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         default:
 205                 return -EINVAL;
 206         }
 207
 208         if (force || state != rfkill->state) {
 209                 retval = rfkill->toggle_radio(rfkill->data, state);
 210                 /* never allow a HARD->SOFT downgrade! */
 211                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 212                         rfkill->state = state;
 213         }
 214
 215         if (force || rfkill->state != oldstate) {
 216                 rfkill_led_trigger(rfkill, rfkill->state);
 217                 notify_rfkill_state_change(rfkill);
 218         }
 219
 220         return retval;
 221 }
 222
 223 /**
 224  * __rfkill_switch_all - Toggle state of all switches of given type
 225  * @type: type of interfaces to be affected
 226  * @state: the new state
 227  *
 228  * This function toggles the state of all switches of given type,
 229  * unless a specific switch is claimed by userspace (in which case,
 230  * that switch is left alone) or suspended.
 231  *
 232  * Caller must have acquired rfkill_mutex.
 233  */
 234 static void __rfkill_switch_all(const enum rfkill_type type,
 235                                 const enum rfkill_state state)
 236 {
 237         struct rfkill *rfkill;
 238
 239         if (unlikely(state >= RFKILL_STATE_MAX))
 240                 return;
 241
 242         rfkill_global_states[type].current_state = state;
 243         list_for_each_entry(rfkill, &rfkill_list, node) {
 244                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
 245                         mutex_lock(&rfkill->mutex);
 246                         rfkill_toggle_radio(rfkill, state, 0);
 247                         mutex_unlock(&rfkill->mutex);
 248                 }
 249         }
 250 }
 251
 252 /**
 253  * rfkill_switch_all - Toggle state of all switches of given type
 254  * @type: type of interfaces to be affected
 255  * @state: the new state
 256  *
 257  * Acquires rfkill_mutex and calls __rfkill_switch_all(@type, @state).
 258  * Please refer to __rfkill_switch_all() for details.
 259  */
 260 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 261 {
 262         mutex_lock(&rfkill_mutex);
 263         __rfkill_switch_all(type, state);
 264         mutex_unlock(&rfkill_mutex);
 265 }
 266 EXPORT_SYMBOL(rfkill_switch_all);
 267
 268 /**
 269  * rfkill_epo - emergency power off all transmitters
 270  *
 271  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
 272  * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
 273  *
 274  * The global state before the EPO is saved and can be restored later
 275  * using rfkill_restore_states().
 276  */
 277 void rfkill_epo(void)
 278 {
 279         struct rfkill *rfkill;
 280         int i;
 281
 282         mutex_lock(&rfkill_mutex);
 283         list_for_each_entry(rfkill, &rfkill_list, node) {
 284                 mutex_lock(&rfkill->mutex);
 285                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 286                 mutex_unlock(&rfkill->mutex);
 287         }
 288         for (i = 0; i < RFKILL_TYPE_MAX; i++) {
 289                 rfkill_global_states[i].default_state =
 290                                 rfkill_global_states[i].current_state;
 291                 rfkill_global_states[i].current_state =
 292                                 RFKILL_STATE_SOFT_BLOCKED;
 293         }
 294         mutex_unlock(&rfkill_mutex);
 295 }
 296 EXPORT_SYMBOL_GPL(rfkill_epo);
 297
 298 /**
 299  * rfkill_restore_states - restore global states
 300  *
 301  * Restore (and sync switches to) the global state from the
 302  * states in rfkill_default_states.  This can undo the effects of
 303  * a call to rfkill_epo().
 304  */
 305 void rfkill_restore_states(void)
 306 {
 307         int i;
 308
 309         mutex_lock(&rfkill_mutex);
 310         for (i = 0; i < RFKILL_TYPE_MAX; i++)
 311                 __rfkill_switch_all(i, rfkill_global_states[i].default_state);
 312         mutex_unlock(&rfkill_mutex);
 313 }
 314 EXPORT_SYMBOL_GPL(rfkill_restore_states);
 315
 316 /**
 317  * rfkill_force_state - Force the internal rfkill radio state
 318  * @rfkill: pointer to the rfkill class to modify.
 319  * @state: the current radio state the class should be forced to.
 320  *
 321  * This function updates the internal state of the radio cached
 322  * by the rfkill class.  It should be used when the driver gets
 323  * a notification by the firmware/hardware of the current *real*
 324  * state of the radio rfkill switch.
 325  *
 326  * Devices which are subject to external changes on their rfkill
 327  * state (such as those caused by a hardware rfkill line) MUST
 328  * have their driver arrange to call rfkill_force_state() as soon
 329  * as possible after such a change.
 330  *
 331  * This function may not be called from an atomic context.
 332  */
 333 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 334 {
 335         enum rfkill_state oldstate;
 336
 337         if (unlikely(state >= RFKILL_STATE_MAX))
 338                 return -EINVAL;
 339
 340         mutex_lock(&rfkill->mutex);
 341
 342         oldstate = rfkill->state;
 343         rfkill->state = state;
 344
 345         if (state != oldstate)
 346                 notify_rfkill_state_change(rfkill);
 347
 348         mutex_unlock(&rfkill->mutex);
 349
 350         return 0;
 351 }
 352 EXPORT_SYMBOL(rfkill_force_state);
 353
 354 static ssize_t rfkill_name_show(struct device *dev,
 355                                 struct device_attribute *attr,
 356                                 char *buf)
 357 {
 358         struct rfkill *rfkill = to_rfkill(dev);
 359
 360         return sprintf(buf, "%s\n", rfkill->name);
 361 }
 362
 363 static const char *rfkill_get_type_str(enum rfkill_type type)
 364 {
 365         switch (type) {
 366         case RFKILL_TYPE_WLAN:
 367                 return "wlan";
 368         case RFKILL_TYPE_BLUETOOTH:
 369                 return "bluetooth";
 370         case RFKILL_TYPE_UWB:
 371                 return "ultrawideband";
 372         case RFKILL_TYPE_WIMAX:
 373                 return "wimax";
 374         case RFKILL_TYPE_WWAN:
 375                 return "wwan";
 376         default:
 377                 BUG();
 378         }
 379 }
 380
 381 static ssize_t rfkill_type_show(struct device *dev,
 382                                 struct device_attribute *attr,
 383                                 char *buf)
 384 {
 385         struct rfkill *rfkill = to_rfkill(dev);
 386
 387         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 388 }
 389
 390 static ssize_t rfkill_state_show(struct device *dev,
 391                                  struct device_attribute *attr,
 392                                  char *buf)
 393 {
 394         struct rfkill *rfkill = to_rfkill(dev);
 395
 396         update_rfkill_state(rfkill);
 397         return sprintf(buf, "%d\n", rfkill->state);
 398 }
 399
 400 static ssize_t rfkill_state_store(struct device *dev,
 401                                   struct device_attribute *attr,
 402                                   const char *buf, size_t count)
 403 {
 404         struct rfkill *rfkill = to_rfkill(dev);
 405         unsigned long state;
 406         int error;
 407
 408         if (!capable(CAP_NET_ADMIN))
 409                 return -EPERM;
 410
 411         error = strict_strtoul(buf, 0, &state);
 412         if (error)
 413                 return error;
 414
 415         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 416         if (state != RFKILL_STATE_UNBLOCKED &&
 417             state != RFKILL_STATE_SOFT_BLOCKED)
 418                 return -EINVAL;
 419
 420         if (mutex_lock_interruptible(&rfkill->mutex))
 421                 return -ERESTARTSYS;
 422         error = rfkill_toggle_radio(rfkill, state, 0);
 423         mutex_unlock(&rfkill->mutex);
 424
 425         return error ? error : count;
 426 }
 427
 428 static ssize_t rfkill_claim_show(struct device *dev,
 429                                  struct device_attribute *attr,
 430                                  char *buf)
 431 {
 432         struct rfkill *rfkill = to_rfkill(dev);
 433
 434         return sprintf(buf, "%d\n", rfkill->user_claim);
 435 }
 436
 437 static ssize_t rfkill_claim_store(struct device *dev,
 438                                   struct device_attribute *attr,
 439                                   const char *buf, size_t count)
 440 {
 441         struct rfkill *rfkill = to_rfkill(dev);
 442         unsigned long claim_tmp;
 443         bool claim;
 444         int error;
 445
 446         if (!capable(CAP_NET_ADMIN))
 447                 return -EPERM;
 448
 449         if (rfkill->user_claim_unsupported)
 450                 return -EOPNOTSUPP;
 451
 452         error = strict_strtoul(buf, 0, &claim_tmp);
 453         if (error)
 454                 return error;
 455         claim = !!claim_tmp;
 456
 457         /*
 458          * Take the global lock to make sure the kernel is not in
 459          * the middle of rfkill_switch_all
 460          */
 461         error = mutex_lock_interruptible(&rfkill_mutex);
 462         if (error)
 463                 return error;
 464
 465         if (rfkill->user_claim != claim) {
 466                 if (!claim) {
 467                         mutex_lock(&rfkill->mutex);
 468                         rfkill_toggle_radio(rfkill,
 469                                         rfkill_global_states[rfkill->type].current_state,
 470                                         0);
 471                         mutex_unlock(&rfkill->mutex);
 472                 }
 473                 rfkill->user_claim = claim;
 474         }
 475
 476         mutex_unlock(&rfkill_mutex);
 477
 478         return error ? error : count;
 479 }
 480
 481 static struct device_attribute rfkill_dev_attrs[] = {
 482         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 483         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 484         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 485         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 486         __ATTR_NULL
 487 };
 488
 489 static void rfkill_release(struct device *dev)
 490 {
 491         struct rfkill *rfkill = to_rfkill(dev);
 492
 493         kfree(rfkill);
 494         module_put(THIS_MODULE);
 495 }
 496
 497 #ifdef CONFIG_PM
 498 static int rfkill_suspend(struct device *dev, pm_message_t state)
 499 {
 500         struct rfkill *rfkill = to_rfkill(dev);
 501
 502         if (dev->power.power_state.event != state.event) {
 503                 if (state.event & PM_EVENT_SLEEP) {
 504                         /* Stop transmitter, keep state, no notifies */
 505                         update_rfkill_state(rfkill);
 506
 507                         mutex_lock(&rfkill->mutex);
 508                         rfkill->toggle_radio(rfkill->data,
 509                                                 RFKILL_STATE_SOFT_BLOCKED);
 510                         mutex_unlock(&rfkill->mutex);
 511                 }
 512
 513                 dev->power.power_state = state;
 514         }
 515
 516         return 0;
 517 }
 518
 519 static int rfkill_resume(struct device *dev)
 520 {
 521         struct rfkill *rfkill = to_rfkill(dev);
 522
 523         if (dev->power.power_state.event != PM_EVENT_ON) {
 524                 mutex_lock(&rfkill->mutex);
 525
 526                 dev->power.power_state.event = PM_EVENT_ON;
 527
 528                 /* restore radio state AND notify everybody */
 529                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 530
 531                 mutex_unlock(&rfkill->mutex);
 532         }
 533
 534         return 0;
 535 }
 536 #else
 537 #define rfkill_suspend NULL
 538 #define rfkill_resume NULL
 539 #endif
 540
 541 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 542                                         unsigned long eventid,
 543                                         void *data)
 544 {
 545         struct rfkill *rfkill = (struct rfkill *)data;
 546
 547         switch (eventid) {
 548         case RFKILL_STATE_CHANGED:
 549                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 550                 break;
 551         default:
 552                 break;
 553         }
 554
 555         return NOTIFY_DONE;
 556 }
 557
 558 static struct notifier_block rfkill_blocking_uevent_nb = {
 559         .notifier_call  = rfkill_blocking_uevent_notifier,
 560         .priority       = 0,
 561 };
 562
 563 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 564 {
 565         struct rfkill *rfkill = to_rfkill(dev);
 566         int error;
 567
 568         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 569         if (error)
 570                 return error;
 571         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 572                                 rfkill_get_type_str(rfkill->type));
 573         if (error)
 574                 return error;
 575         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 576         return error;
 577 }
 578
 579 static struct class rfkill_class = {
 580         .name           = "rfkill",
 581         .dev_release    = rfkill_release,
 582         .dev_attrs      = rfkill_dev_attrs,
 583         .suspend        = rfkill_suspend,
 584         .resume         = rfkill_resume,
 585         .dev_uevent     = rfkill_dev_uevent,
 586 };
 587
 588 static int rfkill_check_duplicity(const struct rfkill *rfkill)
 589 {
 590         struct rfkill *p;
 591         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
 592
 593         memset(seen, 0, sizeof(seen));
 594
 595         list_for_each_entry(p, &rfkill_list, node) {
 596                 if (p == rfkill) {
 597                         WARN_ON(1);
 598                         return -EEXIST;
 599                 }
 600                 set_bit(p->type, seen);
 601         }
 602
 603         /* 0: first switch of its kind */
 604         return test_bit(rfkill->type, seen);
 605 }
 606
 607 static int rfkill_add_switch(struct rfkill *rfkill)
 608 {
 609         int error;
 610
 611         mutex_lock(&rfkill_mutex);
 612
 613         error = rfkill_check_duplicity(rfkill);
 614         if (error < 0)
 615                 goto unlock_out;
 616
 617         if (!error) {
 618                 /* lock default after first use */
 619                 set_bit(rfkill->type, rfkill_states_lockdflt);
 620                 rfkill_global_states[rfkill->type].current_state =
 621                         rfkill_global_states[rfkill->type].default_state;
 622         }
 623
 624         rfkill_toggle_radio(rfkill,
 625                             rfkill_global_states[rfkill->type].current_state,
 626                             0);
 627
 628         list_add_tail(&rfkill->node, &rfkill_list);
 629
 630         error = 0;
 631 unlock_out:
 632         mutex_unlock(&rfkill_mutex);
 633
 634         return error;
 635 }
 636
 637 static void rfkill_remove_switch(struct rfkill *rfkill)
 638 {
 639         mutex_lock(&rfkill_mutex);
 640         list_del_init(&rfkill->node);
 641         mutex_unlock(&rfkill_mutex);
 642
 643         mutex_lock(&rfkill->mutex);
 644         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 645         mutex_unlock(&rfkill->mutex);
 646 }
 647
 648 /**
 649  * rfkill_allocate - allocate memory for rfkill structure.
 650  * @parent: device that has rf switch on it
 651  * @type: type of the switch (RFKILL_TYPE_*)
 652  *
 653  * This function should be called by the network driver when it needs
 654  * rfkill structure.  Once the structure is allocated the driver should
 655  * finish its initialization by setting the name, private data, enable_radio
 656  * and disable_radio methods and then register it with rfkill_register().
 657  *
 658  * NOTE: If registration fails the structure shoudl be freed by calling
 659  * rfkill_free() otherwise rfkill_unregister() should be used.
 660  */
 661 struct rfkill * __must_check rfkill_allocate(struct device *parent,
 662                                              enum rfkill_type type)
 663 {
 664         struct rfkill *rfkill;
 665         struct device *dev;
 666
 667         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 668         if (!rfkill)
 669                 return NULL;
 670
 671         mutex_init(&rfkill->mutex);
 672         INIT_LIST_HEAD(&rfkill->node);
 673         rfkill->type = type;
 674
 675         dev = &rfkill->dev;
 676         dev->class = &rfkill_class;
 677         dev->parent = parent;
 678         device_initialize(dev);
 679
 680         __module_get(THIS_MODULE);
 681
 682         return rfkill;
 683 }
 684 EXPORT_SYMBOL(rfkill_allocate);
 685
 686 /**
 687  * rfkill_free - Mark rfkill structure for deletion
 688  * @rfkill: rfkill structure to be destroyed
 689  *
 690  * Decrements reference count of the rfkill structure so it is destroyed.
 691  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 692  */
 693 void rfkill_free(struct rfkill *rfkill)
 694 {
 695         if (rfkill)
 696                 put_device(&rfkill->dev);
 697 }
 698 EXPORT_SYMBOL(rfkill_free);
 699
 700 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 701 {
 702 #ifdef CONFIG_RFKILL_LEDS
 703         int error;
 704
 705         if (!rfkill->led_trigger.name)
 706                 rfkill->led_trigger.name = rfkill->dev.bus_id;
 707         if (!rfkill->led_trigger.activate)
 708                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
 709         error = led_trigger_register(&rfkill->led_trigger);
 710         if (error)
 711                 rfkill->led_trigger.name = NULL;
 712 #endif /* CONFIG_RFKILL_LEDS */
 713 }
 714
 715 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 716 {
 717 #ifdef CONFIG_RFKILL_LEDS
 718         if (rfkill->led_trigger.name) {
 719                 led_trigger_unregister(&rfkill->led_trigger);
 720                 rfkill->led_trigger.name = NULL;
 721         }
 722 #endif
 723 }
 724
 725 /**
 726  * rfkill_register - Register a rfkill structure.
 727  * @rfkill: rfkill structure to be registered
 728  *
 729  * This function should be called by the network driver when the rfkill
 730  * structure needs to be registered. Immediately from registration the
 731  * switch driver should be able to service calls to toggle_radio.
 732  */
 733 int __must_check rfkill_register(struct rfkill *rfkill)
 734 {
 735         static atomic_t rfkill_no = ATOMIC_INIT(0);
 736         struct device *dev = &rfkill->dev;
 737         int error;
 738
 739         if (!rfkill->toggle_radio)
 740                 return -EINVAL;
 741         if (rfkill->type >= RFKILL_TYPE_MAX)
 742                 return -EINVAL;
 743         if (rfkill->state >= RFKILL_STATE_MAX)
 744                 return -EINVAL;
 745
 746         snprintf(dev->bus_id, sizeof(dev->bus_id),
 747                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 748
 749         rfkill_led_trigger_register(rfkill);
 750
 751         error = rfkill_add_switch(rfkill);
 752         if (error) {
 753                 rfkill_led_trigger_unregister(rfkill);
 754                 return error;
 755         }
 756
 757         error = device_add(dev);
 758         if (error) {
 759                 rfkill_remove_switch(rfkill);
 760                 rfkill_led_trigger_unregister(rfkill);
 761                 return error;
 762         }
 763
 764         return 0;
 765 }
 766 EXPORT_SYMBOL(rfkill_register);
 767
 768 /**
 769  * rfkill_unregister - Unregister a rfkill structure.
 770  * @rfkill: rfkill structure to be unregistered
 771  *
 772  * This function should be called by the network driver during device
 773  * teardown to destroy rfkill structure. Note that rfkill_free() should
 774  * _not_ be called after rfkill_unregister().
 775  */
 776 void rfkill_unregister(struct rfkill *rfkill)
 777 {
 778         device_del(&rfkill->dev);
 779         rfkill_remove_switch(rfkill);
 780         rfkill_led_trigger_unregister(rfkill);
 781         put_device(&rfkill->dev);
 782 }
 783 EXPORT_SYMBOL(rfkill_unregister);
 784
 785 /**
 786  * rfkill_set_default - set initial value for a switch type
 787  * @type - the type of switch to set the default state of
 788  * @state - the new default state for that group of switches
 789  *
 790  * Sets the initial state rfkill should use for a given type.
 791  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
 792  * and RFKILL_STATE_UNBLOCKED.
 793  *
 794  * This function is meant to be used by platform drivers for platforms
 795  * that can save switch state across power down/reboot.
 796  *
 797  * The default state for each switch type can be changed exactly once.
 798  * After a switch of that type is registered, the default state cannot
 799  * be changed anymore.  This guards against multiple drivers it the
 800  * same platform trying to set the initial switch default state, which
 801  * is not allowed.
 802  *
 803  * Returns -EPERM if the state has already been set once or is in use,
 804  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
 805  * if this function returns -EPERM.
 806  *
 807  * Returns 0 if the new default state was set, or an error if it
 808  * could not be set.
 809  */
 810 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
 811 {
 812         int error;
 813
 814         if (type >= RFKILL_TYPE_MAX ||
 815             (state != RFKILL_STATE_SOFT_BLOCKED &&
 816              state != RFKILL_STATE_UNBLOCKED))
 817                 return -EINVAL;
 818
 819         mutex_lock(&rfkill_mutex);
 820
 821         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
 822                 rfkill_global_states[type].default_state = state;
 823                 error = 0;
 824         } else
 825                 error = -EPERM;
 826
 827         mutex_unlock(&rfkill_mutex);
 828         return error;
 829 }
 830 EXPORT_SYMBOL_GPL(rfkill_set_default);
 831
 832 /*
 833  * Rfkill module initialization/deinitialization.
 834  */
 835 static int __init rfkill_init(void)
 836 {
 837         int error;
 838         int i;
 839
 840         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 841         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
 842             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 843                 return -EINVAL;
 844
 845         for (i = 0; i < RFKILL_TYPE_MAX; i++)
 846                 rfkill_global_states[i].default_state = rfkill_default_state;
 847
 848         error = class_register(&rfkill_class);
 849         if (error) {
 850                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 851                 return error;
 852         }
 853
 854         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 855
 856         return 0;
 857 }
 858
 859 static void __exit rfkill_exit(void)
 860 {
 861         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 862         class_unregister(&rfkill_class);
 863 }
 864
 865 subsys_initcall(rfkill_init);
 866 module_exit(rfkill_exit);