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 serio_show_modalias(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 serio_show_id_type(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 serio_show_id_proto(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 serio_show_id_id(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 serio_show_id_extra(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 DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 401 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 402 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 403 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 404
 405 static struct attribute *serio_device_id_attrs[] = {
 406         &dev_attr_type.attr,
 407         &dev_attr_proto.attr,
 408         &dev_attr_id.attr,
 409         &dev_attr_extra.attr,
 410         NULL
 411 };
 412
 413 static struct attribute_group serio_id_attr_group = {
 414         .name   = "id",
 415         .attrs  = serio_device_id_attrs,
 416 };
 417
 418 static const struct attribute_group *serio_device_attr_groups[] = {
 419         &serio_id_attr_group,
 420         NULL
 421 };
 422
 423 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 424 {
 425         struct serio *serio = to_serio_port(dev);
 426         struct device_driver *drv;
 427         int error;
 428
 429         error = mutex_lock_interruptible(&serio_mutex);
 430         if (error)
 431                 return error;
 432
 433         if (!strncmp(buf, "none", count)) {
 434                 serio_disconnect_port(serio);
 435         } else if (!strncmp(buf, "reconnect", count)) {
 436                 serio_reconnect_subtree(serio);
 437         } else if (!strncmp(buf, "rescan", count)) {
 438                 serio_disconnect_port(serio);
 439                 serio_find_driver(serio);
 440                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 441         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 442                 serio_disconnect_port(serio);
 443                 error = serio_bind_driver(serio, to_serio_driver(drv));
 444                 put_driver(drv);
 445                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 446         } else {
 447                 error = -EINVAL;
 448         }
 449
 450         mutex_unlock(&serio_mutex);
 451
 452         return error ? error : count;
 453 }
 454
 455 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 456 {
 457         struct serio *serio = to_serio_port(dev);
 458         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 459 }
 460
 461 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 462 {
 463         struct serio *serio = to_serio_port(dev);
 464         int retval;
 465
 466         retval = count;
 467         if (!strncmp(buf, "manual", count)) {
 468                 serio->manual_bind = true;
 469         } else if (!strncmp(buf, "auto", count)) {
 470                 serio->manual_bind = false;
 471         } else {
 472                 retval = -EINVAL;
 473         }
 474
 475         return retval;
 476 }
 477
 478 static struct device_attribute serio_device_attrs[] = {
 479         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 480         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 481         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 482         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 483         __ATTR_NULL
 484 };
 485
 486
 487 static void serio_release_port(struct device *dev)
 488 {
 489         struct serio *serio = to_serio_port(dev);
 490
 491         kfree(serio);
 492         module_put(THIS_MODULE);
 493 }
 494
 495 /*
 496  * Prepare serio port for registration.
 497  */
 498 static void serio_init_port(struct serio *serio)
 499 {
 500         static atomic_t serio_no = ATOMIC_INIT(0);
 501
 502         __module_get(THIS_MODULE);
 503
 504         INIT_LIST_HEAD(&serio->node);
 505         INIT_LIST_HEAD(&serio->child_node);
 506         INIT_LIST_HEAD(&serio->children);
 507         spin_lock_init(&serio->lock);
 508         mutex_init(&serio->drv_mutex);
 509         device_initialize(&serio->dev);
 510         dev_set_name(&serio->dev, "serio%ld",
 511                         (long)atomic_inc_return(&serio_no) - 1);
 512         serio->dev.bus = &serio_bus;
 513         serio->dev.release = serio_release_port;
 514         serio->dev.groups = serio_device_attr_groups;
 515         if (serio->parent) {
 516                 serio->dev.parent = &serio->parent->dev;
 517                 serio->depth = serio->parent->depth + 1;
 518         } else
 519                 serio->depth = 0;
 520         lockdep_set_subclass(&serio->lock, serio->depth);
 521 }
 522
 523 /*
 524  * Complete serio port registration.
 525  * Driver core will attempt to find appropriate driver for the port.
 526  */
 527 static void serio_add_port(struct serio *serio)
 528 {
 529         struct serio *parent = serio->parent;
 530         int error;
 531
 532         if (parent) {
 533                 serio_pause_rx(parent);
 534                 list_add_tail(&serio->child_node, &parent->children);
 535                 serio_continue_rx(parent);
 536         }
 537
 538         list_add_tail(&serio->node, &serio_list);
 539
 540         if (serio->start)
 541                 serio->start(serio);
 542
 543         error = device_add(&serio->dev);
 544         if (error)
 545                 dev_err(&serio->dev,
 546                         "device_add() failed for %s (%s), error: %d\n",
 547                         serio->phys, serio->name, error);
 548 }
 549
 550 /*
 551  * serio_destroy_port() completes unregistration process and removes
 552  * port from the system
 553  */
 554 static void serio_destroy_port(struct serio *serio)
 555 {
 556         struct serio *child;
 557
 558         while ((child = serio_get_pending_child(serio)) != NULL) {
 559                 serio_remove_pending_events(child);
 560                 put_device(&child->dev);
 561         }
 562
 563         if (serio->stop)
 564                 serio->stop(serio);
 565
 566         if (serio->parent) {
 567                 serio_pause_rx(serio->parent);
 568                 list_del_init(&serio->child_node);
 569                 serio_continue_rx(serio->parent);
 570                 serio->parent = NULL;
 571         }
 572
 573         if (device_is_registered(&serio->dev))
 574                 device_del(&serio->dev);
 575
 576         list_del_init(&serio->node);
 577         serio_remove_pending_events(serio);
 578         put_device(&serio->dev);
 579 }
 580
 581 /*
 582  * Reconnect serio port (re-initialize attached device).
 583  * If reconnect fails (old device is no longer attached or
 584  * there was no device to begin with) we do full rescan in
 585  * hope of finding a driver for the port.
 586  */
 587 static int serio_reconnect_port(struct serio *serio)
 588 {
 589         int error = serio_reconnect_driver(serio);
 590
 591         if (error) {
 592                 serio_disconnect_port(serio);
 593                 serio_find_driver(serio);
 594         }
 595
 596         return error;
 597 }
 598
 599 /*
 600  * Reconnect serio port and all its children (re-initialize attached
 601  * devices).
 602  */
 603 static void serio_reconnect_subtree(struct serio *root)
 604 {
 605         struct serio *s = root;
 606         int error;
 607
 608         do {
 609                 error = serio_reconnect_port(s);
 610                 if (!error) {
 611                         /*
 612                          * Reconnect was successful, move on to do the
 613                          * first child.
 614                          */
 615                         if (!list_empty(&s->children)) {
 616                                 s = list_first_entry(&s->children,
 617                                                      struct serio, child_node);
 618                                 continue;
 619                         }
 620                 }
 621
 622                 /*
 623                  * Either it was a leaf node or reconnect failed and it
 624                  * became a leaf node. Continue reconnecting starting with
 625                  * the next sibling of the parent node.
 626                  */
 627                 while (s != root) {
 628                         struct serio *parent = s->parent;
 629
 630                         if (!list_is_last(&s->child_node, &parent->children)) {
 631                                 s = list_entry(s->child_node.next,
 632                                                struct serio, child_node);
 633                                 break;
 634                         }
 635
 636                         s = parent;
 637                 }
 638         } while (s != root);
 639 }
 640
 641 /*
 642  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 643  * all children ports are unbound and destroyed.
 644  */
 645 static void serio_disconnect_port(struct serio *serio)
 646 {
 647         struct serio *s = serio;
 648
 649         /*
 650          * Children ports should be disconnected and destroyed
 651          * first; we travel the tree in depth-first order.
 652          */
 653         while (!list_empty(&serio->children)) {
 654
 655                 /* Locate a leaf */
 656                 while (!list_empty(&s->children))
 657                         s = list_first_entry(&s->children,
 658                                              struct serio, child_node);
 659
 660                 /*
 661                  * Prune this leaf node unless it is the one we
 662                  * started with.
 663                  */
 664                 if (s != serio) {
 665                         struct serio *parent = s->parent;
 666
 667                         device_release_driver(&s->dev);
 668                         serio_destroy_port(s);
 669
 670                         s = parent;
 671                 }
 672         }
 673
 674         /*
 675          * OK, no children left, now disconnect this port.
 676          */
 677         device_release_driver(&serio->dev);
 678 }
 679
 680 void serio_rescan(struct serio *serio)
 681 {
 682         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 683 }
 684 EXPORT_SYMBOL(serio_rescan);
 685
 686 void serio_reconnect(struct serio *serio)
 687 {
 688         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 689 }
 690 EXPORT_SYMBOL(serio_reconnect);
 691
 692 /*
 693  * Submits register request to kseriod for subsequent execution.
 694  * Note that port registration is always asynchronous.
 695  */
 696 void __serio_register_port(struct serio *serio, struct module *owner)
 697 {
 698         serio_init_port(serio);
 699         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 700 }
 701 EXPORT_SYMBOL(__serio_register_port);
 702
 703 /*
 704  * Synchronously unregisters serio port.
 705  */
 706 void serio_unregister_port(struct serio *serio)
 707 {
 708         mutex_lock(&serio_mutex);
 709         serio_disconnect_port(serio);
 710         serio_destroy_port(serio);
 711         mutex_unlock(&serio_mutex);
 712 }
 713 EXPORT_SYMBOL(serio_unregister_port);
 714
 715 /*
 716  * Safely unregisters children ports if they are present.
 717  */
 718 void serio_unregister_child_port(struct serio *serio)
 719 {
 720         struct serio *s, *next;
 721
 722         mutex_lock(&serio_mutex);
 723         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 724                 serio_disconnect_port(s);
 725                 serio_destroy_port(s);
 726         }
 727         mutex_unlock(&serio_mutex);
 728 }
 729 EXPORT_SYMBOL(serio_unregister_child_port);
 730
 731
 732 /*
 733  * Serio driver operations
 734  */
 735
 736 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 737 {
 738         struct serio_driver *driver = to_serio_driver(drv);
 739         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 740 }
 741
 742 static ssize_t serio_driver_show_bind_mode(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 serio_driver_set_bind_mode(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
 765
 766 static struct driver_attribute serio_driver_attrs[] = {
 767         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 768         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 769                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 770         __ATTR_NULL
 771 };
 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_warning("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 #ifdef CONFIG_HOTPLUG
 896
 897 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 898         do {                                                            \
 899                 int err = add_uevent_var(env, fmt, val);                \
 900                 if (err)                                                \
 901                         return err;                                     \
 902         } while (0)
 903
 904 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 905 {
 906         struct serio *serio;
 907
 908         if (!dev)
 909                 return -ENODEV;
 910
 911         serio = to_serio_port(dev);
 912
 913         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 914         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 915         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 916         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 917         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 918                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 919
 920         return 0;
 921 }
 922 #undef SERIO_ADD_UEVENT_VAR
 923
 924 #else
 925
 926 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 927 {
 928         return -ENODEV;
 929 }
 930
 931 #endif /* CONFIG_HOTPLUG */
 932
 933 #ifdef CONFIG_PM
 934 static int serio_suspend(struct device *dev)
 935 {
 936         struct serio *serio = to_serio_port(dev);
 937
 938         serio_cleanup(serio);
 939
 940         return 0;
 941 }
 942
 943 static int serio_resume(struct device *dev)
 944 {
 945         struct serio *serio = to_serio_port(dev);
 946
 947         /*
 948          * Driver reconnect can take a while, so better let kseriod
 949          * deal with it.
 950          */
 951         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 952
 953         return 0;
 954 }
 955
 956 static const struct dev_pm_ops serio_pm_ops = {
 957         .suspend        = serio_suspend,
 958         .resume         = serio_resume,
 959         .poweroff       = serio_suspend,
 960         .restore        = serio_resume,
 961 };
 962 #endif /* CONFIG_PM */
 963
 964 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 965 int serio_open(struct serio *serio, struct serio_driver *drv)
 966 {
 967         serio_set_drv(serio, drv);
 968
 969         if (serio->open && serio->open(serio)) {
 970                 serio_set_drv(serio, NULL);
 971                 return -1;
 972         }
 973         return 0;
 974 }
 975 EXPORT_SYMBOL(serio_open);
 976
 977 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 978 void serio_close(struct serio *serio)
 979 {
 980         if (serio->close)
 981                 serio->close(serio);
 982
 983         serio_set_drv(serio, NULL);
 984 }
 985 EXPORT_SYMBOL(serio_close);
 986
 987 irqreturn_t serio_interrupt(struct serio *serio,
 988                 unsigned char data, unsigned int dfl)
 989 {
 990         unsigned long flags;
 991         irqreturn_t ret = IRQ_NONE;
 992
 993         spin_lock_irqsave(&serio->lock, flags);
 994
 995         if (likely(serio->drv)) {
 996                 ret = serio->drv->interrupt(serio, data, dfl);
 997         } else if (!dfl && device_is_registered(&serio->dev)) {
 998                 serio_rescan(serio);
 999                 ret = IRQ_HANDLED;
1000         }
1001
1002         spin_unlock_irqrestore(&serio->lock, flags);
1003
1004         return ret;
1005 }
1006 EXPORT_SYMBOL(serio_interrupt);
1007
1008 static struct bus_type serio_bus = {
1009         .name           = "serio",
1010         .dev_attrs      = serio_device_attrs,
1011         .drv_attrs      = serio_driver_attrs,
1012         .match          = serio_bus_match,
1013         .uevent         = serio_uevent,
1014         .probe          = serio_driver_probe,
1015         .remove         = serio_driver_remove,
1016         .shutdown       = serio_shutdown,
1017 #ifdef CONFIG_PM
1018         .pm             = &serio_pm_ops,
1019 #endif
1020 };
1021
1022 static int __init serio_init(void)
1023 {
1024         int error;
1025
1026         error = bus_register(&serio_bus);
1027         if (error) {
1028                 pr_err("Failed to register serio bus, error: %d\n", error);
1029                 return error;
1030         }
1031
1032         return 0;
1033 }
1034
1035 static void __exit serio_exit(void)
1036 {
1037         bus_unregister(&serio_bus);
1038
1039         /*
1040          * There should not be any outstanding events but work may
1041          * still be scheduled so simply cancel it.
1042          */
1043         cancel_work_sync(&serio_event_work);
1044 }
1045
1046 subsys_initcall(serio_init);
1047 module_exit(serio_exit);