4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
6 * This file is part of DevLib - See devlib/README for information.
9 * \brief Hardware independent timer driver (implementation)
12 * \author Bernardo Innocenti <bernie@develer.com>
17 *#* Revision 1.18 2004/10/14 23:14:05 bernie
18 *#* Fix longstanding problem with wrap-arounds.
20 *#* Revision 1.17 2004/10/03 18:52:08 bernie
21 *#* Move \brief on top in header to please Doxygen.
23 *#* Revision 1.16 2004/10/03 18:48:01 bernie
24 *#* timer_delay(): Add a sanity check to avoid sleeping forever.
26 *#* Revision 1.15 2004/09/14 21:07:18 bernie
27 *#* Use debug.h instead of kdebug.h.
29 *#* Revision 1.14 2004/08/25 14:12:08 rasky
30 *#* Aggiornato il comment block dei log RCS
32 *#* Revision 1.13 2004/08/10 06:59:09 bernie
33 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
35 *#* Revision 1.12 2004/08/08 05:59:37 bernie
36 *#* Remove a few useless casts.
38 *#* Revision 1.11 2004/08/02 20:20:29 aleph
39 *#* Merge from project_ks
41 *#* Revision 1.10 2004/07/30 14:15:53 rasky
42 *#* Nuovo supporto unificato per detect della CPU
44 *#* Revision 1.9 2004/07/21 00:15:13 bernie
45 *#* Put timer driver on diet.
47 *#* Revision 1.8 2004/07/18 21:57:07 bernie
48 *#* Fix preprocessor warning with potentially undefined symbol.
50 *#* Revision 1.6 2004/06/07 18:10:06 aleph
51 *#* Remove free pool of timers; use user-provided Timer structure instead
53 *#* Revision 1.5 2004/06/07 15:56:55 aleph
54 *#* Some tabs cleanup and add timer strobe macros
56 *#* Revision 1.4 2004/06/06 18:25:44 bernie
57 *#* Rename event macros to look like regular functions.
59 *#* Revision 1.3 2004/06/06 17:18:42 bernie
60 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
62 *#* Revision 1.2 2004/06/03 11:27:09 bernie
63 *#* Add dual-license information.
65 *#* Revision 1.1 2004/05/23 18:23:30 bernie
66 *#* Import drv/timer module.
72 #include CPU_HEADER(timer)
75 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
76 #include <kern/proc.h>
79 //! Master system clock (1ms accuracy)
80 volatile time_t _clock;
83 #ifndef CONFIG_TIMER_DISABLE_EVENTS
86 * List of active asynchronous timers.
88 REGISTER static List timers_queue;
92 * Add the specified timer to the software timer service queue.
93 * When the delay indicated by the timer expires, the timer
94 * device will execute the event associated with it.
96 * \note Interrupt safe
98 void timer_add(Timer *timer)
103 DISABLE_IRQSAVE(flags);
105 /* Calculate expiration time for this timer */
106 timer->tick = _clock + timer->delay;
109 * Search for the first node whose expiration time is
110 * greater than the timer we want to add.
112 node = (Timer *)timers_queue.head;
113 while (node->link.succ)
116 * Stop just after the insertion point.
117 * (this fancy compare takes care of wrap-arounds).
119 if (node->tick - timer->tick > 0)
122 /* Go to next node */
123 node = (Timer *)node->link.succ;
126 /* Enqueue timer request into the list */
127 INSERTBEFORE(&timer->link, &node->link);
129 ENABLE_IRQRESTORE(flags);
134 * Remove a timer from the timer queue before it has expired
136 Timer *timer_abort(Timer *timer)
139 DISABLE_IRQSAVE(flags);
140 REMOVE(&timer->link);
141 ENABLE_IRQRESTORE(flags);
146 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
150 * Wait for the specified amount of time (expressed in ms)
152 void timer_delay(time_t time)
154 #if defined(IRQ_GETSTATE)
155 /* We shouldn't sleep with interrupts disabled */
156 ASSERT(IRQ_GETSTATE());
159 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
162 ASSERT(!sig_check(SIG_SINGLE));
163 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
164 timer_set_delay(&t, time);
166 sig_wait(SIG_SINGLE);
168 #else /* !CONFIG_KERN_SIGNALS */
170 time_t start = timer_ticks();
173 while (timer_ticks() - start < time) { /* nop */ }
175 #endif /* !CONFIG_KERN_SIGNALS */
179 #ifndef CONFIG_TIMER_DISABLE_UDELAY
181 * Wait for the specified amount of time (expressed in microseconds)
183 * \bug In AVR arch the maximum amount of time that can be used as
184 * delay could be very limited, depending on the hardware timer
185 * used. Check timer_avr.h, and what register is used as hptime_t.
187 void timer_udelay(utime_t usec_delay)
189 if (UNLIKELY(usec_delay > 1000))
191 timer_delay(usec_delay / 1000);
195 // FIXME: This multiplication is too slow at run-time. We should try and move it
196 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
198 hptime_t start = timer_hw_hpread();
199 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
201 while (timer_hw_hpread() - start < delay)
204 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
208 * Timer interrupt handler. Find soft timers expired and
209 * trigger corresponding events.
214 * With the Metrowerks compiler, the only way to force the compiler generate
215 * an interrupt service routine is to put a pragma directive within the function
219 #pragma interrupt saveall
222 #ifndef CONFIG_TIMER_DISABLE_EVENTS
230 /* Update the master ms counter */
233 #ifndef CONFIG_TIMER_DISABLE_EVENTS
235 * Check the first timer request in the list and process
236 * it when it has expired. Repeat this check until the
237 * first node has not yet expired. Since the list is sorted
238 * by expiry time, all the following requests are guaranteed
241 while ((timer = (Timer *)timers_queue.head)->link.succ)
243 /* This request in list has not yet expired? */
244 if (_clock < timer->tick)
247 /* Retreat the expired timer */
248 REMOVE(&timer->link);
250 /* Execute the associated event */
251 event_do(&timer->expire);
253 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
262 void timer_init(void)
266 #ifndef CONFIG_TIMER_DISABLE_EVENTS
267 INITLIST(&timers_queue);