2 * Copyright (C) 2015 Red Hat Inc.
3 * Hans de Goede <hdegoede@redhat.com>
4 * Copyright (C) 2008 SuSE Linux Products GmbH
5 * Thomas Renninger <trenn@suse.de>
7 * May be copied or modified under the terms of the GNU General Public License
10 * After PCI devices are glued with ACPI devices
11 * acpi_get_pci_dev() can be called to identify ACPI graphics
12 * devices for which a real graphics card is plugged in
14 * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
15 * are available, video.ko should be used to handle the device.
17 * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
18 * sony_acpi,... can take care about backlight brightness.
20 * Backlight drivers can use acpi_video_get_backlight_type() to determine which
21 * driver should handle the backlight. RAW/GPU-driver backlight drivers must
22 * use the acpi_video_backlight_use_native() helper for this.
24 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
25 * this file will not be compiled and acpi_video_get_backlight_type() will
26 * always return acpi_backlight_vendor.
29 #include <linux/export.h>
30 #include <linux/acpi.h>
31 #include <linux/apple-gmux.h>
32 #include <linux/backlight.h>
33 #include <linux/dmi.h>
34 #include <linux/module.h>
35 #include <linux/pci.h>
36 #include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
37 #include <linux/pnp.h>
38 #include <linux/types.h>
39 #include <linux/workqueue.h>
40 #include <acpi/video.h>
42 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
43 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
45 static void acpi_video_parse_cmdline(void)
47 if (!strcmp("vendor", acpi_video_backlight_string))
48 acpi_backlight_cmdline = acpi_backlight_vendor;
49 if (!strcmp("video", acpi_video_backlight_string))
50 acpi_backlight_cmdline = acpi_backlight_video;
51 if (!strcmp("native", acpi_video_backlight_string))
52 acpi_backlight_cmdline = acpi_backlight_native;
53 if (!strcmp("nvidia_wmi_ec", acpi_video_backlight_string))
54 acpi_backlight_cmdline = acpi_backlight_nvidia_wmi_ec;
55 if (!strcmp("apple_gmux", acpi_video_backlight_string))
56 acpi_backlight_cmdline = acpi_backlight_apple_gmux;
57 if (!strcmp("none", acpi_video_backlight_string))
58 acpi_backlight_cmdline = acpi_backlight_none;
62 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
64 struct acpi_device *acpi_dev = acpi_fetch_acpi_dev(handle);
68 static const struct acpi_device_id video_ids[] = {
73 if (acpi_dev && !acpi_match_device_ids(acpi_dev, video_ids)) {
74 dev = acpi_get_pci_dev(handle);
78 *cap |= acpi_is_video_device(handle);
83 /* This depends on ACPI_WMI which is X86 only */
85 static bool nvidia_wmi_ec_supported(void)
87 struct wmi_brightness_args args = {
88 .mode = WMI_BRIGHTNESS_MODE_GET,
92 struct acpi_buffer buf = { (acpi_size)sizeof(args), &args };
95 status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0,
96 WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf);
97 if (ACPI_FAILURE(status))
101 * If brightness is handled by the EC then nvidia-wmi-ec-backlight
102 * should be used, else the GPU driver(s) should be used.
104 return args.ret == WMI_BRIGHTNESS_SOURCE_EC;
107 static bool nvidia_wmi_ec_supported(void)
113 /* Force to use vendor driver when the ACPI device is known to be
115 static int video_detect_force_vendor(const struct dmi_system_id *d)
117 acpi_backlight_dmi = acpi_backlight_vendor;
121 static int video_detect_force_video(const struct dmi_system_id *d)
123 acpi_backlight_dmi = acpi_backlight_video;
127 static int video_detect_force_native(const struct dmi_system_id *d)
129 acpi_backlight_dmi = acpi_backlight_native;
133 static int video_detect_force_none(const struct dmi_system_id *d)
135 acpi_backlight_dmi = acpi_backlight_none;
139 static const struct dmi_system_id video_detect_dmi_table[] = {
141 * Models which should use the vendor backlight interface,
142 * because of broken ACPI video backlight control.
145 /* https://bugzilla.redhat.com/show_bug.cgi?id=1128309 */
146 .callback = video_detect_force_vendor,
149 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
150 DMI_MATCH(DMI_PRODUCT_NAME, "KAV80"),
154 .callback = video_detect_force_vendor,
157 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
158 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
162 .callback = video_detect_force_vendor,
165 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
166 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
170 .callback = video_detect_force_vendor,
173 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
174 DMI_MATCH(DMI_PRODUCT_NAME, "X55U"),
178 .callback = video_detect_force_vendor,
181 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
182 DMI_MATCH(DMI_PRODUCT_NAME, "X101CH"),
186 .callback = video_detect_force_vendor,
189 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
190 DMI_MATCH(DMI_PRODUCT_NAME, "X401U"),
194 .callback = video_detect_force_vendor,
197 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
198 DMI_MATCH(DMI_PRODUCT_NAME, "X501U"),
202 .callback = video_detect_force_vendor,
205 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
206 DMI_MATCH(DMI_PRODUCT_NAME, "1015CX"),
210 .callback = video_detect_force_vendor,
211 /* Samsung N150/N210/N220 */
213 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
214 DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
215 DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
219 .callback = video_detect_force_vendor,
220 /* Samsung NF110/NF210/NF310 */
222 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
223 DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
224 DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
228 .callback = video_detect_force_vendor,
231 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
232 DMI_MATCH(DMI_PRODUCT_NAME, "NC210/NC110"),
233 DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
237 .callback = video_detect_force_vendor,
238 /* Xiaomi Mi Pad 2 */
240 DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
241 DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
246 * Models which should use the vendor backlight interface,
247 * because of broken native backlight control.
250 .callback = video_detect_force_vendor,
251 /* Sony Vaio PCG-FRV35 */
253 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
254 DMI_MATCH(DMI_PRODUCT_NAME, "PCG-FRV35"),
259 * Toshiba models with Transflective display, these need to use
260 * the toshiba_acpi vendor driver for proper Transflective handling.
263 .callback = video_detect_force_vendor,
265 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
266 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R500"),
270 .callback = video_detect_force_vendor,
272 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
273 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R600"),
278 * These models have a working acpi_video backlight control, and using
279 * native backlight causes a regression where backlight does not work
280 * when userspace is not handling brightness key events. Disable
281 * native_backlight on these to fix this:
282 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
285 .callback = video_detect_force_video,
288 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
289 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
293 .callback = video_detect_force_video,
296 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
297 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
301 .callback = video_detect_force_video,
304 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
305 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
309 .callback = video_detect_force_video,
312 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
313 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
317 /* The native backlight controls do not work on some older machines */
319 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
320 .callback = video_detect_force_video,
321 /* HP ENVY 15 Notebook */
323 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
324 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
328 .callback = video_detect_force_video,
329 /* SAMSUNG 870Z5E/880Z5E/680Z5E */
331 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
332 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
336 .callback = video_detect_force_video,
337 /* SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V */
339 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
340 DMI_MATCH(DMI_PRODUCT_NAME,
341 "370R4E/370R4V/370R5E/3570RE/370R5V"),
345 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
346 .callback = video_detect_force_video,
347 /* SAMSUNG 3570R/370R/470R/450R/510R/4450RV */
349 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
350 DMI_MATCH(DMI_PRODUCT_NAME,
351 "3570R/370R/470R/450R/510R/4450RV"),
355 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
356 .callback = video_detect_force_video,
359 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
360 DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
364 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
365 .callback = video_detect_force_video,
366 /* SAMSUNG 730U3E/740U3E */
368 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
369 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
373 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
374 .callback = video_detect_force_video,
375 /* SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D */
377 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
378 DMI_MATCH(DMI_PRODUCT_NAME,
379 "900X3C/900X3D/900X3E/900X4C/900X4D"),
383 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
384 .callback = video_detect_force_video,
385 /* Dell XPS14 L421X */
387 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
388 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
392 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
393 .callback = video_detect_force_video,
394 /* Dell XPS15 L521X */
396 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
397 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
401 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
402 .callback = video_detect_force_video,
403 /* SAMSUNG 530U4E/540U4E */
405 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
406 DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
409 /* https://bugs.launchpad.net/bugs/1894667 */
411 .callback = video_detect_force_video,
412 /* HP 635 Notebook */
414 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
415 DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
419 /* Non win8 machines which need native backlight nevertheless */
421 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
422 .callback = video_detect_force_native,
423 /* Lenovo Ideapad S405 */
425 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
426 DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
430 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
431 .callback = video_detect_force_native,
432 /* Lenovo Ideapad Z570 */
434 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
435 DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
439 .callback = video_detect_force_native,
442 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
443 DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
447 .callback = video_detect_force_native,
450 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
451 DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
455 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
456 .callback = video_detect_force_native,
457 /* Apple MacBook Pro 12,1 */
459 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
460 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
464 .callback = video_detect_force_native,
465 /* Dell Inspiron N4010 */
467 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
468 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron N4010"),
472 .callback = video_detect_force_native,
473 /* Dell Vostro V131 */
475 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
476 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
480 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
481 .callback = video_detect_force_native,
482 /* Dell XPS 17 L702X */
484 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
485 DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
489 .callback = video_detect_force_native,
490 /* Dell Precision 7510 */
492 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
493 DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
497 .callback = video_detect_force_native,
498 /* Acer Aspire 4810T */
500 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
501 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4810T"),
505 .callback = video_detect_force_native,
506 /* Acer Aspire 5738z */
508 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
509 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
510 DMI_MATCH(DMI_BOARD_NAME, "JV50"),
514 /* https://bugzilla.redhat.com/show_bug.cgi?id=1012674 */
515 .callback = video_detect_force_native,
516 /* Acer Aspire 5741 */
518 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
519 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5741"),
523 /* https://bugzilla.kernel.org/show_bug.cgi?id=42993 */
524 .callback = video_detect_force_native,
525 /* Acer Aspire 5750 */
527 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
528 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5750"),
532 /* https://bugzilla.kernel.org/show_bug.cgi?id=42833 */
533 .callback = video_detect_force_native,
534 /* Acer Extensa 5235 */
536 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
537 DMI_MATCH(DMI_PRODUCT_NAME, "Extensa 5235"),
541 .callback = video_detect_force_native,
542 /* Acer TravelMate 4750 */
544 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
545 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
549 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
550 .callback = video_detect_force_native,
551 /* Acer TravelMate 5735Z */
553 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
554 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
555 DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
559 /* https://bugzilla.kernel.org/show_bug.cgi?id=36322 */
560 .callback = video_detect_force_native,
561 /* Acer TravelMate 5760 */
563 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
564 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5760"),
568 .callback = video_detect_force_native,
569 /* ASUSTeK COMPUTER INC. GA401 */
571 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
572 DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
576 .callback = video_detect_force_native,
577 /* ASUSTeK COMPUTER INC. GA502 */
579 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
580 DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
584 .callback = video_detect_force_native,
585 /* ASUSTeK COMPUTER INC. GA503 */
587 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
588 DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
592 .callback = video_detect_force_native,
595 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
596 DMI_MATCH(DMI_PRODUCT_NAME, "U46E"),
600 .callback = video_detect_force_native,
603 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
604 DMI_MATCH(DMI_PRODUCT_NAME, "UX303UB"),
608 .callback = video_detect_force_native,
609 /* HP EliteBook 8460p */
611 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
612 DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8460p"),
616 .callback = video_detect_force_native,
617 /* HP Pavilion g6-1d80nr / B4U19UA */
619 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
620 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion g6 Notebook PC"),
621 DMI_MATCH(DMI_PRODUCT_SKU, "B4U19UA"),
625 .callback = video_detect_force_native,
628 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
629 DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
630 DMI_MATCH(DMI_BOARD_NAME, "N150P"),
634 .callback = video_detect_force_native,
635 /* Samsung N145P/N250P/N260P */
637 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
638 DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
639 DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
643 .callback = video_detect_force_native,
646 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
647 DMI_MATCH(DMI_PRODUCT_NAME, "N250P"),
648 DMI_MATCH(DMI_BOARD_NAME, "N250P"),
652 /* https://bugzilla.kernel.org/show_bug.cgi?id=202401 */
653 .callback = video_detect_force_native,
654 /* Sony Vaio VPCEH3U1E */
656 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
657 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
661 .callback = video_detect_force_native,
662 /* Sony Vaio VPCY11S1E */
664 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
665 DMI_MATCH(DMI_PRODUCT_NAME, "VPCY11S1E"),
670 * These Toshibas have a broken acpi-video interface for brightness
671 * control. They also have an issue where the panel is off after
672 * suspend until a special firmware call is made to turn it back
673 * on. This is handled by the toshiba_acpi kernel module, so that
674 * module must be enabled for these models to work correctly.
677 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
678 .callback = video_detect_force_native,
679 /* Toshiba Portégé R700 */
681 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
682 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
686 /* Portégé: https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
687 /* Satellite: https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
688 .callback = video_detect_force_native,
689 /* Toshiba Satellite/Portégé R830 */
691 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
692 DMI_MATCH(DMI_PRODUCT_NAME, "R830"),
696 .callback = video_detect_force_native,
697 /* Toshiba Satellite/Portégé Z830 */
699 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
700 DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
705 * Models which have nvidia-ec-wmi support, but should not use it.
706 * Note this indicates a likely firmware bug on these models and should
707 * be revisited if/when Linux gets support for dynamic mux mode.
710 .callback = video_detect_force_native,
713 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
714 DMI_MATCH(DMI_PRODUCT_NAME, "Dell G15 5515"),
719 * Desktops which falsely report a backlight and which our heuristics
720 * for this do not catch.
723 .callback = video_detect_force_none,
724 /* Dell OptiPlex 9020M */
726 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
727 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
731 .callback = video_detect_force_none,
732 /* GIGABYTE GB-BXBT-2807 */
734 DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
735 DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
739 .callback = video_detect_force_none,
742 DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
743 DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
749 static bool google_cros_ec_present(void)
751 return acpi_dev_found("GOOG0004") || acpi_dev_found("GOOG000C");
755 * Windows 8 and newer no longer use the ACPI video interface, so it often
756 * does not work. So on win8+ systems prefer native brightness control.
757 * Chromebooks should always prefer native backlight control.
759 static bool prefer_native_over_acpi_video(void)
761 return acpi_osi_is_win8() || google_cros_ec_present();
765 * Determine which type of backlight interface to use on this system,
766 * First check cmdline, then dmi quirks, then do autodetect.
768 static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
770 static DEFINE_MUTEX(init_mutex);
771 static bool nvidia_wmi_ec_present;
772 static bool apple_gmux_present;
773 static bool native_available;
774 static bool init_done;
775 static long video_caps;
777 /* Parse cmdline, dmi and acpi only once */
778 mutex_lock(&init_mutex);
780 acpi_video_parse_cmdline();
781 dmi_check_system(video_detect_dmi_table);
782 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
783 ACPI_UINT32_MAX, find_video, NULL,
785 nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
786 apple_gmux_present = apple_gmux_detect(NULL, NULL);
790 native_available = true;
791 mutex_unlock(&init_mutex);
794 * The below heuristics / detection steps are in order of descending
795 * presedence. The commandline takes presedence over anything else.
797 if (acpi_backlight_cmdline != acpi_backlight_undef)
798 return acpi_backlight_cmdline;
800 /* DMI quirks override any autodetection. */
801 if (acpi_backlight_dmi != acpi_backlight_undef)
802 return acpi_backlight_dmi;
804 /* Special cases such as nvidia_wmi_ec and apple gmux. */
805 if (nvidia_wmi_ec_present)
806 return acpi_backlight_nvidia_wmi_ec;
808 if (apple_gmux_present)
809 return acpi_backlight_apple_gmux;
811 /* Use ACPI video if available, except when native should be preferred. */
812 if ((video_caps & ACPI_VIDEO_BACKLIGHT) &&
813 !(native_available && prefer_native_over_acpi_video()))
814 return acpi_backlight_video;
816 /* Use native if available */
817 if (native_available)
818 return acpi_backlight_native;
820 /* No ACPI video/native (old hw), use vendor specific fw methods. */
821 return acpi_backlight_vendor;
824 enum acpi_backlight_type acpi_video_get_backlight_type(void)
826 return __acpi_video_get_backlight_type(false);
828 EXPORT_SYMBOL(acpi_video_get_backlight_type);
830 bool acpi_video_backlight_use_native(void)
832 return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
834 EXPORT_SYMBOL(acpi_video_backlight_use_native);