xref: /openbmc/linux/drivers/acpi/button.c (revision 5d0e4d78)
1 /*
2  *  button.c - ACPI Button Driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *
7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or (at
12  *  your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful, but
15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  *  General Public License for more details.
18  *
19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
20  */
21 
22 #define pr_fmt(fmt) "ACPI: button: " fmt
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/input.h>
31 #include <linux/slab.h>
32 #include <linux/acpi.h>
33 #include <acpi/button.h>
34 
35 #define PREFIX "ACPI: "
36 
37 #define ACPI_BUTTON_CLASS		"button"
38 #define ACPI_BUTTON_FILE_INFO		"info"
39 #define ACPI_BUTTON_FILE_STATE		"state"
40 #define ACPI_BUTTON_TYPE_UNKNOWN	0x00
41 #define ACPI_BUTTON_NOTIFY_STATUS	0x80
42 
43 #define ACPI_BUTTON_SUBCLASS_POWER	"power"
44 #define ACPI_BUTTON_HID_POWER		"PNP0C0C"
45 #define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"
46 #define ACPI_BUTTON_TYPE_POWER		0x01
47 
48 #define ACPI_BUTTON_SUBCLASS_SLEEP	"sleep"
49 #define ACPI_BUTTON_HID_SLEEP		"PNP0C0E"
50 #define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"
51 #define ACPI_BUTTON_TYPE_SLEEP		0x03
52 
53 #define ACPI_BUTTON_SUBCLASS_LID	"lid"
54 #define ACPI_BUTTON_HID_LID		"PNP0C0D"
55 #define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
56 #define ACPI_BUTTON_TYPE_LID		0x05
57 
58 #define ACPI_BUTTON_LID_INIT_IGNORE	0x00
59 #define ACPI_BUTTON_LID_INIT_OPEN	0x01
60 #define ACPI_BUTTON_LID_INIT_METHOD	0x02
61 
62 #define _COMPONENT		ACPI_BUTTON_COMPONENT
63 ACPI_MODULE_NAME("button");
64 
65 MODULE_AUTHOR("Paul Diefenbaugh");
66 MODULE_DESCRIPTION("ACPI Button Driver");
67 MODULE_LICENSE("GPL");
68 
69 static const struct acpi_device_id button_device_ids[] = {
70 	{ACPI_BUTTON_HID_LID,    0},
71 	{ACPI_BUTTON_HID_SLEEP,  0},
72 	{ACPI_BUTTON_HID_SLEEPF, 0},
73 	{ACPI_BUTTON_HID_POWER,  0},
74 	{ACPI_BUTTON_HID_POWERF, 0},
75 	{"", 0},
76 };
77 MODULE_DEVICE_TABLE(acpi, button_device_ids);
78 
79 static int acpi_button_add(struct acpi_device *device);
80 static int acpi_button_remove(struct acpi_device *device);
81 static void acpi_button_notify(struct acpi_device *device, u32 event);
82 
83 #ifdef CONFIG_PM_SLEEP
84 static int acpi_button_suspend(struct device *dev);
85 static int acpi_button_resume(struct device *dev);
86 #else
87 #define acpi_button_suspend NULL
88 #define acpi_button_resume NULL
89 #endif
90 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
91 
92 static struct acpi_driver acpi_button_driver = {
93 	.name = "button",
94 	.class = ACPI_BUTTON_CLASS,
95 	.ids = button_device_ids,
96 	.ops = {
97 		.add = acpi_button_add,
98 		.remove = acpi_button_remove,
99 		.notify = acpi_button_notify,
100 	},
101 	.drv.pm = &acpi_button_pm,
102 };
103 
104 struct acpi_button {
105 	unsigned int type;
106 	struct input_dev *input;
107 	char phys[32];			/* for input device */
108 	unsigned long pushed;
109 	int last_state;
110 	ktime_t last_time;
111 	bool suspended;
112 };
113 
114 static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
115 static struct acpi_device *lid_device;
116 static u8 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
117 
118 static unsigned long lid_report_interval __read_mostly = 500;
119 module_param(lid_report_interval, ulong, 0644);
120 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
121 
122 /* --------------------------------------------------------------------------
123                               FS Interface (/proc)
124    -------------------------------------------------------------------------- */
125 
126 static struct proc_dir_entry *acpi_button_dir;
127 static struct proc_dir_entry *acpi_lid_dir;
128 
129 static int acpi_lid_evaluate_state(struct acpi_device *device)
130 {
131 	unsigned long long lid_state;
132 	acpi_status status;
133 
134 	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
135 	if (ACPI_FAILURE(status))
136 		return -ENODEV;
137 
138 	return lid_state ? 1 : 0;
139 }
140 
141 static int acpi_lid_notify_state(struct acpi_device *device, int state)
142 {
143 	struct acpi_button *button = acpi_driver_data(device);
144 	int ret;
145 	ktime_t next_report;
146 	bool do_update;
147 
148 	/*
149 	 * In lid_init_state=ignore mode, if user opens/closes lid
150 	 * frequently with "open" missing, and "last_time" is also updated
151 	 * frequently, "close" cannot be delivered to the userspace.
152 	 * So "last_time" is only updated after a timeout or an actual
153 	 * switch.
154 	 */
155 	if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
156 	    button->last_state != !!state)
157 		do_update = true;
158 	else
159 		do_update = false;
160 
161 	next_report = ktime_add(button->last_time,
162 				ms_to_ktime(lid_report_interval));
163 	if (button->last_state == !!state &&
164 	    ktime_after(ktime_get(), next_report)) {
165 		/* Complain the buggy firmware */
166 		pr_warn_once("The lid device is not compliant to SW_LID.\n");
167 
168 		/*
169 		 * Send the unreliable complement switch event:
170 		 *
171 		 * On most platforms, the lid device is reliable. However
172 		 * there are exceptions:
173 		 * 1. Platforms returning initial lid state as "close" by
174 		 *    default after booting/resuming:
175 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
176 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
177 		 * 2. Platforms never reporting "open" events:
178 		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
179 		 * On these buggy platforms, the usage model of the ACPI
180 		 * lid device actually is:
181 		 * 1. The initial returning value of _LID may not be
182 		 *    reliable.
183 		 * 2. The open event may not be reliable.
184 		 * 3. The close event is reliable.
185 		 *
186 		 * But SW_LID is typed as input switch event, the input
187 		 * layer checks if the event is redundant. Hence if the
188 		 * state is not switched, the userspace cannot see this
189 		 * platform triggered reliable event. By inserting a
190 		 * complement switch event, it then is guaranteed that the
191 		 * platform triggered reliable one can always be seen by
192 		 * the userspace.
193 		 */
194 		if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
195 			do_update = true;
196 			/*
197 			 * Do generate complement switch event for "close"
198 			 * as "close" is reliable and wrong "open" won't
199 			 * trigger unexpected behaviors.
200 			 * Do not generate complement switch event for
201 			 * "open" as "open" is not reliable and wrong
202 			 * "close" will trigger unexpected behaviors.
203 			 */
204 			if (!state) {
205 				input_report_switch(button->input,
206 						    SW_LID, state);
207 				input_sync(button->input);
208 			}
209 		}
210 	}
211 	/* Send the platform triggered reliable event */
212 	if (do_update) {
213 		input_report_switch(button->input, SW_LID, !state);
214 		input_sync(button->input);
215 		button->last_state = !!state;
216 		button->last_time = ktime_get();
217 	}
218 
219 	if (state)
220 		acpi_pm_wakeup_event(&device->dev);
221 
222 	ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
223 	if (ret == NOTIFY_DONE)
224 		ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
225 						   device);
226 	if (ret == NOTIFY_DONE || ret == NOTIFY_OK) {
227 		/*
228 		 * It is also regarded as success if the notifier_chain
229 		 * returns NOTIFY_OK or NOTIFY_DONE.
230 		 */
231 		ret = 0;
232 	}
233 	return ret;
234 }
235 
236 static int acpi_button_state_seq_show(struct seq_file *seq, void *offset)
237 {
238 	struct acpi_device *device = seq->private;
239 	int state;
240 
241 	state = acpi_lid_evaluate_state(device);
242 	seq_printf(seq, "state:      %s\n",
243 		   state < 0 ? "unsupported" : (state ? "open" : "closed"));
244 	return 0;
245 }
246 
247 static int acpi_button_state_open_fs(struct inode *inode, struct file *file)
248 {
249 	return single_open(file, acpi_button_state_seq_show, PDE_DATA(inode));
250 }
251 
252 static const struct file_operations acpi_button_state_fops = {
253 	.owner = THIS_MODULE,
254 	.open = acpi_button_state_open_fs,
255 	.read = seq_read,
256 	.llseek = seq_lseek,
257 	.release = single_release,
258 };
259 
260 static int acpi_button_add_fs(struct acpi_device *device)
261 {
262 	struct acpi_button *button = acpi_driver_data(device);
263 	struct proc_dir_entry *entry = NULL;
264 	int ret = 0;
265 
266 	/* procfs I/F for ACPI lid device only */
267 	if (button->type != ACPI_BUTTON_TYPE_LID)
268 		return 0;
269 
270 	if (acpi_button_dir || acpi_lid_dir) {
271 		printk(KERN_ERR PREFIX "More than one Lid device found!\n");
272 		return -EEXIST;
273 	}
274 
275 	/* create /proc/acpi/button */
276 	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
277 	if (!acpi_button_dir)
278 		return -ENODEV;
279 
280 	/* create /proc/acpi/button/lid */
281 	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
282 	if (!acpi_lid_dir) {
283 		ret = -ENODEV;
284 		goto remove_button_dir;
285 	}
286 
287 	/* create /proc/acpi/button/lid/LID/ */
288 	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
289 	if (!acpi_device_dir(device)) {
290 		ret = -ENODEV;
291 		goto remove_lid_dir;
292 	}
293 
294 	/* create /proc/acpi/button/lid/LID/state */
295 	entry = proc_create_data(ACPI_BUTTON_FILE_STATE,
296 				 S_IRUGO, acpi_device_dir(device),
297 				 &acpi_button_state_fops, device);
298 	if (!entry) {
299 		ret = -ENODEV;
300 		goto remove_dev_dir;
301 	}
302 
303 done:
304 	return ret;
305 
306 remove_dev_dir:
307 	remove_proc_entry(acpi_device_bid(device),
308 			  acpi_lid_dir);
309 	acpi_device_dir(device) = NULL;
310 remove_lid_dir:
311 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
312 	acpi_lid_dir = NULL;
313 remove_button_dir:
314 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
315 	acpi_button_dir = NULL;
316 	goto done;
317 }
318 
319 static int acpi_button_remove_fs(struct acpi_device *device)
320 {
321 	struct acpi_button *button = acpi_driver_data(device);
322 
323 	if (button->type != ACPI_BUTTON_TYPE_LID)
324 		return 0;
325 
326 	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
327 			  acpi_device_dir(device));
328 	remove_proc_entry(acpi_device_bid(device),
329 			  acpi_lid_dir);
330 	acpi_device_dir(device) = NULL;
331 	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
332 	acpi_lid_dir = NULL;
333 	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
334 	acpi_button_dir = NULL;
335 
336 	return 0;
337 }
338 
339 /* --------------------------------------------------------------------------
340                                 Driver Interface
341    -------------------------------------------------------------------------- */
342 int acpi_lid_notifier_register(struct notifier_block *nb)
343 {
344 	return blocking_notifier_chain_register(&acpi_lid_notifier, nb);
345 }
346 EXPORT_SYMBOL(acpi_lid_notifier_register);
347 
348 int acpi_lid_notifier_unregister(struct notifier_block *nb)
349 {
350 	return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);
351 }
352 EXPORT_SYMBOL(acpi_lid_notifier_unregister);
353 
354 int acpi_lid_open(void)
355 {
356 	if (!lid_device)
357 		return -ENODEV;
358 
359 	return acpi_lid_evaluate_state(lid_device);
360 }
361 EXPORT_SYMBOL(acpi_lid_open);
362 
363 static int acpi_lid_update_state(struct acpi_device *device)
364 {
365 	int state;
366 
367 	state = acpi_lid_evaluate_state(device);
368 	if (state < 0)
369 		return state;
370 
371 	return acpi_lid_notify_state(device, state);
372 }
373 
374 static void acpi_lid_initialize_state(struct acpi_device *device)
375 {
376 	switch (lid_init_state) {
377 	case ACPI_BUTTON_LID_INIT_OPEN:
378 		(void)acpi_lid_notify_state(device, 1);
379 		break;
380 	case ACPI_BUTTON_LID_INIT_METHOD:
381 		(void)acpi_lid_update_state(device);
382 		break;
383 	case ACPI_BUTTON_LID_INIT_IGNORE:
384 	default:
385 		break;
386 	}
387 }
388 
389 static void acpi_button_notify(struct acpi_device *device, u32 event)
390 {
391 	struct acpi_button *button = acpi_driver_data(device);
392 	struct input_dev *input;
393 
394 	switch (event) {
395 	case ACPI_FIXED_HARDWARE_EVENT:
396 		event = ACPI_BUTTON_NOTIFY_STATUS;
397 		/* fall through */
398 	case ACPI_BUTTON_NOTIFY_STATUS:
399 		input = button->input;
400 		if (button->type == ACPI_BUTTON_TYPE_LID) {
401 			acpi_lid_update_state(device);
402 		} else {
403 			int keycode;
404 
405 			acpi_pm_wakeup_event(&device->dev);
406 			if (button->suspended)
407 				break;
408 
409 			keycode = test_bit(KEY_SLEEP, input->keybit) ?
410 						KEY_SLEEP : KEY_POWER;
411 			input_report_key(input, keycode, 1);
412 			input_sync(input);
413 			input_report_key(input, keycode, 0);
414 			input_sync(input);
415 
416 			acpi_bus_generate_netlink_event(
417 					device->pnp.device_class,
418 					dev_name(&device->dev),
419 					event, ++button->pushed);
420 		}
421 		break;
422 	default:
423 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
424 				  "Unsupported event [0x%x]\n", event));
425 		break;
426 	}
427 }
428 
429 #ifdef CONFIG_PM_SLEEP
430 static int acpi_button_suspend(struct device *dev)
431 {
432 	struct acpi_device *device = to_acpi_device(dev);
433 	struct acpi_button *button = acpi_driver_data(device);
434 
435 	button->suspended = true;
436 	return 0;
437 }
438 
439 static int acpi_button_resume(struct device *dev)
440 {
441 	struct acpi_device *device = to_acpi_device(dev);
442 	struct acpi_button *button = acpi_driver_data(device);
443 
444 	button->suspended = false;
445 	if (button->type == ACPI_BUTTON_TYPE_LID)
446 		acpi_lid_initialize_state(device);
447 	return 0;
448 }
449 #endif
450 
451 static int acpi_button_add(struct acpi_device *device)
452 {
453 	struct acpi_button *button;
454 	struct input_dev *input;
455 	const char *hid = acpi_device_hid(device);
456 	char *name, *class;
457 	int error;
458 
459 	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
460 	if (!button)
461 		return -ENOMEM;
462 
463 	device->driver_data = button;
464 
465 	button->input = input = input_allocate_device();
466 	if (!input) {
467 		error = -ENOMEM;
468 		goto err_free_button;
469 	}
470 
471 	name = acpi_device_name(device);
472 	class = acpi_device_class(device);
473 
474 	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
475 	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
476 		button->type = ACPI_BUTTON_TYPE_POWER;
477 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
478 		sprintf(class, "%s/%s",
479 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
480 	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
481 		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
482 		button->type = ACPI_BUTTON_TYPE_SLEEP;
483 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
484 		sprintf(class, "%s/%s",
485 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
486 	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
487 		button->type = ACPI_BUTTON_TYPE_LID;
488 		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
489 		sprintf(class, "%s/%s",
490 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
491 		button->last_state = !!acpi_lid_evaluate_state(device);
492 		button->last_time = ktime_get();
493 	} else {
494 		printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid);
495 		error = -ENODEV;
496 		goto err_free_input;
497 	}
498 
499 	error = acpi_button_add_fs(device);
500 	if (error)
501 		goto err_free_input;
502 
503 	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
504 
505 	input->name = name;
506 	input->phys = button->phys;
507 	input->id.bustype = BUS_HOST;
508 	input->id.product = button->type;
509 	input->dev.parent = &device->dev;
510 
511 	switch (button->type) {
512 	case ACPI_BUTTON_TYPE_POWER:
513 		input_set_capability(input, EV_KEY, KEY_POWER);
514 		break;
515 
516 	case ACPI_BUTTON_TYPE_SLEEP:
517 		input_set_capability(input, EV_KEY, KEY_SLEEP);
518 		break;
519 
520 	case ACPI_BUTTON_TYPE_LID:
521 		input_set_capability(input, EV_SW, SW_LID);
522 		break;
523 	}
524 
525 	error = input_register_device(input);
526 	if (error)
527 		goto err_remove_fs;
528 	if (button->type == ACPI_BUTTON_TYPE_LID) {
529 		acpi_lid_initialize_state(device);
530 		/*
531 		 * This assumes there's only one lid device, or if there are
532 		 * more we only care about the last one...
533 		 */
534 		lid_device = device;
535 	}
536 
537 	device_init_wakeup(&device->dev, true);
538 	printk(KERN_INFO PREFIX "%s [%s]\n", name, acpi_device_bid(device));
539 	return 0;
540 
541  err_remove_fs:
542 	acpi_button_remove_fs(device);
543  err_free_input:
544 	input_free_device(input);
545  err_free_button:
546 	kfree(button);
547 	return error;
548 }
549 
550 static int acpi_button_remove(struct acpi_device *device)
551 {
552 	struct acpi_button *button = acpi_driver_data(device);
553 
554 	acpi_button_remove_fs(device);
555 	input_unregister_device(button->input);
556 	kfree(button);
557 	return 0;
558 }
559 
560 static int param_set_lid_init_state(const char *val, struct kernel_param *kp)
561 {
562 	int result = 0;
563 
564 	if (!strncmp(val, "open", sizeof("open") - 1)) {
565 		lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
566 		pr_info("Notify initial lid state as open\n");
567 	} else if (!strncmp(val, "method", sizeof("method") - 1)) {
568 		lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
569 		pr_info("Notify initial lid state with _LID return value\n");
570 	} else if (!strncmp(val, "ignore", sizeof("ignore") - 1)) {
571 		lid_init_state = ACPI_BUTTON_LID_INIT_IGNORE;
572 		pr_info("Do not notify initial lid state\n");
573 	} else
574 		result = -EINVAL;
575 	return result;
576 }
577 
578 static int param_get_lid_init_state(char *buffer, struct kernel_param *kp)
579 {
580 	switch (lid_init_state) {
581 	case ACPI_BUTTON_LID_INIT_OPEN:
582 		return sprintf(buffer, "open");
583 	case ACPI_BUTTON_LID_INIT_METHOD:
584 		return sprintf(buffer, "method");
585 	case ACPI_BUTTON_LID_INIT_IGNORE:
586 		return sprintf(buffer, "ignore");
587 	default:
588 		return sprintf(buffer, "invalid");
589 	}
590 	return 0;
591 }
592 
593 module_param_call(lid_init_state,
594 		  param_set_lid_init_state, param_get_lid_init_state,
595 		  NULL, 0644);
596 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
597 
598 module_acpi_driver(acpi_button_driver);
599