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.
11 * \author Bernardo Innocenti <bernie@develer.com>
13 * \brief Hardware independent timer driver (implementation)
18 *#* Revision 1.15 2004/09/14 21:07:18 bernie
19 *#* Use debug.h instead of kdebug.h.
21 *#* Revision 1.14 2004/08/25 14:12:08 rasky
22 *#* Aggiornato il comment block dei log RCS
24 *#* Revision 1.13 2004/08/10 06:59:09 bernie
25 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
27 *#* Revision 1.12 2004/08/08 05:59:37 bernie
28 *#* Remove a few useless casts.
30 *#* Revision 1.11 2004/08/02 20:20:29 aleph
31 *#* Merge from project_ks
33 *#* Revision 1.10 2004/07/30 14:15:53 rasky
34 *#* Nuovo supporto unificato per detect della CPU
36 *#* Revision 1.9 2004/07/21 00:15:13 bernie
37 *#* Put timer driver on diet.
39 *#* Revision 1.8 2004/07/18 21:57:07 bernie
40 *#* Fix preprocessor warning with potentially undefined symbol.
42 *#* Revision 1.6 2004/06/07 18:10:06 aleph
43 *#* Remove free pool of timers; use user-provided Timer structure instead
45 *#* Revision 1.5 2004/06/07 15:56:55 aleph
46 *#* Some tabs cleanup and add timer strobe macros
48 *#* Revision 1.4 2004/06/06 18:25:44 bernie
49 *#* Rename event macros to look like regular functions.
51 *#* Revision 1.3 2004/06/06 17:18:42 bernie
52 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
54 *#* Revision 1.2 2004/06/03 11:27:09 bernie
55 *#* Add dual-license information.
57 *#* Revision 1.1 2004/05/23 18:23:30 bernie
58 *#* Import drv/timer module.
64 #include CPU_HEADER(timer)
67 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
68 #include <kern/proc.h>
71 //! Master system clock (1ms accuracy)
72 volatile time_t _clock;
75 #ifndef CONFIG_TIMER_DISABLE_EVENTS
78 * List of active asynchronous timers.
80 REGISTER static List timers_queue;
84 * Add the specified timer to the software timer service queue.
85 * When the delay indicated by the timer expires, the timer
86 * device will execute the event associated with it.
88 * \note Interrupt safe
90 void timer_add(Timer *timer)
95 DISABLE_IRQSAVE(flags);
97 /* Calculate expiration time for this timer */
98 timer->tick = _clock + timer->delay;
100 /* Search for the first node whose expiration time is
101 * greater than the timer we want to add.
103 node = (Timer *)timers_queue.head;
104 while (node->link.succ)
106 /* Stop just after the insertion point */
107 if (node->tick > timer->tick)
110 /* Go to next node */
111 node = (Timer *)node->link.succ;
114 /* Enqueue timer request into the list */
115 INSERTBEFORE(&timer->link, &node->link);
117 ENABLE_IRQRESTORE(flags);
122 * Remove a timer from the timer queue before it has expired
124 Timer *timer_abort(Timer *timer)
127 DISABLE_IRQSAVE(flags);
128 REMOVE(&timer->link);
129 ENABLE_IRQRESTORE(flags);
134 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
138 * Wait for the specified amount of time (expressed in ms)
140 void timer_delay(time_t time)
142 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
145 ASSERT(!sig_check(SIG_SINGLE));
146 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
147 timer_set_delay(&t, time);
149 sig_wait(SIG_SINGLE);
151 #else /* !CONFIG_KERN_SIGNALS */
153 time_t start = timer_ticks();
156 while (timer_ticks() - start < time) { /* nop */ }
158 #endif /* !CONFIG_KERN_SIGNALS */
162 #ifndef CONFIG_TIMER_DISABLE_UDELAY
164 * Wait for the specified amount of time (expressed in microseconds)
166 * \bug In AVR arch the maximum amount of time that can be used as
167 * delay could be very limited, depending on the hardware timer
168 * used. Check timer_avr.h, and what register is used as hptime_t.
170 void timer_udelay(utime_t usec_delay)
172 if (UNLIKELY(usec_delay > 1000))
174 timer_delay(usec_delay / 1000);
178 // FIXME: This multiplication is too slow at run-time. We should try and move it
179 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
181 hptime_t start = timer_hw_hpread();
182 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
184 while (timer_hw_hpread() - start < delay)
187 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
191 * Timer interrupt handler. Find soft timers expired and
192 * trigger corresponding events.
197 * With the Metrowerks compiler, the only way to force the compiler generate
198 * an interrupt service routine is to put a pragma directive within the function
202 #pragma interrupt saveall
205 #ifndef CONFIG_TIMER_DISABLE_EVENTS
213 /* Update the master ms counter */
216 #ifndef CONFIG_TIMER_DISABLE_EVENTS
218 * Check the first timer request in the list and process
219 * it when it has expired. Repeat this check until the
220 * first node has not yet expired. Since the list is sorted
221 * by expiry time, all the following requests are guaranteed
224 while ((timer = (Timer *)timers_queue.head)->link.succ)
226 /* This request in list has not yet expired? */
227 if (_clock < timer->tick)
230 /* Retreat the expired timer */
231 REMOVE(&timer->link);
233 /* Execute the associated event */
234 event_do(&timer->expire);
236 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
245 void timer_init(void)
249 #ifndef CONFIG_TIMER_DISABLE_EVENTS
250 INITLIST(&timers_queue);