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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
19#include <linux/config.h>
20#include <linux/module.h>
21#include <linux/kernel.h>
22#include <linux/interrupt.h>
23#include <linux/time.h>
24#include <linux/init.h>
25#include <linux/smp.h>
26#include <linux/timex.h>
27#include <linux/errno.h>
28#include <linux/profile.h>
29#include <linux/sysdev.h>
30#include <linux/timer.h>
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <asm/leds.h>
33#include <asm/thread_info.h>
34#include <asm/mach/time.h>
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036/*
37 * Our system timer.
38 */
39struct sys_timer *system_timer;
40
41extern unsigned long wall_jiffies;
42
43/* this needs a better home */
44DEFINE_SPINLOCK(rtc_lock);
45
46#ifdef CONFIG_SA1100_RTC_MODULE
47EXPORT_SYMBOL(rtc_lock);
48#endif
49
50/* change this if you have some constant time drift */
51#define USECS_PER_JIFFY (1000000/HZ)
52
53#ifdef CONFIG_SMP
54unsigned long profile_pc(struct pt_regs *regs)
55{
56 unsigned long fp, pc = instruction_pointer(regs);
57
58 if (in_lock_functions(pc)) {
59 fp = regs->ARM_fp;
60 pc = pc_pointer(((unsigned long *)fp)[-1]);
61 }
62
63 return pc;
64}
65EXPORT_SYMBOL(profile_pc);
66#endif
67
68/*
69 * hook for setting the RTC's idea of the current time.
70 */
71int (*set_rtc)(void);
72
73static unsigned long dummy_gettimeoffset(void)
74{
75 return 0;
76}
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 */
83unsigned long long __attribute__((weak)) sched_clock(void)
84{
85 return (unsigned long long)jiffies * (1000000000 / HZ);
86}
87
88static 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 */
96static inline void do_set_rtc(void)
97{
john stultzb149ee22005-09-06 15:17:46 -070098 if (!ntp_synced() || set_rtc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 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
120static void dummy_leds_event(led_event_t evt)
121{
122}
123
124void (*leds_event)(led_event_t) = dummy_leds_event;
125
126struct leds_evt_name {
127 const char name[8];
128 int on;
129 int off;
130};
131
132static 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
139static 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
172static SYSDEV_ATTR(event, 0200, NULL, leds_store);
173
174static int leds_suspend(struct sys_device *dev, pm_message_t state)
175{
176 leds_event(led_stop);
177 return 0;
178}
179
180static int leds_resume(struct sys_device *dev)
181{
182 leds_event(led_start);
183 return 0;
184}
185
186static int leds_shutdown(struct sys_device *dev)
187{
188 leds_event(led_halted);
189 return 0;
190}
191
192static struct sysdev_class leds_sysclass = {
193 set_kset_name("leds"),
194 .shutdown = leds_shutdown,
195 .suspend = leds_suspend,
196 .resume = leds_resume,
197};
198
199static struct sys_device leds_device = {
200 .id = 0,
201 .cls = &leds_sysclass,
202};
203
204static 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
215device_initcall(leds_init);
216
217EXPORT_SYMBOL(leds_event);
218#endif
219
220#ifdef CONFIG_LEDS_TIMER
221static 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
234void do_gettimeofday(struct timeval *tv)
235{
236 unsigned long flags;
237 unsigned long seq;
238 unsigned long usec, sec, lost;
239
240 do {
241 seq = read_seqbegin_irqsave(&xtime_lock, flags);
242 usec = system_timer->offset();
243
244 lost = jiffies - wall_jiffies;
245 if (lost)
246 usec += lost * USECS_PER_JIFFY;
247
248 sec = xtime.tv_sec;
249 usec += xtime.tv_nsec / 1000;
250 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
251
252 /* usec may have gone up a lot: be safe */
253 while (usec >= 1000000) {
254 usec -= 1000000;
255 sec++;
256 }
257
258 tv->tv_sec = sec;
259 tv->tv_usec = usec;
260}
261
262EXPORT_SYMBOL(do_gettimeofday);
263
264int do_settimeofday(struct timespec *tv)
265{
266 time_t wtm_sec, sec = tv->tv_sec;
267 long wtm_nsec, nsec = tv->tv_nsec;
268
269 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
270 return -EINVAL;
271
272 write_seqlock_irq(&xtime_lock);
273 /*
274 * This is revolting. We need to set "xtime" correctly. However, the
275 * value in this location is the value at the most recent update of
276 * wall time. Discover what correction gettimeofday() would have
277 * done, and then undo it!
278 */
279 nsec -= system_timer->offset() * NSEC_PER_USEC;
280 nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
281
282 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
283 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
284
285 set_normalized_timespec(&xtime, sec, nsec);
286 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
287
john stultzb149ee22005-09-06 15:17:46 -0700288 ntp_clear();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 write_sequnlock_irq(&xtime_lock);
290 clock_was_set();
291 return 0;
292}
293
294EXPORT_SYMBOL(do_settimeofday);
295
296/**
297 * save_time_delta - Save the offset between system time and RTC time
298 * @delta: pointer to timespec to store delta
299 * @rtc: pointer to timespec for current RTC time
300 *
301 * Return a delta between the system time and the RTC time, such
302 * that system time can be restored later with restore_time_delta()
303 */
304void save_time_delta(struct timespec *delta, struct timespec *rtc)
305{
306 set_normalized_timespec(delta,
307 xtime.tv_sec - rtc->tv_sec,
308 xtime.tv_nsec - rtc->tv_nsec);
309}
310EXPORT_SYMBOL(save_time_delta);
311
312/**
313 * restore_time_delta - Restore the current system time
314 * @delta: delta returned by save_time_delta()
315 * @rtc: pointer to timespec for current RTC time
316 */
317void restore_time_delta(struct timespec *delta, struct timespec *rtc)
318{
319 struct timespec ts;
320
321 set_normalized_timespec(&ts,
322 delta->tv_sec + rtc->tv_sec,
323 delta->tv_nsec + rtc->tv_nsec);
324
325 do_settimeofday(&ts);
326}
327EXPORT_SYMBOL(restore_time_delta);
328
329/*
330 * Kernel system timer support.
331 */
332void timer_tick(struct pt_regs *regs)
333{
334 profile_tick(CPU_PROFILING, regs);
335 do_leds();
336 do_set_rtc();
337 do_timer(regs);
338#ifndef CONFIG_SMP
339 update_process_times(user_mode(regs));
340#endif
341}
342
343#ifdef CONFIG_PM
344static int timer_suspend(struct sys_device *dev, pm_message_t state)
345{
346 struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
347
348 if (timer->suspend != NULL)
349 timer->suspend();
350
351 return 0;
352}
353
354static int timer_resume(struct sys_device *dev)
355{
356 struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
357
358 if (timer->resume != NULL)
359 timer->resume();
360
361 return 0;
362}
363#else
364#define timer_suspend NULL
365#define timer_resume NULL
366#endif
367
368static struct sysdev_class timer_sysclass = {
369 set_kset_name("timer"),
370 .suspend = timer_suspend,
371 .resume = timer_resume,
372};
373
Russell King8749af62005-06-25 19:39:45 +0100374#ifdef CONFIG_NO_IDLE_HZ
375static int timer_dyn_tick_enable(void)
376{
377 struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
378 unsigned long flags;
379 int ret = -ENODEV;
380
381 if (dyn_tick) {
382 write_seqlock_irqsave(&xtime_lock, flags);
383 ret = 0;
384 if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
385 ret = dyn_tick->enable();
386
387 if (ret == 0)
388 dyn_tick->state |= DYN_TICK_ENABLED;
389 }
390 write_sequnlock_irqrestore(&xtime_lock, flags);
391 }
392
393 return ret;
394}
395
396static int timer_dyn_tick_disable(void)
397{
398 struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
399 unsigned long flags;
400 int ret = -ENODEV;
401
402 if (dyn_tick) {
403 write_seqlock_irqsave(&xtime_lock, flags);
404 ret = 0;
405 if (dyn_tick->state & DYN_TICK_ENABLED) {
406 ret = dyn_tick->disable();
407
408 if (ret == 0)
409 dyn_tick->state &= ~DYN_TICK_ENABLED;
410 }
411 write_sequnlock_irqrestore(&xtime_lock, flags);
412 }
413
414 return ret;
415}
416
Russell King2ea83392005-06-27 14:04:05 +0100417/*
418 * Reprogram the system timer for at least the calculated time interval.
419 * This function should be called from the idle thread with IRQs disabled,
420 * immediately before sleeping.
421 */
Russell King8749af62005-06-25 19:39:45 +0100422void timer_dyn_reprogram(void)
423{
424 struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
Tony Lindgren69239742006-03-06 15:42:45 -0800425 unsigned long next, seq;
Russell King8749af62005-06-25 19:39:45 +0100426
Tony Lindgren69239742006-03-06 15:42:45 -0800427 if (dyn_tick && (dyn_tick->state & DYN_TICK_ENABLED)) {
428 next = next_timer_interrupt();
429 do {
430 seq = read_seqbegin(&xtime_lock);
Ben Dooks36188862005-08-31 09:42:14 +0100431 dyn_tick->reprogram(next_timer_interrupt() - jiffies);
Tony Lindgren69239742006-03-06 15:42:45 -0800432 } while (read_seqretry(&xtime_lock, seq));
Ben Dooks36188862005-08-31 09:42:14 +0100433 }
Russell King8749af62005-06-25 19:39:45 +0100434}
435
436static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf)
437{
438 return sprintf(buf, "%i\n",
439 (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
440}
441
442static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf,
443 size_t count)
444{
445 unsigned int enable = simple_strtoul(buf, NULL, 2);
446
447 if (enable)
448 timer_dyn_tick_enable();
449 else
450 timer_dyn_tick_disable();
451
452 return count;
453}
454static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
455
456/*
457 * dyntick=enable|disable
458 */
459static char dyntick_str[4] __initdata = "";
460
461static int __init dyntick_setup(char *str)
462{
463 if (str)
464 strlcpy(dyntick_str, str, sizeof(dyntick_str));
465 return 1;
466}
467
468__setup("dyntick=", dyntick_setup);
469#endif
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471static int __init timer_init_sysfs(void)
472{
473 int ret = sysdev_class_register(&timer_sysclass);
474 if (ret == 0) {
475 system_timer->dev.cls = &timer_sysclass;
476 ret = sysdev_register(&system_timer->dev);
477 }
Russell King8749af62005-06-25 19:39:45 +0100478
479#ifdef CONFIG_NO_IDLE_HZ
480 if (ret == 0 && system_timer->dyn_tick) {
481 ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick);
482
483 /*
484 * Turn on dynamic tick after calibrate delay
485 * for correct bogomips
486 */
487 if (ret == 0 && dyntick_str[0] == 'e')
488 ret = timer_dyn_tick_enable();
489 }
490#endif
491
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 return ret;
493}
494
495device_initcall(timer_init_sysfs);
496
497void __init time_init(void)
498{
499 if (system_timer->offset == NULL)
500 system_timer->offset = dummy_gettimeoffset;
501 system_timer->init();
502}
503