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);