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.
11 * \author Bernardo Innocenti <bernie@develer.com>
13 * \brief Hardware independent timer driver (implementation)
18 * Revision 1.13 2004/08/10 06:59:09 bernie
19 * timer_gettick(): Rename to timer_ticks() and add backwards compatibility inline.
21 * Revision 1.12 2004/08/08 05:59:37 bernie
22 * Remove a few useless casts.
24 * Revision 1.11 2004/08/02 20:20:29 aleph
25 * Merge from project_ks
27 * Revision 1.10 2004/07/30 14:15:53 rasky
28 * Nuovo supporto unificato per detect della CPU
30 * Revision 1.9 2004/07/21 00:15:13 bernie
31 * Put timer driver on diet.
33 * Revision 1.8 2004/07/18 21:57:07 bernie
34 * Fix preprocessor warning with potentially undefined symbol.
36 * Revision 1.6 2004/06/07 18:10:06 aleph
37 * Remove free pool of timers; use user-provided Timer structure instead
39 * Revision 1.5 2004/06/07 15:56:55 aleph
40 * Some tabs cleanup and add timer strobe macros
42 * Revision 1.4 2004/06/06 18:25:44 bernie
43 * Rename event macros to look like regular functions.
45 * Revision 1.3 2004/06/06 17:18:42 bernie
46 * Fix \!CONFIG_KERN_SIGNALS code paths.
48 * Revision 1.2 2004/06/03 11:27:09 bernie
49 * Add dual-license information.
51 * Revision 1.1 2004/05/23 18:23:30 bernie
52 * Import drv/timer module.
59 #include CPU_HEADER(timer)
61 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
62 #include <kern/proc.h>
65 //! Master system clock (1ms accuracy)
66 volatile time_t _clock;
69 #ifndef CONFIG_TIMER_DISABLE_EVENTS
72 * List of active asynchronous timers.
74 REGISTER static List timers_queue;
78 * Add the specified timer to the software timer service queue.
79 * When the delay indicated by the timer expires, the timer
80 * device will execute the event associated with it.
82 * \note Interrupt safe
84 void timer_add(Timer *timer)
89 DISABLE_IRQSAVE(flags);
91 /* Calculate expiration time for this timer */
92 timer->tick = _clock + timer->delay;
94 /* Search for the first node whose expiration time is
95 * greater than the timer we want to add.
97 node = (Timer *)timers_queue.head;
98 while (node->link.succ)
100 /* Stop just after the insertion point */
101 if (node->tick > timer->tick)
104 /* Go to next node */
105 node = (Timer *)node->link.succ;
108 /* Enqueue timer request into the list */
109 INSERTBEFORE(&timer->link, &node->link);
111 ENABLE_IRQRESTORE(flags);
116 * Remove a timer from the timer queue before it has expired
118 Timer *timer_abort(Timer *timer)
121 DISABLE_IRQSAVE(flags);
122 REMOVE(&timer->link);
123 ENABLE_IRQRESTORE(flags);
128 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
132 * Wait for the specified amount of time (expressed in ms)
134 void timer_delay(time_t time)
136 #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
139 ASSERT(!sig_check(SIG_SINGLE));
140 timer_set_event_signal(&t, proc_current(), SIG_SINGLE);
141 timer_set_delay(&t, time);
143 sig_wait(SIG_SINGLE);
145 #else /* !CONFIG_KERN_SIGNALS */
147 time_t start = timer_ticks();
150 while (timer_ticks() - start < time) { /* nop */ }
152 #endif /* !CONFIG_KERN_SIGNALS */
156 #ifndef CONFIG_TIMER_DISABLE_UDELAY
158 * Wait for the specified amount of time (expressed in microseconds)
160 * \bug In AVR arch the maximum amount of time that can be used as
161 * delay could be very limited, depending on the hardware timer
162 * used. Check timer_avr.h, and what register is used as hptime_t.
164 void timer_udelay(utime_t usec_delay)
166 if (UNLIKELY(usec_delay > 1000))
168 timer_delay(usec_delay / 1000);
172 // FIXME: This multiplication is too slow at run-time. We should try and move it
173 // to compile-time by exposing the TIMER_HW_HPTICKS_PER_SEC in the header
175 hptime_t start = timer_hw_hpread();
176 hptime_t delay = (uint32_t)usec_delay * TIMER_HW_HPTICKS_PER_SEC / 1000000ul;
178 while (timer_hw_hpread() - start < delay)
181 #endif /* CONFIG_TIMER_DISABLE_UDELAY */
185 * Timer interrupt handler. Find soft timers expired and
186 * trigger corresponding events.
191 * With the Metrowerks compiler, the only way to force the compiler generate
192 * an interrupt service routine is to put a pragma directive within the function
196 #pragma interrupt saveall
199 #ifndef CONFIG_TIMER_DISABLE_EVENTS
207 /* Update the master ms counter */
210 #ifndef CONFIG_TIMER_DISABLE_EVENTS
212 * Check the first timer request in the list and process
213 * it when it has expired. Repeat this check until the
214 * first node has not yet expired. Since the list is sorted
215 * by expiry time, all the following requests are guaranteed
218 while ((timer = (Timer *)timers_queue.head)->link.succ)
220 /* This request in list has not yet expired? */
221 if (_clock < timer->tick)
224 /* Retreat the expired timer */
225 REMOVE(&timer->link);
227 /* Execute the associated event */
228 event_do(&timer->expire);
230 #endif /* CONFIG_TIMER_DISABLE_EVENTS */
239 void timer_init(void)
243 #ifndef CONFIG_TIMER_DISABLE_EVENTS
244 INITLIST(&timers_queue);