drivers/char/joystick/gameport.c

   1 /*
   2  * $Id: gameport.c,v 1.5 2000/05/29 10:54:53 vojtech Exp $
   3  *
   4  *  Copyright (c) 1999-2000 Vojtech Pavlik
   5  *
   6  *  Sponsored by SuSE
   7  */
   8
   9 /*
  10  * Generic gameport layer
  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@suse.cz>, or by paper mail:
  30  * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
  31  */
  32
  33 #include <asm/io.h>
  34 #include <linux/module.h>
  35 #include <linux/ioport.h>
  36 #include <linux/init.h>
  37 #include <linux/gameport.h>
  38 #include <linux/malloc.h>
  39 #include <linux/isapnp.h>
  40 #include <linux/stddef.h>
  41 #include <linux/module.h>
  42 #include <linux/gameport.h>
  43 #include <linux/delay.h>
  44
  45 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  46
  47 EXPORT_SYMBOL(gameport_register_port);
  48 EXPORT_SYMBOL(gameport_unregister_port);
  49 EXPORT_SYMBOL(gameport_register_device);
  50 EXPORT_SYMBOL(gameport_unregister_device);
  51 EXPORT_SYMBOL(gameport_open);
  52 EXPORT_SYMBOL(gameport_close);
  53 EXPORT_SYMBOL(gameport_rescan);
  54 EXPORT_SYMBOL(gameport_cooked_read);
  55
  56 static struct gameport *gameport_list = NULL;
  57 static struct gameport_dev *gameport_dev = NULL;
  58 static int gameport_number = 0;
  59
  60 /*
  61  * gameport_measure_speed() measures the gameport i/o speed.
  62  */
  63
  64 static int gameport_measure_speed(struct gameport *gameport)
  65 {
  66 #ifdef __i386__
  67
  68 #define GET_TIME(x)     do { outb(0, 0x43); x = inb(0x40); x |= inb(0x40) << 8; } while (0)
  69 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193180L/HZ:0))
  70
  71         unsigned int i, t, t1, t2, t3, tx;
  72         unsigned long flags;
  73
  74         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
  75                 return 0;
  76
  77         tx = 1 << 30;
  78
  79         for(i = 0; i < 50; i++) {
  80                 save_flags(flags);      /* Yes, all CPUs */
  81                 cli();
  82                 GET_TIME(t1);
  83                 for(t = 0; t < 50; t++) gameport_read(gameport);
  84                 GET_TIME(t2);
  85                 GET_TIME(t3);
  86                 restore_flags(flags);
  87                 udelay(i * 10);
  88                 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
  89         }
  90
  91         return 59659 / (tx < 1 ? 1 : tx);
  92
  93 #else
  94
  95         unsigned int j, t = 0;
  96
  97         j = jiffies; while (j == jiffies);
  98         j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
  99
 100         return t * HZ / 1000;
 101
 102 #endif
 103
 104         gameport_close(gameport);
 105 }
 106
 107 static void gameport_find_dev(struct gameport *gameport)
 108 {
 109         struct gameport_dev *dev = gameport_dev;
 110
 111         while (dev && !gameport->dev) {
 112                 if (dev->connect)
 113                         dev->connect(gameport, dev);
 114                 dev = dev->next;
 115         }
 116 }
 117
 118 void gameport_rescan(struct gameport *gameport)
 119 {
 120         gameport_close(gameport);
 121         gameport_find_dev(gameport);
 122 }
 123
 124 void gameport_register_port(struct gameport *gameport)
 125 {
 126         gameport->number = gameport_number++;
 127         gameport->next = gameport_list;
 128         gameport_list = gameport;
 129
 130         gameport->speed = gameport_measure_speed(gameport);
 131
 132         gameport_find_dev(gameport);
 133 }
 134
 135 void gameport_unregister_port(struct gameport *gameport)
 136 {
 137         struct gameport **gameportptr = &gameport_list;
 138
 139         while (*gameportptr && (*gameportptr != gameport)) gameportptr = &((*gameportptr)->next);
 140         *gameportptr = (*gameportptr)->next;
 141
 142         if (gameport->dev && gameport->dev->disconnect)
 143                 gameport->dev->disconnect(gameport);
 144
 145         gameport_number--;
 146 }
 147
 148 void gameport_register_device(struct gameport_dev *dev)
 149 {
 150         struct gameport *gameport = gameport_list;
 151
 152         dev->next = gameport_dev;
 153         gameport_dev = dev;
 154
 155         while (gameport) {
 156                 if (!gameport->dev && dev->connect)
 157                         dev->connect(gameport, dev);
 158                 gameport = gameport->next;
 159         }
 160 }
 161
 162 void gameport_unregister_device(struct gameport_dev *dev)
 163 {
 164         struct gameport_dev **devptr = &gameport_dev;
 165         struct gameport *gameport = gameport_list;
 166
 167         while (*devptr && (*devptr != dev)) devptr = &((*devptr)->next);
 168         *devptr = (*devptr)->next;
 169
 170         while (gameport) {
 171                 if (gameport->dev == dev && dev->disconnect)
 172                         dev->disconnect(gameport);
 173                 gameport_find_dev(gameport);
 174                 gameport = gameport->next;
 175         }
 176 }
 177
 178 int gameport_open(struct gameport *gameport, struct gameport_dev *dev, int mode)
 179 {
 180         if (gameport->open) {
 181                 if (gameport->open(gameport, mode))
 182                         return -1;
 183         } else {
 184                 if (mode != GAMEPORT_MODE_RAW)
 185                         return -1;
 186         }
 187
 188         if (gameport->dev)
 189                 return -1;
 190
 191         gameport->dev = dev;
 192
 193         return 0;
 194 }
 195
 196 void gameport_close(struct gameport *gameport)
 197 {
 198         gameport->dev = NULL;
 199         if (gameport->close) gameport->close(gameport);
 200 }