[deliverable/linux.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 <linux/timex.h>
#include <linux/sched.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>
65e5d90d PM	16	#include <linux/timex.h>
65e5d90d PM	17	#include <linux/sched.h>
36ddf31b	18	#include <asm/clock.h>
1da177e4	19	#include <asm/rtc.h>
36ddf31b	20	#include <asm/timer.h>
1da177e4	21	#include <asm/kgdb.h>
1da177e4	22
36ddf31b PM	23	struct sys_timer *sys_timer;
	24
	25	/* Move this somewhere more sensible.. */
	26	DEFINE_SPINLOCK(rtc_lock);
	27	EXPORT_SYMBOL(rtc_lock);
1da177e4	28
91550f71 PM	29	/* Dummy RTC ops */
	30	static void null_rtc_get_time(struct timespec *tv)
	31	{
	32	tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
	33	tv->tv_nsec = 0;
	34	}
	35
	36	static int null_rtc_set_time(const time_t secs)
	37	{
	38	return 0;
	39	}
	40
	41	void (rtc_sh_get_time)(struct timespec ) = null_rtc_get_time;
	42	int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time;
1da177e4	43
1da177e4 LT	44	/*
	45	* Scheduler clock - returns current time in nanosec units.
	46	*/
36ddf31b	47	unsigned long long __attribute__ ((weak)) sched_clock(void)
1da177e4 LT	48	{
	49	return (unsigned long long)jiffies * (1000000000 / HZ);
	50	}
	51
45882145	52	#ifndef CONFIG_GENERIC_TIME
1da177e4 LT	53	void do_gettimeofday(struct timeval *tv)
1da177e4 LT	54	{
e74b5680	55	unsigned long flags;
1da177e4 LT	56	unsigned long seq;
1da177e4 LT	57	unsigned long usec, sec;
1da177e4 LT	58
1da177e4 LT	59	do {
e74b5680 PM	60	/*
	61	* Turn off IRQs when grabbing xtime_lock, so that
	62	* the sys_timer get_offset code doesn't have to handle it.
	63	*/
	64	seq = read_seqbegin_irqsave(&xtime_lock, flags);
36ddf31b	65	usec = get_timer_offset();
1da177e4	66	sec = xtime.tv_sec;
e74b5680 PM	67	usec += xtime.tv_nsec / NSEC_PER_USEC;
e74b5680 PM	68	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
1da177e4 LT	69
	70	while (usec >= 1000000) {
	71	usec -= 1000000;
	72	sec++;
	73	}
	74
	75	tv->tv_sec = sec;
	76	tv->tv_usec = usec;
	77	}
1da177e4 LT	78	EXPORT_SYMBOL(do_gettimeofday);
	79
	80	int do_settimeofday(struct timespec *tv)
	81	{
	82	time_t wtm_sec, sec = tv->tv_sec;
	83	long wtm_nsec, nsec = tv->tv_nsec;
	84
	85	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
	86	return -EINVAL;
	87
	88	write_seqlock_irq(&xtime_lock);
	89	/*
	90	* This is revolting. We need to set "xtime" correctly. However, the
	91	* value in this location is the value at the most recent update of
	92	* wall time. Discover what correction gettimeofday() would have
	93	* made, and then undo it!
	94	*/
e74b5680	95	nsec -= get_timer_offset() * NSEC_PER_USEC;
1da177e4 LT	96
	97	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	98	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
	99
	100	set_normalized_timespec(&xtime, sec, nsec);
	101	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
	102
b149ee22	103	ntp_clear();
1da177e4 LT	104	write_sequnlock_irq(&xtime_lock);
	105	clock_was_set();
	106
	107	return 0;
	108	}
1da177e4	109	EXPORT_SYMBOL(do_settimeofday);
45882145	110	#endif /* !CONFIG_GENERIC_TIME */
1da177e4 LT	111
	112	/* last time the RTC clock got updated */
	113	static long last_rtc_update;
	114
	115	/*
36ddf31b	116	* handle_timer_tick() needs to keep up the real-time clock,
1da177e4 LT	117	* as well as call the "do_timer()" routine every clocktick
1da177e4 LT	118	*/
35f3c518	119	void handle_timer_tick(void)
1da177e4	120	{
3171a030	121	do_timer(1);
1da177e4	122	#ifndef CONFIG_SMP
35f3c518	123	update_process_times(user_mode(get_irq_regs()));
1da177e4	124	#endif
35f3c518 PM	125	if (current->pid)
35f3c518 PM	126	profile_tick(CPU_PROFILING);
1da177e4 LT	127
	128	#ifdef CONFIG_HEARTBEAT
	129	if (sh_mv.mv_heartbeat != NULL)
	130	sh_mv.mv_heartbeat();
	131	#endif
	132
	133	/*
	134	* If we have an externally synchronized Linux clock, then update
	135	* RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	136	* called as close as possible to 500 ms before the new second starts.
	137	*/
b149ee22	138	if (ntp_synced() &&
1da177e4 LT	139	xtime.tv_sec > last_rtc_update + 660 &&
	140	(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	141	(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
af514ca7	142	if (rtc_sh_set_time(xtime.tv_sec) == 0)
1da177e4 LT	143	last_rtc_update = xtime.tv_sec;
1da177e4 LT	144	else
36ddf31b PM	145	/* do it again in 60s */
36ddf31b PM	146	last_rtc_update = xtime.tv_sec - 600;
1da177e4 LT	147	}
	148	}
	149
3aa770e7 AS	150	#ifdef CONFIG_PM
	151	int timer_suspend(struct sys_device *dev, pm_message_t state)
	152	{
	153	struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
	154
	155	sys_timer->ops->stop();
	156
	157	return 0;
	158	}
	159
	160	int timer_resume(struct sys_device *dev)
	161	{
	162	struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev);
	163
	164	sys_timer->ops->start();
	165
	166	return 0;
	167	}
	168	#else
	169	#define timer_suspend NULL
	170	#define timer_resume NULL
	171	#endif
	172
36ddf31b PM	173	static struct sysdev_class timer_sysclass = {
36ddf31b PM	174	set_kset_name("timer"),
3aa770e7 AS	175	.suspend = timer_suspend,
3aa770e7 AS	176	.resume = timer_resume,
1da177e4 LT	177	};
1da177e4 LT	178
bd156147 PM	179	#ifdef CONFIG_NO_IDLE_HZ
	180	static int timer_dyn_tick_enable(void)
	181	{
	182	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	183	unsigned long flags;
	184	int ret = -ENODEV;
	185
	186	if (dyn_tick) {
	187	spin_lock_irqsave(&dyn_tick->lock, flags);
	188	ret = 0;
	189	if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
	190	ret = dyn_tick->enable();
	191
	192	if (ret == 0)
	193	dyn_tick->state \|= DYN_TICK_ENABLED;
	194	}
	195	spin_unlock_irqrestore(&dyn_tick->lock, flags);
	196	}
	197
	198	return ret;
	199	}
	200
	201	static int timer_dyn_tick_disable(void)
	202	{
	203	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	204	unsigned long flags;
	205	int ret = -ENODEV;
	206
	207	if (dyn_tick) {
	208	spin_lock_irqsave(&dyn_tick->lock, flags);
	209	ret = 0;
	210	if (dyn_tick->state & DYN_TICK_ENABLED) {
	211	ret = dyn_tick->disable();
	212
	213	if (ret == 0)
	214	dyn_tick->state &= ~DYN_TICK_ENABLED;
	215	}
	216	spin_unlock_irqrestore(&dyn_tick->lock, flags);
	217	}
	218
	219	return ret;
	220	}
	221
	222	/*
	223	* Reprogram the system timer for at least the calculated time interval.
	224	* This function should be called from the idle thread with IRQs disabled,
	225	* immediately before sleeping.
	226	*/
	227	void timer_dyn_reprogram(void)
	228	{
	229	struct dyn_tick_timer *dyn_tick = sys_timer->dyn_tick;
	230	unsigned long next, seq, flags;
	231
	232	if (!dyn_tick)
	233	return;
	234
	235	spin_lock_irqsave(&dyn_tick->lock, flags);
	236	if (dyn_tick->state & DYN_TICK_ENABLED) {
	237	next = next_timer_interrupt();
	238	do {
	239	seq = read_seqbegin(&xtime_lock);
	240	dyn_tick->reprogram(next - jiffies);
	241	} while (read_seqretry(&xtime_lock, seq));
	242	}
243	spin_unlock_irqrestore(&dyn_tick->lock, flags);
244	}
245
246	static ssize_t timer_show_dyn_tick(struct sys_device dev, char buf)
247	{
248	return sprintf(buf, "%i\n",
249	(sys_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
250	}
251
252	static ssize_t timer_set_dyn_tick(struct sys_device dev, const char buf,
253	size_t count)
254	{
255	unsigned int enable = simple_strtoul(buf, NULL, 2);
256
257	if (enable)
258	timer_dyn_tick_enable();
259	else
260	timer_dyn_tick_disable();
261
262	return count;
263	}
264	static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
265
266	/*
267	* dyntick=enable\|disable
268	*/
269	static char dyntick_str[4] __initdata = "";
270
271	static int __init dyntick_setup(char *str)
272	{
273	if (str)
274	strlcpy(dyntick_str, str, sizeof(dyntick_str));
275	return 1;
276	}
277
278	__setup("dyntick=", dyntick_setup);
279	#endif
280
36ddf31b	281	static int __init timer_init_sysfs(void)
1da177e4	282	{
36ddf31b PM	283	int ret = sysdev_class_register(&timer_sysclass);
	284	if (ret != 0)
	285	return ret;
1da177e4	286
36ddf31b	287	sys_timer->dev.cls = &timer_sysclass;
bd156147 PM	288	ret = sysdev_register(&sys_timer->dev);
	289
	290	#ifdef CONFIG_NO_IDLE_HZ
	291	if (ret == 0 && sys_timer->dyn_tick) {
	292	ret = sysdev_create_file(&sys_timer->dev, &attr_dyn_tick);
	293
	294	/*
	295	* Turn on dynamic tick after calibrate delay
	296	* for correct bogomips
	297	*/
	298	if (ret == 0 && dyntick_str[0] == 'e')
	299	ret = timer_dyn_tick_enable();
	300	}
	301	#endif
	302
	303	return ret;
36ddf31b	304	}
36ddf31b	305	device_initcall(timer_init_sysfs);
1da177e4	306
36ddf31b	307	void (*board_time_init)(void);
1da177e4 LT	308
	309	void __init time_init(void)
	310	{
1da177e4 LT	311	if (board_time_init)
	312	board_time_init();
	313
36ddf31b	314	clk_init();
1da177e4	315
91550f71 PM	316	rtc_sh_get_time(&xtime);
	317	set_normalized_timespec(&wall_to_monotonic,
	318	-xtime.tv_sec, -xtime.tv_nsec);
1da177e4	319
1da177e4	320	/*
36ddf31b PM	321	* Find the timer to use as the system timer, it will be
36ddf31b PM	322	* initialized for us.
1da177e4	323	*/
36ddf31b PM	324	sys_timer = get_sys_timer();
36ddf31b PM	325	printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);
1da177e4	326
bd156147 PM	327	#ifdef CONFIG_NO_IDLE_HZ
	328	if (sys_timer->dyn_tick)
	329	spin_lock_init(&sys_timer->dyn_tick->lock);
	330	#endif
	331
1da177e4 LT	332	#if defined(CONFIG_SH_KGDB)
	333	/*
	334	* Set up kgdb as requested. We do it here because the serial
	335	* init uses the timer vars we just set up for figuring baud.
	336	*/
	337	kgdb_init();
	338	#endif
	339	}