firmware/events.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Miika Pekkarinen
  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 <stdio.h>
  23 #include "events.h"
  24 #include "panic.h"
  25
  26 #define MAX_SYS_EVENTS 16
  27
  28 struct sysevent {
  29     unsigned short id;
  30     bool oneshot;
  31     void (*callback)(void *data);
  32 };
  33
  34 static struct sysevent events[MAX_SYS_EVENTS];
  35
  36 bool add_event(unsigned short id, bool oneshot, void (*handler))
  37 {
  38     int i;
  39
  40     /* Check if the event already exists. */
  41     for (i = 0; i < MAX_SYS_EVENTS; i++)
  42     {
  43         if (events[i].callback == handler && events[i].id == id)
  44             return false;
  45     }
  46
  47     /* Try to find a free slot. */
  48     for (i = 0; i < MAX_SYS_EVENTS; i++)
  49     {
  50         if (events[i].callback == NULL)
  51         {
  52             events[i].id = id;
  53             events[i].oneshot = oneshot;
  54             events[i].callback = handler;
  55             return true;
  56         }
  57     }
  58
  59     panicf("event line full");
  60     return false;
  61 }
  62
  63 void remove_event(unsigned short id, void (*handler))
  64 {
  65     int i;
  66
  67     for (i = 0; i < MAX_SYS_EVENTS; i++)
  68     {
  69         if (events[i].id == id && events[i].callback == handler)
  70         {
  71             events[i].callback = NULL;
  72             return;
  73         }
  74     }
  75 }
  76
  77 void send_event(unsigned short id, void *data)
  78 {
  79     int i;
  80
  81     for (i = 0; i < MAX_SYS_EVENTS; i++)
  82     {
  83         if (events[i].id == id && events[i].callback != NULL)
  84         {
  85             events[i].callback(data);
  86
  87             if (events[i].oneshot)
  88                 events[i].callback = NULL;
  89         }
  90     }
  91 }
  92