rfkill: remove transmitter blocking on suspend
[linux-2.6.git] / 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_global_mutex);
41
42 static unsigned int rfkill_default_state = RFKILL_STATE_UNBLOCKED;
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 struct rfkill_gsw_state {
48         enum rfkill_state current_state;
49         enum rfkill_state default_state;
50 };
51
52 static struct rfkill_gsw_state rfkill_global_states[RFKILL_TYPE_MAX];
53 static unsigned long rfkill_states_lockdflt[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
54
55 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
56
57
58 /**
59  * register_rfkill_notifier - Add notifier to rfkill notifier chain
60  * @nb: pointer to the new entry to add to the chain
61  *
62  * See blocking_notifier_chain_register() for return value and further
63  * observations.
64  *
65  * Adds a notifier to the rfkill notifier chain.  The chain will be
66  * called with a pointer to the relevant rfkill structure as a parameter,
67  * refer to include/linux/rfkill.h for the possible events.
68  *
69  * Notifiers added to this chain are to always return NOTIFY_DONE.  This
70  * chain is a blocking notifier chain: notifiers can sleep.
71  *
72  * Calls to this chain may have been done through a workqueue.  One must
73  * assume unordered asynchronous behaviour, there is no way to know if
74  * actions related to the event that generated the notification have been
75  * carried out already.
76  */
77 int register_rfkill_notifier(struct notifier_block *nb)
78 {
79         BUG_ON(!nb);
80         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
81 }
82 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
83
84 /**
85  * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
86  * @nb: pointer to the entry to remove from the chain
87  *
88  * See blocking_notifier_chain_unregister() for return value and further
89  * observations.
90  *
91  * Removes a notifier from the rfkill notifier chain.
92  */
93 int unregister_rfkill_notifier(struct notifier_block *nb)
94 {
95         BUG_ON(!nb);
96         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
97 }
98 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
99
100
101 static void rfkill_led_trigger(struct rfkill *rfkill,
102                                enum rfkill_state state)
103 {
104 #ifdef CONFIG_RFKILL_LEDS
105         struct led_trigger *led = &rfkill->led_trigger;
106
107         if (!led->name)
108                 return;
109         if (state != RFKILL_STATE_UNBLOCKED)
110                 led_trigger_event(led, LED_OFF);
111         else
112                 led_trigger_event(led, LED_FULL);
113 #endif /* CONFIG_RFKILL_LEDS */
114 }
115
116 #ifdef CONFIG_RFKILL_LEDS
117 static void rfkill_led_trigger_activate(struct led_classdev *led)
118 {
119         struct rfkill *rfkill = container_of(led->trigger,
120                         struct rfkill, led_trigger);
121
122         rfkill_led_trigger(rfkill, rfkill->state);
123 }
124 #endif /* CONFIG_RFKILL_LEDS */
125
126 static void notify_rfkill_state_change(struct rfkill *rfkill)
127 {
128         blocking_notifier_call_chain(&rfkill_notifier_list,
129                         RFKILL_STATE_CHANGED,
130                         rfkill);
131 }
132
133 static void update_rfkill_state(struct rfkill *rfkill)
134 {
135         enum rfkill_state newstate, oldstate;
136
137         if (rfkill->get_state) {
138                 mutex_lock(&rfkill->mutex);
139                 if (!rfkill->get_state(rfkill->data, &newstate)) {
140                         oldstate = rfkill->state;
141                         rfkill->state = newstate;
142                         if (oldstate != newstate)
143                                 notify_rfkill_state_change(rfkill);
144                 }
145                 mutex_unlock(&rfkill->mutex);
146         }
147 }
148
149 /**
150  * rfkill_toggle_radio - wrapper for toggle_radio hook
151  * @rfkill: the rfkill struct to use
152  * @force: calls toggle_radio even if cache says it is not needed,
153  *      and also makes sure notifications of the state will be
154  *      sent even if it didn't change
155  * @state: the new state to call toggle_radio() with
156  *
157  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
158  * calls and handling all the red tape such as issuing notifications
159  * if the call is successful.
160  *
161  * Suspended devices are not touched at all, and -EAGAIN is returned.
162  *
163  * Note that the @force parameter cannot override a (possibly cached)
164  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
165  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
166  * rfkill_force_state(), so the cache either is bypassed or valid.
167  *
168  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
169  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
170  * give the driver a hint that it should double-BLOCK the transmitter.
171  *
172  * Caller must have acquired rfkill->mutex.
173  */
174 static int rfkill_toggle_radio(struct rfkill *rfkill,
175                                 enum rfkill_state state,
176                                 int force)
177 {
178         int retval = 0;
179         enum rfkill_state oldstate, newstate;
180
181         if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
182                 return -EBUSY;
183
184         oldstate = rfkill->state;
185
186         if (rfkill->get_state && !force &&
187             !rfkill->get_state(rfkill->data, &newstate))
188                 rfkill->state = newstate;
189
190         switch (state) {
191         case RFKILL_STATE_HARD_BLOCKED:
192                 /* typically happens when refreshing hardware state,
193                  * such as on resume */
194                 state = RFKILL_STATE_SOFT_BLOCKED;
195                 break;
196         case RFKILL_STATE_UNBLOCKED:
197                 /* force can't override this, only rfkill_force_state() can */
198                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
199                         return -EPERM;
200                 break;
201         case RFKILL_STATE_SOFT_BLOCKED:
202                 /* nothing to do, we want to give drivers the hint to double
203                  * BLOCK even a transmitter that is already in state
204                  * RFKILL_STATE_HARD_BLOCKED */
205                 break;
206         default:
207                 WARN(1, KERN_WARNING
208                         "rfkill: illegal state %d passed as parameter "
209                         "to rfkill_toggle_radio\n", state);
210                 return -EINVAL;
211         }
212
213         if (force || state != rfkill->state) {
214                 retval = rfkill->toggle_radio(rfkill->data, state);
215                 /* never allow a HARD->SOFT downgrade! */
216                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
217                         rfkill->state = state;
218         }
219
220         if (force || rfkill->state != oldstate) {
221                 rfkill_led_trigger(rfkill, rfkill->state);
222                 notify_rfkill_state_change(rfkill);
223         }
224
225         return retval;
226 }
227
228 /**
229  * __rfkill_switch_all - Toggle state of all switches of given type
230  * @type: type of interfaces to be affected
231  * @state: the new state
232  *
233  * This function toggles the state of all switches of given type,
234  * unless a specific switch is claimed by userspace (in which case,
235  * that switch is left alone) or suspended.
236  *
237  * Caller must have acquired rfkill_global_mutex.
238  */
239 static void __rfkill_switch_all(const enum rfkill_type type,
240                                 const enum rfkill_state state)
241 {
242         struct rfkill *rfkill;
243
244         if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
245                         KERN_WARNING
246                         "rfkill: illegal state %d or type %d "
247                         "passed as parameter to __rfkill_switch_all\n",
248                         state, type))
249                 return;
250
251         rfkill_global_states[type].current_state = state;
252         list_for_each_entry(rfkill, &rfkill_list, node) {
253                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
254                         mutex_lock(&rfkill->mutex);
255                         rfkill_toggle_radio(rfkill, state, 0);
256                         mutex_unlock(&rfkill->mutex);
257                 }
258         }
259 }
260
261 /**
262  * rfkill_switch_all - Toggle state of all switches of given type
263  * @type: type of interfaces to be affected
264  * @state: the new state
265  *
266  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
267  * Please refer to __rfkill_switch_all() for details.
268  */
269 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
270 {
271         mutex_lock(&rfkill_global_mutex);
272         __rfkill_switch_all(type, state);
273         mutex_unlock(&rfkill_global_mutex);
274 }
275 EXPORT_SYMBOL(rfkill_switch_all);
276
277 /**
278  * rfkill_epo - emergency power off all transmitters
279  *
280  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
281  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
282  *
283  * The global state before the EPO is saved and can be restored later
284  * using rfkill_restore_states().
285  */
286 void rfkill_epo(void)
287 {
288         struct rfkill *rfkill;
289         int i;
290
291         mutex_lock(&rfkill_global_mutex);
292
293         list_for_each_entry(rfkill, &rfkill_list, node) {
294                 mutex_lock(&rfkill->mutex);
295                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
296                 mutex_unlock(&rfkill->mutex);
297         }
298         for (i = 0; i < RFKILL_TYPE_MAX; i++) {
299                 rfkill_global_states[i].default_state =
300                                 rfkill_global_states[i].current_state;
301                 rfkill_global_states[i].current_state =
302                                 RFKILL_STATE_SOFT_BLOCKED;
303         }
304         mutex_unlock(&rfkill_global_mutex);
305 }
306 EXPORT_SYMBOL_GPL(rfkill_epo);
307
308 /**
309  * rfkill_restore_states - restore global states
310  *
311  * Restore (and sync switches to) the global state from the
312  * states in rfkill_default_states.  This can undo the effects of
313  * a call to rfkill_epo().
314  */
315 void rfkill_restore_states(void)
316 {
317         int i;
318
319         mutex_lock(&rfkill_global_mutex);
320
321         for (i = 0; i < RFKILL_TYPE_MAX; i++)
322                 __rfkill_switch_all(i, rfkill_global_states[i].default_state);
323         mutex_unlock(&rfkill_global_mutex);
324 }
325 EXPORT_SYMBOL_GPL(rfkill_restore_states);
326
327 /**
328  * rfkill_force_state - Force the internal rfkill radio state
329  * @rfkill: pointer to the rfkill class to modify.
330  * @state: the current radio state the class should be forced to.
331  *
332  * This function updates the internal state of the radio cached
333  * by the rfkill class.  It should be used when the driver gets
334  * a notification by the firmware/hardware of the current *real*
335  * state of the radio rfkill switch.
336  *
337  * Devices which are subject to external changes on their rfkill
338  * state (such as those caused by a hardware rfkill line) MUST
339  * have their driver arrange to call rfkill_force_state() as soon
340  * as possible after such a change.
341  *
342  * This function may not be called from an atomic context.
343  */
344 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
345 {
346         enum rfkill_state oldstate;
347
348         BUG_ON(!rfkill);
349         if (WARN((state >= RFKILL_STATE_MAX),
350                         KERN_WARNING
351                         "rfkill: illegal state %d passed as parameter "
352                         "to rfkill_force_state\n", state))
353                 return -EINVAL;
354
355         mutex_lock(&rfkill->mutex);
356
357         oldstate = rfkill->state;
358         rfkill->state = state;
359
360         if (state != oldstate)
361                 notify_rfkill_state_change(rfkill);
362
363         mutex_unlock(&rfkill->mutex);
364
365         return 0;
366 }
367 EXPORT_SYMBOL(rfkill_force_state);
368
369 static ssize_t rfkill_name_show(struct device *dev,
370                                 struct device_attribute *attr,
371                                 char *buf)
372 {
373         struct rfkill *rfkill = to_rfkill(dev);
374
375         return sprintf(buf, "%s\n", rfkill->name);
376 }
377
378 static const char *rfkill_get_type_str(enum rfkill_type type)
379 {
380         switch (type) {
381         case RFKILL_TYPE_WLAN:
382                 return "wlan";
383         case RFKILL_TYPE_BLUETOOTH:
384                 return "bluetooth";
385         case RFKILL_TYPE_UWB:
386                 return "ultrawideband";
387         case RFKILL_TYPE_WIMAX:
388                 return "wimax";
389         case RFKILL_TYPE_WWAN:
390                 return "wwan";
391         default:
392                 BUG();
393         }
394 }
395
396 static ssize_t rfkill_type_show(struct device *dev,
397                                 struct device_attribute *attr,
398                                 char *buf)
399 {
400         struct rfkill *rfkill = to_rfkill(dev);
401
402         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
403 }
404
405 static ssize_t rfkill_state_show(struct device *dev,
406                                  struct device_attribute *attr,
407                                  char *buf)
408 {
409         struct rfkill *rfkill = to_rfkill(dev);
410
411         update_rfkill_state(rfkill);
412         return sprintf(buf, "%d\n", rfkill->state);
413 }
414
415 static ssize_t rfkill_state_store(struct device *dev,
416                                   struct device_attribute *attr,
417                                   const char *buf, size_t count)
418 {
419         struct rfkill *rfkill = to_rfkill(dev);
420         unsigned long state;
421         int error;
422
423         if (!capable(CAP_NET_ADMIN))
424                 return -EPERM;
425
426         error = strict_strtoul(buf, 0, &state);
427         if (error)
428                 return error;
429
430         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
431         if (state != RFKILL_STATE_UNBLOCKED &&
432             state != RFKILL_STATE_SOFT_BLOCKED)
433                 return -EINVAL;
434
435         if (mutex_lock_interruptible(&rfkill->mutex))
436                 return -ERESTARTSYS;
437         error = rfkill_toggle_radio(rfkill, state, 0);
438         mutex_unlock(&rfkill->mutex);
439
440         return error ? error : count;
441 }
442
443 static ssize_t rfkill_claim_show(struct device *dev,
444                                  struct device_attribute *attr,
445                                  char *buf)
446 {
447         struct rfkill *rfkill = to_rfkill(dev);
448
449         return sprintf(buf, "%d\n", rfkill->user_claim);
450 }
451
452 static ssize_t rfkill_claim_store(struct device *dev,
453                                   struct device_attribute *attr,
454                                   const char *buf, size_t count)
455 {
456         struct rfkill *rfkill = to_rfkill(dev);
457         unsigned long claim_tmp;
458         bool claim;
459         int error;
460
461         if (!capable(CAP_NET_ADMIN))
462                 return -EPERM;
463
464         if (rfkill->user_claim_unsupported)
465                 return -EOPNOTSUPP;
466
467         error = strict_strtoul(buf, 0, &claim_tmp);
468         if (error)
469                 return error;
470         claim = !!claim_tmp;
471
472         /*
473          * Take the global lock to make sure the kernel is not in
474          * the middle of rfkill_switch_all
475          */
476         error = mutex_lock_interruptible(&rfkill_global_mutex);
477         if (error)
478                 return error;
479
480         if (rfkill->user_claim != claim) {
481                 if (!claim) {
482                         mutex_lock(&rfkill->mutex);
483                         rfkill_toggle_radio(rfkill,
484                                         rfkill_global_states[rfkill->type].current_state,
485                                         0);
486                         mutex_unlock(&rfkill->mutex);
487                 }
488                 rfkill->user_claim = claim;
489         }
490
491         mutex_unlock(&rfkill_global_mutex);
492
493         return error ? error : count;
494 }
495
496 static struct device_attribute rfkill_dev_attrs[] = {
497         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
498         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
499         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
500         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
501         __ATTR_NULL
502 };
503
504 static void rfkill_release(struct device *dev)
505 {
506         struct rfkill *rfkill = to_rfkill(dev);
507
508         kfree(rfkill);
509         module_put(THIS_MODULE);
510 }
511
512 #ifdef CONFIG_PM
513 static int rfkill_suspend(struct device *dev, pm_message_t state)
514 {
515         /* mark class device as suspended */
516         if (dev->power.power_state.event != state.event)
517                 dev->power.power_state = state;
518
519         return 0;
520 }
521
522 static int rfkill_resume(struct device *dev)
523 {
524         struct rfkill *rfkill = to_rfkill(dev);
525
526         if (dev->power.power_state.event != PM_EVENT_ON) {
527                 mutex_lock(&rfkill->mutex);
528
529                 dev->power.power_state.event = PM_EVENT_ON;
530
531                 /* restore radio state AND notify everybody */
532                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
533
534                 mutex_unlock(&rfkill->mutex);
535         }
536
537         return 0;
538 }
539 #else
540 #define rfkill_suspend NULL
541 #define rfkill_resume NULL
542 #endif
543
544 static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
545                                         unsigned long eventid,
546                                         void *data)
547 {
548         struct rfkill *rfkill = (struct rfkill *)data;
549
550         switch (eventid) {
551         case RFKILL_STATE_CHANGED:
552                 kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
553                 break;
554         default:
555                 break;
556         }
557
558         return NOTIFY_DONE;
559 }
560
561 static struct notifier_block rfkill_blocking_uevent_nb = {
562         .notifier_call  = rfkill_blocking_uevent_notifier,
563         .priority       = 0,
564 };
565
566 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
567 {
568         struct rfkill *rfkill = to_rfkill(dev);
569         int error;
570
571         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
572         if (error)
573                 return error;
574         error = add_uevent_var(env, "RFKILL_TYPE=%s",
575                                 rfkill_get_type_str(rfkill->type));
576         if (error)
577                 return error;
578         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
579         return error;
580 }
581
582 static struct class rfkill_class = {
583         .name           = "rfkill",
584         .dev_release    = rfkill_release,
585         .dev_attrs      = rfkill_dev_attrs,
586         .suspend        = rfkill_suspend,
587         .resume         = rfkill_resume,
588         .dev_uevent     = rfkill_dev_uevent,
589 };
590
591 static int rfkill_check_duplicity(const struct rfkill *rfkill)
592 {
593         struct rfkill *p;
594         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
595
596         memset(seen, 0, sizeof(seen));
597
598         list_for_each_entry(p, &rfkill_list, node) {
599                 if (WARN((p == rfkill), KERN_WARNING
600                                 "rfkill: illegal attempt to register "
601                                 "an already registered rfkill struct\n"))
602                         return -EEXIST;
603                 set_bit(p->type, seen);
604         }
605
606         /* 0: first switch of its kind */
607         return test_bit(rfkill->type, seen);
608 }
609
610 static int rfkill_add_switch(struct rfkill *rfkill)
611 {
612         int error;
613
614         mutex_lock(&rfkill_global_mutex);
615
616         error = rfkill_check_duplicity(rfkill);
617         if (error < 0)
618                 goto unlock_out;
619
620         if (!error) {
621                 /* lock default after first use */
622                 set_bit(rfkill->type, rfkill_states_lockdflt);
623                 rfkill_global_states[rfkill->type].current_state =
624                         rfkill_global_states[rfkill->type].default_state;
625         }
626
627         rfkill_toggle_radio(rfkill,
628                             rfkill_global_states[rfkill->type].current_state,
629                             0);
630
631         list_add_tail(&rfkill->node, &rfkill_list);
632
633         error = 0;
634 unlock_out:
635         mutex_unlock(&rfkill_global_mutex);
636
637         return error;
638 }
639
640 static void rfkill_remove_switch(struct rfkill *rfkill)
641 {
642         mutex_lock(&rfkill_global_mutex);
643         list_del_init(&rfkill->node);
644         mutex_unlock(&rfkill_global_mutex);
645
646         mutex_lock(&rfkill->mutex);
647         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
648         mutex_unlock(&rfkill->mutex);
649 }
650
651 /**
652  * rfkill_allocate - allocate memory for rfkill structure.
653  * @parent: device that has rf switch on it
654  * @type: type of the switch (RFKILL_TYPE_*)
655  *
656  * This function should be called by the network driver when it needs
657  * rfkill structure.  Once the structure is allocated the driver should
658  * finish its initialization by setting the name, private data, enable_radio
659  * and disable_radio methods and then register it with rfkill_register().
660  *
661  * NOTE: If registration fails the structure shoudl be freed by calling
662  * rfkill_free() otherwise rfkill_unregister() should be used.
663  */
664 struct rfkill * __must_check rfkill_allocate(struct device *parent,
665                                              enum rfkill_type type)
666 {
667         struct rfkill *rfkill;
668         struct device *dev;
669
670         if (WARN((type >= RFKILL_TYPE_MAX),
671                         KERN_WARNING
672                         "rfkill: illegal type %d passed as parameter "
673                         "to rfkill_allocate\n", type))
674                 return NULL;
675
676         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
677         if (!rfkill)
678                 return NULL;
679
680         mutex_init(&rfkill->mutex);
681         INIT_LIST_HEAD(&rfkill->node);
682         rfkill->type = type;
683
684         dev = &rfkill->dev;
685         dev->class = &rfkill_class;
686         dev->parent = parent;
687         device_initialize(dev);
688
689         __module_get(THIS_MODULE);
690
691         return rfkill;
692 }
693 EXPORT_SYMBOL(rfkill_allocate);
694
695 /**
696  * rfkill_free - Mark rfkill structure for deletion
697  * @rfkill: rfkill structure to be destroyed
698  *
699  * Decrements reference count of the rfkill structure so it is destroyed.
700  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
701  */
702 void rfkill_free(struct rfkill *rfkill)
703 {
704         if (rfkill)
705                 put_device(&rfkill->dev);
706 }
707 EXPORT_SYMBOL(rfkill_free);
708
709 static void rfkill_led_trigger_register(struct rfkill *rfkill)
710 {
711 #ifdef CONFIG_RFKILL_LEDS
712         int error;
713
714         if (!rfkill->led_trigger.name)
715                 rfkill->led_trigger.name = rfkill->dev.bus_id;
716         if (!rfkill->led_trigger.activate)
717                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
718         error = led_trigger_register(&rfkill->led_trigger);
719         if (error)
720                 rfkill->led_trigger.name = NULL;
721 #endif /* CONFIG_RFKILL_LEDS */
722 }
723
724 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
725 {
726 #ifdef CONFIG_RFKILL_LEDS
727         if (rfkill->led_trigger.name) {
728                 led_trigger_unregister(&rfkill->led_trigger);
729                 rfkill->led_trigger.name = NULL;
730         }
731 #endif
732 }
733
734 /**
735  * rfkill_register - Register a rfkill structure.
736  * @rfkill: rfkill structure to be registered
737  *
738  * This function should be called by the network driver when the rfkill
739  * structure needs to be registered. Immediately from registration the
740  * switch driver should be able to service calls to toggle_radio.
741  */
742 int __must_check rfkill_register(struct rfkill *rfkill)
743 {
744         static atomic_t rfkill_no = ATOMIC_INIT(0);
745         struct device *dev = &rfkill->dev;
746         int error;
747
748         if (WARN((!rfkill || !rfkill->toggle_radio ||
749                         rfkill->type >= RFKILL_TYPE_MAX ||
750                         rfkill->state >= RFKILL_STATE_MAX),
751                         KERN_WARNING
752                         "rfkill: attempt to register a "
753                         "badly initialized rfkill struct\n"))
754                 return -EINVAL;
755
756         snprintf(dev->bus_id, sizeof(dev->bus_id),
757                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
758
759         rfkill_led_trigger_register(rfkill);
760
761         error = rfkill_add_switch(rfkill);
762         if (error) {
763                 rfkill_led_trigger_unregister(rfkill);
764                 return error;
765         }
766
767         error = device_add(dev);
768         if (error) {
769                 rfkill_remove_switch(rfkill);
770                 rfkill_led_trigger_unregister(rfkill);
771                 return error;
772         }
773
774         return 0;
775 }
776 EXPORT_SYMBOL(rfkill_register);
777
778 /**
779  * rfkill_unregister - Unregister a rfkill structure.
780  * @rfkill: rfkill structure to be unregistered
781  *
782  * This function should be called by the network driver during device
783  * teardown to destroy rfkill structure. Note that rfkill_free() should
784  * _not_ be called after rfkill_unregister().
785  */
786 void rfkill_unregister(struct rfkill *rfkill)
787 {
788         BUG_ON(!rfkill);
789         device_del(&rfkill->dev);
790         rfkill_remove_switch(rfkill);
791         rfkill_led_trigger_unregister(rfkill);
792         put_device(&rfkill->dev);
793 }
794 EXPORT_SYMBOL(rfkill_unregister);
795
796 /**
797  * rfkill_set_default - set initial value for a switch type
798  * @type - the type of switch to set the default state of
799  * @state - the new default state for that group of switches
800  *
801  * Sets the initial state rfkill should use for a given type.
802  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
803  * and RFKILL_STATE_UNBLOCKED.
804  *
805  * This function is meant to be used by platform drivers for platforms
806  * that can save switch state across power down/reboot.
807  *
808  * The default state for each switch type can be changed exactly once.
809  * After a switch of that type is registered, the default state cannot
810  * be changed anymore.  This guards against multiple drivers it the
811  * same platform trying to set the initial switch default state, which
812  * is not allowed.
813  *
814  * Returns -EPERM if the state has already been set once or is in use,
815  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
816  * if this function returns -EPERM.
817  *
818  * Returns 0 if the new default state was set, or an error if it
819  * could not be set.
820  */
821 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
822 {
823         int error;
824
825         if (WARN((type >= RFKILL_TYPE_MAX ||
826                         (state != RFKILL_STATE_SOFT_BLOCKED &&
827                          state != RFKILL_STATE_UNBLOCKED)),
828                         KERN_WARNING
829                         "rfkill: illegal state %d or type %d passed as "
830                         "parameter to rfkill_set_default\n", state, type))
831                 return -EINVAL;
832
833         mutex_lock(&rfkill_global_mutex);
834
835         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
836                 rfkill_global_states[type].default_state = state;
837                 error = 0;
838         } else
839                 error = -EPERM;
840
841         mutex_unlock(&rfkill_global_mutex);
842         return error;
843 }
844 EXPORT_SYMBOL_GPL(rfkill_set_default);
845
846 /*
847  * Rfkill module initialization/deinitialization.
848  */
849 static int __init rfkill_init(void)
850 {
851         int error;
852         int i;
853
854         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
855         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
856             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
857                 return -EINVAL;
858
859         for (i = 0; i < RFKILL_TYPE_MAX; i++)
860                 rfkill_global_states[i].default_state = rfkill_default_state;
861
862         error = class_register(&rfkill_class);
863         if (error) {
864                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
865                 return error;
866         }
867
868         register_rfkill_notifier(&rfkill_blocking_uevent_nb);
869
870         return 0;
871 }
872
873 static void __exit rfkill_exit(void)
874 {
875         unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
876         class_unregister(&rfkill_class);
877 }
878
879 subsys_initcall(rfkill_init);
880 module_exit(rfkill_exit);