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();
 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, char *buf)
 386 {
 387         struct serio *serio = to_serio_port(dev);
 388         return sprintf(buf, "%02x\n", serio->id.extra);
 389 }
 390
 391 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 392 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 393 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 394 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 395
 396 static struct attribute *serio_device_id_attrs[] = {
 397         &dev_attr_type.attr,
 398         &dev_attr_proto.attr,
 399         &dev_attr_id.attr,
 400         &dev_attr_extra.attr,
 401         NULL
 402 };
 403
 404 static struct attribute_group serio_id_attr_group = {
 405         .name   = "id",
 406         .attrs  = serio_device_id_attrs,
 407 };
 408
 409 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 410 {
 411         struct serio *serio = to_serio_port(dev);
 412         struct device_driver *drv;
 413         int retval;
 414
 415         retval = down_interruptible(&serio_sem);
 416         if (retval)
 417                 return retval;
 418
 419         retval = count;
 420         if (!strncmp(buf, "none", count)) {
 421                 serio_disconnect_port(serio);
 422         } else if (!strncmp(buf, "reconnect", count)) {
 423                 serio_reconnect_port(serio);
 424         } else if (!strncmp(buf, "rescan", count)) {
 425                 serio_disconnect_port(serio);
 426                 serio_find_driver(serio);
 427         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 428                 serio_disconnect_port(serio);
 429                 serio_bind_driver(serio, to_serio_driver(drv));
 430                 put_driver(drv);
 431         } else {
 432                 retval = -EINVAL;
 433         }
 434
 435         up(&serio_sem);
 436
 437         return retval;
 438 }
 439
 440 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 441 {
 442         struct serio *serio = to_serio_port(dev);
 443         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 444 }
 445
 446 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 447 {
 448         struct serio *serio = to_serio_port(dev);
 449         int retval;
 450
 451         retval = count;
 452         if (!strncmp(buf, "manual", count)) {
 453                 serio->manual_bind = 1;
 454         } else if (!strncmp(buf, "auto", count)) {
 455                 serio->manual_bind = 0;
 456         } else {
 457                 retval = -EINVAL;
 458         }
 459
 460         return retval;
 461 }
 462
 463 static struct device_attribute serio_device_attrs[] = {
 464         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 465         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 466         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 467         __ATTR_NULL
 468 };
 469
 470
 471 static void serio_release_port(struct device *dev)
 472 {
 473         struct serio *serio = to_serio_port(dev);
 474
 475         kfree(serio);
 476         module_put(THIS_MODULE);
 477 }
 478
 479 /*
 480  * Prepare serio port for registration.
 481  */
 482 static void serio_init_port(struct serio *serio)
 483 {
 484         static atomic_t serio_no = ATOMIC_INIT(0);
 485
 486         __module_get(THIS_MODULE);
 487
 488         spin_lock_init(&serio->lock);
 489         init_MUTEX(&serio->drv_sem);
 490         device_initialize(&serio->dev);
 491         snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
 492                  "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
 493         serio->dev.bus = &serio_bus;
 494         serio->dev.release = serio_release_port;
 495         if (serio->parent)
 496                 serio->dev.parent = &serio->parent->dev;
 497 }
 498
 499 /*
 500  * Complete serio port registration.
 501  * Driver core will attempt to find appropriate driver for the port.
 502  */
 503 static void serio_add_port(struct serio *serio)
 504 {
 505         if (serio->parent) {
 506                 serio_pause_rx(serio->parent);
 507                 serio->parent->child = serio;
 508                 serio_continue_rx(serio->parent);
 509         }
 510
 511         list_add_tail(&serio->node, &serio_list);
 512         if (serio->start)
 513                 serio->start(serio);
 514         device_add(&serio->dev);
 515         sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
 516         serio->registered = 1;
 517 }
 518
 519 /*
 520  * serio_destroy_port() completes deregistration process and removes
 521  * port from the system
 522  */
 523 static void serio_destroy_port(struct serio *serio)
 524 {
 525         struct serio *child;
 526
 527         child = serio_get_pending_child(serio);
 528         if (child) {
 529                 serio_remove_pending_events(child);
 530                 put_device(&child->dev);
 531         }
 532
 533         if (serio->stop)
 534                 serio->stop(serio);
 535
 536         if (serio->parent) {
 537                 serio_pause_rx(serio->parent);
 538                 serio->parent->child = NULL;
 539                 serio_continue_rx(serio->parent);
 540                 serio->parent = NULL;
 541         }
 542
 543         if (serio->registered) {
 544                 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
 545                 device_del(&serio->dev);
 546                 list_del_init(&serio->node);
 547                 serio->registered = 0;
 548         }
 549
 550         serio_remove_pending_events(serio);
 551         put_device(&serio->dev);
 552 }
 553
 554 /*
 555  * Reconnect serio port and all its children (re-initialize attached devices)
 556  */
 557 static void serio_reconnect_port(struct serio *serio)
 558 {
 559         do {
 560                 if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
 561                         serio_disconnect_port(serio);
 562                         serio_find_driver(serio);
 563                         /* Ok, old children are now gone, we are done */
 564                         break;
 565                 }
 566                 serio = serio->child;
 567         } while (serio);
 568 }
 569
 570 /*
 571  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 572  * all child ports are unbound and destroyed.
 573  */
 574 static void serio_disconnect_port(struct serio *serio)
 575 {
 576         struct serio *s, *parent;
 577
 578         if (serio->child) {
 579                 /*
 580                  * Children ports should be disconnected and destroyed
 581                  * first, staring with the leaf one, since we don't want
 582                  * to do recursion
 583                  */
 584                 for (s = serio; s->child; s = s->child)
 585                         /* empty */;
 586
 587                 do {
 588                         parent = s->parent;
 589
 590                         serio_release_driver(s);
 591                         serio_destroy_port(s);
 592                 } while ((s = parent) != serio);
 593         }
 594
 595         /*
 596          * Ok, no children left, now disconnect this port
 597          */
 598         serio_release_driver(serio);
 599 }
 600
 601 void serio_rescan(struct serio *serio)
 602 {
 603         serio_queue_event(serio, NULL, SERIO_RESCAN);
 604 }
 605
 606 void serio_reconnect(struct serio *serio)
 607 {
 608         serio_queue_event(serio, NULL, SERIO_RECONNECT);
 609 }
 610
 611 /*
 612  * Submits register request to kseriod for subsequent execution.
 613  * Note that port registration is always asynchronous.
 614  */
 615 void __serio_register_port(struct serio *serio, struct module *owner)
 616 {
 617         serio_init_port(serio);
 618         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 619 }
 620
 621 /*
 622  * Synchronously unregisters serio port.
 623  */
 624 void serio_unregister_port(struct serio *serio)
 625 {
 626         down(&serio_sem);
 627         serio_disconnect_port(serio);
 628         serio_destroy_port(serio);
 629         up(&serio_sem);
 630 }
 631
 632 /*
 633  * Submits register request to kseriod for subsequent execution.
 634  * Can be used when it is not obvious whether the serio_sem is
 635  * taken or not and when delayed execution is feasible.
 636  */
 637 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
 638 {
 639         serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
 640 }
 641
 642
 643 /*
 644  * Serio driver operations
 645  */
 646
 647 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 648 {
 649         struct serio_driver *driver = to_serio_driver(drv);
 650         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 651 }
 652
 653 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 654 {
 655         struct serio_driver *serio_drv = to_serio_driver(drv);
 656         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 657 }
 658
 659 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 660 {
 661         struct serio_driver *serio_drv = to_serio_driver(drv);
 662         int retval;
 663
 664         retval = count;
 665         if (!strncmp(buf, "manual", count)) {
 666                 serio_drv->manual_bind = 1;
 667         } else if (!strncmp(buf, "auto", count)) {
 668                 serio_drv->manual_bind = 0;
 669         } else {
 670                 retval = -EINVAL;
 671         }
 672
 673         return retval;
 674 }
 675
 676
 677 static struct driver_attribute serio_driver_attrs[] = {
 678         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 679         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 680                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 681         __ATTR_NULL
 682 };
 683
 684 static int serio_driver_probe(struct device *dev)
 685 {
 686         struct serio *serio = to_serio_port(dev);
 687         struct serio_driver *drv = to_serio_driver(dev->driver);
 688
 689         return drv->connect(serio, drv);
 690 }
 691
 692 static int serio_driver_remove(struct device *dev)
 693 {
 694         struct serio *serio = to_serio_port(dev);
 695         struct serio_driver *drv = to_serio_driver(dev->driver);
 696
 697         drv->disconnect(serio);
 698         return 0;
 699 }
 700
 701 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
 702 {
 703         drv->driver.bus = &serio_bus;
 704         drv->driver.probe = serio_driver_probe;
 705         drv->driver.remove = serio_driver_remove;
 706
 707         serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
 708 }
 709
 710 void serio_unregister_driver(struct serio_driver *drv)
 711 {
 712         struct serio *serio;
 713
 714         down(&serio_sem);
 715         drv->manual_bind = 1;   /* so serio_find_driver ignores it */
 716
 717 start_over:
 718         list_for_each_entry(serio, &serio_list, node) {
 719                 if (serio->drv == drv) {
 720                         serio_disconnect_port(serio);
 721                         serio_find_driver(serio);
 722                         /* we could've deleted some ports, restart */
 723                         goto start_over;
 724                 }
 725         }
 726
 727         driver_unregister(&drv->driver);
 728         up(&serio_sem);
 729 }
 730
 731 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 732 {
 733         down(&serio->drv_sem);
 734         serio_pause_rx(serio);
 735         serio->drv = drv;
 736         serio_continue_rx(serio);
 737         up(&serio->drv_sem);
 738 }
 739
 740 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 741 {
 742         struct serio *serio = to_serio_port(dev);
 743         struct serio_driver *serio_drv = to_serio_driver(drv);
 744
 745         if (serio->manual_bind || serio_drv->manual_bind)
 746                 return 0;
 747
 748         return serio_match_port(serio_drv->id_table, serio);
 749 }
 750
 751 #ifdef CONFIG_HOTPLUG
 752
 753 #define PUT_ENVP(fmt, val)                                              \
 754 do {                                                                    \
 755         envp[i++] = buffer;                                             \
 756         length += snprintf(buffer, buffer_size - length, fmt, val);     \
 757         if (buffer_size - length <= 0 || i >= num_envp)                 \
 758                 return -ENOMEM;                                         \
 759         length++;                                                       \
 760         buffer += length;                                               \
 761 } while (0)
 762 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 763 {
 764         struct serio *serio;
 765         int i = 0;
 766         int length = 0;
 767
 768         if (!dev)
 769                 return -ENODEV;
 770
 771         serio = to_serio_port(dev);
 772
 773         PUT_ENVP("SERIO_TYPE=%02x", serio->id.type);
 774         PUT_ENVP("SERIO_PROTO=%02x", serio->id.proto);
 775         PUT_ENVP("SERIO_ID=%02x", serio->id.id);
 776         PUT_ENVP("SERIO_EXTRA=%02x", serio->id.extra);
 777
 778         envp[i] = NULL;
 779
 780         return 0;
 781 }
 782 #undef PUT_ENVP
 783
 784 #else
 785
 786 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 787 {
 788         return -ENODEV;
 789 }
 790
 791 #endif /* CONFIG_HOTPLUG */
 792
 793 static int serio_resume(struct device *dev)
 794 {
 795         struct serio *serio = to_serio_port(dev);
 796
 797         if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
 798                 /*
 799                  * Driver re-probing can take a while, so better let kseriod
 800                  * deal with it.
 801                  */
 802                 serio_rescan(serio);
 803         }
 804
 805         return 0;
 806 }
 807
 808 /* called from serio_driver->connect/disconnect methods under serio_sem */
 809 int serio_open(struct serio *serio, struct serio_driver *drv)
 810 {
 811         serio_set_drv(serio, drv);
 812
 813         if (serio->open && serio->open(serio)) {
 814                 serio_set_drv(serio, NULL);
 815                 return -1;
 816         }
 817         return 0;
 818 }
 819
 820 /* called from serio_driver->connect/disconnect methods under serio_sem */
 821 void serio_close(struct serio *serio)
 822 {
 823         if (serio->close)
 824                 serio->close(serio);
 825
 826         serio_set_drv(serio, NULL);
 827 }
 828
 829 irqreturn_t serio_interrupt(struct serio *serio,
 830                 unsigned char data, unsigned int dfl, struct pt_regs *regs)
 831 {
 832         unsigned long flags;
 833         irqreturn_t ret = IRQ_NONE;
 834
 835         spin_lock_irqsave(&serio->lock, flags);
 836
 837         if (likely(serio->drv)) {
 838                 ret = serio->drv->interrupt(serio, data, dfl, regs);
 839         } else if (!dfl && serio->registered) {
 840                 serio_rescan(serio);
 841                 ret = IRQ_HANDLED;
 842         }
 843
 844         spin_unlock_irqrestore(&serio->lock, flags);
 845
 846         return ret;
 847 }
 848
 849 static int __init serio_init(void)
 850 {
 851         if (!(serio_pid = kernel_thread(serio_thread, NULL, CLONE_KERNEL))) {
 852                 printk(KERN_ERR "serio: Failed to start kseriod\n");
 853                 return -1;
 854         }
 855
 856         serio_bus.dev_attrs = serio_device_attrs;
 857         serio_bus.drv_attrs = serio_driver_attrs;
 858         serio_bus.match = serio_bus_match;
 859         serio_bus.hotplug = serio_hotplug;
 860         serio_bus.resume = serio_resume;
 861         bus_register(&serio_bus);
 862
 863         return 0;
 864 }
 865
 866 static void __exit serio_exit(void)
 867 {
 868         bus_unregister(&serio_bus);
 869         kill_proc(serio_pid, SIGTERM, 1);
 870         wait_for_completion(&serio_exited);
 871 }
 872
 873 module_init(serio_init);
 874 module_exit(serio_exit);