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1/*
2 Dell Airplane Mode Switch driver
3 Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
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
16#include <linux/module.h>
17#include <linux/acpi.h>
18#include <linux/rfkill.h>
19#include <linux/input.h>
20
21enum rbtn_type {
22 RBTN_UNKNOWN,
23 RBTN_TOGGLE,
24 RBTN_SLIDER,
25};
26
27struct rbtn_data {
28 enum rbtn_type type;
29 struct rfkill *rfkill;
30 struct input_dev *input_dev;
31};
32
33
34/*
35 * acpi functions
36 */
37
38static enum rbtn_type rbtn_check(struct acpi_device *device)
39{
40 unsigned long long output;
41 acpi_status status;
42
43 status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
44 if (ACPI_FAILURE(status))
45 return RBTN_UNKNOWN;
46
47 switch (output) {
48 case 0:
49 case 1:
50 return RBTN_TOGGLE;
51 case 2:
52 case 3:
53 return RBTN_SLIDER;
54 default:
55 return RBTN_UNKNOWN;
56 }
57}
58
59static int rbtn_get(struct acpi_device *device)
60{
61 unsigned long long output;
62 acpi_status status;
63
64 status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
65 if (ACPI_FAILURE(status))
66 return -EINVAL;
67
68 return !output;
69}
70
71static int rbtn_acquire(struct acpi_device *device, bool enable)
72{
73 struct acpi_object_list input;
74 union acpi_object param;
75 acpi_status status;
76
77 param.type = ACPI_TYPE_INTEGER;
78 param.integer.value = enable;
79 input.count = 1;
80 input.pointer = ¶m;
81
82 status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
83 if (ACPI_FAILURE(status))
84 return -EINVAL;
85
86 return 0;
87}
88
89
90/*
91 * rfkill device
92 */
93
94static void rbtn_rfkill_query(struct rfkill *rfkill, void *data)
95{
96 struct acpi_device *device = data;
97 int state;
98
99 state = rbtn_get(device);
100 if (state < 0)
101 return;
102
103 rfkill_set_states(rfkill, state, state);
104}
105
106static int rbtn_rfkill_set_block(void *data, bool blocked)
107{
108 /* NOTE: setting soft rfkill state is not supported */
109 return -EINVAL;
110}
111
112static struct rfkill_ops rbtn_ops = {
113 .query = rbtn_rfkill_query,
114 .set_block = rbtn_rfkill_set_block,
115};
116
117static int rbtn_rfkill_init(struct acpi_device *device)
118{
119 struct rbtn_data *rbtn_data = device->driver_data;
120 int ret;
121
122 if (rbtn_data->rfkill)
123 return 0;
124
125 /*
126 * NOTE: rbtn controls all radio devices, not only WLAN
127 * but rfkill interface does not support "ANY" type
128 * so "WLAN" type is used
129 */
130 rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
131 RFKILL_TYPE_WLAN, &rbtn_ops, device);
132 if (!rbtn_data->rfkill)
133 return -ENOMEM;
134
135 ret = rfkill_register(rbtn_data->rfkill);
136 if (ret) {
137 rfkill_destroy(rbtn_data->rfkill);
138 rbtn_data->rfkill = NULL;
139 return ret;
140 }
141
142 return 0;
143}
144
145static void rbtn_rfkill_exit(struct acpi_device *device)
146{
147 struct rbtn_data *rbtn_data = device->driver_data;
148
149 if (!rbtn_data->rfkill)
150 return;
151
152 rfkill_unregister(rbtn_data->rfkill);
153 rfkill_destroy(rbtn_data->rfkill);
154 rbtn_data->rfkill = NULL;
155}
156
157static void rbtn_rfkill_event(struct acpi_device *device)
158{
159 struct rbtn_data *rbtn_data = device->driver_data;
160
161 if (rbtn_data->rfkill)
162 rbtn_rfkill_query(rbtn_data->rfkill, device);
163}
164
165
166/*
167 * input device
168 */
169
170static int rbtn_input_init(struct rbtn_data *rbtn_data)
171{
172 int ret;
173
174 rbtn_data->input_dev = input_allocate_device();
175 if (!rbtn_data->input_dev)
176 return -ENOMEM;
177
178 rbtn_data->input_dev->name = "DELL Wireless hotkeys";
179 rbtn_data->input_dev->phys = "dellabce/input0";
180 rbtn_data->input_dev->id.bustype = BUS_HOST;
181 rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
182 set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
183
184 ret = input_register_device(rbtn_data->input_dev);
185 if (ret) {
186 input_free_device(rbtn_data->input_dev);
187 rbtn_data->input_dev = NULL;
188 return ret;
189 }
190
191 return 0;
192}
193
194static void rbtn_input_exit(struct rbtn_data *rbtn_data)
195{
196 input_unregister_device(rbtn_data->input_dev);
197 rbtn_data->input_dev = NULL;
198}
199
200static void rbtn_input_event(struct rbtn_data *rbtn_data)
201{
202 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
203 input_sync(rbtn_data->input_dev);
204 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
205 input_sync(rbtn_data->input_dev);
206}
207
208
209/*
210 * acpi driver
211 */
212
213static int rbtn_add(struct acpi_device *device);
214static int rbtn_remove(struct acpi_device *device);
215static void rbtn_notify(struct acpi_device *device, u32 event);
216
217static const struct acpi_device_id rbtn_ids[] = {
218 { "DELRBTN", 0 },
219 { "DELLABCE", 0 },
220
221 /*
222 * This driver can also handle the "DELLABC6" device that
223 * appears on the XPS 13 9350, but that device is disabled
224 * by the DSDT unless booted with acpi_osi="!Windows 2012"
225 * acpi_osi="!Windows 2013". Even if we boot that and bind
226 * the driver, we seem to have inconsistent behavior in
227 * which NetworkManager can get out of sync with the rfkill
228 * state.
229 *
230 * On the XPS 13 9350 and similar laptops, we're not supposed to
231 * use DELLABC6 at all. Instead, we handle the rfkill button
232 * via the intel-hid driver.
233 */
234
235 { "", 0 },
236};
237
238static struct acpi_driver rbtn_driver = {
239 .name = "dell-rbtn",
240 .ids = rbtn_ids,
241 .ops = {
242 .add = rbtn_add,
243 .remove = rbtn_remove,
244 .notify = rbtn_notify,
245 },
246 .owner = THIS_MODULE,
247};
248
249
250/*
251 * notifier export functions
252 */
253
254static bool auto_remove_rfkill = true;
255
256static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
257
258static int rbtn_inc_count(struct device *dev, void *data)
259{
260 struct acpi_device *device = to_acpi_device(dev);
261 struct rbtn_data *rbtn_data = device->driver_data;
262 int *count = data;
263
264 if (rbtn_data->type == RBTN_SLIDER)
265 (*count)++;
266
267 return 0;
268}
269
270static int rbtn_switch_dev(struct device *dev, void *data)
271{
272 struct acpi_device *device = to_acpi_device(dev);
273 struct rbtn_data *rbtn_data = device->driver_data;
274 bool enable = data;
275
276 if (rbtn_data->type != RBTN_SLIDER)
277 return 0;
278
279 if (enable)
280 rbtn_rfkill_init(device);
281 else
282 rbtn_rfkill_exit(device);
283
284 return 0;
285}
286
287int dell_rbtn_notifier_register(struct notifier_block *nb)
288{
289 bool first;
290 int count;
291 int ret;
292
293 count = 0;
294 ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
295 rbtn_inc_count);
296 if (ret || count == 0)
297 return -ENODEV;
298
299 first = !rbtn_chain_head.head;
300
301 ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
302 if (ret != 0)
303 return ret;
304
305 if (auto_remove_rfkill && first)
306 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
307 (void *)false, rbtn_switch_dev);
308
309 return ret;
310}
311EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
312
313int dell_rbtn_notifier_unregister(struct notifier_block *nb)
314{
315 int ret;
316
317 ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
318 if (ret != 0)
319 return ret;
320
321 if (auto_remove_rfkill && !rbtn_chain_head.head)
322 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
323 (void *)true, rbtn_switch_dev);
324
325 return ret;
326}
327EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
328
329
330/*
331 * acpi driver functions
332 */
333
334static int rbtn_add(struct acpi_device *device)
335{
336 struct rbtn_data *rbtn_data;
337 enum rbtn_type type;
338 int ret = 0;
339
340 type = rbtn_check(device);
341 if (type == RBTN_UNKNOWN) {
342 dev_info(&device->dev, "Unknown device type\n");
343 return -EINVAL;
344 }
345
346 ret = rbtn_acquire(device, true);
347 if (ret < 0) {
348 dev_err(&device->dev, "Cannot enable device\n");
349 return ret;
350 }
351
352 rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
353 if (!rbtn_data)
354 return -ENOMEM;
355
356 rbtn_data->type = type;
357 device->driver_data = rbtn_data;
358
359 switch (rbtn_data->type) {
360 case RBTN_TOGGLE:
361 ret = rbtn_input_init(rbtn_data);
362 break;
363 case RBTN_SLIDER:
364 if (auto_remove_rfkill && rbtn_chain_head.head)
365 ret = 0;
366 else
367 ret = rbtn_rfkill_init(device);
368 break;
369 default:
370 ret = -EINVAL;
371 }
372
373 return ret;
374
375}
376
377static int rbtn_remove(struct acpi_device *device)
378{
379 struct rbtn_data *rbtn_data = device->driver_data;
380
381 switch (rbtn_data->type) {
382 case RBTN_TOGGLE:
383 rbtn_input_exit(rbtn_data);
384 break;
385 case RBTN_SLIDER:
386 rbtn_rfkill_exit(device);
387 break;
388 default:
389 break;
390 }
391
392 rbtn_acquire(device, false);
393 device->driver_data = NULL;
394
395 return 0;
396}
397
398static void rbtn_notify(struct acpi_device *device, u32 event)
399{
400 struct rbtn_data *rbtn_data = device->driver_data;
401
402 if (event != 0x80) {
403 dev_info(&device->dev, "Received unknown event (0x%x)\n",
404 event);
405 return;
406 }
407
408 switch (rbtn_data->type) {
409 case RBTN_TOGGLE:
410 rbtn_input_event(rbtn_data);
411 break;
412 case RBTN_SLIDER:
413 rbtn_rfkill_event(device);
414 atomic_notifier_call_chain(&rbtn_chain_head, event, device);
415 break;
416 default:
417 break;
418 }
419}
420
421
422/*
423 * module functions
424 */
425
426module_acpi_driver(rbtn_driver);
427
428module_param(auto_remove_rfkill, bool, 0444);
429
430MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
431 "other modules start receiving events "
432 "from this module and re-add them when "
433 "the last module stops receiving events "
434 "(default true)");
435MODULE_DEVICE_TABLE(acpi, rbtn_ids);
436MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
437MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
438MODULE_LICENSE("GPL");