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/wait.h>
  36 #include <linux/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/kthread.h>
  39 #include <linux/mutex.h>
  40
  41 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  42 MODULE_DESCRIPTION("Serio abstraction core");
  43 MODULE_LICENSE("GPL");
  44
  45 /*
  46  * serio_mutex protects entire serio subsystem and is taken every time
  47  * serio port or driver registrered or unregistered.
  48  */
  49 static DEFINE_MUTEX(serio_mutex);
  50
  51 static LIST_HEAD(serio_list);
  52
  53 static struct bus_type serio_bus;
  54
  55 static void serio_add_port(struct serio *serio);
  56 static int serio_reconnect_port(struct serio *serio);
  57 static void serio_disconnect_port(struct serio *serio);
  58 static void serio_reconnect_subtree(struct serio *serio);
  59 static void serio_attach_driver(struct serio_driver *drv);
  60
  61 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  62 {
  63         int retval;
  64
  65         mutex_lock(&serio->drv_mutex);
  66         retval = drv->connect(serio, drv);
  67         mutex_unlock(&serio->drv_mutex);
  68
  69         return retval;
  70 }
  71
  72 static int serio_reconnect_driver(struct serio *serio)
  73 {
  74         int retval = -1;
  75
  76         mutex_lock(&serio->drv_mutex);
  77         if (serio->drv && serio->drv->reconnect)
  78                 retval = serio->drv->reconnect(serio);
  79         mutex_unlock(&serio->drv_mutex);
  80
  81         return retval;
  82 }
  83
  84 static void serio_disconnect_driver(struct serio *serio)
  85 {
  86         mutex_lock(&serio->drv_mutex);
  87         if (serio->drv)
  88                 serio->drv->disconnect(serio);
  89         mutex_unlock(&serio->drv_mutex);
  90 }
  91
  92 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
  93 {
  94         while (ids->type || ids->proto) {
  95                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
  96                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
  97                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
  98                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
  99                         return 1;
 100                 ids++;
 101         }
 102         return 0;
 103 }
 104
 105 /*
 106  * Basic serio -> driver core mappings
 107  */
 108
 109 static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 110 {
 111         int error;
 112
 113         if (serio_match_port(drv->id_table, serio)) {
 114
 115                 serio->dev.driver = &drv->driver;
 116                 if (serio_connect_driver(serio, drv)) {
 117                         serio->dev.driver = NULL;
 118                         return -ENODEV;
 119                 }
 120
 121                 error = device_bind_driver(&serio->dev);
 122                 if (error) {
 123                         dev_warn(&serio->dev,
 124                                  "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
 125                                  serio->phys, serio->name,
 126                                  drv->description, error);
 127                         serio_disconnect_driver(serio);
 128                         serio->dev.driver = NULL;
 129                         return error;
 130                 }
 131         }
 132         return 0;
 133 }
 134
 135 static void serio_find_driver(struct serio *serio)
 136 {
 137         int error;
 138
 139         error = device_attach(&serio->dev);
 140         if (error < 0)
 141                 dev_warn(&serio->dev,
 142                          "device_attach() failed for %s (%s), error: %d\n",
 143                          serio->phys, serio->name, error);
 144 }
 145
 146
 147 /*
 148  * Serio event processing.
 149  */
 150
 151 enum serio_event_type {
 152         SERIO_RESCAN_PORT,
 153         SERIO_RECONNECT_PORT,
 154         SERIO_RECONNECT_SUBTREE,
 155         SERIO_REGISTER_PORT,
 156         SERIO_ATTACH_DRIVER,
 157 };
 158
 159 struct serio_event {
 160         enum serio_event_type type;
 161         void *object;
 162         struct module *owner;
 163         struct list_head node;
 164 };
 165
 166 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 167 static LIST_HEAD(serio_event_list);
 168 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 169 static struct task_struct *serio_task;
 170
 171 static int serio_queue_event(void *object, struct module *owner,
 172                              enum serio_event_type event_type)
 173 {
 174         unsigned long flags;
 175         struct serio_event *event;
 176         int retval = 0;
 177
 178         spin_lock_irqsave(&serio_event_lock, flags);
 179
 180         /*
 181          * Scan event list for the other events for the same serio port,
 182          * starting with the most recent one. If event is the same we
 183          * do not need add new one. If event is of different type we
 184          * need to add this event and should not look further because
 185          * we need to preseve sequence of distinct events.
 186          */
 187         list_for_each_entry_reverse(event, &serio_event_list, node) {
 188                 if (event->object == object) {
 189                         if (event->type == event_type)
 190                                 goto out;
 191                         break;
 192                 }
 193         }
 194
 195         event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
 196         if (!event) {
 197                 pr_err("Not enough memory to queue event %d\n", event_type);
 198                 retval = -ENOMEM;
 199                 goto out;
 200         }
 201
 202         if (!try_module_get(owner)) {
 203                 pr_warning("Can't get module reference, dropping event %d\n",
 204                            event_type);
 205                 kfree(event);
 206                 retval = -EINVAL;
 207                 goto out;
 208         }
 209
 210         event->type = event_type;
 211         event->object = object;
 212         event->owner = owner;
 213
 214         list_add_tail(&event->node, &serio_event_list);
 215         wake_up(&serio_wait);
 216
 217 out:
 218         spin_unlock_irqrestore(&serio_event_lock, flags);
 219         return retval;
 220 }
 221
 222 static void serio_free_event(struct serio_event *event)
 223 {
 224         module_put(event->owner);
 225         kfree(event);
 226 }
 227
 228 static void serio_remove_duplicate_events(struct serio_event *event)
 229 {
 230         struct serio_event *e, *next;
 231         unsigned long flags;
 232
 233         spin_lock_irqsave(&serio_event_lock, flags);
 234
 235         list_for_each_entry_safe(e, next, &serio_event_list, node) {
 236                 if (event->object == e->object) {
 237                         /*
 238                          * If this event is of different type we should not
 239                          * look further - we only suppress duplicate events
 240                          * that were sent back-to-back.
 241                          */
 242                         if (event->type != e->type)
 243                                 break;
 244
 245                         list_del_init(&e->node);
 246                         serio_free_event(e);
 247                 }
 248         }
 249
 250         spin_unlock_irqrestore(&serio_event_lock, flags);
 251 }
 252
 253
 254 static struct serio_event *serio_get_event(void)
 255 {
 256         struct serio_event *event = NULL;
 257         unsigned long flags;
 258
 259         spin_lock_irqsave(&serio_event_lock, flags);
 260
 261         if (!list_empty(&serio_event_list)) {
 262                 event = list_first_entry(&serio_event_list,
 263                                          struct serio_event, node);
 264                 list_del_init(&event->node);
 265         }
 266
 267         spin_unlock_irqrestore(&serio_event_lock, flags);
 268         return event;
 269 }
 270
 271 static void serio_handle_event(void)
 272 {
 273         struct serio_event *event;
 274
 275         mutex_lock(&serio_mutex);
 276
 277         while ((event = serio_get_event())) {
 278
 279                 switch (event->type) {
 280
 281                 case SERIO_REGISTER_PORT:
 282                         serio_add_port(event->object);
 283                         break;
 284
 285                 case SERIO_RECONNECT_PORT:
 286                         serio_reconnect_port(event->object);
 287                         break;
 288
 289                 case SERIO_RESCAN_PORT:
 290                         serio_disconnect_port(event->object);
 291                         serio_find_driver(event->object);
 292                         break;
 293
 294                 case SERIO_RECONNECT_SUBTREE:
 295                         serio_reconnect_subtree(event->object);
 296                         break;
 297
 298                 case SERIO_ATTACH_DRIVER:
 299                         serio_attach_driver(event->object);
 300                         break;
 301                 }
 302
 303                 serio_remove_duplicate_events(event);
 304                 serio_free_event(event);
 305         }
 306
 307         mutex_unlock(&serio_mutex);
 308 }
 309
 310 /*
 311  * Remove all events that have been submitted for a given
 312  * object, be it serio port or driver.
 313  */
 314 static void serio_remove_pending_events(void *object)
 315 {
 316         struct serio_event *event, *next;
 317         unsigned long flags;
 318
 319         spin_lock_irqsave(&serio_event_lock, flags);
 320
 321         list_for_each_entry_safe(event, next, &serio_event_list, node) {
 322                 if (event->object == object) {
 323                         list_del_init(&event->node);
 324                         serio_free_event(event);
 325                 }
 326         }
 327
 328         spin_unlock_irqrestore(&serio_event_lock, flags);
 329 }
 330
 331 /*
 332  * Locate child serio port (if any) that has not been fully registered yet.
 333  *
 334  * Children are registered by driver's connect() handler so there can't be a
 335  * grandchild pending registration together with a child.
 336  */
 337 static struct serio *serio_get_pending_child(struct serio *parent)
 338 {
 339         struct serio_event *event;
 340         struct serio *serio, *child = NULL;
 341         unsigned long flags;
 342
 343         spin_lock_irqsave(&serio_event_lock, flags);
 344
 345         list_for_each_entry(event, &serio_event_list, node) {
 346                 if (event->type == SERIO_REGISTER_PORT) {
 347                         serio = event->object;
 348                         if (serio->parent == parent) {
 349                                 child = serio;
 350                                 break;
 351                         }
 352                 }
 353         }
 354
 355         spin_unlock_irqrestore(&serio_event_lock, flags);
 356         return child;
 357 }
 358
 359 static int serio_thread(void *nothing)
 360 {
 361         do {
 362                 serio_handle_event();
 363                 wait_event_interruptible(serio_wait,
 364                         kthread_should_stop() || !list_empty(&serio_event_list));
 365         } while (!kthread_should_stop());
 366
 367         return 0;
 368 }
 369
 370
 371 /*
 372  * Serio port operations
 373  */
 374
 375 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 376 {
 377         struct serio *serio = to_serio_port(dev);
 378         return sprintf(buf, "%s\n", serio->name);
 379 }
 380
 381 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 382 {
 383         struct serio *serio = to_serio_port(dev);
 384
 385         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 386                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 387 }
 388
 389 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
 390 {
 391         struct serio *serio = to_serio_port(dev);
 392         return sprintf(buf, "%02x\n", serio->id.type);
 393 }
 394
 395 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
 396 {
 397         struct serio *serio = to_serio_port(dev);
 398         return sprintf(buf, "%02x\n", serio->id.proto);
 399 }
 400
 401 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
 402 {
 403         struct serio *serio = to_serio_port(dev);
 404         return sprintf(buf, "%02x\n", serio->id.id);
 405 }
 406
 407 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
 408 {
 409         struct serio *serio = to_serio_port(dev);
 410         return sprintf(buf, "%02x\n", serio->id.extra);
 411 }
 412
 413 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 414 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 415 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 416 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 417
 418 static struct attribute *serio_device_id_attrs[] = {
 419         &dev_attr_type.attr,
 420         &dev_attr_proto.attr,
 421         &dev_attr_id.attr,
 422         &dev_attr_extra.attr,
 423         NULL
 424 };
 425
 426 static struct attribute_group serio_id_attr_group = {
 427         .name   = "id",
 428         .attrs  = serio_device_id_attrs,
 429 };
 430
 431 static const struct attribute_group *serio_device_attr_groups[] = {
 432         &serio_id_attr_group,
 433         NULL
 434 };
 435
 436 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 437 {
 438         struct serio *serio = to_serio_port(dev);
 439         struct device_driver *drv;
 440         int error;
 441
 442         error = mutex_lock_interruptible(&serio_mutex);
 443         if (error)
 444                 return error;
 445
 446         if (!strncmp(buf, "none", count)) {
 447                 serio_disconnect_port(serio);
 448         } else if (!strncmp(buf, "reconnect", count)) {
 449                 serio_reconnect_subtree(serio);
 450         } else if (!strncmp(buf, "rescan", count)) {
 451                 serio_disconnect_port(serio);
 452                 serio_find_driver(serio);
 453         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 454                 serio_disconnect_port(serio);
 455                 error = serio_bind_driver(serio, to_serio_driver(drv));
 456                 put_driver(drv);
 457         } else {
 458                 error = -EINVAL;
 459         }
 460
 461         mutex_unlock(&serio_mutex);
 462
 463         return error ? error : count;
 464 }
 465
 466 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 467 {
 468         struct serio *serio = to_serio_port(dev);
 469         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 470 }
 471
 472 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 473 {
 474         struct serio *serio = to_serio_port(dev);
 475         int retval;
 476
 477         retval = count;
 478         if (!strncmp(buf, "manual", count)) {
 479                 serio->manual_bind = true;
 480         } else if (!strncmp(buf, "auto", count)) {
 481                 serio->manual_bind = false;
 482         } else {
 483                 retval = -EINVAL;
 484         }
 485
 486         return retval;
 487 }
 488
 489 static struct device_attribute serio_device_attrs[] = {
 490         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 491         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 492         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 493         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 494         __ATTR_NULL
 495 };
 496
 497
 498 static void serio_release_port(struct device *dev)
 499 {
 500         struct serio *serio = to_serio_port(dev);
 501
 502         kfree(serio);
 503         module_put(THIS_MODULE);
 504 }
 505
 506 /*
 507  * Prepare serio port for registration.
 508  */
 509 static void serio_init_port(struct serio *serio)
 510 {
 511         static atomic_t serio_no = ATOMIC_INIT(0);
 512
 513         __module_get(THIS_MODULE);
 514
 515         INIT_LIST_HEAD(&serio->node);
 516         INIT_LIST_HEAD(&serio->child_node);
 517         INIT_LIST_HEAD(&serio->children);
 518         spin_lock_init(&serio->lock);
 519         mutex_init(&serio->drv_mutex);
 520         device_initialize(&serio->dev);
 521         dev_set_name(&serio->dev, "serio%ld",
 522                         (long)atomic_inc_return(&serio_no) - 1);
 523         serio->dev.bus = &serio_bus;
 524         serio->dev.release = serio_release_port;
 525         serio->dev.groups = serio_device_attr_groups;
 526         if (serio->parent) {
 527                 serio->dev.parent = &serio->parent->dev;
 528                 serio->depth = serio->parent->depth + 1;
 529         } else
 530                 serio->depth = 0;
 531         lockdep_set_subclass(&serio->lock, serio->depth);
 532 }
 533
 534 /*
 535  * Complete serio port registration.
 536  * Driver core will attempt to find appropriate driver for the port.
 537  */
 538 static void serio_add_port(struct serio *serio)
 539 {
 540         struct serio *parent = serio->parent;
 541         int error;
 542
 543         if (parent) {
 544                 serio_pause_rx(parent);
 545                 list_add_tail(&serio->child_node, &parent->children);
 546                 serio_continue_rx(parent);
 547         }
 548
 549         list_add_tail(&serio->node, &serio_list);
 550
 551         if (serio->start)
 552                 serio->start(serio);
 553
 554         error = device_add(&serio->dev);
 555         if (error)
 556                 dev_err(&serio->dev,
 557                         "device_add() failed for %s (%s), error: %d\n",
 558                         serio->phys, serio->name, error);
 559 }
 560
 561 /*
 562  * serio_destroy_port() completes unregistration process and removes
 563  * port from the system
 564  */
 565 static void serio_destroy_port(struct serio *serio)
 566 {
 567         struct serio *child;
 568
 569         while ((child = serio_get_pending_child(serio)) != NULL) {
 570                 serio_remove_pending_events(child);
 571                 put_device(&child->dev);
 572         }
 573
 574         if (serio->stop)
 575                 serio->stop(serio);
 576
 577         if (serio->parent) {
 578                 serio_pause_rx(serio->parent);
 579                 list_del_init(&serio->child_node);
 580                 serio_continue_rx(serio->parent);
 581                 serio->parent = NULL;
 582         }
 583
 584         if (device_is_registered(&serio->dev))
 585                 device_del(&serio->dev);
 586
 587         list_del_init(&serio->node);
 588         serio_remove_pending_events(serio);
 589         put_device(&serio->dev);
 590 }
 591
 592 /*
 593  * Reconnect serio port (re-initialize attached device).
 594  * If reconnect fails (old device is no longer attached or
 595  * there was no device to begin with) we do full rescan in
 596  * hope of finding a driver for the port.
 597  */
 598 static int serio_reconnect_port(struct serio *serio)
 599 {
 600         int error = serio_reconnect_driver(serio);
 601
 602         if (error) {
 603                 serio_disconnect_port(serio);
 604                 serio_find_driver(serio);
 605         }
 606
 607         return error;
 608 }
 609
 610 /*
 611  * Reconnect serio port and all its children (re-initialize attached
 612  * devices).
 613  */
 614 static void serio_reconnect_subtree(struct serio *root)
 615 {
 616         struct serio *s = root;
 617         int error;
 618
 619         do {
 620                 error = serio_reconnect_port(s);
 621                 if (!error) {
 622                         /*
 623                          * Reconnect was successful, move on to do the
 624                          * first child.
 625                          */
 626                         if (!list_empty(&s->children)) {
 627                                 s = list_first_entry(&s->children,
 628                                                      struct serio, child_node);
 629                                 continue;
 630                         }
 631                 }
 632
 633                 /*
 634                  * Either it was a leaf node or reconnect failed and it
 635                  * became a leaf node. Continue reconnecting starting with
 636                  * the next sibling of the parent node.
 637                  */
 638                 while (s != root) {
 639                         struct serio *parent = s->parent;
 640
 641                         if (!list_is_last(&s->child_node, &parent->children)) {
 642                                 s = list_entry(s->child_node.next,
 643                                                struct serio, child_node);
 644                                 break;
 645                         }
 646
 647                         s = parent;
 648                 }
 649         } while (s != root);
 650 }
 651
 652 /*
 653  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 654  * all children ports are unbound and destroyed.
 655  */
 656 static void serio_disconnect_port(struct serio *serio)
 657 {
 658         struct serio *s = serio;
 659
 660         /*
 661          * Children ports should be disconnected and destroyed
 662          * first; we travel the tree in depth-first order.
 663          */
 664         while (!list_empty(&serio->children)) {
 665
 666                 /* Locate a leaf */
 667                 while (!list_empty(&s->children))
 668                         s = list_first_entry(&s->children,
 669                                              struct serio, child_node);
 670
 671                 /*
 672                  * Prune this leaf node unless it is the one we
 673                  * started with.
 674                  */
 675                 if (s != serio) {
 676                         struct serio *parent = s->parent;
 677
 678                         device_release_driver(&s->dev);
 679                         serio_destroy_port(s);
 680
 681                         s = parent;
 682                 }
 683         }
 684
 685         /*
 686          * OK, no children left, now disconnect this port.
 687          */
 688         device_release_driver(&serio->dev);
 689 }
 690
 691 void serio_rescan(struct serio *serio)
 692 {
 693         serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 694 }
 695 EXPORT_SYMBOL(serio_rescan);
 696
 697 void serio_reconnect(struct serio *serio)
 698 {
 699         serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 700 }
 701 EXPORT_SYMBOL(serio_reconnect);
 702
 703 /*
 704  * Submits register request to kseriod for subsequent execution.
 705  * Note that port registration is always asynchronous.
 706  */
 707 void __serio_register_port(struct serio *serio, struct module *owner)
 708 {
 709         serio_init_port(serio);
 710         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 711 }
 712 EXPORT_SYMBOL(__serio_register_port);
 713
 714 /*
 715  * Synchronously unregisters serio port.
 716  */
 717 void serio_unregister_port(struct serio *serio)
 718 {
 719         mutex_lock(&serio_mutex);
 720         serio_disconnect_port(serio);
 721         serio_destroy_port(serio);
 722         mutex_unlock(&serio_mutex);
 723 }
 724 EXPORT_SYMBOL(serio_unregister_port);
 725
 726 /*
 727  * Safely unregisters children ports if they are present.
 728  */
 729 void serio_unregister_child_port(struct serio *serio)
 730 {
 731         struct serio *s, *next;
 732
 733         mutex_lock(&serio_mutex);
 734         list_for_each_entry_safe(s, next, &serio->children, child_node) {
 735                 serio_disconnect_port(s);
 736                 serio_destroy_port(s);
 737         }
 738         mutex_unlock(&serio_mutex);
 739 }
 740 EXPORT_SYMBOL(serio_unregister_child_port);
 741
 742
 743 /*
 744  * Serio driver operations
 745  */
 746
 747 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 748 {
 749         struct serio_driver *driver = to_serio_driver(drv);
 750         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 751 }
 752
 753 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 754 {
 755         struct serio_driver *serio_drv = to_serio_driver(drv);
 756         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 757 }
 758
 759 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 760 {
 761         struct serio_driver *serio_drv = to_serio_driver(drv);
 762         int retval;
 763
 764         retval = count;
 765         if (!strncmp(buf, "manual", count)) {
 766                 serio_drv->manual_bind = true;
 767         } else if (!strncmp(buf, "auto", count)) {
 768                 serio_drv->manual_bind = false;
 769         } else {
 770                 retval = -EINVAL;
 771         }
 772
 773         return retval;
 774 }
 775
 776
 777 static struct driver_attribute serio_driver_attrs[] = {
 778         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 779         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 780                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 781         __ATTR_NULL
 782 };
 783
 784 static int serio_driver_probe(struct device *dev)
 785 {
 786         struct serio *serio = to_serio_port(dev);
 787         struct serio_driver *drv = to_serio_driver(dev->driver);
 788
 789         return serio_connect_driver(serio, drv);
 790 }
 791
 792 static int serio_driver_remove(struct device *dev)
 793 {
 794         struct serio *serio = to_serio_port(dev);
 795
 796         serio_disconnect_driver(serio);
 797         return 0;
 798 }
 799
 800 static void serio_cleanup(struct serio *serio)
 801 {
 802         mutex_lock(&serio->drv_mutex);
 803         if (serio->drv && serio->drv->cleanup)
 804                 serio->drv->cleanup(serio);
 805         mutex_unlock(&serio->drv_mutex);
 806 }
 807
 808 static void serio_shutdown(struct device *dev)
 809 {
 810         struct serio *serio = to_serio_port(dev);
 811
 812         serio_cleanup(serio);
 813 }
 814
 815 static void serio_attach_driver(struct serio_driver *drv)
 816 {
 817         int error;
 818
 819         error = driver_attach(&drv->driver);
 820         if (error)
 821                 pr_warning("driver_attach() failed for %s with error %d\n",
 822                            drv->driver.name, error);
 823 }
 824
 825 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
 826 {
 827         bool manual_bind = drv->manual_bind;
 828         int error;
 829
 830         drv->driver.bus = &serio_bus;
 831         drv->driver.owner = owner;
 832         drv->driver.mod_name = mod_name;
 833
 834         /*
 835          * Temporarily disable automatic binding because probing
 836          * takes long time and we are better off doing it in kseriod
 837          */
 838         drv->manual_bind = true;
 839
 840         error = driver_register(&drv->driver);
 841         if (error) {
 842                 pr_err("driver_register() failed for %s, error: %d\n",
 843                         drv->driver.name, error);
 844                 return error;
 845         }
 846
 847         /*
 848          * Restore original bind mode and let kseriod bind the
 849          * driver to free ports
 850          */
 851         if (!manual_bind) {
 852                 drv->manual_bind = false;
 853                 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
 854                 if (error) {
 855                         driver_unregister(&drv->driver);
 856                         return error;
 857                 }
 858         }
 859
 860         return 0;
 861 }
 862 EXPORT_SYMBOL(__serio_register_driver);
 863
 864 void serio_unregister_driver(struct serio_driver *drv)
 865 {
 866         struct serio *serio;
 867
 868         mutex_lock(&serio_mutex);
 869
 870         drv->manual_bind = true;        /* so serio_find_driver ignores it */
 871         serio_remove_pending_events(drv);
 872
 873 start_over:
 874         list_for_each_entry(serio, &serio_list, node) {
 875                 if (serio->drv == drv) {
 876                         serio_disconnect_port(serio);
 877                         serio_find_driver(serio);
 878                         /* we could've deleted some ports, restart */
 879                         goto start_over;
 880                 }
 881         }
 882
 883         driver_unregister(&drv->driver);
 884         mutex_unlock(&serio_mutex);
 885 }
 886 EXPORT_SYMBOL(serio_unregister_driver);
 887
 888 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 889 {
 890         serio_pause_rx(serio);
 891         serio->drv = drv;
 892         serio_continue_rx(serio);
 893 }
 894
 895 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 896 {
 897         struct serio *serio = to_serio_port(dev);
 898         struct serio_driver *serio_drv = to_serio_driver(drv);
 899
 900         if (serio->manual_bind || serio_drv->manual_bind)
 901                 return 0;
 902
 903         return serio_match_port(serio_drv->id_table, serio);
 904 }
 905
 906 #ifdef CONFIG_HOTPLUG
 907
 908 #define SERIO_ADD_UEVENT_VAR(fmt, val...)                               \
 909         do {                                                            \
 910                 int err = add_uevent_var(env, fmt, val);                \
 911                 if (err)                                                \
 912                         return err;                                     \
 913         } while (0)
 914
 915 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 916 {
 917         struct serio *serio;
 918
 919         if (!dev)
 920                 return -ENODEV;
 921
 922         serio = to_serio_port(dev);
 923
 924         SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
 925         SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
 926         SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
 927         SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 928         SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 929                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 930
 931         return 0;
 932 }
 933 #undef SERIO_ADD_UEVENT_VAR
 934
 935 #else
 936
 937 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
 938 {
 939         return -ENODEV;
 940 }
 941
 942 #endif /* CONFIG_HOTPLUG */
 943
 944 #ifdef CONFIG_PM
 945 static int serio_suspend(struct device *dev)
 946 {
 947         struct serio *serio = to_serio_port(dev);
 948
 949         serio_cleanup(serio);
 950
 951         return 0;
 952 }
 953
 954 static int serio_resume(struct device *dev)
 955 {
 956         struct serio *serio = to_serio_port(dev);
 957
 958         /*
 959          * Driver reconnect can take a while, so better let kseriod
 960          * deal with it.
 961          */
 962         serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 963
 964         return 0;
 965 }
 966
 967 static const struct dev_pm_ops serio_pm_ops = {
 968         .suspend        = serio_suspend,
 969         .resume         = serio_resume,
 970         .poweroff       = serio_suspend,
 971         .restore        = serio_resume,
 972 };
 973 #endif /* CONFIG_PM */
 974
 975 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 976 int serio_open(struct serio *serio, struct serio_driver *drv)
 977 {
 978         serio_set_drv(serio, drv);
 979
 980         if (serio->open && serio->open(serio)) {
 981                 serio_set_drv(serio, NULL);
 982                 return -1;
 983         }
 984         return 0;
 985 }
 986 EXPORT_SYMBOL(serio_open);
 987
 988 /* called from serio_driver->connect/disconnect methods under serio_mutex */
 989 void serio_close(struct serio *serio)
 990 {
 991         if (serio->close)
 992                 serio->close(serio);
 993
 994         serio_set_drv(serio, NULL);
 995 }
 996 EXPORT_SYMBOL(serio_close);
 997
 998 irqreturn_t serio_interrupt(struct serio *serio,
 999                 unsigned char data, unsigned int dfl)
1000 {
1001         unsigned long flags;
1002         irqreturn_t ret = IRQ_NONE;
1003
1004         spin_lock_irqsave(&serio->lock, flags);
1005
1006         if (likely(serio->drv)) {
1007                 ret = serio->drv->interrupt(serio, data, dfl);
1008         } else if (!dfl && device_is_registered(&serio->dev)) {
1009                 serio_rescan(serio);
1010                 ret = IRQ_HANDLED;
1011         }
1012
1013         spin_unlock_irqrestore(&serio->lock, flags);
1014
1015         return ret;
1016 }
1017 EXPORT_SYMBOL(serio_interrupt);
1018
1019 static struct bus_type serio_bus = {
1020         .name           = "serio",
1021         .dev_attrs      = serio_device_attrs,
1022         .drv_attrs      = serio_driver_attrs,
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         serio_task = kthread_run(serio_thread, NULL, "kseriod");
1044         if (IS_ERR(serio_task)) {
1045                 bus_unregister(&serio_bus);
1046                 error = PTR_ERR(serio_task);
1047                 pr_err("Failed to start kseriod, error: %d\n", error);
1048                 return error;
1049         }
1050
1051         return 0;
1052 }
1053
1054 static void __exit serio_exit(void)
1055 {
1056         bus_unregister(&serio_bus);
1057         kthread_stop(serio_task);
1058 }
1059
1060 subsys_initcall(serio_init);
1061 module_exit(serio_exit);