xref: /linux/drivers/acpi/button.c (revision 2c373e75155bcc9c81060cdc07ee1b59e113bd2b)
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 
41 enum {
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 
48 static 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 
55 MODULE_AUTHOR("Paul Diefenbaugh");
56 MODULE_DESCRIPTION("ACPI Button Driver");
57 MODULE_LICENSE("GPL");
58 
59 static 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 };
67 MODULE_DEVICE_TABLE(acpi, button_device_ids);
68 
69 /* Please keep this list sorted alphabetically by vendor and model */
70 static 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 
136 static int acpi_button_add(struct acpi_device *device);
137 static void acpi_button_remove(struct acpi_device *device);
138 
139 #ifdef CONFIG_PM_SLEEP
140 static int acpi_button_suspend(struct device *dev);
141 static int acpi_button_resume(struct device *dev);
142 #else
143 #define acpi_button_suspend NULL
144 #define acpi_button_resume NULL
145 #endif
146 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
147 
148 static 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 
159 struct 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 
170 static struct acpi_device *lid_device;
171 static long lid_init_state = -1;
172 
173 static unsigned long lid_report_interval __read_mostly = 500;
174 module_param(lid_report_interval, ulong, 0644);
175 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
176 
177 /* FS Interface (/proc) */
178 static struct proc_dir_entry *acpi_button_dir;
179 static struct proc_dir_entry *acpi_lid_dir;
180 
181 static 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 
193 static 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 
275 static 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 
287 static 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 
330 done:
331 	return ret;
332 
333 remove_dev_dir:
334 	remove_proc_entry(acpi_device_bid(device),
335 			  acpi_lid_dir);
336 	acpi_device_dir(device) = NULL;
337 remove_lid_dir:
338 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
339 	acpi_lid_dir = NULL;
340 remove_button_dir:
341 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
342 	acpi_button_dir = NULL;
343 	goto done;
344 }
345 
346 static 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 */
367 int acpi_lid_open(void)
368 {
369 	if (!lid_device)
370 		return -ENODEV;
371 
372 	return acpi_lid_evaluate_state(lid_device);
373 }
374 EXPORT_SYMBOL(acpi_lid_open);
375 
376 static 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 
391 static 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 
410 static 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 
428 static 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 
460 static void acpi_button_notify_run(void *data)
461 {
462 	acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
463 }
464 
465 static 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
472 static 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 
481 static 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 
505 static 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 
517 static 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 
642 err_input_unregister:
643 	input_unregister_device(input);
644 err_remove_fs:
645 	acpi_button_remove_fs(device);
646 err_free_button:
647 	kfree(button);
648 	return error;
649 }
650 
651 static 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 
678 static 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 
692 static 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 
707 module_param_call(lid_init_state,
708 		  param_set_lid_init_state, param_get_lid_init_state,
709 		  NULL, 0644);
710 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
711 
712 static 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 
737 static void acpi_button_unregister_driver(struct acpi_driver *driver)
738 {
739 	if (!acpi_disabled)
740 		acpi_bus_unregister_driver(driver);
741 }
742 
743 module_driver(acpi_button_driver, acpi_button_register_driver,
744 	       acpi_button_unregister_driver);
745