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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * button.c - ACPI Button Driver
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 */
8
9#define pr_fmt(fmt) "ACPI: button: " fmt
10
11#include <linux/compiler.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/input.h>
19#include <linux/slab.h>
20#include <linux/acpi.h>
21#include <linux/dmi.h>
22#include <acpi/button.h>
23
24#define ACPI_BUTTON_CLASS "button"
25#define ACPI_BUTTON_FILE_STATE "state"
26#define ACPI_BUTTON_TYPE_UNKNOWN 0x00
27#define ACPI_BUTTON_NOTIFY_STATUS 0x80
28
29#define ACPI_BUTTON_SUBCLASS_POWER "power"
30#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button"
31#define ACPI_BUTTON_TYPE_POWER 0x01
32
33#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"
34#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button"
35#define ACPI_BUTTON_TYPE_SLEEP 0x03
36
37#define ACPI_BUTTON_SUBCLASS_LID "lid"
38#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
39#define ACPI_BUTTON_TYPE_LID 0x05
40
41enum {
42 ACPI_BUTTON_LID_INIT_IGNORE,
43 ACPI_BUTTON_LID_INIT_OPEN,
44 ACPI_BUTTON_LID_INIT_METHOD,
45 ACPI_BUTTON_LID_INIT_DISABLED,
46};
47
48static const char * const lid_init_state_str[] = {
49 [ACPI_BUTTON_LID_INIT_IGNORE] = "ignore",
50 [ACPI_BUTTON_LID_INIT_OPEN] = "open",
51 [ACPI_BUTTON_LID_INIT_METHOD] = "method",
52 [ACPI_BUTTON_LID_INIT_DISABLED] = "disabled",
53};
54
55MODULE_AUTHOR("Paul Diefenbaugh");
56MODULE_DESCRIPTION("ACPI Button Driver");
57MODULE_LICENSE("GPL");
58
59static const struct acpi_device_id button_device_ids[] = {
60 {ACPI_BUTTON_HID_LID, 0},
61 {ACPI_BUTTON_HID_SLEEP, 0},
62 {ACPI_BUTTON_HID_SLEEPF, 0},
63 {ACPI_BUTTON_HID_POWER, 0},
64 {ACPI_BUTTON_HID_POWERF, 0},
65 {"", 0},
66};
67MODULE_DEVICE_TABLE(acpi, button_device_ids);
68
69/* Please keep this list sorted alphabetically by vendor and model */
70static const struct dmi_system_id dmi_lid_quirks[] = {
71 {
72 /* GP-electronic T701, _LID method points to a floating GPIO */
73 .matches = {
74 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
75 DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
76 DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
77 },
78 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
79 },
80 {
81 /* Nextbook Ares 8A tablet, _LID device always reports lid closed */
82 .matches = {
83 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
84 DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),
85 DMI_MATCH(DMI_BIOS_VERSION, "M882"),
86 },
87 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
88 },
89 {
90 /*
91 * Lenovo Yoga 9 14ITL5, initial notification of the LID device
92 * never happens.
93 */
94 .matches = {
95 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
96 DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),
97 },
98 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
99 },
100 {
101 /*
102 * Medion Akoya E2215T, notification of the LID device only
103 * happens on close, not on open and _LID always returns closed.
104 */
105 .matches = {
106 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
107 DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
108 },
109 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
110 },
111 {
112 /*
113 * Medion Akoya E2228T, notification of the LID device only
114 * happens on close, not on open and _LID always returns closed.
115 */
116 .matches = {
117 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
118 DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
119 },
120 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
121 },
122 {
123 /*
124 * Razer Blade Stealth 13 late 2019, notification of the LID device
125 * only happens on close, not on open and _LID always returns closed.
126 */
127 .matches = {
128 DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
129 DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
130 },
131 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
132 },
133 {}
134};
135
136static int acpi_button_add(struct acpi_device *device);
137static void acpi_button_remove(struct acpi_device *device);
138
139#ifdef CONFIG_PM_SLEEP
140static int acpi_button_suspend(struct device *dev);
141static int acpi_button_resume(struct device *dev);
142#else
143#define acpi_button_suspend NULL
144#define acpi_button_resume NULL
145#endif
146static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
147
148static struct acpi_driver acpi_button_driver = {
149 .name = "button",
150 .class = ACPI_BUTTON_CLASS,
151 .ids = button_device_ids,
152 .ops = {
153 .add = acpi_button_add,
154 .remove = acpi_button_remove,
155 },
156 .drv.pm = &acpi_button_pm,
157};
158
159struct acpi_button {
160 unsigned int type;
161 struct input_dev *input;
162 char phys[32]; /* for input device */
163 unsigned long pushed;
164 int last_state;
165 ktime_t last_time;
166 bool suspended;
167 bool lid_state_initialized;
168};
169
170static struct acpi_device *lid_device;
171static long lid_init_state = -1;
172
173static unsigned long lid_report_interval __read_mostly = 500;
174module_param(lid_report_interval, ulong, 0644);
175MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
176
177/* FS Interface (/proc) */
178static struct proc_dir_entry *acpi_button_dir;
179static struct proc_dir_entry *acpi_lid_dir;
180
181static int acpi_lid_evaluate_state(struct acpi_device *device)
182{
183 unsigned long long lid_state;
184 acpi_status status;
185
186 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
187 if (ACPI_FAILURE(status))
188 return -ENODEV;
189
190 return lid_state ? 1 : 0;
191}
192
193static int acpi_lid_notify_state(struct acpi_device *device, int state)
194{
195 struct acpi_button *button = acpi_driver_data(device);
196 ktime_t next_report;
197 bool do_update;
198
199 /*
200 * In lid_init_state=ignore mode, if user opens/closes lid
201 * frequently with "open" missing, and "last_time" is also updated
202 * frequently, "close" cannot be delivered to the userspace.
203 * So "last_time" is only updated after a timeout or an actual
204 * switch.
205 */
206 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
207 button->last_state != !!state)
208 do_update = true;
209 else
210 do_update = false;
211
212 next_report = ktime_add(button->last_time,
213 ms_to_ktime(lid_report_interval));
214 if (button->last_state == !!state &&
215 ktime_after(ktime_get(), next_report)) {
216 /* Complain the buggy firmware */
217 pr_warn_once("The lid device is not compliant to SW_LID.\n");
218
219 /*
220 * Send the unreliable complement switch event:
221 *
222 * On most platforms, the lid device is reliable. However
223 * there are exceptions:
224 * 1. Platforms returning initial lid state as "close" by
225 * default after booting/resuming:
226 * https://bugzilla.kernel.org/show_bug.cgi?id=89211
227 * https://bugzilla.kernel.org/show_bug.cgi?id=106151
228 * 2. Platforms never reporting "open" events:
229 * https://bugzilla.kernel.org/show_bug.cgi?id=106941
230 * On these buggy platforms, the usage model of the ACPI
231 * lid device actually is:
232 * 1. The initial returning value of _LID may not be
233 * reliable.
234 * 2. The open event may not be reliable.
235 * 3. The close event is reliable.
236 *
237 * But SW_LID is typed as input switch event, the input
238 * layer checks if the event is redundant. Hence if the
239 * state is not switched, the userspace cannot see this
240 * platform triggered reliable event. By inserting a
241 * complement switch event, it then is guaranteed that the
242 * platform triggered reliable one can always be seen by
243 * the userspace.
244 */
245 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
246 do_update = true;
247 /*
248 * Do generate complement switch event for "close"
249 * as "close" is reliable and wrong "open" won't
250 * trigger unexpected behaviors.
251 * Do not generate complement switch event for
252 * "open" as "open" is not reliable and wrong
253 * "close" will trigger unexpected behaviors.
254 */
255 if (!state) {
256 input_report_switch(button->input,
257 SW_LID, state);
258 input_sync(button->input);
259 }
260 }
261 }
262 /* Send the platform triggered reliable event */
263 if (do_update) {
264 acpi_handle_debug(device->handle, "ACPI LID %s\n",
265 state ? "open" : "closed");
266 input_report_switch(button->input, SW_LID, !state);
267 input_sync(button->input);
268 button->last_state = !!state;
269 button->last_time = ktime_get();
270 }
271
272 return 0;
273}
274
275static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
276 void *offset)
277{
278 struct acpi_device *device = seq->private;
279 int state;
280
281 state = acpi_lid_evaluate_state(device);
282 seq_printf(seq, "state: %s\n",
283 state < 0 ? "unsupported" : (state ? "open" : "closed"));
284 return 0;
285}
286
287static int acpi_button_add_fs(struct acpi_device *device)
288{
289 struct acpi_button *button = acpi_driver_data(device);
290 struct proc_dir_entry *entry = NULL;
291 int ret = 0;
292
293 /* procfs I/F for ACPI lid device only */
294 if (button->type != ACPI_BUTTON_TYPE_LID)
295 return 0;
296
297 if (acpi_button_dir || acpi_lid_dir) {
298 pr_info("More than one Lid device found!\n");
299 return -EEXIST;
300 }
301
302 /* create /proc/acpi/button */
303 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
304 if (!acpi_button_dir)
305 return -ENODEV;
306
307 /* create /proc/acpi/button/lid */
308 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
309 if (!acpi_lid_dir) {
310 ret = -ENODEV;
311 goto remove_button_dir;
312 }
313
314 /* create /proc/acpi/button/lid/LID/ */
315 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
316 if (!acpi_device_dir(device)) {
317 ret = -ENODEV;
318 goto remove_lid_dir;
319 }
320
321 /* create /proc/acpi/button/lid/LID/state */
322 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
323 acpi_device_dir(device), acpi_button_state_seq_show,
324 device);
325 if (!entry) {
326 ret = -ENODEV;
327 goto remove_dev_dir;
328 }
329
330done:
331 return ret;
332
333remove_dev_dir:
334 remove_proc_entry(acpi_device_bid(device),
335 acpi_lid_dir);
336 acpi_device_dir(device) = NULL;
337remove_lid_dir:
338 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
339 acpi_lid_dir = NULL;
340remove_button_dir:
341 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
342 acpi_button_dir = NULL;
343 goto done;
344}
345
346static int acpi_button_remove_fs(struct acpi_device *device)
347{
348 struct acpi_button *button = acpi_driver_data(device);
349
350 if (button->type != ACPI_BUTTON_TYPE_LID)
351 return 0;
352
353 remove_proc_entry(ACPI_BUTTON_FILE_STATE,
354 acpi_device_dir(device));
355 remove_proc_entry(acpi_device_bid(device),
356 acpi_lid_dir);
357 acpi_device_dir(device) = NULL;
358 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
359 acpi_lid_dir = NULL;
360 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
361 acpi_button_dir = NULL;
362
363 return 0;
364}
365
366/* Driver Interface */
367int acpi_lid_open(void)
368{
369 if (!lid_device)
370 return -ENODEV;
371
372 return acpi_lid_evaluate_state(lid_device);
373}
374EXPORT_SYMBOL(acpi_lid_open);
375
376static int acpi_lid_update_state(struct acpi_device *device,
377 bool signal_wakeup)
378{
379 int state;
380
381 state = acpi_lid_evaluate_state(device);
382 if (state < 0)
383 return state;
384
385 if (state && signal_wakeup)
386 acpi_pm_wakeup_event(&device->dev);
387
388 return acpi_lid_notify_state(device, state);
389}
390
391static void acpi_lid_initialize_state(struct acpi_device *device)
392{
393 struct acpi_button *button = acpi_driver_data(device);
394
395 switch (lid_init_state) {
396 case ACPI_BUTTON_LID_INIT_OPEN:
397 (void)acpi_lid_notify_state(device, 1);
398 break;
399 case ACPI_BUTTON_LID_INIT_METHOD:
400 (void)acpi_lid_update_state(device, false);
401 break;
402 case ACPI_BUTTON_LID_INIT_IGNORE:
403 default:
404 break;
405 }
406
407 button->lid_state_initialized = true;
408}
409
410static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)
411{
412 struct acpi_device *device = data;
413 struct acpi_button *button;
414
415 if (event != ACPI_BUTTON_NOTIFY_STATUS) {
416 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
417 event);
418 return;
419 }
420
421 button = acpi_driver_data(device);
422 if (!button->lid_state_initialized)
423 return;
424
425 acpi_lid_update_state(device, true);
426}
427
428static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
429{
430 struct acpi_device *device = data;
431 struct acpi_button *button;
432 struct input_dev *input;
433 int keycode;
434
435 if (event != ACPI_BUTTON_NOTIFY_STATUS) {
436 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
437 event);
438 return;
439 }
440
441 acpi_pm_wakeup_event(&device->dev);
442
443 button = acpi_driver_data(device);
444 if (button->suspended)
445 return;
446
447 input = button->input;
448 keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
449
450 input_report_key(input, keycode, 1);
451 input_sync(input);
452 input_report_key(input, keycode, 0);
453 input_sync(input);
454
455 acpi_bus_generate_netlink_event(device->pnp.device_class,
456 dev_name(&device->dev),
457 event, ++button->pushed);
458}
459
460static void acpi_button_notify_run(void *data)
461{
462 acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
463}
464
465static u32 acpi_button_event(void *data)
466{
467 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);
468 return ACPI_INTERRUPT_HANDLED;
469}
470
471#ifdef CONFIG_PM_SLEEP
472static int acpi_button_suspend(struct device *dev)
473{
474 struct acpi_device *device = to_acpi_device(dev);
475 struct acpi_button *button = acpi_driver_data(device);
476
477 button->suspended = true;
478 return 0;
479}
480
481static int acpi_button_resume(struct device *dev)
482{
483 struct input_dev *input;
484 struct acpi_device *device = to_acpi_device(dev);
485 struct acpi_button *button = acpi_driver_data(device);
486
487 button->suspended = false;
488 if (button->type == ACPI_BUTTON_TYPE_LID) {
489 button->last_state = !!acpi_lid_evaluate_state(device);
490 button->last_time = ktime_get();
491 acpi_lid_initialize_state(device);
492 }
493
494 if (button->type == ACPI_BUTTON_TYPE_POWER) {
495 input = button->input;
496 input_report_key(input, KEY_WAKEUP, 1);
497 input_sync(input);
498 input_report_key(input, KEY_WAKEUP, 0);
499 input_sync(input);
500 }
501 return 0;
502}
503#endif
504
505static int acpi_lid_input_open(struct input_dev *input)
506{
507 struct acpi_device *device = input_get_drvdata(input);
508 struct acpi_button *button = acpi_driver_data(device);
509
510 button->last_state = !!acpi_lid_evaluate_state(device);
511 button->last_time = ktime_get();
512 acpi_lid_initialize_state(device);
513
514 return 0;
515}
516
517static int acpi_button_add(struct acpi_device *device)
518{
519 acpi_notify_handler handler;
520 struct acpi_button *button;
521 struct input_dev *input;
522 const char *hid = acpi_device_hid(device);
523 acpi_status status;
524 char *name, *class;
525 int error = 0;
526
527 if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
528 lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
529 return -ENODEV;
530
531 button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
532 if (!button)
533 return -ENOMEM;
534
535 device->driver_data = button;
536
537 button->input = input = input_allocate_device();
538 if (!input) {
539 error = -ENOMEM;
540 goto err_free_button;
541 }
542
543 name = acpi_device_name(device);
544 class = acpi_device_class(device);
545
546 if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
547 !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
548 button->type = ACPI_BUTTON_TYPE_POWER;
549 handler = acpi_button_notify;
550 strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
551 sprintf(class, "%s/%s",
552 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
553 } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
554 !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
555 button->type = ACPI_BUTTON_TYPE_SLEEP;
556 handler = acpi_button_notify;
557 strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
558 sprintf(class, "%s/%s",
559 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
560 } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
561 button->type = ACPI_BUTTON_TYPE_LID;
562 handler = acpi_lid_notify;
563 strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
564 sprintf(class, "%s/%s",
565 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
566 input->open = acpi_lid_input_open;
567 } else {
568 pr_info("Unsupported hid [%s]\n", hid);
569 error = -ENODEV;
570 }
571
572 if (!error)
573 error = acpi_button_add_fs(device);
574
575 if (error) {
576 input_free_device(input);
577 goto err_free_button;
578 }
579
580 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
581
582 input->name = name;
583 input->phys = button->phys;
584 input->id.bustype = BUS_HOST;
585 input->id.product = button->type;
586 input->dev.parent = &device->dev;
587
588 switch (button->type) {
589 case ACPI_BUTTON_TYPE_POWER:
590 input_set_capability(input, EV_KEY, KEY_POWER);
591 input_set_capability(input, EV_KEY, KEY_WAKEUP);
592 break;
593
594 case ACPI_BUTTON_TYPE_SLEEP:
595 input_set_capability(input, EV_KEY, KEY_SLEEP);
596 break;
597
598 case ACPI_BUTTON_TYPE_LID:
599 input_set_capability(input, EV_SW, SW_LID);
600 break;
601 }
602
603 input_set_drvdata(input, device);
604 error = input_register_device(input);
605 if (error)
606 goto err_remove_fs;
607
608 switch (device->device_type) {
609 case ACPI_BUS_TYPE_POWER_BUTTON:
610 status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
611 acpi_button_event,
612 device);
613 break;
614 case ACPI_BUS_TYPE_SLEEP_BUTTON:
615 status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
616 acpi_button_event,
617 device);
618 break;
619 default:
620 status = acpi_install_notify_handler(device->handle,
621 ACPI_DEVICE_NOTIFY, handler,
622 device);
623 break;
624 }
625 if (ACPI_FAILURE(status)) {
626 error = -ENODEV;
627 goto err_input_unregister;
628 }
629
630 if (button->type == ACPI_BUTTON_TYPE_LID) {
631 /*
632 * This assumes there's only one lid device, or if there are
633 * more we only care about the last one...
634 */
635 lid_device = device;
636 }
637
638 device_init_wakeup(&device->dev, true);
639 pr_info("%s [%s]\n", name, acpi_device_bid(device));
640 return 0;
641
642err_input_unregister:
643 input_unregister_device(input);
644err_remove_fs:
645 acpi_button_remove_fs(device);
646err_free_button:
647 kfree(button);
648 return error;
649}
650
651static void acpi_button_remove(struct acpi_device *device)
652{
653 struct acpi_button *button = acpi_driver_data(device);
654
655 switch (device->device_type) {
656 case ACPI_BUS_TYPE_POWER_BUTTON:
657 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
658 acpi_button_event);
659 break;
660 case ACPI_BUS_TYPE_SLEEP_BUTTON:
661 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
662 acpi_button_event);
663 break;
664 default:
665 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
666 button->type == ACPI_BUTTON_TYPE_LID ?
667 acpi_lid_notify :
668 acpi_button_notify);
669 break;
670 }
671 acpi_os_wait_events_complete();
672
673 acpi_button_remove_fs(device);
674 input_unregister_device(button->input);
675 kfree(button);
676}
677
678static int param_set_lid_init_state(const char *val,
679 const struct kernel_param *kp)
680{
681 int i;
682
683 i = sysfs_match_string(lid_init_state_str, val);
684 if (i < 0)
685 return i;
686
687 lid_init_state = i;
688 pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
689 return 0;
690}
691
692static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
693{
694 int i, c = 0;
695
696 for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
697 if (i == lid_init_state)
698 c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
699 else
700 c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
701
702 buf[c - 1] = '\n'; /* Replace the final space with a newline */
703
704 return c;
705}
706
707module_param_call(lid_init_state,
708 param_set_lid_init_state, param_get_lid_init_state,
709 NULL, 0644);
710MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
711
712static int acpi_button_register_driver(struct acpi_driver *driver)
713{
714 const struct dmi_system_id *dmi_id;
715
716 if (lid_init_state == -1) {
717 dmi_id = dmi_first_match(dmi_lid_quirks);
718 if (dmi_id)
719 lid_init_state = (long)dmi_id->driver_data;
720 else
721 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
722 }
723
724 /*
725 * Modules such as nouveau.ko and i915.ko have a link time dependency
726 * on acpi_lid_open(), and would therefore not be loadable on ACPI
727 * capable kernels booted in non-ACPI mode if the return value of
728 * acpi_bus_register_driver() is returned from here with ACPI disabled
729 * when this driver is built as a module.
730 */
731 if (acpi_disabled)
732 return 0;
733
734 return acpi_bus_register_driver(driver);
735}
736
737static void acpi_button_unregister_driver(struct acpi_driver *driver)
738{
739 if (!acpi_disabled)
740 acpi_bus_unregister_driver(driver);
741}
742
743module_driver(acpi_button_driver, acpi_button_register_driver,
744 acpi_button_unregister_driver);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * button.c - ACPI Button Driver
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 */
8
9#define pr_fmt(fmt) "ACPI: button: " fmt
10
11#include <linux/compiler.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/input.h>
19#include <linux/slab.h>
20#include <linux/acpi.h>
21#include <linux/dmi.h>
22#include <acpi/button.h>
23
24#define ACPI_BUTTON_CLASS "button"
25#define ACPI_BUTTON_FILE_STATE "state"
26#define ACPI_BUTTON_TYPE_UNKNOWN 0x00
27#define ACPI_BUTTON_NOTIFY_STATUS 0x80
28
29#define ACPI_BUTTON_SUBCLASS_POWER "power"
30#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button"
31#define ACPI_BUTTON_TYPE_POWER 0x01
32
33#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"
34#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button"
35#define ACPI_BUTTON_TYPE_SLEEP 0x03
36
37#define ACPI_BUTTON_SUBCLASS_LID "lid"
38#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
39#define ACPI_BUTTON_TYPE_LID 0x05
40
41enum {
42 ACPI_BUTTON_LID_INIT_IGNORE,
43 ACPI_BUTTON_LID_INIT_OPEN,
44 ACPI_BUTTON_LID_INIT_METHOD,
45 ACPI_BUTTON_LID_INIT_DISABLED,
46};
47
48static const char * const lid_init_state_str[] = {
49 [ACPI_BUTTON_LID_INIT_IGNORE] = "ignore",
50 [ACPI_BUTTON_LID_INIT_OPEN] = "open",
51 [ACPI_BUTTON_LID_INIT_METHOD] = "method",
52 [ACPI_BUTTON_LID_INIT_DISABLED] = "disabled",
53};
54
55MODULE_AUTHOR("Paul Diefenbaugh");
56MODULE_DESCRIPTION("ACPI Button Driver");
57MODULE_LICENSE("GPL");
58
59static const struct acpi_device_id button_device_ids[] = {
60 {ACPI_BUTTON_HID_LID, 0},
61 {ACPI_BUTTON_HID_SLEEP, 0},
62 {ACPI_BUTTON_HID_SLEEPF, 0},
63 {ACPI_BUTTON_HID_POWER, 0},
64 {ACPI_BUTTON_HID_POWERF, 0},
65 {"", 0},
66};
67MODULE_DEVICE_TABLE(acpi, button_device_ids);
68
69/* Please keep this list sorted alphabetically by vendor and model */
70static const struct dmi_system_id dmi_lid_quirks[] = {
71 {
72 /* GP-electronic T701, _LID method points to a floating GPIO */
73 .matches = {
74 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
75 DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
76 DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
77 },
78 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
79 },
80 {
81 /*
82 * Lenovo Yoga 9 14ITL5, initial notification of the LID device
83 * never happens.
84 */
85 .matches = {
86 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
87 DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),
88 },
89 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
90 },
91 {
92 /*
93 * Medion Akoya E2215T, notification of the LID device only
94 * happens on close, not on open and _LID always returns closed.
95 */
96 .matches = {
97 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
98 DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
99 },
100 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
101 },
102 {
103 /*
104 * Medion Akoya E2228T, notification of the LID device only
105 * happens on close, not on open and _LID always returns closed.
106 */
107 .matches = {
108 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
109 DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
110 },
111 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
112 },
113 {
114 /*
115 * Razer Blade Stealth 13 late 2019, notification of the LID device
116 * only happens on close, not on open and _LID always returns closed.
117 */
118 .matches = {
119 DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
120 DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
121 },
122 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
123 },
124 {}
125};
126
127static int acpi_button_add(struct acpi_device *device);
128static void acpi_button_remove(struct acpi_device *device);
129static void acpi_button_notify(struct acpi_device *device, u32 event);
130
131#ifdef CONFIG_PM_SLEEP
132static int acpi_button_suspend(struct device *dev);
133static int acpi_button_resume(struct device *dev);
134#else
135#define acpi_button_suspend NULL
136#define acpi_button_resume NULL
137#endif
138static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
139
140static struct acpi_driver acpi_button_driver = {
141 .name = "button",
142 .class = ACPI_BUTTON_CLASS,
143 .ids = button_device_ids,
144 .ops = {
145 .add = acpi_button_add,
146 .remove = acpi_button_remove,
147 .notify = acpi_button_notify,
148 },
149 .drv.pm = &acpi_button_pm,
150};
151
152struct acpi_button {
153 unsigned int type;
154 struct input_dev *input;
155 char phys[32]; /* for input device */
156 unsigned long pushed;
157 int last_state;
158 ktime_t last_time;
159 bool suspended;
160 bool lid_state_initialized;
161};
162
163static struct acpi_device *lid_device;
164static long lid_init_state = -1;
165
166static unsigned long lid_report_interval __read_mostly = 500;
167module_param(lid_report_interval, ulong, 0644);
168MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
169
170/* FS Interface (/proc) */
171static struct proc_dir_entry *acpi_button_dir;
172static struct proc_dir_entry *acpi_lid_dir;
173
174static int acpi_lid_evaluate_state(struct acpi_device *device)
175{
176 unsigned long long lid_state;
177 acpi_status status;
178
179 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
180 if (ACPI_FAILURE(status))
181 return -ENODEV;
182
183 return lid_state ? 1 : 0;
184}
185
186static int acpi_lid_notify_state(struct acpi_device *device, int state)
187{
188 struct acpi_button *button = acpi_driver_data(device);
189 ktime_t next_report;
190 bool do_update;
191
192 /*
193 * In lid_init_state=ignore mode, if user opens/closes lid
194 * frequently with "open" missing, and "last_time" is also updated
195 * frequently, "close" cannot be delivered to the userspace.
196 * So "last_time" is only updated after a timeout or an actual
197 * switch.
198 */
199 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
200 button->last_state != !!state)
201 do_update = true;
202 else
203 do_update = false;
204
205 next_report = ktime_add(button->last_time,
206 ms_to_ktime(lid_report_interval));
207 if (button->last_state == !!state &&
208 ktime_after(ktime_get(), next_report)) {
209 /* Complain the buggy firmware */
210 pr_warn_once("The lid device is not compliant to SW_LID.\n");
211
212 /*
213 * Send the unreliable complement switch event:
214 *
215 * On most platforms, the lid device is reliable. However
216 * there are exceptions:
217 * 1. Platforms returning initial lid state as "close" by
218 * default after booting/resuming:
219 * https://bugzilla.kernel.org/show_bug.cgi?id=89211
220 * https://bugzilla.kernel.org/show_bug.cgi?id=106151
221 * 2. Platforms never reporting "open" events:
222 * https://bugzilla.kernel.org/show_bug.cgi?id=106941
223 * On these buggy platforms, the usage model of the ACPI
224 * lid device actually is:
225 * 1. The initial returning value of _LID may not be
226 * reliable.
227 * 2. The open event may not be reliable.
228 * 3. The close event is reliable.
229 *
230 * But SW_LID is typed as input switch event, the input
231 * layer checks if the event is redundant. Hence if the
232 * state is not switched, the userspace cannot see this
233 * platform triggered reliable event. By inserting a
234 * complement switch event, it then is guaranteed that the
235 * platform triggered reliable one can always be seen by
236 * the userspace.
237 */
238 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
239 do_update = true;
240 /*
241 * Do generate complement switch event for "close"
242 * as "close" is reliable and wrong "open" won't
243 * trigger unexpected behaviors.
244 * Do not generate complement switch event for
245 * "open" as "open" is not reliable and wrong
246 * "close" will trigger unexpected behaviors.
247 */
248 if (!state) {
249 input_report_switch(button->input,
250 SW_LID, state);
251 input_sync(button->input);
252 }
253 }
254 }
255 /* Send the platform triggered reliable event */
256 if (do_update) {
257 acpi_handle_debug(device->handle, "ACPI LID %s\n",
258 state ? "open" : "closed");
259 input_report_switch(button->input, SW_LID, !state);
260 input_sync(button->input);
261 button->last_state = !!state;
262 button->last_time = ktime_get();
263 }
264
265 return 0;
266}
267
268static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
269 void *offset)
270{
271 struct acpi_device *device = seq->private;
272 int state;
273
274 state = acpi_lid_evaluate_state(device);
275 seq_printf(seq, "state: %s\n",
276 state < 0 ? "unsupported" : (state ? "open" : "closed"));
277 return 0;
278}
279
280static int acpi_button_add_fs(struct acpi_device *device)
281{
282 struct acpi_button *button = acpi_driver_data(device);
283 struct proc_dir_entry *entry = NULL;
284 int ret = 0;
285
286 /* procfs I/F for ACPI lid device only */
287 if (button->type != ACPI_BUTTON_TYPE_LID)
288 return 0;
289
290 if (acpi_button_dir || acpi_lid_dir) {
291 pr_info("More than one Lid device found!\n");
292 return -EEXIST;
293 }
294
295 /* create /proc/acpi/button */
296 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
297 if (!acpi_button_dir)
298 return -ENODEV;
299
300 /* create /proc/acpi/button/lid */
301 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
302 if (!acpi_lid_dir) {
303 ret = -ENODEV;
304 goto remove_button_dir;
305 }
306
307 /* create /proc/acpi/button/lid/LID/ */
308 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
309 if (!acpi_device_dir(device)) {
310 ret = -ENODEV;
311 goto remove_lid_dir;
312 }
313
314 /* create /proc/acpi/button/lid/LID/state */
315 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
316 acpi_device_dir(device), acpi_button_state_seq_show,
317 device);
318 if (!entry) {
319 ret = -ENODEV;
320 goto remove_dev_dir;
321 }
322
323done:
324 return ret;
325
326remove_dev_dir:
327 remove_proc_entry(acpi_device_bid(device),
328 acpi_lid_dir);
329 acpi_device_dir(device) = NULL;
330remove_lid_dir:
331 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
332 acpi_lid_dir = NULL;
333remove_button_dir:
334 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
335 acpi_button_dir = NULL;
336 goto done;
337}
338
339static int acpi_button_remove_fs(struct acpi_device *device)
340{
341 struct acpi_button *button = acpi_driver_data(device);
342
343 if (button->type != ACPI_BUTTON_TYPE_LID)
344 return 0;
345
346 remove_proc_entry(ACPI_BUTTON_FILE_STATE,
347 acpi_device_dir(device));
348 remove_proc_entry(acpi_device_bid(device),
349 acpi_lid_dir);
350 acpi_device_dir(device) = NULL;
351 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
352 acpi_lid_dir = NULL;
353 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
354 acpi_button_dir = NULL;
355
356 return 0;
357}
358
359/* Driver Interface */
360int acpi_lid_open(void)
361{
362 if (!lid_device)
363 return -ENODEV;
364
365 return acpi_lid_evaluate_state(lid_device);
366}
367EXPORT_SYMBOL(acpi_lid_open);
368
369static int acpi_lid_update_state(struct acpi_device *device,
370 bool signal_wakeup)
371{
372 int state;
373
374 state = acpi_lid_evaluate_state(device);
375 if (state < 0)
376 return state;
377
378 if (state && signal_wakeup)
379 acpi_pm_wakeup_event(&device->dev);
380
381 return acpi_lid_notify_state(device, state);
382}
383
384static void acpi_lid_initialize_state(struct acpi_device *device)
385{
386 struct acpi_button *button = acpi_driver_data(device);
387
388 switch (lid_init_state) {
389 case ACPI_BUTTON_LID_INIT_OPEN:
390 (void)acpi_lid_notify_state(device, 1);
391 break;
392 case ACPI_BUTTON_LID_INIT_METHOD:
393 (void)acpi_lid_update_state(device, false);
394 break;
395 case ACPI_BUTTON_LID_INIT_IGNORE:
396 default:
397 break;
398 }
399
400 button->lid_state_initialized = true;
401}
402
403static void acpi_button_notify(struct acpi_device *device, u32 event)
404{
405 struct acpi_button *button = acpi_driver_data(device);
406 struct input_dev *input;
407
408 switch (event) {
409 case ACPI_FIXED_HARDWARE_EVENT:
410 event = ACPI_BUTTON_NOTIFY_STATUS;
411 fallthrough;
412 case ACPI_BUTTON_NOTIFY_STATUS:
413 input = button->input;
414 if (button->type == ACPI_BUTTON_TYPE_LID) {
415 if (button->lid_state_initialized)
416 acpi_lid_update_state(device, true);
417 } else {
418 int keycode;
419
420 acpi_pm_wakeup_event(&device->dev);
421 if (button->suspended)
422 break;
423
424 keycode = test_bit(KEY_SLEEP, input->keybit) ?
425 KEY_SLEEP : KEY_POWER;
426 input_report_key(input, keycode, 1);
427 input_sync(input);
428 input_report_key(input, keycode, 0);
429 input_sync(input);
430
431 acpi_bus_generate_netlink_event(
432 device->pnp.device_class,
433 dev_name(&device->dev),
434 event, ++button->pushed);
435 }
436 break;
437 default:
438 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
439 event);
440 break;
441 }
442}
443
444#ifdef CONFIG_PM_SLEEP
445static int acpi_button_suspend(struct device *dev)
446{
447 struct acpi_device *device = to_acpi_device(dev);
448 struct acpi_button *button = acpi_driver_data(device);
449
450 button->suspended = true;
451 return 0;
452}
453
454static int acpi_button_resume(struct device *dev)
455{
456 struct acpi_device *device = to_acpi_device(dev);
457 struct acpi_button *button = acpi_driver_data(device);
458
459 button->suspended = false;
460 if (button->type == ACPI_BUTTON_TYPE_LID) {
461 button->last_state = !!acpi_lid_evaluate_state(device);
462 button->last_time = ktime_get();
463 acpi_lid_initialize_state(device);
464 }
465 return 0;
466}
467#endif
468
469static int acpi_lid_input_open(struct input_dev *input)
470{
471 struct acpi_device *device = input_get_drvdata(input);
472 struct acpi_button *button = acpi_driver_data(device);
473
474 button->last_state = !!acpi_lid_evaluate_state(device);
475 button->last_time = ktime_get();
476 acpi_lid_initialize_state(device);
477
478 return 0;
479}
480
481static int acpi_button_add(struct acpi_device *device)
482{
483 struct acpi_button *button;
484 struct input_dev *input;
485 const char *hid = acpi_device_hid(device);
486 char *name, *class;
487 int error;
488
489 if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
490 lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
491 return -ENODEV;
492
493 button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
494 if (!button)
495 return -ENOMEM;
496
497 device->driver_data = button;
498
499 button->input = input = input_allocate_device();
500 if (!input) {
501 error = -ENOMEM;
502 goto err_free_button;
503 }
504
505 name = acpi_device_name(device);
506 class = acpi_device_class(device);
507
508 if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
509 !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
510 button->type = ACPI_BUTTON_TYPE_POWER;
511 strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
512 sprintf(class, "%s/%s",
513 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
514 } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
515 !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
516 button->type = ACPI_BUTTON_TYPE_SLEEP;
517 strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
518 sprintf(class, "%s/%s",
519 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
520 } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
521 button->type = ACPI_BUTTON_TYPE_LID;
522 strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
523 sprintf(class, "%s/%s",
524 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
525 input->open = acpi_lid_input_open;
526 } else {
527 pr_info("Unsupported hid [%s]\n", hid);
528 error = -ENODEV;
529 goto err_free_input;
530 }
531
532 error = acpi_button_add_fs(device);
533 if (error)
534 goto err_free_input;
535
536 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
537
538 input->name = name;
539 input->phys = button->phys;
540 input->id.bustype = BUS_HOST;
541 input->id.product = button->type;
542 input->dev.parent = &device->dev;
543
544 switch (button->type) {
545 case ACPI_BUTTON_TYPE_POWER:
546 input_set_capability(input, EV_KEY, KEY_POWER);
547 break;
548
549 case ACPI_BUTTON_TYPE_SLEEP:
550 input_set_capability(input, EV_KEY, KEY_SLEEP);
551 break;
552
553 case ACPI_BUTTON_TYPE_LID:
554 input_set_capability(input, EV_SW, SW_LID);
555 break;
556 }
557
558 input_set_drvdata(input, device);
559 error = input_register_device(input);
560 if (error)
561 goto err_remove_fs;
562 if (button->type == ACPI_BUTTON_TYPE_LID) {
563 /*
564 * This assumes there's only one lid device, or if there are
565 * more we only care about the last one...
566 */
567 lid_device = device;
568 }
569
570 device_init_wakeup(&device->dev, true);
571 pr_info("%s [%s]\n", name, acpi_device_bid(device));
572 return 0;
573
574 err_remove_fs:
575 acpi_button_remove_fs(device);
576 err_free_input:
577 input_free_device(input);
578 err_free_button:
579 kfree(button);
580 return error;
581}
582
583static void acpi_button_remove(struct acpi_device *device)
584{
585 struct acpi_button *button = acpi_driver_data(device);
586
587 acpi_button_remove_fs(device);
588 input_unregister_device(button->input);
589 kfree(button);
590}
591
592static int param_set_lid_init_state(const char *val,
593 const struct kernel_param *kp)
594{
595 int i;
596
597 i = sysfs_match_string(lid_init_state_str, val);
598 if (i < 0)
599 return i;
600
601 lid_init_state = i;
602 pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
603 return 0;
604}
605
606static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
607{
608 int i, c = 0;
609
610 for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
611 if (i == lid_init_state)
612 c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
613 else
614 c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
615
616 buf[c - 1] = '\n'; /* Replace the final space with a newline */
617
618 return c;
619}
620
621module_param_call(lid_init_state,
622 param_set_lid_init_state, param_get_lid_init_state,
623 NULL, 0644);
624MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
625
626static int acpi_button_register_driver(struct acpi_driver *driver)
627{
628 const struct dmi_system_id *dmi_id;
629
630 if (lid_init_state == -1) {
631 dmi_id = dmi_first_match(dmi_lid_quirks);
632 if (dmi_id)
633 lid_init_state = (long)dmi_id->driver_data;
634 else
635 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
636 }
637
638 /*
639 * Modules such as nouveau.ko and i915.ko have a link time dependency
640 * on acpi_lid_open(), and would therefore not be loadable on ACPI
641 * capable kernels booted in non-ACPI mode if the return value of
642 * acpi_bus_register_driver() is returned from here with ACPI disabled
643 * when this driver is built as a module.
644 */
645 if (acpi_disabled)
646 return 0;
647
648 return acpi_bus_register_driver(driver);
649}
650
651static void acpi_button_unregister_driver(struct acpi_driver *driver)
652{
653 if (!acpi_disabled)
654 acpi_bus_unregister_driver(driver);
655}
656
657module_driver(acpi_button_driver, acpi_button_register_driver,
658 acpi_button_unregister_driver);