SAFE public projects git trees. - safe/jmp/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 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
  31 MODULE_VERSION("1.0");
  32 MODULE_DESCRIPTION("RF switch support");
  33 MODULE_LICENSE("GPL");
  34
  35 static LIST_HEAD(rfkill_list);  /* list of registered rf switches */
  36 static DEFINE_MUTEX(rfkill_mutex);
  37
  38 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
  39
  40
  41 static void rfkill_led_trigger(struct rfkill *rfkill,
  42                                enum rfkill_state state)
  43 {
  44 #ifdef CONFIG_RFKILL_LEDS
  45         struct led_trigger *led = &rfkill->led_trigger;
  46
  47         if (!led->name)
  48                 return;
  49         if (state == RFKILL_STATE_OFF)
  50                 led_trigger_event(led, LED_OFF);
  51         else
  52                 led_trigger_event(led, LED_FULL);
  53 #endif /* CONFIG_RFKILL_LEDS */
  54 }
  55
  56 static int rfkill_toggle_radio(struct rfkill *rfkill,
  57                                 enum rfkill_state state)
  58 {
  59         int retval;
  60
  61         retval = mutex_lock_interruptible(&rfkill->mutex);
  62         if (retval)
  63                 return retval;
  64
  65         if (state != rfkill->state) {
  66                 retval = rfkill->toggle_radio(rfkill->data, state);
  67                 if (!retval) {
  68                         rfkill->state = state;
  69                         rfkill_led_trigger(rfkill, state);
  70                 }
  71         }
  72
  73         mutex_unlock(&rfkill->mutex);
  74         return retval;
  75 }
  76
  77 /**
  78  * rfkill_switch_all - Toggle state of all switches of given type
  79  * @type: type of interfaces to be affeceted
  80  * @state: the new state
  81  *
  82  * This function toggles state of all switches of given type unless
  83  * a specific switch is claimed by userspace in which case it is
  84  * left alone.
  85  */
  86
  87 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
  88 {
  89         struct rfkill *rfkill;
  90
  91         mutex_lock(&rfkill_mutex);
  92
  93         rfkill_states[type] = state;
  94
  95         list_for_each_entry(rfkill, &rfkill_list, node) {
  96                 if (!rfkill->user_claim)
  97                         rfkill_toggle_radio(rfkill, state);
  98         }
  99
 100         mutex_unlock(&rfkill_mutex);
 101 }
 102 EXPORT_SYMBOL(rfkill_switch_all);
 103
 104 static ssize_t rfkill_name_show(struct device *dev,
 105                                 struct device_attribute *attr,
 106                                 char *buf)
 107 {
 108         struct rfkill *rfkill = to_rfkill(dev);
 109
 110         return sprintf(buf, "%s\n", rfkill->name);
 111 }
 112
 113 static ssize_t rfkill_type_show(struct device *dev,
 114                                 struct device_attribute *attr,
 115                                 char *buf)
 116 {
 117         struct rfkill *rfkill = to_rfkill(dev);
 118         const char *type;
 119
 120         switch (rfkill->type) {
 121         case RFKILL_TYPE_WLAN:
 122                 type = "wlan";
 123                 break;
 124         case RFKILL_TYPE_BLUETOOTH:
 125                 type = "bluetooth";
 126                 break;
 127         case RFKILL_TYPE_UWB:
 128                 type = "ultrawideband";
 129                 break;
 130         default:
 131                 BUG();
 132         }
 133
 134         return sprintf(buf, "%s\n", type);
 135 }
 136
 137 static ssize_t rfkill_state_show(struct device *dev,
 138                                  struct device_attribute *attr,
 139                                  char *buf)
 140 {
 141         struct rfkill *rfkill = to_rfkill(dev);
 142
 143         return sprintf(buf, "%d\n", rfkill->state);
 144 }
 145
 146 static ssize_t rfkill_state_store(struct device *dev,
 147                                   struct device_attribute *attr,
 148                                   const char *buf, size_t count)
 149 {
 150         struct rfkill *rfkill = to_rfkill(dev);
 151         unsigned int state = simple_strtoul(buf, NULL, 0);
 152         int error;
 153
 154         if (!capable(CAP_NET_ADMIN))
 155                 return -EPERM;
 156
 157         error = rfkill_toggle_radio(rfkill,
 158                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
 159         if (error)
 160                 return error;
 161
 162         return count;
 163 }
 164
 165 static ssize_t rfkill_claim_show(struct device *dev,
 166                                  struct device_attribute *attr,
 167                                  char *buf)
 168 {
 169         struct rfkill *rfkill = to_rfkill(dev);
 170
 171         return sprintf(buf, "%d", rfkill->user_claim);
 172 }
 173
 174 static ssize_t rfkill_claim_store(struct device *dev,
 175                                   struct device_attribute *attr,
 176                                   const char *buf, size_t count)
 177 {
 178         struct rfkill *rfkill = to_rfkill(dev);
 179         bool claim = !!simple_strtoul(buf, NULL, 0);
 180         int error;
 181
 182         if (!capable(CAP_NET_ADMIN))
 183                 return -EPERM;
 184
 185         /*
 186          * Take the global lock to make sure the kernel is not in
 187          * the middle of rfkill_switch_all
 188          */
 189         error = mutex_lock_interruptible(&rfkill_mutex);
 190         if (error)
 191                 return error;
 192
 193         if (rfkill->user_claim != claim) {
 194                 if (!claim)
 195                         rfkill_toggle_radio(rfkill,
 196                                             rfkill_states[rfkill->type]);
 197                 rfkill->user_claim = claim;
 198         }
 199
 200         mutex_unlock(&rfkill_mutex);
 201
 202         return count;
 203 }
 204
 205 static struct device_attribute rfkill_dev_attrs[] = {
 206         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 207         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 208         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 209         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 210         __ATTR_NULL
 211 };
 212
 213 static void rfkill_release(struct device *dev)
 214 {
 215         struct rfkill *rfkill = to_rfkill(dev);
 216
 217         kfree(rfkill);
 218         module_put(THIS_MODULE);
 219 }
 220
 221 #ifdef CONFIG_PM
 222 static int rfkill_suspend(struct device *dev, pm_message_t state)
 223 {
 224         struct rfkill *rfkill = to_rfkill(dev);
 225
 226         if (dev->power.power_state.event != state.event) {
 227                 if (state.event == PM_EVENT_SUSPEND) {
 228                         mutex_lock(&rfkill->mutex);
 229
 230                         if (rfkill->state == RFKILL_STATE_ON)
 231                                 rfkill->toggle_radio(rfkill->data,
 232                                                      RFKILL_STATE_OFF);
 233
 234                         mutex_unlock(&rfkill->mutex);
 235                 }
 236
 237                 dev->power.power_state = state;
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int rfkill_resume(struct device *dev)
 244 {
 245         struct rfkill *rfkill = to_rfkill(dev);
 246
 247         if (dev->power.power_state.event != PM_EVENT_ON) {
 248                 mutex_lock(&rfkill->mutex);
 249
 250                 if (rfkill->state == RFKILL_STATE_ON)
 251                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
 252
 253                 mutex_unlock(&rfkill->mutex);
 254         }
 255
 256         dev->power.power_state = PMSG_ON;
 257         return 0;
 258 }
 259 #else
 260 #define rfkill_suspend NULL
 261 #define rfkill_resume NULL
 262 #endif
 263
 264 static struct class rfkill_class = {
 265         .name           = "rfkill",
 266         .dev_release    = rfkill_release,
 267         .dev_attrs      = rfkill_dev_attrs,
 268         .suspend        = rfkill_suspend,
 269         .resume         = rfkill_resume,
 270 };
 271
 272 static int rfkill_add_switch(struct rfkill *rfkill)
 273 {
 274         int retval;
 275
 276         retval = mutex_lock_interruptible(&rfkill_mutex);
 277         if (retval)
 278                 return retval;
 279
 280         retval = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
 281         if (retval)
 282                 goto out;
 283
 284         list_add_tail(&rfkill->node, &rfkill_list);
 285
 286  out:
 287         mutex_unlock(&rfkill_mutex);
 288         return retval;
 289 }
 290
 291 static void rfkill_remove_switch(struct rfkill *rfkill)
 292 {
 293         mutex_lock(&rfkill_mutex);
 294         list_del_init(&rfkill->node);
 295         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
 296         mutex_unlock(&rfkill_mutex);
 297 }
 298
 299 /**
 300  * rfkill_allocate - allocate memory for rfkill structure.
 301  * @parent: device that has rf switch on it
 302  * @type: type of the switch (RFKILL_TYPE_*)
 303  *
 304  * This function should be called by the network driver when it needs
 305  * rfkill structure. Once the structure is allocated the driver shoud
 306  * finish its initialization by setting name, private data, enable_radio
 307  * and disable_radio methods and then register it with rfkill_register().
 308  * NOTE: If registration fails the structure shoudl be freed by calling
 309  * rfkill_free() otherwise rfkill_unregister() should be used.
 310  */
 311 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 312 {
 313         struct rfkill *rfkill;
 314         struct device *dev;
 315
 316         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 317         if (!rfkill)
 318                 return NULL;
 319
 320         mutex_init(&rfkill->mutex);
 321         INIT_LIST_HEAD(&rfkill->node);
 322         rfkill->type = type;
 323
 324         dev = &rfkill->dev;
 325         dev->class = &rfkill_class;
 326         dev->parent = parent;
 327         device_initialize(dev);
 328
 329         __module_get(THIS_MODULE);
 330
 331         return rfkill;
 332 }
 333 EXPORT_SYMBOL(rfkill_allocate);
 334
 335 /**
 336  * rfkill_free - Mark rfkill structure for deletion
 337  * @rfkill: rfkill structure to be destroyed
 338  *
 339  * Decrements reference count of rfkill structure so it is destoryed.
 340  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 341  */
 342 void rfkill_free(struct rfkill *rfkill)
 343 {
 344         if (rfkill)
 345                 put_device(&rfkill->dev);
 346 }
 347 EXPORT_SYMBOL(rfkill_free);
 348
 349 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 350 {
 351 #ifdef CONFIG_RFKILL_LEDS
 352         int error;
 353
 354         rfkill->led_trigger.name = rfkill->dev.bus_id;
 355         error = led_trigger_register(&rfkill->led_trigger);
 356         if (error)
 357                 rfkill->led_trigger.name = NULL;
 358 #endif /* CONFIG_RFKILL_LEDS */
 359 }
 360
 361 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 362 {
 363 #ifdef CONFIG_RFKILL_LEDS
 364         if (rfkill->led_trigger.name)
 365                 led_trigger_unregister(&rfkill->led_trigger);
 366 #endif
 367 }
 368
 369 /**
 370  * rfkill_register - Register a rfkill structure.
 371  * @rfkill: rfkill structure to be registered
 372  *
 373  * This function should be called by the network driver when the rfkill
 374  * structure needs to be registered. Immediately from registration the
 375  * switch driver should be able to service calls to toggle_radio.
 376  */
 377 int rfkill_register(struct rfkill *rfkill)
 378 {
 379         static atomic_t rfkill_no = ATOMIC_INIT(0);
 380         struct device *dev = &rfkill->dev;
 381         int error;
 382
 383         if (!rfkill->toggle_radio)
 384                 return -EINVAL;
 385
 386         error = rfkill_add_switch(rfkill);
 387         if (error)
 388                 return error;
 389
 390         snprintf(dev->bus_id, sizeof(dev->bus_id),
 391                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 392
 393         error = device_add(dev);
 394         if (error) {
 395                 rfkill_remove_switch(rfkill);
 396                 return error;
 397         }
 398         rfkill_led_trigger_register(rfkill);
 399
 400         return 0;
 401 }
 402 EXPORT_SYMBOL(rfkill_register);
 403
 404 /**
 405  * rfkill_unregister - Uegister a rfkill structure.
 406  * @rfkill: rfkill structure to be unregistered
 407  *
 408  * This function should be called by the network driver during device
 409  * teardown to destroy rfkill structure. Note that rfkill_free() should
 410  * _not_ be called after rfkill_unregister().
 411  */
 412 void rfkill_unregister(struct rfkill *rfkill)
 413 {
 414         rfkill_led_trigger_unregister(rfkill);
 415         device_del(&rfkill->dev);
 416         rfkill_remove_switch(rfkill);
 417         put_device(&rfkill->dev);
 418 }
 419 EXPORT_SYMBOL(rfkill_unregister);
 420
 421 /*
 422  * Rfkill module initialization/deinitialization.
 423  */
 424 static int __init rfkill_init(void)
 425 {
 426         int error;
 427         int i;
 428
 429         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 430                 rfkill_states[i] = RFKILL_STATE_ON;
 431
 432         error = class_register(&rfkill_class);
 433         if (error) {
 434                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 435                 return error;
 436         }
 437
 438         return 0;
 439 }
 440
 441 static void __exit rfkill_exit(void)
 442 {
 443         class_unregister(&rfkill_class);
 444 }
 445
 446 module_init(rfkill_init);
 447 module_exit(rfkill_exit);