xref: /linux/drivers/platform/x86/dell/dell-wmi-base.c (revision 54de8b835b5d3f78081ad17c964ffc7fcf771716)
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 
dmi_matched(const struct dmi_system_id * dmi)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 	/* Audio mute toggle */
84 	{ KE_KEY,    0x0109, { KEY_MUTE } },
85 
86 	/* Mic mute toggle */
87 	{ KE_KEY,    0x0150, { KEY_MICMUTE } },
88 
89 	/* Meta key lock */
90 	{ KE_IGNORE, 0xe000, { KEY_RIGHTMETA } },
91 
92 	/* Meta key unlock */
93 	{ KE_IGNORE, 0xe001, { KEY_RIGHTMETA } },
94 
95 	/* Key code is followed by brightness level */
96 	{ KE_KEY,    0xe005, { KEY_BRIGHTNESSDOWN } },
97 	{ KE_KEY,    0xe006, { KEY_BRIGHTNESSUP } },
98 
99 	/* Battery health status button */
100 	{ KE_KEY,    0xe007, { KEY_BATTERY } },
101 
102 	/* Radio devices state change, key code is followed by other values */
103 	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
104 
105 	{ KE_KEY,    0xe009, { KEY_EJECTCD } },
106 
107 	/* Key code is followed by: next, active and attached devices */
108 	{ KE_KEY,    0xe00b, { KEY_SWITCHVIDEOMODE } },
109 
110 	/* Key code is followed by keyboard illumination level */
111 	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
112 
113 	/* BIOS error detected */
114 	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
115 
116 	/* Battery was removed or inserted */
117 	{ KE_IGNORE, 0xe00e, { KEY_RESERVED } },
118 
119 	/* Wifi Catcher */
120 	{ KE_KEY,    0xe011, { KEY_WLAN } },
121 
122 	/* Ambient light sensor toggle */
123 	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
124 
125 	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
126 
127 	/* Unknown, defined in ACPI DSDT */
128 	/* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */
129 
130 	/* Untested, Dell Instant Launch key on Inspiron 7520 */
131 	/* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */
132 
133 	/* Dell Instant Launch key */
134 	{ KE_KEY,    0xe025, { KEY_PROG4 } },
135 
136 	/* Audio panel key */
137 	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },
138 
139 	/* LCD Display On/Off Control key */
140 	{ KE_KEY,    0xe027, { KEY_DISPLAYTOGGLE } },
141 
142 	/* Untested, Multimedia key on Dell Vostro 3560 */
143 	/* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */
144 
145 	/* Dell Instant Launch key */
146 	{ KE_KEY,    0xe029, { KEY_PROG4 } },
147 
148 	/* Untested, Windows Mobility Center button on Inspiron 7520 */
149 	/* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
150 
151 	/* Unknown, defined in ACPI DSDT */
152 	/* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */
153 
154 	/* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
155 	/* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */
156 
157 	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
158 	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
159 	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
160 	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
161 	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
162 
163 	/* NIC Link is Up */
164 	{ KE_IGNORE, 0xe043, { KEY_RESERVED } },
165 
166 	/* NIC Link is Down */
167 	{ KE_IGNORE, 0xe044, { KEY_RESERVED } },
168 
169 	/*
170 	 * This entry is very suspicious!
171 	 * Originally Matthew Garrett created this dell-wmi driver specially for
172 	 * "button with a picture of a battery" which has event code 0xe045.
173 	 * Later Mario Limonciello from Dell told us that event code 0xe045 is
174 	 * reported by Num Lock and should be ignored because key is send also
175 	 * by keyboard controller.
176 	 * So for now we will ignore this event to prevent potential double
177 	 * Num Lock key press.
178 	 */
179 	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
180 
181 	/* Scroll lock and also going to tablet mode on portable devices */
182 	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
183 
184 	/* Untested, going from tablet mode on portable devices */
185 	/* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */
186 
187 	/* Dell Support Center key */
188 	{ KE_IGNORE, 0xe06e, { KEY_RESERVED } },
189 
190 	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
191 	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
192 	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
193 };
194 
195 struct dell_bios_keymap_entry {
196 	u16 scancode;
197 	u16 keycode;
198 };
199 
200 struct dell_bios_hotkey_table {
201 	struct dmi_header header;
202 	struct dell_bios_keymap_entry keymap[];
203 
204 };
205 
206 struct dell_dmi_results {
207 	int err;
208 	int keymap_size;
209 	struct key_entry *keymap;
210 };
211 
212 /* Uninitialized entries here are KEY_RESERVED == 0. */
213 static const u16 bios_to_linux_keycode[256] = {
214 	[0]	= KEY_MEDIA,
215 	[1]	= KEY_NEXTSONG,
216 	[2]	= KEY_PLAYPAUSE,
217 	[3]	= KEY_PREVIOUSSONG,
218 	[4]	= KEY_STOPCD,
219 	[5]	= KEY_UNKNOWN,
220 	[6]	= KEY_UNKNOWN,
221 	[7]	= KEY_UNKNOWN,
222 	[8]	= KEY_WWW,
223 	[9]	= KEY_UNKNOWN,
224 	[10]	= KEY_VOLUMEDOWN,
225 	[11]	= KEY_MUTE,
226 	[12]	= KEY_VOLUMEUP,
227 	[13]	= KEY_UNKNOWN,
228 	[14]	= KEY_BATTERY,
229 	[15]	= KEY_EJECTCD,
230 	[16]	= KEY_UNKNOWN,
231 	[17]	= KEY_SLEEP,
232 	[18]	= KEY_PROG1,
233 	[19]	= KEY_BRIGHTNESSDOWN,
234 	[20]	= KEY_BRIGHTNESSUP,
235 	[21]	= KEY_BRIGHTNESS_AUTO,
236 	[22]	= KEY_KBDILLUMTOGGLE,
237 	[23]	= KEY_UNKNOWN,
238 	[24]	= KEY_SWITCHVIDEOMODE,
239 	[25]	= KEY_UNKNOWN,
240 	[26]	= KEY_UNKNOWN,
241 	[27]	= KEY_SWITCHVIDEOMODE,
242 	[28]	= KEY_UNKNOWN,
243 	[29]	= KEY_UNKNOWN,
244 	[30]	= KEY_PROG2,
245 	[31]	= KEY_UNKNOWN,
246 	[32]	= KEY_UNKNOWN,
247 	[33]	= KEY_UNKNOWN,
248 	[34]	= KEY_UNKNOWN,
249 	[35]	= KEY_UNKNOWN,
250 	[36]	= KEY_UNKNOWN,
251 	[37]	= KEY_UNKNOWN,
252 	[38]	= KEY_MICMUTE,
253 	[255]	= KEY_PROG3,
254 };
255 
256 /*
257  * Keymap for WMI events of type 0x0010
258  *
259  * These are applied if the 0xB2 DMI hotkey table is present and doesn't
260  * override them.
261  */
262 static const struct key_entry dell_wmi_keymap_type_0010[] = {
263 	/* Fn-lock switched to function keys */
264 	{ KE_IGNORE, 0x0, { KEY_RESERVED } },
265 
266 	/* Fn-lock switched to multimedia keys */
267 	{ KE_IGNORE, 0x1, { KEY_RESERVED } },
268 
269 	/* Keyboard backlight change notification */
270 	{ KE_IGNORE, 0x3f, { KEY_RESERVED } },
271 
272 	/* Backlight brightness level */
273 	{ KE_KEY,    0x57, { KEY_BRIGHTNESSDOWN } },
274 	{ KE_KEY,    0x58, { KEY_BRIGHTNESSUP } },
275 
276 	/*Speaker Mute*/
277 	{ KE_KEY, 0x109, { KEY_MUTE} },
278 
279 	/* S2Idle screen off */
280 	{ KE_IGNORE, 0x120, { KEY_RESERVED }},
281 
282 	/* Leaving S4 or S2Idle suspend */
283 	{ KE_IGNORE, 0x130, { KEY_RESERVED }},
284 
285 	/* Entering S2Idle suspend */
286 	{ KE_IGNORE, 0x140, { KEY_RESERVED }},
287 
288 	/* Mic mute */
289 	{ KE_KEY, 0x150, { KEY_MICMUTE } },
290 
291 	/* Fn-lock */
292 	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
293 
294 	/* Change keyboard illumination */
295 	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
296 
297 	/*
298 	 * Radio disable (notify only -- there is no model for which the
299 	 * WMI event is supposed to trigger an action).
300 	 */
301 	{ KE_IGNORE, 0x153, { KEY_RFKILL } },
302 
303 	/* RGB keyboard backlight control */
304 	{ KE_IGNORE, 0x154, { KEY_RESERVED } },
305 
306 	/*
307 	 * Stealth mode toggle. This will "disable all lights and sounds".
308 	 * The action is performed by the BIOS and EC; the WMI event is just
309 	 * a notification. On the XPS 13 9350, this is Fn+F7, and there's
310 	 * a BIOS setting to enable and disable the hotkey.
311 	 */
312 	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
313 
314 	/* Rugged magnetic dock attach/detach events */
315 	{ KE_IGNORE, 0x156, { KEY_RESERVED } },
316 	{ KE_IGNORE, 0x157, { KEY_RESERVED } },
317 
318 	/* Rugged programmable (P1/P2/P3 keys) */
319 	{ KE_KEY,    0x850, { KEY_PROG1 } },
320 	{ KE_KEY,    0x851, { KEY_PROG2 } },
321 	{ KE_KEY,    0x852, { KEY_PROG3 } },
322 
323 	/*
324 	 * Radio disable (notify only -- there is no model for which the
325 	 * WMI event is supposed to trigger an action).
326 	 */
327 	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
328 
329 	/* Fn-lock */
330 	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
331 };
332 
333 /*
334  * Keymap for WMI events of type 0x0011
335  */
336 static const struct key_entry dell_wmi_keymap_type_0011[] = {
337 	/* Reflex keyboard switch on 2n1 devices */
338 	{ KE_IGNORE, 0xe070, { KEY_RESERVED } },
339 
340 	/* Battery unplugged */
341 	{ KE_IGNORE, 0xfff0, { KEY_RESERVED } },
342 
343 	/* Battery inserted */
344 	{ KE_IGNORE, 0xfff1, { KEY_RESERVED } },
345 
346 	/*
347 	 * Detachable keyboard detached / undocked
348 	 * Note SW_TABLET_MODE is already reported through the intel_vbtn
349 	 * driver for this, so we ignore it.
350 	 */
351 	{ KE_IGNORE, 0xfff2, { KEY_RESERVED } },
352 
353 	/* Detachable keyboard attached / docked */
354 	{ KE_IGNORE, 0xfff3, { KEY_RESERVED } },
355 
356 	/* Keyboard backlight level changed */
357 	{ KE_IGNORE, KBD_LED_OFF_TOKEN,      { KEY_RESERVED } },
358 	{ KE_IGNORE, KBD_LED_ON_TOKEN,       { KEY_RESERVED } },
359 	{ KE_IGNORE, KBD_LED_AUTO_TOKEN,     { KEY_RESERVED } },
360 	{ KE_IGNORE, KBD_LED_AUTO_25_TOKEN,  { KEY_RESERVED } },
361 	{ KE_IGNORE, KBD_LED_AUTO_50_TOKEN,  { KEY_RESERVED } },
362 	{ KE_IGNORE, KBD_LED_AUTO_75_TOKEN,  { KEY_RESERVED } },
363 	{ KE_IGNORE, KBD_LED_AUTO_100_TOKEN, { KEY_RESERVED } },
364 };
365 
366 /*
367  * Keymap for WMI events of type 0x0012
368  * They are events with extended data
369  */
370 static const struct key_entry dell_wmi_keymap_type_0012[] = {
371 	/* Backlight brightness change event */
372 	{ KE_IGNORE, 0x0003, { KEY_RESERVED } },
373 
374 	/*
375 	 * Electronic privacy screen toggled, extended data gives state,
376 	 * separate entries for on/off see handling in dell_wmi_process_key().
377 	 */
378 	{ KE_KEY, 0x000c, { KEY_EPRIVACY_SCREEN_OFF } },
379 	{ KE_KEY, 0x000c, { KEY_EPRIVACY_SCREEN_ON } },
380 
381 	/* Ultra-performance mode switch request */
382 	{ KE_IGNORE, 0x000d, { KEY_RESERVED } },
383 
384 	/* Fn-lock button pressed */
385 	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
386 };
387 
dell_wmi_switch_event(struct input_dev ** subdev,const char * devname,int switchid,int value)388 static void dell_wmi_switch_event(struct input_dev **subdev,
389 				  const char *devname,
390 				  int switchid,
391 				  int value)
392 {
393 	if (!*subdev) {
394 		struct input_dev *dev = input_allocate_device();
395 
396 		if (!dev) {
397 			pr_warn("could not allocate device for %s\n", devname);
398 			return;
399 		}
400 		__set_bit(EV_SW, (dev)->evbit);
401 		__set_bit(switchid, (dev)->swbit);
402 
403 		(dev)->name = devname;
404 		(dev)->id.bustype = BUS_HOST;
405 		if (input_register_device(dev)) {
406 			input_free_device(dev);
407 			pr_warn("could not register device for %s\n", devname);
408 			return;
409 		}
410 		*subdev = dev;
411 	}
412 
413 	input_report_switch(*subdev, switchid, value);
414 	input_sync(*subdev);
415 }
416 
dell_wmi_process_key(struct wmi_device * wdev,int type,int code,u16 * buffer,int remaining)417 static int dell_wmi_process_key(struct wmi_device *wdev, int type, int code, u16 *buffer, int remaining)
418 {
419 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
420 	const struct key_entry *key;
421 	int used = 0;
422 	int value = 1;
423 
424 	key = sparse_keymap_entry_from_scancode(priv->input_dev,
425 						(type << 16) | code);
426 	if (!key) {
427 		pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
428 			type, code);
429 		return 0;
430 	}
431 
432 	pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);
433 
434 	/* Don't report brightness notifications that will also come via ACPI */
435 	if ((key->keycode == KEY_BRIGHTNESSUP ||
436 	     key->keycode == KEY_BRIGHTNESSDOWN) &&
437 	    acpi_video_handles_brightness_key_presses())
438 		return 0;
439 
440 	if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
441 		return 0;
442 
443 	if (key->keycode == KEY_KBDILLUMTOGGLE) {
444 		dell_laptop_call_notifier(
445 			DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);
446 	} else if (type == 0x0011 && code == 0xe070 && remaining > 0) {
447 		dell_wmi_switch_event(&priv->tabletswitch_dev,
448 				      "Dell tablet mode switch",
449 				      SW_TABLET_MODE, !buffer[0]);
450 		return 1;
451 	} else if (type == 0x0012 && code == 0x000c && remaining > 0) {
452 		/* Eprivacy toggle, switch to "on" key entry for on events */
453 		if (buffer[0] == 2)
454 			key++;
455 		used = 1;
456 	} else if (type == 0x0012 && code == 0x000d && remaining > 0) {
457 		value = (buffer[2] == 2);
458 		used = 1;
459 	}
460 
461 	sparse_keymap_report_entry(priv->input_dev, key, value, true);
462 
463 	return used;
464 }
465 
dell_wmi_notify(struct wmi_device * wdev,union acpi_object * obj)466 static void dell_wmi_notify(struct wmi_device *wdev,
467 			    union acpi_object *obj)
468 {
469 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
470 	u16 *buffer_entry, *buffer_end;
471 	acpi_size buffer_size;
472 	int len, i;
473 
474 	if (obj->type != ACPI_TYPE_BUFFER) {
475 		pr_warn("bad response type %x\n", obj->type);
476 		return;
477 	}
478 
479 	pr_debug("Received WMI event (%*ph)\n",
480 		obj->buffer.length, obj->buffer.pointer);
481 
482 	buffer_entry = (u16 *)obj->buffer.pointer;
483 	buffer_size = obj->buffer.length/2;
484 	buffer_end = buffer_entry + buffer_size;
485 
486 	/*
487 	 * BIOS/ACPI on devices with WMI interface version 0 does not clear
488 	 * buffer before filling it. So next time when BIOS/ACPI send WMI event
489 	 * which is smaller as previous then it contains garbage in buffer from
490 	 * previous event.
491 	 *
492 	 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
493 	 * sometimes send more events in buffer at one call.
494 	 *
495 	 * So to prevent reading garbage from buffer we will process only first
496 	 * one event on devices with WMI interface version 0.
497 	 */
498 	if (priv->interface_version == 0 && buffer_entry < buffer_end)
499 		if (buffer_end > buffer_entry + buffer_entry[0] + 1)
500 			buffer_end = buffer_entry + buffer_entry[0] + 1;
501 
502 	while (buffer_entry < buffer_end) {
503 
504 		len = buffer_entry[0];
505 		if (len == 0)
506 			break;
507 
508 		len++;
509 
510 		if (buffer_entry + len > buffer_end) {
511 			pr_warn("Invalid length of WMI event\n");
512 			break;
513 		}
514 
515 		pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
516 
517 		switch (buffer_entry[1]) {
518 		case 0x0000: /* One key pressed or event occurred */
519 			if (len > 2)
520 				dell_wmi_process_key(wdev, buffer_entry[1],
521 						     buffer_entry[2],
522 						     buffer_entry + 3,
523 						     len - 3);
524 			/* Extended data is currently ignored */
525 			break;
526 		case 0x0010: /* Sequence of keys pressed */
527 		case 0x0011: /* Sequence of events occurred */
528 			for (i = 2; i < len; ++i)
529 				i += dell_wmi_process_key(wdev, buffer_entry[1],
530 							  buffer_entry[i],
531 							  buffer_entry + i,
532 							  len - i - 1);
533 			break;
534 		case 0x0012:
535 			if ((len > 4) && dell_privacy_process_event(buffer_entry[1], buffer_entry[3],
536 								    buffer_entry[4]))
537 				/* dell_privacy_process_event has handled the event */;
538 			else if (len > 2)
539 				dell_wmi_process_key(wdev, buffer_entry[1], buffer_entry[2],
540 						     buffer_entry + 3, len - 3);
541 			break;
542 		default: /* Unknown event */
543 			pr_info("Unknown WMI event type 0x%x\n",
544 				(int)buffer_entry[1]);
545 			break;
546 		}
547 
548 		buffer_entry += len;
549 
550 	}
551 
552 }
553 
have_scancode(u32 scancode,const struct key_entry * keymap,int len)554 static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
555 {
556 	int i;
557 
558 	for (i = 0; i < len; i++)
559 		if (keymap[i].code == scancode)
560 			return true;
561 
562 	return false;
563 }
564 
handle_dmi_entry(const struct dmi_header * dm,void * opaque)565 static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
566 {
567 	struct dell_dmi_results *results = opaque;
568 	struct dell_bios_hotkey_table *table;
569 	int hotkey_num, i, pos = 0;
570 	struct key_entry *keymap;
571 
572 	if (results->err || results->keymap)
573 		return;		/* We already found the hotkey table. */
574 
575 	/* The Dell hotkey table is type 0xB2.  Scan until we find it. */
576 	if (dm->type != 0xb2)
577 		return;
578 
579 	table = container_of(dm, struct dell_bios_hotkey_table, header);
580 
581 	hotkey_num = (table->header.length -
582 		      sizeof(struct dell_bios_hotkey_table)) /
583 				sizeof(struct dell_bios_keymap_entry);
584 	if (hotkey_num < 1) {
585 		/*
586 		 * Historically, dell-wmi would ignore a DMI entry of
587 		 * fewer than 7 bytes.  Sizes between 4 and 8 bytes are
588 		 * nonsensical (both the header and all entries are 4
589 		 * bytes), so we approximate the old behavior by
590 		 * ignoring tables with fewer than one entry.
591 		 */
592 		return;
593 	}
594 
595 	keymap = kzalloc_objs(struct key_entry, hotkey_num);
596 	if (!keymap) {
597 		results->err = -ENOMEM;
598 		return;
599 	}
600 
601 	for (i = 0; i < hotkey_num; i++) {
602 		const struct dell_bios_keymap_entry *bios_entry =
603 					&table->keymap[i];
604 
605 		/* Uninitialized entries are 0 aka KEY_RESERVED. */
606 		u16 keycode = (bios_entry->keycode <
607 			       ARRAY_SIZE(bios_to_linux_keycode)) ?
608 			bios_to_linux_keycode[bios_entry->keycode] :
609 			(bios_entry->keycode == 0xffff ? KEY_UNKNOWN : KEY_RESERVED);
610 
611 		/*
612 		 * Log if we find an entry in the DMI table that we don't
613 		 * understand.  If this happens, we should figure out what
614 		 * the entry means and add it to bios_to_linux_keycode.
615 		 */
616 		if (keycode == KEY_RESERVED) {
617 			pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
618 				bios_entry->scancode, bios_entry->keycode);
619 			continue;
620 		}
621 
622 		if (keycode == KEY_KBDILLUMTOGGLE)
623 			keymap[pos].type = KE_IGNORE;
624 		else
625 			keymap[pos].type = KE_KEY;
626 		keymap[pos].code = bios_entry->scancode;
627 		keymap[pos].keycode = keycode;
628 
629 		pos++;
630 	}
631 
632 	results->keymap = keymap;
633 	results->keymap_size = pos;
634 }
635 
dell_wmi_input_setup(struct wmi_device * wdev)636 static int dell_wmi_input_setup(struct wmi_device *wdev)
637 {
638 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
639 	struct dell_dmi_results dmi_results = {};
640 	struct key_entry *keymap;
641 	int err, i, pos = 0;
642 
643 	priv->input_dev = input_allocate_device();
644 	if (!priv->input_dev)
645 		return -ENOMEM;
646 
647 	priv->input_dev->name = "Dell WMI hotkeys";
648 	priv->input_dev->id.bustype = BUS_HOST;
649 	priv->input_dev->dev.parent = &wdev->dev;
650 
651 	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
652 		/*
653 		 * Historically, dell-wmi ignored dmi_walk errors.  A failure
654 		 * is certainly surprising, but it probably just indicates
655 		 * a very old laptop.
656 		 */
657 		pr_warn("no DMI; using the old-style hotkey interface\n");
658 	}
659 
660 	if (dmi_results.err) {
661 		err = dmi_results.err;
662 		goto err_free_dev;
663 	}
664 
665 	keymap = kzalloc_objs(struct key_entry,
666 			      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) + ARRAY_SIZE(dell_wmi_keymap_type_0012) + 1);
667 	if (!keymap) {
668 		kfree(dmi_results.keymap);
669 		err = -ENOMEM;
670 		goto err_free_dev;
671 	}
672 
673 	/* Append table with events of type 0x0010 which comes from DMI */
674 	for (i = 0; i < dmi_results.keymap_size; i++) {
675 		keymap[pos] = dmi_results.keymap[i];
676 		keymap[pos].code |= (0x0010 << 16);
677 		pos++;
678 	}
679 
680 	kfree(dmi_results.keymap);
681 
682 	/* Append table with extra events of type 0x0010 which are not in DMI */
683 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
684 		const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];
685 
686 		/*
687 		 * Check if we've already found this scancode.  This takes
688 		 * quadratic time, but it doesn't matter unless the list
689 		 * of extra keys gets very long.
690 		 */
691 		if (dmi_results.keymap_size &&
692 		    have_scancode(entry->code | (0x0010 << 16),
693 				  keymap, dmi_results.keymap_size)
694 		   )
695 			continue;
696 
697 		keymap[pos] = *entry;
698 		keymap[pos].code |= (0x0010 << 16);
699 		pos++;
700 	}
701 
702 	/* Append table with events of type 0x0011 */
703 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
704 		keymap[pos] = dell_wmi_keymap_type_0011[i];
705 		keymap[pos].code |= (0x0011 << 16);
706 		pos++;
707 	}
708 
709 	/* Append table with events of type 0x0012 */
710 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0012); i++) {
711 		keymap[pos] = dell_wmi_keymap_type_0012[i];
712 		keymap[pos].code |= (0x0012 << 16);
713 		pos++;
714 	}
715 
716 	/*
717 	 * Now append also table with "legacy" events of type 0x0000. Some of
718 	 * them are reported also on laptops which have scancodes in DMI.
719 	 */
720 	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
721 		keymap[pos] = dell_wmi_keymap_type_0000[i];
722 		pos++;
723 	}
724 
725 	keymap[pos].type = KE_END;
726 
727 	err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
728 	/*
729 	 * Sparse keymap library makes a copy of keymap so we don't need the
730 	 * original one that was allocated.
731 	 */
732 	kfree(keymap);
733 	if (err)
734 		goto err_free_dev;
735 
736 	err = input_register_device(priv->input_dev);
737 	if (err)
738 		goto err_free_dev;
739 
740 	return 0;
741 
742  err_free_dev:
743 	input_free_device(priv->input_dev);
744 	return err;
745 }
746 
dell_wmi_input_destroy(struct wmi_device * wdev)747 static void dell_wmi_input_destroy(struct wmi_device *wdev)
748 {
749 	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
750 
751 	input_unregister_device(priv->input_dev);
752 	if (priv->tabletswitch_dev)
753 		input_unregister_device(priv->tabletswitch_dev);
754 }
755 
756 /*
757  * According to Dell SMBIOS documentation:
758  *
759  * 17  3  Application Program Registration
760  *
761  *     cbArg1 Application ID 1 = 0x00010000
762  *     cbArg2 Application ID 2
763  *            QUICKSET/DCP = 0x51534554 "QSET"
764  *            ALS Driver   = 0x416c7353 "AlsS"
765  *            Latitude ON  = 0x4c6f6e52 "LonR"
766  *     cbArg3 Application version or revision number
767  *     cbArg4 0 = Unregister application
768  *            1 = Register application
769  *     cbRes1 Standard return codes (0, -1, -2)
770  */
771 
dell_wmi_events_set_enabled(bool enable)772 static int dell_wmi_events_set_enabled(bool enable)
773 {
774 	struct calling_interface_buffer *buffer;
775 	int ret;
776 
777 	buffer = kzalloc_obj(struct calling_interface_buffer);
778 	if (!buffer)
779 		return -ENOMEM;
780 	buffer->cmd_class = CLASS_INFO;
781 	buffer->cmd_select = SELECT_APP_REGISTRATION;
782 	buffer->input[0] = 0x10000;
783 	buffer->input[1] = 0x51534554;
784 	buffer->input[3] = enable;
785 	ret = dell_smbios_call(buffer);
786 	if (ret == 0)
787 		ret = buffer->output[0];
788 	kfree(buffer);
789 
790 	return dell_smbios_error(ret);
791 }
792 
dell_wmi_probe(struct wmi_device * wdev,const void * context)793 static int dell_wmi_probe(struct wmi_device *wdev, const void *context)
794 {
795 	struct dell_wmi_priv *priv;
796 	int ret;
797 
798 	ret = dell_wmi_get_descriptor_valid();
799 	if (ret)
800 		return ret;
801 
802 	priv = devm_kzalloc(
803 		&wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
804 	if (!priv)
805 		return -ENOMEM;
806 	dev_set_drvdata(&wdev->dev, priv);
807 
808 	if (!dell_wmi_get_interface_version(&priv->interface_version))
809 		return -EPROBE_DEFER;
810 
811 	return dell_wmi_input_setup(wdev);
812 }
813 
dell_wmi_remove(struct wmi_device * wdev)814 static void dell_wmi_remove(struct wmi_device *wdev)
815 {
816 	dell_wmi_input_destroy(wdev);
817 }
818 static const struct wmi_device_id dell_wmi_id_table[] = {
819 	{ .guid_string = DELL_EVENT_GUID },
820 	{ },
821 };
822 
823 static struct wmi_driver dell_wmi_driver = {
824 	.driver = {
825 		.name = "dell-wmi",
826 	},
827 	.id_table = dell_wmi_id_table,
828 	.probe = dell_wmi_probe,
829 	.remove = dell_wmi_remove,
830 	.notify = dell_wmi_notify,
831 };
832 
dell_wmi_init(void)833 static int __init dell_wmi_init(void)
834 {
835 	int err;
836 
837 	dmi_check_system(dell_wmi_smbios_list);
838 
839 	if (wmi_requires_smbios_request) {
840 		err = dell_wmi_events_set_enabled(true);
841 		if (err) {
842 			pr_err("Failed to enable WMI events\n");
843 			return err;
844 		}
845 	}
846 
847 	err = dell_privacy_register_driver();
848 	if (err)
849 		return err;
850 
851 	return wmi_driver_register(&dell_wmi_driver);
852 }
853 late_initcall(dell_wmi_init);
854 
dell_wmi_exit(void)855 static void __exit dell_wmi_exit(void)
856 {
857 	if (wmi_requires_smbios_request)
858 		dell_wmi_events_set_enabled(false);
859 
860 	wmi_driver_unregister(&dell_wmi_driver);
861 	dell_privacy_unregister_driver();
862 }
863 module_exit(dell_wmi_exit);
864 
865 MODULE_DEVICE_TABLE(wmi, dell_wmi_id_table);
866