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_WAKE		0x02
28 #define ACPI_BUTTON_NOTIFY_STATUS	0x80
29 
30 #define ACPI_BUTTON_SUBCLASS_POWER	"power"
31 #define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"
32 #define ACPI_BUTTON_TYPE_POWER		0x01
33 
34 #define ACPI_BUTTON_SUBCLASS_SLEEP	"sleep"
35 #define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"
36 #define ACPI_BUTTON_TYPE_SLEEP		0x03
37 
38 #define ACPI_BUTTON_SUBCLASS_LID	"lid"
39 #define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
40 #define ACPI_BUTTON_TYPE_LID		0x05
41 
42 enum {
43 	ACPI_BUTTON_LID_INIT_IGNORE,
44 	ACPI_BUTTON_LID_INIT_OPEN,
45 	ACPI_BUTTON_LID_INIT_METHOD,
46 	ACPI_BUTTON_LID_INIT_DISABLED,
47 };
48 
49 static const char * const lid_init_state_str[] = {
50 	[ACPI_BUTTON_LID_INIT_IGNORE]		= "ignore",
51 	[ACPI_BUTTON_LID_INIT_OPEN]		= "open",
52 	[ACPI_BUTTON_LID_INIT_METHOD]		= "method",
53 	[ACPI_BUTTON_LID_INIT_DISABLED]		= "disabled",
54 };
55 
56 MODULE_AUTHOR("Paul Diefenbaugh");
57 MODULE_DESCRIPTION("ACPI Button Driver");
58 MODULE_LICENSE("GPL");
59 
60 static const struct acpi_device_id button_device_ids[] = {
61 	{ACPI_BUTTON_HID_LID,    0},
62 	{ACPI_BUTTON_HID_SLEEP,  0},
63 	{ACPI_BUTTON_HID_SLEEPF, 0},
64 	{ACPI_BUTTON_HID_POWER,  0},
65 	{ACPI_BUTTON_HID_POWERF, 0},
66 	{"", 0},
67 };
68 MODULE_DEVICE_TABLE(acpi, button_device_ids);
69 
70 /* Please keep this list sorted alphabetically by vendor and model */
71 static const struct dmi_system_id dmi_lid_quirks[] = {
72 	{
73 		/* GP-electronic T701, _LID method points to a floating GPIO */
74 		.matches = {
75 			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
76 			DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
77 			DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
78 		},
79 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
80 	},
81 	{
82 		/* Nextbook Ares 8A tablet, _LID device always reports lid closed */
83 		.matches = {
84 			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
85 			DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),
86 			DMI_MATCH(DMI_BIOS_VERSION, "M882"),
87 		},
88 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
89 	},
90 	{
91 		/*
92 		 * Lenovo Yoga 9 14ITL5, initial notification of the LID device
93 		 * never happens.
94 		 */
95 		.matches = {
96 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
97 			DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),
98 		},
99 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
100 	},
101 	{
102 		/*
103 		 * Medion Akoya E2215T, notification of the LID device only
104 		 * happens on close, not on open and _LID always returns closed.
105 		 */
106 		.matches = {
107 			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
108 			DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
109 		},
110 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
111 	},
112 	{
113 		/*
114 		 * Medion Akoya E2228T, notification of the LID device only
115 		 * happens on close, not on open and _LID always returns closed.
116 		 */
117 		.matches = {
118 			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
119 			DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
120 		},
121 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
122 	},
123 	{
124 		/*
125 		 * Razer Blade Stealth 13 late 2019, notification of the LID device
126 		 * only happens on close, not on open and _LID always returns closed.
127 		 */
128 		.matches = {
129 			DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
130 			DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
131 		},
132 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
133 	},
134 	{
135 		/*
136 		 * Samsung galaxybook2 ,initial _LID device notification returns
137 		 * lid closed.
138 		 */
139 		.matches = {
140 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
141 			DMI_MATCH(DMI_PRODUCT_NAME, "750XED"),
142 		},
143 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
144 	},
145 	{}
146 };
147 
148 static int acpi_button_add(struct acpi_device *device);
149 static void acpi_button_remove(struct acpi_device *device);
150 
151 #ifdef CONFIG_PM_SLEEP
152 static int acpi_button_suspend(struct device *dev);
153 static int acpi_button_resume(struct device *dev);
154 #else
155 #define acpi_button_suspend NULL
156 #define acpi_button_resume NULL
157 #endif
158 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
159 
160 static struct acpi_driver acpi_button_driver = {
161 	.name = "button",
162 	.class = ACPI_BUTTON_CLASS,
163 	.ids = button_device_ids,
164 	.ops = {
165 		.add = acpi_button_add,
166 		.remove = acpi_button_remove,
167 	},
168 	.drv.pm = &acpi_button_pm,
169 };
170 
171 struct acpi_button {
172 	unsigned int type;
173 	struct input_dev *input;
174 	char phys[32];			/* for input device */
175 	unsigned long pushed;
176 	int last_state;
177 	ktime_t last_time;
178 	bool suspended;
179 	bool lid_state_initialized;
180 };
181 
182 static struct acpi_device *lid_device;
183 static long lid_init_state = -1;
184 
185 static unsigned long lid_report_interval __read_mostly = 500;
186 module_param(lid_report_interval, ulong, 0644);
187 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
188 
189 /* FS Interface (/proc) */
190 static struct proc_dir_entry *acpi_button_dir;
191 static struct proc_dir_entry *acpi_lid_dir;
192 
193 static int acpi_lid_evaluate_state(struct acpi_device *device)
194 {
195 	unsigned long long lid_state;
196 	acpi_status status;
197 
198 	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
199 	if (ACPI_FAILURE(status))
200 		return -ENODEV;
201 
202 	return lid_state ? 1 : 0;
203 }
204 
205 static int acpi_lid_notify_state(struct acpi_device *device, int state)
206 {
207 	struct acpi_button *button = acpi_driver_data(device);
208 	ktime_t next_report;
209 	bool do_update;
210 
211 	/*
212 	 * In lid_init_state=ignore mode, if user opens/closes lid
213 	 * frequently with "open" missing, and "last_time" is also updated
214 	 * frequently, "close" cannot be delivered to the userspace.
215 	 * So "last_time" is only updated after a timeout or an actual
216 	 * switch.
217 	 */
218 	if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
219 	    button->last_state != !!state)
220 		do_update = true;
221 	else
222 		do_update = false;
223 
224 	next_report = ktime_add(button->last_time,
225 				ms_to_ktime(lid_report_interval));
226 	if (button->last_state == !!state &&
227 	    ktime_after(ktime_get(), next_report)) {
228 		/* Complain the buggy firmware */
229 		pr_warn_once("The lid device is not compliant to SW_LID.\n");
230 
231 		/*
232 		 * Send the unreliable complement switch event:
233 		 *
234 		 * On most platforms, the lid device is reliable. However
235 		 * there are exceptions:
236 		 * 1. Platforms returning initial lid state as "close" by
237 		 *    default after booting/resuming:
238 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
239 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
240 		 * 2. Platforms never reporting "open" events:
241 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
242 		 * On these buggy platforms, the usage model of the ACPI
243 		 * lid device actually is:
244 		 * 1. The initial returning value of _LID may not be
245 		 *    reliable.
246 		 * 2. The open event may not be reliable.
247 		 * 3. The close event is reliable.
248 		 *
249 		 * But SW_LID is typed as input switch event, the input
250 		 * layer checks if the event is redundant. Hence if the
251 		 * state is not switched, the userspace cannot see this
252 		 * platform triggered reliable event. By inserting a
253 		 * complement switch event, it then is guaranteed that the
254 		 * platform triggered reliable one can always be seen by
255 		 * the userspace.
256 		 */
257 		if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
258 			do_update = true;
259 			/*
260 			 * Do generate complement switch event for "close"
261 			 * as "close" is reliable and wrong "open" won't
262 			 * trigger unexpected behaviors.
263 			 * Do not generate complement switch event for
264 			 * "open" as "open" is not reliable and wrong
265 			 * "close" will trigger unexpected behaviors.
266 			 */
267 			if (!state) {
268 				input_report_switch(button->input,
269 						    SW_LID, state);
270 				input_sync(button->input);
271 			}
272 		}
273 	}
274 	/* Send the platform triggered reliable event */
275 	if (do_update) {
276 		acpi_handle_debug(device->handle, "ACPI LID %s\n",
277 				  state ? "open" : "closed");
278 		input_report_switch(button->input, SW_LID, !state);
279 		input_sync(button->input);
280 		button->last_state = !!state;
281 		button->last_time = ktime_get();
282 	}
283 
284 	return 0;
285 }
286 
287 static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
288 						     void *offset)
289 {
290 	struct acpi_device *device = seq->private;
291 	int state;
292 
293 	state = acpi_lid_evaluate_state(device);
294 	seq_printf(seq, "state:      %s\n",
295 		   state < 0 ? "unsupported" : (state ? "open" : "closed"));
296 	return 0;
297 }
298 
299 static int acpi_button_add_fs(struct acpi_device *device)
300 {
301 	struct acpi_button *button = acpi_driver_data(device);
302 	struct proc_dir_entry *entry = NULL;
303 	int ret = 0;
304 
305 	/* procfs I/F for ACPI lid device only */
306 	if (button->type != ACPI_BUTTON_TYPE_LID)
307 		return 0;
308 
309 	if (acpi_button_dir || acpi_lid_dir) {
310 		pr_info("More than one Lid device found!\n");
311 		return -EEXIST;
312 	}
313 
314 	/* create /proc/acpi/button */
315 	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
316 	if (!acpi_button_dir)
317 		return -ENODEV;
318 
319 	/* create /proc/acpi/button/lid */
320 	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
321 	if (!acpi_lid_dir) {
322 		ret = -ENODEV;
323 		goto remove_button_dir;
324 	}
325 
326 	/* create /proc/acpi/button/lid/LID/ */
327 	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
328 	if (!acpi_device_dir(device)) {
329 		ret = -ENODEV;
330 		goto remove_lid_dir;
331 	}
332 
333 	/* create /proc/acpi/button/lid/LID/state */
334 	entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
335 			acpi_device_dir(device), acpi_button_state_seq_show,
336 			device);
337 	if (!entry) {
338 		ret = -ENODEV;
339 		goto remove_dev_dir;
340 	}
341 
342 done:
343 	return ret;
344 
345 remove_dev_dir:
346 	remove_proc_entry(acpi_device_bid(device),
347 			  acpi_lid_dir);
348 	acpi_device_dir(device) = NULL;
349 remove_lid_dir:
350 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
351 	acpi_lid_dir = NULL;
352 remove_button_dir:
353 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
354 	acpi_button_dir = NULL;
355 	goto done;
356 }
357 
358 static int acpi_button_remove_fs(struct acpi_device *device)
359 {
360 	struct acpi_button *button = acpi_driver_data(device);
361 
362 	if (button->type != ACPI_BUTTON_TYPE_LID)
363 		return 0;
364 
365 	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
366 			  acpi_device_dir(device));
367 	remove_proc_entry(acpi_device_bid(device),
368 			  acpi_lid_dir);
369 	acpi_device_dir(device) = NULL;
370 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
371 	acpi_lid_dir = NULL;
372 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
373 	acpi_button_dir = NULL;
374 
375 	return 0;
376 }
377 
378 /* Driver Interface */
379 int acpi_lid_open(void)
380 {
381 	if (!lid_device)
382 		return -ENODEV;
383 
384 	return acpi_lid_evaluate_state(lid_device);
385 }
386 EXPORT_SYMBOL(acpi_lid_open);
387 
388 static int acpi_lid_update_state(struct acpi_device *device,
389 				 bool signal_wakeup)
390 {
391 	int state;
392 
393 	state = acpi_lid_evaluate_state(device);
394 	if (state < 0)
395 		return state;
396 
397 	if (state && signal_wakeup)
398 		acpi_pm_wakeup_event(&device->dev);
399 
400 	return acpi_lid_notify_state(device, state);
401 }
402 
403 static void acpi_lid_initialize_state(struct acpi_device *device)
404 {
405 	struct acpi_button *button = acpi_driver_data(device);
406 
407 	switch (lid_init_state) {
408 	case ACPI_BUTTON_LID_INIT_OPEN:
409 		(void)acpi_lid_notify_state(device, 1);
410 		break;
411 	case ACPI_BUTTON_LID_INIT_METHOD:
412 		(void)acpi_lid_update_state(device, false);
413 		break;
414 	case ACPI_BUTTON_LID_INIT_IGNORE:
415 	default:
416 		break;
417 	}
418 
419 	button->lid_state_initialized = true;
420 }
421 
422 static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)
423 {
424 	struct acpi_device *device = data;
425 	struct acpi_button *button;
426 
427 	if (event != ACPI_BUTTON_NOTIFY_STATUS) {
428 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
429 				  event);
430 		return;
431 	}
432 
433 	button = acpi_driver_data(device);
434 	if (!button->lid_state_initialized)
435 		return;
436 
437 	acpi_lid_update_state(device, true);
438 }
439 
440 static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
441 {
442 	struct acpi_device *device = data;
443 	struct acpi_button *button;
444 	struct input_dev *input;
445 	int keycode;
446 
447 	switch (event) {
448 	case ACPI_BUTTON_NOTIFY_STATUS:
449 		break;
450 	case ACPI_BUTTON_NOTIFY_WAKE:
451 		break;
452 	default:
453 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
454 				  event);
455 		return;
456 	}
457 
458 	acpi_pm_wakeup_event(&device->dev);
459 
460 	button = acpi_driver_data(device);
461 	if (button->suspended || event == ACPI_BUTTON_NOTIFY_WAKE)
462 		return;
463 
464 	input = button->input;
465 	keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
466 
467 	input_report_key(input, keycode, 1);
468 	input_sync(input);
469 	input_report_key(input, keycode, 0);
470 	input_sync(input);
471 
472 	acpi_bus_generate_netlink_event(device->pnp.device_class,
473 					dev_name(&device->dev),
474 					event, ++button->pushed);
475 }
476 
477 static void acpi_button_notify_run(void *data)
478 {
479 	acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
480 }
481 
482 static u32 acpi_button_event(void *data)
483 {
484 	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);
485 	return ACPI_INTERRUPT_HANDLED;
486 }
487 
488 #ifdef CONFIG_PM_SLEEP
489 static int acpi_button_suspend(struct device *dev)
490 {
491 	struct acpi_device *device = to_acpi_device(dev);
492 	struct acpi_button *button = acpi_driver_data(device);
493 
494 	button->suspended = true;
495 	return 0;
496 }
497 
498 static int acpi_button_resume(struct device *dev)
499 {
500 	struct input_dev *input;
501 	struct acpi_device *device = to_acpi_device(dev);
502 	struct acpi_button *button = acpi_driver_data(device);
503 
504 	button->suspended = false;
505 	if (button->type == ACPI_BUTTON_TYPE_LID) {
506 		button->last_state = !!acpi_lid_evaluate_state(device);
507 		button->last_time = ktime_get();
508 		acpi_lid_initialize_state(device);
509 	}
510 
511 	if (button->type == ACPI_BUTTON_TYPE_POWER) {
512 		input = button->input;
513 		input_report_key(input, KEY_WAKEUP, 1);
514 		input_sync(input);
515 		input_report_key(input, KEY_WAKEUP, 0);
516 		input_sync(input);
517 	}
518 	return 0;
519 }
520 #endif
521 
522 static int acpi_lid_input_open(struct input_dev *input)
523 {
524 	struct acpi_device *device = input_get_drvdata(input);
525 	struct acpi_button *button = acpi_driver_data(device);
526 
527 	button->last_state = !!acpi_lid_evaluate_state(device);
528 	button->last_time = ktime_get();
529 	acpi_lid_initialize_state(device);
530 
531 	return 0;
532 }
533 
534 static int acpi_button_add(struct acpi_device *device)
535 {
536 	acpi_notify_handler handler;
537 	struct acpi_button *button;
538 	struct input_dev *input;
539 	const char *hid = acpi_device_hid(device);
540 	acpi_status status;
541 	char *name, *class;
542 	int error = 0;
543 
544 	if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
545 	     lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
546 		return -ENODEV;
547 
548 	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
549 	if (!button)
550 		return -ENOMEM;
551 
552 	device->driver_data = button;
553 
554 	button->input = input = input_allocate_device();
555 	if (!input) {
556 		error = -ENOMEM;
557 		goto err_free_button;
558 	}
559 
560 	name = acpi_device_name(device);
561 	class = acpi_device_class(device);
562 
563 	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
564 	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
565 		button->type = ACPI_BUTTON_TYPE_POWER;
566 		handler = acpi_button_notify;
567 		strscpy(name, ACPI_BUTTON_DEVICE_NAME_POWER, MAX_ACPI_DEVICE_NAME_LEN);
568 		sprintf(class, "%s/%s",
569 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
570 	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
571 		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
572 		button->type = ACPI_BUTTON_TYPE_SLEEP;
573 		handler = acpi_button_notify;
574 		strscpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP, MAX_ACPI_DEVICE_NAME_LEN);
575 		sprintf(class, "%s/%s",
576 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
577 	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
578 		button->type = ACPI_BUTTON_TYPE_LID;
579 		handler = acpi_lid_notify;
580 		strscpy(name, ACPI_BUTTON_DEVICE_NAME_LID, MAX_ACPI_DEVICE_NAME_LEN);
581 		sprintf(class, "%s/%s",
582 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
583 		input->open = acpi_lid_input_open;
584 	} else {
585 		pr_info("Unsupported hid [%s]\n", hid);
586 		error = -ENODEV;
587 	}
588 
589 	if (!error)
590 		error = acpi_button_add_fs(device);
591 
592 	if (error) {
593 		input_free_device(input);
594 		goto err_free_button;
595 	}
596 
597 	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
598 
599 	input->name = name;
600 	input->phys = button->phys;
601 	input->id.bustype = BUS_HOST;
602 	input->id.product = button->type;
603 	input->dev.parent = &device->dev;
604 
605 	switch (button->type) {
606 	case ACPI_BUTTON_TYPE_POWER:
607 		input_set_capability(input, EV_KEY, KEY_POWER);
608 		input_set_capability(input, EV_KEY, KEY_WAKEUP);
609 		break;
610 
611 	case ACPI_BUTTON_TYPE_SLEEP:
612 		input_set_capability(input, EV_KEY, KEY_SLEEP);
613 		break;
614 
615 	case ACPI_BUTTON_TYPE_LID:
616 		input_set_capability(input, EV_SW, SW_LID);
617 		break;
618 	}
619 
620 	input_set_drvdata(input, device);
621 	error = input_register_device(input);
622 	if (error)
623 		goto err_remove_fs;
624 
625 	switch (device->device_type) {
626 	case ACPI_BUS_TYPE_POWER_BUTTON:
627 		status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
628 							  acpi_button_event,
629 							  device);
630 		break;
631 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
632 		status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
633 							  acpi_button_event,
634 							  device);
635 		break;
636 	default:
637 		status = acpi_install_notify_handler(device->handle,
638 						     ACPI_ALL_NOTIFY, handler,
639 						     device);
640 		break;
641 	}
642 	if (ACPI_FAILURE(status)) {
643 		error = -ENODEV;
644 		goto err_input_unregister;
645 	}
646 
647 	if (button->type == ACPI_BUTTON_TYPE_LID) {
648 		/*
649 		 * This assumes there's only one lid device, or if there are
650 		 * more we only care about the last one...
651 		 */
652 		lid_device = device;
653 	}
654 
655 	device_init_wakeup(&device->dev, true);
656 	pr_info("%s [%s]\n", name, acpi_device_bid(device));
657 	return 0;
658 
659 err_input_unregister:
660 	input_unregister_device(input);
661 err_remove_fs:
662 	acpi_button_remove_fs(device);
663 err_free_button:
664 	kfree(button);
665 	return error;
666 }
667 
668 static void acpi_button_remove(struct acpi_device *device)
669 {
670 	struct acpi_button *button = acpi_driver_data(device);
671 
672 	switch (device->device_type) {
673 	case ACPI_BUS_TYPE_POWER_BUTTON:
674 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
675 						acpi_button_event);
676 		break;
677 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
678 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
679 						acpi_button_event);
680 		break;
681 	default:
682 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
683 					   button->type == ACPI_BUTTON_TYPE_LID ?
684 						acpi_lid_notify :
685 						acpi_button_notify);
686 		break;
687 	}
688 	acpi_os_wait_events_complete();
689 
690 	acpi_button_remove_fs(device);
691 	input_unregister_device(button->input);
692 	kfree(button);
693 }
694 
695 static int param_set_lid_init_state(const char *val,
696 				    const struct kernel_param *kp)
697 {
698 	int i;
699 
700 	i = sysfs_match_string(lid_init_state_str, val);
701 	if (i < 0)
702 		return i;
703 
704 	lid_init_state = i;
705 	pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
706 	return 0;
707 }
708 
709 static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
710 {
711 	int i, c = 0;
712 
713 	for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
714 		if (i == lid_init_state)
715 			c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
716 		else
717 			c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
718 
719 	buf[c - 1] = '\n'; /* Replace the final space with a newline */
720 
721 	return c;
722 }
723 
724 module_param_call(lid_init_state,
725 		  param_set_lid_init_state, param_get_lid_init_state,
726 		  NULL, 0644);
727 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
728 
729 static int acpi_button_register_driver(struct acpi_driver *driver)
730 {
731 	const struct dmi_system_id *dmi_id;
732 
733 	if (lid_init_state == -1) {
734 		dmi_id = dmi_first_match(dmi_lid_quirks);
735 		if (dmi_id)
736 			lid_init_state = (long)dmi_id->driver_data;
737 		else
738 			lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
739 	}
740 
741 	/*
742 	 * Modules such as nouveau.ko and i915.ko have a link time dependency
743 	 * on acpi_lid_open(), and would therefore not be loadable on ACPI
744 	 * capable kernels booted in non-ACPI mode if the return value of
745 	 * acpi_bus_register_driver() is returned from here with ACPI disabled
746 	 * when this driver is built as a module.
747 	 */
748 	if (acpi_disabled)
749 		return 0;
750 
751 	return acpi_bus_register_driver(driver);
752 }
753 
754 static void acpi_button_unregister_driver(struct acpi_driver *driver)
755 {
756 	if (!acpi_disabled)
757 		acpi_bus_unregister_driver(driver);
758 }
759 
760 module_driver(acpi_button_driver, acpi_button_register_driver,
761 	       acpi_button_unregister_driver);
762