drivers/input/gameport/gameport.c

   1 /*
   2  * Generic gameport layer
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  * Copyright (c) 2005 Dmitry Torokhov
   6  */
   7
   8 /*
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License version 2 as published by
  11  * the Free Software Foundation.
  12  */
  13
  14 #include <linux/stddef.h>
  15 #include <linux/module.h>
  16 #include <linux/ioport.h>
  17 #include <linux/init.h>
  18 #include <linux/gameport.h>
  19 #include <linux/wait.h>
  20 #include <linux/completion.h>
  21 #include <linux/sched.h>
  22 #include <linux/smp_lock.h>
  23 #include <linux/slab.h>
  24 #include <linux/delay.h>
  25
  26 /*#include <asm/io.h>*/
  27
  28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  29 MODULE_DESCRIPTION("Generic gameport layer");
  30 MODULE_LICENSE("GPL");
  31
  32 EXPORT_SYMBOL(__gameport_register_port);
  33 EXPORT_SYMBOL(gameport_unregister_port);
  34 EXPORT_SYMBOL(__gameport_register_driver);
  35 EXPORT_SYMBOL(gameport_unregister_driver);
  36 EXPORT_SYMBOL(gameport_open);
  37 EXPORT_SYMBOL(gameport_close);
  38 EXPORT_SYMBOL(gameport_rescan);
  39 EXPORT_SYMBOL(gameport_cooked_read);
  40 EXPORT_SYMBOL(gameport_set_name);
  41 EXPORT_SYMBOL(gameport_set_phys);
  42 EXPORT_SYMBOL(gameport_start_polling);
  43 EXPORT_SYMBOL(gameport_stop_polling);
  44
  45 /*
  46  * gameport_sem protects entire gameport subsystem and is taken
  47  * every time gameport port or driver registrered or unregistered.
  48  */
  49 static DECLARE_MUTEX(gameport_sem);
  50
  51 static LIST_HEAD(gameport_list);
  52
  53 static struct bus_type gameport_bus = {
  54         .name = "gameport",
  55 };
  56
  57 static void gameport_add_port(struct gameport *gameport);
  58 static void gameport_destroy_port(struct gameport *gameport);
  59 static void gameport_reconnect_port(struct gameport *gameport);
  60 static void gameport_disconnect_port(struct gameport *gameport);
  61
  62 #if defined(__i386__)
  63
  64 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
  65 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
  66
  67 static unsigned int get_time_pit(void)
  68 {
  69         extern spinlock_t i8253_lock;
  70         unsigned long flags;
  71         unsigned int count;
  72
  73         spin_lock_irqsave(&i8253_lock, flags);
  74         outb_p(0x00, 0x43);
  75         count = inb_p(0x40);
  76         count |= inb_p(0x40) << 8;
  77         spin_unlock_irqrestore(&i8253_lock, flags);
  78
  79         return count;
  80 }
  81
  82 #endif
  83
  84
  85
  86 /*
  87  * gameport_measure_speed() measures the gameport i/o speed.
  88  */
  89
  90 static int gameport_measure_speed(struct gameport *gameport)
  91 {
  92 #if defined(__i386__)
  93
  94         unsigned int i, t, t1, t2, t3, tx;
  95         unsigned long flags;
  96
  97         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
  98                 return 0;
  99
 100         tx = 1 << 30;
 101
 102         for(i = 0; i < 50; i++) {
 103                 local_irq_save(flags);
 104                 GET_TIME(t1);
 105                 for (t = 0; t < 50; t++) gameport_read(gameport);
 106                 GET_TIME(t2);
 107                 GET_TIME(t3);
 108                 local_irq_restore(flags);
 109                 udelay(i * 10);
 110                 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
 111         }
 112
 113         gameport_close(gameport);
 114         return 59659 / (tx < 1 ? 1 : tx);
 115
 116 #elif defined (__x86_64__)
 117
 118         unsigned int i, t;
 119         unsigned long tx, t1, t2, flags;
 120
 121         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
 122                 return 0;
 123
 124         tx = 1 << 30;
 125
 126         for(i = 0; i < 50; i++) {
 127                 local_irq_save(flags);
 128                 rdtscl(t1);
 129                 for (t = 0; t < 50; t++) gameport_read(gameport);
 130                 rdtscl(t2);
 131                 local_irq_restore(flags);
 132                 udelay(i * 10);
 133                 if (t2 - t1 < tx) tx = t2 - t1;
 134         }
 135
 136         gameport_close(gameport);
 137         return (cpu_data[_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
 138
 139 #else
 140
 141         unsigned int j, t = 0;
 142
 143         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
 144                 return 0;
 145
 146         j = jiffies; while (j == jiffies);
 147         j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
 148
 149         gameport_close(gameport);
 150         return t * HZ / 1000;
 151
 152 #endif
 153 }
 154
 155 void gameport_start_polling(struct gameport *gameport)
 156 {
 157         spin_lock(&gameport->timer_lock);
 158
 159         if (!gameport->poll_cnt++) {
 160                 BUG_ON(!gameport->poll_handler);
 161                 BUG_ON(!gameport->poll_interval);
 162                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
 163         }
 164
 165         spin_unlock(&gameport->timer_lock);
 166 }
 167
 168 void gameport_stop_polling(struct gameport *gameport)
 169 {
 170         spin_lock(&gameport->timer_lock);
 171
 172         if (!--gameport->poll_cnt)
 173                 del_timer(&gameport->poll_timer);
 174
 175         spin_unlock(&gameport->timer_lock);
 176 }
 177
 178 static void gameport_run_poll_handler(unsigned long d)
 179 {
 180         struct gameport *gameport = (struct gameport *)d;
 181
 182         gameport->poll_handler(gameport);
 183         if (gameport->poll_cnt)
 184                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
 185 }
 186
 187 /*
 188  * Basic gameport -> driver core mappings
 189  */
 190
 191 static void gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
 192 {
 193         down_write(&gameport_bus.subsys.rwsem);
 194
 195         gameport->dev.driver = &drv->driver;
 196         if (drv->connect(gameport, drv)) {
 197                 gameport->dev.driver = NULL;
 198                 goto out;
 199         }
 200         device_bind_driver(&gameport->dev);
 201 out:
 202         up_write(&gameport_bus.subsys.rwsem);
 203 }
 204
 205 static void gameport_release_driver(struct gameport *gameport)
 206 {
 207         down_write(&gameport_bus.subsys.rwsem);
 208         device_release_driver(&gameport->dev);
 209         up_write(&gameport_bus.subsys.rwsem);
 210 }
 211
 212 static void gameport_find_driver(struct gameport *gameport)
 213 {
 214         down_write(&gameport_bus.subsys.rwsem);
 215         device_attach(&gameport->dev);
 216         up_write(&gameport_bus.subsys.rwsem);
 217 }
 218
 219
 220 /*
 221  * Gameport event processing.
 222  */
 223
 224 enum gameport_event_type {
 225         GAMEPORT_RESCAN,
 226         GAMEPORT_RECONNECT,
 227         GAMEPORT_REGISTER_PORT,
 228         GAMEPORT_REGISTER_DRIVER,
 229 };
 230
 231 struct gameport_event {
 232         enum gameport_event_type type;
 233         void *object;
 234         struct module *owner;
 235         struct list_head node;
 236 };
 237
 238 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
 239 static LIST_HEAD(gameport_event_list);
 240 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
 241 static DECLARE_COMPLETION(gameport_exited);
 242 static int gameport_pid;
 243
 244 static void gameport_queue_event(void *object, struct module *owner,
 245                               enum gameport_event_type event_type)
 246 {
 247         unsigned long flags;
 248         struct gameport_event *event;
 249
 250         spin_lock_irqsave(&gameport_event_lock, flags);
 251
 252         /*
 253          * Scan event list for the other events for the same gameport port,
 254          * starting with the most recent one. If event is the same we
 255          * do not need add new one. If event is of different type we
 256          * need to add this event and should not look further because
 257          * we need to preseve sequence of distinct events.
 258          */
 259         list_for_each_entry_reverse(event, &gameport_event_list, node) {
 260                 if (event->object == object) {
 261                         if (event->type == event_type)
 262                                 goto out;
 263                         break;
 264                 }
 265         }
 266
 267         if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
 268                 if (!try_module_get(owner)) {
 269                         printk(KERN_WARNING "gameport: Can't get module reference, dropping event %d\n", event_type);
 270                         goto out;
 271                 }
 272
 273                 event->type = event_type;
 274                 event->object = object;
 275                 event->owner = owner;
 276
 277                 list_add_tail(&event->node, &gameport_event_list);
 278                 wake_up(&gameport_wait);
 279         } else {
 280                 printk(KERN_ERR "gameport: Not enough memory to queue event %d\n", event_type);
 281         }
 282 out:
 283         spin_unlock_irqrestore(&gameport_event_lock, flags);
 284 }
 285
 286 static void gameport_free_event(struct gameport_event *event)
 287 {
 288         module_put(event->owner);
 289         kfree(event);
 290 }
 291
 292 static void gameport_remove_duplicate_events(struct gameport_event *event)
 293 {
 294         struct list_head *node, *next;
 295         struct gameport_event *e;
 296         unsigned long flags;
 297
 298         spin_lock_irqsave(&gameport_event_lock, flags);
 299
 300         list_for_each_safe(node, next, &gameport_event_list) {
 301                 e = list_entry(node, struct gameport_event, node);
 302                 if (event->object == e->object) {
 303                         /*
 304                          * If this event is of different type we should not
 305                          * look further - we only suppress duplicate events
 306                          * that were sent back-to-back.
 307                          */
 308                         if (event->type != e->type)
 309                                 break;
 310
 311                         list_del_init(node);
 312                         gameport_free_event(e);
 313                 }
 314         }
 315
 316         spin_unlock_irqrestore(&gameport_event_lock, flags);
 317 }
 318
 319
 320 static struct gameport_event *gameport_get_event(void)
 321 {
 322         struct gameport_event *event;
 323         struct list_head *node;
 324         unsigned long flags;
 325
 326         spin_lock_irqsave(&gameport_event_lock, flags);
 327
 328         if (list_empty(&gameport_event_list)) {
 329                 spin_unlock_irqrestore(&gameport_event_lock, flags);
 330                 return NULL;
 331         }
 332
 333         node = gameport_event_list.next;
 334         event = list_entry(node, struct gameport_event, node);
 335         list_del_init(node);
 336
 337         spin_unlock_irqrestore(&gameport_event_lock, flags);
 338
 339         return event;
 340 }
 341
 342 static void gameport_handle_events(void)
 343 {
 344         struct gameport_event *event;
 345         struct gameport_driver *gameport_drv;
 346
 347         down(&gameport_sem);
 348
 349         while ((event = gameport_get_event())) {
 350
 351                 switch (event->type) {
 352                         case GAMEPORT_REGISTER_PORT:
 353                                 gameport_add_port(event->object);
 354                                 break;
 355
 356                         case GAMEPORT_RECONNECT:
 357                                 gameport_reconnect_port(event->object);
 358                                 break;
 359
 360                         case GAMEPORT_RESCAN:
 361                                 gameport_disconnect_port(event->object);
 362                                 gameport_find_driver(event->object);
 363                                 break;
 364
 365                         case GAMEPORT_REGISTER_DRIVER:
 366                                 gameport_drv = event->object;
 367                                 driver_register(&gameport_drv->driver);
 368                                 break;
 369
 370                         default:
 371                                 break;
 372                 }
 373
 374                 gameport_remove_duplicate_events(event);
 375                 gameport_free_event(event);
 376         }
 377
 378         up(&gameport_sem);
 379 }
 380
 381 /*
 382  * Remove all events that have been submitted for a given gameport port.
 383  */
 384 static void gameport_remove_pending_events(struct gameport *gameport)
 385 {
 386         struct list_head *node, *next;
 387         struct gameport_event *event;
 388         unsigned long flags;
 389
 390         spin_lock_irqsave(&gameport_event_lock, flags);
 391
 392         list_for_each_safe(node, next, &gameport_event_list) {
 393                 event = list_entry(node, struct gameport_event, node);
 394                 if (event->object == gameport) {
 395                         list_del_init(node);
 396                         gameport_free_event(event);
 397                 }
 398         }
 399
 400         spin_unlock_irqrestore(&gameport_event_lock, flags);
 401 }
 402
 403 /*
 404  * Destroy child gameport port (if any) that has not been fully registered yet.
 405  *
 406  * Note that we rely on the fact that port can have only one child and therefore
 407  * only one child registration request can be pending. Additionally, children
 408  * are registered by driver's connect() handler so there can't be a grandchild
 409  * pending registration together with a child.
 410  */
 411 static struct gameport *gameport_get_pending_child(struct gameport *parent)
 412 {
 413         struct gameport_event *event;
 414         struct gameport *gameport, *child = NULL;
 415         unsigned long flags;
 416
 417         spin_lock_irqsave(&gameport_event_lock, flags);
 418
 419         list_for_each_entry(event, &gameport_event_list, node) {
 420                 if (event->type == GAMEPORT_REGISTER_PORT) {
 421                         gameport = event->object;
 422                         if (gameport->parent == parent) {
 423                                 child = gameport;
 424                                 break;
 425                         }
 426                 }
 427         }
 428
 429         spin_unlock_irqrestore(&gameport_event_lock, flags);
 430         return child;
 431 }
 432
 433 static int gameport_thread(void *nothing)
 434 {
 435         lock_kernel();
 436         daemonize("kgameportd");
 437         allow_signal(SIGTERM);
 438
 439         do {
 440                 gameport_handle_events();
 441                 wait_event_interruptible(gameport_wait, !list_empty(&gameport_event_list));
 442                 try_to_freeze(PF_FREEZE);
 443         } while (!signal_pending(current));
 444
 445         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
 446
 447         unlock_kernel();
 448         complete_and_exit(&gameport_exited, 0);
 449 }
 450
 451
 452 /*
 453  * Gameport port operations
 454  */
 455
 456 static ssize_t gameport_show_description(struct device *dev, char *buf)
 457 {
 458         struct gameport *gameport = to_gameport_port(dev);
 459         return sprintf(buf, "%s\n", gameport->name);
 460 }
 461
 462 static ssize_t gameport_rebind_driver(struct device *dev, const char *buf, size_t count)
 463 {
 464         struct gameport *gameport = to_gameport_port(dev);
 465         struct device_driver *drv;
 466         int retval;
 467
 468         retval = down_interruptible(&gameport_sem);
 469         if (retval)
 470                 return retval;
 471
 472         retval = count;
 473         if (!strncmp(buf, "none", count)) {
 474                 gameport_disconnect_port(gameport);
 475         } else if (!strncmp(buf, "reconnect", count)) {
 476                 gameport_reconnect_port(gameport);
 477         } else if (!strncmp(buf, "rescan", count)) {
 478                 gameport_disconnect_port(gameport);
 479                 gameport_find_driver(gameport);
 480         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
 481                 gameport_disconnect_port(gameport);
 482                 gameport_bind_driver(gameport, to_gameport_driver(drv));
 483                 put_driver(drv);
 484         } else {
 485                 retval = -EINVAL;
 486         }
 487
 488         up(&gameport_sem);
 489
 490         return retval;
 491 }
 492
 493 static struct device_attribute gameport_device_attrs[] = {
 494         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
 495         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
 496         __ATTR_NULL
 497 };
 498
 499 static void gameport_release_port(struct device *dev)
 500 {
 501         struct gameport *gameport = to_gameport_port(dev);
 502
 503         kfree(gameport);
 504         module_put(THIS_MODULE);
 505 }
 506
 507 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
 508 {
 509         va_list args;
 510
 511         va_start(args, fmt);
 512         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
 513         va_end(args);
 514 }
 515
 516 /*
 517  * Prepare gameport port for registration.
 518  */
 519 static void gameport_init_port(struct gameport *gameport)
 520 {
 521         static atomic_t gameport_no = ATOMIC_INIT(0);
 522
 523         __module_get(THIS_MODULE);
 524
 525         init_MUTEX(&gameport->drv_sem);
 526         device_initialize(&gameport->dev);
 527         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
 528                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
 529         gameport->dev.bus = &gameport_bus;
 530         gameport->dev.release = gameport_release_port;
 531         if (gameport->parent)
 532                 gameport->dev.parent = &gameport->parent->dev;
 533
 534         spin_lock_init(&gameport->timer_lock);
 535         init_timer(&gameport->poll_timer);
 536         gameport->poll_timer.function = gameport_run_poll_handler;
 537         gameport->poll_timer.data = (unsigned long)gameport;
 538 }
 539
 540 /*
 541  * Complete gameport port registration.
 542  * Driver core will attempt to find appropriate driver for the port.
 543  */
 544 static void gameport_add_port(struct gameport *gameport)
 545 {
 546         if (gameport->parent)
 547                 gameport->parent->child = gameport;
 548
 549         gameport->speed = gameport_measure_speed(gameport);
 550
 551         list_add_tail(&gameport->node, &gameport_list);
 552
 553         if (gameport->io)
 554                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
 555                         gameport->name, gameport->phys, gameport->io, gameport->speed);
 556         else
 557                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
 558                         gameport->name, gameport->phys, gameport->speed);
 559
 560         device_add(&gameport->dev);
 561         gameport->registered = 1;
 562 }
 563
 564 /*
 565  * gameport_destroy_port() completes deregistration process and removes
 566  * port from the system
 567  */
 568 static void gameport_destroy_port(struct gameport *gameport)
 569 {
 570         struct gameport *child;
 571
 572         child = gameport_get_pending_child(gameport);
 573         if (child) {
 574                 gameport_remove_pending_events(child);
 575                 put_device(&child->dev);
 576         }
 577
 578         if (gameport->parent) {
 579                 gameport->parent->child = NULL;
 580                 gameport->parent = NULL;
 581         }
 582
 583         if (gameport->registered) {
 584                 device_del(&gameport->dev);
 585                 list_del_init(&gameport->node);
 586                 gameport->registered = 0;
 587         }
 588
 589         gameport_remove_pending_events(gameport);
 590         put_device(&gameport->dev);
 591 }
 592
 593 /*
 594  * Reconnect gameport port and all its children (re-initialize attached devices)
 595  */
 596 static void gameport_reconnect_port(struct gameport *gameport)
 597 {
 598         do {
 599                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
 600                         gameport_disconnect_port(gameport);
 601                         gameport_find_driver(gameport);
 602                         /* Ok, old children are now gone, we are done */
 603                         break;
 604                 }
 605                 gameport = gameport->child;
 606         } while (gameport);
 607 }
 608
 609 /*
 610  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
 611  * all child ports are unbound and destroyed.
 612  */
 613 static void gameport_disconnect_port(struct gameport *gameport)
 614 {
 615         struct gameport *s, *parent;
 616
 617         if (gameport->child) {
 618                 /*
 619                  * Children ports should be disconnected and destroyed
 620                  * first, staring with the leaf one, since we don't want
 621                  * to do recursion
 622                  */
 623                 for (s = gameport; s->child; s = s->child)
 624                         /* empty */;
 625
 626                 do {
 627                         parent = s->parent;
 628
 629                         gameport_release_driver(s);
 630                         gameport_destroy_port(s);
 631                 } while ((s = parent) != gameport);
 632         }
 633
 634         /*
 635          * Ok, no children left, now disconnect this port
 636          */
 637         gameport_release_driver(gameport);
 638 }
 639
 640 void gameport_rescan(struct gameport *gameport)
 641 {
 642         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
 643 }
 644
 645 void gameport_reconnect(struct gameport *gameport)
 646 {
 647         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
 648 }
 649
 650 /*
 651  * Submits register request to kgameportd for subsequent execution.
 652  * Note that port registration is always asynchronous.
 653  */
 654 void __gameport_register_port(struct gameport *gameport, struct module *owner)
 655 {
 656         gameport_init_port(gameport);
 657         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
 658 }
 659
 660 /*
 661  * Synchronously unregisters gameport port.
 662  */
 663 void gameport_unregister_port(struct gameport *gameport)
 664 {
 665         down(&gameport_sem);
 666         gameport_disconnect_port(gameport);
 667         gameport_destroy_port(gameport);
 668         up(&gameport_sem);
 669 }
 670
 671
 672 /*
 673  * Gameport driver operations
 674  */
 675
 676 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
 677 {
 678         struct gameport_driver *driver = to_gameport_driver(drv);
 679         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 680 }
 681
 682 static struct driver_attribute gameport_driver_attrs[] = {
 683         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
 684         __ATTR_NULL
 685 };
 686
 687 static int gameport_driver_probe(struct device *dev)
 688 {
 689         struct gameport *gameport = to_gameport_port(dev);
 690         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 691
 692         drv->connect(gameport, drv);
 693         return gameport->drv ? 0 : -ENODEV;
 694 }
 695
 696 static int gameport_driver_remove(struct device *dev)
 697 {
 698         struct gameport *gameport = to_gameport_port(dev);
 699         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 700
 701         drv->disconnect(gameport);
 702         return 0;
 703 }
 704
 705 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
 706 {
 707         drv->driver.bus = &gameport_bus;
 708         drv->driver.probe = gameport_driver_probe;
 709         drv->driver.remove = gameport_driver_remove;
 710         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
 711 }
 712
 713 void gameport_unregister_driver(struct gameport_driver *drv)
 714 {
 715         struct gameport *gameport;
 716
 717         down(&gameport_sem);
 718         drv->ignore = 1;        /* so gameport_find_driver ignores it */
 719
 720 start_over:
 721         list_for_each_entry(gameport, &gameport_list, node) {
 722                 if (gameport->drv == drv) {
 723                         gameport_disconnect_port(gameport);
 724                         gameport_find_driver(gameport);
 725                         /* we could've deleted some ports, restart */
 726                         goto start_over;
 727                 }
 728         }
 729
 730         driver_unregister(&drv->driver);
 731         up(&gameport_sem);
 732 }
 733
 734 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 735 {
 736         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
 737
 738         return !gameport_drv->ignore;
 739 }
 740
 741 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
 742 {
 743         down(&gameport->drv_sem);
 744         gameport->drv = drv;
 745         up(&gameport->drv_sem);
 746 }
 747
 748 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
 749 {
 750
 751         if (gameport->open) {
 752                 if (gameport->open(gameport, mode)) {
 753                         return -1;
 754                 }
 755         } else {
 756                 if (mode != GAMEPORT_MODE_RAW)
 757                         return -1;
 758         }
 759
 760         gameport_set_drv(gameport, drv);
 761         return 0;
 762 }
 763
 764 void gameport_close(struct gameport *gameport)
 765 {
 766         del_timer_sync(&gameport->poll_timer);
 767         gameport->poll_handler = NULL;
 768         gameport->poll_interval = 0;
 769         gameport_set_drv(gameport, NULL);
 770         if (gameport->close)
 771                 gameport->close(gameport);
 772 }
 773
 774 static int __init gameport_init(void)
 775 {
 776         if (!(gameport_pid = kernel_thread(gameport_thread, NULL, CLONE_KERNEL))) {
 777                 printk(KERN_ERR "gameport: Failed to start kgameportd\n");
 778                 return -1;
 779         }
 780
 781         gameport_bus.dev_attrs = gameport_device_attrs;
 782         gameport_bus.drv_attrs = gameport_driver_attrs;
 783         gameport_bus.match = gameport_bus_match;
 784         bus_register(&gameport_bus);
 785
 786         return 0;
 787 }
 788
 789 static void __exit gameport_exit(void)
 790 {
 791         bus_unregister(&gameport_bus);
 792         kill_proc(gameport_pid, SIGTERM, 1);
 793         wait_for_completion(&gameport_exited);
 794 }
 795
 796 module_init(gameport_init);
 797 module_exit(gameport_exit);