xref: /openbmc/linux/net/rfkill/core.c (revision 95e9fd10)
1 /*
2  * Copyright (C) 2006 - 2007 Ivo van Doorn
3  * Copyright (C) 2007 Dmitry Torokhov
4  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the
18  * Free Software Foundation, Inc.,
19  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  */
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/workqueue.h>
26 #include <linux/capability.h>
27 #include <linux/list.h>
28 #include <linux/mutex.h>
29 #include <linux/rfkill.h>
30 #include <linux/sched.h>
31 #include <linux/spinlock.h>
32 #include <linux/device.h>
33 #include <linux/miscdevice.h>
34 #include <linux/wait.h>
35 #include <linux/poll.h>
36 #include <linux/fs.h>
37 #include <linux/slab.h>
38 
39 #include "rfkill.h"
40 
41 #define POLL_INTERVAL		(5 * HZ)
42 
43 #define RFKILL_BLOCK_HW		BIT(0)
44 #define RFKILL_BLOCK_SW		BIT(1)
45 #define RFKILL_BLOCK_SW_PREV	BIT(2)
46 #define RFKILL_BLOCK_ANY	(RFKILL_BLOCK_HW |\
47 				 RFKILL_BLOCK_SW |\
48 				 RFKILL_BLOCK_SW_PREV)
49 #define RFKILL_BLOCK_SW_SETCALL	BIT(31)
50 
51 struct rfkill {
52 	spinlock_t		lock;
53 
54 	const char		*name;
55 	enum rfkill_type	type;
56 
57 	unsigned long		state;
58 
59 	u32			idx;
60 
61 	bool			registered;
62 	bool			persistent;
63 
64 	const struct rfkill_ops	*ops;
65 	void			*data;
66 
67 #ifdef CONFIG_RFKILL_LEDS
68 	struct led_trigger	led_trigger;
69 	const char		*ledtrigname;
70 #endif
71 
72 	struct device		dev;
73 	struct list_head	node;
74 
75 	struct delayed_work	poll_work;
76 	struct work_struct	uevent_work;
77 	struct work_struct	sync_work;
78 };
79 #define to_rfkill(d)	container_of(d, struct rfkill, dev)
80 
81 struct rfkill_int_event {
82 	struct list_head	list;
83 	struct rfkill_event	ev;
84 };
85 
86 struct rfkill_data {
87 	struct list_head	list;
88 	struct list_head	events;
89 	struct mutex		mtx;
90 	wait_queue_head_t	read_wait;
91 	bool			input_handler;
92 };
93 
94 
95 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
96 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
97 MODULE_DESCRIPTION("RF switch support");
98 MODULE_LICENSE("GPL");
99 
100 
101 /*
102  * The locking here should be made much smarter, we currently have
103  * a bit of a stupid situation because drivers might want to register
104  * the rfkill struct under their own lock, and take this lock during
105  * rfkill method calls -- which will cause an AB-BA deadlock situation.
106  *
107  * To fix that, we need to rework this code here to be mostly lock-free
108  * and only use the mutex for list manipulations, not to protect the
109  * various other global variables. Then we can avoid holding the mutex
110  * around driver operations, and all is happy.
111  */
112 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
113 static DEFINE_MUTEX(rfkill_global_mutex);
114 static LIST_HEAD(rfkill_fds);	/* list of open fds of /dev/rfkill */
115 
116 static unsigned int rfkill_default_state = 1;
117 module_param_named(default_state, rfkill_default_state, uint, 0444);
118 MODULE_PARM_DESC(default_state,
119 		 "Default initial state for all radio types, 0 = radio off");
120 
121 static struct {
122 	bool cur, sav;
123 } rfkill_global_states[NUM_RFKILL_TYPES];
124 
125 static bool rfkill_epo_lock_active;
126 
127 
128 #ifdef CONFIG_RFKILL_LEDS
129 static void rfkill_led_trigger_event(struct rfkill *rfkill)
130 {
131 	struct led_trigger *trigger;
132 
133 	if (!rfkill->registered)
134 		return;
135 
136 	trigger = &rfkill->led_trigger;
137 
138 	if (rfkill->state & RFKILL_BLOCK_ANY)
139 		led_trigger_event(trigger, LED_OFF);
140 	else
141 		led_trigger_event(trigger, LED_FULL);
142 }
143 
144 static void rfkill_led_trigger_activate(struct led_classdev *led)
145 {
146 	struct rfkill *rfkill;
147 
148 	rfkill = container_of(led->trigger, struct rfkill, led_trigger);
149 
150 	rfkill_led_trigger_event(rfkill);
151 }
152 
153 static int rfkill_led_trigger_register(struct rfkill *rfkill)
154 {
155 	rfkill->led_trigger.name = rfkill->ledtrigname
156 					? : dev_name(&rfkill->dev);
157 	rfkill->led_trigger.activate = rfkill_led_trigger_activate;
158 	return led_trigger_register(&rfkill->led_trigger);
159 }
160 
161 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
162 {
163 	led_trigger_unregister(&rfkill->led_trigger);
164 }
165 #else
166 static void rfkill_led_trigger_event(struct rfkill *rfkill)
167 {
168 }
169 
170 static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
171 {
172 	return 0;
173 }
174 
175 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
176 {
177 }
178 #endif /* CONFIG_RFKILL_LEDS */
179 
180 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
181 			      enum rfkill_operation op)
182 {
183 	unsigned long flags;
184 
185 	ev->idx = rfkill->idx;
186 	ev->type = rfkill->type;
187 	ev->op = op;
188 
189 	spin_lock_irqsave(&rfkill->lock, flags);
190 	ev->hard = !!(rfkill->state & RFKILL_BLOCK_HW);
191 	ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW |
192 					RFKILL_BLOCK_SW_PREV));
193 	spin_unlock_irqrestore(&rfkill->lock, flags);
194 }
195 
196 static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op)
197 {
198 	struct rfkill_data *data;
199 	struct rfkill_int_event *ev;
200 
201 	list_for_each_entry(data, &rfkill_fds, list) {
202 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
203 		if (!ev)
204 			continue;
205 		rfkill_fill_event(&ev->ev, rfkill, op);
206 		mutex_lock(&data->mtx);
207 		list_add_tail(&ev->list, &data->events);
208 		mutex_unlock(&data->mtx);
209 		wake_up_interruptible(&data->read_wait);
210 	}
211 }
212 
213 static void rfkill_event(struct rfkill *rfkill)
214 {
215 	if (!rfkill->registered)
216 		return;
217 
218 	kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
219 
220 	/* also send event to /dev/rfkill */
221 	rfkill_send_events(rfkill, RFKILL_OP_CHANGE);
222 }
223 
224 static bool __rfkill_set_hw_state(struct rfkill *rfkill,
225 				  bool blocked, bool *change)
226 {
227 	unsigned long flags;
228 	bool prev, any;
229 
230 	BUG_ON(!rfkill);
231 
232 	spin_lock_irqsave(&rfkill->lock, flags);
233 	prev = !!(rfkill->state & RFKILL_BLOCK_HW);
234 	if (blocked)
235 		rfkill->state |= RFKILL_BLOCK_HW;
236 	else
237 		rfkill->state &= ~RFKILL_BLOCK_HW;
238 	*change = prev != blocked;
239 	any = !!(rfkill->state & RFKILL_BLOCK_ANY);
240 	spin_unlock_irqrestore(&rfkill->lock, flags);
241 
242 	rfkill_led_trigger_event(rfkill);
243 
244 	return any;
245 }
246 
247 /**
248  * rfkill_set_block - wrapper for set_block method
249  *
250  * @rfkill: the rfkill struct to use
251  * @blocked: the new software state
252  *
253  * Calls the set_block method (when applicable) and handles notifications
254  * etc. as well.
255  */
256 static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
257 {
258 	unsigned long flags;
259 	int err;
260 
261 	if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP))
262 		return;
263 
264 	/*
265 	 * Some platforms (...!) generate input events which affect the
266 	 * _hard_ kill state -- whenever something tries to change the
267 	 * current software state query the hardware state too.
268 	 */
269 	if (rfkill->ops->query)
270 		rfkill->ops->query(rfkill, rfkill->data);
271 
272 	spin_lock_irqsave(&rfkill->lock, flags);
273 	if (rfkill->state & RFKILL_BLOCK_SW)
274 		rfkill->state |= RFKILL_BLOCK_SW_PREV;
275 	else
276 		rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
277 
278 	if (blocked)
279 		rfkill->state |= RFKILL_BLOCK_SW;
280 	else
281 		rfkill->state &= ~RFKILL_BLOCK_SW;
282 
283 	rfkill->state |= RFKILL_BLOCK_SW_SETCALL;
284 	spin_unlock_irqrestore(&rfkill->lock, flags);
285 
286 	err = rfkill->ops->set_block(rfkill->data, blocked);
287 
288 	spin_lock_irqsave(&rfkill->lock, flags);
289 	if (err) {
290 		/*
291 		 * Failed -- reset status to _prev, this may be different
292 		 * from what set set _PREV to earlier in this function
293 		 * if rfkill_set_sw_state was invoked.
294 		 */
295 		if (rfkill->state & RFKILL_BLOCK_SW_PREV)
296 			rfkill->state |= RFKILL_BLOCK_SW;
297 		else
298 			rfkill->state &= ~RFKILL_BLOCK_SW;
299 	}
300 	rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL;
301 	rfkill->state &= ~RFKILL_BLOCK_SW_PREV;
302 	spin_unlock_irqrestore(&rfkill->lock, flags);
303 
304 	rfkill_led_trigger_event(rfkill);
305 	rfkill_event(rfkill);
306 }
307 
308 #ifdef CONFIG_RFKILL_INPUT
309 static atomic_t rfkill_input_disabled = ATOMIC_INIT(0);
310 
311 /**
312  * __rfkill_switch_all - Toggle state of all switches of given type
313  * @type: type of interfaces to be affected
314  * @state: the new state
315  *
316  * This function sets the state of all switches of given type,
317  * unless a specific switch is claimed by userspace (in which case,
318  * that switch is left alone) or suspended.
319  *
320  * Caller must have acquired rfkill_global_mutex.
321  */
322 static void __rfkill_switch_all(const enum rfkill_type type, bool blocked)
323 {
324 	struct rfkill *rfkill;
325 
326 	rfkill_global_states[type].cur = blocked;
327 	list_for_each_entry(rfkill, &rfkill_list, node) {
328 		if (rfkill->type != type && type != RFKILL_TYPE_ALL)
329 			continue;
330 
331 		rfkill_set_block(rfkill, blocked);
332 	}
333 }
334 
335 /**
336  * rfkill_switch_all - Toggle state of all switches of given type
337  * @type: type of interfaces to be affected
338  * @state: the new state
339  *
340  * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
341  * Please refer to __rfkill_switch_all() for details.
342  *
343  * Does nothing if the EPO lock is active.
344  */
345 void rfkill_switch_all(enum rfkill_type type, bool blocked)
346 {
347 	if (atomic_read(&rfkill_input_disabled))
348 		return;
349 
350 	mutex_lock(&rfkill_global_mutex);
351 
352 	if (!rfkill_epo_lock_active)
353 		__rfkill_switch_all(type, blocked);
354 
355 	mutex_unlock(&rfkill_global_mutex);
356 }
357 
358 /**
359  * rfkill_epo - emergency power off all transmitters
360  *
361  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
362  * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
363  *
364  * The global state before the EPO is saved and can be restored later
365  * using rfkill_restore_states().
366  */
367 void rfkill_epo(void)
368 {
369 	struct rfkill *rfkill;
370 	int i;
371 
372 	if (atomic_read(&rfkill_input_disabled))
373 		return;
374 
375 	mutex_lock(&rfkill_global_mutex);
376 
377 	rfkill_epo_lock_active = true;
378 	list_for_each_entry(rfkill, &rfkill_list, node)
379 		rfkill_set_block(rfkill, true);
380 
381 	for (i = 0; i < NUM_RFKILL_TYPES; i++) {
382 		rfkill_global_states[i].sav = rfkill_global_states[i].cur;
383 		rfkill_global_states[i].cur = true;
384 	}
385 
386 	mutex_unlock(&rfkill_global_mutex);
387 }
388 
389 /**
390  * rfkill_restore_states - restore global states
391  *
392  * Restore (and sync switches to) the global state from the
393  * states in rfkill_default_states.  This can undo the effects of
394  * a call to rfkill_epo().
395  */
396 void rfkill_restore_states(void)
397 {
398 	int i;
399 
400 	if (atomic_read(&rfkill_input_disabled))
401 		return;
402 
403 	mutex_lock(&rfkill_global_mutex);
404 
405 	rfkill_epo_lock_active = false;
406 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
407 		__rfkill_switch_all(i, rfkill_global_states[i].sav);
408 	mutex_unlock(&rfkill_global_mutex);
409 }
410 
411 /**
412  * rfkill_remove_epo_lock - unlock state changes
413  *
414  * Used by rfkill-input manually unlock state changes, when
415  * the EPO switch is deactivated.
416  */
417 void rfkill_remove_epo_lock(void)
418 {
419 	if (atomic_read(&rfkill_input_disabled))
420 		return;
421 
422 	mutex_lock(&rfkill_global_mutex);
423 	rfkill_epo_lock_active = false;
424 	mutex_unlock(&rfkill_global_mutex);
425 }
426 
427 /**
428  * rfkill_is_epo_lock_active - returns true EPO is active
429  *
430  * Returns 0 (false) if there is NOT an active EPO contidion,
431  * and 1 (true) if there is an active EPO contition, which
432  * locks all radios in one of the BLOCKED states.
433  *
434  * Can be called in atomic context.
435  */
436 bool rfkill_is_epo_lock_active(void)
437 {
438 	return rfkill_epo_lock_active;
439 }
440 
441 /**
442  * rfkill_get_global_sw_state - returns global state for a type
443  * @type: the type to get the global state of
444  *
445  * Returns the current global state for a given wireless
446  * device type.
447  */
448 bool rfkill_get_global_sw_state(const enum rfkill_type type)
449 {
450 	return rfkill_global_states[type].cur;
451 }
452 #endif
453 
454 
455 bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
456 {
457 	bool ret, change;
458 
459 	ret = __rfkill_set_hw_state(rfkill, blocked, &change);
460 
461 	if (!rfkill->registered)
462 		return ret;
463 
464 	if (change)
465 		schedule_work(&rfkill->uevent_work);
466 
467 	return ret;
468 }
469 EXPORT_SYMBOL(rfkill_set_hw_state);
470 
471 static void __rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
472 {
473 	u32 bit = RFKILL_BLOCK_SW;
474 
475 	/* if in a ops->set_block right now, use other bit */
476 	if (rfkill->state & RFKILL_BLOCK_SW_SETCALL)
477 		bit = RFKILL_BLOCK_SW_PREV;
478 
479 	if (blocked)
480 		rfkill->state |= bit;
481 	else
482 		rfkill->state &= ~bit;
483 }
484 
485 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
486 {
487 	unsigned long flags;
488 	bool prev, hwblock;
489 
490 	BUG_ON(!rfkill);
491 
492 	spin_lock_irqsave(&rfkill->lock, flags);
493 	prev = !!(rfkill->state & RFKILL_BLOCK_SW);
494 	__rfkill_set_sw_state(rfkill, blocked);
495 	hwblock = !!(rfkill->state & RFKILL_BLOCK_HW);
496 	blocked = blocked || hwblock;
497 	spin_unlock_irqrestore(&rfkill->lock, flags);
498 
499 	if (!rfkill->registered)
500 		return blocked;
501 
502 	if (prev != blocked && !hwblock)
503 		schedule_work(&rfkill->uevent_work);
504 
505 	rfkill_led_trigger_event(rfkill);
506 
507 	return blocked;
508 }
509 EXPORT_SYMBOL(rfkill_set_sw_state);
510 
511 void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
512 {
513 	unsigned long flags;
514 
515 	BUG_ON(!rfkill);
516 	BUG_ON(rfkill->registered);
517 
518 	spin_lock_irqsave(&rfkill->lock, flags);
519 	__rfkill_set_sw_state(rfkill, blocked);
520 	rfkill->persistent = true;
521 	spin_unlock_irqrestore(&rfkill->lock, flags);
522 }
523 EXPORT_SYMBOL(rfkill_init_sw_state);
524 
525 void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
526 {
527 	unsigned long flags;
528 	bool swprev, hwprev;
529 
530 	BUG_ON(!rfkill);
531 
532 	spin_lock_irqsave(&rfkill->lock, flags);
533 
534 	/*
535 	 * No need to care about prev/setblock ... this is for uevent only
536 	 * and that will get triggered by rfkill_set_block anyway.
537 	 */
538 	swprev = !!(rfkill->state & RFKILL_BLOCK_SW);
539 	hwprev = !!(rfkill->state & RFKILL_BLOCK_HW);
540 	__rfkill_set_sw_state(rfkill, sw);
541 	if (hw)
542 		rfkill->state |= RFKILL_BLOCK_HW;
543 	else
544 		rfkill->state &= ~RFKILL_BLOCK_HW;
545 
546 	spin_unlock_irqrestore(&rfkill->lock, flags);
547 
548 	if (!rfkill->registered) {
549 		rfkill->persistent = true;
550 	} else {
551 		if (swprev != sw || hwprev != hw)
552 			schedule_work(&rfkill->uevent_work);
553 
554 		rfkill_led_trigger_event(rfkill);
555 	}
556 }
557 EXPORT_SYMBOL(rfkill_set_states);
558 
559 static ssize_t rfkill_name_show(struct device *dev,
560 				struct device_attribute *attr,
561 				char *buf)
562 {
563 	struct rfkill *rfkill = to_rfkill(dev);
564 
565 	return sprintf(buf, "%s\n", rfkill->name);
566 }
567 
568 static const char *rfkill_get_type_str(enum rfkill_type type)
569 {
570 	BUILD_BUG_ON(NUM_RFKILL_TYPES != RFKILL_TYPE_FM + 1);
571 
572 	switch (type) {
573 	case RFKILL_TYPE_WLAN:
574 		return "wlan";
575 	case RFKILL_TYPE_BLUETOOTH:
576 		return "bluetooth";
577 	case RFKILL_TYPE_UWB:
578 		return "ultrawideband";
579 	case RFKILL_TYPE_WIMAX:
580 		return "wimax";
581 	case RFKILL_TYPE_WWAN:
582 		return "wwan";
583 	case RFKILL_TYPE_GPS:
584 		return "gps";
585 	case RFKILL_TYPE_FM:
586 		return "fm";
587 	default:
588 		BUG();
589 	}
590 }
591 
592 static ssize_t rfkill_type_show(struct device *dev,
593 				struct device_attribute *attr,
594 				char *buf)
595 {
596 	struct rfkill *rfkill = to_rfkill(dev);
597 
598 	return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
599 }
600 
601 static ssize_t rfkill_idx_show(struct device *dev,
602 			       struct device_attribute *attr,
603 			       char *buf)
604 {
605 	struct rfkill *rfkill = to_rfkill(dev);
606 
607 	return sprintf(buf, "%d\n", rfkill->idx);
608 }
609 
610 static ssize_t rfkill_persistent_show(struct device *dev,
611 			       struct device_attribute *attr,
612 			       char *buf)
613 {
614 	struct rfkill *rfkill = to_rfkill(dev);
615 
616 	return sprintf(buf, "%d\n", rfkill->persistent);
617 }
618 
619 static ssize_t rfkill_hard_show(struct device *dev,
620 				 struct device_attribute *attr,
621 				 char *buf)
622 {
623 	struct rfkill *rfkill = to_rfkill(dev);
624 
625 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
626 }
627 
628 static ssize_t rfkill_soft_show(struct device *dev,
629 				 struct device_attribute *attr,
630 				 char *buf)
631 {
632 	struct rfkill *rfkill = to_rfkill(dev);
633 
634 	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
635 }
636 
637 static ssize_t rfkill_soft_store(struct device *dev,
638 				  struct device_attribute *attr,
639 				  const char *buf, size_t count)
640 {
641 	struct rfkill *rfkill = to_rfkill(dev);
642 	unsigned long state;
643 	int err;
644 
645 	if (!capable(CAP_NET_ADMIN))
646 		return -EPERM;
647 
648 	err = kstrtoul(buf, 0, &state);
649 	if (err)
650 		return err;
651 
652 	if (state > 1 )
653 		return -EINVAL;
654 
655 	mutex_lock(&rfkill_global_mutex);
656 	rfkill_set_block(rfkill, state);
657 	mutex_unlock(&rfkill_global_mutex);
658 
659 	return err ?: count;
660 }
661 
662 static u8 user_state_from_blocked(unsigned long state)
663 {
664 	if (state & RFKILL_BLOCK_HW)
665 		return RFKILL_USER_STATE_HARD_BLOCKED;
666 	if (state & RFKILL_BLOCK_SW)
667 		return RFKILL_USER_STATE_SOFT_BLOCKED;
668 
669 	return RFKILL_USER_STATE_UNBLOCKED;
670 }
671 
672 static ssize_t rfkill_state_show(struct device *dev,
673 				 struct device_attribute *attr,
674 				 char *buf)
675 {
676 	struct rfkill *rfkill = to_rfkill(dev);
677 
678 	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
679 }
680 
681 static ssize_t rfkill_state_store(struct device *dev,
682 				  struct device_attribute *attr,
683 				  const char *buf, size_t count)
684 {
685 	struct rfkill *rfkill = to_rfkill(dev);
686 	unsigned long state;
687 	int err;
688 
689 	if (!capable(CAP_NET_ADMIN))
690 		return -EPERM;
691 
692 	err = kstrtoul(buf, 0, &state);
693 	if (err)
694 		return err;
695 
696 	if (state != RFKILL_USER_STATE_SOFT_BLOCKED &&
697 	    state != RFKILL_USER_STATE_UNBLOCKED)
698 		return -EINVAL;
699 
700 	mutex_lock(&rfkill_global_mutex);
701 	rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED);
702 	mutex_unlock(&rfkill_global_mutex);
703 
704 	return err ?: count;
705 }
706 
707 static ssize_t rfkill_claim_show(struct device *dev,
708 				 struct device_attribute *attr,
709 				 char *buf)
710 {
711 	return sprintf(buf, "%d\n", 0);
712 }
713 
714 static ssize_t rfkill_claim_store(struct device *dev,
715 				  struct device_attribute *attr,
716 				  const char *buf, size_t count)
717 {
718 	return -EOPNOTSUPP;
719 }
720 
721 static struct device_attribute rfkill_dev_attrs[] = {
722 	__ATTR(name, S_IRUGO, rfkill_name_show, NULL),
723 	__ATTR(type, S_IRUGO, rfkill_type_show, NULL),
724 	__ATTR(index, S_IRUGO, rfkill_idx_show, NULL),
725 	__ATTR(persistent, S_IRUGO, rfkill_persistent_show, NULL),
726 	__ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
727 	__ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
728 	__ATTR(soft, S_IRUGO|S_IWUSR, rfkill_soft_show, rfkill_soft_store),
729 	__ATTR(hard, S_IRUGO, rfkill_hard_show, NULL),
730 	__ATTR_NULL
731 };
732 
733 static void rfkill_release(struct device *dev)
734 {
735 	struct rfkill *rfkill = to_rfkill(dev);
736 
737 	kfree(rfkill);
738 }
739 
740 static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
741 {
742 	struct rfkill *rfkill = to_rfkill(dev);
743 	unsigned long flags;
744 	u32 state;
745 	int error;
746 
747 	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
748 	if (error)
749 		return error;
750 	error = add_uevent_var(env, "RFKILL_TYPE=%s",
751 			       rfkill_get_type_str(rfkill->type));
752 	if (error)
753 		return error;
754 	spin_lock_irqsave(&rfkill->lock, flags);
755 	state = rfkill->state;
756 	spin_unlock_irqrestore(&rfkill->lock, flags);
757 	error = add_uevent_var(env, "RFKILL_STATE=%d",
758 			       user_state_from_blocked(state));
759 	return error;
760 }
761 
762 void rfkill_pause_polling(struct rfkill *rfkill)
763 {
764 	BUG_ON(!rfkill);
765 
766 	if (!rfkill->ops->poll)
767 		return;
768 
769 	cancel_delayed_work_sync(&rfkill->poll_work);
770 }
771 EXPORT_SYMBOL(rfkill_pause_polling);
772 
773 void rfkill_resume_polling(struct rfkill *rfkill)
774 {
775 	BUG_ON(!rfkill);
776 
777 	if (!rfkill->ops->poll)
778 		return;
779 
780 	schedule_work(&rfkill->poll_work.work);
781 }
782 EXPORT_SYMBOL(rfkill_resume_polling);
783 
784 static int rfkill_suspend(struct device *dev, pm_message_t state)
785 {
786 	struct rfkill *rfkill = to_rfkill(dev);
787 
788 	rfkill_pause_polling(rfkill);
789 
790 	return 0;
791 }
792 
793 static int rfkill_resume(struct device *dev)
794 {
795 	struct rfkill *rfkill = to_rfkill(dev);
796 	bool cur;
797 
798 	if (!rfkill->persistent) {
799 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
800 		rfkill_set_block(rfkill, cur);
801 	}
802 
803 	rfkill_resume_polling(rfkill);
804 
805 	return 0;
806 }
807 
808 static struct class rfkill_class = {
809 	.name		= "rfkill",
810 	.dev_release	= rfkill_release,
811 	.dev_attrs	= rfkill_dev_attrs,
812 	.dev_uevent	= rfkill_dev_uevent,
813 	.suspend	= rfkill_suspend,
814 	.resume		= rfkill_resume,
815 };
816 
817 bool rfkill_blocked(struct rfkill *rfkill)
818 {
819 	unsigned long flags;
820 	u32 state;
821 
822 	spin_lock_irqsave(&rfkill->lock, flags);
823 	state = rfkill->state;
824 	spin_unlock_irqrestore(&rfkill->lock, flags);
825 
826 	return !!(state & RFKILL_BLOCK_ANY);
827 }
828 EXPORT_SYMBOL(rfkill_blocked);
829 
830 
831 struct rfkill * __must_check rfkill_alloc(const char *name,
832 					  struct device *parent,
833 					  const enum rfkill_type type,
834 					  const struct rfkill_ops *ops,
835 					  void *ops_data)
836 {
837 	struct rfkill *rfkill;
838 	struct device *dev;
839 
840 	if (WARN_ON(!ops))
841 		return NULL;
842 
843 	if (WARN_ON(!ops->set_block))
844 		return NULL;
845 
846 	if (WARN_ON(!name))
847 		return NULL;
848 
849 	if (WARN_ON(type == RFKILL_TYPE_ALL || type >= NUM_RFKILL_TYPES))
850 		return NULL;
851 
852 	rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL);
853 	if (!rfkill)
854 		return NULL;
855 
856 	spin_lock_init(&rfkill->lock);
857 	INIT_LIST_HEAD(&rfkill->node);
858 	rfkill->type = type;
859 	rfkill->name = name;
860 	rfkill->ops = ops;
861 	rfkill->data = ops_data;
862 
863 	dev = &rfkill->dev;
864 	dev->class = &rfkill_class;
865 	dev->parent = parent;
866 	device_initialize(dev);
867 
868 	return rfkill;
869 }
870 EXPORT_SYMBOL(rfkill_alloc);
871 
872 static void rfkill_poll(struct work_struct *work)
873 {
874 	struct rfkill *rfkill;
875 
876 	rfkill = container_of(work, struct rfkill, poll_work.work);
877 
878 	/*
879 	 * Poll hardware state -- driver will use one of the
880 	 * rfkill_set{,_hw,_sw}_state functions and use its
881 	 * return value to update the current status.
882 	 */
883 	rfkill->ops->poll(rfkill, rfkill->data);
884 
885 	schedule_delayed_work(&rfkill->poll_work,
886 		round_jiffies_relative(POLL_INTERVAL));
887 }
888 
889 static void rfkill_uevent_work(struct work_struct *work)
890 {
891 	struct rfkill *rfkill;
892 
893 	rfkill = container_of(work, struct rfkill, uevent_work);
894 
895 	mutex_lock(&rfkill_global_mutex);
896 	rfkill_event(rfkill);
897 	mutex_unlock(&rfkill_global_mutex);
898 }
899 
900 static void rfkill_sync_work(struct work_struct *work)
901 {
902 	struct rfkill *rfkill;
903 	bool cur;
904 
905 	rfkill = container_of(work, struct rfkill, sync_work);
906 
907 	mutex_lock(&rfkill_global_mutex);
908 	cur = rfkill_global_states[rfkill->type].cur;
909 	rfkill_set_block(rfkill, cur);
910 	mutex_unlock(&rfkill_global_mutex);
911 }
912 
913 int __must_check rfkill_register(struct rfkill *rfkill)
914 {
915 	static unsigned long rfkill_no;
916 	struct device *dev = &rfkill->dev;
917 	int error;
918 
919 	BUG_ON(!rfkill);
920 
921 	mutex_lock(&rfkill_global_mutex);
922 
923 	if (rfkill->registered) {
924 		error = -EALREADY;
925 		goto unlock;
926 	}
927 
928 	rfkill->idx = rfkill_no;
929 	dev_set_name(dev, "rfkill%lu", rfkill_no);
930 	rfkill_no++;
931 
932 	list_add_tail(&rfkill->node, &rfkill_list);
933 
934 	error = device_add(dev);
935 	if (error)
936 		goto remove;
937 
938 	error = rfkill_led_trigger_register(rfkill);
939 	if (error)
940 		goto devdel;
941 
942 	rfkill->registered = true;
943 
944 	INIT_DELAYED_WORK(&rfkill->poll_work, rfkill_poll);
945 	INIT_WORK(&rfkill->uevent_work, rfkill_uevent_work);
946 	INIT_WORK(&rfkill->sync_work, rfkill_sync_work);
947 
948 	if (rfkill->ops->poll)
949 		schedule_delayed_work(&rfkill->poll_work,
950 			round_jiffies_relative(POLL_INTERVAL));
951 
952 	if (!rfkill->persistent || rfkill_epo_lock_active) {
953 		schedule_work(&rfkill->sync_work);
954 	} else {
955 #ifdef CONFIG_RFKILL_INPUT
956 		bool soft_blocked = !!(rfkill->state & RFKILL_BLOCK_SW);
957 
958 		if (!atomic_read(&rfkill_input_disabled))
959 			__rfkill_switch_all(rfkill->type, soft_blocked);
960 #endif
961 	}
962 
963 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
964 
965 	mutex_unlock(&rfkill_global_mutex);
966 	return 0;
967 
968  devdel:
969 	device_del(&rfkill->dev);
970  remove:
971 	list_del_init(&rfkill->node);
972  unlock:
973 	mutex_unlock(&rfkill_global_mutex);
974 	return error;
975 }
976 EXPORT_SYMBOL(rfkill_register);
977 
978 void rfkill_unregister(struct rfkill *rfkill)
979 {
980 	BUG_ON(!rfkill);
981 
982 	if (rfkill->ops->poll)
983 		cancel_delayed_work_sync(&rfkill->poll_work);
984 
985 	cancel_work_sync(&rfkill->uevent_work);
986 	cancel_work_sync(&rfkill->sync_work);
987 
988 	rfkill->registered = false;
989 
990 	device_del(&rfkill->dev);
991 
992 	mutex_lock(&rfkill_global_mutex);
993 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
994 	list_del_init(&rfkill->node);
995 	mutex_unlock(&rfkill_global_mutex);
996 
997 	rfkill_led_trigger_unregister(rfkill);
998 }
999 EXPORT_SYMBOL(rfkill_unregister);
1000 
1001 void rfkill_destroy(struct rfkill *rfkill)
1002 {
1003 	if (rfkill)
1004 		put_device(&rfkill->dev);
1005 }
1006 EXPORT_SYMBOL(rfkill_destroy);
1007 
1008 static int rfkill_fop_open(struct inode *inode, struct file *file)
1009 {
1010 	struct rfkill_data *data;
1011 	struct rfkill *rfkill;
1012 	struct rfkill_int_event *ev, *tmp;
1013 
1014 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1015 	if (!data)
1016 		return -ENOMEM;
1017 
1018 	INIT_LIST_HEAD(&data->events);
1019 	mutex_init(&data->mtx);
1020 	init_waitqueue_head(&data->read_wait);
1021 
1022 	mutex_lock(&rfkill_global_mutex);
1023 	mutex_lock(&data->mtx);
1024 	/*
1025 	 * start getting events from elsewhere but hold mtx to get
1026 	 * startup events added first
1027 	 */
1028 
1029 	list_for_each_entry(rfkill, &rfkill_list, node) {
1030 		ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1031 		if (!ev)
1032 			goto free;
1033 		rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD);
1034 		list_add_tail(&ev->list, &data->events);
1035 	}
1036 	list_add(&data->list, &rfkill_fds);
1037 	mutex_unlock(&data->mtx);
1038 	mutex_unlock(&rfkill_global_mutex);
1039 
1040 	file->private_data = data;
1041 
1042 	return nonseekable_open(inode, file);
1043 
1044  free:
1045 	mutex_unlock(&data->mtx);
1046 	mutex_unlock(&rfkill_global_mutex);
1047 	mutex_destroy(&data->mtx);
1048 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1049 		kfree(ev);
1050 	kfree(data);
1051 	return -ENOMEM;
1052 }
1053 
1054 static unsigned int rfkill_fop_poll(struct file *file, poll_table *wait)
1055 {
1056 	struct rfkill_data *data = file->private_data;
1057 	unsigned int res = POLLOUT | POLLWRNORM;
1058 
1059 	poll_wait(file, &data->read_wait, wait);
1060 
1061 	mutex_lock(&data->mtx);
1062 	if (!list_empty(&data->events))
1063 		res = POLLIN | POLLRDNORM;
1064 	mutex_unlock(&data->mtx);
1065 
1066 	return res;
1067 }
1068 
1069 static bool rfkill_readable(struct rfkill_data *data)
1070 {
1071 	bool r;
1072 
1073 	mutex_lock(&data->mtx);
1074 	r = !list_empty(&data->events);
1075 	mutex_unlock(&data->mtx);
1076 
1077 	return r;
1078 }
1079 
1080 static ssize_t rfkill_fop_read(struct file *file, char __user *buf,
1081 			       size_t count, loff_t *pos)
1082 {
1083 	struct rfkill_data *data = file->private_data;
1084 	struct rfkill_int_event *ev;
1085 	unsigned long sz;
1086 	int ret;
1087 
1088 	mutex_lock(&data->mtx);
1089 
1090 	while (list_empty(&data->events)) {
1091 		if (file->f_flags & O_NONBLOCK) {
1092 			ret = -EAGAIN;
1093 			goto out;
1094 		}
1095 		mutex_unlock(&data->mtx);
1096 		ret = wait_event_interruptible(data->read_wait,
1097 					       rfkill_readable(data));
1098 		mutex_lock(&data->mtx);
1099 
1100 		if (ret)
1101 			goto out;
1102 	}
1103 
1104 	ev = list_first_entry(&data->events, struct rfkill_int_event,
1105 				list);
1106 
1107 	sz = min_t(unsigned long, sizeof(ev->ev), count);
1108 	ret = sz;
1109 	if (copy_to_user(buf, &ev->ev, sz))
1110 		ret = -EFAULT;
1111 
1112 	list_del(&ev->list);
1113 	kfree(ev);
1114  out:
1115 	mutex_unlock(&data->mtx);
1116 	return ret;
1117 }
1118 
1119 static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
1120 				size_t count, loff_t *pos)
1121 {
1122 	struct rfkill *rfkill;
1123 	struct rfkill_event ev;
1124 
1125 	/* we don't need the 'hard' variable but accept it */
1126 	if (count < RFKILL_EVENT_SIZE_V1 - 1)
1127 		return -EINVAL;
1128 
1129 	/*
1130 	 * Copy as much data as we can accept into our 'ev' buffer,
1131 	 * but tell userspace how much we've copied so it can determine
1132 	 * our API version even in a write() call, if it cares.
1133 	 */
1134 	count = min(count, sizeof(ev));
1135 	if (copy_from_user(&ev, buf, count))
1136 		return -EFAULT;
1137 
1138 	if (ev.op != RFKILL_OP_CHANGE && ev.op != RFKILL_OP_CHANGE_ALL)
1139 		return -EINVAL;
1140 
1141 	if (ev.type >= NUM_RFKILL_TYPES)
1142 		return -EINVAL;
1143 
1144 	mutex_lock(&rfkill_global_mutex);
1145 
1146 	if (ev.op == RFKILL_OP_CHANGE_ALL) {
1147 		if (ev.type == RFKILL_TYPE_ALL) {
1148 			enum rfkill_type i;
1149 			for (i = 0; i < NUM_RFKILL_TYPES; i++)
1150 				rfkill_global_states[i].cur = ev.soft;
1151 		} else {
1152 			rfkill_global_states[ev.type].cur = ev.soft;
1153 		}
1154 	}
1155 
1156 	list_for_each_entry(rfkill, &rfkill_list, node) {
1157 		if (rfkill->idx != ev.idx && ev.op != RFKILL_OP_CHANGE_ALL)
1158 			continue;
1159 
1160 		if (rfkill->type != ev.type && ev.type != RFKILL_TYPE_ALL)
1161 			continue;
1162 
1163 		rfkill_set_block(rfkill, ev.soft);
1164 	}
1165 	mutex_unlock(&rfkill_global_mutex);
1166 
1167 	return count;
1168 }
1169 
1170 static int rfkill_fop_release(struct inode *inode, struct file *file)
1171 {
1172 	struct rfkill_data *data = file->private_data;
1173 	struct rfkill_int_event *ev, *tmp;
1174 
1175 	mutex_lock(&rfkill_global_mutex);
1176 	list_del(&data->list);
1177 	mutex_unlock(&rfkill_global_mutex);
1178 
1179 	mutex_destroy(&data->mtx);
1180 	list_for_each_entry_safe(ev, tmp, &data->events, list)
1181 		kfree(ev);
1182 
1183 #ifdef CONFIG_RFKILL_INPUT
1184 	if (data->input_handler)
1185 		if (atomic_dec_return(&rfkill_input_disabled) == 0)
1186 			printk(KERN_DEBUG "rfkill: input handler enabled\n");
1187 #endif
1188 
1189 	kfree(data);
1190 
1191 	return 0;
1192 }
1193 
1194 #ifdef CONFIG_RFKILL_INPUT
1195 static long rfkill_fop_ioctl(struct file *file, unsigned int cmd,
1196 			     unsigned long arg)
1197 {
1198 	struct rfkill_data *data = file->private_data;
1199 
1200 	if (_IOC_TYPE(cmd) != RFKILL_IOC_MAGIC)
1201 		return -ENOSYS;
1202 
1203 	if (_IOC_NR(cmd) != RFKILL_IOC_NOINPUT)
1204 		return -ENOSYS;
1205 
1206 	mutex_lock(&data->mtx);
1207 
1208 	if (!data->input_handler) {
1209 		if (atomic_inc_return(&rfkill_input_disabled) == 1)
1210 			printk(KERN_DEBUG "rfkill: input handler disabled\n");
1211 		data->input_handler = true;
1212 	}
1213 
1214 	mutex_unlock(&data->mtx);
1215 
1216 	return 0;
1217 }
1218 #endif
1219 
1220 static const struct file_operations rfkill_fops = {
1221 	.owner		= THIS_MODULE,
1222 	.open		= rfkill_fop_open,
1223 	.read		= rfkill_fop_read,
1224 	.write		= rfkill_fop_write,
1225 	.poll		= rfkill_fop_poll,
1226 	.release	= rfkill_fop_release,
1227 #ifdef CONFIG_RFKILL_INPUT
1228 	.unlocked_ioctl	= rfkill_fop_ioctl,
1229 	.compat_ioctl	= rfkill_fop_ioctl,
1230 #endif
1231 	.llseek		= no_llseek,
1232 };
1233 
1234 static struct miscdevice rfkill_miscdev = {
1235 	.name	= "rfkill",
1236 	.fops	= &rfkill_fops,
1237 	.minor	= MISC_DYNAMIC_MINOR,
1238 };
1239 
1240 static int __init rfkill_init(void)
1241 {
1242 	int error;
1243 	int i;
1244 
1245 	for (i = 0; i < NUM_RFKILL_TYPES; i++)
1246 		rfkill_global_states[i].cur = !rfkill_default_state;
1247 
1248 	error = class_register(&rfkill_class);
1249 	if (error)
1250 		goto out;
1251 
1252 	error = misc_register(&rfkill_miscdev);
1253 	if (error) {
1254 		class_unregister(&rfkill_class);
1255 		goto out;
1256 	}
1257 
1258 #ifdef CONFIG_RFKILL_INPUT
1259 	error = rfkill_handler_init();
1260 	if (error) {
1261 		misc_deregister(&rfkill_miscdev);
1262 		class_unregister(&rfkill_class);
1263 		goto out;
1264 	}
1265 #endif
1266 
1267  out:
1268 	return error;
1269 }
1270 subsys_initcall(rfkill_init);
1271 
1272 static void __exit rfkill_exit(void)
1273 {
1274 #ifdef CONFIG_RFKILL_INPUT
1275 	rfkill_handler_exit();
1276 #endif
1277 	misc_deregister(&rfkill_miscdev);
1278 	class_unregister(&rfkill_class);
1279 }
1280 module_exit(rfkill_exit);
1281