11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/arch/arm/kernel/time.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 1991, 1992, 1995 Linus Torvalds 51da177e4SLinus Torvalds * Modifications for ARM (C) 1994-2001 Russell King 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4SLinus Torvalds * it under the terms of the GNU General Public License version 2 as 91da177e4SLinus Torvalds * published by the Free Software Foundation. 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * This file contains the ARM-specific time handling details: 121da177e4SLinus Torvalds * reading the RTC at bootup, etc... 131da177e4SLinus Torvalds * 141da177e4SLinus Torvalds * 1994-07-02 Alan Modra 151da177e4SLinus Torvalds * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime 161da177e4SLinus Torvalds * 1998-12-20 Updated NTP code according to technical memorandum Jan '96 171da177e4SLinus Torvalds * "A Kernel Model for Precision Timekeeping" by Dave Mills 181da177e4SLinus Torvalds */ 191da177e4SLinus Torvalds #include <linux/module.h> 201da177e4SLinus Torvalds #include <linux/kernel.h> 211da177e4SLinus Torvalds #include <linux/interrupt.h> 221da177e4SLinus Torvalds #include <linux/time.h> 231da177e4SLinus Torvalds #include <linux/init.h> 241da177e4SLinus Torvalds #include <linux/smp.h> 251da177e4SLinus Torvalds #include <linux/timex.h> 261da177e4SLinus Torvalds #include <linux/errno.h> 271da177e4SLinus Torvalds #include <linux/profile.h> 281da177e4SLinus Torvalds #include <linux/sysdev.h> 291da177e4SLinus Torvalds #include <linux/timer.h> 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds #include <asm/leds.h> 321da177e4SLinus Torvalds #include <asm/thread_info.h> 331da177e4SLinus Torvalds #include <asm/mach/time.h> 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds /* 361da177e4SLinus Torvalds * Our system timer. 371da177e4SLinus Torvalds */ 381da177e4SLinus Torvalds struct sys_timer *system_timer; 391da177e4SLinus Torvalds 401da177e4SLinus Torvalds extern unsigned long wall_jiffies; 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds /* this needs a better home */ 431da177e4SLinus Torvalds DEFINE_SPINLOCK(rtc_lock); 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds #ifdef CONFIG_SA1100_RTC_MODULE 461da177e4SLinus Torvalds EXPORT_SYMBOL(rtc_lock); 471da177e4SLinus Torvalds #endif 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds /* change this if you have some constant time drift */ 501da177e4SLinus Torvalds #define USECS_PER_JIFFY (1000000/HZ) 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds #ifdef CONFIG_SMP 531da177e4SLinus Torvalds unsigned long profile_pc(struct pt_regs *regs) 541da177e4SLinus Torvalds { 551da177e4SLinus Torvalds unsigned long fp, pc = instruction_pointer(regs); 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds if (in_lock_functions(pc)) { 581da177e4SLinus Torvalds fp = regs->ARM_fp; 591da177e4SLinus Torvalds pc = pc_pointer(((unsigned long *)fp)[-1]); 601da177e4SLinus Torvalds } 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds return pc; 631da177e4SLinus Torvalds } 641da177e4SLinus Torvalds EXPORT_SYMBOL(profile_pc); 651da177e4SLinus Torvalds #endif 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds /* 681da177e4SLinus Torvalds * hook for setting the RTC's idea of the current time. 691da177e4SLinus Torvalds */ 701da177e4SLinus Torvalds int (*set_rtc)(void); 711da177e4SLinus Torvalds 72746140c7SKevin Hilman #ifndef CONFIG_GENERIC_TIME 731da177e4SLinus Torvalds static unsigned long dummy_gettimeoffset(void) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds return 0; 761da177e4SLinus Torvalds } 77746140c7SKevin Hilman #endif 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds /* 801da177e4SLinus Torvalds * Scheduler clock - returns current time in nanosec units. 811da177e4SLinus Torvalds * This is the default implementation. Sub-architecture 821da177e4SLinus Torvalds * implementations can override this. 831da177e4SLinus Torvalds */ 841da177e4SLinus Torvalds unsigned long long __attribute__((weak)) sched_clock(void) 851da177e4SLinus Torvalds { 861da177e4SLinus Torvalds return (unsigned long long)jiffies * (1000000000 / HZ); 871da177e4SLinus Torvalds } 881da177e4SLinus Torvalds 891da177e4SLinus Torvalds static unsigned long next_rtc_update; 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds /* 921da177e4SLinus Torvalds * If we have an externally synchronized linux clock, then update 931da177e4SLinus Torvalds * CMOS clock accordingly every ~11 minutes. set_rtc() has to be 941da177e4SLinus Torvalds * called as close as possible to 500 ms before the new second 951da177e4SLinus Torvalds * starts. 961da177e4SLinus Torvalds */ 971da177e4SLinus Torvalds static inline void do_set_rtc(void) 981da177e4SLinus Torvalds { 99b149ee22Sjohn stultz if (!ntp_synced() || set_rtc == NULL) 1001da177e4SLinus Torvalds return; 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds if (next_rtc_update && 1031da177e4SLinus Torvalds time_before((unsigned long)xtime.tv_sec, next_rtc_update)) 1041da177e4SLinus Torvalds return; 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) && 1071da177e4SLinus Torvalds xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1)) 1081da177e4SLinus Torvalds return; 1091da177e4SLinus Torvalds 1101da177e4SLinus Torvalds if (set_rtc()) 1111da177e4SLinus Torvalds /* 1121da177e4SLinus Torvalds * rtc update failed. Try again in 60s 1131da177e4SLinus Torvalds */ 1141da177e4SLinus Torvalds next_rtc_update = xtime.tv_sec + 60; 1151da177e4SLinus Torvalds else 1161da177e4SLinus Torvalds next_rtc_update = xtime.tv_sec + 660; 1171da177e4SLinus Torvalds } 1181da177e4SLinus Torvalds 1191da177e4SLinus Torvalds #ifdef CONFIG_LEDS 1201da177e4SLinus Torvalds 1211da177e4SLinus Torvalds static void dummy_leds_event(led_event_t evt) 1221da177e4SLinus Torvalds { 1231da177e4SLinus Torvalds } 1241da177e4SLinus Torvalds 1251da177e4SLinus Torvalds void (*leds_event)(led_event_t) = dummy_leds_event; 1261da177e4SLinus Torvalds 1271da177e4SLinus Torvalds struct leds_evt_name { 1281da177e4SLinus Torvalds const char name[8]; 1291da177e4SLinus Torvalds int on; 1301da177e4SLinus Torvalds int off; 1311da177e4SLinus Torvalds }; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds static const struct leds_evt_name evt_names[] = { 1341da177e4SLinus Torvalds { "amber", led_amber_on, led_amber_off }, 1351da177e4SLinus Torvalds { "blue", led_blue_on, led_blue_off }, 1361da177e4SLinus Torvalds { "green", led_green_on, led_green_off }, 1371da177e4SLinus Torvalds { "red", led_red_on, led_red_off }, 1381da177e4SLinus Torvalds }; 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size) 1411da177e4SLinus Torvalds { 1421da177e4SLinus Torvalds int ret = -EINVAL, len = strcspn(buf, " "); 1431da177e4SLinus Torvalds 1441da177e4SLinus Torvalds if (len > 0 && buf[len] == '\0') 1451da177e4SLinus Torvalds len--; 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds if (strncmp(buf, "claim", len) == 0) { 1481da177e4SLinus Torvalds leds_event(led_claim); 1491da177e4SLinus Torvalds ret = size; 1501da177e4SLinus Torvalds } else if (strncmp(buf, "release", len) == 0) { 1511da177e4SLinus Torvalds leds_event(led_release); 1521da177e4SLinus Torvalds ret = size; 1531da177e4SLinus Torvalds } else { 1541da177e4SLinus Torvalds int i; 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds for (i = 0; i < ARRAY_SIZE(evt_names); i++) { 1571da177e4SLinus Torvalds if (strlen(evt_names[i].name) != len || 1581da177e4SLinus Torvalds strncmp(buf, evt_names[i].name, len) != 0) 1591da177e4SLinus Torvalds continue; 1601da177e4SLinus Torvalds if (strncmp(buf+len, " on", 3) == 0) { 1611da177e4SLinus Torvalds leds_event(evt_names[i].on); 1621da177e4SLinus Torvalds ret = size; 1631da177e4SLinus Torvalds } else if (strncmp(buf+len, " off", 4) == 0) { 1641da177e4SLinus Torvalds leds_event(evt_names[i].off); 1651da177e4SLinus Torvalds ret = size; 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds break; 1681da177e4SLinus Torvalds } 1691da177e4SLinus Torvalds } 1701da177e4SLinus Torvalds return ret; 1711da177e4SLinus Torvalds } 1721da177e4SLinus Torvalds 1731da177e4SLinus Torvalds static SYSDEV_ATTR(event, 0200, NULL, leds_store); 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds static int leds_suspend(struct sys_device *dev, pm_message_t state) 1761da177e4SLinus Torvalds { 1771da177e4SLinus Torvalds leds_event(led_stop); 1781da177e4SLinus Torvalds return 0; 1791da177e4SLinus Torvalds } 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds static int leds_resume(struct sys_device *dev) 1821da177e4SLinus Torvalds { 1831da177e4SLinus Torvalds leds_event(led_start); 1841da177e4SLinus Torvalds return 0; 1851da177e4SLinus Torvalds } 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds static int leds_shutdown(struct sys_device *dev) 1881da177e4SLinus Torvalds { 1891da177e4SLinus Torvalds leds_event(led_halted); 1901da177e4SLinus Torvalds return 0; 1911da177e4SLinus Torvalds } 1921da177e4SLinus Torvalds 1931da177e4SLinus Torvalds static struct sysdev_class leds_sysclass = { 1941da177e4SLinus Torvalds set_kset_name("leds"), 1951da177e4SLinus Torvalds .shutdown = leds_shutdown, 1961da177e4SLinus Torvalds .suspend = leds_suspend, 1971da177e4SLinus Torvalds .resume = leds_resume, 1981da177e4SLinus Torvalds }; 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds static struct sys_device leds_device = { 2011da177e4SLinus Torvalds .id = 0, 2021da177e4SLinus Torvalds .cls = &leds_sysclass, 2031da177e4SLinus Torvalds }; 2041da177e4SLinus Torvalds 2051da177e4SLinus Torvalds static int __init leds_init(void) 2061da177e4SLinus Torvalds { 2071da177e4SLinus Torvalds int ret; 2081da177e4SLinus Torvalds ret = sysdev_class_register(&leds_sysclass); 2091da177e4SLinus Torvalds if (ret == 0) 2101da177e4SLinus Torvalds ret = sysdev_register(&leds_device); 2111da177e4SLinus Torvalds if (ret == 0) 2121da177e4SLinus Torvalds ret = sysdev_create_file(&leds_device, &attr_event); 2131da177e4SLinus Torvalds return ret; 2141da177e4SLinus Torvalds } 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds device_initcall(leds_init); 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds EXPORT_SYMBOL(leds_event); 2191da177e4SLinus Torvalds #endif 2201da177e4SLinus Torvalds 2211da177e4SLinus Torvalds #ifdef CONFIG_LEDS_TIMER 2221da177e4SLinus Torvalds static inline void do_leds(void) 2231da177e4SLinus Torvalds { 2241da177e4SLinus Torvalds static unsigned int count = 50; 2251da177e4SLinus Torvalds 2261da177e4SLinus Torvalds if (--count == 0) { 2271da177e4SLinus Torvalds count = 50; 2281da177e4SLinus Torvalds leds_event(led_timer); 2291da177e4SLinus Torvalds } 2301da177e4SLinus Torvalds } 2311da177e4SLinus Torvalds #else 2321da177e4SLinus Torvalds #define do_leds() 2331da177e4SLinus Torvalds #endif 2341da177e4SLinus Torvalds 235746140c7SKevin Hilman #ifndef CONFIG_GENERIC_TIME 2361da177e4SLinus Torvalds void do_gettimeofday(struct timeval *tv) 2371da177e4SLinus Torvalds { 2381da177e4SLinus Torvalds unsigned long flags; 2391da177e4SLinus Torvalds unsigned long seq; 2401da177e4SLinus Torvalds unsigned long usec, sec, lost; 2411da177e4SLinus Torvalds 2421da177e4SLinus Torvalds do { 2431da177e4SLinus Torvalds seq = read_seqbegin_irqsave(&xtime_lock, flags); 2441da177e4SLinus Torvalds usec = system_timer->offset(); 2451da177e4SLinus Torvalds 2461da177e4SLinus Torvalds lost = jiffies - wall_jiffies; 2471da177e4SLinus Torvalds if (lost) 2481da177e4SLinus Torvalds usec += lost * USECS_PER_JIFFY; 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds sec = xtime.tv_sec; 2511da177e4SLinus Torvalds usec += xtime.tv_nsec / 1000; 2521da177e4SLinus Torvalds } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds /* usec may have gone up a lot: be safe */ 2551da177e4SLinus Torvalds while (usec >= 1000000) { 2561da177e4SLinus Torvalds usec -= 1000000; 2571da177e4SLinus Torvalds sec++; 2581da177e4SLinus Torvalds } 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds tv->tv_sec = sec; 2611da177e4SLinus Torvalds tv->tv_usec = usec; 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds EXPORT_SYMBOL(do_gettimeofday); 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds int do_settimeofday(struct timespec *tv) 2671da177e4SLinus Torvalds { 2681da177e4SLinus Torvalds time_t wtm_sec, sec = tv->tv_sec; 2691da177e4SLinus Torvalds long wtm_nsec, nsec = tv->tv_nsec; 2701da177e4SLinus Torvalds 2711da177e4SLinus Torvalds if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) 2721da177e4SLinus Torvalds return -EINVAL; 2731da177e4SLinus Torvalds 2741da177e4SLinus Torvalds write_seqlock_irq(&xtime_lock); 2751da177e4SLinus Torvalds /* 2761da177e4SLinus Torvalds * This is revolting. We need to set "xtime" correctly. However, the 2771da177e4SLinus Torvalds * value in this location is the value at the most recent update of 2781da177e4SLinus Torvalds * wall time. Discover what correction gettimeofday() would have 2791da177e4SLinus Torvalds * done, and then undo it! 2801da177e4SLinus Torvalds */ 2811da177e4SLinus Torvalds nsec -= system_timer->offset() * NSEC_PER_USEC; 2821da177e4SLinus Torvalds nsec -= (jiffies - wall_jiffies) * TICK_NSEC; 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); 2851da177e4SLinus Torvalds wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); 2861da177e4SLinus Torvalds 2871da177e4SLinus Torvalds set_normalized_timespec(&xtime, sec, nsec); 2881da177e4SLinus Torvalds set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); 2891da177e4SLinus Torvalds 290b149ee22Sjohn stultz ntp_clear(); 2911da177e4SLinus Torvalds write_sequnlock_irq(&xtime_lock); 2921da177e4SLinus Torvalds clock_was_set(); 2931da177e4SLinus Torvalds return 0; 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds EXPORT_SYMBOL(do_settimeofday); 297746140c7SKevin Hilman #endif /* !CONFIG_GENERIC_TIME */ 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds /** 3001da177e4SLinus Torvalds * save_time_delta - Save the offset between system time and RTC time 3011da177e4SLinus Torvalds * @delta: pointer to timespec to store delta 3021da177e4SLinus Torvalds * @rtc: pointer to timespec for current RTC time 3031da177e4SLinus Torvalds * 3041da177e4SLinus Torvalds * Return a delta between the system time and the RTC time, such 3051da177e4SLinus Torvalds * that system time can be restored later with restore_time_delta() 3061da177e4SLinus Torvalds */ 3071da177e4SLinus Torvalds void save_time_delta(struct timespec *delta, struct timespec *rtc) 3081da177e4SLinus Torvalds { 3091da177e4SLinus Torvalds set_normalized_timespec(delta, 3101da177e4SLinus Torvalds xtime.tv_sec - rtc->tv_sec, 3111da177e4SLinus Torvalds xtime.tv_nsec - rtc->tv_nsec); 3121da177e4SLinus Torvalds } 3131da177e4SLinus Torvalds EXPORT_SYMBOL(save_time_delta); 3141da177e4SLinus Torvalds 3151da177e4SLinus Torvalds /** 3161da177e4SLinus Torvalds * restore_time_delta - Restore the current system time 3171da177e4SLinus Torvalds * @delta: delta returned by save_time_delta() 3181da177e4SLinus Torvalds * @rtc: pointer to timespec for current RTC time 3191da177e4SLinus Torvalds */ 3201da177e4SLinus Torvalds void restore_time_delta(struct timespec *delta, struct timespec *rtc) 3211da177e4SLinus Torvalds { 3221da177e4SLinus Torvalds struct timespec ts; 3231da177e4SLinus Torvalds 3241da177e4SLinus Torvalds set_normalized_timespec(&ts, 3251da177e4SLinus Torvalds delta->tv_sec + rtc->tv_sec, 3261da177e4SLinus Torvalds delta->tv_nsec + rtc->tv_nsec); 3271da177e4SLinus Torvalds 3281da177e4SLinus Torvalds do_settimeofday(&ts); 3291da177e4SLinus Torvalds } 3301da177e4SLinus Torvalds EXPORT_SYMBOL(restore_time_delta); 3311da177e4SLinus Torvalds 3321da177e4SLinus Torvalds /* 3331da177e4SLinus Torvalds * Kernel system timer support. 3341da177e4SLinus Torvalds */ 3351da177e4SLinus Torvalds void timer_tick(struct pt_regs *regs) 3361da177e4SLinus Torvalds { 3371da177e4SLinus Torvalds profile_tick(CPU_PROFILING, regs); 3381da177e4SLinus Torvalds do_leds(); 3391da177e4SLinus Torvalds do_set_rtc(); 3403171a030SAtsushi Nemoto do_timer(1); 3411da177e4SLinus Torvalds #ifndef CONFIG_SMP 3421da177e4SLinus Torvalds update_process_times(user_mode(regs)); 3431da177e4SLinus Torvalds #endif 3441da177e4SLinus Torvalds } 3451da177e4SLinus Torvalds 3461da177e4SLinus Torvalds #ifdef CONFIG_PM 3471da177e4SLinus Torvalds static int timer_suspend(struct sys_device *dev, pm_message_t state) 3481da177e4SLinus Torvalds { 3491da177e4SLinus Torvalds struct sys_timer *timer = container_of(dev, struct sys_timer, dev); 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvalds if (timer->suspend != NULL) 3521da177e4SLinus Torvalds timer->suspend(); 3531da177e4SLinus Torvalds 3541da177e4SLinus Torvalds return 0; 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds 3571da177e4SLinus Torvalds static int timer_resume(struct sys_device *dev) 3581da177e4SLinus Torvalds { 3591da177e4SLinus Torvalds struct sys_timer *timer = container_of(dev, struct sys_timer, dev); 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds if (timer->resume != NULL) 3621da177e4SLinus Torvalds timer->resume(); 3631da177e4SLinus Torvalds 3641da177e4SLinus Torvalds return 0; 3651da177e4SLinus Torvalds } 3661da177e4SLinus Torvalds #else 3671da177e4SLinus Torvalds #define timer_suspend NULL 3681da177e4SLinus Torvalds #define timer_resume NULL 3691da177e4SLinus Torvalds #endif 3701da177e4SLinus Torvalds 3711da177e4SLinus Torvalds static struct sysdev_class timer_sysclass = { 3721da177e4SLinus Torvalds set_kset_name("timer"), 3731da177e4SLinus Torvalds .suspend = timer_suspend, 3741da177e4SLinus Torvalds .resume = timer_resume, 3751da177e4SLinus Torvalds }; 3761da177e4SLinus Torvalds 3778749af68SRussell King #ifdef CONFIG_NO_IDLE_HZ 3788749af68SRussell King static int timer_dyn_tick_enable(void) 3798749af68SRussell King { 3808749af68SRussell King struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; 3818749af68SRussell King unsigned long flags; 3828749af68SRussell King int ret = -ENODEV; 3838749af68SRussell King 3848749af68SRussell King if (dyn_tick) { 385ebc67da6STony Lindgren spin_lock_irqsave(&dyn_tick->lock, flags); 3868749af68SRussell King ret = 0; 3878749af68SRussell King if (!(dyn_tick->state & DYN_TICK_ENABLED)) { 3888749af68SRussell King ret = dyn_tick->enable(); 3898749af68SRussell King 3908749af68SRussell King if (ret == 0) 3918749af68SRussell King dyn_tick->state |= DYN_TICK_ENABLED; 3928749af68SRussell King } 393ebc67da6STony Lindgren spin_unlock_irqrestore(&dyn_tick->lock, flags); 3948749af68SRussell King } 3958749af68SRussell King 3968749af68SRussell King return ret; 3978749af68SRussell King } 3988749af68SRussell King 3998749af68SRussell King static int timer_dyn_tick_disable(void) 4008749af68SRussell King { 4018749af68SRussell King struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; 4028749af68SRussell King unsigned long flags; 4038749af68SRussell King int ret = -ENODEV; 4048749af68SRussell King 4058749af68SRussell King if (dyn_tick) { 406ebc67da6STony Lindgren spin_lock_irqsave(&dyn_tick->lock, flags); 4078749af68SRussell King ret = 0; 4088749af68SRussell King if (dyn_tick->state & DYN_TICK_ENABLED) { 4098749af68SRussell King ret = dyn_tick->disable(); 4108749af68SRussell King 4118749af68SRussell King if (ret == 0) 4128749af68SRussell King dyn_tick->state &= ~DYN_TICK_ENABLED; 4138749af68SRussell King } 414ebc67da6STony Lindgren spin_unlock_irqrestore(&dyn_tick->lock, flags); 4158749af68SRussell King } 4168749af68SRussell King 4178749af68SRussell King return ret; 4188749af68SRussell King } 4198749af68SRussell King 4202ea83398SRussell King /* 4212ea83398SRussell King * Reprogram the system timer for at least the calculated time interval. 4222ea83398SRussell King * This function should be called from the idle thread with IRQs disabled, 4232ea83398SRussell King * immediately before sleeping. 4242ea83398SRussell King */ 4258749af68SRussell King void timer_dyn_reprogram(void) 4268749af68SRussell King { 4278749af68SRussell King struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; 428ebc67da6STony Lindgren unsigned long next, seq, flags; 4298749af68SRussell King 430ebc67da6STony Lindgren if (!dyn_tick) 431ebc67da6STony Lindgren return; 432ebc67da6STony Lindgren 433ebc67da6STony Lindgren spin_lock_irqsave(&dyn_tick->lock, flags); 434ebc67da6STony Lindgren if (dyn_tick->state & DYN_TICK_ENABLED) { 43569239749STony Lindgren next = next_timer_interrupt(); 43669239749STony Lindgren do { 43769239749STony Lindgren seq = read_seqbegin(&xtime_lock); 438ebc67da6STony Lindgren dyn_tick->reprogram(next - jiffies); 43969239749STony Lindgren } while (read_seqretry(&xtime_lock, seq)); 4408749af68SRussell King } 441ebc67da6STony Lindgren spin_unlock_irqrestore(&dyn_tick->lock, flags); 4423618886fSBen Dooks } 4438749af68SRussell King 4448749af68SRussell King static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf) 4458749af68SRussell King { 4468749af68SRussell King return sprintf(buf, "%i\n", 4478749af68SRussell King (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1); 4488749af68SRussell King } 4498749af68SRussell King 4508749af68SRussell King static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf, 4518749af68SRussell King size_t count) 4528749af68SRussell King { 4538749af68SRussell King unsigned int enable = simple_strtoul(buf, NULL, 2); 4548749af68SRussell King 4558749af68SRussell King if (enable) 4568749af68SRussell King timer_dyn_tick_enable(); 4578749af68SRussell King else 4588749af68SRussell King timer_dyn_tick_disable(); 4598749af68SRussell King 4608749af68SRussell King return count; 4618749af68SRussell King } 4628749af68SRussell King static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick); 4638749af68SRussell King 4648749af68SRussell King /* 4658749af68SRussell King * dyntick=enable|disable 4668749af68SRussell King */ 4678749af68SRussell King static char dyntick_str[4] __initdata = ""; 4688749af68SRussell King 4698749af68SRussell King static int __init dyntick_setup(char *str) 4708749af68SRussell King { 4718749af68SRussell King if (str) 4728749af68SRussell King strlcpy(dyntick_str, str, sizeof(dyntick_str)); 4738749af68SRussell King return 1; 4748749af68SRussell King } 4758749af68SRussell King 4768749af68SRussell King __setup("dyntick=", dyntick_setup); 4778749af68SRussell King #endif 4788749af68SRussell King 4791da177e4SLinus Torvalds static int __init timer_init_sysfs(void) 4801da177e4SLinus Torvalds { 4811da177e4SLinus Torvalds int ret = sysdev_class_register(&timer_sysclass); 4821da177e4SLinus Torvalds if (ret == 0) { 4831da177e4SLinus Torvalds system_timer->dev.cls = &timer_sysclass; 4841da177e4SLinus Torvalds ret = sysdev_register(&system_timer->dev); 4851da177e4SLinus Torvalds } 4868749af68SRussell King 4878749af68SRussell King #ifdef CONFIG_NO_IDLE_HZ 4888749af68SRussell King if (ret == 0 && system_timer->dyn_tick) { 4898749af68SRussell King ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick); 4908749af68SRussell King 4918749af68SRussell King /* 4928749af68SRussell King * Turn on dynamic tick after calibrate delay 4938749af68SRussell King * for correct bogomips 4948749af68SRussell King */ 4958749af68SRussell King if (ret == 0 && dyntick_str[0] == 'e') 4968749af68SRussell King ret = timer_dyn_tick_enable(); 4978749af68SRussell King } 4988749af68SRussell King #endif 4998749af68SRussell King 5001da177e4SLinus Torvalds return ret; 5011da177e4SLinus Torvalds } 5021da177e4SLinus Torvalds 5031da177e4SLinus Torvalds device_initcall(timer_init_sysfs); 5041da177e4SLinus Torvalds 5051da177e4SLinus Torvalds void __init time_init(void) 5061da177e4SLinus Torvalds { 507746140c7SKevin Hilman #ifndef CONFIG_GENERIC_TIME 5081da177e4SLinus Torvalds if (system_timer->offset == NULL) 5091da177e4SLinus Torvalds system_timer->offset = dummy_gettimeoffset; 510746140c7SKevin Hilman #endif 5111da177e4SLinus Torvalds system_timer->init(); 512ebc67da6STony Lindgren 513ebc67da6STony Lindgren #ifdef CONFIG_NO_IDLE_HZ 514ebc67da6STony Lindgren if (system_timer->dyn_tick) 515ebc67da6STony Lindgren system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED; 516ebc67da6STony Lindgren #endif 5171da177e4SLinus Torvalds } 5181da177e4SLinus Torvalds 519