xref: /openbmc/linux/drivers/acpi/button.c (revision c67ce71d)
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 		 * 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 
147 static int acpi_button_add(struct acpi_device *device);
148 static void acpi_button_remove(struct acpi_device *device);
149 
150 #ifdef CONFIG_PM_SLEEP
151 static int acpi_button_suspend(struct device *dev);
152 static int acpi_button_resume(struct device *dev);
153 #else
154 #define acpi_button_suspend NULL
155 #define acpi_button_resume NULL
156 #endif
157 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
158 
159 static 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 
170 struct 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 
181 static struct acpi_device *lid_device;
182 static long lid_init_state = -1;
183 
184 static unsigned long lid_report_interval __read_mostly = 500;
185 module_param(lid_report_interval, ulong, 0644);
186 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
187 
188 /* FS Interface (/proc) */
189 static struct proc_dir_entry *acpi_button_dir;
190 static struct proc_dir_entry *acpi_lid_dir;
191 
192 static 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 
204 static 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 
286 static 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 
298 static 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 
341 done:
342 	return ret;
343 
344 remove_dev_dir:
345 	remove_proc_entry(acpi_device_bid(device),
346 			  acpi_lid_dir);
347 	acpi_device_dir(device) = NULL;
348 remove_lid_dir:
349 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
350 	acpi_lid_dir = NULL;
351 remove_button_dir:
352 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
353 	acpi_button_dir = NULL;
354 	goto done;
355 }
356 
357 static 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 */
378 int acpi_lid_open(void)
379 {
380 	if (!lid_device)
381 		return -ENODEV;
382 
383 	return acpi_lid_evaluate_state(lid_device);
384 }
385 EXPORT_SYMBOL(acpi_lid_open);
386 
387 static 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 
402 static 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 
421 static 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 
439 static 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 
471 static void acpi_button_notify_run(void *data)
472 {
473 	acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
474 }
475 
476 static 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
483 static 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 
492 static int acpi_button_resume(struct device *dev)
493 {
494 	struct acpi_device *device = to_acpi_device(dev);
495 	struct acpi_button *button = acpi_driver_data(device);
496 
497 	button->suspended = false;
498 	if (button->type == ACPI_BUTTON_TYPE_LID) {
499 		button->last_state = !!acpi_lid_evaluate_state(device);
500 		button->last_time = ktime_get();
501 		acpi_lid_initialize_state(device);
502 	}
503 	return 0;
504 }
505 #endif
506 
507 static int acpi_lid_input_open(struct input_dev *input)
508 {
509 	struct acpi_device *device = input_get_drvdata(input);
510 	struct acpi_button *button = acpi_driver_data(device);
511 
512 	button->last_state = !!acpi_lid_evaluate_state(device);
513 	button->last_time = ktime_get();
514 	acpi_lid_initialize_state(device);
515 
516 	return 0;
517 }
518 
519 static int acpi_button_add(struct acpi_device *device)
520 {
521 	acpi_notify_handler handler;
522 	struct acpi_button *button;
523 	struct input_dev *input;
524 	const char *hid = acpi_device_hid(device);
525 	acpi_status status;
526 	char *name, *class;
527 	int error = 0;
528 
529 	if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
530 	     lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
531 		return -ENODEV;
532 
533 	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
534 	if (!button)
535 		return -ENOMEM;
536 
537 	device->driver_data = button;
538 
539 	button->input = input = input_allocate_device();
540 	if (!input) {
541 		error = -ENOMEM;
542 		goto err_free_button;
543 	}
544 
545 	name = acpi_device_name(device);
546 	class = acpi_device_class(device);
547 
548 	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
549 	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
550 		button->type = ACPI_BUTTON_TYPE_POWER;
551 		handler = acpi_button_notify;
552 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
553 		sprintf(class, "%s/%s",
554 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
555 	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
556 		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
557 		button->type = ACPI_BUTTON_TYPE_SLEEP;
558 		handler = acpi_button_notify;
559 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
560 		sprintf(class, "%s/%s",
561 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
562 	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
563 		button->type = ACPI_BUTTON_TYPE_LID;
564 		handler = acpi_lid_notify;
565 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
566 		sprintf(class, "%s/%s",
567 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
568 		input->open = acpi_lid_input_open;
569 	} else {
570 		pr_info("Unsupported hid [%s]\n", hid);
571 		error = -ENODEV;
572 	}
573 
574 	if (!error)
575 		error = acpi_button_add_fs(device);
576 
577 	if (error) {
578 		input_free_device(input);
579 		goto err_free_button;
580 	}
581 
582 	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
583 
584 	input->name = name;
585 	input->phys = button->phys;
586 	input->id.bustype = BUS_HOST;
587 	input->id.product = button->type;
588 	input->dev.parent = &device->dev;
589 
590 	switch (button->type) {
591 	case ACPI_BUTTON_TYPE_POWER:
592 		input_set_capability(input, EV_KEY, KEY_POWER);
593 		break;
594 
595 	case ACPI_BUTTON_TYPE_SLEEP:
596 		input_set_capability(input, EV_KEY, KEY_SLEEP);
597 		break;
598 
599 	case ACPI_BUTTON_TYPE_LID:
600 		input_set_capability(input, EV_SW, SW_LID);
601 		break;
602 	}
603 
604 	input_set_drvdata(input, device);
605 	error = input_register_device(input);
606 	if (error)
607 		goto err_remove_fs;
608 
609 	switch (device->device_type) {
610 	case ACPI_BUS_TYPE_POWER_BUTTON:
611 		status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
612 							  acpi_button_event,
613 							  device);
614 		break;
615 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
616 		status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
617 							  acpi_button_event,
618 							  device);
619 		break;
620 	default:
621 		status = acpi_install_notify_handler(device->handle,
622 						     ACPI_DEVICE_NOTIFY, handler,
623 						     device);
624 		break;
625 	}
626 	if (ACPI_FAILURE(status)) {
627 		error = -ENODEV;
628 		goto err_input_unregister;
629 	}
630 
631 	if (button->type == ACPI_BUTTON_TYPE_LID) {
632 		/*
633 		 * This assumes there's only one lid device, or if there are
634 		 * more we only care about the last one...
635 		 */
636 		lid_device = device;
637 	}
638 
639 	device_init_wakeup(&device->dev, true);
640 	pr_info("%s [%s]\n", name, acpi_device_bid(device));
641 	return 0;
642 
643 err_input_unregister:
644 	input_unregister_device(input);
645 err_remove_fs:
646 	acpi_button_remove_fs(device);
647 err_free_button:
648 	kfree(button);
649 	return error;
650 }
651 
652 static void acpi_button_remove(struct acpi_device *device)
653 {
654 	struct acpi_button *button = acpi_driver_data(device);
655 
656 	switch (device->device_type) {
657 	case ACPI_BUS_TYPE_POWER_BUTTON:
658 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
659 						acpi_button_event);
660 		break;
661 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
662 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
663 						acpi_button_event);
664 		break;
665 	default:
666 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
667 					   button->type == ACPI_BUTTON_TYPE_LID ?
668 						acpi_lid_notify :
669 						acpi_button_notify);
670 		break;
671 	}
672 	acpi_os_wait_events_complete();
673 
674 	acpi_button_remove_fs(device);
675 	input_unregister_device(button->input);
676 	kfree(button);
677 }
678 
679 static int param_set_lid_init_state(const char *val,
680 				    const struct kernel_param *kp)
681 {
682 	int i;
683 
684 	i = sysfs_match_string(lid_init_state_str, val);
685 	if (i < 0)
686 		return i;
687 
688 	lid_init_state = i;
689 	pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
690 	return 0;
691 }
692 
693 static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
694 {
695 	int i, c = 0;
696 
697 	for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
698 		if (i == lid_init_state)
699 			c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
700 		else
701 			c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
702 
703 	buf[c - 1] = '\n'; /* Replace the final space with a newline */
704 
705 	return c;
706 }
707 
708 module_param_call(lid_init_state,
709 		  param_set_lid_init_state, param_get_lid_init_state,
710 		  NULL, 0644);
711 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
712 
713 static int acpi_button_register_driver(struct acpi_driver *driver)
714 {
715 	const struct dmi_system_id *dmi_id;
716 
717 	if (lid_init_state == -1) {
718 		dmi_id = dmi_first_match(dmi_lid_quirks);
719 		if (dmi_id)
720 			lid_init_state = (long)dmi_id->driver_data;
721 		else
722 			lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
723 	}
724 
725 	/*
726 	 * Modules such as nouveau.ko and i915.ko have a link time dependency
727 	 * on acpi_lid_open(), and would therefore not be loadable on ACPI
728 	 * capable kernels booted in non-ACPI mode if the return value of
729 	 * acpi_bus_register_driver() is returned from here with ACPI disabled
730 	 * when this driver is built as a module.
731 	 */
732 	if (acpi_disabled)
733 		return 0;
734 
735 	return acpi_bus_register_driver(driver);
736 }
737 
738 static void acpi_button_unregister_driver(struct acpi_driver *driver)
739 {
740 	if (!acpi_disabled)
741 		acpi_bus_unregister_driver(driver);
742 }
743 
744 module_driver(acpi_button_driver, acpi_button_register_driver,
745 	       acpi_button_unregister_driver);
746