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 1.24 2005/04/11 19:10:28 bernie
18 *#* Include top-level headers from cfg/ subdir.
20 *#* Revision 1.23 2004/12/13 12:07:06 bernie
21 *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
23 *#* Revision 1.22 2004/12/08 09:12:09 bernie
24 *#* Rename time_t to mtime_t.
26 *#* Revision 1.21 2004/11/28 23:20:25 bernie
27 *#* Remove obsolete INITLIST macro.
29 *#* Revision 1.20 2004/11/16 20:59:06 bernie
30 *#* Add watchdog timer support.
32 *#* Revision 1.19 2004/10/19 08:56:49 bernie
33 *#* TIMER_STROBE_ON, TIMER_STROBE_OFF, TIMER_STROBE_INIT: Move from timer_avr.h to timer.h, where they really belong.
35 *#* Revision 1.18 2004/10/14 23:14:05 bernie
36 *#* Fix longstanding problem with wrap-arounds.
38 *#* Revision 1.17 2004/10/03 18:52:08 bernie
39 *#* Move \brief on top in header to please Doxygen.
41 *#* Revision 1.16 2004/10/03 18:48:01 bernie
42 *#* timer_delay(): Add a sanity check to avoid sleeping forever.
44 *#* Revision 1.15 2004/09/14 21:07:18 bernie
45 *#* Use debug.h instead of kdebug.h.
47 *#* Revision 1.14 2004/08/25 14:12:08 rasky
48 *#* Aggiornato il comment block dei log RCS
50 *#* Revision 1.13 2004/08/10 06:59:09 bernie
51 *#* timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
53 *#* Revision 1.12 2004/08/08 05:59:37 bernie
54 *#* Remove a few useless casts.
56 *#* Revision 1.11 2004/08/02 20:20:29 aleph
57 *#* Merge from project_ks
59 *#* Revision 1.10 2004/07/30 14:15:53 rasky
60 *#* Nuovo supporto unificato per detect della CPU
62 *#* Revision 1.9 2004/07/21 00:15:13 bernie
63 *#* Put timer driver on diet.
65 *#* Revision 1.8 2004/07/18 21:57:07 bernie
66 *#* Fix preprocessor warning with potentially undefined symbol.
68 *#* Revision 1.6 2004/06/07 18:10:06 aleph
69 *#* Remove free pool of timers; use user-provided Timer structure instead
71 *#* Revision 1.5 2004/06/07 15:56:55 aleph
72 *#* Some tabs cleanup and add timer strobe macros
74 *#* Revision 1.4 2004/06/06 18:25:44 bernie
75 *#* Rename event macros to look like regular functions.
77 *#* Revision 1.3 2004/06/06 17:18:42 bernie
78 *#* Fix \!CONFIG_KERN_SIGNALS code paths.
80 *#* Revision 1.2 2004/06/03 11:27:09 bernie
81 *#* Add dual-license information.
83 *#* Revision 1.1 2004/05/23 18:23:30 bernie
84 *#* Import drv/timer module.
91 #include CPU_HEADER(timer)
92 #include <cfg/debug.h>
93 #include <cfg/config.h>
96 * Sanity check for config parameters required by this module.
98 #if !defined(CONFIG_KERNEL) || ((CONFIG_KERNEL != 0) && CONFIG_KERNEL != 1)
99 #error CONFIG_KERNEL must be set to either 0 or 1 in config.h
101 #if !defined(CONFIG_WATCHDOG) || ((CONFIG_WATCHDOG != 0) && CONFIG_WATCHDOG != 1)
102 #error CONFIG_WATCHDOG must be set to either 0 or 1 in config.h
109 #if CONFIG_KERNEL && CONFIG_KERN_SIGNALS
110 #include <kern/proc.h>
115 * \def CONFIG_TIMER_STROBE
117 * This is a debug facility that can be used to
118 * monitor timer interrupt activity on an external pin.
120 * To use strobes, redefine the macros TIMER_STROBE_ON,
121 * TIMER_STROBE_OFF and TIMER_STROBE_INIT and set
122 * CONFIG_TIMER_STROBE to 1.
124 #if !defined(CONFIG_TIMER_STROBE) || !CONFIG_TIMER_STROBE
125 #define TIMER_STROBE_ON do {/*nop*/} while(0)
126 #define TIMER_STROBE_OFF do {/*nop*/} while(0)
127 #define TIMER_STROBE_INIT do {/*nop*/} while(0)
131 //! Master system clock (1ms accuracy)
132 volatile mtime_t _clock;
135 #ifndef CONFIG_TIMER_DISABLE_EVENTS
138 * List of active asynchronous timers.
140 REGISTER static List timers_queue;
144 * Add the specified timer to the software timer service queue.
145 * When the delay indicated by the timer expires, the timer
146 * device will execute the event associated with it.
148 * \note Interrupt safe
150 void timer_add(Timer *timer)
155 IRQ_SAVE_DISABLE(flags);
157 /* Calculate expiration time for this timer */
158 timer->tick = _clock + timer->delay;
161 * Search for the first node whose expiration time is
162 * greater than the timer we want to add.
164 node = (Timer *)timers_queue.head;
165 while (node->link.succ)
168 * Stop just after the insertion point.
169 * (this fancy compare takes care of wrap-arounds).
171 if (node->tick - timer->tick > 0)
174 /* Go to next node */
175 node = (Timer *)node->link.succ;
178 /* Enqueue timer request into the list */
179 INSERTBEFORE(&timer->link, &node->link);
186 * Remove a timer from the timer queue before it has expired.
188 Timer *timer_abort(Timer *timer)
190 ATOMIC(REMOVE(&timer->link));
195 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
199 * Wait for the specified amount of time (expressed in ms).
201 void timer_delay(mtime_t time)
203 #if defined(IRQ_GETSTATE)
204 /* We shouldn't sleep with interrupts disabled */
205 ASSERT(IRQ_GETSTATE());
208 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
211 ASSERT(!sig_check(SIG_SINGLE));
212 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
213 timer_set_delay(&t, time);
215 sig_wait(SIG_SINGLE);
217 #else /* !CONFIG_KERN_SIGNALS */
219 mtime_t start = timer_ticks();
222 while (timer_ticks() - start < time)
229 #endif /* !CONFIG_KERN_SIGNALS */
233 #ifndef CONFIG_TIMER_DISABLE_UDELAY
235 * Wait for the specified amount of time (expressed in microseconds).
237 * \bug In AVR arch the maximum amount of time that can be used as
238 * delay could be very limited, depending on the hardware timer
239 * used. Check timer_avr.h, and what register is used as hptime_t.
241 void timer_udelay(utime_t usec_delay)
243 if (UNLIKELY(usec_delay > 1000))
245 timer_delay(usec_delay / 1000);
249 // FIXME: This multiplication is too slow at run-time. We should try and move it
250 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
252 hptime_t start = timer_hw_hpread();
253 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
255 while (timer_hw_hpread() - start < delay)
258 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
262 * Timer interrupt handler. Find soft timers expired and
263 * trigger corresponding events.
268 * With the Metrowerks compiler, the only way to force the compiler generate
269 * an interrupt service routine is to put a pragma directive within the function
273 #pragma interrupt saveall
276 #ifndef CONFIG_TIMER_DISABLE_EVENTS
284 /* Update the master ms counter */
287 #ifndef CONFIG_TIMER_DISABLE_EVENTS
289 * Check the first timer request in the list and process
290 * it when it has expired. Repeat this check until the
291 * first node has not yet expired. Since the list is sorted
292 * by expiry time, all the following requests are guaranteed
295 while ((timer = (Timer *)timers_queue.head)->link.succ)
297 /* This request in list has not yet expired? */
298 if (_clock < timer->tick)
301 /* Retreat the expired timer */
302 REMOVE(&timer->link);
304 /* Execute the associated event */
305 event_do(&timer->expire);
307 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
316 void timer_init(void)
320 #ifndef CONFIG_TIMER_DISABLE_EVENTS
321 LIST_INIT(&timers_queue);