firmware/timer.c

   1 /***************************************************************************
   2 *             __________               __   ___.
   3 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7 *                     \/            \/     \/    \/            \/
   8 * $Id$
   9 *
  10 * Copyright (C) 2005 Jens Arnold
  11 *
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License
  14 * as published by the Free Software Foundation; either version 2
  15 * of the License, or (at your option) any later version.
  16 *
  17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18 * KIND, either express or implied.
  19 *
  20 ****************************************************************************/
  21
  22 #include <stdbool.h>
  23 #include "config.h"
  24 #include "cpu.h"
  25 #include "system.h"
  26 #include "timer.h"
  27 #include "logf.h"
  28
  29 static int timer_prio = -1;
  30 void SHAREDBSS_ATTR (*pfn_timer)(void) = NULL;      /* timer callback */
  31 void SHAREDBSS_ATTR (*pfn_unregister)(void) = NULL; /* unregister callback */
  32
  33 /* Register a user timer, called every <cycles> TIMER_FREQ cycles */
  34 bool timer_register(int reg_prio, void (*unregister_callback)(void),
  35                     long cycles, void (*timer_callback)(void)
  36                     IF_COP(, int core))
  37 {
  38     if (reg_prio <= timer_prio || cycles == 0)
  39         return false;
  40
  41     if (!timer_set(cycles, true))
  42         return false;
  43
  44     pfn_timer = timer_callback;
  45     pfn_unregister = unregister_callback;
  46     timer_prio = reg_prio;
  47
  48     return timer_start(IF_COP(core));
  49 }
  50
  51 bool timer_set_period(long cycles)
  52 {
  53     return timer_set(cycles, false);
  54 }
  55
  56 void timer_unregister(void)
  57 {
  58     timer_stop();
  59
  60     pfn_timer = NULL;
  61     pfn_unregister = NULL;
  62     timer_prio = -1;
  63 }
  64