xref: /kernel/linux/linux-5.10/drivers/acpi/button.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  button.c - ACPI Button Driver
4 *
5 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 */
8
9#define pr_fmt(fmt) "ACPI: button: " fmt
10
11#include <linux/compiler.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/input.h>
19#include <linux/slab.h>
20#include <linux/acpi.h>
21#include <linux/dmi.h>
22#include <acpi/button.h>
23
24#define PREFIX "ACPI: "
25
26#define ACPI_BUTTON_CLASS		"button"
27#define ACPI_BUTTON_FILE_STATE		"state"
28#define ACPI_BUTTON_TYPE_UNKNOWN	0x00
29#define ACPI_BUTTON_NOTIFY_STATUS	0x80
30
31#define ACPI_BUTTON_SUBCLASS_POWER	"power"
32#define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"
33#define ACPI_BUTTON_TYPE_POWER		0x01
34
35#define ACPI_BUTTON_SUBCLASS_SLEEP	"sleep"
36#define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"
37#define ACPI_BUTTON_TYPE_SLEEP		0x03
38
39#define ACPI_BUTTON_SUBCLASS_LID	"lid"
40#define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
41#define ACPI_BUTTON_TYPE_LID		0x05
42
43enum {
44	ACPI_BUTTON_LID_INIT_IGNORE,
45	ACPI_BUTTON_LID_INIT_OPEN,
46	ACPI_BUTTON_LID_INIT_METHOD,
47	ACPI_BUTTON_LID_INIT_DISABLED,
48};
49
50static const char * const lid_init_state_str[] = {
51	[ACPI_BUTTON_LID_INIT_IGNORE]		= "ignore",
52	[ACPI_BUTTON_LID_INIT_OPEN]		= "open",
53	[ACPI_BUTTON_LID_INIT_METHOD]		= "method",
54	[ACPI_BUTTON_LID_INIT_DISABLED]		= "disabled",
55};
56
57#define _COMPONENT		ACPI_BUTTON_COMPONENT
58ACPI_MODULE_NAME("button");
59
60MODULE_AUTHOR("Paul Diefenbaugh");
61MODULE_DESCRIPTION("ACPI Button Driver");
62MODULE_LICENSE("GPL");
63
64static const struct acpi_device_id button_device_ids[] = {
65	{ACPI_BUTTON_HID_LID,    0},
66	{ACPI_BUTTON_HID_SLEEP,  0},
67	{ACPI_BUTTON_HID_SLEEPF, 0},
68	{ACPI_BUTTON_HID_POWER,  0},
69	{ACPI_BUTTON_HID_POWERF, 0},
70	{"", 0},
71};
72MODULE_DEVICE_TABLE(acpi, button_device_ids);
73
74/* Please keep this list sorted alphabetically by vendor and model */
75static const struct dmi_system_id dmi_lid_quirks[] = {
76	{
77		/* GP-electronic T701, _LID method points to a floating GPIO */
78		.matches = {
79			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
80			DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
81			DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
82		},
83		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
84	},
85	{
86		/* Nextbook Ares 8A tablet, _LID device always reports lid closed */
87		.matches = {
88			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
89			DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),
90			DMI_MATCH(DMI_BIOS_VERSION, "M882"),
91		},
92		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
93	},
94	{
95		/*
96		 * Medion Akoya E2215T, notification of the LID device only
97		 * happens on close, not on open and _LID always returns closed.
98		 */
99		.matches = {
100			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
101			DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
102		},
103		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
104	},
105	{
106		/*
107		 * Medion Akoya E2228T, notification of the LID device only
108		 * happens on close, not on open and _LID always returns closed.
109		 */
110		.matches = {
111			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
112			DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
113		},
114		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
115	},
116	{
117		/*
118		 * Razer Blade Stealth 13 late 2019, notification of the LID device
119		 * only happens on close, not on open and _LID always returns closed.
120		 */
121		.matches = {
122			DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
123			DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
124		},
125		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
126	},
127	{}
128};
129
130static int acpi_button_add(struct acpi_device *device);
131static int acpi_button_remove(struct acpi_device *device);
132static void acpi_button_notify(struct acpi_device *device, u32 event);
133
134#ifdef CONFIG_PM_SLEEP
135static int acpi_button_suspend(struct device *dev);
136static int acpi_button_resume(struct device *dev);
137#else
138#define acpi_button_suspend NULL
139#define acpi_button_resume NULL
140#endif
141static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
142
143static struct acpi_driver acpi_button_driver = {
144	.name = "button",
145	.class = ACPI_BUTTON_CLASS,
146	.ids = button_device_ids,
147	.ops = {
148		.add = acpi_button_add,
149		.remove = acpi_button_remove,
150		.notify = acpi_button_notify,
151	},
152	.drv.pm = &acpi_button_pm,
153};
154
155struct acpi_button {
156	unsigned int type;
157	struct input_dev *input;
158	char phys[32];			/* for input device */
159	unsigned long pushed;
160	int last_state;
161	ktime_t last_time;
162	bool suspended;
163	bool lid_state_initialized;
164};
165
166static struct acpi_device *lid_device;
167static long lid_init_state = -1;
168
169static unsigned long lid_report_interval __read_mostly = 500;
170module_param(lid_report_interval, ulong, 0644);
171MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
172
173/* --------------------------------------------------------------------------
174                              FS Interface (/proc)
175   -------------------------------------------------------------------------- */
176
177static struct proc_dir_entry *acpi_button_dir;
178static struct proc_dir_entry *acpi_lid_dir;
179
180static int acpi_lid_evaluate_state(struct acpi_device *device)
181{
182	unsigned long long lid_state;
183	acpi_status status;
184
185	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
186	if (ACPI_FAILURE(status))
187		return -ENODEV;
188
189	return lid_state ? 1 : 0;
190}
191
192static int acpi_lid_notify_state(struct acpi_device *device, int state)
193{
194	struct acpi_button *button = acpi_driver_data(device);
195	ktime_t next_report;
196	bool do_update;
197
198	/*
199	 * In lid_init_state=ignore mode, if user opens/closes lid
200	 * frequently with "open" missing, and "last_time" is also updated
201	 * frequently, "close" cannot be delivered to the userspace.
202	 * So "last_time" is only updated after a timeout or an actual
203	 * switch.
204	 */
205	if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
206	    button->last_state != !!state)
207		do_update = true;
208	else
209		do_update = false;
210
211	next_report = ktime_add(button->last_time,
212				ms_to_ktime(lid_report_interval));
213	if (button->last_state == !!state &&
214	    ktime_after(ktime_get(), next_report)) {
215		/* Complain the buggy firmware */
216		pr_warn_once("The lid device is not compliant to SW_LID.\n");
217
218		/*
219		 * Send the unreliable complement switch event:
220		 *
221		 * On most platforms, the lid device is reliable. However
222		 * there are exceptions:
223		 * 1. Platforms returning initial lid state as "close" by
224		 *    default after booting/resuming:
225		 *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
226		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
227		 * 2. Platforms never reporting "open" events:
228		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
229		 * On these buggy platforms, the usage model of the ACPI
230		 * lid device actually is:
231		 * 1. The initial returning value of _LID may not be
232		 *    reliable.
233		 * 2. The open event may not be reliable.
234		 * 3. The close event is reliable.
235		 *
236		 * But SW_LID is typed as input switch event, the input
237		 * layer checks if the event is redundant. Hence if the
238		 * state is not switched, the userspace cannot see this
239		 * platform triggered reliable event. By inserting a
240		 * complement switch event, it then is guaranteed that the
241		 * platform triggered reliable one can always be seen by
242		 * the userspace.
243		 */
244		if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
245			do_update = true;
246			/*
247			 * Do generate complement switch event for "close"
248			 * as "close" is reliable and wrong "open" won't
249			 * trigger unexpected behaviors.
250			 * Do not generate complement switch event for
251			 * "open" as "open" is not reliable and wrong
252			 * "close" will trigger unexpected behaviors.
253			 */
254			if (!state) {
255				input_report_switch(button->input,
256						    SW_LID, state);
257				input_sync(button->input);
258			}
259		}
260	}
261	/* Send the platform triggered reliable event */
262	if (do_update) {
263		acpi_handle_debug(device->handle, "ACPI LID %s\n",
264				  state ? "open" : "closed");
265		input_report_switch(button->input, SW_LID, !state);
266		input_sync(button->input);
267		button->last_state = !!state;
268		button->last_time = ktime_get();
269	}
270
271	return 0;
272}
273
274static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
275						     void *offset)
276{
277	struct acpi_device *device = seq->private;
278	int state;
279
280	state = acpi_lid_evaluate_state(device);
281	seq_printf(seq, "state:      %s\n",
282		   state < 0 ? "unsupported" : (state ? "open" : "closed"));
283	return 0;
284}
285
286static int acpi_button_add_fs(struct acpi_device *device)
287{
288	struct acpi_button *button = acpi_driver_data(device);
289	struct proc_dir_entry *entry = NULL;
290	int ret = 0;
291
292	/* procfs I/F for ACPI lid device only */
293	if (button->type != ACPI_BUTTON_TYPE_LID)
294		return 0;
295
296	if (acpi_button_dir || acpi_lid_dir) {
297		printk(KERN_ERR PREFIX "More than one Lid device found!\n");
298		return -EEXIST;
299	}
300
301	/* create /proc/acpi/button */
302	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
303	if (!acpi_button_dir)
304		return -ENODEV;
305
306	/* create /proc/acpi/button/lid */
307	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
308	if (!acpi_lid_dir) {
309		ret = -ENODEV;
310		goto remove_button_dir;
311	}
312
313	/* create /proc/acpi/button/lid/LID/ */
314	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
315	if (!acpi_device_dir(device)) {
316		ret = -ENODEV;
317		goto remove_lid_dir;
318	}
319
320	/* create /proc/acpi/button/lid/LID/state */
321	entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
322			acpi_device_dir(device), acpi_button_state_seq_show,
323			device);
324	if (!entry) {
325		ret = -ENODEV;
326		goto remove_dev_dir;
327	}
328
329done:
330	return ret;
331
332remove_dev_dir:
333	remove_proc_entry(acpi_device_bid(device),
334			  acpi_lid_dir);
335	acpi_device_dir(device) = NULL;
336remove_lid_dir:
337	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
338	acpi_lid_dir = NULL;
339remove_button_dir:
340	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
341	acpi_button_dir = NULL;
342	goto done;
343}
344
345static int acpi_button_remove_fs(struct acpi_device *device)
346{
347	struct acpi_button *button = acpi_driver_data(device);
348
349	if (button->type != ACPI_BUTTON_TYPE_LID)
350		return 0;
351
352	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
353			  acpi_device_dir(device));
354	remove_proc_entry(acpi_device_bid(device),
355			  acpi_lid_dir);
356	acpi_device_dir(device) = NULL;
357	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
358	acpi_lid_dir = NULL;
359	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
360	acpi_button_dir = NULL;
361
362	return 0;
363}
364
365/* --------------------------------------------------------------------------
366                                Driver Interface
367   -------------------------------------------------------------------------- */
368int acpi_lid_open(void)
369{
370	if (!lid_device)
371		return -ENODEV;
372
373	return acpi_lid_evaluate_state(lid_device);
374}
375EXPORT_SYMBOL(acpi_lid_open);
376
377static int acpi_lid_update_state(struct acpi_device *device,
378				 bool signal_wakeup)
379{
380	int state;
381
382	state = acpi_lid_evaluate_state(device);
383	if (state < 0)
384		return state;
385
386	if (state && signal_wakeup)
387		acpi_pm_wakeup_event(&device->dev);
388
389	return acpi_lid_notify_state(device, state);
390}
391
392static void acpi_lid_initialize_state(struct acpi_device *device)
393{
394	struct acpi_button *button = acpi_driver_data(device);
395
396	switch (lid_init_state) {
397	case ACPI_BUTTON_LID_INIT_OPEN:
398		(void)acpi_lid_notify_state(device, 1);
399		break;
400	case ACPI_BUTTON_LID_INIT_METHOD:
401		(void)acpi_lid_update_state(device, false);
402		break;
403	case ACPI_BUTTON_LID_INIT_IGNORE:
404	default:
405		break;
406	}
407
408	button->lid_state_initialized = true;
409}
410
411static void acpi_button_notify(struct acpi_device *device, u32 event)
412{
413	struct acpi_button *button = acpi_driver_data(device);
414	struct input_dev *input;
415
416	switch (event) {
417	case ACPI_FIXED_HARDWARE_EVENT:
418		event = ACPI_BUTTON_NOTIFY_STATUS;
419		fallthrough;
420	case ACPI_BUTTON_NOTIFY_STATUS:
421		input = button->input;
422		if (button->type == ACPI_BUTTON_TYPE_LID) {
423			if (button->lid_state_initialized)
424				acpi_lid_update_state(device, true);
425		} else {
426			int keycode;
427
428			acpi_pm_wakeup_event(&device->dev);
429			if (button->suspended)
430				break;
431
432			keycode = test_bit(KEY_SLEEP, input->keybit) ?
433						KEY_SLEEP : KEY_POWER;
434			input_report_key(input, keycode, 1);
435			input_sync(input);
436			input_report_key(input, keycode, 0);
437			input_sync(input);
438
439			acpi_bus_generate_netlink_event(
440					device->pnp.device_class,
441					dev_name(&device->dev),
442					event, ++button->pushed);
443		}
444		break;
445	default:
446		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
447				  "Unsupported event [0x%x]\n", event));
448		break;
449	}
450}
451
452#ifdef CONFIG_PM_SLEEP
453static int acpi_button_suspend(struct device *dev)
454{
455	struct acpi_device *device = to_acpi_device(dev);
456	struct acpi_button *button = acpi_driver_data(device);
457
458	button->suspended = true;
459	return 0;
460}
461
462static int acpi_button_resume(struct device *dev)
463{
464	struct acpi_device *device = to_acpi_device(dev);
465	struct acpi_button *button = acpi_driver_data(device);
466
467	button->suspended = false;
468	if (button->type == ACPI_BUTTON_TYPE_LID) {
469		button->last_state = !!acpi_lid_evaluate_state(device);
470		button->last_time = ktime_get();
471		acpi_lid_initialize_state(device);
472	}
473	return 0;
474}
475#endif
476
477static int acpi_lid_input_open(struct input_dev *input)
478{
479	struct acpi_device *device = input_get_drvdata(input);
480	struct acpi_button *button = acpi_driver_data(device);
481
482	button->last_state = !!acpi_lid_evaluate_state(device);
483	button->last_time = ktime_get();
484	acpi_lid_initialize_state(device);
485
486	return 0;
487}
488
489static int acpi_button_add(struct acpi_device *device)
490{
491	struct acpi_button *button;
492	struct input_dev *input;
493	const char *hid = acpi_device_hid(device);
494	char *name, *class;
495	int error;
496
497	if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
498	     lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
499		return -ENODEV;
500
501	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
502	if (!button)
503		return -ENOMEM;
504
505	device->driver_data = button;
506
507	button->input = input = input_allocate_device();
508	if (!input) {
509		error = -ENOMEM;
510		goto err_free_button;
511	}
512
513	name = acpi_device_name(device);
514	class = acpi_device_class(device);
515
516	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
517	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
518		button->type = ACPI_BUTTON_TYPE_POWER;
519		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
520		sprintf(class, "%s/%s",
521			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
522	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
523		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
524		button->type = ACPI_BUTTON_TYPE_SLEEP;
525		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
526		sprintf(class, "%s/%s",
527			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
528	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
529		button->type = ACPI_BUTTON_TYPE_LID;
530		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
531		sprintf(class, "%s/%s",
532			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
533		input->open = acpi_lid_input_open;
534	} else {
535		printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid);
536		error = -ENODEV;
537		goto err_free_input;
538	}
539
540	error = acpi_button_add_fs(device);
541	if (error)
542		goto err_free_input;
543
544	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
545
546	input->name = name;
547	input->phys = button->phys;
548	input->id.bustype = BUS_HOST;
549	input->id.product = button->type;
550	input->dev.parent = &device->dev;
551
552	switch (button->type) {
553	case ACPI_BUTTON_TYPE_POWER:
554		input_set_capability(input, EV_KEY, KEY_POWER);
555		break;
556
557	case ACPI_BUTTON_TYPE_SLEEP:
558		input_set_capability(input, EV_KEY, KEY_SLEEP);
559		break;
560
561	case ACPI_BUTTON_TYPE_LID:
562		input_set_capability(input, EV_SW, SW_LID);
563		break;
564	}
565
566	input_set_drvdata(input, device);
567	error = input_register_device(input);
568	if (error)
569		goto err_remove_fs;
570	if (button->type == ACPI_BUTTON_TYPE_LID) {
571		/*
572		 * This assumes there's only one lid device, or if there are
573		 * more we only care about the last one...
574		 */
575		lid_device = device;
576	}
577
578	device_init_wakeup(&device->dev, true);
579	printk(KERN_INFO PREFIX "%s [%s]\n", name, acpi_device_bid(device));
580	return 0;
581
582 err_remove_fs:
583	acpi_button_remove_fs(device);
584 err_free_input:
585	input_free_device(input);
586 err_free_button:
587	kfree(button);
588	return error;
589}
590
591static int acpi_button_remove(struct acpi_device *device)
592{
593	struct acpi_button *button = acpi_driver_data(device);
594
595	acpi_button_remove_fs(device);
596	input_unregister_device(button->input);
597	kfree(button);
598	return 0;
599}
600
601static int param_set_lid_init_state(const char *val,
602				    const struct kernel_param *kp)
603{
604	int i;
605
606	i = sysfs_match_string(lid_init_state_str, val);
607	if (i < 0)
608		return i;
609
610	lid_init_state = i;
611	pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
612	return 0;
613}
614
615static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
616{
617	int i, c = 0;
618
619	for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
620		if (i == lid_init_state)
621			c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
622		else
623			c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
624
625	buf[c - 1] = '\n'; /* Replace the final space with a newline */
626
627	return c;
628}
629
630module_param_call(lid_init_state,
631		  param_set_lid_init_state, param_get_lid_init_state,
632		  NULL, 0644);
633MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
634
635static int acpi_button_register_driver(struct acpi_driver *driver)
636{
637	const struct dmi_system_id *dmi_id;
638
639	if (lid_init_state == -1) {
640		dmi_id = dmi_first_match(dmi_lid_quirks);
641		if (dmi_id)
642			lid_init_state = (long)dmi_id->driver_data;
643		else
644			lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
645	}
646
647	/*
648	 * Modules such as nouveau.ko and i915.ko have a link time dependency
649	 * on acpi_lid_open(), and would therefore not be loadable on ACPI
650	 * capable kernels booted in non-ACPI mode if the return value of
651	 * acpi_bus_register_driver() is returned from here with ACPI disabled
652	 * when this driver is built as a module.
653	 */
654	if (acpi_disabled)
655		return 0;
656
657	return acpi_bus_register_driver(driver);
658}
659
660static void acpi_button_unregister_driver(struct acpi_driver *driver)
661{
662	if (!acpi_disabled)
663		acpi_bus_unregister_driver(driver);
664}
665
666module_driver(acpi_button_driver, acpi_button_register_driver,
667	       acpi_button_unregister_driver);
668