summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/dell-wmi.c
blob: 6669db2555fb0eea54689b24253239cca8b0da2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Dell WMI hotkeys
 *
 * Copyright (C) 2008 Red Hat <mjg@redhat.com>
 * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
 *
 * Portions based on wistron_btns.c:
 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/acpi.h>
#include <linux/string.h>
#include <linux/dmi.h>
#include <linux/wmi.h>
#include <acpi/video.h>
#include "dell-smbios.h"
#include "dell-wmi-descriptor.h"

MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
MODULE_LICENSE("GPL");

#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"

static bool wmi_requires_smbios_request;

struct dell_wmi_priv {
	struct input_dev *input_dev;
	u32 interface_version;
};

static int __init dmi_matched(const struct dmi_system_id *dmi)
{
	wmi_requires_smbios_request = 1;
	return 1;
}

static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
	{
		.callback = dmi_matched,
		.ident = "Dell Inspiron M5110",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
		},
	},
	{
		.callback = dmi_matched,
		.ident = "Dell Vostro V131",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
		},
	},
	{ }
};

/*
 * Keymap for WMI events of type 0x0000
 *
 * Certain keys are flagged as KE_IGNORE. All of these are either
 * notifications (rather than requests for change) or are also sent
 * via the keyboard controller so should not be sent again.
 */
static const struct key_entry dell_wmi_keymap_type_0000[] = {
	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },

	/* Key code is followed by brightness level */
	{ KE_KEY,    0xe005, { KEY_BRIGHTNESSDOWN } },
	{ KE_KEY,    0xe006, { KEY_BRIGHTNESSUP } },

	/* Battery health status button */
	{ KE_KEY,    0xe007, { KEY_BATTERY } },

	/* Radio devices state change, key code is followed by other values */
	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },

	{ KE_KEY,    0xe009, { KEY_EJECTCD } },

	/* Key code is followed by: next, active and attached devices */
	{ KE_KEY,    0xe00b, { KEY_SWITCHVIDEOMODE } },

	/* Key code is followed by keyboard illumination level */
	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },

	/* BIOS error detected */
	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },

	/* Battery was removed or inserted */
	{ KE_IGNORE, 0xe00e, { KEY_RESERVED } },

	/* Wifi Catcher */
	{ KE_KEY,    0xe011, { KEY_WLAN } },

	/* Ambient light sensor toggle */
	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },

	{ KE_IGNORE, 0xe020, { KEY_MUTE } },

	/* Unknown, defined in ACPI DSDT */
	/* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */

	/* Untested, Dell Instant Launch key on Inspiron 7520 */
	/* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */

	/* Dell Instant Launch key */
	{ KE_KEY,    0xe025, { KEY_PROG4 } },

	/* Audio panel key */
	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },

	/* LCD Display On/Off Control key */
	{ KE_KEY,    0xe027, { KEY_DISPLAYTOGGLE } },

	/* Untested, Multimedia key on Dell Vostro 3560 */
	/* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */

	/* Dell Instant Launch key */
	{ KE_KEY,    0xe029, { KEY_PROG4 } },

	/* Untested, Windows Mobility Center button on Inspiron 7520 */
	/* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */

	/* Unknown, defined in ACPI DSDT */
	/* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */

	/* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
	/* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */

	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },

	/* NIC Link is Up */
	{ KE_IGNORE, 0xe043, { KEY_RESERVED } },

	/* NIC Link is Down */
	{ KE_IGNORE, 0xe044, { KEY_RESERVED } },

	/*
	 * This entry is very suspicious!
	 * Originally Matthew Garrett created this dell-wmi driver specially for
	 * "button with a picture of a battery" which has event code 0xe045.
	 * Later Mario Limonciello from Dell told us that event code 0xe045 is
	 * reported by Num Lock and should be ignored because key is send also
	 * by keyboard controller.
	 * So for now we will ignore this event to prevent potential double
	 * Num Lock key press.
	 */
	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },

	/* Scroll lock and also going to tablet mode on portable devices */
	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },

	/* Untested, going from tablet mode on portable devices */
	/* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */

	/* Dell Support Center key */
	{ KE_IGNORE, 0xe06e, { KEY_RESERVED } },

	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
};

struct dell_bios_keymap_entry {
	u16 scancode;
	u16 keycode;
};

struct dell_bios_hotkey_table {
	struct dmi_header header;
	struct dell_bios_keymap_entry keymap[];

};

struct dell_dmi_results {
	int err;
	int keymap_size;
	struct key_entry *keymap;
};

/* Uninitialized entries here are KEY_RESERVED == 0. */
static const u16 bios_to_linux_keycode[256] = {
	[0]	= KEY_MEDIA,
	[1]	= KEY_NEXTSONG,
	[2]	= KEY_PLAYPAUSE,
	[3]	= KEY_PREVIOUSSONG,
	[4]	= KEY_STOPCD,
	[5]	= KEY_UNKNOWN,
	[6]	= KEY_UNKNOWN,
	[7]	= KEY_UNKNOWN,
	[8]	= KEY_WWW,
	[9]	= KEY_UNKNOWN,
	[10]	= KEY_VOLUMEDOWN,
	[11]	= KEY_MUTE,
	[12]	= KEY_VOLUMEUP,
	[13]	= KEY_UNKNOWN,
	[14]	= KEY_BATTERY,
	[15]	= KEY_EJECTCD,
	[16]	= KEY_UNKNOWN,
	[17]	= KEY_SLEEP,
	[18]	= KEY_PROG1,
	[19]	= KEY_BRIGHTNESSDOWN,
	[20]	= KEY_BRIGHTNESSUP,
	[21]	= KEY_BRIGHTNESS_AUTO,
	[22]	= KEY_KBDILLUMTOGGLE,
	[23]	= KEY_UNKNOWN,
	[24]	= KEY_SWITCHVIDEOMODE,
	[25]	= KEY_UNKNOWN,
	[26]	= KEY_UNKNOWN,
	[27]	= KEY_SWITCHVIDEOMODE,
	[28]	= KEY_UNKNOWN,
	[29]	= KEY_UNKNOWN,
	[30]	= KEY_PROG2,
	[31]	= KEY_UNKNOWN,
	[32]	= KEY_UNKNOWN,
	[33]	= KEY_UNKNOWN,
	[34]	= KEY_UNKNOWN,
	[35]	= KEY_UNKNOWN,
	[36]	= KEY_UNKNOWN,
	[37]	= KEY_UNKNOWN,
	[38]	= KEY_MICMUTE,
	[255]	= KEY_PROG3,
};

/*
 * Keymap for WMI events of type 0x0010
 *
 * These are applied if the 0xB2 DMI hotkey table is present and doesn't
 * override them.
 */
static const struct key_entry dell_wmi_keymap_type_0010[] = {
	/* Fn-lock switched to function keys */
	{ KE_IGNORE, 0x0, { KEY_RESERVED } },

	/* Fn-lock switched to multimedia keys */
	{ KE_IGNORE, 0x1, { KEY_RESERVED } },

	/* Keyboard backlight change notification */
	{ KE_IGNORE, 0x3f, { KEY_RESERVED } },

	/* Mic mute */
	{ KE_KEY, 0x150, { KEY_MICMUTE } },

	/* Fn-lock */
	{ KE_IGNORE, 0x151, { KEY_RESERVED } },

	/* Change keyboard illumination */
	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },

	/*
	 * Radio disable (notify only -- there is no model for which the
	 * WMI event is supposed to trigger an action).
	 */
	{ KE_IGNORE, 0x153, { KEY_RFKILL } },

	/* RGB keyboard backlight control */
	{ KE_IGNORE, 0x154, { KEY_RESERVED } },

	/*
	 * Stealth mode toggle. This will "disable all lights and sounds".
	 * The action is performed by the BIOS and EC; the WMI event is just
	 * a notification. On the XPS 13 9350, this is Fn+F7, and there's
	 * a BIOS setting to enable and disable the hotkey.
	 */
	{ KE_IGNORE, 0x155, { KEY_RESERVED } },

	/* Rugged magnetic dock attach/detach events */
	{ KE_IGNORE, 0x156, { KEY_RESERVED } },
	{ KE_IGNORE, 0x157, { KEY_RESERVED } },

	/* Rugged programmable (P1/P2/P3 keys) */
	{ KE_KEY,    0x850, { KEY_PROG1 } },
	{ KE_KEY,    0x851, { KEY_PROG2 } },
	{ KE_KEY,    0x852, { KEY_PROG3 } },

	/*
	 * Radio disable (notify only -- there is no model for which the
	 * WMI event is supposed to trigger an action).
	 */
	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },

	/* Fn-lock */
	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
};

/*
 * Keymap for WMI events of type 0x0011
 */
static const struct key_entry dell_wmi_keymap_type_0011[] = {
	/* Battery unplugged */
	{ KE_IGNORE, 0xfff0, { KEY_RESERVED } },

	/* Battery inserted */
	{ KE_IGNORE, 0xfff1, { KEY_RESERVED } },

	/* Keyboard backlight level changed */
	{ KE_IGNORE, KBD_LED_OFF_TOKEN,      { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_ON_TOKEN,       { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_AUTO_TOKEN,     { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_AUTO_25_TOKEN,  { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_AUTO_50_TOKEN,  { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_AUTO_75_TOKEN,  { KEY_RESERVED } },
	{ KE_IGNORE, KBD_LED_AUTO_100_TOKEN, { KEY_RESERVED } },
};

static void dell_wmi_process_key(struct wmi_device *wdev, int type, int code)
{
	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
	const struct key_entry *key;

	key = sparse_keymap_entry_from_scancode(priv->input_dev,
						(type << 16) | code);
	if (!key) {
		pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
			type, code);
		return;
	}

	pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);

	/* Don't report brightness notifications that will also come via ACPI */
	if ((key->keycode == KEY_BRIGHTNESSUP ||
	     key->keycode == KEY_BRIGHTNESSDOWN) &&
	    acpi_video_handles_brightness_key_presses())
		return;

	if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
		return;

	if (key->keycode == KEY_KBDILLUMTOGGLE)
		dell_laptop_call_notifier(
			DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);

	sparse_keymap_report_entry(priv->input_dev, key, 1, true);
}

static void dell_wmi_notify(struct wmi_device *wdev,
			    union acpi_object *obj)
{
	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
	u16 *buffer_entry, *buffer_end;
	acpi_size buffer_size;
	int len, i;

	if (obj->type != ACPI_TYPE_BUFFER) {
		pr_warn("bad response type %x\n", obj->type);
		return;
	}

	pr_debug("Received WMI event (%*ph)\n",
		obj->buffer.length, obj->buffer.pointer);

	buffer_entry = (u16 *)obj->buffer.pointer;
	buffer_size = obj->buffer.length/2;
	buffer_end = buffer_entry + buffer_size;

	/*
	 * BIOS/ACPI on devices with WMI interface version 0 does not clear
	 * buffer before filling it. So next time when BIOS/ACPI send WMI event
	 * which is smaller as previous then it contains garbage in buffer from
	 * previous event.
	 *
	 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
	 * sometimes send more events in buffer at one call.
	 *
	 * So to prevent reading garbage from buffer we will process only first
	 * one event on devices with WMI interface version 0.
	 */
	if (priv->interface_version == 0 && buffer_entry < buffer_end)
		if (buffer_end > buffer_entry + buffer_entry[0] + 1)
			buffer_end = buffer_entry + buffer_entry[0] + 1;

	while (buffer_entry < buffer_end) {

		len = buffer_entry[0];
		if (len == 0)
			break;

		len++;

		if (buffer_entry + len > buffer_end) {
			pr_warn("Invalid length of WMI event\n");
			break;
		}

		pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);

		switch (buffer_entry[1]) {
		case 0x0000: /* One key pressed or event occurred */
			if (len > 2)
				dell_wmi_process_key(wdev, 0x0000,
						     buffer_entry[2]);
			/* Other entries could contain additional information */
			break;
		case 0x0010: /* Sequence of keys pressed */
		case 0x0011: /* Sequence of events occurred */
			for (i = 2; i < len; ++i)
				dell_wmi_process_key(wdev, buffer_entry[1],
						     buffer_entry[i]);
			break;
		default: /* Unknown event */
			pr_info("Unknown WMI event type 0x%x\n",
				(int)buffer_entry[1]);
			break;
		}

		buffer_entry += len;

	}

}

static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
{
	int i;

	for (i = 0; i < len; i++)
		if (keymap[i].code == scancode)
			return true;

	return false;
}

static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
{
	struct dell_dmi_results *results = opaque;
	struct dell_bios_hotkey_table *table;
	int hotkey_num, i, pos = 0;
	struct key_entry *keymap;

	if (results->err || results->keymap)
		return;		/* We already found the hotkey table. */

	/* The Dell hotkey table is type 0xB2.  Scan until we find it. */
	if (dm->type != 0xb2)
		return;

	table = container_of(dm, struct dell_bios_hotkey_table, header);

	hotkey_num = (table->header.length -
		      sizeof(struct dell_bios_hotkey_table)) /
				sizeof(struct dell_bios_keymap_entry);
	if (hotkey_num < 1) {
		/*
		 * Historically, dell-wmi would ignore a DMI entry of
		 * fewer than 7 bytes.  Sizes between 4 and 8 bytes are
		 * nonsensical (both the header and all entries are 4
		 * bytes), so we approximate the old behavior by
		 * ignoring tables with fewer than one entry.
		 */
		return;
	}

	keymap = kcalloc(hotkey_num, sizeof(struct key_entry), GFP_KERNEL);
	if (!keymap) {
		results->err = -ENOMEM;
		return;
	}

	for (i = 0; i < hotkey_num; i++) {
		const struct dell_bios_keymap_entry *bios_entry =
					&table->keymap[i];

		/* Uninitialized entries are 0 aka KEY_RESERVED. */
		u16 keycode = (bios_entry->keycode <
			       ARRAY_SIZE(bios_to_linux_keycode)) ?
			bios_to_linux_keycode[bios_entry->keycode] :
			KEY_RESERVED;

		/*
		 * Log if we find an entry in the DMI table that we don't
		 * understand.  If this happens, we should figure out what
		 * the entry means and add it to bios_to_linux_keycode.
		 */
		if (keycode == KEY_RESERVED) {
			pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
				bios_entry->scancode, bios_entry->keycode);
			continue;
		}

		if (keycode == KEY_KBDILLUMTOGGLE)
			keymap[pos].type = KE_IGNORE;
		else
			keymap[pos].type = KE_KEY;
		keymap[pos].code = bios_entry->scancode;
		keymap[pos].keycode = keycode;

		pos++;
	}

	results->keymap = keymap;
	results->keymap_size = pos;
}

static int dell_wmi_input_setup(struct wmi_device *wdev)
{
	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
	struct dell_dmi_results dmi_results = {};
	struct key_entry *keymap;
	int err, i, pos = 0;

	priv->input_dev = input_allocate_device();
	if (!priv->input_dev)
		return -ENOMEM;

	priv->input_dev->name = "Dell WMI hotkeys";
	priv->input_dev->id.bustype = BUS_HOST;
	priv->input_dev->dev.parent = &wdev->dev;

	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
		/*
		 * Historically, dell-wmi ignored dmi_walk errors.  A failure
		 * is certainly surprising, but it probably just indicates
		 * a very old laptop.
		 */
		pr_warn("no DMI; using the old-style hotkey interface\n");
	}

	if (dmi_results.err) {
		err = dmi_results.err;
		goto err_free_dev;
	}

	keymap = kcalloc(dmi_results.keymap_size +
			 ARRAY_SIZE(dell_wmi_keymap_type_0000) +
			 ARRAY_SIZE(dell_wmi_keymap_type_0010) +
			 ARRAY_SIZE(dell_wmi_keymap_type_0011) +
			 1,
			 sizeof(struct key_entry), GFP_KERNEL);
	if (!keymap) {
		kfree(dmi_results.keymap);
		err = -ENOMEM;
		goto err_free_dev;
	}

	/* Append table with events of type 0x0010 which comes from DMI */
	for (i = 0; i < dmi_results.keymap_size; i++) {
		keymap[pos] = dmi_results.keymap[i];
		keymap[pos].code |= (0x0010 << 16);
		pos++;
	}

	kfree(dmi_results.keymap);

	/* Append table with extra events of type 0x0010 which are not in DMI */
	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
		const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];

		/*
		 * Check if we've already found this scancode.  This takes
		 * quadratic time, but it doesn't matter unless the list
		 * of extra keys gets very long.
		 */
		if (dmi_results.keymap_size &&
		    have_scancode(entry->code | (0x0010 << 16),
				  keymap, dmi_results.keymap_size)
		   )
			continue;

		keymap[pos] = *entry;
		keymap[pos].code |= (0x0010 << 16);
		pos++;
	}

	/* Append table with events of type 0x0011 */
	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
		keymap[pos] = dell_wmi_keymap_type_0011[i];
		keymap[pos].code |= (0x0011 << 16);
		pos++;
	}

	/*
	 * Now append also table with "legacy" events of type 0x0000. Some of
	 * them are reported also on laptops which have scancodes in DMI.
	 */
	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
		keymap[pos] = dell_wmi_keymap_type_0000[i];
		pos++;
	}

	keymap[pos].type = KE_END;

	err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
	/*
	 * Sparse keymap library makes a copy of keymap so we don't need the
	 * original one that was allocated.
	 */
	kfree(keymap);
	if (err)
		goto err_free_dev;

	err = input_register_device(priv->input_dev);
	if (err)
		goto err_free_dev;

	return 0;

 err_free_dev:
	input_free_device(priv->input_dev);
	return err;
}

static void dell_wmi_input_destroy(struct wmi_device *wdev)
{
	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);

	input_unregister_device(priv->input_dev);
}

/*
 * According to Dell SMBIOS documentation:
 *
 * 17  3  Application Program Registration
 *
 *     cbArg1 Application ID 1 = 0x00010000
 *     cbArg2 Application ID 2
 *            QUICKSET/DCP = 0x51534554 "QSET"
 *            ALS Driver   = 0x416c7353 "AlsS"
 *            Latitude ON  = 0x4c6f6e52 "LonR"
 *     cbArg3 Application version or revision number
 *     cbArg4 0 = Unregister application
 *            1 = Register application
 *     cbRes1 Standard return codes (0, -1, -2)
 */

static int dell_wmi_events_set_enabled(bool enable)
{
	struct calling_interface_buffer *buffer;
	int ret;

	buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;
	buffer->cmd_class = CLASS_INFO;
	buffer->cmd_select = SELECT_APP_REGISTRATION;
	buffer->input[0] = 0x10000;
	buffer->input[1] = 0x51534554;
	buffer->input[3] = enable;
	ret = dell_smbios_call(buffer);
	if (ret == 0)
		ret = buffer->output[0];
	kfree(buffer);

	return dell_smbios_error(ret);
}

static int dell_wmi_probe(struct wmi_device *wdev, const void *context)
{
	struct dell_wmi_priv *priv;
	int ret;

	ret = dell_wmi_get_descriptor_valid();
	if (ret)
		return ret;

	priv = devm_kzalloc(
		&wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	dev_set_drvdata(&wdev->dev, priv);

	if (!dell_wmi_get_interface_version(&priv->interface_version))
		return -EPROBE_DEFER;

	return dell_wmi_input_setup(wdev);
}

static int dell_wmi_remove(struct wmi_device *wdev)
{
	dell_wmi_input_destroy(wdev);
	return 0;
}
static const struct wmi_device_id dell_wmi_id_table[] = {
	{ .guid_string = DELL_EVENT_GUID },
	{ },
};

static struct wmi_driver dell_wmi_driver = {
	.driver = {
		.name = "dell-wmi",
	},
	.id_table = dell_wmi_id_table,
	.probe = dell_wmi_probe,
	.remove = dell_wmi_remove,
	.notify = dell_wmi_notify,
};

static int __init dell_wmi_init(void)
{
	int err;

	dmi_check_system(dell_wmi_smbios_list);

	if (wmi_requires_smbios_request) {
		err = dell_wmi_events_set_enabled(true);
		if (err) {
			pr_err("Failed to enable WMI events\n");
			return err;
		}
	}

	return wmi_driver_register(&dell_wmi_driver);
}
late_initcall(dell_wmi_init);

static void __exit dell_wmi_exit(void)
{
	if (wmi_requires_smbios_request)
		dell_wmi_events_set_enabled(false);

	wmi_driver_unregister(&dell_wmi_driver);
}
module_exit(dell_wmi_exit);

MODULE_DEVICE_TABLE(wmi, dell_wmi_id_table);