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 1.16 2004/10/03 18:48:01 bernie
19 *#* timer_delay(): Add a sanity check to avoid sleeping forever.
21 *#* Revision 1.15 2004/09/14 21:07:18 bernie
22 *#* Use debug.h instead of kdebug.h.
24 *#* Revision 1.14 2004/08/25 14:12:08 rasky
25 *#* Aggiornato il comment block dei log RCS
27 *#* Revision 1.13 2004/08/10 06:59:09 bernie
28 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
30 *#* Revision 1.12 2004/08/08 05:59:37 bernie
31 *#* Remove a few useless casts.
33 *#* Revision 1.11 2004/08/02 20:20:29 aleph
34 *#* Merge from project_ks
36 *#* Revision 1.10 2004/07/30 14:15:53 rasky
37 *#* Nuovo supporto unificato per detect della CPU
39 *#* Revision 1.9 2004/07/21 00:15:13 bernie
40 *#* Put timer driver on diet.
42 *#* Revision 1.8 2004/07/18 21:57:07 bernie
43 *#* Fix preprocessor warning with potentially undefined symbol.
45 *#* Revision 1.6 2004/06/07 18:10:06 aleph
46 *#* Remove free pool of timers; use user-provided Timer structure instead
48 *#* Revision 1.5 2004/06/07 15:56:55 aleph
49 *#* Some tabs cleanup and add timer strobe macros
51 *#* Revision 1.4 2004/06/06 18:25:44 bernie
52 *#* Rename event macros to look like regular functions.
54 *#* Revision 1.3 2004/06/06 17:18:42 bernie
55 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
57 *#* Revision 1.2 2004/06/03 11:27:09 bernie
58 *#* Add dual-license information.
60 *#* Revision 1.1 2004/05/23 18:23:30 bernie
61 *#* Import drv/timer module.
67 #include CPU_HEADER(timer)
70 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
71 #include <kern/proc.h>
74 //! Master system clock (1ms accuracy)
75 volatile time_t _clock;
78 #ifndef CONFIG_TIMER_DISABLE_EVENTS
81 * List of active asynchronous timers.
83 REGISTER static List timers_queue;
87 * Add the specified timer to the software timer service queue.
88 * When the delay indicated by the timer expires, the timer
89 * device will execute the event associated with it.
91 * \note Interrupt safe
93 void timer_add(Timer *timer)
98 DISABLE_IRQSAVE(flags);
100 /* Calculate expiration time for this timer */
101 timer->tick = _clock + timer->delay;
103 /* Search for the first node whose expiration time is
104 * greater than the timer we want to add.
106 node = (Timer *)timers_queue.head;
107 while (node->link.succ)
109 /* Stop just after the insertion point */
110 if (node->tick > timer->tick)
113 /* Go to next node */
114 node = (Timer *)node->link.succ;
117 /* Enqueue timer request into the list */
118 INSERTBEFORE(&timer->link, &node->link);
120 ENABLE_IRQRESTORE(flags);
125 * Remove a timer from the timer queue before it has expired
127 Timer *timer_abort(Timer *timer)
130 DISABLE_IRQSAVE(flags);
131 REMOVE(&timer->link);
132 ENABLE_IRQRESTORE(flags);
137 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
141 * Wait for the specified amount of time (expressed in ms)
143 void timer_delay(time_t time)
145 #if defined(IRQ_GETSTATE)
146 /* We shouldn't sleep with interrupts disabled */
147 ASSERT(IRQ_GETSTATE());
150 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
153 ASSERT(!sig_check(SIG_SINGLE));
154 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
155 timer_set_delay(&t, time);
157 sig_wait(SIG_SINGLE);
159 #else /* !CONFIG_KERN_SIGNALS */
161 time_t start = timer_ticks();
164 while (timer_ticks() - start < time) { /* nop */ }
166 #endif /* !CONFIG_KERN_SIGNALS */
170 #ifndef CONFIG_TIMER_DISABLE_UDELAY
172 * Wait for the specified amount of time (expressed in microseconds)
174 * \bug In AVR arch the maximum amount of time that can be used as
175 * delay could be very limited, depending on the hardware timer
176 * used. Check timer_avr.h, and what register is used as hptime_t.
178 void timer_udelay(utime_t usec_delay)
180 if (UNLIKELY(usec_delay > 1000))
182 timer_delay(usec_delay / 1000);
186 // FIXME: This multiplication is too slow at run-time. We should try and move it
187 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
189 hptime_t start = timer_hw_hpread();
190 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
192 while (timer_hw_hpread() - start < delay)
195 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
199 * Timer interrupt handler. Find soft timers expired and
200 * trigger corresponding events.
205 * With the Metrowerks compiler, the only way to force the compiler generate
206 * an interrupt service routine is to put a pragma directive within the function
210 #pragma interrupt saveall
213 #ifndef CONFIG_TIMER_DISABLE_EVENTS
221 /* Update the master ms counter */
224 #ifndef CONFIG_TIMER_DISABLE_EVENTS
226 * Check the first timer request in the list and process
227 * it when it has expired. Repeat this check until the
228 * first node has not yet expired. Since the list is sorted
229 * by expiry time, all the following requests are guaranteed
232 while ((timer = (Timer *)timers_queue.head)->link.succ)
234 /* This request in list has not yet expired? */
235 if (_clock < timer->tick)
238 /* Retreat the expired timer */
239 REMOVE(&timer->link);
241 /* Execute the associated event */
242 event_do(&timer->expire);
244 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
253 void timer_init(void)
257 #ifndef CONFIG_TIMER_DISABLE_EVENTS
258 INITLIST(&timers_queue);