git.oblomov.eu Git - linux-2.6/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
  55 static void gameport_add_port(struct gameport *gameport);
  56 static void gameport_destroy_port(struct gameport *gameport);
  57 static void gameport_reconnect_port(struct gameport *gameport);
  58 static void gameport_disconnect_port(struct gameport *gameport);
  59
  60 #if defined(__i386__)
  61
  62 #include <asm/i8253.h>
  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         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_event(void)
 341 {
 342         struct gameport_event *event;
 343         struct gameport_driver *gameport_drv;
 344
 345         down(&gameport_sem);
 346
 347         /*
 348          * Note that we handle only one event here to give swsusp
 349          * a chance to freeze kgameportd thread. Gameport events
 350          * should be pretty rare so we are not concerned about
 351          * taking performance hit.
 352          */
 353         if ((event = gameport_get_event())) {
 354
 355                 switch (event->type) {
 356                         case GAMEPORT_REGISTER_PORT:
 357                                 gameport_add_port(event->object);
 358                                 break;
 359
 360                         case GAMEPORT_RECONNECT:
 361                                 gameport_reconnect_port(event->object);
 362                                 break;
 363
 364                         case GAMEPORT_RESCAN:
 365                                 gameport_disconnect_port(event->object);
 366                                 gameport_find_driver(event->object);
 367                                 break;
 368
 369                         case GAMEPORT_REGISTER_DRIVER:
 370                                 gameport_drv = event->object;
 371                                 driver_register(&gameport_drv->driver);
 372                                 break;
 373
 374                         default:
 375                                 break;
 376                 }
 377
 378                 gameport_remove_duplicate_events(event);
 379                 gameport_free_event(event);
 380         }
 381
 382         up(&gameport_sem);
 383 }
 384
 385 /*
 386  * Remove all events that have been submitted for a given gameport port.
 387  */
 388 static void gameport_remove_pending_events(struct gameport *gameport)
 389 {
 390         struct list_head *node, *next;
 391         struct gameport_event *event;
 392         unsigned long flags;
 393
 394         spin_lock_irqsave(&gameport_event_lock, flags);
 395
 396         list_for_each_safe(node, next, &gameport_event_list) {
 397                 event = list_entry(node, struct gameport_event, node);
 398                 if (event->object == gameport) {
 399                         list_del_init(node);
 400                         gameport_free_event(event);
 401                 }
 402         }
 403
 404         spin_unlock_irqrestore(&gameport_event_lock, flags);
 405 }
 406
 407 /*
 408  * Destroy child gameport port (if any) that has not been fully registered yet.
 409  *
 410  * Note that we rely on the fact that port can have only one child and therefore
 411  * only one child registration request can be pending. Additionally, children
 412  * are registered by driver's connect() handler so there can't be a grandchild
 413  * pending registration together with a child.
 414  */
 415 static struct gameport *gameport_get_pending_child(struct gameport *parent)
 416 {
 417         struct gameport_event *event;
 418         struct gameport *gameport, *child = NULL;
 419         unsigned long flags;
 420
 421         spin_lock_irqsave(&gameport_event_lock, flags);
 422
 423         list_for_each_entry(event, &gameport_event_list, node) {
 424                 if (event->type == GAMEPORT_REGISTER_PORT) {
 425                         gameport = event->object;
 426                         if (gameport->parent == parent) {
 427                                 child = gameport;
 428                                 break;
 429                         }
 430                 }
 431         }
 432
 433         spin_unlock_irqrestore(&gameport_event_lock, flags);
 434         return child;
 435 }
 436
 437 static int gameport_thread(void *nothing)
 438 {
 439         do {
 440                 gameport_handle_event();
 441                 wait_event_interruptible(gameport_wait,
 442                         kthread_should_stop() || !list_empty(&gameport_event_list));
 443                 try_to_freeze();
 444         } while (!kthread_should_stop());
 445
 446         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
 447         return 0;
 448 }
 449
 450
 451 /*
 452  * Gameport port operations
 453  */
 454
 455 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 456 {
 457         struct gameport *gameport = to_gameport_port(dev);
 458         return sprintf(buf, "%s\n", gameport->name);
 459 }
 460
 461 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 462 {
 463         struct gameport *gameport = to_gameport_port(dev);
 464         struct device_driver *drv;
 465         int retval;
 466
 467         retval = down_interruptible(&gameport_sem);
 468         if (retval)
 469                 return retval;
 470
 471         retval = count;
 472         if (!strncmp(buf, "none", count)) {
 473                 gameport_disconnect_port(gameport);
 474         } else if (!strncmp(buf, "reconnect", count)) {
 475                 gameport_reconnect_port(gameport);
 476         } else if (!strncmp(buf, "rescan", count)) {
 477                 gameport_disconnect_port(gameport);
 478                 gameport_find_driver(gameport);
 479         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
 480                 gameport_disconnect_port(gameport);
 481                 gameport_bind_driver(gameport, to_gameport_driver(drv));
 482                 put_driver(drv);
 483         } else {
 484                 retval = -EINVAL;
 485         }
 486
 487         up(&gameport_sem);
 488
 489         return retval;
 490 }
 491
 492 static struct device_attribute gameport_device_attrs[] = {
 493         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
 494         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
 495         __ATTR_NULL
 496 };
 497
 498 static void gameport_release_port(struct device *dev)
 499 {
 500         struct gameport *gameport = to_gameport_port(dev);
 501
 502         kfree(gameport);
 503         module_put(THIS_MODULE);
 504 }
 505
 506 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
 507 {
 508         va_list args;
 509
 510         va_start(args, fmt);
 511         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
 512         va_end(args);
 513 }
 514
 515 /*
 516  * Prepare gameport port for registration.
 517  */
 518 static void gameport_init_port(struct gameport *gameport)
 519 {
 520         static atomic_t gameport_no = ATOMIC_INIT(0);
 521
 522         __module_get(THIS_MODULE);
 523
 524         init_MUTEX(&gameport->drv_sem);
 525         device_initialize(&gameport->dev);
 526         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
 527                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
 528         gameport->dev.bus = &gameport_bus;
 529         gameport->dev.release = gameport_release_port;
 530         if (gameport->parent)
 531                 gameport->dev.parent = &gameport->parent->dev;
 532
 533         spin_lock_init(&gameport->timer_lock);
 534         init_timer(&gameport->poll_timer);
 535         gameport->poll_timer.function = gameport_run_poll_handler;
 536         gameport->poll_timer.data = (unsigned long)gameport;
 537 }
 538
 539 /*
 540  * Complete gameport port registration.
 541  * Driver core will attempt to find appropriate driver for the port.
 542  */
 543 static void gameport_add_port(struct gameport *gameport)
 544 {
 545         if (gameport->parent)
 546                 gameport->parent->child = gameport;
 547
 548         gameport->speed = gameport_measure_speed(gameport);
 549
 550         list_add_tail(&gameport->node, &gameport_list);
 551
 552         if (gameport->io)
 553                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
 554                         gameport->name, gameport->phys, gameport->io, gameport->speed);
 555         else
 556                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
 557                         gameport->name, gameport->phys, gameport->speed);
 558
 559         device_add(&gameport->dev);
 560         gameport->registered = 1;
 561 }
 562
 563 /*
 564  * gameport_destroy_port() completes deregistration process and removes
 565  * port from the system
 566  */
 567 static void gameport_destroy_port(struct gameport *gameport)
 568 {
 569         struct gameport *child;
 570
 571         child = gameport_get_pending_child(gameport);
 572         if (child) {
 573                 gameport_remove_pending_events(child);
 574                 put_device(&child->dev);
 575         }
 576
 577         if (gameport->parent) {
 578                 gameport->parent->child = NULL;
 579                 gameport->parent = NULL;
 580         }
 581
 582         if (gameport->registered) {
 583                 device_del(&gameport->dev);
 584                 list_del_init(&gameport->node);
 585                 gameport->registered = 0;
 586         }
 587
 588         gameport_remove_pending_events(gameport);
 589         put_device(&gameport->dev);
 590 }
 591
 592 /*
 593  * Reconnect gameport port and all its children (re-initialize attached devices)
 594  */
 595 static void gameport_reconnect_port(struct gameport *gameport)
 596 {
 597         do {
 598                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
 599                         gameport_disconnect_port(gameport);
 600                         gameport_find_driver(gameport);
 601                         /* Ok, old children are now gone, we are done */
 602                         break;
 603                 }
 604                 gameport = gameport->child;
 605         } while (gameport);
 606 }
 607
 608 /*
 609  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
 610  * all child ports are unbound and destroyed.
 611  */
 612 static void gameport_disconnect_port(struct gameport *gameport)
 613 {
 614         struct gameport *s, *parent;
 615
 616         if (gameport->child) {
 617                 /*
 618                  * Children ports should be disconnected and destroyed
 619                  * first, staring with the leaf one, since we don't want
 620                  * to do recursion
 621                  */
 622                 for (s = gameport; s->child; s = s->child)
 623                         /* empty */;
 624
 625                 do {
 626                         parent = s->parent;
 627
 628                         gameport_release_driver(s);
 629                         gameport_destroy_port(s);
 630                 } while ((s = parent) != gameport);
 631         }
 632
 633         /*
 634          * Ok, no children left, now disconnect this port
 635          */
 636         gameport_release_driver(gameport);
 637 }
 638
 639 void gameport_rescan(struct gameport *gameport)
 640 {
 641         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
 642 }
 643
 644 void gameport_reconnect(struct gameport *gameport)
 645 {
 646         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
 647 }
 648
 649 /*
 650  * Submits register request to kgameportd for subsequent execution.
 651  * Note that port registration is always asynchronous.
 652  */
 653 void __gameport_register_port(struct gameport *gameport, struct module *owner)
 654 {
 655         gameport_init_port(gameport);
 656         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
 657 }
 658
 659 /*
 660  * Synchronously unregisters gameport port.
 661  */
 662 void gameport_unregister_port(struct gameport *gameport)
 663 {
 664         down(&gameport_sem);
 665         gameport_disconnect_port(gameport);
 666         gameport_destroy_port(gameport);
 667         up(&gameport_sem);
 668 }
 669
 670
 671 /*
 672  * Gameport driver operations
 673  */
 674
 675 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
 676 {
 677         struct gameport_driver *driver = to_gameport_driver(drv);
 678         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 679 }
 680
 681 static struct driver_attribute gameport_driver_attrs[] = {
 682         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
 683         __ATTR_NULL
 684 };
 685
 686 static int gameport_driver_probe(struct device *dev)
 687 {
 688         struct gameport *gameport = to_gameport_port(dev);
 689         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 690
 691         drv->connect(gameport, drv);
 692         return gameport->drv ? 0 : -ENODEV;
 693 }
 694
 695 static int gameport_driver_remove(struct device *dev)
 696 {
 697         struct gameport *gameport = to_gameport_port(dev);
 698         struct gameport_driver *drv = to_gameport_driver(dev->driver);
 699
 700         drv->disconnect(gameport);
 701         return 0;
 702 }
 703
 704 static struct bus_type gameport_bus = {
 705         .name = "gameport",
 706         .probe = gameport_driver_probe,
 707         .remove = gameport_driver_remove,
 708 };
 709
 710 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
 711 {
 712         drv->driver.bus = &gameport_bus;
 713         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
 714 }
 715
 716 void gameport_unregister_driver(struct gameport_driver *drv)
 717 {
 718         struct gameport *gameport;
 719
 720         down(&gameport_sem);
 721         drv->ignore = 1;        /* so gameport_find_driver ignores it */
 722
 723 start_over:
 724         list_for_each_entry(gameport, &gameport_list, node) {
 725                 if (gameport->drv == drv) {
 726                         gameport_disconnect_port(gameport);
 727                         gameport_find_driver(gameport);
 728                         /* we could've deleted some ports, restart */
 729                         goto start_over;
 730                 }
 731         }
 732
 733         driver_unregister(&drv->driver);
 734         up(&gameport_sem);
 735 }
 736
 737 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 738 {
 739         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
 740
 741         return !gameport_drv->ignore;
 742 }
 743
 744 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
 745 {
 746         down(&gameport->drv_sem);
 747         gameport->drv = drv;
 748         up(&gameport->drv_sem);
 749 }
 750
 751 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
 752 {
 753
 754         if (gameport->open) {
 755                 if (gameport->open(gameport, mode)) {
 756                         return -1;
 757                 }
 758         } else {
 759                 if (mode != GAMEPORT_MODE_RAW)
 760                         return -1;
 761         }
 762
 763         gameport_set_drv(gameport, drv);
 764         return 0;
 765 }
 766
 767 void gameport_close(struct gameport *gameport)
 768 {
 769         del_timer_sync(&gameport->poll_timer);
 770         gameport->poll_handler = NULL;
 771         gameport->poll_interval = 0;
 772         gameport_set_drv(gameport, NULL);
 773         if (gameport->close)
 774                 gameport->close(gameport);
 775 }
 776
 777 static int __init gameport_init(void)
 778 {
 779         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
 780         if (IS_ERR(gameport_task)) {
 781                 printk(KERN_ERR "gameport: Failed to start kgameportd\n");
 782                 return PTR_ERR(gameport_task);
 783         }
 784
 785         gameport_bus.dev_attrs = gameport_device_attrs;
 786         gameport_bus.drv_attrs = gameport_driver_attrs;
 787         gameport_bus.match = gameport_bus_match;
 788         bus_register(&gameport_bus);
 789
 790         return 0;
 791 }
 792
 793 static void __exit gameport_exit(void)
 794 {
 795         bus_unregister(&gameport_bus);
 796         kthread_stop(gameport_task);
 797 }
 798
 799 module_init(gameport_init);
 800 module_exit(gameport_exit);