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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 * Samsung galaxybook2 ,initial _LID device notification returns
136 * lid closed.
137 */
138 .matches = {
139 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
140 DMI_MATCH(DMI_PRODUCT_NAME, "750XED"),
141 },
142 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
143 },
144 {}
145};
146
147static int acpi_button_add(struct acpi_device *device);
148static void acpi_button_remove(struct acpi_device *device);
149
150#ifdef CONFIG_PM_SLEEP
151static int acpi_button_suspend(struct device *dev);
152static int acpi_button_resume(struct device *dev);
153#else
154#define acpi_button_suspend NULL
155#define acpi_button_resume NULL
156#endif
157static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
158
159static struct acpi_driver acpi_button_driver = {
160 .name = "button",
161 .class = ACPI_BUTTON_CLASS,
162 .ids = button_device_ids,
163 .ops = {
164 .add = acpi_button_add,
165 .remove = acpi_button_remove,
166 },
167 .drv.pm = &acpi_button_pm,
168};
169
170struct acpi_button {
171 unsigned int type;
172 struct input_dev *input;
173 char phys[32]; /* for input device */
174 unsigned long pushed;
175 int last_state;
176 ktime_t last_time;
177 bool suspended;
178 bool lid_state_initialized;
179};
180
181static struct acpi_device *lid_device;
182static long lid_init_state = -1;
183
184static unsigned long lid_report_interval __read_mostly = 500;
185module_param(lid_report_interval, ulong, 0644);
186MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
187
188/* FS Interface (/proc) */
189static struct proc_dir_entry *acpi_button_dir;
190static struct proc_dir_entry *acpi_lid_dir;
191
192static int acpi_lid_evaluate_state(struct acpi_device *device)
193{
194 unsigned long long lid_state;
195 acpi_status status;
196
197 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
198 if (ACPI_FAILURE(status))
199 return -ENODEV;
200
201 return lid_state ? 1 : 0;
202}
203
204static int acpi_lid_notify_state(struct acpi_device *device, int state)
205{
206 struct acpi_button *button = acpi_driver_data(device);
207 ktime_t next_report;
208 bool do_update;
209
210 /*
211 * In lid_init_state=ignore mode, if user opens/closes lid
212 * frequently with "open" missing, and "last_time" is also updated
213 * frequently, "close" cannot be delivered to the userspace.
214 * So "last_time" is only updated after a timeout or an actual
215 * switch.
216 */
217 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
218 button->last_state != !!state)
219 do_update = true;
220 else
221 do_update = false;
222
223 next_report = ktime_add(button->last_time,
224 ms_to_ktime(lid_report_interval));
225 if (button->last_state == !!state &&
226 ktime_after(ktime_get(), next_report)) {
227 /* Complain the buggy firmware */
228 pr_warn_once("The lid device is not compliant to SW_LID.\n");
229
230 /*
231 * Send the unreliable complement switch event:
232 *
233 * On most platforms, the lid device is reliable. However
234 * there are exceptions:
235 * 1. Platforms returning initial lid state as "close" by
236 * default after booting/resuming:
237 * https://bugzilla.kernel.org/show_bug.cgi?id=89211
238 * https://bugzilla.kernel.org/show_bug.cgi?id=106151
239 * 2. Platforms never reporting "open" events:
240 * https://bugzilla.kernel.org/show_bug.cgi?id=106941
241 * On these buggy platforms, the usage model of the ACPI
242 * lid device actually is:
243 * 1. The initial returning value of _LID may not be
244 * reliable.
245 * 2. The open event may not be reliable.
246 * 3. The close event is reliable.
247 *
248 * But SW_LID is typed as input switch event, the input
249 * layer checks if the event is redundant. Hence if the
250 * state is not switched, the userspace cannot see this
251 * platform triggered reliable event. By inserting a
252 * complement switch event, it then is guaranteed that the
253 * platform triggered reliable one can always be seen by
254 * the userspace.
255 */
256 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
257 do_update = true;
258 /*
259 * Do generate complement switch event for "close"
260 * as "close" is reliable and wrong "open" won't
261 * trigger unexpected behaviors.
262 * Do not generate complement switch event for
263 * "open" as "open" is not reliable and wrong
264 * "close" will trigger unexpected behaviors.
265 */
266 if (!state) {
267 input_report_switch(button->input,
268 SW_LID, state);
269 input_sync(button->input);
270 }
271 }
272 }
273 /* Send the platform triggered reliable event */
274 if (do_update) {
275 acpi_handle_debug(device->handle, "ACPI LID %s\n",
276 state ? "open" : "closed");
277 input_report_switch(button->input, SW_LID, !state);
278 input_sync(button->input);
279 button->last_state = !!state;
280 button->last_time = ktime_get();
281 }
282
283 return 0;
284}
285
286static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
287 void *offset)
288{
289 struct acpi_device *device = seq->private;
290 int state;
291
292 state = acpi_lid_evaluate_state(device);
293 seq_printf(seq, "state: %s\n",
294 state < 0 ? "unsupported" : (state ? "open" : "closed"));
295 return 0;
296}
297
298static int acpi_button_add_fs(struct acpi_device *device)
299{
300 struct acpi_button *button = acpi_driver_data(device);
301 struct proc_dir_entry *entry = NULL;
302 int ret = 0;
303
304 /* procfs I/F for ACPI lid device only */
305 if (button->type != ACPI_BUTTON_TYPE_LID)
306 return 0;
307
308 if (acpi_button_dir || acpi_lid_dir) {
309 pr_info("More than one Lid device found!\n");
310 return -EEXIST;
311 }
312
313 /* create /proc/acpi/button */
314 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
315 if (!acpi_button_dir)
316 return -ENODEV;
317
318 /* create /proc/acpi/button/lid */
319 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
320 if (!acpi_lid_dir) {
321 ret = -ENODEV;
322 goto remove_button_dir;
323 }
324
325 /* create /proc/acpi/button/lid/LID/ */
326 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
327 if (!acpi_device_dir(device)) {
328 ret = -ENODEV;
329 goto remove_lid_dir;
330 }
331
332 /* create /proc/acpi/button/lid/LID/state */
333 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
334 acpi_device_dir(device), acpi_button_state_seq_show,
335 device);
336 if (!entry) {
337 ret = -ENODEV;
338 goto remove_dev_dir;
339 }
340
341done:
342 return ret;
343
344remove_dev_dir:
345 remove_proc_entry(acpi_device_bid(device),
346 acpi_lid_dir);
347 acpi_device_dir(device) = NULL;
348remove_lid_dir:
349 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
350 acpi_lid_dir = NULL;
351remove_button_dir:
352 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
353 acpi_button_dir = NULL;
354 goto done;
355}
356
357static int acpi_button_remove_fs(struct acpi_device *device)
358{
359 struct acpi_button *button = acpi_driver_data(device);
360
361 if (button->type != ACPI_BUTTON_TYPE_LID)
362 return 0;
363
364 remove_proc_entry(ACPI_BUTTON_FILE_STATE,
365 acpi_device_dir(device));
366 remove_proc_entry(acpi_device_bid(device),
367 acpi_lid_dir);
368 acpi_device_dir(device) = NULL;
369 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
370 acpi_lid_dir = NULL;
371 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
372 acpi_button_dir = NULL;
373
374 return 0;
375}
376
377/* Driver Interface */
378int acpi_lid_open(void)
379{
380 if (!lid_device)
381 return -ENODEV;
382
383 return acpi_lid_evaluate_state(lid_device);
384}
385EXPORT_SYMBOL(acpi_lid_open);
386
387static int acpi_lid_update_state(struct acpi_device *device,
388 bool signal_wakeup)
389{
390 int state;
391
392 state = acpi_lid_evaluate_state(device);
393 if (state < 0)
394 return state;
395
396 if (state && signal_wakeup)
397 acpi_pm_wakeup_event(&device->dev);
398
399 return acpi_lid_notify_state(device, state);
400}
401
402static void acpi_lid_initialize_state(struct acpi_device *device)
403{
404 struct acpi_button *button = acpi_driver_data(device);
405
406 switch (lid_init_state) {
407 case ACPI_BUTTON_LID_INIT_OPEN:
408 (void)acpi_lid_notify_state(device, 1);
409 break;
410 case ACPI_BUTTON_LID_INIT_METHOD:
411 (void)acpi_lid_update_state(device, false);
412 break;
413 case ACPI_BUTTON_LID_INIT_IGNORE:
414 default:
415 break;
416 }
417
418 button->lid_state_initialized = true;
419}
420
421static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)
422{
423 struct acpi_device *device = data;
424 struct acpi_button *button;
425
426 if (event != ACPI_BUTTON_NOTIFY_STATUS) {
427 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
428 event);
429 return;
430 }
431
432 button = acpi_driver_data(device);
433 if (!button->lid_state_initialized)
434 return;
435
436 acpi_lid_update_state(device, true);
437}
438
439static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
440{
441 struct acpi_device *device = data;
442 struct acpi_button *button;
443 struct input_dev *input;
444 int keycode;
445
446 if (event != ACPI_BUTTON_NOTIFY_STATUS) {
447 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
448 event);
449 return;
450 }
451
452 acpi_pm_wakeup_event(&device->dev);
453
454 button = acpi_driver_data(device);
455 if (button->suspended)
456 return;
457
458 input = button->input;
459 keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
460
461 input_report_key(input, keycode, 1);
462 input_sync(input);
463 input_report_key(input, keycode, 0);
464 input_sync(input);
465
466 acpi_bus_generate_netlink_event(device->pnp.device_class,
467 dev_name(&device->dev),
468 event, ++button->pushed);
469}
470
471static void acpi_button_notify_run(void *data)
472{
473 acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
474}
475
476static u32 acpi_button_event(void *data)
477{
478 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);
479 return ACPI_INTERRUPT_HANDLED;
480}
481
482#ifdef CONFIG_PM_SLEEP
483static int acpi_button_suspend(struct device *dev)
484{
485 struct acpi_device *device = to_acpi_device(dev);
486 struct acpi_button *button = acpi_driver_data(device);
487
488 button->suspended = true;
489 return 0;
490}
491
492static int acpi_button_resume(struct device *dev)
493{
494 struct input_dev *input;
495 struct acpi_device *device = to_acpi_device(dev);
496 struct acpi_button *button = acpi_driver_data(device);
497
498 button->suspended = false;
499 if (button->type == ACPI_BUTTON_TYPE_LID) {
500 button->last_state = !!acpi_lid_evaluate_state(device);
501 button->last_time = ktime_get();
502 acpi_lid_initialize_state(device);
503 }
504
505 if (button->type == ACPI_BUTTON_TYPE_POWER) {
506 input = button->input;
507 input_report_key(input, KEY_WAKEUP, 1);
508 input_sync(input);
509 input_report_key(input, KEY_WAKEUP, 0);
510 input_sync(input);
511 }
512 return 0;
513}
514#endif
515
516static int acpi_lid_input_open(struct input_dev *input)
517{
518 struct acpi_device *device = input_get_drvdata(input);
519 struct acpi_button *button = acpi_driver_data(device);
520
521 button->last_state = !!acpi_lid_evaluate_state(device);
522 button->last_time = ktime_get();
523 acpi_lid_initialize_state(device);
524
525 return 0;
526}
527
528static int acpi_button_add(struct acpi_device *device)
529{
530 acpi_notify_handler handler;
531 struct acpi_button *button;
532 struct input_dev *input;
533 const char *hid = acpi_device_hid(device);
534 acpi_status status;
535 char *name, *class;
536 int error = 0;
537
538 if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
539 lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
540 return -ENODEV;
541
542 button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
543 if (!button)
544 return -ENOMEM;
545
546 device->driver_data = button;
547
548 button->input = input = input_allocate_device();
549 if (!input) {
550 error = -ENOMEM;
551 goto err_free_button;
552 }
553
554 name = acpi_device_name(device);
555 class = acpi_device_class(device);
556
557 if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
558 !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
559 button->type = ACPI_BUTTON_TYPE_POWER;
560 handler = acpi_button_notify;
561 strscpy(name, ACPI_BUTTON_DEVICE_NAME_POWER, MAX_ACPI_DEVICE_NAME_LEN);
562 sprintf(class, "%s/%s",
563 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
564 } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
565 !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
566 button->type = ACPI_BUTTON_TYPE_SLEEP;
567 handler = acpi_button_notify;
568 strscpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP, MAX_ACPI_DEVICE_NAME_LEN);
569 sprintf(class, "%s/%s",
570 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
571 } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
572 button->type = ACPI_BUTTON_TYPE_LID;
573 handler = acpi_lid_notify;
574 strscpy(name, ACPI_BUTTON_DEVICE_NAME_LID, MAX_ACPI_DEVICE_NAME_LEN);
575 sprintf(class, "%s/%s",
576 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
577 input->open = acpi_lid_input_open;
578 } else {
579 pr_info("Unsupported hid [%s]\n", hid);
580 error = -ENODEV;
581 }
582
583 if (!error)
584 error = acpi_button_add_fs(device);
585
586 if (error) {
587 input_free_device(input);
588 goto err_free_button;
589 }
590
591 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
592
593 input->name = name;
594 input->phys = button->phys;
595 input->id.bustype = BUS_HOST;
596 input->id.product = button->type;
597 input->dev.parent = &device->dev;
598
599 switch (button->type) {
600 case ACPI_BUTTON_TYPE_POWER:
601 input_set_capability(input, EV_KEY, KEY_POWER);
602 input_set_capability(input, EV_KEY, KEY_WAKEUP);
603 break;
604
605 case ACPI_BUTTON_TYPE_SLEEP:
606 input_set_capability(input, EV_KEY, KEY_SLEEP);
607 break;
608
609 case ACPI_BUTTON_TYPE_LID:
610 input_set_capability(input, EV_SW, SW_LID);
611 break;
612 }
613
614 input_set_drvdata(input, device);
615 error = input_register_device(input);
616 if (error)
617 goto err_remove_fs;
618
619 switch (device->device_type) {
620 case ACPI_BUS_TYPE_POWER_BUTTON:
621 status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
622 acpi_button_event,
623 device);
624 break;
625 case ACPI_BUS_TYPE_SLEEP_BUTTON:
626 status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
627 acpi_button_event,
628 device);
629 break;
630 default:
631 status = acpi_install_notify_handler(device->handle,
632 ACPI_DEVICE_NOTIFY, handler,
633 device);
634 break;
635 }
636 if (ACPI_FAILURE(status)) {
637 error = -ENODEV;
638 goto err_input_unregister;
639 }
640
641 if (button->type == ACPI_BUTTON_TYPE_LID) {
642 /*
643 * This assumes there's only one lid device, or if there are
644 * more we only care about the last one...
645 */
646 lid_device = device;
647 }
648
649 device_init_wakeup(&device->dev, true);
650 pr_info("%s [%s]\n", name, acpi_device_bid(device));
651 return 0;
652
653err_input_unregister:
654 input_unregister_device(input);
655err_remove_fs:
656 acpi_button_remove_fs(device);
657err_free_button:
658 kfree(button);
659 return error;
660}
661
662static void acpi_button_remove(struct acpi_device *device)
663{
664 struct acpi_button *button = acpi_driver_data(device);
665
666 switch (device->device_type) {
667 case ACPI_BUS_TYPE_POWER_BUTTON:
668 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
669 acpi_button_event);
670 break;
671 case ACPI_BUS_TYPE_SLEEP_BUTTON:
672 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
673 acpi_button_event);
674 break;
675 default:
676 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
677 button->type == ACPI_BUTTON_TYPE_LID ?
678 acpi_lid_notify :
679 acpi_button_notify);
680 break;
681 }
682 acpi_os_wait_events_complete();
683
684 acpi_button_remove_fs(device);
685 input_unregister_device(button->input);
686 kfree(button);
687}
688
689static int param_set_lid_init_state(const char *val,
690 const struct kernel_param *kp)
691{
692 int i;
693
694 i = sysfs_match_string(lid_init_state_str, val);
695 if (i < 0)
696 return i;
697
698 lid_init_state = i;
699 pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
700 return 0;
701}
702
703static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
704{
705 int i, c = 0;
706
707 for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
708 if (i == lid_init_state)
709 c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
710 else
711 c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
712
713 buf[c - 1] = '\n'; /* Replace the final space with a newline */
714
715 return c;
716}
717
718module_param_call(lid_init_state,
719 param_set_lid_init_state, param_get_lid_init_state,
720 NULL, 0644);
721MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
722
723static int acpi_button_register_driver(struct acpi_driver *driver)
724{
725 const struct dmi_system_id *dmi_id;
726
727 if (lid_init_state == -1) {
728 dmi_id = dmi_first_match(dmi_lid_quirks);
729 if (dmi_id)
730 lid_init_state = (long)dmi_id->driver_data;
731 else
732 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
733 }
734
735 /*
736 * Modules such as nouveau.ko and i915.ko have a link time dependency
737 * on acpi_lid_open(), and would therefore not be loadable on ACPI
738 * capable kernels booted in non-ACPI mode if the return value of
739 * acpi_bus_register_driver() is returned from here with ACPI disabled
740 * when this driver is built as a module.
741 */
742 if (acpi_disabled)
743 return 0;
744
745 return acpi_bus_register_driver(driver);
746}
747
748static void acpi_button_unregister_driver(struct acpi_driver *driver)
749{
750 if (!acpi_disabled)
751 acpi_bus_unregister_driver(driver);
752}
753
754module_driver(acpi_button_driver, acpi_button_register_driver,
755 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 PREFIX "ACPI: "
25
26#define ACPI_BUTTON_CLASS "button"
27#define ACPI_BUTTON_FILE_INFO "info"
28#define ACPI_BUTTON_FILE_STATE "state"
29#define ACPI_BUTTON_TYPE_UNKNOWN 0x00
30#define ACPI_BUTTON_NOTIFY_STATUS 0x80
31
32#define ACPI_BUTTON_SUBCLASS_POWER "power"
33#define ACPI_BUTTON_HID_POWER "PNP0C0C"
34#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button"
35#define ACPI_BUTTON_TYPE_POWER 0x01
36
37#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"
38#define ACPI_BUTTON_HID_SLEEP "PNP0C0E"
39#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button"
40#define ACPI_BUTTON_TYPE_SLEEP 0x03
41
42#define ACPI_BUTTON_SUBCLASS_LID "lid"
43#define ACPI_BUTTON_HID_LID "PNP0C0D"
44#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
45#define ACPI_BUTTON_TYPE_LID 0x05
46
47#define ACPI_BUTTON_LID_INIT_IGNORE 0x00
48#define ACPI_BUTTON_LID_INIT_OPEN 0x01
49#define ACPI_BUTTON_LID_INIT_METHOD 0x02
50
51#define _COMPONENT ACPI_BUTTON_COMPONENT
52ACPI_MODULE_NAME("button");
53
54MODULE_AUTHOR("Paul Diefenbaugh");
55MODULE_DESCRIPTION("ACPI Button Driver");
56MODULE_LICENSE("GPL");
57
58static const struct acpi_device_id button_device_ids[] = {
59 {ACPI_BUTTON_HID_LID, 0},
60 {ACPI_BUTTON_HID_SLEEP, 0},
61 {ACPI_BUTTON_HID_SLEEPF, 0},
62 {ACPI_BUTTON_HID_POWER, 0},
63 {ACPI_BUTTON_HID_POWERF, 0},
64 {"", 0},
65};
66MODULE_DEVICE_TABLE(acpi, button_device_ids);
67
68/*
69 * Some devices which don't even have a lid in anyway have a broken _LID
70 * method (e.g. pointing to a floating gpio pin) causing spurious LID events.
71 */
72static const struct dmi_system_id lid_blacklst[] = {
73 {
74 /* GP-electronic T701 */
75 .matches = {
76 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
77 DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
78 DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
79 },
80 },
81 {}
82};
83
84static int acpi_button_add(struct acpi_device *device);
85static int acpi_button_remove(struct acpi_device *device);
86static void acpi_button_notify(struct acpi_device *device, u32 event);
87
88#ifdef CONFIG_PM_SLEEP
89static int acpi_button_suspend(struct device *dev);
90static int acpi_button_resume(struct device *dev);
91#else
92#define acpi_button_suspend NULL
93#define acpi_button_resume NULL
94#endif
95static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
96
97static struct acpi_driver acpi_button_driver = {
98 .name = "button",
99 .class = ACPI_BUTTON_CLASS,
100 .ids = button_device_ids,
101 .ops = {
102 .add = acpi_button_add,
103 .remove = acpi_button_remove,
104 .notify = acpi_button_notify,
105 },
106 .drv.pm = &acpi_button_pm,
107};
108
109struct acpi_button {
110 unsigned int type;
111 struct input_dev *input;
112 char phys[32]; /* for input device */
113 unsigned long pushed;
114 int last_state;
115 ktime_t last_time;
116 bool suspended;
117};
118
119static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
120static struct acpi_device *lid_device;
121static u8 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
122
123static unsigned long lid_report_interval __read_mostly = 500;
124module_param(lid_report_interval, ulong, 0644);
125MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
126
127/* --------------------------------------------------------------------------
128 FS Interface (/proc)
129 -------------------------------------------------------------------------- */
130
131static struct proc_dir_entry *acpi_button_dir;
132static struct proc_dir_entry *acpi_lid_dir;
133
134static int acpi_lid_evaluate_state(struct acpi_device *device)
135{
136 unsigned long long lid_state;
137 acpi_status status;
138
139 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
140 if (ACPI_FAILURE(status))
141 return -ENODEV;
142
143 return lid_state ? 1 : 0;
144}
145
146static int acpi_lid_notify_state(struct acpi_device *device, int state)
147{
148 struct acpi_button *button = acpi_driver_data(device);
149 int ret;
150 ktime_t next_report;
151 bool do_update;
152
153 /*
154 * In lid_init_state=ignore mode, if user opens/closes lid
155 * frequently with "open" missing, and "last_time" is also updated
156 * frequently, "close" cannot be delivered to the userspace.
157 * So "last_time" is only updated after a timeout or an actual
158 * switch.
159 */
160 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
161 button->last_state != !!state)
162 do_update = true;
163 else
164 do_update = false;
165
166 next_report = ktime_add(button->last_time,
167 ms_to_ktime(lid_report_interval));
168 if (button->last_state == !!state &&
169 ktime_after(ktime_get(), next_report)) {
170 /* Complain the buggy firmware */
171 pr_warn_once("The lid device is not compliant to SW_LID.\n");
172
173 /*
174 * Send the unreliable complement switch event:
175 *
176 * On most platforms, the lid device is reliable. However
177 * there are exceptions:
178 * 1. Platforms returning initial lid state as "close" by
179 * default after booting/resuming:
180 * https://bugzilla.kernel.org/show_bug.cgi?id=89211
181 * https://bugzilla.kernel.org/show_bug.cgi?id=106151
182 * 2. Platforms never reporting "open" events:
183 * https://bugzilla.kernel.org/show_bug.cgi?id=106941
184 * On these buggy platforms, the usage model of the ACPI
185 * lid device actually is:
186 * 1. The initial returning value of _LID may not be
187 * reliable.
188 * 2. The open event may not be reliable.
189 * 3. The close event is reliable.
190 *
191 * But SW_LID is typed as input switch event, the input
192 * layer checks if the event is redundant. Hence if the
193 * state is not switched, the userspace cannot see this
194 * platform triggered reliable event. By inserting a
195 * complement switch event, it then is guaranteed that the
196 * platform triggered reliable one can always be seen by
197 * the userspace.
198 */
199 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
200 do_update = true;
201 /*
202 * Do generate complement switch event for "close"
203 * as "close" is reliable and wrong "open" won't
204 * trigger unexpected behaviors.
205 * Do not generate complement switch event for
206 * "open" as "open" is not reliable and wrong
207 * "close" will trigger unexpected behaviors.
208 */
209 if (!state) {
210 input_report_switch(button->input,
211 SW_LID, state);
212 input_sync(button->input);
213 }
214 }
215 }
216 /* Send the platform triggered reliable event */
217 if (do_update) {
218 acpi_handle_debug(device->handle, "ACPI LID %s\n",
219 state ? "open" : "closed");
220 input_report_switch(button->input, SW_LID, !state);
221 input_sync(button->input);
222 button->last_state = !!state;
223 button->last_time = ktime_get();
224 }
225
226 ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
227 if (ret == NOTIFY_DONE)
228 ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
229 device);
230 if (ret == NOTIFY_DONE || ret == NOTIFY_OK) {
231 /*
232 * It is also regarded as success if the notifier_chain
233 * returns NOTIFY_OK or NOTIFY_DONE.
234 */
235 ret = 0;
236 }
237 return ret;
238}
239
240static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
241 void *offset)
242{
243 struct acpi_device *device = seq->private;
244 int state;
245
246 state = acpi_lid_evaluate_state(device);
247 seq_printf(seq, "state: %s\n",
248 state < 0 ? "unsupported" : (state ? "open" : "closed"));
249 return 0;
250}
251
252static int acpi_button_add_fs(struct acpi_device *device)
253{
254 struct acpi_button *button = acpi_driver_data(device);
255 struct proc_dir_entry *entry = NULL;
256 int ret = 0;
257
258 /* procfs I/F for ACPI lid device only */
259 if (button->type != ACPI_BUTTON_TYPE_LID)
260 return 0;
261
262 if (acpi_button_dir || acpi_lid_dir) {
263 printk(KERN_ERR PREFIX "More than one Lid device found!\n");
264 return -EEXIST;
265 }
266
267 /* create /proc/acpi/button */
268 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
269 if (!acpi_button_dir)
270 return -ENODEV;
271
272 /* create /proc/acpi/button/lid */
273 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
274 if (!acpi_lid_dir) {
275 ret = -ENODEV;
276 goto remove_button_dir;
277 }
278
279 /* create /proc/acpi/button/lid/LID/ */
280 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
281 if (!acpi_device_dir(device)) {
282 ret = -ENODEV;
283 goto remove_lid_dir;
284 }
285
286 /* create /proc/acpi/button/lid/LID/state */
287 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
288 acpi_device_dir(device), acpi_button_state_seq_show,
289 device);
290 if (!entry) {
291 ret = -ENODEV;
292 goto remove_dev_dir;
293 }
294
295done:
296 return ret;
297
298remove_dev_dir:
299 remove_proc_entry(acpi_device_bid(device),
300 acpi_lid_dir);
301 acpi_device_dir(device) = NULL;
302remove_lid_dir:
303 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
304 acpi_lid_dir = NULL;
305remove_button_dir:
306 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
307 acpi_button_dir = NULL;
308 goto done;
309}
310
311static int acpi_button_remove_fs(struct acpi_device *device)
312{
313 struct acpi_button *button = acpi_driver_data(device);
314
315 if (button->type != ACPI_BUTTON_TYPE_LID)
316 return 0;
317
318 remove_proc_entry(ACPI_BUTTON_FILE_STATE,
319 acpi_device_dir(device));
320 remove_proc_entry(acpi_device_bid(device),
321 acpi_lid_dir);
322 acpi_device_dir(device) = NULL;
323 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
324 acpi_lid_dir = NULL;
325 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
326 acpi_button_dir = NULL;
327
328 return 0;
329}
330
331/* --------------------------------------------------------------------------
332 Driver Interface
333 -------------------------------------------------------------------------- */
334int acpi_lid_notifier_register(struct notifier_block *nb)
335{
336 return blocking_notifier_chain_register(&acpi_lid_notifier, nb);
337}
338EXPORT_SYMBOL(acpi_lid_notifier_register);
339
340int acpi_lid_notifier_unregister(struct notifier_block *nb)
341{
342 return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);
343}
344EXPORT_SYMBOL(acpi_lid_notifier_unregister);
345
346int acpi_lid_open(void)
347{
348 if (!lid_device)
349 return -ENODEV;
350
351 return acpi_lid_evaluate_state(lid_device);
352}
353EXPORT_SYMBOL(acpi_lid_open);
354
355static int acpi_lid_update_state(struct acpi_device *device,
356 bool signal_wakeup)
357{
358 int state;
359
360 state = acpi_lid_evaluate_state(device);
361 if (state < 0)
362 return state;
363
364 if (state && signal_wakeup)
365 acpi_pm_wakeup_event(&device->dev);
366
367 return acpi_lid_notify_state(device, state);
368}
369
370static void acpi_lid_initialize_state(struct acpi_device *device)
371{
372 switch (lid_init_state) {
373 case ACPI_BUTTON_LID_INIT_OPEN:
374 (void)acpi_lid_notify_state(device, 1);
375 break;
376 case ACPI_BUTTON_LID_INIT_METHOD:
377 (void)acpi_lid_update_state(device, false);
378 break;
379 case ACPI_BUTTON_LID_INIT_IGNORE:
380 default:
381 break;
382 }
383}
384
385static void acpi_button_notify(struct acpi_device *device, u32 event)
386{
387 struct acpi_button *button = acpi_driver_data(device);
388 struct input_dev *input;
389 int users;
390
391 switch (event) {
392 case ACPI_FIXED_HARDWARE_EVENT:
393 event = ACPI_BUTTON_NOTIFY_STATUS;
394 /* fall through */
395 case ACPI_BUTTON_NOTIFY_STATUS:
396 input = button->input;
397 if (button->type == ACPI_BUTTON_TYPE_LID) {
398 mutex_lock(&button->input->mutex);
399 users = button->input->users;
400 mutex_unlock(&button->input->mutex);
401 if (users)
402 acpi_lid_update_state(device, true);
403 } else {
404 int keycode;
405
406 acpi_pm_wakeup_event(&device->dev);
407 if (button->suspended)
408 break;
409
410 keycode = test_bit(KEY_SLEEP, input->keybit) ?
411 KEY_SLEEP : KEY_POWER;
412 input_report_key(input, keycode, 1);
413 input_sync(input);
414 input_report_key(input, keycode, 0);
415 input_sync(input);
416
417 acpi_bus_generate_netlink_event(
418 device->pnp.device_class,
419 dev_name(&device->dev),
420 event, ++button->pushed);
421 }
422 break;
423 default:
424 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
425 "Unsupported event [0x%x]\n", event));
426 break;
427 }
428}
429
430#ifdef CONFIG_PM_SLEEP
431static int acpi_button_suspend(struct device *dev)
432{
433 struct acpi_device *device = to_acpi_device(dev);
434 struct acpi_button *button = acpi_driver_data(device);
435
436 button->suspended = true;
437 return 0;
438}
439
440static int acpi_button_resume(struct device *dev)
441{
442 struct acpi_device *device = to_acpi_device(dev);
443 struct acpi_button *button = acpi_driver_data(device);
444
445 button->suspended = false;
446 if (button->type == ACPI_BUTTON_TYPE_LID && button->input->users) {
447 button->last_state = !!acpi_lid_evaluate_state(device);
448 button->last_time = ktime_get();
449 acpi_lid_initialize_state(device);
450 }
451 return 0;
452}
453#endif
454
455static int acpi_lid_input_open(struct input_dev *input)
456{
457 struct acpi_device *device = input_get_drvdata(input);
458 struct acpi_button *button = acpi_driver_data(device);
459
460 button->last_state = !!acpi_lid_evaluate_state(device);
461 button->last_time = ktime_get();
462 acpi_lid_initialize_state(device);
463
464 return 0;
465}
466
467static int acpi_button_add(struct acpi_device *device)
468{
469 struct acpi_button *button;
470 struct input_dev *input;
471 const char *hid = acpi_device_hid(device);
472 char *name, *class;
473 int error;
474
475 if (!strcmp(hid, ACPI_BUTTON_HID_LID) && dmi_check_system(lid_blacklst))
476 return -ENODEV;
477
478 button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
479 if (!button)
480 return -ENOMEM;
481
482 device->driver_data = button;
483
484 button->input = input = input_allocate_device();
485 if (!input) {
486 error = -ENOMEM;
487 goto err_free_button;
488 }
489
490 name = acpi_device_name(device);
491 class = acpi_device_class(device);
492
493 if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
494 !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
495 button->type = ACPI_BUTTON_TYPE_POWER;
496 strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
497 sprintf(class, "%s/%s",
498 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
499 } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
500 !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
501 button->type = ACPI_BUTTON_TYPE_SLEEP;
502 strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
503 sprintf(class, "%s/%s",
504 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
505 } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
506 button->type = ACPI_BUTTON_TYPE_LID;
507 strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
508 sprintf(class, "%s/%s",
509 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
510 input->open = acpi_lid_input_open;
511 } else {
512 printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid);
513 error = -ENODEV;
514 goto err_free_input;
515 }
516
517 error = acpi_button_add_fs(device);
518 if (error)
519 goto err_free_input;
520
521 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
522
523 input->name = name;
524 input->phys = button->phys;
525 input->id.bustype = BUS_HOST;
526 input->id.product = button->type;
527 input->dev.parent = &device->dev;
528
529 switch (button->type) {
530 case ACPI_BUTTON_TYPE_POWER:
531 input_set_capability(input, EV_KEY, KEY_POWER);
532 break;
533
534 case ACPI_BUTTON_TYPE_SLEEP:
535 input_set_capability(input, EV_KEY, KEY_SLEEP);
536 break;
537
538 case ACPI_BUTTON_TYPE_LID:
539 input_set_capability(input, EV_SW, SW_LID);
540 break;
541 }
542
543 input_set_drvdata(input, device);
544 error = input_register_device(input);
545 if (error)
546 goto err_remove_fs;
547 if (button->type == ACPI_BUTTON_TYPE_LID) {
548 /*
549 * This assumes there's only one lid device, or if there are
550 * more we only care about the last one...
551 */
552 lid_device = device;
553 }
554
555 device_init_wakeup(&device->dev, true);
556 printk(KERN_INFO PREFIX "%s [%s]\n", name, acpi_device_bid(device));
557 return 0;
558
559 err_remove_fs:
560 acpi_button_remove_fs(device);
561 err_free_input:
562 input_free_device(input);
563 err_free_button:
564 kfree(button);
565 return error;
566}
567
568static int acpi_button_remove(struct acpi_device *device)
569{
570 struct acpi_button *button = acpi_driver_data(device);
571
572 acpi_button_remove_fs(device);
573 input_unregister_device(button->input);
574 kfree(button);
575 return 0;
576}
577
578static int param_set_lid_init_state(const char *val,
579 const struct kernel_param *kp)
580{
581 int result = 0;
582
583 if (!strncmp(val, "open", sizeof("open") - 1)) {
584 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
585 pr_info("Notify initial lid state as open\n");
586 } else if (!strncmp(val, "method", sizeof("method") - 1)) {
587 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
588 pr_info("Notify initial lid state with _LID return value\n");
589 } else if (!strncmp(val, "ignore", sizeof("ignore") - 1)) {
590 lid_init_state = ACPI_BUTTON_LID_INIT_IGNORE;
591 pr_info("Do not notify initial lid state\n");
592 } else
593 result = -EINVAL;
594 return result;
595}
596
597static int param_get_lid_init_state(char *buffer,
598 const struct kernel_param *kp)
599{
600 switch (lid_init_state) {
601 case ACPI_BUTTON_LID_INIT_OPEN:
602 return sprintf(buffer, "open");
603 case ACPI_BUTTON_LID_INIT_METHOD:
604 return sprintf(buffer, "method");
605 case ACPI_BUTTON_LID_INIT_IGNORE:
606 return sprintf(buffer, "ignore");
607 default:
608 return sprintf(buffer, "invalid");
609 }
610 return 0;
611}
612
613module_param_call(lid_init_state,
614 param_set_lid_init_state, param_get_lid_init_state,
615 NULL, 0644);
616MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
617
618static int acpi_button_register_driver(struct acpi_driver *driver)
619{
620 /*
621 * Modules such as nouveau.ko and i915.ko have a link time dependency
622 * on acpi_lid_open(), and would therefore not be loadable on ACPI
623 * capable kernels booted in non-ACPI mode if the return value of
624 * acpi_bus_register_driver() is returned from here with ACPI disabled
625 * when this driver is built as a module.
626 */
627 if (acpi_disabled)
628 return 0;
629
630 return acpi_bus_register_driver(driver);
631}
632
633static void acpi_button_unregister_driver(struct acpi_driver *driver)
634{
635 if (!acpi_disabled)
636 acpi_bus_unregister_driver(driver);
637}
638
639module_driver(acpi_button_driver, acpi_button_register_driver,
640 acpi_button_unregister_driver);