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 1.14 2004/08/25 14:12:08 rasky
19 *#* Aggiornato il comment block dei log RCS
21 *#* Revision 1.13 2004/08/10 06:59:09 bernie
22 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
24 *#* Revision 1.12 2004/08/08 05:59:37 bernie
25 *#* Remove a few useless casts.
27 *#* Revision 1.11 2004/08/02 20:20:29 aleph
28 *#* Merge from project_ks
30 *#* Revision 1.10 2004/07/30 14:15:53 rasky
31 *#* Nuovo supporto unificato per detect della CPU
33 *#* Revision 1.9 2004/07/21 00:15:13 bernie
34 *#* Put timer driver on diet.
36 *#* Revision 1.8 2004/07/18 21:57:07 bernie
37 *#* Fix preprocessor warning with potentially undefined symbol.
39 *#* Revision 1.6 2004/06/07 18:10:06 aleph
40 *#* Remove free pool of timers; use user-provided Timer structure instead
42 *#* Revision 1.5 2004/06/07 15:56:55 aleph
43 *#* Some tabs cleanup and add timer strobe macros
45 *#* Revision 1.4 2004/06/06 18:25:44 bernie
46 *#* Rename event macros to look like regular functions.
48 *#* Revision 1.3 2004/06/06 17:18:42 bernie
49 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
51 *#* Revision 1.2 2004/06/03 11:27:09 bernie
52 *#* Add dual-license information.
54 *#* Revision 1.1 2004/05/23 18:23:30 bernie
55 *#* Import drv/timer module.
62 #include CPU_HEADER(timer)
64 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
65 #include <kern/proc.h>
68 //! Master system clock (1ms accuracy)
69 volatile time_t _clock;
72 #ifndef CONFIG_TIMER_DISABLE_EVENTS
75 * List of active asynchronous timers.
77 REGISTER static List timers_queue;
81 * Add the specified timer to the software timer service queue.
82 * When the delay indicated by the timer expires, the timer
83 * device will execute the event associated with it.
85 * \note Interrupt safe
87 void timer_add(Timer *timer)
92 DISABLE_IRQSAVE(flags);
94 /* Calculate expiration time for this timer */
95 timer->tick = _clock + timer->delay;
97 /* Search for the first node whose expiration time is
98 * greater than the timer we want to add.
100 node = (Timer *)timers_queue.head;
101 while (node->link.succ)
103 /* Stop just after the insertion point */
104 if (node->tick > timer->tick)
107 /* Go to next node */
108 node = (Timer *)node->link.succ;
111 /* Enqueue timer request into the list */
112 INSERTBEFORE(&timer->link, &node->link);
114 ENABLE_IRQRESTORE(flags);
119 * Remove a timer from the timer queue before it has expired
121 Timer *timer_abort(Timer *timer)
124 DISABLE_IRQSAVE(flags);
125 REMOVE(&timer->link);
126 ENABLE_IRQRESTORE(flags);
131 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
135 * Wait for the specified amount of time (expressed in ms)
137 void timer_delay(time_t time)
139 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
142 ASSERT(!sig_check(SIG_SINGLE));
143 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
144 timer_set_delay(&t, time);
146 sig_wait(SIG_SINGLE);
148 #else /* !CONFIG_KERN_SIGNALS */
150 time_t start = timer_ticks();
153 while (timer_ticks() - start < time) { /* nop */ }
155 #endif /* !CONFIG_KERN_SIGNALS */
159 #ifndef CONFIG_TIMER_DISABLE_UDELAY
161 * Wait for the specified amount of time (expressed in microseconds)
163 * \bug In AVR arch the maximum amount of time that can be used as
164 * delay could be very limited, depending on the hardware timer
165 * used. Check timer_avr.h, and what register is used as hptime_t.
167 void timer_udelay(utime_t usec_delay)
169 if (UNLIKELY(usec_delay > 1000))
171 timer_delay(usec_delay / 1000);
175 // FIXME: This multiplication is too slow at run-time. We should try and move it
176 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
178 hptime_t start = timer_hw_hpread();
179 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
181 while (timer_hw_hpread() - start < delay)
184 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
188 * Timer interrupt handler. Find soft timers expired and
189 * trigger corresponding events.
194 * With the Metrowerks compiler, the only way to force the compiler generate
195 * an interrupt service routine is to put a pragma directive within the function
199 #pragma interrupt saveall
202 #ifndef CONFIG_TIMER_DISABLE_EVENTS
210 /* Update the master ms counter */
213 #ifndef CONFIG_TIMER_DISABLE_EVENTS
215 * Check the first timer request in the list and process
216 * it when it has expired. Repeat this check until the
217 * first node has not yet expired. Since the list is sorted
218 * by expiry time, all the following requests are guaranteed
221 while ((timer = (Timer *)timers_queue.head)->link.succ)
223 /* This request in list has not yet expired? */
224 if (_clock < timer->tick)
227 /* Retreat the expired timer */
228 REMOVE(&timer->link);
230 /* Execute the associated event */
231 event_do(&timer->expire);
233 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
242 void timer_init(void)
246 #ifndef CONFIG_TIMER_DISABLE_EVENTS
247 INITLIST(&timers_queue);