Merge branch 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...
[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/sched.h>
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/kthread.h>
24 #include <linux/sched.h>        /* HZ */
25 #include <linux/mutex.h>
26 #include <linux/freezer.h>
27
28 /*#include <asm/io.h>*/
29
30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31 MODULE_DESCRIPTION("Generic gameport layer");
32 MODULE_LICENSE("GPL");
33
34 EXPORT_SYMBOL(__gameport_register_port);
35 EXPORT_SYMBOL(gameport_unregister_port);
36 EXPORT_SYMBOL(__gameport_register_driver);
37 EXPORT_SYMBOL(gameport_unregister_driver);
38 EXPORT_SYMBOL(gameport_open);
39 EXPORT_SYMBOL(gameport_close);
40 EXPORT_SYMBOL(gameport_rescan);
41 EXPORT_SYMBOL(gameport_cooked_read);
42 EXPORT_SYMBOL(gameport_set_name);
43 EXPORT_SYMBOL(gameport_set_phys);
44 EXPORT_SYMBOL(gameport_start_polling);
45 EXPORT_SYMBOL(gameport_stop_polling);
46
47 /*
48  * gameport_mutex protects entire gameport subsystem and is taken
49  * every time gameport port or driver registrered or unregistered.
50  */
51 static DEFINE_MUTEX(gameport_mutex);
52
53 static LIST_HEAD(gameport_list);
54
55 static struct bus_type gameport_bus;
56
57 static void gameport_add_driver(struct gameport_driver *drv);
58 static void gameport_add_port(struct gameport *gameport);
59 static void gameport_destroy_port(struct gameport *gameport);
60 static void gameport_reconnect_port(struct gameport *gameport);
61 static void gameport_disconnect_port(struct gameport *gameport);
62
63 #if defined(__i386__)
64
65 #include <asm/i8253.h>
66
67 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
68 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
69
70 static unsigned int get_time_pit(void)
71 {
72         unsigned long flags;
73         unsigned int count;
74
75         spin_lock_irqsave(&i8253_lock, flags);
76         outb_p(0x00, 0x43);
77         count = inb_p(0x40);
78         count |= inb_p(0x40) << 8;
79         spin_unlock_irqrestore(&i8253_lock, flags);
80
81         return count;
82 }
83
84 #endif
85
86
87
88 /*
89  * gameport_measure_speed() measures the gameport i/o speed.
90  */
91
92 static int gameport_measure_speed(struct gameport *gameport)
93 {
94 #if defined(__i386__)
95
96         unsigned int i, t, t1, t2, t3, tx;
97         unsigned long flags;
98
99         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
100                 return 0;
101
102         tx = 1 << 30;
103
104         for(i = 0; i < 50; i++) {
105                 local_irq_save(flags);
106                 GET_TIME(t1);
107                 for (t = 0; t < 50; t++) gameport_read(gameport);
108                 GET_TIME(t2);
109                 GET_TIME(t3);
110                 local_irq_restore(flags);
111                 udelay(i * 10);
112                 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
113         }
114
115         gameport_close(gameport);
116         return 59659 / (tx < 1 ? 1 : tx);
117
118 #elif defined (__x86_64__)
119
120         unsigned int i, t;
121         unsigned long tx, t1, t2, flags;
122
123         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
124                 return 0;
125
126         tx = 1 << 30;
127
128         for(i = 0; i < 50; i++) {
129                 local_irq_save(flags);
130                 rdtscl(t1);
131                 for (t = 0; t < 50; t++) gameport_read(gameport);
132                 rdtscl(t2);
133                 local_irq_restore(flags);
134                 udelay(i * 10);
135                 if (t2 - t1 < tx) tx = t2 - t1;
136         }
137
138         gameport_close(gameport);
139         return (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
140
141 #else
142
143         unsigned int j, t = 0;
144
145         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
146                 return 0;
147
148         j = jiffies; while (j == jiffies);
149         j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
150
151         gameport_close(gameport);
152         return t * HZ / 1000;
153
154 #endif
155 }
156
157 void gameport_start_polling(struct gameport *gameport)
158 {
159         spin_lock(&gameport->timer_lock);
160
161         if (!gameport->poll_cnt++) {
162                 BUG_ON(!gameport->poll_handler);
163                 BUG_ON(!gameport->poll_interval);
164                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
165         }
166
167         spin_unlock(&gameport->timer_lock);
168 }
169
170 void gameport_stop_polling(struct gameport *gameport)
171 {
172         spin_lock(&gameport->timer_lock);
173
174         if (!--gameport->poll_cnt)
175                 del_timer(&gameport->poll_timer);
176
177         spin_unlock(&gameport->timer_lock);
178 }
179
180 static void gameport_run_poll_handler(unsigned long d)
181 {
182         struct gameport *gameport = (struct gameport *)d;
183
184         gameport->poll_handler(gameport);
185         if (gameport->poll_cnt)
186                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
187 }
188
189 /*
190  * Basic gameport -> driver core mappings
191  */
192
193 static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
194 {
195         int error;
196
197         gameport->dev.driver = &drv->driver;
198         if (drv->connect(gameport, drv)) {
199                 gameport->dev.driver = NULL;
200                 return -ENODEV;
201         }
202
203         error = device_bind_driver(&gameport->dev);
204         if (error) {
205                 printk(KERN_WARNING
206                         "gameport: device_bind_driver() failed "
207                         "for %s (%s) and %s, error: %d\n",
208                         gameport->phys, gameport->name,
209                         drv->description, error);
210                 drv->disconnect(gameport);
211                 gameport->dev.driver = NULL;
212                 return error;
213         }
214
215         return 0;
216 }
217
218 static void gameport_find_driver(struct gameport *gameport)
219 {
220         int error;
221
222         error = device_attach(&gameport->dev);
223         if (error < 0)
224                 printk(KERN_WARNING
225                         "gameport: device_attach() failed for %s (%s), error: %d\n",
226                         gameport->phys, gameport->name, error);
227 }
228
229
230 /*
231  * Gameport event processing.
232  */
233
234 enum gameport_event_type {
235         GAMEPORT_RESCAN,
236         GAMEPORT_RECONNECT,
237         GAMEPORT_REGISTER_PORT,
238         GAMEPORT_REGISTER_DRIVER,
239 };
240
241 struct gameport_event {
242         enum gameport_event_type type;
243         void *object;
244         struct module *owner;
245         struct list_head node;
246 };
247
248 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
249 static LIST_HEAD(gameport_event_list);
250 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
251 static struct task_struct *gameport_task;
252
253 static void gameport_queue_event(void *object, struct module *owner,
254                               enum gameport_event_type event_type)
255 {
256         unsigned long flags;
257         struct gameport_event *event;
258
259         spin_lock_irqsave(&gameport_event_lock, flags);
260
261         /*
262          * Scan event list for the other events for the same gameport port,
263          * starting with the most recent one. If event is the same we
264          * do not need add new one. If event is of different type we
265          * need to add this event and should not look further because
266          * we need to preseve sequence of distinct events.
267          */
268         list_for_each_entry_reverse(event, &gameport_event_list, node) {
269                 if (event->object == object) {
270                         if (event->type == event_type)
271                                 goto out;
272                         break;
273                 }
274         }
275
276         if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
277                 if (!try_module_get(owner)) {
278                         printk(KERN_WARNING "gameport: Can't get module reference, dropping event %d\n", event_type);
279                         kfree(event);
280                         goto out;
281                 }
282
283                 event->type = event_type;
284                 event->object = object;
285                 event->owner = owner;
286
287                 list_add_tail(&event->node, &gameport_event_list);
288                 wake_up(&gameport_wait);
289         } else {
290                 printk(KERN_ERR "gameport: Not enough memory to queue event %d\n", event_type);
291         }
292 out:
293         spin_unlock_irqrestore(&gameport_event_lock, flags);
294 }
295
296 static void gameport_free_event(struct gameport_event *event)
297 {
298         module_put(event->owner);
299         kfree(event);
300 }
301
302 static void gameport_remove_duplicate_events(struct gameport_event *event)
303 {
304         struct list_head *node, *next;
305         struct gameport_event *e;
306         unsigned long flags;
307
308         spin_lock_irqsave(&gameport_event_lock, flags);
309
310         list_for_each_safe(node, next, &gameport_event_list) {
311                 e = list_entry(node, struct gameport_event, node);
312                 if (event->object == e->object) {
313                         /*
314                          * If this event is of different type we should not
315                          * look further - we only suppress duplicate events
316                          * that were sent back-to-back.
317                          */
318                         if (event->type != e->type)
319                                 break;
320
321                         list_del_init(node);
322                         gameport_free_event(e);
323                 }
324         }
325
326         spin_unlock_irqrestore(&gameport_event_lock, flags);
327 }
328
329 static struct gameport_event *gameport_get_event(void)
330 {
331         struct gameport_event *event;
332         struct list_head *node;
333         unsigned long flags;
334
335         spin_lock_irqsave(&gameport_event_lock, flags);
336
337         if (list_empty(&gameport_event_list)) {
338                 spin_unlock_irqrestore(&gameport_event_lock, flags);
339                 return NULL;
340         }
341
342         node = gameport_event_list.next;
343         event = list_entry(node, struct gameport_event, node);
344         list_del_init(node);
345
346         spin_unlock_irqrestore(&gameport_event_lock, flags);
347
348         return event;
349 }
350
351 static void gameport_handle_event(void)
352 {
353         struct gameport_event *event;
354
355         mutex_lock(&gameport_mutex);
356
357         /*
358          * Note that we handle only one event here to give swsusp
359          * a chance to freeze kgameportd thread. Gameport events
360          * should be pretty rare so we are not concerned about
361          * taking performance hit.
362          */
363         if ((event = gameport_get_event())) {
364
365                 switch (event->type) {
366                         case GAMEPORT_REGISTER_PORT:
367                                 gameport_add_port(event->object);
368                                 break;
369
370                         case GAMEPORT_RECONNECT:
371                                 gameport_reconnect_port(event->object);
372                                 break;
373
374                         case GAMEPORT_RESCAN:
375                                 gameport_disconnect_port(event->object);
376                                 gameport_find_driver(event->object);
377                                 break;
378
379                         case GAMEPORT_REGISTER_DRIVER:
380                                 gameport_add_driver(event->object);
381                                 break;
382
383                         default:
384                                 break;
385                 }
386
387                 gameport_remove_duplicate_events(event);
388                 gameport_free_event(event);
389         }
390
391         mutex_unlock(&gameport_mutex);
392 }
393
394 /*
395  * Remove all events that have been submitted for a given gameport port.
396  */
397 static void gameport_remove_pending_events(struct gameport *gameport)
398 {
399         struct list_head *node, *next;
400         struct gameport_event *event;
401         unsigned long flags;
402
403         spin_lock_irqsave(&gameport_event_lock, flags);
404
405         list_for_each_safe(node, next, &gameport_event_list) {
406                 event = list_entry(node, struct gameport_event, node);
407                 if (event->object == gameport) {
408                         list_del_init(node);
409                         gameport_free_event(event);
410                 }
411         }
412
413         spin_unlock_irqrestore(&gameport_event_lock, flags);
414 }
415
416 /*
417  * Destroy child gameport port (if any) that has not been fully registered yet.
418  *
419  * Note that we rely on the fact that port can have only one child and therefore
420  * only one child registration request can be pending. Additionally, children
421  * are registered by driver's connect() handler so there can't be a grandchild
422  * pending registration together with a child.
423  */
424 static struct gameport *gameport_get_pending_child(struct gameport *parent)
425 {
426         struct gameport_event *event;
427         struct gameport *gameport, *child = NULL;
428         unsigned long flags;
429
430         spin_lock_irqsave(&gameport_event_lock, flags);
431
432         list_for_each_entry(event, &gameport_event_list, node) {
433                 if (event->type == GAMEPORT_REGISTER_PORT) {
434                         gameport = event->object;
435                         if (gameport->parent == parent) {
436                                 child = gameport;
437                                 break;
438                         }
439                 }
440         }
441
442         spin_unlock_irqrestore(&gameport_event_lock, flags);
443         return child;
444 }
445
446 static int gameport_thread(void *nothing)
447 {
448         do {
449                 gameport_handle_event();
450                 wait_event_interruptible(gameport_wait,
451                         kthread_should_stop() || !list_empty(&gameport_event_list));
452                 try_to_freeze();
453         } while (!kthread_should_stop());
454
455         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
456         return 0;
457 }
458
459
460 /*
461  * Gameport port operations
462  */
463
464 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
465 {
466         struct gameport *gameport = to_gameport_port(dev);
467         return sprintf(buf, "%s\n", gameport->name);
468 }
469
470 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
471 {
472         struct gameport *gameport = to_gameport_port(dev);
473         struct device_driver *drv;
474         int error;
475
476         error = mutex_lock_interruptible(&gameport_mutex);
477         if (error)
478                 return error;
479
480         if (!strncmp(buf, "none", count)) {
481                 gameport_disconnect_port(gameport);
482         } else if (!strncmp(buf, "reconnect", count)) {
483                 gameport_reconnect_port(gameport);
484         } else if (!strncmp(buf, "rescan", count)) {
485                 gameport_disconnect_port(gameport);
486                 gameport_find_driver(gameport);
487         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
488                 gameport_disconnect_port(gameport);
489                 error = gameport_bind_driver(gameport, to_gameport_driver(drv));
490                 put_driver(drv);
491         } else {
492                 error = -EINVAL;
493         }
494
495         mutex_unlock(&gameport_mutex);
496
497         return error ? error : count;
498 }
499
500 static struct device_attribute gameport_device_attrs[] = {
501         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
502         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
503         __ATTR_NULL
504 };
505
506 static void gameport_release_port(struct device *dev)
507 {
508         struct gameport *gameport = to_gameport_port(dev);
509
510         kfree(gameport);
511         module_put(THIS_MODULE);
512 }
513
514 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
515 {
516         va_list args;
517
518         va_start(args, fmt);
519         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
520         va_end(args);
521 }
522
523 /*
524  * Prepare gameport port for registration.
525  */
526 static void gameport_init_port(struct gameport *gameport)
527 {
528         static atomic_t gameport_no = ATOMIC_INIT(0);
529
530         __module_get(THIS_MODULE);
531
532         mutex_init(&gameport->drv_mutex);
533         device_initialize(&gameport->dev);
534         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
535                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
536         gameport->dev.bus = &gameport_bus;
537         gameport->dev.release = gameport_release_port;
538         if (gameport->parent)
539                 gameport->dev.parent = &gameport->parent->dev;
540
541         INIT_LIST_HEAD(&gameport->node);
542         spin_lock_init(&gameport->timer_lock);
543         init_timer(&gameport->poll_timer);
544         gameport->poll_timer.function = gameport_run_poll_handler;
545         gameport->poll_timer.data = (unsigned long)gameport;
546 }
547
548 /*
549  * Complete gameport port registration.
550  * Driver core will attempt to find appropriate driver for the port.
551  */
552 static void gameport_add_port(struct gameport *gameport)
553 {
554         int error;
555
556         if (gameport->parent)
557                 gameport->parent->child = gameport;
558
559         gameport->speed = gameport_measure_speed(gameport);
560
561         list_add_tail(&gameport->node, &gameport_list);
562
563         if (gameport->io)
564                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
565                         gameport->name, gameport->phys, gameport->io, gameport->speed);
566         else
567                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
568                         gameport->name, gameport->phys, gameport->speed);
569
570         error = device_add(&gameport->dev);
571         if (error)
572                 printk(KERN_ERR
573                         "gameport: device_add() failed for %s (%s), error: %d\n",
574                         gameport->phys, gameport->name, error);
575         else
576                 gameport->registered = 1;
577 }
578
579 /*
580  * gameport_destroy_port() completes deregistration process and removes
581  * port from the system
582  */
583 static void gameport_destroy_port(struct gameport *gameport)
584 {
585         struct gameport *child;
586
587         child = gameport_get_pending_child(gameport);
588         if (child) {
589                 gameport_remove_pending_events(child);
590                 put_device(&child->dev);
591         }
592
593         if (gameport->parent) {
594                 gameport->parent->child = NULL;
595                 gameport->parent = NULL;
596         }
597
598         if (gameport->registered) {
599                 device_del(&gameport->dev);
600                 gameport->registered = 0;
601         }
602
603         list_del_init(&gameport->node);
604
605         gameport_remove_pending_events(gameport);
606         put_device(&gameport->dev);
607 }
608
609 /*
610  * Reconnect gameport port and all its children (re-initialize attached devices)
611  */
612 static void gameport_reconnect_port(struct gameport *gameport)
613 {
614         do {
615                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
616                         gameport_disconnect_port(gameport);
617                         gameport_find_driver(gameport);
618                         /* Ok, old children are now gone, we are done */
619                         break;
620                 }
621                 gameport = gameport->child;
622         } while (gameport);
623 }
624
625 /*
626  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
627  * all child ports are unbound and destroyed.
628  */
629 static void gameport_disconnect_port(struct gameport *gameport)
630 {
631         struct gameport *s, *parent;
632
633         if (gameport->child) {
634                 /*
635                  * Children ports should be disconnected and destroyed
636                  * first, staring with the leaf one, since we don't want
637                  * to do recursion
638                  */
639                 for (s = gameport; s->child; s = s->child)
640                         /* empty */;
641
642                 do {
643                         parent = s->parent;
644
645                         device_release_driver(&s->dev);
646                         gameport_destroy_port(s);
647                 } while ((s = parent) != gameport);
648         }
649
650         /*
651          * Ok, no children left, now disconnect this port
652          */
653         device_release_driver(&gameport->dev);
654 }
655
656 void gameport_rescan(struct gameport *gameport)
657 {
658         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
659 }
660
661 void gameport_reconnect(struct gameport *gameport)
662 {
663         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
664 }
665
666 /*
667  * Submits register request to kgameportd for subsequent execution.
668  * Note that port registration is always asynchronous.
669  */
670 void __gameport_register_port(struct gameport *gameport, struct module *owner)
671 {
672         gameport_init_port(gameport);
673         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
674 }
675
676 /*
677  * Synchronously unregisters gameport port.
678  */
679 void gameport_unregister_port(struct gameport *gameport)
680 {
681         mutex_lock(&gameport_mutex);
682         gameport_disconnect_port(gameport);
683         gameport_destroy_port(gameport);
684         mutex_unlock(&gameport_mutex);
685 }
686
687
688 /*
689  * Gameport driver operations
690  */
691
692 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
693 {
694         struct gameport_driver *driver = to_gameport_driver(drv);
695         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
696 }
697
698 static struct driver_attribute gameport_driver_attrs[] = {
699         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
700         __ATTR_NULL
701 };
702
703 static int gameport_driver_probe(struct device *dev)
704 {
705         struct gameport *gameport = to_gameport_port(dev);
706         struct gameport_driver *drv = to_gameport_driver(dev->driver);
707
708         drv->connect(gameport, drv);
709         return gameport->drv ? 0 : -ENODEV;
710 }
711
712 static int gameport_driver_remove(struct device *dev)
713 {
714         struct gameport *gameport = to_gameport_port(dev);
715         struct gameport_driver *drv = to_gameport_driver(dev->driver);
716
717         drv->disconnect(gameport);
718         return 0;
719 }
720
721 static void gameport_add_driver(struct gameport_driver *drv)
722 {
723         int error;
724
725         error = driver_register(&drv->driver);
726         if (error)
727                 printk(KERN_ERR
728                         "gameport: driver_register() failed for %s, error: %d\n",
729                         drv->driver.name, error);
730 }
731
732 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
733 {
734         drv->driver.bus = &gameport_bus;
735         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
736 }
737
738 void gameport_unregister_driver(struct gameport_driver *drv)
739 {
740         struct gameport *gameport;
741
742         mutex_lock(&gameport_mutex);
743         drv->ignore = 1;        /* so gameport_find_driver ignores it */
744
745 start_over:
746         list_for_each_entry(gameport, &gameport_list, node) {
747                 if (gameport->drv == drv) {
748                         gameport_disconnect_port(gameport);
749                         gameport_find_driver(gameport);
750                         /* we could've deleted some ports, restart */
751                         goto start_over;
752                 }
753         }
754
755         driver_unregister(&drv->driver);
756         mutex_unlock(&gameport_mutex);
757 }
758
759 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
760 {
761         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
762
763         return !gameport_drv->ignore;
764 }
765
766 static struct bus_type gameport_bus = {
767         .name           = "gameport",
768         .dev_attrs      = gameport_device_attrs,
769         .drv_attrs      = gameport_driver_attrs,
770         .match          = gameport_bus_match,
771         .probe          = gameport_driver_probe,
772         .remove         = gameport_driver_remove,
773 };
774
775 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
776 {
777         mutex_lock(&gameport->drv_mutex);
778         gameport->drv = drv;
779         mutex_unlock(&gameport->drv_mutex);
780 }
781
782 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
783 {
784         if (gameport->open) {
785                 if (gameport->open(gameport, mode)) {
786                         return -1;
787                 }
788         } else {
789                 if (mode != GAMEPORT_MODE_RAW)
790                         return -1;
791         }
792
793         gameport_set_drv(gameport, drv);
794         return 0;
795 }
796
797 void gameport_close(struct gameport *gameport)
798 {
799         del_timer_sync(&gameport->poll_timer);
800         gameport->poll_handler = NULL;
801         gameport->poll_interval = 0;
802         gameport_set_drv(gameport, NULL);
803         if (gameport->close)
804                 gameport->close(gameport);
805 }
806
807 static int __init gameport_init(void)
808 {
809         int error;
810
811         error = bus_register(&gameport_bus);
812         if (error) {
813                 printk(KERN_ERR "gameport: failed to register gameport bus, error: %d\n", error);
814                 return error;
815         }
816
817         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
818         if (IS_ERR(gameport_task)) {
819                 bus_unregister(&gameport_bus);
820                 error = PTR_ERR(gameport_task);
821                 printk(KERN_ERR "gameport: Failed to start kgameportd, error: %d\n", error);
822                 return error;
823         }
824
825         return 0;
826 }
827
828 static void __exit gameport_exit(void)
829 {
830         bus_unregister(&gameport_bus);
831         kthread_stop(gameport_task);
832 }
833
834 subsys_initcall(gameport_init);
835 module_exit(gameport_exit);