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  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include <stdio.h>
  21 #include "events.h"
  22 #include "panic.h"
  23
  24 #define MAX_SYS_EVENTS 16
  25
  26 struct sysevent {
  27     unsigned short id;
  28     bool oneshot;
  29     void (*callback)(void *data);
  30 };
  31
  32 static struct sysevent events[MAX_SYS_EVENTS];
  33
  34 bool add_event(unsigned short id, bool oneshot, void (*handler))
  35 {
  36     int i;
  37
  38     /* Check if the event already exists. */
  39     for (i = 0; i < MAX_SYS_EVENTS; i++)
  40     {
  41         if (events[i].callback == handler && events[i].id == id)
  42             return false;
  43     }
  44
  45     /* Try to find a free slot. */
  46     for (i = 0; i < MAX_SYS_EVENTS; i++)
  47     {
  48         if (events[i].callback == NULL)
  49         {
  50             events[i].id = id;
  51             events[i].oneshot = oneshot;
  52             events[i].callback = handler;
  53             return true;
  54         }
  55     }
  56
  57     panicf("event line full");
  58     return false;
  59 }
  60
  61 void remove_event(unsigned short id, void (*handler))
  62 {
  63     int i;
  64
  65     for (i = 0; i < MAX_SYS_EVENTS; i++)
  66     {
  67         if (events[i].id == id && events[i].callback == handler)
  68         {
  69             events[i].callback = NULL;
  70             return;
  71         }
  72     }
  73
  74     panicf("event %d not found", (int)id);
  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