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