Pileus Git - ~andy/linux/blob - 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
  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 #include <asm/i8253.h>
  65
  66 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
  67 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
  68
  69 static unsigned int get_time_pit(void)
  70 {
  71         unsigned long flags;
  72         unsigned int count;
  73
  74         spin_lock_irqsave(&i8253_lock, flags);
  75         outb_p(0x00, 0x43);
  76         count = inb_p(0x40);
  77         count |= inb_p(0x40) << 8;
  78         spin_unlock_irqrestore(&i8253_lock, flags);
  79
  80         return count;
  81 }
  82
  83 #endif
  84
  85
  86
  87 /*
  88  * gameport_measure_speed() measures the gameport i/o speed.
  89  */
  90
  91 static int gameport_measure_speed(struct gameport *gameport)
  92 {
  93 #if defined(__i386__)
  94
  95         unsigned int i, t, t1, t2, t3, tx;
  96         unsigned long flags;
  97
  98         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
  99                 return 0;
 100
 101         tx = 1 << 30;
 102
 103         for(i = 0; i < 50; i++) {
 104                 local_irq_save(flags);
 105                 GET_TIME(t1);
 106                 for (t = 0; t < 50; t++) gameport_read(gameport);
 107                 GET_TIME(t2);
 108                 GET_TIME(t3);
 109                 local_irq_restore(flags);
 110                 udelay(i * 10);
 111                 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
 112         }
 113
 114         gameport_close(gameport);
 115         return 59659 / (tx < 1 ? 1 : tx);
 116
 117 #elif defined (__x86_64__)
 118
 119         unsigned int i, t;
 120         unsigned long tx, t1, t2, flags;
 121
 122         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
 123                 return 0;
 124
 125         tx = 1 << 30;
 126
 127         for(i = 0; i < 50; i++) {
 128                 local_irq_save(flags);
 129                 rdtscl(t1);
 130                 for (t = 0; t < 50; t++) gameport_read(gameport);
 131                 rdtscl(t2);
 132                 local_irq_restore(flags);
 133                 udelay(i * 10);
 134                 if (t2 - t1 < tx) tx = t2 - t1;
 135         }
 136
 137         gameport_close(gameport);
 138         return (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
 139
 140 #else
 141
 142         unsigned int j, t = 0;
 143
 144         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
 145                 return 0;
 146
 147         j = jiffies; while (j == jiffies);
 148         j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
 149
 150         gameport_close(gameport);
 151         return t * HZ / 1000;
 152
 153 #endif
 154 }
 155
 156 void gameport_start_polling(struct gameport *gameport)
 157 {
 158         spin_lock(&gameport->timer_lock);
 159
 160         if (!gameport->poll_cnt++) {
 161                 BUG_ON(!gameport->poll_handler);
 162                 BUG_ON(!gameport->poll_interval);
 163                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
 164         }
 165
 166         spin_unlock(&gameport->timer_lock);
 167 }
 168
 169 void gameport_stop_polling(struct gameport *gameport)
 170 {
 171         spin_lock(&gameport->timer_lock);
 172
 173         if (!--gameport->poll_cnt)
 174                 del_timer(&gameport->poll_timer);
 175
 176         spin_unlock(&gameport->timer_lock);
 177 }
 178
 179 static void gameport_run_poll_handler(unsigned long d)
 180 {
 181         struct gameport *gameport = (struct gameport *)d;
 182
 183         gameport->poll_handler(gameport);
 184         if (gameport->poll_cnt)
 185                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
 186 }
 187
 188 /*
 189  * Basic gameport -> driver core mappings
 190  */
 191
 192 static void gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
 193 {
 194         down_write(&gameport_bus.subsys.rwsem);
 195
 196         gameport->dev.driver = &drv->driver;
 197         if (drv->connect(gameport, drv)) {
 198                 gameport->dev.driver = NULL;
 199                 goto out;
 200         }
 201         device_bind_driver(&gameport->dev);
 202 out:
 203         up_write(&gameport_bus.subsys.rwsem);
 204 }
 205
 206 static void gameport_release_driver(struct gameport *gameport)
 207 {
 208         down_write(&gameport_bus.subsys.rwsem);
 209         device_release_driver(&gameport->dev);
 210         up_write(&gameport_bus.subsys.rwsem);
 211 }
 212
 213 static void gameport_find_driver(struct gameport *gameport)
 214 {
 215         down_write(&gameport_bus.subsys.rwsem);
 216         device_attach(&gameport->dev);
 217         up_write(&gameport_bus.subsys.rwsem);
 218 }
 219
 220
 221 /*
 222  * Gameport event processing.
 223  */
 224
 225 enum gameport_event_type {
 226         GAMEPORT_RESCAN,
 227         GAMEPORT_RECONNECT,
 228         GAMEPORT_REGISTER_PORT,
 229         GAMEPORT_REGISTER_DRIVER,
 230 };
 231
 232 struct gameport_event {
 233         enum gameport_event_type type;
 234         void *object;
 235         struct module *owner;
 236         struct list_head node;
 237 };
 238
 239 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
 240 static LIST_HEAD(gameport_event_list);
 241 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
 242 static struct task_struct *gameport_task;
 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         do {
 436                 gameport_handle_events();
 437                 wait_event_interruptible(gameport_wait,
 438                         kthread_should_stop() || !list_empty(&gameport_event_list));
 439                 try_to_freeze();
 440         } while (!kthread_should_stop());
 441
 442         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
 443         return 0;
 444 }
 445
 446
 447 /*
 448  * Gameport port operations
 449  */
 450
 451 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 452 {
 453         struct gameport *gameport = to_gameport_port(dev);
 454         return sprintf(buf, "%s\n", gameport->name);
 455 }
 456
 457 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 458 {
 459         struct gameport *gameport = to_gameport_port(dev);
 460         struct device_driver *drv;
 461         int retval;
 462
 463         retval = down_interruptible(&gameport_sem);
 464         if (retval)
 465                 return retval;
 466
 467         retval = count;
 468         if (!strncmp(buf, "none", count)) {
 469                 gameport_disconnect_port(gameport);
 470         } else if (!strncmp(buf, "reconnect", count)) {
 471                 gameport_reconnect_port(gameport);
 472         } else if (!strncmp(buf, "rescan", count)) {
 473                 gameport_disconnect_port(gameport);
 474                 gameport_find_driver(gameport);
 475         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
 476                 gameport_disconnect_port(gameport);
 477                 gameport_bind_driver(gameport, to_gameport_driver(drv));
 478                 put_driver(drv);
 479         } else {
 480                 retval = -EINVAL;
 481         }
 482
 483         up(&gameport_sem);
 484
 485         return retval;
 486 }
 487
 488 static struct device_attribute gameport_device_attrs[] = {
 489         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
 490         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
 491         __ATTR_NULL
 492 };
 493
 494 static void gameport_release_port(struct device *dev)
 495 {
 496         struct gameport *gameport = to_gameport_port(dev);
 497
 498         kfree(gameport);
 499         module_put(THIS_MODULE);
 500 }
 501
 502 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
 503 {
 504         va_list args;
 505
 506         va_start(args, fmt);
 507         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
 508         va_end(args);
 509 }
 510
 511 /*
 512  * Prepare gameport port for registration.
 513  */
 514 static void gameport_init_port(struct gameport *gameport)
 515 {
 516         static atomic_t gameport_no = ATOMIC_INIT(0);
 517
 518         __module_get(THIS_MODULE);
 519
 520         init_MUTEX(&gameport->drv_sem);
 521         device_initialize(&gameport->dev);
 522         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
 523                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
 524         gameport->dev.bus = &gameport_bus;
 525         gameport->dev.release = gameport_release_port;
 526         if (gameport->parent)
 527                 gameport->dev.parent = &gameport->parent->dev;
 528
 529         spin_lock_init(&gameport->timer_lock);
 530         init_timer(&gameport->poll_timer);
 531         gameport->poll_timer.function = gameport_run_poll_handler;
 532         gameport->poll_timer.data = (unsigned long)gameport;
 533 }
 534
 535 /*
 536  * Complete gameport port registration.
 537  * Driver core will attempt to find appropriate driver for the port.
 538  */
 539 static void gameport_add_port(struct gameport *gameport)
 540 {
 541         if (gameport->parent)
 542                 gameport->parent->child = gameport;
 543
 544         gameport->speed = gameport_measure_speed(gameport);
 545
 546         list_add_tail(&gameport->node, &gameport_list);
 547
 548         if (gameport->io)
 549                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
 550                         gameport->name, gameport->phys, gameport->io, gameport->speed);
 551         else
 552                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
 553                         gameport->name, gameport->phys, gameport->speed);
 554
 555         device_add(&gameport->dev);
 556         gameport->registered = 1;
 557 }
 558
 559 /*
 560  * gameport_destroy_port() completes deregistration process and removes
 561  * port from the system
 562  */
 563 static void gameport_destroy_port(struct gameport *gameport)
 564 {
 565         struct gameport *child;
 566
 567         child = gameport_get_pending_child(gameport);
 568         if (child) {
 569                 gameport_remove_pending_events(child);
 570                 put_device(&child->dev);
 571         }
 572
 573         if (gameport->parent) {
 574                 gameport->parent->child = NULL;
 575                 gameport->parent = NULL;
 576         }
 577
 578         if (gameport->registered) {
 579                 device_del(&gameport->dev);
 580                 list_del_init(&gameport->node);
 581                 gameport->registered = 0;
 582         }
 583
 584         gameport_remove_pending_events(gameport);
 585         put_device(&gameport->dev);
 586 }
 587
 588 /*
 589  * Reconnect gameport port and all its children (re-initialize attached devices)
 590  */
 591 static void gameport_reconnect_port(struct gameport *gameport)
 592 {
 593         do {
 594                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
 595                         gameport_disconnect_port(gameport);
 596                         gameport_find_driver(gameport);
 597                         /* Ok, old children are now gone, we are done */
 598                         break;
 599                 }
 600                 gameport = gameport->child;
 601         } while (gameport);
 602 }
 603
 604 /*
 605  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
 606  * all child ports are unbound and destroyed.
 607  */
 608 static void gameport_disconnect_port(struct gameport *gameport)
 609 {
 610         struct gameport *s, *parent;
 611
 612         if (gameport->child) {
 613                 /*
 614                  * Children ports should be disconnected and destroyed
 615                  * first, staring with the leaf one, since we don't want
 616                  * to do recursion
 617                  */
 618                 for (s = gameport; s->child; s = s->child)
 619                         /* empty */;
 620
 621                 do {
 622                         parent = s->parent;
 623
 624                         gameport_release_driver(s);
 625                         gameport_destroy_port(s);
 626                 } while ((s = parent) != gameport);
 627         }
 628
 629         /*
 630          * Ok, no children left, now disconnect this port
 631          */
 632         gameport_release_driver(gameport);
 633 }
 634
 635 void gameport_rescan(struct gameport *gameport)
 636 {
 637         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
 638 }
 639
 640 void gameport_reconnect(struct gameport *gameport)
 641 {
 642         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
 643 }
 644
 645 /*
 646  * Submits register request to kgameportd for subsequent execution.
 647  * Note that port registration is always asynchronous.
 648  */
 649 void __gameport_register_port(struct gameport *gameport, struct module *owner)
 650 {
 651         gameport_init_port(gameport);
 652         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
 653 }
 654
 655 /*
 656  * Synchronously unregisters gameport port.
 657  */
 658 void gameport_unregister_port(struct gameport *gameport)
 659 {
 660         down(&gameport_sem);
 661         gameport_disconnect_port(gameport);
 662         gameport_destroy_port(gameport);
 663         up(&gameport_sem);
 664 }
 665
 666
 667 /*
 668  * Gameport driver operations
 669  */
 670
 671 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
 672 {
 673         struct gameport_driver *driver = to_gameport_driver(drv);
 674         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 675 }
 676
 677 static struct driver_attribute gameport_driver_attrs[] = {
 678         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
 679         __ATTR_NULL
 680 };
 681
 682 static int gameport_driver_probe(struct device *dev)
 683 {
 684         struct gameport *gameport = to_gameport_port(dev);
 685         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 686
 687         drv->connect(gameport, drv);
 688         return gameport->drv ? 0 : -ENODEV;
 689 }
 690
 691 static int gameport_driver_remove(struct device *dev)
 692 {
 693         struct gameport *gameport = to_gameport_port(dev);
 694         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 695
 696         drv->disconnect(gameport);
 697         return 0;
 698 }
 699
 700 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
 701 {
 702         drv->driver.bus = &gameport_bus;
 703         drv->driver.probe = gameport_driver_probe;
 704         drv->driver.remove = gameport_driver_remove;
 705         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
 706 }
 707
 708 void gameport_unregister_driver(struct gameport_driver *drv)
 709 {
 710         struct gameport *gameport;
 711
 712         down(&gameport_sem);
 713         drv->ignore = 1;        /* so gameport_find_driver ignores it */
 714
 715 start_over:
 716         list_for_each_entry(gameport, &gameport_list, node) {
 717                 if (gameport->drv == drv) {
 718                         gameport_disconnect_port(gameport);
 719                         gameport_find_driver(gameport);
 720                         /* we could've deleted some ports, restart */
 721                         goto start_over;
 722                 }
 723         }
 724
 725         driver_unregister(&drv->driver);
 726         up(&gameport_sem);
 727 }
 728
 729 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 730 {
 731         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
 732
 733         return !gameport_drv->ignore;
 734 }
 735
 736 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
 737 {
 738         down(&gameport->drv_sem);
 739         gameport->drv = drv;
 740         up(&gameport->drv_sem);
 741 }
 742
 743 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
 744 {
 745
 746         if (gameport->open) {
 747                 if (gameport->open(gameport, mode)) {
 748                         return -1;
 749                 }
 750         } else {
 751                 if (mode != GAMEPORT_MODE_RAW)
 752                         return -1;
 753         }
 754
 755         gameport_set_drv(gameport, drv);
 756         return 0;
 757 }
 758
 759 void gameport_close(struct gameport *gameport)
 760 {
 761         del_timer_sync(&gameport->poll_timer);
 762         gameport->poll_handler = NULL;
 763         gameport->poll_interval = 0;
 764         gameport_set_drv(gameport, NULL);
 765         if (gameport->close)
 766                 gameport->close(gameport);
 767 }
 768
 769 static int __init gameport_init(void)
 770 {
 771         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
 772         if (IS_ERR(gameport_task)) {
 773                 printk(KERN_ERR "gameport: Failed to start kgameportd\n");
 774                 return PTR_ERR(gameport_task);
 775         }
 776
 777         gameport_bus.dev_attrs = gameport_device_attrs;
 778         gameport_bus.drv_attrs = gameport_driver_attrs;
 779         gameport_bus.match = gameport_bus_match;
 780         bus_register(&gameport_bus);
 781
 782         return 0;
 783 }
 784
 785 static void __exit gameport_exit(void)
 786 {
 787         bus_unregister(&gameport_bus);
 788         kthread_stop(gameport_task);
 789 }
 790
 791 module_init(gameport_init);
 792 module_exit(gameport_exit);