drivers/input/serio/serio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  The Serio abstraction module
   4  *
   5  *  Copyright (c) 1999-2004 Vojtech Pavlik
   6  *  Copyright (c) 2004 Dmitry Torokhov
   7  *  Copyright (c) 2003 Daniele Bellucci
   8  */
   9
  10 /*
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/stddef.h>
  16 #include <linux/module.h>
  17 #include <linux/serio.h>
  18 #include <linux/errno.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/mutex.h>
  23
  24 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  25 MODULE_DESCRIPTION("Serio abstraction core");
  26 MODULE_LICENSE("GPL");
  27
  28 /*
  29  * serio_mutex protects entire serio subsystem and is taken every time
  30  * serio port or driver registered or unregistered.
  31  */
  32 static DEFINE_MUTEX(serio_mutex);
  33
  34 static LIST_HEAD(serio_list);
  35
  36 static void serio_add_port(struct serio *serio);
  37 static int serio_reconnect_port(struct serio *serio);
  38 static void serio_disconnect_port(struct serio *serio);
  39 static void serio_reconnect_subtree(struct serio *serio);
  40 static void serio_attach_driver(struct serio_driver *drv);
  41
  42 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  43 {
  44         int retval;
  45
  46         mutex_lock(&serio->drv_mutex);
  47         retval = drv->connect(serio, drv);
  48         mutex_unlock(&serio->drv_mutex);
  49
  50         return retval;
  51 }
  52
  53 static int serio_reconnect_driver(struct serio *serio)
  54 {
  55         int retval = -1;
  56
  57         mutex_lock(&serio->drv_mutex);
  58         if (serio->drv && serio->drv->reconnect)
  59                 retval = serio->drv->reconnect(serio);
  60         mutex_unlock(&serio->drv_mutex);
  61
  62         return retval;
  63 }
  64
  65 static void serio_disconnect_driver(struct serio *serio)
  66 {
  67         mutex_lock(&serio->drv_mutex);
  68         if (serio->drv)
  69                 serio->drv->disconnect(serio);
  70         mutex_unlock(&serio->drv_mutex);
  71 }
  72
  73 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
  74 {
  75         while (ids->type || ids->proto) {
  76                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
  77                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
  78                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
  79                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
  80                         return 1;
  81                 ids++;
  82         }
  83         return 0;
  84 }
  85
  86 /*
  87  * Basic serio -> driver core mappings
  88  */
  89
  90 static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
  91 {
  92         int error;
  93
  94         if (serio_match_port(drv->id_table, serio)) {
  95
  96                 serio->dev.driver = &drv->driver;
  97                 if (serio_connect_driver(serio, drv)) {
  98                         serio->dev.driver = NULL;
  99                         return -ENODEV;
 100                 }
 101
 102                 error = device_bind_driver(&serio->dev);
 103                 if (error) {
 104                         dev_warn(&serio->dev,
 105                                  "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
 106                                  serio->phys, serio->name,
 107                                  drv->description, error);
 108                         serio_disconnect_driver(serio);
 109                         serio->dev.driver = NULL;
 110                         return error;
 111                 }
 112         }
 113         return 0;
 114 }
 115
 116 static void serio_find_driver(struct serio *serio)
 117 {
 118         int error;
 119
 120         error = device_attach(&serio->dev);
 121         if (error < 0 && error != -EPROBE_DEFER)
 122                 dev_warn(&serio->dev,
 123                          "device_attach() failed for %s (%s), error: %d\n",
 124                          serio->phys, serio->name, error);
 125 }
 126
 127
 128 /*
 129  * Serio event processing.
 130  */
 131
 132 enum serio_event_type {
 133         SERIO_RESCAN_PORT,
 134         SERIO_RECONNECT_PORT,
 135         SERIO_RECONNECT_SUBTREE,
 136         SERIO_REGISTER_PORT,
 137         SERIO_ATTACH_DRIVER,
 138 };
 139
 140 struct serio_event {
 141         enum serio_event_type type;
 142         void *object;
 143         struct module *owner;
 144         struct list_head node;
 145 };
 146
 147 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 148 static LIST_HEAD(serio_event_list);
 149
 150 static struct serio_event *serio_get_event(void)
 151 {
 152         struct serio_event *event = NULL;
 153         unsigned long flags;
 154
 155         spin_lock_irqsave(&serio_event_lock, flags);
 156
 157         if (!list_empty(&serio_event_list)) {
 158                 event = list_first_entry(&serio_event_list,
 159                                          struct serio_event, node);
 160                 list_del_init(&event->node);
 161         }
 162
 163         spin_unlock_irqrestore(&serio_event_lock, flags);
 164         return event;
 165 }
 166
 167 static void serio_free_event(struct serio_event *event)
 168 {
 169         module_put(event->owner);
 170         kfree(event);
 171 }
 172
 173 static void serio_remove_duplicate_events(void *object,
 174                                           enum serio_event_type type)
 175 {
 176         struct serio_event *e, *next;
 177         unsigned long flags;
 178
 179         spin_lock_irqsave(&serio_event_lock, flags);
 180
 181         list_for_each_entry_safe(e, next, &serio_event_list, node) {
 182                 if (object == e->object) {
 183                         /*
 184                          * If this event is of different type we should not
 185                          * look further - we only suppress duplicate events
 186                          * that were sent back-to-back.
 187                          */
 188                         if (type != e->type)
 189                                 break;
 190
 191                         list_del_init(&e->node);
 192                         serio_free_event(e);
 193                 }
 194         }
 195
 196         spin_unlock_irqrestore(&serio_event_lock, flags);
 197 }
 198
 199 static void serio_handle_event(struct work_struct *work)
 200 {
 201         struct serio_event *event;
 202
 203         mutex_lock(&serio_mutex);
 204
 205         while ((event = serio_get_event())) {
 206
 207                 switch (event->type) {
 208
 209                 case SERIO_REGISTER_PORT:
 210                         serio_add_port(event->object);
 211                         break;
 212
 213                 case SERIO_RECONNECT_PORT:
 214                         serio_reconnect_port(event->object);
 215                         break;
 216
 217                 case SERIO_RESCAN_PORT:
 218                         serio_disconnect_port(event->object);
 219                         serio_find_driver(event->object);
 220                         break;
 221
 222                 case SERIO_RECONNECT_SUBTREE:
 223                         serio_reconnect_subtree(event->object);
 224                         break;
 225
 226                 case SERIO_ATTACH_DRIVER:
 227                         serio_attach_driver(event->object);
 228                         break;
 229                 }
 230
 231                 serio_remove_duplicate_events(event->object, event->type);
 232                 serio_free_event(event);
 233         }
 234
 235         mutex_unlock(&serio_mutex);
 236 }
 237
 238 static DECLARE_WORK(serio_event_work, serio_handle_event);
 239
 240 static int serio_queue_event(void *object, struct module *owner,
 241                              enum serio_event_type event_type)
 242 {
 243         unsigned long flags;
 244         struct serio_event *event;
 245         int retval = 0;
 246
 247         spin_lock_irqsave(&serio_event_lock, flags);
 248
 249         /*
 250          * Scan event list for the other events for the same serio port,
 251          * starting with the most recent one. If event is the same we
 252          * do not need add new one. If event is of different type we
 253          * need to add this event and should not look further because
 254          * we need to preseve sequence of distinct events.
 255          */
 256         list_for_each_entry_reverse(event, &serio_event_list, node) {
 257                 if (event->object == object) {
 258                         if (event->type == event_type)
 259                                 goto out;
 260                         break;
 261                 }
 262         }
 263
 264         event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
 265         if (!event) {
 266                 pr_err("Not enough memory to queue event %d\n", event_type);
 267                 retval = -ENOMEM;
 268                 goto out;
 269         }
 270
 271         if (!try_module_get(owner)) {
 272                 pr_warn("Can't get module reference, dropping event %d\n",
 273                         event_type);
 274                 kfree(event);
 275                 retval = -EINVAL;
 276                 goto out;
 277         }
 278
 279         event->type = event_type;
 280         event->object = object;
 281         event->owner = owner;
 282
 283         list_add_tail(&event->node, &serio_event_list);
 284         queue_work(system_long_wq, &serio_event_work);
 285
 286 out:
 287         spin_unlock_irqrestore(&serio_event_lock, flags);
 288         return retval;
 289 }
 290
 291 /*
 292  * Remove all events that have been submitted for a given
 293  * object, be it serio port or driver.
 294  */
 295 static void serio_remove_pending_events(void *object)
 296 {
 297         struct serio_event *event, *next;
 298         unsigned long flags;
 299
 300         spin_lock_irqsave(&serio_event_lock, flags);
 301
 302         list_for_each_entry_safe(event, next, &serio_event_list, node) {
 303                 if (event->object == object) {
 304                         list_del_init(&event->node);
 305                         serio_free_event(event);
 306                 }
 307         }
 308
 309         spin_unlock_irqrestore(&serio_event_lock, flags);
 310 }
 311
 312 /*
 313  * Locate child serio port (if any) that has not been fully registered yet.
 314  *
 315  * Children are registered by driver's connect() handler so there can't be a
 316  * grandchild pending registration together with a child.
 317  */
 318 static struct serio *serio_get_pending_child(struct serio *parent)
 319 {
 320         struct serio_event *event;
 321         struct serio *serio, *child = NULL;
 322         unsigned long flags;
 323
 324         spin_lock_irqsave(&serio_event_lock, flags);
 325
 326         list_for_each_entry(event, &serio_event_list, node) {
 327                 if (event->type == SERIO_REGISTER_PORT) {
 328                         serio = event->object;
 329                         if (serio->parent == parent) {
 330                                 child = serio;
 331                                 break;
 332                         }
 333                 }
 334         }
 335
 336         spin_unlock_irqrestore(&serio_event_lock, flags);
 337         return child;
 338 }
 339
 340 /*
 341  * Serio port operations
 342  */
 343
 344 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 345 {
 346         struct serio *serio = to_serio_port(dev);
 347         return sprintf(buf, "%s\n", serio->name);
 348 }
 349
 350 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 351 {
 352         struct serio *serio = to_serio_port(dev);
 353
 354         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 355                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 356 }
 357
 358 static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
 359 {
 360         struct serio *serio = to_serio_port(dev);
 361         return sprintf(buf, "%02x\n", serio->id.type);
 362 }
 363
 364 static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
 365 {
 366         struct serio *serio = to_serio_port(dev);
 367         return sprintf(buf, "%02x\n", serio->id.proto);
 368 }
 369
 370 static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
 371 {
 372         struct serio *serio = to_serio_port(dev);
 373         return sprintf(buf, "%02x\n", serio->id.id);
 374 }
 375
 376 static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
 377 {
 378         struct serio *serio = to_serio_port(dev);
 379         return sprintf(buf, "%02x\n", serio->id.extra);
 380 }
 381
 382 static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 383 {
 384         struct serio *serio = to_serio_port(dev);
 385         struct device_driver *drv;
 386         int error;
 387
 388         error = mutex_lock_interruptible(&serio_mutex);
 389         if (error)
 390                 return error;
 391
 392         if (!strncmp(buf, "none", count)) {
 393                 serio_disconnect_port(serio);
 394         } else if (!strncmp(buf, "reconnect", count)) {
 395                 serio_reconnect_subtree(serio);
 396         } else if (!strncmp(buf, "rescan", count)) {
 397                 serio_disconnect_port(serio);
 398                 serio_find_driver(serio);
 399                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 400         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 401                 serio_disconnect_port(serio);
 402                 error = serio_bind_driver(serio, to_serio_driver(drv));
 403                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 404         } else {
 405                 error = -EINVAL;
 406         }
 407
 408         mutex_unlock(&serio_mutex);
 409
 410         return error ? error : count;
 411 }
 412
 413 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 414 {
 415         struct serio *serio = to_serio_port(dev);
 416         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 417 }
 418
 419 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 420 {
 421         struct serio *serio = to_serio_port(dev);
 422         int retval;
 423
 424         retval = count;
 425         if (!strncmp(buf, "manual", count)) {
 426                 serio->manual_bind = true;
 427         } else if (!strncmp(buf, "auto", count)) {
 428                 serio->manual_bind = false;
 429         } else {
 430                 retval = -EINVAL;
 431         }
 432
 433         return retval;
 434 }
 435
 436 static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
 437 {
 438         struct serio *serio = to_serio_port(dev);
 439
 440         return sprintf(buf, "%s\n", serio->firmware_id);
 441 }
 442
 443 static DEVICE_ATTR_RO(type);
 444 static DEVICE_ATTR_RO(proto);
 445 static DEVICE_ATTR_RO(id);
 446 static DEVICE_ATTR_RO(extra);
 447
 448 static struct attribute *serio_device_id_attrs[] = {
 449         &dev_attr_type.attr,
 450         &dev_attr_proto.attr,
 451         &dev_attr_id.attr,
 452         &dev_attr_extra.attr,
 453         NULL
 454 };
 455
 456 static const struct attribute_group serio_id_attr_group = {
 457         .name   = "id",
 458         .attrs  = serio_device_id_attrs,
 459 };
 460
 461 static DEVICE_ATTR_RO(modalias);
 462 static DEVICE_ATTR_WO(drvctl);
 463 static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
 464 static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
 465 static DEVICE_ATTR_RO(firmware_id);
 466
 467 static struct attribute *serio_device_attrs[] = {
 468         &dev_attr_modalias.attr,
 469         &dev_attr_description.attr,
 470         &dev_attr_drvctl.attr,
 471         &dev_attr_bind_mode.attr,
 472         &dev_attr_firmware_id.attr,
 473         NULL
 474 };
 475
 476 static const struct attribute_group serio_device_attr_group = {
 477         .attrs  = serio_device_attrs,
 478 };
 479
 480 static const struct attribute_group *serio_device_attr_groups[] = {
 481         &serio_id_attr_group,
 482         &serio_device_attr_group,
 483         NULL
 484 };
 485
 486 static void serio_release_port(struct device *dev)
 487 {
 488         struct serio *serio = to_serio_port(dev);
 489
 490         kfree(serio);
 491         module_put(THIS_MODULE);
 492 }
 493
 494 /*
 495  * Prepare serio port for registration.
 496  */
 497 static void serio_init_port(struct serio *serio)
 498 {
 499         static atomic_t serio_no = ATOMIC_INIT(-1);
 500
 501         __module_get(THIS_MODULE);
 502
 503         INIT_LIST_HEAD(&serio->node);
 504         INIT_LIST_HEAD(&serio->child_node);
 505         INIT_LIST_HEAD(&serio->children);
 506         spin_lock_init(&serio->lock);
 507         mutex_init(&serio->drv_mutex);
 508         device_initialize(&serio->dev);
 509         dev_set_name(&serio->dev, "serio%lu",
 510                      (unsigned long)atomic_inc_return(&serio_no));
 511         serio->dev.bus = &serio_bus;
 512         serio->dev.release = serio_release_port;
 513         serio->dev.groups = serio_device_attr_groups;
 514         if (serio->parent) {
 515                 serio->dev.parent = &serio->parent->dev;
 516                 serio->depth = serio->parent->depth + 1;
 517         } else
 518                 serio->depth = 0;
 519         lockdep_set_subclass(&serio->lock, serio->depth);
 520 }
 521
 522 /*
 523  * Complete serio port registration.
 524  * Driver core will attempt to find appropriate driver for the port.
 525  */
 526 static void serio_add_port(struct serio *serio)
 527 {
 528         struct serio *parent = serio->parent;
 529         int error;
 530
 531         if (parent) {
 532                 serio_pause_rx(parent);
 533                 list_add_tail(&serio->child_node, &parent->children);
 534                 serio_continue_rx(parent);
 535         }
 536
 537         list_add_tail(&serio->node, &serio_list);
 538
 539         if (serio->start)
 540                 serio->start(serio);
 541
 542         error = device_add(&serio->dev);
 543         if (error)
 544                 dev_err(&serio->dev,
 545                         "device_add() failed for %s (%s), error: %d\n",
 546                         serio->phys, serio->name, error);
 547 }
 548
 549 /*
 550  * serio_destroy_port() completes unregistration process and removes
 551  * port from the system
 552  */
 553 static void serio_destroy_port(struct serio *serio)
 554 {
 555         struct serio *child;
 556
 557         while ((child = serio_get_pending_child(serio)) != NULL) {
 558                 serio_remove_pending_events(child);
 559                 put_device(&child->dev);
 560         }
 561
 562         if (serio->stop)
 563                 serio->stop(serio);
 564
 565         if (serio->parent) {
 566                 serio_pause_rx(serio->parent);
 567                 list_del_init(&serio->child_node);
 568                 serio_continue_rx(serio->parent);
 569                 serio->parent = NULL;
 570         }
 571
 572         if (device_is_registered(&serio->dev))
 573                 device_del(&serio->dev);
 574
 575         list_del_init(&serio->node);
 576         serio_remove_pending_events(serio);
 577         put_device(&serio->dev);
 578 }
 579
 580 /*
 581  * Reconnect serio port (re-initialize attached device).
 582  * If reconnect fails (old device is no longer attached or
 583  * there was no device to begin with) we do full rescan in
 584  * hope of finding a driver for the port.
 585  */
 586 static int serio_reconnect_port(struct serio *serio)
 587 {
 588         int error = serio_reconnect_driver(serio);
 589
 590         if (error) {
 591                 serio_disconnect_port(serio);
 592                 serio_find_driver(serio);
 593         }
 594
 595         return error;
 596 }
 597
 598 /*
 599  * Reconnect serio port and all its children (re-initialize attached
 600  * devices).
 601  */
 602 static void serio_reconnect_subtree(struct serio *root)
 603 {
 604         struct serio *s = root;
 605         int error;
 606
 607         do {
 608                 error = serio_reconnect_port(s);
 609                 if (!error) {
 610                         /*
 611                          * Reconnect was successful, move on to do the
 612                          * first child.
 613                          */
 614                         if (!list_empty(&s->children)) {
 615                                 s = list_first_entry(&s->children,
 616                                                      struct serio, child_node);
 617                                 continue;
 618                         }
 619                 }
 620
 621                 /*
 622                  * Either it was a leaf node or reconnect failed and it
 623                  * became a leaf node. Continue reconnecting starting with
 624                  * the next sibling of the parent node.
 625                  */
 626                 while (s != root) {
 627                         struct serio *parent = s->parent;
 628
 629                         if (!list_is_last(&s->child_node, &parent->children)) {
 630                                 s = list_entry(s->child_node.next,
 631                                                struct serio, child_node);
 632                                 break;
 633                         }
 634
 635                         s = parent;
 636                 }
 637         } while (s != root);
 638 }
 639
 640 /*
 641  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 642  * all children ports are unbound and destroyed.
 643  */
 644 static void serio_disconnect_port(struct serio *serio)
 645 {
 646         struct serio *s = serio;
 647
 648         /*
 649          * Children ports should be disconnected and destroyed
 650          * first; we travel the tree in depth-first order.
 651          */
 652         while (!list_empty(&serio->children)) {
 653
 654                 /* Locate a leaf */
 655                 while (!list_empty(&s->children))
 656                         s = list_first_entry(&s->children,
 657                                              struct serio, child_node);
 658
 659                 /*
 660                  * Prune this leaf node unless it is the one we
 661                  * started with.
 662                  */
 663                 if (s != serio) {
 664                         struct serio *parent = s->parent;
 665
 666                         device_release_driver(&s->dev);
 667                         serio_destroy_port(s);
 668
 669                         s = parent;
 670                 }
 671         }
 672
 673         /*
 674          * OK, no children left, now disconnect this port.
 675          */
 676         device_release_driver(&serio->dev);
 677 }
 678
 679 void serio_rescan(struct serio *serio)
 680 {
 681         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 682 }
 683 EXPORT_SYMBOL(serio_rescan);
 684
 685 void serio_reconnect(struct serio *serio)
 686 {
 687         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 688 }
 689 EXPORT_SYMBOL(serio_reconnect);
 690
 691 /*
 692  * Submits register request to kseriod for subsequent execution.
 693  * Note that port registration is always asynchronous.
 694  */
 695 void __serio_register_port(struct serio *serio, struct module *owner)
 696 {
 697         serio_init_port(serio);
 698         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 699 }
 700 EXPORT_SYMBOL(__serio_register_port);
 701
 702 /*
 703  * Synchronously unregisters serio port.
 704  */
 705 void serio_unregister_port(struct serio *serio)
 706 {
 707         mutex_lock(&serio_mutex);
 708         serio_disconnect_port(serio);
 709         serio_destroy_port(serio);
 710         mutex_unlock(&serio_mutex);
 711 }
 712 EXPORT_SYMBOL(serio_unregister_port);
 713
 714 /*
 715  * Safely unregisters children ports if they are present.
 716  */
 717 void serio_unregister_child_port(struct serio *serio)
 718 {
 719         struct serio *s, *next;
 720
 721         mutex_lock(&serio_mutex);
 722         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 723                 serio_disconnect_port(s);
 724                 serio_destroy_port(s);
 725         }
 726         mutex_unlock(&serio_mutex);
 727 }
 728 EXPORT_SYMBOL(serio_unregister_child_port);
 729
 730
 731 /*
 732  * Serio driver operations
 733  */
 734
 735 static ssize_t description_show(struct device_driver *drv, char *buf)
 736 {
 737         struct serio_driver *driver = to_serio_driver(drv);
 738         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 739 }
 740 static DRIVER_ATTR_RO(description);
 741
 742 static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
 743 {
 744         struct serio_driver *serio_drv = to_serio_driver(drv);
 745         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 746 }
 747
 748 static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
 749 {
 750         struct serio_driver *serio_drv = to_serio_driver(drv);
 751         int retval;
 752
 753         retval = count;
 754         if (!strncmp(buf, "manual", count)) {
 755                 serio_drv->manual_bind = true;
 756         } else if (!strncmp(buf, "auto", count)) {
 757                 serio_drv->manual_bind = false;
 758         } else {
 759                 retval = -EINVAL;
 760         }
 761
 762         return retval;
 763 }
 764 static DRIVER_ATTR_RW(bind_mode);
 765
 766 static struct attribute *serio_driver_attrs[] = {
 767         &driver_attr_description.attr,
 768         &driver_attr_bind_mode.attr,
 769         NULL,
 770 };
 771 ATTRIBUTE_GROUPS(serio_driver);
 772
 773 static int serio_driver_probe(struct device *dev)
 774 {
 775         struct serio *serio = to_serio_port(dev);
 776         struct serio_driver *drv = to_serio_driver(dev->driver);
 777
 778         return serio_connect_driver(serio, drv);
 779 }
 780
 781 static int serio_driver_remove(struct device *dev)
 782 {
 783         struct serio *serio = to_serio_port(dev);
 784
 785         serio_disconnect_driver(serio);
 786         return 0;
 787 }
 788
 789 static void serio_cleanup(struct serio *serio)
 790 {
 791         mutex_lock(&serio->drv_mutex);
 792         if (serio->drv && serio->drv->cleanup)
 793                 serio->drv->cleanup(serio);
 794         mutex_unlock(&serio->drv_mutex);
 795 }
 796
 797 static void serio_shutdown(struct device *dev)
 798 {
 799         struct serio *serio = to_serio_port(dev);
 800
 801         serio_cleanup(serio);
 802 }
 803
 804 static void serio_attach_driver(struct serio_driver *drv)
 805 {
 806         int error;
 807
 808         error = driver_attach(&drv->driver);
 809         if (error)
 810                 pr_warn("driver_attach() failed for %s with error %d\n",
 811                         drv->driver.name, error);
 812 }
 813
 814 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 815 {
 816         bool manual_bind = drv->manual_bind;
 817         int error;
 818
 819         drv->driver.bus = &serio_bus;
 820         drv->driver.owner = owner;
 821         drv->driver.mod_name = mod_name;
 822
 823         /*
 824          * Temporarily disable automatic binding because probing
 825          * takes long time and we are better off doing it in kseriod
 826          */
 827         drv->manual_bind = true;
 828
 829         error = driver_register(&drv->driver);
 830         if (error) {
 831                 pr_err("driver_register() failed for %s, error: %d\n",
 832                         drv->driver.name, error);
 833                 return error;
 834         }
 835
 836         /*
 837          * Restore original bind mode and let kseriod bind the
 838          * driver to free ports
 839          */
 840         if (!manual_bind) {
 841                 drv->manual_bind = false;
 842                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 843                 if (error) {
 844                         driver_unregister(&drv->driver);
 845                         return error;
 846                 }
 847         }
 848
 849         return 0;
 850 }
 851 EXPORT_SYMBOL(__serio_register_driver);
 852
 853 void serio_unregister_driver(struct serio_driver *drv)
 854 {
 855         struct serio *serio;
 856
 857         mutex_lock(&serio_mutex);
 858
 859         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 860         serio_remove_pending_events(drv);
 861
 862 start_over:
 863         list_for_each_entry(serio, &serio_list, node) {
 864                 if (serio->drv == drv) {
 865                         serio_disconnect_port(serio);
 866                         serio_find_driver(serio);
 867                         /* we could've deleted some ports, restart */
 868                         goto start_over;
 869                 }
 870         }
 871
 872         driver_unregister(&drv->driver);
 873         mutex_unlock(&serio_mutex);
 874 }
 875 EXPORT_SYMBOL(serio_unregister_driver);
 876
 877 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 878 {
 879         serio_pause_rx(serio);
 880         serio->drv = drv;
 881         serio_continue_rx(serio);
 882 }
 883
 884 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 885 {
 886         struct serio *serio = to_serio_port(dev);
 887         struct serio_driver *serio_drv = to_serio_driver(drv);
 888
 889         if (serio->manual_bind || serio_drv->manual_bind)
 890                 return 0;
 891
 892         return serio_match_port(serio_drv->id_table, serio);
 893 }
 894
 895 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 896         do {                                                            \
 897                 int err = add_uevent_var(env, fmt, val);                \
 898                 if (err)                                                \
 899                         return err;                                     \
 900         } while (0)
 901
 902 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 903 {
 904         struct serio *serio;
 905
 906         if (!dev)
 907                 return -ENODEV;
 908
 909         serio = to_serio_port(dev);
 910
 911         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 912         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 913         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 914         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 915
 916         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 917                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 918
 919         if (serio->firmware_id[0])
 920                 SERIO_ADD_UEVENT_VAR("SERIO_FIRMWARE_ID=%s",
 921                                      serio->firmware_id);
 922
 923         return 0;
 924 }
 925 #undef SERIO_ADD_UEVENT_VAR
 926
 927 #ifdef CONFIG_PM
 928 static int serio_suspend(struct device *dev)
 929 {
 930         struct serio *serio = to_serio_port(dev);
 931
 932         serio_cleanup(serio);
 933
 934         return 0;
 935 }
 936
 937 static int serio_resume(struct device *dev)
 938 {
 939         struct serio *serio = to_serio_port(dev);
 940         int error = -ENOENT;
 941
 942         mutex_lock(&serio->drv_mutex);
 943         if (serio->drv && serio->drv->fast_reconnect) {
 944                 error = serio->drv->fast_reconnect(serio);
 945                 if (error && error != -ENOENT)
 946                         dev_warn(dev, "fast reconnect failed with error %d\n",
 947                                  error);
 948         }
 949         mutex_unlock(&serio->drv_mutex);
 950
 951         if (error) {
 952                 /*
 953                  * Driver reconnect can take a while, so better let
 954                  * kseriod deal with it.
 955                  */
 956                 serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 957         }
 958
 959         return 0;
 960 }
 961
 962 static const struct dev_pm_ops serio_pm_ops = {
 963         .suspend        = serio_suspend,
 964         .resume         = serio_resume,
 965         .poweroff       = serio_suspend,
 966         .restore        = serio_resume,
 967 };
 968 #endif /* CONFIG_PM */
 969
 970 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 971 int serio_open(struct serio *serio, struct serio_driver *drv)
 972 {
 973         serio_set_drv(serio, drv);
 974
 975         if (serio->open && serio->open(serio)) {
 976                 serio_set_drv(serio, NULL);
 977                 return -1;
 978         }
 979         return 0;
 980 }
 981 EXPORT_SYMBOL(serio_open);
 982
 983 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 984 void serio_close(struct serio *serio)
 985 {
 986         if (serio->close)
 987                 serio->close(serio);
 988
 989         serio_set_drv(serio, NULL);
 990 }
 991 EXPORT_SYMBOL(serio_close);
 992
 993 irqreturn_t serio_interrupt(struct serio *serio,
 994                 unsigned char data, unsigned int dfl)
 995 {
 996         unsigned long flags;
 997         irqreturn_t ret = IRQ_NONE;
 998
 999         spin_lock_irqsave(&serio->lock, flags);
1000
1001         if (likely(serio->drv)) {
1002                 ret = serio->drv->interrupt(serio, data, dfl);
1003         } else if (!dfl && device_is_registered(&serio->dev)) {
1004                 serio_rescan(serio);
1005                 ret = IRQ_HANDLED;
1006         }
1007
1008         spin_unlock_irqrestore(&serio->lock, flags);
1009
1010         return ret;
1011 }
1012 EXPORT_SYMBOL(serio_interrupt);
1013
1014 struct bus_type serio_bus = {
1015         .name           = "serio",
1016         .drv_groups     = serio_driver_groups,
1017         .match          = serio_bus_match,
1018         .uevent         = serio_uevent,
1019         .probe          = serio_driver_probe,
1020         .remove         = serio_driver_remove,
1021         .shutdown       = serio_shutdown,
1022 #ifdef CONFIG_PM
1023         .pm             = &serio_pm_ops,
1024 #endif
1025 };
1026 EXPORT_SYMBOL(serio_bus);
1027
1028 static int __init serio_init(void)
1029 {
1030         int error;
1031
1032         error = bus_register(&serio_bus);
1033         if (error) {
1034                 pr_err("Failed to register serio bus, error: %d\n", error);
1035                 return error;
1036         }
1037
1038         return 0;
1039 }
1040
1041 static void __exit serio_exit(void)
1042 {
1043         bus_unregister(&serio_bus);
1044
1045         /*
1046          * There should not be any outstanding events but work may
1047          * still be scheduled so simply cancel it.
1048          */
1049         cancel_work_sync(&serio_event_work);
1050 }
1051
1052 subsys_initcall(serio_init);
1053 module_exit(serio_exit);