2 * linux/arch/cris/kernel/fasttimer.c
4 * Fast timers for ETRAX FS
6 * Copyright (C) 2000-2006 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>
14 #include <linux/vmalloc.h>
15 #include <linux/interrupt.h>
16 #include <linux/time.h>
17 #include <linux/delay.h>
21 #include <hwregs/reg_map.h>
22 #include <hwregs/reg_rdwr.h>
23 #include <hwregs/timer_defs.h>
24 #include <asm/fasttimer.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
29 * timer0 is running at 100MHz and generating jiffies timer ticks
31 * fasttimer gives an API that gives timers that expire "between" the jiffies
32 * giving microsecond resolution (10 ns).
33 * fasttimer uses reg_timer_rw_trig register to get interrupt when
34 * r_time reaches a certain value.
38 #define DEBUG_LOG_INCLUDED
39 #define FAST_TIMER_LOG
40 /* #define FAST_TIMER_TEST */
42 #define FAST_TIMER_SANITY_CHECKS
44 #ifdef FAST_TIMER_SANITY_CHECKS
45 static int sanity_failed
;
52 static unsigned int fast_timer_running
;
53 static unsigned int fast_timers_added
;
54 static unsigned int fast_timers_started
;
55 static unsigned int fast_timers_expired
;
56 static unsigned int fast_timers_deleted
;
57 static unsigned int fast_timer_is_init
;
58 static unsigned int fast_timer_ints
;
60 struct fast_timer
*fast_timer_list
= NULL
;
62 #ifdef DEBUG_LOG_INCLUDED
63 #define DEBUG_LOG_MAX 128
64 static const char * debug_log_string
[DEBUG_LOG_MAX
];
65 static unsigned long debug_log_value
[DEBUG_LOG_MAX
];
66 static unsigned int debug_log_cnt
;
67 static unsigned int debug_log_cnt_wrapped
;
69 #define DEBUG_LOG(string, value) \
71 unsigned long log_flags; \
72 local_irq_save(log_flags); \
73 debug_log_string[debug_log_cnt] = (string); \
74 debug_log_value[debug_log_cnt] = (unsigned long)(value); \
75 if (++debug_log_cnt >= DEBUG_LOG_MAX) \
77 debug_log_cnt = debug_log_cnt % DEBUG_LOG_MAX; \
78 debug_log_cnt_wrapped = 1; \
80 local_irq_restore(log_flags); \
83 #define DEBUG_LOG(string, value)
87 #define NUM_TIMER_STATS 16
89 struct fast_timer timer_added_log
[NUM_TIMER_STATS
];
90 struct fast_timer timer_started_log
[NUM_TIMER_STATS
];
91 struct fast_timer timer_expired_log
[NUM_TIMER_STATS
];
94 int timer_div_settings
[NUM_TIMER_STATS
];
95 int timer_delay_settings
[NUM_TIMER_STATS
];
97 struct work_struct fast_work
;
100 timer_trig_handler(struct work_struct
*work
);
104 /* Not true gettimeofday, only checks the jiffies (uptime) + useconds */
105 inline void do_gettimeofday_fast(struct fasttime_t
*tv
)
107 tv
->tv_jiff
= jiffies
;
108 tv
->tv_usec
= GET_JIFFIES_USEC();
111 inline int fasttime_cmp(struct fasttime_t
*t0
, struct fasttime_t
*t1
)
113 /* Compare jiffies. Takes care of wrapping */
114 if (time_before(t0
->tv_jiff
, t1
->tv_jiff
))
116 else if (time_after(t0
->tv_jiff
, t1
->tv_jiff
))
120 if (t0
->tv_usec
< t1
->tv_usec
)
122 else if (t0
->tv_usec
> t1
->tv_usec
)
127 /* Called with ints off */
128 inline void start_timer_trig(unsigned long delay_us
)
130 reg_timer_rw_ack_intr ack_intr
= { 0 };
131 reg_timer_rw_intr_mask intr_mask
;
132 reg_timer_rw_trig trig
;
133 reg_timer_rw_trig_cfg trig_cfg
= { 0 };
134 reg_timer_r_time r_time0
;
135 reg_timer_r_time r_time1
;
136 unsigned char trig_wrap
;
137 unsigned char time_wrap
;
139 r_time0
= REG_RD(timer
, regi_timer0
, r_time
);
141 D1(printk("start_timer_trig : %d us freq: %i div: %i\n",
142 delay_us
, freq_index
, div
));
144 intr_mask
= REG_RD(timer
, regi_timer0
, rw_intr_mask
);
146 REG_WR(timer
, regi_timer0
, rw_intr_mask
, intr_mask
);
148 /* Set timer values and check if trigger wraps. */
149 /* r_time is 100MHz (10 ns resolution) */
150 trig_wrap
= (trig
= r_time0
+ delay_us
*(1000/10)) < r_time0
;
152 timer_div_settings
[fast_timers_started
% NUM_TIMER_STATS
] = trig
;
153 timer_delay_settings
[fast_timers_started
% NUM_TIMER_STATS
] = delay_us
;
157 REG_WR(timer
, regi_timer0
, rw_ack_intr
, ack_intr
);
160 REG_WR(timer
, regi_timer0
, rw_trig
, trig
);
161 trig_cfg
.tmr
= regk_timer_time
;
162 REG_WR(timer
, regi_timer0
, rw_trig_cfg
, trig_cfg
);
164 /* Check if we have already passed the trig time */
165 r_time1
= REG_RD(timer
, regi_timer0
, r_time
);
166 time_wrap
= r_time1
< r_time0
;
168 if ((trig_wrap
&& !time_wrap
) || (r_time1
< trig
)) {
169 /* No, Enable trig irq */
170 intr_mask
= REG_RD(timer
, regi_timer0
, rw_intr_mask
);
172 REG_WR(timer
, regi_timer0
, rw_intr_mask
, intr_mask
);
173 fast_timers_started
++;
174 fast_timer_running
= 1;
176 /* We have passed the time, disable trig point, ack intr */
177 trig_cfg
.tmr
= regk_timer_off
;
178 REG_WR(timer
, regi_timer0
, rw_trig_cfg
, trig_cfg
);
179 REG_WR(timer
, regi_timer0
, rw_ack_intr
, ack_intr
);
180 /* call the int routine */
181 INIT_WORK(&fast_work
, timer_trig_handler
);
182 schedule_work(&fast_work
);
187 /* In version 1.4 this function takes 27 - 50 us */
188 void start_one_shot_timer(struct fast_timer
*t
,
189 fast_timer_function_type
*function
,
191 unsigned long delay_us
,
195 struct fast_timer
*tmp
;
197 D1(printk("sft %s %d us\n", name
, delay_us
));
199 local_irq_save(flags
);
201 do_gettimeofday_fast(&t
->tv_set
);
202 tmp
= fast_timer_list
;
204 #ifdef FAST_TIMER_SANITY_CHECKS
205 /* Check so this is not in the list already... */
206 while (tmp
!= NULL
) {
209 "timer name: %s data: 0x%08lX already "
210 "in list!\n", name
, data
);
216 tmp
= fast_timer_list
;
219 t
->delay_us
= delay_us
;
220 t
->function
= function
;
224 t
->tv_expires
.tv_usec
= t
->tv_set
.tv_usec
+ delay_us
% 1000000;
225 t
->tv_expires
.tv_jiff
= t
->tv_set
.tv_jiff
+ delay_us
/ 1000000 / HZ
;
226 if (t
->tv_expires
.tv_usec
> 1000000) {
227 t
->tv_expires
.tv_usec
-= 1000000;
228 t
->tv_expires
.tv_jiff
+= HZ
;
230 #ifdef FAST_TIMER_LOG
231 timer_added_log
[fast_timers_added
% NUM_TIMER_STATS
] = *t
;
235 /* Check if this should timeout before anything else */
236 if (tmp
== NULL
|| fasttime_cmp(&t
->tv_expires
, &tmp
->tv_expires
) < 0) {
237 /* Put first in list and modify the timer value */
239 t
->next
= fast_timer_list
;
241 fast_timer_list
->prev
= t
;
243 #ifdef FAST_TIMER_LOG
244 timer_started_log
[fast_timers_started
% NUM_TIMER_STATS
] = *t
;
246 start_timer_trig(delay_us
);
248 /* Put in correct place in list */
250 fasttime_cmp(&t
->tv_expires
, &tmp
->next
->tv_expires
) > 0)
252 /* Insert t after tmp */
262 D2(printk("start_one_shot_timer: %d us done\n", delay_us
));
265 local_irq_restore(flags
);
266 } /* start_one_shot_timer */
268 static inline int fast_timer_pending (const struct fast_timer
* t
)
270 return (t
->next
!= NULL
) || (t
->prev
!= NULL
) || (t
== fast_timer_list
);
273 static inline int detach_fast_timer (struct fast_timer
*t
)
275 struct fast_timer
*next
, *prev
;
276 if (!fast_timer_pending(t
))
285 fast_timer_list
= next
;
286 fast_timers_deleted
++;
290 int del_fast_timer(struct fast_timer
* t
)
295 local_irq_save(flags
);
296 ret
= detach_fast_timer(t
);
297 t
->next
= t
->prev
= NULL
;
298 local_irq_restore(flags
);
300 } /* del_fast_timer */
303 /* Interrupt routines or functions called in interrupt context */
305 /* Timer interrupt handler for trig interrupts */
308 timer_trig_interrupt(int irq
, void *dev_id
)
310 reg_timer_r_masked_intr masked_intr
;
311 /* Check if the timer interrupt is for us (a trig int) */
312 masked_intr
= REG_RD(timer
, regi_timer0
, r_masked_intr
);
313 if (!masked_intr
.trig
)
315 timer_trig_handler(NULL
);
319 static void timer_trig_handler(struct work_struct
*work
)
321 reg_timer_rw_ack_intr ack_intr
= { 0 };
322 reg_timer_rw_intr_mask intr_mask
;
323 reg_timer_rw_trig_cfg trig_cfg
= { 0 };
324 struct fast_timer
*t
;
327 /* We keep interrupts disabled not only when we modify the
328 * fast timer list, but any time we hold a reference to a
329 * timer in the list, since del_fast_timer may be called
330 * from (another) interrupt context. Thus, the only time
331 * when interrupts are enabled is when calling the timer
334 local_irq_save(flags
);
336 /* Clear timer trig interrupt */
337 intr_mask
= REG_RD(timer
, regi_timer0
, rw_intr_mask
);
339 REG_WR(timer
, regi_timer0
, rw_intr_mask
, intr_mask
);
341 /* First stop timer, then ack interrupt */
343 trig_cfg
.tmr
= regk_timer_off
;
344 REG_WR(timer
, regi_timer0
, rw_trig_cfg
, trig_cfg
);
348 REG_WR(timer
, regi_timer0
, rw_ack_intr
, ack_intr
);
350 fast_timer_running
= 0;
353 fast_timer_function_type
*f
;
358 struct fasttime_t tv
;
360 /* Has it really expired? */
361 do_gettimeofday_fast(&tv
);
363 "t: %is %06ius\n", tv
.tv_jiff
, tv
.tv_usec
));
365 if (fasttime_cmp(&t
->tv_expires
, &tv
) <= 0) {
366 /* Yes it has expired */
367 #ifdef FAST_TIMER_LOG
368 timer_expired_log
[fast_timers_expired
% NUM_TIMER_STATS
] = *t
;
370 fast_timers_expired
++;
372 /* Remove this timer before call, since it may reuse the timer */
374 t
->prev
->next
= t
->next
;
376 fast_timer_list
= t
->next
;
378 t
->next
->prev
= t
->prev
;
382 /* Save function callback data before enabling
383 * interrupts, since the timer may be removed and we
384 * don't know how it was allocated (e.g. ->function
385 * and ->data may become overwritten after deletion
386 * if the timer was stack-allocated).
392 /* Run the callback function with interrupts
394 local_irq_restore(flags
);
396 local_irq_save(flags
);
398 DEBUG_LOG("!trimertrig %i function==NULL!\n", fast_timer_ints
);
400 /* Timer is to early, let's set it again using the normal routines */
406 /* Start next timer.. */
408 struct fasttime_t tv
;
410 do_gettimeofday_fast(&tv
);
412 /* time_after_eq takes care of wrapping */
413 if (time_after_eq(t
->tv_expires
.tv_jiff
, tv
.tv_jiff
))
414 us
= ((t
->tv_expires
.tv_jiff
- tv
.tv_jiff
) *
415 1000000 / HZ
+ t
->tv_expires
.tv_usec
-
419 if (!fast_timer_running
) {
420 #ifdef FAST_TIMER_LOG
421 timer_started_log
[fast_timers_started
% NUM_TIMER_STATS
] = *t
;
423 start_timer_trig(us
);
427 /* Timer already expired, let's handle it better late than never.
428 * The normal loop handles it
430 D1(printk("e! %d\n", us
));
435 local_irq_restore(flags
);
438 D1(printk("ttrig stop!\n"));
441 static void wake_up_func(unsigned long data
)
443 wait_queue_head_t
*sleep_wait_p
= (wait_queue_head_t
*)data
;
444 wake_up(sleep_wait_p
);
450 void schedule_usleep(unsigned long us
)
453 wait_queue_head_t sleep_wait
;
454 init_waitqueue_head(&sleep_wait
);
456 D1(printk("schedule_usleep(%d)\n", us
));
457 start_one_shot_timer(&t
, wake_up_func
, (unsigned long)&sleep_wait
, us
,
459 /* Uninterruptible sleep on the fast timer. (The condition is
460 * somewhat redundant since the timer is what wakes us up.) */
461 wait_event(sleep_wait
, !fast_timer_pending(&t
));
463 D1(printk("done schedule_usleep(%d)\n", us
));
466 #ifdef CONFIG_PROC_FS
467 /* This value is very much based on testing */
468 #define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300)
470 static int proc_fasttimer_show(struct seq_file
*m
, void *v
)
475 struct fasttime_t tv
;
476 struct fast_timer
*t
, *nextt
;
478 do_gettimeofday_fast(&tv
);
480 seq_printf(m
, "Fast timers added: %i\n", fast_timers_added
);
481 seq_printf(m
, "Fast timers started: %i\n", fast_timers_started
);
482 seq_printf(m
, "Fast timer interrupts: %i\n", fast_timer_ints
);
483 seq_printf(m
, "Fast timers expired: %i\n", fast_timers_expired
);
484 seq_printf(m
, "Fast timers deleted: %i\n", fast_timers_deleted
);
485 seq_printf(m
, "Fast timer running: %s\n",
486 fast_timer_running
? "yes" : "no");
487 seq_printf(m
, "Current time: %lu.%06lu\n",
488 (unsigned long)tv
.tv_jiff
,
489 (unsigned long)tv
.tv_usec
);
490 #ifdef FAST_TIMER_SANITY_CHECKS
491 seq_printf(m
, "Sanity failed: %i\n", sanity_failed
);
495 #ifdef DEBUG_LOG_INCLUDED
497 int end_i
= debug_log_cnt
;
500 if (debug_log_cnt_wrapped
)
503 while ((i
!= end_i
|| debug_log_cnt_wrapped
)) {
504 if (seq_printf(m
, debug_log_string
[i
], debug_log_value
[i
]) < 0)
506 i
= (i
+1) % DEBUG_LOG_MAX
;
512 num_to_show
= (fast_timers_started
< NUM_TIMER_STATS
? fast_timers_started
:
514 seq_printf(m
, "Timers started: %i\n", fast_timers_started
);
515 for (i
= 0; i
< num_to_show
; i
++) {
516 int cur
= (fast_timers_started
- i
- 1) % NUM_TIMER_STATS
;
518 #if 1 //ndef FAST_TIMER_LOG
519 seq_printf(m
, "div: %i delay: %i"
521 timer_div_settings
[cur
],
522 timer_delay_settings
[cur
]);
524 #ifdef FAST_TIMER_LOG
525 t
= &timer_started_log
[cur
];
526 if (seq_printf(m
, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
527 "d: %6li us data: 0x%08lX"
530 (unsigned long)t
->tv_set
.tv_jiff
,
531 (unsigned long)t
->tv_set
.tv_usec
,
532 (unsigned long)t
->tv_expires
.tv_jiff
,
533 (unsigned long)t
->tv_expires
.tv_usec
,
541 #ifdef FAST_TIMER_LOG
542 num_to_show
= (fast_timers_added
< NUM_TIMER_STATS
? fast_timers_added
:
544 seq_printf(m
, "Timers added: %i\n", fast_timers_added
);
545 for (i
= 0; i
< num_to_show
; i
++) {
546 t
= &timer_added_log
[(fast_timers_added
- i
- 1) % NUM_TIMER_STATS
];
547 if (seq_printf(m
, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
548 "d: %6li us data: 0x%08lX"
551 (unsigned long)t
->tv_set
.tv_jiff
,
552 (unsigned long)t
->tv_set
.tv_usec
,
553 (unsigned long)t
->tv_expires
.tv_jiff
,
554 (unsigned long)t
->tv_expires
.tv_usec
,
561 num_to_show
= (fast_timers_expired
< NUM_TIMER_STATS
? fast_timers_expired
:
563 seq_printf(m
, "Timers expired: %i\n", fast_timers_expired
);
564 for (i
= 0; i
< num_to_show
; i
++){
565 t
= &timer_expired_log
[(fast_timers_expired
- i
- 1) % NUM_TIMER_STATS
];
566 if (seq_printf(m
, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
567 "d: %6li us data: 0x%08lX"
570 (unsigned long)t
->tv_set
.tv_jiff
,
571 (unsigned long)t
->tv_set
.tv_usec
,
572 (unsigned long)t
->tv_expires
.tv_jiff
,
573 (unsigned long)t
->tv_expires
.tv_usec
,
581 seq_puts(m
, "Active timers:\n");
582 local_irq_save(flags
);
586 local_irq_restore(flags
);
587 if (seq_printf(m
, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
588 "d: %6li us data: 0x%08lX"
589 /* " func: 0x%08lX" */
592 (unsigned long)t
->tv_set
.tv_jiff
,
593 (unsigned long)t
->tv_set
.tv_usec
,
594 (unsigned long)t
->tv_expires
.tv_jiff
,
595 (unsigned long)t
->tv_expires
.tv_usec
,
601 local_irq_save(flags
);
602 if (t
->next
!= nextt
)
603 printk("timer removed!\n");
606 local_irq_restore(flags
);
610 static int proc_fasttimer_open(struct inode
*inode
, struct file
*file
)
612 return single_open_size(file
, proc_fasttimer_show
, PDE_DATA(inode
), BIG_BUF_SIZE
);
615 static const struct file_operations proc_fasttimer_fops
= {
616 .open
= proc_fasttimer_open
,
619 .release
= single_release
,
624 #ifdef FAST_TIMER_TEST
625 static volatile unsigned long i
= 0;
626 static volatile int num_test_timeout
= 0;
627 static struct fast_timer tr
[10];
628 static int exp_num
[10];
630 static struct fasttime_t tv_exp
[100];
632 static void test_timeout(unsigned long data
)
634 do_gettimeofday_fast(&tv_exp
[data
]);
635 exp_num
[data
] = num_test_timeout
;
640 static void test_timeout1(unsigned long data
)
642 do_gettimeofday_fast(&tv_exp
[data
]);
643 exp_num
[data
] = num_test_timeout
;
646 start_one_shot_timer(&tr
[i
], test_timeout1
, i
, 1000, "timeout1");
653 static char buf0
[2000];
654 static char buf1
[2000];
655 static char buf2
[2000];
656 static char buf3
[2000];
657 static char buf4
[2000];
660 static char buf5
[6000];
661 static int j_u
[1000];
663 static void fast_timer_test(void)
668 struct fasttime_t tv
, tv0
, tv1
, tv2
;
670 printk("fast_timer_test() start\n");
671 do_gettimeofday_fast(&tv
);
673 for (j
= 0; j
< 1000; j
++)
675 j_u
[j
] = GET_JIFFIES_USEC();
677 for (j
= 0; j
< 100; j
++)
679 do_gettimeofday_fast(&tv_exp
[j
]);
681 printk(KERN_DEBUG
"fast_timer_test() %is %06i\n", tv
.tv_jiff
, tv
.tv_usec
);
683 for (j
= 0; j
< 1000; j
++)
685 printk(KERN_DEBUG
"%i %i %i %i %i\n",
686 j_u
[j
], j_u
[j
+1], j_u
[j
+2], j_u
[j
+3], j_u
[j
+4]);
689 for (j
= 0; j
< 100; j
++)
691 printk(KERN_DEBUG
"%i.%i %i.%i %i.%i %i.%i %i.%i\n",
692 tv_exp
[j
].tv_jiff
, tv_exp
[j
].tv_usec
,
693 tv_exp
[j
+1].tv_jiff
, tv_exp
[j
+1].tv_usec
,
694 tv_exp
[j
+2].tv_jiff
, tv_exp
[j
+2].tv_usec
,
695 tv_exp
[j
+3].tv_jiff
, tv_exp
[j
+3].tv_usec
,
696 tv_exp
[j
+4].tv_jiff
, tv_exp
[j
+4].tv_usec
);
699 do_gettimeofday_fast(&tv0
);
700 start_one_shot_timer(&tr
[i
], test_timeout
, i
, 50000, "test0");
701 DP(proc_fasttimer_read(buf0
, NULL
, 0, 0, 0));
703 start_one_shot_timer(&tr
[i
], test_timeout
, i
, 70000, "test1");
704 DP(proc_fasttimer_read(buf1
, NULL
, 0, 0, 0));
706 start_one_shot_timer(&tr
[i
], test_timeout
, i
, 40000, "test2");
707 DP(proc_fasttimer_read(buf2
, NULL
, 0, 0, 0));
709 start_one_shot_timer(&tr
[i
], test_timeout
, i
, 60000, "test3");
710 DP(proc_fasttimer_read(buf3
, NULL
, 0, 0, 0));
712 start_one_shot_timer(&tr
[i
], test_timeout1
, i
, 55000, "test4xx");
713 DP(proc_fasttimer_read(buf4
, NULL
, 0, 0, 0));
715 do_gettimeofday_fast(&tv1
);
717 proc_fasttimer_read(buf5
, NULL
, 0, 0, 0);
719 prev_num
= num_test_timeout
;
720 while (num_test_timeout
< i
)
722 if (num_test_timeout
!= prev_num
)
723 prev_num
= num_test_timeout
;
725 do_gettimeofday_fast(&tv2
);
726 printk(KERN_INFO
"Timers started %is %06i\n",
727 tv0
.tv_jiff
, tv0
.tv_usec
);
728 printk(KERN_INFO
"Timers started at %is %06i\n",
729 tv1
.tv_jiff
, tv1
.tv_usec
);
730 printk(KERN_INFO
"Timers done %is %06i\n",
731 tv2
.tv_jiff
, tv2
.tv_usec
);
732 DP(printk("buf0:\n");
746 printk("timers set:\n");
749 struct fast_timer
*t
= &tr
[j
];
750 printk("%-10s set: %6is %06ius exp: %6is %06ius "
751 "data: 0x%08X func: 0x%08X\n",
755 t
->tv_expires
.tv_jiff
,
756 t
->tv_expires
.tv_usec
,
761 printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n",
766 (tv_exp
[j
].tv_jiff
- t
->tv_expires
.tv_jiff
) *
767 1000000 + tv_exp
[j
].tv_usec
-
768 t
->tv_expires
.tv_usec
);
770 proc_fasttimer_read(buf5
, NULL
, 0, 0, 0);
771 printk("buf5 after all done:\n");
773 printk("fast_timer_test() done\n");
778 int fast_timer_init(void)
780 /* For some reason, request_irq() hangs when called froom time_init() */
781 if (!fast_timer_is_init
)
783 printk("fast_timer_init()\n");
785 #ifdef CONFIG_PROC_FS
786 proc_create("fasttimer", 0, NULL
, &proc_fasttimer_fops
);
788 if (request_irq(TIMER0_INTR_VECT
, timer_trig_interrupt
,
789 IRQF_SHARED
| IRQF_DISABLED
,
790 "fast timer int", &fast_timer_list
))
791 printk(KERN_ERR
"err: fasttimer irq\n");
792 fast_timer_is_init
= 1;
793 #ifdef FAST_TIMER_TEST
800 __initcall(fast_timer_init
);