
53 | { | |
54 | unsigned long fp, pc = instruction_pointer(regs); | |
55 | ||
56 | if (in_lock_functions(pc)) { | |
57 | fp = regs->ARM_fp; | |
58 | pc = pc_pointer(((unsigned long *)fp)[-1]); | |
59 | } | |
60 | ||
61 | return pc; | |
62 | } | |
63 | EXPORT_SYMBOL(profile_pc); | |
64 | #endif | |
65 | ||
66 | /* | |
67 | * hook for setting the RTC's idea of the current time. | |
68 | */ | |
69 | int (*set_rtc)(void); | |
70 | ||
746140c7 | 71 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
72 | static unsigned long dummy_gettimeoffset(void) |
73 | { | |
74 | return 0; | |
75 | } | |
746140c7 | 76 | #endif |
1da177e4 LT |
77 | |
78 | /* | |
79 | * Scheduler clock - returns current time in nanosec units. | |
80 | * This is the default implementation. Sub-architecture | |
81 | * implementations can override this. | |
82 | */ | |
83 | unsigned long long __attribute__((weak)) sched_clock(void) | |
84 | { | |
85 | return (unsigned long long)jiffies * (1000000000 / HZ); | |
86 | } | |
87 | ||
88 | static unsigned long next_rtc_update; | |
89 | ||
90 | /* | |
91 | * If we have an externally synchronized linux clock, then update | |
92 | * CMOS clock accordingly every ~11 minutes. set_rtc() has to be | |
93 | * called as close as possible to 500 ms before the new second | |
94 | * starts. | |
95 | */ | |
96 | static inline void do_set_rtc(void) | |
97 | { | |
b149ee22 | 98 | if (!ntp_synced() || set_rtc == NULL) |
1da177e4 LT |
99 | return; |
100 | ||
101 | if (next_rtc_update && | |
102 | time_before((unsigned long)xtime.tv_sec, next_rtc_update)) | |
103 | return; | |
104 | ||
105 | if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) && | |
106 | xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1)) | |
107 | return; | |
108 | ||
109 | if (set_rtc()) | |
110 | /* | |
111 | * rtc update failed. Try again in 60s | |
112 | */ | |
113 | next_rtc_update = xtime.tv_sec + 60; | |
114 | else | |
115 | next_rtc_update = xtime.tv_sec + 660; | |
116 | } | |
117 | ||
118 | #ifdef CONFIG_LEDS | |
119 | ||
120 | static void dummy_leds_event(led_event_t evt) | |
121 | { | |
122 | } | |
123 | ||
124 | void (*leds_event)(led_event_t) = dummy_leds_event; | |
125 | ||
126 | struct leds_evt_name { | |
127 | const char name[8]; | |
128 | int on; | |
129 | int off; | |
130 | }; | |
131 | ||
132 | static const struct leds_evt_name evt_names[] = { | |
133 | { "amber", led_amber_on, led_amber_off }, | |
134 | { "blue", led_blue_on, led_blue_off }, | |
135 | { "green", led_green_on, led_green_off }, | |
136 | { "red", led_red_on, led_red_off }, | |
137 | }; | |
138 | ||
139 | static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size) | |
140 | { | |
141 | int ret = -EINVAL, len = strcspn(buf, " "); | |
142 | ||
143 | if (len > 0 && buf[len] == '\0') | |
144 | len--; | |
145 | ||
146 | if (strncmp(buf, "claim", len) == 0) { | |
147 | leds_event(led_claim); | |
148 | ret = size; | |
149 | } else if (strncmp(buf, "release", len) == 0) { | |
150 | leds_event(led_release); | |
151 | ret = size; | |
152 | } else { | |
153 | int i; | |
154 | ||
155 | for (i = 0; i < ARRAY_SIZE(evt_names); i++) { | |
156 | if (strlen(evt_names[i].name) != len || | |
157 | strncmp(buf, evt_names[i].name, len) != 0) | |
158 | continue; | |
159 | if (strncmp(buf+len, " on", 3) == 0) { | |
160 | leds_event(evt_names[i].on); | |
161 | ret = size; | |
162 | } else if (strncmp(buf+len, " off", 4) == 0) { | |
163 | leds_event(evt_names[i].off); | |
164 | ret = size; | |
165 | } | |
166 | break; | |
167 | } | |
168 | } | |
169 | return ret; | |
170 | } | |
171 | ||
172 | static SYSDEV_ATTR(event, 0200, NULL, leds_store); | |
173 | ||
174 | static int leds_suspend(struct sys_device *dev, pm_message_t state) | |
175 | { | |
176 | leds_event(led_stop); | |
177 | return 0; | |
178 | } | |
179 | ||
180 | static int leds_resume(struct sys_device *dev) | |
181 | { | |
182 | leds_event(led_start); | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static int leds_shutdown(struct sys_device *dev) | |
187 | { | |
188 | leds_event(led_halted); | |
189 | return 0; | |
190 | } | |
191 | ||
192 | static struct sysdev_class leds_sysclass = { | |
193 | set_kset_name("leds"), | |
194 | .shutdown = leds_shutdown, | |
195 | .suspend = leds_suspend, | |
196 | .resume = leds_resume, | |
197 | }; | |
198 | ||
199 | static struct sys_device leds_device = { | |
200 | .id = 0, | |
201 | .cls = &leds_sysclass, | |
202 | }; | |
203 | ||
204 | static int __init leds_init(void) | |
205 | { | |
206 | int ret; | |
207 | ret = sysdev_class_register(&leds_sysclass); | |
208 | if (ret == 0) | |
209 | ret = sysdev_register(&leds_device); | |
210 | if (ret == 0) | |
211 | ret = sysdev_create_file(&leds_device, &attr_event); | |
212 | return ret; | |
213 | } | |
214 | ||
215 | device_initcall(leds_init); | |
216 | ||
217 | EXPORT_SYMBOL(leds_event); | |
218 | #endif | |
219 | ||
220 | #ifdef CONFIG_LEDS_TIMER | |
221 | static inline void do_leds(void) | |
222 | { | |
223 | static unsigned int count = 50; | |
224 | ||
225 | if (--count == 0) { | |
226 | count = 50; | |
227 | leds_event(led_timer); | |
228 | } | |
229 | } | |
230 | #else | |
231 | #define do_leds() | |
232 | #endif | |
233 | ||
746140c7 | 234 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
235 | void do_gettimeofday(struct timeval *tv) |
236 | { | |
237 | unsigned long flags; | |
238 | unsigned long seq; | |
8ef38609 | 239 | unsigned long usec, sec; |
1da177e4 LT |
240 | |
241 | do { | |
242 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | |
243 | usec = system_timer->offset(); | |
1da177e4 LT |
244 | sec = xtime.tv_sec; |
245 | usec += xtime.tv_nsec / 1000; | |
246 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | |
247 | ||
248 | /* usec may have gone up a lot: be safe */ | |
249 | while (usec >= 1000000) { | |
250 | usec -= 1000000; | |
251 | sec++; | |
252 | } | |
253 | ||
254 | tv->tv_sec = sec; | |
255 | tv->tv_usec = usec; | |
256 | } | |
257 | ||
258 | EXPORT_SYMBOL(do_gettimeofday); | |
259 | ||
260 | int do_settimeofday(struct timespec *tv) | |
261 | { | |
262 | time_t wtm_sec, sec = tv->tv_sec; | |
263 | long wtm_nsec, nsec = tv->tv_nsec; | |
264 | ||
265 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
266 | return -EINVAL; | |
267 | ||
268 | write_seqlock_irq(&xtime_lock); | |
269 | /* | |
270 | * This is revolting. We need to set "xtime" correctly. However, the | |
271 | * value in this location is the value at the most recent update of | |
272 | * wall time. Discover what correction gettimeofday() would have | |
273 | * done, and then undo it! | |
274 | */ | |
275 | nsec -= system_timer->offset() * NSEC_PER_USEC; | |
1da177e4 LT |
276 | |
277 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | |
278 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
279 | ||
280 | set_normalized_timespec(&xtime, sec, nsec); | |
281 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
282 | ||
b149ee22 | 283 | ntp_clear(); |
1da177e4 LT |
284 | write_sequnlock_irq(&xtime_lock); |
285 | clock_was_set(); | |
286 | return 0; | |
287 | } | |
288 | ||
289 | EXPORT_SYMBOL(do_settimeofday); | |
746140c7 | 290 | #endif /* !CONFIG_GENERIC_TIME */ |
1da177e4 LT |
291 | |
292 | /** | |
293 | * save_time_delta - Save the offset between system time and RTC time | |
294 | * @delta: pointer to timespec to store delta | |
295 | * @rtc: pointer to timespec for current RTC time | |
296 | * | |
297 | * Return a delta between the system time and the RTC time, such | |
298 | * that system time can be restored later with restore_time_delta() | |
299 | */ | |
300 | void save_time_delta(struct timespec *delta, struct timespec *rtc) | |
301 | { | |
302 | set_normalized_timespec(delta, | |
303 | xtime.tv_sec - rtc->tv_sec, | |
304 | xtime.tv_nsec - rtc->tv_nsec); | |
305 | } | |
306 | EXPORT_SYMBOL(save_time_delta); | |
307 | ||
308 | /** | |
309 | * restore_time_delta - Restore the current system time | |
310 | * @delta: delta returned by save_time_delta() | |
311 | * @rtc: pointer to timespec for current RTC time | |
312 | */ | |
313 | void restore_time_delta(struct timespec *delta, struct timespec *rtc) | |
314 | { | |
315 | struct timespec ts; | |
316 | ||
317 | set_normalized_timespec(&ts, | |
318 | delta->tv_sec + rtc->tv_sec, | |
319 | delta->tv_nsec + rtc->tv_nsec); | |
320 | ||
321 | do_settimeofday(&ts); | |
322 | } | |
323 | EXPORT_SYMBOL(restore_time_delta); | |
324 | ||
325 | /* | |
326 | * Kernel system timer support. | |
327 | */ | |
0cd61b68 | 328 | void timer_tick(void) |
1da177e4 | 329 | { |
0cd61b68 | 330 | struct pt_regs *regs = get_irq_regs(); |
e317c8cc | 331 | profile_tick(CPU_PROFILING); |
1da177e4 LT |
332 | do_leds(); |
333 | do_set_rtc(); | |
3171a030 | 334 | do_timer(1); |
1da177e4 LT |
335 | #ifndef CONFIG_SMP |
336 | update_process_times(user_mode(regs)); | |
337 | #endif | |
338 | } | |
339 | ||
340 | #ifdef CONFIG_PM | |
341 | static int timer_suspend(struct sys_device *dev, pm_message_t state) | |
342 | { | |
343 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
344 | ||
345 | if (timer->suspend != NULL) | |
346 | timer->suspend(); | |
347 | ||
348 | return 0; | |
349 | } | |
350 | ||
351 | static int timer_resume(struct sys_device *dev) | |
352 | { | |
353 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
354 | ||
355 | if (timer->resume != NULL) | |
356 | timer->resume(); | |
357 | ||
358 | return 0; | |
359 | } | |
360 | #else | |
361 | #define timer_suspend NULL | |
362 | #define timer_resume NULL | |
363 | #endif | |
364 | ||
365 | static struct sysdev_class timer_sysclass = { | |
366 | set_kset_name("timer"), | |
367 | .suspend = timer_suspend, | |
368 | .resume = timer_resume, | |
369 | }; | |
370 | ||
8749af68 RK |
371 | #ifdef CONFIG_NO_IDLE_HZ |
372 | static int timer_dyn_tick_enable(void) | |
373 | { | |
374 | struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; | |
375 | unsigned long flags; | |
376 | int ret = -ENODEV; | |
377 | ||
378 | if (dyn_tick) { | |
ebc67da6 | 379 | spin_lock_irqsave(&dyn_tick->lock, flags); |
8749af68 RK |
380 | ret = 0; |
381 | if (!(dyn_tick->state & DYN_TICK_ENABLED)) { | |
382 | ret = dyn_tick->enable(); | |
383 | ||
384 | if (ret == 0) | |
385 | dyn_tick->state |= DYN_TICK_ENABLED; | |
386 | } | |
ebc67da6 | 387 | spin_unlock_irqrestore(&dyn_tick->lock, flags); |
8749af68 RK |
388 | } |
389 | ||
390 | return ret; | |
391 | } | |
392 | ||
393 | static int timer_dyn_tick_disable(void) | |
394 | { | |
395 | struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; | |
396 | unsigned long flags; | |
397 | int ret = -ENODEV; | |
398 | ||
399 | if (dyn_tick) { | |
ebc67da6 | 400 | spin_lock_irqsave(&dyn_tick->lock, flags); |
8749af68 RK |
401 | ret = 0; |
402 | if (dyn_tick->state & DYN_TICK_ENABLED) { | |
403 | ret = dyn_tick->disable(); | |
404 | ||
405 | if (ret == 0) | |
406 | dyn_tick->state &= ~DYN_TICK_ENABLED; | |
407 | } | |
ebc67da6 | 408 | spin_unlock_irqrestore(&dyn_tick->lock, flags); |
8749af68 RK |
409 | } |
410 | ||
411 | return ret; | |
412 | } | |
413 | ||
2ea83398 RK |
414 | /* |
415 | * Reprogram the system timer for at least the calculated time interval. | |
416 | * This function should be called from the idle thread with IRQs disabled, | |
417 | * immediately before sleeping. | |
418 | */ | |
8749af68 RK |
419 | void timer_dyn_reprogram(void) |
420 | { | |
421 | struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; | |
ebc67da6 | 422 | unsigned long next, seq, flags; |
8749af68 | 423 | |
ebc67da6 TL |
424 | if (!dyn_tick) |
425 | return; | |
426 | ||
427 | spin_lock_irqsave(&dyn_tick->lock, flags); | |
428 | if (dyn_tick->state & DYN_TICK_ENABLED) { | |
69239749 TL |
429 | next = next_timer_interrupt(); |
430 | do { | |
431 | seq = read_seqbegin(&xtime_lock); | |
ebc67da6 | 432 | dyn_tick->reprogram(next - jiffies); |
69239749 | 433 | } while (read_seqretry(&xtime_lock, seq)); |
3618886f | 434 | } |
ebc67da6 | 435 | spin_unlock_irqrestore(&dyn_tick->lock, flags); |
8749af68 RK |
436 | } |
437 | ||
438 | static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf) | |
439 | { | |
440 | return sprintf(buf, "%i\n", | |
441 | (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1); | |
442 | } | |
443 | ||
444 | static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf, | |
445 | size_t count) | |
446 | { | |
447 | unsigned int enable = simple_strtoul(buf, NULL, 2); | |
448 | ||
449 | if (enable) | |
450 | timer_dyn_tick_enable(); | |
451 | else | |
452 | timer_dyn_tick_disable(); | |
453 | ||
454 | return count; | |
455 | } | |
456 | static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick); | |
457 | ||
458 | /* | |
459 | * dyntick=enable|disable | |
460 | */ | |
461 | static char dyntick_str[4] __initdata = ""; | |
462 | ||
463 | static int __init dyntick_setup(char *str) | |
464 | { | |
465 | if (str) | |
466 | strlcpy(dyntick_str, str, sizeof(dyntick_str)); | |
467 | return 1; | |
468 | } | |
469 | ||
470 | __setup("dyntick=", dyntick_setup); | |
471 | #endif | |
472 | ||
1da177e4 LT |
473 | static int __init timer_init_sysfs(void) |
474 | { | |
475 | int ret = sysdev_class_register(&timer_sysclass); | |
476 | if (ret == 0) { | |
477 | system_timer->dev.cls = &timer_sysclass; | |
478 | ret = sysdev_register(&system_timer->dev); | |
479 | } | |
8749af68 RK |
480 | |
481 | #ifdef CONFIG_NO_IDLE_HZ | |
482 | if (ret == 0 && system_timer->dyn_tick) { | |
483 | ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick); | |
484 | ||
485 | /* | |
486 | * Turn on dynamic tick after calibrate delay | |
487 | * for correct bogomips | |
488 | */ | |
489 | if (ret == 0 && dyntick_str[0] == 'e') | |
490 | ret = timer_dyn_tick_enable(); | |
491 | } | |
492 | #endif | |
493 | ||
1da177e4 LT |
494 | return ret; |
495 | } | |
496 | ||
497 | device_initcall(timer_init_sysfs); | |
498 | ||
499 | void __init time_init(void) | |
500 | { | |
746140c7 | 501 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
502 | if (system_timer->offset == NULL) |
503 | system_timer->offset = dummy_gettimeoffset; | |
746140c7 | 504 | #endif |
1da177e4 | 505 | system_timer->init(); |
ebc67da6 TL |
506 | |
507 | #ifdef CONFIG_NO_IDLE_HZ | |
508 | if (system_timer->dyn_tick) | |
509 | system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED; | |
510 | #endif | |
1da177e4 LT |
511 | } |
512 |