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/sched.h>
  21 #include <linux/slab.h>
  22 #include <linux/delay.h>
  23 #include <linux/kthread.h>
  24 #include <linux/sched.h>        /* HZ */
  25 #include <linux/mutex.h>
  26
  27 /*#include <asm/io.h>*/
  28
  29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  30 MODULE_DESCRIPTION("Generic gameport layer");
  31 MODULE_LICENSE("GPL");
  32
  33 EXPORT_SYMBOL(__gameport_register_port);
  34 EXPORT_SYMBOL(gameport_unregister_port);
  35 EXPORT_SYMBOL(__gameport_register_driver);
  36 EXPORT_SYMBOL(gameport_unregister_driver);
  37 EXPORT_SYMBOL(gameport_open);
  38 EXPORT_SYMBOL(gameport_close);
  39 EXPORT_SYMBOL(gameport_rescan);
  40 EXPORT_SYMBOL(gameport_cooked_read);
  41 EXPORT_SYMBOL(gameport_set_name);
  42 EXPORT_SYMBOL(gameport_set_phys);
  43 EXPORT_SYMBOL(gameport_start_polling);
  44 EXPORT_SYMBOL(gameport_stop_polling);
  45
  46 /*
  47  * gameport_mutex protects entire gameport subsystem and is taken
  48  * every time gameport port or driver registrered or unregistered.
  49  */
  50 static DEFINE_MUTEX(gameport_mutex);
  51
  52 static LIST_HEAD(gameport_list);
  53
  54 static struct bus_type gameport_bus;
  55
  56 static void gameport_add_port(struct gameport *gameport);
  57 static void gameport_destroy_port(struct gameport *gameport);
  58 static void gameport_reconnect_port(struct gameport *gameport);
  59 static void gameport_disconnect_port(struct gameport *gameport);
  60
  61 #if defined(__i386__)
  62
  63 #include <asm/i8253.h>
  64
  65 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
  66 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
  67
  68 static unsigned int get_time_pit(void)
  69 {
  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[raw_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 struct task_struct *gameport_task;
 242
 243 static void gameport_queue_event(void *object, struct module *owner,
 244                               enum gameport_event_type event_type)
 245 {
 246         unsigned long flags;
 247         struct gameport_event *event;
 248
 249         spin_lock_irqsave(&gameport_event_lock, flags);
 250
 251         /*
 252          * Scan event list for the other events for the same gameport port,
 253          * starting with the most recent one. If event is the same we
 254          * do not need add new one. If event is of different type we
 255          * need to add this event and should not look further because
 256          * we need to preseve sequence of distinct events.
 257          */
 258         list_for_each_entry_reverse(event, &gameport_event_list, node) {
 259                 if (event->object == object) {
 260                         if (event->type == event_type)
 261                                 goto out;
 262                         break;
 263                 }
 264         }
 265
 266         if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
 267                 if (!try_module_get(owner)) {
 268                         printk(KERN_WARNING "gameport: Can't get module reference, dropping event %d\n", event_type);
 269                         kfree(event);
 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_event(void)
 343 {
 344         struct gameport_event *event;
 345         struct gameport_driver *gameport_drv;
 346
 347         mutex_lock(&gameport_mutex);
 348
 349         /*
 350          * Note that we handle only one event here to give swsusp
 351          * a chance to freeze kgameportd thread. Gameport events
 352          * should be pretty rare so we are not concerned about
 353          * taking performance hit.
 354          */
 355         if ((event = gameport_get_event())) {
 356
 357                 switch (event->type) {
 358                         case GAMEPORT_REGISTER_PORT:
 359                                 gameport_add_port(event->object);
 360                                 break;
 361
 362                         case GAMEPORT_RECONNECT:
 363                                 gameport_reconnect_port(event->object);
 364                                 break;
 365
 366                         case GAMEPORT_RESCAN:
 367                                 gameport_disconnect_port(event->object);
 368                                 gameport_find_driver(event->object);
 369                                 break;
 370
 371                         case GAMEPORT_REGISTER_DRIVER:
 372                                 gameport_drv = event->object;
 373                                 driver_register(&gameport_drv->driver);
 374                                 break;
 375
 376                         default:
 377                                 break;
 378                 }
 379
 380                 gameport_remove_duplicate_events(event);
 381                 gameport_free_event(event);
 382         }
 383
 384         mutex_unlock(&gameport_mutex);
 385 }
 386
 387 /*
 388  * Remove all events that have been submitted for a given gameport port.
 389  */
 390 static void gameport_remove_pending_events(struct gameport *gameport)
 391 {
 392         struct list_head *node, *next;
 393         struct gameport_event *event;
 394         unsigned long flags;
 395
 396         spin_lock_irqsave(&gameport_event_lock, flags);
 397
 398         list_for_each_safe(node, next, &gameport_event_list) {
 399                 event = list_entry(node, struct gameport_event, node);
 400                 if (event->object == gameport) {
 401                         list_del_init(node);
 402                         gameport_free_event(event);
 403                 }
 404         }
 405
 406         spin_unlock_irqrestore(&gameport_event_lock, flags);
 407 }
 408
 409 /*
 410  * Destroy child gameport port (if any) that has not been fully registered yet.
 411  *
 412  * Note that we rely on the fact that port can have only one child and therefore
 413  * only one child registration request can be pending. Additionally, children
 414  * are registered by driver's connect() handler so there can't be a grandchild
 415  * pending registration together with a child.
 416  */
 417 static struct gameport *gameport_get_pending_child(struct gameport *parent)
 418 {
 419         struct gameport_event *event;
 420         struct gameport *gameport, *child = NULL;
 421         unsigned long flags;
 422
 423         spin_lock_irqsave(&gameport_event_lock, flags);
 424
 425         list_for_each_entry(event, &gameport_event_list, node) {
 426                 if (event->type == GAMEPORT_REGISTER_PORT) {
 427                         gameport = event->object;
 428                         if (gameport->parent == parent) {
 429                                 child = gameport;
 430                                 break;
 431                         }
 432                 }
 433         }
 434
 435         spin_unlock_irqrestore(&gameport_event_lock, flags);
 436         return child;
 437 }
 438
 439 static int gameport_thread(void *nothing)
 440 {
 441         do {
 442                 gameport_handle_event();
 443                 wait_event_interruptible(gameport_wait,
 444                         kthread_should_stop() || !list_empty(&gameport_event_list));
 445                 try_to_freeze();
 446         } while (!kthread_should_stop());
 447
 448         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
 449         return 0;
 450 }
 451
 452
 453 /*
 454  * Gameport port operations
 455  */
 456
 457 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 458 {
 459         struct gameport *gameport = to_gameport_port(dev);
 460         return sprintf(buf, "%s\n", gameport->name);
 461 }
 462
 463 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 464 {
 465         struct gameport *gameport = to_gameport_port(dev);
 466         struct device_driver *drv;
 467         int retval;
 468
 469         retval = mutex_lock_interruptible(&gameport_mutex);
 470         if (retval)
 471                 return retval;
 472
 473         retval = count;
 474         if (!strncmp(buf, "none", count)) {
 475                 gameport_disconnect_port(gameport);
 476         } else if (!strncmp(buf, "reconnect", count)) {
 477                 gameport_reconnect_port(gameport);
 478         } else if (!strncmp(buf, "rescan", count)) {
 479                 gameport_disconnect_port(gameport);
 480                 gameport_find_driver(gameport);
 481         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
 482                 gameport_disconnect_port(gameport);
 483                 gameport_bind_driver(gameport, to_gameport_driver(drv));
 484                 put_driver(drv);
 485         } else {
 486                 retval = -EINVAL;
 487         }
 488
 489         mutex_unlock(&gameport_mutex);
 490
 491         return retval;
 492 }
 493
 494 static struct device_attribute gameport_device_attrs[] = {
 495         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
 496         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
 497         __ATTR_NULL
 498 };
 499
 500 static void gameport_release_port(struct device *dev)
 501 {
 502         struct gameport *gameport = to_gameport_port(dev);
 503
 504         kfree(gameport);
 505         module_put(THIS_MODULE);
 506 }
 507
 508 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
 509 {
 510         va_list args;
 511
 512         va_start(args, fmt);
 513         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
 514         va_end(args);
 515 }
 516
 517 /*
 518  * Prepare gameport port for registration.
 519  */
 520 static void gameport_init_port(struct gameport *gameport)
 521 {
 522         static atomic_t gameport_no = ATOMIC_INIT(0);
 523
 524         __module_get(THIS_MODULE);
 525
 526         mutex_init(&gameport->drv_mutex);
 527         device_initialize(&gameport->dev);
 528         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
 529                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
 530         gameport->dev.bus = &gameport_bus;
 531         gameport->dev.release = gameport_release_port;
 532         if (gameport->parent)
 533                 gameport->dev.parent = &gameport->parent->dev;
 534
 535         spin_lock_init(&gameport->timer_lock);
 536         init_timer(&gameport->poll_timer);
 537         gameport->poll_timer.function = gameport_run_poll_handler;
 538         gameport->poll_timer.data = (unsigned long)gameport;
 539 }
 540
 541 /*
 542  * Complete gameport port registration.
 543  * Driver core will attempt to find appropriate driver for the port.
 544  */
 545 static void gameport_add_port(struct gameport *gameport)
 546 {
 547         if (gameport->parent)
 548                 gameport->parent->child = gameport;
 549
 550         gameport->speed = gameport_measure_speed(gameport);
 551
 552         list_add_tail(&gameport->node, &gameport_list);
 553
 554         if (gameport->io)
 555                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
 556                         gameport->name, gameport->phys, gameport->io, gameport->speed);
 557         else
 558                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
 559                         gameport->name, gameport->phys, gameport->speed);
 560
 561         device_add(&gameport->dev);
 562         gameport->registered = 1;
 563 }
 564
 565 /*
 566  * gameport_destroy_port() completes deregistration process and removes
 567  * port from the system
 568  */
 569 static void gameport_destroy_port(struct gameport *gameport)
 570 {
 571         struct gameport *child;
 572
 573         child = gameport_get_pending_child(gameport);
 574         if (child) {
 575                 gameport_remove_pending_events(child);
 576                 put_device(&child->dev);
 577         }
 578
 579         if (gameport->parent) {
 580                 gameport->parent->child = NULL;
 581                 gameport->parent = NULL;
 582         }
 583
 584         if (gameport->registered) {
 585                 device_del(&gameport->dev);
 586                 list_del_init(&gameport->node);
 587                 gameport->registered = 0;
 588         }
 589
 590         gameport_remove_pending_events(gameport);
 591         put_device(&gameport->dev);
 592 }
 593
 594 /*
 595  * Reconnect gameport port and all its children (re-initialize attached devices)
 596  */
 597 static void gameport_reconnect_port(struct gameport *gameport)
 598 {
 599         do {
 600                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
 601                         gameport_disconnect_port(gameport);
 602                         gameport_find_driver(gameport);
 603                         /* Ok, old children are now gone, we are done */
 604                         break;
 605                 }
 606                 gameport = gameport->child;
 607         } while (gameport);
 608 }
 609
 610 /*
 611  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
 612  * all child ports are unbound and destroyed.
 613  */
 614 static void gameport_disconnect_port(struct gameport *gameport)
 615 {
 616         struct gameport *s, *parent;
 617
 618         if (gameport->child) {
 619                 /*
 620                  * Children ports should be disconnected and destroyed
 621                  * first, staring with the leaf one, since we don't want
 622                  * to do recursion
 623                  */
 624                 for (s = gameport; s->child; s = s->child)
 625                         /* empty */;
 626
 627                 do {
 628                         parent = s->parent;
 629
 630                         gameport_release_driver(s);
 631                         gameport_destroy_port(s);
 632                 } while ((s = parent) != gameport);
 633         }
 634
 635         /*
 636          * Ok, no children left, now disconnect this port
 637          */
 638         gameport_release_driver(gameport);
 639 }
 640
 641 void gameport_rescan(struct gameport *gameport)
 642 {
 643         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
 644 }
 645
 646 void gameport_reconnect(struct gameport *gameport)
 647 {
 648         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
 649 }
 650
 651 /*
 652  * Submits register request to kgameportd for subsequent execution.
 653  * Note that port registration is always asynchronous.
 654  */
 655 void __gameport_register_port(struct gameport *gameport, struct module *owner)
 656 {
 657         gameport_init_port(gameport);
 658         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
 659 }
 660
 661 /*
 662  * Synchronously unregisters gameport port.
 663  */
 664 void gameport_unregister_port(struct gameport *gameport)
 665 {
 666         mutex_lock(&gameport_mutex);
 667         gameport_disconnect_port(gameport);
 668         gameport_destroy_port(gameport);
 669         mutex_unlock(&gameport_mutex);
 670 }
 671
 672
 673 /*
 674  * Gameport driver operations
 675  */
 676
 677 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
 678 {
 679         struct gameport_driver *driver = to_gameport_driver(drv);
 680         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 681 }
 682
 683 static struct driver_attribute gameport_driver_attrs[] = {
 684         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
 685         __ATTR_NULL
 686 };
 687
 688 static int gameport_driver_probe(struct device *dev)
 689 {
 690         struct gameport *gameport = to_gameport_port(dev);
 691         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 692
 693         drv->connect(gameport, drv);
 694         return gameport->drv ? 0 : -ENODEV;
 695 }
 696
 697 static int gameport_driver_remove(struct device *dev)
 698 {
 699         struct gameport *gameport = to_gameport_port(dev);
 700         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 701
 702         drv->disconnect(gameport);
 703         return 0;
 704 }
 705
 706 static struct bus_type gameport_bus = {
 707         .name = "gameport",
 708         .probe = gameport_driver_probe,
 709         .remove = gameport_driver_remove,
 710 };
 711
 712 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
 713 {
 714         drv->driver.bus = &gameport_bus;
 715         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
 716 }
 717
 718 void gameport_unregister_driver(struct gameport_driver *drv)
 719 {
 720         struct gameport *gameport;
 721
 722         mutex_lock(&gameport_mutex);
 723         drv->ignore = 1;        /* so gameport_find_driver ignores it */
 724
 725 start_over:
 726         list_for_each_entry(gameport, &gameport_list, node) {
 727                 if (gameport->drv == drv) {
 728                         gameport_disconnect_port(gameport);
 729                         gameport_find_driver(gameport);
 730                         /* we could've deleted some ports, restart */
 731                         goto start_over;
 732                 }
 733         }
 734
 735         driver_unregister(&drv->driver);
 736         mutex_unlock(&gameport_mutex);
 737 }
 738
 739 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 740 {
 741         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
 742
 743         return !gameport_drv->ignore;
 744 }
 745
 746 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
 747 {
 748         mutex_lock(&gameport->drv_mutex);
 749         gameport->drv = drv;
 750         mutex_unlock(&gameport->drv_mutex);
 751 }
 752
 753 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
 754 {
 755
 756         if (gameport->open) {
 757                 if (gameport->open(gameport, mode)) {
 758                         return -1;
 759                 }
 760         } else {
 761                 if (mode != GAMEPORT_MODE_RAW)
 762                         return -1;
 763         }
 764
 765         gameport_set_drv(gameport, drv);
 766         return 0;
 767 }
 768
 769 void gameport_close(struct gameport *gameport)
 770 {
 771         del_timer_sync(&gameport->poll_timer);
 772         gameport->poll_handler = NULL;
 773         gameport->poll_interval = 0;
 774         gameport_set_drv(gameport, NULL);
 775         if (gameport->close)
 776                 gameport->close(gameport);
 777 }
 778
 779 static int __init gameport_init(void)
 780 {
 781         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
 782         if (IS_ERR(gameport_task)) {
 783                 printk(KERN_ERR "gameport: Failed to start kgameportd\n");
 784                 return PTR_ERR(gameport_task);
 785         }
 786
 787         gameport_bus.dev_attrs = gameport_device_attrs;
 788         gameport_bus.drv_attrs = gameport_driver_attrs;
 789         gameport_bus.match = gameport_bus_match;
 790         bus_register(&gameport_bus);
 791
 792         return 0;
 793 }
 794
 795 static void __exit gameport_exit(void)
 796 {
 797         bus_unregister(&gameport_bus);
 798         kthread_stop(gameport_task);
 799 }
 800
 801 subsys_initcall(gameport_init);
 802 module_exit(gameport_exit);