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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 | */ | |
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 | ||
32 | #include <asm/hardware.h> | |
33 | #include <asm/io.h> | |
34 | #include <asm/irq.h> | |
35 | #include <asm/leds.h> | |
36 | #include <asm/thread_info.h> | |
37 | #include <asm/mach/time.h> | |
38 | ||
39 | u64 jiffies_64 = INITIAL_JIFFIES; | |
40 | ||
41 | EXPORT_SYMBOL(jiffies_64); | |
42 | ||
43 | /* | |
44 | * Our system timer. | |
45 | */ | |
46 | struct sys_timer *system_timer; | |
47 | ||
48 | extern unsigned long wall_jiffies; | |
49 | ||
50 | /* this needs a better home */ | |
51 | DEFINE_SPINLOCK(rtc_lock); | |
52 | ||
53 | #ifdef CONFIG_SA1100_RTC_MODULE | |
54 | EXPORT_SYMBOL(rtc_lock); | |
55 | #endif | |
56 | ||
57 | /* change this if you have some constant time drift */ | |
58 | #define USECS_PER_JIFFY (1000000/HZ) | |
59 | ||
60 | #ifdef CONFIG_SMP | |
61 | unsigned long profile_pc(struct pt_regs *regs) | |
62 | { | |
63 | unsigned long fp, pc = instruction_pointer(regs); | |
64 | ||
65 | if (in_lock_functions(pc)) { | |
66 | fp = regs->ARM_fp; | |
67 | pc = pc_pointer(((unsigned long *)fp)[-1]); | |
68 | } | |
69 | ||
70 | return pc; | |
71 | } | |
72 | EXPORT_SYMBOL(profile_pc); | |
73 | #endif | |
74 | ||
75 | /* | |
76 | * hook for setting the RTC's idea of the current time. | |
77 | */ | |
78 | int (*set_rtc)(void); | |
79 | ||
80 | static unsigned long dummy_gettimeoffset(void) | |
81 | { | |
82 | return 0; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Scheduler clock - returns current time in nanosec units. | |
87 | * This is the default implementation. Sub-architecture | |
88 | * implementations can override this. | |
89 | */ | |
90 | unsigned long long __attribute__((weak)) sched_clock(void) | |
91 | { | |
92 | return (unsigned long long)jiffies * (1000000000 / HZ); | |
93 | } | |
94 | ||
95 | static unsigned long next_rtc_update; | |
96 | ||
97 | /* | |
98 | * If we have an externally synchronized linux clock, then update | |
99 | * CMOS clock accordingly every ~11 minutes. set_rtc() has to be | |
100 | * called as close as possible to 500 ms before the new second | |
101 | * starts. | |
102 | */ | |
103 | static inline void do_set_rtc(void) | |
104 | { | |
105 | if (time_status & STA_UNSYNC || set_rtc == NULL) | |
106 | return; | |
107 | ||
108 | if (next_rtc_update && | |
109 | time_before((unsigned long)xtime.tv_sec, next_rtc_update)) | |
110 | return; | |
111 | ||
112 | if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) && | |
113 | xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1)) | |
114 | return; | |
115 | ||
116 | if (set_rtc()) | |
117 | /* | |
118 | * rtc update failed. Try again in 60s | |
119 | */ | |
120 | next_rtc_update = xtime.tv_sec + 60; | |
121 | else | |
122 | next_rtc_update = xtime.tv_sec + 660; | |
123 | } | |
124 | ||
125 | #ifdef CONFIG_LEDS | |
126 | ||
127 | static void dummy_leds_event(led_event_t evt) | |
128 | { | |
129 | } | |
130 | ||
131 | void (*leds_event)(led_event_t) = dummy_leds_event; | |
132 | ||
133 | struct leds_evt_name { | |
134 | const char name[8]; | |
135 | int on; | |
136 | int off; | |
137 | }; | |
138 | ||
139 | static const struct leds_evt_name evt_names[] = { | |
140 | { "amber", led_amber_on, led_amber_off }, | |
141 | { "blue", led_blue_on, led_blue_off }, | |
142 | { "green", led_green_on, led_green_off }, | |
143 | { "red", led_red_on, led_red_off }, | |
144 | }; | |
145 | ||
146 | static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size) | |
147 | { | |
148 | int ret = -EINVAL, len = strcspn(buf, " "); | |
149 | ||
150 | if (len > 0 && buf[len] == '\0') | |
151 | len--; | |
152 | ||
153 | if (strncmp(buf, "claim", len) == 0) { | |
154 | leds_event(led_claim); | |
155 | ret = size; | |
156 | } else if (strncmp(buf, "release", len) == 0) { | |
157 | leds_event(led_release); | |
158 | ret = size; | |
159 | } else { | |
160 | int i; | |
161 | ||
162 | for (i = 0; i < ARRAY_SIZE(evt_names); i++) { | |
163 | if (strlen(evt_names[i].name) != len || | |
164 | strncmp(buf, evt_names[i].name, len) != 0) | |
165 | continue; | |
166 | if (strncmp(buf+len, " on", 3) == 0) { | |
167 | leds_event(evt_names[i].on); | |
168 | ret = size; | |
169 | } else if (strncmp(buf+len, " off", 4) == 0) { | |
170 | leds_event(evt_names[i].off); | |
171 | ret = size; | |
172 | } | |
173 | break; | |
174 | } | |
175 | } | |
176 | return ret; | |
177 | } | |
178 | ||
179 | static SYSDEV_ATTR(event, 0200, NULL, leds_store); | |
180 | ||
181 | static int leds_suspend(struct sys_device *dev, pm_message_t state) | |
182 | { | |
183 | leds_event(led_stop); | |
184 | return 0; | |
185 | } | |
186 | ||
187 | static int leds_resume(struct sys_device *dev) | |
188 | { | |
189 | leds_event(led_start); | |
190 | return 0; | |
191 | } | |
192 | ||
193 | static int leds_shutdown(struct sys_device *dev) | |
194 | { | |
195 | leds_event(led_halted); | |
196 | return 0; | |
197 | } | |
198 | ||
199 | static struct sysdev_class leds_sysclass = { | |
200 | set_kset_name("leds"), | |
201 | .shutdown = leds_shutdown, | |
202 | .suspend = leds_suspend, | |
203 | .resume = leds_resume, | |
204 | }; | |
205 | ||
206 | static struct sys_device leds_device = { | |
207 | .id = 0, | |
208 | .cls = &leds_sysclass, | |
209 | }; | |
210 | ||
211 | static int __init leds_init(void) | |
212 | { | |
213 | int ret; | |
214 | ret = sysdev_class_register(&leds_sysclass); | |
215 | if (ret == 0) | |
216 | ret = sysdev_register(&leds_device); | |
217 | if (ret == 0) | |
218 | ret = sysdev_create_file(&leds_device, &attr_event); | |
219 | return ret; | |
220 | } | |
221 | ||
222 | device_initcall(leds_init); | |
223 | ||
224 | EXPORT_SYMBOL(leds_event); | |
225 | #endif | |
226 | ||
227 | #ifdef CONFIG_LEDS_TIMER | |
228 | static inline void do_leds(void) | |
229 | { | |
230 | static unsigned int count = 50; | |
231 | ||
232 | if (--count == 0) { | |
233 | count = 50; | |
234 | leds_event(led_timer); | |
235 | } | |
236 | } | |
237 | #else | |
238 | #define do_leds() | |
239 | #endif | |
240 | ||
241 | void do_gettimeofday(struct timeval *tv) | |
242 | { | |
243 | unsigned long flags; | |
244 | unsigned long seq; | |
245 | unsigned long usec, sec, lost; | |
246 | ||
247 | do { | |
248 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | |
249 | usec = system_timer->offset(); | |
250 | ||
251 | lost = jiffies - wall_jiffies; | |
252 | if (lost) | |
253 | usec += lost * USECS_PER_JIFFY; | |
254 | ||
255 | sec = xtime.tv_sec; | |
256 | usec += xtime.tv_nsec / 1000; | |
257 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | |
258 | ||
259 | /* usec may have gone up a lot: be safe */ | |
260 | while (usec >= 1000000) { | |
261 | usec -= 1000000; | |
262 | sec++; | |
263 | } | |
264 | ||
265 | tv->tv_sec = sec; | |
266 | tv->tv_usec = usec; | |
267 | } | |
268 | ||
269 | EXPORT_SYMBOL(do_gettimeofday); | |
270 | ||
271 | int do_settimeofday(struct timespec *tv) | |
272 | { | |
273 | time_t wtm_sec, sec = tv->tv_sec; | |
274 | long wtm_nsec, nsec = tv->tv_nsec; | |
275 | ||
276 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
277 | return -EINVAL; | |
278 | ||
279 | write_seqlock_irq(&xtime_lock); | |
280 | /* | |
281 | * This is revolting. We need to set "xtime" correctly. However, the | |
282 | * value in this location is the value at the most recent update of | |
283 | * wall time. Discover what correction gettimeofday() would have | |
284 | * done, and then undo it! | |
285 | */ | |
286 | nsec -= system_timer->offset() * NSEC_PER_USEC; | |
287 | nsec -= (jiffies - wall_jiffies) * TICK_NSEC; | |
288 | ||
289 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | |
290 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
291 | ||
292 | set_normalized_timespec(&xtime, sec, nsec); | |
293 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
294 | ||
295 | time_adjust = 0; /* stop active adjtime() */ | |
296 | time_status |= STA_UNSYNC; | |
297 | time_maxerror = NTP_PHASE_LIMIT; | |
298 | time_esterror = NTP_PHASE_LIMIT; | |
299 | write_sequnlock_irq(&xtime_lock); | |
300 | clock_was_set(); | |
301 | return 0; | |
302 | } | |
303 | ||
304 | EXPORT_SYMBOL(do_settimeofday); | |
305 | ||
306 | /** | |
307 | * save_time_delta - Save the offset between system time and RTC time | |
308 | * @delta: pointer to timespec to store delta | |
309 | * @rtc: pointer to timespec for current RTC time | |
310 | * | |
311 | * Return a delta between the system time and the RTC time, such | |
312 | * that system time can be restored later with restore_time_delta() | |
313 | */ | |
314 | void save_time_delta(struct timespec *delta, struct timespec *rtc) | |
315 | { | |
316 | set_normalized_timespec(delta, | |
317 | xtime.tv_sec - rtc->tv_sec, | |
318 | xtime.tv_nsec - rtc->tv_nsec); | |
319 | } | |
320 | EXPORT_SYMBOL(save_time_delta); | |
321 | ||
322 | /** | |
323 | * restore_time_delta - Restore the current system time | |
324 | * @delta: delta returned by save_time_delta() | |
325 | * @rtc: pointer to timespec for current RTC time | |
326 | */ | |
327 | void restore_time_delta(struct timespec *delta, struct timespec *rtc) | |
328 | { | |
329 | struct timespec ts; | |
330 | ||
331 | set_normalized_timespec(&ts, | |
332 | delta->tv_sec + rtc->tv_sec, | |
333 | delta->tv_nsec + rtc->tv_nsec); | |
334 | ||
335 | do_settimeofday(&ts); | |
336 | } | |
337 | EXPORT_SYMBOL(restore_time_delta); | |
338 | ||
339 | /* | |
340 | * Kernel system timer support. | |
341 | */ | |
342 | void timer_tick(struct pt_regs *regs) | |
343 | { | |
344 | profile_tick(CPU_PROFILING, regs); | |
345 | do_leds(); | |
346 | do_set_rtc(); | |
347 | do_timer(regs); | |
348 | #ifndef CONFIG_SMP | |
349 | update_process_times(user_mode(regs)); | |
350 | #endif | |
351 | } | |
352 | ||
353 | #ifdef CONFIG_PM | |
354 | static int timer_suspend(struct sys_device *dev, pm_message_t state) | |
355 | { | |
356 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
357 | ||
358 | if (timer->suspend != NULL) | |
359 | timer->suspend(); | |
360 | ||
361 | return 0; | |
362 | } | |
363 | ||
364 | static int timer_resume(struct sys_device *dev) | |
365 | { | |
366 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
367 | ||
368 | if (timer->resume != NULL) | |
369 | timer->resume(); | |
370 | ||
371 | return 0; | |
372 | } | |
373 | #else | |
374 | #define timer_suspend NULL | |
375 | #define timer_resume NULL | |
376 | #endif | |
377 | ||
378 | static struct sysdev_class timer_sysclass = { | |
379 | set_kset_name("timer"), | |
380 | .suspend = timer_suspend, | |
381 | .resume = timer_resume, | |
382 | }; | |
383 | ||
384 | static int __init timer_init_sysfs(void) | |
385 | { | |
386 | int ret = sysdev_class_register(&timer_sysclass); | |
387 | if (ret == 0) { | |
388 | system_timer->dev.cls = &timer_sysclass; | |
389 | ret = sysdev_register(&system_timer->dev); | |
390 | } | |
391 | return ret; | |
392 | } | |
393 | ||
394 | device_initcall(timer_init_sysfs); | |
395 | ||
396 | void __init time_init(void) | |
397 | { | |
398 | if (system_timer->offset == NULL) | |
399 | system_timer->offset = dummy_gettimeoffset; | |
400 | system_timer->init(); | |
401 | } | |
402 |