xref: /openbmc/linux/net/rfkill/core.c (revision 96de2506)
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, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/workqueue.h>
24 #include <linux/capability.h>
25 #include <linux/list.h>
26 #include <linux/mutex.h>
27 #include <linux/rfkill.h>
28 #include <linux/sched.h>
29 #include <linux/spinlock.h>
30 #include <linux/device.h>
31 #include <linux/miscdevice.h>
32 #include <linux/wait.h>
33 #include <linux/poll.h>
34 #include <linux/fs.h>
35 #include <linux/slab.h>
36 
37 #include "rfkill.h"
38 
39 #define POLL_INTERVAL		(5 * HZ)
40 
41 #define RFKILL_BLOCK_HW		BIT(0)
42 #define RFKILL_BLOCK_SW		BIT(1)
43 #define RFKILL_BLOCK_SW_PREV	BIT(2)
44 #define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
45 				 RFKILL_BLOCK_SW |\
46 				 RFKILL_BLOCK_SW_PREV)
47 #define RFKILL_BLOCK_SW_SETCALL	BIT(31)
48 
49 struct rfkill {
50 	spinlock_t		lock;
51 
52 	enum rfkill_type	type;
53 
54 	unsigned long		state;
55 
56 	u32			idx;
57 
58 	bool			registered;
59 	bool			persistent;
60 	bool			polling_paused;
61 	bool			suspended;
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 	char			name[];
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 int 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 	return 0;
153 }
154 
155 const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
156 {
157 	return rfkill->led_trigger.name;
158 }
159 EXPORT_SYMBOL(rfkill_get_led_trigger_name);
160 
161 void rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name)
162 {
163 	BUG_ON(!rfkill);
164 
165 	rfkill->ledtrigname = name;
166 }
167 EXPORT_SYMBOL(rfkill_set_led_trigger_name);
168 
169 static int rfkill_led_trigger_register(struct rfkill *rfkill)
170 {
171 	rfkill->led_trigger.name = rfkill->ledtrigname
172 					? : dev_name(&rfkill->dev);
173 	rfkill->led_trigger.activate = rfkill_led_trigger_activate;
174 	return led_trigger_register(&rfkill->led_trigger);
175 }
176 
177 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
178 {
179 	led_trigger_unregister(&rfkill->led_trigger);
180 }
181 
182 static struct led_trigger rfkill_any_led_trigger;
183 static struct led_trigger rfkill_none_led_trigger;
184 static struct work_struct rfkill_global_led_trigger_work;
185 
186 static void rfkill_global_led_trigger_worker(struct work_struct *work)
187 {
188 	enum led_brightness brightness = LED_OFF;
189 	struct rfkill *rfkill;
190 
191 	mutex_lock(&rfkill_global_mutex);
192 	list_for_each_entry(rfkill, &rfkill_list, node) {
193 		if (!(rfkill->state & RFKILL_BLOCK_ANY)) {
194 			brightness = LED_FULL;
195 			break;
196 		}
197 	}
198 	mutex_unlock(&rfkill_global_mutex);
199 
200 	led_trigger_event(&rfkill_any_led_trigger, brightness);
201 	led_trigger_event(&rfkill_none_led_trigger,
202 			  brightness == LED_OFF ? LED_FULL : LED_OFF);
203 }
204 
205 static void rfkill_global_led_trigger_event(void)
206 {
207 	schedule_work(&rfkill_global_led_trigger_work);
208 }
209 
210 static int rfkill_global_led_trigger_register(void)
211 {
212 	int ret;
213 
214 	INIT_WORK(&rfkill_global_led_trigger_work,
215 			rfkill_global_led_trigger_worker);
216 
217 	rfkill_any_led_trigger.name = "rfkill-any";
218 	ret = led_trigger_register(&rfkill_any_led_trigger);
219 	if (ret)
220 		return ret;
221 
222 	rfkill_none_led_trigger.name = "rfkill-none";
223 	ret = led_trigger_register(&rfkill_none_led_trigger);
224 	if (ret)
225 		led_trigger_unregister(&rfkill_any_led_trigger);
226 	else
227 		/* Delay activation until all global triggers are registered */
228 		rfkill_global_led_trigger_event();
229 
230 	return ret;
231 }
232 
233 static void rfkill_global_led_trigger_unregister(void)
234 {
235 	led_trigger_unregister(&rfkill_none_led_trigger);
236 	led_trigger_unregister(&rfkill_any_led_trigger);
237 	cancel_work_sync(&rfkill_global_led_trigger_work);
238 }
239 #else
240 static void rfkill_led_trigger_event(struct rfkill *rfkill)
241 {
242 }
243 
244 static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
245 {
246 	return 0;
247 }
248 
249 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
250 {
251 }
252 
253 static void rfkill_global_led_trigger_event(void)
254 {
255 }
256 
257 static int rfkill_global_led_trigger_register(void)
258 {
259 	return 0;
260 }
261 
262 static void rfkill_global_led_trigger_unregister(void)
263 {
264 }
265 #endif /* CONFIG_RFKILL_LEDS */
266 
267 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
268 			      enum rfkill_operation op)
269 {
270 	unsigned long flags;
271 
272 	ev->idx = rfkill->idx;
273 	ev->type = rfkill->type;
274 	ev->op = op;
275 
276 	spin_lock_irqsave(&rfkill->lock, flags);
277 	ev->hard = !!(rfkill->state & RFKILL_BLOCK_HW);
278 	ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW |
279 					RFKILL_BLOCK_SW_PREV));
280 	spin_unlock_irqrestore(&rfkill->lock, flags);
281 }
282 
283 static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op)
284 {
285 	struct rfkill_data *data;
286 	struct rfkill_int_event *ev;
287 
288 	list_for_each_entry(data, &rfkill_fds, list) {
289 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
290 		if (!ev)
291 			continue;
292 		rfkill_fill_event(&ev->ev, rfkill, op);
293 		mutex_lock(&data->mtx);
294 		list_add_tail(&ev->list, &data->events);
295 		mutex_unlock(&data->mtx);
296 		wake_up_interruptible(&data->read_wait);
297 	}
298 }
299 
300 static void rfkill_event(struct rfkill *rfkill)
301 {
302 	if (!rfkill->registered)
303 		return;
304 
305 	kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
306 
307 	/* also send event to /dev/rfkill */
308 	rfkill_send_events(rfkill, RFKILL_OP_CHANGE);
309 }
310 
311 /**
312  * rfkill_set_block - wrapper for set_block method
313  *
314  * @rfkill: the rfkill struct to use
315  * @blocked: the new software state
316  *
317  * Calls the set_block method (when applicable) and handles notifications
318  * etc. as well.
319  */
320 static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
321 {
322 	unsigned long flags;
323 	bool prev, curr;
324 	int err;
325 
326 	if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
327 		return;
328 
329 	/*
330 	 * Some platforms (...!) generate input events which affect the
331 	 * _hard_ kill state -- whenever something tries to change the
332 	 * current software state query the hardware state too.
333 	 */
334 	if (rfkill->ops->query)
335 		rfkill->ops->query(rfkill, rfkill->data);
336 
337 	spin_lock_irqsave(&rfkill->lock, flags);
338 	prev = rfkill->state & RFKILL_BLOCK_SW;
339 
340 	if (prev)
341 		rfkill->state |= RFKILL_BLOCK_SW_PREV;
342 	else
343 		rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
344 
345 	if (blocked)
346 		rfkill->state |= RFKILL_BLOCK_SW;
347 	else
348 		rfkill->state &= ~RFKILL_BLOCK_SW;
349 
350 	rfkill->state |= RFKILL_BLOCK_SW_SETCALL;
351 	spin_unlock_irqrestore(&rfkill->lock, flags);
352 
353 	err = rfkill->ops->set_block(rfkill->data, blocked);
354 
355 	spin_lock_irqsave(&rfkill->lock, flags);
356 	if (err) {
357 		/*
358 		 * Failed -- reset status to _PREV, which may be different
359 		 * from what we have set _PREV to earlier in this function
360 		 * if rfkill_set_sw_state was invoked.
361 		 */
362 		if (rfkill->state & RFKILL_BLOCK_SW_PREV)
363 			rfkill->state |= RFKILL_BLOCK_SW;
364 		else
365 			rfkill->state &= ~RFKILL_BLOCK_SW;
366 	}
367 	rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL;
368 	rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
369 	curr = rfkill->state & RFKILL_BLOCK_SW;
370 	spin_unlock_irqrestore(&rfkill->lock, flags);
371 
372 	rfkill_led_trigger_event(rfkill);
373 	rfkill_global_led_trigger_event();
374 
375 	if (prev != curr)
376 		rfkill_event(rfkill);
377 }
378 
379 static void rfkill_update_global_state(enum rfkill_type type, bool blocked)
380 {
381 	int i;
382 
383 	if (type != RFKILL_TYPE_ALL) {
384 		rfkill_global_states[type].cur = blocked;
385 		return;
386 	}
387 
388 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
389 		rfkill_global_states[i].cur = blocked;
390 }
391 
392 #ifdef CONFIG_RFKILL_INPUT
393 static atomic_t rfkill_input_disabled = ATOMIC_INIT(0);
394 
395 /**
396  * __rfkill_switch_all - Toggle state of all switches of given type
397  * @type: type of interfaces to be affected
398  * @blocked: the new state
399  *
400  * This function sets the state of all switches of given type,
401  * unless a specific switch is suspended.
402  *
403  * Caller must have acquired rfkill_global_mutex.
404  */
405 static void __rfkill_switch_all(const enum rfkill_type type, bool blocked)
406 {
407 	struct rfkill *rfkill;
408 
409 	rfkill_update_global_state(type, blocked);
410 	list_for_each_entry(rfkill, &rfkill_list, node) {
411 		if (rfkill->type != type && type != RFKILL_TYPE_ALL)
412 			continue;
413 
414 		rfkill_set_block(rfkill, blocked);
415 	}
416 }
417 
418 /**
419  * rfkill_switch_all - Toggle state of all switches of given type
420  * @type: type of interfaces to be affected
421  * @blocked: the new state
422  *
423  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
424  * Please refer to __rfkill_switch_all() for details.
425  *
426  * Does nothing if the EPO lock is active.
427  */
428 void rfkill_switch_all(enum rfkill_type type, bool blocked)
429 {
430 	if (atomic_read(&rfkill_input_disabled))
431 		return;
432 
433 	mutex_lock(&rfkill_global_mutex);
434 
435 	if (!rfkill_epo_lock_active)
436 		__rfkill_switch_all(type, blocked);
437 
438 	mutex_unlock(&rfkill_global_mutex);
439 }
440 
441 /**
442  * rfkill_epo - emergency power off all transmitters
443  *
444  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
445  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
446  *
447  * The global state before the EPO is saved and can be restored later
448  * using rfkill_restore_states().
449  */
450 void rfkill_epo(void)
451 {
452 	struct rfkill *rfkill;
453 	int i;
454 
455 	if (atomic_read(&rfkill_input_disabled))
456 		return;
457 
458 	mutex_lock(&rfkill_global_mutex);
459 
460 	rfkill_epo_lock_active = true;
461 	list_for_each_entry(rfkill, &rfkill_list, node)
462 		rfkill_set_block(rfkill, true);
463 
464 	for (i = 0; i < NUM_RFKILL_TYPES; i++) {
465 		rfkill_global_states[i].sav = rfkill_global_states[i].cur;
466 		rfkill_global_states[i].cur = true;
467 	}
468 
469 	mutex_unlock(&rfkill_global_mutex);
470 }
471 
472 /**
473  * rfkill_restore_states - restore global states
474  *
475  * Restore (and sync switches to) the global state from the
476  * states in rfkill_default_states.  This can undo the effects of
477  * a call to rfkill_epo().
478  */
479 void rfkill_restore_states(void)
480 {
481 	int i;
482 
483 	if (atomic_read(&rfkill_input_disabled))
484 		return;
485 
486 	mutex_lock(&rfkill_global_mutex);
487 
488 	rfkill_epo_lock_active = false;
489 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
490 		__rfkill_switch_all(i, rfkill_global_states[i].sav);
491 	mutex_unlock(&rfkill_global_mutex);
492 }
493 
494 /**
495  * rfkill_remove_epo_lock - unlock state changes
496  *
497  * Used by rfkill-input manually unlock state changes, when
498  * the EPO switch is deactivated.
499  */
500 void rfkill_remove_epo_lock(void)
501 {
502 	if (atomic_read(&rfkill_input_disabled))
503 		return;
504 
505 	mutex_lock(&rfkill_global_mutex);
506 	rfkill_epo_lock_active = false;
507 	mutex_unlock(&rfkill_global_mutex);
508 }
509 
510 /**
511  * rfkill_is_epo_lock_active - returns true EPO is active
512  *
513  * Returns 0 (false) if there is NOT an active EPO condition,
514  * and 1 (true) if there is an active EPO condition, which
515  * locks all radios in one of the BLOCKED states.
516  *
517  * Can be called in atomic context.
518  */
519 bool rfkill_is_epo_lock_active(void)
520 {
521 	return rfkill_epo_lock_active;
522 }
523 
524 /**
525  * rfkill_get_global_sw_state - returns global state for a type
526  * @type: the type to get the global state of
527  *
528  * Returns the current global state for a given wireless
529  * device type.
530  */
531 bool rfkill_get_global_sw_state(const enum rfkill_type type)
532 {
533 	return rfkill_global_states[type].cur;
534 }
535 #endif
536 
537 bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
538 {
539 	unsigned long flags;
540 	bool ret, prev;
541 
542 	BUG_ON(!rfkill);
543 
544 	spin_lock_irqsave(&rfkill->lock, flags);
545 	prev = !!(rfkill->state & RFKILL_BLOCK_HW);
546 	if (blocked)
547 		rfkill->state |= RFKILL_BLOCK_HW;
548 	else
549 		rfkill->state &= ~RFKILL_BLOCK_HW;
550 	ret = !!(rfkill->state & RFKILL_BLOCK_ANY);
551 	spin_unlock_irqrestore(&rfkill->lock, flags);
552 
553 	rfkill_led_trigger_event(rfkill);
554 	rfkill_global_led_trigger_event();
555 
556 	if (rfkill->registered && prev != blocked)
557 		schedule_work(&rfkill->uevent_work);
558 
559 	return ret;
560 }
561 EXPORT_SYMBOL(rfkill_set_hw_state);
562 
563 static void __rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
564 {
565 	u32 bit = RFKILL_BLOCK_SW;
566 
567 	/* if in a ops->set_block right now, use other bit */
568 	if (rfkill->state & RFKILL_BLOCK_SW_SETCALL)
569 		bit = RFKILL_BLOCK_SW_PREV;
570 
571 	if (blocked)
572 		rfkill->state |= bit;
573 	else
574 		rfkill->state &= ~bit;
575 }
576 
577 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
578 {
579 	unsigned long flags;
580 	bool prev, hwblock;
581 
582 	BUG_ON(!rfkill);
583 
584 	spin_lock_irqsave(&rfkill->lock, flags);
585 	prev = !!(rfkill->state & RFKILL_BLOCK_SW);
586 	__rfkill_set_sw_state(rfkill, blocked);
587 	hwblock = !!(rfkill->state & RFKILL_BLOCK_HW);
588 	blocked = blocked || hwblock;
589 	spin_unlock_irqrestore(&rfkill->lock, flags);
590 
591 	if (!rfkill->registered)
592 		return blocked;
593 
594 	if (prev != blocked && !hwblock)
595 		schedule_work(&rfkill->uevent_work);
596 
597 	rfkill_led_trigger_event(rfkill);
598 	rfkill_global_led_trigger_event();
599 
600 	return blocked;
601 }
602 EXPORT_SYMBOL(rfkill_set_sw_state);
603 
604 void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
605 {
606 	unsigned long flags;
607 
608 	BUG_ON(!rfkill);
609 	BUG_ON(rfkill->registered);
610 
611 	spin_lock_irqsave(&rfkill->lock, flags);
612 	__rfkill_set_sw_state(rfkill, blocked);
613 	rfkill->persistent = true;
614 	spin_unlock_irqrestore(&rfkill->lock, flags);
615 }
616 EXPORT_SYMBOL(rfkill_init_sw_state);
617 
618 void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
619 {
620 	unsigned long flags;
621 	bool swprev, hwprev;
622 
623 	BUG_ON(!rfkill);
624 
625 	spin_lock_irqsave(&rfkill->lock, flags);
626 
627 	/*
628 	 * No need to care about prev/setblock ... this is for uevent only
629 	 * and that will get triggered by rfkill_set_block anyway.
630 	 */
631 	swprev = !!(rfkill->state & RFKILL_BLOCK_SW);
632 	hwprev = !!(rfkill->state & RFKILL_BLOCK_HW);
633 	__rfkill_set_sw_state(rfkill, sw);
634 	if (hw)
635 		rfkill->state |= RFKILL_BLOCK_HW;
636 	else
637 		rfkill->state &= ~RFKILL_BLOCK_HW;
638 
639 	spin_unlock_irqrestore(&rfkill->lock, flags);
640 
641 	if (!rfkill->registered) {
642 		rfkill->persistent = true;
643 	} else {
644 		if (swprev != sw || hwprev != hw)
645 			schedule_work(&rfkill->uevent_work);
646 
647 		rfkill_led_trigger_event(rfkill);
648 		rfkill_global_led_trigger_event();
649 	}
650 }
651 EXPORT_SYMBOL(rfkill_set_states);
652 
653 static const char * const rfkill_types[] = {
654 	NULL, /* RFKILL_TYPE_ALL */
655 	"wlan",
656 	"bluetooth",
657 	"ultrawideband",
658 	"wimax",
659 	"wwan",
660 	"gps",
661 	"fm",
662 	"nfc",
663 };
664 
665 enum rfkill_type rfkill_find_type(const char *name)
666 {
667 	int i;
668 
669 	BUILD_BUG_ON(ARRAY_SIZE(rfkill_types) != NUM_RFKILL_TYPES);
670 
671 	if (!name)
672 		return RFKILL_TYPE_ALL;
673 
674 	for (i = 1; i < NUM_RFKILL_TYPES; i++)
675 		if (!strcmp(name, rfkill_types[i]))
676 			return i;
677 	return RFKILL_TYPE_ALL;
678 }
679 EXPORT_SYMBOL(rfkill_find_type);
680 
681 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
682 			 char *buf)
683 {
684 	struct rfkill *rfkill = to_rfkill(dev);
685 
686 	return sprintf(buf, "%s\n", rfkill->name);
687 }
688 static DEVICE_ATTR_RO(name);
689 
690 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
691 			 char *buf)
692 {
693 	struct rfkill *rfkill = to_rfkill(dev);
694 
695 	return sprintf(buf, "%s\n", rfkill_types[rfkill->type]);
696 }
697 static DEVICE_ATTR_RO(type);
698 
699 static ssize_t index_show(struct device *dev, struct device_attribute *attr,
700 			  char *buf)
701 {
702 	struct rfkill *rfkill = to_rfkill(dev);
703 
704 	return sprintf(buf, "%d\n", rfkill->idx);
705 }
706 static DEVICE_ATTR_RO(index);
707 
708 static ssize_t persistent_show(struct device *dev,
709 			       struct device_attribute *attr, char *buf)
710 {
711 	struct rfkill *rfkill = to_rfkill(dev);
712 
713 	return sprintf(buf, "%d\n", rfkill->persistent);
714 }
715 static DEVICE_ATTR_RO(persistent);
716 
717 static ssize_t hard_show(struct device *dev, struct device_attribute *attr,
718 			 char *buf)
719 {
720 	struct rfkill *rfkill = to_rfkill(dev);
721 
722 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
723 }
724 static DEVICE_ATTR_RO(hard);
725 
726 static ssize_t soft_show(struct device *dev, struct device_attribute *attr,
727 			 char *buf)
728 {
729 	struct rfkill *rfkill = to_rfkill(dev);
730 
731 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
732 }
733 
734 static ssize_t soft_store(struct device *dev, struct device_attribute *attr,
735 			  const char *buf, size_t count)
736 {
737 	struct rfkill *rfkill = to_rfkill(dev);
738 	unsigned long state;
739 	int err;
740 
741 	if (!capable(CAP_NET_ADMIN))
742 		return -EPERM;
743 
744 	err = kstrtoul(buf, 0, &state);
745 	if (err)
746 		return err;
747 
748 	if (state > 1 )
749 		return -EINVAL;
750 
751 	mutex_lock(&rfkill_global_mutex);
752 	rfkill_set_block(rfkill, state);
753 	mutex_unlock(&rfkill_global_mutex);
754 
755 	return count;
756 }
757 static DEVICE_ATTR_RW(soft);
758 
759 static u8 user_state_from_blocked(unsigned long state)
760 {
761 	if (state & RFKILL_BLOCK_HW)
762 		return RFKILL_USER_STATE_HARD_BLOCKED;
763 	if (state & RFKILL_BLOCK_SW)
764 		return RFKILL_USER_STATE_SOFT_BLOCKED;
765 
766 	return RFKILL_USER_STATE_UNBLOCKED;
767 }
768 
769 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
770 			  char *buf)
771 {
772 	struct rfkill *rfkill = to_rfkill(dev);
773 
774 	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
775 }
776 
777 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
778 			   const char *buf, size_t count)
779 {
780 	struct rfkill *rfkill = to_rfkill(dev);
781 	unsigned long state;
782 	int err;
783 
784 	if (!capable(CAP_NET_ADMIN))
785 		return -EPERM;
786 
787 	err = kstrtoul(buf, 0, &state);
788 	if (err)
789 		return err;
790 
791 	if (state != RFKILL_USER_STATE_SOFT_BLOCKED &&
792 	    state != RFKILL_USER_STATE_UNBLOCKED)
793 		return -EINVAL;
794 
795 	mutex_lock(&rfkill_global_mutex);
796 	rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED);
797 	mutex_unlock(&rfkill_global_mutex);
798 
799 	return count;
800 }
801 static DEVICE_ATTR_RW(state);
802 
803 static struct attribute *rfkill_dev_attrs[] = {
804 	&dev_attr_name.attr,
805 	&dev_attr_type.attr,
806 	&dev_attr_index.attr,
807 	&dev_attr_persistent.attr,
808 	&dev_attr_state.attr,
809 	&dev_attr_soft.attr,
810 	&dev_attr_hard.attr,
811 	NULL,
812 };
813 ATTRIBUTE_GROUPS(rfkill_dev);
814 
815 static void rfkill_release(struct device *dev)
816 {
817 	struct rfkill *rfkill = to_rfkill(dev);
818 
819 	kfree(rfkill);
820 }
821 
822 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
823 {
824 	struct rfkill *rfkill = to_rfkill(dev);
825 	unsigned long flags;
826 	u32 state;
827 	int error;
828 
829 	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
830 	if (error)
831 		return error;
832 	error = add_uevent_var(env, "RFKILL_TYPE=%s",
833 			       rfkill_types[rfkill->type]);
834 	if (error)
835 		return error;
836 	spin_lock_irqsave(&rfkill->lock, flags);
837 	state = rfkill->state;
838 	spin_unlock_irqrestore(&rfkill->lock, flags);
839 	error = add_uevent_var(env, "RFKILL_STATE=%d",
840 			       user_state_from_blocked(state));
841 	return error;
842 }
843 
844 void rfkill_pause_polling(struct rfkill *rfkill)
845 {
846 	BUG_ON(!rfkill);
847 
848 	if (!rfkill->ops->poll)
849 		return;
850 
851 	rfkill->polling_paused = true;
852 	cancel_delayed_work_sync(&rfkill->poll_work);
853 }
854 EXPORT_SYMBOL(rfkill_pause_polling);
855 
856 void rfkill_resume_polling(struct rfkill *rfkill)
857 {
858 	BUG_ON(!rfkill);
859 
860 	if (!rfkill->ops->poll)
861 		return;
862 
863 	rfkill->polling_paused = false;
864 
865 	if (rfkill->suspended)
866 		return;
867 
868 	queue_delayed_work(system_power_efficient_wq,
869 			   &rfkill->poll_work, 0);
870 }
871 EXPORT_SYMBOL(rfkill_resume_polling);
872 
873 #ifdef CONFIG_PM_SLEEP
874 static int rfkill_suspend(struct device *dev)
875 {
876 	struct rfkill *rfkill = to_rfkill(dev);
877 
878 	rfkill->suspended = true;
879 	cancel_delayed_work_sync(&rfkill->poll_work);
880 
881 	return 0;
882 }
883 
884 static int rfkill_resume(struct device *dev)
885 {
886 	struct rfkill *rfkill = to_rfkill(dev);
887 	bool cur;
888 
889 	rfkill->suspended = false;
890 
891 	if (!rfkill->persistent) {
892 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
893 		rfkill_set_block(rfkill, cur);
894 	}
895 
896 	if (rfkill->ops->poll && !rfkill->polling_paused)
897 		queue_delayed_work(system_power_efficient_wq,
898 				   &rfkill->poll_work, 0);
899 
900 	return 0;
901 }
902 
903 static SIMPLE_DEV_PM_OPS(rfkill_pm_ops, rfkill_suspend, rfkill_resume);
904 #define RFKILL_PM_OPS (&rfkill_pm_ops)
905 #else
906 #define RFKILL_PM_OPS NULL
907 #endif
908 
909 static struct class rfkill_class = {
910 	.name		= "rfkill",
911 	.dev_release	= rfkill_release,
912 	.dev_groups	= rfkill_dev_groups,
913 	.dev_uevent	= rfkill_dev_uevent,
914 	.pm		= RFKILL_PM_OPS,
915 };
916 
917 bool rfkill_blocked(struct rfkill *rfkill)
918 {
919 	unsigned long flags;
920 	u32 state;
921 
922 	spin_lock_irqsave(&rfkill->lock, flags);
923 	state = rfkill->state;
924 	spin_unlock_irqrestore(&rfkill->lock, flags);
925 
926 	return !!(state & RFKILL_BLOCK_ANY);
927 }
928 EXPORT_SYMBOL(rfkill_blocked);
929 
930 
931 struct rfkill * __must_check rfkill_alloc(const char *name,
932 					  struct device *parent,
933 					  const enum rfkill_type type,
934 					  const struct rfkill_ops *ops,
935 					  void *ops_data)
936 {
937 	struct rfkill *rfkill;
938 	struct device *dev;
939 
940 	if (WARN_ON(!ops))
941 		return NULL;
942 
943 	if (WARN_ON(!ops->set_block))
944 		return NULL;
945 
946 	if (WARN_ON(!name))
947 		return NULL;
948 
949 	if (WARN_ON(type == RFKILL_TYPE_ALL || type >= NUM_RFKILL_TYPES))
950 		return NULL;
951 
952 	rfkill = kzalloc(sizeof(*rfkill) + strlen(name) + 1, GFP_KERNEL);
953 	if (!rfkill)
954 		return NULL;
955 
956 	spin_lock_init(&rfkill->lock);
957 	INIT_LIST_HEAD(&rfkill->node);
958 	rfkill->type = type;
959 	strcpy(rfkill->name, name);
960 	rfkill->ops = ops;
961 	rfkill->data = ops_data;
962 
963 	dev = &rfkill->dev;
964 	dev->class = &rfkill_class;
965 	dev->parent = parent;
966 	device_initialize(dev);
967 
968 	return rfkill;
969 }
970 EXPORT_SYMBOL(rfkill_alloc);
971 
972 static void rfkill_poll(struct work_struct *work)
973 {
974 	struct rfkill *rfkill;
975 
976 	rfkill = container_of(work, struct rfkill, poll_work.work);
977 
978 	/*
979 	 * Poll hardware state -- driver will use one of the
980 	 * rfkill_set{,_hw,_sw}_state functions and use its
981 	 * return value to update the current status.
982 	 */
983 	rfkill->ops->poll(rfkill, rfkill->data);
984 
985 	queue_delayed_work(system_power_efficient_wq,
986 		&rfkill->poll_work,
987 		round_jiffies_relative(POLL_INTERVAL));
988 }
989 
990 static void rfkill_uevent_work(struct work_struct *work)
991 {
992 	struct rfkill *rfkill;
993 
994 	rfkill = container_of(work, struct rfkill, uevent_work);
995 
996 	mutex_lock(&rfkill_global_mutex);
997 	rfkill_event(rfkill);
998 	mutex_unlock(&rfkill_global_mutex);
999 }
1000 
1001 static void rfkill_sync_work(struct work_struct *work)
1002 {
1003 	struct rfkill *rfkill;
1004 	bool cur;
1005 
1006 	rfkill = container_of(work, struct rfkill, sync_work);
1007 
1008 	mutex_lock(&rfkill_global_mutex);
1009 	cur = rfkill_global_states[rfkill->type].cur;
1010 	rfkill_set_block(rfkill, cur);
1011 	mutex_unlock(&rfkill_global_mutex);
1012 }
1013 
1014 int __must_check rfkill_register(struct rfkill *rfkill)
1015 {
1016 	static unsigned long rfkill_no;
1017 	struct device *dev = &rfkill->dev;
1018 	int error;
1019 
1020 	BUG_ON(!rfkill);
1021 
1022 	mutex_lock(&rfkill_global_mutex);
1023 
1024 	if (rfkill->registered) {
1025 		error = -EALREADY;
1026 		goto unlock;
1027 	}
1028 
1029 	rfkill->idx = rfkill_no;
1030 	dev_set_name(dev, "rfkill%lu", rfkill_no);
1031 	rfkill_no++;
1032 
1033 	list_add_tail(&rfkill->node, &rfkill_list);
1034 
1035 	error = device_add(dev);
1036 	if (error)
1037 		goto remove;
1038 
1039 	error = rfkill_led_trigger_register(rfkill);
1040 	if (error)
1041 		goto devdel;
1042 
1043 	rfkill->registered = true;
1044 
1045 	INIT_DELAYED_WORK(&rfkill->poll_work, rfkill_poll);
1046 	INIT_WORK(&rfkill->uevent_work, rfkill_uevent_work);
1047 	INIT_WORK(&rfkill->sync_work, rfkill_sync_work);
1048 
1049 	if (rfkill->ops->poll)
1050 		queue_delayed_work(system_power_efficient_wq,
1051 			&rfkill->poll_work,
1052 			round_jiffies_relative(POLL_INTERVAL));
1053 
1054 	if (!rfkill->persistent || rfkill_epo_lock_active) {
1055 		schedule_work(&rfkill->sync_work);
1056 	} else {
1057 #ifdef CONFIG_RFKILL_INPUT
1058 		bool soft_blocked = !!(rfkill->state & RFKILL_BLOCK_SW);
1059 
1060 		if (!atomic_read(&rfkill_input_disabled))
1061 			__rfkill_switch_all(rfkill->type, soft_blocked);
1062 #endif
1063 	}
1064 
1065 	rfkill_global_led_trigger_event();
1066 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
1067 
1068 	mutex_unlock(&rfkill_global_mutex);
1069 	return 0;
1070 
1071  devdel:
1072 	device_del(&rfkill->dev);
1073  remove:
1074 	list_del_init(&rfkill->node);
1075  unlock:
1076 	mutex_unlock(&rfkill_global_mutex);
1077 	return error;
1078 }
1079 EXPORT_SYMBOL(rfkill_register);
1080 
1081 void rfkill_unregister(struct rfkill *rfkill)
1082 {
1083 	BUG_ON(!rfkill);
1084 
1085 	if (rfkill->ops->poll)
1086 		cancel_delayed_work_sync(&rfkill->poll_work);
1087 
1088 	cancel_work_sync(&rfkill->uevent_work);
1089 	cancel_work_sync(&rfkill->sync_work);
1090 
1091 	rfkill->registered = false;
1092 
1093 	device_del(&rfkill->dev);
1094 
1095 	mutex_lock(&rfkill_global_mutex);
1096 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
1097 	list_del_init(&rfkill->node);
1098 	rfkill_global_led_trigger_event();
1099 	mutex_unlock(&rfkill_global_mutex);
1100 
1101 	rfkill_led_trigger_unregister(rfkill);
1102 }
1103 EXPORT_SYMBOL(rfkill_unregister);
1104 
1105 void rfkill_destroy(struct rfkill *rfkill)
1106 {
1107 	if (rfkill)
1108 		put_device(&rfkill->dev);
1109 }
1110 EXPORT_SYMBOL(rfkill_destroy);
1111 
1112 static int rfkill_fop_open(struct inode *inode, struct file *file)
1113 {
1114 	struct rfkill_data *data;
1115 	struct rfkill *rfkill;
1116 	struct rfkill_int_event *ev, *tmp;
1117 
1118 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1119 	if (!data)
1120 		return -ENOMEM;
1121 
1122 	INIT_LIST_HEAD(&data->events);
1123 	mutex_init(&data->mtx);
1124 	init_waitqueue_head(&data->read_wait);
1125 
1126 	mutex_lock(&rfkill_global_mutex);
1127 	mutex_lock(&data->mtx);
1128 	/*
1129 	 * start getting events from elsewhere but hold mtx to get
1130 	 * startup events added first
1131 	 */
1132 
1133 	list_for_each_entry(rfkill, &rfkill_list, node) {
1134 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1135 		if (!ev)
1136 			goto free;
1137 		rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD);
1138 		list_add_tail(&ev->list, &data->events);
1139 	}
1140 	list_add(&data->list, &rfkill_fds);
1141 	mutex_unlock(&data->mtx);
1142 	mutex_unlock(&rfkill_global_mutex);
1143 
1144 	file->private_data = data;
1145 
1146 	return nonseekable_open(inode, file);
1147 
1148  free:
1149 	mutex_unlock(&data->mtx);
1150 	mutex_unlock(&rfkill_global_mutex);
1151 	mutex_destroy(&data->mtx);
1152 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1153 		kfree(ev);
1154 	kfree(data);
1155 	return -ENOMEM;
1156 }
1157 
1158 static __poll_t rfkill_fop_poll(struct file *file, poll_table *wait)
1159 {
1160 	struct rfkill_data *data = file->private_data;
1161 	__poll_t res = EPOLLOUT | EPOLLWRNORM;
1162 
1163 	poll_wait(file, &data->read_wait, wait);
1164 
1165 	mutex_lock(&data->mtx);
1166 	if (!list_empty(&data->events))
1167 		res = EPOLLIN | EPOLLRDNORM;
1168 	mutex_unlock(&data->mtx);
1169 
1170 	return res;
1171 }
1172 
1173 static ssize_t rfkill_fop_read(struct file *file, char __user *buf,
1174 			       size_t count, loff_t *pos)
1175 {
1176 	struct rfkill_data *data = file->private_data;
1177 	struct rfkill_int_event *ev;
1178 	unsigned long sz;
1179 	int ret;
1180 
1181 	mutex_lock(&data->mtx);
1182 
1183 	while (list_empty(&data->events)) {
1184 		if (file->f_flags & O_NONBLOCK) {
1185 			ret = -EAGAIN;
1186 			goto out;
1187 		}
1188 		mutex_unlock(&data->mtx);
1189 		/* since we re-check and it just compares pointers,
1190 		 * using !list_empty() without locking isn't a problem
1191 		 */
1192 		ret = wait_event_interruptible(data->read_wait,
1193 					       !list_empty(&data->events));
1194 		mutex_lock(&data->mtx);
1195 
1196 		if (ret)
1197 			goto out;
1198 	}
1199 
1200 	ev = list_first_entry(&data->events, struct rfkill_int_event,
1201 				list);
1202 
1203 	sz = min_t(unsigned long, sizeof(ev->ev), count);
1204 	ret = sz;
1205 	if (copy_to_user(buf, &ev->ev, sz))
1206 		ret = -EFAULT;
1207 
1208 	list_del(&ev->list);
1209 	kfree(ev);
1210  out:
1211 	mutex_unlock(&data->mtx);
1212 	return ret;
1213 }
1214 
1215 static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
1216 				size_t count, loff_t *pos)
1217 {
1218 	struct rfkill *rfkill;
1219 	struct rfkill_event ev;
1220 	int ret;
1221 
1222 	/* we don't need the 'hard' variable but accept it */
1223 	if (count < RFKILL_EVENT_SIZE_V1 - 1)
1224 		return -EINVAL;
1225 
1226 	/*
1227 	 * Copy as much data as we can accept into our 'ev' buffer,
1228 	 * but tell userspace how much we've copied so it can determine
1229 	 * our API version even in a write() call, if it cares.
1230 	 */
1231 	count = min(count, sizeof(ev));
1232 	if (copy_from_user(&ev, buf, count))
1233 		return -EFAULT;
1234 
1235 	if (ev.type >= NUM_RFKILL_TYPES)
1236 		return -EINVAL;
1237 
1238 	mutex_lock(&rfkill_global_mutex);
1239 
1240 	switch (ev.op) {
1241 	case RFKILL_OP_CHANGE_ALL:
1242 		rfkill_update_global_state(ev.type, ev.soft);
1243 		list_for_each_entry(rfkill, &rfkill_list, node)
1244 			if (rfkill->type == ev.type ||
1245 			    ev.type == RFKILL_TYPE_ALL)
1246 				rfkill_set_block(rfkill, ev.soft);
1247 		ret = 0;
1248 		break;
1249 	case RFKILL_OP_CHANGE:
1250 		list_for_each_entry(rfkill, &rfkill_list, node)
1251 			if (rfkill->idx == ev.idx &&
1252 			    (rfkill->type == ev.type ||
1253 			     ev.type == RFKILL_TYPE_ALL))
1254 				rfkill_set_block(rfkill, ev.soft);
1255 		ret = 0;
1256 		break;
1257 	default:
1258 		ret = -EINVAL;
1259 		break;
1260 	}
1261 
1262 	mutex_unlock(&rfkill_global_mutex);
1263 
1264 	return ret ?: count;
1265 }
1266 
1267 static int rfkill_fop_release(struct inode *inode, struct file *file)
1268 {
1269 	struct rfkill_data *data = file->private_data;
1270 	struct rfkill_int_event *ev, *tmp;
1271 
1272 	mutex_lock(&rfkill_global_mutex);
1273 	list_del(&data->list);
1274 	mutex_unlock(&rfkill_global_mutex);
1275 
1276 	mutex_destroy(&data->mtx);
1277 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1278 		kfree(ev);
1279 
1280 #ifdef CONFIG_RFKILL_INPUT
1281 	if (data->input_handler)
1282 		if (atomic_dec_return(&rfkill_input_disabled) == 0)
1283 			printk(KERN_DEBUG "rfkill: input handler enabled\n");
1284 #endif
1285 
1286 	kfree(data);
1287 
1288 	return 0;
1289 }
1290 
1291 #ifdef CONFIG_RFKILL_INPUT
1292 static long rfkill_fop_ioctl(struct file *file, unsigned int cmd,
1293 			     unsigned long arg)
1294 {
1295 	struct rfkill_data *data = file->private_data;
1296 
1297 	if (_IOC_TYPE(cmd) != RFKILL_IOC_MAGIC)
1298 		return -ENOSYS;
1299 
1300 	if (_IOC_NR(cmd) != RFKILL_IOC_NOINPUT)
1301 		return -ENOSYS;
1302 
1303 	mutex_lock(&data->mtx);
1304 
1305 	if (!data->input_handler) {
1306 		if (atomic_inc_return(&rfkill_input_disabled) == 1)
1307 			printk(KERN_DEBUG "rfkill: input handler disabled\n");
1308 		data->input_handler = true;
1309 	}
1310 
1311 	mutex_unlock(&data->mtx);
1312 
1313 	return 0;
1314 }
1315 #endif
1316 
1317 static const struct file_operations rfkill_fops = {
1318 	.owner		= THIS_MODULE,
1319 	.open		= rfkill_fop_open,
1320 	.read		= rfkill_fop_read,
1321 	.write		= rfkill_fop_write,
1322 	.poll		= rfkill_fop_poll,
1323 	.release	= rfkill_fop_release,
1324 #ifdef CONFIG_RFKILL_INPUT
1325 	.unlocked_ioctl	= rfkill_fop_ioctl,
1326 	.compat_ioctl	= rfkill_fop_ioctl,
1327 #endif
1328 	.llseek		= no_llseek,
1329 };
1330 
1331 static struct miscdevice rfkill_miscdev = {
1332 	.name	= "rfkill",
1333 	.fops	= &rfkill_fops,
1334 	.minor	= MISC_DYNAMIC_MINOR,
1335 };
1336 
1337 static int __init rfkill_init(void)
1338 {
1339 	int error;
1340 
1341 	rfkill_update_global_state(RFKILL_TYPE_ALL, !rfkill_default_state);
1342 
1343 	error = class_register(&rfkill_class);
1344 	if (error)
1345 		goto error_class;
1346 
1347 	error = misc_register(&rfkill_miscdev);
1348 	if (error)
1349 		goto error_misc;
1350 
1351 	error = rfkill_global_led_trigger_register();
1352 	if (error)
1353 		goto error_led_trigger;
1354 
1355 #ifdef CONFIG_RFKILL_INPUT
1356 	error = rfkill_handler_init();
1357 	if (error)
1358 		goto error_input;
1359 #endif
1360 
1361 	return 0;
1362 
1363 #ifdef CONFIG_RFKILL_INPUT
1364 error_input:
1365 	rfkill_global_led_trigger_unregister();
1366 #endif
1367 error_led_trigger:
1368 	misc_deregister(&rfkill_miscdev);
1369 error_misc:
1370 	class_unregister(&rfkill_class);
1371 error_class:
1372 	return error;
1373 }
1374 subsys_initcall(rfkill_init);
1375 
1376 static void __exit rfkill_exit(void)
1377 {
1378 #ifdef CONFIG_RFKILL_INPUT
1379 	rfkill_handler_exit();
1380 #endif
1381 	rfkill_global_led_trigger_unregister();
1382 	misc_deregister(&rfkill_miscdev);
1383 	class_unregister(&rfkill_class);
1384 }
1385 module_exit(rfkill_exit);
1386