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 1.19 2004/10/19 08:56:49 bernie
18 *#* TIMER_STROBE_ON, TIMER_STROBE_OFF, TIMER_STROBE_INIT: Move from timer_avr.h to timer.h, where they really belong.
20 *#* Revision 1.18 2004/10/14 23:14:05 bernie
21 *#* Fix longstanding problem with wrap-arounds.
23 *#* Revision 1.17 2004/10/03 18:52:08 bernie
24 *#* Move \brief on top in header to please Doxygen.
26 *#* Revision 1.16 2004/10/03 18:48:01 bernie
27 *#* timer_delay(): Add a sanity check to avoid sleeping forever.
29 *#* Revision 1.15 2004/09/14 21:07:18 bernie
30 *#* Use debug.h instead of kdebug.h.
32 *#* Revision 1.14 2004/08/25 14:12:08 rasky
33 *#* Aggiornato il comment block dei log RCS
35 *#* Revision 1.13 2004/08/10 06:59:09 bernie
36 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
38 *#* Revision 1.12 2004/08/08 05:59:37 bernie
39 *#* Remove a few useless casts.
41 *#* Revision 1.11 2004/08/02 20:20:29 aleph
42 *#* Merge from project_ks
44 *#* Revision 1.10 2004/07/30 14:15:53 rasky
45 *#* Nuovo supporto unificato per detect della CPU
47 *#* Revision 1.9 2004/07/21 00:15:13 bernie
48 *#* Put timer driver on diet.
50 *#* Revision 1.8 2004/07/18 21:57:07 bernie
51 *#* Fix preprocessor warning with potentially undefined symbol.
53 *#* Revision 1.6 2004/06/07 18:10:06 aleph
54 *#* Remove free pool of timers; use user-provided Timer structure instead
56 *#* Revision 1.5 2004/06/07 15:56:55 aleph
57 *#* Some tabs cleanup and add timer strobe macros
59 *#* Revision 1.4 2004/06/06 18:25:44 bernie
60 *#* Rename event macros to look like regular functions.
62 *#* Revision 1.3 2004/06/06 17:18:42 bernie
63 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
65 *#* Revision 1.2 2004/06/03 11:27:09 bernie
66 *#* Add dual-license information.
68 *#* Revision 1.1 2004/05/23 18:23:30 bernie
69 *#* Import drv/timer module.
76 #include CPU_HEADER(timer)
79 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
80 #include <kern/proc.h>
85 * \def CONFIG_TIMER_STROBE
87 * This is a debug facility that can be used to
88 * monitor timer interrupt activity on an external pin.
90 * To use strobes, redefine the macros TIMER_STROBE_ON,
91 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
92 * CONFIG_TIMER_STROBE to 1.
94 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
95 #define TIMER_STROBE_ON do {/*nop*/} while(0)
96 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
97 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
101 //! Master system clock (1ms accuracy)
102 volatile time_t _clock;
105 #ifndef CONFIG_TIMER_DISABLE_EVENTS
108 * List of active asynchronous timers.
110 REGISTER static List timers_queue;
114 * Add the specified timer to the software timer service queue.
115 * When the delay indicated by the timer expires, the timer
116 * device will execute the event associated with it.
118 * \note Interrupt safe
120 void timer_add(Timer *timer)
125 DISABLE_IRQSAVE(flags);
127 /* Calculate expiration time for this timer */
128 timer->tick = _clock + timer->delay;
131 * Search for the first node whose expiration time is
132 * greater than the timer we want to add.
134 node = (Timer *)timers_queue.head;
135 while (node->link.succ)
138 * Stop just after the insertion point.
139 * (this fancy compare takes care of wrap-arounds).
141 if (node->tick - timer->tick > 0)
144 /* Go to next node */
145 node = (Timer *)node->link.succ;
148 /* Enqueue timer request into the list */
149 INSERTBEFORE(&timer->link, &node->link);
151 ENABLE_IRQRESTORE(flags);
156 * Remove a timer from the timer queue before it has expired
158 Timer *timer_abort(Timer *timer)
161 DISABLE_IRQSAVE(flags);
162 REMOVE(&timer->link);
163 ENABLE_IRQRESTORE(flags);
168 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
172 * Wait for the specified amount of time (expressed in ms)
174 void timer_delay(time_t time)
176 #if defined(IRQ_GETSTATE)
177 /* We shouldn't sleep with interrupts disabled */
178 ASSERT(IRQ_GETSTATE());
181 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
184 ASSERT(!sig_check(SIG_SINGLE));
185 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
186 timer_set_delay(&t, time);
188 sig_wait(SIG_SINGLE);
190 #else /* !CONFIG_KERN_SIGNALS */
192 time_t start = timer_ticks();
195 while (timer_ticks() - start < time) { /* nop */ }
197 #endif /* !CONFIG_KERN_SIGNALS */
201 #ifndef CONFIG_TIMER_DISABLE_UDELAY
203 * Wait for the specified amount of time (expressed in microseconds)
205 * \bug In AVR arch the maximum amount of time that can be used as
206 * delay could be very limited, depending on the hardware timer
207 * used. Check timer_avr.h, and what register is used as hptime_t.
209 void timer_udelay(utime_t usec_delay)
211 if (UNLIKELY(usec_delay > 1000))
213 timer_delay(usec_delay / 1000);
217 // FIXME: This multiplication is too slow at run-time. We should try and move it
218 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
220 hptime_t start = timer_hw_hpread();
221 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
223 while (timer_hw_hpread() - start < delay)
226 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
230 * Timer interrupt handler. Find soft timers expired and
231 * trigger corresponding events.
236 * With the Metrowerks compiler, the only way to force the compiler generate
237 * an interrupt service routine is to put a pragma directive within the function
241 #pragma interrupt saveall
244 #ifndef CONFIG_TIMER_DISABLE_EVENTS
252 /* Update the master ms counter */
255 #ifndef CONFIG_TIMER_DISABLE_EVENTS
257 * Check the first timer request in the list and process
258 * it when it has expired. Repeat this check until the
259 * first node has not yet expired. Since the list is sorted
260 * by expiry time, all the following requests are guaranteed
263 while ((timer = (Timer *)timers_queue.head)->link.succ)
265 /* This request in list has not yet expired? */
266 if (_clock < timer->tick)
269 /* Retreat the expired timer */
270 REMOVE(&timer->link);
272 /* Execute the associated event */
273 event_do(&timer->expire);
275 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
284 void timer_init(void)
288 #ifndef CONFIG_TIMER_DISABLE_EVENTS
289 INITLIST(&timers_queue);