2 * linux/arch/arm/kernel/time.c
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
5 * Modifications for ARM (C) 1994-2001 Russell King
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.
11 * This file contains the ARM-specific time handling details:
12 * reading the RTC at bootup, etc...
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
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>
32 #include <asm/hardware.h>
36 #include <asm/thread_info.h>
37 #include <asm/mach/time.h>
39 u64 jiffies_64
= INITIAL_JIFFIES
;
41 EXPORT_SYMBOL(jiffies_64
);
43 extern unsigned long wall_jiffies
;
45 /* this needs a better home */
46 spinlock_t rtc_lock
= SPIN_LOCK_UNLOCKED
;
48 #ifdef CONFIG_SA1100_RTC_MODULE
49 EXPORT_SYMBOL(rtc_lock
);
52 /* change this if you have some constant time drift */
53 #define USECS_PER_JIFFY (1000000/HZ)
56 unsigned long profile_pc(struct pt_regs
*regs
)
58 unsigned long fp
, pc
= instruction_pointer(regs
);
60 if (in_lock_functions(pc
)) {
61 fp
= thread_saved_fp(current
);
62 pc
= pc_pointer(((unsigned long *)fp
)[-1]);
67 EXPORT_SYMBOL(profile_pc
);
71 * hook for setting the RTC's idea of the current time.
75 static unsigned long dummy_gettimeoffset(void)
81 * hook for getting the time offset. Note that it is
82 * always called with interrupts disabled.
84 unsigned long (*gettimeoffset
)(void) = dummy_gettimeoffset
;
87 * Scheduler clock - returns current time in nanosec units.
88 * This is the default implementation. Sub-architecture
89 * implementations can override this.
91 unsigned long long __attribute__((weak
)) sched_clock(void)
93 #if 1 // mask by Victor Yu. 06-06-2005
94 return (unsigned long long)jiffies
* (1000000000 / HZ
);
95 #else // add by Victor Yu. 06-06-2005
96 unsigned long long ret
;
98 ret
= (unsigned long long)((unsigned long long)1000000000 / (unsigned long long)HZ
);
99 ret
*= (unsigned long long)jiffies
;
104 static unsigned long next_rtc_update
;
107 * If we have an externally synchronized linux clock, then update
108 * CMOS clock accordingly every ~11 minutes. set_rtc() has to be
109 * called as close as possible to 500 ms before the new second
112 static inline void do_set_rtc(void)
114 if (time_status
& STA_UNSYNC
|| set_rtc
== NULL
)
117 if (next_rtc_update
&&
118 time_before((unsigned long)xtime
.tv_sec
, next_rtc_update
))
121 if (xtime
.tv_nsec
< 500000000 - ((unsigned) tick_nsec
>> 1) &&
122 xtime
.tv_nsec
>= 500000000 + ((unsigned) tick_nsec
>> 1))
127 * rtc update failed. Try again in 60s
129 next_rtc_update
= xtime
.tv_sec
+ 60;
131 next_rtc_update
= xtime
.tv_sec
+ 660;
136 static void dummy_leds_event(led_event_t evt
)
140 void (*leds_event
)(led_event_t
) = dummy_leds_event
;
142 struct leds_evt_name
{
148 static const struct leds_evt_name evt_names
[] = {
149 { "amber", led_amber_on
, led_amber_off
},
150 { "blue", led_blue_on
, led_blue_off
},
151 { "green", led_green_on
, led_green_off
},
152 { "red", led_red_on
, led_red_off
},
155 static ssize_t
leds_store(struct sys_device
*dev
, const char *buf
, size_t size
)
157 int ret
= -EINVAL
, len
= strcspn(buf
, " ");
159 if (len
> 0 && buf
[len
] == '\0')
162 if (strncmp(buf
, "claim", len
) == 0) {
163 leds_event(led_claim
);
165 } else if (strncmp(buf
, "release", len
) == 0) {
166 leds_event(led_release
);
171 for (i
= 0; i
< ARRAY_SIZE(evt_names
); i
++) {
172 if (strlen(evt_names
[i
].name
) != len
||
173 strncmp(buf
, evt_names
[i
].name
, len
) != 0)
175 if (strncmp(buf
+len
, " on", 3) == 0) {
176 leds_event(evt_names
[i
].on
);
178 } else if (strncmp(buf
+len
, " off", 4) == 0) {
179 leds_event(evt_names
[i
].off
);
188 static SYSDEV_ATTR(event
, 0200, NULL
, leds_store
);
190 static int leds_suspend(struct sys_device
*dev
, u32 state
)
192 leds_event(led_stop
);
196 static int leds_resume(struct sys_device
*dev
)
198 leds_event(led_start
);
202 static int leds_shutdown(struct sys_device
*dev
)
204 leds_event(led_halted
);
208 static struct sysdev_class leds_sysclass
= {
209 set_kset_name("leds"),
210 .shutdown
= leds_shutdown
,
211 .suspend
= leds_suspend
,
212 .resume
= leds_resume
,
215 static struct sys_device leds_device
= {
217 .cls
= &leds_sysclass
,
220 static int __init
leds_init(void)
223 ret
= sysdev_class_register(&leds_sysclass
);
225 ret
= sysdev_register(&leds_device
);
227 ret
= sysdev_create_file(&leds_device
, &attr_event
);
231 device_initcall(leds_init
);
233 EXPORT_SYMBOL(leds_event
);
236 #ifdef CONFIG_LEDS_TIMER
237 static inline void do_leds(void)
239 static unsigned int count
= 50;
243 leds_event(led_timer
);
250 void do_gettimeofday(struct timeval
*tv
)
254 unsigned long usec
, sec
, lost
;
257 seq
= read_seqbegin_irqsave(&xtime_lock
, flags
);
258 usec
= gettimeoffset();
260 lost
= jiffies
- wall_jiffies
;
262 usec
+= lost
* USECS_PER_JIFFY
;
265 usec
+= xtime
.tv_nsec
/ 1000;
266 } while (read_seqretry_irqrestore(&xtime_lock
, seq
, flags
));
268 /* usec may have gone up a lot: be safe */
269 while (usec
>= 1000000) {
278 EXPORT_SYMBOL(do_gettimeofday
);
280 int do_settimeofday(struct timespec
*tv
)
282 time_t wtm_sec
, sec
= tv
->tv_sec
;
283 long wtm_nsec
, nsec
= tv
->tv_nsec
;
285 if ((unsigned long)tv
->tv_nsec
>= NSEC_PER_SEC
)
288 write_seqlock_irq(&xtime_lock
);
290 * This is revolting. We need to set "xtime" correctly. However, the
291 * value in this location is the value at the most recent update of
292 * wall time. Discover what correction gettimeofday() would have
293 * done, and then undo it!
295 nsec
-= gettimeoffset() * NSEC_PER_USEC
;
296 nsec
-= (jiffies
- wall_jiffies
) * TICK_NSEC
;
298 wtm_sec
= wall_to_monotonic
.tv_sec
+ (xtime
.tv_sec
- sec
);
299 wtm_nsec
= wall_to_monotonic
.tv_nsec
+ (xtime
.tv_nsec
- nsec
);
301 set_normalized_timespec(&xtime
, sec
, nsec
);
302 set_normalized_timespec(&wall_to_monotonic
, wtm_sec
, wtm_nsec
);
304 time_adjust
= 0; /* stop active adjtime() */
305 time_status
|= STA_UNSYNC
;
306 time_maxerror
= NTP_PHASE_LIMIT
;
307 time_esterror
= NTP_PHASE_LIMIT
;
308 write_sequnlock_irq(&xtime_lock
);
313 EXPORT_SYMBOL(do_settimeofday
);
316 * save_time_delta - Save the offset between system time and RTC time
317 * @delta: pointer to timespec to store delta
318 * @rtc: pointer to timespec for current RTC time
320 * Return a delta between the system time and the RTC time, such
321 * that system time can be restored later with restore_time_delta()
323 void save_time_delta(struct timespec
*delta
, struct timespec
*rtc
)
325 set_normalized_timespec(delta
,
326 xtime
.tv_sec
- rtc
->tv_sec
,
327 xtime
.tv_nsec
- rtc
->tv_nsec
);
329 EXPORT_SYMBOL(save_time_delta
);
332 * restore_time_delta - Restore the current system time
333 * @delta: delta returned by save_time_delta()
334 * @rtc: pointer to timespec for current RTC time
336 void restore_time_delta(struct timespec
*delta
, struct timespec
*rtc
)
340 set_normalized_timespec(&ts
,
341 delta
->tv_sec
+ rtc
->tv_sec
,
342 delta
->tv_nsec
+ rtc
->tv_nsec
);
344 do_settimeofday(&ts
);
346 EXPORT_SYMBOL(restore_time_delta
);
348 void timer_tick(struct pt_regs
*regs
)
350 profile_tick(CPU_PROFILING
, regs
);
356 void (*init_arch_time
)(void);
358 void __init
time_init(void)