a561e350a70a8d2f3a1efc17a3735f33837ac4a7
[linux-2.6.git] / net / rfkill / rfkill.c
1 /*
2  * Copyright (C) 2006 - 2007 Ivo van Doorn
3  * Copyright (C) 2007 Dmitry Torokhov
4  *
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.
9  *
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.
14  *
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.
19  */
20
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>
29
30 /* Get declaration of rfkill_switch_all() to shut up sparse. */
31 #include "rfkill-input.h"
32
33
34 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
35 MODULE_VERSION("1.0");
36 MODULE_DESCRIPTION("RF switch support");
37 MODULE_LICENSE("GPL");
38
39 static LIST_HEAD(rfkill_list);  /* list of registered rf switches */
40 static DEFINE_MUTEX(rfkill_mutex);
41
42 static unsigned int rfkill_default_state = RFKILL_STATE_ON;
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");
46
47 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
48
49 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
50
51
52 /**
53  * register_rfkill_notifier - Add notifier to rfkill notifier chain
54  * @nb: pointer to the new entry to add to the chain
55  *
56  * See blocking_notifier_chain_register() for return value and further
57  * observations.
58  *
59  * Adds a notifier to the rfkill notifier chain.  The chain will be
60  * called with a pointer to the relevant rfkill structure as a parameter,
61  * refer to include/linux/rfkill.h for the possible events.
62  *
63  * Notifiers added to this chain are to always return NOTIFY_DONE.  This
64  * chain is a blocking notifier chain: notifiers can sleep.
65  *
66  * Calls to this chain may have been done through a workqueue.  One must
67  * assume unordered asynchronous behaviour, there is no way to know if
68  * actions related to the event that generated the notification have been
69  * carried out already.
70  */
71 int register_rfkill_notifier(struct notifier_block *nb)
72 {
73         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
74 }
75 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
76
77 /**
78  * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
79  * @nb: pointer to the entry to remove from the chain
80  *
81  * See blocking_notifier_chain_unregister() for return value and further
82  * observations.
83  *
84  * Removes a notifier from the rfkill notifier chain.
85  */
86 int unregister_rfkill_notifier(struct notifier_block *nb)
87 {
88         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
89 }
90 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
91
92
93 static void rfkill_led_trigger(struct rfkill *rfkill,
94                                enum rfkill_state state)
95 {
96 #ifdef CONFIG_RFKILL_LEDS
97         struct led_trigger *led = &rfkill->led_trigger;
98
99         if (!led->name)
100                 return;
101         if (state == RFKILL_STATE_OFF)
102                 led_trigger_event(led, LED_OFF);
103         else
104                 led_trigger_event(led, LED_FULL);
105 #endif /* CONFIG_RFKILL_LEDS */
106 }
107
108 static void notify_rfkill_state_change(struct rfkill *rfkill)
109 {
110         blocking_notifier_call_chain(&rfkill_notifier_list,
111                         RFKILL_STATE_CHANGED,
112                         rfkill);
113 }
114
115 static void update_rfkill_state(struct rfkill *rfkill)
116 {
117         enum rfkill_state newstate, oldstate;
118
119         if (rfkill->get_state) {
120                 mutex_lock(&rfkill->mutex);
121                 if (!rfkill->get_state(rfkill->data, &newstate)) {
122                         oldstate = rfkill->state;
123                         rfkill->state = newstate;
124                         if (oldstate != newstate)
125                                 notify_rfkill_state_change(rfkill);
126                 }
127                 mutex_unlock(&rfkill->mutex);
128         }
129 }
130
131 static int rfkill_toggle_radio(struct rfkill *rfkill,
132                                 enum rfkill_state state,
133                                 int force)
134 {
135         int retval = 0;
136         enum rfkill_state oldstate, newstate;
137
138         oldstate = rfkill->state;
139
140         if (rfkill->get_state && !force &&
141             !rfkill->get_state(rfkill->data, &newstate))
142                 rfkill->state = newstate;
143
144         if (force || state != rfkill->state) {
145                 retval = rfkill->toggle_radio(rfkill->data, state);
146                 if (!retval)
147                         rfkill->state = state;
148         }
149
150         if (force || rfkill->state != oldstate) {
151                 rfkill_led_trigger(rfkill, rfkill->state);
152                 notify_rfkill_state_change(rfkill);
153         }
154
155         return retval;
156 }
157
158 /**
159  * rfkill_switch_all - Toggle state of all switches of given type
160  * @type: type of interfaces to be affeceted
161  * @state: the new state
162  *
163  * This function toggles state of all switches of given type unless
164  * a specific switch is claimed by userspace in which case it is
165  * left alone.
166  */
167 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
168 {
169         struct rfkill *rfkill;
170
171         mutex_lock(&rfkill_mutex);
172
173         rfkill_states[type] = state;
174
175         list_for_each_entry(rfkill, &rfkill_list, node) {
176                 if ((!rfkill->user_claim) && (rfkill->type == type))
177                         rfkill_toggle_radio(rfkill, state, 0);
178         }
179
180         mutex_unlock(&rfkill_mutex);
181 }
182 EXPORT_SYMBOL(rfkill_switch_all);
183
184 /**
185  * rfkill_force_state - Force the internal rfkill radio state
186  * @rfkill: pointer to the rfkill class to modify.
187  * @state: the current radio state the class should be forced to.
188  *
189  * This function updates the internal state of the radio cached
190  * by the rfkill class.  It should be used when the driver gets
191  * a notification by the firmware/hardware of the current *real*
192  * state of the radio rfkill switch.
193  *
194  * It may not be called from an atomic context.
195  */
196 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
197 {
198         enum rfkill_state oldstate;
199
200         if (state != RFKILL_STATE_OFF &&
201             state != RFKILL_STATE_ON)
202                 return -EINVAL;
203
204         mutex_lock(&rfkill->mutex);
205
206         oldstate = rfkill->state;
207         rfkill->state = state;
208
209         if (state != oldstate)
210                 notify_rfkill_state_change(rfkill);
211
212         mutex_unlock(&rfkill->mutex);
213
214         return 0;
215 }
216 EXPORT_SYMBOL(rfkill_force_state);
217
218 static ssize_t rfkill_name_show(struct device *dev,
219                                 struct device_attribute *attr,
220                                 char *buf)
221 {
222         struct rfkill *rfkill = to_rfkill(dev);
223
224         return sprintf(buf, "%s\n", rfkill->name);
225 }
226
227 static ssize_t rfkill_type_show(struct device *dev,
228                                 struct device_attribute *attr,
229                                 char *buf)
230 {
231         struct rfkill *rfkill = to_rfkill(dev);
232         const char *type;
233
234         switch (rfkill->type) {
235         case RFKILL_TYPE_WLAN:
236                 type = "wlan";
237                 break;
238         case RFKILL_TYPE_BLUETOOTH:
239                 type = "bluetooth";
240                 break;
241         case RFKILL_TYPE_UWB:
242                 type = "ultrawideband";
243                 break;
244         case RFKILL_TYPE_WIMAX:
245                 type = "wimax";
246                 break;
247         case RFKILL_TYPE_WWAN:
248                 type = "wwan";
249                 break;
250         default:
251                 BUG();
252         }
253
254         return sprintf(buf, "%s\n", type);
255 }
256
257 static ssize_t rfkill_state_show(struct device *dev,
258                                  struct device_attribute *attr,
259                                  char *buf)
260 {
261         struct rfkill *rfkill = to_rfkill(dev);
262
263         update_rfkill_state(rfkill);
264         return sprintf(buf, "%d\n", rfkill->state);
265 }
266
267 static ssize_t rfkill_state_store(struct device *dev,
268                                   struct device_attribute *attr,
269                                   const char *buf, size_t count)
270 {
271         struct rfkill *rfkill = to_rfkill(dev);
272         unsigned int state = simple_strtoul(buf, NULL, 0);
273         int error;
274
275         if (!capable(CAP_NET_ADMIN))
276                 return -EPERM;
277
278         if (mutex_lock_interruptible(&rfkill->mutex))
279                 return -ERESTARTSYS;
280         error = rfkill_toggle_radio(rfkill,
281                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF,
282                         0);
283         mutex_unlock(&rfkill->mutex);
284
285         return error ? error : count;
286 }
287
288 static ssize_t rfkill_claim_show(struct device *dev,
289                                  struct device_attribute *attr,
290                                  char *buf)
291 {
292         struct rfkill *rfkill = to_rfkill(dev);
293
294         return sprintf(buf, "%d", rfkill->user_claim);
295 }
296
297 static ssize_t rfkill_claim_store(struct device *dev,
298                                   struct device_attribute *attr,
299                                   const char *buf, size_t count)
300 {
301         struct rfkill *rfkill = to_rfkill(dev);
302         bool claim = !!simple_strtoul(buf, NULL, 0);
303         int error;
304
305         if (!capable(CAP_NET_ADMIN))
306                 return -EPERM;
307
308         /*
309          * Take the global lock to make sure the kernel is not in
310          * the middle of rfkill_switch_all
311          */
312         error = mutex_lock_interruptible(&rfkill_mutex);
313         if (error)
314                 return error;
315
316         if (rfkill->user_claim_unsupported) {
317                 error = -EOPNOTSUPP;
318                 goto out_unlock;
319         }
320         if (rfkill->user_claim != claim) {
321                 if (!claim)
322                         rfkill_toggle_radio(rfkill,
323                                             rfkill_states[rfkill->type],
324                                             0);
325                 rfkill->user_claim = claim;
326         }
327
328 out_unlock:
329         mutex_unlock(&rfkill_mutex);
330
331         return error ? error : count;
332 }
333
334 static struct device_attribute rfkill_dev_attrs[] = {
335         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
336         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
337         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
338         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
339         __ATTR_NULL
340 };
341
342 static void rfkill_release(struct device *dev)
343 {
344         struct rfkill *rfkill = to_rfkill(dev);
345
346         kfree(rfkill);
347         module_put(THIS_MODULE);
348 }
349
350 #ifdef CONFIG_PM
351 static int rfkill_suspend(struct device *dev, pm_message_t state)
352 {
353         struct rfkill *rfkill = to_rfkill(dev);
354
355         if (dev->power.power_state.event != state.event) {
356                 if (state.event & PM_EVENT_SLEEP) {
357                         /* Stop transmitter, keep state, no notifies */
358                         update_rfkill_state(rfkill);
359
360                         mutex_lock(&rfkill->mutex);
361                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_OFF);
362                         mutex_unlock(&rfkill->mutex);
363                 }
364
365                 dev->power.power_state = state;
366         }
367
368         return 0;
369 }
370
371 static int rfkill_resume(struct device *dev)
372 {
373         struct rfkill *rfkill = to_rfkill(dev);
374
375         if (dev->power.power_state.event != PM_EVENT_ON) {
376                 mutex_lock(&rfkill->mutex);
377
378                 /* restore radio state AND notify everybody */
379                 rfkill_toggle_radio(rfkill, rfkill->state, 1);
380
381                 mutex_unlock(&rfkill->mutex);
382         }
383
384         dev->power.power_state = PMSG_ON;
385         return 0;
386 }
387 #else
388 #define rfkill_suspend NULL
389 #define rfkill_resume NULL
390 #endif
391
392 static struct class rfkill_class = {
393         .name           = "rfkill",
394         .dev_release    = rfkill_release,
395         .dev_attrs      = rfkill_dev_attrs,
396         .suspend        = rfkill_suspend,
397         .resume         = rfkill_resume,
398 };
399
400 static int rfkill_add_switch(struct rfkill *rfkill)
401 {
402         int error;
403
404         mutex_lock(&rfkill_mutex);
405
406         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
407         if (!error)
408                 list_add_tail(&rfkill->node, &rfkill_list);
409
410         mutex_unlock(&rfkill_mutex);
411
412         return error;
413 }
414
415 static void rfkill_remove_switch(struct rfkill *rfkill)
416 {
417         mutex_lock(&rfkill_mutex);
418         list_del_init(&rfkill->node);
419         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF, 1);
420         mutex_unlock(&rfkill_mutex);
421 }
422
423 /**
424  * rfkill_allocate - allocate memory for rfkill structure.
425  * @parent: device that has rf switch on it
426  * @type: type of the switch (RFKILL_TYPE_*)
427  *
428  * This function should be called by the network driver when it needs
429  * rfkill structure. Once the structure is allocated the driver shoud
430  * finish its initialization by setting name, private data, enable_radio
431  * and disable_radio methods and then register it with rfkill_register().
432  * NOTE: If registration fails the structure shoudl be freed by calling
433  * rfkill_free() otherwise rfkill_unregister() should be used.
434  */
435 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
436 {
437         struct rfkill *rfkill;
438         struct device *dev;
439
440         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
441         if (!rfkill)
442                 return NULL;
443
444         mutex_init(&rfkill->mutex);
445         INIT_LIST_HEAD(&rfkill->node);
446         rfkill->type = type;
447
448         dev = &rfkill->dev;
449         dev->class = &rfkill_class;
450         dev->parent = parent;
451         device_initialize(dev);
452
453         __module_get(THIS_MODULE);
454
455         return rfkill;
456 }
457 EXPORT_SYMBOL(rfkill_allocate);
458
459 /**
460  * rfkill_free - Mark rfkill structure for deletion
461  * @rfkill: rfkill structure to be destroyed
462  *
463  * Decrements reference count of rfkill structure so it is destroyed.
464  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
465  */
466 void rfkill_free(struct rfkill *rfkill)
467 {
468         if (rfkill)
469                 put_device(&rfkill->dev);
470 }
471 EXPORT_SYMBOL(rfkill_free);
472
473 static void rfkill_led_trigger_register(struct rfkill *rfkill)
474 {
475 #ifdef CONFIG_RFKILL_LEDS
476         int error;
477
478         rfkill->led_trigger.name = rfkill->dev.bus_id;
479         error = led_trigger_register(&rfkill->led_trigger);
480         if (error)
481                 rfkill->led_trigger.name = NULL;
482 #endif /* CONFIG_RFKILL_LEDS */
483 }
484
485 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
486 {
487 #ifdef CONFIG_RFKILL_LEDS
488         if (rfkill->led_trigger.name)
489                 led_trigger_unregister(&rfkill->led_trigger);
490 #endif
491 }
492
493 /**
494  * rfkill_register - Register a rfkill structure.
495  * @rfkill: rfkill structure to be registered
496  *
497  * This function should be called by the network driver when the rfkill
498  * structure needs to be registered. Immediately from registration the
499  * switch driver should be able to service calls to toggle_radio.
500  */
501 int rfkill_register(struct rfkill *rfkill)
502 {
503         static atomic_t rfkill_no = ATOMIC_INIT(0);
504         struct device *dev = &rfkill->dev;
505         int error;
506
507         if (!rfkill->toggle_radio)
508                 return -EINVAL;
509         if (rfkill->type >= RFKILL_TYPE_MAX)
510                 return -EINVAL;
511
512         snprintf(dev->bus_id, sizeof(dev->bus_id),
513                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
514
515         rfkill_led_trigger_register(rfkill);
516
517         error = rfkill_add_switch(rfkill);
518         if (error) {
519                 rfkill_led_trigger_unregister(rfkill);
520                 return error;
521         }
522
523         error = device_add(dev);
524         if (error) {
525                 rfkill_led_trigger_unregister(rfkill);
526                 rfkill_remove_switch(rfkill);
527                 return error;
528         }
529
530         return 0;
531 }
532 EXPORT_SYMBOL(rfkill_register);
533
534 /**
535  * rfkill_unregister - Unregister a rfkill structure.
536  * @rfkill: rfkill structure to be unregistered
537  *
538  * This function should be called by the network driver during device
539  * teardown to destroy rfkill structure. Note that rfkill_free() should
540  * _not_ be called after rfkill_unregister().
541  */
542 void rfkill_unregister(struct rfkill *rfkill)
543 {
544         device_del(&rfkill->dev);
545         rfkill_remove_switch(rfkill);
546         rfkill_led_trigger_unregister(rfkill);
547         put_device(&rfkill->dev);
548 }
549 EXPORT_SYMBOL(rfkill_unregister);
550
551 /*
552  * Rfkill module initialization/deinitialization.
553  */
554 static int __init rfkill_init(void)
555 {
556         int error;
557         int i;
558
559         if (rfkill_default_state != RFKILL_STATE_OFF &&
560             rfkill_default_state != RFKILL_STATE_ON)
561                 return -EINVAL;
562
563         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
564                 rfkill_states[i] = rfkill_default_state;
565
566         error = class_register(&rfkill_class);
567         if (error) {
568                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
569                 return error;
570         }
571
572         return 0;
573 }
574
575 static void __exit rfkill_exit(void)
576 {
577         class_unregister(&rfkill_class);
578 }
579
580 subsys_initcall(rfkill_init);
581 module_exit(rfkill_exit);