[RFKILL]: Add support for hardware-only rfkill buttons
[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 MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
31 MODULE_VERSION("1.0");
32 MODULE_DESCRIPTION("RF switch support");
33 MODULE_LICENSE("GPL");
34
35 static LIST_HEAD(rfkill_list);  /* list of registered rf switches */
36 static DEFINE_MUTEX(rfkill_mutex);
37
38 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
39
40
41 static void rfkill_led_trigger(struct rfkill *rfkill,
42                                enum rfkill_state state)
43 {
44 #ifdef CONFIG_RFKILL_LEDS
45         struct led_trigger *led = &rfkill->led_trigger;
46
47         if (!led->name)
48                 return;
49         if (state == RFKILL_STATE_OFF)
50                 led_trigger_event(led, LED_OFF);
51         else
52                 led_trigger_event(led, LED_FULL);
53 #endif /* CONFIG_RFKILL_LEDS */
54 }
55
56 static int rfkill_toggle_radio(struct rfkill *rfkill,
57                                 enum rfkill_state state)
58 {
59         int retval;
60
61         retval = mutex_lock_interruptible(&rfkill->mutex);
62         if (retval)
63                 return retval;
64
65         if (state != rfkill->state) {
66                 retval = rfkill->toggle_radio(rfkill->data, state);
67                 if (!retval) {
68                         rfkill->state = state;
69                         rfkill_led_trigger(rfkill, state);
70                 }
71         }
72
73         mutex_unlock(&rfkill->mutex);
74         return retval;
75 }
76
77 /**
78  * rfkill_switch_all - Toggle state of all switches of given type
79  * @type: type of interfaces to be affeceted
80  * @state: the new state
81  *
82  * This function toggles state of all switches of given type unless
83  * a specific switch is claimed by userspace in which case it is
84  * left alone.
85  */
86
87 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
88 {
89         struct rfkill *rfkill;
90
91         mutex_lock(&rfkill_mutex);
92
93         rfkill_states[type] = state;
94
95         list_for_each_entry(rfkill, &rfkill_list, node) {
96                 if (!rfkill->user_claim)
97                         rfkill_toggle_radio(rfkill, state);
98         }
99
100         mutex_unlock(&rfkill_mutex);
101 }
102 EXPORT_SYMBOL(rfkill_switch_all);
103
104 static ssize_t rfkill_name_show(struct device *dev,
105                                 struct device_attribute *attr,
106                                 char *buf)
107 {
108         struct rfkill *rfkill = to_rfkill(dev);
109
110         return sprintf(buf, "%s\n", rfkill->name);
111 }
112
113 static ssize_t rfkill_type_show(struct device *dev,
114                                 struct device_attribute *attr,
115                                 char *buf)
116 {
117         struct rfkill *rfkill = to_rfkill(dev);
118         const char *type;
119
120         switch (rfkill->type) {
121         case RFKILL_TYPE_WLAN:
122                 type = "wlan";
123                 break;
124         case RFKILL_TYPE_BLUETOOTH:
125                 type = "bluetooth";
126                 break;
127         case RFKILL_TYPE_UWB:
128                 type = "ultrawideband";
129                 break;
130         default:
131                 BUG();
132         }
133
134         return sprintf(buf, "%s\n", type);
135 }
136
137 static ssize_t rfkill_state_show(struct device *dev,
138                                  struct device_attribute *attr,
139                                  char *buf)
140 {
141         struct rfkill *rfkill = to_rfkill(dev);
142
143         return sprintf(buf, "%d\n", rfkill->state);
144 }
145
146 static ssize_t rfkill_state_store(struct device *dev,
147                                   struct device_attribute *attr,
148                                   const char *buf, size_t count)
149 {
150         struct rfkill *rfkill = to_rfkill(dev);
151         unsigned int state = simple_strtoul(buf, NULL, 0);
152         int error;
153
154         if (!capable(CAP_NET_ADMIN))
155                 return -EPERM;
156
157         error = rfkill_toggle_radio(rfkill,
158                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
159         if (error)
160                 return error;
161
162         return count;
163 }
164
165 static ssize_t rfkill_claim_show(struct device *dev,
166                                  struct device_attribute *attr,
167                                  char *buf)
168 {
169         struct rfkill *rfkill = to_rfkill(dev);
170
171         return sprintf(buf, "%d", rfkill->user_claim);
172 }
173
174 static ssize_t rfkill_claim_store(struct device *dev,
175                                   struct device_attribute *attr,
176                                   const char *buf, size_t count)
177 {
178         struct rfkill *rfkill = to_rfkill(dev);
179         bool claim = !!simple_strtoul(buf, NULL, 0);
180         int error;
181
182         if (!capable(CAP_NET_ADMIN))
183                 return -EPERM;
184
185         /*
186          * Take the global lock to make sure the kernel is not in
187          * the middle of rfkill_switch_all
188          */
189         error = mutex_lock_interruptible(&rfkill_mutex);
190         if (error)
191                 return error;
192
193         if (rfkill->user_claim_unsupported) {
194                 error = -EOPNOTSUPP;
195                 goto out_unlock;
196         }
197         if (rfkill->user_claim != claim) {
198                 if (!claim)
199                         rfkill_toggle_radio(rfkill,
200                                             rfkill_states[rfkill->type]);
201                 rfkill->user_claim = claim;
202         }
203
204 out_unlock:
205         mutex_unlock(&rfkill_mutex);
206
207         return error ? error : count;
208 }
209
210 static struct device_attribute rfkill_dev_attrs[] = {
211         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
212         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
213         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
214         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
215         __ATTR_NULL
216 };
217
218 static void rfkill_release(struct device *dev)
219 {
220         struct rfkill *rfkill = to_rfkill(dev);
221
222         kfree(rfkill);
223         module_put(THIS_MODULE);
224 }
225
226 #ifdef CONFIG_PM
227 static int rfkill_suspend(struct device *dev, pm_message_t state)
228 {
229         struct rfkill *rfkill = to_rfkill(dev);
230
231         if (dev->power.power_state.event != state.event) {
232                 if (state.event == PM_EVENT_SUSPEND) {
233                         mutex_lock(&rfkill->mutex);
234
235                         if (rfkill->state == RFKILL_STATE_ON)
236                                 rfkill->toggle_radio(rfkill->data,
237                                                      RFKILL_STATE_OFF);
238
239                         mutex_unlock(&rfkill->mutex);
240                 }
241
242                 dev->power.power_state = state;
243         }
244
245         return 0;
246 }
247
248 static int rfkill_resume(struct device *dev)
249 {
250         struct rfkill *rfkill = to_rfkill(dev);
251
252         if (dev->power.power_state.event != PM_EVENT_ON) {
253                 mutex_lock(&rfkill->mutex);
254
255                 if (rfkill->state == RFKILL_STATE_ON)
256                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
257
258                 mutex_unlock(&rfkill->mutex);
259         }
260
261         dev->power.power_state = PMSG_ON;
262         return 0;
263 }
264 #else
265 #define rfkill_suspend NULL
266 #define rfkill_resume NULL
267 #endif
268
269 static struct class rfkill_class = {
270         .name           = "rfkill",
271         .dev_release    = rfkill_release,
272         .dev_attrs      = rfkill_dev_attrs,
273         .suspend        = rfkill_suspend,
274         .resume         = rfkill_resume,
275 };
276
277 static int rfkill_add_switch(struct rfkill *rfkill)
278 {
279         int retval;
280
281         retval = mutex_lock_interruptible(&rfkill_mutex);
282         if (retval)
283                 return retval;
284
285         retval = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
286         if (retval)
287                 goto out;
288
289         list_add_tail(&rfkill->node, &rfkill_list);
290
291  out:
292         mutex_unlock(&rfkill_mutex);
293         return retval;
294 }
295
296 static void rfkill_remove_switch(struct rfkill *rfkill)
297 {
298         mutex_lock(&rfkill_mutex);
299         list_del_init(&rfkill->node);
300         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
301         mutex_unlock(&rfkill_mutex);
302 }
303
304 /**
305  * rfkill_allocate - allocate memory for rfkill structure.
306  * @parent: device that has rf switch on it
307  * @type: type of the switch (RFKILL_TYPE_*)
308  *
309  * This function should be called by the network driver when it needs
310  * rfkill structure. Once the structure is allocated the driver shoud
311  * finish its initialization by setting name, private data, enable_radio
312  * and disable_radio methods and then register it with rfkill_register().
313  * NOTE: If registration fails the structure shoudl be freed by calling
314  * rfkill_free() otherwise rfkill_unregister() should be used.
315  */
316 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
317 {
318         struct rfkill *rfkill;
319         struct device *dev;
320
321         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
322         if (!rfkill)
323                 return NULL;
324
325         mutex_init(&rfkill->mutex);
326         INIT_LIST_HEAD(&rfkill->node);
327         rfkill->type = type;
328
329         dev = &rfkill->dev;
330         dev->class = &rfkill_class;
331         dev->parent = parent;
332         device_initialize(dev);
333
334         __module_get(THIS_MODULE);
335
336         return rfkill;
337 }
338 EXPORT_SYMBOL(rfkill_allocate);
339
340 /**
341  * rfkill_free - Mark rfkill structure for deletion
342  * @rfkill: rfkill structure to be destroyed
343  *
344  * Decrements reference count of rfkill structure so it is destoryed.
345  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
346  */
347 void rfkill_free(struct rfkill *rfkill)
348 {
349         if (rfkill)
350                 put_device(&rfkill->dev);
351 }
352 EXPORT_SYMBOL(rfkill_free);
353
354 static void rfkill_led_trigger_register(struct rfkill *rfkill)
355 {
356 #ifdef CONFIG_RFKILL_LEDS
357         int error;
358
359         rfkill->led_trigger.name = rfkill->dev.bus_id;
360         error = led_trigger_register(&rfkill->led_trigger);
361         if (error)
362                 rfkill->led_trigger.name = NULL;
363 #endif /* CONFIG_RFKILL_LEDS */
364 }
365
366 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
367 {
368 #ifdef CONFIG_RFKILL_LEDS
369         if (rfkill->led_trigger.name)
370                 led_trigger_unregister(&rfkill->led_trigger);
371 #endif
372 }
373
374 /**
375  * rfkill_register - Register a rfkill structure.
376  * @rfkill: rfkill structure to be registered
377  *
378  * This function should be called by the network driver when the rfkill
379  * structure needs to be registered. Immediately from registration the
380  * switch driver should be able to service calls to toggle_radio.
381  */
382 int rfkill_register(struct rfkill *rfkill)
383 {
384         static atomic_t rfkill_no = ATOMIC_INIT(0);
385         struct device *dev = &rfkill->dev;
386         int error;
387
388         if (!rfkill->toggle_radio)
389                 return -EINVAL;
390
391         error = rfkill_add_switch(rfkill);
392         if (error)
393                 return error;
394
395         snprintf(dev->bus_id, sizeof(dev->bus_id),
396                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
397
398         error = device_add(dev);
399         if (error) {
400                 rfkill_remove_switch(rfkill);
401                 return error;
402         }
403         rfkill_led_trigger_register(rfkill);
404
405         return 0;
406 }
407 EXPORT_SYMBOL(rfkill_register);
408
409 /**
410  * rfkill_unregister - Uegister a rfkill structure.
411  * @rfkill: rfkill structure to be unregistered
412  *
413  * This function should be called by the network driver during device
414  * teardown to destroy rfkill structure. Note that rfkill_free() should
415  * _not_ be called after rfkill_unregister().
416  */
417 void rfkill_unregister(struct rfkill *rfkill)
418 {
419         rfkill_led_trigger_unregister(rfkill);
420         device_del(&rfkill->dev);
421         rfkill_remove_switch(rfkill);
422         put_device(&rfkill->dev);
423 }
424 EXPORT_SYMBOL(rfkill_unregister);
425
426 /*
427  * Rfkill module initialization/deinitialization.
428  */
429 static int __init rfkill_init(void)
430 {
431         int error;
432         int i;
433
434         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
435                 rfkill_states[i] = RFKILL_STATE_ON;
436
437         error = class_register(&rfkill_class);
438         if (error) {
439                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
440                 return error;
441         }
442
443         return 0;
444 }
445
446 static void __exit rfkill_exit(void)
447 {
448         class_unregister(&rfkill_class);
449 }
450
451 module_init(rfkill_init);
452 module_exit(rfkill_exit);