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/sched.h>
  35 #include <linux/slab.h>
  36 #include <linux/kthread.h>
  37
  38 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  39 MODULE_DESCRIPTION("Serio abstraction core");
  40 MODULE_LICENSE("GPL");
  41
  42 EXPORT_SYMBOL(serio_interrupt);
  43 EXPORT_SYMBOL(__serio_register_port);
  44 EXPORT_SYMBOL(serio_unregister_port);
  45 EXPORT_SYMBOL(serio_unregister_child_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
  64 static void serio_add_port(struct serio *serio);
  65 static void serio_destroy_port(struct serio *serio);
  66 static void serio_reconnect_port(struct serio *serio);
  67 static void serio_disconnect_port(struct serio *serio);
  68
  69 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  70 {
  71         int retval;
  72
  73         down(&serio->drv_sem);
  74         retval = drv->connect(serio, drv);
  75         up(&serio->drv_sem);
  76
  77         return retval;
  78 }
  79
  80 static int serio_reconnect_driver(struct serio *serio)
  81 {
  82         int retval = -1;
  83
  84         down(&serio->drv_sem);
  85         if (serio->drv && serio->drv->reconnect)
  86                 retval = serio->drv->reconnect(serio);
  87         up(&serio->drv_sem);
  88
  89         return retval;
  90 }
  91
  92 static void serio_disconnect_driver(struct serio *serio)
  93 {
  94         down(&serio->drv_sem);
  95         if (serio->drv)
  96                 serio->drv->disconnect(serio);
  97         up(&serio->drv_sem);
  98 }
  99
 100 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
 101 {
 102         while (ids->type || ids->proto) {
 103                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
 104                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
 105                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
 106                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
 107                         return 1;
 108                 ids++;
 109         }
 110         return 0;
 111 }
 112
 113 /*
 114  * Basic serio -> driver core mappings
 115  */
 116
 117 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 118 {
 119         down_write(&serio_bus.subsys.rwsem);
 120
 121         if (serio_match_port(drv->id_table, serio)) {
 122                 serio->dev.driver = &drv->driver;
 123                 if (serio_connect_driver(serio, drv)) {
 124                         serio->dev.driver = NULL;
 125                         goto out;
 126                 }
 127                 device_bind_driver(&serio->dev);
 128         }
 129 out:
 130         up_write(&serio_bus.subsys.rwsem);
 131 }
 132
 133 static void serio_release_driver(struct serio *serio)
 134 {
 135         down_write(&serio_bus.subsys.rwsem);
 136         device_release_driver(&serio->dev);
 137         up_write(&serio_bus.subsys.rwsem);
 138 }
 139
 140 static void serio_find_driver(struct serio *serio)
 141 {
 142         down_write(&serio_bus.subsys.rwsem);
 143         device_attach(&serio->dev);
 144         up_write(&serio_bus.subsys.rwsem);
 145 }
 146
 147
 148 /*
 149  * Serio event processing.
 150  */
 151
 152 enum serio_event_type {
 153         SERIO_RESCAN,
 154         SERIO_RECONNECT,
 155         SERIO_REGISTER_PORT,
 156         SERIO_UNREGISTER_PORT,
 157         SERIO_REGISTER_DRIVER,
 158 };
 159
 160 struct serio_event {
 161         enum serio_event_type type;
 162         void *object;
 163         struct module *owner;
 164         struct list_head node;
 165 };
 166
 167 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 168 static LIST_HEAD(serio_event_list);
 169 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 170 static struct task_struct *serio_task;
 171
 172 static void serio_queue_event(void *object, struct module *owner,
 173                               enum serio_event_type event_type)
 174 {
 175         unsigned long flags;
 176         struct serio_event *event;
 177
 178         spin_lock_irqsave(&serio_event_lock, flags);
 179
 180         /*
 181          * Scan event list for the other events for the same serio port,
 182          * starting with the most recent one. If event is the same we
 183          * do not need add new one. If event is of different type we
 184          * need to add this event and should not look further because
 185          * we need to preseve sequence of distinct events.
 186          */
 187         list_for_each_entry_reverse(event, &serio_event_list, node) {
 188                 if (event->object == object) {
 189                         if (event->type == event_type)
 190                                 goto out;
 191                         break;
 192                 }
 193         }
 194
 195         if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
 196                 if (!try_module_get(owner)) {
 197                         printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
 198                         goto out;
 199                 }
 200
 201                 event->type = event_type;
 202                 event->object = object;
 203                 event->owner = owner;
 204
 205                 list_add_tail(&event->node, &serio_event_list);
 206                 wake_up(&serio_wait);
 207         } else {
 208                 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
 209         }
 210 out:
 211         spin_unlock_irqrestore(&serio_event_lock, flags);
 212 }
 213
 214 static void serio_free_event(struct serio_event *event)
 215 {
 216         module_put(event->owner);
 217         kfree(event);
 218 }
 219
 220 static void serio_remove_duplicate_events(struct serio_event *event)
 221 {
 222         struct list_head *node, *next;
 223         struct serio_event *e;
 224         unsigned long flags;
 225
 226         spin_lock_irqsave(&serio_event_lock, flags);
 227
 228         list_for_each_safe(node, next, &serio_event_list) {
 229                 e = list_entry(node, struct serio_event, node);
 230                 if (event->object == e->object) {
 231                         /*
 232                          * If this event is of different type we should not
 233                          * look further - we only suppress duplicate events
 234                          * that were sent back-to-back.
 235                          */
 236                         if (event->type != e->type)
 237                                 break;
 238
 239                         list_del_init(node);
 240                         serio_free_event(e);
 241                 }
 242         }
 243
 244         spin_unlock_irqrestore(&serio_event_lock, flags);
 245 }
 246
 247
 248 static struct serio_event *serio_get_event(void)
 249 {
 250         struct serio_event *event;
 251         struct list_head *node;
 252         unsigned long flags;
 253
 254         spin_lock_irqsave(&serio_event_lock, flags);
 255
 256         if (list_empty(&serio_event_list)) {
 257                 spin_unlock_irqrestore(&serio_event_lock, flags);
 258                 return NULL;
 259         }
 260
 261         node = serio_event_list.next;
 262         event = list_entry(node, struct serio_event, node);
 263         list_del_init(node);
 264
 265         spin_unlock_irqrestore(&serio_event_lock, flags);
 266
 267         return event;
 268 }
 269
 270 static void serio_handle_event(void)
 271 {
 272         struct serio_event *event;
 273         struct serio_driver *serio_drv;
 274
 275         down(&serio_sem);
 276
 277         /*
 278          * Note that we handle only one event here to give swsusp
 279          * a chance to freeze kseriod thread. Serio events should
 280          * be pretty rare so we are not concerned about taking
 281          * performance hit.
 282          */
 283         if ((event = serio_get_event())) {
 284
 285                 switch (event->type) {
 286                         case SERIO_REGISTER_PORT:
 287                                 serio_add_port(event->object);
 288                                 break;
 289
 290                         case SERIO_UNREGISTER_PORT:
 291                                 serio_disconnect_port(event->object);
 292                                 serio_destroy_port(event->object);
 293                                 break;
 294
 295                         case SERIO_RECONNECT:
 296                                 serio_reconnect_port(event->object);
 297                                 break;
 298
 299                         case SERIO_RESCAN:
 300                                 serio_disconnect_port(event->object);
 301                                 serio_find_driver(event->object);
 302                                 break;
 303
 304                         case SERIO_REGISTER_DRIVER:
 305                                 serio_drv = event->object;
 306                                 driver_register(&serio_drv->driver);
 307                                 break;
 308
 309                         default:
 310                                 break;
 311                 }
 312
 313                 serio_remove_duplicate_events(event);
 314                 serio_free_event(event);
 315         }
 316
 317         up(&serio_sem);
 318 }
 319
 320 /*
 321  * Remove all events that have been submitted for a given serio port.
 322  */
 323 static void serio_remove_pending_events(struct serio *serio)
 324 {
 325         struct list_head *node, *next;
 326         struct serio_event *event;
 327         unsigned long flags;
 328
 329         spin_lock_irqsave(&serio_event_lock, flags);
 330
 331         list_for_each_safe(node, next, &serio_event_list) {
 332                 event = list_entry(node, struct serio_event, node);
 333                 if (event->object == serio) {
 334                         list_del_init(node);
 335                         serio_free_event(event);
 336                 }
 337         }
 338
 339         spin_unlock_irqrestore(&serio_event_lock, flags);
 340 }
 341
 342 /*
 343  * Destroy child serio port (if any) that has not been fully registered yet.
 344  *
 345  * Note that we rely on the fact that port can have only one child and therefore
 346  * only one child registration request can be pending. Additionally, children
 347  * are registered by driver's connect() handler so there can't be a grandchild
 348  * pending registration together with a child.
 349  */
 350 static struct serio *serio_get_pending_child(struct serio *parent)
 351 {
 352         struct serio_event *event;
 353         struct serio *serio, *child = NULL;
 354         unsigned long flags;
 355
 356         spin_lock_irqsave(&serio_event_lock, flags);
 357
 358         list_for_each_entry(event, &serio_event_list, node) {
 359                 if (event->type == SERIO_REGISTER_PORT) {
 360                         serio = event->object;
 361                         if (serio->parent == parent) {
 362                                 child = serio;
 363                                 break;
 364                         }
 365                 }
 366         }
 367
 368         spin_unlock_irqrestore(&serio_event_lock, flags);
 369         return child;
 370 }
 371
 372 static int serio_thread(void *nothing)
 373 {
 374         do {
 375                 serio_handle_event();
 376                 wait_event_interruptible(serio_wait,
 377                         kthread_should_stop() || !list_empty(&serio_event_list));
 378                 try_to_freeze();
 379         } while (!kthread_should_stop());
 380
 381         printk(KERN_DEBUG "serio: kseriod exiting\n");
 382         return 0;
 383 }
 384
 385
 386 /*
 387  * Serio port operations
 388  */
 389
 390 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 391 {
 392         struct serio *serio = to_serio_port(dev);
 393         return sprintf(buf, "%s\n", serio->name);
 394 }
 395
 396 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 397 {
 398         struct serio *serio = to_serio_port(dev);
 399
 400         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 401                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 402 }
 403
 404 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
 405 {
 406         struct serio *serio = to_serio_port(dev);
 407         return sprintf(buf, "%02x\n", serio->id.type);
 408 }
 409
 410 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
 411 {
 412         struct serio *serio = to_serio_port(dev);
 413         return sprintf(buf, "%02x\n", serio->id.proto);
 414 }
 415
 416 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
 417 {
 418         struct serio *serio = to_serio_port(dev);
 419         return sprintf(buf, "%02x\n", serio->id.id);
 420 }
 421
 422 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
 423 {
 424         struct serio *serio = to_serio_port(dev);
 425         return sprintf(buf, "%02x\n", serio->id.extra);
 426 }
 427
 428 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 429 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 430 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 431 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 432
 433 static struct attribute *serio_device_id_attrs[] = {
 434         &dev_attr_type.attr,
 435         &dev_attr_proto.attr,
 436         &dev_attr_id.attr,
 437         &dev_attr_extra.attr,
 438         NULL
 439 };
 440
 441 static struct attribute_group serio_id_attr_group = {
 442         .name   = "id",
 443         .attrs  = serio_device_id_attrs,
 444 };
 445
 446 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 447 {
 448         struct serio *serio = to_serio_port(dev);
 449         struct device_driver *drv;
 450         int retval;
 451
 452         retval = down_interruptible(&serio_sem);
 453         if (retval)
 454                 return retval;
 455
 456         retval = count;
 457         if (!strncmp(buf, "none", count)) {
 458                 serio_disconnect_port(serio);
 459         } else if (!strncmp(buf, "reconnect", count)) {
 460                 serio_reconnect_port(serio);
 461         } else if (!strncmp(buf, "rescan", count)) {
 462                 serio_disconnect_port(serio);
 463                 serio_find_driver(serio);
 464         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 465                 serio_disconnect_port(serio);
 466                 serio_bind_driver(serio, to_serio_driver(drv));
 467                 put_driver(drv);
 468         } else {
 469                 retval = -EINVAL;
 470         }
 471
 472         up(&serio_sem);
 473
 474         return retval;
 475 }
 476
 477 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 478 {
 479         struct serio *serio = to_serio_port(dev);
 480         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 481 }
 482
 483 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 484 {
 485         struct serio *serio = to_serio_port(dev);
 486         int retval;
 487
 488         retval = count;
 489         if (!strncmp(buf, "manual", count)) {
 490                 serio->manual_bind = 1;
 491         } else if (!strncmp(buf, "auto", count)) {
 492                 serio->manual_bind = 0;
 493         } else {
 494                 retval = -EINVAL;
 495         }
 496
 497         return retval;
 498 }
 499
 500 static struct device_attribute serio_device_attrs[] = {
 501         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 502         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 503         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 504         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 505         __ATTR_NULL
 506 };
 507
 508
 509 static void serio_release_port(struct device *dev)
 510 {
 511         struct serio *serio = to_serio_port(dev);
 512
 513         kfree(serio);
 514         module_put(THIS_MODULE);
 515 }
 516
 517 /*
 518  * Prepare serio port for registration.
 519  */
 520 static void serio_init_port(struct serio *serio)
 521 {
 522         static atomic_t serio_no = ATOMIC_INIT(0);
 523
 524         __module_get(THIS_MODULE);
 525
 526         spin_lock_init(&serio->lock);
 527         init_MUTEX(&serio->drv_sem);
 528         device_initialize(&serio->dev);
 529         snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
 530                  "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
 531         serio->dev.bus = &serio_bus;
 532         serio->dev.release = serio_release_port;
 533         if (serio->parent)
 534                 serio->dev.parent = &serio->parent->dev;
 535 }
 536
 537 /*
 538  * Complete serio port registration.
 539  * Driver core will attempt to find appropriate driver for the port.
 540  */
 541 static void serio_add_port(struct serio *serio)
 542 {
 543         if (serio->parent) {
 544                 serio_pause_rx(serio->parent);
 545                 serio->parent->child = serio;
 546                 serio_continue_rx(serio->parent);
 547         }
 548
 549         list_add_tail(&serio->node, &serio_list);
 550         if (serio->start)
 551                 serio->start(serio);
 552         device_add(&serio->dev);
 553         sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
 554         serio->registered = 1;
 555 }
 556
 557 /*
 558  * serio_destroy_port() completes deregistration process and removes
 559  * port from the system
 560  */
 561 static void serio_destroy_port(struct serio *serio)
 562 {
 563         struct serio *child;
 564
 565         child = serio_get_pending_child(serio);
 566         if (child) {
 567                 serio_remove_pending_events(child);
 568                 put_device(&child->dev);
 569         }
 570
 571         if (serio->stop)
 572                 serio->stop(serio);
 573
 574         if (serio->parent) {
 575                 serio_pause_rx(serio->parent);
 576                 serio->parent->child = NULL;
 577                 serio_continue_rx(serio->parent);
 578                 serio->parent = NULL;
 579         }
 580
 581         if (serio->registered) {
 582                 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
 583                 device_del(&serio->dev);
 584                 list_del_init(&serio->node);
 585                 serio->registered = 0;
 586         }
 587
 588         serio_remove_pending_events(serio);
 589         put_device(&serio->dev);
 590 }
 591
 592 /*
 593  * Reconnect serio port and all its children (re-initialize attached devices)
 594  */
 595 static void serio_reconnect_port(struct serio *serio)
 596 {
 597         do {
 598                 if (serio_reconnect_driver(serio)) {
 599                         serio_disconnect_port(serio);
 600                         serio_find_driver(serio);
 601                         /* Ok, old children are now gone, we are done */
 602                         break;
 603                 }
 604                 serio = serio->child;
 605         } while (serio);
 606 }
 607
 608 /*
 609  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 610  * all child ports are unbound and destroyed.
 611  */
 612 static void serio_disconnect_port(struct serio *serio)
 613 {
 614         struct serio *s, *parent;
 615
 616         if (serio->child) {
 617                 /*
 618                  * Children ports should be disconnected and destroyed
 619                  * first, staring with the leaf one, since we don't want
 620                  * to do recursion
 621                  */
 622                 for (s = serio; s->child; s = s->child)
 623                         /* empty */;
 624
 625                 do {
 626                         parent = s->parent;
 627
 628                         serio_release_driver(s);
 629                         serio_destroy_port(s);
 630                 } while ((s = parent) != serio);
 631         }
 632
 633         /*
 634          * Ok, no children left, now disconnect this port
 635          */
 636         serio_release_driver(serio);
 637 }
 638
 639 void serio_rescan(struct serio *serio)
 640 {
 641         serio_queue_event(serio, NULL, SERIO_RESCAN);
 642 }
 643
 644 void serio_reconnect(struct serio *serio)
 645 {
 646         serio_queue_event(serio, NULL, SERIO_RECONNECT);
 647 }
 648
 649 /*
 650  * Submits register request to kseriod for subsequent execution.
 651  * Note that port registration is always asynchronous.
 652  */
 653 void __serio_register_port(struct serio *serio, struct module *owner)
 654 {
 655         serio_init_port(serio);
 656         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 657 }
 658
 659 /*
 660  * Synchronously unregisters serio port.
 661  */
 662 void serio_unregister_port(struct serio *serio)
 663 {
 664         down(&serio_sem);
 665         serio_disconnect_port(serio);
 666         serio_destroy_port(serio);
 667         up(&serio_sem);
 668 }
 669
 670 /*
 671  * Safely unregisters child port if one is present.
 672  */
 673 void serio_unregister_child_port(struct serio *serio)
 674 {
 675         down(&serio_sem);
 676         if (serio->child) {
 677                 serio_disconnect_port(serio->child);
 678                 serio_destroy_port(serio->child);
 679         }
 680         up(&serio_sem);
 681 }
 682
 683 /*
 684  * Submits register request to kseriod for subsequent execution.
 685  * Can be used when it is not obvious whether the serio_sem is
 686  * taken or not and when delayed execution is feasible.
 687  */
 688 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
 689 {
 690         serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
 691 }
 692
 693
 694 /*
 695  * Serio driver operations
 696  */
 697
 698 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 699 {
 700         struct serio_driver *driver = to_serio_driver(drv);
 701         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 702 }
 703
 704 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 705 {
 706         struct serio_driver *serio_drv = to_serio_driver(drv);
 707         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 708 }
 709
 710 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 711 {
 712         struct serio_driver *serio_drv = to_serio_driver(drv);
 713         int retval;
 714
 715         retval = count;
 716         if (!strncmp(buf, "manual", count)) {
 717                 serio_drv->manual_bind = 1;
 718         } else if (!strncmp(buf, "auto", count)) {
 719                 serio_drv->manual_bind = 0;
 720         } else {
 721                 retval = -EINVAL;
 722         }
 723
 724         return retval;
 725 }
 726
 727
 728 static struct driver_attribute serio_driver_attrs[] = {
 729         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 730         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 731                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 732         __ATTR_NULL
 733 };
 734
 735 static int serio_driver_probe(struct device *dev)
 736 {
 737         struct serio *serio = to_serio_port(dev);
 738         struct serio_driver *drv = to_serio_driver(dev->driver);
 739
 740         return serio_connect_driver(serio, drv);
 741 }
 742
 743 static int serio_driver_remove(struct device *dev)
 744 {
 745         struct serio *serio = to_serio_port(dev);
 746
 747         serio_disconnect_driver(serio);
 748         return 0;
 749 }
 750
 751 static struct bus_type serio_bus = {
 752         .name = "serio",
 753         .probe = serio_driver_probe,
 754         .remove = serio_driver_remove,
 755 };
 756
 757 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
 758 {
 759         drv->driver.bus = &serio_bus;
 760
 761         serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
 762 }
 763
 764 void serio_unregister_driver(struct serio_driver *drv)
 765 {
 766         struct serio *serio;
 767
 768         down(&serio_sem);
 769         drv->manual_bind = 1;   /* so serio_find_driver ignores it */
 770
 771 start_over:
 772         list_for_each_entry(serio, &serio_list, node) {
 773                 if (serio->drv == drv) {
 774                         serio_disconnect_port(serio);
 775                         serio_find_driver(serio);
 776                         /* we could've deleted some ports, restart */
 777                         goto start_over;
 778                 }
 779         }
 780
 781         driver_unregister(&drv->driver);
 782         up(&serio_sem);
 783 }
 784
 785 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 786 {
 787         serio_pause_rx(serio);
 788         serio->drv = drv;
 789         serio_continue_rx(serio);
 790 }
 791
 792 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 793 {
 794         struct serio *serio = to_serio_port(dev);
 795         struct serio_driver *serio_drv = to_serio_driver(drv);
 796
 797         if (serio->manual_bind || serio_drv->manual_bind)
 798                 return 0;
 799
 800         return serio_match_port(serio_drv->id_table, serio);
 801 }
 802
 803 #ifdef CONFIG_HOTPLUG
 804
 805 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 806         do {                                                            \
 807                 int err = add_uevent_var(envp, num_envp, &i,    \
 808                                         buffer, buffer_size, &len,      \
 809                                         fmt, val);                      \
 810                 if (err)                                                \
 811                         return err;                                     \
 812         } while (0)
 813
 814 static int serio_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 815 {
 816         struct serio *serio;
 817         int i = 0;
 818         int len = 0;
 819
 820         if (!dev)
 821                 return -ENODEV;
 822
 823         serio = to_serio_port(dev);
 824
 825         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 826         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 827         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 828         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 829         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 830                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 831         envp[i] = NULL;
 832
 833         return 0;
 834 }
 835 #undef SERIO_ADD_UEVENT_VAR
 836
 837 #else
 838
 839 static int serio_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 840 {
 841         return -ENODEV;
 842 }
 843
 844 #endif /* CONFIG_HOTPLUG */
 845
 846 static int serio_resume(struct device *dev)
 847 {
 848         struct serio *serio = to_serio_port(dev);
 849
 850         if (serio_reconnect_driver(serio)) {
 851                 /*
 852                  * Driver re-probing can take a while, so better let kseriod
 853                  * deal with it.
 854                  */
 855                 serio_rescan(serio);
 856         }
 857
 858         return 0;
 859 }
 860
 861 /* called from serio_driver->connect/disconnect methods under serio_sem */
 862 int serio_open(struct serio *serio, struct serio_driver *drv)
 863 {
 864         serio_set_drv(serio, drv);
 865
 866         if (serio->open && serio->open(serio)) {
 867                 serio_set_drv(serio, NULL);
 868                 return -1;
 869         }
 870         return 0;
 871 }
 872
 873 /* called from serio_driver->connect/disconnect methods under serio_sem */
 874 void serio_close(struct serio *serio)
 875 {
 876         if (serio->close)
 877                 serio->close(serio);
 878
 879         serio_set_drv(serio, NULL);
 880 }
 881
 882 irqreturn_t serio_interrupt(struct serio *serio,
 883                 unsigned char data, unsigned int dfl, struct pt_regs *regs)
 884 {
 885         unsigned long flags;
 886         irqreturn_t ret = IRQ_NONE;
 887
 888         spin_lock_irqsave(&serio->lock, flags);
 889
 890         if (likely(serio->drv)) {
 891                 ret = serio->drv->interrupt(serio, data, dfl, regs);
 892         } else if (!dfl && serio->registered) {
 893                 serio_rescan(serio);
 894                 ret = IRQ_HANDLED;
 895         }
 896
 897         spin_unlock_irqrestore(&serio->lock, flags);
 898
 899         return ret;
 900 }
 901
 902 static int __init serio_init(void)
 903 {
 904         serio_task = kthread_run(serio_thread, NULL, "kseriod");
 905         if (IS_ERR(serio_task)) {
 906                 printk(KERN_ERR "serio: Failed to start kseriod\n");
 907                 return PTR_ERR(serio_task);
 908         }
 909
 910         serio_bus.dev_attrs = serio_device_attrs;
 911         serio_bus.drv_attrs = serio_driver_attrs;
 912         serio_bus.match = serio_bus_match;
 913         serio_bus.uevent = serio_uevent;
 914         serio_bus.resume = serio_resume;
 915         bus_register(&serio_bus);
 916
 917         return 0;
 918 }
 919
 920 static void __exit serio_exit(void)
 921 {
 922         bus_unregister(&serio_bus);
 923         kthread_stop(serio_task);
 924 }
 925
 926 module_init(serio_init);
 927 module_exit(serio_exit);