err.no 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_ON;
  43 module_param_named(default_state, rfkill_default_state, uint, 0444);
  44 MODULE_PARM_DESC(default_state,
  45                  "Default initial state for all radio types, 0 = radio off");
  46
  47 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
  48
  49 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  50
  51
  52 /**
  53  * register_rfkill_notifier - Add notifier to rfkill notifier chain
  54  * @nb: pointer to the new entry to add to the chain
  55  *
  56  * See blocking_notifier_chain_register() for return value and further
  57  * observations.
  58  *
  59  * Adds a notifier to the rfkill notifier chain.  The chain will be
  60  * called with a pointer to the relevant rfkill structure as a parameter,
  61  * refer to include/linux/rfkill.h for the possible events.
  62  *
  63  * Notifiers added to this chain are to always return NOTIFY_DONE.  This
  64  * chain is a blocking notifier chain: notifiers can sleep.
  65  *
  66  * Calls to this chain may have been done through a workqueue.  One must
  67  * assume unordered asynchronous behaviour, there is no way to know if
  68  * actions related to the event that generated the notification have been
  69  * carried out already.
  70  */
  71 int register_rfkill_notifier(struct notifier_block *nb)
  72 {
  73         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
  74 }
  75 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  76
  77 /**
  78  * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
  79  * @nb: pointer to the entry to remove from the chain
  80  *
  81  * See blocking_notifier_chain_unregister() for return value and further
  82  * observations.
  83  *
  84  * Removes a notifier from the rfkill notifier chain.
  85  */
  86 int unregister_rfkill_notifier(struct notifier_block *nb)
  87 {
  88         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
  89 }
  90 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
  91
  92
  93 static void rfkill_led_trigger(struct rfkill *rfkill,
  94                                enum rfkill_state state)
  95 {
  96 #ifdef CONFIG_RFKILL_LEDS
  97         struct led_trigger *led = &rfkill->led_trigger;
  98
  99         if (!led->name)
 100                 return;
 101         if (state == RFKILL_STATE_OFF)
 102                 led_trigger_event(led, LED_OFF);
 103         else
 104                 led_trigger_event(led, LED_FULL);
 105 #endif /* CONFIG_RFKILL_LEDS */
 106 }
 107
 108 static void notify_rfkill_state_change(struct rfkill *rfkill)
 109 {
 110         blocking_notifier_call_chain(&rfkill_notifier_list,
 111                         RFKILL_STATE_CHANGED,
 112                         rfkill);
 113 }
 114
 115 static void update_rfkill_state(struct rfkill *rfkill)
 116 {
 117         enum rfkill_state newstate, oldstate;
 118
 119         if (rfkill->get_state) {
 120                 mutex_lock(&rfkill->mutex);
 121                 if (!rfkill->get_state(rfkill->data, &newstate)) {
 122                         oldstate = rfkill->state;
 123                         rfkill->state = newstate;
 124                         if (oldstate != newstate)
 125                                 notify_rfkill_state_change(rfkill);
 126                 }
 127                 mutex_unlock(&rfkill->mutex);
 128         }
 129 }
 130
 131 static int rfkill_toggle_radio(struct rfkill *rfkill,
 132                                 enum rfkill_state state,
 133                                 int force)
 134 {
 135         int retval = 0;
 136         enum rfkill_state oldstate, newstate;
 137
 138         oldstate = rfkill->state;
 139
 140         if (rfkill->get_state && !force &&
 141             !rfkill->get_state(rfkill->data, &newstate))
 142                 rfkill->state = newstate;
 143
 144         if (force || state != rfkill->state) {
 145                 retval = rfkill->toggle_radio(rfkill->data, state);
 146                 if (!retval)
 147                         rfkill->state = state;
 148         }
 149
 150         if (force || rfkill->state != oldstate) {
 151                 rfkill_led_trigger(rfkill, rfkill->state);
 152                 notify_rfkill_state_change(rfkill);
 153         }
 154
 155         return retval;
 156 }
 157
 158 /**
 159  * rfkill_switch_all - Toggle state of all switches of given type
 160  * @type: type of interfaces to be affeceted
 161  * @state: the new state
 162  *
 163  * This function toggles state of all switches of given type unless
 164  * a specific switch is claimed by userspace in which case it is
 165  * left alone.
 166  */
 167 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 168 {
 169         struct rfkill *rfkill;
 170
 171         mutex_lock(&rfkill_mutex);
 172
 173         rfkill_states[type] = state;
 174
 175         list_for_each_entry(rfkill, &rfkill_list, node) {
 176                 if ((!rfkill->user_claim) && (rfkill->type == type))
 177                         rfkill_toggle_radio(rfkill, state, 0);
 178         }
 179
 180         mutex_unlock(&rfkill_mutex);
 181 }
 182 EXPORT_SYMBOL(rfkill_switch_all);
 183
 184 /**
 185  * rfkill_epo - emergency power off all transmitters
 186  *
 187  * This kicks all rfkill devices to RFKILL_STATE_OFF, ignoring
 188  * everything in its path but rfkill_mutex.
 189  */
 190 void rfkill_epo(void)
 191 {
 192         struct rfkill *rfkill;
 193
 194         mutex_lock(&rfkill_mutex);
 195         list_for_each_entry(rfkill, &rfkill_list, node) {
 196                 rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF, 1);
 197         }
 198         mutex_unlock(&rfkill_mutex);
 199 }
 200 EXPORT_SYMBOL_GPL(rfkill_epo);
 201
 202 /**
 203  * rfkill_force_state - Force the internal rfkill radio state
 204  * @rfkill: pointer to the rfkill class to modify.
 205  * @state: the current radio state the class should be forced to.
 206  *
 207  * This function updates the internal state of the radio cached
 208  * by the rfkill class.  It should be used when the driver gets
 209  * a notification by the firmware/hardware of the current *real*
 210  * state of the radio rfkill switch.
 211  *
 212  * It may not be called from an atomic context.
 213  */
 214 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 215 {
 216         enum rfkill_state oldstate;
 217
 218         if (state != RFKILL_STATE_OFF &&
 219             state != RFKILL_STATE_ON)
 220                 return -EINVAL;
 221
 222         mutex_lock(&rfkill->mutex);
 223
 224         oldstate = rfkill->state;
 225         rfkill->state = state;
 226
 227         if (state != oldstate)
 228                 notify_rfkill_state_change(rfkill);
 229
 230         mutex_unlock(&rfkill->mutex);
 231
 232         return 0;
 233 }
 234 EXPORT_SYMBOL(rfkill_force_state);
 235
 236 static ssize_t rfkill_name_show(struct device *dev,
 237                                 struct device_attribute *attr,
 238                                 char *buf)
 239 {
 240         struct rfkill *rfkill = to_rfkill(dev);
 241
 242         return sprintf(buf, "%s\n", rfkill->name);
 243 }
 244
 245 static const char *rfkill_get_type_str(enum rfkill_type type)
 246 {
 247         switch (type) {
 248         case RFKILL_TYPE_WLAN:
 249                 return "wlan";
 250         case RFKILL_TYPE_BLUETOOTH:
 251                 return "bluetooth";
 252         case RFKILL_TYPE_UWB:
 253                 return "ultrawideband";
 254         case RFKILL_TYPE_WIMAX:
 255                 return "wimax";
 256         case RFKILL_TYPE_WWAN:
 257                 return "wwan";
 258         default:
 259                 BUG();
 260         }
 261 }
 262
 263 static ssize_t rfkill_type_show(struct device *dev,
 264                                 struct device_attribute *attr,
 265                                 char *buf)
 266 {
 267         struct rfkill *rfkill = to_rfkill(dev);
 268
 269         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 270 }
 271
 272 static ssize_t rfkill_state_show(struct device *dev,
 273                                  struct device_attribute *attr,
 274                                  char *buf)
 275 {
 276         struct rfkill *rfkill = to_rfkill(dev);
 277
 278         update_rfkill_state(rfkill);
 279         return sprintf(buf, "%d\n", rfkill->state);
 280 }
 281
 282 static ssize_t rfkill_state_store(struct device *dev,
 283                                   struct device_attribute *attr,
 284                                   const char *buf, size_t count)
 285 {
 286         struct rfkill *rfkill = to_rfkill(dev);
 287         unsigned int state = simple_strtoul(buf, NULL, 0);
 288         int error;
 289
 290         if (!capable(CAP_NET_ADMIN))
 291                 return -EPERM;
 292
 293         if (mutex_lock_interruptible(&rfkill->mutex))
 294                 return -ERESTARTSYS;
 295         error = rfkill_toggle_radio(rfkill,
 296                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF,
 297                         0);
 298         mutex_unlock(&rfkill->mutex);
 299
 300         return error ? error : count;
 301 }
 302
 303 static ssize_t rfkill_claim_show(struct device *dev,
 304                                  struct device_attribute *attr,
 305                                  char *buf)
 306 {
 307         struct rfkill *rfkill = to_rfkill(dev);
 308
 309         return sprintf(buf, "%d", rfkill->user_claim);
 310 }
 311
 312 static ssize_t rfkill_claim_store(struct device *dev,
 313                                   struct device_attribute *attr,
 314                                   const char *buf, size_t count)
 315 {
 316         struct rfkill *rfkill = to_rfkill(dev);
 317         bool claim = !!simple_strtoul(buf, NULL, 0);
 318         int error;
 319
 320         if (!capable(CAP_NET_ADMIN))
 321                 return -EPERM;
 322
 323         /*
 324          * Take the global lock to make sure the kernel is not in
 325          * the middle of rfkill_switch_all
 326          */
 327         error = mutex_lock_interruptible(&rfkill_mutex);
 328         if (error)
 329                 return error;
 330
 331         if (rfkill->user_claim_unsupported) {
 332                 error = -EOPNOTSUPP;
 333                 goto out_unlock;
 334         }
 335         if (rfkill->user_claim != claim) {
 336                 if (!claim)
 337                         rfkill_toggle_radio(rfkill,
 338                                             rfkill_states[rfkill->type],
 339                                             0);
 340                 rfkill->user_claim = claim;
 341         }
 342
 343 out_unlock:
 344         mutex_unlock(&rfkill_mutex);
 345
 346         return error ? error : count;
 347 }
 348
 349 static struct device_attribute rfkill_dev_attrs[] = {
 350         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 351         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 352         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 353         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 354         __ATTR_NULL
 355 };
 356
 357 static void rfkill_release(struct device *dev)
 358 {
 359         struct rfkill *rfkill = to_rfkill(dev);
 360
 361         kfree(rfkill);
 362         module_put(THIS_MODULE);
 363 }
 364
 365 #ifdef CONFIG_PM
 366 static int rfkill_suspend(struct device *dev, pm_message_t state)
 367 {
 368         struct rfkill *rfkill = to_rfkill(dev);
 369
 370         if (dev->power.power_state.event != state.event) {
 371                 if (state.event & PM_EVENT_SLEEP) {
 372                         /* Stop transmitter, keep state, no notifies */
 373                         update_rfkill_state(rfkill);
 374
 375                         mutex_lock(&rfkill->mutex);
 376                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_OFF);
 377                         mutex_unlock(&rfkill->mutex);
 378                 }
 379
 380                 dev->power.power_state = state;
 381         }
 382
 383         return 0;
 384 }
 385
 386 static int rfkill_resume(struct device *dev)
 387 {
 388         struct rfkill *rfkill = to_rfkill(dev);
 389
 390         if (dev->power.power_state.event != PM_EVENT_ON) {
 391                 mutex_lock(&rfkill->mutex);
 392
 393                 /* restore radio state AND notify everybody */
 394                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
 395
 396                 mutex_unlock(&rfkill->mutex);
 397         }
 398
 399         dev->power.power_state = PMSG_ON;
 400         return 0;
 401 }
 402 #else
 403 #define rfkill_suspend NULL
 404 #define rfkill_resume NULL
 405 #endif
 406
 407 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
 408                                         unsigned long eventid,
 409                                         void *data)
 410 {
 411         struct rfkill *rfkill = (struct rfkill *)data;
 412
 413         switch (eventid) {
 414         case RFKILL_STATE_CHANGED:
 415                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
 416                 break;
 417         default:
 418                 break;
 419         }
 420
 421         return NOTIFY_DONE;
 422 }
 423
 424 static struct notifier_block rfkill_blocking_uevent_nb = {
 425         .notifier_call  = rfkill_blocking_uevent_notifier,
 426         .priority       = 0,
 427 };
 428
 429 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 430 {
 431         struct rfkill *rfkill = to_rfkill(dev);
 432         int error;
 433
 434         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
 435         if (error)
 436                 return error;
 437         error = add_uevent_var(env, "RFKILL_TYPE=%s",
 438                                 rfkill_get_type_str(rfkill->type));
 439         if (error)
 440                 return error;
 441         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
 442         return error;
 443 }
 444
 445 static struct class rfkill_class = {
 446         .name           = "rfkill",
 447         .dev_release    = rfkill_release,
 448         .dev_attrs      = rfkill_dev_attrs,
 449         .suspend        = rfkill_suspend,
 450         .resume         = rfkill_resume,
 451         .dev_uevent     = rfkill_dev_uevent,
 452 };
 453
 454 static int rfkill_add_switch(struct rfkill *rfkill)
 455 {
 456         int error;
 457
 458         mutex_lock(&rfkill_mutex);
 459
 460         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
 461         if (!error)
 462                 list_add_tail(&rfkill->node, &rfkill_list);
 463
 464         mutex_unlock(&rfkill_mutex);
 465
 466         return error;
 467 }
 468
 469 static void rfkill_remove_switch(struct rfkill *rfkill)
 470 {
 471         mutex_lock(&rfkill_mutex);
 472         list_del_init(&rfkill->node);
 473         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF, 1);
 474         mutex_unlock(&rfkill_mutex);
 475 }
 476
 477 /**
 478  * rfkill_allocate - allocate memory for rfkill structure.
 479  * @parent: device that has rf switch on it
 480  * @type: type of the switch (RFKILL_TYPE_*)
 481  *
 482  * This function should be called by the network driver when it needs
 483  * rfkill structure. Once the structure is allocated the driver shoud
 484  * finish its initialization by setting name, private data, enable_radio
 485  * and disable_radio methods and then register it with rfkill_register().
 486  * NOTE: If registration fails the structure shoudl be freed by calling
 487  * rfkill_free() otherwise rfkill_unregister() should be used.
 488  */
 489 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 490 {
 491         struct rfkill *rfkill;
 492         struct device *dev;
 493
 494         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 495         if (!rfkill)
 496                 return NULL;
 497
 498         mutex_init(&rfkill->mutex);
 499         INIT_LIST_HEAD(&rfkill->node);
 500         rfkill->type = type;
 501
 502         dev = &rfkill->dev;
 503         dev->class = &rfkill_class;
 504         dev->parent = parent;
 505         device_initialize(dev);
 506
 507         __module_get(THIS_MODULE);
 508
 509         return rfkill;
 510 }
 511 EXPORT_SYMBOL(rfkill_allocate);
 512
 513 /**
 514  * rfkill_free - Mark rfkill structure for deletion
 515  * @rfkill: rfkill structure to be destroyed
 516  *
 517  * Decrements reference count of rfkill structure so it is destroyed.
 518  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 519  */
 520 void rfkill_free(struct rfkill *rfkill)
 521 {
 522         if (rfkill)
 523                 put_device(&rfkill->dev);
 524 }
 525 EXPORT_SYMBOL(rfkill_free);
 526
 527 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 528 {
 529 #ifdef CONFIG_RFKILL_LEDS
 530         int error;
 531
 532         rfkill->led_trigger.name = rfkill->dev.bus_id;
 533         error = led_trigger_register(&rfkill->led_trigger);
 534         if (error)
 535                 rfkill->led_trigger.name = NULL;
 536 #endif /* CONFIG_RFKILL_LEDS */
 537 }
 538
 539 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 540 {
 541 #ifdef CONFIG_RFKILL_LEDS
 542         if (rfkill->led_trigger.name)
 543                 led_trigger_unregister(&rfkill->led_trigger);
 544 #endif
 545 }
 546
 547 /**
 548  * rfkill_register - Register a rfkill structure.
 549  * @rfkill: rfkill structure to be registered
 550  *
 551  * This function should be called by the network driver when the rfkill
 552  * structure needs to be registered. Immediately from registration the
 553  * switch driver should be able to service calls to toggle_radio.
 554  */
 555 int rfkill_register(struct rfkill *rfkill)
 556 {
 557         static atomic_t rfkill_no = ATOMIC_INIT(0);
 558         struct device *dev = &rfkill->dev;
 559         int error;
 560
 561         if (!rfkill->toggle_radio)
 562                 return -EINVAL;
 563         if (rfkill->type >= RFKILL_TYPE_MAX)
 564                 return -EINVAL;
 565
 566         snprintf(dev->bus_id, sizeof(dev->bus_id),
 567                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 568
 569         rfkill_led_trigger_register(rfkill);
 570
 571         error = rfkill_add_switch(rfkill);
 572         if (error) {
 573                 rfkill_led_trigger_unregister(rfkill);
 574                 return error;
 575         }
 576
 577         error = device_add(dev);
 578         if (error) {
 579                 rfkill_led_trigger_unregister(rfkill);
 580                 rfkill_remove_switch(rfkill);
 581                 return error;
 582         }
 583
 584         return 0;
 585 }
 586 EXPORT_SYMBOL(rfkill_register);
 587
 588 /**
 589  * rfkill_unregister - Unregister a rfkill structure.
 590  * @rfkill: rfkill structure to be unregistered
 591  *
 592  * This function should be called by the network driver during device
 593  * teardown to destroy rfkill structure. Note that rfkill_free() should
 594  * _not_ be called after rfkill_unregister().
 595  */
 596 void rfkill_unregister(struct rfkill *rfkill)
 597 {
 598         device_del(&rfkill->dev);
 599         rfkill_remove_switch(rfkill);
 600         rfkill_led_trigger_unregister(rfkill);
 601         put_device(&rfkill->dev);
 602 }
 603 EXPORT_SYMBOL(rfkill_unregister);
 604
 605 /*
 606  * Rfkill module initialization/deinitialization.
 607  */
 608 static int __init rfkill_init(void)
 609 {
 610         int error;
 611         int i;
 612
 613         if (rfkill_default_state != RFKILL_STATE_OFF &&
 614             rfkill_default_state != RFKILL_STATE_ON)
 615                 return -EINVAL;
 616
 617         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 618                 rfkill_states[i] = rfkill_default_state;
 619
 620         error = class_register(&rfkill_class);
 621         if (error) {
 622                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 623                 return error;
 624         }
 625
 626         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
 627
 628         return 0;
 629 }
 630
 631 static void __exit rfkill_exit(void)
 632 {
 633         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 634         class_unregister(&rfkill_class);
 635 }
 636
 637 subsys_initcall(rfkill_init);
 638 module_exit(rfkill_exit);