xref: /linux/net/rfkill/core.c (revision 9baa0b0364103dd726384c71db30b74044754743)
1 /*
2  * Copyright (C) 2006 - 2007 Ivo van Doorn
3  * Copyright (C) 2007 Dmitry Torokhov
4  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the
18  * Free Software Foundation, Inc.,
19  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  */
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/workqueue.h>
26 #include <linux/capability.h>
27 #include <linux/list.h>
28 #include <linux/mutex.h>
29 #include <linux/rfkill.h>
30 #include <linux/sched.h>
31 #include <linux/spinlock.h>
32 #include <linux/device.h>
33 #include <linux/miscdevice.h>
34 #include <linux/wait.h>
35 #include <linux/poll.h>
36 #include <linux/fs.h>
37 #include <linux/slab.h>
38 
39 #include "rfkill.h"
40 
41 #define POLL_INTERVAL		(5 * HZ)
42 
43 #define RFKILL_BLOCK_HW		BIT(0)
44 #define RFKILL_BLOCK_SW		BIT(1)
45 #define RFKILL_BLOCK_SW_PREV	BIT(2)
46 #define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
47 				 RFKILL_BLOCK_SW |\
48 				 RFKILL_BLOCK_SW_PREV)
49 #define RFKILL_BLOCK_SW_SETCALL	BIT(31)
50 
51 struct rfkill {
52 	spinlock_t		lock;
53 
54 	const char		*name;
55 	enum rfkill_type	type;
56 
57 	unsigned long		state;
58 
59 	u32			idx;
60 
61 	bool			registered;
62 	bool			persistent;
63 
64 	const struct rfkill_ops	*ops;
65 	void			*data;
66 
67 #ifdef CONFIG_RFKILL_LEDS
68 	struct led_trigger	led_trigger;
69 	const char		*ledtrigname;
70 #endif
71 
72 	struct device		dev;
73 	struct list_head	node;
74 
75 	struct delayed_work	poll_work;
76 	struct work_struct	uevent_work;
77 	struct work_struct	sync_work;
78 };
79 #define to_rfkill(d)	container_of(d, struct rfkill, dev)
80 
81 struct rfkill_int_event {
82 	struct list_head	list;
83 	struct rfkill_event	ev;
84 };
85 
86 struct rfkill_data {
87 	struct list_head	list;
88 	struct list_head	events;
89 	struct mutex		mtx;
90 	wait_queue_head_t	read_wait;
91 	bool			input_handler;
92 };
93 
94 
95 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
96 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
97 MODULE_DESCRIPTION("RF switch support");
98 MODULE_LICENSE("GPL");
99 
100 
101 /*
102  * The locking here should be made much smarter, we currently have
103  * a bit of a stupid situation because drivers might want to register
104  * the rfkill struct under their own lock, and take this lock during
105  * rfkill method calls -- which will cause an AB-BA deadlock situation.
106  *
107  * To fix that, we need to rework this code here to be mostly lock-free
108  * and only use the mutex for list manipulations, not to protect the
109  * various other global variables. Then we can avoid holding the mutex
110  * around driver operations, and all is happy.
111  */
112 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
113 static DEFINE_MUTEX(rfkill_global_mutex);
114 static LIST_HEAD(rfkill_fds);	/* list of open fds of /dev/rfkill */
115 
116 static unsigned int rfkill_default_state = 1;
117 module_param_named(default_state, rfkill_default_state, uint, 0444);
118 MODULE_PARM_DESC(default_state,
119 		 "Default initial state for all radio types, 0 = radio off");
120 
121 static struct {
122 	bool cur, sav;
123 } rfkill_global_states[NUM_RFKILL_TYPES];
124 
125 static bool rfkill_epo_lock_active;
126 
127 
128 #ifdef CONFIG_RFKILL_LEDS
129 static void rfkill_led_trigger_event(struct rfkill *rfkill)
130 {
131 	struct led_trigger *trigger;
132 
133 	if (!rfkill->registered)
134 		return;
135 
136 	trigger = &rfkill->led_trigger;
137 
138 	if (rfkill->state & RFKILL_BLOCK_ANY)
139 		led_trigger_event(trigger, LED_OFF);
140 	else
141 		led_trigger_event(trigger, LED_FULL);
142 }
143 
144 static void rfkill_led_trigger_activate(struct led_classdev *led)
145 {
146 	struct rfkill *rfkill;
147 
148 	rfkill = container_of(led->trigger, struct rfkill, led_trigger);
149 
150 	rfkill_led_trigger_event(rfkill);
151 }
152 
153 const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
154 {
155 	return rfkill->led_trigger.name;
156 }
157 EXPORT_SYMBOL(rfkill_get_led_trigger_name);
158 
159 void rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name)
160 {
161 	BUG_ON(!rfkill);
162 
163 	rfkill->ledtrigname = name;
164 }
165 EXPORT_SYMBOL(rfkill_set_led_trigger_name);
166 
167 static int rfkill_led_trigger_register(struct rfkill *rfkill)
168 {
169 	rfkill->led_trigger.name = rfkill->ledtrigname
170 					? : dev_name(&rfkill->dev);
171 	rfkill->led_trigger.activate = rfkill_led_trigger_activate;
172 	return led_trigger_register(&rfkill->led_trigger);
173 }
174 
175 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
176 {
177 	led_trigger_unregister(&rfkill->led_trigger);
178 }
179 #else
180 static void rfkill_led_trigger_event(struct rfkill *rfkill)
181 {
182 }
183 
184 static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
185 {
186 	return 0;
187 }
188 
189 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
190 {
191 }
192 #endif /* CONFIG_RFKILL_LEDS */
193 
194 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
195 			      enum rfkill_operation op)
196 {
197 	unsigned long flags;
198 
199 	ev->idx = rfkill->idx;
200 	ev->type = rfkill->type;
201 	ev->op = op;
202 
203 	spin_lock_irqsave(&rfkill->lock, flags);
204 	ev->hard = !!(rfkill->state & RFKILL_BLOCK_HW);
205 	ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW |
206 					RFKILL_BLOCK_SW_PREV));
207 	spin_unlock_irqrestore(&rfkill->lock, flags);
208 }
209 
210 static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op)
211 {
212 	struct rfkill_data *data;
213 	struct rfkill_int_event *ev;
214 
215 	list_for_each_entry(data, &rfkill_fds, list) {
216 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
217 		if (!ev)
218 			continue;
219 		rfkill_fill_event(&ev->ev, rfkill, op);
220 		mutex_lock(&data->mtx);
221 		list_add_tail(&ev->list, &data->events);
222 		mutex_unlock(&data->mtx);
223 		wake_up_interruptible(&data->read_wait);
224 	}
225 }
226 
227 static void rfkill_event(struct rfkill *rfkill)
228 {
229 	if (!rfkill->registered)
230 		return;
231 
232 	kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
233 
234 	/* also send event to /dev/rfkill */
235 	rfkill_send_events(rfkill, RFKILL_OP_CHANGE);
236 }
237 
238 static bool __rfkill_set_hw_state(struct rfkill *rfkill,
239 				  bool blocked, bool *change)
240 {
241 	unsigned long flags;
242 	bool prev, any;
243 
244 	BUG_ON(!rfkill);
245 
246 	spin_lock_irqsave(&rfkill->lock, flags);
247 	prev = !!(rfkill->state & RFKILL_BLOCK_HW);
248 	if (blocked)
249 		rfkill->state |= RFKILL_BLOCK_HW;
250 	else
251 		rfkill->state &= ~RFKILL_BLOCK_HW;
252 	*change = prev != blocked;
253 	any = !!(rfkill->state & RFKILL_BLOCK_ANY);
254 	spin_unlock_irqrestore(&rfkill->lock, flags);
255 
256 	rfkill_led_trigger_event(rfkill);
257 
258 	return any;
259 }
260 
261 /**
262  * rfkill_set_block - wrapper for set_block method
263  *
264  * @rfkill: the rfkill struct to use
265  * @blocked: the new software state
266  *
267  * Calls the set_block method (when applicable) and handles notifications
268  * etc. as well.
269  */
270 static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
271 {
272 	unsigned long flags;
273 	int err;
274 
275 	if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
276 		return;
277 
278 	/*
279 	 * Some platforms (...!) generate input events which affect the
280 	 * _hard_ kill state -- whenever something tries to change the
281 	 * current software state query the hardware state too.
282 	 */
283 	if (rfkill->ops->query)
284 		rfkill->ops->query(rfkill, rfkill->data);
285 
286 	spin_lock_irqsave(&rfkill->lock, flags);
287 	if (rfkill->state & RFKILL_BLOCK_SW)
288 		rfkill->state |= RFKILL_BLOCK_SW_PREV;
289 	else
290 		rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
291 
292 	if (blocked)
293 		rfkill->state |= RFKILL_BLOCK_SW;
294 	else
295 		rfkill->state &= ~RFKILL_BLOCK_SW;
296 
297 	rfkill->state |= RFKILL_BLOCK_SW_SETCALL;
298 	spin_unlock_irqrestore(&rfkill->lock, flags);
299 
300 	err = rfkill->ops->set_block(rfkill->data, blocked);
301 
302 	spin_lock_irqsave(&rfkill->lock, flags);
303 	if (err) {
304 		/*
305 		 * Failed -- reset status to _prev, this may be different
306 		 * from what set set _PREV to earlier in this function
307 		 * if rfkill_set_sw_state was invoked.
308 		 */
309 		if (rfkill->state & RFKILL_BLOCK_SW_PREV)
310 			rfkill->state |= RFKILL_BLOCK_SW;
311 		else
312 			rfkill->state &= ~RFKILL_BLOCK_SW;
313 	}
314 	rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL;
315 	rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
316 	spin_unlock_irqrestore(&rfkill->lock, flags);
317 
318 	rfkill_led_trigger_event(rfkill);
319 	rfkill_event(rfkill);
320 }
321 
322 #ifdef CONFIG_RFKILL_INPUT
323 static atomic_t rfkill_input_disabled = ATOMIC_INIT(0);
324 
325 /**
326  * __rfkill_switch_all - Toggle state of all switches of given type
327  * @type: type of interfaces to be affected
328  * @state: the new state
329  *
330  * This function sets the state of all switches of given type,
331  * unless a specific switch is claimed by userspace (in which case,
332  * that switch is left alone) or suspended.
333  *
334  * Caller must have acquired rfkill_global_mutex.
335  */
336 static void __rfkill_switch_all(const enum rfkill_type type, bool blocked)
337 {
338 	struct rfkill *rfkill;
339 
340 	rfkill_global_states[type].cur = blocked;
341 	list_for_each_entry(rfkill, &rfkill_list, node) {
342 		if (rfkill->type != type && type != RFKILL_TYPE_ALL)
343 			continue;
344 
345 		rfkill_set_block(rfkill, blocked);
346 	}
347 }
348 
349 /**
350  * rfkill_switch_all - Toggle state of all switches of given type
351  * @type: type of interfaces to be affected
352  * @state: the new state
353  *
354  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
355  * Please refer to __rfkill_switch_all() for details.
356  *
357  * Does nothing if the EPO lock is active.
358  */
359 void rfkill_switch_all(enum rfkill_type type, bool blocked)
360 {
361 	if (atomic_read(&rfkill_input_disabled))
362 		return;
363 
364 	mutex_lock(&rfkill_global_mutex);
365 
366 	if (!rfkill_epo_lock_active)
367 		__rfkill_switch_all(type, blocked);
368 
369 	mutex_unlock(&rfkill_global_mutex);
370 }
371 
372 /**
373  * rfkill_epo - emergency power off all transmitters
374  *
375  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
376  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
377  *
378  * The global state before the EPO is saved and can be restored later
379  * using rfkill_restore_states().
380  */
381 void rfkill_epo(void)
382 {
383 	struct rfkill *rfkill;
384 	int i;
385 
386 	if (atomic_read(&rfkill_input_disabled))
387 		return;
388 
389 	mutex_lock(&rfkill_global_mutex);
390 
391 	rfkill_epo_lock_active = true;
392 	list_for_each_entry(rfkill, &rfkill_list, node)
393 		rfkill_set_block(rfkill, true);
394 
395 	for (i = 0; i < NUM_RFKILL_TYPES; i++) {
396 		rfkill_global_states[i].sav = rfkill_global_states[i].cur;
397 		rfkill_global_states[i].cur = true;
398 	}
399 
400 	mutex_unlock(&rfkill_global_mutex);
401 }
402 
403 /**
404  * rfkill_restore_states - restore global states
405  *
406  * Restore (and sync switches to) the global state from the
407  * states in rfkill_default_states.  This can undo the effects of
408  * a call to rfkill_epo().
409  */
410 void rfkill_restore_states(void)
411 {
412 	int i;
413 
414 	if (atomic_read(&rfkill_input_disabled))
415 		return;
416 
417 	mutex_lock(&rfkill_global_mutex);
418 
419 	rfkill_epo_lock_active = false;
420 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
421 		__rfkill_switch_all(i, rfkill_global_states[i].sav);
422 	mutex_unlock(&rfkill_global_mutex);
423 }
424 
425 /**
426  * rfkill_remove_epo_lock - unlock state changes
427  *
428  * Used by rfkill-input manually unlock state changes, when
429  * the EPO switch is deactivated.
430  */
431 void rfkill_remove_epo_lock(void)
432 {
433 	if (atomic_read(&rfkill_input_disabled))
434 		return;
435 
436 	mutex_lock(&rfkill_global_mutex);
437 	rfkill_epo_lock_active = false;
438 	mutex_unlock(&rfkill_global_mutex);
439 }
440 
441 /**
442  * rfkill_is_epo_lock_active - returns true EPO is active
443  *
444  * Returns 0 (false) if there is NOT an active EPO contidion,
445  * and 1 (true) if there is an active EPO contition, which
446  * locks all radios in one of the BLOCKED states.
447  *
448  * Can be called in atomic context.
449  */
450 bool rfkill_is_epo_lock_active(void)
451 {
452 	return rfkill_epo_lock_active;
453 }
454 
455 /**
456  * rfkill_get_global_sw_state - returns global state for a type
457  * @type: the type to get the global state of
458  *
459  * Returns the current global state for a given wireless
460  * device type.
461  */
462 bool rfkill_get_global_sw_state(const enum rfkill_type type)
463 {
464 	return rfkill_global_states[type].cur;
465 }
466 #endif
467 
468 
469 bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
470 {
471 	bool ret, change;
472 
473 	ret = __rfkill_set_hw_state(rfkill, blocked, &change);
474 
475 	if (!rfkill->registered)
476 		return ret;
477 
478 	if (change)
479 		schedule_work(&rfkill->uevent_work);
480 
481 	return ret;
482 }
483 EXPORT_SYMBOL(rfkill_set_hw_state);
484 
485 static void __rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
486 {
487 	u32 bit = RFKILL_BLOCK_SW;
488 
489 	/* if in a ops->set_block right now, use other bit */
490 	if (rfkill->state & RFKILL_BLOCK_SW_SETCALL)
491 		bit = RFKILL_BLOCK_SW_PREV;
492 
493 	if (blocked)
494 		rfkill->state |= bit;
495 	else
496 		rfkill->state &= ~bit;
497 }
498 
499 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
500 {
501 	unsigned long flags;
502 	bool prev, hwblock;
503 
504 	BUG_ON(!rfkill);
505 
506 	spin_lock_irqsave(&rfkill->lock, flags);
507 	prev = !!(rfkill->state & RFKILL_BLOCK_SW);
508 	__rfkill_set_sw_state(rfkill, blocked);
509 	hwblock = !!(rfkill->state & RFKILL_BLOCK_HW);
510 	blocked = blocked || hwblock;
511 	spin_unlock_irqrestore(&rfkill->lock, flags);
512 
513 	if (!rfkill->registered)
514 		return blocked;
515 
516 	if (prev != blocked && !hwblock)
517 		schedule_work(&rfkill->uevent_work);
518 
519 	rfkill_led_trigger_event(rfkill);
520 
521 	return blocked;
522 }
523 EXPORT_SYMBOL(rfkill_set_sw_state);
524 
525 void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
526 {
527 	unsigned long flags;
528 
529 	BUG_ON(!rfkill);
530 	BUG_ON(rfkill->registered);
531 
532 	spin_lock_irqsave(&rfkill->lock, flags);
533 	__rfkill_set_sw_state(rfkill, blocked);
534 	rfkill->persistent = true;
535 	spin_unlock_irqrestore(&rfkill->lock, flags);
536 }
537 EXPORT_SYMBOL(rfkill_init_sw_state);
538 
539 void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
540 {
541 	unsigned long flags;
542 	bool swprev, hwprev;
543 
544 	BUG_ON(!rfkill);
545 
546 	spin_lock_irqsave(&rfkill->lock, flags);
547 
548 	/*
549 	 * No need to care about prev/setblock ... this is for uevent only
550 	 * and that will get triggered by rfkill_set_block anyway.
551 	 */
552 	swprev = !!(rfkill->state & RFKILL_BLOCK_SW);
553 	hwprev = !!(rfkill->state & RFKILL_BLOCK_HW);
554 	__rfkill_set_sw_state(rfkill, sw);
555 	if (hw)
556 		rfkill->state |= RFKILL_BLOCK_HW;
557 	else
558 		rfkill->state &= ~RFKILL_BLOCK_HW;
559 
560 	spin_unlock_irqrestore(&rfkill->lock, flags);
561 
562 	if (!rfkill->registered) {
563 		rfkill->persistent = true;
564 	} else {
565 		if (swprev != sw || hwprev != hw)
566 			schedule_work(&rfkill->uevent_work);
567 
568 		rfkill_led_trigger_event(rfkill);
569 	}
570 }
571 EXPORT_SYMBOL(rfkill_set_states);
572 
573 static ssize_t rfkill_name_show(struct device *dev,
574 				struct device_attribute *attr,
575 				char *buf)
576 {
577 	struct rfkill *rfkill = to_rfkill(dev);
578 
579 	return sprintf(buf, "%s\n", rfkill->name);
580 }
581 
582 static const char *rfkill_get_type_str(enum rfkill_type type)
583 {
584 	BUILD_BUG_ON(NUM_RFKILL_TYPES != RFKILL_TYPE_FM + 1);
585 
586 	switch (type) {
587 	case RFKILL_TYPE_WLAN:
588 		return "wlan";
589 	case RFKILL_TYPE_BLUETOOTH:
590 		return "bluetooth";
591 	case RFKILL_TYPE_UWB:
592 		return "ultrawideband";
593 	case RFKILL_TYPE_WIMAX:
594 		return "wimax";
595 	case RFKILL_TYPE_WWAN:
596 		return "wwan";
597 	case RFKILL_TYPE_GPS:
598 		return "gps";
599 	case RFKILL_TYPE_FM:
600 		return "fm";
601 	default:
602 		BUG();
603 	}
604 }
605 
606 static ssize_t rfkill_type_show(struct device *dev,
607 				struct device_attribute *attr,
608 				char *buf)
609 {
610 	struct rfkill *rfkill = to_rfkill(dev);
611 
612 	return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
613 }
614 
615 static ssize_t rfkill_idx_show(struct device *dev,
616 			       struct device_attribute *attr,
617 			       char *buf)
618 {
619 	struct rfkill *rfkill = to_rfkill(dev);
620 
621 	return sprintf(buf, "%d\n", rfkill->idx);
622 }
623 
624 static ssize_t rfkill_persistent_show(struct device *dev,
625 			       struct device_attribute *attr,
626 			       char *buf)
627 {
628 	struct rfkill *rfkill = to_rfkill(dev);
629 
630 	return sprintf(buf, "%d\n", rfkill->persistent);
631 }
632 
633 static ssize_t rfkill_hard_show(struct device *dev,
634 				 struct device_attribute *attr,
635 				 char *buf)
636 {
637 	struct rfkill *rfkill = to_rfkill(dev);
638 
639 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
640 }
641 
642 static ssize_t rfkill_soft_show(struct device *dev,
643 				 struct device_attribute *attr,
644 				 char *buf)
645 {
646 	struct rfkill *rfkill = to_rfkill(dev);
647 
648 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
649 }
650 
651 static ssize_t rfkill_soft_store(struct device *dev,
652 				  struct device_attribute *attr,
653 				  const char *buf, size_t count)
654 {
655 	struct rfkill *rfkill = to_rfkill(dev);
656 	unsigned long state;
657 	int err;
658 
659 	if (!capable(CAP_NET_ADMIN))
660 		return -EPERM;
661 
662 	err = kstrtoul(buf, 0, &state);
663 	if (err)
664 		return err;
665 
666 	if (state > 1 )
667 		return -EINVAL;
668 
669 	mutex_lock(&rfkill_global_mutex);
670 	rfkill_set_block(rfkill, state);
671 	mutex_unlock(&rfkill_global_mutex);
672 
673 	return err ?: count;
674 }
675 
676 static u8 user_state_from_blocked(unsigned long state)
677 {
678 	if (state & RFKILL_BLOCK_HW)
679 		return RFKILL_USER_STATE_HARD_BLOCKED;
680 	if (state & RFKILL_BLOCK_SW)
681 		return RFKILL_USER_STATE_SOFT_BLOCKED;
682 
683 	return RFKILL_USER_STATE_UNBLOCKED;
684 }
685 
686 static ssize_t rfkill_state_show(struct device *dev,
687 				 struct device_attribute *attr,
688 				 char *buf)
689 {
690 	struct rfkill *rfkill = to_rfkill(dev);
691 
692 	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
693 }
694 
695 static ssize_t rfkill_state_store(struct device *dev,
696 				  struct device_attribute *attr,
697 				  const char *buf, size_t count)
698 {
699 	struct rfkill *rfkill = to_rfkill(dev);
700 	unsigned long state;
701 	int err;
702 
703 	if (!capable(CAP_NET_ADMIN))
704 		return -EPERM;
705 
706 	err = kstrtoul(buf, 0, &state);
707 	if (err)
708 		return err;
709 
710 	if (state != RFKILL_USER_STATE_SOFT_BLOCKED &&
711 	    state != RFKILL_USER_STATE_UNBLOCKED)
712 		return -EINVAL;
713 
714 	mutex_lock(&rfkill_global_mutex);
715 	rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED);
716 	mutex_unlock(&rfkill_global_mutex);
717 
718 	return err ?: count;
719 }
720 
721 static ssize_t rfkill_claim_show(struct device *dev,
722 				 struct device_attribute *attr,
723 				 char *buf)
724 {
725 	return sprintf(buf, "%d\n", 0);
726 }
727 
728 static ssize_t rfkill_claim_store(struct device *dev,
729 				  struct device_attribute *attr,
730 				  const char *buf, size_t count)
731 {
732 	return -EOPNOTSUPP;
733 }
734 
735 static struct device_attribute rfkill_dev_attrs[] = {
736 	__ATTR(name, S_IRUGO, rfkill_name_show, NULL),
737 	__ATTR(type, S_IRUGO, rfkill_type_show, NULL),
738 	__ATTR(index, S_IRUGO, rfkill_idx_show, NULL),
739 	__ATTR(persistent, S_IRUGO, rfkill_persistent_show, NULL),
740 	__ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
741 	__ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
742 	__ATTR(soft, S_IRUGO|S_IWUSR, rfkill_soft_show, rfkill_soft_store),
743 	__ATTR(hard, S_IRUGO, rfkill_hard_show, NULL),
744 	__ATTR_NULL
745 };
746 
747 static void rfkill_release(struct device *dev)
748 {
749 	struct rfkill *rfkill = to_rfkill(dev);
750 
751 	kfree(rfkill);
752 }
753 
754 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
755 {
756 	struct rfkill *rfkill = to_rfkill(dev);
757 	unsigned long flags;
758 	u32 state;
759 	int error;
760 
761 	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
762 	if (error)
763 		return error;
764 	error = add_uevent_var(env, "RFKILL_TYPE=%s",
765 			       rfkill_get_type_str(rfkill->type));
766 	if (error)
767 		return error;
768 	spin_lock_irqsave(&rfkill->lock, flags);
769 	state = rfkill->state;
770 	spin_unlock_irqrestore(&rfkill->lock, flags);
771 	error = add_uevent_var(env, "RFKILL_STATE=%d",
772 			       user_state_from_blocked(state));
773 	return error;
774 }
775 
776 void rfkill_pause_polling(struct rfkill *rfkill)
777 {
778 	BUG_ON(!rfkill);
779 
780 	if (!rfkill->ops->poll)
781 		return;
782 
783 	cancel_delayed_work_sync(&rfkill->poll_work);
784 }
785 EXPORT_SYMBOL(rfkill_pause_polling);
786 
787 void rfkill_resume_polling(struct rfkill *rfkill)
788 {
789 	BUG_ON(!rfkill);
790 
791 	if (!rfkill->ops->poll)
792 		return;
793 
794 	schedule_work(&rfkill->poll_work.work);
795 }
796 EXPORT_SYMBOL(rfkill_resume_polling);
797 
798 static int rfkill_suspend(struct device *dev, pm_message_t state)
799 {
800 	struct rfkill *rfkill = to_rfkill(dev);
801 
802 	rfkill_pause_polling(rfkill);
803 
804 	return 0;
805 }
806 
807 static int rfkill_resume(struct device *dev)
808 {
809 	struct rfkill *rfkill = to_rfkill(dev);
810 	bool cur;
811 
812 	if (!rfkill->persistent) {
813 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
814 		rfkill_set_block(rfkill, cur);
815 	}
816 
817 	rfkill_resume_polling(rfkill);
818 
819 	return 0;
820 }
821 
822 static struct class rfkill_class = {
823 	.name		= "rfkill",
824 	.dev_release	= rfkill_release,
825 	.dev_attrs	= rfkill_dev_attrs,
826 	.dev_uevent	= rfkill_dev_uevent,
827 	.suspend	= rfkill_suspend,
828 	.resume		= rfkill_resume,
829 };
830 
831 bool rfkill_blocked(struct rfkill *rfkill)
832 {
833 	unsigned long flags;
834 	u32 state;
835 
836 	spin_lock_irqsave(&rfkill->lock, flags);
837 	state = rfkill->state;
838 	spin_unlock_irqrestore(&rfkill->lock, flags);
839 
840 	return !!(state & RFKILL_BLOCK_ANY);
841 }
842 EXPORT_SYMBOL(rfkill_blocked);
843 
844 
845 struct rfkill * __must_check rfkill_alloc(const char *name,
846 					  struct device *parent,
847 					  const enum rfkill_type type,
848 					  const struct rfkill_ops *ops,
849 					  void *ops_data)
850 {
851 	struct rfkill *rfkill;
852 	struct device *dev;
853 
854 	if (WARN_ON(!ops))
855 		return NULL;
856 
857 	if (WARN_ON(!ops->set_block))
858 		return NULL;
859 
860 	if (WARN_ON(!name))
861 		return NULL;
862 
863 	if (WARN_ON(type == RFKILL_TYPE_ALL || type >= NUM_RFKILL_TYPES))
864 		return NULL;
865 
866 	rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL);
867 	if (!rfkill)
868 		return NULL;
869 
870 	spin_lock_init(&rfkill->lock);
871 	INIT_LIST_HEAD(&rfkill->node);
872 	rfkill->type = type;
873 	rfkill->name = name;
874 	rfkill->ops = ops;
875 	rfkill->data = ops_data;
876 
877 	dev = &rfkill->dev;
878 	dev->class = &rfkill_class;
879 	dev->parent = parent;
880 	device_initialize(dev);
881 
882 	return rfkill;
883 }
884 EXPORT_SYMBOL(rfkill_alloc);
885 
886 static void rfkill_poll(struct work_struct *work)
887 {
888 	struct rfkill *rfkill;
889 
890 	rfkill = container_of(work, struct rfkill, poll_work.work);
891 
892 	/*
893 	 * Poll hardware state -- driver will use one of the
894 	 * rfkill_set{,_hw,_sw}_state functions and use its
895 	 * return value to update the current status.
896 	 */
897 	rfkill->ops->poll(rfkill, rfkill->data);
898 
899 	schedule_delayed_work(&rfkill->poll_work,
900 		round_jiffies_relative(POLL_INTERVAL));
901 }
902 
903 static void rfkill_uevent_work(struct work_struct *work)
904 {
905 	struct rfkill *rfkill;
906 
907 	rfkill = container_of(work, struct rfkill, uevent_work);
908 
909 	mutex_lock(&rfkill_global_mutex);
910 	rfkill_event(rfkill);
911 	mutex_unlock(&rfkill_global_mutex);
912 }
913 
914 static void rfkill_sync_work(struct work_struct *work)
915 {
916 	struct rfkill *rfkill;
917 	bool cur;
918 
919 	rfkill = container_of(work, struct rfkill, sync_work);
920 
921 	mutex_lock(&rfkill_global_mutex);
922 	cur = rfkill_global_states[rfkill->type].cur;
923 	rfkill_set_block(rfkill, cur);
924 	mutex_unlock(&rfkill_global_mutex);
925 }
926 
927 int __must_check rfkill_register(struct rfkill *rfkill)
928 {
929 	static unsigned long rfkill_no;
930 	struct device *dev = &rfkill->dev;
931 	int error;
932 
933 	BUG_ON(!rfkill);
934 
935 	mutex_lock(&rfkill_global_mutex);
936 
937 	if (rfkill->registered) {
938 		error = -EALREADY;
939 		goto unlock;
940 	}
941 
942 	rfkill->idx = rfkill_no;
943 	dev_set_name(dev, "rfkill%lu", rfkill_no);
944 	rfkill_no++;
945 
946 	list_add_tail(&rfkill->node, &rfkill_list);
947 
948 	error = device_add(dev);
949 	if (error)
950 		goto remove;
951 
952 	error = rfkill_led_trigger_register(rfkill);
953 	if (error)
954 		goto devdel;
955 
956 	rfkill->registered = true;
957 
958 	INIT_DELAYED_WORK(&rfkill->poll_work, rfkill_poll);
959 	INIT_WORK(&rfkill->uevent_work, rfkill_uevent_work);
960 	INIT_WORK(&rfkill->sync_work, rfkill_sync_work);
961 
962 	if (rfkill->ops->poll)
963 		schedule_delayed_work(&rfkill->poll_work,
964 			round_jiffies_relative(POLL_INTERVAL));
965 
966 	if (!rfkill->persistent || rfkill_epo_lock_active) {
967 		schedule_work(&rfkill->sync_work);
968 	} else {
969 #ifdef CONFIG_RFKILL_INPUT
970 		bool soft_blocked = !!(rfkill->state & RFKILL_BLOCK_SW);
971 
972 		if (!atomic_read(&rfkill_input_disabled))
973 			__rfkill_switch_all(rfkill->type, soft_blocked);
974 #endif
975 	}
976 
977 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
978 
979 	mutex_unlock(&rfkill_global_mutex);
980 	return 0;
981 
982  devdel:
983 	device_del(&rfkill->dev);
984  remove:
985 	list_del_init(&rfkill->node);
986  unlock:
987 	mutex_unlock(&rfkill_global_mutex);
988 	return error;
989 }
990 EXPORT_SYMBOL(rfkill_register);
991 
992 void rfkill_unregister(struct rfkill *rfkill)
993 {
994 	BUG_ON(!rfkill);
995 
996 	if (rfkill->ops->poll)
997 		cancel_delayed_work_sync(&rfkill->poll_work);
998 
999 	cancel_work_sync(&rfkill->uevent_work);
1000 	cancel_work_sync(&rfkill->sync_work);
1001 
1002 	rfkill->registered = false;
1003 
1004 	device_del(&rfkill->dev);
1005 
1006 	mutex_lock(&rfkill_global_mutex);
1007 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
1008 	list_del_init(&rfkill->node);
1009 	mutex_unlock(&rfkill_global_mutex);
1010 
1011 	rfkill_led_trigger_unregister(rfkill);
1012 }
1013 EXPORT_SYMBOL(rfkill_unregister);
1014 
1015 void rfkill_destroy(struct rfkill *rfkill)
1016 {
1017 	if (rfkill)
1018 		put_device(&rfkill->dev);
1019 }
1020 EXPORT_SYMBOL(rfkill_destroy);
1021 
1022 static int rfkill_fop_open(struct inode *inode, struct file *file)
1023 {
1024 	struct rfkill_data *data;
1025 	struct rfkill *rfkill;
1026 	struct rfkill_int_event *ev, *tmp;
1027 
1028 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1029 	if (!data)
1030 		return -ENOMEM;
1031 
1032 	INIT_LIST_HEAD(&data->events);
1033 	mutex_init(&data->mtx);
1034 	init_waitqueue_head(&data->read_wait);
1035 
1036 	mutex_lock(&rfkill_global_mutex);
1037 	mutex_lock(&data->mtx);
1038 	/*
1039 	 * start getting events from elsewhere but hold mtx to get
1040 	 * startup events added first
1041 	 */
1042 
1043 	list_for_each_entry(rfkill, &rfkill_list, node) {
1044 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1045 		if (!ev)
1046 			goto free;
1047 		rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD);
1048 		list_add_tail(&ev->list, &data->events);
1049 	}
1050 	list_add(&data->list, &rfkill_fds);
1051 	mutex_unlock(&data->mtx);
1052 	mutex_unlock(&rfkill_global_mutex);
1053 
1054 	file->private_data = data;
1055 
1056 	return nonseekable_open(inode, file);
1057 
1058  free:
1059 	mutex_unlock(&data->mtx);
1060 	mutex_unlock(&rfkill_global_mutex);
1061 	mutex_destroy(&data->mtx);
1062 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1063 		kfree(ev);
1064 	kfree(data);
1065 	return -ENOMEM;
1066 }
1067 
1068 static unsigned int rfkill_fop_poll(struct file *file, poll_table *wait)
1069 {
1070 	struct rfkill_data *data = file->private_data;
1071 	unsigned int res = POLLOUT | POLLWRNORM;
1072 
1073 	poll_wait(file, &data->read_wait, wait);
1074 
1075 	mutex_lock(&data->mtx);
1076 	if (!list_empty(&data->events))
1077 		res = POLLIN | POLLRDNORM;
1078 	mutex_unlock(&data->mtx);
1079 
1080 	return res;
1081 }
1082 
1083 static bool rfkill_readable(struct rfkill_data *data)
1084 {
1085 	bool r;
1086 
1087 	mutex_lock(&data->mtx);
1088 	r = !list_empty(&data->events);
1089 	mutex_unlock(&data->mtx);
1090 
1091 	return r;
1092 }
1093 
1094 static ssize_t rfkill_fop_read(struct file *file, char __user *buf,
1095 			       size_t count, loff_t *pos)
1096 {
1097 	struct rfkill_data *data = file->private_data;
1098 	struct rfkill_int_event *ev;
1099 	unsigned long sz;
1100 	int ret;
1101 
1102 	mutex_lock(&data->mtx);
1103 
1104 	while (list_empty(&data->events)) {
1105 		if (file->f_flags & O_NONBLOCK) {
1106 			ret = -EAGAIN;
1107 			goto out;
1108 		}
1109 		mutex_unlock(&data->mtx);
1110 		ret = wait_event_interruptible(data->read_wait,
1111 					       rfkill_readable(data));
1112 		mutex_lock(&data->mtx);
1113 
1114 		if (ret)
1115 			goto out;
1116 	}
1117 
1118 	ev = list_first_entry(&data->events, struct rfkill_int_event,
1119 				list);
1120 
1121 	sz = min_t(unsigned long, sizeof(ev->ev), count);
1122 	ret = sz;
1123 	if (copy_to_user(buf, &ev->ev, sz))
1124 		ret = -EFAULT;
1125 
1126 	list_del(&ev->list);
1127 	kfree(ev);
1128  out:
1129 	mutex_unlock(&data->mtx);
1130 	return ret;
1131 }
1132 
1133 static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
1134 				size_t count, loff_t *pos)
1135 {
1136 	struct rfkill *rfkill;
1137 	struct rfkill_event ev;
1138 
1139 	/* we don't need the 'hard' variable but accept it */
1140 	if (count < RFKILL_EVENT_SIZE_V1 - 1)
1141 		return -EINVAL;
1142 
1143 	/*
1144 	 * Copy as much data as we can accept into our 'ev' buffer,
1145 	 * but tell userspace how much we've copied so it can determine
1146 	 * our API version even in a write() call, if it cares.
1147 	 */
1148 	count = min(count, sizeof(ev));
1149 	if (copy_from_user(&ev, buf, count))
1150 		return -EFAULT;
1151 
1152 	if (ev.op != RFKILL_OP_CHANGE && ev.op != RFKILL_OP_CHANGE_ALL)
1153 		return -EINVAL;
1154 
1155 	if (ev.type >= NUM_RFKILL_TYPES)
1156 		return -EINVAL;
1157 
1158 	mutex_lock(&rfkill_global_mutex);
1159 
1160 	if (ev.op == RFKILL_OP_CHANGE_ALL) {
1161 		if (ev.type == RFKILL_TYPE_ALL) {
1162 			enum rfkill_type i;
1163 			for (i = 0; i < NUM_RFKILL_TYPES; i++)
1164 				rfkill_global_states[i].cur = ev.soft;
1165 		} else {
1166 			rfkill_global_states[ev.type].cur = ev.soft;
1167 		}
1168 	}
1169 
1170 	list_for_each_entry(rfkill, &rfkill_list, node) {
1171 		if (rfkill->idx != ev.idx && ev.op != RFKILL_OP_CHANGE_ALL)
1172 			continue;
1173 
1174 		if (rfkill->type != ev.type && ev.type != RFKILL_TYPE_ALL)
1175 			continue;
1176 
1177 		rfkill_set_block(rfkill, ev.soft);
1178 	}
1179 	mutex_unlock(&rfkill_global_mutex);
1180 
1181 	return count;
1182 }
1183 
1184 static int rfkill_fop_release(struct inode *inode, struct file *file)
1185 {
1186 	struct rfkill_data *data = file->private_data;
1187 	struct rfkill_int_event *ev, *tmp;
1188 
1189 	mutex_lock(&rfkill_global_mutex);
1190 	list_del(&data->list);
1191 	mutex_unlock(&rfkill_global_mutex);
1192 
1193 	mutex_destroy(&data->mtx);
1194 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1195 		kfree(ev);
1196 
1197 #ifdef CONFIG_RFKILL_INPUT
1198 	if (data->input_handler)
1199 		if (atomic_dec_return(&rfkill_input_disabled) == 0)
1200 			printk(KERN_DEBUG "rfkill: input handler enabled\n");
1201 #endif
1202 
1203 	kfree(data);
1204 
1205 	return 0;
1206 }
1207 
1208 #ifdef CONFIG_RFKILL_INPUT
1209 static long rfkill_fop_ioctl(struct file *file, unsigned int cmd,
1210 			     unsigned long arg)
1211 {
1212 	struct rfkill_data *data = file->private_data;
1213 
1214 	if (_IOC_TYPE(cmd) != RFKILL_IOC_MAGIC)
1215 		return -ENOSYS;
1216 
1217 	if (_IOC_NR(cmd) != RFKILL_IOC_NOINPUT)
1218 		return -ENOSYS;
1219 
1220 	mutex_lock(&data->mtx);
1221 
1222 	if (!data->input_handler) {
1223 		if (atomic_inc_return(&rfkill_input_disabled) == 1)
1224 			printk(KERN_DEBUG "rfkill: input handler disabled\n");
1225 		data->input_handler = true;
1226 	}
1227 
1228 	mutex_unlock(&data->mtx);
1229 
1230 	return 0;
1231 }
1232 #endif
1233 
1234 static const struct file_operations rfkill_fops = {
1235 	.owner		= THIS_MODULE,
1236 	.open		= rfkill_fop_open,
1237 	.read		= rfkill_fop_read,
1238 	.write		= rfkill_fop_write,
1239 	.poll		= rfkill_fop_poll,
1240 	.release	= rfkill_fop_release,
1241 #ifdef CONFIG_RFKILL_INPUT
1242 	.unlocked_ioctl	= rfkill_fop_ioctl,
1243 	.compat_ioctl	= rfkill_fop_ioctl,
1244 #endif
1245 	.llseek		= no_llseek,
1246 };
1247 
1248 static struct miscdevice rfkill_miscdev = {
1249 	.name	= "rfkill",
1250 	.fops	= &rfkill_fops,
1251 	.minor	= MISC_DYNAMIC_MINOR,
1252 };
1253 
1254 static int __init rfkill_init(void)
1255 {
1256 	int error;
1257 	int i;
1258 
1259 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
1260 		rfkill_global_states[i].cur = !rfkill_default_state;
1261 
1262 	error = class_register(&rfkill_class);
1263 	if (error)
1264 		goto out;
1265 
1266 	error = misc_register(&rfkill_miscdev);
1267 	if (error) {
1268 		class_unregister(&rfkill_class);
1269 		goto out;
1270 	}
1271 
1272 #ifdef CONFIG_RFKILL_INPUT
1273 	error = rfkill_handler_init();
1274 	if (error) {
1275 		misc_deregister(&rfkill_miscdev);
1276 		class_unregister(&rfkill_class);
1277 		goto out;
1278 	}
1279 #endif
1280 
1281  out:
1282 	return error;
1283 }
1284 subsys_initcall(rfkill_init);
1285 
1286 static void __exit rfkill_exit(void)
1287 {
1288 #ifdef CONFIG_RFKILL_INPUT
1289 	rfkill_handler_exit();
1290 #endif
1291 	misc_deregister(&rfkill_miscdev);
1292 	class_unregister(&rfkill_class);
1293 }
1294 module_exit(rfkill_exit);
1295