xref: /linux/net/rfkill/core.c (revision af873fcecef567abf8a3468b06dd4e4aab46da6d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2006 - 2007 Ivo van Doorn
4  * Copyright (C) 2007 Dmitry Torokhov
5  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/workqueue.h>
12 #include <linux/capability.h>
13 #include <linux/list.h>
14 #include <linux/mutex.h>
15 #include <linux/rfkill.h>
16 #include <linux/sched.h>
17 #include <linux/spinlock.h>
18 #include <linux/device.h>
19 #include <linux/miscdevice.h>
20 #include <linux/wait.h>
21 #include <linux/poll.h>
22 #include <linux/fs.h>
23 #include <linux/slab.h>
24 
25 #include "rfkill.h"
26 
27 #define POLL_INTERVAL		(5 * HZ)
28 
29 #define RFKILL_BLOCK_HW		BIT(0)
30 #define RFKILL_BLOCK_SW		BIT(1)
31 #define RFKILL_BLOCK_SW_PREV	BIT(2)
32 #define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
33 				 RFKILL_BLOCK_SW |\
34 				 RFKILL_BLOCK_SW_PREV)
35 #define RFKILL_BLOCK_SW_SETCALL	BIT(31)
36 
37 struct rfkill {
38 	spinlock_t		lock;
39 
40 	enum rfkill_type	type;
41 
42 	unsigned long		state;
43 
44 	u32			idx;
45 
46 	bool			registered;
47 	bool			persistent;
48 	bool			polling_paused;
49 	bool			suspended;
50 
51 	const struct rfkill_ops	*ops;
52 	void			*data;
53 
54 #ifdef CONFIG_RFKILL_LEDS
55 	struct led_trigger	led_trigger;
56 	const char		*ledtrigname;
57 #endif
58 
59 	struct device		dev;
60 	struct list_head	node;
61 
62 	struct delayed_work	poll_work;
63 	struct work_struct	uevent_work;
64 	struct work_struct	sync_work;
65 	char			name[];
66 };
67 #define to_rfkill(d)	container_of(d, struct rfkill, dev)
68 
69 struct rfkill_int_event {
70 	struct list_head	list;
71 	struct rfkill_event	ev;
72 };
73 
74 struct rfkill_data {
75 	struct list_head	list;
76 	struct list_head	events;
77 	struct mutex		mtx;
78 	wait_queue_head_t	read_wait;
79 	bool			input_handler;
80 };
81 
82 
83 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
84 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
85 MODULE_DESCRIPTION("RF switch support");
86 MODULE_LICENSE("GPL");
87 
88 
89 /*
90  * The locking here should be made much smarter, we currently have
91  * a bit of a stupid situation because drivers might want to register
92  * the rfkill struct under their own lock, and take this lock during
93  * rfkill method calls -- which will cause an AB-BA deadlock situation.
94  *
95  * To fix that, we need to rework this code here to be mostly lock-free
96  * and only use the mutex for list manipulations, not to protect the
97  * various other global variables. Then we can avoid holding the mutex
98  * around driver operations, and all is happy.
99  */
100 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
101 static DEFINE_MUTEX(rfkill_global_mutex);
102 static LIST_HEAD(rfkill_fds);	/* list of open fds of /dev/rfkill */
103 
104 static unsigned int rfkill_default_state = 1;
105 module_param_named(default_state, rfkill_default_state, uint, 0444);
106 MODULE_PARM_DESC(default_state,
107 		 "Default initial state for all radio types, 0 = radio off");
108 
109 static struct {
110 	bool cur, sav;
111 } rfkill_global_states[NUM_RFKILL_TYPES];
112 
113 static bool rfkill_epo_lock_active;
114 
115 
116 #ifdef CONFIG_RFKILL_LEDS
117 static void rfkill_led_trigger_event(struct rfkill *rfkill)
118 {
119 	struct led_trigger *trigger;
120 
121 	if (!rfkill->registered)
122 		return;
123 
124 	trigger = &rfkill->led_trigger;
125 
126 	if (rfkill->state & RFKILL_BLOCK_ANY)
127 		led_trigger_event(trigger, LED_OFF);
128 	else
129 		led_trigger_event(trigger, LED_FULL);
130 }
131 
132 static int rfkill_led_trigger_activate(struct led_classdev *led)
133 {
134 	struct rfkill *rfkill;
135 
136 	rfkill = container_of(led->trigger, struct rfkill, led_trigger);
137 
138 	rfkill_led_trigger_event(rfkill);
139 
140 	return 0;
141 }
142 
143 const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
144 {
145 	return rfkill->led_trigger.name;
146 }
147 EXPORT_SYMBOL(rfkill_get_led_trigger_name);
148 
149 void rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name)
150 {
151 	BUG_ON(!rfkill);
152 
153 	rfkill->ledtrigname = name;
154 }
155 EXPORT_SYMBOL(rfkill_set_led_trigger_name);
156 
157 static int rfkill_led_trigger_register(struct rfkill *rfkill)
158 {
159 	rfkill->led_trigger.name = rfkill->ledtrigname
160 					? : dev_name(&rfkill->dev);
161 	rfkill->led_trigger.activate = rfkill_led_trigger_activate;
162 	return led_trigger_register(&rfkill->led_trigger);
163 }
164 
165 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
166 {
167 	led_trigger_unregister(&rfkill->led_trigger);
168 }
169 
170 static struct led_trigger rfkill_any_led_trigger;
171 static struct led_trigger rfkill_none_led_trigger;
172 static struct work_struct rfkill_global_led_trigger_work;
173 
174 static void rfkill_global_led_trigger_worker(struct work_struct *work)
175 {
176 	enum led_brightness brightness = LED_OFF;
177 	struct rfkill *rfkill;
178 
179 	mutex_lock(&rfkill_global_mutex);
180 	list_for_each_entry(rfkill, &rfkill_list, node) {
181 		if (!(rfkill->state & RFKILL_BLOCK_ANY)) {
182 			brightness = LED_FULL;
183 			break;
184 		}
185 	}
186 	mutex_unlock(&rfkill_global_mutex);
187 
188 	led_trigger_event(&rfkill_any_led_trigger, brightness);
189 	led_trigger_event(&rfkill_none_led_trigger,
190 			  brightness == LED_OFF ? LED_FULL : LED_OFF);
191 }
192 
193 static void rfkill_global_led_trigger_event(void)
194 {
195 	schedule_work(&rfkill_global_led_trigger_work);
196 }
197 
198 static int rfkill_global_led_trigger_register(void)
199 {
200 	int ret;
201 
202 	INIT_WORK(&rfkill_global_led_trigger_work,
203 			rfkill_global_led_trigger_worker);
204 
205 	rfkill_any_led_trigger.name = "rfkill-any";
206 	ret = led_trigger_register(&rfkill_any_led_trigger);
207 	if (ret)
208 		return ret;
209 
210 	rfkill_none_led_trigger.name = "rfkill-none";
211 	ret = led_trigger_register(&rfkill_none_led_trigger);
212 	if (ret)
213 		led_trigger_unregister(&rfkill_any_led_trigger);
214 	else
215 		/* Delay activation until all global triggers are registered */
216 		rfkill_global_led_trigger_event();
217 
218 	return ret;
219 }
220 
221 static void rfkill_global_led_trigger_unregister(void)
222 {
223 	led_trigger_unregister(&rfkill_none_led_trigger);
224 	led_trigger_unregister(&rfkill_any_led_trigger);
225 	cancel_work_sync(&rfkill_global_led_trigger_work);
226 }
227 #else
228 static void rfkill_led_trigger_event(struct rfkill *rfkill)
229 {
230 }
231 
232 static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
233 {
234 	return 0;
235 }
236 
237 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
238 {
239 }
240 
241 static void rfkill_global_led_trigger_event(void)
242 {
243 }
244 
245 static int rfkill_global_led_trigger_register(void)
246 {
247 	return 0;
248 }
249 
250 static void rfkill_global_led_trigger_unregister(void)
251 {
252 }
253 #endif /* CONFIG_RFKILL_LEDS */
254 
255 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
256 			      enum rfkill_operation op)
257 {
258 	unsigned long flags;
259 
260 	ev->idx = rfkill->idx;
261 	ev->type = rfkill->type;
262 	ev->op = op;
263 
264 	spin_lock_irqsave(&rfkill->lock, flags);
265 	ev->hard = !!(rfkill->state & RFKILL_BLOCK_HW);
266 	ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW |
267 					RFKILL_BLOCK_SW_PREV));
268 	spin_unlock_irqrestore(&rfkill->lock, flags);
269 }
270 
271 static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op)
272 {
273 	struct rfkill_data *data;
274 	struct rfkill_int_event *ev;
275 
276 	list_for_each_entry(data, &rfkill_fds, list) {
277 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
278 		if (!ev)
279 			continue;
280 		rfkill_fill_event(&ev->ev, rfkill, op);
281 		mutex_lock(&data->mtx);
282 		list_add_tail(&ev->list, &data->events);
283 		mutex_unlock(&data->mtx);
284 		wake_up_interruptible(&data->read_wait);
285 	}
286 }
287 
288 static void rfkill_event(struct rfkill *rfkill)
289 {
290 	if (!rfkill->registered)
291 		return;
292 
293 	kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
294 
295 	/* also send event to /dev/rfkill */
296 	rfkill_send_events(rfkill, RFKILL_OP_CHANGE);
297 }
298 
299 /**
300  * rfkill_set_block - wrapper for set_block method
301  *
302  * @rfkill: the rfkill struct to use
303  * @blocked: the new software state
304  *
305  * Calls the set_block method (when applicable) and handles notifications
306  * etc. as well.
307  */
308 static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
309 {
310 	unsigned long flags;
311 	bool prev, curr;
312 	int err;
313 
314 	if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
315 		return;
316 
317 	/*
318 	 * Some platforms (...!) generate input events which affect the
319 	 * _hard_ kill state -- whenever something tries to change the
320 	 * current software state query the hardware state too.
321 	 */
322 	if (rfkill->ops->query)
323 		rfkill->ops->query(rfkill, rfkill->data);
324 
325 	spin_lock_irqsave(&rfkill->lock, flags);
326 	prev = rfkill->state & RFKILL_BLOCK_SW;
327 
328 	if (prev)
329 		rfkill->state |= RFKILL_BLOCK_SW_PREV;
330 	else
331 		rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
332 
333 	if (blocked)
334 		rfkill->state |= RFKILL_BLOCK_SW;
335 	else
336 		rfkill->state &= ~RFKILL_BLOCK_SW;
337 
338 	rfkill->state |= RFKILL_BLOCK_SW_SETCALL;
339 	spin_unlock_irqrestore(&rfkill->lock, flags);
340 
341 	err = rfkill->ops->set_block(rfkill->data, blocked);
342 
343 	spin_lock_irqsave(&rfkill->lock, flags);
344 	if (err) {
345 		/*
346 		 * Failed -- reset status to _PREV, which may be different
347 		 * from what we have set _PREV to earlier in this function
348 		 * if rfkill_set_sw_state was invoked.
349 		 */
350 		if (rfkill->state & RFKILL_BLOCK_SW_PREV)
351 			rfkill->state |= RFKILL_BLOCK_SW;
352 		else
353 			rfkill->state &= ~RFKILL_BLOCK_SW;
354 	}
355 	rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL;
356 	rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
357 	curr = rfkill->state & RFKILL_BLOCK_SW;
358 	spin_unlock_irqrestore(&rfkill->lock, flags);
359 
360 	rfkill_led_trigger_event(rfkill);
361 	rfkill_global_led_trigger_event();
362 
363 	if (prev != curr)
364 		rfkill_event(rfkill);
365 }
366 
367 static void rfkill_update_global_state(enum rfkill_type type, bool blocked)
368 {
369 	int i;
370 
371 	if (type != RFKILL_TYPE_ALL) {
372 		rfkill_global_states[type].cur = blocked;
373 		return;
374 	}
375 
376 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
377 		rfkill_global_states[i].cur = blocked;
378 }
379 
380 #ifdef CONFIG_RFKILL_INPUT
381 static atomic_t rfkill_input_disabled = ATOMIC_INIT(0);
382 
383 /**
384  * __rfkill_switch_all - Toggle state of all switches of given type
385  * @type: type of interfaces to be affected
386  * @blocked: the new state
387  *
388  * This function sets the state of all switches of given type,
389  * unless a specific switch is suspended.
390  *
391  * Caller must have acquired rfkill_global_mutex.
392  */
393 static void __rfkill_switch_all(const enum rfkill_type type, bool blocked)
394 {
395 	struct rfkill *rfkill;
396 
397 	rfkill_update_global_state(type, blocked);
398 	list_for_each_entry(rfkill, &rfkill_list, node) {
399 		if (rfkill->type != type && type != RFKILL_TYPE_ALL)
400 			continue;
401 
402 		rfkill_set_block(rfkill, blocked);
403 	}
404 }
405 
406 /**
407  * rfkill_switch_all - Toggle state of all switches of given type
408  * @type: type of interfaces to be affected
409  * @blocked: the new state
410  *
411  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
412  * Please refer to __rfkill_switch_all() for details.
413  *
414  * Does nothing if the EPO lock is active.
415  */
416 void rfkill_switch_all(enum rfkill_type type, bool blocked)
417 {
418 	if (atomic_read(&rfkill_input_disabled))
419 		return;
420 
421 	mutex_lock(&rfkill_global_mutex);
422 
423 	if (!rfkill_epo_lock_active)
424 		__rfkill_switch_all(type, blocked);
425 
426 	mutex_unlock(&rfkill_global_mutex);
427 }
428 
429 /**
430  * rfkill_epo - emergency power off all transmitters
431  *
432  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
433  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
434  *
435  * The global state before the EPO is saved and can be restored later
436  * using rfkill_restore_states().
437  */
438 void rfkill_epo(void)
439 {
440 	struct rfkill *rfkill;
441 	int i;
442 
443 	if (atomic_read(&rfkill_input_disabled))
444 		return;
445 
446 	mutex_lock(&rfkill_global_mutex);
447 
448 	rfkill_epo_lock_active = true;
449 	list_for_each_entry(rfkill, &rfkill_list, node)
450 		rfkill_set_block(rfkill, true);
451 
452 	for (i = 0; i < NUM_RFKILL_TYPES; i++) {
453 		rfkill_global_states[i].sav = rfkill_global_states[i].cur;
454 		rfkill_global_states[i].cur = true;
455 	}
456 
457 	mutex_unlock(&rfkill_global_mutex);
458 }
459 
460 /**
461  * rfkill_restore_states - restore global states
462  *
463  * Restore (and sync switches to) the global state from the
464  * states in rfkill_default_states.  This can undo the effects of
465  * a call to rfkill_epo().
466  */
467 void rfkill_restore_states(void)
468 {
469 	int i;
470 
471 	if (atomic_read(&rfkill_input_disabled))
472 		return;
473 
474 	mutex_lock(&rfkill_global_mutex);
475 
476 	rfkill_epo_lock_active = false;
477 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
478 		__rfkill_switch_all(i, rfkill_global_states[i].sav);
479 	mutex_unlock(&rfkill_global_mutex);
480 }
481 
482 /**
483  * rfkill_remove_epo_lock - unlock state changes
484  *
485  * Used by rfkill-input manually unlock state changes, when
486  * the EPO switch is deactivated.
487  */
488 void rfkill_remove_epo_lock(void)
489 {
490 	if (atomic_read(&rfkill_input_disabled))
491 		return;
492 
493 	mutex_lock(&rfkill_global_mutex);
494 	rfkill_epo_lock_active = false;
495 	mutex_unlock(&rfkill_global_mutex);
496 }
497 
498 /**
499  * rfkill_is_epo_lock_active - returns true EPO is active
500  *
501  * Returns 0 (false) if there is NOT an active EPO condition,
502  * and 1 (true) if there is an active EPO condition, which
503  * locks all radios in one of the BLOCKED states.
504  *
505  * Can be called in atomic context.
506  */
507 bool rfkill_is_epo_lock_active(void)
508 {
509 	return rfkill_epo_lock_active;
510 }
511 
512 /**
513  * rfkill_get_global_sw_state - returns global state for a type
514  * @type: the type to get the global state of
515  *
516  * Returns the current global state for a given wireless
517  * device type.
518  */
519 bool rfkill_get_global_sw_state(const enum rfkill_type type)
520 {
521 	return rfkill_global_states[type].cur;
522 }
523 #endif
524 
525 bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
526 {
527 	unsigned long flags;
528 	bool ret, prev;
529 
530 	BUG_ON(!rfkill);
531 
532 	spin_lock_irqsave(&rfkill->lock, flags);
533 	prev = !!(rfkill->state & RFKILL_BLOCK_HW);
534 	if (blocked)
535 		rfkill->state |= RFKILL_BLOCK_HW;
536 	else
537 		rfkill->state &= ~RFKILL_BLOCK_HW;
538 	ret = !!(rfkill->state & RFKILL_BLOCK_ANY);
539 	spin_unlock_irqrestore(&rfkill->lock, flags);
540 
541 	rfkill_led_trigger_event(rfkill);
542 	rfkill_global_led_trigger_event();
543 
544 	if (rfkill->registered && prev != blocked)
545 		schedule_work(&rfkill->uevent_work);
546 
547 	return ret;
548 }
549 EXPORT_SYMBOL(rfkill_set_hw_state);
550 
551 static void __rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
552 {
553 	u32 bit = RFKILL_BLOCK_SW;
554 
555 	/* if in a ops->set_block right now, use other bit */
556 	if (rfkill->state & RFKILL_BLOCK_SW_SETCALL)
557 		bit = RFKILL_BLOCK_SW_PREV;
558 
559 	if (blocked)
560 		rfkill->state |= bit;
561 	else
562 		rfkill->state &= ~bit;
563 }
564 
565 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
566 {
567 	unsigned long flags;
568 	bool prev, hwblock;
569 
570 	BUG_ON(!rfkill);
571 
572 	spin_lock_irqsave(&rfkill->lock, flags);
573 	prev = !!(rfkill->state & RFKILL_BLOCK_SW);
574 	__rfkill_set_sw_state(rfkill, blocked);
575 	hwblock = !!(rfkill->state & RFKILL_BLOCK_HW);
576 	blocked = blocked || hwblock;
577 	spin_unlock_irqrestore(&rfkill->lock, flags);
578 
579 	if (!rfkill->registered)
580 		return blocked;
581 
582 	if (prev != blocked && !hwblock)
583 		schedule_work(&rfkill->uevent_work);
584 
585 	rfkill_led_trigger_event(rfkill);
586 	rfkill_global_led_trigger_event();
587 
588 	return blocked;
589 }
590 EXPORT_SYMBOL(rfkill_set_sw_state);
591 
592 void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
593 {
594 	unsigned long flags;
595 
596 	BUG_ON(!rfkill);
597 	BUG_ON(rfkill->registered);
598 
599 	spin_lock_irqsave(&rfkill->lock, flags);
600 	__rfkill_set_sw_state(rfkill, blocked);
601 	rfkill->persistent = true;
602 	spin_unlock_irqrestore(&rfkill->lock, flags);
603 }
604 EXPORT_SYMBOL(rfkill_init_sw_state);
605 
606 void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
607 {
608 	unsigned long flags;
609 	bool swprev, hwprev;
610 
611 	BUG_ON(!rfkill);
612 
613 	spin_lock_irqsave(&rfkill->lock, flags);
614 
615 	/*
616 	 * No need to care about prev/setblock ... this is for uevent only
617 	 * and that will get triggered by rfkill_set_block anyway.
618 	 */
619 	swprev = !!(rfkill->state & RFKILL_BLOCK_SW);
620 	hwprev = !!(rfkill->state & RFKILL_BLOCK_HW);
621 	__rfkill_set_sw_state(rfkill, sw);
622 	if (hw)
623 		rfkill->state |= RFKILL_BLOCK_HW;
624 	else
625 		rfkill->state &= ~RFKILL_BLOCK_HW;
626 
627 	spin_unlock_irqrestore(&rfkill->lock, flags);
628 
629 	if (!rfkill->registered) {
630 		rfkill->persistent = true;
631 	} else {
632 		if (swprev != sw || hwprev != hw)
633 			schedule_work(&rfkill->uevent_work);
634 
635 		rfkill_led_trigger_event(rfkill);
636 		rfkill_global_led_trigger_event();
637 	}
638 }
639 EXPORT_SYMBOL(rfkill_set_states);
640 
641 static const char * const rfkill_types[] = {
642 	NULL, /* RFKILL_TYPE_ALL */
643 	"wlan",
644 	"bluetooth",
645 	"ultrawideband",
646 	"wimax",
647 	"wwan",
648 	"gps",
649 	"fm",
650 	"nfc",
651 };
652 
653 enum rfkill_type rfkill_find_type(const char *name)
654 {
655 	int i;
656 
657 	BUILD_BUG_ON(ARRAY_SIZE(rfkill_types) != NUM_RFKILL_TYPES);
658 
659 	if (!name)
660 		return RFKILL_TYPE_ALL;
661 
662 	for (i = 1; i < NUM_RFKILL_TYPES; i++)
663 		if (!strcmp(name, rfkill_types[i]))
664 			return i;
665 	return RFKILL_TYPE_ALL;
666 }
667 EXPORT_SYMBOL(rfkill_find_type);
668 
669 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
670 			 char *buf)
671 {
672 	struct rfkill *rfkill = to_rfkill(dev);
673 
674 	return sprintf(buf, "%s\n", rfkill->name);
675 }
676 static DEVICE_ATTR_RO(name);
677 
678 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
679 			 char *buf)
680 {
681 	struct rfkill *rfkill = to_rfkill(dev);
682 
683 	return sprintf(buf, "%s\n", rfkill_types[rfkill->type]);
684 }
685 static DEVICE_ATTR_RO(type);
686 
687 static ssize_t index_show(struct device *dev, struct device_attribute *attr,
688 			  char *buf)
689 {
690 	struct rfkill *rfkill = to_rfkill(dev);
691 
692 	return sprintf(buf, "%d\n", rfkill->idx);
693 }
694 static DEVICE_ATTR_RO(index);
695 
696 static ssize_t persistent_show(struct device *dev,
697 			       struct device_attribute *attr, char *buf)
698 {
699 	struct rfkill *rfkill = to_rfkill(dev);
700 
701 	return sprintf(buf, "%d\n", rfkill->persistent);
702 }
703 static DEVICE_ATTR_RO(persistent);
704 
705 static ssize_t hard_show(struct device *dev, struct device_attribute *attr,
706 			 char *buf)
707 {
708 	struct rfkill *rfkill = to_rfkill(dev);
709 
710 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
711 }
712 static DEVICE_ATTR_RO(hard);
713 
714 static ssize_t soft_show(struct device *dev, struct device_attribute *attr,
715 			 char *buf)
716 {
717 	struct rfkill *rfkill = to_rfkill(dev);
718 
719 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
720 }
721 
722 static ssize_t soft_store(struct device *dev, struct device_attribute *attr,
723 			  const char *buf, size_t count)
724 {
725 	struct rfkill *rfkill = to_rfkill(dev);
726 	unsigned long state;
727 	int err;
728 
729 	if (!capable(CAP_NET_ADMIN))
730 		return -EPERM;
731 
732 	err = kstrtoul(buf, 0, &state);
733 	if (err)
734 		return err;
735 
736 	if (state > 1 )
737 		return -EINVAL;
738 
739 	mutex_lock(&rfkill_global_mutex);
740 	rfkill_set_block(rfkill, state);
741 	mutex_unlock(&rfkill_global_mutex);
742 
743 	return count;
744 }
745 static DEVICE_ATTR_RW(soft);
746 
747 static u8 user_state_from_blocked(unsigned long state)
748 {
749 	if (state & RFKILL_BLOCK_HW)
750 		return RFKILL_USER_STATE_HARD_BLOCKED;
751 	if (state & RFKILL_BLOCK_SW)
752 		return RFKILL_USER_STATE_SOFT_BLOCKED;
753 
754 	return RFKILL_USER_STATE_UNBLOCKED;
755 }
756 
757 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
758 			  char *buf)
759 {
760 	struct rfkill *rfkill = to_rfkill(dev);
761 
762 	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
763 }
764 
765 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
766 			   const char *buf, size_t count)
767 {
768 	struct rfkill *rfkill = to_rfkill(dev);
769 	unsigned long state;
770 	int err;
771 
772 	if (!capable(CAP_NET_ADMIN))
773 		return -EPERM;
774 
775 	err = kstrtoul(buf, 0, &state);
776 	if (err)
777 		return err;
778 
779 	if (state != RFKILL_USER_STATE_SOFT_BLOCKED &&
780 	    state != RFKILL_USER_STATE_UNBLOCKED)
781 		return -EINVAL;
782 
783 	mutex_lock(&rfkill_global_mutex);
784 	rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED);
785 	mutex_unlock(&rfkill_global_mutex);
786 
787 	return count;
788 }
789 static DEVICE_ATTR_RW(state);
790 
791 static struct attribute *rfkill_dev_attrs[] = {
792 	&dev_attr_name.attr,
793 	&dev_attr_type.attr,
794 	&dev_attr_index.attr,
795 	&dev_attr_persistent.attr,
796 	&dev_attr_state.attr,
797 	&dev_attr_soft.attr,
798 	&dev_attr_hard.attr,
799 	NULL,
800 };
801 ATTRIBUTE_GROUPS(rfkill_dev);
802 
803 static void rfkill_release(struct device *dev)
804 {
805 	struct rfkill *rfkill = to_rfkill(dev);
806 
807 	kfree(rfkill);
808 }
809 
810 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
811 {
812 	struct rfkill *rfkill = to_rfkill(dev);
813 	unsigned long flags;
814 	u32 state;
815 	int error;
816 
817 	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
818 	if (error)
819 		return error;
820 	error = add_uevent_var(env, "RFKILL_TYPE=%s",
821 			       rfkill_types[rfkill->type]);
822 	if (error)
823 		return error;
824 	spin_lock_irqsave(&rfkill->lock, flags);
825 	state = rfkill->state;
826 	spin_unlock_irqrestore(&rfkill->lock, flags);
827 	error = add_uevent_var(env, "RFKILL_STATE=%d",
828 			       user_state_from_blocked(state));
829 	return error;
830 }
831 
832 void rfkill_pause_polling(struct rfkill *rfkill)
833 {
834 	BUG_ON(!rfkill);
835 
836 	if (!rfkill->ops->poll)
837 		return;
838 
839 	rfkill->polling_paused = true;
840 	cancel_delayed_work_sync(&rfkill->poll_work);
841 }
842 EXPORT_SYMBOL(rfkill_pause_polling);
843 
844 void rfkill_resume_polling(struct rfkill *rfkill)
845 {
846 	BUG_ON(!rfkill);
847 
848 	if (!rfkill->ops->poll)
849 		return;
850 
851 	rfkill->polling_paused = false;
852 
853 	if (rfkill->suspended)
854 		return;
855 
856 	queue_delayed_work(system_power_efficient_wq,
857 			   &rfkill->poll_work, 0);
858 }
859 EXPORT_SYMBOL(rfkill_resume_polling);
860 
861 #ifdef CONFIG_PM_SLEEP
862 static int rfkill_suspend(struct device *dev)
863 {
864 	struct rfkill *rfkill = to_rfkill(dev);
865 
866 	rfkill->suspended = true;
867 	cancel_delayed_work_sync(&rfkill->poll_work);
868 
869 	return 0;
870 }
871 
872 static int rfkill_resume(struct device *dev)
873 {
874 	struct rfkill *rfkill = to_rfkill(dev);
875 	bool cur;
876 
877 	rfkill->suspended = false;
878 
879 	if (!rfkill->persistent) {
880 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
881 		rfkill_set_block(rfkill, cur);
882 	}
883 
884 	if (rfkill->ops->poll && !rfkill->polling_paused)
885 		queue_delayed_work(system_power_efficient_wq,
886 				   &rfkill->poll_work, 0);
887 
888 	return 0;
889 }
890 
891 static SIMPLE_DEV_PM_OPS(rfkill_pm_ops, rfkill_suspend, rfkill_resume);
892 #define RFKILL_PM_OPS (&rfkill_pm_ops)
893 #else
894 #define RFKILL_PM_OPS NULL
895 #endif
896 
897 static struct class rfkill_class = {
898 	.name		= "rfkill",
899 	.dev_release	= rfkill_release,
900 	.dev_groups	= rfkill_dev_groups,
901 	.dev_uevent	= rfkill_dev_uevent,
902 	.pm		= RFKILL_PM_OPS,
903 };
904 
905 bool rfkill_blocked(struct rfkill *rfkill)
906 {
907 	unsigned long flags;
908 	u32 state;
909 
910 	spin_lock_irqsave(&rfkill->lock, flags);
911 	state = rfkill->state;
912 	spin_unlock_irqrestore(&rfkill->lock, flags);
913 
914 	return !!(state & RFKILL_BLOCK_ANY);
915 }
916 EXPORT_SYMBOL(rfkill_blocked);
917 
918 
919 struct rfkill * __must_check rfkill_alloc(const char *name,
920 					  struct device *parent,
921 					  const enum rfkill_type type,
922 					  const struct rfkill_ops *ops,
923 					  void *ops_data)
924 {
925 	struct rfkill *rfkill;
926 	struct device *dev;
927 
928 	if (WARN_ON(!ops))
929 		return NULL;
930 
931 	if (WARN_ON(!ops->set_block))
932 		return NULL;
933 
934 	if (WARN_ON(!name))
935 		return NULL;
936 
937 	if (WARN_ON(type == RFKILL_TYPE_ALL || type >= NUM_RFKILL_TYPES))
938 		return NULL;
939 
940 	rfkill = kzalloc(sizeof(*rfkill) + strlen(name) + 1, GFP_KERNEL);
941 	if (!rfkill)
942 		return NULL;
943 
944 	spin_lock_init(&rfkill->lock);
945 	INIT_LIST_HEAD(&rfkill->node);
946 	rfkill->type = type;
947 	strcpy(rfkill->name, name);
948 	rfkill->ops = ops;
949 	rfkill->data = ops_data;
950 
951 	dev = &rfkill->dev;
952 	dev->class = &rfkill_class;
953 	dev->parent = parent;
954 	device_initialize(dev);
955 
956 	return rfkill;
957 }
958 EXPORT_SYMBOL(rfkill_alloc);
959 
960 static void rfkill_poll(struct work_struct *work)
961 {
962 	struct rfkill *rfkill;
963 
964 	rfkill = container_of(work, struct rfkill, poll_work.work);
965 
966 	/*
967 	 * Poll hardware state -- driver will use one of the
968 	 * rfkill_set{,_hw,_sw}_state functions and use its
969 	 * return value to update the current status.
970 	 */
971 	rfkill->ops->poll(rfkill, rfkill->data);
972 
973 	queue_delayed_work(system_power_efficient_wq,
974 		&rfkill->poll_work,
975 		round_jiffies_relative(POLL_INTERVAL));
976 }
977 
978 static void rfkill_uevent_work(struct work_struct *work)
979 {
980 	struct rfkill *rfkill;
981 
982 	rfkill = container_of(work, struct rfkill, uevent_work);
983 
984 	mutex_lock(&rfkill_global_mutex);
985 	rfkill_event(rfkill);
986 	mutex_unlock(&rfkill_global_mutex);
987 }
988 
989 static void rfkill_sync_work(struct work_struct *work)
990 {
991 	struct rfkill *rfkill;
992 	bool cur;
993 
994 	rfkill = container_of(work, struct rfkill, sync_work);
995 
996 	mutex_lock(&rfkill_global_mutex);
997 	cur = rfkill_global_states[rfkill->type].cur;
998 	rfkill_set_block(rfkill, cur);
999 	mutex_unlock(&rfkill_global_mutex);
1000 }
1001 
1002 int __must_check rfkill_register(struct rfkill *rfkill)
1003 {
1004 	static unsigned long rfkill_no;
1005 	struct device *dev = &rfkill->dev;
1006 	int error;
1007 
1008 	BUG_ON(!rfkill);
1009 
1010 	mutex_lock(&rfkill_global_mutex);
1011 
1012 	if (rfkill->registered) {
1013 		error = -EALREADY;
1014 		goto unlock;
1015 	}
1016 
1017 	rfkill->idx = rfkill_no;
1018 	dev_set_name(dev, "rfkill%lu", rfkill_no);
1019 	rfkill_no++;
1020 
1021 	list_add_tail(&rfkill->node, &rfkill_list);
1022 
1023 	error = device_add(dev);
1024 	if (error)
1025 		goto remove;
1026 
1027 	error = rfkill_led_trigger_register(rfkill);
1028 	if (error)
1029 		goto devdel;
1030 
1031 	rfkill->registered = true;
1032 
1033 	INIT_DELAYED_WORK(&rfkill->poll_work, rfkill_poll);
1034 	INIT_WORK(&rfkill->uevent_work, rfkill_uevent_work);
1035 	INIT_WORK(&rfkill->sync_work, rfkill_sync_work);
1036 
1037 	if (rfkill->ops->poll)
1038 		queue_delayed_work(system_power_efficient_wq,
1039 			&rfkill->poll_work,
1040 			round_jiffies_relative(POLL_INTERVAL));
1041 
1042 	if (!rfkill->persistent || rfkill_epo_lock_active) {
1043 		schedule_work(&rfkill->sync_work);
1044 	} else {
1045 #ifdef CONFIG_RFKILL_INPUT
1046 		bool soft_blocked = !!(rfkill->state & RFKILL_BLOCK_SW);
1047 
1048 		if (!atomic_read(&rfkill_input_disabled))
1049 			__rfkill_switch_all(rfkill->type, soft_blocked);
1050 #endif
1051 	}
1052 
1053 	rfkill_global_led_trigger_event();
1054 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
1055 
1056 	mutex_unlock(&rfkill_global_mutex);
1057 	return 0;
1058 
1059  devdel:
1060 	device_del(&rfkill->dev);
1061  remove:
1062 	list_del_init(&rfkill->node);
1063  unlock:
1064 	mutex_unlock(&rfkill_global_mutex);
1065 	return error;
1066 }
1067 EXPORT_SYMBOL(rfkill_register);
1068 
1069 void rfkill_unregister(struct rfkill *rfkill)
1070 {
1071 	BUG_ON(!rfkill);
1072 
1073 	if (rfkill->ops->poll)
1074 		cancel_delayed_work_sync(&rfkill->poll_work);
1075 
1076 	cancel_work_sync(&rfkill->uevent_work);
1077 	cancel_work_sync(&rfkill->sync_work);
1078 
1079 	rfkill->registered = false;
1080 
1081 	device_del(&rfkill->dev);
1082 
1083 	mutex_lock(&rfkill_global_mutex);
1084 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
1085 	list_del_init(&rfkill->node);
1086 	rfkill_global_led_trigger_event();
1087 	mutex_unlock(&rfkill_global_mutex);
1088 
1089 	rfkill_led_trigger_unregister(rfkill);
1090 }
1091 EXPORT_SYMBOL(rfkill_unregister);
1092 
1093 void rfkill_destroy(struct rfkill *rfkill)
1094 {
1095 	if (rfkill)
1096 		put_device(&rfkill->dev);
1097 }
1098 EXPORT_SYMBOL(rfkill_destroy);
1099 
1100 static int rfkill_fop_open(struct inode *inode, struct file *file)
1101 {
1102 	struct rfkill_data *data;
1103 	struct rfkill *rfkill;
1104 	struct rfkill_int_event *ev, *tmp;
1105 
1106 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1107 	if (!data)
1108 		return -ENOMEM;
1109 
1110 	INIT_LIST_HEAD(&data->events);
1111 	mutex_init(&data->mtx);
1112 	init_waitqueue_head(&data->read_wait);
1113 
1114 	mutex_lock(&rfkill_global_mutex);
1115 	mutex_lock(&data->mtx);
1116 	/*
1117 	 * start getting events from elsewhere but hold mtx to get
1118 	 * startup events added first
1119 	 */
1120 
1121 	list_for_each_entry(rfkill, &rfkill_list, node) {
1122 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1123 		if (!ev)
1124 			goto free;
1125 		rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD);
1126 		list_add_tail(&ev->list, &data->events);
1127 	}
1128 	list_add(&data->list, &rfkill_fds);
1129 	mutex_unlock(&data->mtx);
1130 	mutex_unlock(&rfkill_global_mutex);
1131 
1132 	file->private_data = data;
1133 
1134 	return stream_open(inode, file);
1135 
1136  free:
1137 	mutex_unlock(&data->mtx);
1138 	mutex_unlock(&rfkill_global_mutex);
1139 	mutex_destroy(&data->mtx);
1140 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1141 		kfree(ev);
1142 	kfree(data);
1143 	return -ENOMEM;
1144 }
1145 
1146 static __poll_t rfkill_fop_poll(struct file *file, poll_table *wait)
1147 {
1148 	struct rfkill_data *data = file->private_data;
1149 	__poll_t res = EPOLLOUT | EPOLLWRNORM;
1150 
1151 	poll_wait(file, &data->read_wait, wait);
1152 
1153 	mutex_lock(&data->mtx);
1154 	if (!list_empty(&data->events))
1155 		res = EPOLLIN | EPOLLRDNORM;
1156 	mutex_unlock(&data->mtx);
1157 
1158 	return res;
1159 }
1160 
1161 static ssize_t rfkill_fop_read(struct file *file, char __user *buf,
1162 			       size_t count, loff_t *pos)
1163 {
1164 	struct rfkill_data *data = file->private_data;
1165 	struct rfkill_int_event *ev;
1166 	unsigned long sz;
1167 	int ret;
1168 
1169 	mutex_lock(&data->mtx);
1170 
1171 	while (list_empty(&data->events)) {
1172 		if (file->f_flags & O_NONBLOCK) {
1173 			ret = -EAGAIN;
1174 			goto out;
1175 		}
1176 		mutex_unlock(&data->mtx);
1177 		/* since we re-check and it just compares pointers,
1178 		 * using !list_empty() without locking isn't a problem
1179 		 */
1180 		ret = wait_event_interruptible(data->read_wait,
1181 					       !list_empty(&data->events));
1182 		mutex_lock(&data->mtx);
1183 
1184 		if (ret)
1185 			goto out;
1186 	}
1187 
1188 	ev = list_first_entry(&data->events, struct rfkill_int_event,
1189 				list);
1190 
1191 	sz = min_t(unsigned long, sizeof(ev->ev), count);
1192 	ret = sz;
1193 	if (copy_to_user(buf, &ev->ev, sz))
1194 		ret = -EFAULT;
1195 
1196 	list_del(&ev->list);
1197 	kfree(ev);
1198  out:
1199 	mutex_unlock(&data->mtx);
1200 	return ret;
1201 }
1202 
1203 static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
1204 				size_t count, loff_t *pos)
1205 {
1206 	struct rfkill *rfkill;
1207 	struct rfkill_event ev;
1208 	int ret;
1209 
1210 	/* we don't need the 'hard' variable but accept it */
1211 	if (count < RFKILL_EVENT_SIZE_V1 - 1)
1212 		return -EINVAL;
1213 
1214 	/*
1215 	 * Copy as much data as we can accept into our 'ev' buffer,
1216 	 * but tell userspace how much we've copied so it can determine
1217 	 * our API version even in a write() call, if it cares.
1218 	 */
1219 	count = min(count, sizeof(ev));
1220 	if (copy_from_user(&ev, buf, count))
1221 		return -EFAULT;
1222 
1223 	if (ev.type >= NUM_RFKILL_TYPES)
1224 		return -EINVAL;
1225 
1226 	mutex_lock(&rfkill_global_mutex);
1227 
1228 	switch (ev.op) {
1229 	case RFKILL_OP_CHANGE_ALL:
1230 		rfkill_update_global_state(ev.type, ev.soft);
1231 		list_for_each_entry(rfkill, &rfkill_list, node)
1232 			if (rfkill->type == ev.type ||
1233 			    ev.type == RFKILL_TYPE_ALL)
1234 				rfkill_set_block(rfkill, ev.soft);
1235 		ret = 0;
1236 		break;
1237 	case RFKILL_OP_CHANGE:
1238 		list_for_each_entry(rfkill, &rfkill_list, node)
1239 			if (rfkill->idx == ev.idx &&
1240 			    (rfkill->type == ev.type ||
1241 			     ev.type == RFKILL_TYPE_ALL))
1242 				rfkill_set_block(rfkill, ev.soft);
1243 		ret = 0;
1244 		break;
1245 	default:
1246 		ret = -EINVAL;
1247 		break;
1248 	}
1249 
1250 	mutex_unlock(&rfkill_global_mutex);
1251 
1252 	return ret ?: count;
1253 }
1254 
1255 static int rfkill_fop_release(struct inode *inode, struct file *file)
1256 {
1257 	struct rfkill_data *data = file->private_data;
1258 	struct rfkill_int_event *ev, *tmp;
1259 
1260 	mutex_lock(&rfkill_global_mutex);
1261 	list_del(&data->list);
1262 	mutex_unlock(&rfkill_global_mutex);
1263 
1264 	mutex_destroy(&data->mtx);
1265 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1266 		kfree(ev);
1267 
1268 #ifdef CONFIG_RFKILL_INPUT
1269 	if (data->input_handler)
1270 		if (atomic_dec_return(&rfkill_input_disabled) == 0)
1271 			printk(KERN_DEBUG "rfkill: input handler enabled\n");
1272 #endif
1273 
1274 	kfree(data);
1275 
1276 	return 0;
1277 }
1278 
1279 #ifdef CONFIG_RFKILL_INPUT
1280 static long rfkill_fop_ioctl(struct file *file, unsigned int cmd,
1281 			     unsigned long arg)
1282 {
1283 	struct rfkill_data *data = file->private_data;
1284 
1285 	if (_IOC_TYPE(cmd) != RFKILL_IOC_MAGIC)
1286 		return -ENOSYS;
1287 
1288 	if (_IOC_NR(cmd) != RFKILL_IOC_NOINPUT)
1289 		return -ENOSYS;
1290 
1291 	mutex_lock(&data->mtx);
1292 
1293 	if (!data->input_handler) {
1294 		if (atomic_inc_return(&rfkill_input_disabled) == 1)
1295 			printk(KERN_DEBUG "rfkill: input handler disabled\n");
1296 		data->input_handler = true;
1297 	}
1298 
1299 	mutex_unlock(&data->mtx);
1300 
1301 	return 0;
1302 }
1303 #endif
1304 
1305 static const struct file_operations rfkill_fops = {
1306 	.owner		= THIS_MODULE,
1307 	.open		= rfkill_fop_open,
1308 	.read		= rfkill_fop_read,
1309 	.write		= rfkill_fop_write,
1310 	.poll		= rfkill_fop_poll,
1311 	.release	= rfkill_fop_release,
1312 #ifdef CONFIG_RFKILL_INPUT
1313 	.unlocked_ioctl	= rfkill_fop_ioctl,
1314 	.compat_ioctl	= rfkill_fop_ioctl,
1315 #endif
1316 	.llseek		= no_llseek,
1317 };
1318 
1319 static struct miscdevice rfkill_miscdev = {
1320 	.name	= "rfkill",
1321 	.fops	= &rfkill_fops,
1322 	.minor	= MISC_DYNAMIC_MINOR,
1323 };
1324 
1325 static int __init rfkill_init(void)
1326 {
1327 	int error;
1328 
1329 	rfkill_update_global_state(RFKILL_TYPE_ALL, !rfkill_default_state);
1330 
1331 	error = class_register(&rfkill_class);
1332 	if (error)
1333 		goto error_class;
1334 
1335 	error = misc_register(&rfkill_miscdev);
1336 	if (error)
1337 		goto error_misc;
1338 
1339 	error = rfkill_global_led_trigger_register();
1340 	if (error)
1341 		goto error_led_trigger;
1342 
1343 #ifdef CONFIG_RFKILL_INPUT
1344 	error = rfkill_handler_init();
1345 	if (error)
1346 		goto error_input;
1347 #endif
1348 
1349 	return 0;
1350 
1351 #ifdef CONFIG_RFKILL_INPUT
1352 error_input:
1353 	rfkill_global_led_trigger_unregister();
1354 #endif
1355 error_led_trigger:
1356 	misc_deregister(&rfkill_miscdev);
1357 error_misc:
1358 	class_unregister(&rfkill_class);
1359 error_class:
1360 	return error;
1361 }
1362 subsys_initcall(rfkill_init);
1363 
1364 static void __exit rfkill_exit(void)
1365 {
1366 #ifdef CONFIG_RFKILL_INPUT
1367 	rfkill_handler_exit();
1368 #endif
1369 	rfkill_global_led_trigger_unregister();
1370 	misc_deregister(&rfkill_miscdev);
1371 	class_unregister(&rfkill_class);
1372 }
1373 module_exit(rfkill_exit);
1374