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 */
206 if (force
|| state
!= rfkill
->state
) {
207 retval
= rfkill
->toggle_radio(rfkill
->data
, state
);
208 /* never allow a HARD->SOFT downgrade! */
209 if (!retval
&& rfkill
->state
!= RFKILL_STATE_HARD_BLOCKED
)
210 rfkill
->state
= state
;
213 if (force
|| rfkill
->state
!= oldstate
) {
214 rfkill_led_trigger(rfkill
, rfkill
->state
);
215 notify_rfkill_state_change(rfkill
);
222 * __rfkill_switch_all - Toggle state of all switches of given type
223 * @type: type of interfaces to be affected
224 * @state: the new state
226 * This function toggles the state of all switches of given type,
227 * unless a specific switch is claimed by userspace (in which case,
228 * that switch is left alone) or suspended.
230 * Caller must have acquired rfkill_mutex.
232 static void __rfkill_switch_all(const enum rfkill_type type
,
233 const enum rfkill_state state
)
235 struct rfkill
*rfkill
;
237 rfkill_global_states
[type
].current_state
= state
;
238 list_for_each_entry(rfkill
, &rfkill_list
, node
) {
239 if ((!rfkill
->user_claim
) && (rfkill
->type
== type
)) {
240 mutex_lock(&rfkill
->mutex
);
241 rfkill_toggle_radio(rfkill
, state
, 0);
242 mutex_unlock(&rfkill
->mutex
);
248 * rfkill_switch_all - Toggle state of all switches of given type
249 * @type: type of interfaces to be affected
250 * @state: the new state
252 * Acquires rfkill_mutex and calls __rfkill_switch_all(@type, @state).
253 * Please refer to __rfkill_switch_all() for details.
255 void rfkill_switch_all(enum rfkill_type type
, enum rfkill_state state
)
257 mutex_lock(&rfkill_mutex
);
258 __rfkill_switch_all(type
, state
);
259 mutex_unlock(&rfkill_mutex
);
261 EXPORT_SYMBOL(rfkill_switch_all
);
264 * rfkill_epo - emergency power off all transmitters
266 * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
267 * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
269 * The global state before the EPO is saved and can be restored later
270 * using rfkill_restore_states().
272 void rfkill_epo(void)
274 struct rfkill
*rfkill
;
277 mutex_lock(&rfkill_mutex
);
278 list_for_each_entry(rfkill
, &rfkill_list
, node
) {
279 mutex_lock(&rfkill
->mutex
);
280 rfkill_toggle_radio(rfkill
, RFKILL_STATE_SOFT_BLOCKED
, 1);
281 mutex_unlock(&rfkill
->mutex
);
283 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++) {
284 rfkill_global_states
[i
].default_state
=
285 rfkill_global_states
[i
].current_state
;
286 rfkill_global_states
[i
].current_state
=
287 RFKILL_STATE_SOFT_BLOCKED
;
289 mutex_unlock(&rfkill_mutex
);
291 EXPORT_SYMBOL_GPL(rfkill_epo
);
294 * rfkill_restore_states - restore global states
296 * Restore (and sync switches to) the global state from the
297 * states in rfkill_default_states. This can undo the effects of
298 * a call to rfkill_epo().
300 void rfkill_restore_states(void)
304 mutex_lock(&rfkill_mutex
);
305 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++)
306 __rfkill_switch_all(i
, rfkill_global_states
[i
].default_state
);
307 mutex_unlock(&rfkill_mutex
);
309 EXPORT_SYMBOL_GPL(rfkill_restore_states
);
312 * rfkill_force_state - Force the internal rfkill radio state
313 * @rfkill: pointer to the rfkill class to modify.
314 * @state: the current radio state the class should be forced to.
316 * This function updates the internal state of the radio cached
317 * by the rfkill class. It should be used when the driver gets
318 * a notification by the firmware/hardware of the current *real*
319 * state of the radio rfkill switch.
321 * Devices which are subject to external changes on their rfkill
322 * state (such as those caused by a hardware rfkill line) MUST
323 * have their driver arrange to call rfkill_force_state() as soon
324 * as possible after such a change.
326 * This function may not be called from an atomic context.
328 int rfkill_force_state(struct rfkill
*rfkill
, enum rfkill_state state
)
330 enum rfkill_state oldstate
;
332 if (state
!= RFKILL_STATE_SOFT_BLOCKED
&&
333 state
!= RFKILL_STATE_UNBLOCKED
&&
334 state
!= RFKILL_STATE_HARD_BLOCKED
)
337 mutex_lock(&rfkill
->mutex
);
339 oldstate
= rfkill
->state
;
340 rfkill
->state
= state
;
342 if (state
!= oldstate
)
343 notify_rfkill_state_change(rfkill
);
345 mutex_unlock(&rfkill
->mutex
);
349 EXPORT_SYMBOL(rfkill_force_state
);
351 static ssize_t
rfkill_name_show(struct device
*dev
,
352 struct device_attribute
*attr
,
355 struct rfkill
*rfkill
= to_rfkill(dev
);
357 return sprintf(buf
, "%s\n", rfkill
->name
);
360 static const char *rfkill_get_type_str(enum rfkill_type type
)
363 case RFKILL_TYPE_WLAN
:
365 case RFKILL_TYPE_BLUETOOTH
:
367 case RFKILL_TYPE_UWB
:
368 return "ultrawideband";
369 case RFKILL_TYPE_WIMAX
:
371 case RFKILL_TYPE_WWAN
:
378 static ssize_t
rfkill_type_show(struct device
*dev
,
379 struct device_attribute
*attr
,
382 struct rfkill
*rfkill
= to_rfkill(dev
);
384 return sprintf(buf
, "%s\n", rfkill_get_type_str(rfkill
->type
));
387 static ssize_t
rfkill_state_show(struct device
*dev
,
388 struct device_attribute
*attr
,
391 struct rfkill
*rfkill
= to_rfkill(dev
);
393 update_rfkill_state(rfkill
);
394 return sprintf(buf
, "%d\n", rfkill
->state
);
397 static ssize_t
rfkill_state_store(struct device
*dev
,
398 struct device_attribute
*attr
,
399 const char *buf
, size_t count
)
401 struct rfkill
*rfkill
= to_rfkill(dev
);
402 unsigned int state
= simple_strtoul(buf
, NULL
, 0);
405 if (!capable(CAP_NET_ADMIN
))
408 /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
409 if (state
!= RFKILL_STATE_UNBLOCKED
&&
410 state
!= RFKILL_STATE_SOFT_BLOCKED
)
413 if (mutex_lock_interruptible(&rfkill
->mutex
))
415 error
= rfkill_toggle_radio(rfkill
, state
, 0);
416 mutex_unlock(&rfkill
->mutex
);
418 return error
? error
: count
;
421 static ssize_t
rfkill_claim_show(struct device
*dev
,
422 struct device_attribute
*attr
,
425 struct rfkill
*rfkill
= to_rfkill(dev
);
427 return sprintf(buf
, "%d\n", rfkill
->user_claim
);
430 static ssize_t
rfkill_claim_store(struct device
*dev
,
431 struct device_attribute
*attr
,
432 const char *buf
, size_t count
)
434 struct rfkill
*rfkill
= to_rfkill(dev
);
435 bool claim
= !!simple_strtoul(buf
, NULL
, 0);
438 if (!capable(CAP_NET_ADMIN
))
441 if (rfkill
->user_claim_unsupported
)
445 * Take the global lock to make sure the kernel is not in
446 * the middle of rfkill_switch_all
448 error
= mutex_lock_interruptible(&rfkill_mutex
);
452 if (rfkill
->user_claim
!= claim
) {
454 mutex_lock(&rfkill
->mutex
);
455 rfkill_toggle_radio(rfkill
,
456 rfkill_global_states
[rfkill
->type
].current_state
,
458 mutex_unlock(&rfkill
->mutex
);
460 rfkill
->user_claim
= claim
;
463 mutex_unlock(&rfkill_mutex
);
465 return error
? error
: count
;
468 static struct device_attribute rfkill_dev_attrs
[] = {
469 __ATTR(name
, S_IRUGO
, rfkill_name_show
, NULL
),
470 __ATTR(type
, S_IRUGO
, rfkill_type_show
, NULL
),
471 __ATTR(state
, S_IRUGO
|S_IWUSR
, rfkill_state_show
, rfkill_state_store
),
472 __ATTR(claim
, S_IRUGO
|S_IWUSR
, rfkill_claim_show
, rfkill_claim_store
),
476 static void rfkill_release(struct device
*dev
)
478 struct rfkill
*rfkill
= to_rfkill(dev
);
481 module_put(THIS_MODULE
);
485 static int rfkill_suspend(struct device
*dev
, pm_message_t state
)
487 struct rfkill
*rfkill
= to_rfkill(dev
);
489 if (dev
->power
.power_state
.event
!= state
.event
) {
490 if (state
.event
& PM_EVENT_SLEEP
) {
491 /* Stop transmitter, keep state, no notifies */
492 update_rfkill_state(rfkill
);
494 mutex_lock(&rfkill
->mutex
);
495 rfkill
->toggle_radio(rfkill
->data
,
496 RFKILL_STATE_SOFT_BLOCKED
);
497 mutex_unlock(&rfkill
->mutex
);
500 dev
->power
.power_state
= state
;
506 static int rfkill_resume(struct device
*dev
)
508 struct rfkill
*rfkill
= to_rfkill(dev
);
510 if (dev
->power
.power_state
.event
!= PM_EVENT_ON
) {
511 mutex_lock(&rfkill
->mutex
);
513 dev
->power
.power_state
.event
= PM_EVENT_ON
;
515 /* restore radio state AND notify everybody */
516 rfkill_toggle_radio(rfkill
, rfkill
->state
, 1);
518 mutex_unlock(&rfkill
->mutex
);
524 #define rfkill_suspend NULL
525 #define rfkill_resume NULL
528 static int rfkill_blocking_uevent_notifier(struct notifier_block
*nb
,
529 unsigned long eventid
,
532 struct rfkill
*rfkill
= (struct rfkill
*)data
;
535 case RFKILL_STATE_CHANGED
:
536 kobject_uevent(&rfkill
->dev
.kobj
, KOBJ_CHANGE
);
545 static struct notifier_block rfkill_blocking_uevent_nb
= {
546 .notifier_call
= rfkill_blocking_uevent_notifier
,
550 static int rfkill_dev_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
552 struct rfkill
*rfkill
= to_rfkill(dev
);
555 error
= add_uevent_var(env
, "RFKILL_NAME=%s", rfkill
->name
);
558 error
= add_uevent_var(env
, "RFKILL_TYPE=%s",
559 rfkill_get_type_str(rfkill
->type
));
562 error
= add_uevent_var(env
, "RFKILL_STATE=%d", rfkill
->state
);
566 static struct class rfkill_class
= {
568 .dev_release
= rfkill_release
,
569 .dev_attrs
= rfkill_dev_attrs
,
570 .suspend
= rfkill_suspend
,
571 .resume
= rfkill_resume
,
572 .dev_uevent
= rfkill_dev_uevent
,
575 static int rfkill_check_duplicity(const struct rfkill
*rfkill
)
578 unsigned long seen
[BITS_TO_LONGS(RFKILL_TYPE_MAX
)];
580 memset(seen
, 0, sizeof(seen
));
582 list_for_each_entry(p
, &rfkill_list
, node
) {
587 set_bit(p
->type
, seen
);
590 /* 0: first switch of its kind */
591 return test_bit(rfkill
->type
, seen
);
594 static int rfkill_add_switch(struct rfkill
*rfkill
)
598 mutex_lock(&rfkill_mutex
);
600 error
= rfkill_check_duplicity(rfkill
);
605 /* lock default after first use */
606 set_bit(rfkill
->type
, rfkill_states_lockdflt
);
607 rfkill_global_states
[rfkill
->type
].current_state
=
608 rfkill_global_states
[rfkill
->type
].default_state
;
611 rfkill_toggle_radio(rfkill
,
612 rfkill_global_states
[rfkill
->type
].current_state
,
615 list_add_tail(&rfkill
->node
, &rfkill_list
);
619 mutex_unlock(&rfkill_mutex
);
624 static void rfkill_remove_switch(struct rfkill
*rfkill
)
626 mutex_lock(&rfkill_mutex
);
627 list_del_init(&rfkill
->node
);
628 mutex_unlock(&rfkill_mutex
);
630 mutex_lock(&rfkill
->mutex
);
631 rfkill_toggle_radio(rfkill
, RFKILL_STATE_SOFT_BLOCKED
, 1);
632 mutex_unlock(&rfkill
->mutex
);
636 * rfkill_allocate - allocate memory for rfkill structure.
637 * @parent: device that has rf switch on it
638 * @type: type of the switch (RFKILL_TYPE_*)
640 * This function should be called by the network driver when it needs
641 * rfkill structure. Once the structure is allocated the driver should
642 * finish its initialization by setting the name, private data, enable_radio
643 * and disable_radio methods and then register it with rfkill_register().
645 * NOTE: If registration fails the structure shoudl be freed by calling
646 * rfkill_free() otherwise rfkill_unregister() should be used.
648 struct rfkill
*rfkill_allocate(struct device
*parent
, enum rfkill_type type
)
650 struct rfkill
*rfkill
;
653 rfkill
= kzalloc(sizeof(struct rfkill
), GFP_KERNEL
);
657 mutex_init(&rfkill
->mutex
);
658 INIT_LIST_HEAD(&rfkill
->node
);
662 dev
->class = &rfkill_class
;
663 dev
->parent
= parent
;
664 device_initialize(dev
);
666 __module_get(THIS_MODULE
);
670 EXPORT_SYMBOL(rfkill_allocate
);
673 * rfkill_free - Mark rfkill structure for deletion
674 * @rfkill: rfkill structure to be destroyed
676 * Decrements reference count of the rfkill structure so it is destroyed.
677 * Note that rfkill_free() should _not_ be called after rfkill_unregister().
679 void rfkill_free(struct rfkill
*rfkill
)
682 put_device(&rfkill
->dev
);
684 EXPORT_SYMBOL(rfkill_free
);
686 static void rfkill_led_trigger_register(struct rfkill
*rfkill
)
688 #ifdef CONFIG_RFKILL_LEDS
691 if (!rfkill
->led_trigger
.name
)
692 rfkill
->led_trigger
.name
= rfkill
->dev
.bus_id
;
693 if (!rfkill
->led_trigger
.activate
)
694 rfkill
->led_trigger
.activate
= rfkill_led_trigger_activate
;
695 error
= led_trigger_register(&rfkill
->led_trigger
);
697 rfkill
->led_trigger
.name
= NULL
;
698 #endif /* CONFIG_RFKILL_LEDS */
701 static void rfkill_led_trigger_unregister(struct rfkill
*rfkill
)
703 #ifdef CONFIG_RFKILL_LEDS
704 if (rfkill
->led_trigger
.name
) {
705 led_trigger_unregister(&rfkill
->led_trigger
);
706 rfkill
->led_trigger
.name
= NULL
;
712 * rfkill_register - Register a rfkill structure.
713 * @rfkill: rfkill structure to be registered
715 * This function should be called by the network driver when the rfkill
716 * structure needs to be registered. Immediately from registration the
717 * switch driver should be able to service calls to toggle_radio.
719 int rfkill_register(struct rfkill
*rfkill
)
721 static atomic_t rfkill_no
= ATOMIC_INIT(0);
722 struct device
*dev
= &rfkill
->dev
;
725 if (!rfkill
->toggle_radio
)
727 if (rfkill
->type
>= RFKILL_TYPE_MAX
)
730 snprintf(dev
->bus_id
, sizeof(dev
->bus_id
),
731 "rfkill%ld", (long)atomic_inc_return(&rfkill_no
) - 1);
733 rfkill_led_trigger_register(rfkill
);
735 error
= rfkill_add_switch(rfkill
);
737 rfkill_led_trigger_unregister(rfkill
);
741 error
= device_add(dev
);
743 rfkill_remove_switch(rfkill
);
744 rfkill_led_trigger_unregister(rfkill
);
750 EXPORT_SYMBOL(rfkill_register
);
753 * rfkill_unregister - Unregister a rfkill structure.
754 * @rfkill: rfkill structure to be unregistered
756 * This function should be called by the network driver during device
757 * teardown to destroy rfkill structure. Note that rfkill_free() should
758 * _not_ be called after rfkill_unregister().
760 void rfkill_unregister(struct rfkill
*rfkill
)
762 device_del(&rfkill
->dev
);
763 rfkill_remove_switch(rfkill
);
764 rfkill_led_trigger_unregister(rfkill
);
765 put_device(&rfkill
->dev
);
767 EXPORT_SYMBOL(rfkill_unregister
);
770 * rfkill_set_default - set initial value for a switch type
771 * @type - the type of switch to set the default state of
772 * @state - the new default state for that group of switches
774 * Sets the initial state rfkill should use for a given type.
775 * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
776 * and RFKILL_STATE_UNBLOCKED.
778 * This function is meant to be used by platform drivers for platforms
779 * that can save switch state across power down/reboot.
781 * The default state for each switch type can be changed exactly once.
782 * After a switch of that type is registered, the default state cannot
783 * be changed anymore. This guards against multiple drivers it the
784 * same platform trying to set the initial switch default state, which
787 * Returns -EPERM if the state has already been set once or is in use,
788 * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
789 * if this function returns -EPERM.
791 * Returns 0 if the new default state was set, or an error if it
794 int rfkill_set_default(enum rfkill_type type
, enum rfkill_state state
)
798 if (type
>= RFKILL_TYPE_MAX
||
799 (state
!= RFKILL_STATE_SOFT_BLOCKED
&&
800 state
!= RFKILL_STATE_UNBLOCKED
))
803 mutex_lock(&rfkill_mutex
);
805 if (!test_and_set_bit(type
, rfkill_states_lockdflt
)) {
806 rfkill_global_states
[type
].default_state
= state
;
811 mutex_unlock(&rfkill_mutex
);
814 EXPORT_SYMBOL_GPL(rfkill_set_default
);
817 * Rfkill module initialization/deinitialization.
819 static int __init
rfkill_init(void)
824 /* RFKILL_STATE_HARD_BLOCKED is illegal here... */
825 if (rfkill_default_state
!= RFKILL_STATE_SOFT_BLOCKED
&&
826 rfkill_default_state
!= RFKILL_STATE_UNBLOCKED
)
829 for (i
= 0; i
< RFKILL_TYPE_MAX
; i
++)
830 rfkill_global_states
[i
].default_state
= rfkill_default_state
;
832 error
= class_register(&rfkill_class
);
834 printk(KERN_ERR
"rfkill: unable to register rfkill class\n");
838 register_rfkill_notifier(&rfkill_blocking_uevent_nb
);
843 static void __exit
rfkill_exit(void)
845 unregister_rfkill_notifier(&rfkill_blocking_uevent_nb
);
846 class_unregister(&rfkill_class
);
849 subsys_initcall(rfkill_init
);
850 module_exit(rfkill_exit
);