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
  50 static void rfkill_led_trigger(struct rfkill *rfkill,
  51                                enum rfkill_state state)
  52 {
  53 #ifdef CONFIG_RFKILL_LEDS
  54         struct led_trigger *led = &rfkill->led_trigger;
  55
  56         if (!led->name)
  57                 return;
  58         if (state == RFKILL_STATE_OFF)
  59                 led_trigger_event(led, LED_OFF);
  60         else
  61                 led_trigger_event(led, LED_FULL);
  62 #endif /* CONFIG_RFKILL_LEDS */
  63 }
  64
  65 static void update_rfkill_state(struct rfkill *rfkill)
  66 {
  67         enum rfkill_state newstate;
  68
  69         if (rfkill->get_state) {
  70                 mutex_lock(&rfkill->mutex);
  71                 if (!rfkill->get_state(rfkill->data, &newstate))
  72                         rfkill->state = newstate;
  73                 mutex_unlock(&rfkill->mutex);
  74         }
  75 }
  76
  77 static int rfkill_toggle_radio(struct rfkill *rfkill,
  78                                 enum rfkill_state state)
  79 {
  80         int retval = 0;
  81         enum rfkill_state oldstate, newstate;
  82
  83         oldstate = rfkill->state;
  84
  85         if (rfkill->get_state &&
  86             !rfkill->get_state(rfkill->data, &newstate))
  87                 rfkill->state = newstate;
  88
  89         if (state != rfkill->state) {
  90                 retval = rfkill->toggle_radio(rfkill->data, state);
  91                 if (!retval)
  92                         rfkill->state = state;
  93         }
  94
  95         if (rfkill->state != oldstate)
  96                 rfkill_led_trigger(rfkill, rfkill->state);
  97
  98         return retval;
  99 }
 100
 101 /**
 102  * rfkill_switch_all - Toggle state of all switches of given type
 103  * @type: type of interfaces to be affeceted
 104  * @state: the new state
 105  *
 106  * This function toggles state of all switches of given type unless
 107  * a specific switch is claimed by userspace in which case it is
 108  * left alone.
 109  */
 110
 111 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 112 {
 113         struct rfkill *rfkill;
 114
 115         mutex_lock(&rfkill_mutex);
 116
 117         rfkill_states[type] = state;
 118
 119         list_for_each_entry(rfkill, &rfkill_list, node) {
 120                 if ((!rfkill->user_claim) && (rfkill->type == type))
 121                         rfkill_toggle_radio(rfkill, state);
 122         }
 123
 124         mutex_unlock(&rfkill_mutex);
 125 }
 126 EXPORT_SYMBOL(rfkill_switch_all);
 127
 128 /**
 129  * rfkill_force_state - Force the internal rfkill radio state
 130  * @rfkill: pointer to the rfkill class to modify.
 131  * @state: the current radio state the class should be forced to.
 132  *
 133  * This function updates the internal state of the radio cached
 134  * by the rfkill class.  It should be used when the driver gets
 135  * a notification by the firmware/hardware of the current *real*
 136  * state of the radio rfkill switch.
 137  *
 138  * It may not be called from an atomic context.
 139  */
 140 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 141 {
 142         if (state != RFKILL_STATE_OFF &&
 143             state != RFKILL_STATE_ON)
 144                 return -EINVAL;
 145
 146         mutex_lock(&rfkill->mutex);
 147         rfkill->state = state;
 148         mutex_unlock(&rfkill->mutex);
 149
 150         return 0;
 151 }
 152 EXPORT_SYMBOL(rfkill_force_state);
 153
 154 static ssize_t rfkill_name_show(struct device *dev,
 155                                 struct device_attribute *attr,
 156                                 char *buf)
 157 {
 158         struct rfkill *rfkill = to_rfkill(dev);
 159
 160         return sprintf(buf, "%s\n", rfkill->name);
 161 }
 162
 163 static ssize_t rfkill_type_show(struct device *dev,
 164                                 struct device_attribute *attr,
 165                                 char *buf)
 166 {
 167         struct rfkill *rfkill = to_rfkill(dev);
 168         const char *type;
 169
 170         switch (rfkill->type) {
 171         case RFKILL_TYPE_WLAN:
 172                 type = "wlan";
 173                 break;
 174         case RFKILL_TYPE_BLUETOOTH:
 175                 type = "bluetooth";
 176                 break;
 177         case RFKILL_TYPE_UWB:
 178                 type = "ultrawideband";
 179                 break;
 180         case RFKILL_TYPE_WIMAX:
 181                 type = "wimax";
 182                 break;
 183         default:
 184                 BUG();
 185         }
 186
 187         return sprintf(buf, "%s\n", type);
 188 }
 189
 190 static ssize_t rfkill_state_show(struct device *dev,
 191                                  struct device_attribute *attr,
 192                                  char *buf)
 193 {
 194         struct rfkill *rfkill = to_rfkill(dev);
 195
 196         update_rfkill_state(rfkill);
 197         return sprintf(buf, "%d\n", rfkill->state);
 198 }
 199
 200 static ssize_t rfkill_state_store(struct device *dev,
 201                                   struct device_attribute *attr,
 202                                   const char *buf, size_t count)
 203 {
 204         struct rfkill *rfkill = to_rfkill(dev);
 205         unsigned int state = simple_strtoul(buf, NULL, 0);
 206         int error;
 207
 208         if (!capable(CAP_NET_ADMIN))
 209                 return -EPERM;
 210
 211         if (mutex_lock_interruptible(&rfkill->mutex))
 212                 return -ERESTARTSYS;
 213         error = rfkill_toggle_radio(rfkill,
 214                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
 215         mutex_unlock(&rfkill->mutex);
 216
 217         return error ? error : count;
 218 }
 219
 220 static ssize_t rfkill_claim_show(struct device *dev,
 221                                  struct device_attribute *attr,
 222                                  char *buf)
 223 {
 224         struct rfkill *rfkill = to_rfkill(dev);
 225
 226         return sprintf(buf, "%d", rfkill->user_claim);
 227 }
 228
 229 static ssize_t rfkill_claim_store(struct device *dev,
 230                                   struct device_attribute *attr,
 231                                   const char *buf, size_t count)
 232 {
 233         struct rfkill *rfkill = to_rfkill(dev);
 234         bool claim = !!simple_strtoul(buf, NULL, 0);
 235         int error;
 236
 237         if (!capable(CAP_NET_ADMIN))
 238                 return -EPERM;
 239
 240         /*
 241          * Take the global lock to make sure the kernel is not in
 242          * the middle of rfkill_switch_all
 243          */
 244         error = mutex_lock_interruptible(&rfkill_mutex);
 245         if (error)
 246                 return error;
 247
 248         if (rfkill->user_claim_unsupported) {
 249                 error = -EOPNOTSUPP;
 250                 goto out_unlock;
 251         }
 252         if (rfkill->user_claim != claim) {
 253                 if (!claim)
 254                         rfkill_toggle_radio(rfkill,
 255                                             rfkill_states[rfkill->type]);
 256                 rfkill->user_claim = claim;
 257         }
 258
 259 out_unlock:
 260         mutex_unlock(&rfkill_mutex);
 261
 262         return error ? error : count;
 263 }
 264
 265 static struct device_attribute rfkill_dev_attrs[] = {
 266         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 267         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 268         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 269         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 270         __ATTR_NULL
 271 };
 272
 273 static void rfkill_release(struct device *dev)
 274 {
 275         struct rfkill *rfkill = to_rfkill(dev);
 276
 277         kfree(rfkill);
 278         module_put(THIS_MODULE);
 279 }
 280
 281 #ifdef CONFIG_PM
 282 static int rfkill_suspend(struct device *dev, pm_message_t state)
 283 {
 284         struct rfkill *rfkill = to_rfkill(dev);
 285
 286         if (dev->power.power_state.event != state.event) {
 287                 if (state.event & PM_EVENT_SLEEP) {
 288                         mutex_lock(&rfkill->mutex);
 289
 290                         if (rfkill->state == RFKILL_STATE_ON)
 291                                 rfkill->toggle_radio(rfkill->data,
 292                                                      RFKILL_STATE_OFF);
 293
 294                         mutex_unlock(&rfkill->mutex);
 295                 }
 296
 297                 dev->power.power_state = state;
 298         }
 299
 300         return 0;
 301 }
 302
 303 static int rfkill_resume(struct device *dev)
 304 {
 305         struct rfkill *rfkill = to_rfkill(dev);
 306
 307         if (dev->power.power_state.event != PM_EVENT_ON) {
 308                 mutex_lock(&rfkill->mutex);
 309
 310                 if (rfkill->state == RFKILL_STATE_ON)
 311                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
 312
 313                 mutex_unlock(&rfkill->mutex);
 314         }
 315
 316         dev->power.power_state = PMSG_ON;
 317         return 0;
 318 }
 319 #else
 320 #define rfkill_suspend NULL
 321 #define rfkill_resume NULL
 322 #endif
 323
 324 static struct class rfkill_class = {
 325         .name           = "rfkill",
 326         .dev_release    = rfkill_release,
 327         .dev_attrs      = rfkill_dev_attrs,
 328         .suspend        = rfkill_suspend,
 329         .resume         = rfkill_resume,
 330 };
 331
 332 static int rfkill_add_switch(struct rfkill *rfkill)
 333 {
 334         int error;
 335
 336         mutex_lock(&rfkill_mutex);
 337
 338         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
 339         if (!error)
 340                 list_add_tail(&rfkill->node, &rfkill_list);
 341
 342         mutex_unlock(&rfkill_mutex);
 343
 344         return error;
 345 }
 346
 347 static void rfkill_remove_switch(struct rfkill *rfkill)
 348 {
 349         mutex_lock(&rfkill_mutex);
 350         list_del_init(&rfkill->node);
 351         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
 352         mutex_unlock(&rfkill_mutex);
 353 }
 354
 355 /**
 356  * rfkill_allocate - allocate memory for rfkill structure.
 357  * @parent: device that has rf switch on it
 358  * @type: type of the switch (RFKILL_TYPE_*)
 359  *
 360  * This function should be called by the network driver when it needs
 361  * rfkill structure. Once the structure is allocated the driver shoud
 362  * finish its initialization by setting name, private data, enable_radio
 363  * and disable_radio methods and then register it with rfkill_register().
 364  * NOTE: If registration fails the structure shoudl be freed by calling
 365  * rfkill_free() otherwise rfkill_unregister() should be used.
 366  */
 367 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 368 {
 369         struct rfkill *rfkill;
 370         struct device *dev;
 371
 372         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 373         if (!rfkill)
 374                 return NULL;
 375
 376         mutex_init(&rfkill->mutex);
 377         INIT_LIST_HEAD(&rfkill->node);
 378         rfkill->type = type;
 379
 380         dev = &rfkill->dev;
 381         dev->class = &rfkill_class;
 382         dev->parent = parent;
 383         device_initialize(dev);
 384
 385         __module_get(THIS_MODULE);
 386
 387         return rfkill;
 388 }
 389 EXPORT_SYMBOL(rfkill_allocate);
 390
 391 /**
 392  * rfkill_free - Mark rfkill structure for deletion
 393  * @rfkill: rfkill structure to be destroyed
 394  *
 395  * Decrements reference count of rfkill structure so it is destroyed.
 396  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 397  */
 398 void rfkill_free(struct rfkill *rfkill)
 399 {
 400         if (rfkill)
 401                 put_device(&rfkill->dev);
 402 }
 403 EXPORT_SYMBOL(rfkill_free);
 404
 405 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 406 {
 407 #ifdef CONFIG_RFKILL_LEDS
 408         int error;
 409
 410         rfkill->led_trigger.name = rfkill->dev.bus_id;
 411         error = led_trigger_register(&rfkill->led_trigger);
 412         if (error)
 413                 rfkill->led_trigger.name = NULL;
 414 #endif /* CONFIG_RFKILL_LEDS */
 415 }
 416
 417 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 418 {
 419 #ifdef CONFIG_RFKILL_LEDS
 420         if (rfkill->led_trigger.name)
 421                 led_trigger_unregister(&rfkill->led_trigger);
 422 #endif
 423 }
 424
 425 /**
 426  * rfkill_register - Register a rfkill structure.
 427  * @rfkill: rfkill structure to be registered
 428  *
 429  * This function should be called by the network driver when the rfkill
 430  * structure needs to be registered. Immediately from registration the
 431  * switch driver should be able to service calls to toggle_radio.
 432  */
 433 int rfkill_register(struct rfkill *rfkill)
 434 {
 435         static atomic_t rfkill_no = ATOMIC_INIT(0);
 436         struct device *dev = &rfkill->dev;
 437         int error;
 438
 439         if (!rfkill->toggle_radio)
 440                 return -EINVAL;
 441         if (rfkill->type >= RFKILL_TYPE_MAX)
 442                 return -EINVAL;
 443
 444         snprintf(dev->bus_id, sizeof(dev->bus_id),
 445                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 446
 447         rfkill_led_trigger_register(rfkill);
 448
 449         error = rfkill_add_switch(rfkill);
 450         if (error) {
 451                 rfkill_led_trigger_unregister(rfkill);
 452                 return error;
 453         }
 454
 455         error = device_add(dev);
 456         if (error) {
 457                 rfkill_led_trigger_unregister(rfkill);
 458                 rfkill_remove_switch(rfkill);
 459                 return error;
 460         }
 461
 462         return 0;
 463 }
 464 EXPORT_SYMBOL(rfkill_register);
 465
 466 /**
 467  * rfkill_unregister - Unregister a rfkill structure.
 468  * @rfkill: rfkill structure to be unregistered
 469  *
 470  * This function should be called by the network driver during device
 471  * teardown to destroy rfkill structure. Note that rfkill_free() should
 472  * _not_ be called after rfkill_unregister().
 473  */
 474 void rfkill_unregister(struct rfkill *rfkill)
 475 {
 476         device_del(&rfkill->dev);
 477         rfkill_remove_switch(rfkill);
 478         rfkill_led_trigger_unregister(rfkill);
 479         put_device(&rfkill->dev);
 480 }
 481 EXPORT_SYMBOL(rfkill_unregister);
 482
 483 /*
 484  * Rfkill module initialization/deinitialization.
 485  */
 486 static int __init rfkill_init(void)
 487 {
 488         int error;
 489         int i;
 490
 491         if (rfkill_default_state != RFKILL_STATE_OFF &&
 492             rfkill_default_state != RFKILL_STATE_ON)
 493                 return -EINVAL;
 494
 495         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 496                 rfkill_states[i] = rfkill_default_state;
 497
 498         error = class_register(&rfkill_class);
 499         if (error) {
 500                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 501                 return error;
 502         }
 503
 504         return 0;
 505 }
 506
 507 static void __exit rfkill_exit(void)
 508 {
 509         class_unregister(&rfkill_class);
 510 }
 511
 512 subsys_initcall(rfkill_init);
 513 module_exit(rfkill_exit);