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 enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
  43
  44
  45 static void rfkill_led_trigger(struct rfkill *rfkill,
  46                                enum rfkill_state state)
  47 {
  48 #ifdef CONFIG_RFKILL_LEDS
  49         struct led_trigger *led = &rfkill->led_trigger;
  50
  51         if (!led->name)
  52                 return;
  53         if (state == RFKILL_STATE_OFF)
  54                 led_trigger_event(led, LED_OFF);
  55         else
  56                 led_trigger_event(led, LED_FULL);
  57 #endif /* CONFIG_RFKILL_LEDS */
  58 }
  59
  60 static int rfkill_toggle_radio(struct rfkill *rfkill,
  61                                 enum rfkill_state state)
  62 {
  63         int retval = 0;
  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         return retval;
  74 }
  75
  76 /**
  77  * rfkill_switch_all - Toggle state of all switches of given type
  78  * @type: type of interfaces to be affeceted
  79  * @state: the new state
  80  *
  81  * This function toggles state of all switches of given type unless
  82  * a specific switch is claimed by userspace in which case it is
  83  * left alone.
  84  */
  85
  86 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
  87 {
  88         struct rfkill *rfkill;
  89
  90         mutex_lock(&rfkill_mutex);
  91
  92         rfkill_states[type] = state;
  93
  94         list_for_each_entry(rfkill, &rfkill_list, node) {
  95                 if (!rfkill->user_claim)
  96                         rfkill_toggle_radio(rfkill, state);
  97         }
  98
  99         mutex_unlock(&rfkill_mutex);
 100 }
 101 EXPORT_SYMBOL(rfkill_switch_all);
 102
 103 static ssize_t rfkill_name_show(struct device *dev,
 104                                 struct device_attribute *attr,
 105                                 char *buf)
 106 {
 107         struct rfkill *rfkill = to_rfkill(dev);
 108
 109         return sprintf(buf, "%s\n", rfkill->name);
 110 }
 111
 112 static ssize_t rfkill_type_show(struct device *dev,
 113                                 struct device_attribute *attr,
 114                                 char *buf)
 115 {
 116         struct rfkill *rfkill = to_rfkill(dev);
 117         const char *type;
 118
 119         switch (rfkill->type) {
 120         case RFKILL_TYPE_WLAN:
 121                 type = "wlan";
 122                 break;
 123         case RFKILL_TYPE_BLUETOOTH:
 124                 type = "bluetooth";
 125                 break;
 126         case RFKILL_TYPE_UWB:
 127                 type = "ultrawideband";
 128                 break;
 129         case RFKILL_TYPE_WIMAX:
 130                 type = "wimax";
 131                 break;
 132         default:
 133                 BUG();
 134         }
 135
 136         return sprintf(buf, "%s\n", type);
 137 }
 138
 139 static ssize_t rfkill_state_show(struct device *dev,
 140                                  struct device_attribute *attr,
 141                                  char *buf)
 142 {
 143         struct rfkill *rfkill = to_rfkill(dev);
 144
 145         return sprintf(buf, "%d\n", rfkill->state);
 146 }
 147
 148 static ssize_t rfkill_state_store(struct device *dev,
 149                                   struct device_attribute *attr,
 150                                   const char *buf, size_t count)
 151 {
 152         struct rfkill *rfkill = to_rfkill(dev);
 153         unsigned int state = simple_strtoul(buf, NULL, 0);
 154         int error;
 155
 156         if (!capable(CAP_NET_ADMIN))
 157                 return -EPERM;
 158
 159         if (mutex_lock_interruptible(&rfkill->mutex))
 160                 return -ERESTARTSYS;
 161         error = rfkill_toggle_radio(rfkill,
 162                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
 163         mutex_unlock(&rfkill->mutex);
 164
 165         return error ? error : count;
 166 }
 167
 168 static ssize_t rfkill_claim_show(struct device *dev,
 169                                  struct device_attribute *attr,
 170                                  char *buf)
 171 {
 172         struct rfkill *rfkill = to_rfkill(dev);
 173
 174         return sprintf(buf, "%d", rfkill->user_claim);
 175 }
 176
 177 static ssize_t rfkill_claim_store(struct device *dev,
 178                                   struct device_attribute *attr,
 179                                   const char *buf, size_t count)
 180 {
 181         struct rfkill *rfkill = to_rfkill(dev);
 182         bool claim = !!simple_strtoul(buf, NULL, 0);
 183         int error;
 184
 185         if (!capable(CAP_NET_ADMIN))
 186                 return -EPERM;
 187
 188         /*
 189          * Take the global lock to make sure the kernel is not in
 190          * the middle of rfkill_switch_all
 191          */
 192         error = mutex_lock_interruptible(&rfkill_mutex);
 193         if (error)
 194                 return error;
 195
 196         if (rfkill->user_claim_unsupported) {
 197                 error = -EOPNOTSUPP;
 198                 goto out_unlock;
 199         }
 200         if (rfkill->user_claim != claim) {
 201                 if (!claim)
 202                         rfkill_toggle_radio(rfkill,
 203                                             rfkill_states[rfkill->type]);
 204                 rfkill->user_claim = claim;
 205         }
 206
 207 out_unlock:
 208         mutex_unlock(&rfkill_mutex);
 209
 210         return error ? error : count;
 211 }
 212
 213 static struct device_attribute rfkill_dev_attrs[] = {
 214         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 215         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 216         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 217         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 218         __ATTR_NULL
 219 };
 220
 221 static void rfkill_release(struct device *dev)
 222 {
 223         struct rfkill *rfkill = to_rfkill(dev);
 224
 225         kfree(rfkill);
 226         module_put(THIS_MODULE);
 227 }
 228
 229 #ifdef CONFIG_PM
 230 static int rfkill_suspend(struct device *dev, pm_message_t state)
 231 {
 232         struct rfkill *rfkill = to_rfkill(dev);
 233
 234         if (dev->power.power_state.event != state.event) {
 235                 if (state.event == PM_EVENT_SUSPEND) {
 236                         mutex_lock(&rfkill->mutex);
 237
 238                         if (rfkill->state == RFKILL_STATE_ON)
 239                                 rfkill->toggle_radio(rfkill->data,
 240                                                      RFKILL_STATE_OFF);
 241
 242                         mutex_unlock(&rfkill->mutex);
 243                 }
 244
 245                 dev->power.power_state = state;
 246         }
 247
 248         return 0;
 249 }
 250
 251 static int rfkill_resume(struct device *dev)
 252 {
 253         struct rfkill *rfkill = to_rfkill(dev);
 254
 255         if (dev->power.power_state.event != PM_EVENT_ON) {
 256                 mutex_lock(&rfkill->mutex);
 257
 258                 if (rfkill->state == RFKILL_STATE_ON)
 259                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
 260
 261                 mutex_unlock(&rfkill->mutex);
 262         }
 263
 264         dev->power.power_state = PMSG_ON;
 265         return 0;
 266 }
 267 #else
 268 #define rfkill_suspend NULL
 269 #define rfkill_resume NULL
 270 #endif
 271
 272 static struct class rfkill_class = {
 273         .name           = "rfkill",
 274         .dev_release    = rfkill_release,
 275         .dev_attrs      = rfkill_dev_attrs,
 276         .suspend        = rfkill_suspend,
 277         .resume         = rfkill_resume,
 278 };
 279
 280 static int rfkill_add_switch(struct rfkill *rfkill)
 281 {
 282         int error;
 283
 284         mutex_lock(&rfkill_mutex);
 285
 286         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
 287         if (!error)
 288                 list_add_tail(&rfkill->node, &rfkill_list);
 289
 290         mutex_unlock(&rfkill_mutex);
 291
 292         return error;
 293 }
 294
 295 static void rfkill_remove_switch(struct rfkill *rfkill)
 296 {
 297         mutex_lock(&rfkill_mutex);
 298         list_del_init(&rfkill->node);
 299         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
 300         mutex_unlock(&rfkill_mutex);
 301 }
 302
 303 /**
 304  * rfkill_allocate - allocate memory for rfkill structure.
 305  * @parent: device that has rf switch on it
 306  * @type: type of the switch (RFKILL_TYPE_*)
 307  *
 308  * This function should be called by the network driver when it needs
 309  * rfkill structure. Once the structure is allocated the driver shoud
 310  * finish its initialization by setting name, private data, enable_radio
 311  * and disable_radio methods and then register it with rfkill_register().
 312  * NOTE: If registration fails the structure shoudl be freed by calling
 313  * rfkill_free() otherwise rfkill_unregister() should be used.
 314  */
 315 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 316 {
 317         struct rfkill *rfkill;
 318         struct device *dev;
 319
 320         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 321         if (!rfkill)
 322                 return NULL;
 323
 324         mutex_init(&rfkill->mutex);
 325         INIT_LIST_HEAD(&rfkill->node);
 326         rfkill->type = type;
 327
 328         dev = &rfkill->dev;
 329         dev->class = &rfkill_class;
 330         dev->parent = parent;
 331         device_initialize(dev);
 332
 333         __module_get(THIS_MODULE);
 334
 335         return rfkill;
 336 }
 337 EXPORT_SYMBOL(rfkill_allocate);
 338
 339 /**
 340  * rfkill_free - Mark rfkill structure for deletion
 341  * @rfkill: rfkill structure to be destroyed
 342  *
 343  * Decrements reference count of rfkill structure so it is destoryed.
 344  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 345  */
 346 void rfkill_free(struct rfkill *rfkill)
 347 {
 348         if (rfkill)
 349                 put_device(&rfkill->dev);
 350 }
 351 EXPORT_SYMBOL(rfkill_free);
 352
 353 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 354 {
 355 #ifdef CONFIG_RFKILL_LEDS
 356         int error;
 357
 358         rfkill->led_trigger.name = rfkill->dev.bus_id;
 359         error = led_trigger_register(&rfkill->led_trigger);
 360         if (error)
 361                 rfkill->led_trigger.name = NULL;
 362 #endif /* CONFIG_RFKILL_LEDS */
 363 }
 364
 365 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 366 {
 367 #ifdef CONFIG_RFKILL_LEDS
 368         if (rfkill->led_trigger.name)
 369                 led_trigger_unregister(&rfkill->led_trigger);
 370 #endif
 371 }
 372
 373 /**
 374  * rfkill_register - Register a rfkill structure.
 375  * @rfkill: rfkill structure to be registered
 376  *
 377  * This function should be called by the network driver when the rfkill
 378  * structure needs to be registered. Immediately from registration the
 379  * switch driver should be able to service calls to toggle_radio.
 380  */
 381 int rfkill_register(struct rfkill *rfkill)
 382 {
 383         static atomic_t rfkill_no = ATOMIC_INIT(0);
 384         struct device *dev = &rfkill->dev;
 385         int error;
 386
 387         if (!rfkill->toggle_radio)
 388                 return -EINVAL;
 389         if (rfkill->type >= RFKILL_TYPE_MAX)
 390                 return -EINVAL;
 391
 392         snprintf(dev->bus_id, sizeof(dev->bus_id),
 393                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 394
 395         rfkill_led_trigger_register(rfkill);
 396
 397         error = rfkill_add_switch(rfkill);
 398         if (error) {
 399                 rfkill_led_trigger_unregister(rfkill);
 400                 return error;
 401         }
 402
 403         error = device_add(dev);
 404         if (error) {
 405                 rfkill_led_trigger_unregister(rfkill);
 406                 rfkill_remove_switch(rfkill);
 407                 return error;
 408         }
 409
 410         return 0;
 411 }
 412 EXPORT_SYMBOL(rfkill_register);
 413
 414 /**
 415  * rfkill_unregister - Uegister a rfkill structure.
 416  * @rfkill: rfkill structure to be unregistered
 417  *
 418  * This function should be called by the network driver during device
 419  * teardown to destroy rfkill structure. Note that rfkill_free() should
 420  * _not_ be called after rfkill_unregister().
 421  */
 422 void rfkill_unregister(struct rfkill *rfkill)
 423 {
 424         device_del(&rfkill->dev);
 425         rfkill_remove_switch(rfkill);
 426         rfkill_led_trigger_unregister(rfkill);
 427         put_device(&rfkill->dev);
 428 }
 429 EXPORT_SYMBOL(rfkill_unregister);
 430
 431 /*
 432  * Rfkill module initialization/deinitialization.
 433  */
 434 static int __init rfkill_init(void)
 435 {
 436         int error;
 437         int i;
 438
 439         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 440                 rfkill_states[i] = RFKILL_STATE_ON;
 441
 442         error = class_register(&rfkill_class);
 443         if (error) {
 444                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 445                 return error;
 446         }
 447
 448         return 0;
 449 }
 450
 451 static void __exit rfkill_exit(void)
 452 {
 453         class_unregister(&rfkill_class);
 454 }
 455
 456 subsys_initcall(rfkill_init);
 457 module_exit(rfkill_exit);