2 * linux/arch/cris/kernel/fasttimer.c
4 * Fast timers for ETRAX100/ETRAX100LX
6 * Copyright (C) 2000-2007 Axis Communications AB, Lund, Sweden
9 #include <linux/errno.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/param.h>
13 #include <linux/string.h>
15 #include <linux/vmalloc.h>
16 #include <linux/interrupt.h>
17 #include <linux/time.h>
18 #include <linux/delay.h>
20 #include <asm/segment.h>
23 #include <asm/delay.h>
27 #include <asm/arch/svinto.h>
28 #include <asm/fasttimer.h>
29 #include <linux/proc_fs.h>
32 #define DEBUG_LOG_INCLUDED
33 #define FAST_TIMER_LOG
34 //#define FAST_TIMER_TEST
36 #define FAST_TIMER_SANITY_CHECKS
38 #ifdef FAST_TIMER_SANITY_CHECKS
39 #define SANITYCHECK(x) x
40 static int sanity_failed;
42 #define SANITYCHECK(x)
49 static unsigned int fast_timer_running;
50 static unsigned int fast_timers_added;
51 static unsigned int fast_timers_started;
52 static unsigned int fast_timers_expired;
53 static unsigned int fast_timers_deleted;
54 static unsigned int fast_timer_is_init;
55 static unsigned int fast_timer_ints;
57 struct fast_timer *fast_timer_list = NULL;
59 #ifdef DEBUG_LOG_INCLUDED
60 #define DEBUG_LOG_MAX 128
61 static const char * debug_log_string[DEBUG_LOG_MAX];
62 static unsigned long debug_log_value[DEBUG_LOG_MAX];
63 static unsigned int debug_log_cnt;
64 static unsigned int debug_log_cnt_wrapped;
66 #define DEBUG_LOG(string, value) \
68 unsigned long log_flags; \
69 local_irq_save(log_flags); \
70 debug_log_string[debug_log_cnt] = (string); \
71 debug_log_value[debug_log_cnt] = (unsigned long)(value); \
72 if (++debug_log_cnt >= DEBUG_LOG_MAX) \
74 debug_log_cnt = debug_log_cnt % DEBUG_LOG_MAX; \
75 debug_log_cnt_wrapped = 1; \
77 local_irq_restore(log_flags); \
80 #define DEBUG_LOG(string, value)
84 /* The frequencies for index = clkselx number in R_TIMER_CTRL */
85 #define NUM_TIMER_FREQ 15
86 #define MAX_USABLE_TIMER_FREQ 7
87 #define MAX_DELAY_US 853333L
88 const unsigned long timer_freq_100[NUM_TIMER_FREQ] =
90 3, /* 0 3333 - 853333 us */
91 6, /* 1 1666 - 426666 us */
92 12, /* 2 833 - 213333 us */
93 24, /* 3 416 - 106666 us */
94 48, /* 4 208 - 53333 us */
95 96, /* 5 104 - 26666 us */
96 192, /* 6 52 - 13333 us */
97 384, /* 7 26 - 6666 us */
107 #define NUM_TIMER_STATS 16
108 #ifdef FAST_TIMER_LOG
109 struct fast_timer timer_added_log[NUM_TIMER_STATS];
110 struct fast_timer timer_started_log[NUM_TIMER_STATS];
111 struct fast_timer timer_expired_log[NUM_TIMER_STATS];
114 int timer_div_settings[NUM_TIMER_STATS];
115 int timer_freq_settings[NUM_TIMER_STATS];
116 int timer_delay_settings[NUM_TIMER_STATS];
118 /* Not true gettimeofday, only checks the jiffies (uptime) + useconds */
119 inline void do_gettimeofday_fast(struct fasttime_t *tv)
121 tv->tv_jiff = jiffies;
122 tv->tv_usec = GET_JIFFIES_USEC();
125 inline int fasttime_cmp(struct fasttime_t *t0, struct fasttime_t *t1)
127 /* Compare jiffies. Takes care of wrapping */
128 if (time_before(t0->tv_jiff, t1->tv_jiff))
130 else if (time_after(t0->tv_jiff, t1->tv_jiff))
134 if (t0->tv_usec < t1->tv_usec)
136 else if (t0->tv_usec > t1->tv_usec)
141 inline void start_timer1(unsigned long delay_us)
143 int freq_index = 0; /* This is the lowest resolution */
144 unsigned long upper_limit = MAX_DELAY_US;
147 /* Start/Restart the timer to the new shorter value */
148 /* t = 1/freq = 1/19200 = 53us
149 * T=div*t, div = T/t = delay_us*freq/1000000
151 #if 1 /* Adaptive timer settings */
152 while (delay_us < upper_limit && freq_index < MAX_USABLE_TIMER_FREQ)
155 upper_limit >>= 1; /* Divide by 2 using shift */
164 div = delay_us * timer_freq_100[freq_index]/10000;
167 /* Maybe increase timer freq? */
172 div = 0; /* This means 256, the max the timer takes */
173 /* If a longer timeout than the timer can handle is used,
174 * then we must restart it when it goes off.
178 timer_div_settings[fast_timers_started % NUM_TIMER_STATS] = div;
179 timer_freq_settings[fast_timers_started % NUM_TIMER_STATS] = freq_index;
180 timer_delay_settings[fast_timers_started % NUM_TIMER_STATS] = delay_us;
182 D1(printk(KERN_DEBUG "start_timer1 : %d us freq: %i div: %i\n",
183 delay_us, freq_index, div));
184 /* Clear timer1 irq */
185 *R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, timer1, clr);
187 /* Set timer values */
188 *R_TIMER_CTRL = r_timer_ctrl_shadow =
189 (r_timer_ctrl_shadow &
190 ~IO_MASK(R_TIMER_CTRL, timerdiv1) &
191 ~IO_MASK(R_TIMER_CTRL, tm1) &
192 ~IO_MASK(R_TIMER_CTRL, clksel1)) |
193 IO_FIELD(R_TIMER_CTRL, timerdiv1, div) |
194 IO_STATE(R_TIMER_CTRL, tm1, stop_ld) |
195 IO_FIELD(R_TIMER_CTRL, clksel1, freq_index ); /* 6=c19k2Hz */
198 *R_TIMER_CTRL = r_timer_ctrl_shadow |
199 IO_STATE(R_TIMER_CTRL, i1, clr);
202 *R_TIMER_CTRL = r_timer_ctrl_shadow =
203 (r_timer_ctrl_shadow & ~IO_MASK(R_TIMER_CTRL, tm1)) |
204 IO_STATE(R_TIMER_CTRL, tm1, run);
206 /* Enable timer1 irq */
207 *R_IRQ_MASK0_SET = IO_STATE(R_IRQ_MASK0_SET, timer1, set);
208 fast_timers_started++;
209 fast_timer_running = 1;
212 /* In version 1.4 this function takes 27 - 50 us */
213 void start_one_shot_timer(struct fast_timer *t,
214 fast_timer_function_type *function,
216 unsigned long delay_us,
220 struct fast_timer *tmp;
222 D1(printk("sft %s %d us\n", name, delay_us));
224 local_irq_save(flags);
226 do_gettimeofday_fast(&t->tv_set);
227 tmp = fast_timer_list;
229 SANITYCHECK({ /* Check so this is not in the list already... */
235 "timer name: %s data: 0x%08lX already in list!\n", name, data);
244 tmp = fast_timer_list;
247 t->delay_us = delay_us;
248 t->function = function;
252 t->tv_expires.tv_usec = t->tv_set.tv_usec + delay_us % 1000000;
253 t->tv_expires.tv_jiff = t->tv_set.tv_jiff + delay_us / 1000000 / HZ;
254 if (t->tv_expires.tv_usec > 1000000)
256 t->tv_expires.tv_usec -= 1000000;
257 t->tv_expires.tv_jiff += HZ;
259 #ifdef FAST_TIMER_LOG
260 timer_added_log[fast_timers_added % NUM_TIMER_STATS] = *t;
264 /* Check if this should timeout before anything else */
265 if (tmp == NULL || fasttime_cmp(&t->tv_expires, &tmp->tv_expires) < 0)
267 /* Put first in list and modify the timer value */
269 t->next = fast_timer_list;
272 fast_timer_list->prev = t;
275 #ifdef FAST_TIMER_LOG
276 timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
278 start_timer1(delay_us);
280 /* Put in correct place in list */
281 while (tmp->next && fasttime_cmp(&t->tv_expires,
282 &tmp->next->tv_expires) > 0)
286 /* Insert t after tmp */
296 D2(printk("start_one_shot_timer: %d us done\n", delay_us));
299 local_irq_restore(flags);
300 } /* start_one_shot_timer */
302 static inline int fast_timer_pending (const struct fast_timer * t)
304 return (t->next != NULL) || (t->prev != NULL) || (t == fast_timer_list);
307 static inline int detach_fast_timer (struct fast_timer *t)
309 struct fast_timer *next, *prev;
310 if (!fast_timer_pending(t))
319 fast_timer_list = next;
320 fast_timers_deleted++;
324 int del_fast_timer(struct fast_timer * t)
329 local_irq_save(flags);
330 ret = detach_fast_timer(t);
331 t->next = t->prev = NULL;
332 local_irq_restore(flags);
334 } /* del_fast_timer */
337 /* Interrupt routines or functions called in interrupt context */
339 /* Timer 1 interrupt handler */
342 timer1_handler(int irq, void *dev_id)
344 struct fast_timer *t;
347 /* We keep interrupts disabled not only when we modify the
348 * fast timer list, but any time we hold a reference to a
349 * timer in the list, since del_fast_timer may be called
350 * from (another) interrupt context. Thus, the only time
351 * when interrupts are enabled is when calling the timer
354 local_irq_save(flags);
356 /* Clear timer1 irq */
357 *R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, timer1, clr);
359 /* First stop timer, then ack interrupt */
361 *R_TIMER_CTRL = r_timer_ctrl_shadow =
362 (r_timer_ctrl_shadow & ~IO_MASK(R_TIMER_CTRL, tm1)) |
363 IO_STATE(R_TIMER_CTRL, tm1, stop_ld);
366 *R_TIMER_CTRL = r_timer_ctrl_shadow | IO_STATE(R_TIMER_CTRL, i1, clr);
368 fast_timer_running = 0;
374 struct fasttime_t tv;
375 fast_timer_function_type *f;
378 /* Has it really expired? */
379 do_gettimeofday_fast(&tv);
380 D1(printk(KERN_DEBUG "t: %is %06ius\n",
381 tv.tv_jiff, tv.tv_usec));
383 if (fasttime_cmp(&t->tv_expires, &tv) <= 0)
385 /* Yes it has expired */
386 #ifdef FAST_TIMER_LOG
387 timer_expired_log[fast_timers_expired % NUM_TIMER_STATS] = *t;
389 fast_timers_expired++;
391 /* Remove this timer before call, since it may reuse the timer */
394 t->prev->next = t->next;
398 fast_timer_list = t->next;
402 t->next->prev = t->prev;
407 /* Save function callback data before enabling
408 * interrupts, since the timer may be removed and
409 * we don't know how it was allocated
410 * (e.g. ->function and ->data may become overwritten
411 * after deletion if the timer was stack-allocated).
417 /* Run callback with interrupts enabled. */
418 local_irq_restore(flags);
420 local_irq_save(flags);
422 DEBUG_LOG("!timer1 %i function==NULL!\n", fast_timer_ints);
426 /* Timer is to early, let's set it again using the normal routines */
430 if ((t = fast_timer_list) != NULL)
432 /* Start next timer.. */
434 struct fasttime_t tv;
436 do_gettimeofday_fast(&tv);
438 /* time_after_eq takes care of wrapping */
439 if (time_after_eq(t->tv_expires.tv_jiff, tv.tv_jiff))
440 us = ((t->tv_expires.tv_jiff - tv.tv_jiff) *
441 1000000 / HZ + t->tv_expires.tv_usec -
446 if (!fast_timer_running)
448 #ifdef FAST_TIMER_LOG
449 timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
457 /* Timer already expired, let's handle it better late than never.
458 * The normal loop handles it
460 D1(printk("e! %d\n", us));
465 local_irq_restore(flags);
469 D1(printk("t1 stop!\n"));
475 static void wake_up_func(unsigned long data)
477 #ifdef DECLARE_WAITQUEUE
478 wait_queue_head_t *sleep_wait_p = (wait_queue_head_t*)data;
480 struct wait_queue **sleep_wait_p = (struct wait_queue **)data;
482 wake_up(sleep_wait_p);
488 void schedule_usleep(unsigned long us)
491 wait_queue_head_t sleep_wait;
492 init_waitqueue_head(&sleep_wait);
494 D1(printk("schedule_usleep(%d)\n", us));
495 start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
497 /* Uninterruptible sleep on the fast timer. (The condition is somewhat
498 * redundant since the timer is what wakes us up.) */
499 wait_event(sleep_wait, !fast_timer_pending(&t));
501 D1(printk("done schedule_usleep(%d)\n", us));
504 #ifdef CONFIG_PROC_FS
505 static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
506 ,int *eof, void *data_unused);
507 static struct proc_dir_entry *fasttimer_proc_entry;
508 #endif /* CONFIG_PROC_FS */
510 #ifdef CONFIG_PROC_FS
512 /* This value is very much based on testing */
513 #define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300)
515 static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
516 ,int *eof, void *data_unused)
521 struct fasttime_t tv;
522 struct fast_timer *t, *nextt;
523 static char *bigbuf = NULL;
524 static unsigned long used;
526 if (!bigbuf && !(bigbuf = vmalloc(BIG_BUF_SIZE)))
534 if (!offset || !used)
536 do_gettimeofday_fast(&tv);
539 used += sprintf(bigbuf + used, "Fast timers added: %i\n",
541 used += sprintf(bigbuf + used, "Fast timers started: %i\n",
542 fast_timers_started);
543 used += sprintf(bigbuf + used, "Fast timer interrupts: %i\n",
545 used += sprintf(bigbuf + used, "Fast timers expired: %i\n",
546 fast_timers_expired);
547 used += sprintf(bigbuf + used, "Fast timers deleted: %i\n",
548 fast_timers_deleted);
549 used += sprintf(bigbuf + used, "Fast timer running: %s\n",
550 fast_timer_running ? "yes" : "no");
551 used += sprintf(bigbuf + used, "Current time: %lu.%06lu\n",
552 (unsigned long)tv.tv_jiff,
553 (unsigned long)tv.tv_usec);
554 #ifdef FAST_TIMER_SANITY_CHECKS
555 used += sprintf(bigbuf + used, "Sanity failed: %i\n",
558 used += sprintf(bigbuf + used, "\n");
560 #ifdef DEBUG_LOG_INCLUDED
562 int end_i = debug_log_cnt;
565 if (debug_log_cnt_wrapped)
570 while ((i != end_i || (debug_log_cnt_wrapped && !used)) &&
571 used+100 < BIG_BUF_SIZE)
573 used += sprintf(bigbuf + used, debug_log_string[i],
575 i = (i+1) % DEBUG_LOG_MAX;
578 used += sprintf(bigbuf + used, "\n");
581 num_to_show = (fast_timers_started < NUM_TIMER_STATS ? fast_timers_started:
583 used += sprintf(bigbuf + used, "Timers started: %i\n", fast_timers_started);
584 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE) ; i++)
586 int cur = (fast_timers_started - i - 1) % NUM_TIMER_STATS;
588 #if 1 //ndef FAST_TIMER_LOG
589 used += sprintf(bigbuf + used, "div: %i freq: %i delay: %i"
591 timer_div_settings[cur],
592 timer_freq_settings[cur],
593 timer_delay_settings[cur]
596 #ifdef FAST_TIMER_LOG
597 t = &timer_started_log[cur];
598 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
599 "d: %6li us data: 0x%08lX"
602 (unsigned long)t->tv_set.tv_jiff,
603 (unsigned long)t->tv_set.tv_usec,
604 (unsigned long)t->tv_expires.tv_jiff,
605 (unsigned long)t->tv_expires.tv_usec,
611 used += sprintf(bigbuf + used, "\n");
613 #ifdef FAST_TIMER_LOG
614 num_to_show = (fast_timers_added < NUM_TIMER_STATS ? fast_timers_added:
616 used += sprintf(bigbuf + used, "Timers added: %i\n", fast_timers_added);
617 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
619 t = &timer_added_log[(fast_timers_added - i - 1) % NUM_TIMER_STATS];
620 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
621 "d: %6li us data: 0x%08lX"
624 (unsigned long)t->tv_set.tv_jiff,
625 (unsigned long)t->tv_set.tv_usec,
626 (unsigned long)t->tv_expires.tv_jiff,
627 (unsigned long)t->tv_expires.tv_usec,
632 used += sprintf(bigbuf + used, "\n");
634 num_to_show = (fast_timers_expired < NUM_TIMER_STATS ? fast_timers_expired:
636 used += sprintf(bigbuf + used, "Timers expired: %i\n", fast_timers_expired);
637 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
639 t = &timer_expired_log[(fast_timers_expired - i - 1) % NUM_TIMER_STATS];
640 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
641 "d: %6li us data: 0x%08lX"
644 (unsigned long)t->tv_set.tv_jiff,
645 (unsigned long)t->tv_set.tv_usec,
646 (unsigned long)t->tv_expires.tv_jiff,
647 (unsigned long)t->tv_expires.tv_usec,
652 used += sprintf(bigbuf + used, "\n");
655 used += sprintf(bigbuf + used, "Active timers:\n");
656 local_irq_save(flags);
658 while (t != NULL && (used+100 < BIG_BUF_SIZE))
661 local_irq_restore(flags);
662 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
663 "d: %6li us data: 0x%08lX"
664 /* " func: 0x%08lX" */
667 (unsigned long)t->tv_set.tv_jiff,
668 (unsigned long)t->tv_set.tv_usec,
669 (unsigned long)t->tv_expires.tv_jiff,
670 (unsigned long)t->tv_expires.tv_usec,
675 local_irq_save(flags);
676 if (t->next != nextt)
678 printk(KERN_WARNING "timer removed!\n");
682 local_irq_restore(flags);
685 if (used - offset < len)
690 memcpy(buf, bigbuf + offset, len);
698 #ifdef FAST_TIMER_TEST
699 static volatile unsigned long i = 0;
700 static volatile int num_test_timeout = 0;
701 static struct fast_timer tr[10];
702 static int exp_num[10];
704 static struct fasttime_t tv_exp[100];
706 static void test_timeout(unsigned long data)
708 do_gettimeofday_fast(&tv_exp[data]);
709 exp_num[data] = num_test_timeout;
714 static void test_timeout1(unsigned long data)
716 do_gettimeofday_fast(&tv_exp[data]);
717 exp_num[data] = num_test_timeout;
720 start_one_shot_timer(&tr[i], test_timeout1, i, 1000, "timeout1");
727 static char buf0[2000];
728 static char buf1[2000];
729 static char buf2[2000];
730 static char buf3[2000];
731 static char buf4[2000];
734 static char buf5[6000];
735 static int j_u[1000];
737 static void fast_timer_test(void)
742 struct fasttime_t tv, tv0, tv1, tv2;
744 printk("fast_timer_test() start\n");
745 do_gettimeofday_fast(&tv);
747 for (j = 0; j < 1000; j++)
749 j_u[j] = GET_JIFFIES_USEC();
751 for (j = 0; j < 100; j++)
753 do_gettimeofday_fast(&tv_exp[j]);
755 printk(KERN_DEBUG "fast_timer_test() %is %06i\n",
756 tv.tv_jiff, tv.tv_usec);
758 for (j = 0; j < 1000; j++)
760 printk("%i %i %i %i %i\n",j_u[j], j_u[j+1], j_u[j+2], j_u[j+3], j_u[j+4]);
763 for (j = 0; j < 100; j++)
765 printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n",
766 tv_exp[j].tv_jiff, tv_exp[j].tv_usec,
767 tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec,
768 tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec,
769 tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec,
770 tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec);
773 do_gettimeofday_fast(&tv0);
774 start_one_shot_timer(&tr[i], test_timeout, i, 50000, "test0");
775 DP(proc_fasttimer_read(buf0, NULL, 0, 0, 0));
777 start_one_shot_timer(&tr[i], test_timeout, i, 70000, "test1");
778 DP(proc_fasttimer_read(buf1, NULL, 0, 0, 0));
780 start_one_shot_timer(&tr[i], test_timeout, i, 40000, "test2");
781 DP(proc_fasttimer_read(buf2, NULL, 0, 0, 0));
783 start_one_shot_timer(&tr[i], test_timeout, i, 60000, "test3");
784 DP(proc_fasttimer_read(buf3, NULL, 0, 0, 0));
786 start_one_shot_timer(&tr[i], test_timeout1, i, 55000, "test4xx");
787 DP(proc_fasttimer_read(buf4, NULL, 0, 0, 0));
789 do_gettimeofday_fast(&tv1);
791 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
793 prev_num = num_test_timeout;
794 while (num_test_timeout < i)
796 if (num_test_timeout != prev_num)
798 prev_num = num_test_timeout;
801 do_gettimeofday_fast(&tv2);
802 printk(KERN_DEBUG "Timers started %is %06i\n",
803 tv0.tv_jiff, tv0.tv_usec);
804 printk(KERN_DEBUG "Timers started at %is %06i\n",
805 tv1.tv_jiff, tv1.tv_usec);
806 printk(KERN_DEBUG "Timers done %is %06i\n",
807 tv2.tv_jiff, tv2.tv_usec);
808 DP(printk("buf0:\n");
822 printk("timers set:\n");
825 struct fast_timer *t = &tr[j];
826 printk("%-10s set: %6is %06ius exp: %6is %06ius "
827 "data: 0x%08X func: 0x%08X\n",
831 t->tv_expires.tv_jiff,
832 t->tv_expires.tv_usec,
837 printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n",
842 (tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) *
843 1000000 + tv_exp[j].tv_usec -
844 t->tv_expires.tv_usec);
846 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
847 printk("buf5 after all done:\n");
849 printk("fast_timer_test() done\n");
854 int fast_timer_init(void)
856 /* For some reason, request_irq() hangs when called froom time_init() */
857 if (!fast_timer_is_init)
859 #if 0 && defined(FAST_TIMER_TEST)
863 printk(KERN_INFO "fast_timer_init()\n");
865 #if 0 && defined(FAST_TIMER_TEST)
866 for (i = 0; i <= TIMER0_DIV; i++)
868 /* We must be careful not to get overflow... */
869 printk("%3i %6u\n", i, timer0_value_us[i]);
872 #ifdef CONFIG_PROC_FS
873 if ((fasttimer_proc_entry = create_proc_entry( "fasttimer", 0, 0 )))
874 fasttimer_proc_entry->read_proc = proc_fasttimer_read;
876 if(request_irq(TIMER1_IRQ_NBR, timer1_handler, 0,
877 "fast timer int", NULL))
879 printk("err: timer1 irq\n");
881 fast_timer_is_init = 1;
882 #ifdef FAST_TIMER_TEST
889 __initcall(fast_timer_init);