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/io.h> 15#include <linux/ioport.h> 16#include <linux/init.h> 17#include <linux/gameport.h> 18#include <linux/slab.h> 19#include <linux/delay.h> 20#include <linux/workqueue.h> 21#include <linux/sched.h> /* HZ */ 22#include <linux/mutex.h> 23#include <linux/timekeeping.h> 24 25MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 26MODULE_DESCRIPTION("Generic gameport layer"); 27MODULE_LICENSE("GPL"); 28 29static bool use_ktime = true; 30module_param(use_ktime, bool, 0400); 31MODULE_PARM_DESC(use_ktime, "Use ktime for measuring I/O speed"); 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 const 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 unsigned int i, t, tx; 80 u64 t1, t2, t3; 81 unsigned long flags; 82 83 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) 84 return 0; 85 86 tx = ~0; 87 88 for (i = 0; i < 50; i++) { 89 local_irq_save(flags); 90 t1 = ktime_get_ns(); 91 for (t = 0; t < 50; t++) 92 gameport_read(gameport); 93 t2 = ktime_get_ns(); 94 t3 = ktime_get_ns(); 95 local_irq_restore(flags); 96 udelay(i * 10); 97 t = (t2 - t1) - (t3 - t2); 98 if (t < tx) 99 tx = t; 100 } 101 102 gameport_close(gameport); 103 t = 1000000 * 50; 104 if (tx) 105 t /= tx; 106 return t; 107} 108 109static int old_gameport_measure_speed(struct gameport *gameport) 110{ 111#if defined(__i386__) 112 113 unsigned int i, t, t1, t2, t3, tx; 114 unsigned long flags; 115 116 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) 117 return 0; 118 119 tx = 1 << 30; 120 121 for(i = 0; i < 50; i++) { 122 local_irq_save(flags); 123 GET_TIME(t1); 124 for (t = 0; t < 50; t++) gameport_read(gameport); 125 GET_TIME(t2); 126 GET_TIME(t3); 127 local_irq_restore(flags); 128 udelay(i * 10); 129 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t; 130 } 131 132 gameport_close(gameport); 133 return 59659 / (tx < 1 ? 1 : tx); 134 135#elif defined (__x86_64__) 136 137 unsigned int i, t; 138 unsigned long tx, t1, t2, flags; 139 140 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) 141 return 0; 142 143 tx = 1 << 30; 144 145 for(i = 0; i < 50; i++) { 146 local_irq_save(flags); 147 t1 = rdtsc(); 148 for (t = 0; t < 50; t++) gameport_read(gameport); 149 t2 = rdtsc(); 150 local_irq_restore(flags); 151 udelay(i * 10); 152 if (t2 - t1 < tx) tx = t2 - t1; 153 } 154 155 gameport_close(gameport); 156 return (this_cpu_read(cpu_info.loops_per_jiffy) * 157 (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx); 158 159#else 160 161 unsigned int j, t = 0; 162 163 if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) 164 return 0; 165 166 j = jiffies; while (j == jiffies); 167 j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); } 168 169 gameport_close(gameport); 170 return t * HZ / 1000; 171 172#endif 173} 174 175void gameport_start_polling(struct gameport *gameport) 176{ 177 spin_lock(&gameport->timer_lock); 178 179 if (!gameport->poll_cnt++) { 180 BUG_ON(!gameport->poll_handler); 181 BUG_ON(!gameport->poll_interval); 182 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval)); 183 } 184 185 spin_unlock(&gameport->timer_lock); 186} 187EXPORT_SYMBOL(gameport_start_polling); 188 189void gameport_stop_polling(struct gameport *gameport) 190{ 191 spin_lock(&gameport->timer_lock); 192 193 if (!--gameport->poll_cnt) 194 del_timer(&gameport->poll_timer); 195 196 spin_unlock(&gameport->timer_lock); 197} 198EXPORT_SYMBOL(gameport_stop_polling); 199 200static void gameport_run_poll_handler(struct timer_list *t) 201{ 202 struct gameport *gameport = from_timer(gameport, t, poll_timer); 203 204 gameport->poll_handler(gameport); 205 if (gameport->poll_cnt) 206 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval)); 207} 208 209/* 210 * Basic gameport -> driver core mappings 211 */ 212 213static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv) 214{ 215 int error; 216 217 gameport->dev.driver = &drv->driver; 218 if (drv->connect(gameport, drv)) { 219 gameport->dev.driver = NULL; 220 return -ENODEV; 221 } 222 223 error = device_bind_driver(&gameport->dev); 224 if (error) { 225 dev_warn(&gameport->dev, 226 "device_bind_driver() failed for %s (%s) and %s, error: %d\n", 227 gameport->phys, gameport->name, 228 drv->description, error); 229 drv->disconnect(gameport); 230 gameport->dev.driver = NULL; 231 return error; 232 } 233 234 return 0; 235} 236 237static void gameport_find_driver(struct gameport *gameport) 238{ 239 int error; 240 241 error = device_attach(&gameport->dev); 242 if (error < 0) 243 dev_warn(&gameport->dev, 244 "device_attach() failed for %s (%s), error: %d\n", 245 gameport->phys, gameport->name, error); 246} 247 248 249/* 250 * Gameport event processing. 251 */ 252 253enum gameport_event_type { 254 GAMEPORT_REGISTER_PORT, 255 GAMEPORT_ATTACH_DRIVER, 256}; 257 258struct gameport_event { 259 enum gameport_event_type type; 260 void *object; 261 struct module *owner; 262 struct list_head node; 263}; 264 265static DEFINE_SPINLOCK(gameport_event_lock); /* protects gameport_event_list */ 266static LIST_HEAD(gameport_event_list); 267 268static struct gameport_event *gameport_get_event(void) 269{ 270 struct gameport_event *event = NULL; 271 unsigned long flags; 272 273 spin_lock_irqsave(&gameport_event_lock, flags); 274 275 if (!list_empty(&gameport_event_list)) { 276 event = list_first_entry(&gameport_event_list, 277 struct gameport_event, node); 278 list_del_init(&event->node); 279 } 280 281 spin_unlock_irqrestore(&gameport_event_lock, flags); 282 return event; 283} 284 285static void gameport_free_event(struct gameport_event *event) 286{ 287 module_put(event->owner); 288 kfree(event); 289} 290 291static void gameport_remove_duplicate_events(struct gameport_event *event) 292{ 293 struct gameport_event *e, *next; 294 unsigned long flags; 295 296 spin_lock_irqsave(&gameport_event_lock, flags); 297 298 list_for_each_entry_safe(e, next, &gameport_event_list, node) { 299 if (event->object == e->object) { 300 /* 301 * If this event is of different type we should not 302 * look further - we only suppress duplicate events 303 * that were sent back-to-back. 304 */ 305 if (event->type != e->type) 306 break; 307 308 list_del_init(&e->node); 309 gameport_free_event(e); 310 } 311 } 312 313 spin_unlock_irqrestore(&gameport_event_lock, flags); 314} 315 316 317static void gameport_handle_events(struct work_struct *work) 318{ 319 struct gameport_event *event; 320 321 mutex_lock(&gameport_mutex); 322 323 /* 324 * Note that we handle only one event here to give swsusp 325 * a chance to freeze kgameportd thread. Gameport events 326 * should be pretty rare so we are not concerned about 327 * taking performance hit. 328 */ 329 if ((event = gameport_get_event())) { 330 331 switch (event->type) { 332 333 case GAMEPORT_REGISTER_PORT: 334 gameport_add_port(event->object); 335 break; 336 337 case GAMEPORT_ATTACH_DRIVER: 338 gameport_attach_driver(event->object); 339 break; 340 } 341 342 gameport_remove_duplicate_events(event); 343 gameport_free_event(event); 344 } 345 346 mutex_unlock(&gameport_mutex); 347} 348 349static DECLARE_WORK(gameport_event_work, gameport_handle_events); 350 351static int gameport_queue_event(void *object, struct module *owner, 352 enum gameport_event_type event_type) 353{ 354 unsigned long flags; 355 struct gameport_event *event; 356 int retval = 0; 357 358 spin_lock_irqsave(&gameport_event_lock, flags); 359 360 /* 361 * Scan event list for the other events for the same gameport port, 362 * starting with the most recent one. If event is the same we 363 * do not need add new one. If event is of different type we 364 * need to add this event and should not look further because 365 * we need to preserve sequence of distinct events. 366 */ 367 list_for_each_entry_reverse(event, &gameport_event_list, node) { 368 if (event->object == object) { 369 if (event->type == event_type) 370 goto out; 371 break; 372 } 373 } 374 375 event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC); 376 if (!event) { 377 pr_err("Not enough memory to queue event %d\n", event_type); 378 retval = -ENOMEM; 379 goto out; 380 } 381 382 if (!try_module_get(owner)) { 383 pr_warn("Can't get module reference, dropping event %d\n", 384 event_type); 385 kfree(event); 386 retval = -EINVAL; 387 goto out; 388 } 389 390 event->type = event_type; 391 event->object = object; 392 event->owner = owner; 393 394 list_add_tail(&event->node, &gameport_event_list); 395 queue_work(system_long_wq, &gameport_event_work); 396 397out: 398 spin_unlock_irqrestore(&gameport_event_lock, flags); 399 return retval; 400} 401 402/* 403 * Remove all events that have been submitted for a given object, 404 * be it a gameport port or a driver. 405 */ 406static void gameport_remove_pending_events(void *object) 407{ 408 struct gameport_event *event, *next; 409 unsigned long flags; 410 411 spin_lock_irqsave(&gameport_event_lock, flags); 412 413 list_for_each_entry_safe(event, next, &gameport_event_list, node) { 414 if (event->object == object) { 415 list_del_init(&event->node); 416 gameport_free_event(event); 417 } 418 } 419 420 spin_unlock_irqrestore(&gameport_event_lock, flags); 421} 422 423/* 424 * Destroy child gameport port (if any) that has not been fully registered yet. 425 * 426 * Note that we rely on the fact that port can have only one child and therefore 427 * only one child registration request can be pending. Additionally, children 428 * are registered by driver's connect() handler so there can't be a grandchild 429 * pending registration together with a child. 430 */ 431static struct gameport *gameport_get_pending_child(struct gameport *parent) 432{ 433 struct gameport_event *event; 434 struct gameport *gameport, *child = NULL; 435 unsigned long flags; 436 437 spin_lock_irqsave(&gameport_event_lock, flags); 438 439 list_for_each_entry(event, &gameport_event_list, node) { 440 if (event->type == GAMEPORT_REGISTER_PORT) { 441 gameport = event->object; 442 if (gameport->parent == parent) { 443 child = gameport; 444 break; 445 } 446 } 447 } 448 449 spin_unlock_irqrestore(&gameport_event_lock, flags); 450 return child; 451} 452 453/* 454 * Gameport port operations 455 */ 456 457static ssize_t gameport_description_show(struct device *dev, struct device_attribute *attr, char *buf) 458{ 459 struct gameport *gameport = to_gameport_port(dev); 460 461 return sprintf(buf, "%s\n", gameport->name); 462} 463static DEVICE_ATTR(description, S_IRUGO, gameport_description_show, NULL); 464 465static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 466{ 467 struct gameport *gameport = to_gameport_port(dev); 468 struct device_driver *drv; 469 int error; 470 471 error = mutex_lock_interruptible(&gameport_mutex); 472 if (error) 473 return error; 474 475 if (!strncmp(buf, "none", count)) { 476 gameport_disconnect_port(gameport); 477 } else if (!strncmp(buf, "reconnect", count)) { 478 gameport_reconnect_port(gameport); 479 } else if (!strncmp(buf, "rescan", count)) { 480 gameport_disconnect_port(gameport); 481 gameport_find_driver(gameport); 482 } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) { 483 gameport_disconnect_port(gameport); 484 error = gameport_bind_driver(gameport, to_gameport_driver(drv)); 485 } else { 486 error = -EINVAL; 487 } 488 489 mutex_unlock(&gameport_mutex); 490 491 return error ? error : count; 492} 493static DEVICE_ATTR_WO(drvctl); 494 495static struct attribute *gameport_device_attrs[] = { 496 &dev_attr_description.attr, 497 &dev_attr_drvctl.attr, 498 NULL, 499}; 500ATTRIBUTE_GROUPS(gameport_device); 501 502static void gameport_release_port(struct device *dev) 503{ 504 struct gameport *gameport = to_gameport_port(dev); 505 506 kfree(gameport); 507 module_put(THIS_MODULE); 508} 509 510void gameport_set_phys(struct gameport *gameport, const char *fmt, ...) 511{ 512 va_list args; 513 514 va_start(args, fmt); 515 vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args); 516 va_end(args); 517} 518EXPORT_SYMBOL(gameport_set_phys); 519 520static void gameport_default_trigger(struct gameport *gameport) 521{ 522#ifdef CONFIG_HAS_IOPORT 523 outb(0xff, gameport->io); 524#endif 525} 526 527static unsigned char gameport_default_read(struct gameport *gameport) 528{ 529#ifdef CONFIG_HAS_IOPORT 530 return inb(gameport->io); 531#else 532 return 0xff; 533#endif 534} 535 536static void gameport_setup_default_handlers(struct gameport *gameport) 537{ 538 if ((!gameport->trigger || !gameport->read) && 539 !IS_ENABLED(CONFIG_HAS_IOPORT)) 540 dev_err(&gameport->dev, 541 "I/O port access is required for %s (%s) but is not available\n", 542 gameport->phys, gameport->name); 543 544 if (!gameport->trigger) 545 gameport->trigger = gameport_default_trigger; 546 if (!gameport->read) 547 gameport->read = gameport_default_read; 548} 549 550/* 551 * Prepare gameport port for registration. 552 */ 553static void gameport_init_port(struct gameport *gameport) 554{ 555 static atomic_t gameport_no = ATOMIC_INIT(-1); 556 557 __module_get(THIS_MODULE); 558 559 mutex_init(&gameport->drv_mutex); 560 device_initialize(&gameport->dev); 561 dev_set_name(&gameport->dev, "gameport%lu", 562 (unsigned long)atomic_inc_return(&gameport_no)); 563 gameport->dev.bus = &gameport_bus; 564 gameport->dev.release = gameport_release_port; 565 if (gameport->parent) 566 gameport->dev.parent = &gameport->parent->dev; 567 568 gameport_setup_default_handlers(gameport); 569 INIT_LIST_HEAD(&gameport->node); 570 spin_lock_init(&gameport->timer_lock); 571 timer_setup(&gameport->poll_timer, gameport_run_poll_handler, 0); 572} 573 574/* 575 * Complete gameport port registration. 576 * Driver core will attempt to find appropriate driver for the port. 577 */ 578static void gameport_add_port(struct gameport *gameport) 579{ 580 int error; 581 582 if (gameport->parent) 583 gameport->parent->child = gameport; 584 585 gameport->speed = use_ktime ? 586 gameport_measure_speed(gameport) : 587 old_gameport_measure_speed(gameport); 588 589 list_add_tail(&gameport->node, &gameport_list); 590 591 if (gameport->io) 592 dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n", 593 gameport->name, gameport->phys, gameport->io, gameport->speed); 594 else 595 dev_info(&gameport->dev, "%s is %s, speed %dkHz\n", 596 gameport->name, gameport->phys, gameport->speed); 597 598 error = device_add(&gameport->dev); 599 if (error) 600 dev_err(&gameport->dev, 601 "device_add() failed for %s (%s), error: %d\n", 602 gameport->phys, gameport->name, error); 603} 604 605/* 606 * gameport_destroy_port() completes deregistration process and removes 607 * port from the system 608 */ 609static void gameport_destroy_port(struct gameport *gameport) 610{ 611 struct gameport *child; 612 613 child = gameport_get_pending_child(gameport); 614 if (child) { 615 gameport_remove_pending_events(child); 616 put_device(&child->dev); 617 } 618 619 if (gameport->parent) { 620 gameport->parent->child = NULL; 621 gameport->parent = NULL; 622 } 623 624 if (device_is_registered(&gameport->dev)) 625 device_del(&gameport->dev); 626 627 list_del_init(&gameport->node); 628 629 gameport_remove_pending_events(gameport); 630 put_device(&gameport->dev); 631} 632 633/* 634 * Reconnect gameport port and all its children (re-initialize attached devices) 635 */ 636static void gameport_reconnect_port(struct gameport *gameport) 637{ 638 do { 639 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) { 640 gameport_disconnect_port(gameport); 641 gameport_find_driver(gameport); 642 /* Ok, old children are now gone, we are done */ 643 break; 644 } 645 gameport = gameport->child; 646 } while (gameport); 647} 648 649/* 650 * gameport_disconnect_port() unbinds a port from its driver. As a side effect 651 * all child ports are unbound and destroyed. 652 */ 653static void gameport_disconnect_port(struct gameport *gameport) 654{ 655 struct gameport *s, *parent; 656 657 if (gameport->child) { 658 /* 659 * Children ports should be disconnected and destroyed 660 * first, staring with the leaf one, since we don't want 661 * to do recursion 662 */ 663 for (s = gameport; s->child; s = s->child) 664 /* empty */; 665 666 do { 667 parent = s->parent; 668 669 device_release_driver(&s->dev); 670 gameport_destroy_port(s); 671 } while ((s = parent) != gameport); 672 } 673 674 /* 675 * Ok, no children left, now disconnect this port 676 */ 677 device_release_driver(&gameport->dev); 678} 679 680/* 681 * Submits register request to kgameportd for subsequent execution. 682 * Note that port registration is always asynchronous. 683 */ 684void __gameport_register_port(struct gameport *gameport, struct module *owner) 685{ 686 gameport_init_port(gameport); 687 gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT); 688} 689EXPORT_SYMBOL(__gameport_register_port); 690 691/* 692 * Synchronously unregisters gameport port. 693 */ 694void gameport_unregister_port(struct gameport *gameport) 695{ 696 mutex_lock(&gameport_mutex); 697 gameport_disconnect_port(gameport); 698 gameport_destroy_port(gameport); 699 mutex_unlock(&gameport_mutex); 700} 701EXPORT_SYMBOL(gameport_unregister_port); 702 703 704/* 705 * Gameport driver operations 706 */ 707 708static ssize_t description_show(struct device_driver *drv, char *buf) 709{ 710 struct gameport_driver *driver = to_gameport_driver(drv); 711 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)"); 712} 713static DRIVER_ATTR_RO(description); 714 715static struct attribute *gameport_driver_attrs[] = { 716 &driver_attr_description.attr, 717 NULL 718}; 719ATTRIBUTE_GROUPS(gameport_driver); 720 721static int gameport_driver_probe(struct device *dev) 722{ 723 struct gameport *gameport = to_gameport_port(dev); 724 struct gameport_driver *drv = to_gameport_driver(dev->driver); 725 726 drv->connect(gameport, drv); 727 return gameport->drv ? 0 : -ENODEV; 728} 729 730static void gameport_driver_remove(struct device *dev) 731{ 732 struct gameport *gameport = to_gameport_port(dev); 733 struct gameport_driver *drv = to_gameport_driver(dev->driver); 734 735 drv->disconnect(gameport); 736} 737 738static void gameport_attach_driver(struct gameport_driver *drv) 739{ 740 int error; 741 742 error = driver_attach(&drv->driver); 743 if (error) 744 pr_err("driver_attach() failed for %s, error: %d\n", 745 drv->driver.name, error); 746} 747 748int __gameport_register_driver(struct gameport_driver *drv, struct module *owner, 749 const char *mod_name) 750{ 751 int error; 752 753 drv->driver.bus = &gameport_bus; 754 drv->driver.owner = owner; 755 drv->driver.mod_name = mod_name; 756 757 /* 758 * Temporarily disable automatic binding because probing 759 * takes long time and we are better off doing it in kgameportd 760 */ 761 drv->ignore = true; 762 763 error = driver_register(&drv->driver); 764 if (error) { 765 pr_err("driver_register() failed for %s, error: %d\n", 766 drv->driver.name, error); 767 return error; 768 } 769 770 /* 771 * Reset ignore flag and let kgameportd bind the driver to free ports 772 */ 773 drv->ignore = false; 774 error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER); 775 if (error) { 776 driver_unregister(&drv->driver); 777 return error; 778 } 779 780 return 0; 781} 782EXPORT_SYMBOL(__gameport_register_driver); 783 784void gameport_unregister_driver(struct gameport_driver *drv) 785{ 786 struct gameport *gameport; 787 788 mutex_lock(&gameport_mutex); 789 790 drv->ignore = true; /* so gameport_find_driver ignores it */ 791 gameport_remove_pending_events(drv); 792 793start_over: 794 list_for_each_entry(gameport, &gameport_list, node) { 795 if (gameport->drv == drv) { 796 gameport_disconnect_port(gameport); 797 gameport_find_driver(gameport); 798 /* we could've deleted some ports, restart */ 799 goto start_over; 800 } 801 } 802 803 driver_unregister(&drv->driver); 804 805 mutex_unlock(&gameport_mutex); 806} 807EXPORT_SYMBOL(gameport_unregister_driver); 808 809static int gameport_bus_match(struct device *dev, struct device_driver *drv) 810{ 811 struct gameport_driver *gameport_drv = to_gameport_driver(drv); 812 813 return !gameport_drv->ignore; 814} 815 816static const struct bus_type gameport_bus = { 817 .name = "gameport", 818 .dev_groups = gameport_device_groups, 819 .drv_groups = gameport_driver_groups, 820 .match = gameport_bus_match, 821 .probe = gameport_driver_probe, 822 .remove = gameport_driver_remove, 823}; 824 825static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv) 826{ 827 mutex_lock(&gameport->drv_mutex); 828 gameport->drv = drv; 829 mutex_unlock(&gameport->drv_mutex); 830} 831 832int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode) 833{ 834 if (gameport->open) { 835 if (gameport->open(gameport, mode)) { 836 return -1; 837 } 838 } else { 839 if (mode != GAMEPORT_MODE_RAW) 840 return -1; 841 } 842 843 gameport_set_drv(gameport, drv); 844 return 0; 845} 846EXPORT_SYMBOL(gameport_open); 847 848void gameport_close(struct gameport *gameport) 849{ 850 del_timer_sync(&gameport->poll_timer); 851 gameport->poll_handler = NULL; 852 gameport->poll_interval = 0; 853 gameport_set_drv(gameport, NULL); 854 if (gameport->close) 855 gameport->close(gameport); 856} 857EXPORT_SYMBOL(gameport_close); 858 859static int __init gameport_init(void) 860{ 861 int error; 862 863 error = bus_register(&gameport_bus); 864 if (error) { 865 pr_err("failed to register gameport bus, error: %d\n", error); 866 return error; 867 } 868 869 870 return 0; 871} 872 873static void __exit gameport_exit(void) 874{ 875 bus_unregister(&gameport_bus); 876 877 /* 878 * There should not be any outstanding events but work may 879 * still be scheduled so simply cancel it. 880 */ 881 cancel_work_sync(&gameport_event_work); 882} 883 884subsys_initcall(gameport_init); 885module_exit(gameport_exit); 886