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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 bool suspended;
32};
33
34
35/*
36 * acpi functions
37 */
38
39static enum rbtn_type rbtn_check(struct acpi_device *device)
40{
41 unsigned long long output;
42 acpi_status status;
43
44 status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
45 if (ACPI_FAILURE(status))
46 return RBTN_UNKNOWN;
47
48 switch (output) {
49 case 0:
50 case 1:
51 return RBTN_TOGGLE;
52 case 2:
53 case 3:
54 return RBTN_SLIDER;
55 default:
56 return RBTN_UNKNOWN;
57 }
58}
59
60static int rbtn_get(struct acpi_device *device)
61{
62 unsigned long long output;
63 acpi_status status;
64
65 status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
66 if (ACPI_FAILURE(status))
67 return -EINVAL;
68
69 return !output;
70}
71
72static int rbtn_acquire(struct acpi_device *device, bool enable)
73{
74 struct acpi_object_list input;
75 union acpi_object param;
76 acpi_status status;
77
78 param.type = ACPI_TYPE_INTEGER;
79 param.integer.value = enable;
80 input.count = 1;
81 input.pointer = ¶m;
82
83 status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
84 if (ACPI_FAILURE(status))
85 return -EINVAL;
86
87 return 0;
88}
89
90
91/*
92 * rfkill device
93 */
94
95static void rbtn_rfkill_query(struct rfkill *rfkill, void *data)
96{
97 struct acpi_device *device = data;
98 int state;
99
100 state = rbtn_get(device);
101 if (state < 0)
102 return;
103
104 rfkill_set_states(rfkill, state, state);
105}
106
107static int rbtn_rfkill_set_block(void *data, bool blocked)
108{
109 /* NOTE: setting soft rfkill state is not supported */
110 return -EINVAL;
111}
112
113static struct rfkill_ops rbtn_ops = {
114 .query = rbtn_rfkill_query,
115 .set_block = rbtn_rfkill_set_block,
116};
117
118static int rbtn_rfkill_init(struct acpi_device *device)
119{
120 struct rbtn_data *rbtn_data = device->driver_data;
121 int ret;
122
123 if (rbtn_data->rfkill)
124 return 0;
125
126 /*
127 * NOTE: rbtn controls all radio devices, not only WLAN
128 * but rfkill interface does not support "ANY" type
129 * so "WLAN" type is used
130 */
131 rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
132 RFKILL_TYPE_WLAN, &rbtn_ops, device);
133 if (!rbtn_data->rfkill)
134 return -ENOMEM;
135
136 ret = rfkill_register(rbtn_data->rfkill);
137 if (ret) {
138 rfkill_destroy(rbtn_data->rfkill);
139 rbtn_data->rfkill = NULL;
140 return ret;
141 }
142
143 return 0;
144}
145
146static void rbtn_rfkill_exit(struct acpi_device *device)
147{
148 struct rbtn_data *rbtn_data = device->driver_data;
149
150 if (!rbtn_data->rfkill)
151 return;
152
153 rfkill_unregister(rbtn_data->rfkill);
154 rfkill_destroy(rbtn_data->rfkill);
155 rbtn_data->rfkill = NULL;
156}
157
158static void rbtn_rfkill_event(struct acpi_device *device)
159{
160 struct rbtn_data *rbtn_data = device->driver_data;
161
162 if (rbtn_data->rfkill)
163 rbtn_rfkill_query(rbtn_data->rfkill, device);
164}
165
166
167/*
168 * input device
169 */
170
171static int rbtn_input_init(struct rbtn_data *rbtn_data)
172{
173 int ret;
174
175 rbtn_data->input_dev = input_allocate_device();
176 if (!rbtn_data->input_dev)
177 return -ENOMEM;
178
179 rbtn_data->input_dev->name = "DELL Wireless hotkeys";
180 rbtn_data->input_dev->phys = "dellabce/input0";
181 rbtn_data->input_dev->id.bustype = BUS_HOST;
182 rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
183 set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
184
185 ret = input_register_device(rbtn_data->input_dev);
186 if (ret) {
187 input_free_device(rbtn_data->input_dev);
188 rbtn_data->input_dev = NULL;
189 return ret;
190 }
191
192 return 0;
193}
194
195static void rbtn_input_exit(struct rbtn_data *rbtn_data)
196{
197 input_unregister_device(rbtn_data->input_dev);
198 rbtn_data->input_dev = NULL;
199}
200
201static void rbtn_input_event(struct rbtn_data *rbtn_data)
202{
203 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
204 input_sync(rbtn_data->input_dev);
205 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
206 input_sync(rbtn_data->input_dev);
207}
208
209
210/*
211 * acpi driver
212 */
213
214static int rbtn_add(struct acpi_device *device);
215static int rbtn_remove(struct acpi_device *device);
216static void rbtn_notify(struct acpi_device *device, u32 event);
217
218static const struct acpi_device_id rbtn_ids[] = {
219 { "DELRBTN", 0 },
220 { "DELLABCE", 0 },
221
222 /*
223 * This driver can also handle the "DELLABC6" device that
224 * appears on the XPS 13 9350, but that device is disabled
225 * by the DSDT unless booted with acpi_osi="!Windows 2012"
226 * acpi_osi="!Windows 2013". Even if we boot that and bind
227 * the driver, we seem to have inconsistent behavior in
228 * which NetworkManager can get out of sync with the rfkill
229 * state.
230 *
231 * On the XPS 13 9350 and similar laptops, we're not supposed to
232 * use DELLABC6 at all. Instead, we handle the rfkill button
233 * via the intel-hid driver.
234 */
235
236 { "", 0 },
237};
238
239#ifdef CONFIG_PM_SLEEP
240static void ACPI_SYSTEM_XFACE rbtn_clear_suspended_flag(void *context)
241{
242 struct rbtn_data *rbtn_data = context;
243
244 rbtn_data->suspended = false;
245}
246
247static int rbtn_suspend(struct device *dev)
248{
249 struct acpi_device *device = to_acpi_device(dev);
250 struct rbtn_data *rbtn_data = acpi_driver_data(device);
251
252 rbtn_data->suspended = true;
253
254 return 0;
255}
256
257static int rbtn_resume(struct device *dev)
258{
259 struct acpi_device *device = to_acpi_device(dev);
260 struct rbtn_data *rbtn_data = acpi_driver_data(device);
261 acpi_status status;
262
263 /*
264 * Upon resume, some BIOSes send an ACPI notification thet triggers
265 * an unwanted input event. In order to ignore it, we use a flag
266 * that we set at suspend and clear once we have received the extra
267 * ACPI notification. Since ACPI notifications are delivered
268 * asynchronously to drivers, we clear the flag from the workqueue
269 * used to deliver the notifications. This should be enough
270 * to have the flag cleared only after we received the extra
271 * notification, if any.
272 */
273 status = acpi_os_execute(OSL_NOTIFY_HANDLER,
274 rbtn_clear_suspended_flag, rbtn_data);
275 if (ACPI_FAILURE(status))
276 rbtn_clear_suspended_flag(rbtn_data);
277
278 return 0;
279}
280#endif
281
282static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
283
284static struct acpi_driver rbtn_driver = {
285 .name = "dell-rbtn",
286 .ids = rbtn_ids,
287 .drv.pm = &rbtn_pm_ops,
288 .ops = {
289 .add = rbtn_add,
290 .remove = rbtn_remove,
291 .notify = rbtn_notify,
292 },
293 .owner = THIS_MODULE,
294};
295
296
297/*
298 * notifier export functions
299 */
300
301static bool auto_remove_rfkill = true;
302
303static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
304
305static int rbtn_inc_count(struct device *dev, void *data)
306{
307 struct acpi_device *device = to_acpi_device(dev);
308 struct rbtn_data *rbtn_data = device->driver_data;
309 int *count = data;
310
311 if (rbtn_data->type == RBTN_SLIDER)
312 (*count)++;
313
314 return 0;
315}
316
317static int rbtn_switch_dev(struct device *dev, void *data)
318{
319 struct acpi_device *device = to_acpi_device(dev);
320 struct rbtn_data *rbtn_data = device->driver_data;
321 bool enable = data;
322
323 if (rbtn_data->type != RBTN_SLIDER)
324 return 0;
325
326 if (enable)
327 rbtn_rfkill_init(device);
328 else
329 rbtn_rfkill_exit(device);
330
331 return 0;
332}
333
334int dell_rbtn_notifier_register(struct notifier_block *nb)
335{
336 bool first;
337 int count;
338 int ret;
339
340 count = 0;
341 ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
342 rbtn_inc_count);
343 if (ret || count == 0)
344 return -ENODEV;
345
346 first = !rbtn_chain_head.head;
347
348 ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
349 if (ret != 0)
350 return ret;
351
352 if (auto_remove_rfkill && first)
353 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
354 (void *)false, rbtn_switch_dev);
355
356 return ret;
357}
358EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
359
360int dell_rbtn_notifier_unregister(struct notifier_block *nb)
361{
362 int ret;
363
364 ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
365 if (ret != 0)
366 return ret;
367
368 if (auto_remove_rfkill && !rbtn_chain_head.head)
369 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
370 (void *)true, rbtn_switch_dev);
371
372 return ret;
373}
374EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
375
376
377/*
378 * acpi driver functions
379 */
380
381static int rbtn_add(struct acpi_device *device)
382{
383 struct rbtn_data *rbtn_data;
384 enum rbtn_type type;
385 int ret = 0;
386
387 type = rbtn_check(device);
388 if (type == RBTN_UNKNOWN) {
389 dev_info(&device->dev, "Unknown device type\n");
390 return -EINVAL;
391 }
392
393 ret = rbtn_acquire(device, true);
394 if (ret < 0) {
395 dev_err(&device->dev, "Cannot enable device\n");
396 return ret;
397 }
398
399 rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
400 if (!rbtn_data)
401 return -ENOMEM;
402
403 rbtn_data->type = type;
404 device->driver_data = rbtn_data;
405
406 switch (rbtn_data->type) {
407 case RBTN_TOGGLE:
408 ret = rbtn_input_init(rbtn_data);
409 break;
410 case RBTN_SLIDER:
411 if (auto_remove_rfkill && rbtn_chain_head.head)
412 ret = 0;
413 else
414 ret = rbtn_rfkill_init(device);
415 break;
416 default:
417 ret = -EINVAL;
418 }
419
420 return ret;
421
422}
423
424static int rbtn_remove(struct acpi_device *device)
425{
426 struct rbtn_data *rbtn_data = device->driver_data;
427
428 switch (rbtn_data->type) {
429 case RBTN_TOGGLE:
430 rbtn_input_exit(rbtn_data);
431 break;
432 case RBTN_SLIDER:
433 rbtn_rfkill_exit(device);
434 break;
435 default:
436 break;
437 }
438
439 rbtn_acquire(device, false);
440 device->driver_data = NULL;
441
442 return 0;
443}
444
445static void rbtn_notify(struct acpi_device *device, u32 event)
446{
447 struct rbtn_data *rbtn_data = device->driver_data;
448
449 /*
450 * Some BIOSes send a notification at resume.
451 * Ignore it to prevent unwanted input events.
452 */
453 if (rbtn_data->suspended) {
454 dev_dbg(&device->dev, "ACPI notification ignored\n");
455 return;
456 }
457
458 if (event != 0x80) {
459 dev_info(&device->dev, "Received unknown event (0x%x)\n",
460 event);
461 return;
462 }
463
464 switch (rbtn_data->type) {
465 case RBTN_TOGGLE:
466 rbtn_input_event(rbtn_data);
467 break;
468 case RBTN_SLIDER:
469 rbtn_rfkill_event(device);
470 atomic_notifier_call_chain(&rbtn_chain_head, event, device);
471 break;
472 default:
473 break;
474 }
475}
476
477
478/*
479 * module functions
480 */
481
482module_acpi_driver(rbtn_driver);
483
484module_param(auto_remove_rfkill, bool, 0444);
485
486MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
487 "other modules start receiving events "
488 "from this module and re-add them when "
489 "the last module stops receiving events "
490 "(default true)");
491MODULE_DEVICE_TABLE(acpi, rbtn_ids);
492MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
493MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
494MODULE_LICENSE("GPL");