Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/leds.h> |
| 33 | #include <asm/thread_info.h> |
| 34 | #include <asm/mach/time.h> |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | /* |
| 37 | * Our system timer. |
| 38 | */ |
| 39 | struct sys_timer *system_timer; |
| 40 | |
| 41 | extern unsigned long wall_jiffies; |
| 42 | |
| 43 | /* this needs a better home */ |
| 44 | DEFINE_SPINLOCK(rtc_lock); |
| 45 | |
| 46 | #ifdef CONFIG_SA1100_RTC_MODULE |
| 47 | EXPORT_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 |
| 54 | unsigned 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 | } |
| 65 | EXPORT_SYMBOL(profile_pc); |
| 66 | #endif |
| 67 | |
| 68 | /* |
| 69 | * hook for setting the RTC's idea of the current time. |
| 70 | */ |
| 71 | int (*set_rtc)(void); |
| 72 | |
| 73 | static 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 | */ |
| 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 | { |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 98 | if (!ntp_synced() || set_rtc == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 234 | void 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 | |
| 262 | EXPORT_SYMBOL(do_gettimeofday); |
| 263 | |
| 264 | int 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 stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 288 | ntp_clear(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | write_sequnlock_irq(&xtime_lock); |
| 290 | clock_was_set(); |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | EXPORT_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 | */ |
| 304 | void 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 | } |
| 310 | EXPORT_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 | */ |
| 317 | void 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 | } |
| 327 | EXPORT_SYMBOL(restore_time_delta); |
| 328 | |
| 329 | /* |
| 330 | * Kernel system timer support. |
| 331 | */ |
| 332 | void 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 |
| 344 | static 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 | |
| 354 | static 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 | |
| 368 | static struct sysdev_class timer_sysclass = { |
| 369 | set_kset_name("timer"), |
| 370 | .suspend = timer_suspend, |
| 371 | .resume = timer_resume, |
| 372 | }; |
| 373 | |
Russell King | 8749af6 | 2005-06-25 19:39:45 +0100 | [diff] [blame] | 374 | #ifdef CONFIG_NO_IDLE_HZ |
| 375 | static 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 | |
| 396 | static 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 King | 2ea8339 | 2005-06-27 14:04:05 +0100 | [diff] [blame] | 417 | /* |
| 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 King | 8749af6 | 2005-06-25 19:39:45 +0100 | [diff] [blame] | 422 | void timer_dyn_reprogram(void) |
| 423 | { |
| 424 | struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 425 | unsigned long next, seq; |
Russell King | 8749af6 | 2005-06-25 19:39:45 +0100 | [diff] [blame] | 426 | |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 427 | if (dyn_tick && (dyn_tick->state & DYN_TICK_ENABLED)) { |
| 428 | next = next_timer_interrupt(); |
| 429 | do { |
| 430 | seq = read_seqbegin(&xtime_lock); |
Ben Dooks | 3618886 | 2005-08-31 09:42:14 +0100 | [diff] [blame] | 431 | dyn_tick->reprogram(next_timer_interrupt() - jiffies); |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 432 | } while (read_seqretry(&xtime_lock, seq)); |
Ben Dooks | 3618886 | 2005-08-31 09:42:14 +0100 | [diff] [blame] | 433 | } |
Russell King | 8749af6 | 2005-06-25 19:39:45 +0100 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | static 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 | |
| 442 | static 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 | } |
| 454 | static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick); |
| 455 | |
| 456 | /* |
| 457 | * dyntick=enable|disable |
| 458 | */ |
| 459 | static char dyntick_str[4] __initdata = ""; |
| 460 | |
| 461 | static 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 Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | static 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 King | 8749af6 | 2005-06-25 19:39:45 +0100 | [diff] [blame] | 478 | |
| 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 Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | return ret; |
| 493 | } |
| 494 | |
| 495 | device_initcall(timer_init_sysfs); |
| 496 | |
| 497 | void __init time_init(void) |
| 498 | { |
| 499 | if (system_timer->offset == NULL) |
| 500 | system_timer->offset = dummy_gettimeoffset; |
| 501 | system_timer->init(); |
| 502 | } |
| 503 | |