[linux-2.6-block.git] / arch / sh / kernel / time.c

/*
 *  arch/sh/kernel/time.c
 *
 *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
 *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
 *  Copyright (C) 2002 - 2006  Paul Mundt
 *  Copyright (C) 2002  M. R. Brown  <mrbrown@linux-sh.org>
 *
 *  Some code taken from i386 version.
 *    Copyright (C) 1991, 1992, 1995  Linus Torvalds
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <asm/clock.h>
#include <asm/rtc.h>
#include <asm/timer.h>
#include <asm/kgdb.h>

struct sys_timer *sys_timer;

/* Move this somewhere more sensible.. */
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);

/* Dummy RTC ops */
static void null_rtc_get_time(struct timespec *tv)
{
	tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
	tv->tv_nsec = 0;
}

static int null_rtc_set_time(const time_t secs)
{
	return 0;
}

void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time;
int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;

/*
 * Scheduler clock - returns current time in nanosec units.
 */
unsigned long long __attribute__ ((weak)) sched_clock(void)
{
	return (unsigned long long)jiffies * (1000000000 / HZ);
}

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

	do {
		/*
		 * Turn off IRQs when grabbing xtime_lock, so that
		 * the sys_timer get_offset code doesn't have to handle it.
		 */
		seq = read_seqbegin_irqsave(&xtime_lock, flags);
		usec = get_timer_offset();
		sec = xtime.tv_sec;
		usec += xtime.tv_nsec / NSEC_PER_USEC;
	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));

	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
	 * made, and then undo it!
	 */
	nsec -= get_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 */

/* last time the RTC clock got updated */
static long last_rtc_update;

/*
 * handle_timer_tick() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
void handle_timer_tick(void)
{
	do_timer(1);
#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
	if (current->pid)
		profile_tick(CPU_PROFILING);

#ifdef CONFIG_HEARTBEAT
	if (sh_mv.mv_heartbeat != NULL)
		sh_mv.mv_heartbeat();
#endif

	/*
	 * If we have an externally synchronized Linux clock, then update
	 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	 * called as close as possible to 500 ms before the new second starts.
	 */
	if (ntp_synced() &&
	    xtime.tv_sec > last_rtc_update + 660 &&
	    (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	    (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
		if (rtc_sh_set_time(xtime.tv_sec) == 0)
			last_rtc_update = xtime.tv_sec;
		else
			/* do it again in 60s */
			last_rtc_update = xtime.tv_sec - 600;
	}
}

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

	sys_timer->ops->stop();

	return 0;
}

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

	sys_timer->ops->start();

	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 = sys_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 = sys_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 = sys_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",
		       (sys_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)
		return ret;

	sys_timer->dev.cls = &timer_sysclass;
	ret = sysdev_register(&sys_timer->dev);

#ifdef CONFIG_NO_IDLE_HZ
	if (ret == 0 && sys_timer->dyn_tick) {
		ret = sysdev_create_file(&sys_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 (*board_time_init)(void);

void __init time_init(void)
{
	if (board_time_init)
		board_time_init();

	clk_init();

	rtc_sh_get_time(&xtime);
	set_normalized_timespec(&wall_to_monotonic,
				-xtime.tv_sec, -xtime.tv_nsec);

	/*
	 * Find the timer to use as the system timer, it will be
	 * initialized for us.
	 */
	sys_timer = get_sys_timer();
	printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);

#ifdef CONFIG_NO_IDLE_HZ
	if (sys_timer->dyn_tick)
		spin_lock_init(&sys_timer->dyn_tick->lock);
#endif

#if defined(CONFIG_SH_KGDB)
	/*
	 * Set up kgdb as requested. We do it here because the serial
	 * init uses the timer vars we just set up for figuring baud.
	 */
	kgdb_init();
#endif
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/sh/kernel/time.c
	3	*
	4	* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
	5	* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
91550f71	6	* Copyright (C) 2002 - 2006 Paul Mundt
1da177e4 LT	7	* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
	8	*
	9	* Some code taken from i386 version.
	10	* Copyright (C) 1991, 1992, 1995 Linus Torvalds
	11	*/
1da177e4	12	#include <linux/kernel.h>
36ddf31b	13	#include <linux/module.h>
1da177e4	14	#include <linux/init.h>
1da177e4	15	#include <linux/profile.h>
36ddf31b	16	#include <asm/clock.h>
1da177e4	17	#include <asm/rtc.h>
36ddf31b	18	#include <asm/timer.h>
1da177e4	19	#include <asm/kgdb.h>
1da177e4	20
36ddf31b PM	21	struct sys_timer *sys_timer;
	22
	23	/* Move this somewhere more sensible.. */
	24	DEFINE_SPINLOCK(rtc_lock);
	25	EXPORT_SYMBOL(rtc_lock);
1da177e4	26
91550f71 PM	27	/* Dummy RTC ops */
	28	static void null_rtc_get_time(struct timespec *tv)
	29	{
	30	tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
	31	tv->tv_nsec = 0;
	32	}
	33
	34	static int null_rtc_set_time(const time_t secs)
	35	{
	36	return 0;
	37	}
	38
	39	void (rtc_sh_get_time)(struct timespec ) = null_rtc_get_time;
	40	int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
1da177e4	41
1da177e4 LT	42	/*
	43	* Scheduler clock - returns current time in nanosec units.
	44	*/
36ddf31b	45	unsigned long long __attribute__ ((weak)) sched_clock(void)
1da177e4 LT	46	{
	47	return (unsigned long long)jiffies * (1000000000 / HZ);
	48	}
	49
45882145	50	#ifndef CONFIG_GENERIC_TIME
1da177e4 LT	51	void do_gettimeofday(struct timeval *tv)
1da177e4 LT	52	{
e74b5680	53	unsigned long flags;
1da177e4 LT	54	unsigned long seq;
1da177e4 LT	55	unsigned long usec, sec;
1da177e4 LT	56
1da177e4 LT	57	do {
e74b5680 PM	58	/*
	59	* Turn off IRQs when grabbing xtime_lock, so that
	60	* the sys_timer get_offset code doesn't have to handle it.
	61	*/
	62	seq = read_seqbegin_irqsave(&xtime_lock, flags);
36ddf31b	63	usec = get_timer_offset();
1da177e4	64	sec = xtime.tv_sec;
e74b5680 PM	65	usec += xtime.tv_nsec / NSEC_PER_USEC;
e74b5680 PM	66	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
1da177e4 LT	67
	68	while (usec >= 1000000) {
	69	usec -= 1000000;
	70	sec++;
	71	}
	72
	73	tv->tv_sec = sec;
	74	tv->tv_usec = usec;
	75	}
1da177e4 LT	76	EXPORT_SYMBOL(do_gettimeofday);
	77
	78	int do_settimeofday(struct timespec *tv)
	79	{
	80	time_t wtm_sec, sec = tv->tv_sec;
	81	long wtm_nsec, nsec = tv->tv_nsec;
	82
	83	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
	84	return -EINVAL;
	85
	86	write_seqlock_irq(&xtime_lock);
	87	/*
	88	* This is revolting. We need to set "xtime" correctly. However, the
	89	* value in this location is the value at the most recent update of
	90	* wall time. Discover what correction gettimeofday() would have
	91	* made, and then undo it!
	92	*/
e74b5680	93	nsec -= get_timer_offset() * NSEC_PER_USEC;
1da177e4 LT	94
	95	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	96	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
	97
	98	set_normalized_timespec(&xtime, sec, nsec);
	99	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
	100
b149ee22	101	ntp_clear();
1da177e4 LT	102	write_sequnlock_irq(&xtime_lock);
	103	clock_was_set();
	104
	105	return 0;
	106	}
1da177e4	107	EXPORT_SYMBOL(do_settimeofday);
45882145	108	#endif /* !CONFIG_GENERIC_TIME */
1da177e4 LT	109
	110	/* last time the RTC clock got updated */
	111	static long last_rtc_update;
	112
	113	/*
36ddf31b	114	* handle_timer_tick() needs to keep up the real-time clock,
1da177e4 LT	115	* as well as call the "do_timer()" routine every clocktick
1da177e4 LT	116	*/
35f3c518	117	void handle_timer_tick(void)
1da177e4	118	{
3171a030	119	do_timer(1);
1da177e4	120	#ifndef CONFIG_SMP
35f3c518	121	update_process_times(user_mode(get_irq_regs()));
1da177e4	122	#endif
35f3c518 PM	123	if (current->pid)
35f3c518 PM	124	profile_tick(CPU_PROFILING);
1da177e4 LT	125
	126	#ifdef CONFIG_HEARTBEAT
	127	if (sh_mv.mv_heartbeat != NULL)
	128	sh_mv.mv_heartbeat();
	129	#endif
	130
	131	/*
	132	* If we have an externally synchronized Linux clock, then update
	133	* RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	134	* called as close as possible to 500 ms before the new second starts.
	135	*/
b149ee22	136	if (ntp_synced() &&
1da177e4 LT	137	xtime.tv_sec > last_rtc_update + 660 &&
	138	(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	139	(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
af514ca7	140	if (rtc_sh_set_time(xtime.tv_sec) == 0)
1da177e4 LT	141	last_rtc_update = xtime.tv_sec;
1da177e4 LT	142	else
36ddf31b PM	143	/* do it again in 60s */
36ddf31b PM	144	last_rtc_update = xtime.tv_sec - 600;
1da177e4 LT	145	}
	146	}
	147
3aa770e7 AS	148	#ifdef CONFIG_PM
	149	int timer_suspend(struct sys_device *dev, pm_message_t state)
	150	{
	151	struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
	152
	153	sys_timer->ops->stop();
	154
	155	return 0;
	156	}
	157
	158	int timer_resume(struct sys_device *dev)
	159	{
	160	struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
	161
	162	sys_timer->ops->start();
	163
	164	return 0;
	165	}
	166	#else
	167	#define timer_suspend NULL
	168	#define timer_resume NULL
	169	#endif
	170
36ddf31b PM	171	static struct sysdev_class timer_sysclass = {
36ddf31b PM	172	set_kset_name("timer"),
3aa770e7 AS	173	.suspend = timer_suspend,
3aa770e7 AS	174	.resume = timer_resume,
1da177e4 LT	175	};
1da177e4 LT	176
bd156147 PM	177	#ifdef CONFIG_NO_IDLE_HZ
	178	static int timer_dyn_tick_enable(void)
	179	{
	180	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	181	unsigned long flags;
	182	int ret = -ENODEV;
	183
	184	if (dyn_tick) {
	185	spin_lock_irqsave(&dyn_tick->lock, flags);
	186	ret = 0;
	187	if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
	188	ret = dyn_tick->enable();
	189
	190	if (ret == 0)
	191	dyn_tick->state \|= DYN_TICK_ENABLED;
	192	}
	193	spin_unlock_irqrestore(&dyn_tick->lock, flags);
	194	}
	195
	196	return ret;
	197	}
	198
	199	static int timer_dyn_tick_disable(void)
	200	{
	201	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	202	unsigned long flags;
	203	int ret = -ENODEV;
	204
	205	if (dyn_tick) {
	206	spin_lock_irqsave(&dyn_tick->lock, flags);
	207	ret = 0;
	208	if (dyn_tick->state & DYN_TICK_ENABLED) {
	209	ret = dyn_tick->disable();
	210
	211	if (ret == 0)
	212	dyn_tick->state &= ~DYN_TICK_ENABLED;
	213	}
	214	spin_unlock_irqrestore(&dyn_tick->lock, flags);
	215	}
	216
	217	return ret;
	218	}
	219
	220	/*
	221	* Reprogram the system timer for at least the calculated time interval.
	222	* This function should be called from the idle thread with IRQs disabled,
	223	* immediately before sleeping.
	224	*/
	225	void timer_dyn_reprogram(void)
	226	{
	227	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	228	unsigned long next, seq, flags;
	229
	230	if (!dyn_tick)
	231	return;
	232
	233	spin_lock_irqsave(&dyn_tick->lock, flags);
	234	if (dyn_tick->state & DYN_TICK_ENABLED) {
	235	next = next_timer_interrupt();
	236	do {
	237	seq = read_seqbegin(&xtime_lock);
	238	dyn_tick->reprogram(next - jiffies);
	239	} while (read_seqretry(&xtime_lock, seq));
	240	}
241	spin_unlock_irqrestore(&dyn_tick->lock, flags);
242	}
243
244	static ssize_t timer_show_dyn_tick(struct sys_device dev, char buf)
245	{
246	return sprintf(buf, "%i\n",
247	(sys_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
248	}
249
250	static ssize_t timer_set_dyn_tick(struct sys_device dev, const char buf,
251	size_t count)
252	{
253	unsigned int enable = simple_strtoul(buf, NULL, 2);
254
255	if (enable)
256	timer_dyn_tick_enable();
257	else
258	timer_dyn_tick_disable();
259
260	return count;
261	}
262	static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
263
264	/*
265	* dyntick=enable\|disable
266	*/
267	static char dyntick_str[4] __initdata = "";
268
269	static int __init dyntick_setup(char *str)
270	{
271	if (str)
272	strlcpy(dyntick_str, str, sizeof(dyntick_str));
273	return 1;
274	}
275
276	__setup("dyntick=", dyntick_setup);
277	#endif
278
36ddf31b	279	static int __init timer_init_sysfs(void)
1da177e4	280	{
36ddf31b PM	281	int ret = sysdev_class_register(&timer_sysclass);
	282	if (ret != 0)
	283	return ret;
1da177e4	284
36ddf31b	285	sys_timer->dev.cls = &timer_sysclass;
bd156147 PM	286	ret = sysdev_register(&sys_timer->dev);
	287
	288	#ifdef CONFIG_NO_IDLE_HZ
	289	if (ret == 0 && sys_timer->dyn_tick) {
	290	ret = sysdev_create_file(&sys_timer->dev, &attr_dyn_tick);
	291
	292	/*
	293	* Turn on dynamic tick after calibrate delay
	294	* for correct bogomips
	295	*/
	296	if (ret == 0 && dyntick_str[0] == 'e')
	297	ret = timer_dyn_tick_enable();
	298	}
	299	#endif
	300
	301	return ret;
36ddf31b	302	}
36ddf31b	303	device_initcall(timer_init_sysfs);
1da177e4	304
36ddf31b	305	void (*board_time_init)(void);
1da177e4 LT	306
	307	void __init time_init(void)
	308	{
1da177e4 LT	309	if (board_time_init)
	310	board_time_init();
	311
36ddf31b	312	clk_init();
1da177e4	313
91550f71 PM	314	rtc_sh_get_time(&xtime);
	315	set_normalized_timespec(&wall_to_monotonic,
	316	-xtime.tv_sec, -xtime.tv_nsec);
1da177e4	317
1da177e4	318	/*
36ddf31b PM	319	* Find the timer to use as the system timer, it will be
36ddf31b PM	320	* initialized for us.
1da177e4	321	*/
36ddf31b PM	322	sys_timer = get_sys_timer();
36ddf31b PM	323	printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
1da177e4	324
bd156147 PM	325	#ifdef CONFIG_NO_IDLE_HZ
	326	if (sys_timer->dyn_tick)
	327	spin_lock_init(&sys_timer->dyn_tick->lock);
	328	#endif
	329
1da177e4 LT	330	#if defined(CONFIG_SH_KGDB)
	331	/*
	332	* Set up kgdb as requested. We do it here because the serial
	333	* init uses the timer vars we just set up for figuring baud.
	334	*/
	335	kgdb_init();
	336	#endif
	337	}