Merge branch 'linus' into stackprotector
[linux-2.6] / 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 static bool rfkill_epo_lock_active;
55
56
57 static void rfkill_led_trigger(struct rfkill *rfkill,
58                                enum rfkill_state state)
59 {
60 #ifdef CONFIG_RFKILL_LEDS
61         struct led_trigger *led = &rfkill->led_trigger;
62
63         if (!led->name)
64                 return;
65         if (state != RFKILL_STATE_UNBLOCKED)
66                 led_trigger_event(led, LED_OFF);
67         else
68                 led_trigger_event(led, LED_FULL);
69 #endif /* CONFIG_RFKILL_LEDS */
70 }
71
72 #ifdef CONFIG_RFKILL_LEDS
73 static void rfkill_led_trigger_activate(struct led_classdev *led)
74 {
75         struct rfkill *rfkill = container_of(led->trigger,
76                         struct rfkill, led_trigger);
77
78         rfkill_led_trigger(rfkill, rfkill->state);
79 }
80 #endif /* CONFIG_RFKILL_LEDS */
81
82 static void rfkill_uevent(struct rfkill *rfkill)
83 {
84         kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
85 }
86
87 static void update_rfkill_state(struct rfkill *rfkill)
88 {
89         enum rfkill_state newstate, oldstate;
90
91         if (rfkill->get_state) {
92                 mutex_lock(&rfkill->mutex);
93                 if (!rfkill->get_state(rfkill->data, &newstate)) {
94                         oldstate = rfkill->state;
95                         rfkill->state = newstate;
96                         if (oldstate != newstate)
97                                 rfkill_uevent(rfkill);
98                 }
99                 mutex_unlock(&rfkill->mutex);
100         }
101 }
102
103 /**
104  * rfkill_toggle_radio - wrapper for toggle_radio hook
105  * @rfkill: the rfkill struct to use
106  * @force: calls toggle_radio even if cache says it is not needed,
107  *      and also makes sure notifications of the state will be
108  *      sent even if it didn't change
109  * @state: the new state to call toggle_radio() with
110  *
111  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
112  * calls and handling all the red tape such as issuing notifications
113  * if the call is successful.
114  *
115  * Suspended devices are not touched at all, and -EAGAIN is returned.
116  *
117  * Note that the @force parameter cannot override a (possibly cached)
118  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
119  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
120  * rfkill_force_state(), so the cache either is bypassed or valid.
121  *
122  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
123  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
124  * give the driver a hint that it should double-BLOCK the transmitter.
125  *
126  * Caller must have acquired rfkill->mutex.
127  */
128 static int rfkill_toggle_radio(struct rfkill *rfkill,
129                                 enum rfkill_state state,
130                                 int force)
131 {
132         int retval = 0;
133         enum rfkill_state oldstate, newstate;
134
135         if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
136                 return -EBUSY;
137
138         oldstate = rfkill->state;
139
140         if (rfkill->get_state && !force &&
141             !rfkill->get_state(rfkill->data, &newstate))
142                 rfkill->state = newstate;
143
144         switch (state) {
145         case RFKILL_STATE_HARD_BLOCKED:
146                 /* typically happens when refreshing hardware state,
147                  * such as on resume */
148                 state = RFKILL_STATE_SOFT_BLOCKED;
149                 break;
150         case RFKILL_STATE_UNBLOCKED:
151                 /* force can't override this, only rfkill_force_state() can */
152                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
153                         return -EPERM;
154                 break;
155         case RFKILL_STATE_SOFT_BLOCKED:
156                 /* nothing to do, we want to give drivers the hint to double
157                  * BLOCK even a transmitter that is already in state
158                  * RFKILL_STATE_HARD_BLOCKED */
159                 break;
160         default:
161                 WARN(1, KERN_WARNING
162                         "rfkill: illegal state %d passed as parameter "
163                         "to rfkill_toggle_radio\n", state);
164                 return -EINVAL;
165         }
166
167         if (force || state != rfkill->state) {
168                 retval = rfkill->toggle_radio(rfkill->data, state);
169                 /* never allow a HARD->SOFT downgrade! */
170                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
171                         rfkill->state = state;
172         }
173
174         if (force || rfkill->state != oldstate)
175                 rfkill_uevent(rfkill);
176
177         return retval;
178 }
179
180 /**
181  * __rfkill_switch_all - Toggle state of all switches of given type
182  * @type: type of interfaces to be affected
183  * @state: the new state
184  *
185  * This function toggles the state of all switches of given type,
186  * unless a specific switch is claimed by userspace (in which case,
187  * that switch is left alone) or suspended.
188  *
189  * Caller must have acquired rfkill_global_mutex.
190  */
191 static void __rfkill_switch_all(const enum rfkill_type type,
192                                 const enum rfkill_state state)
193 {
194         struct rfkill *rfkill;
195
196         if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
197                         KERN_WARNING
198                         "rfkill: illegal state %d or type %d "
199                         "passed as parameter to __rfkill_switch_all\n",
200                         state, type))
201                 return;
202
203         rfkill_global_states[type].current_state = state;
204         list_for_each_entry(rfkill, &rfkill_list, node) {
205                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
206                         mutex_lock(&rfkill->mutex);
207                         rfkill_toggle_radio(rfkill, state, 0);
208                         mutex_unlock(&rfkill->mutex);
209                 }
210         }
211 }
212
213 /**
214  * rfkill_switch_all - Toggle state of all switches of given type
215  * @type: type of interfaces to be affected
216  * @state: the new state
217  *
218  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
219  * Please refer to __rfkill_switch_all() for details.
220  *
221  * Does nothing if the EPO lock is active.
222  */
223 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
224 {
225         mutex_lock(&rfkill_global_mutex);
226         if (!rfkill_epo_lock_active)
227                 __rfkill_switch_all(type, state);
228         mutex_unlock(&rfkill_global_mutex);
229 }
230 EXPORT_SYMBOL(rfkill_switch_all);
231
232 /**
233  * rfkill_epo - emergency power off all transmitters
234  *
235  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
236  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
237  *
238  * The global state before the EPO is saved and can be restored later
239  * using rfkill_restore_states().
240  */
241 void rfkill_epo(void)
242 {
243         struct rfkill *rfkill;
244         int i;
245
246         mutex_lock(&rfkill_global_mutex);
247
248         rfkill_epo_lock_active = true;
249         list_for_each_entry(rfkill, &rfkill_list, node) {
250                 mutex_lock(&rfkill->mutex);
251                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
252                 mutex_unlock(&rfkill->mutex);
253         }
254         for (i = 0; i < RFKILL_TYPE_MAX; i++) {
255                 rfkill_global_states[i].default_state =
256                                 rfkill_global_states[i].current_state;
257                 rfkill_global_states[i].current_state =
258                                 RFKILL_STATE_SOFT_BLOCKED;
259         }
260         mutex_unlock(&rfkill_global_mutex);
261 }
262 EXPORT_SYMBOL_GPL(rfkill_epo);
263
264 /**
265  * rfkill_restore_states - restore global states
266  *
267  * Restore (and sync switches to) the global state from the
268  * states in rfkill_default_states.  This can undo the effects of
269  * a call to rfkill_epo().
270  */
271 void rfkill_restore_states(void)
272 {
273         int i;
274
275         mutex_lock(&rfkill_global_mutex);
276
277         rfkill_epo_lock_active = false;
278         for (i = 0; i < RFKILL_TYPE_MAX; i++)
279                 __rfkill_switch_all(i, rfkill_global_states[i].default_state);
280         mutex_unlock(&rfkill_global_mutex);
281 }
282 EXPORT_SYMBOL_GPL(rfkill_restore_states);
283
284 /**
285  * rfkill_remove_epo_lock - unlock state changes
286  *
287  * Used by rfkill-input manually unlock state changes, when
288  * the EPO switch is deactivated.
289  */
290 void rfkill_remove_epo_lock(void)
291 {
292         mutex_lock(&rfkill_global_mutex);
293         rfkill_epo_lock_active = false;
294         mutex_unlock(&rfkill_global_mutex);
295 }
296 EXPORT_SYMBOL_GPL(rfkill_remove_epo_lock);
297
298 /**
299  * rfkill_is_epo_lock_active - returns true EPO is active
300  *
301  * Returns 0 (false) if there is NOT an active EPO contidion,
302  * and 1 (true) if there is an active EPO contition, which
303  * locks all radios in one of the BLOCKED states.
304  *
305  * Can be called in atomic context.
306  */
307 bool rfkill_is_epo_lock_active(void)
308 {
309         return rfkill_epo_lock_active;
310 }
311 EXPORT_SYMBOL_GPL(rfkill_is_epo_lock_active);
312
313 /**
314  * rfkill_get_global_state - returns global state for a type
315  * @type: the type to get the global state of
316  *
317  * Returns the current global state for a given wireless
318  * device type.
319  */
320 enum rfkill_state rfkill_get_global_state(const enum rfkill_type type)
321 {
322         return rfkill_global_states[type].current_state;
323 }
324 EXPORT_SYMBOL_GPL(rfkill_get_global_state);
325
326 /**
327  * rfkill_force_state - Force the internal rfkill radio state
328  * @rfkill: pointer to the rfkill class to modify.
329  * @state: the current radio state the class should be forced to.
330  *
331  * This function updates the internal state of the radio cached
332  * by the rfkill class.  It should be used when the driver gets
333  * a notification by the firmware/hardware of the current *real*
334  * state of the radio rfkill switch.
335  *
336  * Devices which are subject to external changes on their rfkill
337  * state (such as those caused by a hardware rfkill line) MUST
338  * have their driver arrange to call rfkill_force_state() as soon
339  * as possible after such a change.
340  *
341  * This function may not be called from an atomic context.
342  */
343 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
344 {
345         enum rfkill_state oldstate;
346
347         BUG_ON(!rfkill);
348         if (WARN((state >= RFKILL_STATE_MAX),
349                         KERN_WARNING
350                         "rfkill: illegal state %d passed as parameter "
351                         "to rfkill_force_state\n", state))
352                 return -EINVAL;
353
354         mutex_lock(&rfkill->mutex);
355
356         oldstate = rfkill->state;
357         rfkill->state = state;
358
359         if (state != oldstate)
360                 rfkill_uevent(rfkill);
361
362         mutex_unlock(&rfkill->mutex);
363
364         return 0;
365 }
366 EXPORT_SYMBOL(rfkill_force_state);
367
368 static ssize_t rfkill_name_show(struct device *dev,
369                                 struct device_attribute *attr,
370                                 char *buf)
371 {
372         struct rfkill *rfkill = to_rfkill(dev);
373
374         return sprintf(buf, "%s\n", rfkill->name);
375 }
376
377 static const char *rfkill_get_type_str(enum rfkill_type type)
378 {
379         switch (type) {
380         case RFKILL_TYPE_WLAN:
381                 return "wlan";
382         case RFKILL_TYPE_BLUETOOTH:
383                 return "bluetooth";
384         case RFKILL_TYPE_UWB:
385                 return "ultrawideband";
386         case RFKILL_TYPE_WIMAX:
387                 return "wimax";
388         case RFKILL_TYPE_WWAN:
389                 return "wwan";
390         default:
391                 BUG();
392         }
393 }
394
395 static ssize_t rfkill_type_show(struct device *dev,
396                                 struct device_attribute *attr,
397                                 char *buf)
398 {
399         struct rfkill *rfkill = to_rfkill(dev);
400
401         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
402 }
403
404 static ssize_t rfkill_state_show(struct device *dev,
405                                  struct device_attribute *attr,
406                                  char *buf)
407 {
408         struct rfkill *rfkill = to_rfkill(dev);
409
410         update_rfkill_state(rfkill);
411         return sprintf(buf, "%d\n", rfkill->state);
412 }
413
414 static ssize_t rfkill_state_store(struct device *dev,
415                                   struct device_attribute *attr,
416                                   const char *buf, size_t count)
417 {
418         struct rfkill *rfkill = to_rfkill(dev);
419         unsigned long state;
420         int error;
421
422         if (!capable(CAP_NET_ADMIN))
423                 return -EPERM;
424
425         error = strict_strtoul(buf, 0, &state);
426         if (error)
427                 return error;
428
429         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
430         if (state != RFKILL_STATE_UNBLOCKED &&
431             state != RFKILL_STATE_SOFT_BLOCKED)
432                 return -EINVAL;
433
434         error = mutex_lock_killable(&rfkill->mutex);
435         if (error)
436                 return error;
437
438         if (!rfkill_epo_lock_active)
439                 error = rfkill_toggle_radio(rfkill, state, 0);
440         else
441                 error = -EPERM;
442
443         mutex_unlock(&rfkill->mutex);
444
445         return error ? error : count;
446 }
447
448 static ssize_t rfkill_claim_show(struct device *dev,
449                                  struct device_attribute *attr,
450                                  char *buf)
451 {
452         struct rfkill *rfkill = to_rfkill(dev);
453
454         return sprintf(buf, "%d\n", rfkill->user_claim);
455 }
456
457 static ssize_t rfkill_claim_store(struct device *dev,
458                                   struct device_attribute *attr,
459                                   const char *buf, size_t count)
460 {
461         struct rfkill *rfkill = to_rfkill(dev);
462         unsigned long claim_tmp;
463         bool claim;
464         int error;
465
466         if (!capable(CAP_NET_ADMIN))
467                 return -EPERM;
468
469         if (rfkill->user_claim_unsupported)
470                 return -EOPNOTSUPP;
471
472         error = strict_strtoul(buf, 0, &claim_tmp);
473         if (error)
474                 return error;
475         claim = !!claim_tmp;
476
477         /*
478          * Take the global lock to make sure the kernel is not in
479          * the middle of rfkill_switch_all
480          */
481         error = mutex_lock_killable(&rfkill_global_mutex);
482         if (error)
483                 return error;
484
485         if (rfkill->user_claim != claim) {
486                 if (!claim && !rfkill_epo_lock_active) {
487                         mutex_lock(&rfkill->mutex);
488                         rfkill_toggle_radio(rfkill,
489                                         rfkill_global_states[rfkill->type].current_state,
490                                         0);
491                         mutex_unlock(&rfkill->mutex);
492                 }
493                 rfkill->user_claim = claim;
494         }
495
496         mutex_unlock(&rfkill_global_mutex);
497
498         return error ? error : count;
499 }
500
501 static struct device_attribute rfkill_dev_attrs[] = {
502         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
503         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
504         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
505         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
506         __ATTR_NULL
507 };
508
509 static void rfkill_release(struct device *dev)
510 {
511         struct rfkill *rfkill = to_rfkill(dev);
512
513         kfree(rfkill);
514         module_put(THIS_MODULE);
515 }
516
517 #ifdef CONFIG_PM
518 static int rfkill_suspend(struct device *dev, pm_message_t state)
519 {
520         struct rfkill *rfkill = to_rfkill(dev);
521
522         /* mark class device as suspended */
523         if (dev->power.power_state.event != state.event)
524                 dev->power.power_state = state;
525
526         /* store state for the resume handler */
527         rfkill->state_for_resume = rfkill->state;
528
529         return 0;
530 }
531
532 static int rfkill_resume(struct device *dev)
533 {
534         struct rfkill *rfkill = to_rfkill(dev);
535         enum rfkill_state newstate;
536
537         if (dev->power.power_state.event != PM_EVENT_ON) {
538                 mutex_lock(&rfkill->mutex);
539
540                 dev->power.power_state.event = PM_EVENT_ON;
541
542                 /*
543                  * rfkill->state could have been modified before we got
544                  * called, and won't be updated by rfkill_toggle_radio()
545                  * in force mode.  Sync it FIRST.
546                  */
547                 if (rfkill->get_state &&
548                     !rfkill->get_state(rfkill->data, &newstate))
549                         rfkill->state = newstate;
550
551                 /*
552                  * If we are under EPO, kick transmitter offline,
553                  * otherwise restore to pre-suspend state.
554                  *
555                  * Issue a notification in any case
556                  */
557                 rfkill_toggle_radio(rfkill,
558                                 rfkill_epo_lock_active ?
559                                         RFKILL_STATE_SOFT_BLOCKED :
560                                         rfkill->state_for_resume,
561                                 1);
562
563                 mutex_unlock(&rfkill->mutex);
564         }
565
566         return 0;
567 }
568 #else
569 #define rfkill_suspend NULL
570 #define rfkill_resume NULL
571 #endif
572
573 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
574 {
575         struct rfkill *rfkill = to_rfkill(dev);
576         int error;
577
578         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
579         if (error)
580                 return error;
581         error = add_uevent_var(env, "RFKILL_TYPE=%s",
582                                 rfkill_get_type_str(rfkill->type));
583         if (error)
584                 return error;
585         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
586         return error;
587 }
588
589 static struct class rfkill_class = {
590         .name           = "rfkill",
591         .dev_release    = rfkill_release,
592         .dev_attrs      = rfkill_dev_attrs,
593         .suspend        = rfkill_suspend,
594         .resume         = rfkill_resume,
595         .dev_uevent     = rfkill_dev_uevent,
596 };
597
598 static int rfkill_check_duplicity(const struct rfkill *rfkill)
599 {
600         struct rfkill *p;
601         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
602
603         memset(seen, 0, sizeof(seen));
604
605         list_for_each_entry(p, &rfkill_list, node) {
606                 if (WARN((p == rfkill), KERN_WARNING
607                                 "rfkill: illegal attempt to register "
608                                 "an already registered rfkill struct\n"))
609                         return -EEXIST;
610                 set_bit(p->type, seen);
611         }
612
613         /* 0: first switch of its kind */
614         return (test_bit(rfkill->type, seen)) ? 1 : 0;
615 }
616
617 static int rfkill_add_switch(struct rfkill *rfkill)
618 {
619         int error;
620
621         mutex_lock(&rfkill_global_mutex);
622
623         error = rfkill_check_duplicity(rfkill);
624         if (error < 0)
625                 goto unlock_out;
626
627         if (!error) {
628                 /* lock default after first use */
629                 set_bit(rfkill->type, rfkill_states_lockdflt);
630                 rfkill_global_states[rfkill->type].current_state =
631                         rfkill_global_states[rfkill->type].default_state;
632         }
633
634         rfkill_toggle_radio(rfkill,
635                             rfkill_global_states[rfkill->type].current_state,
636                             0);
637
638         list_add_tail(&rfkill->node, &rfkill_list);
639
640         error = 0;
641 unlock_out:
642         mutex_unlock(&rfkill_global_mutex);
643
644         return error;
645 }
646
647 static void rfkill_remove_switch(struct rfkill *rfkill)
648 {
649         mutex_lock(&rfkill_global_mutex);
650         list_del_init(&rfkill->node);
651         mutex_unlock(&rfkill_global_mutex);
652
653         mutex_lock(&rfkill->mutex);
654         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
655         mutex_unlock(&rfkill->mutex);
656 }
657
658 /**
659  * rfkill_allocate - allocate memory for rfkill structure.
660  * @parent: device that has rf switch on it
661  * @type: type of the switch (RFKILL_TYPE_*)
662  *
663  * This function should be called by the network driver when it needs
664  * rfkill structure.  Once the structure is allocated the driver should
665  * finish its initialization by setting the name, private data, enable_radio
666  * and disable_radio methods and then register it with rfkill_register().
667  *
668  * NOTE: If registration fails the structure shoudl be freed by calling
669  * rfkill_free() otherwise rfkill_unregister() should be used.
670  */
671 struct rfkill * __must_check rfkill_allocate(struct device *parent,
672                                              enum rfkill_type type)
673 {
674         struct rfkill *rfkill;
675         struct device *dev;
676
677         if (WARN((type >= RFKILL_TYPE_MAX),
678                         KERN_WARNING
679                         "rfkill: illegal type %d passed as parameter "
680                         "to rfkill_allocate\n", type))
681                 return NULL;
682
683         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
684         if (!rfkill)
685                 return NULL;
686
687         mutex_init(&rfkill->mutex);
688         INIT_LIST_HEAD(&rfkill->node);
689         rfkill->type = type;
690
691         dev = &rfkill->dev;
692         dev->class = &rfkill_class;
693         dev->parent = parent;
694         device_initialize(dev);
695
696         __module_get(THIS_MODULE);
697
698         return rfkill;
699 }
700 EXPORT_SYMBOL(rfkill_allocate);
701
702 /**
703  * rfkill_free - Mark rfkill structure for deletion
704  * @rfkill: rfkill structure to be destroyed
705  *
706  * Decrements reference count of the rfkill structure so it is destroyed.
707  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
708  */
709 void rfkill_free(struct rfkill *rfkill)
710 {
711         if (rfkill)
712                 put_device(&rfkill->dev);
713 }
714 EXPORT_SYMBOL(rfkill_free);
715
716 static void rfkill_led_trigger_register(struct rfkill *rfkill)
717 {
718 #ifdef CONFIG_RFKILL_LEDS
719         int error;
720
721         if (!rfkill->led_trigger.name)
722                 rfkill->led_trigger.name = dev_name(&rfkill->dev);
723         if (!rfkill->led_trigger.activate)
724                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
725         error = led_trigger_register(&rfkill->led_trigger);
726         if (error)
727                 rfkill->led_trigger.name = NULL;
728 #endif /* CONFIG_RFKILL_LEDS */
729 }
730
731 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
732 {
733 #ifdef CONFIG_RFKILL_LEDS
734         if (rfkill->led_trigger.name) {
735                 led_trigger_unregister(&rfkill->led_trigger);
736                 rfkill->led_trigger.name = NULL;
737         }
738 #endif
739 }
740
741 /**
742  * rfkill_register - Register a rfkill structure.
743  * @rfkill: rfkill structure to be registered
744  *
745  * This function should be called by the network driver when the rfkill
746  * structure needs to be registered. Immediately from registration the
747  * switch driver should be able to service calls to toggle_radio.
748  */
749 int __must_check rfkill_register(struct rfkill *rfkill)
750 {
751         static atomic_t rfkill_no = ATOMIC_INIT(0);
752         struct device *dev = &rfkill->dev;
753         int error;
754
755         if (WARN((!rfkill || !rfkill->toggle_radio ||
756                         rfkill->type >= RFKILL_TYPE_MAX ||
757                         rfkill->state >= RFKILL_STATE_MAX),
758                         KERN_WARNING
759                         "rfkill: attempt to register a "
760                         "badly initialized rfkill struct\n"))
761                 return -EINVAL;
762
763         dev_set_name(dev, "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
764
765         rfkill_led_trigger_register(rfkill);
766
767         error = rfkill_add_switch(rfkill);
768         if (error) {
769                 rfkill_led_trigger_unregister(rfkill);
770                 return error;
771         }
772
773         error = device_add(dev);
774         if (error) {
775                 rfkill_remove_switch(rfkill);
776                 rfkill_led_trigger_unregister(rfkill);
777                 return error;
778         }
779
780         return 0;
781 }
782 EXPORT_SYMBOL(rfkill_register);
783
784 /**
785  * rfkill_unregister - Unregister a rfkill structure.
786  * @rfkill: rfkill structure to be unregistered
787  *
788  * This function should be called by the network driver during device
789  * teardown to destroy rfkill structure. Note that rfkill_free() should
790  * _not_ be called after rfkill_unregister().
791  */
792 void rfkill_unregister(struct rfkill *rfkill)
793 {
794         BUG_ON(!rfkill);
795         device_del(&rfkill->dev);
796         rfkill_remove_switch(rfkill);
797         rfkill_led_trigger_unregister(rfkill);
798         put_device(&rfkill->dev);
799 }
800 EXPORT_SYMBOL(rfkill_unregister);
801
802 /**
803  * rfkill_set_default - set initial value for a switch type
804  * @type - the type of switch to set the default state of
805  * @state - the new default state for that group of switches
806  *
807  * Sets the initial state rfkill should use for a given type.
808  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
809  * and RFKILL_STATE_UNBLOCKED.
810  *
811  * This function is meant to be used by platform drivers for platforms
812  * that can save switch state across power down/reboot.
813  *
814  * The default state for each switch type can be changed exactly once.
815  * After a switch of that type is registered, the default state cannot
816  * be changed anymore.  This guards against multiple drivers it the
817  * same platform trying to set the initial switch default state, which
818  * is not allowed.
819  *
820  * Returns -EPERM if the state has already been set once or is in use,
821  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
822  * if this function returns -EPERM.
823  *
824  * Returns 0 if the new default state was set, or an error if it
825  * could not be set.
826  */
827 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
828 {
829         int error;
830
831         if (WARN((type >= RFKILL_TYPE_MAX ||
832                         (state != RFKILL_STATE_SOFT_BLOCKED &&
833                          state != RFKILL_STATE_UNBLOCKED)),
834                         KERN_WARNING
835                         "rfkill: illegal state %d or type %d passed as "
836                         "parameter to rfkill_set_default\n", state, type))
837                 return -EINVAL;
838
839         mutex_lock(&rfkill_global_mutex);
840
841         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
842                 rfkill_global_states[type].default_state = state;
843                 rfkill_global_states[type].current_state = state;
844                 error = 0;
845         } else
846                 error = -EPERM;
847
848         mutex_unlock(&rfkill_global_mutex);
849         return error;
850 }
851 EXPORT_SYMBOL_GPL(rfkill_set_default);
852
853 /*
854  * Rfkill module initialization/deinitialization.
855  */
856 static int __init rfkill_init(void)
857 {
858         int error;
859         int i;
860
861         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
862         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
863             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
864                 return -EINVAL;
865
866         for (i = 0; i < RFKILL_TYPE_MAX; i++)
867                 rfkill_global_states[i].default_state = rfkill_default_state;
868
869         error = class_register(&rfkill_class);
870         if (error) {
871                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
872                 return error;
873         }
874
875         return 0;
876 }
877
878 static void __exit rfkill_exit(void)
879 {
880         class_unregister(&rfkill_class);
881 }
882
883 subsys_initcall(rfkill_init);
884 module_exit(rfkill_exit);