Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux...
[linux-2.6] / 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 enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
43
44
45 static void rfkill_led_trigger(struct rfkill *rfkill,
46                                enum rfkill_state state)
47 {
48 #ifdef CONFIG_RFKILL_LEDS
49         struct led_trigger *led = &rfkill->led_trigger;
50
51         if (!led->name)
52                 return;
53         if (state == RFKILL_STATE_OFF)
54                 led_trigger_event(led, LED_OFF);
55         else
56                 led_trigger_event(led, LED_FULL);
57 #endif /* CONFIG_RFKILL_LEDS */
58 }
59
60 static int rfkill_toggle_radio(struct rfkill *rfkill,
61                                 enum rfkill_state state)
62 {
63         int retval = 0;
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         return retval;
74 }
75
76 /**
77  * rfkill_switch_all - Toggle state of all switches of given type
78  * @type: type of interfaces to be affeceted
79  * @state: the new state
80  *
81  * This function toggles state of all switches of given type unless
82  * a specific switch is claimed by userspace in which case it is
83  * left alone.
84  */
85
86 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
87 {
88         struct rfkill *rfkill;
89
90         mutex_lock(&rfkill_mutex);
91
92         rfkill_states[type] = state;
93
94         list_for_each_entry(rfkill, &rfkill_list, node) {
95                 if ((!rfkill->user_claim) && (rfkill->type == type))
96                         rfkill_toggle_radio(rfkill, state);
97         }
98
99         mutex_unlock(&rfkill_mutex);
100 }
101 EXPORT_SYMBOL(rfkill_switch_all);
102
103 static ssize_t rfkill_name_show(struct device *dev,
104                                 struct device_attribute *attr,
105                                 char *buf)
106 {
107         struct rfkill *rfkill = to_rfkill(dev);
108
109         return sprintf(buf, "%s\n", rfkill->name);
110 }
111
112 static ssize_t rfkill_type_show(struct device *dev,
113                                 struct device_attribute *attr,
114                                 char *buf)
115 {
116         struct rfkill *rfkill = to_rfkill(dev);
117         const char *type;
118
119         switch (rfkill->type) {
120         case RFKILL_TYPE_WLAN:
121                 type = "wlan";
122                 break;
123         case RFKILL_TYPE_BLUETOOTH:
124                 type = "bluetooth";
125                 break;
126         case RFKILL_TYPE_UWB:
127                 type = "ultrawideband";
128                 break;
129         case RFKILL_TYPE_WIMAX:
130                 type = "wimax";
131                 break;
132         default:
133                 BUG();
134         }
135
136         return sprintf(buf, "%s\n", type);
137 }
138
139 static ssize_t rfkill_state_show(struct device *dev,
140                                  struct device_attribute *attr,
141                                  char *buf)
142 {
143         struct rfkill *rfkill = to_rfkill(dev);
144
145         return sprintf(buf, "%d\n", rfkill->state);
146 }
147
148 static ssize_t rfkill_state_store(struct device *dev,
149                                   struct device_attribute *attr,
150                                   const char *buf, size_t count)
151 {
152         struct rfkill *rfkill = to_rfkill(dev);
153         unsigned int state = simple_strtoul(buf, NULL, 0);
154         int error;
155
156         if (!capable(CAP_NET_ADMIN))
157                 return -EPERM;
158
159         if (mutex_lock_interruptible(&rfkill->mutex))
160                 return -ERESTARTSYS;
161         error = rfkill_toggle_radio(rfkill,
162                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
163         mutex_unlock(&rfkill->mutex);
164
165         return error ? error : count;
166 }
167
168 static ssize_t rfkill_claim_show(struct device *dev,
169                                  struct device_attribute *attr,
170                                  char *buf)
171 {
172         struct rfkill *rfkill = to_rfkill(dev);
173
174         return sprintf(buf, "%d", rfkill->user_claim);
175 }
176
177 static ssize_t rfkill_claim_store(struct device *dev,
178                                   struct device_attribute *attr,
179                                   const char *buf, size_t count)
180 {
181         struct rfkill *rfkill = to_rfkill(dev);
182         bool claim = !!simple_strtoul(buf, NULL, 0);
183         int error;
184
185         if (!capable(CAP_NET_ADMIN))
186                 return -EPERM;
187
188         /*
189          * Take the global lock to make sure the kernel is not in
190          * the middle of rfkill_switch_all
191          */
192         error = mutex_lock_interruptible(&rfkill_mutex);
193         if (error)
194                 return error;
195
196         if (rfkill->user_claim_unsupported) {
197                 error = -EOPNOTSUPP;
198                 goto out_unlock;
199         }
200         if (rfkill->user_claim != claim) {
201                 if (!claim)
202                         rfkill_toggle_radio(rfkill,
203                                             rfkill_states[rfkill->type]);
204                 rfkill->user_claim = claim;
205         }
206
207 out_unlock:
208         mutex_unlock(&rfkill_mutex);
209
210         return error ? error : count;
211 }
212
213 static struct device_attribute rfkill_dev_attrs[] = {
214         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
215         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
216         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
217         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
218         __ATTR_NULL
219 };
220
221 static void rfkill_release(struct device *dev)
222 {
223         struct rfkill *rfkill = to_rfkill(dev);
224
225         kfree(rfkill);
226         module_put(THIS_MODULE);
227 }
228
229 #ifdef CONFIG_PM
230 static int rfkill_suspend(struct device *dev, pm_message_t state)
231 {
232         struct rfkill *rfkill = to_rfkill(dev);
233
234         if (dev->power.power_state.event != state.event) {
235                 if (state.event & PM_EVENT_SLEEP) {
236                         mutex_lock(&rfkill->mutex);
237
238                         if (rfkill->state == RFKILL_STATE_ON)
239                                 rfkill->toggle_radio(rfkill->data,
240                                                      RFKILL_STATE_OFF);
241
242                         mutex_unlock(&rfkill->mutex);
243                 }
244
245                 dev->power.power_state = state;
246         }
247
248         return 0;
249 }
250
251 static int rfkill_resume(struct device *dev)
252 {
253         struct rfkill *rfkill = to_rfkill(dev);
254
255         if (dev->power.power_state.event != PM_EVENT_ON) {
256                 mutex_lock(&rfkill->mutex);
257
258                 if (rfkill->state == RFKILL_STATE_ON)
259                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
260
261                 mutex_unlock(&rfkill->mutex);
262         }
263
264         dev->power.power_state = PMSG_ON;
265         return 0;
266 }
267 #else
268 #define rfkill_suspend NULL
269 #define rfkill_resume NULL
270 #endif
271
272 static struct class rfkill_class = {
273         .name           = "rfkill",
274         .dev_release    = rfkill_release,
275         .dev_attrs      = rfkill_dev_attrs,
276         .suspend        = rfkill_suspend,
277         .resume         = rfkill_resume,
278 };
279
280 static int rfkill_add_switch(struct rfkill *rfkill)
281 {
282         int error;
283
284         mutex_lock(&rfkill_mutex);
285
286         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
287         if (!error)
288                 list_add_tail(&rfkill->node, &rfkill_list);
289
290         mutex_unlock(&rfkill_mutex);
291
292         return error;
293 }
294
295 static void rfkill_remove_switch(struct rfkill *rfkill)
296 {
297         mutex_lock(&rfkill_mutex);
298         list_del_init(&rfkill->node);
299         rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
300         mutex_unlock(&rfkill_mutex);
301 }
302
303 /**
304  * rfkill_allocate - allocate memory for rfkill structure.
305  * @parent: device that has rf switch on it
306  * @type: type of the switch (RFKILL_TYPE_*)
307  *
308  * This function should be called by the network driver when it needs
309  * rfkill structure. Once the structure is allocated the driver shoud
310  * finish its initialization by setting name, private data, enable_radio
311  * and disable_radio methods and then register it with rfkill_register().
312  * NOTE: If registration fails the structure shoudl be freed by calling
313  * rfkill_free() otherwise rfkill_unregister() should be used.
314  */
315 struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
316 {
317         struct rfkill *rfkill;
318         struct device *dev;
319
320         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
321         if (!rfkill)
322                 return NULL;
323
324         mutex_init(&rfkill->mutex);
325         INIT_LIST_HEAD(&rfkill->node);
326         rfkill->type = type;
327
328         dev = &rfkill->dev;
329         dev->class = &rfkill_class;
330         dev->parent = parent;
331         device_initialize(dev);
332
333         __module_get(THIS_MODULE);
334
335         return rfkill;
336 }
337 EXPORT_SYMBOL(rfkill_allocate);
338
339 /**
340  * rfkill_free - Mark rfkill structure for deletion
341  * @rfkill: rfkill structure to be destroyed
342  *
343  * Decrements reference count of rfkill structure so it is destroyed.
344  * Note that rfkill_free() should _not_ be called after rfkill_unregister().
345  */
346 void rfkill_free(struct rfkill *rfkill)
347 {
348         if (rfkill)
349                 put_device(&rfkill->dev);
350 }
351 EXPORT_SYMBOL(rfkill_free);
352
353 static void rfkill_led_trigger_register(struct rfkill *rfkill)
354 {
355 #ifdef CONFIG_RFKILL_LEDS
356         int error;
357
358         rfkill->led_trigger.name = rfkill->dev.bus_id;
359         error = led_trigger_register(&rfkill->led_trigger);
360         if (error)
361                 rfkill->led_trigger.name = NULL;
362 #endif /* CONFIG_RFKILL_LEDS */
363 }
364
365 static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
366 {
367 #ifdef CONFIG_RFKILL_LEDS
368         if (rfkill->led_trigger.name)
369                 led_trigger_unregister(&rfkill->led_trigger);
370 #endif
371 }
372
373 /**
374  * rfkill_register - Register a rfkill structure.
375  * @rfkill: rfkill structure to be registered
376  *
377  * This function should be called by the network driver when the rfkill
378  * structure needs to be registered. Immediately from registration the
379  * switch driver should be able to service calls to toggle_radio.
380  */
381 int rfkill_register(struct rfkill *rfkill)
382 {
383         static atomic_t rfkill_no = ATOMIC_INIT(0);
384         struct device *dev = &rfkill->dev;
385         int error;
386
387         if (!rfkill->toggle_radio)
388                 return -EINVAL;
389         if (rfkill->type >= RFKILL_TYPE_MAX)
390                 return -EINVAL;
391
392         snprintf(dev->bus_id, sizeof(dev->bus_id),
393                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
394
395         rfkill_led_trigger_register(rfkill);
396
397         error = rfkill_add_switch(rfkill);
398         if (error) {
399                 rfkill_led_trigger_unregister(rfkill);
400                 return error;
401         }
402
403         error = device_add(dev);
404         if (error) {
405                 rfkill_led_trigger_unregister(rfkill);
406                 rfkill_remove_switch(rfkill);
407                 return error;
408         }
409
410         return 0;
411 }
412 EXPORT_SYMBOL(rfkill_register);
413
414 /**
415  * rfkill_unregister - Uegister a rfkill structure.
416  * @rfkill: rfkill structure to be unregistered
417  *
418  * This function should be called by the network driver during device
419  * teardown to destroy rfkill structure. Note that rfkill_free() should
420  * _not_ be called after rfkill_unregister().
421  */
422 void rfkill_unregister(struct rfkill *rfkill)
423 {
424         device_del(&rfkill->dev);
425         rfkill_remove_switch(rfkill);
426         rfkill_led_trigger_unregister(rfkill);
427         put_device(&rfkill->dev);
428 }
429 EXPORT_SYMBOL(rfkill_unregister);
430
431 /*
432  * Rfkill module initialization/deinitialization.
433  */
434 static int __init rfkill_init(void)
435 {
436         int error;
437         int i;
438
439         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
440                 rfkill_states[i] = RFKILL_STATE_ON;
441
442         error = class_register(&rfkill_class);
443         if (error) {
444                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
445                 return error;
446         }
447
448         return 0;
449 }
450
451 static void __exit rfkill_exit(void)
452 {
453         class_unregister(&rfkill_class);
454 }
455
456 subsys_initcall(rfkill_init);
457 module_exit(rfkill_exit);