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