rfkill: Fix sparse warning
[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 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;
64
65         retval = mutex_lock_interruptible(&rfkill->mutex);
66         if (retval)
67                 return retval;
68
69         if (state != rfkill->state) {
70                 retval = rfkill->toggle_radio(rfkill->data, state);
71                 if (!retval) {
72                         rfkill->state = state;
73                         rfkill_led_trigger(rfkill, state);
74                 }
75         }
76
77         mutex_unlock(&rfkill->mutex);
78         return retval;
79 }
80
81 /**
82  * rfkill_switch_all - Toggle state of all switches of given type
83  * @type: type of interfaces to be affeceted
84  * @state: the new state
85  *
86  * This function toggles state of all switches of given type unless
87  * a specific switch is claimed by userspace in which case it is
88  * left alone.
89  */
90
91 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
92 {
93         struct rfkill *rfkill;
94
95         mutex_lock(&rfkill_mutex);
96
97         rfkill_states[type] = state;
98
99         list_for_each_entry(rfkill, &rfkill_list, node) {
100                 if (!rfkill->user_claim)
101                         rfkill_toggle_radio(rfkill, state);
102         }
103
104         mutex_unlock(&rfkill_mutex);
105 }
106 EXPORT_SYMBOL(rfkill_switch_all);
107
108 static ssize_t rfkill_name_show(struct device *dev,
109                                 struct device_attribute *attr,
110                                 char *buf)
111 {
112         struct rfkill *rfkill = to_rfkill(dev);
113
114         return sprintf(buf, "%s\n", rfkill->name);
115 }
116
117 static ssize_t rfkill_type_show(struct device *dev,
118                                 struct device_attribute *attr,
119                                 char *buf)
120 {
121         struct rfkill *rfkill = to_rfkill(dev);
122         const char *type;
123
124         switch (rfkill->type) {
125         case RFKILL_TYPE_WLAN:
126                 type = "wlan";
127                 break;
128         case RFKILL_TYPE_BLUETOOTH:
129                 type = "bluetooth";
130                 break;
131         case RFKILL_TYPE_UWB:
132                 type = "ultrawideband";
133                 break;
134         default:
135                 BUG();
136         }
137
138         return sprintf(buf, "%s\n", type);
139 }
140
141 static ssize_t rfkill_state_show(struct device *dev,
142                                  struct device_attribute *attr,
143                                  char *buf)
144 {
145         struct rfkill *rfkill = to_rfkill(dev);
146
147         return sprintf(buf, "%d\n", rfkill->state);
148 }
149
150 static ssize_t rfkill_state_store(struct device *dev,
151                                   struct device_attribute *attr,
152                                   const char *buf, size_t count)
153 {
154         struct rfkill *rfkill = to_rfkill(dev);
155         unsigned int state = simple_strtoul(buf, NULL, 0);
156         int error;
157
158         if (!capable(CAP_NET_ADMIN))
159                 return -EPERM;
160
161         error = rfkill_toggle_radio(rfkill,
162                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
163         if (error)
164                 return error;
165
166         return count;
167 }
168
169 static ssize_t rfkill_claim_show(struct device *dev,
170                                  struct device_attribute *attr,
171                                  char *buf)
172 {
173         struct rfkill *rfkill = to_rfkill(dev);
174
175         return sprintf(buf, "%d", rfkill->user_claim);
176 }
177
178 static ssize_t rfkill_claim_store(struct device *dev,
179                                   struct device_attribute *attr,
180                                   const char *buf, size_t count)
181 {
182         struct rfkill *rfkill = to_rfkill(dev);
183         bool claim = !!simple_strtoul(buf, NULL, 0);
184         int error;
185
186         if (!capable(CAP_NET_ADMIN))
187                 return -EPERM;
188
189         /*
190          * Take the global lock to make sure the kernel is not in
191          * the middle of rfkill_switch_all
192          */
193         error = mutex_lock_interruptible(&rfkill_mutex);
194         if (error)
195                 return error;
196
197         if (rfkill->user_claim_unsupported) {
198                 error = -EOPNOTSUPP;
199                 goto out_unlock;
200         }
201         if (rfkill->user_claim != claim) {
202                 if (!claim)
203                         rfkill_toggle_radio(rfkill,
204                                             rfkill_states[rfkill->type]);
205                 rfkill->user_claim = claim;
206         }
207
208 out_unlock:
209         mutex_unlock(&rfkill_mutex);
210
211         return error ? error : count;
212 }
213
214 static struct device_attribute rfkill_dev_attrs[] = {
215         __ATTR(name, S_IRUGO, rfkill_name_show, NULL),
216         __ATTR(type, S_IRUGO, rfkill_type_show, NULL),
217         __ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
218         __ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
219         __ATTR_NULL
220 };
221
222 static void rfkill_release(struct device *dev)
223 {
224         struct rfkill *rfkill = to_rfkill(dev);
225
226         kfree(rfkill);
227         module_put(THIS_MODULE);
228 }
229
230 #ifdef CONFIG_PM
231 static int rfkill_suspend(struct device *dev, pm_message_t state)
232 {
233         struct rfkill *rfkill = to_rfkill(dev);
234
235         if (dev->power.power_state.event != state.event) {
236                 if (state.event == PM_EVENT_SUSPEND) {
237                         mutex_lock(&rfkill->mutex);
238
239                         if (rfkill->state == RFKILL_STATE_ON)
240                                 rfkill->toggle_radio(rfkill->data,
241                                                      RFKILL_STATE_OFF);
242
243                         mutex_unlock(&rfkill->mutex);
244                 }
245
246                 dev->power.power_state = state;
247         }
248
249         return 0;
250 }
251
252 static int rfkill_resume(struct device *dev)
253 {
254         struct rfkill *rfkill = to_rfkill(dev);
255
256         if (dev->power.power_state.event != PM_EVENT_ON) {
257                 mutex_lock(&rfkill->mutex);
258
259                 if (rfkill->state == RFKILL_STATE_ON)
260                         rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
261
262                 mutex_unlock(&rfkill->mutex);
263         }
264
265         dev->power.power_state = PMSG_ON;
266         return 0;
267 }
268 #else
269 #define rfkill_suspend NULL
270 #define rfkill_resume NULL
271 #endif
272
273 static struct class rfkill_class = {
274         .name           = "rfkill",
275         .dev_release    = rfkill_release,
276         .dev_attrs      = rfkill_dev_attrs,
277         .suspend        = rfkill_suspend,
278         .resume         = rfkill_resume,
279 };
280
281 static int rfkill_add_switch(struct rfkill *rfkill)
282 {
283         int error;
284
285         mutex_lock(&rfkill_mutex);
286
287         error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
288         if (!error)
289                 list_add_tail(&rfkill->node, &rfkill_list);
290
291         mutex_unlock(&rfkill_mutex);
292
293         return error;
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         if (rfkill->type >= RFKILL_TYPE_MAX)
391                 return -EINVAL;
392
393         snprintf(dev->bus_id, sizeof(dev->bus_id),
394                  "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);
395
396         rfkill_led_trigger_register(rfkill);
397
398         error = rfkill_add_switch(rfkill);
399         if (error)
400                 return error;
401
402         error = device_add(dev);
403         if (error) {
404                 rfkill_remove_switch(rfkill);
405                 return error;
406         }
407
408         return 0;
409 }
410 EXPORT_SYMBOL(rfkill_register);
411
412 /**
413  * rfkill_unregister - Uegister a rfkill structure.
414  * @rfkill: rfkill structure to be unregistered
415  *
416  * This function should be called by the network driver during device
417  * teardown to destroy rfkill structure. Note that rfkill_free() should
418  * _not_ be called after rfkill_unregister().
419  */
420 void rfkill_unregister(struct rfkill *rfkill)
421 {
422         device_del(&rfkill->dev);
423         rfkill_remove_switch(rfkill);
424         rfkill_led_trigger_unregister(rfkill);
425         put_device(&rfkill->dev);
426 }
427 EXPORT_SYMBOL(rfkill_unregister);
428
429 /*
430  * Rfkill module initialization/deinitialization.
431  */
432 static int __init rfkill_init(void)
433 {
434         int error;
435         int i;
436
437         for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
438                 rfkill_states[i] = RFKILL_STATE_ON;
439
440         error = class_register(&rfkill_class);
441         if (error) {
442                 printk(KERN_ERR "rfkill: unable to register rfkill class\n");
443                 return error;
444         }
445
446         return 0;
447 }
448
449 static void __exit rfkill_exit(void)
450 {
451         class_unregister(&rfkill_class);
452 }
453
454 subsys_initcall(rfkill_init);
455 module_exit(rfkill_exit);