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  * @rfkill: the rfkill struct to use
 134  * @force: calls toggle_radio even if cache says it is not needed,
 135  *      and also makes sure notifications of the state will be
 136  *      sent even if it didn't change
 137  * @state: the new state to call toggle_radio() with
 138  *
 139  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
 140  * calls and handling all the red tape such as issuing notifications
 141  * if the call is successful.
 142  *
 143  * Note that the @force parameter cannot override a (possibly cached)
 144  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
 145  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
 146  * rfkill_force_state(), so the cache either is bypassed or valid.
 147  *
 148  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
 149  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
 150  * give the driver a hint that it should double-BLOCK the transmitter.
 151  *
 152  * Caller must have acquired rfkill->mutex.
 153  */
 154 static int rfkill_toggle_radio(struct rfkill *rfkill,
 155                                 enum rfkill_state state,
 156                                 int force)
 157 {
 158         int retval = 0;
 159         enum rfkill_state oldstate, newstate;
 160
 161         oldstate = rfkill->state;
 162
 163         if (rfkill->get_state && !force &&
 164             !rfkill->get_state(rfkill->data, &newstate))
 165                 rfkill->state = newstate;
 166
 167         switch (state) {
 168         case RFKILL_STATE_HARD_BLOCKED:
 169                 /* typically happens when refreshing hardware state,
 170                  * such as on resume */
 171                 state = RFKILL_STATE_SOFT_BLOCKED;
 172                 break;
 173         case RFKILL_STATE_UNBLOCKED:
 174                 /* force can't override this, only rfkill_force_state() can */
 175                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
 176                         return -EPERM;
 177                 break;
 178         case RFKILL_STATE_SOFT_BLOCKED:
 179                 /* nothing to do, we want to give drivers the hint to double
 180                  * BLOCK even a transmitter that is already in state
 181                  * RFKILL_STATE_HARD_BLOCKED */
 182                 break;
 183         }
 184
 185         if (force || state != rfkill->state) {
 186                 retval = rfkill->toggle_radio(rfkill->data, state);
 187                 /* never allow a HARD->SOFT downgrade! */
 188                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 189                         rfkill->state = state;
 190         }
 191
 192         if (force || rfkill->state != oldstate) {
 193                 rfkill_led_trigger(rfkill, rfkill->state);
 194                 notify_rfkill_state_change(rfkill);
 195         }
 196
 197         return retval;
 198 }
 199
 200 /**
 201  * rfkill_switch_all - Toggle state of all switches of given type
 202  * @type: type of interfaces to be affected
 203  * @state: the new state
 204  *
 205  * This function toggles the state of all switches of given type,
 206  * unless a specific switch is claimed by userspace (in which case,
 207  * that switch is left alone).
 208  */
 209 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 210 {
 211         struct rfkill *rfkill;
 212
 213         mutex_lock(&rfkill_mutex);
 214
 215         rfkill_states[type] = state;
 216
 217         list_for_each_entry(rfkill, &rfkill_list, node) {
 218                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
 219                         mutex_lock(&rfkill->mutex);
 220                         rfkill_toggle_radio(rfkill, state, 0);
 221                         mutex_unlock(&rfkill->mutex);
 222                 }
 223         }
 224
 225         mutex_unlock(&rfkill_mutex);
 226 }
 227 EXPORT_SYMBOL(rfkill_switch_all);
 228
 229 /**
 230  * rfkill_epo - emergency power off all transmitters
 231  *
 232  * This kicks all rfkill devices to RFKILL_STATE_SOFT_BLOCKED, ignoring
 233  * everything in its path but rfkill_mutex and rfkill->mutex.
 234  */
 235 void rfkill_epo(void)
 236 {
 237         struct rfkill *rfkill;
 238
 239         mutex_lock(&rfkill_mutex);
 240         list_for_each_entry(rfkill, &rfkill_list, node) {
 241                 mutex_lock(&rfkill->mutex);
 242                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 243                 mutex_unlock(&rfkill->mutex);
 244         }
 245         mutex_unlock(&rfkill_mutex);
 246 }
 247 EXPORT_SYMBOL_GPL(rfkill_epo);
 248
 249 /**
 250  * rfkill_force_state - Force the internal rfkill radio state
 251  * @rfkill: pointer to the rfkill class to modify.
 252  * @state: the current radio state the class should be forced to.
 253  *
 254  * This function updates the internal state of the radio cached
 255  * by the rfkill class.  It should be used when the driver gets
 256  * a notification by the firmware/hardware of the current *real*
 257  * state of the radio rfkill switch.
 258  *
 259  * Devices which are subject to external changes on their rfkill
 260  * state (such as those caused by a hardware rfkill line) MUST
 261  * have their driver arrange to call rfkill_force_state() as soon
 262  * as possible after such a change.
 263  *
 264  * This function may not be called from an atomic context.
 265  */
 266 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 267 {
 268         enum rfkill_state oldstate;
 269
 270         if (state != RFKILL_STATE_SOFT_BLOCKED &&
 271             state != RFKILL_STATE_UNBLOCKED &&
 272             state != RFKILL_STATE_HARD_BLOCKED)
 273                 return -EINVAL;
 274
 275         mutex_lock(&rfkill->mutex);
 276
 277         oldstate = rfkill->state;
 278         rfkill->state = state;
 279
 280         if (state != oldstate)
 281                 notify_rfkill_state_change(rfkill);
 282
 283         mutex_unlock(&rfkill->mutex);
 284
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(rfkill_force_state);
 288
 289 static ssize_t rfkill_name_show(struct device *dev,
 290                                 struct device_attribute *attr,
 291                                 char *buf)
 292 {
 293         struct rfkill *rfkill = to_rfkill(dev);
 294
 295         return sprintf(buf, "%s\n", rfkill->name);
 296 }
 297
 298 static const char *rfkill_get_type_str(enum rfkill_type type)
 299 {
 300         switch (type) {
 301         case RFKILL_TYPE_WLAN:
 302                 return "wlan";
 303         case RFKILL_TYPE_BLUETOOTH:
 304                 return "bluetooth";
 305         case RFKILL_TYPE_UWB:
 306                 return "ultrawideband";
 307         case RFKILL_TYPE_WIMAX:
 308                 return "wimax";
 309         case RFKILL_TYPE_WWAN:
 310                 return "wwan";
 311         default:
 312                 BUG();
 313         }
 314 }
 315
 316 static ssize_t rfkill_type_show(struct device *dev,
 317                                 struct device_attribute *attr,
 318                                 char *buf)
 319 {
 320         struct rfkill *rfkill = to_rfkill(dev);
 321
 322         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 323 }
 324
 325 static ssize_t rfkill_state_show(struct device *dev,
 326                                  struct device_attribute *attr,
 327                                  char *buf)
 328 {
 329         struct rfkill *rfkill = to_rfkill(dev);
 330
 331         update_rfkill_state(rfkill);
 332         return sprintf(buf, "%d\n", rfkill->state);
 333 }
 334
 335 static ssize_t rfkill_state_store(struct device *dev,
 336                                   struct device_attribute *attr,
 337                                   const char *buf, size_t count)
 338 {
 339         struct rfkill *rfkill = to_rfkill(dev);
 340         unsigned int state = simple_strtoul(buf, NULL, 0);
 341         int error;
 342
 343         if (!capable(CAP_NET_ADMIN))
 344                 return -EPERM;
 345
 346         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 347         if (state != RFKILL_STATE_UNBLOCKED &&
 348             state != RFKILL_STATE_SOFT_BLOCKED)
 349                 return -EINVAL;
 350
 351         if (mutex_lock_interruptible(&rfkill->mutex))
 352                 return -ERESTARTSYS;
 353         error = rfkill_toggle_radio(rfkill, state, 0);
 354         mutex_unlock(&rfkill->mutex);
 355
 356         return error ? error : count;
 357 }
 358
 359 static ssize_t rfkill_claim_show(struct device *dev,
 360                                  struct device_attribute *attr,
 361                                  char *buf)
 362 {
 363         struct rfkill *rfkill = to_rfkill(dev);
 364
 365         return sprintf(buf, "%d", rfkill->user_claim);
 366 }
 367
 368 static ssize_t rfkill_claim_store(struct device *dev,
 369                                   struct device_attribute *attr,
 370                                   const char *buf, size_t count)
 371 {
 372         struct rfkill *rfkill = to_rfkill(dev);
 373         bool claim = !!simple_strtoul(buf, NULL, 0);
 374         int error;
 375
 376         if (!capable(CAP_NET_ADMIN))
 377                 return -EPERM;
 378
 379         if (rfkill->user_claim_unsupported)
 380                 return -EOPNOTSUPP;
 381
 382         /*
 383          * Take the global lock to make sure the kernel is not in
 384          * the middle of rfkill_switch_all
 385          */
 386         error = mutex_lock_interruptible(&rfkill_mutex);
 387         if (error)
 388                 return error;
 389
 390         if (rfkill->user_claim != claim) {
 391                 if (!claim) {
 392                         mutex_lock(&rfkill->mutex);
 393                         rfkill_toggle_radio(rfkill,
 394                                             rfkill_states[rfkill->type],
 395                                             0);
 396                         mutex_unlock(&rfkill->mutex);
 397                 }
 398                 rfkill->user_claim = claim;
 399         }
 400
 401         mutex_unlock(&rfkill_mutex);
 402
 403         return error ? error : count;
 404 }
 405
 406 static struct device_attribute rfkill_dev_attrs[] = {
 407         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 408         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 409         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 410         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 411         __ATTR_NULL
 412 };
 413
 414 static void rfkill_release(struct device *dev)
 415 {
 416         struct rfkill *rfkill = to_rfkill(dev);
 417
 418         kfree(rfkill);
 419         module_put(THIS_MODULE);
 420 }
 421
 422 #ifdef CONFIG_PM
 423 static int rfkill_suspend(struct device *dev, pm_message_t state)
 424 {
 425         struct rfkill *rfkill = to_rfkill(dev);
 426
 427         if (dev->power.power_state.event != state.event) {
 428                 if (state.event & PM_EVENT_SLEEP) {
 429                         /* Stop transmitter, keep state, no notifies */
 430                         update_rfkill_state(rfkill);
 431
 432                         mutex_lock(&rfkill->mutex);
 433                         rfkill->toggle_radio(rfkill->data,
 434                                                 RFKILL_STATE_SOFT_BLOCKED);
 435                         mutex_unlock(&rfkill->mutex);
 436                 }
 437
 438                 dev->power.power_state = state;
 439         }
 440
 441         return 0;
 442 }
 443
 444 static int rfkill_resume(struct device *dev)
 445 {
 446         struct rfkill *rfkill = to_rfkill(dev);
 447
 448         if (dev->power.power_state.event != PM_EVENT_ON) {
 449                 mutex_lock(&rfkill->mutex);
 450
 451                 /* restore radio state AND notify everybody */
 452                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 453
 454                 mutex_unlock(&rfkill->mutex);
 455         }
 456
 457         dev->power.power_state = PMSG_ON;
 458         return 0;
 459 }
 460 #else
 461 #define rfkill_suspend NULL
 462 #define rfkill_resume NULL
 463 #endif
 464
 465 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 466                                         unsigned long eventid,
 467                                         void *data)
 468 {
 469         struct rfkill *rfkill = (struct rfkill *)data;
 470
 471         switch (eventid) {
 472         case RFKILL_STATE_CHANGED:
 473                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 474                 break;
 475         default:
 476                 break;
 477         }
 478
 479         return NOTIFY_DONE;
 480 }
 481
 482 static struct notifier_block rfkill_blocking_uevent_nb = {
 483         .notifier_call  = rfkill_blocking_uevent_notifier,
 484         .priority       = 0,
 485 };
 486
 487 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 488 {
 489         struct rfkill *rfkill = to_rfkill(dev);
 490         int error;
 491
 492         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 493         if (error)
 494                 return error;
 495         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 496                                 rfkill_get_type_str(rfkill->type));
 497         if (error)
 498                 return error;
 499         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 500         return error;
 501 }
 502
 503 static struct class rfkill_class = {
 504         .name           = "rfkill",
 505         .dev_release    = rfkill_release,
 506         .dev_attrs      = rfkill_dev_attrs,
 507         .suspend        = rfkill_suspend,
 508         .resume         = rfkill_resume,
 509         .dev_uevent     = rfkill_dev_uevent,
 510 };
 511
 512 static int rfkill_add_switch(struct rfkill *rfkill)
 513 {
 514         mutex_lock(&rfkill_mutex);
 515
 516         rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
 517
 518         list_add_tail(&rfkill->node, &rfkill_list);
 519
 520         mutex_unlock(&rfkill_mutex);
 521
 522         return 0;
 523 }
 524
 525 static void rfkill_remove_switch(struct rfkill *rfkill)
 526 {
 527         mutex_lock(&rfkill_mutex);
 528         list_del_init(&rfkill->node);
 529         mutex_unlock(&rfkill_mutex);
 530
 531         mutex_lock(&rfkill->mutex);
 532         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 533         mutex_unlock(&rfkill->mutex);
 534 }
 535
 536 /**
 537  * rfkill_allocate - allocate memory for rfkill structure.
 538  * @parent: device that has rf switch on it
 539  * @type: type of the switch (RFKILL_TYPE_*)
 540  *
 541  * This function should be called by the network driver when it needs
 542  * rfkill structure.  Once the structure is allocated the driver should
 543  * finish its initialization by setting the name, private data, enable_radio
 544  * and disable_radio methods and then register it with rfkill_register().
 545  *
 546  * NOTE: If registration fails the structure shoudl be freed by calling
 547  * rfkill_free() otherwise rfkill_unregister() should be used.
 548  */
 549 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 550 {
 551         struct rfkill *rfkill;
 552         struct device *dev;
 553
 554         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 555         if (!rfkill)
 556                 return NULL;
 557
 558         mutex_init(&rfkill->mutex);
 559         INIT_LIST_HEAD(&rfkill->node);
 560         rfkill->type = type;
 561
 562         dev = &rfkill->dev;
 563         dev->class = &rfkill_class;
 564         dev->parent = parent;
 565         device_initialize(dev);
 566
 567         __module_get(THIS_MODULE);
 568
 569         return rfkill;
 570 }
 571 EXPORT_SYMBOL(rfkill_allocate);
 572
 573 /**
 574  * rfkill_free - Mark rfkill structure for deletion
 575  * @rfkill: rfkill structure to be destroyed
 576  *
 577  * Decrements reference count of the rfkill structure so it is destroyed.
 578  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 579  */
 580 void rfkill_free(struct rfkill *rfkill)
 581 {
 582         if (rfkill)
 583                 put_device(&rfkill->dev);
 584 }
 585 EXPORT_SYMBOL(rfkill_free);
 586
 587 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 588 {
 589 #ifdef CONFIG_RFKILL_LEDS
 590         int error;
 591
 592         rfkill->led_trigger.name = rfkill->dev.bus_id;
 593         error = led_trigger_register(&rfkill->led_trigger);
 594         if (error)
 595                 rfkill->led_trigger.name = NULL;
 596 #endif /* CONFIG_RFKILL_LEDS */
 597 }
 598
 599 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 600 {
 601 #ifdef CONFIG_RFKILL_LEDS
 602         if (rfkill->led_trigger.name) {
 603                 led_trigger_unregister(&rfkill->led_trigger);
 604                 rfkill->led_trigger.name = NULL;
 605         }
 606 #endif
 607 }
 608
 609 /**
 610  * rfkill_register - Register a rfkill structure.
 611  * @rfkill: rfkill structure to be registered
 612  *
 613  * This function should be called by the network driver when the rfkill
 614  * structure needs to be registered. Immediately from registration the
 615  * switch driver should be able to service calls to toggle_radio.
 616  */
 617 int rfkill_register(struct rfkill *rfkill)
 618 {
 619         static atomic_t rfkill_no = ATOMIC_INIT(0);
 620         struct device *dev = &rfkill->dev;
 621         int error;
 622
 623         if (!rfkill->toggle_radio)
 624                 return -EINVAL;
 625         if (rfkill->type >= RFKILL_TYPE_MAX)
 626                 return -EINVAL;
 627
 628         snprintf(dev->bus_id, sizeof(dev->bus_id),
 629                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 630
 631         rfkill_led_trigger_register(rfkill);
 632
 633         error = rfkill_add_switch(rfkill);
 634         if (error) {
 635                 rfkill_led_trigger_unregister(rfkill);
 636                 return error;
 637         }
 638
 639         error = device_add(dev);
 640         if (error) {
 641                 rfkill_remove_switch(rfkill);
 642                 rfkill_led_trigger_unregister(rfkill);
 643                 return error;
 644         }
 645
 646         return 0;
 647 }
 648 EXPORT_SYMBOL(rfkill_register);
 649
 650 /**
 651  * rfkill_unregister - Unregister a rfkill structure.
 652  * @rfkill: rfkill structure to be unregistered
 653  *
 654  * This function should be called by the network driver during device
 655  * teardown to destroy rfkill structure. Note that rfkill_free() should
 656  * _not_ be called after rfkill_unregister().
 657  */
 658 void rfkill_unregister(struct rfkill *rfkill)
 659 {
 660         device_del(&rfkill->dev);
 661         rfkill_remove_switch(rfkill);
 662         rfkill_led_trigger_unregister(rfkill);
 663         put_device(&rfkill->dev);
 664 }
 665 EXPORT_SYMBOL(rfkill_unregister);
 666
 667 /*
 668  * Rfkill module initialization/deinitialization.
 669  */
 670 static int __init rfkill_init(void)
 671 {
 672         int error;
 673         int i;
 674
 675         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 676         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
 677             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 678                 return -EINVAL;
 679
 680         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 681                 rfkill_states[i] = rfkill_default_state;
 682
 683         error = class_register(&rfkill_class);
 684         if (error) {
 685                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 686                 return error;
 687         }
 688
 689         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 690
 691         return 0;
 692 }
 693
 694 static void __exit rfkill_exit(void)
 695 {
 696         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 697         class_unregister(&rfkill_class);
 698 }
 699
 700 subsys_initcall(rfkill_init);
 701 module_exit(rfkill_exit);