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