drivers/input/serio/serio.c

   1 /*
   2  *  The Serio abstraction module
   3  *
   4  *  Copyright (c) 1999-2004 Vojtech Pavlik
   5  *  Copyright (c) 2004 Dmitry Torokhov
   6  *  Copyright (c) 2003 Daniele Bellucci
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
  26  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
  27  */
  28
  29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  30
  31 #include <linux/stddef.h>
  32 #include <linux/module.h>
  33 #include <linux/serio.h>
  34 #include <linux/errno.h>
  35 #include <linux/sched.h>
  36 #include <linux/slab.h>
  37 #include <linux/workqueue.h>
  38 #include <linux/mutex.h>
  39
  40 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  41 MODULE_DESCRIPTION("Serio abstraction core");
  42 MODULE_LICENSE("GPL");
  43
  44 /*
  45  * serio_mutex protects entire serio subsystem and is taken every time
  46  * serio port or driver registered or unregistered.
  47  */
  48 static DEFINE_MUTEX(serio_mutex);
  49
  50 static LIST_HEAD(serio_list);
  51
  52 static struct bus_type serio_bus;
  53
  54 static void serio_add_port(struct serio *serio);
  55 static int serio_reconnect_port(struct serio *serio);
  56 static void serio_disconnect_port(struct serio *serio);
  57 static void serio_reconnect_subtree(struct serio *serio);
  58 static void serio_attach_driver(struct serio_driver *drv);
  59
  60 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  61 {
  62         int retval;
  63
  64         mutex_lock(&serio->drv_mutex);
  65         retval = drv->connect(serio, drv);
  66         mutex_unlock(&serio->drv_mutex);
  67
  68         return retval;
  69 }
  70
  71 static int serio_reconnect_driver(struct serio *serio)
  72 {
  73         int retval = -1;
  74
  75         mutex_lock(&serio->drv_mutex);
  76         if (serio->drv && serio->drv->reconnect)
  77                 retval = serio->drv->reconnect(serio);
  78         mutex_unlock(&serio->drv_mutex);
  79
  80         return retval;
  81 }
  82
  83 static void serio_disconnect_driver(struct serio *serio)
  84 {
  85         mutex_lock(&serio->drv_mutex);
  86         if (serio->drv)
  87                 serio->drv->disconnect(serio);
  88         mutex_unlock(&serio->drv_mutex);
  89 }
  90
  91 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
  92 {
  93         while (ids->type || ids->proto) {
  94                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
  95                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
  96                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
  97                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
  98                         return 1;
  99                 ids++;
 100         }
 101         return 0;
 102 }
 103
 104 /*
 105  * Basic serio -> driver core mappings
 106  */
 107
 108 static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 109 {
 110         int error;
 111
 112         if (serio_match_port(drv->id_table, serio)) {
 113
 114                 serio->dev.driver = &drv->driver;
 115                 if (serio_connect_driver(serio, drv)) {
 116                         serio->dev.driver = NULL;
 117                         return -ENODEV;
 118                 }
 119
 120                 error = device_bind_driver(&serio->dev);
 121                 if (error) {
 122                         dev_warn(&serio->dev,
 123                                  "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
 124                                  serio->phys, serio->name,
 125                                  drv->description, error);
 126                         serio_disconnect_driver(serio);
 127                         serio->dev.driver = NULL;
 128                         return error;
 129                 }
 130         }
 131         return 0;
 132 }
 133
 134 static void serio_find_driver(struct serio *serio)
 135 {
 136         int error;
 137
 138         error = device_attach(&serio->dev);
 139         if (error < 0)
 140                 dev_warn(&serio->dev,
 141                          "device_attach() failed for %s (%s), error: %d\n",
 142                          serio->phys, serio->name, error);
 143 }
 144
 145
 146 /*
 147  * Serio event processing.
 148  */
 149
 150 enum serio_event_type {
 151         SERIO_RESCAN_PORT,
 152         SERIO_RECONNECT_PORT,
 153         SERIO_RECONNECT_SUBTREE,
 154         SERIO_REGISTER_PORT,
 155         SERIO_ATTACH_DRIVER,
 156 };
 157
 158 struct serio_event {
 159         enum serio_event_type type;
 160         void *object;
 161         struct module *owner;
 162         struct list_head node;
 163 };
 164
 165 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 166 static LIST_HEAD(serio_event_list);
 167
 168 static struct serio_event *serio_get_event(void)
 169 {
 170         struct serio_event *event = NULL;
 171         unsigned long flags;
 172
 173         spin_lock_irqsave(&serio_event_lock, flags);
 174
 175         if (!list_empty(&serio_event_list)) {
 176                 event = list_first_entry(&serio_event_list,
 177                                          struct serio_event, node);
 178                 list_del_init(&event->node);
 179         }
 180
 181         spin_unlock_irqrestore(&serio_event_lock, flags);
 182         return event;
 183 }
 184
 185 static void serio_free_event(struct serio_event *event)
 186 {
 187         module_put(event->owner);
 188         kfree(event);
 189 }
 190
 191 static void serio_remove_duplicate_events(void *object,
 192                                           enum serio_event_type type)
 193 {
 194         struct serio_event *e, *next;
 195         unsigned long flags;
 196
 197         spin_lock_irqsave(&serio_event_lock, flags);
 198
 199         list_for_each_entry_safe(e, next, &serio_event_list, node) {
 200                 if (object == e->object) {
 201                         /*
 202                          * If this event is of different type we should not
 203                          * look further - we only suppress duplicate events
 204                          * that were sent back-to-back.
 205                          */
 206                         if (type != e->type)
 207                                 break;
 208
 209                         list_del_init(&e->node);
 210                         serio_free_event(e);
 211                 }
 212         }
 213
 214         spin_unlock_irqrestore(&serio_event_lock, flags);
 215 }
 216
 217 static void serio_handle_event(struct work_struct *work)
 218 {
 219         struct serio_event *event;
 220
 221         mutex_lock(&serio_mutex);
 222
 223         while ((event = serio_get_event())) {
 224
 225                 switch (event->type) {
 226
 227                 case SERIO_REGISTER_PORT:
 228                         serio_add_port(event->object);
 229                         break;
 230
 231                 case SERIO_RECONNECT_PORT:
 232                         serio_reconnect_port(event->object);
 233                         break;
 234
 235                 case SERIO_RESCAN_PORT:
 236                         serio_disconnect_port(event->object);
 237                         serio_find_driver(event->object);
 238                         break;
 239
 240                 case SERIO_RECONNECT_SUBTREE:
 241                         serio_reconnect_subtree(event->object);
 242                         break;
 243
 244                 case SERIO_ATTACH_DRIVER:
 245                         serio_attach_driver(event->object);
 246                         break;
 247                 }
 248
 249                 serio_remove_duplicate_events(event->object, event->type);
 250                 serio_free_event(event);
 251         }
 252
 253         mutex_unlock(&serio_mutex);
 254 }
 255
 256 static DECLARE_WORK(serio_event_work, serio_handle_event);
 257
 258 static int serio_queue_event(void *object, struct module *owner,
 259                              enum serio_event_type event_type)
 260 {
 261         unsigned long flags;
 262         struct serio_event *event;
 263         int retval = 0;
 264
 265         spin_lock_irqsave(&serio_event_lock, flags);
 266
 267         /*
 268          * Scan event list for the other events for the same serio port,
 269          * starting with the most recent one. If event is the same we
 270          * do not need add new one. If event is of different type we
 271          * need to add this event and should not look further because
 272          * we need to preseve sequence of distinct events.
 273          */
 274         list_for_each_entry_reverse(event, &serio_event_list, node) {
 275                 if (event->object == object) {
 276                         if (event->type == event_type)
 277                                 goto out;
 278                         break;
 279                 }
 280         }
 281
 282         event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
 283         if (!event) {
 284                 pr_err("Not enough memory to queue event %d\n", event_type);
 285                 retval = -ENOMEM;
 286                 goto out;
 287         }
 288
 289         if (!try_module_get(owner)) {
 290                 pr_warning("Can't get module reference, dropping event %d\n",
 291                            event_type);
 292                 kfree(event);
 293                 retval = -EINVAL;
 294                 goto out;
 295         }
 296
 297         event->type = event_type;
 298         event->object = object;
 299         event->owner = owner;
 300
 301         list_add_tail(&event->node, &serio_event_list);
 302         queue_work(system_long_wq, &serio_event_work);
 303
 304 out:
 305         spin_unlock_irqrestore(&serio_event_lock, flags);
 306         return retval;
 307 }
 308
 309 /*
 310  * Remove all events that have been submitted for a given
 311  * object, be it serio port or driver.
 312  */
 313 static void serio_remove_pending_events(void *object)
 314 {
 315         struct serio_event *event, *next;
 316         unsigned long flags;
 317
 318         spin_lock_irqsave(&serio_event_lock, flags);
 319
 320         list_for_each_entry_safe(event, next, &serio_event_list, node) {
 321                 if (event->object == object) {
 322                         list_del_init(&event->node);
 323                         serio_free_event(event);
 324                 }
 325         }
 326
 327         spin_unlock_irqrestore(&serio_event_lock, flags);
 328 }
 329
 330 /*
 331  * Locate child serio port (if any) that has not been fully registered yet.
 332  *
 333  * Children are registered by driver's connect() handler so there can't be a
 334  * grandchild pending registration together with a child.
 335  */
 336 static struct serio *serio_get_pending_child(struct serio *parent)
 337 {
 338         struct serio_event *event;
 339         struct serio *serio, *child = NULL;
 340         unsigned long flags;
 341
 342         spin_lock_irqsave(&serio_event_lock, flags);
 343
 344         list_for_each_entry(event, &serio_event_list, node) {
 345                 if (event->type == SERIO_REGISTER_PORT) {
 346                         serio = event->object;
 347                         if (serio->parent == parent) {
 348                                 child = serio;
 349                                 break;
 350                         }
 351                 }
 352         }
 353
 354         spin_unlock_irqrestore(&serio_event_lock, flags);
 355         return child;
 356 }
 357
 358 /*
 359  * Serio port operations
 360  */
 361
 362 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 363 {
 364         struct serio *serio = to_serio_port(dev);
 365         return sprintf(buf, "%s\n", serio->name);
 366 }
 367
 368 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 369 {
 370         struct serio *serio = to_serio_port(dev);
 371
 372         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 373                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 374 }
 375
 376 static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
 377 {
 378         struct serio *serio = to_serio_port(dev);
 379         return sprintf(buf, "%02x\n", serio->id.type);
 380 }
 381
 382 static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
 383 {
 384         struct serio *serio = to_serio_port(dev);
 385         return sprintf(buf, "%02x\n", serio->id.proto);
 386 }
 387
 388 static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
 389 {
 390         struct serio *serio = to_serio_port(dev);
 391         return sprintf(buf, "%02x\n", serio->id.id);
 392 }
 393
 394 static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
 395 {
 396         struct serio *serio = to_serio_port(dev);
 397         return sprintf(buf, "%02x\n", serio->id.extra);
 398 }
 399
 400 static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 401 {
 402         struct serio *serio = to_serio_port(dev);
 403         struct device_driver *drv;
 404         int error;
 405
 406         error = mutex_lock_interruptible(&serio_mutex);
 407         if (error)
 408                 return error;
 409
 410         if (!strncmp(buf, "none", count)) {
 411                 serio_disconnect_port(serio);
 412         } else if (!strncmp(buf, "reconnect", count)) {
 413                 serio_reconnect_subtree(serio);
 414         } else if (!strncmp(buf, "rescan", count)) {
 415                 serio_disconnect_port(serio);
 416                 serio_find_driver(serio);
 417                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 418         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 419                 serio_disconnect_port(serio);
 420                 error = serio_bind_driver(serio, to_serio_driver(drv));
 421                 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
 422         } else {
 423                 error = -EINVAL;
 424         }
 425
 426         mutex_unlock(&serio_mutex);
 427
 428         return error ? error : count;
 429 }
 430
 431 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 432 {
 433         struct serio *serio = to_serio_port(dev);
 434         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 435 }
 436
 437 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 438 {
 439         struct serio *serio = to_serio_port(dev);
 440         int retval;
 441
 442         retval = count;
 443         if (!strncmp(buf, "manual", count)) {
 444                 serio->manual_bind = true;
 445         } else if (!strncmp(buf, "auto", count)) {
 446                 serio->manual_bind = false;
 447         } else {
 448                 retval = -EINVAL;
 449         }
 450
 451         return retval;
 452 }
 453
 454 static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
 455 {
 456         struct serio *serio = to_serio_port(dev);
 457
 458         return sprintf(buf, "%s\n", serio->firmware_id);
 459 }
 460
 461 static DEVICE_ATTR_RO(type);
 462 static DEVICE_ATTR_RO(proto);
 463 static DEVICE_ATTR_RO(id);
 464 static DEVICE_ATTR_RO(extra);
 465
 466 static struct attribute *serio_device_id_attrs[] = {
 467         &dev_attr_type.attr,
 468         &dev_attr_proto.attr,
 469         &dev_attr_id.attr,
 470         &dev_attr_extra.attr,
 471         NULL
 472 };
 473
 474 static struct attribute_group serio_id_attr_group = {
 475         .name   = "id",
 476         .attrs  = serio_device_id_attrs,
 477 };
 478
 479 static DEVICE_ATTR_RO(modalias);
 480 static DEVICE_ATTR_WO(drvctl);
 481 static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
 482 static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
 483 static DEVICE_ATTR_RO(firmware_id);
 484
 485 static struct attribute *serio_device_attrs[] = {
 486         &dev_attr_modalias.attr,
 487         &dev_attr_description.attr,
 488         &dev_attr_drvctl.attr,
 489         &dev_attr_bind_mode.attr,
 490         &dev_attr_firmware_id.attr,
 491         NULL
 492 };
 493
 494 static struct attribute_group serio_device_attr_group = {
 495         .attrs  = serio_device_attrs,
 496 };
 497
 498 static const struct attribute_group *serio_device_attr_groups[] = {
 499         &serio_id_attr_group,
 500         &serio_device_attr_group,
 501         NULL
 502 };
 503
 504 static void serio_release_port(struct device *dev)
 505 {
 506         struct serio *serio = to_serio_port(dev);
 507
 508         kfree(serio);
 509         module_put(THIS_MODULE);
 510 }
 511
 512 /*
 513  * Prepare serio port for registration.
 514  */
 515 static void serio_init_port(struct serio *serio)
 516 {
 517         static atomic_t serio_no = ATOMIC_INIT(-1);
 518
 519         __module_get(THIS_MODULE);
 520
 521         INIT_LIST_HEAD(&serio->node);
 522         INIT_LIST_HEAD(&serio->child_node);
 523         INIT_LIST_HEAD(&serio->children);
 524         spin_lock_init(&serio->lock);
 525         mutex_init(&serio->drv_mutex);
 526         device_initialize(&serio->dev);
 527         dev_set_name(&serio->dev, "serio%lu",
 528                      (unsigned long)atomic_inc_return(&serio_no));
 529         serio->dev.bus = &serio_bus;
 530         serio->dev.release = serio_release_port;
 531         serio->dev.groups = serio_device_attr_groups;
 532         if (serio->parent) {
 533                 serio->dev.parent = &serio->parent->dev;
 534                 serio->depth = serio->parent->depth + 1;
 535         } else
 536                 serio->depth = 0;
 537         lockdep_set_subclass(&serio->lock, serio->depth);
 538 }
 539
 540 /*
 541  * Complete serio port registration.
 542  * Driver core will attempt to find appropriate driver for the port.
 543  */
 544 static void serio_add_port(struct serio *serio)
 545 {
 546         struct serio *parent = serio->parent;
 547         int error;
 548
 549         if (parent) {
 550                 serio_pause_rx(parent);
 551                 list_add_tail(&serio->child_node, &parent->children);
 552                 serio_continue_rx(parent);
 553         }
 554
 555         list_add_tail(&serio->node, &serio_list);
 556
 557         if (serio->start)
 558                 serio->start(serio);
 559
 560         error = device_add(&serio->dev);
 561         if (error)
 562                 dev_err(&serio->dev,
 563                         "device_add() failed for %s (%s), error: %d\n",
 564                         serio->phys, serio->name, error);
 565 }
 566
 567 /*
 568  * serio_destroy_port() completes unregistration process and removes
 569  * port from the system
 570  */
 571 static void serio_destroy_port(struct serio *serio)
 572 {
 573         struct serio *child;
 574
 575         while ((child = serio_get_pending_child(serio)) != NULL) {
 576                 serio_remove_pending_events(child);
 577                 put_device(&child->dev);
 578         }
 579
 580         if (serio->stop)
 581                 serio->stop(serio);
 582
 583         if (serio->parent) {
 584                 serio_pause_rx(serio->parent);
 585                 list_del_init(&serio->child_node);
 586                 serio_continue_rx(serio->parent);
 587                 serio->parent = NULL;
 588         }
 589
 590         if (device_is_registered(&serio->dev))
 591                 device_del(&serio->dev);
 592
 593         list_del_init(&serio->node);
 594         serio_remove_pending_events(serio);
 595         put_device(&serio->dev);
 596 }
 597
 598 /*
 599  * Reconnect serio port (re-initialize attached device).
 600  * If reconnect fails (old device is no longer attached or
 601  * there was no device to begin with) we do full rescan in
 602  * hope of finding a driver for the port.
 603  */
 604 static int serio_reconnect_port(struct serio *serio)
 605 {
 606         int error = serio_reconnect_driver(serio);
 607
 608         if (error) {
 609                 serio_disconnect_port(serio);
 610                 serio_find_driver(serio);
 611         }
 612
 613         return error;
 614 }
 615
 616 /*
 617  * Reconnect serio port and all its children (re-initialize attached
 618  * devices).
 619  */
 620 static void serio_reconnect_subtree(struct serio *root)
 621 {
 622         struct serio *s = root;
 623         int error;
 624
 625         do {
 626                 error = serio_reconnect_port(s);
 627                 if (!error) {
 628                         /*
 629                          * Reconnect was successful, move on to do the
 630                          * first child.
 631                          */
 632                         if (!list_empty(&s->children)) {
 633                                 s = list_first_entry(&s->children,
 634                                                      struct serio, child_node);
 635                                 continue;
 636                         }
 637                 }
 638
 639                 /*
 640                  * Either it was a leaf node or reconnect failed and it
 641                  * became a leaf node. Continue reconnecting starting with
 642                  * the next sibling of the parent node.
 643                  */
 644                 while (s != root) {
 645                         struct serio *parent = s->parent;
 646
 647                         if (!list_is_last(&s->child_node, &parent->children)) {
 648                                 s = list_entry(s->child_node.next,
 649                                                struct serio, child_node);
 650                                 break;
 651                         }
 652
 653                         s = parent;
 654                 }
 655         } while (s != root);
 656 }
 657
 658 /*
 659  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 660  * all children ports are unbound and destroyed.
 661  */
 662 static void serio_disconnect_port(struct serio *serio)
 663 {
 664         struct serio *s = serio;
 665
 666         /*
 667          * Children ports should be disconnected and destroyed
 668          * first; we travel the tree in depth-first order.
 669          */
 670         while (!list_empty(&serio->children)) {
 671
 672                 /* Locate a leaf */
 673                 while (!list_empty(&s->children))
 674                         s = list_first_entry(&s->children,
 675                                              struct serio, child_node);
 676
 677                 /*
 678                  * Prune this leaf node unless it is the one we
 679                  * started with.
 680                  */
 681                 if (s != serio) {
 682                         struct serio *parent = s->parent;
 683
 684                         device_release_driver(&s->dev);
 685                         serio_destroy_port(s);
 686
 687                         s = parent;
 688                 }
 689         }
 690
 691         /*
 692          * OK, no children left, now disconnect this port.
 693          */
 694         device_release_driver(&serio->dev);
 695 }
 696
 697 void serio_rescan(struct serio *serio)
 698 {
 699         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 700 }
 701 EXPORT_SYMBOL(serio_rescan);
 702
 703 void serio_reconnect(struct serio *serio)
 704 {
 705         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 706 }
 707 EXPORT_SYMBOL(serio_reconnect);
 708
 709 /*
 710  * Submits register request to kseriod for subsequent execution.
 711  * Note that port registration is always asynchronous.
 712  */
 713 void __serio_register_port(struct serio *serio, struct module *owner)
 714 {
 715         serio_init_port(serio);
 716         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 717 }
 718 EXPORT_SYMBOL(__serio_register_port);
 719
 720 /*
 721  * Synchronously unregisters serio port.
 722  */
 723 void serio_unregister_port(struct serio *serio)
 724 {
 725         mutex_lock(&serio_mutex);
 726         serio_disconnect_port(serio);
 727         serio_destroy_port(serio);
 728         mutex_unlock(&serio_mutex);
 729 }
 730 EXPORT_SYMBOL(serio_unregister_port);
 731
 732 /*
 733  * Safely unregisters children ports if they are present.
 734  */
 735 void serio_unregister_child_port(struct serio *serio)
 736 {
 737         struct serio *s, *next;
 738
 739         mutex_lock(&serio_mutex);
 740         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 741                 serio_disconnect_port(s);
 742                 serio_destroy_port(s);
 743         }
 744         mutex_unlock(&serio_mutex);
 745 }
 746 EXPORT_SYMBOL(serio_unregister_child_port);
 747
 748
 749 /*
 750  * Serio driver operations
 751  */
 752
 753 static ssize_t description_show(struct device_driver *drv, char *buf)
 754 {
 755         struct serio_driver *driver = to_serio_driver(drv);
 756         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 757 }
 758 static DRIVER_ATTR_RO(description);
 759
 760 static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
 761 {
 762         struct serio_driver *serio_drv = to_serio_driver(drv);
 763         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 764 }
 765
 766 static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
 767 {
 768         struct serio_driver *serio_drv = to_serio_driver(drv);
 769         int retval;
 770
 771         retval = count;
 772         if (!strncmp(buf, "manual", count)) {
 773                 serio_drv->manual_bind = true;
 774         } else if (!strncmp(buf, "auto", count)) {
 775                 serio_drv->manual_bind = false;
 776         } else {
 777                 retval = -EINVAL;
 778         }
 779
 780         return retval;
 781 }
 782 static DRIVER_ATTR_RW(bind_mode);
 783
 784 static struct attribute *serio_driver_attrs[] = {
 785         &driver_attr_description.attr,
 786         &driver_attr_bind_mode.attr,
 787         NULL,
 788 };
 789 ATTRIBUTE_GROUPS(serio_driver);
 790
 791 static int serio_driver_probe(struct device *dev)
 792 {
 793         struct serio *serio = to_serio_port(dev);
 794         struct serio_driver *drv = to_serio_driver(dev->driver);
 795
 796         return serio_connect_driver(serio, drv);
 797 }
 798
 799 static int serio_driver_remove(struct device *dev)
 800 {
 801         struct serio *serio = to_serio_port(dev);
 802
 803         serio_disconnect_driver(serio);
 804         return 0;
 805 }
 806
 807 static void serio_cleanup(struct serio *serio)
 808 {
 809         mutex_lock(&serio->drv_mutex);
 810         if (serio->drv && serio->drv->cleanup)
 811                 serio->drv->cleanup(serio);
 812         mutex_unlock(&serio->drv_mutex);
 813 }
 814
 815 static void serio_shutdown(struct device *dev)
 816 {
 817         struct serio *serio = to_serio_port(dev);
 818
 819         serio_cleanup(serio);
 820 }
 821
 822 static void serio_attach_driver(struct serio_driver *drv)
 823 {
 824         int error;
 825
 826         error = driver_attach(&drv->driver);
 827         if (error)
 828                 pr_warning("driver_attach() failed for %s with error %d\n",
 829                            drv->driver.name, error);
 830 }
 831
 832 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 833 {
 834         bool manual_bind = drv->manual_bind;
 835         int error;
 836
 837         drv->driver.bus = &serio_bus;
 838         drv->driver.owner = owner;
 839         drv->driver.mod_name = mod_name;
 840
 841         /*
 842          * Temporarily disable automatic binding because probing
 843          * takes long time and we are better off doing it in kseriod
 844          */
 845         drv->manual_bind = true;
 846
 847         error = driver_register(&drv->driver);
 848         if (error) {
 849                 pr_err("driver_register() failed for %s, error: %d\n",
 850                         drv->driver.name, error);
 851                 return error;
 852         }
 853
 854         /*
 855          * Restore original bind mode and let kseriod bind the
 856          * driver to free ports
 857          */
 858         if (!manual_bind) {
 859                 drv->manual_bind = false;
 860                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 861                 if (error) {
 862                         driver_unregister(&drv->driver);
 863                         return error;
 864                 }
 865         }
 866
 867         return 0;
 868 }
 869 EXPORT_SYMBOL(__serio_register_driver);
 870
 871 void serio_unregister_driver(struct serio_driver *drv)
 872 {
 873         struct serio *serio;
 874
 875         mutex_lock(&serio_mutex);
 876
 877         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 878         serio_remove_pending_events(drv);
 879
 880 start_over:
 881         list_for_each_entry(serio, &serio_list, node) {
 882                 if (serio->drv == drv) {
 883                         serio_disconnect_port(serio);
 884                         serio_find_driver(serio);
 885                         /* we could've deleted some ports, restart */
 886                         goto start_over;
 887                 }
 888         }
 889
 890         driver_unregister(&drv->driver);
 891         mutex_unlock(&serio_mutex);
 892 }
 893 EXPORT_SYMBOL(serio_unregister_driver);
 894
 895 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 896 {
 897         serio_pause_rx(serio);
 898         serio->drv = drv;
 899         serio_continue_rx(serio);
 900 }
 901
 902 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 903 {
 904         struct serio *serio = to_serio_port(dev);
 905         struct serio_driver *serio_drv = to_serio_driver(drv);
 906
 907         if (serio->manual_bind || serio_drv->manual_bind)
 908                 return 0;
 909
 910         return serio_match_port(serio_drv->id_table, serio);
 911 }
 912
 913 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 914         do {                                                            \
 915                 int err = add_uevent_var(env, fmt, val);                \
 916                 if (err)                                                \
 917                         return err;                                     \
 918         } while (0)
 919
 920 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 921 {
 922         struct serio *serio;
 923
 924         if (!dev)
 925                 return -ENODEV;
 926
 927         serio = to_serio_port(dev);
 928
 929         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 930         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 931         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 932         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 933
 934         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 935                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 936
 937         if (serio->firmware_id[0])
 938                 SERIO_ADD_UEVENT_VAR("SERIO_FIRMWARE_ID=%s",
 939                                      serio->firmware_id);
 940
 941         return 0;
 942 }
 943 #undef SERIO_ADD_UEVENT_VAR
 944
 945 #ifdef CONFIG_PM
 946 static int serio_suspend(struct device *dev)
 947 {
 948         struct serio *serio = to_serio_port(dev);
 949
 950         serio_cleanup(serio);
 951
 952         return 0;
 953 }
 954
 955 static int serio_resume(struct device *dev)
 956 {
 957         struct serio *serio = to_serio_port(dev);
 958
 959         /*
 960          * Driver reconnect can take a while, so better let kseriod
 961          * deal with it.
 962          */
 963         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 964
 965         return 0;
 966 }
 967
 968 static const struct dev_pm_ops serio_pm_ops = {
 969         .suspend        = serio_suspend,
 970         .resume         = serio_resume,
 971         .poweroff       = serio_suspend,
 972         .restore        = serio_resume,
 973 };
 974 #endif /* CONFIG_PM */
 975
 976 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 977 int serio_open(struct serio *serio, struct serio_driver *drv)
 978 {
 979         serio_set_drv(serio, drv);
 980
 981         if (serio->open && serio->open(serio)) {
 982                 serio_set_drv(serio, NULL);
 983                 return -1;
 984         }
 985         return 0;
 986 }
 987 EXPORT_SYMBOL(serio_open);
 988
 989 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 990 void serio_close(struct serio *serio)
 991 {
 992         if (serio->close)
 993                 serio->close(serio);
 994
 995         serio_set_drv(serio, NULL);
 996 }
 997 EXPORT_SYMBOL(serio_close);
 998
 999 irqreturn_t serio_interrupt(struct serio *serio,
1000                 unsigned char data, unsigned int dfl)
1001 {
1002         unsigned long flags;
1003         irqreturn_t ret = IRQ_NONE;
1004
1005         spin_lock_irqsave(&serio->lock, flags);
1006
1007         if (likely(serio->drv)) {
1008                 ret = serio->drv->interrupt(serio, data, dfl);
1009         } else if (!dfl && device_is_registered(&serio->dev)) {
1010                 serio_rescan(serio);
1011                 ret = IRQ_HANDLED;
1012         }
1013
1014         spin_unlock_irqrestore(&serio->lock, flags);
1015
1016         return ret;
1017 }
1018 EXPORT_SYMBOL(serio_interrupt);
1019
1020 static struct bus_type serio_bus = {
1021         .name           = "serio",
1022         .drv_groups     = serio_driver_groups,
1023         .match          = serio_bus_match,
1024         .uevent         = serio_uevent,
1025         .probe          = serio_driver_probe,
1026         .remove         = serio_driver_remove,
1027         .shutdown       = serio_shutdown,
1028 #ifdef CONFIG_PM
1029         .pm             = &serio_pm_ops,
1030 #endif
1031 };
1032
1033 static int __init serio_init(void)
1034 {
1035         int error;
1036
1037         error = bus_register(&serio_bus);
1038         if (error) {
1039                 pr_err("Failed to register serio bus, error: %d\n", error);
1040                 return error;
1041         }
1042
1043         return 0;
1044 }
1045
1046 static void __exit serio_exit(void)
1047 {
1048         bus_unregister(&serio_bus);
1049
1050         /*
1051          * There should not be any outstanding events but work may
1052          * still be scheduled so simply cancel it.
1053          */
1054         cancel_work_sync(&serio_event_work);
1055 }
1056
1057 subsys_initcall(serio_init);
1058 module_exit(serio_exit);