xref: /openbmc/linux/net/rfkill/core.c (revision 1fa6ac37)
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/miscdevice.h>
33 #include <linux/wait.h>
34 #include <linux/poll.h>
35 #include <linux/fs.h>
36 #include <linux/slab.h>
37 
38 #include "rfkill.h"
39 
40 #define POLL_INTERVAL		(5 * HZ)
41 
42 #define RFKILL_BLOCK_HW		BIT(0)
43 #define RFKILL_BLOCK_SW		BIT(1)
44 #define RFKILL_BLOCK_SW_PREV	BIT(2)
45 #define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
46 				 RFKILL_BLOCK_SW |\
47 				 RFKILL_BLOCK_SW_PREV)
48 #define RFKILL_BLOCK_SW_SETCALL	BIT(31)
49 
50 struct rfkill {
51 	spinlock_t		lock;
52 
53 	const char		*name;
54 	enum rfkill_type	type;
55 
56 	unsigned long		state;
57 
58 	u32			idx;
59 
60 	bool			registered;
61 	bool			persistent;
62 
63 	const struct rfkill_ops	*ops;
64 	void			*data;
65 
66 #ifdef CONFIG_RFKILL_LEDS
67 	struct led_trigger	led_trigger;
68 	const char		*ledtrigname;
69 #endif
70 
71 	struct device		dev;
72 	struct list_head	node;
73 
74 	struct delayed_work	poll_work;
75 	struct work_struct	uevent_work;
76 	struct work_struct	sync_work;
77 };
78 #define to_rfkill(d)	container_of(d, struct rfkill, dev)
79 
80 struct rfkill_int_event {
81 	struct list_head	list;
82 	struct rfkill_event	ev;
83 };
84 
85 struct rfkill_data {
86 	struct list_head	list;
87 	struct list_head	events;
88 	struct mutex		mtx;
89 	wait_queue_head_t	read_wait;
90 	bool			input_handler;
91 };
92 
93 
94 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
95 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
96 MODULE_DESCRIPTION("RF switch support");
97 MODULE_LICENSE("GPL");
98 
99 
100 /*
101  * The locking here should be made much smarter, we currently have
102  * a bit of a stupid situation because drivers might want to register
103  * the rfkill struct under their own lock, and take this lock during
104  * rfkill method calls -- which will cause an AB-BA deadlock situation.
105  *
106  * To fix that, we need to rework this code here to be mostly lock-free
107  * and only use the mutex for list manipulations, not to protect the
108  * various other global variables. Then we can avoid holding the mutex
109  * around driver operations, and all is happy.
110  */
111 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
112 static DEFINE_MUTEX(rfkill_global_mutex);
113 static LIST_HEAD(rfkill_fds);	/* list of open fds of /dev/rfkill */
114 
115 static unsigned int rfkill_default_state = 1;
116 module_param_named(default_state, rfkill_default_state, uint, 0444);
117 MODULE_PARM_DESC(default_state,
118 		 "Default initial state for all radio types, 0 = radio off");
119 
120 static struct {
121 	bool cur, sav;
122 } rfkill_global_states[NUM_RFKILL_TYPES];
123 
124 static bool rfkill_epo_lock_active;
125 
126 
127 #ifdef CONFIG_RFKILL_LEDS
128 static void rfkill_led_trigger_event(struct rfkill *rfkill)
129 {
130 	struct led_trigger *trigger;
131 
132 	if (!rfkill->registered)
133 		return;
134 
135 	trigger = &rfkill->led_trigger;
136 
137 	if (rfkill->state & RFKILL_BLOCK_ANY)
138 		led_trigger_event(trigger, LED_OFF);
139 	else
140 		led_trigger_event(trigger, LED_FULL);
141 }
142 
143 static void rfkill_led_trigger_activate(struct led_classdev *led)
144 {
145 	struct rfkill *rfkill;
146 
147 	rfkill = container_of(led->trigger, struct rfkill, led_trigger);
148 
149 	rfkill_led_trigger_event(rfkill);
150 }
151 
152 const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
153 {
154 	return rfkill->led_trigger.name;
155 }
156 EXPORT_SYMBOL(rfkill_get_led_trigger_name);
157 
158 void rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name)
159 {
160 	BUG_ON(!rfkill);
161 
162 	rfkill->ledtrigname = name;
163 }
164 EXPORT_SYMBOL(rfkill_set_led_trigger_name);
165 
166 static int rfkill_led_trigger_register(struct rfkill *rfkill)
167 {
168 	rfkill->led_trigger.name = rfkill->ledtrigname
169 					? : dev_name(&rfkill->dev);
170 	rfkill->led_trigger.activate = rfkill_led_trigger_activate;
171 	return led_trigger_register(&rfkill->led_trigger);
172 }
173 
174 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
175 {
176 	led_trigger_unregister(&rfkill->led_trigger);
177 }
178 #else
179 static void rfkill_led_trigger_event(struct rfkill *rfkill)
180 {
181 }
182 
183 static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
184 {
185 	return 0;
186 }
187 
188 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
189 {
190 }
191 #endif /* CONFIG_RFKILL_LEDS */
192 
193 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
194 			      enum rfkill_operation op)
195 {
196 	unsigned long flags;
197 
198 	ev->idx = rfkill->idx;
199 	ev->type = rfkill->type;
200 	ev->op = op;
201 
202 	spin_lock_irqsave(&rfkill->lock, flags);
203 	ev->hard = !!(rfkill->state & RFKILL_BLOCK_HW);
204 	ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW |
205 					RFKILL_BLOCK_SW_PREV));
206 	spin_unlock_irqrestore(&rfkill->lock, flags);
207 }
208 
209 static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op)
210 {
211 	struct rfkill_data *data;
212 	struct rfkill_int_event *ev;
213 
214 	list_for_each_entry(data, &rfkill_fds, list) {
215 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
216 		if (!ev)
217 			continue;
218 		rfkill_fill_event(&ev->ev, rfkill, op);
219 		mutex_lock(&data->mtx);
220 		list_add_tail(&ev->list, &data->events);
221 		mutex_unlock(&data->mtx);
222 		wake_up_interruptible(&data->read_wait);
223 	}
224 }
225 
226 static void rfkill_event(struct rfkill *rfkill)
227 {
228 	if (!rfkill->registered)
229 		return;
230 
231 	kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
232 
233 	/* also send event to /dev/rfkill */
234 	rfkill_send_events(rfkill, RFKILL_OP_CHANGE);
235 }
236 
237 static bool __rfkill_set_hw_state(struct rfkill *rfkill,
238 				  bool blocked, bool *change)
239 {
240 	unsigned long flags;
241 	bool prev, any;
242 
243 	BUG_ON(!rfkill);
244 
245 	spin_lock_irqsave(&rfkill->lock, flags);
246 	prev = !!(rfkill->state & RFKILL_BLOCK_HW);
247 	if (blocked)
248 		rfkill->state |= RFKILL_BLOCK_HW;
249 	else
250 		rfkill->state &= ~RFKILL_BLOCK_HW;
251 	*change = prev != blocked;
252 	any = rfkill->state & RFKILL_BLOCK_ANY;
253 	spin_unlock_irqrestore(&rfkill->lock, flags);
254 
255 	rfkill_led_trigger_event(rfkill);
256 
257 	return any;
258 }
259 
260 /**
261  * rfkill_set_block - wrapper for set_block method
262  *
263  * @rfkill: the rfkill struct to use
264  * @blocked: the new software state
265  *
266  * Calls the set_block method (when applicable) and handles notifications
267  * etc. as well.
268  */
269 static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
270 {
271 	unsigned long flags;
272 	int err;
273 
274 	if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
275 		return;
276 
277 	/*
278 	 * Some platforms (...!) generate input events which affect the
279 	 * _hard_ kill state -- whenever something tries to change the
280 	 * current software state query the hardware state too.
281 	 */
282 	if (rfkill->ops->query)
283 		rfkill->ops->query(rfkill, rfkill->data);
284 
285 	spin_lock_irqsave(&rfkill->lock, flags);
286 	if (rfkill->state & RFKILL_BLOCK_SW)
287 		rfkill->state |= RFKILL_BLOCK_SW_PREV;
288 	else
289 		rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
290 
291 	if (blocked)
292 		rfkill->state |= RFKILL_BLOCK_SW;
293 	else
294 		rfkill->state &= ~RFKILL_BLOCK_SW;
295 
296 	rfkill->state |= RFKILL_BLOCK_SW_SETCALL;
297 	spin_unlock_irqrestore(&rfkill->lock, flags);
298 
299 	err = rfkill->ops->set_block(rfkill->data, blocked);
300 
301 	spin_lock_irqsave(&rfkill->lock, flags);
302 	if (err) {
303 		/*
304 		 * Failed -- reset status to _prev, this may be different
305 		 * from what set set _PREV to earlier in this function
306 		 * if rfkill_set_sw_state was invoked.
307 		 */
308 		if (rfkill->state & RFKILL_BLOCK_SW_PREV)
309 			rfkill->state |= RFKILL_BLOCK_SW;
310 		else
311 			rfkill->state &= ~RFKILL_BLOCK_SW;
312 	}
313 	rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL;
314 	rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
315 	spin_unlock_irqrestore(&rfkill->lock, flags);
316 
317 	rfkill_led_trigger_event(rfkill);
318 	rfkill_event(rfkill);
319 }
320 
321 #ifdef CONFIG_RFKILL_INPUT
322 static atomic_t rfkill_input_disabled = ATOMIC_INIT(0);
323 
324 /**
325  * __rfkill_switch_all - Toggle state of all switches of given type
326  * @type: type of interfaces to be affected
327  * @state: the new state
328  *
329  * This function sets the state of all switches of given type,
330  * unless a specific switch is claimed by userspace (in which case,
331  * that switch is left alone) or suspended.
332  *
333  * Caller must have acquired rfkill_global_mutex.
334  */
335 static void __rfkill_switch_all(const enum rfkill_type type, bool blocked)
336 {
337 	struct rfkill *rfkill;
338 
339 	rfkill_global_states[type].cur = blocked;
340 	list_for_each_entry(rfkill, &rfkill_list, node) {
341 		if (rfkill->type != type)
342 			continue;
343 
344 		rfkill_set_block(rfkill, blocked);
345 	}
346 }
347 
348 /**
349  * rfkill_switch_all - Toggle state of all switches of given type
350  * @type: type of interfaces to be affected
351  * @state: the new state
352  *
353  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
354  * Please refer to __rfkill_switch_all() for details.
355  *
356  * Does nothing if the EPO lock is active.
357  */
358 void rfkill_switch_all(enum rfkill_type type, bool blocked)
359 {
360 	if (atomic_read(&rfkill_input_disabled))
361 		return;
362 
363 	mutex_lock(&rfkill_global_mutex);
364 
365 	if (!rfkill_epo_lock_active)
366 		__rfkill_switch_all(type, blocked);
367 
368 	mutex_unlock(&rfkill_global_mutex);
369 }
370 
371 /**
372  * rfkill_epo - emergency power off all transmitters
373  *
374  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
375  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
376  *
377  * The global state before the EPO is saved and can be restored later
378  * using rfkill_restore_states().
379  */
380 void rfkill_epo(void)
381 {
382 	struct rfkill *rfkill;
383 	int i;
384 
385 	if (atomic_read(&rfkill_input_disabled))
386 		return;
387 
388 	mutex_lock(&rfkill_global_mutex);
389 
390 	rfkill_epo_lock_active = true;
391 	list_for_each_entry(rfkill, &rfkill_list, node)
392 		rfkill_set_block(rfkill, true);
393 
394 	for (i = 0; i < NUM_RFKILL_TYPES; i++) {
395 		rfkill_global_states[i].sav = rfkill_global_states[i].cur;
396 		rfkill_global_states[i].cur = true;
397 	}
398 
399 	mutex_unlock(&rfkill_global_mutex);
400 }
401 
402 /**
403  * rfkill_restore_states - restore global states
404  *
405  * Restore (and sync switches to) the global state from the
406  * states in rfkill_default_states.  This can undo the effects of
407  * a call to rfkill_epo().
408  */
409 void rfkill_restore_states(void)
410 {
411 	int i;
412 
413 	if (atomic_read(&rfkill_input_disabled))
414 		return;
415 
416 	mutex_lock(&rfkill_global_mutex);
417 
418 	rfkill_epo_lock_active = false;
419 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
420 		__rfkill_switch_all(i, rfkill_global_states[i].sav);
421 	mutex_unlock(&rfkill_global_mutex);
422 }
423 
424 /**
425  * rfkill_remove_epo_lock - unlock state changes
426  *
427  * Used by rfkill-input manually unlock state changes, when
428  * the EPO switch is deactivated.
429  */
430 void rfkill_remove_epo_lock(void)
431 {
432 	if (atomic_read(&rfkill_input_disabled))
433 		return;
434 
435 	mutex_lock(&rfkill_global_mutex);
436 	rfkill_epo_lock_active = false;
437 	mutex_unlock(&rfkill_global_mutex);
438 }
439 
440 /**
441  * rfkill_is_epo_lock_active - returns true EPO is active
442  *
443  * Returns 0 (false) if there is NOT an active EPO contidion,
444  * and 1 (true) if there is an active EPO contition, which
445  * locks all radios in one of the BLOCKED states.
446  *
447  * Can be called in atomic context.
448  */
449 bool rfkill_is_epo_lock_active(void)
450 {
451 	return rfkill_epo_lock_active;
452 }
453 
454 /**
455  * rfkill_get_global_sw_state - returns global state for a type
456  * @type: the type to get the global state of
457  *
458  * Returns the current global state for a given wireless
459  * device type.
460  */
461 bool rfkill_get_global_sw_state(const enum rfkill_type type)
462 {
463 	return rfkill_global_states[type].cur;
464 }
465 #endif
466 
467 
468 bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
469 {
470 	bool ret, change;
471 
472 	ret = __rfkill_set_hw_state(rfkill, blocked, &change);
473 
474 	if (!rfkill->registered)
475 		return ret;
476 
477 	if (change)
478 		schedule_work(&rfkill->uevent_work);
479 
480 	return ret;
481 }
482 EXPORT_SYMBOL(rfkill_set_hw_state);
483 
484 static void __rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
485 {
486 	u32 bit = RFKILL_BLOCK_SW;
487 
488 	/* if in a ops->set_block right now, use other bit */
489 	if (rfkill->state & RFKILL_BLOCK_SW_SETCALL)
490 		bit = RFKILL_BLOCK_SW_PREV;
491 
492 	if (blocked)
493 		rfkill->state |= bit;
494 	else
495 		rfkill->state &= ~bit;
496 }
497 
498 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
499 {
500 	unsigned long flags;
501 	bool prev, hwblock;
502 
503 	BUG_ON(!rfkill);
504 
505 	spin_lock_irqsave(&rfkill->lock, flags);
506 	prev = !!(rfkill->state & RFKILL_BLOCK_SW);
507 	__rfkill_set_sw_state(rfkill, blocked);
508 	hwblock = !!(rfkill->state & RFKILL_BLOCK_HW);
509 	blocked = blocked || hwblock;
510 	spin_unlock_irqrestore(&rfkill->lock, flags);
511 
512 	if (!rfkill->registered)
513 		return blocked;
514 
515 	if (prev != blocked && !hwblock)
516 		schedule_work(&rfkill->uevent_work);
517 
518 	rfkill_led_trigger_event(rfkill);
519 
520 	return blocked;
521 }
522 EXPORT_SYMBOL(rfkill_set_sw_state);
523 
524 void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
525 {
526 	unsigned long flags;
527 
528 	BUG_ON(!rfkill);
529 	BUG_ON(rfkill->registered);
530 
531 	spin_lock_irqsave(&rfkill->lock, flags);
532 	__rfkill_set_sw_state(rfkill, blocked);
533 	rfkill->persistent = true;
534 	spin_unlock_irqrestore(&rfkill->lock, flags);
535 }
536 EXPORT_SYMBOL(rfkill_init_sw_state);
537 
538 void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
539 {
540 	unsigned long flags;
541 	bool swprev, hwprev;
542 
543 	BUG_ON(!rfkill);
544 
545 	spin_lock_irqsave(&rfkill->lock, flags);
546 
547 	/*
548 	 * No need to care about prev/setblock ... this is for uevent only
549 	 * and that will get triggered by rfkill_set_block anyway.
550 	 */
551 	swprev = !!(rfkill->state & RFKILL_BLOCK_SW);
552 	hwprev = !!(rfkill->state & RFKILL_BLOCK_HW);
553 	__rfkill_set_sw_state(rfkill, sw);
554 	if (hw)
555 		rfkill->state |= RFKILL_BLOCK_HW;
556 	else
557 		rfkill->state &= ~RFKILL_BLOCK_HW;
558 
559 	spin_unlock_irqrestore(&rfkill->lock, flags);
560 
561 	if (!rfkill->registered) {
562 		rfkill->persistent = true;
563 	} else {
564 		if (swprev != sw || hwprev != hw)
565 			schedule_work(&rfkill->uevent_work);
566 
567 		rfkill_led_trigger_event(rfkill);
568 	}
569 }
570 EXPORT_SYMBOL(rfkill_set_states);
571 
572 static ssize_t rfkill_name_show(struct device *dev,
573 				struct device_attribute *attr,
574 				char *buf)
575 {
576 	struct rfkill *rfkill = to_rfkill(dev);
577 
578 	return sprintf(buf, "%s\n", rfkill->name);
579 }
580 
581 static const char *rfkill_get_type_str(enum rfkill_type type)
582 {
583 	BUILD_BUG_ON(NUM_RFKILL_TYPES != RFKILL_TYPE_FM + 1);
584 
585 	switch (type) {
586 	case RFKILL_TYPE_WLAN:
587 		return "wlan";
588 	case RFKILL_TYPE_BLUETOOTH:
589 		return "bluetooth";
590 	case RFKILL_TYPE_UWB:
591 		return "ultrawideband";
592 	case RFKILL_TYPE_WIMAX:
593 		return "wimax";
594 	case RFKILL_TYPE_WWAN:
595 		return "wwan";
596 	case RFKILL_TYPE_GPS:
597 		return "gps";
598 	case RFKILL_TYPE_FM:
599 		return "fm";
600 	default:
601 		BUG();
602 	}
603 }
604 
605 static ssize_t rfkill_type_show(struct device *dev,
606 				struct device_attribute *attr,
607 				char *buf)
608 {
609 	struct rfkill *rfkill = to_rfkill(dev);
610 
611 	return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
612 }
613 
614 static ssize_t rfkill_idx_show(struct device *dev,
615 			       struct device_attribute *attr,
616 			       char *buf)
617 {
618 	struct rfkill *rfkill = to_rfkill(dev);
619 
620 	return sprintf(buf, "%d\n", rfkill->idx);
621 }
622 
623 static ssize_t rfkill_persistent_show(struct device *dev,
624 			       struct device_attribute *attr,
625 			       char *buf)
626 {
627 	struct rfkill *rfkill = to_rfkill(dev);
628 
629 	return sprintf(buf, "%d\n", rfkill->persistent);
630 }
631 
632 static ssize_t rfkill_hard_show(struct device *dev,
633 				 struct device_attribute *attr,
634 				 char *buf)
635 {
636 	struct rfkill *rfkill = to_rfkill(dev);
637 
638 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
639 }
640 
641 static ssize_t rfkill_soft_show(struct device *dev,
642 				 struct device_attribute *attr,
643 				 char *buf)
644 {
645 	struct rfkill *rfkill = to_rfkill(dev);
646 
647 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
648 }
649 
650 static ssize_t rfkill_soft_store(struct device *dev,
651 				  struct device_attribute *attr,
652 				  const char *buf, size_t count)
653 {
654 	struct rfkill *rfkill = to_rfkill(dev);
655 	unsigned long state;
656 	int err;
657 
658 	if (!capable(CAP_NET_ADMIN))
659 		return -EPERM;
660 
661 	err = strict_strtoul(buf, 0, &state);
662 	if (err)
663 		return err;
664 
665 	if (state > 1 )
666 		return -EINVAL;
667 
668 	mutex_lock(&rfkill_global_mutex);
669 	rfkill_set_block(rfkill, state);
670 	mutex_unlock(&rfkill_global_mutex);
671 
672 	return err ?: count;
673 }
674 
675 static u8 user_state_from_blocked(unsigned long state)
676 {
677 	if (state & RFKILL_BLOCK_HW)
678 		return RFKILL_USER_STATE_HARD_BLOCKED;
679 	if (state & RFKILL_BLOCK_SW)
680 		return RFKILL_USER_STATE_SOFT_BLOCKED;
681 
682 	return RFKILL_USER_STATE_UNBLOCKED;
683 }
684 
685 static ssize_t rfkill_state_show(struct device *dev,
686 				 struct device_attribute *attr,
687 				 char *buf)
688 {
689 	struct rfkill *rfkill = to_rfkill(dev);
690 
691 	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
692 }
693 
694 static ssize_t rfkill_state_store(struct device *dev,
695 				  struct device_attribute *attr,
696 				  const char *buf, size_t count)
697 {
698 	struct rfkill *rfkill = to_rfkill(dev);
699 	unsigned long state;
700 	int err;
701 
702 	if (!capable(CAP_NET_ADMIN))
703 		return -EPERM;
704 
705 	err = strict_strtoul(buf, 0, &state);
706 	if (err)
707 		return err;
708 
709 	if (state != RFKILL_USER_STATE_SOFT_BLOCKED &&
710 	    state != RFKILL_USER_STATE_UNBLOCKED)
711 		return -EINVAL;
712 
713 	mutex_lock(&rfkill_global_mutex);
714 	rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED);
715 	mutex_unlock(&rfkill_global_mutex);
716 
717 	return err ?: count;
718 }
719 
720 static ssize_t rfkill_claim_show(struct device *dev,
721 				 struct device_attribute *attr,
722 				 char *buf)
723 {
724 	return sprintf(buf, "%d\n", 0);
725 }
726 
727 static ssize_t rfkill_claim_store(struct device *dev,
728 				  struct device_attribute *attr,
729 				  const char *buf, size_t count)
730 {
731 	return -EOPNOTSUPP;
732 }
733 
734 static struct device_attribute rfkill_dev_attrs[] = {
735 	__ATTR(name, S_IRUGO, rfkill_name_show, NULL),
736 	__ATTR(type, S_IRUGO, rfkill_type_show, NULL),
737 	__ATTR(index, S_IRUGO, rfkill_idx_show, NULL),
738 	__ATTR(persistent, S_IRUGO, rfkill_persistent_show, NULL),
739 	__ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
740 	__ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
741 	__ATTR(soft, S_IRUGO|S_IWUSR, rfkill_soft_show, rfkill_soft_store),
742 	__ATTR(hard, S_IRUGO, rfkill_hard_show, NULL),
743 	__ATTR_NULL
744 };
745 
746 static void rfkill_release(struct device *dev)
747 {
748 	struct rfkill *rfkill = to_rfkill(dev);
749 
750 	kfree(rfkill);
751 }
752 
753 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
754 {
755 	struct rfkill *rfkill = to_rfkill(dev);
756 	unsigned long flags;
757 	u32 state;
758 	int error;
759 
760 	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
761 	if (error)
762 		return error;
763 	error = add_uevent_var(env, "RFKILL_TYPE=%s",
764 			       rfkill_get_type_str(rfkill->type));
765 	if (error)
766 		return error;
767 	spin_lock_irqsave(&rfkill->lock, flags);
768 	state = rfkill->state;
769 	spin_unlock_irqrestore(&rfkill->lock, flags);
770 	error = add_uevent_var(env, "RFKILL_STATE=%d",
771 			       user_state_from_blocked(state));
772 	return error;
773 }
774 
775 void rfkill_pause_polling(struct rfkill *rfkill)
776 {
777 	BUG_ON(!rfkill);
778 
779 	if (!rfkill->ops->poll)
780 		return;
781 
782 	cancel_delayed_work_sync(&rfkill->poll_work);
783 }
784 EXPORT_SYMBOL(rfkill_pause_polling);
785 
786 void rfkill_resume_polling(struct rfkill *rfkill)
787 {
788 	BUG_ON(!rfkill);
789 
790 	if (!rfkill->ops->poll)
791 		return;
792 
793 	schedule_work(&rfkill->poll_work.work);
794 }
795 EXPORT_SYMBOL(rfkill_resume_polling);
796 
797 static int rfkill_suspend(struct device *dev, pm_message_t state)
798 {
799 	struct rfkill *rfkill = to_rfkill(dev);
800 
801 	rfkill_pause_polling(rfkill);
802 
803 	return 0;
804 }
805 
806 static int rfkill_resume(struct device *dev)
807 {
808 	struct rfkill *rfkill = to_rfkill(dev);
809 	bool cur;
810 
811 	if (!rfkill->persistent) {
812 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
813 		rfkill_set_block(rfkill, cur);
814 	}
815 
816 	rfkill_resume_polling(rfkill);
817 
818 	return 0;
819 }
820 
821 static struct class rfkill_class = {
822 	.name		= "rfkill",
823 	.dev_release	= rfkill_release,
824 	.dev_attrs	= rfkill_dev_attrs,
825 	.dev_uevent	= rfkill_dev_uevent,
826 	.suspend	= rfkill_suspend,
827 	.resume		= rfkill_resume,
828 };
829 
830 bool rfkill_blocked(struct rfkill *rfkill)
831 {
832 	unsigned long flags;
833 	u32 state;
834 
835 	spin_lock_irqsave(&rfkill->lock, flags);
836 	state = rfkill->state;
837 	spin_unlock_irqrestore(&rfkill->lock, flags);
838 
839 	return !!(state & RFKILL_BLOCK_ANY);
840 }
841 EXPORT_SYMBOL(rfkill_blocked);
842 
843 
844 struct rfkill * __must_check rfkill_alloc(const char *name,
845 					  struct device *parent,
846 					  const enum rfkill_type type,
847 					  const struct rfkill_ops *ops,
848 					  void *ops_data)
849 {
850 	struct rfkill *rfkill;
851 	struct device *dev;
852 
853 	if (WARN_ON(!ops))
854 		return NULL;
855 
856 	if (WARN_ON(!ops->set_block))
857 		return NULL;
858 
859 	if (WARN_ON(!name))
860 		return NULL;
861 
862 	if (WARN_ON(type == RFKILL_TYPE_ALL || type >= NUM_RFKILL_TYPES))
863 		return NULL;
864 
865 	rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL);
866 	if (!rfkill)
867 		return NULL;
868 
869 	spin_lock_init(&rfkill->lock);
870 	INIT_LIST_HEAD(&rfkill->node);
871 	rfkill->type = type;
872 	rfkill->name = name;
873 	rfkill->ops = ops;
874 	rfkill->data = ops_data;
875 
876 	dev = &rfkill->dev;
877 	dev->class = &rfkill_class;
878 	dev->parent = parent;
879 	device_initialize(dev);
880 
881 	return rfkill;
882 }
883 EXPORT_SYMBOL(rfkill_alloc);
884 
885 static void rfkill_poll(struct work_struct *work)
886 {
887 	struct rfkill *rfkill;
888 
889 	rfkill = container_of(work, struct rfkill, poll_work.work);
890 
891 	/*
892 	 * Poll hardware state -- driver will use one of the
893 	 * rfkill_set{,_hw,_sw}_state functions and use its
894 	 * return value to update the current status.
895 	 */
896 	rfkill->ops->poll(rfkill, rfkill->data);
897 
898 	schedule_delayed_work(&rfkill->poll_work,
899 		round_jiffies_relative(POLL_INTERVAL));
900 }
901 
902 static void rfkill_uevent_work(struct work_struct *work)
903 {
904 	struct rfkill *rfkill;
905 
906 	rfkill = container_of(work, struct rfkill, uevent_work);
907 
908 	mutex_lock(&rfkill_global_mutex);
909 	rfkill_event(rfkill);
910 	mutex_unlock(&rfkill_global_mutex);
911 }
912 
913 static void rfkill_sync_work(struct work_struct *work)
914 {
915 	struct rfkill *rfkill;
916 	bool cur;
917 
918 	rfkill = container_of(work, struct rfkill, sync_work);
919 
920 	mutex_lock(&rfkill_global_mutex);
921 	cur = rfkill_global_states[rfkill->type].cur;
922 	rfkill_set_block(rfkill, cur);
923 	mutex_unlock(&rfkill_global_mutex);
924 }
925 
926 int __must_check rfkill_register(struct rfkill *rfkill)
927 {
928 	static unsigned long rfkill_no;
929 	struct device *dev = &rfkill->dev;
930 	int error;
931 
932 	BUG_ON(!rfkill);
933 
934 	mutex_lock(&rfkill_global_mutex);
935 
936 	if (rfkill->registered) {
937 		error = -EALREADY;
938 		goto unlock;
939 	}
940 
941 	rfkill->idx = rfkill_no;
942 	dev_set_name(dev, "rfkill%lu", rfkill_no);
943 	rfkill_no++;
944 
945 	list_add_tail(&rfkill->node, &rfkill_list);
946 
947 	error = device_add(dev);
948 	if (error)
949 		goto remove;
950 
951 	error = rfkill_led_trigger_register(rfkill);
952 	if (error)
953 		goto devdel;
954 
955 	rfkill->registered = true;
956 
957 	INIT_DELAYED_WORK(&rfkill->poll_work, rfkill_poll);
958 	INIT_WORK(&rfkill->uevent_work, rfkill_uevent_work);
959 	INIT_WORK(&rfkill->sync_work, rfkill_sync_work);
960 
961 	if (rfkill->ops->poll)
962 		schedule_delayed_work(&rfkill->poll_work,
963 			round_jiffies_relative(POLL_INTERVAL));
964 
965 	if (!rfkill->persistent || rfkill_epo_lock_active) {
966 		schedule_work(&rfkill->sync_work);
967 	} else {
968 #ifdef CONFIG_RFKILL_INPUT
969 		bool soft_blocked = !!(rfkill->state & RFKILL_BLOCK_SW);
970 
971 		if (!atomic_read(&rfkill_input_disabled))
972 			__rfkill_switch_all(rfkill->type, soft_blocked);
973 #endif
974 	}
975 
976 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
977 
978 	mutex_unlock(&rfkill_global_mutex);
979 	return 0;
980 
981  devdel:
982 	device_del(&rfkill->dev);
983  remove:
984 	list_del_init(&rfkill->node);
985  unlock:
986 	mutex_unlock(&rfkill_global_mutex);
987 	return error;
988 }
989 EXPORT_SYMBOL(rfkill_register);
990 
991 void rfkill_unregister(struct rfkill *rfkill)
992 {
993 	BUG_ON(!rfkill);
994 
995 	if (rfkill->ops->poll)
996 		cancel_delayed_work_sync(&rfkill->poll_work);
997 
998 	cancel_work_sync(&rfkill->uevent_work);
999 	cancel_work_sync(&rfkill->sync_work);
1000 
1001 	rfkill->registered = false;
1002 
1003 	device_del(&rfkill->dev);
1004 
1005 	mutex_lock(&rfkill_global_mutex);
1006 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
1007 	list_del_init(&rfkill->node);
1008 	mutex_unlock(&rfkill_global_mutex);
1009 
1010 	rfkill_led_trigger_unregister(rfkill);
1011 }
1012 EXPORT_SYMBOL(rfkill_unregister);
1013 
1014 void rfkill_destroy(struct rfkill *rfkill)
1015 {
1016 	if (rfkill)
1017 		put_device(&rfkill->dev);
1018 }
1019 EXPORT_SYMBOL(rfkill_destroy);
1020 
1021 static int rfkill_fop_open(struct inode *inode, struct file *file)
1022 {
1023 	struct rfkill_data *data;
1024 	struct rfkill *rfkill;
1025 	struct rfkill_int_event *ev, *tmp;
1026 
1027 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1028 	if (!data)
1029 		return -ENOMEM;
1030 
1031 	INIT_LIST_HEAD(&data->events);
1032 	mutex_init(&data->mtx);
1033 	init_waitqueue_head(&data->read_wait);
1034 
1035 	mutex_lock(&rfkill_global_mutex);
1036 	mutex_lock(&data->mtx);
1037 	/*
1038 	 * start getting events from elsewhere but hold mtx to get
1039 	 * startup events added first
1040 	 */
1041 	list_add(&data->list, &rfkill_fds);
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 	mutex_unlock(&data->mtx);
1051 	mutex_unlock(&rfkill_global_mutex);
1052 
1053 	file->private_data = data;
1054 
1055 	return nonseekable_open(inode, file);
1056 
1057  free:
1058 	mutex_unlock(&data->mtx);
1059 	mutex_unlock(&rfkill_global_mutex);
1060 	mutex_destroy(&data->mtx);
1061 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1062 		kfree(ev);
1063 	kfree(data);
1064 	return -ENOMEM;
1065 }
1066 
1067 static unsigned int rfkill_fop_poll(struct file *file, poll_table *wait)
1068 {
1069 	struct rfkill_data *data = file->private_data;
1070 	unsigned int res = POLLOUT | POLLWRNORM;
1071 
1072 	poll_wait(file, &data->read_wait, wait);
1073 
1074 	mutex_lock(&data->mtx);
1075 	if (!list_empty(&data->events))
1076 		res = POLLIN | POLLRDNORM;
1077 	mutex_unlock(&data->mtx);
1078 
1079 	return res;
1080 }
1081 
1082 static bool rfkill_readable(struct rfkill_data *data)
1083 {
1084 	bool r;
1085 
1086 	mutex_lock(&data->mtx);
1087 	r = !list_empty(&data->events);
1088 	mutex_unlock(&data->mtx);
1089 
1090 	return r;
1091 }
1092 
1093 static ssize_t rfkill_fop_read(struct file *file, char __user *buf,
1094 			       size_t count, loff_t *pos)
1095 {
1096 	struct rfkill_data *data = file->private_data;
1097 	struct rfkill_int_event *ev;
1098 	unsigned long sz;
1099 	int ret;
1100 
1101 	mutex_lock(&data->mtx);
1102 
1103 	while (list_empty(&data->events)) {
1104 		if (file->f_flags & O_NONBLOCK) {
1105 			ret = -EAGAIN;
1106 			goto out;
1107 		}
1108 		mutex_unlock(&data->mtx);
1109 		ret = wait_event_interruptible(data->read_wait,
1110 					       rfkill_readable(data));
1111 		mutex_lock(&data->mtx);
1112 
1113 		if (ret)
1114 			goto out;
1115 	}
1116 
1117 	ev = list_first_entry(&data->events, struct rfkill_int_event,
1118 				list);
1119 
1120 	sz = min_t(unsigned long, sizeof(ev->ev), count);
1121 	ret = sz;
1122 	if (copy_to_user(buf, &ev->ev, sz))
1123 		ret = -EFAULT;
1124 
1125 	list_del(&ev->list);
1126 	kfree(ev);
1127  out:
1128 	mutex_unlock(&data->mtx);
1129 	return ret;
1130 }
1131 
1132 static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
1133 				size_t count, loff_t *pos)
1134 {
1135 	struct rfkill *rfkill;
1136 	struct rfkill_event ev;
1137 
1138 	/* we don't need the 'hard' variable but accept it */
1139 	if (count < RFKILL_EVENT_SIZE_V1 - 1)
1140 		return -EINVAL;
1141 
1142 	/*
1143 	 * Copy as much data as we can accept into our 'ev' buffer,
1144 	 * but tell userspace how much we've copied so it can determine
1145 	 * our API version even in a write() call, if it cares.
1146 	 */
1147 	count = min(count, sizeof(ev));
1148 	if (copy_from_user(&ev, buf, count))
1149 		return -EFAULT;
1150 
1151 	if (ev.op != RFKILL_OP_CHANGE && ev.op != RFKILL_OP_CHANGE_ALL)
1152 		return -EINVAL;
1153 
1154 	if (ev.type >= NUM_RFKILL_TYPES)
1155 		return -EINVAL;
1156 
1157 	mutex_lock(&rfkill_global_mutex);
1158 
1159 	if (ev.op == RFKILL_OP_CHANGE_ALL) {
1160 		if (ev.type == RFKILL_TYPE_ALL) {
1161 			enum rfkill_type i;
1162 			for (i = 0; i < NUM_RFKILL_TYPES; i++)
1163 				rfkill_global_states[i].cur = ev.soft;
1164 		} else {
1165 			rfkill_global_states[ev.type].cur = ev.soft;
1166 		}
1167 	}
1168 
1169 	list_for_each_entry(rfkill, &rfkill_list, node) {
1170 		if (rfkill->idx != ev.idx && ev.op != RFKILL_OP_CHANGE_ALL)
1171 			continue;
1172 
1173 		if (rfkill->type != ev.type && ev.type != RFKILL_TYPE_ALL)
1174 			continue;
1175 
1176 		rfkill_set_block(rfkill, ev.soft);
1177 	}
1178 	mutex_unlock(&rfkill_global_mutex);
1179 
1180 	return count;
1181 }
1182 
1183 static int rfkill_fop_release(struct inode *inode, struct file *file)
1184 {
1185 	struct rfkill_data *data = file->private_data;
1186 	struct rfkill_int_event *ev, *tmp;
1187 
1188 	mutex_lock(&rfkill_global_mutex);
1189 	list_del(&data->list);
1190 	mutex_unlock(&rfkill_global_mutex);
1191 
1192 	mutex_destroy(&data->mtx);
1193 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1194 		kfree(ev);
1195 
1196 #ifdef CONFIG_RFKILL_INPUT
1197 	if (data->input_handler)
1198 		if (atomic_dec_return(&rfkill_input_disabled) == 0)
1199 			printk(KERN_DEBUG "rfkill: input handler enabled\n");
1200 #endif
1201 
1202 	kfree(data);
1203 
1204 	return 0;
1205 }
1206 
1207 #ifdef CONFIG_RFKILL_INPUT
1208 static long rfkill_fop_ioctl(struct file *file, unsigned int cmd,
1209 			     unsigned long arg)
1210 {
1211 	struct rfkill_data *data = file->private_data;
1212 
1213 	if (_IOC_TYPE(cmd) != RFKILL_IOC_MAGIC)
1214 		return -ENOSYS;
1215 
1216 	if (_IOC_NR(cmd) != RFKILL_IOC_NOINPUT)
1217 		return -ENOSYS;
1218 
1219 	mutex_lock(&data->mtx);
1220 
1221 	if (!data->input_handler) {
1222 		if (atomic_inc_return(&rfkill_input_disabled) == 1)
1223 			printk(KERN_DEBUG "rfkill: input handler disabled\n");
1224 		data->input_handler = true;
1225 	}
1226 
1227 	mutex_unlock(&data->mtx);
1228 
1229 	return 0;
1230 }
1231 #endif
1232 
1233 static const struct file_operations rfkill_fops = {
1234 	.owner		= THIS_MODULE,
1235 	.open		= rfkill_fop_open,
1236 	.read		= rfkill_fop_read,
1237 	.write		= rfkill_fop_write,
1238 	.poll		= rfkill_fop_poll,
1239 	.release	= rfkill_fop_release,
1240 #ifdef CONFIG_RFKILL_INPUT
1241 	.unlocked_ioctl	= rfkill_fop_ioctl,
1242 	.compat_ioctl	= rfkill_fop_ioctl,
1243 #endif
1244 };
1245 
1246 static struct miscdevice rfkill_miscdev = {
1247 	.name	= "rfkill",
1248 	.fops	= &rfkill_fops,
1249 	.minor	= MISC_DYNAMIC_MINOR,
1250 };
1251 
1252 static int __init rfkill_init(void)
1253 {
1254 	int error;
1255 	int i;
1256 
1257 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
1258 		rfkill_global_states[i].cur = !rfkill_default_state;
1259 
1260 	error = class_register(&rfkill_class);
1261 	if (error)
1262 		goto out;
1263 
1264 	error = misc_register(&rfkill_miscdev);
1265 	if (error) {
1266 		class_unregister(&rfkill_class);
1267 		goto out;
1268 	}
1269 
1270 #ifdef CONFIG_RFKILL_INPUT
1271 	error = rfkill_handler_init();
1272 	if (error) {
1273 		misc_deregister(&rfkill_miscdev);
1274 		class_unregister(&rfkill_class);
1275 		goto out;
1276 	}
1277 #endif
1278 
1279  out:
1280 	return error;
1281 }
1282 subsys_initcall(rfkill_init);
1283 
1284 static void __exit rfkill_exit(void)
1285 {
1286 #ifdef CONFIG_RFKILL_INPUT
1287 	rfkill_handler_exit();
1288 #endif
1289 	misc_deregister(&rfkill_miscdev);
1290 	class_unregister(&rfkill_class);
1291 }
1292 module_exit(rfkill_exit);
1293