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 #ifdef CONFIG_RFKILL_LEDS
 109 static void rfkill_led_trigger_activate(struct led_classdev *led)
 110 {
 111         struct rfkill *rfkill = container_of(led->trigger,
 112                         struct rfkill, led_trigger);
 113
 114         rfkill_led_trigger(rfkill, rfkill->state);
 115 }
 116 #endif /* CONFIG_RFKILL_LEDS */
 117
 118 static void notify_rfkill_state_change(struct rfkill *rfkill)
 119 {
 120         blocking_notifier_call_chain(&rfkill_notifier_list,
 121                         RFKILL_STATE_CHANGED,
 122                         rfkill);
 123 }
 124
 125 static void update_rfkill_state(struct rfkill *rfkill)
 126 {
 127         enum rfkill_state newstate, oldstate;
 128
 129         if (rfkill->get_state) {
 130                 mutex_lock(&rfkill->mutex);
 131                 if (!rfkill->get_state(rfkill->data, &newstate)) {
 132                         oldstate = rfkill->state;
 133                         rfkill->state = newstate;
 134                         if (oldstate != newstate)
 135                                 notify_rfkill_state_change(rfkill);
 136                 }
 137                 mutex_unlock(&rfkill->mutex);
 138         }
 139 }
 140
 141 /**
 142  * rfkill_toggle_radio - wrapper for toggle_radio hook
 143  * @rfkill: the rfkill struct to use
 144  * @force: calls toggle_radio even if cache says it is not needed,
 145  *      and also makes sure notifications of the state will be
 146  *      sent even if it didn't change
 147  * @state: the new state to call toggle_radio() with
 148  *
 149  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
 150  * calls and handling all the red tape such as issuing notifications
 151  * if the call is successful.
 152  *
 153  * Suspended devices are not touched at all, and -EAGAIN is returned.
 154  *
 155  * Note that the @force parameter cannot override a (possibly cached)
 156  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
 157  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
 158  * rfkill_force_state(), so the cache either is bypassed or valid.
 159  *
 160  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
 161  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
 162  * give the driver a hint that it should double-BLOCK the transmitter.
 163  *
 164  * Caller must have acquired rfkill->mutex.
 165  */
 166 static int rfkill_toggle_radio(struct rfkill *rfkill,
 167                                 enum rfkill_state state,
 168                                 int force)
 169 {
 170         int retval = 0;
 171         enum rfkill_state oldstate, newstate;
 172
 173         if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
 174                 return -EBUSY;
 175
 176         oldstate = rfkill->state;
 177
 178         if (rfkill->get_state && !force &&
 179             !rfkill->get_state(rfkill->data, &newstate))
 180                 rfkill->state = newstate;
 181
 182         switch (state) {
 183         case RFKILL_STATE_HARD_BLOCKED:
 184                 /* typically happens when refreshing hardware state,
 185                  * such as on resume */
 186                 state = RFKILL_STATE_SOFT_BLOCKED;
 187                 break;
 188         case RFKILL_STATE_UNBLOCKED:
 189                 /* force can't override this, only rfkill_force_state() can */
 190                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
 191                         return -EPERM;
 192                 break;
 193         case RFKILL_STATE_SOFT_BLOCKED:
 194                 /* nothing to do, we want to give drivers the hint to double
 195                  * BLOCK even a transmitter that is already in state
 196                  * RFKILL_STATE_HARD_BLOCKED */
 197                 break;
 198         }
 199
 200         if (force || state != rfkill->state) {
 201                 retval = rfkill->toggle_radio(rfkill->data, state);
 202                 /* never allow a HARD->SOFT downgrade! */
 203                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 204                         rfkill->state = state;
 205         }
 206
 207         if (force || rfkill->state != oldstate) {
 208                 rfkill_led_trigger(rfkill, rfkill->state);
 209                 notify_rfkill_state_change(rfkill);
 210         }
 211
 212         return retval;
 213 }
 214
 215 /**
 216  * rfkill_switch_all - Toggle state of all switches of given type
 217  * @type: type of interfaces to be affected
 218  * @state: the new state
 219  *
 220  * This function toggles the state of all switches of given type,
 221  * unless a specific switch is claimed by userspace (in which case,
 222  * that switch is left alone) or suspended.
 223  */
 224 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 225 {
 226         struct rfkill *rfkill;
 227
 228         mutex_lock(&rfkill_mutex);
 229
 230         rfkill_states[type] = state;
 231
 232         list_for_each_entry(rfkill, &rfkill_list, node) {
 233                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
 234                         mutex_lock(&rfkill->mutex);
 235                         rfkill_toggle_radio(rfkill, state, 0);
 236                         mutex_unlock(&rfkill->mutex);
 237                 }
 238         }
 239
 240         mutex_unlock(&rfkill_mutex);
 241 }
 242 EXPORT_SYMBOL(rfkill_switch_all);
 243
 244 /**
 245  * rfkill_epo - emergency power off all transmitters
 246  *
 247  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
 248  * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
 249  */
 250 void rfkill_epo(void)
 251 {
 252         struct rfkill *rfkill;
 253
 254         mutex_lock(&rfkill_mutex);
 255         list_for_each_entry(rfkill, &rfkill_list, node) {
 256                 mutex_lock(&rfkill->mutex);
 257                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 258                 mutex_unlock(&rfkill->mutex);
 259         }
 260         mutex_unlock(&rfkill_mutex);
 261 }
 262 EXPORT_SYMBOL_GPL(rfkill_epo);
 263
 264 /**
 265  * rfkill_force_state - Force the internal rfkill radio state
 266  * @rfkill: pointer to the rfkill class to modify.
 267  * @state: the current radio state the class should be forced to.
 268  *
 269  * This function updates the internal state of the radio cached
 270  * by the rfkill class.  It should be used when the driver gets
 271  * a notification by the firmware/hardware of the current *real*
 272  * state of the radio rfkill switch.
 273  *
 274  * Devices which are subject to external changes on their rfkill
 275  * state (such as those caused by a hardware rfkill line) MUST
 276  * have their driver arrange to call rfkill_force_state() as soon
 277  * as possible after such a change.
 278  *
 279  * This function may not be called from an atomic context.
 280  */
 281 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 282 {
 283         enum rfkill_state oldstate;
 284
 285         if (state != RFKILL_STATE_SOFT_BLOCKED &&
 286             state != RFKILL_STATE_UNBLOCKED &&
 287             state != RFKILL_STATE_HARD_BLOCKED)
 288                 return -EINVAL;
 289
 290         mutex_lock(&rfkill->mutex);
 291
 292         oldstate = rfkill->state;
 293         rfkill->state = state;
 294
 295         if (state != oldstate)
 296                 notify_rfkill_state_change(rfkill);
 297
 298         mutex_unlock(&rfkill->mutex);
 299
 300         return 0;
 301 }
 302 EXPORT_SYMBOL(rfkill_force_state);
 303
 304 static ssize_t rfkill_name_show(struct device *dev,
 305                                 struct device_attribute *attr,
 306                                 char *buf)
 307 {
 308         struct rfkill *rfkill = to_rfkill(dev);
 309
 310         return sprintf(buf, "%s\n", rfkill->name);
 311 }
 312
 313 static const char *rfkill_get_type_str(enum rfkill_type type)
 314 {
 315         switch (type) {
 316         case RFKILL_TYPE_WLAN:
 317                 return "wlan";
 318         case RFKILL_TYPE_BLUETOOTH:
 319                 return "bluetooth";
 320         case RFKILL_TYPE_UWB:
 321                 return "ultrawideband";
 322         case RFKILL_TYPE_WIMAX:
 323                 return "wimax";
 324         case RFKILL_TYPE_WWAN:
 325                 return "wwan";
 326         default:
 327                 BUG();
 328         }
 329 }
 330
 331 static ssize_t rfkill_type_show(struct device *dev,
 332                                 struct device_attribute *attr,
 333                                 char *buf)
 334 {
 335         struct rfkill *rfkill = to_rfkill(dev);
 336
 337         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 338 }
 339
 340 static ssize_t rfkill_state_show(struct device *dev,
 341                                  struct device_attribute *attr,
 342                                  char *buf)
 343 {
 344         struct rfkill *rfkill = to_rfkill(dev);
 345
 346         update_rfkill_state(rfkill);
 347         return sprintf(buf, "%d\n", rfkill->state);
 348 }
 349
 350 static ssize_t rfkill_state_store(struct device *dev,
 351                                   struct device_attribute *attr,
 352                                   const char *buf, size_t count)
 353 {
 354         struct rfkill *rfkill = to_rfkill(dev);
 355         unsigned int state = simple_strtoul(buf, NULL, 0);
 356         int error;
 357
 358         if (!capable(CAP_NET_ADMIN))
 359                 return -EPERM;
 360
 361         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 362         if (state != RFKILL_STATE_UNBLOCKED &&
 363             state != RFKILL_STATE_SOFT_BLOCKED)
 364                 return -EINVAL;
 365
 366         if (mutex_lock_interruptible(&rfkill->mutex))
 367                 return -ERESTARTSYS;
 368         error = rfkill_toggle_radio(rfkill, state, 0);
 369         mutex_unlock(&rfkill->mutex);
 370
 371         return error ? error : count;
 372 }
 373
 374 static ssize_t rfkill_claim_show(struct device *dev,
 375                                  struct device_attribute *attr,
 376                                  char *buf)
 377 {
 378         struct rfkill *rfkill = to_rfkill(dev);
 379
 380         return sprintf(buf, "%d", rfkill->user_claim);
 381 }
 382
 383 static ssize_t rfkill_claim_store(struct device *dev,
 384                                   struct device_attribute *attr,
 385                                   const char *buf, size_t count)
 386 {
 387         struct rfkill *rfkill = to_rfkill(dev);
 388         bool claim = !!simple_strtoul(buf, NULL, 0);
 389         int error;
 390
 391         if (!capable(CAP_NET_ADMIN))
 392                 return -EPERM;
 393
 394         if (rfkill->user_claim_unsupported)
 395                 return -EOPNOTSUPP;
 396
 397         /*
 398          * Take the global lock to make sure the kernel is not in
 399          * the middle of rfkill_switch_all
 400          */
 401         error = mutex_lock_interruptible(&rfkill_mutex);
 402         if (error)
 403                 return error;
 404
 405         if (rfkill->user_claim != claim) {
 406                 if (!claim) {
 407                         mutex_lock(&rfkill->mutex);
 408                         rfkill_toggle_radio(rfkill,
 409                                             rfkill_states[rfkill->type],
 410                                             0);
 411                         mutex_unlock(&rfkill->mutex);
 412                 }
 413                 rfkill->user_claim = claim;
 414         }
 415
 416         mutex_unlock(&rfkill_mutex);
 417
 418         return error ? error : count;
 419 }
 420
 421 static struct device_attribute rfkill_dev_attrs[] = {
 422         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 423         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 424         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 425         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 426         __ATTR_NULL
 427 };
 428
 429 static void rfkill_release(struct device *dev)
 430 {
 431         struct rfkill *rfkill = to_rfkill(dev);
 432
 433         kfree(rfkill);
 434         module_put(THIS_MODULE);
 435 }
 436
 437 #ifdef CONFIG_PM
 438 static int rfkill_suspend(struct device *dev, pm_message_t state)
 439 {
 440         struct rfkill *rfkill = to_rfkill(dev);
 441
 442         if (dev->power.power_state.event != state.event) {
 443                 if (state.event & PM_EVENT_SLEEP) {
 444                         /* Stop transmitter, keep state, no notifies */
 445                         update_rfkill_state(rfkill);
 446
 447                         mutex_lock(&rfkill->mutex);
 448                         rfkill->toggle_radio(rfkill->data,
 449                                                 RFKILL_STATE_SOFT_BLOCKED);
 450                         mutex_unlock(&rfkill->mutex);
 451                 }
 452
 453                 dev->power.power_state = state;
 454         }
 455
 456         return 0;
 457 }
 458
 459 static int rfkill_resume(struct device *dev)
 460 {
 461         struct rfkill *rfkill = to_rfkill(dev);
 462
 463         if (dev->power.power_state.event != PM_EVENT_ON) {
 464                 mutex_lock(&rfkill->mutex);
 465
 466                 dev->power.power_state.event = PM_EVENT_ON;
 467
 468                 /* restore radio state AND notify everybody */
 469                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 470
 471                 mutex_unlock(&rfkill->mutex);
 472         }
 473
 474         return 0;
 475 }
 476 #else
 477 #define rfkill_suspend NULL
 478 #define rfkill_resume NULL
 479 #endif
 480
 481 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 482                                         unsigned long eventid,
 483                                         void *data)
 484 {
 485         struct rfkill *rfkill = (struct rfkill *)data;
 486
 487         switch (eventid) {
 488         case RFKILL_STATE_CHANGED:
 489                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 490                 break;
 491         default:
 492                 break;
 493         }
 494
 495         return NOTIFY_DONE;
 496 }
 497
 498 static struct notifier_block rfkill_blocking_uevent_nb = {
 499         .notifier_call  = rfkill_blocking_uevent_notifier,
 500         .priority       = 0,
 501 };
 502
 503 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 504 {
 505         struct rfkill *rfkill = to_rfkill(dev);
 506         int error;
 507
 508         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 509         if (error)
 510                 return error;
 511         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 512                                 rfkill_get_type_str(rfkill->type));
 513         if (error)
 514                 return error;
 515         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 516         return error;
 517 }
 518
 519 static struct class rfkill_class = {
 520         .name           = "rfkill",
 521         .dev_release    = rfkill_release,
 522         .dev_attrs      = rfkill_dev_attrs,
 523         .suspend        = rfkill_suspend,
 524         .resume         = rfkill_resume,
 525         .dev_uevent     = rfkill_dev_uevent,
 526 };
 527
 528 static int rfkill_check_duplicity(const struct rfkill *rfkill)
 529 {
 530         struct rfkill *p;
 531         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
 532
 533         memset(seen, 0, sizeof(seen));
 534
 535         list_for_each_entry(p, &rfkill_list, node) {
 536                 if (p == rfkill) {
 537                         WARN_ON(1);
 538                         return -EEXIST;
 539                 }
 540                 set_bit(p->type, seen);
 541         }
 542
 543         /* 0: first switch of its kind */
 544         return test_bit(rfkill->type, seen);
 545 }
 546
 547 static int rfkill_add_switch(struct rfkill *rfkill)
 548 {
 549         int error;
 550
 551         mutex_lock(&rfkill_mutex);
 552
 553         error = rfkill_check_duplicity(rfkill);
 554         if (error < 0)
 555                 goto unlock_out;
 556
 557         rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
 558
 559         list_add_tail(&rfkill->node, &rfkill_list);
 560
 561         error = 0;
 562 unlock_out:
 563         mutex_unlock(&rfkill_mutex);
 564
 565         return error;
 566 }
 567
 568 static void rfkill_remove_switch(struct rfkill *rfkill)
 569 {
 570         mutex_lock(&rfkill_mutex);
 571         list_del_init(&rfkill->node);
 572         mutex_unlock(&rfkill_mutex);
 573
 574         mutex_lock(&rfkill->mutex);
 575         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 576         mutex_unlock(&rfkill->mutex);
 577 }
 578
 579 /**
 580  * rfkill_allocate - allocate memory for rfkill structure.
 581  * @parent: device that has rf switch on it
 582  * @type: type of the switch (RFKILL_TYPE_*)
 583  *
 584  * This function should be called by the network driver when it needs
 585  * rfkill structure.  Once the structure is allocated the driver should
 586  * finish its initialization by setting the name, private data, enable_radio
 587  * and disable_radio methods and then register it with rfkill_register().
 588  *
 589  * NOTE: If registration fails the structure shoudl be freed by calling
 590  * rfkill_free() otherwise rfkill_unregister() should be used.
 591  */
 592 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 593 {
 594         struct rfkill *rfkill;
 595         struct device *dev;
 596
 597         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 598         if (!rfkill)
 599                 return NULL;
 600
 601         mutex_init(&rfkill->mutex);
 602         INIT_LIST_HEAD(&rfkill->node);
 603         rfkill->type = type;
 604
 605         dev = &rfkill->dev;
 606         dev->class = &rfkill_class;
 607         dev->parent = parent;
 608         device_initialize(dev);
 609
 610         __module_get(THIS_MODULE);
 611
 612         return rfkill;
 613 }
 614 EXPORT_SYMBOL(rfkill_allocate);
 615
 616 /**
 617  * rfkill_free - Mark rfkill structure for deletion
 618  * @rfkill: rfkill structure to be destroyed
 619  *
 620  * Decrements reference count of the rfkill structure so it is destroyed.
 621  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 622  */
 623 void rfkill_free(struct rfkill *rfkill)
 624 {
 625         if (rfkill)
 626                 put_device(&rfkill->dev);
 627 }
 628 EXPORT_SYMBOL(rfkill_free);
 629
 630 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 631 {
 632 #ifdef CONFIG_RFKILL_LEDS
 633         int error;
 634
 635         if (!rfkill->led_trigger.name)
 636                 rfkill->led_trigger.name = rfkill->dev.bus_id;
 637         if (!rfkill->led_trigger.activate)
 638                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
 639         error = led_trigger_register(&rfkill->led_trigger);
 640         if (error)
 641                 rfkill->led_trigger.name = NULL;
 642 #endif /* CONFIG_RFKILL_LEDS */
 643 }
 644
 645 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 646 {
 647 #ifdef CONFIG_RFKILL_LEDS
 648         if (rfkill->led_trigger.name) {
 649                 led_trigger_unregister(&rfkill->led_trigger);
 650                 rfkill->led_trigger.name = NULL;
 651         }
 652 #endif
 653 }
 654
 655 /**
 656  * rfkill_register - Register a rfkill structure.
 657  * @rfkill: rfkill structure to be registered
 658  *
 659  * This function should be called by the network driver when the rfkill
 660  * structure needs to be registered. Immediately from registration the
 661  * switch driver should be able to service calls to toggle_radio.
 662  */
 663 int rfkill_register(struct rfkill *rfkill)
 664 {
 665         static atomic_t rfkill_no = ATOMIC_INIT(0);
 666         struct device *dev = &rfkill->dev;
 667         int error;
 668
 669         if (!rfkill->toggle_radio)
 670                 return -EINVAL;
 671         if (rfkill->type >= RFKILL_TYPE_MAX)
 672                 return -EINVAL;
 673
 674         snprintf(dev->bus_id, sizeof(dev->bus_id),
 675                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 676
 677         rfkill_led_trigger_register(rfkill);
 678
 679         error = rfkill_add_switch(rfkill);
 680         if (error) {
 681                 rfkill_led_trigger_unregister(rfkill);
 682                 return error;
 683         }
 684
 685         error = device_add(dev);
 686         if (error) {
 687                 rfkill_remove_switch(rfkill);
 688                 rfkill_led_trigger_unregister(rfkill);
 689                 return error;
 690         }
 691
 692         return 0;
 693 }
 694 EXPORT_SYMBOL(rfkill_register);
 695
 696 /**
 697  * rfkill_unregister - Unregister a rfkill structure.
 698  * @rfkill: rfkill structure to be unregistered
 699  *
 700  * This function should be called by the network driver during device
 701  * teardown to destroy rfkill structure. Note that rfkill_free() should
 702  * _not_ be called after rfkill_unregister().
 703  */
 704 void rfkill_unregister(struct rfkill *rfkill)
 705 {
 706         device_del(&rfkill->dev);
 707         rfkill_remove_switch(rfkill);
 708         rfkill_led_trigger_unregister(rfkill);
 709         put_device(&rfkill->dev);
 710 }
 711 EXPORT_SYMBOL(rfkill_unregister);
 712
 713 /*
 714  * Rfkill module initialization/deinitialization.
 715  */
 716 static int __init rfkill_init(void)
 717 {
 718         int error;
 719         int i;
 720
 721         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 722         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
 723             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 724                 return -EINVAL;
 725
 726         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 727                 rfkill_states[i] = rfkill_default_state;
 728
 729         error = class_register(&rfkill_class);
 730         if (error) {
 731                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 732                 return error;
 733         }
 734
 735         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 736
 737         return 0;
 738 }
 739
 740 static void __exit rfkill_exit(void)
 741 {
 742         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 743         class_unregister(&rfkill_class);
 744 }
 745
 746 subsys_initcall(rfkill_init);
 747 module_exit(rfkill_exit);