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(struct serio_event *event)
 192 {
 193         struct serio_event *e, *next;
 194         unsigned long flags;
 195
 196         spin_lock_irqsave(&serio_event_lock, flags);
 197
 198         list_for_each_entry_safe(e, next, &serio_event_list, node) {
 199                 if (event->object == e->object) {
 200                         /*
 201                          * If this event is of different type we should not
 202                          * look further - we only suppress duplicate events
 203                          * that were sent back-to-back.
 204                          */
 205                         if (event->type != e->type)
 206                                 break;
 207
 208                         list_del_init(&e->node);
 209                         serio_free_event(e);
 210                 }
 211         }
 212
 213         spin_unlock_irqrestore(&serio_event_lock, flags);
 214 }
 215
 216 static void serio_handle_event(struct work_struct *work)
 217 {
 218         struct serio_event *event;
 219
 220         mutex_lock(&serio_mutex);
 221
 222         while ((event = serio_get_event())) {
 223
 224                 switch (event->type) {
 225
 226                 case SERIO_REGISTER_PORT:
 227                         serio_add_port(event->object);
 228                         break;
 229
 230                 case SERIO_RECONNECT_PORT:
 231                         serio_reconnect_port(event->object);
 232                         break;
 233
 234                 case SERIO_RESCAN_PORT:
 235                         serio_disconnect_port(event->object);
 236                         serio_find_driver(event->object);
 237                         break;
 238
 239                 case SERIO_RECONNECT_SUBTREE:
 240                         serio_reconnect_subtree(event->object);
 241                         break;
 242
 243                 case SERIO_ATTACH_DRIVER:
 244                         serio_attach_driver(event->object);
 245                         break;
 246                 }
 247
 248                 serio_remove_duplicate_events(event);
 249                 serio_free_event(event);
 250         }
 251
 252         mutex_unlock(&serio_mutex);
 253 }
 254
 255 static DECLARE_WORK(serio_event_work, serio_handle_event);
 256
 257 static int serio_queue_event(void *object, struct module *owner,
 258                              enum serio_event_type event_type)
 259 {
 260         unsigned long flags;
 261         struct serio_event *event;
 262         int retval = 0;
 263
 264         spin_lock_irqsave(&serio_event_lock, flags);
 265
 266         /*
 267          * Scan event list for the other events for the same serio port,
 268          * starting with the most recent one. If event is the same we
 269          * do not need add new one. If event is of different type we
 270          * need to add this event and should not look further because
 271          * we need to preseve sequence of distinct events.
 272          */
 273         list_for_each_entry_reverse(event, &serio_event_list, node) {
 274                 if (event->object == object) {
 275                         if (event->type == event_type)
 276                                 goto out;
 277                         break;
 278                 }
 279         }
 280
 281         event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
 282         if (!event) {
 283                 pr_err("Not enough memory to queue event %d\n", event_type);
 284                 retval = -ENOMEM;
 285                 goto out;
 286         }
 287
 288         if (!try_module_get(owner)) {
 289                 pr_warning("Can't get module reference, dropping event %d\n",
 290                            event_type);
 291                 kfree(event);
 292                 retval = -EINVAL;
 293                 goto out;
 294         }
 295
 296         event->type = event_type;
 297         event->object = object;
 298         event->owner = owner;
 299
 300         list_add_tail(&event->node, &serio_event_list);
 301         schedule_work(&serio_event_work);
 302
 303 out:
 304         spin_unlock_irqrestore(&serio_event_lock, flags);
 305         return retval;
 306 }
 307
 308 /*
 309  * Remove all events that have been submitted for a given
 310  * object, be it serio port or driver.
 311  */
 312 static void serio_remove_pending_events(void *object)
 313 {
 314         struct serio_event *event, *next;
 315         unsigned long flags;
 316
 317         spin_lock_irqsave(&serio_event_lock, flags);
 318
 319         list_for_each_entry_safe(event, next, &serio_event_list, node) {
 320                 if (event->object == object) {
 321                         list_del_init(&event->node);
 322                         serio_free_event(event);
 323                 }
 324         }
 325
 326         spin_unlock_irqrestore(&serio_event_lock, flags);
 327 }
 328
 329 /*
 330  * Locate child serio port (if any) that has not been fully registered yet.
 331  *
 332  * Children are registered by driver's connect() handler so there can't be a
 333  * grandchild pending registration together with a child.
 334  */
 335 static struct serio *serio_get_pending_child(struct serio *parent)
 336 {
 337         struct serio_event *event;
 338         struct serio *serio, *child = NULL;
 339         unsigned long flags;
 340
 341         spin_lock_irqsave(&serio_event_lock, flags);
 342
 343         list_for_each_entry(event, &serio_event_list, node) {
 344                 if (event->type == SERIO_REGISTER_PORT) {
 345                         serio = event->object;
 346                         if (serio->parent == parent) {
 347                                 child = serio;
 348                                 break;
 349                         }
 350                 }
 351         }
 352
 353         spin_unlock_irqrestore(&serio_event_lock, flags);
 354         return child;
 355 }
 356
 357 /*
 358  * Serio port operations
 359  */
 360
 361 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 362 {
 363         struct serio *serio = to_serio_port(dev);
 364         return sprintf(buf, "%s\n", serio->name);
 365 }
 366
 367 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 368 {
 369         struct serio *serio = to_serio_port(dev);
 370
 371         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 372                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 373 }
 374
 375 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
 376 {
 377         struct serio *serio = to_serio_port(dev);
 378         return sprintf(buf, "%02x\n", serio->id.type);
 379 }
 380
 381 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
 382 {
 383         struct serio *serio = to_serio_port(dev);
 384         return sprintf(buf, "%02x\n", serio->id.proto);
 385 }
 386
 387 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
 388 {
 389         struct serio *serio = to_serio_port(dev);
 390         return sprintf(buf, "%02x\n", serio->id.id);
 391 }
 392
 393 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
 394 {
 395         struct serio *serio = to_serio_port(dev);
 396         return sprintf(buf, "%02x\n", serio->id.extra);
 397 }
 398
 399 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 400 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 401 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 402 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 403
 404 static struct attribute *serio_device_id_attrs[] = {
 405         &dev_attr_type.attr,
 406         &dev_attr_proto.attr,
 407         &dev_attr_id.attr,
 408         &dev_attr_extra.attr,
 409         NULL
 410 };
 411
 412 static struct attribute_group serio_id_attr_group = {
 413         .name   = "id",
 414         .attrs  = serio_device_id_attrs,
 415 };
 416
 417 static const struct attribute_group *serio_device_attr_groups[] = {
 418         &serio_id_attr_group,
 419         NULL
 420 };
 421
 422 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 423 {
 424         struct serio *serio = to_serio_port(dev);
 425         struct device_driver *drv;
 426         int error;
 427
 428         error = mutex_lock_interruptible(&serio_mutex);
 429         if (error)
 430                 return error;
 431
 432         if (!strncmp(buf, "none", count)) {
 433                 serio_disconnect_port(serio);
 434         } else if (!strncmp(buf, "reconnect", count)) {
 435                 serio_reconnect_subtree(serio);
 436         } else if (!strncmp(buf, "rescan", count)) {
 437                 serio_disconnect_port(serio);
 438                 serio_find_driver(serio);
 439         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 440                 serio_disconnect_port(serio);
 441                 error = serio_bind_driver(serio, to_serio_driver(drv));
 442                 put_driver(drv);
 443         } else {
 444                 error = -EINVAL;
 445         }
 446
 447         mutex_unlock(&serio_mutex);
 448
 449         return error ? error : count;
 450 }
 451
 452 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 453 {
 454         struct serio *serio = to_serio_port(dev);
 455         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 456 }
 457
 458 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 459 {
 460         struct serio *serio = to_serio_port(dev);
 461         int retval;
 462
 463         retval = count;
 464         if (!strncmp(buf, "manual", count)) {
 465                 serio->manual_bind = true;
 466         } else if (!strncmp(buf, "auto", count)) {
 467                 serio->manual_bind = false;
 468         } else {
 469                 retval = -EINVAL;
 470         }
 471
 472         return retval;
 473 }
 474
 475 static struct device_attribute serio_device_attrs[] = {
 476         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 477         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 478         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 479         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 480         __ATTR_NULL
 481 };
 482
 483
 484 static void serio_release_port(struct device *dev)
 485 {
 486         struct serio *serio = to_serio_port(dev);
 487
 488         kfree(serio);
 489         module_put(THIS_MODULE);
 490 }
 491
 492 /*
 493  * Prepare serio port for registration.
 494  */
 495 static void serio_init_port(struct serio *serio)
 496 {
 497         static atomic_t serio_no = ATOMIC_INIT(0);
 498
 499         __module_get(THIS_MODULE);
 500
 501         INIT_LIST_HEAD(&serio->node);
 502         INIT_LIST_HEAD(&serio->child_node);
 503         INIT_LIST_HEAD(&serio->children);
 504         spin_lock_init(&serio->lock);
 505         mutex_init(&serio->drv_mutex);
 506         device_initialize(&serio->dev);
 507         dev_set_name(&serio->dev, "serio%ld",
 508                         (long)atomic_inc_return(&serio_no) - 1);
 509         serio->dev.bus = &serio_bus;
 510         serio->dev.release = serio_release_port;
 511         serio->dev.groups = serio_device_attr_groups;
 512         if (serio->parent) {
 513                 serio->dev.parent = &serio->parent->dev;
 514                 serio->depth = serio->parent->depth + 1;
 515         } else
 516                 serio->depth = 0;
 517         lockdep_set_subclass(&serio->lock, serio->depth);
 518 }
 519
 520 /*
 521  * Complete serio port registration.
 522  * Driver core will attempt to find appropriate driver for the port.
 523  */
 524 static void serio_add_port(struct serio *serio)
 525 {
 526         struct serio *parent = serio->parent;
 527         int error;
 528
 529         if (parent) {
 530                 serio_pause_rx(parent);
 531                 list_add_tail(&serio->child_node, &parent->children);
 532                 serio_continue_rx(parent);
 533         }
 534
 535         list_add_tail(&serio->node, &serio_list);
 536
 537         if (serio->start)
 538                 serio->start(serio);
 539
 540         error = device_add(&serio->dev);
 541         if (error)
 542                 dev_err(&serio->dev,
 543                         "device_add() failed for %s (%s), error: %d\n",
 544                         serio->phys, serio->name, error);
 545 }
 546
 547 /*
 548  * serio_destroy_port() completes unregistration process and removes
 549  * port from the system
 550  */
 551 static void serio_destroy_port(struct serio *serio)
 552 {
 553         struct serio *child;
 554
 555         while ((child = serio_get_pending_child(serio)) != NULL) {
 556                 serio_remove_pending_events(child);
 557                 put_device(&child->dev);
 558         }
 559
 560         if (serio->stop)
 561                 serio->stop(serio);
 562
 563         if (serio->parent) {
 564                 serio_pause_rx(serio->parent);
 565                 list_del_init(&serio->child_node);
 566                 serio_continue_rx(serio->parent);
 567                 serio->parent = NULL;
 568         }
 569
 570         if (device_is_registered(&serio->dev))
 571                 device_del(&serio->dev);
 572
 573         list_del_init(&serio->node);
 574         serio_remove_pending_events(serio);
 575         put_device(&serio->dev);
 576 }
 577
 578 /*
 579  * Reconnect serio port (re-initialize attached device).
 580  * If reconnect fails (old device is no longer attached or
 581  * there was no device to begin with) we do full rescan in
 582  * hope of finding a driver for the port.
 583  */
 584 static int serio_reconnect_port(struct serio *serio)
 585 {
 586         int error = serio_reconnect_driver(serio);
 587
 588         if (error) {
 589                 serio_disconnect_port(serio);
 590                 serio_find_driver(serio);
 591         }
 592
 593         return error;
 594 }
 595
 596 /*
 597  * Reconnect serio port and all its children (re-initialize attached
 598  * devices).
 599  */
 600 static void serio_reconnect_subtree(struct serio *root)
 601 {
 602         struct serio *s = root;
 603         int error;
 604
 605         do {
 606                 error = serio_reconnect_port(s);
 607                 if (!error) {
 608                         /*
 609                          * Reconnect was successful, move on to do the
 610                          * first child.
 611                          */
 612                         if (!list_empty(&s->children)) {
 613                                 s = list_first_entry(&s->children,
 614                                                      struct serio, child_node);
 615                                 continue;
 616                         }
 617                 }
 618
 619                 /*
 620                  * Either it was a leaf node or reconnect failed and it
 621                  * became a leaf node. Continue reconnecting starting with
 622                  * the next sibling of the parent node.
 623                  */
 624                 while (s != root) {
 625                         struct serio *parent = s->parent;
 626
 627                         if (!list_is_last(&s->child_node, &parent->children)) {
 628                                 s = list_entry(s->child_node.next,
 629                                                struct serio, child_node);
 630                                 break;
 631                         }
 632
 633                         s = parent;
 634                 }
 635         } while (s != root);
 636 }
 637
 638 /*
 639  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 640  * all children ports are unbound and destroyed.
 641  */
 642 static void serio_disconnect_port(struct serio *serio)
 643 {
 644         struct serio *s = serio;
 645
 646         /*
 647          * Children ports should be disconnected and destroyed
 648          * first; we travel the tree in depth-first order.
 649          */
 650         while (!list_empty(&serio->children)) {
 651
 652                 /* Locate a leaf */
 653                 while (!list_empty(&s->children))
 654                         s = list_first_entry(&s->children,
 655                                              struct serio, child_node);
 656
 657                 /*
 658                  * Prune this leaf node unless it is the one we
 659                  * started with.
 660                  */
 661                 if (s != serio) {
 662                         struct serio *parent = s->parent;
 663
 664                         device_release_driver(&s->dev);
 665                         serio_destroy_port(s);
 666
 667                         s = parent;
 668                 }
 669         }
 670
 671         /*
 672          * OK, no children left, now disconnect this port.
 673          */
 674         device_release_driver(&serio->dev);
 675 }
 676
 677 void serio_rescan(struct serio *serio)
 678 {
 679         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 680 }
 681 EXPORT_SYMBOL(serio_rescan);
 682
 683 void serio_reconnect(struct serio *serio)
 684 {
 685         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 686 }
 687 EXPORT_SYMBOL(serio_reconnect);
 688
 689 /*
 690  * Submits register request to kseriod for subsequent execution.
 691  * Note that port registration is always asynchronous.
 692  */
 693 void __serio_register_port(struct serio *serio, struct module *owner)
 694 {
 695         serio_init_port(serio);
 696         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 697 }
 698 EXPORT_SYMBOL(__serio_register_port);
 699
 700 /*
 701  * Synchronously unregisters serio port.
 702  */
 703 void serio_unregister_port(struct serio *serio)
 704 {
 705         mutex_lock(&serio_mutex);
 706         serio_disconnect_port(serio);
 707         serio_destroy_port(serio);
 708         mutex_unlock(&serio_mutex);
 709 }
 710 EXPORT_SYMBOL(serio_unregister_port);
 711
 712 /*
 713  * Safely unregisters children ports if they are present.
 714  */
 715 void serio_unregister_child_port(struct serio *serio)
 716 {
 717         struct serio *s, *next;
 718
 719         mutex_lock(&serio_mutex);
 720         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 721                 serio_disconnect_port(s);
 722                 serio_destroy_port(s);
 723         }
 724         mutex_unlock(&serio_mutex);
 725 }
 726 EXPORT_SYMBOL(serio_unregister_child_port);
 727
 728
 729 /*
 730  * Serio driver operations
 731  */
 732
 733 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 734 {
 735         struct serio_driver *driver = to_serio_driver(drv);
 736         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 737 }
 738
 739 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 740 {
 741         struct serio_driver *serio_drv = to_serio_driver(drv);
 742         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 743 }
 744
 745 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 746 {
 747         struct serio_driver *serio_drv = to_serio_driver(drv);
 748         int retval;
 749
 750         retval = count;
 751         if (!strncmp(buf, "manual", count)) {
 752                 serio_drv->manual_bind = true;
 753         } else if (!strncmp(buf, "auto", count)) {
 754                 serio_drv->manual_bind = false;
 755         } else {
 756                 retval = -EINVAL;
 757         }
 758
 759         return retval;
 760 }
 761
 762
 763 static struct driver_attribute serio_driver_attrs[] = {
 764         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 765         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 766                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 767         __ATTR_NULL
 768 };
 769
 770 static int serio_driver_probe(struct device *dev)
 771 {
 772         struct serio *serio = to_serio_port(dev);
 773         struct serio_driver *drv = to_serio_driver(dev->driver);
 774
 775         return serio_connect_driver(serio, drv);
 776 }
 777
 778 static int serio_driver_remove(struct device *dev)
 779 {
 780         struct serio *serio = to_serio_port(dev);
 781
 782         serio_disconnect_driver(serio);
 783         return 0;
 784 }
 785
 786 static void serio_cleanup(struct serio *serio)
 787 {
 788         mutex_lock(&serio->drv_mutex);
 789         if (serio->drv && serio->drv->cleanup)
 790                 serio->drv->cleanup(serio);
 791         mutex_unlock(&serio->drv_mutex);
 792 }
 793
 794 static void serio_shutdown(struct device *dev)
 795 {
 796         struct serio *serio = to_serio_port(dev);
 797
 798         serio_cleanup(serio);
 799 }
 800
 801 static void serio_attach_driver(struct serio_driver *drv)
 802 {
 803         int error;
 804
 805         error = driver_attach(&drv->driver);
 806         if (error)
 807                 pr_warning("driver_attach() failed for %s with error %d\n",
 808                            drv->driver.name, error);
 809 }
 810
 811 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 812 {
 813         bool manual_bind = drv->manual_bind;
 814         int error;
 815
 816         drv->driver.bus = &serio_bus;
 817         drv->driver.owner = owner;
 818         drv->driver.mod_name = mod_name;
 819
 820         /*
 821          * Temporarily disable automatic binding because probing
 822          * takes long time and we are better off doing it in kseriod
 823          */
 824         drv->manual_bind = true;
 825
 826         error = driver_register(&drv->driver);
 827         if (error) {
 828                 pr_err("driver_register() failed for %s, error: %d\n",
 829                         drv->driver.name, error);
 830                 return error;
 831         }
 832
 833         /*
 834          * Restore original bind mode and let kseriod bind the
 835          * driver to free ports
 836          */
 837         if (!manual_bind) {
 838                 drv->manual_bind = false;
 839                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 840                 if (error) {
 841                         driver_unregister(&drv->driver);
 842                         return error;
 843                 }
 844         }
 845
 846         return 0;
 847 }
 848 EXPORT_SYMBOL(__serio_register_driver);
 849
 850 void serio_unregister_driver(struct serio_driver *drv)
 851 {
 852         struct serio *serio;
 853
 854         mutex_lock(&serio_mutex);
 855
 856         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 857         serio_remove_pending_events(drv);
 858
 859 start_over:
 860         list_for_each_entry(serio, &serio_list, node) {
 861                 if (serio->drv == drv) {
 862                         serio_disconnect_port(serio);
 863                         serio_find_driver(serio);
 864                         /* we could've deleted some ports, restart */
 865                         goto start_over;
 866                 }
 867         }
 868
 869         driver_unregister(&drv->driver);
 870         mutex_unlock(&serio_mutex);
 871 }
 872 EXPORT_SYMBOL(serio_unregister_driver);
 873
 874 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 875 {
 876         serio_pause_rx(serio);
 877         serio->drv = drv;
 878         serio_continue_rx(serio);
 879 }
 880
 881 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 882 {
 883         struct serio *serio = to_serio_port(dev);
 884         struct serio_driver *serio_drv = to_serio_driver(drv);
 885
 886         if (serio->manual_bind || serio_drv->manual_bind)
 887                 return 0;
 888
 889         return serio_match_port(serio_drv->id_table, serio);
 890 }
 891
 892 #ifdef CONFIG_HOTPLUG
 893
 894 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 895         do {                                                            \
 896                 int err = add_uevent_var(env, fmt, val);                \
 897                 if (err)                                                \
 898                         return err;                                     \
 899         } while (0)
 900
 901 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 902 {
 903         struct serio *serio;
 904
 905         if (!dev)
 906                 return -ENODEV;
 907
 908         serio = to_serio_port(dev);
 909
 910         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 911         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 912         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 913         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 914         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 915                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 916
 917         return 0;
 918 }
 919 #undef SERIO_ADD_UEVENT_VAR
 920
 921 #else
 922
 923 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 924 {
 925         return -ENODEV;
 926 }
 927
 928 #endif /* CONFIG_HOTPLUG */
 929
 930 #ifdef CONFIG_PM
 931 static int serio_suspend(struct device *dev)
 932 {
 933         struct serio *serio = to_serio_port(dev);
 934
 935         serio_cleanup(serio);
 936
 937         return 0;
 938 }
 939
 940 static int serio_resume(struct device *dev)
 941 {
 942         struct serio *serio = to_serio_port(dev);
 943
 944         /*
 945          * Driver reconnect can take a while, so better let kseriod
 946          * deal with it.
 947          */
 948         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 949
 950         return 0;
 951 }
 952
 953 static const struct dev_pm_ops serio_pm_ops = {
 954         .suspend        = serio_suspend,
 955         .resume         = serio_resume,
 956         .poweroff       = serio_suspend,
 957         .restore        = serio_resume,
 958 };
 959 #endif /* CONFIG_PM */
 960
 961 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 962 int serio_open(struct serio *serio, struct serio_driver *drv)
 963 {
 964         serio_set_drv(serio, drv);
 965
 966         if (serio->open && serio->open(serio)) {
 967                 serio_set_drv(serio, NULL);
 968                 return -1;
 969         }
 970         return 0;
 971 }
 972 EXPORT_SYMBOL(serio_open);
 973
 974 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 975 void serio_close(struct serio *serio)
 976 {
 977         if (serio->close)
 978                 serio->close(serio);
 979
 980         serio_set_drv(serio, NULL);
 981 }
 982 EXPORT_SYMBOL(serio_close);
 983
 984 irqreturn_t serio_interrupt(struct serio *serio,
 985                 unsigned char data, unsigned int dfl)
 986 {
 987         unsigned long flags;
 988         irqreturn_t ret = IRQ_NONE;
 989
 990         spin_lock_irqsave(&serio->lock, flags);
 991
 992         if (likely(serio->drv)) {
 993                 ret = serio->drv->interrupt(serio, data, dfl);
 994         } else if (!dfl && device_is_registered(&serio->dev)) {
 995                 serio_rescan(serio);
 996                 ret = IRQ_HANDLED;
 997         }
 998
 999         spin_unlock_irqrestore(&serio->lock, flags);
1000
1001         return ret;
1002 }
1003 EXPORT_SYMBOL(serio_interrupt);
1004
1005 static struct bus_type serio_bus = {
1006         .name           = "serio",
1007         .dev_attrs      = serio_device_attrs,
1008         .drv_attrs      = serio_driver_attrs,
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);