4 * Copyright 2003, 2004, 2005, 2006 Develer S.r.l. (http://www.develer.com/)
5 * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
6 * This file is part of DevLib - See README.devlib for information.
9 * \brief Hardware independent timer driver (implementation)
12 * \author Bernardo Innocenti <bernie@develer.com>
17 *#* Revision 1.30 2006/02/24 00:26:49 bernie
18 *#* Fixes for CONFIG_KERNEL.
20 *#* Revision 1.29 2006/02/17 22:24:07 bernie
21 *#* Add MOD_CHECK() checks.
23 *#* Revision 1.28 2006/02/10 12:32:52 bernie
24 *#* Update Copyright year.
26 *#* Revision 1.27 2005/11/27 03:04:08 bernie
27 *#* Move test code to timer_test.c; Add OS_HOSTED support.
29 *#* Revision 1.26 2005/11/04 16:20:02 bernie
30 *#* Fix reference to README.devlib in header.
32 *#* Revision 1.25 2005/07/19 07:26:37 bernie
33 *#* Refactor to decouple timer ticks from milliseconds.
35 *#* Revision 1.24 2005/04/11 19:10:28 bernie
36 *#* Include top-level headers from cfg/ subdir.
38 *#* Revision 1.23 2004/12/13 12:07:06 bernie
39 *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
41 *#* Revision 1.22 2004/12/08 09:12:09 bernie
42 *#* Rename time_t to mtime_t.
44 *#* Revision 1.21 2004/11/28 23:20:25 bernie
45 *#* Remove obsolete INITLIST macro.
47 *#* Revision 1.20 2004/11/16 20:59:06 bernie
48 *#* Add watchdog timer support.
54 #include <cfg/debug.h>
55 #include <cfg/module.h>
56 #include <appconfig.h>
59 * Include platform-specific binding code if we're hosted.
60 * Try the CPU specific one for bare-metal environments.
63 #include OS_CSOURCE(timer)
65 #include CPU_CSOURCE(timer)
69 * Sanity check for config parameters required by this module.
71 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
72 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
74 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
75 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
83 #include <config_kern.h>
84 #if CONFIG_KERN_SIGNALS
85 #include <kern/signal.h> /* sig_wait(), sig_check() */
86 #include <kern/proc.h> /* proc_current() */
87 #include <cfg/macros.h> /* BV() */
93 * \def CONFIG_TIMER_STROBE
95 * This is a debug facility that can be used to
96 * monitor timer interrupt activity on an external pin.
98 * To use strobes, redefine the macros TIMER_STROBE_ON,
99 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
100 * CONFIG_TIMER_STROBE to 1.
102 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
103 #define TIMER_STROBE_ON do {/*nop*/} while(0)
104 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
105 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
109 //! Master system clock (1 tick accuracy)
110 volatile ticks_t _clock;
113 #ifndef CONFIG_TIMER_DISABLE_EVENTS
116 * List of active asynchronous timers.
118 REGISTER static List timers_queue;
122 * Add the specified timer to the software timer service queue.
123 * When the delay indicated by the timer expires, the timer
124 * device will execute the event associated with it.
126 * \note Interrupt safe
128 void timer_add(Timer *timer)
134 /* Inserting timers twice causes mayhem. */
135 ASSERT(timer->magic != TIMER_MAGIC_ACTIVE);
136 DB(timer->magic = TIMER_MAGIC_ACTIVE;)
138 IRQ_SAVE_DISABLE(flags);
140 /* Calculate expiration time for this timer */
141 timer->tick = _clock + timer->_delay;
144 * Search for the first node whose expiration time is
145 * greater than the timer we want to add.
147 node = (Timer *)LIST_HEAD(&timers_queue);
148 while (node->link.succ)
151 * Stop just after the insertion point.
152 * (this fancy compare takes care of wrap-arounds).
154 if (node->tick - timer->tick > 0)
157 /* Go to next node */
158 node = (Timer *)node->link.succ;
161 /* Enqueue timer request into the list */
162 INSERT_BEFORE(&timer->link, &node->link);
169 * Remove a timer from the timer queue before it has expired.
171 Timer *timer_abort(Timer *timer)
173 ATOMIC(REMOVE(&timer->link));
174 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
179 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
183 * Wait for the specified amount of timer ticks.
185 void timer_delayTicks(ticks_t delay)
187 #if defined(IRQ_GETSTATE)
188 /* We shouldn't sleep with interrupts disabled */
189 ASSERT(IRQ_GETSTATE());
192 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
195 ASSERT(!sig_check(SIG_SINGLE));
196 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
197 timer_setDelay(&t, delay);
199 sig_wait(SIG_SINGLE);
201 #else /* !CONFIG_KERN_SIGNALS */
203 ticks_t start = timer_clock();
206 while (timer_clock() - start < delay)
213 #endif /* !CONFIG_KERN_SIGNALS */
217 #ifndef CONFIG_TIMER_DISABLE_UDELAY
220 * Busy wait until the specified amount of high-precision ticks have elapsed.
222 * \note This function is interrupt safe, the only
223 * requirement is a running hardware timer.
225 void timer_busyWait(hptime_t delay)
227 hptime_t now, prev = timer_hw_hpread();
232 now = timer_hw_hpread();
234 * We rely on hptime_t being unsigned here to
235 * reduce the modulo to an AND in the common
236 * case of TIMER_HW_CNT.
238 delta = (now - prev) % TIMER_HW_CNT;
247 * Wait for the specified amount of time (expressed in microseconds).
249 * \bug In AVR arch the maximum amount of time that can be used as
250 * delay could be very limited, depending on the hardware timer
251 * used. Check timer_avr.h, and what register is used as hptime_t.
253 void timer_delayHp(hptime_t delay)
255 if (UNLIKELY(delay > us_to_hptime(1000)))
257 timer_delayTicks(delay / (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC));
258 delay %= (TIMER_HW_HPTICKS_PER_SEC / TIMER_TICKS_PER_SEC);
261 timer_busyWait(delay);
263 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
267 * Timer interrupt handler. Find soft timers expired and
268 * trigger corresponding events.
273 * With the Metrowerks compiler, the only way to force the compiler generate
274 * an interrupt service routine is to put a pragma directive within the function
278 #pragma interrupt saveall
281 #ifndef CONFIG_TIMER_DISABLE_EVENTS
289 /* Update the master ms counter */
292 #ifndef CONFIG_TIMER_DISABLE_EVENTS
294 * Check the first timer request in the list and process
295 * it when it has expired. Repeat this check until the
296 * first node has not yet expired. Since the list is sorted
297 * by expiry time, all the following requests are guaranteed
300 while ((timer = (Timer *)LIST_HEAD(&timers_queue))->link.succ)
302 /* This request in list has not yet expired? */
303 if (_clock - timer->tick < 0)
306 /* Retreat the expired timer */
307 REMOVE(&timer->link);
308 DB(timer->magic = TIMER_MAGIC_INACTIVE;)
310 /* Execute the associated event */
311 event_do(&timer->expire);
313 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
323 void timer_init(void)
327 #ifndef CONFIG_TIMER_DISABLE_EVENTS
328 LIST_INIT(&timers_queue);