[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / time.c

/*
 *  linux/arch/arm/kernel/time.c
 *
 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
 *  Modifications for ARM (C) 1994-2001 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This file contains the ARM-specific time handling details:
 *  reading the RTC at bootup, etc...
 *
 *  1994-07-02  Alan Modra
 *              fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
 *  1998-12-20  Updated NTP code according to technical memorandum Jan '96
 *              "A Kernel Model for Precision Timekeeping" by Dave Mills
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/errno.h>
#include <linux/profile.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <linux/irq.h>

#include <linux/mc146818rtc.h>

#include <asm/leds.h>
#include <asm/thread_info.h>
#include <asm/mach/time.h>

/*
 * Our system timer.
 */
struct sys_timer *system_timer;

/* this needs a better home */
DEFINE_SPINLOCK(rtc_lock);

#ifdef CONFIG_SA1100_RTC_MODULE
EXPORT_SYMBOL(rtc_lock);
#endif

/* change this if you have some constant time drift */
#define USECS_PER_JIFFY	(1000000/HZ)

#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
	unsigned long fp, pc = instruction_pointer(regs);

	if (in_lock_functions(pc)) {
		fp = regs->ARM_fp;
		pc = pc_pointer(((unsigned long *)fp)[-1]);
	}

	return pc;
}
EXPORT_SYMBOL(profile_pc);
#endif

/*
 * hook for setting the RTC's idea of the current time.
 */
int (*set_rtc)(void);

#ifndef CONFIG_GENERIC_TIME
static unsigned long dummy_gettimeoffset(void)
{
	return 0;
}
#endif

/*
 * Scheduler clock - returns current time in nanosec units.
 * This is the default implementation.  Sub-architecture
 * implementations can override this.
 */
unsigned long long __attribute__((weak)) sched_clock(void)
{
	return (unsigned long long)jiffies * (1000000000 / HZ);
}

/*
 * An implementation of printk_clock() independent from
 * sched_clock().  This avoids non-bootable kernels when
 * printk_clock is enabled.
 */
unsigned long long printk_clock(void)
{
	return (unsigned long long)(jiffies - INITIAL_JIFFIES) *
			(1000000000 / HZ);
}

static unsigned long next_rtc_update;

/*
 * If we have an externally synchronized linux clock, then update
 * CMOS clock accordingly every ~11 minutes.  set_rtc() has to be
 * called as close as possible to 500 ms before the new second
 * starts.
 */
static inline void do_set_rtc(void)
{
	if (!ntp_synced() || set_rtc == NULL)
		return;

	if (next_rtc_update &&
	    time_before((unsigned long)xtime.tv_sec, next_rtc_update))
		return;

	if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
	    xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
		return;

	if (set_rtc())
		/*
		 * rtc update failed.  Try again in 60s
		 */
		next_rtc_update = xtime.tv_sec + 60;
	else
		next_rtc_update = xtime.tv_sec + 660;
}

#ifdef CONFIG_LEDS

static void dummy_leds_event(led_event_t evt)
{
}

void (*leds_event)(led_event_t) = dummy_leds_event;

struct leds_evt_name {
	const char	name[8];
	int		on;
	int		off;
};

static const struct leds_evt_name evt_names[] = {
	{ "amber", led_amber_on, led_amber_off },
	{ "blue",  led_blue_on,  led_blue_off  },
	{ "green", led_green_on, led_green_off },
	{ "red",   led_red_on,   led_red_off   },
};

static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size)
{
	int ret = -EINVAL, len = strcspn(buf, " ");

	if (len > 0 && buf[len] == '\0')
		len--;

	if (strncmp(buf, "claim", len) == 0) {
		leds_event(led_claim);
		ret = size;
	} else if (strncmp(buf, "release", len) == 0) {
		leds_event(led_release);
		ret = size;
	} else {
		int i;

		for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
			if (strlen(evt_names[i].name) != len ||
			    strncmp(buf, evt_names[i].name, len) != 0)
				continue;
			if (strncmp(buf+len, " on", 3) == 0) {
				leds_event(evt_names[i].on);
				ret = size;
			} else if (strncmp(buf+len, " off", 4) == 0) {
				leds_event(evt_names[i].off);
				ret = size;
			}
			break;
		}
	}
	return ret;
}

static SYSDEV_ATTR(event, 0200, NULL, leds_store);

static int leds_suspend(struct sys_device *dev, pm_message_t state)
{
	leds_event(led_stop);
	return 0;
}

static int leds_resume(struct sys_device *dev)
{
	leds_event(led_start);
	return 0;
}

static int leds_shutdown(struct sys_device *dev)
{
	leds_event(led_halted);
	return 0;
}

static struct sysdev_class leds_sysclass = {
	set_kset_name("leds"),
	.shutdown	= leds_shutdown,
	.suspend	= leds_suspend,
	.resume		= leds_resume,
};

static struct sys_device leds_device = {
	.id		= 0,
	.cls		= &leds_sysclass,
};

static int __init leds_init(void)
{
	int ret;
	ret = sysdev_class_register(&leds_sysclass);
	if (ret == 0)
		ret = sysdev_register(&leds_device);
	if (ret == 0)
		ret = sysdev_create_file(&leds_device, &attr_event);
	return ret;
}

device_initcall(leds_init);

EXPORT_SYMBOL(leds_event);
#endif

#ifdef CONFIG_LEDS_TIMER
static inline void do_leds(void)
{
	static unsigned int count = HZ/2;

	if (--count == 0) {
		count = HZ/2;
		leds_event(led_timer);
	}
}
#else
#define	do_leds()
#endif

#ifndef CONFIG_GENERIC_TIME
void do_gettimeofday(struct timeval *tv)
{
	unsigned long flags;
	unsigned long seq;
	unsigned long usec, sec;

	do {
		seq = read_seqbegin_irqsave(&xtime_lock, flags);
		usec = system_timer->offset();
		sec = xtime.tv_sec;
		usec += xtime.tv_nsec / 1000;
	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));

	/* usec may have gone up a lot: be safe */
	while (usec >= 1000000) {
		usec -= 1000000;
		sec++;
	}

	tv->tv_sec = sec;
	tv->tv_usec = usec;
}

EXPORT_SYMBOL(do_gettimeofday);

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	/*
	 * This is revolting. We need to set "xtime" correctly. However, the
	 * value in this location is the value at the most recent update of
	 * wall time.  Discover what correction gettimeofday() would have
	 * done, and then undo it!
	 */
	nsec -= system_timer->offset() * NSEC_PER_USEC;

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	ntp_clear();
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return 0;
}

EXPORT_SYMBOL(do_settimeofday);
#endif /* !CONFIG_GENERIC_TIME */

/**
 * save_time_delta - Save the offset between system time and RTC time
 * @delta: pointer to timespec to store delta
 * @rtc: pointer to timespec for current RTC time
 *
 * Return a delta between the system time and the RTC time, such
 * that system time can be restored later with restore_time_delta()
 */
void save_time_delta(struct timespec *delta, struct timespec *rtc)
{
	set_normalized_timespec(delta,
				xtime.tv_sec - rtc->tv_sec,
				xtime.tv_nsec - rtc->tv_nsec);
}
EXPORT_SYMBOL(save_time_delta);

/**
 * restore_time_delta - Restore the current system time
 * @delta: delta returned by save_time_delta()
 * @rtc: pointer to timespec for current RTC time
 */
void restore_time_delta(struct timespec *delta, struct timespec *rtc)
{
	struct timespec ts;

	set_normalized_timespec(&ts,
				delta->tv_sec + rtc->tv_sec,
				delta->tv_nsec + rtc->tv_nsec);

	do_settimeofday(&ts);
}
EXPORT_SYMBOL(restore_time_delta);

/*
 * Kernel system timer support.
 */
void timer_tick(void)
{
	profile_tick(CPU_PROFILING);
	do_leds();
	do_set_rtc();
	do_timer(1);
#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
}

#ifdef CONFIG_PM
static int timer_suspend(struct sys_device *dev, pm_message_t state)
{
	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);

	if (timer->suspend != NULL)
		timer->suspend();

	return 0;
}

static int timer_resume(struct sys_device *dev)
{
	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);

	if (timer->resume != NULL)
		timer->resume();

	return 0;
}
#else
#define timer_suspend NULL
#define timer_resume NULL
#endif

static struct sysdev_class timer_sysclass = {
	set_kset_name("timer"),
	.suspend	= timer_suspend,
	.resume		= timer_resume,
};

#ifdef CONFIG_NO_IDLE_HZ
static int timer_dyn_tick_enable(void)
{
	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
	unsigned long flags;
	int ret = -ENODEV;

	if (dyn_tick) {
		spin_lock_irqsave(&dyn_tick->lock, flags);
		ret = 0;
		if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
			ret = dyn_tick->enable();

			if (ret == 0)
				dyn_tick->state |= DYN_TICK_ENABLED;
		}
		spin_unlock_irqrestore(&dyn_tick->lock, flags);
	}

	return ret;
}

static int timer_dyn_tick_disable(void)
{
	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
	unsigned long flags;
	int ret = -ENODEV;

	if (dyn_tick) {
		spin_lock_irqsave(&dyn_tick->lock, flags);
		ret = 0;
		if (dyn_tick->state & DYN_TICK_ENABLED) {
			ret = dyn_tick->disable();

			if (ret == 0)
				dyn_tick->state &= ~DYN_TICK_ENABLED;
		}
		spin_unlock_irqrestore(&dyn_tick->lock, flags);
	}

	return ret;
}

/*
 * Reprogram the system timer for at least the calculated time interval.
 * This function should be called from the idle thread with IRQs disabled,
 * immediately before sleeping.
 */
void timer_dyn_reprogram(void)
{
	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
	unsigned long next, seq, flags;

	if (!dyn_tick)
		return;

	spin_lock_irqsave(&dyn_tick->lock, flags);
	if (dyn_tick->state & DYN_TICK_ENABLED) {
		next = next_timer_interrupt();
		do {
			seq = read_seqbegin(&xtime_lock);
			dyn_tick->reprogram(next - jiffies);
		} while (read_seqretry(&xtime_lock, seq));
	}
	spin_unlock_irqrestore(&dyn_tick->lock, flags);
}

static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf)
{
	return sprintf(buf, "%i\n",
		       (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
}

static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf,
				  size_t count)
{
	unsigned int enable = simple_strtoul(buf, NULL, 2);

	if (enable)
		timer_dyn_tick_enable();
	else
		timer_dyn_tick_disable();

	return count;
}
static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);

/*
 * dyntick=enable|disable
 */
static char dyntick_str[4] __initdata = "";

static int __init dyntick_setup(char *str)
{
	if (str)
		strlcpy(dyntick_str, str, sizeof(dyntick_str));
	return 1;
}

__setup("dyntick=", dyntick_setup);
#endif

static int __init timer_init_sysfs(void)
{
	int ret = sysdev_class_register(&timer_sysclass);
	if (ret == 0) {
		system_timer->dev.cls = &timer_sysclass;
		ret = sysdev_register(&system_timer->dev);
	}

#ifdef CONFIG_NO_IDLE_HZ
	if (ret == 0 && system_timer->dyn_tick) {
		ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick);

		/*
		 * Turn on dynamic tick after calibrate delay
		 * for correct bogomips
		 */
		if (ret == 0 && dyntick_str[0] == 'e')
			ret = timer_dyn_tick_enable();
	}
#endif

	return ret;
}

device_initcall(timer_init_sysfs);

void __init time_init(void)
{
#ifndef CONFIG_GENERIC_TIME
	if (system_timer->offset == NULL)
		system_timer->offset = dummy_gettimeoffset;
#endif
	system_timer->init();

#ifdef CONFIG_NO_IDLE_HZ
	if (system_timer->dyn_tick)
		system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED;
#endif
}
Commit	Line	Data
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>
9ca3f07b BD	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
1da177e4 LT	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
746140c7	73	#ifndef CONFIG_GENERIC_TIME
1da177e4 LT	74	static unsigned long dummy_gettimeoffset(void)
	75	{
	76	return 0;
	77	}
746140c7	78	#endif
1da177e4 LT	79
	80	/*
	81	* Scheduler clock - returns current time in nanosec units.
	82	* This is the default implementation. Sub-architecture
	83	* implementations can override this.
	84	*/
	85	unsigned long long __attribute__((weak)) sched_clock(void)
	86	{
	87	return (unsigned long long)jiffies * (1000000000 / HZ);
	88	}
	89
e97126cd RK	90	/*
	91	* An implementation of printk_clock() independent from
	92	* sched_clock(). This avoids non-bootable kernels when
	93	* printk_clock is enabled.
	94	*/
	95	unsigned long long printk_clock(void)
	96	{
	97	return (unsigned long long)(jiffies - INITIAL_JIFFIES) *
	98	(1000000000 / HZ);
	99	}
	100
1da177e4 LT	101	static unsigned long next_rtc_update;
	102
	103	/*
	104	* If we have an externally synchronized linux clock, then update
	105	* CMOS clock accordingly every ~11 minutes. set_rtc() has to be
	106	* called as close as possible to 500 ms before the new second
	107	* starts.
	108	*/
	109	static inline void do_set_rtc(void)
	110	{
b149ee22	111	if (!ntp_synced() \|\| set_rtc == NULL)
1da177e4 LT	112	return;
	113
	114	if (next_rtc_update &&
	115	time_before((unsigned long)xtime.tv_sec, next_rtc_update))
	116	return;
	117
	118	if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
	119	xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
	120	return;
	121
	122	if (set_rtc())
	123	/*
	124	* rtc update failed. Try again in 60s
	125	*/
	126	next_rtc_update = xtime.tv_sec + 60;
	127	else
	128	next_rtc_update = xtime.tv_sec + 660;
	129	}
	130
	131	#ifdef CONFIG_LEDS
	132
	133	static void dummy_leds_event(led_event_t evt)
	134	{
	135	}
	136
	137	void (*leds_event)(led_event_t) = dummy_leds_event;
	138
	139	struct leds_evt_name {
	140	const char name[8];
	141	int on;
	142	int off;
	143	};
	144
	145	static const struct leds_evt_name evt_names[] = {
	146	{ "amber", led_amber_on, led_amber_off },
	147	{ "blue", led_blue_on, led_blue_off },
	148	{ "green", led_green_on, led_green_off },
	149	{ "red", led_red_on, led_red_off },
	150	};
	151
	152	static ssize_t leds_store(struct sys_device dev, const char buf, size_t size)
	153	{
	154	int ret = -EINVAL, len = strcspn(buf, " ");
	155
	156	if (len > 0 && buf[len] == '\0')
	157	len--;
	158
	159	if (strncmp(buf, "claim", len) == 0) {
	160	leds_event(led_claim);
	161	ret = size;
	162	} else if (strncmp(buf, "release", len) == 0) {
	163	leds_event(led_release);
	164	ret = size;
	165	} else {
	166	int i;
	167
	168	for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
	169	if (strlen(evt_names[i].name) != len \|\|
	170	strncmp(buf, evt_names[i].name, len) != 0)
	171	continue;
	172	if (strncmp(buf+len, " on", 3) == 0) {
	173	leds_event(evt_names[i].on);
	174	ret = size;
	175	} else if (strncmp(buf+len, " off", 4) == 0) {
176	leds_event(evt_names[i].off);
177	ret = size;
178	}
179	break;
180	}
181	}
182	return ret;
183	}
184
185	static SYSDEV_ATTR(event, 0200, NULL, leds_store);
186
187	static int leds_suspend(struct sys_device *dev, pm_message_t state)
188	{
189	leds_event(led_stop);
190	return 0;
191	}
192
193	static int leds_resume(struct sys_device *dev)
194	{
195	leds_event(led_start);
196	return 0;
197	}
198
199	static int leds_shutdown(struct sys_device *dev)
200	{
201	leds_event(led_halted);
202	return 0;
203	}
204
205	static struct sysdev_class leds_sysclass = {
206	set_kset_name("leds"),
207	.shutdown = leds_shutdown,
208	.suspend = leds_suspend,
209	.resume = leds_resume,
210	};
211
212	static struct sys_device leds_device = {
213	.id = 0,
214	.cls = &leds_sysclass,
215	};
216
217	static int __init leds_init(void)
218	{
219	int ret;
220	ret = sysdev_class_register(&leds_sysclass);
221	if (ret == 0)
222	ret = sysdev_register(&leds_device);
223	if (ret == 0)
224	ret = sysdev_create_file(&leds_device, &attr_event);
225	return ret;
226	}
227
228	device_initcall(leds_init);
229
230	EXPORT_SYMBOL(leds_event);
231	#endif
232
233	#ifdef CONFIG_LEDS_TIMER
234	static inline void do_leds(void)
235	{
6d15cb42	236	static unsigned int count = HZ/2;
1da177e4 LT	237
1da177e4 LT	238	if (--count == 0) {
6d15cb42	239	count = HZ/2;
1da177e4 LT	240	leds_event(led_timer);
	241	}
	242	}
	243	#else
	244	#define do_leds()
	245	#endif
	246
746140c7	247	#ifndef CONFIG_GENERIC_TIME
1da177e4 LT	248	void do_gettimeofday(struct timeval *tv)
	249	{
	250	unsigned long flags;
	251	unsigned long seq;
8ef38609	252	unsigned long usec, sec;
1da177e4 LT	253
	254	do {
	255	seq = read_seqbegin_irqsave(&xtime_lock, flags);
	256	usec = system_timer->offset();
1da177e4 LT	257	sec = xtime.tv_sec;
	258	usec += xtime.tv_nsec / 1000;
	259	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
	260
	261	/* usec may have gone up a lot: be safe */
	262	while (usec >= 1000000) {
	263	usec -= 1000000;
	264	sec++;
	265	}
	266
	267	tv->tv_sec = sec;
	268	tv->tv_usec = usec;
	269	}
	270
	271	EXPORT_SYMBOL(do_gettimeofday);
	272
	273	int do_settimeofday(struct timespec *tv)
	274	{
	275	time_t wtm_sec, sec = tv->tv_sec;
	276	long wtm_nsec, nsec = tv->tv_nsec;
	277
	278	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
	279	return -EINVAL;
	280
	281	write_seqlock_irq(&xtime_lock);
	282	/*
	283	* This is revolting. We need to set "xtime" correctly. However, the
	284	* value in this location is the value at the most recent update of
	285	* wall time. Discover what correction gettimeofday() would have
	286	* done, and then undo it!
	287	*/
	288	nsec -= system_timer->offset() * NSEC_PER_USEC;
1da177e4 LT	289
	290	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	291	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
	292
	293	set_normalized_timespec(&xtime, sec, nsec);
	294	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
	295
b149ee22	296	ntp_clear();
1da177e4 LT	297	write_sequnlock_irq(&xtime_lock);
	298	clock_was_set();
	299	return 0;
	300	}
	301
	302	EXPORT_SYMBOL(do_settimeofday);
746140c7	303	#endif /* !CONFIG_GENERIC_TIME */
1da177e4 LT	304
	305	/**
	306	* save_time_delta - Save the offset between system time and RTC time
	307	* @delta: pointer to timespec to store delta
	308	* @rtc: pointer to timespec for current RTC time
	309	*
	310	* Return a delta between the system time and the RTC time, such
	311	* that system time can be restored later with restore_time_delta()
	312	*/
	313	void save_time_delta(struct timespec delta, struct timespec rtc)
	314	{
	315	set_normalized_timespec(delta,
	316	xtime.tv_sec - rtc->tv_sec,
	317	xtime.tv_nsec - rtc->tv_nsec);
	318	}
	319	EXPORT_SYMBOL(save_time_delta);
	320
	321	/**
	322	* restore_time_delta - Restore the current system time
	323	* @delta: delta returned by save_time_delta()
	324	* @rtc: pointer to timespec for current RTC time
	325	*/
	326	void restore_time_delta(struct timespec delta, struct timespec rtc)
	327	{
	328	struct timespec ts;
	329
	330	set_normalized_timespec(&ts,
	331	delta->tv_sec + rtc->tv_sec,
	332	delta->tv_nsec + rtc->tv_nsec);
	333
	334	do_settimeofday(&ts);
	335	}
	336	EXPORT_SYMBOL(restore_time_delta);
	337
	338	/*
	339	* Kernel system timer support.
	340	*/
0cd61b68	341	void timer_tick(void)
1da177e4	342	{
e317c8cc	343	profile_tick(CPU_PROFILING);
1da177e4 LT	344	do_leds();
1da177e4 LT	345	do_set_rtc();
3171a030	346	do_timer(1);
1da177e4	347	#ifndef CONFIG_SMP
c97d4869	348	update_process_times(user_mode(get_irq_regs()));
1da177e4 LT	349	#endif
	350	}
	351
	352	#ifdef CONFIG_PM
	353	static int timer_suspend(struct sys_device *dev, pm_message_t state)
	354	{
	355	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
	356
	357	if (timer->suspend != NULL)
	358	timer->suspend();
	359
	360	return 0;
	361	}
	362
	363	static int timer_resume(struct sys_device *dev)
	364	{
	365	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
	366
	367	if (timer->resume != NULL)
	368	timer->resume();
	369
	370	return 0;
	371	}
	372	#else
	373	#define timer_suspend NULL
	374	#define timer_resume NULL
	375	#endif
	376
	377	static struct sysdev_class timer_sysclass = {
	378	set_kset_name("timer"),
	379	.suspend = timer_suspend,
	380	.resume = timer_resume,
	381	};
	382
8749af68 RK	383	#ifdef CONFIG_NO_IDLE_HZ
	384	static int timer_dyn_tick_enable(void)
	385	{
	386	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
	387	unsigned long flags;
	388	int ret = -ENODEV;
	389
	390	if (dyn_tick) {
ebc67da6	391	spin_lock_irqsave(&dyn_tick->lock, flags);
8749af68 RK	392	ret = 0;
	393	if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
	394	ret = dyn_tick->enable();
	395
	396	if (ret == 0)
	397	dyn_tick->state \|= DYN_TICK_ENABLED;
	398	}
ebc67da6	399	spin_unlock_irqrestore(&dyn_tick->lock, flags);
8749af68 RK	400	}
	401
	402	return ret;
	403	}
	404
	405	static int timer_dyn_tick_disable(void)
	406	{
	407	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
	408	unsigned long flags;
	409	int ret = -ENODEV;
	410
	411	if (dyn_tick) {
ebc67da6	412	spin_lock_irqsave(&dyn_tick->lock, flags);
8749af68 RK	413	ret = 0;
	414	if (dyn_tick->state & DYN_TICK_ENABLED) {
	415	ret = dyn_tick->disable();
	416
	417	if (ret == 0)
	418	dyn_tick->state &= ~DYN_TICK_ENABLED;
	419	}
ebc67da6	420	spin_unlock_irqrestore(&dyn_tick->lock, flags);
8749af68 RK	421	}
	422
	423	return ret;
	424	}
	425
2ea83398 RK	426	/*
	427	* Reprogram the system timer for at least the calculated time interval.
	428	* This function should be called from the idle thread with IRQs disabled,
	429	* immediately before sleeping.
	430	*/
8749af68 RK	431	void timer_dyn_reprogram(void)
	432	{
	433	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
ebc67da6	434	unsigned long next, seq, flags;
8749af68	435
ebc67da6 TL	436	if (!dyn_tick)
	437	return;
	438
	439	spin_lock_irqsave(&dyn_tick->lock, flags);
	440	if (dyn_tick->state & DYN_TICK_ENABLED) {
69239749 TL	441	next = next_timer_interrupt();
	442	do {
	443	seq = read_seqbegin(&xtime_lock);
ebc67da6	444	dyn_tick->reprogram(next - jiffies);
69239749	445	} while (read_seqretry(&xtime_lock, seq));
3618886f	446	}
ebc67da6	447	spin_unlock_irqrestore(&dyn_tick->lock, flags);
8749af68 RK	448	}
	449
	450	static ssize_t timer_show_dyn_tick(struct sys_device dev, char buf)
	451	{
	452	return sprintf(buf, "%i\n",
	453	(system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
	454	}
	455
	456	static ssize_t timer_set_dyn_tick(struct sys_device dev, const char buf,
	457	size_t count)
	458	{
	459	unsigned int enable = simple_strtoul(buf, NULL, 2);
	460
	461	if (enable)
	462	timer_dyn_tick_enable();
	463	else
	464	timer_dyn_tick_disable();
	465
	466	return count;
	467	}
	468	static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
	469
	470	/*
	471	* dyntick=enable\|disable
	472	*/
	473	static char dyntick_str[4] __initdata = "";
	474
	475	static int __init dyntick_setup(char *str)
	476	{
	477	if (str)
	478	strlcpy(dyntick_str, str, sizeof(dyntick_str));
	479	return 1;
	480	}
	481
	482	__setup("dyntick=", dyntick_setup);
	483	#endif
	484
1da177e4 LT	485	static int __init timer_init_sysfs(void)
	486	{
	487	int ret = sysdev_class_register(&timer_sysclass);
	488	if (ret == 0) {
	489	system_timer->dev.cls = &timer_sysclass;
	490	ret = sysdev_register(&system_timer->dev);
	491	}
8749af68 RK	492
	493	#ifdef CONFIG_NO_IDLE_HZ
	494	if (ret == 0 && system_timer->dyn_tick) {
	495	ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick);
	496
	497	/*
	498	* Turn on dynamic tick after calibrate delay
	499	* for correct bogomips
	500	*/
	501	if (ret == 0 && dyntick_str[0] == 'e')
	502	ret = timer_dyn_tick_enable();
	503	}
	504	#endif
	505
1da177e4 LT	506	return ret;
	507	}
	508
	509	device_initcall(timer_init_sysfs);
	510
	511	void __init time_init(void)
	512	{
746140c7	513	#ifndef CONFIG_GENERIC_TIME
1da177e4 LT	514	if (system_timer->offset == NULL)
1da177e4 LT	515	system_timer->offset = dummy_gettimeoffset;
746140c7	516	#endif
1da177e4	517	system_timer->init();
ebc67da6 TL	518
	519	#ifdef CONFIG_NO_IDLE_HZ
	520	if (system_timer->dyn_tick)
	521	system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED;
	522	#endif
1da177e4 LT	523	}
1da177e4 LT	524