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