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 void serio_add_port(struct serio *serio);
  53 static int serio_reconnect_port(struct serio *serio);
  54 static void serio_disconnect_port(struct serio *serio);
  55 static void serio_reconnect_subtree(struct serio *serio);
  56 static void serio_attach_driver(struct serio_driver *drv);
  57
  58 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  59 {
  60         int retval;
  61
  62         mutex_lock(&serio->drv_mutex);
  63         retval = drv->connect(serio, drv);
  64         mutex_unlock(&serio->drv_mutex);
  65
  66         return retval;
  67 }
  68
  69 static int serio_reconnect_driver(struct serio *serio)
  70 {
  71         int retval = -1;
  72
  73         mutex_lock(&serio->drv_mutex);
  74         if (serio->drv && serio->drv->reconnect)
  75                 retval = serio->drv->reconnect(serio);
  76         mutex_unlock(&serio->drv_mutex);
  77
  78         return retval;
  79 }
  80
  81 static void serio_disconnect_driver(struct serio *serio)
  82 {
  83         mutex_lock(&serio->drv_mutex);
  84         if (serio->drv)
  85                 serio->drv->disconnect(serio);
  86         mutex_unlock(&serio->drv_mutex);
  87 }
  88
  89 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
  90 {
  91         while (ids->type || ids->proto) {
  92                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
  93                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
  94                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
  95                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
  96                         return 1;
  97                 ids++;
  98         }
  99         return 0;
 100 }
 101
 102 /*
 103  * Basic serio -> driver core mappings
 104  */
 105
 106 static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 107 {
 108         int error;
 109
 110         if (serio_match_port(drv->id_table, serio)) {
 111
 112                 serio->dev.driver = &drv->driver;
 113                 if (serio_connect_driver(serio, drv)) {
 114                         serio->dev.driver = NULL;
 115                         return -ENODEV;
 116                 }
 117
 118                 error = device_bind_driver(&serio->dev);
 119                 if (error) {
 120                         dev_warn(&serio->dev,
 121                                  "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
 122                                  serio->phys, serio->name,
 123                                  drv->description, error);
 124                         serio_disconnect_driver(serio);
 125                         serio->dev.driver = NULL;
 126                         return error;
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 static void serio_find_driver(struct serio *serio)
 133 {
 134         int error;
 135
 136         error = device_attach(&serio->dev);
 137         if (error < 0 && error != -EPROBE_DEFER)
 138                 dev_warn(&serio->dev,
 139                          "device_attach() failed for %s (%s), error: %d\n",
 140                          serio->phys, serio->name, error);
 141 }
 142
 143
 144 /*
 145  * Serio event processing.
 146  */
 147
 148 enum serio_event_type {
 149         SERIO_RESCAN_PORT,
 150         SERIO_RECONNECT_PORT,
 151         SERIO_RECONNECT_SUBTREE,
 152         SERIO_REGISTER_PORT,
 153         SERIO_ATTACH_DRIVER,
 154 };
 155
 156 struct serio_event {
 157         enum serio_event_type type;
 158         void *object;
 159         struct module *owner;
 160         struct list_head node;
 161 };
 162
 163 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 164 static LIST_HEAD(serio_event_list);
 165
 166 static struct serio_event *serio_get_event(void)
 167 {
 168         struct serio_event *event = NULL;
 169         unsigned long flags;
 170
 171         spin_lock_irqsave(&serio_event_lock, flags);
 172
 173         if (!list_empty(&serio_event_list)) {
 174                 event = list_first_entry(&serio_event_list,
 175                                          struct serio_event, node);
 176                 list_del_init(&event->node);
 177         }
 178
 179         spin_unlock_irqrestore(&serio_event_lock, flags);
 180         return event;
 181 }
 182
 183 static void serio_free_event(struct serio_event *event)
 184 {
 185         module_put(event->owner);
 186         kfree(event);
 187 }
 188
 189 static void serio_remove_duplicate_events(void *object,
 190                                           enum serio_event_type type)
 191 {
 192         struct serio_event *e, *next;
 193         unsigned long flags;
 194
 195         spin_lock_irqsave(&serio_event_lock, flags);
 196
 197         list_for_each_entry_safe(e, next, &serio_event_list, node) {
 198                 if (object == e->object) {
 199                         /*
 200                          * If this event is of different type we should not
 201                          * look further - we only suppress duplicate events
 202                          * that were sent back-to-back.
 203                          */
 204                         if (type != e->type)
 205                                 break;
 206
 207                         list_del_init(&e->node);
 208                         serio_free_event(e);
 209                 }
 210         }
 211
 212         spin_unlock_irqrestore(&serio_event_lock, flags);
 213 }
 214
 215 static void serio_handle_event(struct work_struct *work)
 216 {
 217         struct serio_event *event;
 218
 219         mutex_lock(&serio_mutex);
 220
 221         while ((event = serio_get_event())) {
 222
 223                 switch (event->type) {
 224
 225                 case SERIO_REGISTER_PORT:
 226                         serio_add_port(event->object);
 227                         break;
 228
 229                 case SERIO_RECONNECT_PORT:
 230                         serio_reconnect_port(event->object);
 231                         break;
 232
 233                 case SERIO_RESCAN_PORT:
 234                         serio_disconnect_port(event->object);
 235                         serio_find_driver(event->object);
 236                         break;
 237
 238                 case SERIO_RECONNECT_SUBTREE:
 239                         serio_reconnect_subtree(event->object);
 240                         break;
 241
 242                 case SERIO_ATTACH_DRIVER:
 243                         serio_attach_driver(event->object);
 244                         break;
 245                 }
 246
 247                 serio_remove_duplicate_events(event->object, event->type);
 248                 serio_free_event(event);
 249         }
 250
 251         mutex_unlock(&serio_mutex);
 252 }
 253
 254 static DECLARE_WORK(serio_event_work, serio_handle_event);
 255
 256 static int serio_queue_event(void *object, struct module *owner,
 257                              enum serio_event_type event_type)
 258 {
 259         unsigned long flags;
 260         struct serio_event *event;
 261         int retval = 0;
 262
 263         spin_lock_irqsave(&serio_event_lock, flags);
 264
 265         /*
 266          * Scan event list for the other events for the same serio port,
 267          * starting with the most recent one. If event is the same we
 268          * do not need add new one. If event is of different type we
 269          * need to add this event and should not look further because
 270          * we need to preseve sequence of distinct events.
 271          */
 272         list_for_each_entry_reverse(event, &serio_event_list, node) {
 273                 if (event->object == object) {
 274                         if (event->type == event_type)
 275                                 goto out;
 276                         break;
 277                 }
 278         }
 279
 280         event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
 281         if (!event) {
 282                 pr_err("Not enough memory to queue event %d\n", event_type);
 283                 retval = -ENOMEM;
 284                 goto out;
 285         }
 286
 287         if (!try_module_get(owner)) {
 288                 pr_warning("Can't get module reference, dropping event %d\n",
 289                            event_type);
 290                 kfree(event);
 291                 retval = -EINVAL;
 292                 goto out;
 293         }
 294
 295         event->type = event_type;
 296         event->object = object;
 297         event->owner = owner;
 298
 299         list_add_tail(&event->node, &serio_event_list);
 300         queue_work(system_long_wq, &serio_event_work);
 301
 302 out:
 303         spin_unlock_irqrestore(&serio_event_lock, flags);
 304         return retval;
 305 }
 306
 307 /*
 308  * Remove all events that have been submitted for a given
 309  * object, be it serio port or driver.
 310  */
 311 static void serio_remove_pending_events(void *object)
 312 {
 313         struct serio_event *event, *next;
 314         unsigned long flags;
 315
 316         spin_lock_irqsave(&serio_event_lock, flags);
 317
 318         list_for_each_entry_safe(event, next, &serio_event_list, node) {
 319                 if (event->object == object) {
 320                         list_del_init(&event->node);
 321                         serio_free_event(event);
 322                 }
 323         }
 324
 325         spin_unlock_irqrestore(&serio_event_lock, flags);
 326 }
 327
 328 /*
 329  * Locate child serio port (if any) that has not been fully registered yet.
 330  *
 331  * Children are registered by driver's connect() handler so there can't be a
 332  * grandchild pending registration together with a child.
 333  */
 334 static struct serio *serio_get_pending_child(struct serio *parent)
 335 {
 336         struct serio_event *event;
 337         struct serio *serio, *child = NULL;
 338         unsigned long flags;
 339
 340         spin_lock_irqsave(&serio_event_lock, flags);
 341
 342         list_for_each_entry(event, &serio_event_list, node) {
 343                 if (event->type == SERIO_REGISTER_PORT) {
 344                         serio = event->object;
 345                         if (serio->parent == parent) {
 346                                 child = serio;
 347                                 break;
 348                         }
 349                 }
 350         }
 351
 352         spin_unlock_irqrestore(&serio_event_lock, flags);
 353         return child;
 354 }
 355
 356 /*
 357  * Serio port operations
 358  */
 359
 360 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 361 {
 362         struct serio *serio = to_serio_port(dev);
 363         return sprintf(buf, "%s\n", serio->name);
 364 }
 365
 366 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 367 {
 368         struct serio *serio = to_serio_port(dev);
 369
 370         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 371                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 372 }
 373
 374 static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
 375 {
 376         struct serio *serio = to_serio_port(dev);
 377         return sprintf(buf, "%02x\n", serio->id.type);
 378 }
 379
 380 static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
 381 {
 382         struct serio *serio = to_serio_port(dev);
 383         return sprintf(buf, "%02x\n", serio->id.proto);
 384 }
 385
 386 static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
 387 {
 388         struct serio *serio = to_serio_port(dev);
 389         return sprintf(buf, "%02x\n", serio->id.id);
 390 }
 391
 392 static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
 393 {
 394         struct serio *serio = to_serio_port(dev);
 395         return sprintf(buf, "%02x\n", serio->id.extra);
 396 }
 397
 398 static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 399 {
 400         struct serio *serio = to_serio_port(dev);
 401         struct device_driver *drv;
 402         int error;
 403
 404         error = mutex_lock_interruptible(&serio_mutex);
 405         if (error)
 406                 return error;
 407
 408         if (!strncmp(buf, "none", count)) {
 409                 serio_disconnect_port(serio);
 410         } else if (!strncmp(buf, "reconnect", count)) {
 411                 serio_reconnect_subtree(serio);
 412         } else if (!strncmp(buf, "rescan", count)) {
 413                 serio_disconnect_port(serio);
 414                 serio_find_driver(serio);
 415                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 416         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 417                 serio_disconnect_port(serio);
 418                 error = serio_bind_driver(serio, to_serio_driver(drv));
 419                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 420         } else {
 421                 error = -EINVAL;
 422         }
 423
 424         mutex_unlock(&serio_mutex);
 425
 426         return error ? error : count;
 427 }
 428
 429 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 430 {
 431         struct serio *serio = to_serio_port(dev);
 432         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 433 }
 434
 435 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 436 {
 437         struct serio *serio = to_serio_port(dev);
 438         int retval;
 439
 440         retval = count;
 441         if (!strncmp(buf, "manual", count)) {
 442                 serio->manual_bind = true;
 443         } else if (!strncmp(buf, "auto", count)) {
 444                 serio->manual_bind = false;
 445         } else {
 446                 retval = -EINVAL;
 447         }
 448
 449         return retval;
 450 }
 451
 452 static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
 453 {
 454         struct serio *serio = to_serio_port(dev);
 455
 456         return sprintf(buf, "%s\n", serio->firmware_id);
 457 }
 458
 459 static DEVICE_ATTR_RO(type);
 460 static DEVICE_ATTR_RO(proto);
 461 static DEVICE_ATTR_RO(id);
 462 static DEVICE_ATTR_RO(extra);
 463
 464 static struct attribute *serio_device_id_attrs[] = {
 465         &dev_attr_type.attr,
 466         &dev_attr_proto.attr,
 467         &dev_attr_id.attr,
 468         &dev_attr_extra.attr,
 469         NULL
 470 };
 471
 472 static struct attribute_group serio_id_attr_group = {
 473         .name   = "id",
 474         .attrs  = serio_device_id_attrs,
 475 };
 476
 477 static DEVICE_ATTR_RO(modalias);
 478 static DEVICE_ATTR_WO(drvctl);
 479 static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
 480 static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
 481 static DEVICE_ATTR_RO(firmware_id);
 482
 483 static struct attribute *serio_device_attrs[] = {
 484         &dev_attr_modalias.attr,
 485         &dev_attr_description.attr,
 486         &dev_attr_drvctl.attr,
 487         &dev_attr_bind_mode.attr,
 488         &dev_attr_firmware_id.attr,
 489         NULL
 490 };
 491
 492 static struct attribute_group serio_device_attr_group = {
 493         .attrs  = serio_device_attrs,
 494 };
 495
 496 static const struct attribute_group *serio_device_attr_groups[] = {
 497         &serio_id_attr_group,
 498         &serio_device_attr_group,
 499         NULL
 500 };
 501
 502 static void serio_release_port(struct device *dev)
 503 {
 504         struct serio *serio = to_serio_port(dev);
 505
 506         kfree(serio);
 507         module_put(THIS_MODULE);
 508 }
 509
 510 /*
 511  * Prepare serio port for registration.
 512  */
 513 static void serio_init_port(struct serio *serio)
 514 {
 515         static atomic_t serio_no = ATOMIC_INIT(-1);
 516
 517         __module_get(THIS_MODULE);
 518
 519         INIT_LIST_HEAD(&serio->node);
 520         INIT_LIST_HEAD(&serio->child_node);
 521         INIT_LIST_HEAD(&serio->children);
 522         spin_lock_init(&serio->lock);
 523         mutex_init(&serio->drv_mutex);
 524         device_initialize(&serio->dev);
 525         dev_set_name(&serio->dev, "serio%lu",
 526                      (unsigned long)atomic_inc_return(&serio_no));
 527         serio->dev.bus = &serio_bus;
 528         serio->dev.release = serio_release_port;
 529         serio->dev.groups = serio_device_attr_groups;
 530         if (serio->parent) {
 531                 serio->dev.parent = &serio->parent->dev;
 532                 serio->depth = serio->parent->depth + 1;
 533         } else
 534                 serio->depth = 0;
 535         lockdep_set_subclass(&serio->lock, serio->depth);
 536 }
 537
 538 /*
 539  * Complete serio port registration.
 540  * Driver core will attempt to find appropriate driver for the port.
 541  */
 542 static void serio_add_port(struct serio *serio)
 543 {
 544         struct serio *parent = serio->parent;
 545         int error;
 546
 547         if (parent) {
 548                 serio_pause_rx(parent);
 549                 list_add_tail(&serio->child_node, &parent->children);
 550                 serio_continue_rx(parent);
 551         }
 552
 553         list_add_tail(&serio->node, &serio_list);
 554
 555         if (serio->start)
 556                 serio->start(serio);
 557
 558         error = device_add(&serio->dev);
 559         if (error)
 560                 dev_err(&serio->dev,
 561                         "device_add() failed for %s (%s), error: %d\n",
 562                         serio->phys, serio->name, error);
 563 }
 564
 565 /*
 566  * serio_destroy_port() completes unregistration process and removes
 567  * port from the system
 568  */
 569 static void serio_destroy_port(struct serio *serio)
 570 {
 571         struct serio *child;
 572
 573         while ((child = serio_get_pending_child(serio)) != NULL) {
 574                 serio_remove_pending_events(child);
 575                 put_device(&child->dev);
 576         }
 577
 578         if (serio->stop)
 579                 serio->stop(serio);
 580
 581         if (serio->parent) {
 582                 serio_pause_rx(serio->parent);
 583                 list_del_init(&serio->child_node);
 584                 serio_continue_rx(serio->parent);
 585                 serio->parent = NULL;
 586         }
 587
 588         if (device_is_registered(&serio->dev))
 589                 device_del(&serio->dev);
 590
 591         list_del_init(&serio->node);
 592         serio_remove_pending_events(serio);
 593         put_device(&serio->dev);
 594 }
 595
 596 /*
 597  * Reconnect serio port (re-initialize attached device).
 598  * If reconnect fails (old device is no longer attached or
 599  * there was no device to begin with) we do full rescan in
 600  * hope of finding a driver for the port.
 601  */
 602 static int serio_reconnect_port(struct serio *serio)
 603 {
 604         int error = serio_reconnect_driver(serio);
 605
 606         if (error) {
 607                 serio_disconnect_port(serio);
 608                 serio_find_driver(serio);
 609         }
 610
 611         return error;
 612 }
 613
 614 /*
 615  * Reconnect serio port and all its children (re-initialize attached
 616  * devices).
 617  */
 618 static void serio_reconnect_subtree(struct serio *root)
 619 {
 620         struct serio *s = root;
 621         int error;
 622
 623         do {
 624                 error = serio_reconnect_port(s);
 625                 if (!error) {
 626                         /*
 627                          * Reconnect was successful, move on to do the
 628                          * first child.
 629                          */
 630                         if (!list_empty(&s->children)) {
 631                                 s = list_first_entry(&s->children,
 632                                                      struct serio, child_node);
 633                                 continue;
 634                         }
 635                 }
 636
 637                 /*
 638                  * Either it was a leaf node or reconnect failed and it
 639                  * became a leaf node. Continue reconnecting starting with
 640                  * the next sibling of the parent node.
 641                  */
 642                 while (s != root) {
 643                         struct serio *parent = s->parent;
 644
 645                         if (!list_is_last(&s->child_node, &parent->children)) {
 646                                 s = list_entry(s->child_node.next,
 647                                                struct serio, child_node);
 648                                 break;
 649                         }
 650
 651                         s = parent;
 652                 }
 653         } while (s != root);
 654 }
 655
 656 /*
 657  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 658  * all children ports are unbound and destroyed.
 659  */
 660 static void serio_disconnect_port(struct serio *serio)
 661 {
 662         struct serio *s = serio;
 663
 664         /*
 665          * Children ports should be disconnected and destroyed
 666          * first; we travel the tree in depth-first order.
 667          */
 668         while (!list_empty(&serio->children)) {
 669
 670                 /* Locate a leaf */
 671                 while (!list_empty(&s->children))
 672                         s = list_first_entry(&s->children,
 673                                              struct serio, child_node);
 674
 675                 /*
 676                  * Prune this leaf node unless it is the one we
 677                  * started with.
 678                  */
 679                 if (s != serio) {
 680                         struct serio *parent = s->parent;
 681
 682                         device_release_driver(&s->dev);
 683                         serio_destroy_port(s);
 684
 685                         s = parent;
 686                 }
 687         }
 688
 689         /*
 690          * OK, no children left, now disconnect this port.
 691          */
 692         device_release_driver(&serio->dev);
 693 }
 694
 695 void serio_rescan(struct serio *serio)
 696 {
 697         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 698 }
 699 EXPORT_SYMBOL(serio_rescan);
 700
 701 void serio_reconnect(struct serio *serio)
 702 {
 703         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 704 }
 705 EXPORT_SYMBOL(serio_reconnect);
 706
 707 /*
 708  * Submits register request to kseriod for subsequent execution.
 709  * Note that port registration is always asynchronous.
 710  */
 711 void __serio_register_port(struct serio *serio, struct module *owner)
 712 {
 713         serio_init_port(serio);
 714         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 715 }
 716 EXPORT_SYMBOL(__serio_register_port);
 717
 718 /*
 719  * Synchronously unregisters serio port.
 720  */
 721 void serio_unregister_port(struct serio *serio)
 722 {
 723         mutex_lock(&serio_mutex);
 724         serio_disconnect_port(serio);
 725         serio_destroy_port(serio);
 726         mutex_unlock(&serio_mutex);
 727 }
 728 EXPORT_SYMBOL(serio_unregister_port);
 729
 730 /*
 731  * Safely unregisters children ports if they are present.
 732  */
 733 void serio_unregister_child_port(struct serio *serio)
 734 {
 735         struct serio *s, *next;
 736
 737         mutex_lock(&serio_mutex);
 738         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 739                 serio_disconnect_port(s);
 740                 serio_destroy_port(s);
 741         }
 742         mutex_unlock(&serio_mutex);
 743 }
 744 EXPORT_SYMBOL(serio_unregister_child_port);
 745
 746
 747 /*
 748  * Serio driver operations
 749  */
 750
 751 static ssize_t description_show(struct device_driver *drv, char *buf)
 752 {
 753         struct serio_driver *driver = to_serio_driver(drv);
 754         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 755 }
 756 static DRIVER_ATTR_RO(description);
 757
 758 static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
 759 {
 760         struct serio_driver *serio_drv = to_serio_driver(drv);
 761         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 762 }
 763
 764 static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
 765 {
 766         struct serio_driver *serio_drv = to_serio_driver(drv);
 767         int retval;
 768
 769         retval = count;
 770         if (!strncmp(buf, "manual", count)) {
 771                 serio_drv->manual_bind = true;
 772         } else if (!strncmp(buf, "auto", count)) {
 773                 serio_drv->manual_bind = false;
 774         } else {
 775                 retval = -EINVAL;
 776         }
 777
 778         return retval;
 779 }
 780 static DRIVER_ATTR_RW(bind_mode);
 781
 782 static struct attribute *serio_driver_attrs[] = {
 783         &driver_attr_description.attr,
 784         &driver_attr_bind_mode.attr,
 785         NULL,
 786 };
 787 ATTRIBUTE_GROUPS(serio_driver);
 788
 789 static int serio_driver_probe(struct device *dev)
 790 {
 791         struct serio *serio = to_serio_port(dev);
 792         struct serio_driver *drv = to_serio_driver(dev->driver);
 793
 794         return serio_connect_driver(serio, drv);
 795 }
 796
 797 static int serio_driver_remove(struct device *dev)
 798 {
 799         struct serio *serio = to_serio_port(dev);
 800
 801         serio_disconnect_driver(serio);
 802         return 0;
 803 }
 804
 805 static void serio_cleanup(struct serio *serio)
 806 {
 807         mutex_lock(&serio->drv_mutex);
 808         if (serio->drv && serio->drv->cleanup)
 809                 serio->drv->cleanup(serio);
 810         mutex_unlock(&serio->drv_mutex);
 811 }
 812
 813 static void serio_shutdown(struct device *dev)
 814 {
 815         struct serio *serio = to_serio_port(dev);
 816
 817         serio_cleanup(serio);
 818 }
 819
 820 static void serio_attach_driver(struct serio_driver *drv)
 821 {
 822         int error;
 823
 824         error = driver_attach(&drv->driver);
 825         if (error)
 826                 pr_warning("driver_attach() failed for %s with error %d\n",
 827                            drv->driver.name, error);
 828 }
 829
 830 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 831 {
 832         bool manual_bind = drv->manual_bind;
 833         int error;
 834
 835         drv->driver.bus = &serio_bus;
 836         drv->driver.owner = owner;
 837         drv->driver.mod_name = mod_name;
 838
 839         /*
 840          * Temporarily disable automatic binding because probing
 841          * takes long time and we are better off doing it in kseriod
 842          */
 843         drv->manual_bind = true;
 844
 845         error = driver_register(&drv->driver);
 846         if (error) {
 847                 pr_err("driver_register() failed for %s, error: %d\n",
 848                         drv->driver.name, error);
 849                 return error;
 850         }
 851
 852         /*
 853          * Restore original bind mode and let kseriod bind the
 854          * driver to free ports
 855          */
 856         if (!manual_bind) {
 857                 drv->manual_bind = false;
 858                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 859                 if (error) {
 860                         driver_unregister(&drv->driver);
 861                         return error;
 862                 }
 863         }
 864
 865         return 0;
 866 }
 867 EXPORT_SYMBOL(__serio_register_driver);
 868
 869 void serio_unregister_driver(struct serio_driver *drv)
 870 {
 871         struct serio *serio;
 872
 873         mutex_lock(&serio_mutex);
 874
 875         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 876         serio_remove_pending_events(drv);
 877
 878 start_over:
 879         list_for_each_entry(serio, &serio_list, node) {
 880                 if (serio->drv == drv) {
 881                         serio_disconnect_port(serio);
 882                         serio_find_driver(serio);
 883                         /* we could've deleted some ports, restart */
 884                         goto start_over;
 885                 }
 886         }
 887
 888         driver_unregister(&drv->driver);
 889         mutex_unlock(&serio_mutex);
 890 }
 891 EXPORT_SYMBOL(serio_unregister_driver);
 892
 893 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 894 {
 895         serio_pause_rx(serio);
 896         serio->drv = drv;
 897         serio_continue_rx(serio);
 898 }
 899
 900 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 901 {
 902         struct serio *serio = to_serio_port(dev);
 903         struct serio_driver *serio_drv = to_serio_driver(drv);
 904
 905         if (serio->manual_bind || serio_drv->manual_bind)
 906                 return 0;
 907
 908         return serio_match_port(serio_drv->id_table, serio);
 909 }
 910
 911 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 912         do {                                                            \
 913                 int err = add_uevent_var(env, fmt, val);                \
 914                 if (err)                                                \
 915                         return err;                                     \
 916         } while (0)
 917
 918 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 919 {
 920         struct serio *serio;
 921
 922         if (!dev)
 923                 return -ENODEV;
 924
 925         serio = to_serio_port(dev);
 926
 927         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 928         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 929         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 930         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 931
 932         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 933                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 934
 935         if (serio->firmware_id[0])
 936                 SERIO_ADD_UEVENT_VAR("SERIO_FIRMWARE_ID=%s",
 937                                      serio->firmware_id);
 938
 939         return 0;
 940 }
 941 #undef SERIO_ADD_UEVENT_VAR
 942
 943 #ifdef CONFIG_PM
 944 static int serio_suspend(struct device *dev)
 945 {
 946         struct serio *serio = to_serio_port(dev);
 947
 948         serio_cleanup(serio);
 949
 950         return 0;
 951 }
 952
 953 static int serio_resume(struct device *dev)
 954 {
 955         struct serio *serio = to_serio_port(dev);
 956
 957         /*
 958          * Driver reconnect can take a while, so better let kseriod
 959          * deal with it.
 960          */
 961         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 962
 963         return 0;
 964 }
 965
 966 static const struct dev_pm_ops serio_pm_ops = {
 967         .suspend        = serio_suspend,
 968         .resume         = serio_resume,
 969         .poweroff       = serio_suspend,
 970         .restore        = serio_resume,
 971 };
 972 #endif /* CONFIG_PM */
 973
 974 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 975 int serio_open(struct serio *serio, struct serio_driver *drv)
 976 {
 977         serio_set_drv(serio, drv);
 978
 979         if (serio->open && serio->open(serio)) {
 980                 serio_set_drv(serio, NULL);
 981                 return -1;
 982         }
 983         return 0;
 984 }
 985 EXPORT_SYMBOL(serio_open);
 986
 987 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 988 void serio_close(struct serio *serio)
 989 {
 990         if (serio->close)
 991                 serio->close(serio);
 992
 993         serio_set_drv(serio, NULL);
 994 }
 995 EXPORT_SYMBOL(serio_close);
 996
 997 irqreturn_t serio_interrupt(struct serio *serio,
 998                 unsigned char data, unsigned int dfl)
 999 {
1000         unsigned long flags;
1001         irqreturn_t ret = IRQ_NONE;
1002
1003         spin_lock_irqsave(&serio->lock, flags);
1004
1005         if (likely(serio->drv)) {
1006                 ret = serio->drv->interrupt(serio, data, dfl);
1007         } else if (!dfl && device_is_registered(&serio->dev)) {
1008                 serio_rescan(serio);
1009                 ret = IRQ_HANDLED;
1010         }
1011
1012         spin_unlock_irqrestore(&serio->lock, flags);
1013
1014         return ret;
1015 }
1016 EXPORT_SYMBOL(serio_interrupt);
1017
1018 struct bus_type serio_bus = {
1019         .name           = "serio",
1020         .drv_groups     = serio_driver_groups,
1021         .match          = serio_bus_match,
1022         .uevent         = serio_uevent,
1023         .probe          = serio_driver_probe,
1024         .remove         = serio_driver_remove,
1025         .shutdown       = serio_shutdown,
1026 #ifdef CONFIG_PM
1027         .pm             = &serio_pm_ops,
1028 #endif
1029 };
1030 EXPORT_SYMBOL(serio_bus);
1031
1032 static int __init serio_init(void)
1033 {
1034         int error;
1035
1036         error = bus_register(&serio_bus);
1037         if (error) {
1038                 pr_err("Failed to register serio bus, error: %d\n", error);
1039                 return error;
1040         }
1041
1042         return 0;
1043 }
1044
1045 static void __exit serio_exit(void)
1046 {
1047         bus_unregister(&serio_bus);
1048
1049         /*
1050          * There should not be any outstanding events but work may
1051          * still be scheduled so simply cancel it.
1052          */
1053         cancel_work_sync(&serio_event_work);
1054 }
1055
1056 subsys_initcall(serio_init);
1057 module_exit(serio_exit);