df1269c5ca70e3bf83ab1374931bf2fe8074e956
[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 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->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         return sprintf(buf, "%d\n", 0);
451 }
452
453 static ssize_t rfkill_claim_store(struct device *dev,
454                                   struct device_attribute *attr,
455                                   const char *buf, size_t count)
456 {
457         return -EOPNOTSUPP;
458 }
459
460 static struct device_attribute rfkill_dev_attrs[] = {
461         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
462         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
463         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
464         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
465         __ATTR_NULL
466 };
467
468 static void rfkill_release(struct device *dev)
469 {
470         struct rfkill *rfkill = to_rfkill(dev);
471
472         kfree(rfkill);
473         module_put(THIS_MODULE);
474 }
475
476 #ifdef CONFIG_PM
477 static int rfkill_suspend(struct device *dev, pm_message_t state)
478 {
479         struct rfkill *rfkill = to_rfkill(dev);
480
481         /* mark class device as suspended */
482         if (dev->power.power_state.event != state.event)
483                 dev->power.power_state = state;
484
485         /* store state for the resume handler */
486         rfkill->state_for_resume = rfkill->state;
487
488         return 0;
489 }
490
491 static int rfkill_resume(struct device *dev)
492 {
493         struct rfkill *rfkill = to_rfkill(dev);
494         enum rfkill_state newstate;
495
496         if (dev->power.power_state.event != PM_EVENT_ON) {
497                 mutex_lock(&rfkill->mutex);
498
499                 dev->power.power_state.event = PM_EVENT_ON;
500
501                 /*
502                  * rfkill->state could have been modified before we got
503                  * called, and won't be updated by rfkill_toggle_radio()
504                  * in force mode.  Sync it FIRST.
505                  */
506                 if (rfkill->get_state &&
507                     !rfkill->get_state(rfkill->data, &newstate))
508                         rfkill->state = newstate;
509
510                 /*
511                  * If we are under EPO, kick transmitter offline,
512                  * otherwise restore to pre-suspend state.
513                  *
514                  * Issue a notification in any case
515                  */
516                 rfkill_toggle_radio(rfkill,
517                                 rfkill_epo_lock_active ?
518                                         RFKILL_STATE_SOFT_BLOCKED :
519                                         rfkill->state_for_resume,
520                                 1);
521
522                 mutex_unlock(&rfkill->mutex);
523         }
524
525         return 0;
526 }
527 #else
528 #define rfkill_suspend NULL
529 #define rfkill_resume NULL
530 #endif
531
532 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
533 {
534         struct rfkill *rfkill = to_rfkill(dev);
535         int error;
536
537         error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
538         if (error)
539                 return error;
540         error = add_uevent_var(env, "RFKILL_TYPE=%s",
541                                 rfkill_get_type_str(rfkill->type));
542         if (error)
543                 return error;
544         error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
545         return error;
546 }
547
548 static struct class rfkill_class = {
549         .name           = "rfkill",
550         .dev_release    = rfkill_release,
551         .dev_attrs      = rfkill_dev_attrs,
552         .suspend        = rfkill_suspend,
553         .resume         = rfkill_resume,
554         .dev_uevent     = rfkill_dev_uevent,
555 };
556
557 static int rfkill_check_duplicity(const struct rfkill *rfkill)
558 {
559         struct rfkill *p;
560         unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
561
562         memset(seen, 0, sizeof(seen));
563
564         list_for_each_entry(p, &rfkill_list, node) {
565                 if (WARN((p == rfkill), KERN_WARNING
566                                 "rfkill: illegal attempt to register "
567                                 "an already registered rfkill struct\n"))
568                         return -EEXIST;
569                 set_bit(p->type, seen);
570         }
571
572         /* 0: first switch of its kind */
573         return (test_bit(rfkill->type, seen)) ? 1 : 0;
574 }
575
576 static int rfkill_add_switch(struct rfkill *rfkill)
577 {
578         int error;
579
580         mutex_lock(&rfkill_global_mutex);
581
582         error = rfkill_check_duplicity(rfkill);
583         if (error < 0)
584                 goto unlock_out;
585
586         if (!error) {
587                 /* lock default after first use */
588                 set_bit(rfkill->type, rfkill_states_lockdflt);
589                 rfkill_global_states[rfkill->type].current_state =
590                         rfkill_global_states[rfkill->type].default_state;
591         }
592
593         rfkill_toggle_radio(rfkill,
594                             rfkill_global_states[rfkill->type].current_state,
595                             0);
596
597         list_add_tail(&rfkill->node, &rfkill_list);
598
599         error = 0;
600 unlock_out:
601         mutex_unlock(&rfkill_global_mutex);
602
603         return error;
604 }
605
606 static void rfkill_remove_switch(struct rfkill *rfkill)
607 {
608         mutex_lock(&rfkill_global_mutex);
609         list_del_init(&rfkill->node);
610         mutex_unlock(&rfkill_global_mutex);
611
612         mutex_lock(&rfkill->mutex);
613         rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
614         mutex_unlock(&rfkill->mutex);
615 }
616
617 /**
618  * rfkill_allocate - allocate memory for rfkill structure.
619  * @parent: device that has rf switch on it
620  * @type: type of the switch (RFKILL_TYPE_*)
621  *
622  * This function should be called by the network driver when it needs
623  * rfkill structure.  Once the structure is allocated the driver should
624  * finish its initialization by setting the name, private data, enable_radio
625  * and disable_radio methods and then register it with rfkill_register().
626  *
627  * NOTE: If registration fails the structure shoudl be freed by calling
628  * rfkill_free() otherwise rfkill_unregister() should be used.
629  */
630 struct rfkill * __must_check rfkill_allocate(struct device *parent,
631                                              enum rfkill_type type)
632 {
633         struct rfkill *rfkill;
634         struct device *dev;
635
636         if (WARN((type >= RFKILL_TYPE_MAX),
637                         KERN_WARNING
638                         "rfkill: illegal type %d passed as parameter "
639                         "to rfkill_allocate\n", type))
640                 return NULL;
641
642         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
643         if (!rfkill)
644                 return NULL;
645
646         mutex_init(&rfkill->mutex);
647         INIT_LIST_HEAD(&rfkill->node);
648         rfkill->type = type;
649
650         dev = &rfkill->dev;
651         dev->class = &rfkill_class;
652         dev->parent = parent;
653         device_initialize(dev);
654
655         __module_get(THIS_MODULE);
656
657         return rfkill;
658 }
659 EXPORT_SYMBOL(rfkill_allocate);
660
661 /**
662  * rfkill_free - Mark rfkill structure for deletion
663  * @rfkill: rfkill structure to be destroyed
664  *
665  * Decrements reference count of the rfkill structure so it is destroyed.
666  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
667  */
668 void rfkill_free(struct rfkill *rfkill)
669 {
670         if (rfkill)
671                 put_device(&rfkill->dev);
672 }
673 EXPORT_SYMBOL(rfkill_free);
674
675 static void rfkill_led_trigger_register(struct rfkill *rfkill)
676 {
677 #ifdef CONFIG_RFKILL_LEDS
678         int error;
679
680         if (!rfkill->led_trigger.name)
681                 rfkill->led_trigger.name = dev_name(&rfkill->dev);
682         if (!rfkill->led_trigger.activate)
683                 rfkill->led_trigger.activate = rfkill_led_trigger_activate;
684         error = led_trigger_register(&rfkill->led_trigger);
685         if (error)
686                 rfkill->led_trigger.name = NULL;
687 #endif /* CONFIG_RFKILL_LEDS */
688 }
689
690 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
691 {
692 #ifdef CONFIG_RFKILL_LEDS
693         if (rfkill->led_trigger.name) {
694                 led_trigger_unregister(&rfkill->led_trigger);
695                 rfkill->led_trigger.name = NULL;
696         }
697 #endif
698 }
699
700 /**
701  * rfkill_register - Register a rfkill structure.
702  * @rfkill: rfkill structure to be registered
703  *
704  * This function should be called by the network driver when the rfkill
705  * structure needs to be registered. Immediately from registration the
706  * switch driver should be able to service calls to toggle_radio.
707  */
708 int __must_check rfkill_register(struct rfkill *rfkill)
709 {
710         static atomic_t rfkill_no = ATOMIC_INIT(0);
711         struct device *dev = &rfkill->dev;
712         int error;
713
714         if (WARN((!rfkill || !rfkill->toggle_radio ||
715                         rfkill->type >= RFKILL_TYPE_MAX ||
716                         rfkill->state >= RFKILL_STATE_MAX),
717                         KERN_WARNING
718                         "rfkill: attempt to register a "
719                         "badly initialized rfkill struct\n"))
720                 return -EINVAL;
721
722         dev_set_name(dev, "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
723
724         rfkill_led_trigger_register(rfkill);
725
726         error = rfkill_add_switch(rfkill);
727         if (error) {
728                 rfkill_led_trigger_unregister(rfkill);
729                 return error;
730         }
731
732         error = device_add(dev);
733         if (error) {
734                 rfkill_remove_switch(rfkill);
735                 rfkill_led_trigger_unregister(rfkill);
736                 return error;
737         }
738
739         return 0;
740 }
741 EXPORT_SYMBOL(rfkill_register);
742
743 /**
744  * rfkill_unregister - Unregister a rfkill structure.
745  * @rfkill: rfkill structure to be unregistered
746  *
747  * This function should be called by the network driver during device
748  * teardown to destroy rfkill structure. Note that rfkill_free() should
749  * _not_ be called after rfkill_unregister().
750  */
751 void rfkill_unregister(struct rfkill *rfkill)
752 {
753         BUG_ON(!rfkill);
754         device_del(&rfkill->dev);
755         rfkill_remove_switch(rfkill);
756         rfkill_led_trigger_unregister(rfkill);
757         put_device(&rfkill->dev);
758 }
759 EXPORT_SYMBOL(rfkill_unregister);
760
761 /**
762  * rfkill_set_default - set initial value for a switch type
763  * @type - the type of switch to set the default state of
764  * @state - the new default state for that group of switches
765  *
766  * Sets the initial state rfkill should use for a given type.
767  * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
768  * and RFKILL_STATE_UNBLOCKED.
769  *
770  * This function is meant to be used by platform drivers for platforms
771  * that can save switch state across power down/reboot.
772  *
773  * The default state for each switch type can be changed exactly once.
774  * After a switch of that type is registered, the default state cannot
775  * be changed anymore.  This guards against multiple drivers it the
776  * same platform trying to set the initial switch default state, which
777  * is not allowed.
778  *
779  * Returns -EPERM if the state has already been set once or is in use,
780  * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
781  * if this function returns -EPERM.
782  *
783  * Returns 0 if the new default state was set, or an error if it
784  * could not be set.
785  */
786 int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
787 {
788         int error;
789
790         if (WARN((type >= RFKILL_TYPE_MAX ||
791                         (state != RFKILL_STATE_SOFT_BLOCKED &&
792                          state != RFKILL_STATE_UNBLOCKED)),
793                         KERN_WARNING
794                         "rfkill: illegal state %d or type %d passed as "
795                         "parameter to rfkill_set_default\n", state, type))
796                 return -EINVAL;
797
798         mutex_lock(&rfkill_global_mutex);
799
800         if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
801                 rfkill_global_states[type].default_state = state;
802                 rfkill_global_states[type].current_state = state;
803                 error = 0;
804         } else
805                 error = -EPERM;
806
807         mutex_unlock(&rfkill_global_mutex);
808         return error;
809 }
810 EXPORT_SYMBOL_GPL(rfkill_set_default);
811
812 /*
813  * Rfkill module initialization/deinitialization.
814  */
815 static int __init rfkill_init(void)
816 {
817         int error;
818         int i;
819
820         /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
821         if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
822             rfkill_default_state != RFKILL_STATE_UNBLOCKED)
823                 return -EINVAL;
824
825         for (i = 0; i < RFKILL_TYPE_MAX; i++)
826                 rfkill_global_states[i].default_state = rfkill_default_state;
827
828         error = class_register(&rfkill_class);
829         if (error) {
830                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
831                 return error;
832         }
833
834         return 0;
835 }
836
837 static void __exit rfkill_exit(void)
838 {
839         class_unregister(&rfkill_class);
840 }
841
842 subsys_initcall(rfkill_init);
843 module_exit(rfkill_exit);