2 * Copyright (C) 2006 - 2007 Ivo van Doorn
3 * Copyright (C) 2007 Dmitry Torokhov
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the
17 * Free Software Foundation, Inc.,
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/workqueue.h>
25 #include <linux/capability.h>
26 #include <linux/list.h>
27 #include <linux/mutex.h>
28 #include <linux/rfkill.h>
30 /* Get declaration of rfkill_switch_all() to shut up sparse. */
31 #include "rfkill-input.h"
34 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
35 MODULE_VERSION("1.0");
36 MODULE_DESCRIPTION("RF switch support");
37 MODULE_LICENSE("GPL");
39 static LIST_HEAD(rfkill_list
); /* list of registered rf switches */
40 static DEFINE_MUTEX(rfkill_mutex
);
42 static unsigned int rfkill_default_state
= RFKILL_STATE_UNBLOCKED
;
43 module_param_named(default_state
, rfkill_default_state
, uint
, 0444);
44 MODULE_PARM_DESC(default_state
,
45 "Default initial state for all radio types, 0 = radio off");
47 struct rfkill_gsw_state
{
48 enum rfkill_state current_state
;
49 enum rfkill_state default_state
;
52 static struct rfkill_gsw_state rfkill_global_states
[RFKILL_TYPE_MAX
];
53 static unsigned long rfkill_states_lockdflt
[BITS_TO_LONGS(RFKILL_TYPE_MAX
)];
55 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list
);
59 * register_rfkill_notifier - Add notifier to rfkill notifier chain
60 * @nb: pointer to the new entry to add to the chain
62 * See blocking_notifier_chain_register() for return value and further
65 * Adds a notifier to the rfkill notifier chain. The chain will be
66 * called with a pointer to the relevant rfkill structure as a parameter,
67 * refer to include/linux/rfkill.h for the possible events.
69 * Notifiers added to this chain are to always return NOTIFY_DONE. This
70 * chain is a blocking notifier chain: notifiers can sleep.
72 * Calls to this chain may have been done through a workqueue. One must
73 * assume unordered asynchronous behaviour, there is no way to know if
74 * actions related to the event that generated the notification have been
75 * carried out already.
77 int register_rfkill_notifier(struct notifier_block
*nb
)
79 return blocking_notifier_chain_register(&rfkill_notifier_list
, nb
);
81 EXPORT_SYMBOL_GPL(register_rfkill_notifier
);
84 * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
85 * @nb: pointer to the entry to remove from the chain
87 * See blocking_notifier_chain_unregister() for return value and further
90 * Removes a notifier from the rfkill notifier chain.
92 int unregister_rfkill_notifier(struct notifier_block
*nb
)
94 return blocking_notifier_chain_unregister(&rfkill_notifier_list
, nb
);
96 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier
);
99 static void rfkill_led_trigger(struct rfkill
*rfkill
,
100 enum rfkill_state state
)
102 #ifdef CONFIG_RFKILL_LEDS
103 struct led_trigger
*led
= &rfkill
->led_trigger
;
107 if (state
!= RFKILL_STATE_UNBLOCKED
)
108 led_trigger_event(led
, LED_OFF
);
110 led_trigger_event(led
, LED_FULL
);
111 #endif /* CONFIG_RFKILL_LEDS */
114 #ifdef CONFIG_RFKILL_LEDS
115 static void rfkill_led_trigger_activate(struct led_classdev
*led
)
117 struct rfkill
*rfkill
= container_of(led
->trigger
,
118 struct rfkill
, led_trigger
);
120 rfkill_led_trigger(rfkill
, rfkill
->state
);
122 #endif /* CONFIG_RFKILL_LEDS */
124 static void notify_rfkill_state_change(struct rfkill
*rfkill
)
126 blocking_notifier_call_chain(&rfkill_notifier_list
,
127 RFKILL_STATE_CHANGED
,
131 static void update_rfkill_state(struct rfkill
*rfkill
)
133 enum rfkill_state newstate
, oldstate
;
135 if (rfkill
->get_state
) {
136 mutex_lock(&rfkill
->mutex
);
137 if (!rfkill
->get_state(rfkill
->data
, &newstate
)) {
138 oldstate
= rfkill
->state
;
139 rfkill
->state
= newstate
;
140 if (oldstate
!= newstate
)
141 notify_rfkill_state_change(rfkill
);
143 mutex_unlock(&rfkill
->mutex
);
148 * rfkill_toggle_radio - wrapper for toggle_radio hook
149 * @rfkill: the rfkill struct to use
150 * @force: calls toggle_radio even if cache says it is not needed,
151 * and also makes sure notifications of the state will be
152 * sent even if it didn't change
153 * @state: the new state to call toggle_radio() with
155 * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
156 * calls and handling all the red tape such as issuing notifications
157 * if the call is successful.
159 * Suspended devices are not touched at all, and -EAGAIN is returned.
161 * Note that the @force parameter cannot override a (possibly cached)
162 * state of RFKILL_STATE_HARD_BLOCKED. Any device making use of
163 * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
164 * rfkill_force_state(), so the cache either is bypassed or valid.
166 * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
167 * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
168 * give the driver a hint that it should double-BLOCK the transmitter.
170 * Caller must have acquired rfkill->mutex.
172 static int rfkill_toggle_radio(struct rfkill
*rfkill
,
173 enum rfkill_state state
,
177 enum rfkill_state oldstate
, newstate
;
179 if (unlikely(rfkill
->dev
.power
.power_state
.event
& PM_EVENT_SLEEP
))
182 oldstate
= rfkill
->state
;
184 if (rfkill
->get_state
&& !force
&&
185 !rfkill
->get_state(rfkill
->data
, &newstate
))
186 rfkill
->state
= newstate
;
189 case RFKILL_STATE_HARD_BLOCKED
:
190 /* typically happens when refreshing hardware state,
191 * such as on resume */
192 state
= RFKILL_STATE_SOFT_BLOCKED
;
194 case RFKILL_STATE_UNBLOCKED
:
195 /* force can't override this, only rfkill_force_state() can */
196 if (rfkill
->state
== RFKILL_STATE_HARD_BLOCKED
)
199 case RFKILL_STATE_SOFT_BLOCKED
:
200 /* nothing to do, we want to give drivers the hint to double
201 * BLOCK even a transmitter that is already in state
202 * RFKILL_STATE_HARD_BLOCKED */
208 if (force
|| state
!= rfkill
->state
) {
209 retval
= rfkill
->toggle_radio(rfkill
->data
, state
);
210 /* never allow a HARD->SOFT downgrade! */
211 if (!retval
&& rfkill
->state
!= RFKILL_STATE_HARD_BLOCKED
)
212 rfkill
->state
= state
;
215 if (force
|| rfkill
->state
!= oldstate
) {
216 rfkill_led_trigger(rfkill
, rfkill
->state
);
217 notify_rfkill_state_change(rfkill
);
224 * __rfkill_switch_all - Toggle state of all switches of given type
225 * @type: type of interfaces to be affected
226 * @state: the new state
228 * This function toggles the state of all switches of given type,
229 * unless a specific switch is claimed by userspace (in which case,
230 * that switch is left alone) or suspended.
232 * Caller must have acquired rfkill_mutex.
234 static void __rfkill_switch_all(const enum rfkill_type type
,
235 const enum rfkill_state state
)
237 struct rfkill
*rfkill
;
239 if (unlikely(state
>= RFKILL_STATE_MAX
))
242 rfkill_global_states
[type
].current_state
= state
;
243 list_for_each_entry(rfkill
, &rfkill_list
, node
) {
244 if ((!rfkill
->user_claim
) && (rfkill
->type
== type
)) {
245 mutex_lock(&rfkill
->mutex
);
246 rfkill_toggle_radio(rfkill
, state
, 0);
247 mutex_unlock(&rfkill
->mutex
);
253 * rfkill_switch_all - Toggle state of all switches of given type
254 * @type: type of interfaces to be affected
255 * @state: the new state
257 * Acquires rfkill_mutex and calls __rfkill_switch_all(@type, @state).
258 * Please refer to __rfkill_switch_all() for details.
260 void rfkill_switch_all(enum rfkill_type type
, enum rfkill_state state
)
262 mutex_lock(&rfkill_mutex
);
263 __rfkill_switch_all(type
, state
);
264 mutex_unlock(&rfkill_mutex
);
266 EXPORT_SYMBOL(rfkill_switch_all
);
269 * rfkill_epo - emergency power off all transmitters
271 * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
272 * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
274 * The global state before the EPO is saved and can be restored later
275 * using rfkill_restore_states().
277 void rfkill_epo(void)
279 struct rfkill
*rfkill
;
282 mutex_lock(&rfkill_mutex
);
283 list_for_each_entry(rfkill
, &rfkill_list
, node
) {
284 mutex_lock(&rfkill
->mutex
);
285 rfkill_toggle_radio(rfkill
, RFKILL_STATE_SOFT_BLOCKED
, 1);
286 mutex_unlock(&rfkill
->mutex
);
288 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++) {
289 rfkill_global_states
[i
].default_state
=
290 rfkill_global_states
[i
].current_state
;
291 rfkill_global_states
[i
].current_state
=
292 RFKILL_STATE_SOFT_BLOCKED
;
294 mutex_unlock(&rfkill_mutex
);
296 EXPORT_SYMBOL_GPL(rfkill_epo
);
299 * rfkill_restore_states - restore global states
301 * Restore (and sync switches to) the global state from the
302 * states in rfkill_default_states. This can undo the effects of
303 * a call to rfkill_epo().
305 void rfkill_restore_states(void)
309 mutex_lock(&rfkill_mutex
);
310 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++)
311 __rfkill_switch_all(i
, rfkill_global_states
[i
].default_state
);
312 mutex_unlock(&rfkill_mutex
);
314 EXPORT_SYMBOL_GPL(rfkill_restore_states
);
317 * rfkill_force_state - Force the internal rfkill radio state
318 * @rfkill: pointer to the rfkill class to modify.
319 * @state: the current radio state the class should be forced to.
321 * This function updates the internal state of the radio cached
322 * by the rfkill class. It should be used when the driver gets
323 * a notification by the firmware/hardware of the current *real*
324 * state of the radio rfkill switch.
326 * Devices which are subject to external changes on their rfkill
327 * state (such as those caused by a hardware rfkill line) MUST
328 * have their driver arrange to call rfkill_force_state() as soon
329 * as possible after such a change.
331 * This function may not be called from an atomic context.
333 int rfkill_force_state(struct rfkill
*rfkill
, enum rfkill_state state
)
335 enum rfkill_state oldstate
;
337 if (unlikely(state
>= RFKILL_STATE_MAX
))
340 mutex_lock(&rfkill
->mutex
);
342 oldstate
= rfkill
->state
;
343 rfkill
->state
= state
;
345 if (state
!= oldstate
)
346 notify_rfkill_state_change(rfkill
);
348 mutex_unlock(&rfkill
->mutex
);
352 EXPORT_SYMBOL(rfkill_force_state
);
354 static ssize_t
rfkill_name_show(struct device
*dev
,
355 struct device_attribute
*attr
,
358 struct rfkill
*rfkill
= to_rfkill(dev
);
360 return sprintf(buf
, "%s\n", rfkill
->name
);
363 static const char *rfkill_get_type_str(enum rfkill_type type
)
366 case RFKILL_TYPE_WLAN
:
368 case RFKILL_TYPE_BLUETOOTH
:
370 case RFKILL_TYPE_UWB
:
371 return "ultrawideband";
372 case RFKILL_TYPE_WIMAX
:
374 case RFKILL_TYPE_WWAN
:
381 static ssize_t
rfkill_type_show(struct device
*dev
,
382 struct device_attribute
*attr
,
385 struct rfkill
*rfkill
= to_rfkill(dev
);
387 return sprintf(buf
, "%s\n", rfkill_get_type_str(rfkill
->type
));
390 static ssize_t
rfkill_state_show(struct device
*dev
,
391 struct device_attribute
*attr
,
394 struct rfkill
*rfkill
= to_rfkill(dev
);
396 update_rfkill_state(rfkill
);
397 return sprintf(buf
, "%d\n", rfkill
->state
);
400 static ssize_t
rfkill_state_store(struct device
*dev
,
401 struct device_attribute
*attr
,
402 const char *buf
, size_t count
)
404 struct rfkill
*rfkill
= to_rfkill(dev
);
405 unsigned int state
= simple_strtoul(buf
, NULL
, 0);
408 if (!capable(CAP_NET_ADMIN
))
411 /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
412 if (state
!= RFKILL_STATE_UNBLOCKED
&&
413 state
!= RFKILL_STATE_SOFT_BLOCKED
)
416 if (mutex_lock_interruptible(&rfkill
->mutex
))
418 error
= rfkill_toggle_radio(rfkill
, state
, 0);
419 mutex_unlock(&rfkill
->mutex
);
421 return error
? error
: count
;
424 static ssize_t
rfkill_claim_show(struct device
*dev
,
425 struct device_attribute
*attr
,
428 struct rfkill
*rfkill
= to_rfkill(dev
);
430 return sprintf(buf
, "%d", rfkill
->user_claim
);
433 static ssize_t
rfkill_claim_store(struct device
*dev
,
434 struct device_attribute
*attr
,
435 const char *buf
, size_t count
)
437 struct rfkill
*rfkill
= to_rfkill(dev
);
438 bool claim
= !!simple_strtoul(buf
, NULL
, 0);
441 if (!capable(CAP_NET_ADMIN
))
444 if (rfkill
->user_claim_unsupported
)
448 * Take the global lock to make sure the kernel is not in
449 * the middle of rfkill_switch_all
451 error
= mutex_lock_interruptible(&rfkill_mutex
);
455 if (rfkill
->user_claim
!= claim
) {
457 mutex_lock(&rfkill
->mutex
);
458 rfkill_toggle_radio(rfkill
,
459 rfkill_global_states
[rfkill
->type
].current_state
,
461 mutex_unlock(&rfkill
->mutex
);
463 rfkill
->user_claim
= claim
;
466 mutex_unlock(&rfkill_mutex
);
468 return error
? error
: count
;
471 static struct device_attribute rfkill_dev_attrs
[] = {
472 __ATTR(name
, S_IRUGO
, rfkill_name_show
, NULL
),
473 __ATTR(type
, S_IRUGO
, rfkill_type_show
, NULL
),
474 __ATTR(state
, S_IRUGO
|S_IWUSR
, rfkill_state_show
, rfkill_state_store
),
475 __ATTR(claim
, S_IRUGO
|S_IWUSR
, rfkill_claim_show
, rfkill_claim_store
),
479 static void rfkill_release(struct device
*dev
)
481 struct rfkill
*rfkill
= to_rfkill(dev
);
484 module_put(THIS_MODULE
);
488 static int rfkill_suspend(struct device
*dev
, pm_message_t state
)
490 struct rfkill
*rfkill
= to_rfkill(dev
);
492 if (dev
->power
.power_state
.event
!= state
.event
) {
493 if (state
.event
& PM_EVENT_SLEEP
) {
494 /* Stop transmitter, keep state, no notifies */
495 update_rfkill_state(rfkill
);
497 mutex_lock(&rfkill
->mutex
);
498 rfkill
->toggle_radio(rfkill
->data
,
499 RFKILL_STATE_SOFT_BLOCKED
);
500 mutex_unlock(&rfkill
->mutex
);
503 dev
->power
.power_state
= state
;
509 static int rfkill_resume(struct device
*dev
)
511 struct rfkill
*rfkill
= to_rfkill(dev
);
513 if (dev
->power
.power_state
.event
!= PM_EVENT_ON
) {
514 mutex_lock(&rfkill
->mutex
);
516 dev
->power
.power_state
.event
= PM_EVENT_ON
;
518 /* restore radio state AND notify everybody */
519 rfkill_toggle_radio(rfkill
, rfkill
->state
, 1);
521 mutex_unlock(&rfkill
->mutex
);
527 #define rfkill_suspend NULL
528 #define rfkill_resume NULL
531 static int rfkill_blocking_uevent_notifier(struct notifier_block
*nb
,
532 unsigned long eventid
,
535 struct rfkill
*rfkill
= (struct rfkill
*)data
;
538 case RFKILL_STATE_CHANGED
:
539 kobject_uevent(&rfkill
->dev
.kobj
, KOBJ_CHANGE
);
548 static struct notifier_block rfkill_blocking_uevent_nb
= {
549 .notifier_call
= rfkill_blocking_uevent_notifier
,
553 static int rfkill_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
555 struct rfkill
*rfkill
= to_rfkill(dev
);
558 error
= add_uevent_var(env
, "RFKILL_NAME=%s", rfkill
->name
);
561 error
= add_uevent_var(env
, "RFKILL_TYPE=%s",
562 rfkill_get_type_str(rfkill
->type
));
565 error
= add_uevent_var(env
, "RFKILL_STATE=%d", rfkill
->state
);
569 static struct class rfkill_class
= {
571 .dev_release
= rfkill_release
,
572 .dev_attrs
= rfkill_dev_attrs
,
573 .suspend
= rfkill_suspend
,
574 .resume
= rfkill_resume
,
575 .dev_uevent
= rfkill_dev_uevent
,
578 static int rfkill_check_duplicity(const struct rfkill
*rfkill
)
581 unsigned long seen
[BITS_TO_LONGS(RFKILL_TYPE_MAX
)];
583 memset(seen
, 0, sizeof(seen
));
585 list_for_each_entry(p
, &rfkill_list
, node
) {
590 set_bit(p
->type
, seen
);
593 /* 0: first switch of its kind */
594 return test_bit(rfkill
->type
, seen
);
597 static int rfkill_add_switch(struct rfkill
*rfkill
)
601 mutex_lock(&rfkill_mutex
);
603 error
= rfkill_check_duplicity(rfkill
);
608 /* lock default after first use */
609 set_bit(rfkill
->type
, rfkill_states_lockdflt
);
610 rfkill_global_states
[rfkill
->type
].current_state
=
611 rfkill_global_states
[rfkill
->type
].default_state
;
614 rfkill_toggle_radio(rfkill
,
615 rfkill_global_states
[rfkill
->type
].current_state
,
618 list_add_tail(&rfkill
->node
, &rfkill_list
);
622 mutex_unlock(&rfkill_mutex
);
627 static void rfkill_remove_switch(struct rfkill
*rfkill
)
629 mutex_lock(&rfkill_mutex
);
630 list_del_init(&rfkill
->node
);
631 mutex_unlock(&rfkill_mutex
);
633 mutex_lock(&rfkill
->mutex
);
634 rfkill_toggle_radio(rfkill
, RFKILL_STATE_SOFT_BLOCKED
, 1);
635 mutex_unlock(&rfkill
->mutex
);
639 * rfkill_allocate - allocate memory for rfkill structure.
640 * @parent: device that has rf switch on it
641 * @type: type of the switch (RFKILL_TYPE_*)
643 * This function should be called by the network driver when it needs
644 * rfkill structure. Once the structure is allocated the driver should
645 * finish its initialization by setting the name, private data, enable_radio
646 * and disable_radio methods and then register it with rfkill_register().
648 * NOTE: If registration fails the structure shoudl be freed by calling
649 * rfkill_free() otherwise rfkill_unregister() should be used.
651 struct rfkill
* __must_check
rfkill_allocate(struct device
*parent
,
652 enum rfkill_type type
)
654 struct rfkill
*rfkill
;
657 rfkill
= kzalloc(sizeof(struct rfkill
), GFP_KERNEL
);
661 mutex_init(&rfkill
->mutex
);
662 INIT_LIST_HEAD(&rfkill
->node
);
666 dev
->class = &rfkill_class
;
667 dev
->parent
= parent
;
668 device_initialize(dev
);
670 __module_get(THIS_MODULE
);
674 EXPORT_SYMBOL(rfkill_allocate
);
677 * rfkill_free - Mark rfkill structure for deletion
678 * @rfkill: rfkill structure to be destroyed
680 * Decrements reference count of the rfkill structure so it is destroyed.
681 * Note that rfkill_free() should _not_ be called after rfkill_unregister().
683 void rfkill_free(struct rfkill
*rfkill
)
686 put_device(&rfkill
->dev
);
688 EXPORT_SYMBOL(rfkill_free
);
690 static void rfkill_led_trigger_register(struct rfkill
*rfkill
)
692 #ifdef CONFIG_RFKILL_LEDS
695 if (!rfkill
->led_trigger
.name
)
696 rfkill
->led_trigger
.name
= rfkill
->dev
.bus_id
;
697 if (!rfkill
->led_trigger
.activate
)
698 rfkill
->led_trigger
.activate
= rfkill_led_trigger_activate
;
699 error
= led_trigger_register(&rfkill
->led_trigger
);
701 rfkill
->led_trigger
.name
= NULL
;
702 #endif /* CONFIG_RFKILL_LEDS */
705 static void rfkill_led_trigger_unregister(struct rfkill
*rfkill
)
707 #ifdef CONFIG_RFKILL_LEDS
708 if (rfkill
->led_trigger
.name
) {
709 led_trigger_unregister(&rfkill
->led_trigger
);
710 rfkill
->led_trigger
.name
= NULL
;
716 * rfkill_register - Register a rfkill structure.
717 * @rfkill: rfkill structure to be registered
719 * This function should be called by the network driver when the rfkill
720 * structure needs to be registered. Immediately from registration the
721 * switch driver should be able to service calls to toggle_radio.
723 int __must_check
rfkill_register(struct rfkill
*rfkill
)
725 static atomic_t rfkill_no
= ATOMIC_INIT(0);
726 struct device
*dev
= &rfkill
->dev
;
729 if (!rfkill
->toggle_radio
)
731 if (rfkill
->type
>= RFKILL_TYPE_MAX
)
733 if (rfkill
->state
>= RFKILL_STATE_MAX
)
736 snprintf(dev
->bus_id
, sizeof(dev
->bus_id
),
737 "rfkill%ld", (long)atomic_inc_return(&rfkill_no
) - 1);
739 rfkill_led_trigger_register(rfkill
);
741 error
= rfkill_add_switch(rfkill
);
743 rfkill_led_trigger_unregister(rfkill
);
747 error
= device_add(dev
);
749 rfkill_remove_switch(rfkill
);
750 rfkill_led_trigger_unregister(rfkill
);
756 EXPORT_SYMBOL(rfkill_register
);
759 * rfkill_unregister - Unregister a rfkill structure.
760 * @rfkill: rfkill structure to be unregistered
762 * This function should be called by the network driver during device
763 * teardown to destroy rfkill structure. Note that rfkill_free() should
764 * _not_ be called after rfkill_unregister().
766 void rfkill_unregister(struct rfkill
*rfkill
)
768 device_del(&rfkill
->dev
);
769 rfkill_remove_switch(rfkill
);
770 rfkill_led_trigger_unregister(rfkill
);
771 put_device(&rfkill
->dev
);
773 EXPORT_SYMBOL(rfkill_unregister
);
776 * rfkill_set_default - set initial value for a switch type
777 * @type - the type of switch to set the default state of
778 * @state - the new default state for that group of switches
780 * Sets the initial state rfkill should use for a given type.
781 * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
782 * and RFKILL_STATE_UNBLOCKED.
784 * This function is meant to be used by platform drivers for platforms
785 * that can save switch state across power down/reboot.
787 * The default state for each switch type can be changed exactly once.
788 * After a switch of that type is registered, the default state cannot
789 * be changed anymore. This guards against multiple drivers it the
790 * same platform trying to set the initial switch default state, which
793 * Returns -EPERM if the state has already been set once or is in use,
794 * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
795 * if this function returns -EPERM.
797 * Returns 0 if the new default state was set, or an error if it
800 int rfkill_set_default(enum rfkill_type type
, enum rfkill_state state
)
804 if (type
>= RFKILL_TYPE_MAX
||
805 (state
!= RFKILL_STATE_SOFT_BLOCKED
&&
806 state
!= RFKILL_STATE_UNBLOCKED
))
809 mutex_lock(&rfkill_mutex
);
811 if (!test_and_set_bit(type
, rfkill_states_lockdflt
)) {
812 rfkill_global_states
[type
].default_state
= state
;
817 mutex_unlock(&rfkill_mutex
);
820 EXPORT_SYMBOL_GPL(rfkill_set_default
);
823 * Rfkill module initialization/deinitialization.
825 static int __init
rfkill_init(void)
830 /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
831 if (rfkill_default_state
!= RFKILL_STATE_SOFT_BLOCKED
&&
832 rfkill_default_state
!= RFKILL_STATE_UNBLOCKED
)
835 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++)
836 rfkill_global_states
[i
].default_state
= rfkill_default_state
;
838 error
= class_register(&rfkill_class
);
840 printk(KERN_ERR
"rfkill: unable to register rfkill class\n");
844 register_rfkill_notifier(&rfkill_blocking_uevent_nb
);
849 static void __exit
rfkill_exit(void)
851 unregister_rfkill_notifier(&rfkill_blocking_uevent_nb
);
852 class_unregister(&rfkill_class
);
855 subsys_initcall(rfkill_init
);
856 module_exit(rfkill_exit
);