drivers/input/serio/serio.c

   1 /*
   2  *  The Serio abstraction module
   3  *
   4  *  Copyright (c) 1999-2004 Vojtech Pavlik
   5  *  Copyright (c) 2004 Dmitry Torokhov
   6  *  Copyright (c) 2003 Daniele Bellucci
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
  26  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
  27  */
  28
  29 #include <linux/stddef.h>
  30 #include <linux/module.h>
  31 #include <linux/serio.h>
  32 #include <linux/errno.h>
  33 #include <linux/wait.h>
  34 #include <linux/completion.h>
  35 #include <linux/sched.h>
  36 #include <linux/smp_lock.h>
  37 #include <linux/slab.h>
  38
  39 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  40 MODULE_DESCRIPTION("Serio abstraction core");
  41 MODULE_LICENSE("GPL");
  42
  43 EXPORT_SYMBOL(serio_interrupt);
  44 EXPORT_SYMBOL(__serio_register_port);
  45 EXPORT_SYMBOL(serio_unregister_port);
  46 EXPORT_SYMBOL(__serio_unregister_port_delayed);
  47 EXPORT_SYMBOL(__serio_register_driver);
  48 EXPORT_SYMBOL(serio_unregister_driver);
  49 EXPORT_SYMBOL(serio_open);
  50 EXPORT_SYMBOL(serio_close);
  51 EXPORT_SYMBOL(serio_rescan);
  52 EXPORT_SYMBOL(serio_reconnect);
  53
  54 /*
  55  * serio_sem protects entire serio subsystem and is taken every time
  56  * serio port or driver registrered or unregistered.
  57  */
  58 static DECLARE_MUTEX(serio_sem);
  59
  60 static LIST_HEAD(serio_list);
  61
  62 static struct bus_type serio_bus = {
  63         .name = "serio",
  64 };
  65
  66 static void serio_add_port(struct serio *serio);
  67 static void serio_destroy_port(struct serio *serio);
  68 static void serio_reconnect_port(struct serio *serio);
  69 static void serio_disconnect_port(struct serio *serio);
  70
  71 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
  72 {
  73         while (ids->type || ids->proto) {
  74                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
  75                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
  76                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
  77                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
  78                         return 1;
  79                 ids++;
  80         }
  81         return 0;
  82 }
  83
  84 /*
  85  * Basic serio -> driver core mappings
  86  */
  87
  88 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
  89 {
  90         down_write(&serio_bus.subsys.rwsem);
  91
  92         if (serio_match_port(drv->id_table, serio)) {
  93                 serio->dev.driver = &drv->driver;
  94                 if (drv->connect(serio, drv)) {
  95                         serio->dev.driver = NULL;
  96                         goto out;
  97                 }
  98                 device_bind_driver(&serio->dev);
  99         }
 100 out:
 101         up_write(&serio_bus.subsys.rwsem);
 102 }
 103
 104 static void serio_release_driver(struct serio *serio)
 105 {
 106         down_write(&serio_bus.subsys.rwsem);
 107         device_release_driver(&serio->dev);
 108         up_write(&serio_bus.subsys.rwsem);
 109 }
 110
 111 static void serio_find_driver(struct serio *serio)
 112 {
 113         down_write(&serio_bus.subsys.rwsem);
 114         device_attach(&serio->dev);
 115         up_write(&serio_bus.subsys.rwsem);
 116 }
 117
 118
 119 /*
 120  * Serio event processing.
 121  */
 122
 123 enum serio_event_type {
 124         SERIO_RESCAN,
 125         SERIO_RECONNECT,
 126         SERIO_REGISTER_PORT,
 127         SERIO_UNREGISTER_PORT,
 128         SERIO_REGISTER_DRIVER,
 129 };
 130
 131 struct serio_event {
 132         enum serio_event_type type;
 133         void *object;
 134         struct module *owner;
 135         struct list_head node;
 136 };
 137
 138 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 139 static LIST_HEAD(serio_event_list);
 140 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 141 static DECLARE_COMPLETION(serio_exited);
 142 static int serio_pid;
 143
 144 static void serio_queue_event(void *object, struct module *owner,
 145                               enum serio_event_type event_type)
 146 {
 147         unsigned long flags;
 148         struct serio_event *event;
 149
 150         spin_lock_irqsave(&serio_event_lock, flags);
 151
 152         /*
 153          * Scan event list for the other events for the same serio port,
 154          * starting with the most recent one. If event is the same we
 155          * do not need add new one. If event is of different type we
 156          * need to add this event and should not look further because
 157          * we need to preseve sequence of distinct events.
 158          */
 159         list_for_each_entry_reverse(event, &serio_event_list, node) {
 160                 if (event->object == object) {
 161                         if (event->type == event_type)
 162                                 goto out;
 163                         break;
 164                 }
 165         }
 166
 167         if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
 168                 if (!try_module_get(owner)) {
 169                         printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
 170                         goto out;
 171                 }
 172
 173                 event->type = event_type;
 174                 event->object = object;
 175                 event->owner = owner;
 176
 177                 list_add_tail(&event->node, &serio_event_list);
 178                 wake_up(&serio_wait);
 179         } else {
 180                 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
 181         }
 182 out:
 183         spin_unlock_irqrestore(&serio_event_lock, flags);
 184 }
 185
 186 static void serio_free_event(struct serio_event *event)
 187 {
 188         module_put(event->owner);
 189         kfree(event);
 190 }
 191
 192 static void serio_remove_duplicate_events(struct serio_event *event)
 193 {
 194         struct list_head *node, *next;
 195         struct serio_event *e;
 196         unsigned long flags;
 197
 198         spin_lock_irqsave(&serio_event_lock, flags);
 199
 200         list_for_each_safe(node, next, &serio_event_list) {
 201                 e = list_entry(node, struct serio_event, node);
 202                 if (event->object == e->object) {
 203                         /*
 204                          * If this event is of different type we should not
 205                          * look further - we only suppress duplicate events
 206                          * that were sent back-to-back.
 207                          */
 208                         if (event->type != e->type)
 209                                 break;
 210
 211                         list_del_init(node);
 212                         serio_free_event(e);
 213                 }
 214         }
 215
 216         spin_unlock_irqrestore(&serio_event_lock, flags);
 217 }
 218
 219
 220 static struct serio_event *serio_get_event(void)
 221 {
 222         struct serio_event *event;
 223         struct list_head *node;
 224         unsigned long flags;
 225
 226         spin_lock_irqsave(&serio_event_lock, flags);
 227
 228         if (list_empty(&serio_event_list)) {
 229                 spin_unlock_irqrestore(&serio_event_lock, flags);
 230                 return NULL;
 231         }
 232
 233         node = serio_event_list.next;
 234         event = list_entry(node, struct serio_event, node);
 235         list_del_init(node);
 236
 237         spin_unlock_irqrestore(&serio_event_lock, flags);
 238
 239         return event;
 240 }
 241
 242 static void serio_handle_events(void)
 243 {
 244         struct serio_event *event;
 245         struct serio_driver *serio_drv;
 246
 247         down(&serio_sem);
 248
 249         while ((event = serio_get_event())) {
 250
 251                 switch (event->type) {
 252                         case SERIO_REGISTER_PORT:
 253                                 serio_add_port(event->object);
 254                                 break;
 255
 256                         case SERIO_UNREGISTER_PORT:
 257                                 serio_disconnect_port(event->object);
 258                                 serio_destroy_port(event->object);
 259                                 break;
 260
 261                         case SERIO_RECONNECT:
 262                                 serio_reconnect_port(event->object);
 263                                 break;
 264
 265                         case SERIO_RESCAN:
 266                                 serio_disconnect_port(event->object);
 267                                 serio_find_driver(event->object);
 268                                 break;
 269
 270                         case SERIO_REGISTER_DRIVER:
 271                                 serio_drv = event->object;
 272                                 driver_register(&serio_drv->driver);
 273                                 break;
 274
 275                         default:
 276                                 break;
 277                 }
 278
 279                 serio_remove_duplicate_events(event);
 280                 serio_free_event(event);
 281         }
 282
 283         up(&serio_sem);
 284 }
 285
 286 /*
 287  * Remove all events that have been submitted for a given serio port.
 288  */
 289 static void serio_remove_pending_events(struct serio *serio)
 290 {
 291         struct list_head *node, *next;
 292         struct serio_event *event;
 293         unsigned long flags;
 294
 295         spin_lock_irqsave(&serio_event_lock, flags);
 296
 297         list_for_each_safe(node, next, &serio_event_list) {
 298                 event = list_entry(node, struct serio_event, node);
 299                 if (event->object == serio) {
 300                         list_del_init(node);
 301                         serio_free_event(event);
 302                 }
 303         }
 304
 305         spin_unlock_irqrestore(&serio_event_lock, flags);
 306 }
 307
 308 /*
 309  * Destroy child serio port (if any) that has not been fully registered yet.
 310  *
 311  * Note that we rely on the fact that port can have only one child and therefore
 312  * only one child registration request can be pending. Additionally, children
 313  * are registered by driver's connect() handler so there can't be a grandchild
 314  * pending registration together with a child.
 315  */
 316 static struct serio *serio_get_pending_child(struct serio *parent)
 317 {
 318         struct serio_event *event;
 319         struct serio *serio, *child = NULL;
 320         unsigned long flags;
 321
 322         spin_lock_irqsave(&serio_event_lock, flags);
 323
 324         list_for_each_entry(event, &serio_event_list, node) {
 325                 if (event->type == SERIO_REGISTER_PORT) {
 326                         serio = event->object;
 327                         if (serio->parent == parent) {
 328                                 child = serio;
 329                                 break;
 330                         }
 331                 }
 332         }
 333
 334         spin_unlock_irqrestore(&serio_event_lock, flags);
 335         return child;
 336 }
 337
 338 static int serio_thread(void *nothing)
 339 {
 340         lock_kernel();
 341         daemonize("kseriod");
 342         allow_signal(SIGTERM);
 343
 344         do {
 345                 serio_handle_events();
 346                 wait_event_interruptible(serio_wait, !list_empty(&serio_event_list));
 347                 try_to_freeze(PF_FREEZE);
 348         } while (!signal_pending(current));
 349
 350         printk(KERN_DEBUG "serio: kseriod exiting\n");
 351
 352         unlock_kernel();
 353         complete_and_exit(&serio_exited, 0);
 354 }
 355
 356
 357 /*
 358  * Serio port operations
 359  */
 360
 361 static ssize_t serio_show_description(struct device *dev, char *buf)
 362 {
 363         struct serio *serio = to_serio_port(dev);
 364         return sprintf(buf, "%s\n", serio->name);
 365 }
 366
 367 static ssize_t serio_show_id_type(struct device *dev, char *buf)
 368 {
 369         struct serio *serio = to_serio_port(dev);
 370         return sprintf(buf, "%02x\n", serio->id.type);
 371 }
 372
 373 static ssize_t serio_show_id_proto(struct device *dev, char *buf)
 374 {
 375         struct serio *serio = to_serio_port(dev);
 376         return sprintf(buf, "%02x\n", serio->id.proto);
 377 }
 378
 379 static ssize_t serio_show_id_id(struct device *dev, char *buf)
 380 {
 381         struct serio *serio = to_serio_port(dev);
 382         return sprintf(buf, "%02x\n", serio->id.id);
 383 }
 384
 385 static ssize_t serio_show_id_extra(struct device *dev, char *buf)
 386 {
 387         struct serio *serio = to_serio_port(dev);
 388         return sprintf(buf, "%02x\n", serio->id.extra);
 389 }
 390
 391 static ssize_t serio_rebind_driver(struct device *dev, const char *buf, size_t count)
 392 {
 393         struct serio *serio = to_serio_port(dev);
 394         struct device_driver *drv;
 395         int retval;
 396
 397         retval = down_interruptible(&serio_sem);
 398         if (retval)
 399                 return retval;
 400
 401         retval = count;
 402         if (!strncmp(buf, "none", count)) {
 403                 serio_disconnect_port(serio);
 404         } else if (!strncmp(buf, "reconnect", count)) {
 405                 serio_reconnect_port(serio);
 406         } else if (!strncmp(buf, "rescan", count)) {
 407                 serio_disconnect_port(serio);
 408                 serio_find_driver(serio);
 409         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 410                 serio_disconnect_port(serio);
 411                 serio_bind_driver(serio, to_serio_driver(drv));
 412                 put_driver(drv);
 413         } else {
 414                 retval = -EINVAL;
 415         }
 416
 417         up(&serio_sem);
 418
 419         return retval;
 420 }
 421
 422 static ssize_t serio_show_bind_mode(struct device *dev, char *buf)
 423 {
 424         struct serio *serio = to_serio_port(dev);
 425         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 426 }
 427
 428 static ssize_t serio_set_bind_mode(struct device *dev, const char *buf, size_t count)
 429 {
 430         struct serio *serio = to_serio_port(dev);
 431         int retval;
 432
 433         retval = count;
 434         if (!strncmp(buf, "manual", count)) {
 435                 serio->manual_bind = 1;
 436         } else if (!strncmp(buf, "auto", count)) {
 437                 serio->manual_bind = 0;
 438         } else {
 439                 retval = -EINVAL;
 440         }
 441
 442         return retval;
 443 }
 444
 445 static struct device_attribute serio_device_attrs[] = {
 446         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 447         __ATTR(id_type, S_IRUGO, serio_show_id_type, NULL),
 448         __ATTR(id_proto, S_IRUGO, serio_show_id_proto, NULL),
 449         __ATTR(id_id, S_IRUGO, serio_show_id_id, NULL),
 450         __ATTR(id_extra, S_IRUGO, serio_show_id_extra, NULL),
 451         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 452         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 453         __ATTR_NULL
 454 };
 455
 456
 457 static void serio_release_port(struct device *dev)
 458 {
 459         struct serio *serio = to_serio_port(dev);
 460
 461         kfree(serio);
 462         module_put(THIS_MODULE);
 463 }
 464
 465 /*
 466  * Prepare serio port for registration.
 467  */
 468 static void serio_init_port(struct serio *serio)
 469 {
 470         static atomic_t serio_no = ATOMIC_INIT(0);
 471
 472         __module_get(THIS_MODULE);
 473
 474         spin_lock_init(&serio->lock);
 475         init_MUTEX(&serio->drv_sem);
 476         device_initialize(&serio->dev);
 477         snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
 478                  "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
 479         serio->dev.bus = &serio_bus;
 480         serio->dev.release = serio_release_port;
 481         if (serio->parent)
 482                 serio->dev.parent = &serio->parent->dev;
 483 }
 484
 485 /*
 486  * Complete serio port registration.
 487  * Driver core will attempt to find appropriate driver for the port.
 488  */
 489 static void serio_add_port(struct serio *serio)
 490 {
 491         if (serio->parent) {
 492                 serio_pause_rx(serio->parent);
 493                 serio->parent->child = serio;
 494                 serio_continue_rx(serio->parent);
 495         }
 496
 497         list_add_tail(&serio->node, &serio_list);
 498         if (serio->start)
 499                 serio->start(serio);
 500         device_add(&serio->dev);
 501         serio->registered = 1;
 502 }
 503
 504 /*
 505  * serio_destroy_port() completes deregistration process and removes
 506  * port from the system
 507  */
 508 static void serio_destroy_port(struct serio *serio)
 509 {
 510         struct serio *child;
 511
 512         child = serio_get_pending_child(serio);
 513         if (child) {
 514                 serio_remove_pending_events(child);
 515                 put_device(&child->dev);
 516         }
 517
 518         if (serio->stop)
 519                 serio->stop(serio);
 520
 521         if (serio->parent) {
 522                 serio_pause_rx(serio->parent);
 523                 serio->parent->child = NULL;
 524                 serio_continue_rx(serio->parent);
 525                 serio->parent = NULL;
 526         }
 527
 528         if (serio->registered) {
 529                 device_del(&serio->dev);
 530                 list_del_init(&serio->node);
 531                 serio->registered = 0;
 532         }
 533
 534         serio_remove_pending_events(serio);
 535         put_device(&serio->dev);
 536 }
 537
 538 /*
 539  * Reconnect serio port and all its children (re-initialize attached devices)
 540  */
 541 static void serio_reconnect_port(struct serio *serio)
 542 {
 543         do {
 544                 if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
 545                         serio_disconnect_port(serio);
 546                         serio_find_driver(serio);
 547                         /* Ok, old children are now gone, we are done */
 548                         break;
 549                 }
 550                 serio = serio->child;
 551         } while (serio);
 552 }
 553
 554 /*
 555  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 556  * all child ports are unbound and destroyed.
 557  */
 558 static void serio_disconnect_port(struct serio *serio)
 559 {
 560         struct serio *s, *parent;
 561
 562         if (serio->child) {
 563                 /*
 564                  * Children ports should be disconnected and destroyed
 565                  * first, staring with the leaf one, since we don't want
 566                  * to do recursion
 567                  */
 568                 for (s = serio; s->child; s = s->child)
 569                         /* empty */;
 570
 571                 do {
 572                         parent = s->parent;
 573
 574                         serio_release_driver(s);
 575                         serio_destroy_port(s);
 576                 } while ((s = parent) != serio);
 577         }
 578
 579         /*
 580          * Ok, no children left, now disconnect this port
 581          */
 582         serio_release_driver(serio);
 583 }
 584
 585 void serio_rescan(struct serio *serio)
 586 {
 587         serio_queue_event(serio, NULL, SERIO_RESCAN);
 588 }
 589
 590 void serio_reconnect(struct serio *serio)
 591 {
 592         serio_queue_event(serio, NULL, SERIO_RECONNECT);
 593 }
 594
 595 /*
 596  * Submits register request to kseriod for subsequent execution.
 597  * Note that port registration is always asynchronous.
 598  */
 599 void __serio_register_port(struct serio *serio, struct module *owner)
 600 {
 601         serio_init_port(serio);
 602         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 603 }
 604
 605 /*
 606  * Synchronously unregisters serio port.
 607  */
 608 void serio_unregister_port(struct serio *serio)
 609 {
 610         down(&serio_sem);
 611         serio_disconnect_port(serio);
 612         serio_destroy_port(serio);
 613         up(&serio_sem);
 614 }
 615
 616 /*
 617  * Submits register request to kseriod for subsequent execution.
 618  * Can be used when it is not obvious whether the serio_sem is
 619  * taken or not and when delayed execution is feasible.
 620  */
 621 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
 622 {
 623         serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
 624 }
 625
 626
 627 /*
 628  * Serio driver operations
 629  */
 630
 631 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 632 {
 633         struct serio_driver *driver = to_serio_driver(drv);
 634         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 635 }
 636
 637 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 638 {
 639         struct serio_driver *serio_drv = to_serio_driver(drv);
 640         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 641 }
 642
 643 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 644 {
 645         struct serio_driver *serio_drv = to_serio_driver(drv);
 646         int retval;
 647
 648         retval = count;
 649         if (!strncmp(buf, "manual", count)) {
 650                 serio_drv->manual_bind = 1;
 651         } else if (!strncmp(buf, "auto", count)) {
 652                 serio_drv->manual_bind = 0;
 653         } else {
 654                 retval = -EINVAL;
 655         }
 656
 657         return retval;
 658 }
 659
 660
 661 static struct driver_attribute serio_driver_attrs[] = {
 662         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 663         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 664                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 665         __ATTR_NULL
 666 };
 667
 668 static int serio_driver_probe(struct device *dev)
 669 {
 670         struct serio *serio = to_serio_port(dev);
 671         struct serio_driver *drv = to_serio_driver(dev->driver);
 672
 673         return drv->connect(serio, drv);
 674 }
 675
 676 static int serio_driver_remove(struct device *dev)
 677 {
 678         struct serio *serio = to_serio_port(dev);
 679         struct serio_driver *drv = to_serio_driver(dev->driver);
 680
 681         drv->disconnect(serio);
 682         return 0;
 683 }
 684
 685 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
 686 {
 687         drv->driver.bus = &serio_bus;
 688         drv->driver.probe = serio_driver_probe;
 689         drv->driver.remove = serio_driver_remove;
 690
 691         serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
 692 }
 693
 694 void serio_unregister_driver(struct serio_driver *drv)
 695 {
 696         struct serio *serio;
 697
 698         down(&serio_sem);
 699         drv->manual_bind = 1;   /* so serio_find_driver ignores it */
 700
 701 start_over:
 702         list_for_each_entry(serio, &serio_list, node) {
 703                 if (serio->drv == drv) {
 704                         serio_disconnect_port(serio);
 705                         serio_find_driver(serio);
 706                         /* we could've deleted some ports, restart */
 707                         goto start_over;
 708                 }
 709         }
 710
 711         driver_unregister(&drv->driver);
 712         up(&serio_sem);
 713 }
 714
 715 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 716 {
 717         down(&serio->drv_sem);
 718         serio_pause_rx(serio);
 719         serio->drv = drv;
 720         serio_continue_rx(serio);
 721         up(&serio->drv_sem);
 722 }
 723
 724 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 725 {
 726         struct serio *serio = to_serio_port(dev);
 727         struct serio_driver *serio_drv = to_serio_driver(drv);
 728
 729         if (serio->manual_bind || serio_drv->manual_bind)
 730                 return 0;
 731
 732         return serio_match_port(serio_drv->id_table, serio);
 733 }
 734
 735 #ifdef CONFIG_HOTPLUG
 736
 737 #define PUT_ENVP(fmt, val)                                              \
 738 do {                                                                    \
 739         envp[i++] = buffer;                                             \
 740         length += snprintf(buffer, buffer_size - length, fmt, val);     \
 741         if (buffer_size - length <= 0 || i >= num_envp)                 \
 742                 return -ENOMEM;                                         \
 743         length++;                                                       \
 744         buffer += length;                                               \
 745 } while (0)
 746 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 747 {
 748         struct serio *serio;
 749         int i = 0;
 750         int length = 0;
 751
 752         if (!dev)
 753                 return -ENODEV;
 754
 755         serio = to_serio_port(dev);
 756
 757         PUT_ENVP("SERIO_TYPE=%02x", serio->id.type);
 758         PUT_ENVP("SERIO_PROTO=%02x", serio->id.proto);
 759         PUT_ENVP("SERIO_ID=%02x", serio->id.id);
 760         PUT_ENVP("SERIO_EXTRA=%02x", serio->id.extra);
 761
 762         envp[i] = NULL;
 763
 764         return 0;
 765 }
 766 #undef PUT_ENVP
 767
 768 #else
 769
 770 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 771 {
 772         return -ENODEV;
 773 }
 774
 775 #endif /* CONFIG_HOTPLUG */
 776
 777 static int serio_resume(struct device *dev)
 778 {
 779         struct serio *serio = to_serio_port(dev);
 780
 781         if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
 782                 /*
 783                  * Driver re-probing can take a while, so better let kseriod
 784                  * deal with it.
 785                  */
 786                 serio_rescan(serio);
 787         }
 788
 789         return 0;
 790 }
 791
 792 /* called from serio_driver->connect/disconnect methods under serio_sem */
 793 int serio_open(struct serio *serio, struct serio_driver *drv)
 794 {
 795         serio_set_drv(serio, drv);
 796
 797         if (serio->open && serio->open(serio)) {
 798                 serio_set_drv(serio, NULL);
 799                 return -1;
 800         }
 801         return 0;
 802 }
 803
 804 /* called from serio_driver->connect/disconnect methods under serio_sem */
 805 void serio_close(struct serio *serio)
 806 {
 807         if (serio->close)
 808                 serio->close(serio);
 809
 810         serio_set_drv(serio, NULL);
 811 }
 812
 813 irqreturn_t serio_interrupt(struct serio *serio,
 814                 unsigned char data, unsigned int dfl, struct pt_regs *regs)
 815 {
 816         unsigned long flags;
 817         irqreturn_t ret = IRQ_NONE;
 818
 819         spin_lock_irqsave(&serio->lock, flags);
 820
 821         if (likely(serio->drv)) {
 822                 ret = serio->drv->interrupt(serio, data, dfl, regs);
 823         } else if (!dfl && serio->registered) {
 824                 serio_rescan(serio);
 825                 ret = IRQ_HANDLED;
 826         }
 827
 828         spin_unlock_irqrestore(&serio->lock, flags);
 829
 830         return ret;
 831 }
 832
 833 static int __init serio_init(void)
 834 {
 835         if (!(serio_pid = kernel_thread(serio_thread, NULL, CLONE_KERNEL))) {
 836                 printk(KERN_ERR "serio: Failed to start kseriod\n");
 837                 return -1;
 838         }
 839
 840         serio_bus.dev_attrs = serio_device_attrs;
 841         serio_bus.drv_attrs = serio_driver_attrs;
 842         serio_bus.match = serio_bus_match;
 843         serio_bus.hotplug = serio_hotplug;
 844         serio_bus.resume = serio_resume;
 845         bus_register(&serio_bus);
 846
 847         return 0;
 848 }
 849
 850 static void __exit serio_exit(void)
 851 {
 852         bus_unregister(&serio_bus);
 853         kill_proc(serio_pid, SIGTERM, 1);
 854         wait_for_completion(&serio_exited);
 855 }
 856
 857 module_init(serio_init);
 858 module_exit(serio_exit);