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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 | |
9ca3f07b BD |
32 | #include <linux/mc146818rtc.h> |
33 | ||
1da177e4 LT |
34 | #include <asm/leds.h> |
35 | #include <asm/thread_info.h> | |
36 | #include <asm/mach/time.h> | |
37 | ||
1da177e4 LT |
38 | /* |
39 | * Our system timer. | |
40 | */ | |
41 | struct sys_timer *system_timer; | |
42 | ||
9dd34948 | 43 | #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) |
1da177e4 LT |
44 | /* this needs a better home */ |
45 | DEFINE_SPINLOCK(rtc_lock); | |
46 | ||
9dd34948 | 47 | #ifdef CONFIG_RTC_DRV_CMOS_MODULE |
1da177e4 LT |
48 | EXPORT_SYMBOL(rtc_lock); |
49 | #endif | |
9dd34948 | 50 | #endif /* pc-style 'CMOS' RTC support */ |
1da177e4 LT |
51 | |
52 | /* change this if you have some constant time drift */ | |
53 | #define USECS_PER_JIFFY (1000000/HZ) | |
54 | ||
55 | #ifdef CONFIG_SMP | |
56 | unsigned long profile_pc(struct pt_regs *regs) | |
57 | { | |
58 | unsigned long fp, pc = instruction_pointer(regs); | |
59 | ||
60 | if (in_lock_functions(pc)) { | |
61 | fp = regs->ARM_fp; | |
62 | pc = pc_pointer(((unsigned long *)fp)[-1]); | |
63 | } | |
64 | ||
65 | return pc; | |
66 | } | |
67 | EXPORT_SYMBOL(profile_pc); | |
68 | #endif | |
69 | ||
70 | /* | |
71 | * hook for setting the RTC's idea of the current time. | |
72 | */ | |
73 | int (*set_rtc)(void); | |
74 | ||
746140c7 | 75 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
76 | static unsigned long dummy_gettimeoffset(void) |
77 | { | |
78 | return 0; | |
79 | } | |
746140c7 | 80 | #endif |
1da177e4 | 81 | |
1da177e4 LT |
82 | static unsigned long next_rtc_update; |
83 | ||
84 | /* | |
85 | * If we have an externally synchronized linux clock, then update | |
86 | * CMOS clock accordingly every ~11 minutes. set_rtc() has to be | |
87 | * called as close as possible to 500 ms before the new second | |
88 | * starts. | |
89 | */ | |
90 | static inline void do_set_rtc(void) | |
91 | { | |
b149ee22 | 92 | if (!ntp_synced() || set_rtc == NULL) |
1da177e4 LT |
93 | return; |
94 | ||
95 | if (next_rtc_update && | |
96 | time_before((unsigned long)xtime.tv_sec, next_rtc_update)) | |
97 | return; | |
98 | ||
99 | if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) && | |
100 | xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1)) | |
101 | return; | |
102 | ||
103 | if (set_rtc()) | |
104 | /* | |
105 | * rtc update failed. Try again in 60s | |
106 | */ | |
107 | next_rtc_update = xtime.tv_sec + 60; | |
108 | else | |
109 | next_rtc_update = xtime.tv_sec + 660; | |
110 | } | |
111 | ||
112 | #ifdef CONFIG_LEDS | |
113 | ||
114 | static void dummy_leds_event(led_event_t evt) | |
115 | { | |
116 | } | |
117 | ||
118 | void (*leds_event)(led_event_t) = dummy_leds_event; | |
119 | ||
120 | struct leds_evt_name { | |
121 | const char name[8]; | |
122 | int on; | |
123 | int off; | |
124 | }; | |
125 | ||
126 | static const struct leds_evt_name evt_names[] = { | |
127 | { "amber", led_amber_on, led_amber_off }, | |
128 | { "blue", led_blue_on, led_blue_off }, | |
129 | { "green", led_green_on, led_green_off }, | |
130 | { "red", led_red_on, led_red_off }, | |
131 | }; | |
132 | ||
4a0b2b4d AK |
133 | static ssize_t leds_store(struct sys_device *dev, |
134 | struct sysdev_attribute *attr, | |
135 | const char *buf, size_t size) | |
1da177e4 LT |
136 | { |
137 | int ret = -EINVAL, len = strcspn(buf, " "); | |
138 | ||
139 | if (len > 0 && buf[len] == '\0') | |
140 | len--; | |
141 | ||
142 | if (strncmp(buf, "claim", len) == 0) { | |
143 | leds_event(led_claim); | |
144 | ret = size; | |
145 | } else if (strncmp(buf, "release", len) == 0) { | |
146 | leds_event(led_release); | |
147 | ret = size; | |
148 | } else { | |
149 | int i; | |
150 | ||
151 | for (i = 0; i < ARRAY_SIZE(evt_names); i++) { | |
152 | if (strlen(evt_names[i].name) != len || | |
153 | strncmp(buf, evt_names[i].name, len) != 0) | |
154 | continue; | |
155 | if (strncmp(buf+len, " on", 3) == 0) { | |
156 | leds_event(evt_names[i].on); | |
157 | ret = size; | |
158 | } else if (strncmp(buf+len, " off", 4) == 0) { | |
159 | leds_event(evt_names[i].off); | |
160 | ret = size; | |
161 | } | |
162 | break; | |
163 | } | |
164 | } | |
165 | return ret; | |
166 | } | |
167 | ||
168 | static SYSDEV_ATTR(event, 0200, NULL, leds_store); | |
169 | ||
170 | static int leds_suspend(struct sys_device *dev, pm_message_t state) | |
171 | { | |
172 | leds_event(led_stop); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static int leds_resume(struct sys_device *dev) | |
177 | { | |
178 | leds_event(led_start); | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static int leds_shutdown(struct sys_device *dev) | |
183 | { | |
184 | leds_event(led_halted); | |
185 | return 0; | |
186 | } | |
187 | ||
188 | static struct sysdev_class leds_sysclass = { | |
af5ca3f4 | 189 | .name = "leds", |
1da177e4 LT |
190 | .shutdown = leds_shutdown, |
191 | .suspend = leds_suspend, | |
192 | .resume = leds_resume, | |
193 | }; | |
194 | ||
195 | static struct sys_device leds_device = { | |
196 | .id = 0, | |
197 | .cls = &leds_sysclass, | |
198 | }; | |
199 | ||
200 | static int __init leds_init(void) | |
201 | { | |
202 | int ret; | |
203 | ret = sysdev_class_register(&leds_sysclass); | |
204 | if (ret == 0) | |
205 | ret = sysdev_register(&leds_device); | |
206 | if (ret == 0) | |
207 | ret = sysdev_create_file(&leds_device, &attr_event); | |
208 | return ret; | |
209 | } | |
210 | ||
211 | device_initcall(leds_init); | |
212 | ||
213 | EXPORT_SYMBOL(leds_event); | |
214 | #endif | |
215 | ||
216 | #ifdef CONFIG_LEDS_TIMER | |
217 | static inline void do_leds(void) | |
218 | { | |
6d15cb42 | 219 | static unsigned int count = HZ/2; |
1da177e4 LT |
220 | |
221 | if (--count == 0) { | |
6d15cb42 | 222 | count = HZ/2; |
1da177e4 LT |
223 | leds_event(led_timer); |
224 | } | |
225 | } | |
226 | #else | |
227 | #define do_leds() | |
228 | #endif | |
229 | ||
746140c7 | 230 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
231 | void do_gettimeofday(struct timeval *tv) |
232 | { | |
233 | unsigned long flags; | |
234 | unsigned long seq; | |
8ef38609 | 235 | unsigned long usec, sec; |
1da177e4 LT |
236 | |
237 | do { | |
238 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | |
239 | usec = system_timer->offset(); | |
1da177e4 LT |
240 | sec = xtime.tv_sec; |
241 | usec += xtime.tv_nsec / 1000; | |
242 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | |
243 | ||
244 | /* usec may have gone up a lot: be safe */ | |
245 | while (usec >= 1000000) { | |
246 | usec -= 1000000; | |
247 | sec++; | |
248 | } | |
249 | ||
250 | tv->tv_sec = sec; | |
251 | tv->tv_usec = usec; | |
252 | } | |
253 | ||
254 | EXPORT_SYMBOL(do_gettimeofday); | |
255 | ||
256 | int do_settimeofday(struct timespec *tv) | |
257 | { | |
258 | time_t wtm_sec, sec = tv->tv_sec; | |
259 | long wtm_nsec, nsec = tv->tv_nsec; | |
260 | ||
261 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
262 | return -EINVAL; | |
263 | ||
264 | write_seqlock_irq(&xtime_lock); | |
265 | /* | |
266 | * This is revolting. We need to set "xtime" correctly. However, the | |
267 | * value in this location is the value at the most recent update of | |
268 | * wall time. Discover what correction gettimeofday() would have | |
269 | * done, and then undo it! | |
270 | */ | |
271 | nsec -= system_timer->offset() * NSEC_PER_USEC; | |
1da177e4 LT |
272 | |
273 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | |
274 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
275 | ||
276 | set_normalized_timespec(&xtime, sec, nsec); | |
277 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
278 | ||
b149ee22 | 279 | ntp_clear(); |
1da177e4 LT |
280 | write_sequnlock_irq(&xtime_lock); |
281 | clock_was_set(); | |
282 | return 0; | |
283 | } | |
284 | ||
285 | EXPORT_SYMBOL(do_settimeofday); | |
746140c7 | 286 | #endif /* !CONFIG_GENERIC_TIME */ |
1da177e4 LT |
287 | |
288 | /** | |
289 | * save_time_delta - Save the offset between system time and RTC time | |
290 | * @delta: pointer to timespec to store delta | |
291 | * @rtc: pointer to timespec for current RTC time | |
292 | * | |
293 | * Return a delta between the system time and the RTC time, such | |
294 | * that system time can be restored later with restore_time_delta() | |
295 | */ | |
296 | void save_time_delta(struct timespec *delta, struct timespec *rtc) | |
297 | { | |
298 | set_normalized_timespec(delta, | |
299 | xtime.tv_sec - rtc->tv_sec, | |
300 | xtime.tv_nsec - rtc->tv_nsec); | |
301 | } | |
302 | EXPORT_SYMBOL(save_time_delta); | |
303 | ||
304 | /** | |
305 | * restore_time_delta - Restore the current system time | |
306 | * @delta: delta returned by save_time_delta() | |
307 | * @rtc: pointer to timespec for current RTC time | |
308 | */ | |
309 | void restore_time_delta(struct timespec *delta, struct timespec *rtc) | |
310 | { | |
311 | struct timespec ts; | |
312 | ||
313 | set_normalized_timespec(&ts, | |
314 | delta->tv_sec + rtc->tv_sec, | |
315 | delta->tv_nsec + rtc->tv_nsec); | |
316 | ||
317 | do_settimeofday(&ts); | |
318 | } | |
319 | EXPORT_SYMBOL(restore_time_delta); | |
320 | ||
9e4559dd | 321 | #ifndef CONFIG_GENERIC_CLOCKEVENTS |
1da177e4 LT |
322 | /* |
323 | * Kernel system timer support. | |
324 | */ | |
0cd61b68 | 325 | void timer_tick(void) |
1da177e4 | 326 | { |
e317c8cc | 327 | profile_tick(CPU_PROFILING); |
1da177e4 LT |
328 | do_leds(); |
329 | do_set_rtc(); | |
193c3cc1 | 330 | write_seqlock(&xtime_lock); |
3171a030 | 331 | do_timer(1); |
193c3cc1 | 332 | write_sequnlock(&xtime_lock); |
1da177e4 | 333 | #ifndef CONFIG_SMP |
c97d4869 | 334 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
335 | #endif |
336 | } | |
9e4559dd | 337 | #endif |
1da177e4 | 338 | |
9e4559dd | 339 | #if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) |
1da177e4 LT |
340 | static int timer_suspend(struct sys_device *dev, pm_message_t state) |
341 | { | |
342 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
343 | ||
344 | if (timer->suspend != NULL) | |
345 | timer->suspend(); | |
346 | ||
347 | return 0; | |
348 | } | |
349 | ||
350 | static int timer_resume(struct sys_device *dev) | |
351 | { | |
352 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
353 | ||
354 | if (timer->resume != NULL) | |
355 | timer->resume(); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | #else | |
360 | #define timer_suspend NULL | |
361 | #define timer_resume NULL | |
362 | #endif | |
363 | ||
364 | static struct sysdev_class timer_sysclass = { | |
af5ca3f4 | 365 | .name = "timer", |
1da177e4 LT |
366 | .suspend = timer_suspend, |
367 | .resume = timer_resume, | |
368 | }; | |
369 | ||
370 | static int __init timer_init_sysfs(void) | |
371 | { | |
372 | int ret = sysdev_class_register(&timer_sysclass); | |
373 | if (ret == 0) { | |
374 | system_timer->dev.cls = &timer_sysclass; | |
375 | ret = sysdev_register(&system_timer->dev); | |
376 | } | |
8749af68 | 377 | |
1da177e4 LT |
378 | return ret; |
379 | } | |
380 | ||
381 | device_initcall(timer_init_sysfs); | |
382 | ||
383 | void __init time_init(void) | |
384 | { | |
746140c7 | 385 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
386 | if (system_timer->offset == NULL) |
387 | system_timer->offset = dummy_gettimeoffset; | |
746140c7 | 388 | #endif |
1da177e4 LT |
389 | system_timer->init(); |
390 | } | |
391 |