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         default:
 130                 BUG();
 131         }
 132
 133         return sprintf(buf, "%s\n", type);
 134 }
 135
 136 static ssize_t rfkill_state_show(struct device *dev,
 137                                  struct device_attribute *attr,
 138                                  char *buf)
 139 {
 140         struct rfkill *rfkill = to_rfkill(dev);
 141
 142         return sprintf(buf, "%d\n", rfkill->state);
 143 }
 144
 145 static ssize_t rfkill_state_store(struct device *dev,
 146                                   struct device_attribute *attr,
 147                                   const char *buf, size_t count)
 148 {
 149         struct rfkill *rfkill = to_rfkill(dev);
 150         unsigned int state = simple_strtoul(buf, NULL, 0);
 151         int error;
 152
 153         if (!capable(CAP_NET_ADMIN))
 154                 return -EPERM;
 155
 156         if (mutex_lock_interruptible(&rfkill->mutex))
 157                 return -ERESTARTSYS;
 158         error = rfkill_toggle_radio(rfkill,
 159                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
 160         mutex_unlock(&rfkill->mutex);
 161
 162         return error ? error : 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_unsupported) {
 194                 error = -EOPNOTSUPP;
 195                 goto out_unlock;
 196         }
 197         if (rfkill->user_claim != claim) {
 198                 if (!claim)
 199                         rfkill_toggle_radio(rfkill,
 200                                             rfkill_states[rfkill->type]);
 201                 rfkill->user_claim = claim;
 202         }
 203
 204 out_unlock:
 205         mutex_unlock(&rfkill_mutex);
 206
 207         return error ? error : count;
 208 }
 209
 210 static struct device_attribute rfkill_dev_attrs[] = {
 211         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
 212         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
 213         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
 214         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
 215         __ATTR_NULL
 216 };
 217
 218 static void rfkill_release(struct device *dev)
 219 {
 220         struct rfkill *rfkill = to_rfkill(dev);
 221
 222         kfree(rfkill);
 223         module_put(THIS_MODULE);
 224 }
 225
 226 #ifdef CONFIG_PM
 227 static int rfkill_suspend(struct device *dev, pm_message_t state)
 228 {
 229         struct rfkill *rfkill = to_rfkill(dev);
 230
 231         if (dev->power.power_state.event != state.event) {
 232                 if (state.event == PM_EVENT_SUSPEND) {
 233                         mutex_lock(&rfkill->mutex);
 234
 235                         if (rfkill->state == RFKILL_STATE_ON)
 236                                 rfkill->toggle_radio(rfkill->data,
 237                                                      RFKILL_STATE_OFF);
 238
 239                         mutex_unlock(&rfkill->mutex);
 240                 }
 241
 242                 dev->power.power_state = state;
 243         }
 244
 245         return 0;
 246 }
 247
 248 static int rfkill_resume(struct device *dev)
 249 {
 250         struct rfkill *rfkill = to_rfkill(dev);
 251
 252         if (dev->power.power_state.event != PM_EVENT_ON) {
 253                 mutex_lock(&rfkill->mutex);
 254
 255                 if (rfkill->state == RFKILL_STATE_ON)
 256                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
 257
 258                 mutex_unlock(&rfkill->mutex);
 259         }
 260
 261         dev->power.power_state = PMSG_ON;
 262         return 0;
 263 }
 264 #else
 265 #define rfkill_suspend NULL
 266 #define rfkill_resume NULL
 267 #endif
 268
 269 static struct class rfkill_class = {
 270         .name           = "rfkill",
 271         .dev_release    = rfkill_release,
 272         .dev_attrs      = rfkill_dev_attrs,
 273         .suspend        = rfkill_suspend,
 274         .resume         = rfkill_resume,
 275 };
 276
 277 static int rfkill_add_switch(struct rfkill *rfkill)
 278 {
 279         int error;
 280
 281         mutex_lock(&rfkill_mutex);
 282
 283         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
 284         if (!error)
 285                 list_add_tail(&rfkill->node, &rfkill_list);
 286
 287         mutex_unlock(&rfkill_mutex);
 288
 289         return error;
 290 }
 291
 292 static void rfkill_remove_switch(struct rfkill *rfkill)
 293 {
 294         mutex_lock(&rfkill_mutex);
 295         list_del_init(&rfkill->node);
 296         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
 297         mutex_unlock(&rfkill_mutex);
 298 }
 299
 300 /**
 301  * rfkill_allocate - allocate memory for rfkill structure.
 302  * @parent: device that has rf switch on it
 303  * @type: type of the switch (RFKILL_TYPE_*)
 304  *
 305  * This function should be called by the network driver when it needs
 306  * rfkill structure. Once the structure is allocated the driver shoud
 307  * finish its initialization by setting name, private data, enable_radio
 308  * and disable_radio methods and then register it with rfkill_register().
 309  * NOTE: If registration fails the structure shoudl be freed by calling
 310  * rfkill_free() otherwise rfkill_unregister() should be used.
 311  */
 312 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
 313 {
 314         struct rfkill *rfkill;
 315         struct device *dev;
 316
 317         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 318         if (!rfkill)
 319                 return NULL;
 320
 321         mutex_init(&rfkill->mutex);
 322         INIT_LIST_HEAD(&rfkill->node);
 323         rfkill->type = type;
 324
 325         dev = &rfkill->dev;
 326         dev->class = &rfkill_class;
 327         dev->parent = parent;
 328         device_initialize(dev);
 329
 330         __module_get(THIS_MODULE);
 331
 332         return rfkill;
 333 }
 334 EXPORT_SYMBOL(rfkill_allocate);
 335
 336 /**
 337  * rfkill_free - Mark rfkill structure for deletion
 338  * @rfkill: rfkill structure to be destroyed
 339  *
 340  * Decrements reference count of rfkill structure so it is destoryed.
 341  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 342  */
 343 void rfkill_free(struct rfkill *rfkill)
 344 {
 345         if (rfkill)
 346                 put_device(&rfkill->dev);
 347 }
 348 EXPORT_SYMBOL(rfkill_free);
 349
 350 static void rfkill_led_trigger_register(struct rfkill *rfkill)
 351 {
 352 #ifdef CONFIG_RFKILL_LEDS
 353         int error;
 354
 355         rfkill->led_trigger.name = rfkill->dev.bus_id;
 356         error = led_trigger_register(&rfkill->led_trigger);
 357         if (error)
 358                 rfkill->led_trigger.name = NULL;
 359 #endif /* CONFIG_RFKILL_LEDS */
 360 }
 361
 362 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 363 {
 364 #ifdef CONFIG_RFKILL_LEDS
 365         if (rfkill->led_trigger.name)
 366                 led_trigger_unregister(&rfkill->led_trigger);
 367 #endif
 368 }
 369
 370 /**
 371  * rfkill_register - Register a rfkill structure.
 372  * @rfkill: rfkill structure to be registered
 373  *
 374  * This function should be called by the network driver when the rfkill
 375  * structure needs to be registered. Immediately from registration the
 376  * switch driver should be able to service calls to toggle_radio.
 377  */
 378 int rfkill_register(struct rfkill *rfkill)
 379 {
 380         static atomic_t rfkill_no = ATOMIC_INIT(0);
 381         struct device *dev = &rfkill->dev;
 382         int error;
 383
 384         if (!rfkill->toggle_radio)
 385                 return -EINVAL;
 386         if (rfkill->type >= RFKILL_TYPE_MAX)
 387                 return -EINVAL;
 388
 389         snprintf(dev->bus_id, sizeof(dev->bus_id),
 390                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
 391
 392         rfkill_led_trigger_register(rfkill);
 393
 394         error = rfkill_add_switch(rfkill);
 395         if (error) {
 396                 rfkill_led_trigger_unregister(rfkill);
 397                 return error;
 398         }
 399
 400         error = device_add(dev);
 401         if (error) {
 402                 rfkill_led_trigger_unregister(rfkill);
 403                 rfkill_remove_switch(rfkill);
 404                 return error;
 405         }
 406
 407         return 0;
 408 }
 409 EXPORT_SYMBOL(rfkill_register);
 410
 411 /**
 412  * rfkill_unregister - Uegister a rfkill structure.
 413  * @rfkill: rfkill structure to be unregistered
 414  *
 415  * This function should be called by the network driver during device
 416  * teardown to destroy rfkill structure. Note that rfkill_free() should
 417  * _not_ be called after rfkill_unregister().
 418  */
 419 void rfkill_unregister(struct rfkill *rfkill)
 420 {
 421         device_del(&rfkill->dev);
 422         rfkill_remove_switch(rfkill);
 423         rfkill_led_trigger_unregister(rfkill);
 424         put_device(&rfkill->dev);
 425 }
 426 EXPORT_SYMBOL(rfkill_unregister);
 427
 428 /*
 429  * Rfkill module initialization/deinitialization.
 430  */
 431 static int __init rfkill_init(void)
 432 {
 433         int error;
 434         int i;
 435
 436         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
 437                 rfkill_states[i] = RFKILL_STATE_ON;
 438
 439         error = class_register(&rfkill_class);
 440         if (error) {
 441                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
 442                 return error;
 443         }
 444
 445         return 0;
 446 }
 447
 448 static void __exit rfkill_exit(void)
 449 {
 450         class_unregister(&rfkill_class);
 451 }
 452
 453 subsys_initcall(rfkill_init);
 454 module_exit(rfkill_exit);