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 #include <linux/stddef.h>
  30 #include <linux/module.h>
  31 #include <linux/serio.h>
  32 #include <linux/errno.h>
  33 #include <linux/wait.h>
  34 #include <linux/sched.h>
  35 #include <linux/slab.h>
  36 #include <linux/kthread.h>
  37
  38 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  39 MODULE_DESCRIPTION("Serio abstraction core");
  40 MODULE_LICENSE("GPL");
  41
  42 EXPORT_SYMBOL(serio_interrupt);
  43 EXPORT_SYMBOL(__serio_register_port);
  44 EXPORT_SYMBOL(serio_unregister_port);
  45 EXPORT_SYMBOL(__serio_unregister_port_delayed);
  46 EXPORT_SYMBOL(__serio_register_driver);
  47 EXPORT_SYMBOL(serio_unregister_driver);
  48 EXPORT_SYMBOL(serio_open);
  49 EXPORT_SYMBOL(serio_close);
  50 EXPORT_SYMBOL(serio_rescan);
  51 EXPORT_SYMBOL(serio_reconnect);
  52
  53 /*
  54  * serio_sem protects entire serio subsystem and is taken every time
  55  * serio port or driver registrered or unregistered.
  56  */
  57 static DECLARE_MUTEX(serio_sem);
  58
  59 static LIST_HEAD(serio_list);
  60
  61 static struct bus_type serio_bus = {
  62         .name = "serio",
  63 };
  64
  65 static void serio_add_port(struct serio *serio);
  66 static void serio_destroy_port(struct serio *serio);
  67 static void serio_reconnect_port(struct serio *serio);
  68 static void serio_disconnect_port(struct serio *serio);
  69
  70 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  71 {
  72         int retval;
  73
  74         down(&serio->drv_sem);
  75         retval = drv->connect(serio, drv);
  76         up(&serio->drv_sem);
  77
  78         return retval;
  79 }
  80
  81 static int serio_reconnect_driver(struct serio *serio)
  82 {
  83         int retval = -1;
  84
  85         down(&serio->drv_sem);
  86         if (serio->drv && serio->drv->reconnect)
  87                 retval = serio->drv->reconnect(serio);
  88         up(&serio->drv_sem);
  89
  90         return retval;
  91 }
  92
  93 static void serio_disconnect_driver(struct serio *serio)
  94 {
  95         down(&serio->drv_sem);
  96         if (serio->drv)
  97                 serio->drv->disconnect(serio);
  98         up(&serio->drv_sem);
  99 }
 100
 101 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
 102 {
 103         while (ids->type || ids->proto) {
 104                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
 105                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
 106                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
 107                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
 108                         return 1;
 109                 ids++;
 110         }
 111         return 0;
 112 }
 113
 114 /*
 115  * Basic serio -> driver core mappings
 116  */
 117
 118 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 119 {
 120         down_write(&serio_bus.subsys.rwsem);
 121
 122         if (serio_match_port(drv->id_table, serio)) {
 123                 serio->dev.driver = &drv->driver;
 124                 if (serio_connect_driver(serio, drv)) {
 125                         serio->dev.driver = NULL;
 126                         goto out;
 127                 }
 128                 device_bind_driver(&serio->dev);
 129         }
 130 out:
 131         up_write(&serio_bus.subsys.rwsem);
 132 }
 133
 134 static void serio_release_driver(struct serio *serio)
 135 {
 136         down_write(&serio_bus.subsys.rwsem);
 137         device_release_driver(&serio->dev);
 138         up_write(&serio_bus.subsys.rwsem);
 139 }
 140
 141 static void serio_find_driver(struct serio *serio)
 142 {
 143         down_write(&serio_bus.subsys.rwsem);
 144         device_attach(&serio->dev);
 145         up_write(&serio_bus.subsys.rwsem);
 146 }
 147
 148
 149 /*
 150  * Serio event processing.
 151  */
 152
 153 enum serio_event_type {
 154         SERIO_RESCAN,
 155         SERIO_RECONNECT,
 156         SERIO_REGISTER_PORT,
 157         SERIO_UNREGISTER_PORT,
 158         SERIO_REGISTER_DRIVER,
 159 };
 160
 161 struct serio_event {
 162         enum serio_event_type type;
 163         void *object;
 164         struct module *owner;
 165         struct list_head node;
 166 };
 167
 168 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 169 static LIST_HEAD(serio_event_list);
 170 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 171 static struct task_struct *serio_task;
 172
 173 static void serio_queue_event(void *object, struct module *owner,
 174                               enum serio_event_type event_type)
 175 {
 176         unsigned long flags;
 177         struct serio_event *event;
 178
 179         spin_lock_irqsave(&serio_event_lock, flags);
 180
 181         /*
 182          * Scan event list for the other events for the same serio port,
 183          * starting with the most recent one. If event is the same we
 184          * do not need add new one. If event is of different type we
 185          * need to add this event and should not look further because
 186          * we need to preseve sequence of distinct events.
 187          */
 188         list_for_each_entry_reverse(event, &serio_event_list, node) {
 189                 if (event->object == object) {
 190                         if (event->type == event_type)
 191                                 goto out;
 192                         break;
 193                 }
 194         }
 195
 196         if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
 197                 if (!try_module_get(owner)) {
 198                         printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
 199                         goto out;
 200                 }
 201
 202                 event->type = event_type;
 203                 event->object = object;
 204                 event->owner = owner;
 205
 206                 list_add_tail(&event->node, &serio_event_list);
 207                 wake_up(&serio_wait);
 208         } else {
 209                 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
 210         }
 211 out:
 212         spin_unlock_irqrestore(&serio_event_lock, flags);
 213 }
 214
 215 static void serio_free_event(struct serio_event *event)
 216 {
 217         module_put(event->owner);
 218         kfree(event);
 219 }
 220
 221 static void serio_remove_duplicate_events(struct serio_event *event)
 222 {
 223         struct list_head *node, *next;
 224         struct serio_event *e;
 225         unsigned long flags;
 226
 227         spin_lock_irqsave(&serio_event_lock, flags);
 228
 229         list_for_each_safe(node, next, &serio_event_list) {
 230                 e = list_entry(node, struct serio_event, node);
 231                 if (event->object == e->object) {
 232                         /*
 233                          * If this event is of different type we should not
 234                          * look further - we only suppress duplicate events
 235                          * that were sent back-to-back.
 236                          */
 237                         if (event->type != e->type)
 238                                 break;
 239
 240                         list_del_init(node);
 241                         serio_free_event(e);
 242                 }
 243         }
 244
 245         spin_unlock_irqrestore(&serio_event_lock, flags);
 246 }
 247
 248
 249 static struct serio_event *serio_get_event(void)
 250 {
 251         struct serio_event *event;
 252         struct list_head *node;
 253         unsigned long flags;
 254
 255         spin_lock_irqsave(&serio_event_lock, flags);
 256
 257         if (list_empty(&serio_event_list)) {
 258                 spin_unlock_irqrestore(&serio_event_lock, flags);
 259                 return NULL;
 260         }
 261
 262         node = serio_event_list.next;
 263         event = list_entry(node, struct serio_event, node);
 264         list_del_init(node);
 265
 266         spin_unlock_irqrestore(&serio_event_lock, flags);
 267
 268         return event;
 269 }
 270
 271 static void serio_handle_events(void)
 272 {
 273         struct serio_event *event;
 274         struct serio_driver *serio_drv;
 275
 276         down(&serio_sem);
 277
 278         while ((event = serio_get_event())) {
 279
 280                 switch (event->type) {
 281                         case SERIO_REGISTER_PORT:
 282                                 serio_add_port(event->object);
 283                                 break;
 284
 285                         case SERIO_UNREGISTER_PORT:
 286                                 serio_disconnect_port(event->object);
 287                                 serio_destroy_port(event->object);
 288                                 break;
 289
 290                         case SERIO_RECONNECT:
 291                                 serio_reconnect_port(event->object);
 292                                 break;
 293
 294                         case SERIO_RESCAN:
 295                                 serio_disconnect_port(event->object);
 296                                 serio_find_driver(event->object);
 297                                 break;
 298
 299                         case SERIO_REGISTER_DRIVER:
 300                                 serio_drv = event->object;
 301                                 driver_register(&serio_drv->driver);
 302                                 break;
 303
 304                         default:
 305                                 break;
 306                 }
 307
 308                 serio_remove_duplicate_events(event);
 309                 serio_free_event(event);
 310         }
 311
 312         up(&serio_sem);
 313 }
 314
 315 /*
 316  * Remove all events that have been submitted for a given serio port.
 317  */
 318 static void serio_remove_pending_events(struct serio *serio)
 319 {
 320         struct list_head *node, *next;
 321         struct serio_event *event;
 322         unsigned long flags;
 323
 324         spin_lock_irqsave(&serio_event_lock, flags);
 325
 326         list_for_each_safe(node, next, &serio_event_list) {
 327                 event = list_entry(node, struct serio_event, node);
 328                 if (event->object == serio) {
 329                         list_del_init(node);
 330                         serio_free_event(event);
 331                 }
 332         }
 333
 334         spin_unlock_irqrestore(&serio_event_lock, flags);
 335 }
 336
 337 /*
 338  * Destroy child serio port (if any) that has not been fully registered yet.
 339  *
 340  * Note that we rely on the fact that port can have only one child and therefore
 341  * only one child registration request can be pending. Additionally, children
 342  * are registered by driver's connect() handler so there can't be a grandchild
 343  * pending registration together with a child.
 344  */
 345 static struct serio *serio_get_pending_child(struct serio *parent)
 346 {
 347         struct serio_event *event;
 348         struct serio *serio, *child = NULL;
 349         unsigned long flags;
 350
 351         spin_lock_irqsave(&serio_event_lock, flags);
 352
 353         list_for_each_entry(event, &serio_event_list, node) {
 354                 if (event->type == SERIO_REGISTER_PORT) {
 355                         serio = event->object;
 356                         if (serio->parent == parent) {
 357                                 child = serio;
 358                                 break;
 359                         }
 360                 }
 361         }
 362
 363         spin_unlock_irqrestore(&serio_event_lock, flags);
 364         return child;
 365 }
 366
 367 static int serio_thread(void *nothing)
 368 {
 369         do {
 370                 serio_handle_events();
 371                 wait_event_interruptible(serio_wait,
 372                         kthread_should_stop() || !list_empty(&serio_event_list));
 373                 try_to_freeze(PF_FREEZE);
 374         } while (!kthread_should_stop());
 375
 376         printk(KERN_DEBUG "serio: kseriod exiting\n");
 377         return 0;
 378 }
 379
 380
 381 /*
 382  * Serio port operations
 383  */
 384
 385 static ssize_t serio_show_description(struct device *dev, char *buf)
 386 {
 387         struct serio *serio = to_serio_port(dev);
 388         return sprintf(buf, "%s\n", serio->name);
 389 }
 390
 391 static ssize_t serio_show_id_type(struct device *dev, char *buf)
 392 {
 393         struct serio *serio = to_serio_port(dev);
 394         return sprintf(buf, "%02x\n", serio->id.type);
 395 }
 396
 397 static ssize_t serio_show_id_proto(struct device *dev, char *buf)
 398 {
 399         struct serio *serio = to_serio_port(dev);
 400         return sprintf(buf, "%02x\n", serio->id.proto);
 401 }
 402
 403 static ssize_t serio_show_id_id(struct device *dev, char *buf)
 404 {
 405         struct serio *serio = to_serio_port(dev);
 406         return sprintf(buf, "%02x\n", serio->id.id);
 407 }
 408
 409 static ssize_t serio_show_id_extra(struct device *dev, char *buf)
 410 {
 411         struct serio *serio = to_serio_port(dev);
 412         return sprintf(buf, "%02x\n", serio->id.extra);
 413 }
 414
 415 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 416 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 417 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 418 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 419
 420 static struct attribute *serio_device_id_attrs[] = {
 421         &dev_attr_type.attr,
 422         &dev_attr_proto.attr,
 423         &dev_attr_id.attr,
 424         &dev_attr_extra.attr,
 425         NULL
 426 };
 427
 428 static struct attribute_group serio_id_attr_group = {
 429         .name   = "id",
 430         .attrs  = serio_device_id_attrs,
 431 };
 432
 433 static ssize_t serio_rebind_driver(struct device *dev, const char *buf, size_t count)
 434 {
 435         struct serio *serio = to_serio_port(dev);
 436         struct device_driver *drv;
 437         int retval;
 438
 439         retval = down_interruptible(&serio_sem);
 440         if (retval)
 441                 return retval;
 442
 443         retval = count;
 444         if (!strncmp(buf, "none", count)) {
 445                 serio_disconnect_port(serio);
 446         } else if (!strncmp(buf, "reconnect", count)) {
 447                 serio_reconnect_port(serio);
 448         } else if (!strncmp(buf, "rescan", count)) {
 449                 serio_disconnect_port(serio);
 450                 serio_find_driver(serio);
 451         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 452                 serio_disconnect_port(serio);
 453                 serio_bind_driver(serio, to_serio_driver(drv));
 454                 put_driver(drv);
 455         } else {
 456                 retval = -EINVAL;
 457         }
 458
 459         up(&serio_sem);
 460
 461         return retval;
 462 }
 463
 464 static ssize_t serio_show_bind_mode(struct device *dev, char *buf)
 465 {
 466         struct serio *serio = to_serio_port(dev);
 467         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 468 }
 469
 470 static ssize_t serio_set_bind_mode(struct device *dev, const char *buf, size_t count)
 471 {
 472         struct serio *serio = to_serio_port(dev);
 473         int retval;
 474
 475         retval = count;
 476         if (!strncmp(buf, "manual", count)) {
 477                 serio->manual_bind = 1;
 478         } else if (!strncmp(buf, "auto", count)) {
 479                 serio->manual_bind = 0;
 480         } else {
 481                 retval = -EINVAL;
 482         }
 483
 484         return retval;
 485 }
 486
 487 static struct device_attribute serio_device_attrs[] = {
 488         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 489         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 490         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 491         __ATTR_NULL
 492 };
 493
 494
 495 static void serio_release_port(struct device *dev)
 496 {
 497         struct serio *serio = to_serio_port(dev);
 498
 499         kfree(serio);
 500         module_put(THIS_MODULE);
 501 }
 502
 503 /*
 504  * Prepare serio port for registration.
 505  */
 506 static void serio_init_port(struct serio *serio)
 507 {
 508         static atomic_t serio_no = ATOMIC_INIT(0);
 509
 510         __module_get(THIS_MODULE);
 511
 512         spin_lock_init(&serio->lock);
 513         init_MUTEX(&serio->drv_sem);
 514         device_initialize(&serio->dev);
 515         snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
 516                  "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
 517         serio->dev.bus = &serio_bus;
 518         serio->dev.release = serio_release_port;
 519         if (serio->parent)
 520                 serio->dev.parent = &serio->parent->dev;
 521 }
 522
 523 /*
 524  * Complete serio port registration.
 525  * Driver core will attempt to find appropriate driver for the port.
 526  */
 527 static void serio_add_port(struct serio *serio)
 528 {
 529         if (serio->parent) {
 530                 serio_pause_rx(serio->parent);
 531                 serio->parent->child = serio;
 532                 serio_continue_rx(serio->parent);
 533         }
 534
 535         list_add_tail(&serio->node, &serio_list);
 536         if (serio->start)
 537                 serio->start(serio);
 538         device_add(&serio->dev);
 539         sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
 540         serio->registered = 1;
 541 }
 542
 543 /*
 544  * serio_destroy_port() completes deregistration process and removes
 545  * port from the system
 546  */
 547 static void serio_destroy_port(struct serio *serio)
 548 {
 549         struct serio *child;
 550
 551         child = serio_get_pending_child(serio);
 552         if (child) {
 553                 serio_remove_pending_events(child);
 554                 put_device(&child->dev);
 555         }
 556
 557         if (serio->stop)
 558                 serio->stop(serio);
 559
 560         if (serio->parent) {
 561                 serio_pause_rx(serio->parent);
 562                 serio->parent->child = NULL;
 563                 serio_continue_rx(serio->parent);
 564                 serio->parent = NULL;
 565         }
 566
 567         if (serio->registered) {
 568                 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
 569                 device_del(&serio->dev);
 570                 list_del_init(&serio->node);
 571                 serio->registered = 0;
 572         }
 573
 574         serio_remove_pending_events(serio);
 575         put_device(&serio->dev);
 576 }
 577
 578 /*
 579  * Reconnect serio port and all its children (re-initialize attached devices)
 580  */
 581 static void serio_reconnect_port(struct serio *serio)
 582 {
 583         do {
 584                 if (serio_reconnect_driver(serio)) {
 585                         serio_disconnect_port(serio);
 586                         serio_find_driver(serio);
 587                         /* Ok, old children are now gone, we are done */
 588                         break;
 589                 }
 590                 serio = serio->child;
 591         } while (serio);
 592 }
 593
 594 /*
 595  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 596  * all child ports are unbound and destroyed.
 597  */
 598 static void serio_disconnect_port(struct serio *serio)
 599 {
 600         struct serio *s, *parent;
 601
 602         if (serio->child) {
 603                 /*
 604                  * Children ports should be disconnected and destroyed
 605                  * first, staring with the leaf one, since we don't want
 606                  * to do recursion
 607                  */
 608                 for (s = serio; s->child; s = s->child)
 609                         /* empty */;
 610
 611                 do {
 612                         parent = s->parent;
 613
 614                         serio_release_driver(s);
 615                         serio_destroy_port(s);
 616                 } while ((s = parent) != serio);
 617         }
 618
 619         /*
 620          * Ok, no children left, now disconnect this port
 621          */
 622         serio_release_driver(serio);
 623 }
 624
 625 void serio_rescan(struct serio *serio)
 626 {
 627         serio_queue_event(serio, NULL, SERIO_RESCAN);
 628 }
 629
 630 void serio_reconnect(struct serio *serio)
 631 {
 632         serio_queue_event(serio, NULL, SERIO_RECONNECT);
 633 }
 634
 635 /*
 636  * Submits register request to kseriod for subsequent execution.
 637  * Note that port registration is always asynchronous.
 638  */
 639 void __serio_register_port(struct serio *serio, struct module *owner)
 640 {
 641         serio_init_port(serio);
 642         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 643 }
 644
 645 /*
 646  * Synchronously unregisters serio port.
 647  */
 648 void serio_unregister_port(struct serio *serio)
 649 {
 650         down(&serio_sem);
 651         serio_disconnect_port(serio);
 652         serio_destroy_port(serio);
 653         up(&serio_sem);
 654 }
 655
 656 /*
 657  * Submits register request to kseriod for subsequent execution.
 658  * Can be used when it is not obvious whether the serio_sem is
 659  * taken or not and when delayed execution is feasible.
 660  */
 661 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
 662 {
 663         serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
 664 }
 665
 666
 667 /*
 668  * Serio driver operations
 669  */
 670
 671 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 672 {
 673         struct serio_driver *driver = to_serio_driver(drv);
 674         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 675 }
 676
 677 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 678 {
 679         struct serio_driver *serio_drv = to_serio_driver(drv);
 680         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 681 }
 682
 683 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 684 {
 685         struct serio_driver *serio_drv = to_serio_driver(drv);
 686         int retval;
 687
 688         retval = count;
 689         if (!strncmp(buf, "manual", count)) {
 690                 serio_drv->manual_bind = 1;
 691         } else if (!strncmp(buf, "auto", count)) {
 692                 serio_drv->manual_bind = 0;
 693         } else {
 694                 retval = -EINVAL;
 695         }
 696
 697         return retval;
 698 }
 699
 700
 701 static struct driver_attribute serio_driver_attrs[] = {
 702         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 703         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 704                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 705         __ATTR_NULL
 706 };
 707
 708 static int serio_driver_probe(struct device *dev)
 709 {
 710         struct serio *serio = to_serio_port(dev);
 711         struct serio_driver *drv = to_serio_driver(dev->driver);
 712
 713         return serio_connect_driver(serio, drv);
 714 }
 715
 716 static int serio_driver_remove(struct device *dev)
 717 {
 718         struct serio *serio = to_serio_port(dev);
 719
 720         serio_disconnect_driver(serio);
 721         return 0;
 722 }
 723
 724 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
 725 {
 726         drv->driver.bus = &serio_bus;
 727         drv->driver.probe = serio_driver_probe;
 728         drv->driver.remove = serio_driver_remove;
 729
 730         serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
 731 }
 732
 733 void serio_unregister_driver(struct serio_driver *drv)
 734 {
 735         struct serio *serio;
 736
 737         down(&serio_sem);
 738         drv->manual_bind = 1;   /* so serio_find_driver ignores it */
 739
 740 start_over:
 741         list_for_each_entry(serio, &serio_list, node) {
 742                 if (serio->drv == drv) {
 743                         serio_disconnect_port(serio);
 744                         serio_find_driver(serio);
 745                         /* we could've deleted some ports, restart */
 746                         goto start_over;
 747                 }
 748         }
 749
 750         driver_unregister(&drv->driver);
 751         up(&serio_sem);
 752 }
 753
 754 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 755 {
 756         serio_pause_rx(serio);
 757         serio->drv = drv;
 758         serio_continue_rx(serio);
 759 }
 760
 761 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 762 {
 763         struct serio *serio = to_serio_port(dev);
 764         struct serio_driver *serio_drv = to_serio_driver(drv);
 765
 766         if (serio->manual_bind || serio_drv->manual_bind)
 767                 return 0;
 768
 769         return serio_match_port(serio_drv->id_table, serio);
 770 }
 771
 772 #ifdef CONFIG_HOTPLUG
 773
 774 #define PUT_ENVP(fmt, val)                                              \
 775 do {                                                                    \
 776         envp[i++] = buffer;                                             \
 777         length += snprintf(buffer, buffer_size - length, fmt, val);     \
 778         if (buffer_size - length <= 0 || i >= num_envp)                 \
 779                 return -ENOMEM;                                         \
 780         length++;                                                       \
 781         buffer += length;                                               \
 782 } while (0)
 783 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 784 {
 785         struct serio *serio;
 786         int i = 0;
 787         int length = 0;
 788
 789         if (!dev)
 790                 return -ENODEV;
 791
 792         serio = to_serio_port(dev);
 793
 794         PUT_ENVP("SERIO_TYPE=%02x", serio->id.type);
 795         PUT_ENVP("SERIO_PROTO=%02x", serio->id.proto);
 796         PUT_ENVP("SERIO_ID=%02x", serio->id.id);
 797         PUT_ENVP("SERIO_EXTRA=%02x", serio->id.extra);
 798
 799         envp[i] = NULL;
 800
 801         return 0;
 802 }
 803 #undef PUT_ENVP
 804
 805 #else
 806
 807 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 808 {
 809         return -ENODEV;
 810 }
 811
 812 #endif /* CONFIG_HOTPLUG */
 813
 814 static int serio_resume(struct device *dev)
 815 {
 816         struct serio *serio = to_serio_port(dev);
 817
 818         if (serio_reconnect_driver(serio)) {
 819                 /*
 820                  * Driver re-probing can take a while, so better let kseriod
 821                  * deal with it.
 822                  */
 823                 serio_rescan(serio);
 824         }
 825
 826         return 0;
 827 }
 828
 829 /* called from serio_driver->connect/disconnect methods under serio_sem */
 830 int serio_open(struct serio *serio, struct serio_driver *drv)
 831 {
 832         serio_set_drv(serio, drv);
 833
 834         if (serio->open && serio->open(serio)) {
 835                 serio_set_drv(serio, NULL);
 836                 return -1;
 837         }
 838         return 0;
 839 }
 840
 841 /* called from serio_driver->connect/disconnect methods under serio_sem */
 842 void serio_close(struct serio *serio)
 843 {
 844         if (serio->close)
 845                 serio->close(serio);
 846
 847         serio_set_drv(serio, NULL);
 848 }
 849
 850 irqreturn_t serio_interrupt(struct serio *serio,
 851                 unsigned char data, unsigned int dfl, struct pt_regs *regs)
 852 {
 853         unsigned long flags;
 854         irqreturn_t ret = IRQ_NONE;
 855
 856         spin_lock_irqsave(&serio->lock, flags);
 857
 858         if (likely(serio->drv)) {
 859                 ret = serio->drv->interrupt(serio, data, dfl, regs);
 860         } else if (!dfl && serio->registered) {
 861                 serio_rescan(serio);
 862                 ret = IRQ_HANDLED;
 863         }
 864
 865         spin_unlock_irqrestore(&serio->lock, flags);
 866
 867         return ret;
 868 }
 869
 870 static int __init serio_init(void)
 871 {
 872         serio_task = kthread_run(serio_thread, NULL, "kseriod");
 873         if (IS_ERR(serio_task)) {
 874                 printk(KERN_ERR "serio: Failed to start kseriod\n");
 875                 return PTR_ERR(serio_task);
 876         }
 877
 878         serio_bus.dev_attrs = serio_device_attrs;
 879         serio_bus.drv_attrs = serio_driver_attrs;
 880         serio_bus.match = serio_bus_match;
 881         serio_bus.hotplug = serio_hotplug;
 882         serio_bus.resume = serio_resume;
 883         bus_register(&serio_bus);
 884
 885         return 0;
 886 }
 887
 888 static void __exit serio_exit(void)
 889 {
 890         bus_unregister(&serio_bus);
 891         kthread_stop(serio_task);
 892 }
 893
 894 module_init(serio_init);
 895 module_exit(serio_exit);