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