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;
325 fast_timer_function_type *f;
329 /* We keep interrupts disabled not only when we modify the
330 * fast timer list, but any time we hold a reference to a
331 * timer in the list, since del_fast_timer may be called
332 * from (another) interrupt context. Thus, the only time
333 * when interrupts are enabled is when calling the timer
336 local_irq_save(flags);
338 /* Clear timer trig interrupt */
339 intr_mask = REG_RD(timer, regi_timer0, rw_intr_mask);
341 REG_WR(timer, regi_timer0, rw_intr_mask, intr_mask);
343 /* First stop timer, then ack interrupt */
345 trig_cfg.tmr = regk_timer_off;
346 REG_WR(timer, regi_timer0, rw_trig_cfg, trig_cfg);
350 REG_WR(timer, regi_timer0, rw_ack_intr, ack_intr);
352 fast_timer_running = 0;
357 struct fasttime_t tv;
359 /* Has it really expired? */
360 do_gettimeofday_fast(&tv);
362 "t: %is %06ius\n", tv.tv_jiff, tv.tv_usec));
364 if (fasttime_cmp(&t->tv_expires, &tv) <= 0) {
365 /* Yes it has expired */
366 #ifdef FAST_TIMER_LOG
367 timer_expired_log[fast_timers_expired % NUM_TIMER_STATS] = *t;
369 fast_timers_expired++;
371 /* Remove this timer before call, since it may reuse the timer */
373 t->prev->next = t->next;
375 fast_timer_list = t->next;
377 t->next->prev = t->prev;
381 /* Save function callback data before enabling
382 * interrupts, since the timer may be removed and we
383 * don't know how it was allocated (e.g. ->function
384 * and ->data may become overwritten after deletion
385 * if the timer was stack-allocated).
391 /* Run the callback function with interrupts
393 local_irq_restore(flags);
395 local_irq_save(flags);
397 DEBUG_LOG("!trimertrig %i function==NULL!\n", fast_timer_ints);
399 /* Timer is to early, let's set it again using the normal routines */
405 /* Start next timer.. */
407 struct fasttime_t tv;
409 do_gettimeofday_fast(&tv);
411 /* time_after_eq takes care of wrapping */
412 if (time_after_eq(t->tv_expires.tv_jiff, tv.tv_jiff))
413 us = ((t->tv_expires.tv_jiff - tv.tv_jiff) *
414 1000000 / HZ + t->tv_expires.tv_usec -
418 if (!fast_timer_running) {
419 #ifdef FAST_TIMER_LOG
420 timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
422 start_timer_trig(us);
426 /* Timer already expired, let's handle it better late than never.
427 * The normal loop handles it
429 D1(printk("e! %d\n", us));
434 local_irq_restore(flags);
437 D1(printk("ttrig stop!\n"));
440 static void wake_up_func(unsigned long data)
442 wait_queue_head_t *sleep_wait_p = (wait_queue_head_t*)data;
443 wake_up(sleep_wait_p);
449 void schedule_usleep(unsigned long us)
452 wait_queue_head_t sleep_wait;
453 init_waitqueue_head(&sleep_wait);
455 D1(printk("schedule_usleep(%d)\n", us));
456 start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
458 /* Uninterruptible sleep on the fast timer. (The condition is
459 * somewhat redundant since the timer is what wakes us up.) */
460 wait_event(sleep_wait, !fast_timer_pending(&t));
462 D1(printk("done schedule_usleep(%d)\n", us));
465 #ifdef CONFIG_PROC_FS
466 /* This value is very much based on testing */
467 #define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300)
469 static int proc_fasttimer_show(struct seq_file *m, void *v)
474 struct fasttime_t tv;
475 struct fast_timer *t, *nextt;
477 do_gettimeofday_fast(&tv);
479 seq_printf(m, "Fast timers added: %i\n", fast_timers_added);
480 seq_printf(m, "Fast timers started: %i\n", fast_timers_started);
481 seq_printf(m, "Fast timer interrupts: %i\n", fast_timer_ints);
482 seq_printf(m, "Fast timers expired: %i\n", fast_timers_expired);
483 seq_printf(m, "Fast timers deleted: %i\n", fast_timers_deleted);
484 seq_printf(m, "Fast timer running: %s\n",
485 fast_timer_running ? "yes" : "no");
486 seq_printf(m, "Current time: %lu.%06lu\n",
487 (unsigned long)tv.tv_jiff,
488 (unsigned long)tv.tv_usec);
489 #ifdef FAST_TIMER_SANITY_CHECKS
490 seq_printf(m, "Sanity failed: %i\n", sanity_failed);
494 #ifdef DEBUG_LOG_INCLUDED
496 int end_i = debug_log_cnt;
499 if (debug_log_cnt_wrapped)
502 while ((i != end_i || debug_log_cnt_wrapped)) {
503 seq_printf(m, debug_log_string[i], debug_log_value[i]);
504 if (seq_has_overflowed(m))
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\n",
520 timer_div_settings[cur],
521 timer_delay_settings[cur]);
523 #ifdef FAST_TIMER_LOG
524 t = &timer_started_log[cur];
525 seq_printf(m, "%-14s s: %6lu.%06lu e: %6lu.%06lu d: %6li us data: 0x%08lX\n",
527 (unsigned long)t->tv_set.tv_jiff,
528 (unsigned long)t->tv_set.tv_usec,
529 (unsigned long)t->tv_expires.tv_jiff,
530 (unsigned long)t->tv_expires.tv_usec,
533 if (seq_has_overflowed(m))
539 #ifdef FAST_TIMER_LOG
540 num_to_show = (fast_timers_added < NUM_TIMER_STATS ? fast_timers_added:
542 seq_printf(m, "Timers added: %i\n", fast_timers_added);
543 for (i = 0; i < num_to_show; i++) {
544 t = &timer_added_log[(fast_timers_added - i - 1) % NUM_TIMER_STATS];
545 seq_printf(m, "%-14s s: %6lu.%06lu e: %6lu.%06lu d: %6li us data: 0x%08lX\n",
547 (unsigned long)t->tv_set.tv_jiff,
548 (unsigned long)t->tv_set.tv_usec,
549 (unsigned long)t->tv_expires.tv_jiff,
550 (unsigned long)t->tv_expires.tv_usec,
553 if (seq_has_overflowed(m))
558 num_to_show = (fast_timers_expired < NUM_TIMER_STATS ? fast_timers_expired:
560 seq_printf(m, "Timers expired: %i\n", fast_timers_expired);
561 for (i = 0; i < num_to_show; i++){
562 t = &timer_expired_log[(fast_timers_expired - i - 1) % NUM_TIMER_STATS];
563 seq_printf(m, "%-14s s: %6lu.%06lu e: %6lu.%06lu d: %6li us data: 0x%08lX\n",
565 (unsigned long)t->tv_set.tv_jiff,
566 (unsigned long)t->tv_set.tv_usec,
567 (unsigned long)t->tv_expires.tv_jiff,
568 (unsigned long)t->tv_expires.tv_usec,
571 if (seq_has_overflowed(m))
577 seq_puts(m, "Active timers:\n");
578 local_irq_save(flags);
582 local_irq_restore(flags);
583 seq_printf(m, "%-14s s: %6lu.%06lu e: %6lu.%06lu d: %6li us data: 0x%08lX\n",
585 (unsigned long)t->tv_set.tv_jiff,
586 (unsigned long)t->tv_set.tv_usec,
587 (unsigned long)t->tv_expires.tv_jiff,
588 (unsigned long)t->tv_expires.tv_usec,
591 if (seq_has_overflowed(m))
593 local_irq_save(flags);
594 if (t->next != nextt)
595 printk("timer removed!\n");
598 local_irq_restore(flags);
602 static int proc_fasttimer_open(struct inode *inode, struct file *file)
604 return single_open_size(file, proc_fasttimer_show, PDE_DATA(inode), BIG_BUF_SIZE);
607 static const struct file_operations proc_fasttimer_fops = {
608 .open = proc_fasttimer_open,
611 .release = single_release,
616 #ifdef FAST_TIMER_TEST
617 static volatile unsigned long i = 0;
618 static volatile int num_test_timeout = 0;
619 static struct fast_timer tr[10];
620 static int exp_num[10];
622 static struct fasttime_t tv_exp[100];
624 static void test_timeout(unsigned long data)
626 do_gettimeofday_fast(&tv_exp[data]);
627 exp_num[data] = num_test_timeout;
632 static void test_timeout1(unsigned long data)
634 do_gettimeofday_fast(&tv_exp[data]);
635 exp_num[data] = num_test_timeout;
638 start_one_shot_timer(&tr[i], test_timeout1, i, 1000, "timeout1");
645 static char buf0[2000];
646 static char buf1[2000];
647 static char buf2[2000];
648 static char buf3[2000];
649 static char buf4[2000];
652 static char buf5[6000];
653 static int j_u[1000];
655 static void fast_timer_test(void)
660 struct fasttime_t tv, tv0, tv1, tv2;
662 printk("fast_timer_test() start\n");
663 do_gettimeofday_fast(&tv);
665 for (j = 0; j < 1000; j++)
667 j_u[j] = GET_JIFFIES_USEC();
669 for (j = 0; j < 100; j++)
671 do_gettimeofday_fast(&tv_exp[j]);
673 printk(KERN_DEBUG "fast_timer_test() %is %06i\n", tv.tv_jiff, tv.tv_usec);
675 for (j = 0; j < 1000; j++)
677 printk(KERN_DEBUG "%i %i %i %i %i\n",
678 j_u[j], j_u[j+1], j_u[j+2], j_u[j+3], j_u[j+4]);
681 for (j = 0; j < 100; j++)
683 printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n",
684 tv_exp[j].tv_jiff, tv_exp[j].tv_usec,
685 tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec,
686 tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec,
687 tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec,
688 tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec);
691 do_gettimeofday_fast(&tv0);
692 start_one_shot_timer(&tr[i], test_timeout, i, 50000, "test0");
693 DP(proc_fasttimer_read(buf0, NULL, 0, 0, 0));
695 start_one_shot_timer(&tr[i], test_timeout, i, 70000, "test1");
696 DP(proc_fasttimer_read(buf1, NULL, 0, 0, 0));
698 start_one_shot_timer(&tr[i], test_timeout, i, 40000, "test2");
699 DP(proc_fasttimer_read(buf2, NULL, 0, 0, 0));
701 start_one_shot_timer(&tr[i], test_timeout, i, 60000, "test3");
702 DP(proc_fasttimer_read(buf3, NULL, 0, 0, 0));
704 start_one_shot_timer(&tr[i], test_timeout1, i, 55000, "test4xx");
705 DP(proc_fasttimer_read(buf4, NULL, 0, 0, 0));
707 do_gettimeofday_fast(&tv1);
709 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
711 prev_num = num_test_timeout;
712 while (num_test_timeout < i)
714 if (num_test_timeout != prev_num)
715 prev_num = num_test_timeout;
717 do_gettimeofday_fast(&tv2);
718 printk(KERN_INFO "Timers started %is %06i\n",
719 tv0.tv_jiff, tv0.tv_usec);
720 printk(KERN_INFO "Timers started at %is %06i\n",
721 tv1.tv_jiff, tv1.tv_usec);
722 printk(KERN_INFO "Timers done %is %06i\n",
723 tv2.tv_jiff, tv2.tv_usec);
724 DP(printk("buf0:\n");
738 printk("timers set:\n");
741 struct fast_timer *t = &tr[j];
742 printk("%-10s set: %6is %06ius exp: %6is %06ius "
743 "data: 0x%08X func: 0x%08X\n",
747 t->tv_expires.tv_jiff,
748 t->tv_expires.tv_usec,
753 printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n",
758 (tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) *
759 1000000 + tv_exp[j].tv_usec -
760 t->tv_expires.tv_usec);
762 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
763 printk("buf5 after all done:\n");
765 printk("fast_timer_test() done\n");
770 int fast_timer_init(void)
772 /* For some reason, request_irq() hangs when called froom time_init() */
773 if (!fast_timer_is_init)
775 printk("fast_timer_init()\n");
777 #ifdef CONFIG_PROC_FS
778 proc_create("fasttimer", 0, NULL, &proc_fasttimer_fops);
780 if (request_irq(TIMER0_INTR_VECT, timer_trig_interrupt,
782 "fast timer int", &fast_timer_list))
783 printk(KERN_ERR "err: fasttimer irq\n");
784 fast_timer_is_init = 1;
785 #ifdef FAST_TIMER_TEST
792 __initcall(fast_timer_init);