xref: /linux/drivers/acpi/button.c (revision ec60aaade71b94a6840b467e656b07f456bf2f60)
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 <linux/platform_device.h>
23 #include <acpi/button.h>
24 
25 #define ACPI_BUTTON_CLASS		"button"
26 #define ACPI_BUTTON_FILE_STATE		"state"
27 #define ACPI_BUTTON_TYPE_UNKNOWN	0x00
28 #define ACPI_BUTTON_NOTIFY_WAKE		0x02
29 #define ACPI_BUTTON_NOTIFY_STATUS	0x80
30 
31 #define ACPI_BUTTON_CLASS_POWER		"button/power"
32 #define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"
33 #define ACPI_BUTTON_TYPE_POWER		0x01
34 
35 #define ACPI_BUTTON_CLASS_SLEEP		"button/sleep"
36 #define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"
37 #define ACPI_BUTTON_TYPE_SLEEP		0x03
38 
39 #define ACPI_BUTTON_CLASS_LID		"button/lid"
40 #define ACPI_BUTTON_SUBCLASS_LID	"lid"
41 #define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
42 #define ACPI_BUTTON_TYPE_LID		0x05
43 
44 enum {
45 	ACPI_BUTTON_LID_INIT_IGNORE,
46 	ACPI_BUTTON_LID_INIT_OPEN,
47 	ACPI_BUTTON_LID_INIT_METHOD,
48 	ACPI_BUTTON_LID_INIT_DISABLED,
49 };
50 
51 static const char * const lid_init_state_str[] = {
52 	[ACPI_BUTTON_LID_INIT_IGNORE]		= "ignore",
53 	[ACPI_BUTTON_LID_INIT_OPEN]		= "open",
54 	[ACPI_BUTTON_LID_INIT_METHOD]		= "method",
55 	[ACPI_BUTTON_LID_INIT_DISABLED]		= "disabled",
56 };
57 
58 MODULE_AUTHOR("Paul Diefenbaugh");
59 MODULE_DESCRIPTION("ACPI Button Driver");
60 MODULE_LICENSE("GPL");
61 
62 static const struct acpi_device_id button_device_ids[] = {
63 	{ACPI_BUTTON_HID_LID, ACPI_BUTTON_TYPE_LID},
64 	{ACPI_BUTTON_HID_SLEEP, ACPI_BUTTON_TYPE_SLEEP},
65 	{ACPI_BUTTON_HID_SLEEPF, ACPI_BUTTON_TYPE_SLEEP},
66 	{ACPI_BUTTON_HID_POWER, ACPI_BUTTON_TYPE_POWER},
67 	{ACPI_BUTTON_HID_POWERF, ACPI_BUTTON_TYPE_POWER},
68 	{"", 0},
69 };
70 MODULE_DEVICE_TABLE(acpi, button_device_ids);
71 
72 /* Please keep this list sorted alphabetically by vendor and model */
73 static const struct dmi_system_id dmi_lid_quirks[] = {
74 	{
75 		/* GP-electronic T701, _LID method points to a floating GPIO */
76 		.matches = {
77 			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
78 			DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
79 			DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
80 		},
81 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
82 	},
83 	{
84 		/* Nextbook Ares 8A tablet, _LID device always reports lid closed */
85 		.matches = {
86 			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
87 			DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),
88 			DMI_MATCH(DMI_BIOS_VERSION, "M882"),
89 		},
90 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
91 	},
92 	{
93 		/*
94 		 * Lenovo Yoga 9 14ITL5, initial notification of the LID device
95 		 * never happens.
96 		 */
97 		.matches = {
98 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
99 			DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),
100 		},
101 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
102 	},
103 	{
104 		/*
105 		 * Medion Akoya E2215T, notification of the LID device only
106 		 * happens on close, not on open and _LID always returns closed.
107 		 */
108 		.matches = {
109 			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
110 			DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
111 		},
112 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
113 	},
114 	{
115 		/*
116 		 * Medion Akoya E2228T, notification of the LID device only
117 		 * happens on close, not on open and _LID always returns closed.
118 		 */
119 		.matches = {
120 			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
121 			DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
122 		},
123 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
124 	},
125 	{
126 		/*
127 		 * Razer Blade Stealth 13 late 2019, notification of the LID device
128 		 * only happens on close, not on open and _LID always returns closed.
129 		 */
130 		.matches = {
131 			DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
132 			DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
133 		},
134 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
135 	},
136 	{
137 		/*
138 		 * Samsung galaxybook2 ,initial _LID device notification returns
139 		 * lid closed.
140 		 */
141 		.matches = {
142 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
143 			DMI_MATCH(DMI_PRODUCT_NAME, "750XED"),
144 		},
145 		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
146 	},
147 	{}
148 };
149 
150 static int acpi_button_probe(struct platform_device *pdev);
151 static void acpi_button_remove(struct platform_device *pdev);
152 
153 #ifdef CONFIG_PM_SLEEP
154 static int acpi_button_suspend(struct device *dev);
155 static int acpi_button_resume(struct device *dev);
156 #else
157 #define acpi_button_suspend NULL
158 #define acpi_button_resume NULL
159 #endif
160 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
161 
162 static struct platform_driver acpi_button_driver = {
163 	.probe = acpi_button_probe,
164 	.remove = acpi_button_remove,
165 	.driver = {
166 		.name = "acpi-button",
167 		.acpi_match_table = button_device_ids,
168 		.pm = &acpi_button_pm,
169 	},
170 };
171 
172 struct acpi_button {
173 	struct acpi_device *adev;
174 	struct device *dev;		/* physical button device */
175 	unsigned int type;
176 	struct input_dev *input;
177 	const char *class;		/* for netlink messages */
178 	char phys[32];			/* for input device */
179 	unsigned long pushed;
180 	bool last_state;
181 	ktime_t last_time;
182 	bool suspended;
183 	bool lid_state_initialized;
184 	bool gpe_enabled;
185 };
186 
187 static long lid_init_state = -1;
188 
189 static unsigned long lid_report_interval __read_mostly = 500;
190 module_param(lid_report_interval, ulong, 0644);
191 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
192 
193 /* FS Interface (/proc) */
194 static struct proc_dir_entry *acpi_button_dir;
195 static struct proc_dir_entry *acpi_lid_dir;
196 
197 static int acpi_lid_evaluate_state(acpi_handle lid_handle)
198 {
199 	unsigned long long lid_state;
200 	acpi_status status;
201 
202 	status = acpi_evaluate_integer(lid_handle, "_LID", NULL, &lid_state);
203 	if (ACPI_FAILURE(status))
204 		return -ENODEV;
205 
206 	return !!lid_state;
207 }
208 
209 static void acpi_lid_notify_state(struct acpi_button *button, bool state)
210 {
211 	struct acpi_device *device = button->adev;
212 	ktime_t next_report;
213 	bool do_update;
214 
215 	/*
216 	 * In lid_init_state=ignore mode, if user opens/closes lid
217 	 * frequently with "open" missing, and "last_time" is also updated
218 	 * frequently, "close" cannot be delivered to the userspace.
219 	 * So "last_time" is only updated after a timeout or an actual
220 	 * switch.
221 	 */
222 	do_update = lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
223 			button->last_state != state;
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 about the buggy firmware. */
229 		pr_warn_once(FW_BUG "Unexpected lid state reported by firmware\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 
285 static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
286 						     void *offset)
287 {
288 	struct acpi_button *button = seq->private;
289 	int state;
290 
291 	state = acpi_lid_evaluate_state(button->adev->handle);
292 	seq_printf(seq, "state:      %s\n",
293 		   state < 0 ? "unsupported" : (state ? "open" : "closed"));
294 	return 0;
295 }
296 
297 static int acpi_lid_add_fs(struct acpi_button *button)
298 {
299 	struct acpi_device *device = button->adev;
300 	struct proc_dir_entry *entry = NULL;
301 
302 	if (acpi_button_dir || acpi_lid_dir) {
303 		pr_info("More than one Lid device found!\n");
304 		return -EEXIST;
305 	}
306 
307 	/* create /proc/acpi/button */
308 	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
309 	if (!acpi_button_dir)
310 		return -ENODEV;
311 
312 	/* create /proc/acpi/button/lid */
313 	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
314 	if (!acpi_lid_dir)
315 		goto remove_button_dir;
316 
317 	/* create /proc/acpi/button/lid/LID/ */
318 	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
319 	if (!acpi_device_dir(device))
320 		goto remove_lid_dir;
321 
322 	/* create /proc/acpi/button/lid/LID/state */
323 	entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
324 			acpi_device_dir(device), acpi_button_state_seq_show,
325 			button);
326 	if (!entry)
327 		goto remove_dev_dir;
328 
329 	return 0;
330 
331 remove_dev_dir:
332 	remove_proc_entry(acpi_device_bid(device), acpi_lid_dir);
333 	acpi_device_dir(device) = NULL;
334 remove_lid_dir:
335 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
336 	acpi_lid_dir = NULL;
337 remove_button_dir:
338 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
339 	acpi_button_dir = NULL;
340 	return -ENODEV;
341 }
342 
343 static void acpi_lid_remove_fs(void *data)
344 {
345 	struct acpi_button *button = data;
346 	struct acpi_device *device = button->adev;
347 
348 	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
349 			  acpi_device_dir(device));
350 	remove_proc_entry(acpi_device_bid(device),
351 			  acpi_lid_dir);
352 	acpi_device_dir(device) = NULL;
353 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
354 	acpi_lid_dir = NULL;
355 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
356 	acpi_button_dir = NULL;
357 }
358 
359 static int devm_acpi_lid_add_fs(struct device *dev, struct acpi_button *button)
360 {
361 	int ret;
362 
363 	ret = acpi_lid_add_fs(button);
364 	if (ret)
365 		return ret;
366 
367 	return devm_add_action_or_reset(dev, acpi_lid_remove_fs, button);
368 }
369 
370 static acpi_handle saved_lid_handle;
371 static DEFINE_MUTEX(acpi_lid_lock);
372 
373 static void acpi_lid_save(struct acpi_device *adev)
374 {
375 	guard(mutex)(&acpi_lid_lock);
376 
377 	saved_lid_handle = adev->handle;
378 }
379 
380 static void acpi_lid_forget(struct acpi_device *adev)
381 {
382 	guard(mutex)(&acpi_lid_lock);
383 
384 	if (saved_lid_handle == adev->handle)
385 		saved_lid_handle = NULL;
386 }
387 
388 /* Driver Interface */
389 int acpi_lid_open(void)
390 {
391 	guard(mutex)(&acpi_lid_lock);
392 
393 	if (!saved_lid_handle)
394 		return -ENODEV;
395 
396 	return acpi_lid_evaluate_state(saved_lid_handle);
397 }
398 EXPORT_SYMBOL(acpi_lid_open);
399 
400 static void acpi_lid_update_state(struct acpi_button *button, bool signal_wakeup)
401 {
402 	int state;
403 
404 	state = acpi_lid_evaluate_state(button->adev->handle);
405 	if (state < 0)
406 		return;
407 
408 	if (state && signal_wakeup)
409 		acpi_pm_wakeup_event(button->dev);
410 
411 	acpi_lid_notify_state(button, state);
412 }
413 
414 static void acpi_lid_initialize_state(struct acpi_button *button)
415 {
416 	switch (lid_init_state) {
417 	case ACPI_BUTTON_LID_INIT_OPEN:
418 		acpi_lid_notify_state(button, true);
419 		break;
420 	case ACPI_BUTTON_LID_INIT_METHOD:
421 		acpi_lid_update_state(button, false);
422 		break;
423 	case ACPI_BUTTON_LID_INIT_IGNORE:
424 	default:
425 		break;
426 	}
427 
428 	button->lid_state_initialized = true;
429 }
430 
431 static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)
432 {
433 	struct acpi_button *button = data;
434 	struct acpi_device *device = button->adev;
435 
436 	if (event != ACPI_BUTTON_NOTIFY_STATUS) {
437 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
438 				  event);
439 		return;
440 	}
441 
442 	if (!button->lid_state_initialized)
443 		return;
444 
445 	acpi_lid_update_state(button, true);
446 }
447 
448 static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
449 {
450 	struct acpi_button *button = data;
451 	struct acpi_device *device = button->adev;
452 	struct input_dev *input;
453 	int keycode;
454 
455 	switch (event) {
456 	case ACPI_BUTTON_NOTIFY_STATUS:
457 		break;
458 	case ACPI_BUTTON_NOTIFY_WAKE:
459 		break;
460 	default:
461 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
462 				  event);
463 		return;
464 	}
465 
466 	acpi_pm_wakeup_event(button->dev);
467 
468 	if (button->suspended || event == ACPI_BUTTON_NOTIFY_WAKE)
469 		return;
470 
471 	input = button->input;
472 	keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
473 
474 	input_report_key(input, keycode, 1);
475 	input_sync(input);
476 	input_report_key(input, keycode, 0);
477 	input_sync(input);
478 
479 	acpi_bus_generate_netlink_event(button->class, dev_name(&device->dev),
480 					event, ++button->pushed);
481 }
482 
483 static void acpi_button_notify_run(void *data)
484 {
485 	acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
486 }
487 
488 static u32 acpi_button_event(void *data)
489 {
490 	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);
491 	return ACPI_INTERRUPT_HANDLED;
492 }
493 
494 #ifdef CONFIG_PM_SLEEP
495 static int acpi_button_suspend(struct device *dev)
496 {
497 	struct acpi_button *button = dev_get_drvdata(dev);
498 
499 	button->suspended = true;
500 	return 0;
501 }
502 
503 static int acpi_button_resume(struct device *dev)
504 {
505 	struct acpi_button *button = dev_get_drvdata(dev);
506 	struct input_dev *input;
507 
508 	button->suspended = false;
509 	if (button->type == ACPI_BUTTON_TYPE_LID) {
510 		button->last_state = !!acpi_lid_evaluate_state(ACPI_HANDLE(dev));
511 		button->last_time = ktime_get();
512 		acpi_lid_initialize_state(button);
513 	}
514 
515 	if (button->type == ACPI_BUTTON_TYPE_POWER) {
516 		input = button->input;
517 		input_report_key(input, KEY_WAKEUP, 1);
518 		input_sync(input);
519 		input_report_key(input, KEY_WAKEUP, 0);
520 		input_sync(input);
521 	}
522 	return 0;
523 }
524 #endif
525 
526 static int acpi_lid_input_open(struct input_dev *input)
527 {
528 	struct acpi_button *button = input_get_drvdata(input);
529 
530 	button->last_state = !!acpi_lid_evaluate_state(button->adev->handle);
531 	button->last_time = ktime_get();
532 	acpi_lid_initialize_state(button);
533 
534 	return 0;
535 }
536 
537 static acpi_notify_handler acpi_button_notify_handler(struct acpi_button *button)
538 {
539 	if (button->type == ACPI_BUTTON_TYPE_LID)
540 		return acpi_lid_notify;
541 
542 	return acpi_button_notify;
543 }
544 
545 static void acpi_button_wakeup_cleanup(void *data)
546 {
547 	device_init_wakeup(data, false);
548 }
549 
550 static int devm_acpi_button_init_wakeup(struct device *dev)
551 {
552 	device_init_wakeup(dev, true);
553 	return devm_add_action_or_reset(dev, acpi_button_wakeup_cleanup, dev);
554 }
555 
556 static void acpi_button_remove_event_handler(void *data)
557 {
558 	struct acpi_button *button = data;
559 	struct acpi_device *adev = button->adev;
560 
561 	switch (adev->device_type) {
562 	case ACPI_BUS_TYPE_POWER_BUTTON:
563 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
564 						acpi_button_event);
565 		break;
566 
567 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
568 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
569 						acpi_button_event);
570 		break;
571 
572 	default:
573 		if (button->gpe_enabled) {
574 			dev_dbg(button->dev, "Disabling ACPI GPE%02llx\n",
575 				adev->wakeup.gpe_number);
576 			acpi_disable_gpe(adev->wakeup.gpe_device,
577 					 adev->wakeup.gpe_number);
578 		}
579 		acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
580 					   acpi_button_notify_handler(button));
581 		break;
582 	}
583 	acpi_os_wait_events_complete();
584 }
585 
586 static int acpi_button_add_fixed_event_handler(u32 event,
587 					       struct acpi_button *button)
588 {
589 	acpi_status status;
590 
591 	status = acpi_install_fixed_event_handler(event, acpi_button_event, button);
592 	if (ACPI_FAILURE(status))
593 		return -ENODEV;
594 
595 	return 0;
596 }
597 
598 static int acpi_button_add_event_handler(struct acpi_button *button)
599 {
600 	struct acpi_device *adev = button->adev;
601 	acpi_status status;
602 
603 	if (adev->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
604 		return acpi_button_add_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
605 							   button);
606 
607 	if (adev->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
608 		return acpi_button_add_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
609 							   button);
610 
611 	status = acpi_install_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
612 					     acpi_button_notify_handler(button),
613 					     button);
614 	if (ACPI_FAILURE(status))
615 		return -ENODEV;
616 
617 	if (!adev->wakeup.flags.valid)
618 		return 0;
619 
620 	/*
621 	 * If the wakeup GPE has a handler method, enable it in case it is also
622 	 * used for signaling runtime events.
623 	 */
624 	status = acpi_enable_gpe_cond(adev->wakeup.gpe_device,
625 				      adev->wakeup.gpe_number,
626 				      ACPI_GPE_DISPATCH_METHOD);
627 	button->gpe_enabled = ACPI_SUCCESS(status);
628 	if (button->gpe_enabled)
629 		dev_dbg(button->dev, "Enabled ACPI GPE%02llx\n",
630 			adev->wakeup.gpe_number);
631 
632 	return 0;
633 }
634 
635 static int devm_acpi_button_add_event_handler(struct device *dev,
636 					      struct acpi_button *button)
637 {
638 	int ret;
639 
640 	ret = acpi_button_add_event_handler(button);
641 	if (ret)
642 		return ret;
643 
644 	return devm_add_action_or_reset(dev, acpi_button_remove_event_handler,
645 					button);
646 }
647 
648 static int acpi_button_probe(struct platform_device *pdev)
649 {
650 	struct device *dev = &pdev->dev;
651 	struct acpi_device *device = ACPI_COMPANION(dev);
652 	const struct acpi_device_id *id;
653 	struct acpi_button *button;
654 	struct input_dev *input;
655 	u8 button_type;
656 	int error = 0;
657 
658 	id = acpi_match_acpi_device(button_device_ids, device);
659 	if (!id || strcmp(acpi_device_hid(device), id->id))
660 		return dev_err_probe(dev, -ENODEV, "Unsupported device\n");
661 
662 	button_type = id->driver_data;
663 	if (button_type == ACPI_BUTTON_TYPE_LID &&
664 	    lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
665 		return -ENODEV;
666 
667 	button = devm_kzalloc(dev, sizeof(*button), GFP_KERNEL);
668 	if (!button)
669 		return -ENOMEM;
670 
671 	platform_set_drvdata(pdev, button);
672 
673 	button->dev = dev;
674 	button->adev = device;
675 	input = devm_input_allocate_device(dev);
676 	if (!input)
677 		return -ENOMEM;
678 
679 	button->input = input;
680 	button->type = button_type;
681 
682 	switch (button_type) {
683 	case ACPI_BUTTON_TYPE_LID:
684 		button->class = ACPI_BUTTON_CLASS_LID;
685 
686 		input->name = ACPI_BUTTON_DEVICE_NAME_LID;
687 		input_set_capability(input, EV_SW, SW_LID);
688 		input->open = acpi_lid_input_open;
689 
690 		error = devm_acpi_lid_add_fs(dev, button);
691 		if (error)
692 			return error;
693 
694 		break;
695 
696 	case ACPI_BUTTON_TYPE_POWER:
697 		button->class = ACPI_BUTTON_CLASS_POWER;
698 
699 		input->name = ACPI_BUTTON_DEVICE_NAME_POWER;
700 		input_set_capability(input, EV_KEY, KEY_POWER);
701 		input_set_capability(input, EV_KEY, KEY_WAKEUP);
702 		break;
703 
704 	case ACPI_BUTTON_TYPE_SLEEP:
705 		button->class = ACPI_BUTTON_CLASS_SLEEP;
706 
707 		input->name = ACPI_BUTTON_DEVICE_NAME_SLEEP;
708 		input_set_capability(input, EV_KEY, KEY_SLEEP);
709 		break;
710 
711 	default:
712 		return dev_err_probe(dev, -ENODEV, "Unrecognized button type\n");
713 	}
714 
715 	snprintf(button->phys, sizeof(button->phys), "%s/button/input0",
716 		 acpi_device_hid(device));
717 
718 	input->phys = button->phys;
719 	input->id.bustype = BUS_HOST;
720 	input->id.product = button_type;
721 
722 	input_set_drvdata(input, button);
723 	error = input_register_device(input);
724 	if (error)
725 		return error;
726 
727 	error = devm_acpi_button_init_wakeup(dev);
728 	if (error)
729 		return error;
730 
731 	error = devm_acpi_button_add_event_handler(dev, button);
732 	if (error)
733 		return error;
734 
735 	if (button_type == ACPI_BUTTON_TYPE_LID) {
736 		/*
737 		 * This assumes there's only one lid device, or if there are
738 		 * more we only care about the last one...
739 		 */
740 		acpi_lid_save(device);
741 	}
742 
743 	pr_info("%s [%s]\n", input->name, acpi_device_bid(device));
744 
745 	return 0;
746 }
747 
748 static void acpi_button_remove(struct platform_device *pdev)
749 {
750 	struct acpi_button *button = platform_get_drvdata(pdev);
751 
752 	if (button->type == ACPI_BUTTON_TYPE_LID)
753 		acpi_lid_forget(button->adev);
754 }
755 
756 static int param_set_lid_init_state(const char *val,
757 				    const struct kernel_param *kp)
758 {
759 	int i;
760 
761 	i = sysfs_match_string(lid_init_state_str, val);
762 	if (i < 0)
763 		return i;
764 
765 	lid_init_state = i;
766 	pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
767 	return 0;
768 }
769 
770 static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
771 {
772 	int i, c = 0;
773 
774 	for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
775 		if (i == lid_init_state)
776 			c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
777 		else
778 			c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
779 
780 	buf[c - 1] = '\n'; /* Replace the final space with a newline */
781 
782 	return c;
783 }
784 
785 module_param_call(lid_init_state,
786 		  param_set_lid_init_state, param_get_lid_init_state,
787 		  NULL, 0644);
788 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
789 
790 static int __init acpi_button_init(void)
791 {
792 	const struct dmi_system_id *dmi_id;
793 
794 	if (lid_init_state == -1) {
795 		dmi_id = dmi_first_match(dmi_lid_quirks);
796 		if (dmi_id)
797 			lid_init_state = (long)dmi_id->driver_data;
798 		else
799 			lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
800 	}
801 
802 	/*
803 	 * Modules such as nouveau.ko and i915.ko have a link time dependency
804 	 * on acpi_lid_open(), and would therefore not be loadable on ACPI
805 	 * capable kernels booted in non-ACPI mode if the return value of
806 	 * platform_driver_register() is returned from here with ACPI disabled
807 	 * when this driver is built as a module.
808 	 */
809 	if (acpi_disabled)
810 		return 0;
811 
812 	return platform_driver_register(&acpi_button_driver);
813 }
814 
815 static void __exit acpi_button_exit(void)
816 {
817 	if (!acpi_disabled)
818 		platform_driver_unregister(&acpi_button_driver);
819 }
820 
821 module_init(acpi_button_init);
822 module_exit(acpi_button_exit);
823