drivers/char/joystick/serio.c

   1 /*
   2  * $Id: serio.c,v 1.5 2000/06/04 17:44:59 vojtech Exp $
   3  *
   4  *  Copyright (c) 1999-2000 Vojtech Pavlik
   5  *
   6  *  Sponsored by SuSE
   7  */
   8
   9 /*
  10  *  The Serio abstraction module
  11  */
  12
  13 /*
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  27  *
  28  * Should you need to contact me, the author, you can do so either by
  29  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
  30  * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
  31  */
  32
  33 #include <linux/stddef.h>
  34 #include <linux/module.h>
  35 #include <linux/serio.h>
  36
  37 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  38
  39 EXPORT_SYMBOL(serio_register_port);
  40 EXPORT_SYMBOL(serio_unregister_port);
  41 EXPORT_SYMBOL(serio_register_device);
  42 EXPORT_SYMBOL(serio_unregister_device);
  43 EXPORT_SYMBOL(serio_open);
  44 EXPORT_SYMBOL(serio_close);
  45 EXPORT_SYMBOL(serio_rescan);
  46
  47 static struct serio *serio_list = NULL;
  48 static struct serio_dev *serio_dev = NULL;
  49 static int serio_number = 0;
  50
  51 static void serio_find_dev(struct serio *serio)
  52 {
  53         struct serio_dev *dev = serio_dev;
  54
  55         while (dev && !serio->dev) {
  56                 if (dev->connect)
  57                         dev->connect(serio, dev);
  58                 dev = dev->next;
  59         }
  60 }
  61
  62 void serio_rescan(struct serio *serio)
  63 {
  64         if (serio->dev && serio->dev->disconnect)
  65                 serio->dev->disconnect(serio);
  66         serio_find_dev(serio);
  67 }
  68
  69 void serio_register_port(struct serio *serio)
  70 {
  71         MOD_INC_USE_COUNT;
  72
  73         serio->number = serio_number++;
  74         serio->next = serio_list;
  75         serio_list = serio;
  76
  77         serio_find_dev(serio);
  78 }
  79
  80 void serio_unregister_port(struct serio *serio)
  81 {
  82         struct serio **serioptr = &serio_list;
  83
  84         while (*serioptr && (*serioptr != serio)) serioptr = &((*serioptr)->next);
  85         *serioptr = (*serioptr)->next;
  86
  87         if (serio->dev && serio->dev->disconnect)
  88                 serio->dev->disconnect(serio);
  89
  90         serio_number--;
  91
  92         MOD_DEC_USE_COUNT;
  93 }
  94
  95 void serio_register_device(struct serio_dev *dev)
  96 {
  97         struct serio *serio = serio_list;
  98
  99         MOD_INC_USE_COUNT;
 100
 101         dev->next = serio_dev;
 102         serio_dev = dev;
 103
 104         while (serio) {
 105                 if (!serio->dev && dev->connect)
 106                         dev->connect(serio, dev);
 107                 serio = serio->next;
 108         }
 109 }
 110
 111 void serio_unregister_device(struct serio_dev *dev)
 112 {
 113         struct serio_dev **devptr = &serio_dev;
 114         struct serio *serio = serio_list;
 115
 116         while (*devptr && (*devptr != dev)) devptr = &((*devptr)->next);
 117         *devptr = (*devptr)->next;
 118
 119         while (serio) {
 120                 if (serio->dev == dev && dev->disconnect)
 121                         dev->disconnect(serio);
 122                 serio_find_dev(serio);
 123                 serio = serio->next;
 124         }
 125
 126         MOD_DEC_USE_COUNT;
 127 }
 128
 129 int serio_open(struct serio *serio, struct serio_dev *dev)
 130 {
 131         MOD_INC_USE_COUNT;
 132         if (serio->open(serio)) {
 133                 MOD_DEC_USE_COUNT;
 134                 return -1;
 135         }
 136         serio->dev = dev;
 137
 138         return 0;
 139 }
 140
 141 void serio_close(struct serio *serio)
 142 {
 143         MOD_DEC_USE_COUNT;
 144         serio->close(serio);
 145         serio->dev = NULL;
 146 }