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 1.22 2004/12/08 09:12:09 bernie
18 *#* Rename time_t to mtime_t.
20 *#* Revision 1.21 2004/11/28 23:20:25 bernie
21 *#* Remove obsolete INITLIST macro.
23 *#* Revision 1.20 2004/11/16 20:59:06 bernie
24 *#* Add watchdog timer support.
26 *#* Revision 1.19 2004/10/19 08:56:49 bernie
27 *#* TIMER_STROBE_ON, TIMER_STROBE_OFF, TIMER_STROBE_INIT: Move from timer_avr.h to timer.h, where they really belong.
29 *#* Revision 1.18 2004/10/14 23:14:05 bernie
30 *#* Fix longstanding problem with wrap-arounds.
32 *#* Revision 1.17 2004/10/03 18:52:08 bernie
33 *#* Move \brief on top in header to please Doxygen.
35 *#* Revision 1.16 2004/10/03 18:48:01 bernie
36 *#* timer_delay(): Add a sanity check to avoid sleeping forever.
38 *#* Revision 1.15 2004/09/14 21:07:18 bernie
39 *#* Use debug.h instead of kdebug.h.
41 *#* Revision 1.14 2004/08/25 14:12:08 rasky
42 *#* Aggiornato il comment block dei log RCS
44 *#* Revision 1.13 2004/08/10 06:59:09 bernie
45 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
47 *#* Revision 1.12 2004/08/08 05:59:37 bernie
48 *#* Remove a few useless casts.
50 *#* Revision 1.11 2004/08/02 20:20:29 aleph
51 *#* Merge from project_ks
53 *#* Revision 1.10 2004/07/30 14:15:53 rasky
54 *#* Nuovo supporto unificato per detect della CPU
56 *#* Revision 1.9 2004/07/21 00:15:13 bernie
57 *#* Put timer driver on diet.
59 *#* Revision 1.8 2004/07/18 21:57:07 bernie
60 *#* Fix preprocessor warning with potentially undefined symbol.
62 *#* Revision 1.6 2004/06/07 18:10:06 aleph
63 *#* Remove free pool of timers; use user-provided Timer structure instead
65 *#* Revision 1.5 2004/06/07 15:56:55 aleph
66 *#* Some tabs cleanup and add timer strobe macros
68 *#* Revision 1.4 2004/06/06 18:25:44 bernie
69 *#* Rename event macros to look like regular functions.
71 *#* Revision 1.3 2004/06/06 17:18:42 bernie
72 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
74 *#* Revision 1.2 2004/06/03 11:27:09 bernie
75 *#* Add dual-license information.
77 *#* Revision 1.1 2004/05/23 18:23:30 bernie
78 *#* Import drv/timer module.
85 #include CPU_HEADER(timer)
90 * Sanity check for config parameters required by this module.
92 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
93 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
95 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
96 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
103 #if CONFIG_KERNEL && CONFIG_KERN_SIGNALS
104 #include <kern/proc.h>
109 * \def CONFIG_TIMER_STROBE
111 * This is a debug facility that can be used to
112 * monitor timer interrupt activity on an external pin.
114 * To use strobes, redefine the macros TIMER_STROBE_ON,
115 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
116 * CONFIG_TIMER_STROBE to 1.
118 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
119 #define TIMER_STROBE_ON do {/*nop*/} while(0)
120 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
121 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
125 //! Master system clock (1ms accuracy)
126 volatile mtime_t _clock;
129 #ifndef CONFIG_TIMER_DISABLE_EVENTS
132 * List of active asynchronous timers.
134 REGISTER static List timers_queue;
138 * Add the specified timer to the software timer service queue.
139 * When the delay indicated by the timer expires, the timer
140 * device will execute the event associated with it.
142 * \note Interrupt safe
144 void timer_add(Timer *timer)
149 DISABLE_IRQSAVE(flags);
151 /* Calculate expiration time for this timer */
152 timer->tick = _clock + timer->delay;
155 * Search for the first node whose expiration time is
156 * greater than the timer we want to add.
158 node = (Timer *)timers_queue.head;
159 while (node->link.succ)
162 * Stop just after the insertion point.
163 * (this fancy compare takes care of wrap-arounds).
165 if (node->tick - timer->tick > 0)
168 /* Go to next node */
169 node = (Timer *)node->link.succ;
172 /* Enqueue timer request into the list */
173 INSERTBEFORE(&timer->link, &node->link);
175 ENABLE_IRQRESTORE(flags);
180 * Remove a timer from the timer queue before it has expired
182 Timer *timer_abort(Timer *timer)
185 DISABLE_IRQSAVE(flags);
186 REMOVE(&timer->link);
187 ENABLE_IRQRESTORE(flags);
192 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
196 * Wait for the specified amount of time (expressed in ms)
198 void timer_delay(mtime_t time)
200 #if defined(IRQ_GETSTATE)
201 /* We shouldn't sleep with interrupts disabled */
202 ASSERT(IRQ_GETSTATE());
205 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
208 ASSERT(!sig_check(SIG_SINGLE));
209 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
210 timer_set_delay(&t, time);
212 sig_wait(SIG_SINGLE);
214 #else /* !CONFIG_KERN_SIGNALS */
216 mtime_t start = timer_ticks();
219 while (timer_ticks() - start < time)
226 #endif /* !CONFIG_KERN_SIGNALS */
230 #ifndef CONFIG_TIMER_DISABLE_UDELAY
232 * Wait for the specified amount of time (expressed in microseconds)
234 * \bug In AVR arch the maximum amount of time that can be used as
235 * delay could be very limited, depending on the hardware timer
236 * used. Check timer_avr.h, and what register is used as hptime_t.
238 void timer_udelay(utime_t usec_delay)
240 if (UNLIKELY(usec_delay > 1000))
242 timer_delay(usec_delay / 1000);
246 // FIXME: This multiplication is too slow at run-time. We should try and move it
247 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
249 hptime_t start = timer_hw_hpread();
250 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
252 while (timer_hw_hpread() - start < delay)
255 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
259 * Timer interrupt handler. Find soft timers expired and
260 * trigger corresponding events.
265 * With the Metrowerks compiler, the only way to force the compiler generate
266 * an interrupt service routine is to put a pragma directive within the function
270 #pragma interrupt saveall
273 #ifndef CONFIG_TIMER_DISABLE_EVENTS
281 /* Update the master ms counter */
284 #ifndef CONFIG_TIMER_DISABLE_EVENTS
286 * Check the first timer request in the list and process
287 * it when it has expired. Repeat this check until the
288 * first node has not yet expired. Since the list is sorted
289 * by expiry time, all the following requests are guaranteed
292 while ((timer = (Timer *)timers_queue.head)->link.succ)
294 /* This request in list has not yet expired? */
295 if (_clock < timer->tick)
298 /* Retreat the expired timer */
299 REMOVE(&timer->link);
301 /* Execute the associated event */
302 event_do(&timer->expire);
304 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
313 void timer_init(void)
317 #ifndef CONFIG_TIMER_DISABLE_EVENTS
318 LIST_INIT(&timers_queue);