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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic gameport layer
4 *
5 * Copyright (c) 1999-2002 Vojtech Pavlik
6 * Copyright (c) 2005 Dmitry Torokhov
7 */
8
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/stddef.h>
13#include <linux/module.h>
14#include <linux/ioport.h>
15#include <linux/init.h>
16#include <linux/gameport.h>
17#include <linux/slab.h>
18#include <linux/delay.h>
19#include <linux/workqueue.h>
20#include <linux/sched.h> /* HZ */
21#include <linux/mutex.h>
22#include <linux/timekeeping.h>
23
24/*#include <asm/io.h>*/
25
26MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
27MODULE_DESCRIPTION("Generic gameport layer");
28MODULE_LICENSE("GPL");
29
30static bool use_ktime = true;
31module_param(use_ktime, bool, 0400);
32MODULE_PARM_DESC(use_ktime, "Use ktime for measuring I/O speed");
33
34/*
35 * gameport_mutex protects entire gameport subsystem and is taken
36 * every time gameport port or driver registrered or unregistered.
37 */
38static DEFINE_MUTEX(gameport_mutex);
39
40static LIST_HEAD(gameport_list);
41
42static struct bus_type gameport_bus;
43
44static void gameport_add_port(struct gameport *gameport);
45static void gameport_attach_driver(struct gameport_driver *drv);
46static void gameport_reconnect_port(struct gameport *gameport);
47static void gameport_disconnect_port(struct gameport *gameport);
48
49#if defined(__i386__)
50
51#include <linux/i8253.h>
52
53#define DELTA(x,y) ((y)-(x)+((y)<(x)?1193182/HZ:0))
54#define GET_TIME(x) do { x = get_time_pit(); } while (0)
55
56static unsigned int get_time_pit(void)
57{
58 unsigned long flags;
59 unsigned int count;
60
61 raw_spin_lock_irqsave(&i8253_lock, flags);
62 outb_p(0x00, 0x43);
63 count = inb_p(0x40);
64 count |= inb_p(0x40) << 8;
65 raw_spin_unlock_irqrestore(&i8253_lock, flags);
66
67 return count;
68}
69
70#endif
71
72
73
74/*
75 * gameport_measure_speed() measures the gameport i/o speed.
76 */
77
78static int gameport_measure_speed(struct gameport *gameport)
79{
80 unsigned int i, t, tx;
81 u64 t1, t2, t3;
82 unsigned long flags;
83
84 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
85 return 0;
86
87 tx = ~0;
88
89 for (i = 0; i < 50; i++) {
90 local_irq_save(flags);
91 t1 = ktime_get_ns();
92 for (t = 0; t < 50; t++)
93 gameport_read(gameport);
94 t2 = ktime_get_ns();
95 t3 = ktime_get_ns();
96 local_irq_restore(flags);
97 udelay(i * 10);
98 t = (t2 - t1) - (t3 - t2);
99 if (t < tx)
100 tx = t;
101 }
102
103 gameport_close(gameport);
104 t = 1000000 * 50;
105 if (tx)
106 t /= tx;
107 return t;
108}
109
110static int old_gameport_measure_speed(struct gameport *gameport)
111{
112#if defined(__i386__)
113
114 unsigned int i, t, t1, t2, t3, tx;
115 unsigned long flags;
116
117 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
118 return 0;
119
120 tx = 1 << 30;
121
122 for(i = 0; i < 50; i++) {
123 local_irq_save(flags);
124 GET_TIME(t1);
125 for (t = 0; t < 50; t++) gameport_read(gameport);
126 GET_TIME(t2);
127 GET_TIME(t3);
128 local_irq_restore(flags);
129 udelay(i * 10);
130 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
131 }
132
133 gameport_close(gameport);
134 return 59659 / (tx < 1 ? 1 : tx);
135
136#elif defined (__x86_64__)
137
138 unsigned int i, t;
139 unsigned long tx, t1, t2, flags;
140
141 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
142 return 0;
143
144 tx = 1 << 30;
145
146 for(i = 0; i < 50; i++) {
147 local_irq_save(flags);
148 t1 = rdtsc();
149 for (t = 0; t < 50; t++) gameport_read(gameport);
150 t2 = rdtsc();
151 local_irq_restore(flags);
152 udelay(i * 10);
153 if (t2 - t1 < tx) tx = t2 - t1;
154 }
155
156 gameport_close(gameport);
157 return (this_cpu_read(cpu_info.loops_per_jiffy) *
158 (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
159
160#else
161
162 unsigned int j, t = 0;
163
164 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
165 return 0;
166
167 j = jiffies; while (j == jiffies);
168 j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
169
170 gameport_close(gameport);
171 return t * HZ / 1000;
172
173#endif
174}
175
176void gameport_start_polling(struct gameport *gameport)
177{
178 spin_lock(&gameport->timer_lock);
179
180 if (!gameport->poll_cnt++) {
181 BUG_ON(!gameport->poll_handler);
182 BUG_ON(!gameport->poll_interval);
183 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
184 }
185
186 spin_unlock(&gameport->timer_lock);
187}
188EXPORT_SYMBOL(gameport_start_polling);
189
190void gameport_stop_polling(struct gameport *gameport)
191{
192 spin_lock(&gameport->timer_lock);
193
194 if (!--gameport->poll_cnt)
195 del_timer(&gameport->poll_timer);
196
197 spin_unlock(&gameport->timer_lock);
198}
199EXPORT_SYMBOL(gameport_stop_polling);
200
201static void gameport_run_poll_handler(struct timer_list *t)
202{
203 struct gameport *gameport = from_timer(gameport, t, poll_timer);
204
205 gameport->poll_handler(gameport);
206 if (gameport->poll_cnt)
207 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
208}
209
210/*
211 * Basic gameport -> driver core mappings
212 */
213
214static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
215{
216 int error;
217
218 gameport->dev.driver = &drv->driver;
219 if (drv->connect(gameport, drv)) {
220 gameport->dev.driver = NULL;
221 return -ENODEV;
222 }
223
224 error = device_bind_driver(&gameport->dev);
225 if (error) {
226 dev_warn(&gameport->dev,
227 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
228 gameport->phys, gameport->name,
229 drv->description, error);
230 drv->disconnect(gameport);
231 gameport->dev.driver = NULL;
232 return error;
233 }
234
235 return 0;
236}
237
238static void gameport_find_driver(struct gameport *gameport)
239{
240 int error;
241
242 error = device_attach(&gameport->dev);
243 if (error < 0)
244 dev_warn(&gameport->dev,
245 "device_attach() failed for %s (%s), error: %d\n",
246 gameport->phys, gameport->name, error);
247}
248
249
250/*
251 * Gameport event processing.
252 */
253
254enum gameport_event_type {
255 GAMEPORT_REGISTER_PORT,
256 GAMEPORT_ATTACH_DRIVER,
257};
258
259struct gameport_event {
260 enum gameport_event_type type;
261 void *object;
262 struct module *owner;
263 struct list_head node;
264};
265
266static DEFINE_SPINLOCK(gameport_event_lock); /* protects gameport_event_list */
267static LIST_HEAD(gameport_event_list);
268
269static struct gameport_event *gameport_get_event(void)
270{
271 struct gameport_event *event = NULL;
272 unsigned long flags;
273
274 spin_lock_irqsave(&gameport_event_lock, flags);
275
276 if (!list_empty(&gameport_event_list)) {
277 event = list_first_entry(&gameport_event_list,
278 struct gameport_event, node);
279 list_del_init(&event->node);
280 }
281
282 spin_unlock_irqrestore(&gameport_event_lock, flags);
283 return event;
284}
285
286static void gameport_free_event(struct gameport_event *event)
287{
288 module_put(event->owner);
289 kfree(event);
290}
291
292static void gameport_remove_duplicate_events(struct gameport_event *event)
293{
294 struct gameport_event *e, *next;
295 unsigned long flags;
296
297 spin_lock_irqsave(&gameport_event_lock, flags);
298
299 list_for_each_entry_safe(e, next, &gameport_event_list, 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(&e->node);
310 gameport_free_event(e);
311 }
312 }
313
314 spin_unlock_irqrestore(&gameport_event_lock, flags);
315}
316
317
318static void gameport_handle_events(struct work_struct *work)
319{
320 struct gameport_event *event;
321
322 mutex_lock(&gameport_mutex);
323
324 /*
325 * Note that we handle only one event here to give swsusp
326 * a chance to freeze kgameportd thread. Gameport events
327 * should be pretty rare so we are not concerned about
328 * taking performance hit.
329 */
330 if ((event = gameport_get_event())) {
331
332 switch (event->type) {
333
334 case GAMEPORT_REGISTER_PORT:
335 gameport_add_port(event->object);
336 break;
337
338 case GAMEPORT_ATTACH_DRIVER:
339 gameport_attach_driver(event->object);
340 break;
341 }
342
343 gameport_remove_duplicate_events(event);
344 gameport_free_event(event);
345 }
346
347 mutex_unlock(&gameport_mutex);
348}
349
350static DECLARE_WORK(gameport_event_work, gameport_handle_events);
351
352static int gameport_queue_event(void *object, struct module *owner,
353 enum gameport_event_type event_type)
354{
355 unsigned long flags;
356 struct gameport_event *event;
357 int retval = 0;
358
359 spin_lock_irqsave(&gameport_event_lock, flags);
360
361 /*
362 * Scan event list for the other events for the same gameport port,
363 * starting with the most recent one. If event is the same we
364 * do not need add new one. If event is of different type we
365 * need to add this event and should not look further because
366 * we need to preserve sequence of distinct events.
367 */
368 list_for_each_entry_reverse(event, &gameport_event_list, node) {
369 if (event->object == object) {
370 if (event->type == event_type)
371 goto out;
372 break;
373 }
374 }
375
376 event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC);
377 if (!event) {
378 pr_err("Not enough memory to queue event %d\n", event_type);
379 retval = -ENOMEM;
380 goto out;
381 }
382
383 if (!try_module_get(owner)) {
384 pr_warn("Can't get module reference, dropping event %d\n",
385 event_type);
386 kfree(event);
387 retval = -EINVAL;
388 goto out;
389 }
390
391 event->type = event_type;
392 event->object = object;
393 event->owner = owner;
394
395 list_add_tail(&event->node, &gameport_event_list);
396 queue_work(system_long_wq, &gameport_event_work);
397
398out:
399 spin_unlock_irqrestore(&gameport_event_lock, flags);
400 return retval;
401}
402
403/*
404 * Remove all events that have been submitted for a given object,
405 * be it a gameport port or a driver.
406 */
407static void gameport_remove_pending_events(void *object)
408{
409 struct gameport_event *event, *next;
410 unsigned long flags;
411
412 spin_lock_irqsave(&gameport_event_lock, flags);
413
414 list_for_each_entry_safe(event, next, &gameport_event_list, node) {
415 if (event->object == object) {
416 list_del_init(&event->node);
417 gameport_free_event(event);
418 }
419 }
420
421 spin_unlock_irqrestore(&gameport_event_lock, flags);
422}
423
424/*
425 * Destroy child gameport port (if any) that has not been fully registered yet.
426 *
427 * Note that we rely on the fact that port can have only one child and therefore
428 * only one child registration request can be pending. Additionally, children
429 * are registered by driver's connect() handler so there can't be a grandchild
430 * pending registration together with a child.
431 */
432static struct gameport *gameport_get_pending_child(struct gameport *parent)
433{
434 struct gameport_event *event;
435 struct gameport *gameport, *child = NULL;
436 unsigned long flags;
437
438 spin_lock_irqsave(&gameport_event_lock, flags);
439
440 list_for_each_entry(event, &gameport_event_list, node) {
441 if (event->type == GAMEPORT_REGISTER_PORT) {
442 gameport = event->object;
443 if (gameport->parent == parent) {
444 child = gameport;
445 break;
446 }
447 }
448 }
449
450 spin_unlock_irqrestore(&gameport_event_lock, flags);
451 return child;
452}
453
454/*
455 * Gameport port operations
456 */
457
458static ssize_t gameport_description_show(struct device *dev, struct device_attribute *attr, char *buf)
459{
460 struct gameport *gameport = to_gameport_port(dev);
461
462 return sprintf(buf, "%s\n", gameport->name);
463}
464static DEVICE_ATTR(description, S_IRUGO, gameport_description_show, NULL);
465
466static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
467{
468 struct gameport *gameport = to_gameport_port(dev);
469 struct device_driver *drv;
470 int error;
471
472 error = mutex_lock_interruptible(&gameport_mutex);
473 if (error)
474 return error;
475
476 if (!strncmp(buf, "none", count)) {
477 gameport_disconnect_port(gameport);
478 } else if (!strncmp(buf, "reconnect", count)) {
479 gameport_reconnect_port(gameport);
480 } else if (!strncmp(buf, "rescan", count)) {
481 gameport_disconnect_port(gameport);
482 gameport_find_driver(gameport);
483 } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
484 gameport_disconnect_port(gameport);
485 error = gameport_bind_driver(gameport, to_gameport_driver(drv));
486 } else {
487 error = -EINVAL;
488 }
489
490 mutex_unlock(&gameport_mutex);
491
492 return error ? error : count;
493}
494static DEVICE_ATTR_WO(drvctl);
495
496static struct attribute *gameport_device_attrs[] = {
497 &dev_attr_description.attr,
498 &dev_attr_drvctl.attr,
499 NULL,
500};
501ATTRIBUTE_GROUPS(gameport_device);
502
503static void gameport_release_port(struct device *dev)
504{
505 struct gameport *gameport = to_gameport_port(dev);
506
507 kfree(gameport);
508 module_put(THIS_MODULE);
509}
510
511void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
512{
513 va_list args;
514
515 va_start(args, fmt);
516 vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
517 va_end(args);
518}
519EXPORT_SYMBOL(gameport_set_phys);
520
521/*
522 * Prepare gameport port for registration.
523 */
524static void gameport_init_port(struct gameport *gameport)
525{
526 static atomic_t gameport_no = ATOMIC_INIT(-1);
527
528 __module_get(THIS_MODULE);
529
530 mutex_init(&gameport->drv_mutex);
531 device_initialize(&gameport->dev);
532 dev_set_name(&gameport->dev, "gameport%lu",
533 (unsigned long)atomic_inc_return(&gameport_no));
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 timer_setup(&gameport->poll_timer, gameport_run_poll_handler, 0);
542}
543
544/*
545 * Complete gameport port registration.
546 * Driver core will attempt to find appropriate driver for the port.
547 */
548static void gameport_add_port(struct gameport *gameport)
549{
550 int error;
551
552 if (gameport->parent)
553 gameport->parent->child = gameport;
554
555 gameport->speed = use_ktime ?
556 gameport_measure_speed(gameport) :
557 old_gameport_measure_speed(gameport);
558
559 list_add_tail(&gameport->node, &gameport_list);
560
561 if (gameport->io)
562 dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n",
563 gameport->name, gameport->phys, gameport->io, gameport->speed);
564 else
565 dev_info(&gameport->dev, "%s is %s, speed %dkHz\n",
566 gameport->name, gameport->phys, gameport->speed);
567
568 error = device_add(&gameport->dev);
569 if (error)
570 dev_err(&gameport->dev,
571 "device_add() failed for %s (%s), error: %d\n",
572 gameport->phys, gameport->name, error);
573}
574
575/*
576 * gameport_destroy_port() completes deregistration process and removes
577 * port from the system
578 */
579static void gameport_destroy_port(struct gameport *gameport)
580{
581 struct gameport *child;
582
583 child = gameport_get_pending_child(gameport);
584 if (child) {
585 gameport_remove_pending_events(child);
586 put_device(&child->dev);
587 }
588
589 if (gameport->parent) {
590 gameport->parent->child = NULL;
591 gameport->parent = NULL;
592 }
593
594 if (device_is_registered(&gameport->dev))
595 device_del(&gameport->dev);
596
597 list_del_init(&gameport->node);
598
599 gameport_remove_pending_events(gameport);
600 put_device(&gameport->dev);
601}
602
603/*
604 * Reconnect gameport port and all its children (re-initialize attached devices)
605 */
606static void gameport_reconnect_port(struct gameport *gameport)
607{
608 do {
609 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
610 gameport_disconnect_port(gameport);
611 gameport_find_driver(gameport);
612 /* Ok, old children are now gone, we are done */
613 break;
614 }
615 gameport = gameport->child;
616 } while (gameport);
617}
618
619/*
620 * gameport_disconnect_port() unbinds a port from its driver. As a side effect
621 * all child ports are unbound and destroyed.
622 */
623static void gameport_disconnect_port(struct gameport *gameport)
624{
625 struct gameport *s, *parent;
626
627 if (gameport->child) {
628 /*
629 * Children ports should be disconnected and destroyed
630 * first, staring with the leaf one, since we don't want
631 * to do recursion
632 */
633 for (s = gameport; s->child; s = s->child)
634 /* empty */;
635
636 do {
637 parent = s->parent;
638
639 device_release_driver(&s->dev);
640 gameport_destroy_port(s);
641 } while ((s = parent) != gameport);
642 }
643
644 /*
645 * Ok, no children left, now disconnect this port
646 */
647 device_release_driver(&gameport->dev);
648}
649
650/*
651 * Submits register request to kgameportd for subsequent execution.
652 * Note that port registration is always asynchronous.
653 */
654void __gameport_register_port(struct gameport *gameport, struct module *owner)
655{
656 gameport_init_port(gameport);
657 gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
658}
659EXPORT_SYMBOL(__gameport_register_port);
660
661/*
662 * Synchronously unregisters gameport port.
663 */
664void gameport_unregister_port(struct gameport *gameport)
665{
666 mutex_lock(&gameport_mutex);
667 gameport_disconnect_port(gameport);
668 gameport_destroy_port(gameport);
669 mutex_unlock(&gameport_mutex);
670}
671EXPORT_SYMBOL(gameport_unregister_port);
672
673
674/*
675 * Gameport driver operations
676 */
677
678static ssize_t description_show(struct device_driver *drv, char *buf)
679{
680 struct gameport_driver *driver = to_gameport_driver(drv);
681 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
682}
683static DRIVER_ATTR_RO(description);
684
685static struct attribute *gameport_driver_attrs[] = {
686 &driver_attr_description.attr,
687 NULL
688};
689ATTRIBUTE_GROUPS(gameport_driver);
690
691static int gameport_driver_probe(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->connect(gameport, drv);
697 return gameport->drv ? 0 : -ENODEV;
698}
699
700static void gameport_driver_remove(struct device *dev)
701{
702 struct gameport *gameport = to_gameport_port(dev);
703 struct gameport_driver *drv = to_gameport_driver(dev->driver);
704
705 drv->disconnect(gameport);
706}
707
708static void gameport_attach_driver(struct gameport_driver *drv)
709{
710 int error;
711
712 error = driver_attach(&drv->driver);
713 if (error)
714 pr_err("driver_attach() failed for %s, error: %d\n",
715 drv->driver.name, error);
716}
717
718int __gameport_register_driver(struct gameport_driver *drv, struct module *owner,
719 const char *mod_name)
720{
721 int error;
722
723 drv->driver.bus = &gameport_bus;
724 drv->driver.owner = owner;
725 drv->driver.mod_name = mod_name;
726
727 /*
728 * Temporarily disable automatic binding because probing
729 * takes long time and we are better off doing it in kgameportd
730 */
731 drv->ignore = true;
732
733 error = driver_register(&drv->driver);
734 if (error) {
735 pr_err("driver_register() failed for %s, error: %d\n",
736 drv->driver.name, error);
737 return error;
738 }
739
740 /*
741 * Reset ignore flag and let kgameportd bind the driver to free ports
742 */
743 drv->ignore = false;
744 error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER);
745 if (error) {
746 driver_unregister(&drv->driver);
747 return error;
748 }
749
750 return 0;
751}
752EXPORT_SYMBOL(__gameport_register_driver);
753
754void gameport_unregister_driver(struct gameport_driver *drv)
755{
756 struct gameport *gameport;
757
758 mutex_lock(&gameport_mutex);
759
760 drv->ignore = true; /* so gameport_find_driver ignores it */
761 gameport_remove_pending_events(drv);
762
763start_over:
764 list_for_each_entry(gameport, &gameport_list, node) {
765 if (gameport->drv == drv) {
766 gameport_disconnect_port(gameport);
767 gameport_find_driver(gameport);
768 /* we could've deleted some ports, restart */
769 goto start_over;
770 }
771 }
772
773 driver_unregister(&drv->driver);
774
775 mutex_unlock(&gameport_mutex);
776}
777EXPORT_SYMBOL(gameport_unregister_driver);
778
779static int gameport_bus_match(struct device *dev, struct device_driver *drv)
780{
781 struct gameport_driver *gameport_drv = to_gameport_driver(drv);
782
783 return !gameport_drv->ignore;
784}
785
786static struct bus_type gameport_bus = {
787 .name = "gameport",
788 .dev_groups = gameport_device_groups,
789 .drv_groups = gameport_driver_groups,
790 .match = gameport_bus_match,
791 .probe = gameport_driver_probe,
792 .remove = gameport_driver_remove,
793};
794
795static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
796{
797 mutex_lock(&gameport->drv_mutex);
798 gameport->drv = drv;
799 mutex_unlock(&gameport->drv_mutex);
800}
801
802int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
803{
804 if (gameport->open) {
805 if (gameport->open(gameport, mode)) {
806 return -1;
807 }
808 } else {
809 if (mode != GAMEPORT_MODE_RAW)
810 return -1;
811 }
812
813 gameport_set_drv(gameport, drv);
814 return 0;
815}
816EXPORT_SYMBOL(gameport_open);
817
818void gameport_close(struct gameport *gameport)
819{
820 del_timer_sync(&gameport->poll_timer);
821 gameport->poll_handler = NULL;
822 gameport->poll_interval = 0;
823 gameport_set_drv(gameport, NULL);
824 if (gameport->close)
825 gameport->close(gameport);
826}
827EXPORT_SYMBOL(gameport_close);
828
829static int __init gameport_init(void)
830{
831 int error;
832
833 error = bus_register(&gameport_bus);
834 if (error) {
835 pr_err("failed to register gameport bus, error: %d\n", error);
836 return error;
837 }
838
839
840 return 0;
841}
842
843static void __exit gameport_exit(void)
844{
845 bus_unregister(&gameport_bus);
846
847 /*
848 * There should not be any outstanding events but work may
849 * still be scheduled so simply cancel it.
850 */
851 cancel_work_sync(&gameport_event_work);
852}
853
854subsys_initcall(gameport_init);
855module_exit(gameport_exit);
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/module.h>
18#include <linux/ioport.h>
19#include <linux/init.h>
20#include <linux/gameport.h>
21#include <linux/slab.h>
22#include <linux/delay.h>
23#include <linux/workqueue.h>
24#include <linux/sched.h> /* HZ */
25#include <linux/mutex.h>
26
27/*#include <asm/io.h>*/
28
29MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30MODULE_DESCRIPTION("Generic gameport layer");
31MODULE_LICENSE("GPL");
32
33/*
34 * gameport_mutex protects entire gameport subsystem and is taken
35 * every time gameport port or driver registrered or unregistered.
36 */
37static DEFINE_MUTEX(gameport_mutex);
38
39static LIST_HEAD(gameport_list);
40
41static struct bus_type gameport_bus;
42
43static void gameport_add_port(struct gameport *gameport);
44static void gameport_attach_driver(struct gameport_driver *drv);
45static void gameport_reconnect_port(struct gameport *gameport);
46static void gameport_disconnect_port(struct gameport *gameport);
47
48#if defined(__i386__)
49
50#include <linux/i8253.h>
51
52#define DELTA(x,y) ((y)-(x)+((y)<(x)?1193182/HZ:0))
53#define GET_TIME(x) do { x = get_time_pit(); } while (0)
54
55static unsigned int get_time_pit(void)
56{
57 unsigned long flags;
58 unsigned int count;
59
60 raw_spin_lock_irqsave(&i8253_lock, flags);
61 outb_p(0x00, 0x43);
62 count = inb_p(0x40);
63 count |= inb_p(0x40) << 8;
64 raw_spin_unlock_irqrestore(&i8253_lock, flags);
65
66 return count;
67}
68
69#endif
70
71
72
73/*
74 * gameport_measure_speed() measures the gameport i/o speed.
75 */
76
77static int gameport_measure_speed(struct gameport *gameport)
78{
79#if defined(__i386__)
80
81 unsigned int i, t, t1, t2, t3, tx;
82 unsigned long flags;
83
84 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
85 return 0;
86
87 tx = 1 << 30;
88
89 for(i = 0; i < 50; i++) {
90 local_irq_save(flags);
91 GET_TIME(t1);
92 for (t = 0; t < 50; t++) gameport_read(gameport);
93 GET_TIME(t2);
94 GET_TIME(t3);
95 local_irq_restore(flags);
96 udelay(i * 10);
97 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
98 }
99
100 gameport_close(gameport);
101 return 59659 / (tx < 1 ? 1 : tx);
102
103#elif defined (__x86_64__)
104
105 unsigned int i, t;
106 unsigned long tx, t1, t2, flags;
107
108 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
109 return 0;
110
111 tx = 1 << 30;
112
113 for(i = 0; i < 50; i++) {
114 local_irq_save(flags);
115 rdtscl(t1);
116 for (t = 0; t < 50; t++) gameport_read(gameport);
117 rdtscl(t2);
118 local_irq_restore(flags);
119 udelay(i * 10);
120 if (t2 - t1 < tx) tx = t2 - t1;
121 }
122
123 gameport_close(gameport);
124 return (this_cpu_read(cpu_info.loops_per_jiffy) *
125 (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
126
127#else
128
129 unsigned int j, t = 0;
130
131 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
132 return 0;
133
134 j = jiffies; while (j == jiffies);
135 j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
136
137 gameport_close(gameport);
138 return t * HZ / 1000;
139
140#endif
141}
142
143void gameport_start_polling(struct gameport *gameport)
144{
145 spin_lock(&gameport->timer_lock);
146
147 if (!gameport->poll_cnt++) {
148 BUG_ON(!gameport->poll_handler);
149 BUG_ON(!gameport->poll_interval);
150 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
151 }
152
153 spin_unlock(&gameport->timer_lock);
154}
155EXPORT_SYMBOL(gameport_start_polling);
156
157void gameport_stop_polling(struct gameport *gameport)
158{
159 spin_lock(&gameport->timer_lock);
160
161 if (!--gameport->poll_cnt)
162 del_timer(&gameport->poll_timer);
163
164 spin_unlock(&gameport->timer_lock);
165}
166EXPORT_SYMBOL(gameport_stop_polling);
167
168static void gameport_run_poll_handler(unsigned long d)
169{
170 struct gameport *gameport = (struct gameport *)d;
171
172 gameport->poll_handler(gameport);
173 if (gameport->poll_cnt)
174 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
175}
176
177/*
178 * Basic gameport -> driver core mappings
179 */
180
181static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
182{
183 int error;
184
185 gameport->dev.driver = &drv->driver;
186 if (drv->connect(gameport, drv)) {
187 gameport->dev.driver = NULL;
188 return -ENODEV;
189 }
190
191 error = device_bind_driver(&gameport->dev);
192 if (error) {
193 dev_warn(&gameport->dev,
194 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
195 gameport->phys, gameport->name,
196 drv->description, error);
197 drv->disconnect(gameport);
198 gameport->dev.driver = NULL;
199 return error;
200 }
201
202 return 0;
203}
204
205static void gameport_find_driver(struct gameport *gameport)
206{
207 int error;
208
209 error = device_attach(&gameport->dev);
210 if (error < 0)
211 dev_warn(&gameport->dev,
212 "device_attach() failed for %s (%s), error: %d\n",
213 gameport->phys, gameport->name, error);
214}
215
216
217/*
218 * Gameport event processing.
219 */
220
221enum gameport_event_type {
222 GAMEPORT_REGISTER_PORT,
223 GAMEPORT_ATTACH_DRIVER,
224};
225
226struct gameport_event {
227 enum gameport_event_type type;
228 void *object;
229 struct module *owner;
230 struct list_head node;
231};
232
233static DEFINE_SPINLOCK(gameport_event_lock); /* protects gameport_event_list */
234static LIST_HEAD(gameport_event_list);
235
236static struct gameport_event *gameport_get_event(void)
237{
238 struct gameport_event *event = NULL;
239 unsigned long flags;
240
241 spin_lock_irqsave(&gameport_event_lock, flags);
242
243 if (!list_empty(&gameport_event_list)) {
244 event = list_first_entry(&gameport_event_list,
245 struct gameport_event, node);
246 list_del_init(&event->node);
247 }
248
249 spin_unlock_irqrestore(&gameport_event_lock, flags);
250 return event;
251}
252
253static void gameport_free_event(struct gameport_event *event)
254{
255 module_put(event->owner);
256 kfree(event);
257}
258
259static void gameport_remove_duplicate_events(struct gameport_event *event)
260{
261 struct gameport_event *e, *next;
262 unsigned long flags;
263
264 spin_lock_irqsave(&gameport_event_lock, flags);
265
266 list_for_each_entry_safe(e, next, &gameport_event_list, node) {
267 if (event->object == e->object) {
268 /*
269 * If this event is of different type we should not
270 * look further - we only suppress duplicate events
271 * that were sent back-to-back.
272 */
273 if (event->type != e->type)
274 break;
275
276 list_del_init(&e->node);
277 gameport_free_event(e);
278 }
279 }
280
281 spin_unlock_irqrestore(&gameport_event_lock, flags);
282}
283
284
285static void gameport_handle_events(struct work_struct *work)
286{
287 struct gameport_event *event;
288
289 mutex_lock(&gameport_mutex);
290
291 /*
292 * Note that we handle only one event here to give swsusp
293 * a chance to freeze kgameportd thread. Gameport events
294 * should be pretty rare so we are not concerned about
295 * taking performance hit.
296 */
297 if ((event = gameport_get_event())) {
298
299 switch (event->type) {
300
301 case GAMEPORT_REGISTER_PORT:
302 gameport_add_port(event->object);
303 break;
304
305 case GAMEPORT_ATTACH_DRIVER:
306 gameport_attach_driver(event->object);
307 break;
308 }
309
310 gameport_remove_duplicate_events(event);
311 gameport_free_event(event);
312 }
313
314 mutex_unlock(&gameport_mutex);
315}
316
317static DECLARE_WORK(gameport_event_work, gameport_handle_events);
318
319static int gameport_queue_event(void *object, struct module *owner,
320 enum gameport_event_type event_type)
321{
322 unsigned long flags;
323 struct gameport_event *event;
324 int retval = 0;
325
326 spin_lock_irqsave(&gameport_event_lock, flags);
327
328 /*
329 * Scan event list for the other events for the same gameport port,
330 * starting with the most recent one. If event is the same we
331 * do not need add new one. If event is of different type we
332 * need to add this event and should not look further because
333 * we need to preserve sequence of distinct events.
334 */
335 list_for_each_entry_reverse(event, &gameport_event_list, node) {
336 if (event->object == object) {
337 if (event->type == event_type)
338 goto out;
339 break;
340 }
341 }
342
343 event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC);
344 if (!event) {
345 pr_err("Not enough memory to queue event %d\n", event_type);
346 retval = -ENOMEM;
347 goto out;
348 }
349
350 if (!try_module_get(owner)) {
351 pr_warning("Can't get module reference, dropping event %d\n",
352 event_type);
353 kfree(event);
354 retval = -EINVAL;
355 goto out;
356 }
357
358 event->type = event_type;
359 event->object = object;
360 event->owner = owner;
361
362 list_add_tail(&event->node, &gameport_event_list);
363 queue_work(system_long_wq, &gameport_event_work);
364
365out:
366 spin_unlock_irqrestore(&gameport_event_lock, flags);
367 return retval;
368}
369
370/*
371 * Remove all events that have been submitted for a given object,
372 * be it a gameport port or a driver.
373 */
374static void gameport_remove_pending_events(void *object)
375{
376 struct gameport_event *event, *next;
377 unsigned long flags;
378
379 spin_lock_irqsave(&gameport_event_lock, flags);
380
381 list_for_each_entry_safe(event, next, &gameport_event_list, node) {
382 if (event->object == object) {
383 list_del_init(&event->node);
384 gameport_free_event(event);
385 }
386 }
387
388 spin_unlock_irqrestore(&gameport_event_lock, flags);
389}
390
391/*
392 * Destroy child gameport port (if any) that has not been fully registered yet.
393 *
394 * Note that we rely on the fact that port can have only one child and therefore
395 * only one child registration request can be pending. Additionally, children
396 * are registered by driver's connect() handler so there can't be a grandchild
397 * pending registration together with a child.
398 */
399static struct gameport *gameport_get_pending_child(struct gameport *parent)
400{
401 struct gameport_event *event;
402 struct gameport *gameport, *child = NULL;
403 unsigned long flags;
404
405 spin_lock_irqsave(&gameport_event_lock, flags);
406
407 list_for_each_entry(event, &gameport_event_list, node) {
408 if (event->type == GAMEPORT_REGISTER_PORT) {
409 gameport = event->object;
410 if (gameport->parent == parent) {
411 child = gameport;
412 break;
413 }
414 }
415 }
416
417 spin_unlock_irqrestore(&gameport_event_lock, flags);
418 return child;
419}
420
421/*
422 * Gameport port operations
423 */
424
425static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
426{
427 struct gameport *gameport = to_gameport_port(dev);
428
429 return sprintf(buf, "%s\n", gameport->name);
430}
431
432static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
433{
434 struct gameport *gameport = to_gameport_port(dev);
435 struct device_driver *drv;
436 int error;
437
438 error = mutex_lock_interruptible(&gameport_mutex);
439 if (error)
440 return error;
441
442 if (!strncmp(buf, "none", count)) {
443 gameport_disconnect_port(gameport);
444 } else if (!strncmp(buf, "reconnect", count)) {
445 gameport_reconnect_port(gameport);
446 } else if (!strncmp(buf, "rescan", count)) {
447 gameport_disconnect_port(gameport);
448 gameport_find_driver(gameport);
449 } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
450 gameport_disconnect_port(gameport);
451 error = gameport_bind_driver(gameport, to_gameport_driver(drv));
452 put_driver(drv);
453 } else {
454 error = -EINVAL;
455 }
456
457 mutex_unlock(&gameport_mutex);
458
459 return error ? error : count;
460}
461
462static struct device_attribute gameport_device_attrs[] = {
463 __ATTR(description, S_IRUGO, gameport_show_description, NULL),
464 __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
465 __ATTR_NULL
466};
467
468static void gameport_release_port(struct device *dev)
469{
470 struct gameport *gameport = to_gameport_port(dev);
471
472 kfree(gameport);
473 module_put(THIS_MODULE);
474}
475
476void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
477{
478 va_list args;
479
480 va_start(args, fmt);
481 vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
482 va_end(args);
483}
484EXPORT_SYMBOL(gameport_set_phys);
485
486/*
487 * Prepare gameport port for registration.
488 */
489static void gameport_init_port(struct gameport *gameport)
490{
491 static atomic_t gameport_no = ATOMIC_INIT(0);
492
493 __module_get(THIS_MODULE);
494
495 mutex_init(&gameport->drv_mutex);
496 device_initialize(&gameport->dev);
497 dev_set_name(&gameport->dev, "gameport%lu",
498 (unsigned long)atomic_inc_return(&gameport_no) - 1);
499 gameport->dev.bus = &gameport_bus;
500 gameport->dev.release = gameport_release_port;
501 if (gameport->parent)
502 gameport->dev.parent = &gameport->parent->dev;
503
504 INIT_LIST_HEAD(&gameport->node);
505 spin_lock_init(&gameport->timer_lock);
506 init_timer(&gameport->poll_timer);
507 gameport->poll_timer.function = gameport_run_poll_handler;
508 gameport->poll_timer.data = (unsigned long)gameport;
509}
510
511/*
512 * Complete gameport port registration.
513 * Driver core will attempt to find appropriate driver for the port.
514 */
515static void gameport_add_port(struct gameport *gameport)
516{
517 int error;
518
519 if (gameport->parent)
520 gameport->parent->child = gameport;
521
522 gameport->speed = gameport_measure_speed(gameport);
523
524 list_add_tail(&gameport->node, &gameport_list);
525
526 if (gameport->io)
527 dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n",
528 gameport->name, gameport->phys, gameport->io, gameport->speed);
529 else
530 dev_info(&gameport->dev, "%s is %s, speed %dkHz\n",
531 gameport->name, gameport->phys, gameport->speed);
532
533 error = device_add(&gameport->dev);
534 if (error)
535 dev_err(&gameport->dev,
536 "device_add() failed for %s (%s), error: %d\n",
537 gameport->phys, gameport->name, error);
538}
539
540/*
541 * gameport_destroy_port() completes deregistration process and removes
542 * port from the system
543 */
544static void gameport_destroy_port(struct gameport *gameport)
545{
546 struct gameport *child;
547
548 child = gameport_get_pending_child(gameport);
549 if (child) {
550 gameport_remove_pending_events(child);
551 put_device(&child->dev);
552 }
553
554 if (gameport->parent) {
555 gameport->parent->child = NULL;
556 gameport->parent = NULL;
557 }
558
559 if (device_is_registered(&gameport->dev))
560 device_del(&gameport->dev);
561
562 list_del_init(&gameport->node);
563
564 gameport_remove_pending_events(gameport);
565 put_device(&gameport->dev);
566}
567
568/*
569 * Reconnect gameport port and all its children (re-initialize attached devices)
570 */
571static void gameport_reconnect_port(struct gameport *gameport)
572{
573 do {
574 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
575 gameport_disconnect_port(gameport);
576 gameport_find_driver(gameport);
577 /* Ok, old children are now gone, we are done */
578 break;
579 }
580 gameport = gameport->child;
581 } while (gameport);
582}
583
584/*
585 * gameport_disconnect_port() unbinds a port from its driver. As a side effect
586 * all child ports are unbound and destroyed.
587 */
588static void gameport_disconnect_port(struct gameport *gameport)
589{
590 struct gameport *s, *parent;
591
592 if (gameport->child) {
593 /*
594 * Children ports should be disconnected and destroyed
595 * first, staring with the leaf one, since we don't want
596 * to do recursion
597 */
598 for (s = gameport; s->child; s = s->child)
599 /* empty */;
600
601 do {
602 parent = s->parent;
603
604 device_release_driver(&s->dev);
605 gameport_destroy_port(s);
606 } while ((s = parent) != gameport);
607 }
608
609 /*
610 * Ok, no children left, now disconnect this port
611 */
612 device_release_driver(&gameport->dev);
613}
614
615/*
616 * Submits register request to kgameportd for subsequent execution.
617 * Note that port registration is always asynchronous.
618 */
619void __gameport_register_port(struct gameport *gameport, struct module *owner)
620{
621 gameport_init_port(gameport);
622 gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
623}
624EXPORT_SYMBOL(__gameport_register_port);
625
626/*
627 * Synchronously unregisters gameport port.
628 */
629void gameport_unregister_port(struct gameport *gameport)
630{
631 mutex_lock(&gameport_mutex);
632 gameport_disconnect_port(gameport);
633 gameport_destroy_port(gameport);
634 mutex_unlock(&gameport_mutex);
635}
636EXPORT_SYMBOL(gameport_unregister_port);
637
638
639/*
640 * Gameport driver operations
641 */
642
643static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
644{
645 struct gameport_driver *driver = to_gameport_driver(drv);
646 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
647}
648
649static struct driver_attribute gameport_driver_attrs[] = {
650 __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
651 __ATTR_NULL
652};
653
654static int gameport_driver_probe(struct device *dev)
655{
656 struct gameport *gameport = to_gameport_port(dev);
657 struct gameport_driver *drv = to_gameport_driver(dev->driver);
658
659 drv->connect(gameport, drv);
660 return gameport->drv ? 0 : -ENODEV;
661}
662
663static int gameport_driver_remove(struct device *dev)
664{
665 struct gameport *gameport = to_gameport_port(dev);
666 struct gameport_driver *drv = to_gameport_driver(dev->driver);
667
668 drv->disconnect(gameport);
669 return 0;
670}
671
672static void gameport_attach_driver(struct gameport_driver *drv)
673{
674 int error;
675
676 error = driver_attach(&drv->driver);
677 if (error)
678 pr_err("driver_attach() failed for %s, error: %d\n",
679 drv->driver.name, error);
680}
681
682int __gameport_register_driver(struct gameport_driver *drv, struct module *owner,
683 const char *mod_name)
684{
685 int error;
686
687 drv->driver.bus = &gameport_bus;
688 drv->driver.owner = owner;
689 drv->driver.mod_name = mod_name;
690
691 /*
692 * Temporarily disable automatic binding because probing
693 * takes long time and we are better off doing it in kgameportd
694 */
695 drv->ignore = true;
696
697 error = driver_register(&drv->driver);
698 if (error) {
699 pr_err("driver_register() failed for %s, error: %d\n",
700 drv->driver.name, error);
701 return error;
702 }
703
704 /*
705 * Reset ignore flag and let kgameportd bind the driver to free ports
706 */
707 drv->ignore = false;
708 error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER);
709 if (error) {
710 driver_unregister(&drv->driver);
711 return error;
712 }
713
714 return 0;
715}
716EXPORT_SYMBOL(__gameport_register_driver);
717
718void gameport_unregister_driver(struct gameport_driver *drv)
719{
720 struct gameport *gameport;
721
722 mutex_lock(&gameport_mutex);
723
724 drv->ignore = true; /* so gameport_find_driver ignores it */
725 gameport_remove_pending_events(drv);
726
727start_over:
728 list_for_each_entry(gameport, &gameport_list, node) {
729 if (gameport->drv == drv) {
730 gameport_disconnect_port(gameport);
731 gameport_find_driver(gameport);
732 /* we could've deleted some ports, restart */
733 goto start_over;
734 }
735 }
736
737 driver_unregister(&drv->driver);
738
739 mutex_unlock(&gameport_mutex);
740}
741EXPORT_SYMBOL(gameport_unregister_driver);
742
743static int gameport_bus_match(struct device *dev, struct device_driver *drv)
744{
745 struct gameport_driver *gameport_drv = to_gameport_driver(drv);
746
747 return !gameport_drv->ignore;
748}
749
750static struct bus_type gameport_bus = {
751 .name = "gameport",
752 .dev_attrs = gameport_device_attrs,
753 .drv_attrs = gameport_driver_attrs,
754 .match = gameport_bus_match,
755 .probe = gameport_driver_probe,
756 .remove = gameport_driver_remove,
757};
758
759static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
760{
761 mutex_lock(&gameport->drv_mutex);
762 gameport->drv = drv;
763 mutex_unlock(&gameport->drv_mutex);
764}
765
766int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
767{
768 if (gameport->open) {
769 if (gameport->open(gameport, mode)) {
770 return -1;
771 }
772 } else {
773 if (mode != GAMEPORT_MODE_RAW)
774 return -1;
775 }
776
777 gameport_set_drv(gameport, drv);
778 return 0;
779}
780EXPORT_SYMBOL(gameport_open);
781
782void gameport_close(struct gameport *gameport)
783{
784 del_timer_sync(&gameport->poll_timer);
785 gameport->poll_handler = NULL;
786 gameport->poll_interval = 0;
787 gameport_set_drv(gameport, NULL);
788 if (gameport->close)
789 gameport->close(gameport);
790}
791EXPORT_SYMBOL(gameport_close);
792
793static int __init gameport_init(void)
794{
795 int error;
796
797 error = bus_register(&gameport_bus);
798 if (error) {
799 pr_err("failed to register gameport bus, error: %d\n", error);
800 return error;
801 }
802
803
804 return 0;
805}
806
807static void __exit gameport_exit(void)
808{
809 bus_unregister(&gameport_bus);
810
811 /*
812 * There should not be any outstanding events but work may
813 * still be scheduled so simply cancel it.
814 */
815 cancel_work_sync(&gameport_event_work);
816}
817
818subsys_initcall(gameport_init);
819module_exit(gameport_exit);