SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/rfkill/rfkill.c

   1 /*
   2  * Copyright (C) 2006 - 2007 Ivo van Doorn
   3  * Copyright (C) 2007 Dmitry Torokhov
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the
  17  * Free Software Foundation, Inc.,
  18  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/capability.h>
  26 #include <linux/list.h>
  27 #include <linux/mutex.h>
  28 #include <linux/rfkill.h>
  29
  30 /* Get declaration of rfkill_switch_all() to shut up sparse. */
  31 #include "rfkill-input.h"
  32
  33
  34 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
  35 MODULE_VERSION("1.0");
  36 MODULE_DESCRIPTION("RF switch support");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(rfkill_list);  /* list of registered rf switches */
  40 static DEFINE_MUTEX(rfkill_mutex);
  41
  42 static unsigned int rfkill_default_state = RFKILL_STATE_UNBLOCKED;
  43 module_param_named(default_state, rfkill_default_state, uint, 0444);
  44 MODULE_PARM_DESC(default_state,
  45                  "Default initial state for all radio types, 0 = radio off");
  46
  47 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
  48
  49 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  50
  51
  52 /**
  53  * register_rfkill_notifier - Add notifier to rfkill notifier chain
  54  * @nb: pointer to the new entry to add to the chain
  55  *
  56  * See blocking_notifier_chain_register() for return value and further
  57  * observations.
  58  *
  59  * Adds a notifier to the rfkill notifier chain.  The chain will be
  60  * called with a pointer to the relevant rfkill structure as a parameter,
  61  * refer to include/linux/rfkill.h for the possible events.
  62  *
  63  * Notifiers added to this chain are to always return NOTIFY_DONE.  This
  64  * chain is a blocking notifier chain: notifiers can sleep.
  65  *
  66  * Calls to this chain may have been done through a workqueue.  One must
  67  * assume unordered asynchronous behaviour, there is no way to know if
  68  * actions related to the event that generated the notification have been
  69  * carried out already.
  70  */
  71 int register_rfkill_notifier(struct notifier_block *nb)
  72 {
  73         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
  74 }
  75 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  76
  77 /**
  78  * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
  79  * @nb: pointer to the entry to remove from the chain
  80  *
  81  * See blocking_notifier_chain_unregister() for return value and further
  82  * observations.
  83  *
  84  * Removes a notifier from the rfkill notifier chain.
  85  */
  86 int unregister_rfkill_notifier(struct notifier_block *nb)
  87 {
  88         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
  89 }
  90 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
  91
  92
  93 static void rfkill_led_trigger(struct rfkill *rfkill,
  94                                enum rfkill_state state)
  95 {
  96 #ifdef CONFIG_RFKILL_LEDS
  97         struct led_trigger *led = &rfkill->led_trigger;
  98
  99         if (!led->name)
 100                 return;
 101         if (state != RFKILL_STATE_UNBLOCKED)
 102                 led_trigger_event(led, LED_OFF);
 103         else
 104                 led_trigger_event(led, LED_FULL);
 105 #endif /* CONFIG_RFKILL_LEDS */
 106 }
 107
 108 static void notify_rfkill_state_change(struct rfkill *rfkill)
 109 {
 110         blocking_notifier_call_chain(&rfkill_notifier_list,
 111                         RFKILL_STATE_CHANGED,
 112                         rfkill);
 113 }
 114
 115 static void update_rfkill_state(struct rfkill *rfkill)
 116 {
 117         enum rfkill_state newstate, oldstate;
 118
 119         if (rfkill->get_state) {
 120                 mutex_lock(&rfkill->mutex);
 121                 if (!rfkill->get_state(rfkill->data, &newstate)) {
 122                         oldstate = rfkill->state;
 123                         rfkill->state = newstate;
 124                         if (oldstate != newstate)
 125                                 notify_rfkill_state_change(rfkill);
 126                 }
 127                 mutex_unlock(&rfkill->mutex);
 128         }
 129 }
 130
 131 /**
 132  * rfkill_toggle_radio - wrapper for toggle_radio hook
 133  *
 134  * @rfkill: the rfkill struct to use
 135  * @force: calls toggle_radio even if cache says it is not needed,
 136  *      and also makes sure notifications of the state will be
 137  *      sent even if it didn't change
 138  * @state: the new state to call toggle_radio() with
 139  *
 140  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
 141  * calls and handling all the red tape such as issuing notifications
 142  * if the call is successful.
 143  *
 144  * Note that @force cannot override a (possibly cached) state of
 145  * RFKILL_STATE_HARD_BLOCKED.  Any device making use of
 146  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
 147  * rfkill_force_state(), so the cache either is bypassed or valid.
 148  *
 149  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
 150  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
 151  * give the driver a hint that it should double-BLOCK the transmitter.
 152  *
 153  * Caller must have aquired rfkill_mutex.
 154  */
 155 static int rfkill_toggle_radio(struct rfkill *rfkill,
 156                                 enum rfkill_state state,
 157                                 int force)
 158 {
 159         int retval = 0;
 160         enum rfkill_state oldstate, newstate;
 161
 162         oldstate = rfkill->state;
 163
 164         if (rfkill->get_state && !force &&
 165             !rfkill->get_state(rfkill->data, &newstate))
 166                 rfkill->state = newstate;
 167
 168         switch (state) {
 169         case RFKILL_STATE_HARD_BLOCKED:
 170                 /* typically happens when refreshing hardware state,
 171                  * such as on resume */
 172                 state = RFKILL_STATE_SOFT_BLOCKED;
 173                 break;
 174         case RFKILL_STATE_UNBLOCKED:
 175                 /* force can't override this, only rfkill_force_state() can */
 176                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
 177                         return -EPERM;
 178                 break;
 179         case RFKILL_STATE_SOFT_BLOCKED:
 180                 /* nothing to do, we want to give drivers the hint to double
 181                  * BLOCK even a transmitter that is already in state
 182                  * RFKILL_STATE_HARD_BLOCKED */
 183                 break;
 184         }
 185
 186         if (force || state != rfkill->state) {
 187                 retval = rfkill->toggle_radio(rfkill->data, state);
 188                 /* never allow a HARD->SOFT downgrade! */
 189                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 190                         rfkill->state = state;
 191         }
 192
 193         if (force || rfkill->state != oldstate) {
 194                 rfkill_led_trigger(rfkill, rfkill->state);
 195                 notify_rfkill_state_change(rfkill);
 196         }
 197
 198         return retval;
 199 }
 200
 201 /**
 202  * rfkill_switch_all - Toggle state of all switches of given type
 203  * @type: type of interfaces to be affeceted
 204  * @state: the new state
 205  *
 206  * This function toggles state of all switches of given type unless
 207  * a specific switch is claimed by userspace in which case it is
 208  * left alone.
 209  */
 210 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 211 {
 212         struct rfkill *rfkill;
 213
 214         mutex_lock(&rfkill_mutex);
 215
 216         rfkill_states[type] = state;
 217
 218         list_for_each_entry(rfkill, &rfkill_list, node) {
 219                 if ((!rfkill->user_claim) && (rfkill->type == type))
 220                         rfkill_toggle_radio(rfkill, state, 0);
 221         }
 222
 223         mutex_unlock(&rfkill_mutex);
 224 }
 225 EXPORT_SYMBOL(rfkill_switch_all);
 226
 227 /**
 228  * rfkill_epo - emergency power off all transmitters
 229  *
 230  * This kicks all rfkill devices to RFKILL_STATE_SOFT_BLOCKED, ignoring
 231  * everything in its path but rfkill_mutex.
 232  */
 233 void rfkill_epo(void)
 234 {
 235         struct rfkill *rfkill;
 236
 237         mutex_lock(&rfkill_mutex);
 238         list_for_each_entry(rfkill, &rfkill_list, node) {
 239                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 240         }
 241         mutex_unlock(&rfkill_mutex);
 242 }
 243 EXPORT_SYMBOL_GPL(rfkill_epo);
 244
 245 /**
 246  * rfkill_force_state - Force the internal rfkill radio state
 247  * @rfkill: pointer to the rfkill class to modify.
 248  * @state: the current radio state the class should be forced to.
 249  *
 250  * This function updates the internal state of the radio cached
 251  * by the rfkill class.  It should be used when the driver gets
 252  * a notification by the firmware/hardware of the current *real*
 253  * state of the radio rfkill switch.
 254  *
 255  * Devices which are subject to external changes on their rfkill
 256  * state (such as those caused by a hardware rfkill line) MUST
 257  * have their driver arrange to call rfkill_force_state() as soon
 258  * as possible after such a change.
 259  *
 260  * This function may not be called from an atomic context.
 261  */
 262 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 263 {
 264         enum rfkill_state oldstate;
 265
 266         if (state != RFKILL_STATE_SOFT_BLOCKED &&
 267             state != RFKILL_STATE_UNBLOCKED &&
 268             state != RFKILL_STATE_HARD_BLOCKED)
 269                 return -EINVAL;
 270
 271         mutex_lock(&rfkill->mutex);
 272
 273         oldstate = rfkill->state;
 274         rfkill->state = state;
 275
 276         if (state != oldstate)
 277                 notify_rfkill_state_change(rfkill);
 278
 279         mutex_unlock(&rfkill->mutex);
 280
 281         return 0;
 282 }
 283 EXPORT_SYMBOL(rfkill_force_state);
 284
 285 static ssize_t rfkill_name_show(struct device *dev,
 286                                 struct device_attribute *attr,
 287                                 char *buf)
 288 {
 289         struct rfkill *rfkill = to_rfkill(dev);
 290
 291         return sprintf(buf, "%s\n", rfkill->name);
 292 }
 293
 294 static const char *rfkill_get_type_str(enum rfkill_type type)
 295 {
 296         switch (type) {
 297         case RFKILL_TYPE_WLAN:
 298                 return "wlan";
 299         case RFKILL_TYPE_BLUETOOTH:
 300                 return "bluetooth";
 301         case RFKILL_TYPE_UWB:
 302                 return "ultrawideband";
 303         case RFKILL_TYPE_WIMAX:
 304                 return "wimax";
 305         case RFKILL_TYPE_WWAN:
 306                 return "wwan";
 307         default:
 308                 BUG();
 309         }
 310 }
 311
 312 static ssize_t rfkill_type_show(struct device *dev,
 313                                 struct device_attribute *attr,
 314                                 char *buf)
 315 {
 316         struct rfkill *rfkill = to_rfkill(dev);
 317
 318         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 319 }
 320
 321 static ssize_t rfkill_state_show(struct device *dev,
 322                                  struct device_attribute *attr,
 323                                  char *buf)
 324 {
 325         struct rfkill *rfkill = to_rfkill(dev);
 326
 327         update_rfkill_state(rfkill);
 328         return sprintf(buf, "%d\n", rfkill->state);
 329 }
 330
 331 static ssize_t rfkill_state_store(struct device *dev,
 332                                   struct device_attribute *attr,
 333                                   const char *buf, size_t count)
 334 {
 335         struct rfkill *rfkill = to_rfkill(dev);
 336         unsigned int state = simple_strtoul(buf, NULL, 0);
 337         int error;
 338
 339         if (!capable(CAP_NET_ADMIN))
 340                 return -EPERM;
 341
 342         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 343         if (state != RFKILL_STATE_UNBLOCKED &&
 344             state != RFKILL_STATE_SOFT_BLOCKED)
 345                 return -EINVAL;
 346
 347         if (mutex_lock_interruptible(&rfkill->mutex))
 348                 return -ERESTARTSYS;
 349         error = rfkill_toggle_radio(rfkill, state, 0);
 350         mutex_unlock(&rfkill->mutex);
 351
 352         return error ? error : count;
 353 }
 354
 355 static ssize_t rfkill_claim_show(struct device *dev,
 356                                  struct device_attribute *attr,
 357                                  char *buf)
 358 {
 359         struct rfkill *rfkill = to_rfkill(dev);
 360
 361         return sprintf(buf, "%d", rfkill->user_claim);
 362 }
 363
 364 static ssize_t rfkill_claim_store(struct device *dev,
 365                                   struct device_attribute *attr,
 366                                   const char *buf, size_t count)
 367 {
 368         struct rfkill *rfkill = to_rfkill(dev);
 369         bool claim = !!simple_strtoul(buf, NULL, 0);
 370         int error;
 371
 372         if (!capable(CAP_NET_ADMIN))
 373                 return -EPERM;
 374
 375         /*
 376          * Take the global lock to make sure the kernel is not in
 377          * the middle of rfkill_switch_all
 378          */
 379         error = mutex_lock_interruptible(&rfkill_mutex);
 380         if (error)
 381                 return error;
 382
 383         if (rfkill->user_claim_unsupported) {
 384                 error = -EOPNOTSUPP;
 385                 goto out_unlock;
 386         }
 387         if (rfkill->user_claim != claim) {
 388                 if (!claim)
 389                         rfkill_toggle_radio(rfkill,
 390                                             rfkill_states[rfkill->type],
 391                                             0);
 392                 rfkill->user_claim = claim;
 393         }
 394
 395 out_unlock:
 396         mutex_unlock(&rfkill_mutex);
 397
 398         return error ? error : count;
 399 }
 400
 401 static struct device_attribute rfkill_dev_attrs[] = {
 402         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 403         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 404         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 405         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 406         __ATTR_NULL
 407 };
 408
 409 static void rfkill_release(struct device *dev)
 410 {
 411         struct rfkill *rfkill = to_rfkill(dev);
 412
 413         kfree(rfkill);
 414         module_put(THIS_MODULE);
 415 }
 416
 417 #ifdef CONFIG_PM
 418 static int rfkill_suspend(struct device *dev, pm_message_t state)
 419 {
 420         struct rfkill *rfkill = to_rfkill(dev);
 421
 422         if (dev->power.power_state.event != state.event) {
 423                 if (state.event & PM_EVENT_SLEEP) {
 424                         /* Stop transmitter, keep state, no notifies */
 425                         update_rfkill_state(rfkill);
 426
 427                         mutex_lock(&rfkill->mutex);
 428                         rfkill->toggle_radio(rfkill->data,
 429                                                 RFKILL_STATE_SOFT_BLOCKED);
 430                         mutex_unlock(&rfkill->mutex);
 431                 }
 432
 433                 dev->power.power_state = state;
 434         }
 435
 436         return 0;
 437 }
 438
 439 static int rfkill_resume(struct device *dev)
 440 {
 441         struct rfkill *rfkill = to_rfkill(dev);
 442
 443         if (dev->power.power_state.event != PM_EVENT_ON) {
 444                 mutex_lock(&rfkill->mutex);
 445
 446                 /* restore radio state AND notify everybody */
 447                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 448
 449                 mutex_unlock(&rfkill->mutex);
 450         }
 451
 452         dev->power.power_state = PMSG_ON;
 453         return 0;
 454 }
 455 #else
 456 #define rfkill_suspend NULL
 457 #define rfkill_resume NULL
 458 #endif
 459
 460 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 461                                         unsigned long eventid,
 462                                         void *data)
 463 {
 464         struct rfkill *rfkill = (struct rfkill *)data;
 465
 466         switch (eventid) {
 467         case RFKILL_STATE_CHANGED:
 468                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 469                 break;
 470         default:
 471                 break;
 472         }
 473
 474         return NOTIFY_DONE;
 475 }
 476
 477 static struct notifier_block rfkill_blocking_uevent_nb = {
 478         .notifier_call  = rfkill_blocking_uevent_notifier,
 479         .priority       = 0,
 480 };
 481
 482 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 483 {
 484         struct rfkill *rfkill = to_rfkill(dev);
 485         int error;
 486
 487         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 488         if (error)
 489                 return error;
 490         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 491                                 rfkill_get_type_str(rfkill->type));
 492         if (error)
 493                 return error;
 494         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 495         return error;
 496 }
 497
 498 static struct class rfkill_class = {
 499         .name           = "rfkill",
 500         .dev_release    = rfkill_release,
 501         .dev_attrs      = rfkill_dev_attrs,
 502         .suspend        = rfkill_suspend,
 503         .resume         = rfkill_resume,
 504         .dev_uevent     = rfkill_dev_uevent,
 505 };
 506
 507 static int rfkill_add_switch(struct rfkill *rfkill)
 508 {
 509         mutex_lock(&rfkill_mutex);
 510
 511         rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
 512
 513         list_add_tail(&rfkill->node, &rfkill_list);
 514
 515         mutex_unlock(&rfkill_mutex);
 516
 517         return 0;
 518 }
 519
 520 static void rfkill_remove_switch(struct rfkill *rfkill)
 521 {
 522         mutex_lock(&rfkill_mutex);
 523         list_del_init(&rfkill->node);
 524         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 525         mutex_unlock(&rfkill_mutex);
 526 }
 527
 528 /**
 529  * rfkill_allocate - allocate memory for rfkill structure.
 530  * @parent: device that has rf switch on it
 531  * @type: type of the switch (RFKILL_TYPE_*)
 532  *
 533  * This function should be called by the network driver when it needs
 534  * rfkill structure. Once the structure is allocated the driver shoud
 535  * finish its initialization by setting name, private data, enable_radio
 536  * and disable_radio methods and then register it with rfkill_register().
 537  * NOTE: If registration fails the structure shoudl be freed by calling
 538  * rfkill_free() otherwise rfkill_unregister() should be used.
 539  */
 540 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 541 {
 542         struct rfkill *rfkill;
 543         struct device *dev;
 544
 545         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 546         if (!rfkill)
 547                 return NULL;
 548
 549         mutex_init(&rfkill->mutex);
 550         INIT_LIST_HEAD(&rfkill->node);
 551         rfkill->type = type;
 552
 553         dev = &rfkill->dev;
 554         dev->class = &rfkill_class;
 555         dev->parent = parent;
 556         device_initialize(dev);
 557
 558         __module_get(THIS_MODULE);
 559
 560         return rfkill;
 561 }
 562 EXPORT_SYMBOL(rfkill_allocate);
 563
 564 /**
 565  * rfkill_free - Mark rfkill structure for deletion
 566  * @rfkill: rfkill structure to be destroyed
 567  *
 568  * Decrements reference count of rfkill structure so it is destroyed.
 569  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 570  */
 571 void rfkill_free(struct rfkill *rfkill)
 572 {
 573         if (rfkill)
 574                 put_device(&rfkill->dev);
 575 }
 576 EXPORT_SYMBOL(rfkill_free);
 577
 578 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 579 {
 580 #ifdef CONFIG_RFKILL_LEDS
 581         int error;
 582
 583         rfkill->led_trigger.name = rfkill->dev.bus_id;
 584         error = led_trigger_register(&rfkill->led_trigger);
 585         if (error)
 586                 rfkill->led_trigger.name = NULL;
 587 #endif /* CONFIG_RFKILL_LEDS */
 588 }
 589
 590 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 591 {
 592 #ifdef CONFIG_RFKILL_LEDS
 593         if (rfkill->led_trigger.name)
 594                 led_trigger_unregister(&rfkill->led_trigger);
 595 #endif
 596 }
 597
 598 /**
 599  * rfkill_register - Register a rfkill structure.
 600  * @rfkill: rfkill structure to be registered
 601  *
 602  * This function should be called by the network driver when the rfkill
 603  * structure needs to be registered. Immediately from registration the
 604  * switch driver should be able to service calls to toggle_radio.
 605  */
 606 int rfkill_register(struct rfkill *rfkill)
 607 {
 608         static atomic_t rfkill_no = ATOMIC_INIT(0);
 609         struct device *dev = &rfkill->dev;
 610         int error;
 611
 612         if (!rfkill->toggle_radio)
 613                 return -EINVAL;
 614         if (rfkill->type >= RFKILL_TYPE_MAX)
 615                 return -EINVAL;
 616
 617         snprintf(dev->bus_id, sizeof(dev->bus_id),
 618                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 619
 620         rfkill_led_trigger_register(rfkill);
 621
 622         error = rfkill_add_switch(rfkill);
 623         if (error) {
 624                 rfkill_led_trigger_unregister(rfkill);
 625                 return error;
 626         }
 627
 628         error = device_add(dev);
 629         if (error) {
 630                 rfkill_led_trigger_unregister(rfkill);
 631                 rfkill_remove_switch(rfkill);
 632                 return error;
 633         }
 634
 635         return 0;
 636 }
 637 EXPORT_SYMBOL(rfkill_register);
 638
 639 /**
 640  * rfkill_unregister - Unregister a rfkill structure.
 641  * @rfkill: rfkill structure to be unregistered
 642  *
 643  * This function should be called by the network driver during device
 644  * teardown to destroy rfkill structure. Note that rfkill_free() should
 645  * _not_ be called after rfkill_unregister().
 646  */
 647 void rfkill_unregister(struct rfkill *rfkill)
 648 {
 649         device_del(&rfkill->dev);
 650         rfkill_remove_switch(rfkill);
 651         rfkill_led_trigger_unregister(rfkill);
 652         put_device(&rfkill->dev);
 653 }
 654 EXPORT_SYMBOL(rfkill_unregister);
 655
 656 /*
 657  * Rfkill module initialization/deinitialization.
 658  */
 659 static int __init rfkill_init(void)
 660 {
 661         int error;
 662         int i;
 663
 664         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 665         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
 666             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 667                 return -EINVAL;
 668
 669         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 670                 rfkill_states[i] = rfkill_default_state;
 671
 672         error = class_register(&rfkill_class);
 673         if (error) {
 674                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 675                 return error;
 676         }
 677
 678         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 679
 680         return 0;
 681 }
 682
 683 static void __exit rfkill_exit(void)
 684 {
 685         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 686         class_unregister(&rfkill_class);
 687 }
 688
 689 subsys_initcall(rfkill_init);
 690 module_exit(rfkill_exit);