Merge branches 'tracing/kmemtrace2' and 'tracing/ftrace' into tracing/urgent
[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 #ifdef CONFIG_RFKILL_LEDS
58 static void rfkill_led_trigger(struct rfkill *rfkill,
59                                enum rfkill_state state)
60 {
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 }
70
71 static void rfkill_led_trigger_activate(struct led_classdev *led)
72 {
73         struct rfkill *rfkill = container_of(led->trigger,
74                         struct rfkill, led_trigger);
75
76         rfkill_led_trigger(rfkill, rfkill->state);
77 }
78 #endif /* CONFIG_RFKILL_LEDS */
79
80 static void rfkill_uevent(struct rfkill *rfkill)
81 {
82         kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
83 }
84
85 static void update_rfkill_state(struct rfkill *rfkill)
86 {
87         enum rfkill_state newstate, oldstate;
88
89         if (rfkill->get_state) {
90                 mutex_lock(&rfkill->mutex);
91                 if (!rfkill->get_state(rfkill->data, &newstate)) {
92                         oldstate = rfkill->state;
93                         rfkill->state = newstate;
94                         if (oldstate != newstate)
95                                 rfkill_uevent(rfkill);
96                 }
97                 mutex_unlock(&rfkill->mutex);
98         }
99 }
100
101 /**
102  * rfkill_toggle_radio - wrapper for toggle_radio hook
103  * @rfkill: the rfkill struct to use
104  * @force: calls toggle_radio even if cache says it is not needed,
105  *      and also makes sure notifications of the state will be
106  *      sent even if it didn't change
107  * @state: the new state to call toggle_radio() with
108  *
109  * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
110  * calls and handling all the red tape such as issuing notifications
111  * if the call is successful.
112  *
113  * Suspended devices are not touched at all, and -EAGAIN is returned.
114  *
115  * Note that the @force parameter cannot override a (possibly cached)
116  * state of RFKILL_STATE_HARD_BLOCKED.  Any device making use of
117  * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
118  * rfkill_force_state(), so the cache either is bypassed or valid.
119  *
120  * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
121  * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
122  * give the driver a hint that it should double-BLOCK the transmitter.
123  *
124  * Caller must have acquired rfkill->mutex.
125  */
126 static int rfkill_toggle_radio(struct rfkill *rfkill,
127                                 enum rfkill_state state,
128                                 int force)
129 {
130         int retval = 0;
131         enum rfkill_state oldstate, newstate;
132
133         if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
134                 return -EBUSY;
135
136         oldstate = rfkill->state;
137
138         if (rfkill->get_state && !force &&
139             !rfkill->get_state(rfkill->data, &newstate))
140                 rfkill->state = newstate;
141
142         switch (state) {
143         case RFKILL_STATE_HARD_BLOCKED:
144                 /* typically happens when refreshing hardware state,
145                  * such as on resume */
146                 state = RFKILL_STATE_SOFT_BLOCKED;
147                 break;
148         case RFKILL_STATE_UNBLOCKED:
149                 /* force can't override this, only rfkill_force_state() can */
150                 if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
151                         return -EPERM;
152                 break;
153         case RFKILL_STATE_SOFT_BLOCKED:
154                 /* nothing to do, we want to give drivers the hint to double
155                  * BLOCK even a transmitter that is already in state
156                  * RFKILL_STATE_HARD_BLOCKED */
157                 break;
158         default:
159                 WARN(1, KERN_WARNING
160                         "rfkill: illegal state %d passed as parameter "
161                         "to rfkill_toggle_radio\n", state);
162                 return -EINVAL;
163         }
164
165         if (force || state != rfkill->state) {
166                 retval = rfkill->toggle_radio(rfkill->data, state);
167                 /* never allow a HARD->SOFT downgrade! */
168                 if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
169                         rfkill->state = state;
170         }
171
172         if (force || rfkill->state != oldstate)
173                 rfkill_uevent(rfkill);
174
175         return retval;
176 }
177
178 /**
179  * __rfkill_switch_all - Toggle state of all switches of given type
180  * @type: type of interfaces to be affected
181  * @state: the new state
182  *
183  * This function toggles the state of all switches of given type,
184  * unless a specific switch is claimed by userspace (in which case,
185  * that switch is left alone) or suspended.
186  *
187  * Caller must have acquired rfkill_global_mutex.
188  */
189 static void __rfkill_switch_all(const enum rfkill_type type,
190                                 const enum rfkill_state state)
191 {
192         struct rfkill *rfkill;
193
194         if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
195                         KERN_WARNING
196                         "rfkill: illegal state %d or type %d "
197                         "passed as parameter to __rfkill_switch_all\n",
198                         state, type))
199                 return;
200
201         rfkill_global_states[type].current_state = state;
202         list_for_each_entry(rfkill, &rfkill_list, node) {
203                 if ((!rfkill->user_claim) && (rfkill->type == type)) {
204                         mutex_lock(&rfkill->mutex);
205                         rfkill_toggle_radio(rfkill, state, 0);
206                         mutex_unlock(&rfkill->mutex);
207                 }
208         }
209 }
210
211 /**
212  * rfkill_switch_all - Toggle state of all switches of given type
213  * @type: type of interfaces to be affected
214  * @state: the new state
215  *
216  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
217  * Please refer to __rfkill_switch_all() for details.
218  *
219  * Does nothing if the EPO lock is active.
220  */
221 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
222 {
223         mutex_lock(&rfkill_global_mutex);
224         if (!rfkill_epo_lock_active)
225                 __rfkill_switch_all(type, state);
226         mutex_unlock(&rfkill_global_mutex);
227 }
228 EXPORT_SYMBOL(rfkill_switch_all);
229
230 /**
231  * rfkill_epo - emergency power off all transmitters
232  *
233  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
234  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
235  *
236  * The global state before the EPO is saved and can be restored later
237  * using rfkill_restore_states().
238  */
239 void rfkill_epo(void)
240 {
241         struct rfkill *rfkill;
242         int i;
243
244         mutex_lock(&rfkill_global_mutex);
245
246         rfkill_epo_lock_active = true;
247         list_for_each_entry(rfkill, &rfkill_list, node) {
248                 mutex_lock(&rfkill->mutex);
249                 rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
250                 mutex_unlock(&rfkill->mutex);
251         }
252         for (i = 0; i < RFKILL_TYPE_MAX; i++) {
253                 rfkill_global_states[i].default_state =
254                                 rfkill_global_states[i].current_state;
255                 rfkill_global_states[i].current_state =
256                                 RFKILL_STATE_SOFT_BLOCKED;
257         }
258         mutex_unlock(&rfkill_global_mutex);
259 }
260 EXPORT_SYMBOL_GPL(rfkill_epo);
261
262 /**
263  * rfkill_restore_states - restore global states
264  *
265  * Restore (and sync switches to) the global state from the
266  * states in rfkill_default_states.  This can undo the effects of
267  * a call to rfkill_epo().
268  */
269 void rfkill_restore_states(void)
270 {
271         int i;
272
273         mutex_lock(&rfkill_global_mutex);
274
275         rfkill_epo_lock_active = false;
276         for (i = 0; i < RFKILL_TYPE_MAX; i++)
277                 __rfkill_switch_all(i, rfkill_global_states[i].default_state);
278         mutex_unlock(&rfkill_global_mutex);
279 }
280 EXPORT_SYMBOL_GPL(rfkill_restore_states);
281
282 /**
283  * rfkill_remove_epo_lock - unlock state changes
284  *
285  * Used by rfkill-input manually unlock state changes, when
286  * the EPO switch is deactivated.
287  */
288 void rfkill_remove_epo_lock(void)
289 {
290         mutex_lock(&rfkill_global_mutex);
291         rfkill_epo_lock_active = false;
292         mutex_unlock(&rfkill_global_mutex);
293 }
294 EXPORT_SYMBOL_GPL(rfkill_remove_epo_lock);
295
296 /**
297  * rfkill_is_epo_lock_active - returns true EPO is active
298  *
299  * Returns 0 (false) if there is NOT an active EPO contidion,
300  * and 1 (true) if there is an active EPO contition, which
301  * locks all radios in one of the BLOCKED states.
302  *
303  * Can be called in atomic context.
304  */
305 bool rfkill_is_epo_lock_active(void)
306 {
307         return rfkill_epo_lock_active;
308 }
309 EXPORT_SYMBOL_GPL(rfkill_is_epo_lock_active);
310
311 /**
312  * rfkill_get_global_state - returns global state for a type
313  * @type: the type to get the global state of
314  *
315  * Returns the current global state for a given wireless
316  * device type.
317  */
318 enum rfkill_state rfkill_get_global_state(const enum rfkill_type type)
319 {
320         return rfkill_global_states[type].current_state;
321 }
322 EXPORT_SYMBOL_GPL(rfkill_get_global_state);
323
324 /**
325  * rfkill_force_state - Force the internal rfkill radio state
326  * @rfkill: pointer to the rfkill class to modify.
327  * @state: the current radio state the class should be forced to.
328  *
329  * This function updates the internal state of the radio cached
330  * by the rfkill class.  It should be used when the driver gets
331  * a notification by the firmware/hardware of the current *real*
332  * state of the radio rfkill switch.
333  *
334  * Devices which are subject to external changes on their rfkill
335  * state (such as those caused by a hardware rfkill line) MUST
336  * have their driver arrange to call rfkill_force_state() as soon
337  * as possible after such a change.
338  *
339  * This function may not be called from an atomic context.
340  */
341 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
342 {
343         enum rfkill_state oldstate;
344
345         BUG_ON(!rfkill);
346         if (WARN((state >= RFKILL_STATE_MAX),
347                         KERN_WARNING
348                         "rfkill: illegal state %d passed as parameter "
349                         "to rfkill_force_state\n", state))
350                 return -EINVAL;
351
352         mutex_lock(&rfkill->mutex);
353
354         oldstate = rfkill->state;
355         rfkill->state = state;
356
357         if (state != oldstate)
358                 rfkill_uevent(rfkill);
359
360         mutex_unlock(&rfkill->mutex);
361
362         return 0;
363 }
364 EXPORT_SYMBOL(rfkill_force_state);
365
366 static ssize_t rfkill_name_show(struct device *dev,
367                                 struct device_attribute *attr,
368                                 char *buf)
369 {
370         struct rfkill *rfkill = to_rfkill(dev);
371
372         return sprintf(buf, "%s\n", rfkill->name);
373 }
374
375 static const char *rfkill_get_type_str(enum rfkill_type type)
376 {
377         switch (type) {
378         case RFKILL_TYPE_WLAN:
379                 return "wlan";
380         case RFKILL_TYPE_BLUETOOTH:
381                 return "bluetooth";
382         case RFKILL_TYPE_UWB:
383                 return "ultrawideband";
384         case RFKILL_TYPE_WIMAX:
385                 return "wimax";
386         case RFKILL_TYPE_WWAN:
387                 return "wwan";
388         default:
389                 BUG();
390         }
391 }
392
393 static ssize_t rfkill_type_show(struct device *dev,
394                                 struct device_attribute *attr,
395                                 char *buf)
396 {
397         struct rfkill *rfkill = to_rfkill(dev);
398
399         return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
400 }
401
402 static ssize_t rfkill_state_show(struct device *dev,
403                                  struct device_attribute *attr,
404                                  char *buf)
405 {
406         struct rfkill *rfkill = to_rfkill(dev);
407
408         update_rfkill_state(rfkill);
409         return sprintf(buf, "%d\n", rfkill->state);
410 }
411
412 static ssize_t rfkill_state_store(struct device *dev,
413                                   struct device_attribute *attr,
414                                   const char *buf, size_t count)
415 {
416         struct rfkill *rfkill = to_rfkill(dev);
417         unsigned long state;
418         int error;
419
420         if (!capable(CAP_NET_ADMIN))
421                 return -EPERM;
422
423         error = strict_strtoul(buf, 0, &state);
424         if (error)
425                 return error;
426
427         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
428         if (state != RFKILL_STATE_UNBLOCKED &&
429             state != RFKILL_STATE_SOFT_BLOCKED)
430                 return -EINVAL;
431
432         error = mutex_lock_killable(&rfkill->mutex);
433         if (error)
434                 return error;
435
436         if (!rfkill_epo_lock_active)
437                 error = rfkill_toggle_radio(rfkill, state, 0);
438         else
439                 error = -EPERM;
440
441         mutex_unlock(&rfkill->mutex);
442
443         return error ? error : count;
444 }
445
446 static ssize_t rfkill_claim_show(struct device *dev,
447                                  struct device_attribute *attr,
448                                  char *buf)
449 {
450         struct rfkill *rfkill = to_rfkill(dev);
451
452         return sprintf(buf, "%d\n", rfkill->user_claim);
453 }
454
455 static ssize_t rfkill_claim_store(struct device *dev,
456                                   struct device_attribute *attr,
457                                   const char *buf, size_t count)
458 {
459         struct rfkill *rfkill = to_rfkill(dev);
460         unsigned long claim_tmp;
461         bool claim;
462         int error;
463
464         if (!capable(CAP_NET_ADMIN))
465                 return -EPERM;
466
467         if (rfkill->user_claim_unsupported)
468                 return -EOPNOTSUPP;
469
470         error = strict_strtoul(buf, 0, &claim_tmp);
471         if (error)
472                 return error;
473         claim = !!claim_tmp;
474
475         /*
476          * Take the global lock to make sure the kernel is not in
477          * the middle of rfkill_switch_all
478          */
479         error = mutex_lock_killable(&rfkill_global_mutex);
480         if (error)
481                 return error;
482
483         if (rfkill->user_claim != claim) {
484                 if (!claim && !rfkill_epo_lock_active) {
485                         mutex_lock(&rfkill->mutex);
486                         rfkill_toggle_radio(rfkill,
487                                         rfkill_global_states[rfkill->type].current_state,
488                                         0);
489                         mutex_unlock(&rfkill->mutex);
490                 }
491                 rfkill->user_claim = claim;
492         }
493
494         mutex_unlock(&rfkill_global_mutex);
495
496         return error ? error : count;
497 }
498
499 static struct device_attribute rfkill_dev_attrs[] = {
500         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
501         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
502         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
503         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
504         __ATTR_NULL
505 };
506
507 static void rfkill_release(struct device *dev)
508 {
509         struct rfkill *rfkill = to_rfkill(dev);
510
511         kfree(rfkill);
512         module_put(THIS_MODULE);
513 }
514
515 #ifdef CONFIG_PM
516 static int rfkill_suspend(struct device *dev, pm_message_t state)
517 {
518         struct rfkill *rfkill = to_rfkill(dev);
519
520         /* mark class device as suspended */
521         if (dev->power.power_state.event != state.event)
522                 dev->power.power_state = state;
523
524         /* store state for the resume handler */
525         rfkill->state_for_resume = rfkill->state;
526
527         return 0;
528 }
529
530 static int rfkill_resume(struct device *dev)
531 {
532         struct rfkill *rfkill = to_rfkill(dev);
533         enum rfkill_state newstate;
534
535         if (dev->power.power_state.event != PM_EVENT_ON) {
536                 mutex_lock(&rfkill->mutex);
537
538                 dev->power.power_state.event = PM_EVENT_ON;
539
540                 /*
541                  * rfkill->state could have been modified before we got
542                  * called, and won't be updated by rfkill_toggle_radio()
543                  * in force mode.  Sync it FIRST.
544                  */
545                 if (rfkill->get_state &&
546                     !rfkill->get_state(rfkill->data, &newstate))
547                         rfkill->state = newstate;
548
549                 /*
550                  * If we are under EPO, kick transmitter offline,
551                  * otherwise restore to pre-suspend state.
552                  *
553                  * Issue a notification in any case
554                  */
555                 rfkill_toggle_radio(rfkill,
556                                 rfkill_epo_lock_active ?
557                                         RFKILL_STATE_SOFT_BLOCKED :
558                                         rfkill->state_for_resume,
559                                 1);
560
561                 mutex_unlock(&rfkill->mutex);
562         }
563
564         return 0;
565 }
566 #else
567 #define rfkill_suspend NULL
568 #define rfkill_resume NULL
569 #endif
570
571 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
572 {
573         struct rfkill *rfkill = to_rfkill(dev);
574         int error;
575
576         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
577         if (error)
578                 return error;
579         error = add_uevent_var(env, "RFKILL_TYPE=%s",
580                                 rfkill_get_type_str(rfkill->type));
581         if (error)
582                 return error;
583         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
584         return error;
585 }
586
587 static struct class rfkill_class = {
588         .name           = "rfkill",
589         .dev_release    = rfkill_release,
590         .dev_attrs      = rfkill_dev_attrs,
591         .suspend        = rfkill_suspend,
592         .resume         = rfkill_resume,
593         .dev_uevent     = rfkill_dev_uevent,
594 };
595
596 static int rfkill_check_duplicity(const struct rfkill *rfkill)
597 {
598         struct rfkill *p;
599         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
600
601         memset(seen, 0, sizeof(seen));
602
603         list_for_each_entry(p, &rfkill_list, node) {
604                 if (WARN((p == rfkill), KERN_WARNING
605                                 "rfkill: illegal attempt to register "
606                                 "an already registered rfkill struct\n"))
607                         return -EEXIST;
608                 set_bit(p->type, seen);
609         }
610
611         /* 0: first switch of its kind */
612         return (test_bit(rfkill->type, seen)) ? 1 : 0;
613 }
614
615 static int rfkill_add_switch(struct rfkill *rfkill)
616 {
617         int error;
618
619         mutex_lock(&rfkill_global_mutex);
620
621         error = rfkill_check_duplicity(rfkill);
622         if (error < 0)
623                 goto unlock_out;
624
625         if (!error) {
626                 /* lock default after first use */
627                 set_bit(rfkill->type, rfkill_states_lockdflt);
628                 rfkill_global_states[rfkill->type].current_state =
629                         rfkill_global_states[rfkill->type].default_state;
630         }
631
632         rfkill_toggle_radio(rfkill,
633                             rfkill_global_states[rfkill->type].current_state,
634                             0);
635
636         list_add_tail(&rfkill->node, &rfkill_list);
637
638         error = 0;
639 unlock_out:
640         mutex_unlock(&rfkill_global_mutex);
641
642         return error;
643 }
644
645 static void rfkill_remove_switch(struct rfkill *rfkill)
646 {
647         mutex_lock(&rfkill_global_mutex);
648         list_del_init(&rfkill->node);
649         mutex_unlock(&rfkill_global_mutex);
650
651         mutex_lock(&rfkill->mutex);
652         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
653         mutex_unlock(&rfkill->mutex);
654 }
655
656 /**
657  * rfkill_allocate - allocate memory for rfkill structure.
658  * @parent: device that has rf switch on it
659  * @type: type of the switch (RFKILL_TYPE_*)
660  *
661  * This function should be called by the network driver when it needs
662  * rfkill structure.  Once the structure is allocated the driver should
663  * finish its initialization by setting the name, private data, enable_radio
664  * and disable_radio methods and then register it with rfkill_register().
665  *
666  * NOTE: If registration fails the structure shoudl be freed by calling
667  * rfkill_free() otherwise rfkill_unregister() should be used.
668  */
669 struct rfkill * __must_check rfkill_allocate(struct device *parent,
670                                              enum rfkill_type type)
671 {
672         struct rfkill *rfkill;
673         struct device *dev;
674
675         if (WARN((type >= RFKILL_TYPE_MAX),
676                         KERN_WARNING
677                         "rfkill: illegal type %d passed as parameter "
678                         "to rfkill_allocate\n", type))
679                 return NULL;
680
681         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
682         if (!rfkill)
683                 return NULL;
684
685         mutex_init(&rfkill->mutex);
686         INIT_LIST_HEAD(&rfkill->node);
687         rfkill->type = type;
688
689         dev = &rfkill->dev;
690         dev->class = &rfkill_class;
691         dev->parent = parent;
692         device_initialize(dev);
693
694         __module_get(THIS_MODULE);
695
696         return rfkill;
697 }
698 EXPORT_SYMBOL(rfkill_allocate);
699
700 /**
701  * rfkill_free - Mark rfkill structure for deletion
702  * @rfkill: rfkill structure to be destroyed
703  *
704  * Decrements reference count of the rfkill structure so it is destroyed.
705  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
706  */
707 void rfkill_free(struct rfkill *rfkill)
708 {
709         if (rfkill)
710                 put_device(&rfkill->dev);
711 }
712 EXPORT_SYMBOL(rfkill_free);
713
714 static void rfkill_led_trigger_register(struct rfkill *rfkill)
715 {
716 #ifdef CONFIG_RFKILL_LEDS
717         int error;
718
719         if (!rfkill->led_trigger.name)
720                 rfkill->led_trigger.name = dev_name(&rfkill->dev);
721         if (!rfkill->led_trigger.activate)
722                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
723         error = led_trigger_register(&rfkill->led_trigger);
724         if (error)
725                 rfkill->led_trigger.name = NULL;
726 #endif /* CONFIG_RFKILL_LEDS */
727 }
728
729 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
730 {
731 #ifdef CONFIG_RFKILL_LEDS
732         if (rfkill->led_trigger.name) {
733                 led_trigger_unregister(&rfkill->led_trigger);
734                 rfkill->led_trigger.name = NULL;
735         }
736 #endif
737 }
738
739 /**
740  * rfkill_register - Register a rfkill structure.
741  * @rfkill: rfkill structure to be registered
742  *
743  * This function should be called by the network driver when the rfkill
744  * structure needs to be registered. Immediately from registration the
745  * switch driver should be able to service calls to toggle_radio.
746  */
747 int __must_check rfkill_register(struct rfkill *rfkill)
748 {
749         static atomic_t rfkill_no = ATOMIC_INIT(0);
750         struct device *dev = &rfkill->dev;
751         int error;
752
753         if (WARN((!rfkill || !rfkill->toggle_radio ||
754                         rfkill->type >= RFKILL_TYPE_MAX ||
755                         rfkill->state >= RFKILL_STATE_MAX),
756                         KERN_WARNING
757                         "rfkill: attempt to register a "
758                         "badly initialized rfkill struct\n"))
759                 return -EINVAL;
760
761         dev_set_name(dev, "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
762
763         rfkill_led_trigger_register(rfkill);
764
765         error = rfkill_add_switch(rfkill);
766         if (error) {
767                 rfkill_led_trigger_unregister(rfkill);
768                 return error;
769         }
770
771         error = device_add(dev);
772         if (error) {
773                 rfkill_remove_switch(rfkill);
774                 rfkill_led_trigger_unregister(rfkill);
775                 return error;
776         }
777
778         return 0;
779 }
780 EXPORT_SYMBOL(rfkill_register);
781
782 /**
783  * rfkill_unregister - Unregister a rfkill structure.
784  * @rfkill: rfkill structure to be unregistered
785  *
786  * This function should be called by the network driver during device
787  * teardown to destroy rfkill structure. Note that rfkill_free() should
788  * _not_ be called after rfkill_unregister().
789  */
790 void rfkill_unregister(struct rfkill *rfkill)
791 {
792         BUG_ON(!rfkill);
793         device_del(&rfkill->dev);
794         rfkill_remove_switch(rfkill);
795         rfkill_led_trigger_unregister(rfkill);
796         put_device(&rfkill->dev);
797 }
798 EXPORT_SYMBOL(rfkill_unregister);
799
800 /**
801  * rfkill_set_default - set initial value for a switch type
802  * @type - the type of switch to set the default state of
803  * @state - the new default state for that group of switches
804  *
805  * Sets the initial state rfkill should use for a given type.
806  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
807  * and RFKILL_STATE_UNBLOCKED.
808  *
809  * This function is meant to be used by platform drivers for platforms
810  * that can save switch state across power down/reboot.
811  *
812  * The default state for each switch type can be changed exactly once.
813  * After a switch of that type is registered, the default state cannot
814  * be changed anymore.  This guards against multiple drivers it the
815  * same platform trying to set the initial switch default state, which
816  * is not allowed.
817  *
818  * Returns -EPERM if the state has already been set once or is in use,
819  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
820  * if this function returns -EPERM.
821  *
822  * Returns 0 if the new default state was set, or an error if it
823  * could not be set.
824  */
825 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
826 {
827         int error;
828
829         if (WARN((type >= RFKILL_TYPE_MAX ||
830                         (state != RFKILL_STATE_SOFT_BLOCKED &&
831                          state != RFKILL_STATE_UNBLOCKED)),
832                         KERN_WARNING
833                         "rfkill: illegal state %d or type %d passed as "
834                         "parameter to rfkill_set_default\n", state, type))
835                 return -EINVAL;
836
837         mutex_lock(&rfkill_global_mutex);
838
839         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
840                 rfkill_global_states[type].default_state = state;
841                 rfkill_global_states[type].current_state = state;
842                 error = 0;
843         } else
844                 error = -EPERM;
845
846         mutex_unlock(&rfkill_global_mutex);
847         return error;
848 }
849 EXPORT_SYMBOL_GPL(rfkill_set_default);
850
851 /*
852  * Rfkill module initialization/deinitialization.
853  */
854 static int __init rfkill_init(void)
855 {
856         int error;
857         int i;
858
859         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
860         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
861             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
862                 return -EINVAL;
863
864         for (i = 0; i < RFKILL_TYPE_MAX; i++)
865                 rfkill_global_states[i].default_state = rfkill_default_state;
866
867         error = class_register(&rfkill_class);
868         if (error) {
869                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
870                 return error;
871         }
872
873         return 0;
874 }
875
876 static void __exit rfkill_exit(void)
877 {
878         class_unregister(&rfkill_class);
879 }
880
881 subsys_initcall(rfkill_init);
882 module_exit(rfkill_exit);