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, 2008 Bernie Innocenti <bernie@codewiz.org>
33 * \brief Hardware independent timer driver (implementation)
35 * \author Bernie Innocenti <bernie@codewiz.org>
36 * \author Francesco Sacchi <batt@develer.com>
40 #include "hw/hw_timer.h"
42 #include "cfg/cfg_timer.h"
43 #include "cfg/cfg_wdt.h"
44 #include "cfg/cfg_proc.h"
45 #include "cfg/cfg_signal.h"
47 #include <cfg/debug.h>
48 #include <cfg/module.h>
51 #include <cpu/types.h>
53 #include <cpu/power.h> // cpu_relax()
56 * Include platform-specific binding code if we're hosted.
57 * Try the CPU specific one for bare-metal environments.
60 //#include OS_CSOURCE(timer)
61 #include <emul/timer_posix.c>
64 #warning Deprecated: now you should include timer_<cpu> directly in the makefile. Remove this line and the following once done.
65 #include CPU_CSOURCE(timer)
70 * Sanity check for config parameters required by this module.
72 #if !defined(CONFIG_KERN) || ((CONFIG_KERN != 0) && CONFIG_KERN != 1)
73 #error CONFIG_KERN must be set to either 0 or 1 in config.h
75 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
76 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
83 #if defined (CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
84 #include <kern/signal.h> /* sig_wait(), sig_check() */
85 #include <kern/proc.h> /* proc_current() */
86 #include <cfg/macros.h> /* BV() */
91 * \def CONFIG_TIMER_STROBE
93 * This is a debug facility that can be used to
94 * monitor timer interrupt activity on an external pin.
96 * To use strobes, redefine the macros TIMER_STROBE_ON,
97 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
98 * CONFIG_TIMER_STROBE to 1.
100 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
101 #define TIMER_STROBE_ON do {/*nop*/} while(0)
102 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
103 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
107 /// Master system clock (1 tick accuracy)
108 volatile ticks_t _clock;
111 #if CONFIG_TIMER_EVENTS
114 * List of active asynchronous timers.
116 REGISTER static List timers_queue;
119 * This function really does the job. It adds \a timer to \a queue.
120 * \see timer_add for details.
122 INLINE void timer_addToList(Timer *timer, List *queue)
124 /* Inserting timers twice causes mayhem. */
125 ASSERT(timer->magic != TIMER_MAGIC_ACTIVE);
126 DB(timer->magic = TIMER_MAGIC_ACTIVE;)
129 /* Calculate expiration time for this timer */
130 timer->tick = _clock + timer->_delay;
133 * Search for the first node whose expiration time is
134 * greater than the timer we want to add.
136 Timer *node = (Timer *)LIST_HEAD(queue);
137 while (node->link.succ)
140 * Stop just after the insertion point.
141 * (this fancy compare takes care of wrap-arounds).
143 if (node->tick - timer->tick > 0)
146 /* Go to next node */
147 node = (Timer *)node->link.succ;
150 /* Enqueue timer request into the list */
151 INSERT_BEFORE(&timer->link, &node->link);
155 * Add the specified timer to the software timer service queue.
156 * When the delay indicated by the timer expires, the timer
157 * device will execute the event associated with it.
159 * \note Interrupt safe
161 void timer_add(Timer *timer)
163 ATOMIC(timer_addToList(timer, &timers_queue));
167 * Remove a timer from the timers queue before it has expired.
169 * \note Attempting to remove a timer already expired cause
170 * undefined behaviour.
172 Timer *timer_abort(Timer *timer)
174 ATOMIC(REMOVE(&timer->link));
175 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
181 INLINE void timer_poll(List *queue)
186 * Check the first timer request in the list and process
187 * it when it has expired. Repeat this check until the
188 * first node has not yet expired. Since the list is sorted
189 * by expiry time, all the following requests are guaranteed
192 while ((timer = (Timer *)LIST_HEAD(queue))->link.succ)
194 /* This request in list has not yet expired? */
195 if (timer_clock() - timer->tick < 0)
198 /* Retreat the expired timer */
199 REMOVE(&timer->link);
200 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
202 /* Execute the associated event */
203 event_do(&timer->expire);
208 * Add \a timer to \a queue.
209 * \see synctimer_poll() for details.
211 void synctimer_add(Timer *timer, List *queue)
213 timer_addToList(timer, queue);
217 * Simple synchronous timer based scheduler polling routine.
219 * Sometimes you would like to have a proper scheduler,
220 * but you can't afford it due to memory constraints.
222 * This is a simple replacement: you can create events and call
223 * them periodically at specific time intervals.
224 * All you have to do is to set up normal timers, and call synctimer_add()
225 * instead of timer_add() to add the events to your specific queue.
226 * Then, in the main loop or wherever you want, you can call
227 * synctimer_poll() to process expired events. The associated callbacks will be
229 * As this is done synchronously you don't have to worry about race conditions.
230 * You can kill an event by simply calling synctimer_abort().
233 void synctimer_poll(List *queue)
238 #endif /* CONFIG_TIMER_EVENTS */
242 * Wait for the specified amount of timer ticks.
244 void timer_delayTicks(ticks_t delay)
246 /* We shouldn't sleep with interrupts disabled */
247 IRQ_ASSERT_ENABLED();
249 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
252 ASSERT(!sig_check(SIG_SINGLE));
253 timer_setSignal(&t, proc_current(), SIG_SINGLE);
254 timer_setDelay(&t, delay);
256 sig_wait(SIG_SINGLE);
258 #else /* !CONFIG_KERN_SIGNALS */
260 ticks_t start = timer_clock();
263 while (timer_clock() - start < delay)
266 #endif /* !CONFIG_KERN_SIGNALS */
270 #if CONFIG_TIMER_UDELAY
273 * Busy wait until the specified amount of high-precision ticks have elapsed.
275 * \note This function is interrupt safe, the only
276 * requirement is a running hardware timer.
278 void timer_busyWait(hptime_t delay)
280 hptime_t now, prev = timer_hw_hpread();
285 now = timer_hw_hpread();
287 * We rely on hptime_t being unsigned here to
288 * reduce the modulo to an AND in the common
289 * case of TIMER_HW_CNT.
291 delta = (now - prev) % TIMER_HW_CNT;
300 * Wait for the specified amount of time (expressed in microseconds).
302 * \bug In AVR arch the maximum amount of time that can be used as
303 * delay could be very limited, depending on the hardware timer
304 * used. Check timer_avr.h, and what register is used as hptime_t.
306 void timer_delayHp(hptime_t delay)
308 if (UNLIKELY(delay > us_to_hptime(1000)))
310 timer_delayTicks(delay / (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC));
311 delay %= (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC);
314 timer_busyWait(delay);
316 #endif /* CONFIG_TIMER_UDELAY */
320 * Timer interrupt handler. Find soft timers expired and
321 * trigger corresponding events.
326 * With the Metrowerks compiler, the only way to force the compiler generate
327 * an interrupt service routine is to put a pragma directive within the function
331 #pragma interrupt saveall
335 * On systems sharing IRQ line and vector, this check is needed
336 * to ensure that IRQ is generated by timer source.
338 if (!timer_hw_triggered())
343 /* Perform hw IRQ handling */
346 /* Update the master ms counter */
349 #if CONFIG_TIMER_EVENTS
350 timer_poll(&timers_queue);
361 void timer_init(void)
367 #if CONFIG_TIMER_EVENTS
368 LIST_INIT(&timers_queue);
381 #if (ARCH & ARCH_EMUL)
383 * Stop timer (only used by emulator)
385 void timer_cleanup(void)
391 // Hmmm... apparently, the demo app does not cleanup properly
392 //ASSERT(LIST_EMPTY(&timers_queue));
394 #endif /* ARCH_EMUL */