Merge branches 'release' and 'dmi' into release
[linux-2.6] / 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/slab.h>
21 #include <linux/delay.h>
22 #include <linux/kthread.h>
23 #include <linux/sched.h>        /* HZ */
24 #include <linux/mutex.h>
25 #include <linux/freezer.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_set_phys);
41 EXPORT_SYMBOL(gameport_start_polling);
42 EXPORT_SYMBOL(gameport_stop_polling);
43
44 /*
45  * gameport_mutex protects entire gameport subsystem and is taken
46  * every time gameport port or driver registrered or unregistered.
47  */
48 static DEFINE_MUTEX(gameport_mutex);
49
50 static LIST_HEAD(gameport_list);
51
52 static struct bus_type gameport_bus;
53
54 static void gameport_add_driver(struct gameport_driver *drv);
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 *
137                 (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 int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
192 {
193         int error;
194
195         gameport->dev.driver = &drv->driver;
196         if (drv->connect(gameport, drv)) {
197                 gameport->dev.driver = NULL;
198                 return -ENODEV;
199         }
200
201         error = device_bind_driver(&gameport->dev);
202         if (error) {
203                 printk(KERN_WARNING
204                         "gameport: device_bind_driver() failed "
205                         "for %s (%s) and %s, error: %d\n",
206                         gameport->phys, gameport->name,
207                         drv->description, error);
208                 drv->disconnect(gameport);
209                 gameport->dev.driver = NULL;
210                 return error;
211         }
212
213         return 0;
214 }
215
216 static void gameport_find_driver(struct gameport *gameport)
217 {
218         int error;
219
220         error = device_attach(&gameport->dev);
221         if (error < 0)
222                 printk(KERN_WARNING
223                         "gameport: device_attach() failed for %s (%s), error: %d\n",
224                         gameport->phys, gameport->name, error);
225 }
226
227
228 /*
229  * Gameport event processing.
230  */
231
232 enum gameport_event_type {
233         GAMEPORT_RESCAN,
234         GAMEPORT_RECONNECT,
235         GAMEPORT_REGISTER_PORT,
236         GAMEPORT_REGISTER_DRIVER,
237 };
238
239 struct gameport_event {
240         enum gameport_event_type type;
241         void *object;
242         struct module *owner;
243         struct list_head node;
244 };
245
246 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
247 static LIST_HEAD(gameport_event_list);
248 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
249 static struct task_struct *gameport_task;
250
251 static void gameport_queue_event(void *object, struct module *owner,
252                               enum gameport_event_type event_type)
253 {
254         unsigned long flags;
255         struct gameport_event *event;
256
257         spin_lock_irqsave(&gameport_event_lock, flags);
258
259         /*
260          * Scan event list for the other events for the same gameport port,
261          * starting with the most recent one. If event is the same we
262          * do not need add new one. If event is of different type we
263          * need to add this event and should not look further because
264          * we need to preseve sequence of distinct events.
265          */
266         list_for_each_entry_reverse(event, &gameport_event_list, node) {
267                 if (event->object == object) {
268                         if (event->type == event_type)
269                                 goto out;
270                         break;
271                 }
272         }
273
274         if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
275                 if (!try_module_get(owner)) {
276                         printk(KERN_WARNING "gameport: Can't get module reference, dropping event %d\n", event_type);
277                         kfree(event);
278                         goto out;
279                 }
280
281                 event->type = event_type;
282                 event->object = object;
283                 event->owner = owner;
284
285                 list_add_tail(&event->node, &gameport_event_list);
286                 wake_up(&gameport_wait);
287         } else {
288                 printk(KERN_ERR "gameport: Not enough memory to queue event %d\n", event_type);
289         }
290 out:
291         spin_unlock_irqrestore(&gameport_event_lock, flags);
292 }
293
294 static void gameport_free_event(struct gameport_event *event)
295 {
296         module_put(event->owner);
297         kfree(event);
298 }
299
300 static void gameport_remove_duplicate_events(struct gameport_event *event)
301 {
302         struct list_head *node, *next;
303         struct gameport_event *e;
304         unsigned long flags;
305
306         spin_lock_irqsave(&gameport_event_lock, flags);
307
308         list_for_each_safe(node, next, &gameport_event_list) {
309                 e = list_entry(node, struct gameport_event, node);
310                 if (event->object == e->object) {
311                         /*
312                          * If this event is of different type we should not
313                          * look further - we only suppress duplicate events
314                          * that were sent back-to-back.
315                          */
316                         if (event->type != e->type)
317                                 break;
318
319                         list_del_init(node);
320                         gameport_free_event(e);
321                 }
322         }
323
324         spin_unlock_irqrestore(&gameport_event_lock, flags);
325 }
326
327 static struct gameport_event *gameport_get_event(void)
328 {
329         struct gameport_event *event;
330         struct list_head *node;
331         unsigned long flags;
332
333         spin_lock_irqsave(&gameport_event_lock, flags);
334
335         if (list_empty(&gameport_event_list)) {
336                 spin_unlock_irqrestore(&gameport_event_lock, flags);
337                 return NULL;
338         }
339
340         node = gameport_event_list.next;
341         event = list_entry(node, struct gameport_event, node);
342         list_del_init(node);
343
344         spin_unlock_irqrestore(&gameport_event_lock, flags);
345
346         return event;
347 }
348
349 static void gameport_handle_event(void)
350 {
351         struct gameport_event *event;
352
353         mutex_lock(&gameport_mutex);
354
355         /*
356          * Note that we handle only one event here to give swsusp
357          * a chance to freeze kgameportd thread. Gameport events
358          * should be pretty rare so we are not concerned about
359          * taking performance hit.
360          */
361         if ((event = gameport_get_event())) {
362
363                 switch (event->type) {
364                         case GAMEPORT_REGISTER_PORT:
365                                 gameport_add_port(event->object);
366                                 break;
367
368                         case GAMEPORT_RECONNECT:
369                                 gameport_reconnect_port(event->object);
370                                 break;
371
372                         case GAMEPORT_RESCAN:
373                                 gameport_disconnect_port(event->object);
374                                 gameport_find_driver(event->object);
375                                 break;
376
377                         case GAMEPORT_REGISTER_DRIVER:
378                                 gameport_add_driver(event->object);
379                                 break;
380
381                         default:
382                                 break;
383                 }
384
385                 gameport_remove_duplicate_events(event);
386                 gameport_free_event(event);
387         }
388
389         mutex_unlock(&gameport_mutex);
390 }
391
392 /*
393  * Remove all events that have been submitted for a given gameport port.
394  */
395 static void gameport_remove_pending_events(struct gameport *gameport)
396 {
397         struct list_head *node, *next;
398         struct gameport_event *event;
399         unsigned long flags;
400
401         spin_lock_irqsave(&gameport_event_lock, flags);
402
403         list_for_each_safe(node, next, &gameport_event_list) {
404                 event = list_entry(node, struct gameport_event, node);
405                 if (event->object == gameport) {
406                         list_del_init(node);
407                         gameport_free_event(event);
408                 }
409         }
410
411         spin_unlock_irqrestore(&gameport_event_lock, flags);
412 }
413
414 /*
415  * Destroy child gameport port (if any) that has not been fully registered yet.
416  *
417  * Note that we rely on the fact that port can have only one child and therefore
418  * only one child registration request can be pending. Additionally, children
419  * are registered by driver's connect() handler so there can't be a grandchild
420  * pending registration together with a child.
421  */
422 static struct gameport *gameport_get_pending_child(struct gameport *parent)
423 {
424         struct gameport_event *event;
425         struct gameport *gameport, *child = NULL;
426         unsigned long flags;
427
428         spin_lock_irqsave(&gameport_event_lock, flags);
429
430         list_for_each_entry(event, &gameport_event_list, node) {
431                 if (event->type == GAMEPORT_REGISTER_PORT) {
432                         gameport = event->object;
433                         if (gameport->parent == parent) {
434                                 child = gameport;
435                                 break;
436                         }
437                 }
438         }
439
440         spin_unlock_irqrestore(&gameport_event_lock, flags);
441         return child;
442 }
443
444 static int gameport_thread(void *nothing)
445 {
446         set_freezable();
447         do {
448                 gameport_handle_event();
449                 wait_event_freezable(gameport_wait,
450                         kthread_should_stop() || !list_empty(&gameport_event_list));
451         } while (!kthread_should_stop());
452
453         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
454         return 0;
455 }
456
457
458 /*
459  * Gameport port operations
460  */
461
462 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
463 {
464         struct gameport *gameport = to_gameport_port(dev);
465         return sprintf(buf, "%s\n", gameport->name);
466 }
467
468 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
469 {
470         struct gameport *gameport = to_gameport_port(dev);
471         struct device_driver *drv;
472         int error;
473
474         error = mutex_lock_interruptible(&gameport_mutex);
475         if (error)
476                 return error;
477
478         if (!strncmp(buf, "none", count)) {
479                 gameport_disconnect_port(gameport);
480         } else if (!strncmp(buf, "reconnect", count)) {
481                 gameport_reconnect_port(gameport);
482         } else if (!strncmp(buf, "rescan", count)) {
483                 gameport_disconnect_port(gameport);
484                 gameport_find_driver(gameport);
485         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
486                 gameport_disconnect_port(gameport);
487                 error = gameport_bind_driver(gameport, to_gameport_driver(drv));
488                 put_driver(drv);
489         } else {
490                 error = -EINVAL;
491         }
492
493         mutex_unlock(&gameport_mutex);
494
495         return error ? error : count;
496 }
497
498 static struct device_attribute gameport_device_attrs[] = {
499         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
500         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
501         __ATTR_NULL
502 };
503
504 static void gameport_release_port(struct device *dev)
505 {
506         struct gameport *gameport = to_gameport_port(dev);
507
508         kfree(gameport);
509         module_put(THIS_MODULE);
510 }
511
512 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
513 {
514         va_list args;
515
516         va_start(args, fmt);
517         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
518         va_end(args);
519 }
520
521 /*
522  * Prepare gameport port for registration.
523  */
524 static void gameport_init_port(struct gameport *gameport)
525 {
526         static atomic_t gameport_no = ATOMIC_INIT(0);
527
528         __module_get(THIS_MODULE);
529
530         mutex_init(&gameport->drv_mutex);
531         device_initialize(&gameport->dev);
532         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
533                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
534         gameport->dev.bus = &gameport_bus;
535         gameport->dev.release = gameport_release_port;
536         if (gameport->parent)
537                 gameport->dev.parent = &gameport->parent->dev;
538
539         INIT_LIST_HEAD(&gameport->node);
540         spin_lock_init(&gameport->timer_lock);
541         init_timer(&gameport->poll_timer);
542         gameport->poll_timer.function = gameport_run_poll_handler;
543         gameport->poll_timer.data = (unsigned long)gameport;
544 }
545
546 /*
547  * Complete gameport port registration.
548  * Driver core will attempt to find appropriate driver for the port.
549  */
550 static void gameport_add_port(struct gameport *gameport)
551 {
552         int error;
553
554         if (gameport->parent)
555                 gameport->parent->child = gameport;
556
557         gameport->speed = gameport_measure_speed(gameport);
558
559         list_add_tail(&gameport->node, &gameport_list);
560
561         if (gameport->io)
562                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
563                         gameport->name, gameport->phys, gameport->io, gameport->speed);
564         else
565                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
566                         gameport->name, gameport->phys, gameport->speed);
567
568         error = device_add(&gameport->dev);
569         if (error)
570                 printk(KERN_ERR
571                         "gameport: device_add() failed for %s (%s), error: %d\n",
572                         gameport->phys, gameport->name, error);
573         else
574                 gameport->registered = 1;
575 }
576
577 /*
578  * gameport_destroy_port() completes deregistration process and removes
579  * port from the system
580  */
581 static void gameport_destroy_port(struct gameport *gameport)
582 {
583         struct gameport *child;
584
585         child = gameport_get_pending_child(gameport);
586         if (child) {
587                 gameport_remove_pending_events(child);
588                 put_device(&child->dev);
589         }
590
591         if (gameport->parent) {
592                 gameport->parent->child = NULL;
593                 gameport->parent = NULL;
594         }
595
596         if (gameport->registered) {
597                 device_del(&gameport->dev);
598                 gameport->registered = 0;
599         }
600
601         list_del_init(&gameport->node);
602
603         gameport_remove_pending_events(gameport);
604         put_device(&gameport->dev);
605 }
606
607 /*
608  * Reconnect gameport port and all its children (re-initialize attached devices)
609  */
610 static void gameport_reconnect_port(struct gameport *gameport)
611 {
612         do {
613                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
614                         gameport_disconnect_port(gameport);
615                         gameport_find_driver(gameport);
616                         /* Ok, old children are now gone, we are done */
617                         break;
618                 }
619                 gameport = gameport->child;
620         } while (gameport);
621 }
622
623 /*
624  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
625  * all child ports are unbound and destroyed.
626  */
627 static void gameport_disconnect_port(struct gameport *gameport)
628 {
629         struct gameport *s, *parent;
630
631         if (gameport->child) {
632                 /*
633                  * Children ports should be disconnected and destroyed
634                  * first, staring with the leaf one, since we don't want
635                  * to do recursion
636                  */
637                 for (s = gameport; s->child; s = s->child)
638                         /* empty */;
639
640                 do {
641                         parent = s->parent;
642
643                         device_release_driver(&s->dev);
644                         gameport_destroy_port(s);
645                 } while ((s = parent) != gameport);
646         }
647
648         /*
649          * Ok, no children left, now disconnect this port
650          */
651         device_release_driver(&gameport->dev);
652 }
653
654 void gameport_rescan(struct gameport *gameport)
655 {
656         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
657 }
658
659 void gameport_reconnect(struct gameport *gameport)
660 {
661         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
662 }
663
664 /*
665  * Submits register request to kgameportd for subsequent execution.
666  * Note that port registration is always asynchronous.
667  */
668 void __gameport_register_port(struct gameport *gameport, struct module *owner)
669 {
670         gameport_init_port(gameport);
671         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
672 }
673
674 /*
675  * Synchronously unregisters gameport port.
676  */
677 void gameport_unregister_port(struct gameport *gameport)
678 {
679         mutex_lock(&gameport_mutex);
680         gameport_disconnect_port(gameport);
681         gameport_destroy_port(gameport);
682         mutex_unlock(&gameport_mutex);
683 }
684
685
686 /*
687  * Gameport driver operations
688  */
689
690 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
691 {
692         struct gameport_driver *driver = to_gameport_driver(drv);
693         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
694 }
695
696 static struct driver_attribute gameport_driver_attrs[] = {
697         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
698         __ATTR_NULL
699 };
700
701 static int gameport_driver_probe(struct device *dev)
702 {
703         struct gameport *gameport = to_gameport_port(dev);
704         struct gameport_driver *drv = to_gameport_driver(dev->driver);
705
706         drv->connect(gameport, drv);
707         return gameport->drv ? 0 : -ENODEV;
708 }
709
710 static int gameport_driver_remove(struct device *dev)
711 {
712         struct gameport *gameport = to_gameport_port(dev);
713         struct gameport_driver *drv = to_gameport_driver(dev->driver);
714
715         drv->disconnect(gameport);
716         return 0;
717 }
718
719 static void gameport_add_driver(struct gameport_driver *drv)
720 {
721         int error;
722
723         error = driver_register(&drv->driver);
724         if (error)
725                 printk(KERN_ERR
726                         "gameport: driver_register() failed for %s, error: %d\n",
727                         drv->driver.name, error);
728 }
729
730 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
731 {
732         drv->driver.bus = &gameport_bus;
733         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
734 }
735
736 void gameport_unregister_driver(struct gameport_driver *drv)
737 {
738         struct gameport *gameport;
739
740         mutex_lock(&gameport_mutex);
741         drv->ignore = 1;        /* so gameport_find_driver ignores it */
742
743 start_over:
744         list_for_each_entry(gameport, &gameport_list, node) {
745                 if (gameport->drv == drv) {
746                         gameport_disconnect_port(gameport);
747                         gameport_find_driver(gameport);
748                         /* we could've deleted some ports, restart */
749                         goto start_over;
750                 }
751         }
752
753         driver_unregister(&drv->driver);
754         mutex_unlock(&gameport_mutex);
755 }
756
757 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
758 {
759         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
760
761         return !gameport_drv->ignore;
762 }
763
764 static struct bus_type gameport_bus = {
765         .name           = "gameport",
766         .dev_attrs      = gameport_device_attrs,
767         .drv_attrs      = gameport_driver_attrs,
768         .match          = gameport_bus_match,
769         .probe          = gameport_driver_probe,
770         .remove         = gameport_driver_remove,
771 };
772
773 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
774 {
775         mutex_lock(&gameport->drv_mutex);
776         gameport->drv = drv;
777         mutex_unlock(&gameport->drv_mutex);
778 }
779
780 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
781 {
782         if (gameport->open) {
783                 if (gameport->open(gameport, mode)) {
784                         return -1;
785                 }
786         } else {
787                 if (mode != GAMEPORT_MODE_RAW)
788                         return -1;
789         }
790
791         gameport_set_drv(gameport, drv);
792         return 0;
793 }
794
795 void gameport_close(struct gameport *gameport)
796 {
797         del_timer_sync(&gameport->poll_timer);
798         gameport->poll_handler = NULL;
799         gameport->poll_interval = 0;
800         gameport_set_drv(gameport, NULL);
801         if (gameport->close)
802                 gameport->close(gameport);
803 }
804
805 static int __init gameport_init(void)
806 {
807         int error;
808
809         error = bus_register(&gameport_bus);
810         if (error) {
811                 printk(KERN_ERR "gameport: failed to register gameport bus, error: %d\n", error);
812                 return error;
813         }
814
815         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
816         if (IS_ERR(gameport_task)) {
817                 bus_unregister(&gameport_bus);
818                 error = PTR_ERR(gameport_task);
819                 printk(KERN_ERR "gameport: Failed to start kgameportd, error: %d\n", error);
820                 return error;
821         }
822
823         return 0;
824 }
825
826 static void __exit gameport_exit(void)
827 {
828         bus_unregister(&gameport_bus);
829         kthread_stop(gameport_task);
830 }
831
832 subsys_initcall(gameport_init);
833 module_exit(gameport_exit);