xref: /linux/drivers/platform/x86/dell/dell-wmi-base.c (revision 74d4432421a3e2669fbccc08c0f4fc2980bf0e39)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Dell WMI hotkeys
4  *
5  * Copyright (C) 2008 Red Hat <mjg@redhat.com>
6  * Copyright (C) 2014-2015 Pali Rohár <pali@kernel.org>
7  *
8  * Portions based on wistron_btns.c:
9  * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
10  * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
11  * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
12  */
13 
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21 #include <linux/input.h>
22 #include <linux/input/sparse-keymap.h>
23 #include <linux/acpi.h>
24 #include <linux/string.h>
25 #include <linux/dmi.h>
26 #include <linux/wmi.h>
27 #include <acpi/video.h>
28 #include "dell-smbios.h"
29 #include "dell-wmi-descriptor.h"
30 #include "dell-wmi-privacy.h"
31 
32 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
33 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
34 MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
35 MODULE_LICENSE("GPL");
36 
37 #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
38 
39 static bool wmi_requires_smbios_request;
40 
41 struct dell_wmi_priv {
42 	struct input_dev *input_dev;
43 	struct input_dev *tabletswitch_dev;
44 	u32 interface_version;
45 };
46 
47 static int __init dmi_matched(const struct dmi_system_id *dmi)
48 {
49 	wmi_requires_smbios_request = 1;
50 	return 1;
51 }
52 
53 static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
54 	{
55 		.callback = dmi_matched,
56 		.ident = "Dell Inspiron M5110",
57 		.matches = {
58 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
59 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
60 		},
61 	},
62 	{
63 		.callback = dmi_matched,
64 		.ident = "Dell Vostro V131",
65 		.matches = {
66 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
67 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
68 		},
69 	},
70 	{ }
71 };
72 
73 /*
74  * Keymap for WMI events of type 0x0000
75  *
76  * Certain keys are flagged as KE_IGNORE. All of these are either
77  * notifications (rather than requests for change) or are also sent
78  * via the keyboard controller so should not be sent again.
79  */
80 static const struct key_entry dell_wmi_keymap_type_0000[] = {
81 	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
82 
83 	/* Meta key lock */
84 	{ KE_IGNORE, 0xe000, { KEY_RIGHTMETA } },
85 
86 	/* Meta key unlock */
87 	{ KE_IGNORE, 0xe001, { KEY_RIGHTMETA } },
88 
89 	/* Key code is followed by brightness level */
90 	{ KE_KEY,    0xe005, { KEY_BRIGHTNESSDOWN } },
91 	{ KE_KEY,    0xe006, { KEY_BRIGHTNESSUP } },
92 
93 	/* Battery health status button */
94 	{ KE_KEY,    0xe007, { KEY_BATTERY } },
95 
96 	/* Radio devices state change, key code is followed by other values */
97 	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
98 
99 	{ KE_KEY,    0xe009, { KEY_EJECTCD } },
100 
101 	/* Key code is followed by: next, active and attached devices */
102 	{ KE_KEY,    0xe00b, { KEY_SWITCHVIDEOMODE } },
103 
104 	/* Key code is followed by keyboard illumination level */
105 	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
106 
107 	/* BIOS error detected */
108 	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
109 
110 	/* Battery was removed or inserted */
111 	{ KE_IGNORE, 0xe00e, { KEY_RESERVED } },
112 
113 	/* Wifi Catcher */
114 	{ KE_KEY,    0xe011, { KEY_WLAN } },
115 
116 	/* Ambient light sensor toggle */
117 	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
118 
119 	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
120 
121 	/* Unknown, defined in ACPI DSDT */
122 	/* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */
123 
124 	/* Untested, Dell Instant Launch key on Inspiron 7520 */
125 	/* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */
126 
127 	/* Dell Instant Launch key */
128 	{ KE_KEY,    0xe025, { KEY_PROG4 } },
129 
130 	/* Audio panel key */
131 	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },
132 
133 	/* LCD Display On/Off Control key */
134 	{ KE_KEY,    0xe027, { KEY_DISPLAYTOGGLE } },
135 
136 	/* Untested, Multimedia key on Dell Vostro 3560 */
137 	/* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */
138 
139 	/* Dell Instant Launch key */
140 	{ KE_KEY,    0xe029, { KEY_PROG4 } },
141 
142 	/* Untested, Windows Mobility Center button on Inspiron 7520 */
143 	/* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
144 
145 	/* Unknown, defined in ACPI DSDT */
146 	/* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */
147 
148 	/* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
149 	/* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */
150 
151 	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
152 	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
153 	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
154 	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
155 	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
156 
157 	/* NIC Link is Up */
158 	{ KE_IGNORE, 0xe043, { KEY_RESERVED } },
159 
160 	/* NIC Link is Down */
161 	{ KE_IGNORE, 0xe044, { KEY_RESERVED } },
162 
163 	/*
164 	 * This entry is very suspicious!
165 	 * Originally Matthew Garrett created this dell-wmi driver specially for
166 	 * "button with a picture of a battery" which has event code 0xe045.
167 	 * Later Mario Limonciello from Dell told us that event code 0xe045 is
168 	 * reported by Num Lock and should be ignored because key is send also
169 	 * by keyboard controller.
170 	 * So for now we will ignore this event to prevent potential double
171 	 * Num Lock key press.
172 	 */
173 	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
174 
175 	/* Scroll lock and also going to tablet mode on portable devices */
176 	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
177 
178 	/* Untested, going from tablet mode on portable devices */
179 	/* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */
180 
181 	/* Dell Support Center key */
182 	{ KE_IGNORE, 0xe06e, { KEY_RESERVED } },
183 
184 	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
185 	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
186 	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
187 };
188 
189 struct dell_bios_keymap_entry {
190 	u16 scancode;
191 	u16 keycode;
192 };
193 
194 struct dell_bios_hotkey_table {
195 	struct dmi_header header;
196 	struct dell_bios_keymap_entry keymap[];
197 
198 };
199 
200 struct dell_dmi_results {
201 	int err;
202 	int keymap_size;
203 	struct key_entry *keymap;
204 };
205 
206 /* Uninitialized entries here are KEY_RESERVED == 0. */
207 static const u16 bios_to_linux_keycode[256] = {
208 	[0]	= KEY_MEDIA,
209 	[1]	= KEY_NEXTSONG,
210 	[2]	= KEY_PLAYPAUSE,
211 	[3]	= KEY_PREVIOUSSONG,
212 	[4]	= KEY_STOPCD,
213 	[5]	= KEY_UNKNOWN,
214 	[6]	= KEY_UNKNOWN,
215 	[7]	= KEY_UNKNOWN,
216 	[8]	= KEY_WWW,
217 	[9]	= KEY_UNKNOWN,
218 	[10]	= KEY_VOLUMEDOWN,
219 	[11]	= KEY_MUTE,
220 	[12]	= KEY_VOLUMEUP,
221 	[13]	= KEY_UNKNOWN,
222 	[14]	= KEY_BATTERY,
223 	[15]	= KEY_EJECTCD,
224 	[16]	= KEY_UNKNOWN,
225 	[17]	= KEY_SLEEP,
226 	[18]	= KEY_PROG1,
227 	[19]	= KEY_BRIGHTNESSDOWN,
228 	[20]	= KEY_BRIGHTNESSUP,
229 	[21]	= KEY_BRIGHTNESS_AUTO,
230 	[22]	= KEY_KBDILLUMTOGGLE,
231 	[23]	= KEY_UNKNOWN,
232 	[24]	= KEY_SWITCHVIDEOMODE,
233 	[25]	= KEY_UNKNOWN,
234 	[26]	= KEY_UNKNOWN,
235 	[27]	= KEY_SWITCHVIDEOMODE,
236 	[28]	= KEY_UNKNOWN,
237 	[29]	= KEY_UNKNOWN,
238 	[30]	= KEY_PROG2,
239 	[31]	= KEY_UNKNOWN,
240 	[32]	= KEY_UNKNOWN,
241 	[33]	= KEY_UNKNOWN,
242 	[34]	= KEY_UNKNOWN,
243 	[35]	= KEY_UNKNOWN,
244 	[36]	= KEY_UNKNOWN,
245 	[37]	= KEY_UNKNOWN,
246 	[38]	= KEY_MICMUTE,
247 	[255]	= KEY_PROG3,
248 };
249 
250 /*
251  * Keymap for WMI events of type 0x0010
252  *
253  * These are applied if the 0xB2 DMI hotkey table is present and doesn't
254  * override them.
255  */
256 static const struct key_entry dell_wmi_keymap_type_0010[] = {
257 	/* Fn-lock switched to function keys */
258 	{ KE_IGNORE, 0x0, { KEY_RESERVED } },
259 
260 	/* Fn-lock switched to multimedia keys */
261 	{ KE_IGNORE, 0x1, { KEY_RESERVED } },
262 
263 	/* Keyboard backlight change notification */
264 	{ KE_IGNORE, 0x3f, { KEY_RESERVED } },
265 
266 	/* Backlight brightness level */
267 	{ KE_KEY,    0x57, { KEY_BRIGHTNESSDOWN } },
268 	{ KE_KEY,    0x58, { KEY_BRIGHTNESSUP } },
269 
270 	/*Speaker Mute*/
271 	{ KE_KEY, 0x109, { KEY_MUTE} },
272 
273 	/* S2Idle screen off */
274 	{ KE_IGNORE, 0x120, { KEY_RESERVED }},
275 
276 	/* Leaving S4 or S2Idle suspend */
277 	{ KE_IGNORE, 0x130, { KEY_RESERVED }},
278 
279 	/* Entering S2Idle suspend */
280 	{ KE_IGNORE, 0x140, { KEY_RESERVED }},
281 
282 	/* Mic mute */
283 	{ KE_KEY, 0x150, { KEY_MICMUTE } },
284 
285 	/* Fn-lock */
286 	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
287 
288 	/* Change keyboard illumination */
289 	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
290 
291 	/*
292 	 * Radio disable (notify only -- there is no model for which the
293 	 * WMI event is supposed to trigger an action).
294 	 */
295 	{ KE_IGNORE, 0x153, { KEY_RFKILL } },
296 
297 	/* RGB keyboard backlight control */
298 	{ KE_IGNORE, 0x154, { KEY_RESERVED } },
299 
300 	/*
301 	 * Stealth mode toggle. This will "disable all lights and sounds".
302 	 * The action is performed by the BIOS and EC; the WMI event is just
303 	 * a notification. On the XPS 13 9350, this is Fn+F7, and there's
304 	 * a BIOS setting to enable and disable the hotkey.
305 	 */
306 	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
307 
308 	/* Rugged magnetic dock attach/detach events */
309 	{ KE_IGNORE, 0x156, { KEY_RESERVED } },
310 	{ KE_IGNORE, 0x157, { KEY_RESERVED } },
311 
312 	/* Rugged programmable (P1/P2/P3 keys) */
313 	{ KE_KEY,    0x850, { KEY_PROG1 } },
314 	{ KE_KEY,    0x851, { KEY_PROG2 } },
315 	{ KE_KEY,    0x852, { KEY_PROG3 } },
316 
317 	/*
318 	 * Radio disable (notify only -- there is no model for which the
319 	 * WMI event is supposed to trigger an action).
320 	 */
321 	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
322 
323 	/* Fn-lock */
324 	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
325 };
326 
327 /*
328  * Keymap for WMI events of type 0x0011
329  */
330 static const struct key_entry dell_wmi_keymap_type_0011[] = {
331 	/* Reflex keyboard switch on 2n1 devices */
332 	{ KE_IGNORE, 0xe070, { KEY_RESERVED } },
333 
334 	/* Battery unplugged */
335 	{ KE_IGNORE, 0xfff0, { KEY_RESERVED } },
336 
337 	/* Battery inserted */
338 	{ KE_IGNORE, 0xfff1, { KEY_RESERVED } },
339 
340 	/*
341 	 * Detachable keyboard detached / undocked
342 	 * Note SW_TABLET_MODE is already reported through the intel_vbtn
343 	 * driver for this, so we ignore it.
344 	 */
345 	{ KE_IGNORE, 0xfff2, { KEY_RESERVED } },
346 
347 	/* Detachable keyboard attached / docked */
348 	{ KE_IGNORE, 0xfff3, { KEY_RESERVED } },
349 
350 	/* Keyboard backlight level changed */
351 	{ KE_IGNORE, KBD_LED_OFF_TOKEN,      { KEY_RESERVED } },
352 	{ KE_IGNORE, KBD_LED_ON_TOKEN,       { KEY_RESERVED } },
353 	{ KE_IGNORE, KBD_LED_AUTO_TOKEN,     { KEY_RESERVED } },
354 	{ KE_IGNORE, KBD_LED_AUTO_25_TOKEN,  { KEY_RESERVED } },
355 	{ KE_IGNORE, KBD_LED_AUTO_50_TOKEN,  { KEY_RESERVED } },
356 	{ KE_IGNORE, KBD_LED_AUTO_75_TOKEN,  { KEY_RESERVED } },
357 	{ KE_IGNORE, KBD_LED_AUTO_100_TOKEN, { KEY_RESERVED } },
358 };
359 
360 /*
361  * Keymap for WMI events of type 0x0012
362  * They are events with extended data
363  */
364 static const struct key_entry dell_wmi_keymap_type_0012[] = {
365 	/* Backlight brightness change event */
366 	{ KE_IGNORE, 0x0003, { KEY_RESERVED } },
367 
368 	/*
369 	 * Electronic privacy screen toggled, extended data gives state,
370 	 * separate entries for on/off see handling in dell_wmi_process_key().
371 	 */
372 	{ KE_KEY, 0x000c, { KEY_EPRIVACY_SCREEN_OFF } },
373 	{ KE_KEY, 0x000c, { KEY_EPRIVACY_SCREEN_ON } },
374 
375 	/* Ultra-performance mode switch request */
376 	{ KE_IGNORE, 0x000d, { KEY_RESERVED } },
377 
378 	/* Fn-lock button pressed */
379 	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
380 };
381 
382 static void dell_wmi_switch_event(struct input_dev **subdev,
383 				  const char *devname,
384 				  int switchid,
385 				  int value)
386 {
387 	if (!*subdev) {
388 		struct input_dev *dev = input_allocate_device();
389 
390 		if (!dev) {
391 			pr_warn("could not allocate device for %s\n", devname);
392 			return;
393 		}
394 		__set_bit(EV_SW, (dev)->evbit);
395 		__set_bit(switchid, (dev)->swbit);
396 
397 		(dev)->name = devname;
398 		(dev)->id.bustype = BUS_HOST;
399 		if (input_register_device(dev)) {
400 			input_free_device(dev);
401 			pr_warn("could not register device for %s\n", devname);
402 			return;
403 		}
404 		*subdev = dev;
405 	}
406 
407 	input_report_switch(*subdev, switchid, value);
408 	input_sync(*subdev);
409 }
410 
411 static int dell_wmi_process_key(struct wmi_device *wdev, int type, int code, u16 *buffer, int remaining)
412 {
413 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
414 	const struct key_entry *key;
415 	int used = 0;
416 	int value = 1;
417 
418 	key = sparse_keymap_entry_from_scancode(priv->input_dev,
419 						(type << 16) | code);
420 	if (!key) {
421 		pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
422 			type, code);
423 		return 0;
424 	}
425 
426 	pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);
427 
428 	/* Don't report brightness notifications that will also come via ACPI */
429 	if ((key->keycode == KEY_BRIGHTNESSUP ||
430 	     key->keycode == KEY_BRIGHTNESSDOWN) &&
431 	    acpi_video_handles_brightness_key_presses())
432 		return 0;
433 
434 	if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
435 		return 0;
436 
437 	if (key->keycode == KEY_KBDILLUMTOGGLE) {
438 		dell_laptop_call_notifier(
439 			DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);
440 	} else if (type == 0x0011 && code == 0xe070 && remaining > 0) {
441 		dell_wmi_switch_event(&priv->tabletswitch_dev,
442 				      "Dell tablet mode switch",
443 				      SW_TABLET_MODE, !buffer[0]);
444 		return 1;
445 	} else if (type == 0x0012 && code == 0x000c && remaining > 0) {
446 		/* Eprivacy toggle, switch to "on" key entry for on events */
447 		if (buffer[0] == 2)
448 			key++;
449 		used = 1;
450 	} else if (type == 0x0012 && code == 0x000d && remaining > 0) {
451 		value = (buffer[2] == 2);
452 		used = 1;
453 	}
454 
455 	sparse_keymap_report_entry(priv->input_dev, key, value, true);
456 
457 	return used;
458 }
459 
460 static void dell_wmi_notify(struct wmi_device *wdev,
461 			    union acpi_object *obj)
462 {
463 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
464 	u16 *buffer_entry, *buffer_end;
465 	acpi_size buffer_size;
466 	int len, i;
467 
468 	if (obj->type != ACPI_TYPE_BUFFER) {
469 		pr_warn("bad response type %x\n", obj->type);
470 		return;
471 	}
472 
473 	pr_debug("Received WMI event (%*ph)\n",
474 		obj->buffer.length, obj->buffer.pointer);
475 
476 	buffer_entry = (u16 *)obj->buffer.pointer;
477 	buffer_size = obj->buffer.length/2;
478 	buffer_end = buffer_entry + buffer_size;
479 
480 	/*
481 	 * BIOS/ACPI on devices with WMI interface version 0 does not clear
482 	 * buffer before filling it. So next time when BIOS/ACPI send WMI event
483 	 * which is smaller as previous then it contains garbage in buffer from
484 	 * previous event.
485 	 *
486 	 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
487 	 * sometimes send more events in buffer at one call.
488 	 *
489 	 * So to prevent reading garbage from buffer we will process only first
490 	 * one event on devices with WMI interface version 0.
491 	 */
492 	if (priv->interface_version == 0 && buffer_entry < buffer_end)
493 		if (buffer_end > buffer_entry + buffer_entry[0] + 1)
494 			buffer_end = buffer_entry + buffer_entry[0] + 1;
495 
496 	while (buffer_entry < buffer_end) {
497 
498 		len = buffer_entry[0];
499 		if (len == 0)
500 			break;
501 
502 		len++;
503 
504 		if (buffer_entry + len > buffer_end) {
505 			pr_warn("Invalid length of WMI event\n");
506 			break;
507 		}
508 
509 		pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
510 
511 		switch (buffer_entry[1]) {
512 		case 0x0000: /* One key pressed or event occurred */
513 			if (len > 2)
514 				dell_wmi_process_key(wdev, buffer_entry[1],
515 						     buffer_entry[2],
516 						     buffer_entry + 3,
517 						     len - 3);
518 			/* Extended data is currently ignored */
519 			break;
520 		case 0x0010: /* Sequence of keys pressed */
521 		case 0x0011: /* Sequence of events occurred */
522 			for (i = 2; i < len; ++i)
523 				i += dell_wmi_process_key(wdev, buffer_entry[1],
524 							  buffer_entry[i],
525 							  buffer_entry + i,
526 							  len - i - 1);
527 			break;
528 		case 0x0012:
529 			if ((len > 4) && dell_privacy_process_event(buffer_entry[1], buffer_entry[3],
530 								    buffer_entry[4]))
531 				/* dell_privacy_process_event has handled the event */;
532 			else if (len > 2)
533 				dell_wmi_process_key(wdev, buffer_entry[1], buffer_entry[2],
534 						     buffer_entry + 3, len - 3);
535 			break;
536 		default: /* Unknown event */
537 			pr_info("Unknown WMI event type 0x%x\n",
538 				(int)buffer_entry[1]);
539 			break;
540 		}
541 
542 		buffer_entry += len;
543 
544 	}
545 
546 }
547 
548 static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
549 {
550 	int i;
551 
552 	for (i = 0; i < len; i++)
553 		if (keymap[i].code == scancode)
554 			return true;
555 
556 	return false;
557 }
558 
559 static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
560 {
561 	struct dell_dmi_results *results = opaque;
562 	struct dell_bios_hotkey_table *table;
563 	int hotkey_num, i, pos = 0;
564 	struct key_entry *keymap;
565 
566 	if (results->err || results->keymap)
567 		return;		/* We already found the hotkey table. */
568 
569 	/* The Dell hotkey table is type 0xB2.  Scan until we find it. */
570 	if (dm->type != 0xb2)
571 		return;
572 
573 	table = container_of(dm, struct dell_bios_hotkey_table, header);
574 
575 	hotkey_num = (table->header.length -
576 		      sizeof(struct dell_bios_hotkey_table)) /
577 				sizeof(struct dell_bios_keymap_entry);
578 	if (hotkey_num < 1) {
579 		/*
580 		 * Historically, dell-wmi would ignore a DMI entry of
581 		 * fewer than 7 bytes.  Sizes between 4 and 8 bytes are
582 		 * nonsensical (both the header and all entries are 4
583 		 * bytes), so we approximate the old behavior by
584 		 * ignoring tables with fewer than one entry.
585 		 */
586 		return;
587 	}
588 
589 	keymap = kcalloc(hotkey_num, sizeof(struct key_entry), GFP_KERNEL);
590 	if (!keymap) {
591 		results->err = -ENOMEM;
592 		return;
593 	}
594 
595 	for (i = 0; i < hotkey_num; i++) {
596 		const struct dell_bios_keymap_entry *bios_entry =
597 					&table->keymap[i];
598 
599 		/* Uninitialized entries are 0 aka KEY_RESERVED. */
600 		u16 keycode = (bios_entry->keycode <
601 			       ARRAY_SIZE(bios_to_linux_keycode)) ?
602 			bios_to_linux_keycode[bios_entry->keycode] :
603 			(bios_entry->keycode == 0xffff ? KEY_UNKNOWN : KEY_RESERVED);
604 
605 		/*
606 		 * Log if we find an entry in the DMI table that we don't
607 		 * understand.  If this happens, we should figure out what
608 		 * the entry means and add it to bios_to_linux_keycode.
609 		 */
610 		if (keycode == KEY_RESERVED) {
611 			pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
612 				bios_entry->scancode, bios_entry->keycode);
613 			continue;
614 		}
615 
616 		if (keycode == KEY_KBDILLUMTOGGLE)
617 			keymap[pos].type = KE_IGNORE;
618 		else
619 			keymap[pos].type = KE_KEY;
620 		keymap[pos].code = bios_entry->scancode;
621 		keymap[pos].keycode = keycode;
622 
623 		pos++;
624 	}
625 
626 	results->keymap = keymap;
627 	results->keymap_size = pos;
628 }
629 
630 static int dell_wmi_input_setup(struct wmi_device *wdev)
631 {
632 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
633 	struct dell_dmi_results dmi_results = {};
634 	struct key_entry *keymap;
635 	int err, i, pos = 0;
636 
637 	priv->input_dev = input_allocate_device();
638 	if (!priv->input_dev)
639 		return -ENOMEM;
640 
641 	priv->input_dev->name = "Dell WMI hotkeys";
642 	priv->input_dev->id.bustype = BUS_HOST;
643 	priv->input_dev->dev.parent = &wdev->dev;
644 
645 	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
646 		/*
647 		 * Historically, dell-wmi ignored dmi_walk errors.  A failure
648 		 * is certainly surprising, but it probably just indicates
649 		 * a very old laptop.
650 		 */
651 		pr_warn("no DMI; using the old-style hotkey interface\n");
652 	}
653 
654 	if (dmi_results.err) {
655 		err = dmi_results.err;
656 		goto err_free_dev;
657 	}
658 
659 	keymap = kcalloc(dmi_results.keymap_size +
660 			 ARRAY_SIZE(dell_wmi_keymap_type_0000) +
661 			 ARRAY_SIZE(dell_wmi_keymap_type_0010) +
662 			 ARRAY_SIZE(dell_wmi_keymap_type_0011) +
663 			 ARRAY_SIZE(dell_wmi_keymap_type_0012) +
664 			 1,
665 			 sizeof(struct key_entry), GFP_KERNEL);
666 	if (!keymap) {
667 		kfree(dmi_results.keymap);
668 		err = -ENOMEM;
669 		goto err_free_dev;
670 	}
671 
672 	/* Append table with events of type 0x0010 which comes from DMI */
673 	for (i = 0; i < dmi_results.keymap_size; i++) {
674 		keymap[pos] = dmi_results.keymap[i];
675 		keymap[pos].code |= (0x0010 << 16);
676 		pos++;
677 	}
678 
679 	kfree(dmi_results.keymap);
680 
681 	/* Append table with extra events of type 0x0010 which are not in DMI */
682 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
683 		const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];
684 
685 		/*
686 		 * Check if we've already found this scancode.  This takes
687 		 * quadratic time, but it doesn't matter unless the list
688 		 * of extra keys gets very long.
689 		 */
690 		if (dmi_results.keymap_size &&
691 		    have_scancode(entry->code | (0x0010 << 16),
692 				  keymap, dmi_results.keymap_size)
693 		   )
694 			continue;
695 
696 		keymap[pos] = *entry;
697 		keymap[pos].code |= (0x0010 << 16);
698 		pos++;
699 	}
700 
701 	/* Append table with events of type 0x0011 */
702 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
703 		keymap[pos] = dell_wmi_keymap_type_0011[i];
704 		keymap[pos].code |= (0x0011 << 16);
705 		pos++;
706 	}
707 
708 	/* Append table with events of type 0x0012 */
709 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0012); i++) {
710 		keymap[pos] = dell_wmi_keymap_type_0012[i];
711 		keymap[pos].code |= (0x0012 << 16);
712 		pos++;
713 	}
714 
715 	/*
716 	 * Now append also table with "legacy" events of type 0x0000. Some of
717 	 * them are reported also on laptops which have scancodes in DMI.
718 	 */
719 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
720 		keymap[pos] = dell_wmi_keymap_type_0000[i];
721 		pos++;
722 	}
723 
724 	keymap[pos].type = KE_END;
725 
726 	err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
727 	/*
728 	 * Sparse keymap library makes a copy of keymap so we don't need the
729 	 * original one that was allocated.
730 	 */
731 	kfree(keymap);
732 	if (err)
733 		goto err_free_dev;
734 
735 	err = input_register_device(priv->input_dev);
736 	if (err)
737 		goto err_free_dev;
738 
739 	return 0;
740 
741  err_free_dev:
742 	input_free_device(priv->input_dev);
743 	return err;
744 }
745 
746 static void dell_wmi_input_destroy(struct wmi_device *wdev)
747 {
748 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
749 
750 	input_unregister_device(priv->input_dev);
751 	if (priv->tabletswitch_dev)
752 		input_unregister_device(priv->tabletswitch_dev);
753 }
754 
755 /*
756  * According to Dell SMBIOS documentation:
757  *
758  * 17  3  Application Program Registration
759  *
760  *     cbArg1 Application ID 1 = 0x00010000
761  *     cbArg2 Application ID 2
762  *            QUICKSET/DCP = 0x51534554 "QSET"
763  *            ALS Driver   = 0x416c7353 "AlsS"
764  *            Latitude ON  = 0x4c6f6e52 "LonR"
765  *     cbArg3 Application version or revision number
766  *     cbArg4 0 = Unregister application
767  *            1 = Register application
768  *     cbRes1 Standard return codes (0, -1, -2)
769  */
770 
771 static int dell_wmi_events_set_enabled(bool enable)
772 {
773 	struct calling_interface_buffer *buffer;
774 	int ret;
775 
776 	buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
777 	if (!buffer)
778 		return -ENOMEM;
779 	buffer->cmd_class = CLASS_INFO;
780 	buffer->cmd_select = SELECT_APP_REGISTRATION;
781 	buffer->input[0] = 0x10000;
782 	buffer->input[1] = 0x51534554;
783 	buffer->input[3] = enable;
784 	ret = dell_smbios_call(buffer);
785 	if (ret == 0)
786 		ret = buffer->output[0];
787 	kfree(buffer);
788 
789 	return dell_smbios_error(ret);
790 }
791 
792 static int dell_wmi_probe(struct wmi_device *wdev, const void *context)
793 {
794 	struct dell_wmi_priv *priv;
795 	int ret;
796 
797 	ret = dell_wmi_get_descriptor_valid();
798 	if (ret)
799 		return ret;
800 
801 	priv = devm_kzalloc(
802 		&wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
803 	if (!priv)
804 		return -ENOMEM;
805 	dev_set_drvdata(&wdev->dev, priv);
806 
807 	if (!dell_wmi_get_interface_version(&priv->interface_version))
808 		return -EPROBE_DEFER;
809 
810 	return dell_wmi_input_setup(wdev);
811 }
812 
813 static void dell_wmi_remove(struct wmi_device *wdev)
814 {
815 	dell_wmi_input_destroy(wdev);
816 }
817 static const struct wmi_device_id dell_wmi_id_table[] = {
818 	{ .guid_string = DELL_EVENT_GUID },
819 	{ },
820 };
821 
822 static struct wmi_driver dell_wmi_driver = {
823 	.driver = {
824 		.name = "dell-wmi",
825 	},
826 	.id_table = dell_wmi_id_table,
827 	.probe = dell_wmi_probe,
828 	.remove = dell_wmi_remove,
829 	.notify = dell_wmi_notify,
830 };
831 
832 static int __init dell_wmi_init(void)
833 {
834 	int err;
835 
836 	dmi_check_system(dell_wmi_smbios_list);
837 
838 	if (wmi_requires_smbios_request) {
839 		err = dell_wmi_events_set_enabled(true);
840 		if (err) {
841 			pr_err("Failed to enable WMI events\n");
842 			return err;
843 		}
844 	}
845 
846 	err = dell_privacy_register_driver();
847 	if (err)
848 		return err;
849 
850 	return wmi_driver_register(&dell_wmi_driver);
851 }
852 late_initcall(dell_wmi_init);
853 
854 static void __exit dell_wmi_exit(void)
855 {
856 	if (wmi_requires_smbios_request)
857 		dell_wmi_events_set_enabled(false);
858 
859 	wmi_driver_unregister(&dell_wmi_driver);
860 	dell_privacy_unregister_driver();
861 }
862 module_exit(dell_wmi_exit);
863 
864 MODULE_DEVICE_TABLE(wmi, dell_wmi_id_table);
865