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1/*
2 * Dell WMI hotkeys
3 *
4 * Copyright (C) 2008 Red Hat <mjg@redhat.com>
5 * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
6 *
7 * Portions based on wistron_btns.c:
8 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
9 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
10 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
26
27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/init.h>
32#include <linux/slab.h>
33#include <linux/types.h>
34#include <linux/input.h>
35#include <linux/input/sparse-keymap.h>
36#include <linux/acpi.h>
37#include <linux/string.h>
38#include <linux/dmi.h>
39#include <acpi/video.h>
40#include "dell-smbios.h"
41
42MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
43MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
44MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
45MODULE_LICENSE("GPL");
46
47#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
48#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
49
50static u32 dell_wmi_interface_version;
51static bool wmi_requires_smbios_request;
52
53MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
54MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
55
56static int __init dmi_matched(const struct dmi_system_id *dmi)
57{
58 wmi_requires_smbios_request = 1;
59 return 1;
60}
61
62static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
63 {
64 .callback = dmi_matched,
65 .ident = "Dell Inspiron M5110",
66 .matches = {
67 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
68 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
69 },
70 },
71 {
72 .callback = dmi_matched,
73 .ident = "Dell Vostro V131",
74 .matches = {
75 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
76 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
77 },
78 },
79 { }
80};
81
82/*
83 * Certain keys are flagged as KE_IGNORE. All of these are either
84 * notifications (rather than requests for change) or are also sent
85 * via the keyboard controller so should not be sent again.
86 */
87
88static const struct key_entry dell_wmi_legacy_keymap[] __initconst = {
89 { KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
90
91 { KE_KEY, 0xe045, { KEY_PROG1 } },
92 { KE_KEY, 0xe009, { KEY_EJECTCD } },
93
94 /* These also contain the brightness level at offset 6 */
95 { KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
96 { KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
97
98 /* Battery health status button */
99 { KE_KEY, 0xe007, { KEY_BATTERY } },
100
101 /* Radio devices state change */
102 { KE_IGNORE, 0xe008, { KEY_RFKILL } },
103
104 /* The next device is at offset 6, the active devices are at
105 offset 8 and the attached devices at offset 10 */
106 { KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
107
108 { KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
109
110 /* BIOS error detected */
111 { KE_IGNORE, 0xe00d, { KEY_RESERVED } },
112
113 /* Wifi Catcher */
114 { KE_KEY, 0xe011, {KEY_PROG2 } },
115
116 /* Ambient light sensor toggle */
117 { KE_IGNORE, 0xe013, { KEY_RESERVED } },
118
119 { KE_IGNORE, 0xe020, { KEY_MUTE } },
120
121 /* Dell Instant Launch key */
122 { KE_KEY, 0xe025, { KEY_PROG4 } },
123 { KE_KEY, 0xe029, { KEY_PROG4 } },
124
125 /* Audio panel key */
126 { KE_IGNORE, 0xe026, { KEY_RESERVED } },
127
128 { KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
129 { KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
130 { KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
131 { KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
132 { KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
133 { KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
134 { KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
135 { KE_IGNORE, 0xe0f7, { KEY_MUTE } },
136 { KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
137 { KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
138 { KE_END, 0 }
139};
140
141static bool dell_new_hk_type;
142
143struct dell_bios_keymap_entry {
144 u16 scancode;
145 u16 keycode;
146};
147
148struct dell_bios_hotkey_table {
149 struct dmi_header header;
150 struct dell_bios_keymap_entry keymap[];
151
152};
153
154struct dell_dmi_results {
155 int err;
156 struct key_entry *keymap;
157};
158
159/* Uninitialized entries here are KEY_RESERVED == 0. */
160static const u16 bios_to_linux_keycode[256] __initconst = {
161 [0] = KEY_MEDIA,
162 [1] = KEY_NEXTSONG,
163 [2] = KEY_PLAYPAUSE,
164 [3] = KEY_PREVIOUSSONG,
165 [4] = KEY_STOPCD,
166 [5] = KEY_UNKNOWN,
167 [6] = KEY_UNKNOWN,
168 [7] = KEY_UNKNOWN,
169 [8] = KEY_WWW,
170 [9] = KEY_UNKNOWN,
171 [10] = KEY_VOLUMEDOWN,
172 [11] = KEY_MUTE,
173 [12] = KEY_VOLUMEUP,
174 [13] = KEY_UNKNOWN,
175 [14] = KEY_BATTERY,
176 [15] = KEY_EJECTCD,
177 [16] = KEY_UNKNOWN,
178 [17] = KEY_SLEEP,
179 [18] = KEY_PROG1,
180 [19] = KEY_BRIGHTNESSDOWN,
181 [20] = KEY_BRIGHTNESSUP,
182 [21] = KEY_UNKNOWN,
183 [22] = KEY_KBDILLUMTOGGLE,
184 [23] = KEY_UNKNOWN,
185 [24] = KEY_SWITCHVIDEOMODE,
186 [25] = KEY_UNKNOWN,
187 [26] = KEY_UNKNOWN,
188 [27] = KEY_SWITCHVIDEOMODE,
189 [28] = KEY_UNKNOWN,
190 [29] = KEY_UNKNOWN,
191 [30] = KEY_PROG2,
192 [31] = KEY_UNKNOWN,
193 [32] = KEY_UNKNOWN,
194 [33] = KEY_UNKNOWN,
195 [34] = KEY_UNKNOWN,
196 [35] = KEY_UNKNOWN,
197 [36] = KEY_UNKNOWN,
198 [37] = KEY_UNKNOWN,
199 [38] = KEY_MICMUTE,
200 [255] = KEY_PROG3,
201};
202
203/*
204 * These are applied if the 0xB2 DMI hotkey table is present and doesn't
205 * override them.
206 */
207static const struct key_entry dell_wmi_extra_keymap[] __initconst = {
208 /* Fn-lock */
209 { KE_IGNORE, 0x151, { KEY_RESERVED } },
210
211 /* Change keyboard illumination */
212 { KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
213
214 /*
215 * Radio disable (notify only -- there is no model for which the
216 * WMI event is supposed to trigger an action).
217 */
218 { KE_IGNORE, 0x153, { KEY_RFKILL } },
219
220 /* RGB keyboard backlight control */
221 { KE_IGNORE, 0x154, { KEY_RESERVED } },
222
223 /* Stealth mode toggle */
224 { KE_IGNORE, 0x155, { KEY_RESERVED } },
225};
226
227static struct input_dev *dell_wmi_input_dev;
228
229static void dell_wmi_process_key(int reported_key)
230{
231 const struct key_entry *key;
232
233 key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
234 reported_key);
235 if (!key) {
236 pr_info("Unknown key with scancode 0x%x pressed\n",
237 reported_key);
238 return;
239 }
240
241 pr_debug("Key %x pressed\n", reported_key);
242
243 /* Don't report brightness notifications that will also come via ACPI */
244 if ((key->keycode == KEY_BRIGHTNESSUP ||
245 key->keycode == KEY_BRIGHTNESSDOWN) &&
246 acpi_video_handles_brightness_key_presses())
247 return;
248
249 if (reported_key == 0xe025 && !wmi_requires_smbios_request)
250 return;
251
252 sparse_keymap_report_entry(dell_wmi_input_dev, key, 1, true);
253}
254
255static void dell_wmi_notify(u32 value, void *context)
256{
257 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
258 union acpi_object *obj;
259 acpi_status status;
260 acpi_size buffer_size;
261 u16 *buffer_entry, *buffer_end;
262 int len, i;
263
264 status = wmi_get_event_data(value, &response);
265 if (status != AE_OK) {
266 pr_warn("bad event status 0x%x\n", status);
267 return;
268 }
269
270 obj = (union acpi_object *)response.pointer;
271 if (!obj) {
272 pr_warn("no response\n");
273 return;
274 }
275
276 if (obj->type != ACPI_TYPE_BUFFER) {
277 pr_warn("bad response type %x\n", obj->type);
278 kfree(obj);
279 return;
280 }
281
282 pr_debug("Received WMI event (%*ph)\n",
283 obj->buffer.length, obj->buffer.pointer);
284
285 buffer_entry = (u16 *)obj->buffer.pointer;
286 buffer_size = obj->buffer.length/2;
287
288 if (!dell_new_hk_type) {
289 if (buffer_size >= 3 && buffer_entry[1] == 0x0)
290 dell_wmi_process_key(buffer_entry[2]);
291 else if (buffer_size >= 2)
292 dell_wmi_process_key(buffer_entry[1]);
293 else
294 pr_info("Received unknown WMI event\n");
295 kfree(obj);
296 return;
297 }
298
299 buffer_end = buffer_entry + buffer_size;
300
301 /*
302 * BIOS/ACPI on devices with WMI interface version 0 does not clear
303 * buffer before filling it. So next time when BIOS/ACPI send WMI event
304 * which is smaller as previous then it contains garbage in buffer from
305 * previous event.
306 *
307 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
308 * sometimes send more events in buffer at one call.
309 *
310 * So to prevent reading garbage from buffer we will process only first
311 * one event on devices with WMI interface version 0.
312 */
313 if (dell_wmi_interface_version == 0 && buffer_entry < buffer_end)
314 if (buffer_end > buffer_entry + buffer_entry[0] + 1)
315 buffer_end = buffer_entry + buffer_entry[0] + 1;
316
317 while (buffer_entry < buffer_end) {
318
319 len = buffer_entry[0];
320 if (len == 0)
321 break;
322
323 len++;
324
325 if (buffer_entry + len > buffer_end) {
326 pr_warn("Invalid length of WMI event\n");
327 break;
328 }
329
330 pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
331
332 switch (buffer_entry[1]) {
333 case 0x00:
334 for (i = 2; i < len; ++i) {
335 switch (buffer_entry[i]) {
336 case 0xe043:
337 /* NIC Link is Up */
338 pr_debug("NIC Link is Up\n");
339 break;
340 case 0xe044:
341 /* NIC Link is Down */
342 pr_debug("NIC Link is Down\n");
343 break;
344 case 0xe045:
345 /* Unknown event but defined in DSDT */
346 default:
347 /* Unknown event */
348 pr_info("Unknown WMI event type 0x00: "
349 "0x%x\n", (int)buffer_entry[i]);
350 break;
351 }
352 }
353 break;
354 case 0x10:
355 /* Keys pressed */
356 for (i = 2; i < len; ++i)
357 dell_wmi_process_key(buffer_entry[i]);
358 break;
359 case 0x11:
360 for (i = 2; i < len; ++i) {
361 switch (buffer_entry[i]) {
362 case 0xfff0:
363 /* Battery unplugged */
364 pr_debug("Battery unplugged\n");
365 break;
366 case 0xfff1:
367 /* Battery inserted */
368 pr_debug("Battery inserted\n");
369 break;
370 case 0x01e1:
371 case 0x02ea:
372 case 0x02eb:
373 case 0x02ec:
374 case 0x02f6:
375 /* Keyboard backlight level changed */
376 pr_debug("Keyboard backlight level "
377 "changed\n");
378 break;
379 default:
380 /* Unknown event */
381 pr_info("Unknown WMI event type 0x11: "
382 "0x%x\n", (int)buffer_entry[i]);
383 break;
384 }
385 }
386 break;
387 default:
388 /* Unknown event */
389 pr_info("Unknown WMI event type 0x%x\n",
390 (int)buffer_entry[1]);
391 break;
392 }
393
394 buffer_entry += len;
395
396 }
397
398 kfree(obj);
399}
400
401static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
402{
403 int i;
404
405 for (i = 0; i < len; i++)
406 if (keymap[i].code == scancode)
407 return true;
408
409 return false;
410}
411
412static void __init handle_dmi_entry(const struct dmi_header *dm,
413
414 void *opaque)
415
416{
417 struct dell_dmi_results *results = opaque;
418 struct dell_bios_hotkey_table *table;
419 int hotkey_num, i, pos = 0;
420 struct key_entry *keymap;
421 int num_bios_keys;
422
423 if (results->err || results->keymap)
424 return; /* We already found the hotkey table. */
425
426 if (dm->type != 0xb2)
427 return;
428
429 table = container_of(dm, struct dell_bios_hotkey_table, header);
430
431 hotkey_num = (table->header.length -
432 sizeof(struct dell_bios_hotkey_table)) /
433 sizeof(struct dell_bios_keymap_entry);
434 if (hotkey_num < 1) {
435 /*
436 * Historically, dell-wmi would ignore a DMI entry of
437 * fewer than 7 bytes. Sizes between 4 and 8 bytes are
438 * nonsensical (both the header and all entries are 4
439 * bytes), so we approximate the old behavior by
440 * ignoring tables with fewer than one entry.
441 */
442 return;
443 }
444
445 keymap = kcalloc(hotkey_num + ARRAY_SIZE(dell_wmi_extra_keymap) + 1,
446 sizeof(struct key_entry), GFP_KERNEL);
447 if (!keymap) {
448 results->err = -ENOMEM;
449 return;
450 }
451
452 for (i = 0; i < hotkey_num; i++) {
453 const struct dell_bios_keymap_entry *bios_entry =
454 &table->keymap[i];
455
456 /* Uninitialized entries are 0 aka KEY_RESERVED. */
457 u16 keycode = (bios_entry->keycode <
458 ARRAY_SIZE(bios_to_linux_keycode)) ?
459 bios_to_linux_keycode[bios_entry->keycode] :
460 KEY_RESERVED;
461
462 /*
463 * Log if we find an entry in the DMI table that we don't
464 * understand. If this happens, we should figure out what
465 * the entry means and add it to bios_to_linux_keycode.
466 */
467 if (keycode == KEY_RESERVED) {
468 pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
469 bios_entry->scancode, bios_entry->keycode);
470 continue;
471 }
472
473 if (keycode == KEY_KBDILLUMTOGGLE)
474 keymap[pos].type = KE_IGNORE;
475 else
476 keymap[pos].type = KE_KEY;
477 keymap[pos].code = bios_entry->scancode;
478 keymap[pos].keycode = keycode;
479
480 pos++;
481 }
482
483 num_bios_keys = pos;
484
485 for (i = 0; i < ARRAY_SIZE(dell_wmi_extra_keymap); i++) {
486 const struct key_entry *entry = &dell_wmi_extra_keymap[i];
487
488 /*
489 * Check if we've already found this scancode. This takes
490 * quadratic time, but it doesn't matter unless the list
491 * of extra keys gets very long.
492 */
493 if (!have_scancode(entry->code, keymap, num_bios_keys)) {
494 keymap[pos] = *entry;
495 pos++;
496 }
497 }
498
499 keymap[pos].type = KE_END;
500
501 results->keymap = keymap;
502}
503
504static int __init dell_wmi_input_setup(void)
505{
506 struct dell_dmi_results dmi_results = {};
507 int err;
508
509 dell_wmi_input_dev = input_allocate_device();
510 if (!dell_wmi_input_dev)
511 return -ENOMEM;
512
513 dell_wmi_input_dev->name = "Dell WMI hotkeys";
514 dell_wmi_input_dev->phys = "wmi/input0";
515 dell_wmi_input_dev->id.bustype = BUS_HOST;
516
517 if (dmi_walk(handle_dmi_entry, &dmi_results)) {
518 /*
519 * Historically, dell-wmi ignored dmi_walk errors. A failure
520 * is certainly surprising, but it probably just indicates
521 * a very old laptop.
522 */
523 pr_warn("no DMI; using the old-style hotkey interface\n");
524 }
525
526 if (dmi_results.err) {
527 err = dmi_results.err;
528 goto err_free_dev;
529 }
530
531 if (dmi_results.keymap) {
532 dell_new_hk_type = true;
533
534 err = sparse_keymap_setup(dell_wmi_input_dev,
535 dmi_results.keymap, NULL);
536
537 /*
538 * Sparse keymap library makes a copy of keymap so we
539 * don't need the original one that was allocated.
540 */
541 kfree(dmi_results.keymap);
542 } else {
543 err = sparse_keymap_setup(dell_wmi_input_dev,
544 dell_wmi_legacy_keymap, NULL);
545 }
546 if (err)
547 goto err_free_dev;
548
549 err = input_register_device(dell_wmi_input_dev);
550 if (err)
551 goto err_free_keymap;
552
553 return 0;
554
555 err_free_keymap:
556 sparse_keymap_free(dell_wmi_input_dev);
557 err_free_dev:
558 input_free_device(dell_wmi_input_dev);
559 return err;
560}
561
562static void dell_wmi_input_destroy(void)
563{
564 sparse_keymap_free(dell_wmi_input_dev);
565 input_unregister_device(dell_wmi_input_dev);
566}
567
568/*
569 * Descriptor buffer is 128 byte long and contains:
570 *
571 * Name Offset Length Value
572 * Vendor Signature 0 4 "DELL"
573 * Object Signature 4 4 " WMI"
574 * WMI Interface Version 8 4 <version>
575 * WMI buffer length 12 4 4096
576 */
577static int __init dell_wmi_check_descriptor_buffer(void)
578{
579 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
580 union acpi_object *obj;
581 acpi_status status;
582 u32 *buffer;
583
584 status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
585 if (ACPI_FAILURE(status)) {
586 pr_err("Cannot read Dell descriptor buffer - %d\n", status);
587 return status;
588 }
589
590 obj = (union acpi_object *)out.pointer;
591 if (!obj) {
592 pr_err("Dell descriptor buffer is empty\n");
593 return -EINVAL;
594 }
595
596 if (obj->type != ACPI_TYPE_BUFFER) {
597 pr_err("Cannot read Dell descriptor buffer\n");
598 kfree(obj);
599 return -EINVAL;
600 }
601
602 if (obj->buffer.length != 128) {
603 pr_err("Dell descriptor buffer has invalid length (%d)\n",
604 obj->buffer.length);
605 if (obj->buffer.length < 16) {
606 kfree(obj);
607 return -EINVAL;
608 }
609 }
610
611 buffer = (u32 *)obj->buffer.pointer;
612
613 if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
614 pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
615 8, buffer);
616
617 if (buffer[2] != 0 && buffer[2] != 1)
618 pr_warn("Dell descriptor buffer has unknown version (%d)\n",
619 buffer[2]);
620
621 if (buffer[3] != 4096)
622 pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
623 buffer[3]);
624
625 dell_wmi_interface_version = buffer[2];
626
627 pr_info("Detected Dell WMI interface version %u\n",
628 dell_wmi_interface_version);
629
630 kfree(obj);
631 return 0;
632}
633
634/*
635 * According to Dell SMBIOS documentation:
636 *
637 * 17 3 Application Program Registration
638 *
639 * cbArg1 Application ID 1 = 0x00010000
640 * cbArg2 Application ID 2
641 * QUICKSET/DCP = 0x51534554 "QSET"
642 * ALS Driver = 0x416c7353 "AlsS"
643 * Latitude ON = 0x4c6f6e52 "LonR"
644 * cbArg3 Application version or revision number
645 * cbArg4 0 = Unregister application
646 * 1 = Register application
647 * cbRes1 Standard return codes (0, -1, -2)
648 */
649
650static int dell_wmi_events_set_enabled(bool enable)
651{
652 struct calling_interface_buffer *buffer;
653 int ret;
654
655 buffer = dell_smbios_get_buffer();
656 buffer->input[0] = 0x10000;
657 buffer->input[1] = 0x51534554;
658 buffer->input[3] = enable;
659 dell_smbios_send_request(17, 3);
660 ret = buffer->output[0];
661 dell_smbios_release_buffer();
662
663 return dell_smbios_error(ret);
664}
665
666static int __init dell_wmi_init(void)
667{
668 int err;
669 acpi_status status;
670
671 if (!wmi_has_guid(DELL_EVENT_GUID) ||
672 !wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
673 pr_warn("Dell WMI GUID were not found\n");
674 return -ENODEV;
675 }
676
677 err = dell_wmi_check_descriptor_buffer();
678 if (err)
679 return err;
680
681 err = dell_wmi_input_setup();
682 if (err)
683 return err;
684
685 status = wmi_install_notify_handler(DELL_EVENT_GUID,
686 dell_wmi_notify, NULL);
687 if (ACPI_FAILURE(status)) {
688 dell_wmi_input_destroy();
689 pr_err("Unable to register notify handler - %d\n", status);
690 return -ENODEV;
691 }
692
693 dmi_check_system(dell_wmi_smbios_list);
694
695 if (wmi_requires_smbios_request) {
696 err = dell_wmi_events_set_enabled(true);
697 if (err) {
698 pr_err("Failed to enable WMI events\n");
699 wmi_remove_notify_handler(DELL_EVENT_GUID);
700 dell_wmi_input_destroy();
701 return err;
702 }
703 }
704
705 return 0;
706}
707module_init(dell_wmi_init);
708
709static void __exit dell_wmi_exit(void)
710{
711 if (wmi_requires_smbios_request)
712 dell_wmi_events_set_enabled(false);
713 wmi_remove_notify_handler(DELL_EVENT_GUID);
714 dell_wmi_input_destroy();
715}
716module_exit(dell_wmi_exit);
1/*
2 * Dell WMI hotkeys
3 *
4 * Copyright (C) 2008 Red Hat <mjg@redhat.com>
5 * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
6 *
7 * Portions based on wistron_btns.c:
8 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
9 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
10 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
26
27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/init.h>
32#include <linux/slab.h>
33#include <linux/types.h>
34#include <linux/input.h>
35#include <linux/input/sparse-keymap.h>
36#include <linux/acpi.h>
37#include <linux/string.h>
38#include <linux/dmi.h>
39#include <acpi/video.h>
40#include "dell-smbios.h"
41
42MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
43MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
44MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
45MODULE_LICENSE("GPL");
46
47#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
48#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
49
50static u32 dell_wmi_interface_version;
51static bool wmi_requires_smbios_request;
52
53MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
54MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
55
56static int __init dmi_matched(const struct dmi_system_id *dmi)
57{
58 wmi_requires_smbios_request = 1;
59 return 1;
60}
61
62static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
63 {
64 .callback = dmi_matched,
65 .ident = "Dell Inspiron M5110",
66 .matches = {
67 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
68 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
69 },
70 },
71 {
72 .callback = dmi_matched,
73 .ident = "Dell Vostro V131",
74 .matches = {
75 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
76 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
77 },
78 },
79 { }
80};
81
82/*
83 * Keymap for WMI events of type 0x0000
84 *
85 * Certain keys are flagged as KE_IGNORE. All of these are either
86 * notifications (rather than requests for change) or are also sent
87 * via the keyboard controller so should not be sent again.
88 */
89static const struct key_entry dell_wmi_keymap_type_0000[] __initconst = {
90 { KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
91
92 /* Key code is followed by brightness level */
93 { KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
94 { KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
95
96 /* Battery health status button */
97 { KE_KEY, 0xe007, { KEY_BATTERY } },
98
99 /* Radio devices state change, key code is followed by other values */
100 { KE_IGNORE, 0xe008, { KEY_RFKILL } },
101
102 { KE_KEY, 0xe009, { KEY_EJECTCD } },
103
104 /* Key code is followed by: next, active and attached devices */
105 { KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
106
107 /* Key code is followed by keyboard illumination level */
108 { KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
109
110 /* BIOS error detected */
111 { KE_IGNORE, 0xe00d, { KEY_RESERVED } },
112
113 /* Battery was removed or inserted */
114 { KE_IGNORE, 0xe00e, { KEY_RESERVED } },
115
116 /* Wifi Catcher */
117 { KE_KEY, 0xe011, { KEY_WLAN } },
118
119 /* Ambient light sensor toggle */
120 { KE_IGNORE, 0xe013, { KEY_RESERVED } },
121
122 { KE_IGNORE, 0xe020, { KEY_MUTE } },
123
124 /* Unknown, defined in ACPI DSDT */
125 /* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */
126
127 /* Untested, Dell Instant Launch key on Inspiron 7520 */
128 /* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */
129
130 /* Dell Instant Launch key */
131 { KE_KEY, 0xe025, { KEY_PROG4 } },
132
133 /* Audio panel key */
134 { KE_IGNORE, 0xe026, { KEY_RESERVED } },
135
136 /* LCD Display On/Off Control key */
137 { KE_KEY, 0xe027, { KEY_DISPLAYTOGGLE } },
138
139 /* Untested, Multimedia key on Dell Vostro 3560 */
140 /* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */
141
142 /* Dell Instant Launch key */
143 { KE_KEY, 0xe029, { KEY_PROG4 } },
144
145 /* Untested, Windows Mobility Center button on Inspiron 7520 */
146 /* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
147
148 /* Unknown, defined in ACPI DSDT */
149 /* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */
150
151 /* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
152 /* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */
153
154 { KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
155 { KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
156 { KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
157 { KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
158 { KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
159
160 /* NIC Link is Up */
161 { KE_IGNORE, 0xe043, { KEY_RESERVED } },
162
163 /* NIC Link is Down */
164 { KE_IGNORE, 0xe044, { KEY_RESERVED } },
165
166 /*
167 * This entry is very suspicious!
168 * Originally Matthew Garrett created this dell-wmi driver specially for
169 * "button with a picture of a battery" which has event code 0xe045.
170 * Later Mario Limonciello from Dell told us that event code 0xe045 is
171 * reported by Num Lock and should be ignored because key is send also
172 * by keyboard controller.
173 * So for now we will ignore this event to prevent potential double
174 * Num Lock key press.
175 */
176 { KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
177
178 /* Scroll lock and also going to tablet mode on portable devices */
179 { KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
180
181 /* Untested, going from tablet mode on portable devices */
182 /* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */
183
184 /* Dell Support Center key */
185 { KE_IGNORE, 0xe06e, { KEY_RESERVED } },
186
187 { KE_IGNORE, 0xe0f7, { KEY_MUTE } },
188 { KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
189 { KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
190};
191
192struct dell_bios_keymap_entry {
193 u16 scancode;
194 u16 keycode;
195};
196
197struct dell_bios_hotkey_table {
198 struct dmi_header header;
199 struct dell_bios_keymap_entry keymap[];
200
201};
202
203struct dell_dmi_results {
204 int err;
205 int keymap_size;
206 struct key_entry *keymap;
207};
208
209/* Uninitialized entries here are KEY_RESERVED == 0. */
210static const u16 bios_to_linux_keycode[256] __initconst = {
211 [0] = KEY_MEDIA,
212 [1] = KEY_NEXTSONG,
213 [2] = KEY_PLAYPAUSE,
214 [3] = KEY_PREVIOUSSONG,
215 [4] = KEY_STOPCD,
216 [5] = KEY_UNKNOWN,
217 [6] = KEY_UNKNOWN,
218 [7] = KEY_UNKNOWN,
219 [8] = KEY_WWW,
220 [9] = KEY_UNKNOWN,
221 [10] = KEY_VOLUMEDOWN,
222 [11] = KEY_MUTE,
223 [12] = KEY_VOLUMEUP,
224 [13] = KEY_UNKNOWN,
225 [14] = KEY_BATTERY,
226 [15] = KEY_EJECTCD,
227 [16] = KEY_UNKNOWN,
228 [17] = KEY_SLEEP,
229 [18] = KEY_PROG1,
230 [19] = KEY_BRIGHTNESSDOWN,
231 [20] = KEY_BRIGHTNESSUP,
232 [21] = KEY_UNKNOWN,
233 [22] = KEY_KBDILLUMTOGGLE,
234 [23] = KEY_UNKNOWN,
235 [24] = KEY_SWITCHVIDEOMODE,
236 [25] = KEY_UNKNOWN,
237 [26] = KEY_UNKNOWN,
238 [27] = KEY_SWITCHVIDEOMODE,
239 [28] = KEY_UNKNOWN,
240 [29] = KEY_UNKNOWN,
241 [30] = KEY_PROG2,
242 [31] = KEY_UNKNOWN,
243 [32] = KEY_UNKNOWN,
244 [33] = KEY_UNKNOWN,
245 [34] = KEY_UNKNOWN,
246 [35] = KEY_UNKNOWN,
247 [36] = KEY_UNKNOWN,
248 [37] = KEY_UNKNOWN,
249 [38] = KEY_MICMUTE,
250 [255] = KEY_PROG3,
251};
252
253/*
254 * Keymap for WMI events of type 0x0010
255 *
256 * These are applied if the 0xB2 DMI hotkey table is present and doesn't
257 * override them.
258 */
259static const struct key_entry dell_wmi_keymap_type_0010[] __initconst = {
260 /* Fn-lock */
261 { KE_IGNORE, 0x151, { KEY_RESERVED } },
262
263 /* Change keyboard illumination */
264 { KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
265
266 /*
267 * Radio disable (notify only -- there is no model for which the
268 * WMI event is supposed to trigger an action).
269 */
270 { KE_IGNORE, 0x153, { KEY_RFKILL } },
271
272 /* RGB keyboard backlight control */
273 { KE_IGNORE, 0x154, { KEY_RESERVED } },
274
275 /* Stealth mode toggle */
276 { KE_IGNORE, 0x155, { KEY_RESERVED } },
277
278 /* Rugged magnetic dock attach/detach events */
279 { KE_IGNORE, 0x156, { KEY_RESERVED } },
280 { KE_IGNORE, 0x157, { KEY_RESERVED } },
281
282 /* Rugged programmable (P1/P2/P3 keys) */
283 { KE_KEY, 0x850, { KEY_PROG1 } },
284 { KE_KEY, 0x851, { KEY_PROG2 } },
285 { KE_KEY, 0x852, { KEY_PROG3 } },
286
287};
288
289/*
290 * Keymap for WMI events of type 0x0011
291 */
292static const struct key_entry dell_wmi_keymap_type_0011[] __initconst = {
293 /* Battery unplugged */
294 { KE_IGNORE, 0xfff0, { KEY_RESERVED } },
295
296 /* Battery inserted */
297 { KE_IGNORE, 0xfff1, { KEY_RESERVED } },
298
299 /* Keyboard backlight level changed */
300 { KE_IGNORE, 0x01e1, { KEY_RESERVED } },
301 { KE_IGNORE, 0x02ea, { KEY_RESERVED } },
302 { KE_IGNORE, 0x02eb, { KEY_RESERVED } },
303 { KE_IGNORE, 0x02ec, { KEY_RESERVED } },
304 { KE_IGNORE, 0x02f6, { KEY_RESERVED } },
305};
306
307static struct input_dev *dell_wmi_input_dev;
308
309static void dell_wmi_process_key(int type, int code)
310{
311 const struct key_entry *key;
312
313 key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
314 (type << 16) | code);
315 if (!key) {
316 pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
317 type, code);
318 return;
319 }
320
321 pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);
322
323 /* Don't report brightness notifications that will also come via ACPI */
324 if ((key->keycode == KEY_BRIGHTNESSUP ||
325 key->keycode == KEY_BRIGHTNESSDOWN) &&
326 acpi_video_handles_brightness_key_presses())
327 return;
328
329 if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
330 return;
331
332 sparse_keymap_report_entry(dell_wmi_input_dev, key, 1, true);
333}
334
335static void dell_wmi_notify(u32 value, void *context)
336{
337 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
338 union acpi_object *obj;
339 acpi_status status;
340 acpi_size buffer_size;
341 u16 *buffer_entry, *buffer_end;
342 int len, i;
343
344 status = wmi_get_event_data(value, &response);
345 if (status != AE_OK) {
346 pr_warn("bad event status 0x%x\n", status);
347 return;
348 }
349
350 obj = (union acpi_object *)response.pointer;
351 if (!obj) {
352 pr_warn("no response\n");
353 return;
354 }
355
356 if (obj->type != ACPI_TYPE_BUFFER) {
357 pr_warn("bad response type %x\n", obj->type);
358 kfree(obj);
359 return;
360 }
361
362 pr_debug("Received WMI event (%*ph)\n",
363 obj->buffer.length, obj->buffer.pointer);
364
365 buffer_entry = (u16 *)obj->buffer.pointer;
366 buffer_size = obj->buffer.length/2;
367 buffer_end = buffer_entry + buffer_size;
368
369 /*
370 * BIOS/ACPI on devices with WMI interface version 0 does not clear
371 * buffer before filling it. So next time when BIOS/ACPI send WMI event
372 * which is smaller as previous then it contains garbage in buffer from
373 * previous event.
374 *
375 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
376 * sometimes send more events in buffer at one call.
377 *
378 * So to prevent reading garbage from buffer we will process only first
379 * one event on devices with WMI interface version 0.
380 */
381 if (dell_wmi_interface_version == 0 && buffer_entry < buffer_end)
382 if (buffer_end > buffer_entry + buffer_entry[0] + 1)
383 buffer_end = buffer_entry + buffer_entry[0] + 1;
384
385 while (buffer_entry < buffer_end) {
386
387 len = buffer_entry[0];
388 if (len == 0)
389 break;
390
391 len++;
392
393 if (buffer_entry + len > buffer_end) {
394 pr_warn("Invalid length of WMI event\n");
395 break;
396 }
397
398 pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
399
400 switch (buffer_entry[1]) {
401 case 0x0000: /* One key pressed or event occurred */
402 if (len > 2)
403 dell_wmi_process_key(0x0000, buffer_entry[2]);
404 /* Other entries could contain additional information */
405 break;
406 case 0x0010: /* Sequence of keys pressed */
407 case 0x0011: /* Sequence of events occurred */
408 for (i = 2; i < len; ++i)
409 dell_wmi_process_key(buffer_entry[1],
410 buffer_entry[i]);
411 break;
412 default: /* Unknown event */
413 pr_info("Unknown WMI event type 0x%x\n",
414 (int)buffer_entry[1]);
415 break;
416 }
417
418 buffer_entry += len;
419
420 }
421
422 kfree(obj);
423}
424
425static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
426{
427 int i;
428
429 for (i = 0; i < len; i++)
430 if (keymap[i].code == scancode)
431 return true;
432
433 return false;
434}
435
436static void __init handle_dmi_entry(const struct dmi_header *dm,
437 void *opaque)
438
439{
440 struct dell_dmi_results *results = opaque;
441 struct dell_bios_hotkey_table *table;
442 int hotkey_num, i, pos = 0;
443 struct key_entry *keymap;
444
445 if (results->err || results->keymap)
446 return; /* We already found the hotkey table. */
447
448 if (dm->type != 0xb2)
449 return;
450
451 table = container_of(dm, struct dell_bios_hotkey_table, header);
452
453 hotkey_num = (table->header.length -
454 sizeof(struct dell_bios_hotkey_table)) /
455 sizeof(struct dell_bios_keymap_entry);
456 if (hotkey_num < 1) {
457 /*
458 * Historically, dell-wmi would ignore a DMI entry of
459 * fewer than 7 bytes. Sizes between 4 and 8 bytes are
460 * nonsensical (both the header and all entries are 4
461 * bytes), so we approximate the old behavior by
462 * ignoring tables with fewer than one entry.
463 */
464 return;
465 }
466
467 keymap = kcalloc(hotkey_num, sizeof(struct key_entry), GFP_KERNEL);
468 if (!keymap) {
469 results->err = -ENOMEM;
470 return;
471 }
472
473 for (i = 0; i < hotkey_num; i++) {
474 const struct dell_bios_keymap_entry *bios_entry =
475 &table->keymap[i];
476
477 /* Uninitialized entries are 0 aka KEY_RESERVED. */
478 u16 keycode = (bios_entry->keycode <
479 ARRAY_SIZE(bios_to_linux_keycode)) ?
480 bios_to_linux_keycode[bios_entry->keycode] :
481 KEY_RESERVED;
482
483 /*
484 * Log if we find an entry in the DMI table that we don't
485 * understand. If this happens, we should figure out what
486 * the entry means and add it to bios_to_linux_keycode.
487 */
488 if (keycode == KEY_RESERVED) {
489 pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
490 bios_entry->scancode, bios_entry->keycode);
491 continue;
492 }
493
494 if (keycode == KEY_KBDILLUMTOGGLE)
495 keymap[pos].type = KE_IGNORE;
496 else
497 keymap[pos].type = KE_KEY;
498 keymap[pos].code = bios_entry->scancode;
499 keymap[pos].keycode = keycode;
500
501 pos++;
502 }
503
504 results->keymap = keymap;
505 results->keymap_size = pos;
506}
507
508static int __init dell_wmi_input_setup(void)
509{
510 struct dell_dmi_results dmi_results = {};
511 struct key_entry *keymap;
512 int err, i, pos = 0;
513
514 dell_wmi_input_dev = input_allocate_device();
515 if (!dell_wmi_input_dev)
516 return -ENOMEM;
517
518 dell_wmi_input_dev->name = "Dell WMI hotkeys";
519 dell_wmi_input_dev->phys = "wmi/input0";
520 dell_wmi_input_dev->id.bustype = BUS_HOST;
521
522 if (dmi_walk(handle_dmi_entry, &dmi_results)) {
523 /*
524 * Historically, dell-wmi ignored dmi_walk errors. A failure
525 * is certainly surprising, but it probably just indicates
526 * a very old laptop.
527 */
528 pr_warn("no DMI; using the old-style hotkey interface\n");
529 }
530
531 if (dmi_results.err) {
532 err = dmi_results.err;
533 goto err_free_dev;
534 }
535
536 keymap = kcalloc(dmi_results.keymap_size +
537 ARRAY_SIZE(dell_wmi_keymap_type_0000) +
538 ARRAY_SIZE(dell_wmi_keymap_type_0010) +
539 ARRAY_SIZE(dell_wmi_keymap_type_0011) +
540 1,
541 sizeof(struct key_entry), GFP_KERNEL);
542 if (!keymap) {
543 kfree(dmi_results.keymap);
544 err = -ENOMEM;
545 goto err_free_dev;
546 }
547
548 /* Append table with events of type 0x0010 which comes from DMI */
549 for (i = 0; i < dmi_results.keymap_size; i++) {
550 keymap[pos] = dmi_results.keymap[i];
551 keymap[pos].code |= (0x0010 << 16);
552 pos++;
553 }
554
555 kfree(dmi_results.keymap);
556
557 /* Append table with extra events of type 0x0010 which are not in DMI */
558 for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
559 const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];
560
561 /*
562 * Check if we've already found this scancode. This takes
563 * quadratic time, but it doesn't matter unless the list
564 * of extra keys gets very long.
565 */
566 if (dmi_results.keymap_size &&
567 have_scancode(entry->code | (0x0010 << 16),
568 keymap, dmi_results.keymap_size)
569 )
570 continue;
571
572 keymap[pos] = *entry;
573 keymap[pos].code |= (0x0010 << 16);
574 pos++;
575 }
576
577 /* Append table with events of type 0x0011 */
578 for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
579 keymap[pos] = dell_wmi_keymap_type_0011[i];
580 keymap[pos].code |= (0x0011 << 16);
581 pos++;
582 }
583
584 /*
585 * Now append also table with "legacy" events of type 0x0000. Some of
586 * them are reported also on laptops which have scancodes in DMI.
587 */
588 for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
589 keymap[pos] = dell_wmi_keymap_type_0000[i];
590 pos++;
591 }
592
593 keymap[pos].type = KE_END;
594
595 err = sparse_keymap_setup(dell_wmi_input_dev, keymap, NULL);
596 /*
597 * Sparse keymap library makes a copy of keymap so we don't need the
598 * original one that was allocated.
599 */
600 kfree(keymap);
601 if (err)
602 goto err_free_dev;
603
604 err = input_register_device(dell_wmi_input_dev);
605 if (err)
606 goto err_free_keymap;
607
608 return 0;
609
610 err_free_keymap:
611 sparse_keymap_free(dell_wmi_input_dev);
612 err_free_dev:
613 input_free_device(dell_wmi_input_dev);
614 return err;
615}
616
617static void dell_wmi_input_destroy(void)
618{
619 sparse_keymap_free(dell_wmi_input_dev);
620 input_unregister_device(dell_wmi_input_dev);
621}
622
623/*
624 * Descriptor buffer is 128 byte long and contains:
625 *
626 * Name Offset Length Value
627 * Vendor Signature 0 4 "DELL"
628 * Object Signature 4 4 " WMI"
629 * WMI Interface Version 8 4 <version>
630 * WMI buffer length 12 4 4096
631 */
632static int __init dell_wmi_check_descriptor_buffer(void)
633{
634 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
635 union acpi_object *obj;
636 acpi_status status;
637 u32 *buffer;
638
639 status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
640 if (ACPI_FAILURE(status)) {
641 pr_err("Cannot read Dell descriptor buffer - %d\n", status);
642 return status;
643 }
644
645 obj = (union acpi_object *)out.pointer;
646 if (!obj) {
647 pr_err("Dell descriptor buffer is empty\n");
648 return -EINVAL;
649 }
650
651 if (obj->type != ACPI_TYPE_BUFFER) {
652 pr_err("Cannot read Dell descriptor buffer\n");
653 kfree(obj);
654 return -EINVAL;
655 }
656
657 if (obj->buffer.length != 128) {
658 pr_err("Dell descriptor buffer has invalid length (%d)\n",
659 obj->buffer.length);
660 if (obj->buffer.length < 16) {
661 kfree(obj);
662 return -EINVAL;
663 }
664 }
665
666 buffer = (u32 *)obj->buffer.pointer;
667
668 if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
669 pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
670 8, buffer);
671
672 if (buffer[2] != 0 && buffer[2] != 1)
673 pr_warn("Dell descriptor buffer has unknown version (%d)\n",
674 buffer[2]);
675
676 if (buffer[3] != 4096)
677 pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
678 buffer[3]);
679
680 dell_wmi_interface_version = buffer[2];
681
682 pr_info("Detected Dell WMI interface version %u\n",
683 dell_wmi_interface_version);
684
685 kfree(obj);
686 return 0;
687}
688
689/*
690 * According to Dell SMBIOS documentation:
691 *
692 * 17 3 Application Program Registration
693 *
694 * cbArg1 Application ID 1 = 0x00010000
695 * cbArg2 Application ID 2
696 * QUICKSET/DCP = 0x51534554 "QSET"
697 * ALS Driver = 0x416c7353 "AlsS"
698 * Latitude ON = 0x4c6f6e52 "LonR"
699 * cbArg3 Application version or revision number
700 * cbArg4 0 = Unregister application
701 * 1 = Register application
702 * cbRes1 Standard return codes (0, -1, -2)
703 */
704
705static int dell_wmi_events_set_enabled(bool enable)
706{
707 struct calling_interface_buffer *buffer;
708 int ret;
709
710 buffer = dell_smbios_get_buffer();
711 buffer->input[0] = 0x10000;
712 buffer->input[1] = 0x51534554;
713 buffer->input[3] = enable;
714 dell_smbios_send_request(17, 3);
715 ret = buffer->output[0];
716 dell_smbios_release_buffer();
717
718 return dell_smbios_error(ret);
719}
720
721static int __init dell_wmi_init(void)
722{
723 int err;
724 acpi_status status;
725
726 if (!wmi_has_guid(DELL_EVENT_GUID) ||
727 !wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
728 pr_warn("Dell WMI GUID were not found\n");
729 return -ENODEV;
730 }
731
732 err = dell_wmi_check_descriptor_buffer();
733 if (err)
734 return err;
735
736 err = dell_wmi_input_setup();
737 if (err)
738 return err;
739
740 status = wmi_install_notify_handler(DELL_EVENT_GUID,
741 dell_wmi_notify, NULL);
742 if (ACPI_FAILURE(status)) {
743 dell_wmi_input_destroy();
744 pr_err("Unable to register notify handler - %d\n", status);
745 return -ENODEV;
746 }
747
748 dmi_check_system(dell_wmi_smbios_list);
749
750 if (wmi_requires_smbios_request) {
751 err = dell_wmi_events_set_enabled(true);
752 if (err) {
753 pr_err("Failed to enable WMI events\n");
754 wmi_remove_notify_handler(DELL_EVENT_GUID);
755 dell_wmi_input_destroy();
756 return err;
757 }
758 }
759
760 return 0;
761}
762module_init(dell_wmi_init);
763
764static void __exit dell_wmi_exit(void)
765{
766 if (wmi_requires_smbios_request)
767 dell_wmi_events_set_enabled(false);
768 wmi_remove_notify_handler(DELL_EVENT_GUID);
769 dell_wmi_input_destroy();
770}
771module_exit(dell_wmi_exit);