summaryrefslogtreecommitdiffstats
path: root/net/rfkill/rfkill.c
blob: 637a9f0c7655f525df79ec9c5f3f370da3f11762 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
/*
 * Copyright (C) 2006 - 2007 Ivo van Doorn
 * Copyright (C) 2007 Dmitry Torokhov
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the
 * Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/workqueue.h>
#include <linux/capability.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rfkill.h>

MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");
MODULE_VERSION("1.0");
MODULE_DESCRIPTION("RF switch support");
MODULE_LICENSE("GPL");

static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
static DEFINE_MUTEX(rfkill_mutex);

static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];

static int rfkill_toggle_radio(struct rfkill *rfkill,
				enum rfkill_state state)
{
	int retval;

	retval = mutex_lock_interruptible(&rfkill->mutex);
	if (retval)
		return retval;

	if (state != rfkill->state) {
		retval = rfkill->toggle_radio(rfkill->data, state);
		if (!retval)
			rfkill->state = state;
	}

	mutex_unlock(&rfkill->mutex);
	return retval;
}

/**
 * rfkill_switch_all - Toggle state of all switches of given type
 * @type: type of interfaces to be affeceted
 * @state: the new state
 *
 * This function toggles state of all switches of given type unless
 * a specific switch is claimed by userspace in which case it is
 * left alone.
 */

void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
{
	struct rfkill *rfkill;

	mutex_lock(&rfkill_mutex);

	rfkill_states[type] = state;

	list_for_each_entry(rfkill, &rfkill_list, node) {
		if (!rfkill->user_claim)
			rfkill_toggle_radio(rfkill, state);
	}

	mutex_unlock(&rfkill_mutex);
}
EXPORT_SYMBOL(rfkill_switch_all);

static ssize_t rfkill_name_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	struct rfkill *rfkill = to_rfkill(dev);

	return sprintf(buf, "%s\n", rfkill->name);
}

static ssize_t rfkill_type_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	struct rfkill *rfkill = to_rfkill(dev);
	const char *type;

	switch (rfkill->type) {
	case RFKILL_TYPE_WLAN:
		type = "wlan";
		break;
	case RFKILL_TYPE_BLUETOOTH:
		type = "bluetooth";
		break;
	case RFKILL_TYPE_UWB:
		type = "ultrawideband";
		break;
	default:
		BUG();
	}

	return sprintf(buf, "%s\n", type);
}

static ssize_t rfkill_state_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct rfkill *rfkill = to_rfkill(dev);

	return sprintf(buf, "%d\n", rfkill->state);
}

static ssize_t rfkill_state_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct rfkill *rfkill = to_rfkill(dev);
	unsigned int state = simple_strtoul(buf, NULL, 0);
	int error;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	error = rfkill_toggle_radio(rfkill,
			state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
	if (error)
		return error;

	return count;
}

static ssize_t rfkill_claim_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct rfkill *rfkill = to_rfkill(dev);

	return sprintf(buf, "%d", rfkill->user_claim);
}

static ssize_t rfkill_claim_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct rfkill *rfkill = to_rfkill(dev);
	bool claim = !!simple_strtoul(buf, NULL, 0);
	int error;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	/*
	 * Take the global lock to make sure the kernel is not in
	 * the middle of rfkill_switch_all
	 */
	error = mutex_lock_interruptible(&rfkill_mutex);
	if (error)
		return error;

	if (rfkill->user_claim != claim) {
		if (!claim)
			rfkill_toggle_radio(rfkill,
					    rfkill_states[rfkill->type]);
		rfkill->user_claim = claim;
	}

	mutex_unlock(&rfkill_mutex);

	return count;
}

static struct device_attribute rfkill_dev_attrs[] = {
	__ATTR(name, S_IRUGO, rfkill_name_show, NULL),
	__ATTR(type, S_IRUGO, rfkill_type_show, NULL),
	__ATTR(state, S_IRUGO|S_IWUSR, rfkill_state_show, rfkill_state_store),
	__ATTR(claim, S_IRUGO|S_IWUSR, rfkill_claim_show, rfkill_claim_store),
	__ATTR_NULL
};

static void rfkill_release(struct device *dev)
{
	struct rfkill *rfkill = to_rfkill(dev);

	kfree(rfkill);
	module_put(THIS_MODULE);
}

#ifdef CONFIG_PM
static int rfkill_suspend(struct device *dev, pm_message_t state)
{
	struct rfkill *rfkill = to_rfkill(dev);

	if (dev->power.power_state.event != state.event) {
		if (state.event == PM_EVENT_SUSPEND) {
			mutex_lock(&rfkill->mutex);

			if (rfkill->state == RFKILL_STATE_ON)
				rfkill->toggle_radio(rfkill->data,
						     RFKILL_STATE_OFF);

			mutex_unlock(&rfkill->mutex);
		}

		dev->power.power_state = state;
	}

	return 0;
}

static int rfkill_resume(struct device *dev)
{
	struct rfkill *rfkill = to_rfkill(dev);

	if (dev->power.power_state.event != PM_EVENT_ON) {
		mutex_lock(&rfkill->mutex);

		if (rfkill->state == RFKILL_STATE_ON)
			rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);

		mutex_unlock(&rfkill->mutex);
	}

	dev->power.power_state = PMSG_ON;
	return 0;
}
#else
#define rfkill_suspend NULL
#define rfkill_resume NULL
#endif

static struct class rfkill_class = {
	.name		= "rfkill",
	.dev_release	= rfkill_release,
	.dev_attrs	= rfkill_dev_attrs,
	.suspend	= rfkill_suspend,
	.resume		= rfkill_resume,
};

static int rfkill_add_switch(struct rfkill *rfkill)
{
	int retval;

	retval = mutex_lock_interruptible(&rfkill_mutex);
	if (retval)
		return retval;

	retval = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
	if (retval)
		goto out;

	list_add_tail(&rfkill->node, &rfkill_list);

 out:
	mutex_unlock(&rfkill_mutex);
	return retval;
}

static void rfkill_remove_switch(struct rfkill *rfkill)
{
	mutex_lock(&rfkill_mutex);
	list_del_init(&rfkill->node);
	rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
	mutex_unlock(&rfkill_mutex);
}

/**
 * rfkill_allocate - allocate memory for rfkill structure.
 * @parent: device that has rf switch on it
 * @type: type of the switch (RFKILL_TYPE_*)
 *
 * This function should be called by the network driver when it needs
 * rfkill structure. Once the structure is allocated the driver shoud
 * finish its initialization by setting name, private data, enable_radio
 * and disable_radio methods and then register it with rfkill_register().
 * NOTE: If registration fails the structure shoudl be freed by calling
 * rfkill_free() otherwise rfkill_unregister() should be used.
 */
struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
{
	struct rfkill *rfkill;
	struct device *dev;

	rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
	if (!rfkill)
		return NULL;

	mutex_init(&rfkill->mutex);
	INIT_LIST_HEAD(&rfkill->node);
	rfkill->type = type;

	dev = &rfkill->dev;
	dev->class = &rfkill_class;
	dev->parent = parent;
	device_initialize(dev);

	__module_get(THIS_MODULE);

	return rfkill;
}
EXPORT_SYMBOL(rfkill_allocate);

/**
 * rfkill_free - Mark rfkill structure for deletion
 * @rfkill: rfkill structure to be destroyed
 *
 * Decrements reference count of rfkill structure so it is destoryed.
 * Note that rfkill_free() should _not_ be called after rfkill_unregister().
 */
void rfkill_free(struct rfkill *rfkill)
{
	if (rfkill)
		put_device(&rfkill->dev);
}
EXPORT_SYMBOL(rfkill_free);

/**
 * rfkill_register - Register a rfkill structure.
 * @rfkill: rfkill structure to be registered
 *
 * This function should be called by the network driver when the rfkill
 * structure needs to be registered. Immediately from registration the
 * switch driver should be able to service calls to toggle_radio.
 */
int rfkill_register(struct rfkill *rfkill)
{
	static atomic_t rfkill_no = ATOMIC_INIT(0);
	struct device *dev = &rfkill->dev;
	int error;

	if (!rfkill->toggle_radio)
		return -EINVAL;

	error = rfkill_add_switch(rfkill);
	if (error)
		return error;

	snprintf(dev->bus_id, sizeof(dev->bus_id),
		 "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1);

	error = device_add(dev);
	if (error) {
		rfkill_remove_switch(rfkill);
		return error;
	}

	return 0;
}
EXPORT_SYMBOL(rfkill_register);

/**
 * rfkill_unregister - Uegister a rfkill structure.
 * @rfkill: rfkill structure to be unregistered
 *
 * This function should be called by the network driver during device
 * teardown to destroy rfkill structure. Note that rfkill_free() should
 * _not_ be called after rfkill_unregister().
 */
void rfkill_unregister(struct rfkill *rfkill)
{
	device_del(&rfkill->dev);
	rfkill_remove_switch(rfkill);
	put_device(&rfkill->dev);
}
EXPORT_SYMBOL(rfkill_unregister);

/*
 * Rfkill module initialization/deinitialization.
 */
static int __init rfkill_init(void)
{
	int error;
	int i;

	for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
		rfkill_states[i] = RFKILL_STATE_ON;

	error = class_register(&rfkill_class);
	if (error) {
		printk(KERN_ERR "rfkill: unable to register rfkill class\n");
		return error;
	}

	return 0;
}

static void __exit rfkill_exit(void)
{
	class_unregister(&rfkill_class);
}

module_init(rfkill_init);
module_exit(rfkill_exit);