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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 PREFIX "ACPI: "
25
26#define ACPI_BUTTON_CLASS "button"
27#define ACPI_BUTTON_FILE_STATE "state"
28#define ACPI_BUTTON_TYPE_UNKNOWN 0x00
29#define ACPI_BUTTON_NOTIFY_STATUS 0x80
30
31#define ACPI_BUTTON_SUBCLASS_POWER "power"
32#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button"
33#define ACPI_BUTTON_TYPE_POWER 0x01
34
35#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"
36#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button"
37#define ACPI_BUTTON_TYPE_SLEEP 0x03
38
39#define ACPI_BUTTON_SUBCLASS_LID "lid"
40#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
41#define ACPI_BUTTON_TYPE_LID 0x05
42
43enum {
44 ACPI_BUTTON_LID_INIT_IGNORE,
45 ACPI_BUTTON_LID_INIT_OPEN,
46 ACPI_BUTTON_LID_INIT_METHOD,
47 ACPI_BUTTON_LID_INIT_DISABLED,
48};
49
50static const char * const lid_init_state_str[] = {
51 [ACPI_BUTTON_LID_INIT_IGNORE] = "ignore",
52 [ACPI_BUTTON_LID_INIT_OPEN] = "open",
53 [ACPI_BUTTON_LID_INIT_METHOD] = "method",
54 [ACPI_BUTTON_LID_INIT_DISABLED] = "disabled",
55};
56
57#define _COMPONENT ACPI_BUTTON_COMPONENT
58ACPI_MODULE_NAME("button");
59
60MODULE_AUTHOR("Paul Diefenbaugh");
61MODULE_DESCRIPTION("ACPI Button Driver");
62MODULE_LICENSE("GPL");
63
64static const struct acpi_device_id button_device_ids[] = {
65 {ACPI_BUTTON_HID_LID, 0},
66 {ACPI_BUTTON_HID_SLEEP, 0},
67 {ACPI_BUTTON_HID_SLEEPF, 0},
68 {ACPI_BUTTON_HID_POWER, 0},
69 {ACPI_BUTTON_HID_POWERF, 0},
70 {"", 0},
71};
72MODULE_DEVICE_TABLE(acpi, button_device_ids);
73
74/* Please keep this list sorted alphabetically by vendor and model */
75static const struct dmi_system_id dmi_lid_quirks[] = {
76 {
77 /*
78 * Acer Switch 10 SW5-012. _LID method messes with home and
79 * power button GPIO IRQ settings causing an interrupt storm on
80 * both GPIOs. This is unfixable without a DSDT override, so we
81 * have to disable the lid-switch functionality altogether :|
82 */
83 .matches = {
84 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
85 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire SW5-012"),
86 },
87 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
88 },
89 {
90 /* GP-electronic T701, _LID method points to a floating GPIO */
91 .matches = {
92 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
93 DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
94 DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
95 },
96 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
97 },
98 {
99 /*
100 * Medion Akoya E2215T, notification of the LID device only
101 * happens on close, not on open and _LID always returns closed.
102 */
103 .matches = {
104 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
105 DMI_MATCH(DMI_PRODUCT_NAME, "E2215T MD60198"),
106 },
107 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
108 },
109 {
110 /*
111 * Razer Blade Stealth 13 late 2019, notification of the LID device
112 * only happens on close, not on open and _LID always returns closed.
113 */
114 .matches = {
115 DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
116 DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
117 },
118 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
119 },
120 {}
121};
122
123static int acpi_button_add(struct acpi_device *device);
124static int acpi_button_remove(struct acpi_device *device);
125static void acpi_button_notify(struct acpi_device *device, u32 event);
126
127#ifdef CONFIG_PM_SLEEP
128static int acpi_button_suspend(struct device *dev);
129static int acpi_button_resume(struct device *dev);
130#else
131#define acpi_button_suspend NULL
132#define acpi_button_resume NULL
133#endif
134static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
135
136static struct acpi_driver acpi_button_driver = {
137 .name = "button",
138 .class = ACPI_BUTTON_CLASS,
139 .ids = button_device_ids,
140 .ops = {
141 .add = acpi_button_add,
142 .remove = acpi_button_remove,
143 .notify = acpi_button_notify,
144 },
145 .drv.pm = &acpi_button_pm,
146};
147
148struct acpi_button {
149 unsigned int type;
150 struct input_dev *input;
151 char phys[32]; /* for input device */
152 unsigned long pushed;
153 int last_state;
154 ktime_t last_time;
155 bool suspended;
156};
157
158static struct acpi_device *lid_device;
159static long lid_init_state = -1;
160
161static unsigned long lid_report_interval __read_mostly = 500;
162module_param(lid_report_interval, ulong, 0644);
163MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
164
165/* --------------------------------------------------------------------------
166 FS Interface (/proc)
167 -------------------------------------------------------------------------- */
168
169static struct proc_dir_entry *acpi_button_dir;
170static struct proc_dir_entry *acpi_lid_dir;
171
172static int acpi_lid_evaluate_state(struct acpi_device *device)
173{
174 unsigned long long lid_state;
175 acpi_status status;
176
177 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
178 if (ACPI_FAILURE(status))
179 return -ENODEV;
180
181 return lid_state ? 1 : 0;
182}
183
184static int acpi_lid_notify_state(struct acpi_device *device, int state)
185{
186 struct acpi_button *button = acpi_driver_data(device);
187 ktime_t next_report;
188 bool do_update;
189
190 /*
191 * In lid_init_state=ignore mode, if user opens/closes lid
192 * frequently with "open" missing, and "last_time" is also updated
193 * frequently, "close" cannot be delivered to the userspace.
194 * So "last_time" is only updated after a timeout or an actual
195 * switch.
196 */
197 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
198 button->last_state != !!state)
199 do_update = true;
200 else
201 do_update = false;
202
203 next_report = ktime_add(button->last_time,
204 ms_to_ktime(lid_report_interval));
205 if (button->last_state == !!state &&
206 ktime_after(ktime_get(), next_report)) {
207 /* Complain the buggy firmware */
208 pr_warn_once("The lid device is not compliant to SW_LID.\n");
209
210 /*
211 * Send the unreliable complement switch event:
212 *
213 * On most platforms, the lid device is reliable. However
214 * there are exceptions:
215 * 1. Platforms returning initial lid state as "close" by
216 * default after booting/resuming:
217 * https://bugzilla.kernel.org/show_bug.cgi?id=89211
218 * https://bugzilla.kernel.org/show_bug.cgi?id=106151
219 * 2. Platforms never reporting "open" events:
220 * https://bugzilla.kernel.org/show_bug.cgi?id=106941
221 * On these buggy platforms, the usage model of the ACPI
222 * lid device actually is:
223 * 1. The initial returning value of _LID may not be
224 * reliable.
225 * 2. The open event may not be reliable.
226 * 3. The close event is reliable.
227 *
228 * But SW_LID is typed as input switch event, the input
229 * layer checks if the event is redundant. Hence if the
230 * state is not switched, the userspace cannot see this
231 * platform triggered reliable event. By inserting a
232 * complement switch event, it then is guaranteed that the
233 * platform triggered reliable one can always be seen by
234 * the userspace.
235 */
236 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
237 do_update = true;
238 /*
239 * Do generate complement switch event for "close"
240 * as "close" is reliable and wrong "open" won't
241 * trigger unexpected behaviors.
242 * Do not generate complement switch event for
243 * "open" as "open" is not reliable and wrong
244 * "close" will trigger unexpected behaviors.
245 */
246 if (!state) {
247 input_report_switch(button->input,
248 SW_LID, state);
249 input_sync(button->input);
250 }
251 }
252 }
253 /* Send the platform triggered reliable event */
254 if (do_update) {
255 acpi_handle_debug(device->handle, "ACPI LID %s\n",
256 state ? "open" : "closed");
257 input_report_switch(button->input, SW_LID, !state);
258 input_sync(button->input);
259 button->last_state = !!state;
260 button->last_time = ktime_get();
261 }
262
263 return 0;
264}
265
266static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
267 void *offset)
268{
269 struct acpi_device *device = seq->private;
270 int state;
271
272 state = acpi_lid_evaluate_state(device);
273 seq_printf(seq, "state: %s\n",
274 state < 0 ? "unsupported" : (state ? "open" : "closed"));
275 return 0;
276}
277
278static int acpi_button_add_fs(struct acpi_device *device)
279{
280 struct acpi_button *button = acpi_driver_data(device);
281 struct proc_dir_entry *entry = NULL;
282 int ret = 0;
283
284 /* procfs I/F for ACPI lid device only */
285 if (button->type != ACPI_BUTTON_TYPE_LID)
286 return 0;
287
288 if (acpi_button_dir || acpi_lid_dir) {
289 printk(KERN_ERR PREFIX "More than one Lid device found!\n");
290 return -EEXIST;
291 }
292
293 /* create /proc/acpi/button */
294 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
295 if (!acpi_button_dir)
296 return -ENODEV;
297
298 /* create /proc/acpi/button/lid */
299 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
300 if (!acpi_lid_dir) {
301 ret = -ENODEV;
302 goto remove_button_dir;
303 }
304
305 /* create /proc/acpi/button/lid/LID/ */
306 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
307 if (!acpi_device_dir(device)) {
308 ret = -ENODEV;
309 goto remove_lid_dir;
310 }
311
312 /* create /proc/acpi/button/lid/LID/state */
313 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
314 acpi_device_dir(device), acpi_button_state_seq_show,
315 device);
316 if (!entry) {
317 ret = -ENODEV;
318 goto remove_dev_dir;
319 }
320
321done:
322 return ret;
323
324remove_dev_dir:
325 remove_proc_entry(acpi_device_bid(device),
326 acpi_lid_dir);
327 acpi_device_dir(device) = NULL;
328remove_lid_dir:
329 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
330 acpi_lid_dir = NULL;
331remove_button_dir:
332 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
333 acpi_button_dir = NULL;
334 goto done;
335}
336
337static int acpi_button_remove_fs(struct acpi_device *device)
338{
339 struct acpi_button *button = acpi_driver_data(device);
340
341 if (button->type != ACPI_BUTTON_TYPE_LID)
342 return 0;
343
344 remove_proc_entry(ACPI_BUTTON_FILE_STATE,
345 acpi_device_dir(device));
346 remove_proc_entry(acpi_device_bid(device),
347 acpi_lid_dir);
348 acpi_device_dir(device) = NULL;
349 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
350 acpi_lid_dir = NULL;
351 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
352 acpi_button_dir = NULL;
353
354 return 0;
355}
356
357/* --------------------------------------------------------------------------
358 Driver Interface
359 -------------------------------------------------------------------------- */
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 switch (lid_init_state) {
387 case ACPI_BUTTON_LID_INIT_OPEN:
388 (void)acpi_lid_notify_state(device, 1);
389 break;
390 case ACPI_BUTTON_LID_INIT_METHOD:
391 (void)acpi_lid_update_state(device, false);
392 break;
393 case ACPI_BUTTON_LID_INIT_IGNORE:
394 default:
395 break;
396 }
397}
398
399static void acpi_button_notify(struct acpi_device *device, u32 event)
400{
401 struct acpi_button *button = acpi_driver_data(device);
402 struct input_dev *input;
403 int users;
404
405 switch (event) {
406 case ACPI_FIXED_HARDWARE_EVENT:
407 event = ACPI_BUTTON_NOTIFY_STATUS;
408 fallthrough;
409 case ACPI_BUTTON_NOTIFY_STATUS:
410 input = button->input;
411 if (button->type == ACPI_BUTTON_TYPE_LID) {
412 mutex_lock(&button->input->mutex);
413 users = button->input->users;
414 mutex_unlock(&button->input->mutex);
415 if (users)
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_DEBUG_PRINT((ACPI_DB_INFO,
439 "Unsupported event [0x%x]\n", 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 && button->input->users) {
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 printk(KERN_ERR PREFIX "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 printk(KERN_INFO PREFIX "%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 int 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 return 0;
591}
592
593static int param_set_lid_init_state(const char *val,
594 const struct kernel_param *kp)
595{
596 int i;
597
598 i = sysfs_match_string(lid_init_state_str, val);
599 if (i < 0)
600 return i;
601
602 lid_init_state = i;
603 pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
604 return 0;
605}
606
607static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
608{
609 int i, c = 0;
610
611 for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
612 if (i == lid_init_state)
613 c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
614 else
615 c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
616
617 buf[c - 1] = '\n'; /* Replace the final space with a newline */
618
619 return c;
620}
621
622module_param_call(lid_init_state,
623 param_set_lid_init_state, param_get_lid_init_state,
624 NULL, 0644);
625MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
626
627static int acpi_button_register_driver(struct acpi_driver *driver)
628{
629 const struct dmi_system_id *dmi_id;
630
631 if (lid_init_state == -1) {
632 dmi_id = dmi_first_match(dmi_lid_quirks);
633 if (dmi_id)
634 lid_init_state = (long)dmi_id->driver_data;
635 else
636 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
637 }
638
639 /*
640 * Modules such as nouveau.ko and i915.ko have a link time dependency
641 * on acpi_lid_open(), and would therefore not be loadable on ACPI
642 * capable kernels booted in non-ACPI mode if the return value of
643 * acpi_bus_register_driver() is returned from here with ACPI disabled
644 * when this driver is built as a module.
645 */
646 if (acpi_disabled)
647 return 0;
648
649 return acpi_bus_register_driver(driver);
650}
651
652static void acpi_button_unregister_driver(struct acpi_driver *driver)
653{
654 if (!acpi_disabled)
655 acpi_bus_unregister_driver(driver);
656}
657
658module_driver(acpi_button_driver, acpi_button_register_driver,
659 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 /* 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);