Loading...
Note: File does not exist in v6.2.
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 Dell Airplane Mode Switch driver
4 Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
5
6*/
7
8#include <linux/module.h>
9#include <linux/acpi.h>
10#include <linux/rfkill.h>
11#include <linux/input.h>
12
13#include "dell-rbtn.h"
14
15enum rbtn_type {
16 RBTN_UNKNOWN,
17 RBTN_TOGGLE,
18 RBTN_SLIDER,
19};
20
21struct rbtn_data {
22 enum rbtn_type type;
23 struct rfkill *rfkill;
24 struct input_dev *input_dev;
25 bool suspended;
26};
27
28
29/*
30 * acpi functions
31 */
32
33static enum rbtn_type rbtn_check(struct acpi_device *device)
34{
35 unsigned long long output;
36 acpi_status status;
37
38 status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
39 if (ACPI_FAILURE(status))
40 return RBTN_UNKNOWN;
41
42 switch (output) {
43 case 0:
44 case 1:
45 return RBTN_TOGGLE;
46 case 2:
47 case 3:
48 return RBTN_SLIDER;
49 default:
50 return RBTN_UNKNOWN;
51 }
52}
53
54static int rbtn_get(struct acpi_device *device)
55{
56 unsigned long long output;
57 acpi_status status;
58
59 status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
60 if (ACPI_FAILURE(status))
61 return -EINVAL;
62
63 return !output;
64}
65
66static int rbtn_acquire(struct acpi_device *device, bool enable)
67{
68 struct acpi_object_list input;
69 union acpi_object param;
70 acpi_status status;
71
72 param.type = ACPI_TYPE_INTEGER;
73 param.integer.value = enable;
74 input.count = 1;
75 input.pointer = ¶m;
76
77 status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
78 if (ACPI_FAILURE(status))
79 return -EINVAL;
80
81 return 0;
82}
83
84
85/*
86 * rfkill device
87 */
88
89static void rbtn_rfkill_query(struct rfkill *rfkill, void *data)
90{
91 struct acpi_device *device = data;
92 int state;
93
94 state = rbtn_get(device);
95 if (state < 0)
96 return;
97
98 rfkill_set_states(rfkill, state, state);
99}
100
101static int rbtn_rfkill_set_block(void *data, bool blocked)
102{
103 /* NOTE: setting soft rfkill state is not supported */
104 return -EINVAL;
105}
106
107static const struct rfkill_ops rbtn_ops = {
108 .query = rbtn_rfkill_query,
109 .set_block = rbtn_rfkill_set_block,
110};
111
112static int rbtn_rfkill_init(struct acpi_device *device)
113{
114 struct rbtn_data *rbtn_data = device->driver_data;
115 int ret;
116
117 if (rbtn_data->rfkill)
118 return 0;
119
120 /*
121 * NOTE: rbtn controls all radio devices, not only WLAN
122 * but rfkill interface does not support "ANY" type
123 * so "WLAN" type is used
124 */
125 rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
126 RFKILL_TYPE_WLAN, &rbtn_ops, device);
127 if (!rbtn_data->rfkill)
128 return -ENOMEM;
129
130 ret = rfkill_register(rbtn_data->rfkill);
131 if (ret) {
132 rfkill_destroy(rbtn_data->rfkill);
133 rbtn_data->rfkill = NULL;
134 return ret;
135 }
136
137 return 0;
138}
139
140static void rbtn_rfkill_exit(struct acpi_device *device)
141{
142 struct rbtn_data *rbtn_data = device->driver_data;
143
144 if (!rbtn_data->rfkill)
145 return;
146
147 rfkill_unregister(rbtn_data->rfkill);
148 rfkill_destroy(rbtn_data->rfkill);
149 rbtn_data->rfkill = NULL;
150}
151
152static void rbtn_rfkill_event(struct acpi_device *device)
153{
154 struct rbtn_data *rbtn_data = device->driver_data;
155
156 if (rbtn_data->rfkill)
157 rbtn_rfkill_query(rbtn_data->rfkill, device);
158}
159
160
161/*
162 * input device
163 */
164
165static int rbtn_input_init(struct rbtn_data *rbtn_data)
166{
167 int ret;
168
169 rbtn_data->input_dev = input_allocate_device();
170 if (!rbtn_data->input_dev)
171 return -ENOMEM;
172
173 rbtn_data->input_dev->name = "DELL Wireless hotkeys";
174 rbtn_data->input_dev->phys = "dellabce/input0";
175 rbtn_data->input_dev->id.bustype = BUS_HOST;
176 rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
177 set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
178
179 ret = input_register_device(rbtn_data->input_dev);
180 if (ret) {
181 input_free_device(rbtn_data->input_dev);
182 rbtn_data->input_dev = NULL;
183 return ret;
184 }
185
186 return 0;
187}
188
189static void rbtn_input_exit(struct rbtn_data *rbtn_data)
190{
191 input_unregister_device(rbtn_data->input_dev);
192 rbtn_data->input_dev = NULL;
193}
194
195static void rbtn_input_event(struct rbtn_data *rbtn_data)
196{
197 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
198 input_sync(rbtn_data->input_dev);
199 input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
200 input_sync(rbtn_data->input_dev);
201}
202
203
204/*
205 * acpi driver
206 */
207
208static int rbtn_add(struct acpi_device *device);
209static int rbtn_remove(struct acpi_device *device);
210static void rbtn_notify(struct acpi_device *device, u32 event);
211
212static const struct acpi_device_id rbtn_ids[] = {
213 { "DELRBTN", 0 },
214 { "DELLABCE", 0 },
215
216 /*
217 * This driver can also handle the "DELLABC6" device that
218 * appears on the XPS 13 9350, but that device is disabled by
219 * the DSDT unless booted with acpi_osi="!Windows 2012"
220 * acpi_osi="!Windows 2013".
221 *
222 * According to Mario at Dell:
223 *
224 * DELLABC6 is a custom interface that was created solely to
225 * have airplane mode support for Windows 7. For Windows 10
226 * the proper interface is to use that which is handled by
227 * intel-hid. A OEM airplane mode driver is not used.
228 *
229 * Since the kernel doesn't identify as Windows 7 it would be
230 * incorrect to do attempt to use that interface.
231 *
232 * Even if we override _OSI and bind to DELLABC6, we end up with
233 * inconsistent behavior in which userspace can get out of sync
234 * with the rfkill state as it conflicts with events from
235 * intel-hid.
236 *
237 * The upshot is that it is better to just ignore DELLABC6
238 * devices.
239 */
240
241 { "", 0 },
242};
243
244#ifdef CONFIG_PM_SLEEP
245static void ACPI_SYSTEM_XFACE rbtn_clear_suspended_flag(void *context)
246{
247 struct rbtn_data *rbtn_data = context;
248
249 rbtn_data->suspended = false;
250}
251
252static int rbtn_suspend(struct device *dev)
253{
254 struct acpi_device *device = to_acpi_device(dev);
255 struct rbtn_data *rbtn_data = acpi_driver_data(device);
256
257 rbtn_data->suspended = true;
258
259 return 0;
260}
261
262static int rbtn_resume(struct device *dev)
263{
264 struct acpi_device *device = to_acpi_device(dev);
265 struct rbtn_data *rbtn_data = acpi_driver_data(device);
266 acpi_status status;
267
268 /*
269 * Upon resume, some BIOSes send an ACPI notification thet triggers
270 * an unwanted input event. In order to ignore it, we use a flag
271 * that we set at suspend and clear once we have received the extra
272 * ACPI notification. Since ACPI notifications are delivered
273 * asynchronously to drivers, we clear the flag from the workqueue
274 * used to deliver the notifications. This should be enough
275 * to have the flag cleared only after we received the extra
276 * notification, if any.
277 */
278 status = acpi_os_execute(OSL_NOTIFY_HANDLER,
279 rbtn_clear_suspended_flag, rbtn_data);
280 if (ACPI_FAILURE(status))
281 rbtn_clear_suspended_flag(rbtn_data);
282
283 return 0;
284}
285#endif
286
287static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
288
289static struct acpi_driver rbtn_driver = {
290 .name = "dell-rbtn",
291 .ids = rbtn_ids,
292 .drv.pm = &rbtn_pm_ops,
293 .ops = {
294 .add = rbtn_add,
295 .remove = rbtn_remove,
296 .notify = rbtn_notify,
297 },
298 .owner = THIS_MODULE,
299};
300
301
302/*
303 * notifier export functions
304 */
305
306static bool auto_remove_rfkill = true;
307
308static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
309
310static int rbtn_inc_count(struct device *dev, void *data)
311{
312 struct acpi_device *device = to_acpi_device(dev);
313 struct rbtn_data *rbtn_data = device->driver_data;
314 int *count = data;
315
316 if (rbtn_data->type == RBTN_SLIDER)
317 (*count)++;
318
319 return 0;
320}
321
322static int rbtn_switch_dev(struct device *dev, void *data)
323{
324 struct acpi_device *device = to_acpi_device(dev);
325 struct rbtn_data *rbtn_data = device->driver_data;
326 bool enable = data;
327
328 if (rbtn_data->type != RBTN_SLIDER)
329 return 0;
330
331 if (enable)
332 rbtn_rfkill_init(device);
333 else
334 rbtn_rfkill_exit(device);
335
336 return 0;
337}
338
339int dell_rbtn_notifier_register(struct notifier_block *nb)
340{
341 bool first;
342 int count;
343 int ret;
344
345 count = 0;
346 ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
347 rbtn_inc_count);
348 if (ret || count == 0)
349 return -ENODEV;
350
351 first = !rbtn_chain_head.head;
352
353 ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
354 if (ret != 0)
355 return ret;
356
357 if (auto_remove_rfkill && first)
358 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
359 (void *)false, rbtn_switch_dev);
360
361 return ret;
362}
363EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
364
365int dell_rbtn_notifier_unregister(struct notifier_block *nb)
366{
367 int ret;
368
369 ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
370 if (ret != 0)
371 return ret;
372
373 if (auto_remove_rfkill && !rbtn_chain_head.head)
374 ret = driver_for_each_device(&rbtn_driver.drv, NULL,
375 (void *)true, rbtn_switch_dev);
376
377 return ret;
378}
379EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
380
381
382/*
383 * acpi driver functions
384 */
385
386static int rbtn_add(struct acpi_device *device)
387{
388 struct rbtn_data *rbtn_data;
389 enum rbtn_type type;
390 int ret = 0;
391
392 type = rbtn_check(device);
393 if (type == RBTN_UNKNOWN) {
394 dev_info(&device->dev, "Unknown device type\n");
395 return -EINVAL;
396 }
397
398 ret = rbtn_acquire(device, true);
399 if (ret < 0) {
400 dev_err(&device->dev, "Cannot enable device\n");
401 return ret;
402 }
403
404 rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
405 if (!rbtn_data)
406 return -ENOMEM;
407
408 rbtn_data->type = type;
409 device->driver_data = rbtn_data;
410
411 switch (rbtn_data->type) {
412 case RBTN_TOGGLE:
413 ret = rbtn_input_init(rbtn_data);
414 break;
415 case RBTN_SLIDER:
416 if (auto_remove_rfkill && rbtn_chain_head.head)
417 ret = 0;
418 else
419 ret = rbtn_rfkill_init(device);
420 break;
421 default:
422 ret = -EINVAL;
423 }
424
425 return ret;
426
427}
428
429static int rbtn_remove(struct acpi_device *device)
430{
431 struct rbtn_data *rbtn_data = device->driver_data;
432
433 switch (rbtn_data->type) {
434 case RBTN_TOGGLE:
435 rbtn_input_exit(rbtn_data);
436 break;
437 case RBTN_SLIDER:
438 rbtn_rfkill_exit(device);
439 break;
440 default:
441 break;
442 }
443
444 rbtn_acquire(device, false);
445 device->driver_data = NULL;
446
447 return 0;
448}
449
450static void rbtn_notify(struct acpi_device *device, u32 event)
451{
452 struct rbtn_data *rbtn_data = device->driver_data;
453
454 /*
455 * Some BIOSes send a notification at resume.
456 * Ignore it to prevent unwanted input events.
457 */
458 if (rbtn_data->suspended) {
459 dev_dbg(&device->dev, "ACPI notification ignored\n");
460 return;
461 }
462
463 if (event != 0x80) {
464 dev_info(&device->dev, "Received unknown event (0x%x)\n",
465 event);
466 return;
467 }
468
469 switch (rbtn_data->type) {
470 case RBTN_TOGGLE:
471 rbtn_input_event(rbtn_data);
472 break;
473 case RBTN_SLIDER:
474 rbtn_rfkill_event(device);
475 atomic_notifier_call_chain(&rbtn_chain_head, event, device);
476 break;
477 default:
478 break;
479 }
480}
481
482
483/*
484 * module functions
485 */
486
487module_acpi_driver(rbtn_driver);
488
489module_param(auto_remove_rfkill, bool, 0444);
490
491MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
492 "other modules start receiving events "
493 "from this module and re-add them when "
494 "the last module stops receiving events "
495 "(default true)");
496MODULE_DEVICE_TABLE(acpi, rbtn_ids);
497MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
498MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
499MODULE_LICENSE("GPL");