4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2003, 2004, 2005, 2006 Develer S.r.l. (http://www.develer.com/)
30 * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
34 * \brief Hardware independent timer driver (implementation)
37 * \author Bernardo Innocenti <bernie@develer.com>
42 *#* Revision 1.32 2007/10/08 12:14:32 batt
43 *#* Fix some review issues.
45 *#* Revision 1.31 2006/07/19 12:56:26 bernie
46 *#* Convert to new Doxygen style.
48 *#* Revision 1.30 2006/02/24 00:26:49 bernie
49 *#* Fixes for CONFIG_KERNEL.
51 *#* Revision 1.29 2006/02/17 22:24:07 bernie
52 *#* Add MOD_CHECK() checks.
54 *#* Revision 1.28 2006/02/10 12:32:52 bernie
55 *#* Update Copyright year.
57 *#* Revision 1.27 2005/11/27 03:04:08 bernie
58 *#* Move test code to timer_test.c; Add OS_HOSTED support.
60 *#* Revision 1.26 2005/11/04 16:20:02 bernie
61 *#* Fix reference to README.devlib in header.
63 *#* Revision 1.25 2005/07/19 07:26:37 bernie
64 *#* Refactor to decouple timer ticks from milliseconds.
66 *#* Revision 1.24 2005/04/11 19:10:28 bernie
67 *#* Include top-level headers from cfg/ subdir.
69 *#* Revision 1.23 2004/12/13 12:07:06 bernie
70 *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
72 *#* Revision 1.22 2004/12/08 09:12:09 bernie
73 *#* Rename time_t to mtime_t.
75 *#* Revision 1.21 2004/11/28 23:20:25 bernie
76 *#* Remove obsolete INITLIST macro.
78 *#* Revision 1.20 2004/11/16 20:59:06 bernie
79 *#* Add watchdog timer support.
85 #include <cfg/debug.h>
86 #include <cfg/module.h>
87 #include <appconfig.h>
90 * Include platform-specific binding code if we're hosted.
91 * Try the CPU specific one for bare-metal environments.
94 #include OS_CSOURCE(timer)
96 #include CPU_CSOURCE(timer)
100 * Sanity check for config parameters required by this module.
102 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
103 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
105 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
106 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
114 #include <config_kern.h>
115 #if CONFIG_KERN_SIGNALS
116 #include <kern/signal.h> /* sig_wait(), sig_check() */
117 #include <kern/proc.h> /* proc_current() */
118 #include <cfg/macros.h> /* BV() */
124 * \def CONFIG_TIMER_STROBE
126 * This is a debug facility that can be used to
127 * monitor timer interrupt activity on an external pin.
129 * To use strobes, redefine the macros TIMER_STROBE_ON,
130 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
131 * CONFIG_TIMER_STROBE to 1.
133 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
134 #define TIMER_STROBE_ON do {/*nop*/} while(0)
135 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
136 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
140 /// Master system clock (1 tick accuracy)
141 volatile ticks_t _clock;
144 #ifndef CONFIG_TIMER_DISABLE_EVENTS
147 * List of active asynchronous timers.
149 REGISTER static List timers_queue;
153 * Add the specified timer to the software timer service queue.
154 * When the delay indicated by the timer expires, the timer
155 * device will execute the event associated with it.
157 * \note Interrupt safe
159 void timer_add(Timer *timer)
165 /* Inserting timers twice causes mayhem. */
166 ASSERT(timer->magic != TIMER_MAGIC_ACTIVE);
167 DB(timer->magic = TIMER_MAGIC_ACTIVE;)
169 IRQ_SAVE_DISABLE(flags);
171 /* Calculate expiration time for this timer */
172 timer->tick = _clock + timer->_delay;
175 * Search for the first node whose expiration time is
176 * greater than the timer we want to add.
178 node = (Timer *)LIST_HEAD(&timers_queue);
179 while (node->link.succ)
182 * Stop just after the insertion point.
183 * (this fancy compare takes care of wrap-arounds).
185 if (node->tick - timer->tick > 0)
188 /* Go to next node */
189 node = (Timer *)node->link.succ;
192 /* Enqueue timer request into the list */
193 INSERT_BEFORE(&timer->link, &node->link);
200 * Remove a timer from the timer queue before it has expired.
202 Timer *timer_abort(Timer *timer)
204 ATOMIC(REMOVE(&timer->link));
205 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
210 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
214 * Wait for the specified amount of timer ticks.
216 void timer_delayTicks(ticks_t delay)
218 #if defined(IRQ_GETSTATE)
219 /* We shouldn't sleep with interrupts disabled */
220 ASSERT(IRQ_GETSTATE());
223 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
226 ASSERT(!sig_check(SIG_SINGLE));
227 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
228 timer_setDelay(&t, delay);
230 sig_wait(SIG_SINGLE);
232 #else /* !CONFIG_KERN_SIGNALS */
234 ticks_t start = timer_clock();
237 while (timer_clock() - start < delay)
244 #endif /* !CONFIG_KERN_SIGNALS */
248 #ifndef CONFIG_TIMER_DISABLE_UDELAY
251 * Busy wait until the specified amount of high-precision ticks have elapsed.
253 * \note This function is interrupt safe, the only
254 * requirement is a running hardware timer.
256 void timer_busyWait(hptime_t delay)
258 hptime_t now, prev = timer_hw_hpread();
263 now = timer_hw_hpread();
265 * We rely on hptime_t being unsigned here to
266 * reduce the modulo to an AND in the common
267 * case of TIMER_HW_CNT.
269 delta = (now - prev) % TIMER_HW_CNT;
278 * Wait for the specified amount of time (expressed in microseconds).
280 * \bug In AVR arch the maximum amount of time that can be used as
281 * delay could be very limited, depending on the hardware timer
282 * used. Check timer_avr.h, and what register is used as hptime_t.
284 void timer_delayHp(hptime_t delay)
286 if (UNLIKELY(delay > us_to_hptime(1000)))
288 timer_delayTicks(delay / (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC));
289 delay %= (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC);
292 timer_busyWait(delay);
294 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
298 * Timer interrupt handler. Find soft timers expired and
299 * trigger corresponding events.
304 * With the Metrowerks compiler, the only way to force the compiler generate
305 * an interrupt service routine is to put a pragma directive within the function
309 #pragma interrupt saveall
312 #ifndef CONFIG_TIMER_DISABLE_EVENTS
316 * On systems sharing IRQ line and vector, this check is needed
317 * to ensure that IRQ is generated by timer source.
319 if (!timer_hw_triggered())
324 /* Perform hw IRQ handling */
327 /* Update the master ms counter */
330 #ifndef CONFIG_TIMER_DISABLE_EVENTS
332 * Check the first timer request in the list and process
333 * it when it has expired. Repeat this check until the
334 * first node has not yet expired. Since the list is sorted
335 * by expiry time, all the following requests are guaranteed
338 while ((timer = (Timer *)LIST_HEAD(&timers_queue))->link.succ)
340 /* This request in list has not yet expired? */
341 if (_clock - timer->tick < 0)
344 /* Retreat the expired timer */
345 REMOVE(&timer->link);
346 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
348 /* Execute the associated event */
349 event_do(&timer->expire);
351 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
361 void timer_init(void)
365 #ifndef CONFIG_TIMER_DISABLE_EVENTS
366 LIST_INIT(&timers_queue);