xref: /openbmc/linux/drivers/acpi/video_detect.c (revision a90fa0ad) 
1 /*
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>
6  *
7  *  May be copied or modified under the terms of the GNU General Public License
8  *
9  * video_detect.c:
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
13  *
14  * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
15  * are available, video.ko should be used to handle the device.
16  *
17  * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
18  * sony_acpi,... can take care about backlight brightness.
19  *
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.
23  *
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.
27  */
28 
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>
41 
42 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
43 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
44 
45 static void acpi_video_parse_cmdline(void)
46 {
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;
59 }
60 
61 static acpi_status
62 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
63 {
64 	struct acpi_device *acpi_dev = acpi_fetch_acpi_dev(handle);
65 	long *cap = context;
66 	struct pci_dev *dev;
67 
68 	static const struct acpi_device_id video_ids[] = {
69 		{ACPI_VIDEO_HID, 0},
70 		{"", 0},
71 	};
72 
73 	if (acpi_dev && !acpi_match_device_ids(acpi_dev, video_ids)) {
74 		dev = acpi_get_pci_dev(handle);
75 		if (!dev)
76 			return AE_OK;
77 		pci_dev_put(dev);
78 		*cap |= acpi_is_video_device(handle);
79 	}
80 	return AE_OK;
81 }
82 
83 /* This depends on ACPI_WMI which is X86 only */
84 #ifdef CONFIG_X86
85 static bool nvidia_wmi_ec_supported(void)
86 {
87 	struct wmi_brightness_args args = {
88 		.mode = WMI_BRIGHTNESS_MODE_GET,
89 		.val = 0,
90 		.ret = 0,
91 	};
92 	struct acpi_buffer buf = { (acpi_size)sizeof(args), &args };
93 	acpi_status status;
94 
95 	status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0,
96 				     WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf);
97 	if (ACPI_FAILURE(status))
98 		return false;
99 
100 	/*
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.
103 	 */
104 	return args.ret == WMI_BRIGHTNESS_SOURCE_EC;
105 }
106 #else
107 static bool nvidia_wmi_ec_supported(void)
108 {
109 	return false;
110 }
111 #endif
112 
113 /* Force to use vendor driver when the ACPI device is known to be
114  * buggy */
115 static int video_detect_force_vendor(const struct dmi_system_id *d)
116 {
117 	acpi_backlight_dmi = acpi_backlight_vendor;
118 	return 0;
119 }
120 
121 static int video_detect_force_video(const struct dmi_system_id *d)
122 {
123 	acpi_backlight_dmi = acpi_backlight_video;
124 	return 0;
125 }
126 
127 static int video_detect_force_native(const struct dmi_system_id *d)
128 {
129 	acpi_backlight_dmi = acpi_backlight_native;
130 	return 0;
131 }
132 
133 static int video_detect_force_none(const struct dmi_system_id *d)
134 {
135 	acpi_backlight_dmi = acpi_backlight_none;
136 	return 0;
137 }
138 
139 static const struct dmi_system_id video_detect_dmi_table[] = {
140 	/*
141 	 * Models which should use the vendor backlight interface,
142 	 * because of broken ACPI video backlight control.
143 	 */
144 	{
145 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1128309 */
146 	 .callback = video_detect_force_vendor,
147 	 /* Acer KAV80 */
148 	 .matches = {
149 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
150 		DMI_MATCH(DMI_PRODUCT_NAME, "KAV80"),
151 		},
152 	},
153 	{
154 	 .callback = video_detect_force_vendor,
155 	 /* Asus UL30VT */
156 	 .matches = {
157 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
158 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
159 		},
160 	},
161 	{
162 	 .callback = video_detect_force_vendor,
163 	 /* Asus UL30A */
164 	 .matches = {
165 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
166 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
167 		},
168 	},
169 	{
170 	 .callback = video_detect_force_vendor,
171 	 /* Asus X55U */
172 	 .matches = {
173 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
174 		DMI_MATCH(DMI_PRODUCT_NAME, "X55U"),
175 		},
176 	},
177 	{
178 	 /* https://bugs.launchpad.net/bugs/1000146 */
179 	 .callback = video_detect_force_vendor,
180 	 /* Asus X101CH */
181 	 .matches = {
182 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
183 		DMI_MATCH(DMI_PRODUCT_NAME, "X101CH"),
184 		},
185 	},
186 	{
187 	 .callback = video_detect_force_vendor,
188 	 /* Asus X401U */
189 	 .matches = {
190 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
191 		DMI_MATCH(DMI_PRODUCT_NAME, "X401U"),
192 		},
193 	},
194 	{
195 	 .callback = video_detect_force_vendor,
196 	 /* Asus X501U */
197 	 .matches = {
198 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
199 		DMI_MATCH(DMI_PRODUCT_NAME, "X501U"),
200 		},
201 	},
202 	{
203 	 /* https://bugs.launchpad.net/bugs/1000146 */
204 	 .callback = video_detect_force_vendor,
205 	 /* Asus 1015CX */
206 	 .matches = {
207 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
208 		DMI_MATCH(DMI_PRODUCT_NAME, "1015CX"),
209 		},
210 	},
211 	{
212 	 .callback = video_detect_force_vendor,
213 	 /* Samsung N150/N210/N220 */
214 	 .matches = {
215 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
216 		DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
217 		DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
218 		},
219 	},
220 	{
221 	 .callback = video_detect_force_vendor,
222 	 /* Samsung NF110/NF210/NF310 */
223 	 .matches = {
224 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
225 		DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
226 		DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
227 		},
228 	},
229 	{
230 	 .callback = video_detect_force_vendor,
231 	 /* Samsung NC210 */
232 	 .matches = {
233 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
234 		DMI_MATCH(DMI_PRODUCT_NAME, "NC210/NC110"),
235 		DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
236 		},
237 	},
238 	{
239 	 .callback = video_detect_force_vendor,
240 	 /* Xiaomi Mi Pad 2 */
241 	 .matches = {
242 			DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
243 			DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
244 		},
245 	},
246 
247 	/*
248 	 * Models which should use the vendor backlight interface,
249 	 * because of broken native backlight control.
250 	 */
251 	{
252 	 .callback = video_detect_force_vendor,
253 	 /* Sony Vaio PCG-FRV35 */
254 	 .matches = {
255 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
256 		DMI_MATCH(DMI_PRODUCT_NAME, "PCG-FRV35"),
257 		},
258 	},
259 
260 	/*
261 	 * Toshiba models with Transflective display, these need to use
262 	 * the toshiba_acpi vendor driver for proper Transflective handling.
263 	 */
264 	{
265 	 .callback = video_detect_force_vendor,
266 	 .matches = {
267 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
268 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R500"),
269 		},
270 	},
271 	{
272 	 .callback = video_detect_force_vendor,
273 	 .matches = {
274 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
275 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R600"),
276 		},
277 	},
278 
279 	/*
280 	 * These models have a working acpi_video backlight control, and using
281 	 * native backlight causes a regression where backlight does not work
282 	 * when userspace is not handling brightness key events. Disable
283 	 * native_backlight on these to fix this:
284 	 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
285 	 */
286 	{
287 	 .callback = video_detect_force_video,
288 	 /* ThinkPad T420 */
289 	 .matches = {
290 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
291 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
292 		},
293 	},
294 	{
295 	 .callback = video_detect_force_video,
296 	 /* ThinkPad T520 */
297 	 .matches = {
298 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
299 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
300 		},
301 	},
302 	{
303 	 .callback = video_detect_force_video,
304 	 /* ThinkPad X201s */
305 	 .matches = {
306 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
307 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
308 		},
309 	},
310 	{
311 	 .callback = video_detect_force_video,
312 	 /* ThinkPad X201T */
313 	 .matches = {
314 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
315 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
316 		},
317 	},
318 
319 	/* The native backlight controls do not work on some older machines */
320 	{
321 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
322 	 .callback = video_detect_force_video,
323 	 /* HP ENVY 15 Notebook */
324 	 .matches = {
325 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
326 		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
327 		},
328 	},
329 	{
330 	 .callback = video_detect_force_video,
331 	 /* SAMSUNG 870Z5E/880Z5E/680Z5E */
332 	 .matches = {
333 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
334 		DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
335 		},
336 	},
337 	{
338 	 .callback = video_detect_force_video,
339 	 /* SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V */
340 	 .matches = {
341 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
342 		DMI_MATCH(DMI_PRODUCT_NAME,
343 			  "370R4E/370R4V/370R5E/3570RE/370R5V"),
344 		},
345 	},
346 	{
347 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
348 	 .callback = video_detect_force_video,
349 	 /* SAMSUNG 3570R/370R/470R/450R/510R/4450RV */
350 	 .matches = {
351 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
352 		DMI_MATCH(DMI_PRODUCT_NAME,
353 			  "3570R/370R/470R/450R/510R/4450RV"),
354 		},
355 	},
356 	{
357 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
358 	 .callback = video_detect_force_video,
359 	 /* SAMSUNG 670Z5E */
360 	 .matches = {
361 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
362 		DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
363 		},
364 	},
365 	{
366 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
367 	 .callback = video_detect_force_video,
368 	 /* SAMSUNG 730U3E/740U3E */
369 	 .matches = {
370 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
371 		DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
372 		},
373 	},
374 	{
375 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
376 	 .callback = video_detect_force_video,
377 	 /* SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D */
378 	 .matches = {
379 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
380 		DMI_MATCH(DMI_PRODUCT_NAME,
381 			  "900X3C/900X3D/900X3E/900X4C/900X4D"),
382 		},
383 	},
384 	{
385 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
386 	 .callback = video_detect_force_video,
387 	 /* Dell XPS14 L421X */
388 	 .matches = {
389 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
390 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
391 		},
392 	},
393 	{
394 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
395 	 .callback = video_detect_force_video,
396 	 /* Dell XPS15 L521X */
397 	 .matches = {
398 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
399 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
400 		},
401 	},
402 	{
403 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
404 	 .callback = video_detect_force_video,
405 	 /* SAMSUNG 530U4E/540U4E */
406 	 .matches = {
407 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
408 		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
409 		},
410 	},
411 	{
412 	 /* https://bugs.launchpad.net/bugs/1894667 */
413 	 .callback = video_detect_force_video,
414 	 /* HP 635 Notebook */
415 	 .matches = {
416 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
417 		DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
418 		},
419 	},
420 
421 	/* Non win8 machines which need native backlight nevertheless */
422 	{
423 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
424 	 .callback = video_detect_force_native,
425 	 /* Lenovo Ideapad S405 */
426 	 .matches = {
427 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
428 		DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
429 		},
430 	},
431 	{
432 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
433 	 .callback = video_detect_force_native,
434 	 /* Lenovo Ideapad Z570 */
435 	 .matches = {
436 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
437 		DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
438 		},
439 	},
440 	{
441 	 .callback = video_detect_force_native,
442 	 /* Lenovo E41-25 */
443 	 .matches = {
444 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
445 		DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
446 		},
447 	},
448 	{
449 	 .callback = video_detect_force_native,
450 	 /* Lenovo E41-45 */
451 	 .matches = {
452 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
453 		DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
454 		},
455 	},
456 	{
457 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
458 	 .callback = video_detect_force_native,
459 	 /* Apple MacBook Pro 12,1 */
460 	 .matches = {
461 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
462 		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
463 		},
464 	},
465 	{
466 	 .callback = video_detect_force_native,
467 	 /* Dell Inspiron N4010 */
468 	 .matches = {
469 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
470 		DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron N4010"),
471 		},
472 	},
473 	{
474 	 .callback = video_detect_force_native,
475 	 /* Dell Vostro V131 */
476 	 .matches = {
477 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
478 		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
479 		},
480 	},
481 	{
482 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
483 	 .callback = video_detect_force_native,
484 	 /* Dell XPS 17 L702X */
485 	 .matches = {
486 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
487 		DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
488 		},
489 	},
490 	{
491 	 .callback = video_detect_force_native,
492 	 /* Dell Precision 7510 */
493 	 .matches = {
494 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
495 		DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
496 		},
497 	},
498 	{
499 	 .callback = video_detect_force_native,
500 	 /* Acer Aspire 4810T */
501 	 .matches = {
502 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
503 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4810T"),
504 		},
505 	},
506 	{
507 	 .callback = video_detect_force_native,
508 	 /* Acer Aspire 5738z */
509 	 .matches = {
510 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
511 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
512 		DMI_MATCH(DMI_BOARD_NAME, "JV50"),
513 		},
514 	},
515 	{
516 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1012674 */
517 	 .callback = video_detect_force_native,
518 	 /* Acer Aspire 5741 */
519 	 .matches = {
520 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
521 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5741"),
522 		},
523 	},
524 	{
525 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=42993 */
526 	 .callback = video_detect_force_native,
527 	 /* Acer Aspire 5750 */
528 	 .matches = {
529 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
530 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5750"),
531 		},
532 	},
533 	{
534 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=42833 */
535 	 .callback = video_detect_force_native,
536 	 /* Acer Extensa 5235 */
537 	 .matches = {
538 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
539 		DMI_MATCH(DMI_PRODUCT_NAME, "Extensa 5235"),
540 		},
541 	},
542 	{
543 	 .callback = video_detect_force_native,
544 	 /* Acer TravelMate 4750 */
545 	 .matches = {
546 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
547 		DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
548 		},
549 	},
550 	{
551 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
552 	 .callback = video_detect_force_native,
553 	 /* Acer TravelMate 5735Z */
554 	 .matches = {
555 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
556 		DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
557 		DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
558 		},
559 	},
560 	{
561 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=36322 */
562 	 .callback = video_detect_force_native,
563 	 /* Acer TravelMate 5760 */
564 	 .matches = {
565 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
566 		DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5760"),
567 		},
568 	},
569 	{
570 	 .callback = video_detect_force_native,
571 	 /* ASUSTeK COMPUTER INC. GA401 */
572 	 .matches = {
573 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
574 		DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
575 		},
576 	},
577 	{
578 	 .callback = video_detect_force_native,
579 	 /* ASUSTeK COMPUTER INC. GA502 */
580 	 .matches = {
581 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
582 		DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
583 		},
584 	},
585 	{
586 	 .callback = video_detect_force_native,
587 	 /* ASUSTeK COMPUTER INC. GA503 */
588 	 .matches = {
589 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
590 		DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
591 		},
592 	},
593 	{
594 	 .callback = video_detect_force_native,
595 	 /* Asus U46E */
596 	 .matches = {
597 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
598 		DMI_MATCH(DMI_PRODUCT_NAME, "U46E"),
599 		},
600 	},
601 	{
602 	 .callback = video_detect_force_native,
603 	 /* Asus UX303UB */
604 	 .matches = {
605 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
606 		DMI_MATCH(DMI_PRODUCT_NAME, "UX303UB"),
607 		},
608 	},
609 	{
610 	 .callback = video_detect_force_native,
611 	 /* HP EliteBook 8460p */
612 	 .matches = {
613 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
614 		DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8460p"),
615 		},
616 	},
617 	{
618 	 .callback = video_detect_force_native,
619 	 /* HP Pavilion g6-1d80nr / B4U19UA */
620 	 .matches = {
621 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
622 		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion g6 Notebook PC"),
623 		DMI_MATCH(DMI_PRODUCT_SKU, "B4U19UA"),
624 		},
625 	},
626 	{
627 	 .callback = video_detect_force_native,
628 	 /* Samsung N150P */
629 	 .matches = {
630 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
631 		DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
632 		DMI_MATCH(DMI_BOARD_NAME, "N150P"),
633 		},
634 	},
635 	{
636 	 .callback = video_detect_force_native,
637 	 /* Samsung N145P/N250P/N260P */
638 	 .matches = {
639 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
640 		DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
641 		DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
642 		},
643 	},
644 	{
645 	 .callback = video_detect_force_native,
646 	 /* Samsung N250P */
647 	 .matches = {
648 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
649 		DMI_MATCH(DMI_PRODUCT_NAME, "N250P"),
650 		DMI_MATCH(DMI_BOARD_NAME, "N250P"),
651 		},
652 	},
653 	{
654 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=202401 */
655 	 .callback = video_detect_force_native,
656 	 /* Sony Vaio VPCEH3U1E */
657 	 .matches = {
658 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
659 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
660 		},
661 	},
662 	{
663 	 .callback = video_detect_force_native,
664 	 /* Sony Vaio VPCY11S1E */
665 	 .matches = {
666 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
667 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCY11S1E"),
668 		},
669 	},
670 
671 	/*
672 	 * These Toshibas have a broken acpi-video interface for brightness
673 	 * control. They also have an issue where the panel is off after
674 	 * suspend until a special firmware call is made to turn it back
675 	 * on. This is handled by the toshiba_acpi kernel module, so that
676 	 * module must be enabled for these models to work correctly.
677 	 */
678 	{
679 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
680 	 .callback = video_detect_force_native,
681 	 /* Toshiba Portégé R700 */
682 	 .matches = {
683 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
684 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
685 		},
686 	},
687 	{
688 	 /* Portégé: https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
689 	 /* Satellite: https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
690 	 .callback = video_detect_force_native,
691 	 /* Toshiba Satellite/Portégé R830 */
692 	 .matches = {
693 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
694 		DMI_MATCH(DMI_PRODUCT_NAME, "R830"),
695 		},
696 	},
697 	{
698 	 .callback = video_detect_force_native,
699 	 /* Toshiba Satellite/Portégé Z830 */
700 	 .matches = {
701 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
702 		DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
703 		},
704 	},
705 
706 	/*
707 	 * Models which have nvidia-ec-wmi support, but should not use it.
708 	 * Note this indicates a likely firmware bug on these models and should
709 	 * be revisited if/when Linux gets support for dynamic mux mode.
710 	 */
711 	{
712 	 .callback = video_detect_force_native,
713 	 /* Dell G15 5515 */
714 	 .matches = {
715 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
716 		DMI_MATCH(DMI_PRODUCT_NAME, "Dell G15 5515"),
717 		},
718 	},
719 
720 	/*
721 	 * Desktops which falsely report a backlight and which our heuristics
722 	 * for this do not catch.
723 	 */
724 	{
725 	 .callback = video_detect_force_none,
726 	 /* Dell OptiPlex 9020M */
727 	 .matches = {
728 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
729 		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
730 		},
731 	},
732 	{
733 	 .callback = video_detect_force_none,
734 	 /* GIGABYTE GB-BXBT-2807 */
735 	 .matches = {
736 		DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
737 		DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
738 		},
739 	},
740 	{
741 	 .callback = video_detect_force_none,
742 	 /* MSI MS-7721 */
743 	 .matches = {
744 		DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
745 		DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
746 		},
747 	},
748 	{ },
749 };
750 
751 static bool google_cros_ec_present(void)
752 {
753 	return acpi_dev_found("GOOG0004") || acpi_dev_found("GOOG000C");
754 }
755 
756 /*
757  * Windows 8 and newer no longer use the ACPI video interface, so it often
758  * does not work. So on win8+ systems prefer native brightness control.
759  * Chromebooks should always prefer native backlight control.
760  */
761 static bool prefer_native_over_acpi_video(void)
762 {
763 	return acpi_osi_is_win8() || google_cros_ec_present();
764 }
765 
766 /*
767  * Determine which type of backlight interface to use on this system,
768  * First check cmdline, then dmi quirks, then do autodetect.
769  */
770 static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
771 {
772 	static DEFINE_MUTEX(init_mutex);
773 	static bool nvidia_wmi_ec_present;
774 	static bool apple_gmux_present;
775 	static bool native_available;
776 	static bool init_done;
777 	static long video_caps;
778 
779 	/* Parse cmdline, dmi and acpi only once */
780 	mutex_lock(&init_mutex);
781 	if (!init_done) {
782 		acpi_video_parse_cmdline();
783 		dmi_check_system(video_detect_dmi_table);
784 		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
785 				    ACPI_UINT32_MAX, find_video, NULL,
786 				    &video_caps, NULL);
787 		nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
788 		apple_gmux_present = apple_gmux_detect(NULL, NULL);
789 		init_done = true;
790 	}
791 	if (native)
792 		native_available = true;
793 	mutex_unlock(&init_mutex);
794 
795 	/*
796 	 * The below heuristics / detection steps are in order of descending
797 	 * presedence. The commandline takes presedence over anything else.
798 	 */
799 	if (acpi_backlight_cmdline != acpi_backlight_undef)
800 		return acpi_backlight_cmdline;
801 
802 	/* DMI quirks override any autodetection. */
803 	if (acpi_backlight_dmi != acpi_backlight_undef)
804 		return acpi_backlight_dmi;
805 
806 	/* Special cases such as nvidia_wmi_ec and apple gmux. */
807 	if (nvidia_wmi_ec_present)
808 		return acpi_backlight_nvidia_wmi_ec;
809 
810 	if (apple_gmux_present)
811 		return acpi_backlight_apple_gmux;
812 
813 	/* Use ACPI video if available, except when native should be preferred. */
814 	if ((video_caps & ACPI_VIDEO_BACKLIGHT) &&
815 	     !(native_available && prefer_native_over_acpi_video()))
816 		return acpi_backlight_video;
817 
818 	/* Use native if available */
819 	if (native_available)
820 		return acpi_backlight_native;
821 
822 	/* No ACPI video/native (old hw), use vendor specific fw methods. */
823 	return acpi_backlight_vendor;
824 }
825 
826 enum acpi_backlight_type acpi_video_get_backlight_type(void)
827 {
828 	return __acpi_video_get_backlight_type(false);
829 }
830 EXPORT_SYMBOL(acpi_video_get_backlight_type);
831 
832 bool acpi_video_backlight_use_native(void)
833 {
834 	return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
835 }
836 EXPORT_SYMBOL(acpi_video_backlight_use_native);
837