79f3bbb027ffc4cab50a6cdfe7d4a00c66bdb81d
[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
50 static void rfkill_led_trigger(struct rfkill *rfkill,
51                                enum rfkill_state state)
52 {
53 #ifdef CONFIG_RFKILL_LEDS
54         struct led_trigger *led = &rfkill->led_trigger;
55
56         if (!led->name)
57                 return;
58         if (state == RFKILL_STATE_OFF)
59                 led_trigger_event(led, LED_OFF);
60         else
61                 led_trigger_event(led, LED_FULL);
62 #endif /* CONFIG_RFKILL_LEDS */
63 }
64
65 static void update_rfkill_state(struct rfkill *rfkill)
66 {
67         enum rfkill_state newstate;
68
69         if (rfkill->get_state) {
70                 mutex_lock(&rfkill->mutex);
71                 if (!rfkill->get_state(rfkill->data, &newstate))
72                         rfkill->state = newstate;
73                 mutex_unlock(&rfkill->mutex);
74         }
75 }
76
77 static int rfkill_toggle_radio(struct rfkill *rfkill,
78                                 enum rfkill_state state)
79 {
80         int retval = 0;
81         enum rfkill_state oldstate, newstate;
82
83         oldstate = rfkill->state;
84
85         if (rfkill->get_state &&
86             !rfkill->get_state(rfkill->data, &newstate))
87                 rfkill->state = newstate;
88
89         if (state != rfkill->state) {
90                 retval = rfkill->toggle_radio(rfkill->data, state);
91                 if (!retval)
92                         rfkill->state = state;
93         }
94
95         if (rfkill->state != oldstate)
96                 rfkill_led_trigger(rfkill, rfkill->state);
97
98         return retval;
99 }
100
101 /**
102  * rfkill_switch_all - Toggle state of all switches of given type
103  * @type: type of interfaces to be affeceted
104  * @state: the new state
105  *
106  * This function toggles state of all switches of given type unless
107  * a specific switch is claimed by userspace in which case it is
108  * left alone.
109  */
110
111 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
112 {
113         struct rfkill *rfkill;
114
115         mutex_lock(&rfkill_mutex);
116
117         rfkill_states[type] = state;
118
119         list_for_each_entry(rfkill, &rfkill_list, node) {
120                 if ((!rfkill->user_claim) && (rfkill->type == type))
121                         rfkill_toggle_radio(rfkill, state);
122         }
123
124         mutex_unlock(&rfkill_mutex);
125 }
126 EXPORT_SYMBOL(rfkill_switch_all);
127
128 /**
129  * rfkill_force_state - Force the internal rfkill radio state
130  * @rfkill: pointer to the rfkill class to modify.
131  * @state: the current radio state the class should be forced to.
132  *
133  * This function updates the internal state of the radio cached
134  * by the rfkill class.  It should be used when the driver gets
135  * a notification by the firmware/hardware of the current *real*
136  * state of the radio rfkill switch.
137  *
138  * It may not be called from an atomic context.
139  */
140 int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
141 {
142         if (state != RFKILL_STATE_OFF &&
143             state != RFKILL_STATE_ON)
144                 return -EINVAL;
145
146         mutex_lock(&rfkill->mutex);
147         rfkill->state = state;
148         mutex_unlock(&rfkill->mutex);
149
150         return 0;
151 }
152 EXPORT_SYMBOL(rfkill_force_state);
153
154 static ssize_t rfkill_name_show(struct device *dev,
155                                 struct device_attribute *attr,
156                                 char *buf)
157 {
158         struct rfkill *rfkill = to_rfkill(dev);
159
160         return sprintf(buf, "%s\n", rfkill->name);
161 }
162
163 static ssize_t rfkill_type_show(struct device *dev,
164                                 struct device_attribute *attr,
165                                 char *buf)
166 {
167         struct rfkill *rfkill = to_rfkill(dev);
168         const char *type;
169
170         switch (rfkill->type) {
171         case RFKILL_TYPE_WLAN:
172                 type = "wlan";
173                 break;
174         case RFKILL_TYPE_BLUETOOTH:
175                 type = "bluetooth";
176                 break;
177         case RFKILL_TYPE_UWB:
178                 type = "ultrawideband";
179                 break;
180         case RFKILL_TYPE_WIMAX:
181                 type = "wimax";
182                 break;
183         case RFKILL_TYPE_WWAN:
184                 type = "wwan";
185                 break;
186         default:
187                 BUG();
188         }
189
190         return sprintf(buf, "%s\n", type);
191 }
192
193 static ssize_t rfkill_state_show(struct device *dev,
194                                  struct device_attribute *attr,
195                                  char *buf)
196 {
197         struct rfkill *rfkill = to_rfkill(dev);
198
199         update_rfkill_state(rfkill);
200         return sprintf(buf, "%d\n", rfkill->state);
201 }
202
203 static ssize_t rfkill_state_store(struct device *dev,
204                                   struct device_attribute *attr,
205                                   const char *buf, size_t count)
206 {
207         struct rfkill *rfkill = to_rfkill(dev);
208         unsigned int state = simple_strtoul(buf, NULL, 0);
209         int error;
210
211         if (!capable(CAP_NET_ADMIN))
212                 return -EPERM;
213
214         if (mutex_lock_interruptible(&rfkill->mutex))
215                 return -ERESTARTSYS;
216         error = rfkill_toggle_radio(rfkill,
217                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
218         mutex_unlock(&rfkill->mutex);
219
220         return error ? error : count;
221 }
222
223 static ssize_t rfkill_claim_show(struct device *dev,
224                                  struct device_attribute *attr,
225                                  char *buf)
226 {
227         struct rfkill *rfkill = to_rfkill(dev);
228
229         return sprintf(buf, "%d", rfkill->user_claim);
230 }
231
232 static ssize_t rfkill_claim_store(struct device *dev,
233                                   struct device_attribute *attr,
234                                   const char *buf, size_t count)
235 {
236         struct rfkill *rfkill = to_rfkill(dev);
237         bool claim = !!simple_strtoul(buf, NULL, 0);
238         int error;
239
240         if (!capable(CAP_NET_ADMIN))
241                 return -EPERM;
242
243         /*
244          * Take the global lock to make sure the kernel is not in
245          * the middle of rfkill_switch_all
246          */
247         error = mutex_lock_interruptible(&rfkill_mutex);
248         if (error)
249                 return error;
250
251         if (rfkill->user_claim_unsupported) {
252                 error = -EOPNOTSUPP;
253                 goto out_unlock;
254         }
255         if (rfkill->user_claim != claim) {
256                 if (!claim)
257                         rfkill_toggle_radio(rfkill,
258                                             rfkill_states[rfkill->type]);
259                 rfkill->user_claim = claim;
260         }
261
262 out_unlock:
263         mutex_unlock(&rfkill_mutex);
264
265         return error ? error : count;
266 }
267
268 static struct device_attribute rfkill_dev_attrs[] = {
269         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
270         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
271         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
272         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
273         __ATTR_NULL
274 };
275
276 static void rfkill_release(struct device *dev)
277 {
278         struct rfkill *rfkill = to_rfkill(dev);
279
280         kfree(rfkill);
281         module_put(THIS_MODULE);
282 }
283
284 #ifdef CONFIG_PM
285 static int rfkill_suspend(struct device *dev, pm_message_t state)
286 {
287         struct rfkill *rfkill = to_rfkill(dev);
288
289         if (dev->power.power_state.event != state.event) {
290                 if (state.event & PM_EVENT_SLEEP) {
291                         mutex_lock(&rfkill->mutex);
292
293                         if (rfkill->state == RFKILL_STATE_ON)
294                                 rfkill->toggle_radio(rfkill->data,
295                                                      RFKILL_STATE_OFF);
296
297                         mutex_unlock(&rfkill->mutex);
298                 }
299
300                 dev->power.power_state = state;
301         }
302
303         return 0;
304 }
305
306 static int rfkill_resume(struct device *dev)
307 {
308         struct rfkill *rfkill = to_rfkill(dev);
309
310         if (dev->power.power_state.event != PM_EVENT_ON) {
311                 mutex_lock(&rfkill->mutex);
312
313                 if (rfkill->state == RFKILL_STATE_ON)
314                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
315
316                 mutex_unlock(&rfkill->mutex);
317         }
318
319         dev->power.power_state = PMSG_ON;
320         return 0;
321 }
322 #else
323 #define rfkill_suspend NULL
324 #define rfkill_resume NULL
325 #endif
326
327 static struct class rfkill_class = {
328         .name           = "rfkill",
329         .dev_release    = rfkill_release,
330         .dev_attrs      = rfkill_dev_attrs,
331         .suspend        = rfkill_suspend,
332         .resume         = rfkill_resume,
333 };
334
335 static int rfkill_add_switch(struct rfkill *rfkill)
336 {
337         int error;
338
339         mutex_lock(&rfkill_mutex);
340
341         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
342         if (!error)
343                 list_add_tail(&rfkill->node, &rfkill_list);
344
345         mutex_unlock(&rfkill_mutex);
346
347         return error;
348 }
349
350 static void rfkill_remove_switch(struct rfkill *rfkill)
351 {
352         mutex_lock(&rfkill_mutex);
353         list_del_init(&rfkill->node);
354         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
355         mutex_unlock(&rfkill_mutex);
356 }
357
358 /**
359  * rfkill_allocate - allocate memory for rfkill structure.
360  * @parent: device that has rf switch on it
361  * @type: type of the switch (RFKILL_TYPE_*)
362  *
363  * This function should be called by the network driver when it needs
364  * rfkill structure. Once the structure is allocated the driver shoud
365  * finish its initialization by setting name, private data, enable_radio
366  * and disable_radio methods and then register it with rfkill_register().
367  * NOTE: If registration fails the structure shoudl be freed by calling
368  * rfkill_free() otherwise rfkill_unregister() should be used.
369  */
370 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
371 {
372         struct rfkill *rfkill;
373         struct device *dev;
374
375         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
376         if (!rfkill)
377                 return NULL;
378
379         mutex_init(&rfkill->mutex);
380         INIT_LIST_HEAD(&rfkill->node);
381         rfkill->type = type;
382
383         dev = &rfkill->dev;
384         dev->class = &rfkill_class;
385         dev->parent = parent;
386         device_initialize(dev);
387
388         __module_get(THIS_MODULE);
389
390         return rfkill;
391 }
392 EXPORT_SYMBOL(rfkill_allocate);
393
394 /**
395  * rfkill_free - Mark rfkill structure for deletion
396  * @rfkill: rfkill structure to be destroyed
397  *
398  * Decrements reference count of rfkill structure so it is destroyed.
399  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
400  */
401 void rfkill_free(struct rfkill *rfkill)
402 {
403         if (rfkill)
404                 put_device(&rfkill->dev);
405 }
406 EXPORT_SYMBOL(rfkill_free);
407
408 static void rfkill_led_trigger_register(struct rfkill *rfkill)
409 {
410 #ifdef CONFIG_RFKILL_LEDS
411         int error;
412
413         rfkill->led_trigger.name = rfkill->dev.bus_id;
414         error = led_trigger_register(&rfkill->led_trigger);
415         if (error)
416                 rfkill->led_trigger.name = NULL;
417 #endif /* CONFIG_RFKILL_LEDS */
418 }
419
420 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
421 {
422 #ifdef CONFIG_RFKILL_LEDS
423         if (rfkill->led_trigger.name)
424                 led_trigger_unregister(&rfkill->led_trigger);
425 #endif
426 }
427
428 /**
429  * rfkill_register - Register a rfkill structure.
430  * @rfkill: rfkill structure to be registered
431  *
432  * This function should be called by the network driver when the rfkill
433  * structure needs to be registered. Immediately from registration the
434  * switch driver should be able to service calls to toggle_radio.
435  */
436 int rfkill_register(struct rfkill *rfkill)
437 {
438         static atomic_t rfkill_no = ATOMIC_INIT(0);
439         struct device *dev = &rfkill->dev;
440         int error;
441
442         if (!rfkill->toggle_radio)
443                 return -EINVAL;
444         if (rfkill->type >= RFKILL_TYPE_MAX)
445                 return -EINVAL;
446
447         snprintf(dev->bus_id, sizeof(dev->bus_id),
448                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
449
450         rfkill_led_trigger_register(rfkill);
451
452         error = rfkill_add_switch(rfkill);
453         if (error) {
454                 rfkill_led_trigger_unregister(rfkill);
455                 return error;
456         }
457
458         error = device_add(dev);
459         if (error) {
460                 rfkill_led_trigger_unregister(rfkill);
461                 rfkill_remove_switch(rfkill);
462                 return error;
463         }
464
465         return 0;
466 }
467 EXPORT_SYMBOL(rfkill_register);
468
469 /**
470  * rfkill_unregister - Unregister a rfkill structure.
471  * @rfkill: rfkill structure to be unregistered
472  *
473  * This function should be called by the network driver during device
474  * teardown to destroy rfkill structure. Note that rfkill_free() should
475  * _not_ be called after rfkill_unregister().
476  */
477 void rfkill_unregister(struct rfkill *rfkill)
478 {
479         device_del(&rfkill->dev);
480         rfkill_remove_switch(rfkill);
481         rfkill_led_trigger_unregister(rfkill);
482         put_device(&rfkill->dev);
483 }
484 EXPORT_SYMBOL(rfkill_unregister);
485
486 /*
487  * Rfkill module initialization/deinitialization.
488  */
489 static int __init rfkill_init(void)
490 {
491         int error;
492         int i;
493
494         if (rfkill_default_state != RFKILL_STATE_OFF &&
495             rfkill_default_state != RFKILL_STATE_ON)
496                 return -EINVAL;
497
498         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
499                 rfkill_states[i] = rfkill_default_state;
500
501         error = class_register(&rfkill_class);
502         if (error) {
503                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
504                 return error;
505         }
506
507         return 0;
508 }
509
510 static void __exit rfkill_exit(void)
511 {
512         class_unregister(&rfkill_class);
513 }
514
515 subsys_initcall(rfkill_init);
516 module_exit(rfkill_exit);