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>
43 #include <cfg/debug.h>
44 #include <cfg/module.h>
45 #include <appconfig.h>
48 * Include platform-specific binding code if we're hosted.
49 * Try the CPU specific one for bare-metal environments.
52 #include OS_CSOURCE(timer)
54 #include CPU_CSOURCE(timer)
58 * Sanity check for config parameters required by this module.
60 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
61 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
63 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
64 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
72 #include <config_kern.h>
73 #if CONFIG_KERN_SIGNALS
74 #include <kern/signal.h> /* sig_wait(), sig_check() */
75 #include <kern/proc.h> /* proc_current() */
76 #include <cfg/macros.h> /* BV() */
82 * \def CONFIG_TIMER_STROBE
84 * This is a debug facility that can be used to
85 * monitor timer interrupt activity on an external pin.
87 * To use strobes, redefine the macros TIMER_STROBE_ON,
88 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
89 * CONFIG_TIMER_STROBE to 1.
91 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
92 #define TIMER_STROBE_ON do {/*nop*/} while(0)
93 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
94 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
98 /// Master system clock (1 tick accuracy)
99 volatile ticks_t _clock;
102 #ifndef CONFIG_TIMER_DISABLE_EVENTS
105 * List of active asynchronous timers.
107 REGISTER static List timers_queue;
111 * Add the specified timer to the software timer service queue.
112 * When the delay indicated by the timer expires, the timer
113 * device will execute the event associated with it.
115 * \note Interrupt safe
117 void timer_add(Timer *timer)
123 /* Inserting timers twice causes mayhem. */
124 ASSERT(timer->magic != TIMER_MAGIC_ACTIVE);
125 DB(timer->magic = TIMER_MAGIC_ACTIVE;)
127 IRQ_SAVE_DISABLE(flags);
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 node = (Timer *)LIST_HEAD(&timers_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);
158 * Remove a timer from the timer queue before it has expired.
160 Timer *timer_abort(Timer *timer)
162 ATOMIC(REMOVE(&timer->link));
163 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
168 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
172 * Wait for the specified amount of timer ticks.
174 void timer_delayTicks(ticks_t delay)
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_setDelay(&t, delay);
188 sig_wait(SIG_SINGLE);
190 #else /* !CONFIG_KERN_SIGNALS */
192 ticks_t start = timer_clock();
195 while (timer_clock() - start < delay)
202 #endif /* !CONFIG_KERN_SIGNALS */
206 #ifndef CONFIG_TIMER_DISABLE_UDELAY
209 * Busy wait until the specified amount of high-precision ticks have elapsed.
211 * \note This function is interrupt safe, the only
212 * requirement is a running hardware timer.
214 void timer_busyWait(hptime_t delay)
216 hptime_t now, prev = timer_hw_hpread();
221 now = timer_hw_hpread();
223 * We rely on hptime_t being unsigned here to
224 * reduce the modulo to an AND in the common
225 * case of TIMER_HW_CNT.
227 delta = (now - prev) % TIMER_HW_CNT;
236 * Wait for the specified amount of time (expressed in microseconds).
238 * \bug In AVR arch the maximum amount of time that can be used as
239 * delay could be very limited, depending on the hardware timer
240 * used. Check timer_avr.h, and what register is used as hptime_t.
242 void timer_delayHp(hptime_t delay)
244 if (UNLIKELY(delay > us_to_hptime(1000)))
246 timer_delayTicks(delay / (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC));
247 delay %= (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC);
250 timer_busyWait(delay);
252 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
256 * Timer interrupt handler. Find soft timers expired and
257 * trigger corresponding events.
262 * With the Metrowerks compiler, the only way to force the compiler generate
263 * an interrupt service routine is to put a pragma directive within the function
267 #pragma interrupt saveall
270 #ifndef CONFIG_TIMER_DISABLE_EVENTS
274 * On systems sharing IRQ line and vector, this check is needed
275 * to ensure that IRQ is generated by timer source.
277 if (!timer_hw_triggered())
282 /* Perform hw IRQ handling */
285 /* Update the master ms counter */
288 #ifndef CONFIG_TIMER_DISABLE_EVENTS
290 * Check the first timer request in the list and process
291 * it when it has expired. Repeat this check until the
292 * first node has not yet expired. Since the list is sorted
293 * by expiry time, all the following requests are guaranteed
296 while ((timer = (Timer *)LIST_HEAD(&timers_queue))->link.succ)
298 /* This request in list has not yet expired? */
299 if (_clock - timer->tick < 0)
302 /* Retreat the expired timer */
303 REMOVE(&timer->link);
304 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
306 /* Execute the associated event */
307 event_do(&timer->expire);
309 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
319 void timer_init(void)
323 #ifndef CONFIG_TIMER_DISABLE_EVENTS
324 LIST_INIT(&timers_queue);