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 struct rfkill_gsw_state {
  48         enum rfkill_state current_state;
  49         enum rfkill_state default_state;
  50 };
  51
  52 static struct rfkill_gsw_state rfkill_global_states[RFKILL_TYPE_MAX];
  53 static unsigned long rfkill_states_lockdflt[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
  54
  55 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  56
  57
  58 /**
  59  * register_rfkill_notifier - Add notifier to rfkill notifier chain
  60  * @nb: pointer to the new entry to add to the chain
  61  *
  62  * See blocking_notifier_chain_register() for return value and further
  63  * observations.
  64  *
  65  * Adds a notifier to the rfkill notifier chain.  The chain will be
  66  * called with a pointer to the relevant rfkill structure as a parameter,
  67  * refer to include/linux/rfkill.h for the possible events.
  68  *
  69  * Notifiers added to this chain are to always return NOTIFY_DONE.  This
  70  * chain is a blocking notifier chain: notifiers can sleep.
  71  *
  72  * Calls to this chain may have been done through a workqueue.  One must
  73  * assume unordered asynchronous behaviour, there is no way to know if
  74  * actions related to the event that generated the notification have been
  75  * carried out already.
  76  */
  77 int register_rfkill_notifier(struct notifier_block *nb)
  78 {
  79         BUG_ON(!nb);
  80         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
  81 }
  82 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  83
  84 /**
  85  * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
  86  * @nb: pointer to the entry to remove from the chain
  87  *
  88  * See blocking_notifier_chain_unregister() for return value and further
  89  * observations.
  90  *
  91  * Removes a notifier from the rfkill notifier chain.
  92  */
  93 int unregister_rfkill_notifier(struct notifier_block *nb)
  94 {
  95         BUG_ON(!nb);
  96         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
  97 }
  98 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
  99
 100
 101 static void rfkill_led_trigger(struct rfkill *rfkill,
 102                                enum rfkill_state state)
 103 {
 104 #ifdef CONFIG_RFKILL_LEDS
 105         struct led_trigger *led = &rfkill->led_trigger;
 106
 107         if (!led->name)
 108                 return;
 109         if (state != RFKILL_STATE_UNBLOCKED)
 110                 led_trigger_event(led, LED_OFF);
 111         else
 112                 led_trigger_event(led, LED_FULL);
 113 #endif /* CONFIG_RFKILL_LEDS */
 114 }
 115
 116 #ifdef CONFIG_RFKILL_LEDS
 117 static void rfkill_led_trigger_activate(struct led_classdev *led)
 118 {
 119         struct rfkill *rfkill = container_of(led->trigger,
 120                         struct rfkill, led_trigger);
 121
 122         rfkill_led_trigger(rfkill, rfkill->state);
 123 }
 124 #endif /* CONFIG_RFKILL_LEDS */
 125
 126 static void notify_rfkill_state_change(struct rfkill *rfkill)
 127 {
 128         blocking_notifier_call_chain(&rfkill_notifier_list,
 129                         RFKILL_STATE_CHANGED,
 130                         rfkill);
 131 }
 132
 133 static void update_rfkill_state(struct rfkill *rfkill)
 134 {
 135         enum rfkill_state newstate, oldstate;
 136
 137         if (rfkill->get_state) {
 138                 mutex_lock(&rfkill->mutex);
 139                 if (!rfkill->get_state(rfkill->data, &newstate)) {
 140                         oldstate = rfkill->state;
 141                         rfkill->state = newstate;
 142                         if (oldstate != newstate)
 143                                 notify_rfkill_state_change(rfkill);
 144                 }
 145                 mutex_unlock(&rfkill->mutex);
 146         }
 147 }
 148
 149 /**
 150  * rfkill_toggle_radio - wrapper for toggle_radio hook
 151  * @rfkill: the rfkill struct to use
 152  * @force: calls toggle_radio even if cache says it is not needed,
 153  *      and also makes sure notifications of the state will be
 154  *      sent even if it didn't change
 155  * @state: the new state to call toggle_radio() with
 156  *
 157  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
 158  * calls and handling all the red tape such as issuing notifications
 159  * if the call is successful.
 160  *
 161  * Suspended devices are not touched at all, and -EAGAIN is returned.
 162  *
 163  * Note that the @force parameter cannot override a (possibly cached)
 164  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
 165  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
 166  * rfkill_force_state(), so the cache either is bypassed or valid.
 167  *
 168  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
 169  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
 170  * give the driver a hint that it should double-BLOCK the transmitter.
 171  *
 172  * Caller must have acquired rfkill->mutex.
 173  */
 174 static int rfkill_toggle_radio(struct rfkill *rfkill,
 175                                 enum rfkill_state state,
 176                                 int force)
 177 {
 178         int retval = 0;
 179         enum rfkill_state oldstate, newstate;
 180
 181         if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
 182                 return -EBUSY;
 183
 184         oldstate = rfkill->state;
 185
 186         if (rfkill->get_state && !force &&
 187             !rfkill->get_state(rfkill->data, &newstate))
 188                 rfkill->state = newstate;
 189
 190         switch (state) {
 191         case RFKILL_STATE_HARD_BLOCKED:
 192                 /* typically happens when refreshing hardware state,
 193                  * such as on resume */
 194                 state = RFKILL_STATE_SOFT_BLOCKED;
 195                 break;
 196         case RFKILL_STATE_UNBLOCKED:
 197                 /* force can't override this, only rfkill_force_state() can */
 198                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
 199                         return -EPERM;
 200                 break;
 201         case RFKILL_STATE_SOFT_BLOCKED:
 202                 /* nothing to do, we want to give drivers the hint to double
 203                  * BLOCK even a transmitter that is already in state
 204                  * RFKILL_STATE_HARD_BLOCKED */
 205                 break;
 206         default:
 207                 WARN(1, KERN_WARNING
 208                         "rfkill: illegal state %d passed as parameter "
 209                         "to rfkill_toggle_radio\n", state);
 210                 return -EINVAL;
 211         }
 212
 213         if (force || state != rfkill->state) {
 214                 retval = rfkill->toggle_radio(rfkill->data, state);
 215                 /* never allow a HARD->SOFT downgrade! */
 216                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 217                         rfkill->state = state;
 218         }
 219
 220         if (force || rfkill->state != oldstate) {
 221                 rfkill_led_trigger(rfkill, rfkill->state);
 222                 notify_rfkill_state_change(rfkill);
 223         }
 224
 225         return retval;
 226 }
 227
 228 /**
 229  * __rfkill_switch_all - Toggle state of all switches of given type
 230  * @type: type of interfaces to be affected
 231  * @state: the new state
 232  *
 233  * This function toggles the state of all switches of given type,
 234  * unless a specific switch is claimed by userspace (in which case,
 235  * that switch is left alone) or suspended.
 236  *
 237  * Caller must have acquired rfkill_mutex.
 238  */
 239 static void __rfkill_switch_all(const enum rfkill_type type,
 240                                 const enum rfkill_state state)
 241 {
 242         struct rfkill *rfkill;
 243
 244         if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
 245                         KERN_WARNING
 246                         "rfkill: illegal state %d or type %d "
 247                         "passed as parameter to __rfkill_switch_all\n",
 248                         state, type))
 249                 return;
 250
 251         rfkill_global_states[type].current_state = state;
 252         list_for_each_entry(rfkill, &rfkill_list, node) {
 253                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
 254                         mutex_lock(&rfkill->mutex);
 255                         rfkill_toggle_radio(rfkill, state, 0);
 256                         mutex_unlock(&rfkill->mutex);
 257                 }
 258         }
 259 }
 260
 261 /**
 262  * rfkill_switch_all - Toggle state of all switches of given type
 263  * @type: type of interfaces to be affected
 264  * @state: the new state
 265  *
 266  * Acquires rfkill_mutex and calls __rfkill_switch_all(@type, @state).
 267  * Please refer to __rfkill_switch_all() for details.
 268  */
 269 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 270 {
 271         mutex_lock(&rfkill_mutex);
 272         __rfkill_switch_all(type, state);
 273         mutex_unlock(&rfkill_mutex);
 274 }
 275 EXPORT_SYMBOL(rfkill_switch_all);
 276
 277 /**
 278  * rfkill_epo - emergency power off all transmitters
 279  *
 280  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
 281  * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
 282  *
 283  * The global state before the EPO is saved and can be restored later
 284  * using rfkill_restore_states().
 285  */
 286 void rfkill_epo(void)
 287 {
 288         struct rfkill *rfkill;
 289         int i;
 290
 291         mutex_lock(&rfkill_mutex);
 292         list_for_each_entry(rfkill, &rfkill_list, node) {
 293                 mutex_lock(&rfkill->mutex);
 294                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 295                 mutex_unlock(&rfkill->mutex);
 296         }
 297         for (i = 0; i < RFKILL_TYPE_MAX; i++) {
 298                 rfkill_global_states[i].default_state =
 299                                 rfkill_global_states[i].current_state;
 300                 rfkill_global_states[i].current_state =
 301                                 RFKILL_STATE_SOFT_BLOCKED;
 302         }
 303         mutex_unlock(&rfkill_mutex);
 304 }
 305 EXPORT_SYMBOL_GPL(rfkill_epo);
 306
 307 /**
 308  * rfkill_restore_states - restore global states
 309  *
 310  * Restore (and sync switches to) the global state from the
 311  * states in rfkill_default_states.  This can undo the effects of
 312  * a call to rfkill_epo().
 313  */
 314 void rfkill_restore_states(void)
 315 {
 316         int i;
 317
 318         mutex_lock(&rfkill_mutex);
 319         for (i = 0; i < RFKILL_TYPE_MAX; i++)
 320                 __rfkill_switch_all(i, rfkill_global_states[i].default_state);
 321         mutex_unlock(&rfkill_mutex);
 322 }
 323 EXPORT_SYMBOL_GPL(rfkill_restore_states);
 324
 325 /**
 326  * rfkill_force_state - Force the internal rfkill radio state
 327  * @rfkill: pointer to the rfkill class to modify.
 328  * @state: the current radio state the class should be forced to.
 329  *
 330  * This function updates the internal state of the radio cached
 331  * by the rfkill class.  It should be used when the driver gets
 332  * a notification by the firmware/hardware of the current *real*
 333  * state of the radio rfkill switch.
 334  *
 335  * Devices which are subject to external changes on their rfkill
 336  * state (such as those caused by a hardware rfkill line) MUST
 337  * have their driver arrange to call rfkill_force_state() as soon
 338  * as possible after such a change.
 339  *
 340  * This function may not be called from an atomic context.
 341  */
 342 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 343 {
 344         enum rfkill_state oldstate;
 345
 346         BUG_ON(!rfkill);
 347         if (WARN((state >= RFKILL_STATE_MAX),
 348                         KERN_WARNING
 349                         "rfkill: illegal state %d passed as parameter "
 350                         "to rfkill_force_state\n", state))
 351                 return -EINVAL;
 352
 353         mutex_lock(&rfkill->mutex);
 354
 355         oldstate = rfkill->state;
 356         rfkill->state = state;
 357
 358         if (state != oldstate)
 359                 notify_rfkill_state_change(rfkill);
 360
 361         mutex_unlock(&rfkill->mutex);
 362
 363         return 0;
 364 }
 365 EXPORT_SYMBOL(rfkill_force_state);
 366
 367 static ssize_t rfkill_name_show(struct device *dev,
 368                                 struct device_attribute *attr,
 369                                 char *buf)
 370 {
 371         struct rfkill *rfkill = to_rfkill(dev);
 372
 373         return sprintf(buf, "%s\n", rfkill->name);
 374 }
 375
 376 static const char *rfkill_get_type_str(enum rfkill_type type)
 377 {
 378         switch (type) {
 379         case RFKILL_TYPE_WLAN:
 380                 return "wlan";
 381         case RFKILL_TYPE_BLUETOOTH:
 382                 return "bluetooth";
 383         case RFKILL_TYPE_UWB:
 384                 return "ultrawideband";
 385         case RFKILL_TYPE_WIMAX:
 386                 return "wimax";
 387         case RFKILL_TYPE_WWAN:
 388                 return "wwan";
 389         default:
 390                 BUG();
 391         }
 392 }
 393
 394 static ssize_t rfkill_type_show(struct device *dev,
 395                                 struct device_attribute *attr,
 396                                 char *buf)
 397 {
 398         struct rfkill *rfkill = to_rfkill(dev);
 399
 400         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 401 }
 402
 403 static ssize_t rfkill_state_show(struct device *dev,
 404                                  struct device_attribute *attr,
 405                                  char *buf)
 406 {
 407         struct rfkill *rfkill = to_rfkill(dev);
 408
 409         update_rfkill_state(rfkill);
 410         return sprintf(buf, "%d\n", rfkill->state);
 411 }
 412
 413 static ssize_t rfkill_state_store(struct device *dev,
 414                                   struct device_attribute *attr,
 415                                   const char *buf, size_t count)
 416 {
 417         struct rfkill *rfkill = to_rfkill(dev);
 418         unsigned long state;
 419         int error;
 420
 421         if (!capable(CAP_NET_ADMIN))
 422                 return -EPERM;
 423
 424         error = strict_strtoul(buf, 0, &state);
 425         if (error)
 426                 return error;
 427
 428         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 429         if (state != RFKILL_STATE_UNBLOCKED &&
 430             state != RFKILL_STATE_SOFT_BLOCKED)
 431                 return -EINVAL;
 432
 433         if (mutex_lock_interruptible(&rfkill->mutex))
 434                 return -ERESTARTSYS;
 435         error = rfkill_toggle_radio(rfkill, state, 0);
 436         mutex_unlock(&rfkill->mutex);
 437
 438         return error ? error : count;
 439 }
 440
 441 static ssize_t rfkill_claim_show(struct device *dev,
 442                                  struct device_attribute *attr,
 443                                  char *buf)
 444 {
 445         struct rfkill *rfkill = to_rfkill(dev);
 446
 447         return sprintf(buf, "%d\n", rfkill->user_claim);
 448 }
 449
 450 static ssize_t rfkill_claim_store(struct device *dev,
 451                                   struct device_attribute *attr,
 452                                   const char *buf, size_t count)
 453 {
 454         struct rfkill *rfkill = to_rfkill(dev);
 455         unsigned long claim_tmp;
 456         bool claim;
 457         int error;
 458
 459         if (!capable(CAP_NET_ADMIN))
 460                 return -EPERM;
 461
 462         if (rfkill->user_claim_unsupported)
 463                 return -EOPNOTSUPP;
 464
 465         error = strict_strtoul(buf, 0, &claim_tmp);
 466         if (error)
 467                 return error;
 468         claim = !!claim_tmp;
 469
 470         /*
 471          * Take the global lock to make sure the kernel is not in
 472          * the middle of rfkill_switch_all
 473          */
 474         error = mutex_lock_interruptible(&rfkill_mutex);
 475         if (error)
 476                 return error;
 477
 478         if (rfkill->user_claim != claim) {
 479                 if (!claim) {
 480                         mutex_lock(&rfkill->mutex);
 481                         rfkill_toggle_radio(rfkill,
 482                                         rfkill_global_states[rfkill->type].current_state,
 483                                         0);
 484                         mutex_unlock(&rfkill->mutex);
 485                 }
 486                 rfkill->user_claim = claim;
 487         }
 488
 489         mutex_unlock(&rfkill_mutex);
 490
 491         return error ? error : count;
 492 }
 493
 494 static struct device_attribute rfkill_dev_attrs[] = {
 495         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 496         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 497         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 498         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 499         __ATTR_NULL
 500 };
 501
 502 static void rfkill_release(struct device *dev)
 503 {
 504         struct rfkill *rfkill = to_rfkill(dev);
 505
 506         kfree(rfkill);
 507         module_put(THIS_MODULE);
 508 }
 509
 510 #ifdef CONFIG_PM
 511 static int rfkill_suspend(struct device *dev, pm_message_t state)
 512 {
 513         struct rfkill *rfkill = to_rfkill(dev);
 514
 515         if (dev->power.power_state.event != state.event) {
 516                 if (state.event & PM_EVENT_SLEEP) {
 517                         /* Stop transmitter, keep state, no notifies */
 518                         update_rfkill_state(rfkill);
 519
 520                         mutex_lock(&rfkill->mutex);
 521                         rfkill->toggle_radio(rfkill->data,
 522                                                 RFKILL_STATE_SOFT_BLOCKED);
 523                         mutex_unlock(&rfkill->mutex);
 524                 }
 525
 526                 dev->power.power_state = state;
 527         }
 528
 529         return 0;
 530 }
 531
 532 static int rfkill_resume(struct device *dev)
 533 {
 534         struct rfkill *rfkill = to_rfkill(dev);
 535
 536         if (dev->power.power_state.event != PM_EVENT_ON) {
 537                 mutex_lock(&rfkill->mutex);
 538
 539                 dev->power.power_state.event = PM_EVENT_ON;
 540
 541                 /* restore radio state AND notify everybody */
 542                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 543
 544                 mutex_unlock(&rfkill->mutex);
 545         }
 546
 547         return 0;
 548 }
 549 #else
 550 #define rfkill_suspend NULL
 551 #define rfkill_resume NULL
 552 #endif
 553
 554 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 555                                         unsigned long eventid,
 556                                         void *data)
 557 {
 558         struct rfkill *rfkill = (struct rfkill *)data;
 559
 560         switch (eventid) {
 561         case RFKILL_STATE_CHANGED:
 562                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 563                 break;
 564         default:
 565                 break;
 566         }
 567
 568         return NOTIFY_DONE;
 569 }
 570
 571 static struct notifier_block rfkill_blocking_uevent_nb = {
 572         .notifier_call  = rfkill_blocking_uevent_notifier,
 573         .priority       = 0,
 574 };
 575
 576 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 577 {
 578         struct rfkill *rfkill = to_rfkill(dev);
 579         int error;
 580
 581         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 582         if (error)
 583                 return error;
 584         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 585                                 rfkill_get_type_str(rfkill->type));
 586         if (error)
 587                 return error;
 588         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 589         return error;
 590 }
 591
 592 static struct class rfkill_class = {
 593         .name           = "rfkill",
 594         .dev_release    = rfkill_release,
 595         .dev_attrs      = rfkill_dev_attrs,
 596         .suspend        = rfkill_suspend,
 597         .resume         = rfkill_resume,
 598         .dev_uevent     = rfkill_dev_uevent,
 599 };
 600
 601 static int rfkill_check_duplicity(const struct rfkill *rfkill)
 602 {
 603         struct rfkill *p;
 604         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
 605
 606         memset(seen, 0, sizeof(seen));
 607
 608         list_for_each_entry(p, &rfkill_list, node) {
 609                 if (WARN((p == rfkill), KERN_WARNING
 610                                 "rfkill: illegal attempt to register "
 611                                 "an already registered rfkill struct\n"))
 612                         return -EEXIST;
 613                 set_bit(p->type, seen);
 614         }
 615
 616         /* 0: first switch of its kind */
 617         return test_bit(rfkill->type, seen);
 618 }
 619
 620 static int rfkill_add_switch(struct rfkill *rfkill)
 621 {
 622         int error;
 623
 624         mutex_lock(&rfkill_mutex);
 625
 626         error = rfkill_check_duplicity(rfkill);
 627         if (error < 0)
 628                 goto unlock_out;
 629
 630         if (!error) {
 631                 /* lock default after first use */
 632                 set_bit(rfkill->type, rfkill_states_lockdflt);
 633                 rfkill_global_states[rfkill->type].current_state =
 634                         rfkill_global_states[rfkill->type].default_state;
 635         }
 636
 637         rfkill_toggle_radio(rfkill,
 638                             rfkill_global_states[rfkill->type].current_state,
 639                             0);
 640
 641         list_add_tail(&rfkill->node, &rfkill_list);
 642
 643         error = 0;
 644 unlock_out:
 645         mutex_unlock(&rfkill_mutex);
 646
 647         return error;
 648 }
 649
 650 static void rfkill_remove_switch(struct rfkill *rfkill)
 651 {
 652         mutex_lock(&rfkill_mutex);
 653         list_del_init(&rfkill->node);
 654         mutex_unlock(&rfkill_mutex);
 655
 656         mutex_lock(&rfkill->mutex);
 657         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 658         mutex_unlock(&rfkill->mutex);
 659 }
 660
 661 /**
 662  * rfkill_allocate - allocate memory for rfkill structure.
 663  * @parent: device that has rf switch on it
 664  * @type: type of the switch (RFKILL_TYPE_*)
 665  *
 666  * This function should be called by the network driver when it needs
 667  * rfkill structure.  Once the structure is allocated the driver should
 668  * finish its initialization by setting the name, private data, enable_radio
 669  * and disable_radio methods and then register it with rfkill_register().
 670  *
 671  * NOTE: If registration fails the structure shoudl be freed by calling
 672  * rfkill_free() otherwise rfkill_unregister() should be used.
 673  */
 674 struct rfkill * __must_check rfkill_allocate(struct device *parent,
 675                                              enum rfkill_type type)
 676 {
 677         struct rfkill *rfkill;
 678         struct device *dev;
 679
 680         if (WARN((type >= RFKILL_TYPE_MAX),
 681                         KERN_WARNING
 682                         "rfkill: illegal type %d passed as parameter "
 683                         "to rfkill_allocate\n", type))
 684                 return NULL;
 685
 686         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 687         if (!rfkill)
 688                 return NULL;
 689
 690         mutex_init(&rfkill->mutex);
 691         INIT_LIST_HEAD(&rfkill->node);
 692         rfkill->type = type;
 693
 694         dev = &rfkill->dev;
 695         dev->class = &rfkill_class;
 696         dev->parent = parent;
 697         device_initialize(dev);
 698
 699         __module_get(THIS_MODULE);
 700
 701         return rfkill;
 702 }
 703 EXPORT_SYMBOL(rfkill_allocate);
 704
 705 /**
 706  * rfkill_free - Mark rfkill structure for deletion
 707  * @rfkill: rfkill structure to be destroyed
 708  *
 709  * Decrements reference count of the rfkill structure so it is destroyed.
 710  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 711  */
 712 void rfkill_free(struct rfkill *rfkill)
 713 {
 714         if (rfkill)
 715                 put_device(&rfkill->dev);
 716 }
 717 EXPORT_SYMBOL(rfkill_free);
 718
 719 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 720 {
 721 #ifdef CONFIG_RFKILL_LEDS
 722         int error;
 723
 724         if (!rfkill->led_trigger.name)
 725                 rfkill->led_trigger.name = rfkill->dev.bus_id;
 726         if (!rfkill->led_trigger.activate)
 727                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
 728         error = led_trigger_register(&rfkill->led_trigger);
 729         if (error)
 730                 rfkill->led_trigger.name = NULL;
 731 #endif /* CONFIG_RFKILL_LEDS */
 732 }
 733
 734 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 735 {
 736 #ifdef CONFIG_RFKILL_LEDS
 737         if (rfkill->led_trigger.name) {
 738                 led_trigger_unregister(&rfkill->led_trigger);
 739                 rfkill->led_trigger.name = NULL;
 740         }
 741 #endif
 742 }
 743
 744 /**
 745  * rfkill_register - Register a rfkill structure.
 746  * @rfkill: rfkill structure to be registered
 747  *
 748  * This function should be called by the network driver when the rfkill
 749  * structure needs to be registered. Immediately from registration the
 750  * switch driver should be able to service calls to toggle_radio.
 751  */
 752 int __must_check rfkill_register(struct rfkill *rfkill)
 753 {
 754         static atomic_t rfkill_no = ATOMIC_INIT(0);
 755         struct device *dev = &rfkill->dev;
 756         int error;
 757
 758         if (WARN((!rfkill || !rfkill->toggle_radio ||
 759                         rfkill->type >= RFKILL_TYPE_MAX ||
 760                         rfkill->state >= RFKILL_STATE_MAX),
 761                         KERN_WARNING
 762                         "rfkill: attempt to register a "
 763                         "badly initialized rfkill struct\n"))
 764                 return -EINVAL;
 765
 766         snprintf(dev->bus_id, sizeof(dev->bus_id),
 767                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 768
 769         rfkill_led_trigger_register(rfkill);
 770
 771         error = rfkill_add_switch(rfkill);
 772         if (error) {
 773                 rfkill_led_trigger_unregister(rfkill);
 774                 return error;
 775         }
 776
 777         error = device_add(dev);
 778         if (error) {
 779                 rfkill_remove_switch(rfkill);
 780                 rfkill_led_trigger_unregister(rfkill);
 781                 return error;
 782         }
 783
 784         return 0;
 785 }
 786 EXPORT_SYMBOL(rfkill_register);
 787
 788 /**
 789  * rfkill_unregister - Unregister a rfkill structure.
 790  * @rfkill: rfkill structure to be unregistered
 791  *
 792  * This function should be called by the network driver during device
 793  * teardown to destroy rfkill structure. Note that rfkill_free() should
 794  * _not_ be called after rfkill_unregister().
 795  */
 796 void rfkill_unregister(struct rfkill *rfkill)
 797 {
 798         BUG_ON(!rfkill);
 799         device_del(&rfkill->dev);
 800         rfkill_remove_switch(rfkill);
 801         rfkill_led_trigger_unregister(rfkill);
 802         put_device(&rfkill->dev);
 803 }
 804 EXPORT_SYMBOL(rfkill_unregister);
 805
 806 /**
 807  * rfkill_set_default - set initial value for a switch type
 808  * @type - the type of switch to set the default state of
 809  * @state - the new default state for that group of switches
 810  *
 811  * Sets the initial state rfkill should use for a given type.
 812  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
 813  * and RFKILL_STATE_UNBLOCKED.
 814  *
 815  * This function is meant to be used by platform drivers for platforms
 816  * that can save switch state across power down/reboot.
 817  *
 818  * The default state for each switch type can be changed exactly once.
 819  * After a switch of that type is registered, the default state cannot
 820  * be changed anymore.  This guards against multiple drivers it the
 821  * same platform trying to set the initial switch default state, which
 822  * is not allowed.
 823  *
 824  * Returns -EPERM if the state has already been set once or is in use,
 825  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
 826  * if this function returns -EPERM.
 827  *
 828  * Returns 0 if the new default state was set, or an error if it
 829  * could not be set.
 830  */
 831 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
 832 {
 833         int error;
 834
 835         if (WARN((type >= RFKILL_TYPE_MAX ||
 836                         (state != RFKILL_STATE_SOFT_BLOCKED &&
 837                          state != RFKILL_STATE_UNBLOCKED)),
 838                         KERN_WARNING
 839                         "rfkill: illegal state %d or type %d passed as "
 840                         "parameter to rfkill_set_default\n", state, type))
 841                 return -EINVAL;
 842
 843         mutex_lock(&rfkill_mutex);
 844
 845         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
 846                 rfkill_global_states[type].default_state = state;
 847                 error = 0;
 848         } else
 849                 error = -EPERM;
 850
 851         mutex_unlock(&rfkill_mutex);
 852         return error;
 853 }
 854 EXPORT_SYMBOL_GPL(rfkill_set_default);
 855
 856 /*
 857  * Rfkill module initialization/deinitialization.
 858  */
 859 static int __init rfkill_init(void)
 860 {
 861         int error;
 862         int i;
 863
 864         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 865         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
 866             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 867                 return -EINVAL;
 868
 869         for (i = 0; i < RFKILL_TYPE_MAX; i++)
 870                 rfkill_global_states[i].default_state = rfkill_default_state;
 871
 872         error = class_register(&rfkill_class);
 873         if (error) {
 874                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 875                 return error;
 876         }
 877
 878         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 879
 880         return 0;
 881 }
 882
 883 static void __exit rfkill_exit(void)
 884 {
 885         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 886         class_unregister(&rfkill_class);
 887 }
 888
 889 subsys_initcall(rfkill_init);
 890 module_exit(rfkill_exit);