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                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 445         } else {
 446                 error = -EINVAL;
 447         }
 448
 449         mutex_unlock(&serio_mutex);
 450
 451         return error ? error : count;
 452 }
 453
 454 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 455 {
 456         struct serio *serio = to_serio_port(dev);
 457         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 458 }
 459
 460 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 461 {
 462         struct serio *serio = to_serio_port(dev);
 463         int retval;
 464
 465         retval = count;
 466         if (!strncmp(buf, "manual", count)) {
 467                 serio->manual_bind = true;
 468         } else if (!strncmp(buf, "auto", count)) {
 469                 serio->manual_bind = false;
 470         } else {
 471                 retval = -EINVAL;
 472         }
 473
 474         return retval;
 475 }
 476
 477 static struct device_attribute serio_device_attrs[] = {
 478         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 479         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 480         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 481         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 482         __ATTR_NULL
 483 };
 484
 485
 486 static void serio_release_port(struct device *dev)
 487 {
 488         struct serio *serio = to_serio_port(dev);
 489
 490         kfree(serio);
 491         module_put(THIS_MODULE);
 492 }
 493
 494 /*
 495  * Prepare serio port for registration.
 496  */
 497 static void serio_init_port(struct serio *serio)
 498 {
 499         static atomic_t serio_no = ATOMIC_INIT(0);
 500
 501         __module_get(THIS_MODULE);
 502
 503         INIT_LIST_HEAD(&serio->node);
 504         INIT_LIST_HEAD(&serio->child_node);
 505         INIT_LIST_HEAD(&serio->children);
 506         spin_lock_init(&serio->lock);
 507         mutex_init(&serio->drv_mutex);
 508         device_initialize(&serio->dev);
 509         dev_set_name(&serio->dev, "serio%ld",
 510                         (long)atomic_inc_return(&serio_no) - 1);
 511         serio->dev.bus = &serio_bus;
 512         serio->dev.release = serio_release_port;
 513         serio->dev.groups = serio_device_attr_groups;
 514         if (serio->parent) {
 515                 serio->dev.parent = &serio->parent->dev;
 516                 serio->depth = serio->parent->depth + 1;
 517         } else
 518                 serio->depth = 0;
 519         lockdep_set_subclass(&serio->lock, serio->depth);
 520 }
 521
 522 /*
 523  * Complete serio port registration.
 524  * Driver core will attempt to find appropriate driver for the port.
 525  */
 526 static void serio_add_port(struct serio *serio)
 527 {
 528         struct serio *parent = serio->parent;
 529         int error;
 530
 531         if (parent) {
 532                 serio_pause_rx(parent);
 533                 list_add_tail(&serio->child_node, &parent->children);
 534                 serio_continue_rx(parent);
 535         }
 536
 537         list_add_tail(&serio->node, &serio_list);
 538
 539         if (serio->start)
 540                 serio->start(serio);
 541
 542         error = device_add(&serio->dev);
 543         if (error)
 544                 dev_err(&serio->dev,
 545                         "device_add() failed for %s (%s), error: %d\n",
 546                         serio->phys, serio->name, error);
 547 }
 548
 549 /*
 550  * serio_destroy_port() completes unregistration process and removes
 551  * port from the system
 552  */
 553 static void serio_destroy_port(struct serio *serio)
 554 {
 555         struct serio *child;
 556
 557         while ((child = serio_get_pending_child(serio)) != NULL) {
 558                 serio_remove_pending_events(child);
 559                 put_device(&child->dev);
 560         }
 561
 562         if (serio->stop)
 563                 serio->stop(serio);
 564
 565         if (serio->parent) {
 566                 serio_pause_rx(serio->parent);
 567                 list_del_init(&serio->child_node);
 568                 serio_continue_rx(serio->parent);
 569                 serio->parent = NULL;
 570         }
 571
 572         if (device_is_registered(&serio->dev))
 573                 device_del(&serio->dev);
 574
 575         list_del_init(&serio->node);
 576         serio_remove_pending_events(serio);
 577         put_device(&serio->dev);
 578 }
 579
 580 /*
 581  * Reconnect serio port (re-initialize attached device).
 582  * If reconnect fails (old device is no longer attached or
 583  * there was no device to begin with) we do full rescan in
 584  * hope of finding a driver for the port.
 585  */
 586 static int serio_reconnect_port(struct serio *serio)
 587 {
 588         int error = serio_reconnect_driver(serio);
 589
 590         if (error) {
 591                 serio_disconnect_port(serio);
 592                 serio_find_driver(serio);
 593         }
 594
 595         return error;
 596 }
 597
 598 /*
 599  * Reconnect serio port and all its children (re-initialize attached
 600  * devices).
 601  */
 602 static void serio_reconnect_subtree(struct serio *root)
 603 {
 604         struct serio *s = root;
 605         int error;
 606
 607         do {
 608                 error = serio_reconnect_port(s);
 609                 if (!error) {
 610                         /*
 611                          * Reconnect was successful, move on to do the
 612                          * first child.
 613                          */
 614                         if (!list_empty(&s->children)) {
 615                                 s = list_first_entry(&s->children,
 616                                                      struct serio, child_node);
 617                                 continue;
 618                         }
 619                 }
 620
 621                 /*
 622                  * Either it was a leaf node or reconnect failed and it
 623                  * became a leaf node. Continue reconnecting starting with
 624                  * the next sibling of the parent node.
 625                  */
 626                 while (s != root) {
 627                         struct serio *parent = s->parent;
 628
 629                         if (!list_is_last(&s->child_node, &parent->children)) {
 630                                 s = list_entry(s->child_node.next,
 631                                                struct serio, child_node);
 632                                 break;
 633                         }
 634
 635                         s = parent;
 636                 }
 637         } while (s != root);
 638 }
 639
 640 /*
 641  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 642  * all children ports are unbound and destroyed.
 643  */
 644 static void serio_disconnect_port(struct serio *serio)
 645 {
 646         struct serio *s = serio;
 647
 648         /*
 649          * Children ports should be disconnected and destroyed
 650          * first; we travel the tree in depth-first order.
 651          */
 652         while (!list_empty(&serio->children)) {
 653
 654                 /* Locate a leaf */
 655                 while (!list_empty(&s->children))
 656                         s = list_first_entry(&s->children,
 657                                              struct serio, child_node);
 658
 659                 /*
 660                  * Prune this leaf node unless it is the one we
 661                  * started with.
 662                  */
 663                 if (s != serio) {
 664                         struct serio *parent = s->parent;
 665
 666                         device_release_driver(&s->dev);
 667                         serio_destroy_port(s);
 668
 669                         s = parent;
 670                 }
 671         }
 672
 673         /*
 674          * OK, no children left, now disconnect this port.
 675          */
 676         device_release_driver(&serio->dev);
 677 }
 678
 679 void serio_rescan(struct serio *serio)
 680 {
 681         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 682 }
 683 EXPORT_SYMBOL(serio_rescan);
 684
 685 void serio_reconnect(struct serio *serio)
 686 {
 687         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 688 }
 689 EXPORT_SYMBOL(serio_reconnect);
 690
 691 /*
 692  * Submits register request to kseriod for subsequent execution.
 693  * Note that port registration is always asynchronous.
 694  */
 695 void __serio_register_port(struct serio *serio, struct module *owner)
 696 {
 697         serio_init_port(serio);
 698         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 699 }
 700 EXPORT_SYMBOL(__serio_register_port);
 701
 702 /*
 703  * Synchronously unregisters serio port.
 704  */
 705 void serio_unregister_port(struct serio *serio)
 706 {
 707         mutex_lock(&serio_mutex);
 708         serio_disconnect_port(serio);
 709         serio_destroy_port(serio);
 710         mutex_unlock(&serio_mutex);
 711 }
 712 EXPORT_SYMBOL(serio_unregister_port);
 713
 714 /*
 715  * Safely unregisters children ports if they are present.
 716  */
 717 void serio_unregister_child_port(struct serio *serio)
 718 {
 719         struct serio *s, *next;
 720
 721         mutex_lock(&serio_mutex);
 722         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 723                 serio_disconnect_port(s);
 724                 serio_destroy_port(s);
 725         }
 726         mutex_unlock(&serio_mutex);
 727 }
 728 EXPORT_SYMBOL(serio_unregister_child_port);
 729
 730
 731 /*
 732  * Serio driver operations
 733  */
 734
 735 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 736 {
 737         struct serio_driver *driver = to_serio_driver(drv);
 738         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 739 }
 740
 741 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 742 {
 743         struct serio_driver *serio_drv = to_serio_driver(drv);
 744         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 745 }
 746
 747 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 748 {
 749         struct serio_driver *serio_drv = to_serio_driver(drv);
 750         int retval;
 751
 752         retval = count;
 753         if (!strncmp(buf, "manual", count)) {
 754                 serio_drv->manual_bind = true;
 755         } else if (!strncmp(buf, "auto", count)) {
 756                 serio_drv->manual_bind = false;
 757         } else {
 758                 retval = -EINVAL;
 759         }
 760
 761         return retval;
 762 }
 763
 764
 765 static struct driver_attribute serio_driver_attrs[] = {
 766         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 767         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 768                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 769         __ATTR_NULL
 770 };
 771
 772 static int serio_driver_probe(struct device *dev)
 773 {
 774         struct serio *serio = to_serio_port(dev);
 775         struct serio_driver *drv = to_serio_driver(dev->driver);
 776
 777         return serio_connect_driver(serio, drv);
 778 }
 779
 780 static int serio_driver_remove(struct device *dev)
 781 {
 782         struct serio *serio = to_serio_port(dev);
 783
 784         serio_disconnect_driver(serio);
 785         return 0;
 786 }
 787
 788 static void serio_cleanup(struct serio *serio)
 789 {
 790         mutex_lock(&serio->drv_mutex);
 791         if (serio->drv && serio->drv->cleanup)
 792                 serio->drv->cleanup(serio);
 793         mutex_unlock(&serio->drv_mutex);
 794 }
 795
 796 static void serio_shutdown(struct device *dev)
 797 {
 798         struct serio *serio = to_serio_port(dev);
 799
 800         serio_cleanup(serio);
 801 }
 802
 803 static void serio_attach_driver(struct serio_driver *drv)
 804 {
 805         int error;
 806
 807         error = driver_attach(&drv->driver);
 808         if (error)
 809                 pr_warning("driver_attach() failed for %s with error %d\n",
 810                            drv->driver.name, error);
 811 }
 812
 813 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 814 {
 815         bool manual_bind = drv->manual_bind;
 816         int error;
 817
 818         drv->driver.bus = &serio_bus;
 819         drv->driver.owner = owner;
 820         drv->driver.mod_name = mod_name;
 821
 822         /*
 823          * Temporarily disable automatic binding because probing
 824          * takes long time and we are better off doing it in kseriod
 825          */
 826         drv->manual_bind = true;
 827
 828         error = driver_register(&drv->driver);
 829         if (error) {
 830                 pr_err("driver_register() failed for %s, error: %d\n",
 831                         drv->driver.name, error);
 832                 return error;
 833         }
 834
 835         /*
 836          * Restore original bind mode and let kseriod bind the
 837          * driver to free ports
 838          */
 839         if (!manual_bind) {
 840                 drv->manual_bind = false;
 841                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 842                 if (error) {
 843                         driver_unregister(&drv->driver);
 844                         return error;
 845                 }
 846         }
 847
 848         return 0;
 849 }
 850 EXPORT_SYMBOL(__serio_register_driver);
 851
 852 void serio_unregister_driver(struct serio_driver *drv)
 853 {
 854         struct serio *serio;
 855
 856         mutex_lock(&serio_mutex);
 857
 858         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 859         serio_remove_pending_events(drv);
 860
 861 start_over:
 862         list_for_each_entry(serio, &serio_list, node) {
 863                 if (serio->drv == drv) {
 864                         serio_disconnect_port(serio);
 865                         serio_find_driver(serio);
 866                         /* we could've deleted some ports, restart */
 867                         goto start_over;
 868                 }
 869         }
 870
 871         driver_unregister(&drv->driver);
 872         mutex_unlock(&serio_mutex);
 873 }
 874 EXPORT_SYMBOL(serio_unregister_driver);
 875
 876 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 877 {
 878         serio_pause_rx(serio);
 879         serio->drv = drv;
 880         serio_continue_rx(serio);
 881 }
 882
 883 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 884 {
 885         struct serio *serio = to_serio_port(dev);
 886         struct serio_driver *serio_drv = to_serio_driver(drv);
 887
 888         if (serio->manual_bind || serio_drv->manual_bind)
 889                 return 0;
 890
 891         return serio_match_port(serio_drv->id_table, serio);
 892 }
 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 #ifdef CONFIG_PM
 922 static int serio_suspend(struct device *dev)
 923 {
 924         struct serio *serio = to_serio_port(dev);
 925
 926         serio_cleanup(serio);
 927
 928         return 0;
 929 }
 930
 931 static int serio_resume(struct device *dev)
 932 {
 933         struct serio *serio = to_serio_port(dev);
 934
 935         /*
 936          * Driver reconnect can take a while, so better let kseriod
 937          * deal with it.
 938          */
 939         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 940
 941         return 0;
 942 }
 943
 944 static const struct dev_pm_ops serio_pm_ops = {
 945         .suspend        = serio_suspend,
 946         .resume         = serio_resume,
 947         .poweroff       = serio_suspend,
 948         .restore        = serio_resume,
 949 };
 950 #endif /* CONFIG_PM */
 951
 952 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 953 int serio_open(struct serio *serio, struct serio_driver *drv)
 954 {
 955         serio_set_drv(serio, drv);
 956
 957         if (serio->open && serio->open(serio)) {
 958                 serio_set_drv(serio, NULL);
 959                 return -1;
 960         }
 961         return 0;
 962 }
 963 EXPORT_SYMBOL(serio_open);
 964
 965 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 966 void serio_close(struct serio *serio)
 967 {
 968         if (serio->close)
 969                 serio->close(serio);
 970
 971         serio_set_drv(serio, NULL);
 972 }
 973 EXPORT_SYMBOL(serio_close);
 974
 975 irqreturn_t serio_interrupt(struct serio *serio,
 976                 unsigned char data, unsigned int dfl)
 977 {
 978         unsigned long flags;
 979         irqreturn_t ret = IRQ_NONE;
 980
 981         spin_lock_irqsave(&serio->lock, flags);
 982
 983         if (likely(serio->drv)) {
 984                 ret = serio->drv->interrupt(serio, data, dfl);
 985         } else if (!dfl && device_is_registered(&serio->dev)) {
 986                 serio_rescan(serio);
 987                 ret = IRQ_HANDLED;
 988         }
 989
 990         spin_unlock_irqrestore(&serio->lock, flags);
 991
 992         return ret;
 993 }
 994 EXPORT_SYMBOL(serio_interrupt);
 995
 996 static struct bus_type serio_bus = {
 997         .name           = "serio",
 998         .dev_attrs      = serio_device_attrs,
 999         .drv_attrs      = serio_driver_attrs,
1000         .match          = serio_bus_match,
1001         .uevent         = serio_uevent,
1002         .probe          = serio_driver_probe,
1003         .remove         = serio_driver_remove,
1004         .shutdown       = serio_shutdown,
1005 #ifdef CONFIG_PM
1006         .pm             = &serio_pm_ops,
1007 #endif
1008 };
1009
1010 static int __init serio_init(void)
1011 {
1012         int error;
1013
1014         error = bus_register(&serio_bus);
1015         if (error) {
1016                 pr_err("Failed to register serio bus, error: %d\n", error);
1017                 return error;
1018         }
1019
1020         return 0;
1021 }
1022
1023 static void __exit serio_exit(void)
1024 {
1025         bus_unregister(&serio_bus);
1026
1027         /*
1028          * There should not be any outstanding events but work may
1029          * still be scheduled so simply cancel it.
1030          */
1031         cancel_work_sync(&serio_event_work);
1032 }
1033
1034 subsys_initcall(serio_init);
1035 module_exit(serio_exit);