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
21 * which driver should handle the backlight.
22 *
23 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
24 * this file will not be compiled and acpi_video_get_backlight_type() will
25 * always return acpi_backlight_vendor.
26 */
27
28#include <linux/export.h>
29#include <linux/acpi.h>
30#include <linux/backlight.h>
31#include <linux/dmi.h>
32#include <linux/module.h>
33#include <linux/pci.h>
34#include <linux/types.h>
35#include <linux/workqueue.h>
36#include <acpi/video.h>
37
38void acpi_video_unregister_backlight(void);
39
40static bool backlight_notifier_registered;
41static struct notifier_block backlight_nb;
42static struct work_struct backlight_notify_work;
43
44static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
45static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
46
47static void acpi_video_parse_cmdline(void)
48{
49	if (!strcmp("vendor", acpi_video_backlight_string))
50		acpi_backlight_cmdline = acpi_backlight_vendor;
51	if (!strcmp("video", acpi_video_backlight_string))
52		acpi_backlight_cmdline = acpi_backlight_video;
53	if (!strcmp("native", acpi_video_backlight_string))
54		acpi_backlight_cmdline = acpi_backlight_native;
55	if (!strcmp("none", acpi_video_backlight_string))
56		acpi_backlight_cmdline = acpi_backlight_none;
57}
58
59static acpi_status
60find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
61{
62	long *cap = context;
63	struct pci_dev *dev;
64	struct acpi_device *acpi_dev;
65
66	static const struct acpi_device_id video_ids[] = {
67		{ACPI_VIDEO_HID, 0},
68		{"", 0},
69	};
70	if (acpi_bus_get_device(handle, &acpi_dev))
71		return AE_OK;
72
73	if (!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/* Force to use vendor driver when the ACPI device is known to be
84 * buggy */
85static int video_detect_force_vendor(const struct dmi_system_id *d)
86{
87	acpi_backlight_dmi = acpi_backlight_vendor;
88	return 0;
89}
90
91static int video_detect_force_video(const struct dmi_system_id *d)
92{
93	acpi_backlight_dmi = acpi_backlight_video;
94	return 0;
95}
96
97static int video_detect_force_native(const struct dmi_system_id *d)
98{
99	acpi_backlight_dmi = acpi_backlight_native;
100	return 0;
101}
102
103static int video_detect_force_none(const struct dmi_system_id *d)
104{
105	acpi_backlight_dmi = acpi_backlight_none;
106	return 0;
107}
108
109static const struct dmi_system_id video_detect_dmi_table[] = {
110	/* On Samsung X360, the BIOS will set a flag (VDRV) if generic
111	 * ACPI backlight device is used. This flag will definitively break
112	 * the backlight interface (even the vendor interface) until next
113	 * reboot. It's why we should prevent video.ko from being used here
114	 * and we can't rely on a later call to acpi_video_unregister().
115	 */
116	{
117	 .callback = video_detect_force_vendor,
118	 .ident = "X360",
119	 .matches = {
120		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
121		DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
122		DMI_MATCH(DMI_BOARD_NAME, "X360"),
123		},
124	},
125	{
126	.callback = video_detect_force_vendor,
127	.ident = "Asus UL30VT",
128	.matches = {
129		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
130		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
131		},
132	},
133	{
134	.callback = video_detect_force_vendor,
135	.ident = "Asus UL30A",
136	.matches = {
137		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
138		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
139		},
140	},
141	{
142	.callback = video_detect_force_vendor,
143	.ident = "GIGABYTE GB-BXBT-2807",
144	.matches = {
145		DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
146		DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
147		},
148	},
149	{
150	.callback = video_detect_force_vendor,
151	.ident = "Sony VPCEH3U1E",
152	.matches = {
153		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
154		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
155		},
156	},
157
158	/*
159	 * These models have a working acpi_video backlight control, and using
160	 * native backlight causes a regression where backlight does not work
161	 * when userspace is not handling brightness key events. Disable
162	 * native_backlight on these to fix this:
163	 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
164	 */
165	{
166	 .callback = video_detect_force_video,
167	 .ident = "ThinkPad T420",
168	 .matches = {
169		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
170		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
171		},
172	},
173	{
174	 .callback = video_detect_force_video,
175	 .ident = "ThinkPad T520",
176	 .matches = {
177		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
178		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
179		},
180	},
181	{
182	 .callback = video_detect_force_video,
183	 .ident = "ThinkPad X201s",
184	 .matches = {
185		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
186		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
187		},
188	},
189	{
190	 .callback = video_detect_force_video,
191	 .ident = "ThinkPad X201T",
192	 .matches = {
193		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
194		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
195		},
196	},
197
198	/* The native backlight controls do not work on some older machines */
199	{
200	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
201	 .callback = video_detect_force_video,
202	 .ident = "HP ENVY 15 Notebook",
203	 .matches = {
204		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
205		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
206		},
207	},
208	{
209	 .callback = video_detect_force_video,
210	 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
211	 .matches = {
212		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
213		DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
214		},
215	},
216	{
217	 .callback = video_detect_force_video,
218	 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
219	 .matches = {
220		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
221		DMI_MATCH(DMI_PRODUCT_NAME,
222			  "370R4E/370R4V/370R5E/3570RE/370R5V"),
223		},
224	},
225	{
226	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
227	 .callback = video_detect_force_video,
228	 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
229	 .matches = {
230		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
231		DMI_MATCH(DMI_PRODUCT_NAME,
232			  "3570R/370R/470R/450R/510R/4450RV"),
233		},
234	},
235	{
236	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
237	 .callback = video_detect_force_video,
238	 .ident = "SAMSUNG 670Z5E",
239	 .matches = {
240		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
241		DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
242		},
243	},
244	{
245	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
246	 .callback = video_detect_force_video,
247	 .ident = "SAMSUNG 730U3E/740U3E",
248	 .matches = {
249		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
250		DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
251		},
252	},
253	{
254	 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
255	 .callback = video_detect_force_video,
256	 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
257	 .matches = {
258		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
259		DMI_MATCH(DMI_PRODUCT_NAME,
260			  "900X3C/900X3D/900X3E/900X4C/900X4D"),
261		},
262	},
263	{
264	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
265	 .callback = video_detect_force_video,
266	 .ident = "Dell XPS14 L421X",
267	 .matches = {
268		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
269		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
270		},
271	},
272	{
273	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
274	 .callback = video_detect_force_video,
275	 .ident = "Dell XPS15 L521X",
276	 .matches = {
277		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
278		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
279		},
280	},
281	{
282	 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
283	 .callback = video_detect_force_video,
284	 .ident = "SAMSUNG 530U4E/540U4E",
285	 .matches = {
286		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
287		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
288		},
289	},
290	/* https://bugs.launchpad.net/bugs/1894667 */
291	{
292	 .callback = video_detect_force_video,
293	 .ident = "HP 635 Notebook",
294	 .matches = {
295		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
296		DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
297		},
298	},
299
300	/* Non win8 machines which need native backlight nevertheless */
301	{
302	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
303	 .callback = video_detect_force_native,
304	 .ident = "Lenovo Ideapad S405",
305	 .matches = {
306		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
307		DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
308		},
309	},
310	{
311	 /* https://bugzilla.suse.com/show_bug.cgi?id=1208724 */
312	 .callback = video_detect_force_native,
313	 /* Lenovo Ideapad Z470 */
314	 .matches = {
315		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
316		DMI_MATCH(DMI_PRODUCT_VERSION, "IdeaPad Z470"),
317		},
318	},
319	{
320	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
321	 .callback = video_detect_force_native,
322	 .ident = "Lenovo Ideapad Z570",
323	 .matches = {
324		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
325		DMI_MATCH(DMI_PRODUCT_VERSION, "Ideapad Z570"),
326		},
327	},
328	{
329	 .callback = video_detect_force_native,
330	 .ident = "Lenovo E41-25",
331	 .matches = {
332		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
333		DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
334		},
335	},
336	{
337	 .callback = video_detect_force_native,
338	 .ident = "Lenovo E41-45",
339	 .matches = {
340		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
341		DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
342		},
343	},
344	{
345	 .callback = video_detect_force_native,
346	 /* Lenovo ThinkPad X131e (3371 AMD version) */
347	 .matches = {
348		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
349		DMI_MATCH(DMI_PRODUCT_NAME, "3371"),
350		},
351	},
352	{
353	 .callback = video_detect_force_native,
354	 /* Apple iMac11,3 */
355	 .matches = {
356		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
357		DMI_MATCH(DMI_PRODUCT_NAME, "iMac11,3"),
358		},
359	},
360	{
361	 /* https://gitlab.freedesktop.org/drm/amd/-/issues/1838 */
362	 .callback = video_detect_force_native,
363	 /* Apple iMac12,1 */
364	 .matches = {
365		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
366		DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,1"),
367		},
368	},
369	{
370	 /* https://gitlab.freedesktop.org/drm/amd/-/issues/2753 */
371	 .callback = video_detect_force_native,
372	 /* Apple iMac12,2 */
373	 .matches = {
374		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
375		DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,2"),
376		},
377	},
378	{
379	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
380	 .callback = video_detect_force_native,
381	 .ident = "Apple MacBook Pro 12,1",
382	 .matches = {
383		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
384		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
385		},
386	},
387	{
388	 .callback = video_detect_force_native,
389	 .ident = "Dell Vostro V131",
390	 .matches = {
391		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
392		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
393		},
394	},
395	{
396	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
397	 .callback = video_detect_force_native,
398	 .ident = "Dell XPS 17 L702X",
399	 .matches = {
400		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
401		DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
402		},
403	},
404	{
405	 .callback = video_detect_force_native,
406	 .ident = "Dell Precision 7510",
407	 .matches = {
408		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
409		DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
410		},
411	},
412	{
413	 .callback = video_detect_force_native,
414	 .ident = "Acer Aspire 5738z",
415	 .matches = {
416		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
417		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
418		DMI_MATCH(DMI_BOARD_NAME, "JV50"),
419		},
420	},
421	{
422	 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
423	 .callback = video_detect_force_native,
424	 .ident = "Acer TravelMate 5735Z",
425	 .matches = {
426		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
427		DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
428		DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
429		},
430	},
431	{
432	.callback = video_detect_force_native,
433	.ident = "ASUSTeK COMPUTER INC. GA401",
434	.matches = {
435		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
436		DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
437		},
438	},
439	{
440	.callback = video_detect_force_native,
441	.ident = "ASUSTeK COMPUTER INC. GA502",
442	.matches = {
443		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
444		DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
445		},
446	},
447	{
448	.callback = video_detect_force_native,
449	.ident = "ASUSTeK COMPUTER INC. GA503",
450	.matches = {
451		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
452		DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
453		},
454	},
455	/*
456	 * Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a
457	 * working native and video interface. However the default detection
458	 * mechanism first registers the video interface before unregistering
459	 * it again and switching to the native interface during boot. This
460	 * results in a dangling SBIOS request for backlight change for some
461	 * reason, causing the backlight to switch to ~2% once per boot on the
462	 * first power cord connect or disconnect event. Setting the native
463	 * interface explicitly circumvents this buggy behaviour, by avoiding
464	 * the unregistering process.
465	 */
466	{
467	.callback = video_detect_force_native,
468	.ident = "Clevo NL5xRU",
469	.matches = {
470		DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
471		},
472	},
473	{
474	.callback = video_detect_force_native,
475	.ident = "Clevo NL5xRU",
476	.matches = {
477		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
478		DMI_MATCH(DMI_BOARD_NAME, "AURA1501"),
479		},
480	},
481	{
482	.callback = video_detect_force_native,
483	.ident = "Clevo NL5xRU",
484	.matches = {
485		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
486		DMI_MATCH(DMI_BOARD_NAME, "EDUBOOK1502"),
487		},
488	},
489	{
490	.callback = video_detect_force_native,
491	.ident = "Clevo NL5xNU",
492	.matches = {
493		DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
494		},
495	},
496	/*
497	 * The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
498	 * Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
499	 * NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description
500	 * above.
501	 */
502	{
503	.callback = video_detect_force_native,
504	.ident = "TongFang PF5PU1G",
505	.matches = {
506		DMI_MATCH(DMI_BOARD_NAME, "PF5PU1G"),
507		},
508	},
509	{
510	.callback = video_detect_force_native,
511	.ident = "TongFang PF4NU1F",
512	.matches = {
513		DMI_MATCH(DMI_BOARD_NAME, "PF4NU1F"),
514		},
515	},
516	{
517	.callback = video_detect_force_native,
518	.ident = "TongFang PF4NU1F",
519	.matches = {
520		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
521		DMI_MATCH(DMI_BOARD_NAME, "PULSE1401"),
522		},
523	},
524	{
525	.callback = video_detect_force_native,
526	.ident = "TongFang PF5NU1G",
527	.matches = {
528		DMI_MATCH(DMI_BOARD_NAME, "PF5NU1G"),
529		},
530	},
531	{
532	.callback = video_detect_force_native,
533	.ident = "TongFang PF5NU1G",
534	.matches = {
535		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
536		DMI_MATCH(DMI_BOARD_NAME, "PULSE1501"),
537		},
538	},
539	{
540	.callback = video_detect_force_native,
541	.ident = "TongFang PF5LUXG",
542	.matches = {
543		DMI_MATCH(DMI_BOARD_NAME, "PF5LUXG"),
544		},
545	},
546	/*
547	 * More Tongfang devices with the same issue as the Clevo NL5xRU and
548	 * NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description above.
549	 */
550	{
551	.callback = video_detect_force_native,
552	.ident = "TongFang GKxNRxx",
553	.matches = {
554		DMI_MATCH(DMI_BOARD_NAME, "GKxNRxx"),
555		},
556	},
557	{
558	.callback = video_detect_force_native,
559	.ident = "TongFang GKxNRxx",
560	.matches = {
561		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
562		DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A1650TI"),
563		},
564	},
565	{
566	.callback = video_detect_force_native,
567	.ident = "TongFang GKxNRxx",
568	.matches = {
569		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
570		DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A2060"),
571		},
572	},
573	{
574	.callback = video_detect_force_native,
575	.ident = "TongFang GKxNRxx",
576	.matches = {
577		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
578		DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A1650TI"),
579		},
580	},
581	{
582	.callback = video_detect_force_native,
583	.ident = "TongFang GKxNRxx",
584	.matches = {
585		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
586		DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A2060"),
587		},
588	},
589	{
590	.callback = video_detect_force_native,
591	.ident = "TongFang GMxNGxx",
592	.matches = {
593		DMI_MATCH(DMI_BOARD_NAME, "GMxNGxx"),
594		},
595	},
596	{
597	.callback = video_detect_force_native,
598	.ident = "TongFang GMxZGxx",
599	.matches = {
600		DMI_MATCH(DMI_BOARD_NAME, "GMxZGxx"),
601		},
602	},
603	{
604	.callback = video_detect_force_native,
605	.ident = "TongFang GMxRGxx",
606	.matches = {
607		DMI_MATCH(DMI_BOARD_NAME, "GMxRGxx"),
608		},
609	},
610	/*
611	 * Desktops which falsely report a backlight and which our heuristics
612	 * for this do not catch.
613	 */
614	{
615	 .callback = video_detect_force_none,
616	 .ident = "Dell OptiPlex 9020M",
617	 .matches = {
618		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
619		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
620		},
621	},
622	{
623	 .callback = video_detect_force_none,
624	 .ident = "MSI MS-7721",
625	 .matches = {
626		DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
627		DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
628		},
629	},
630	{ },
631};
632
633/* This uses a workqueue to avoid various locking ordering issues */
634static void acpi_video_backlight_notify_work(struct work_struct *work)
635{
636	if (acpi_video_get_backlight_type() != acpi_backlight_video)
637		acpi_video_unregister_backlight();
638}
639
640static int acpi_video_backlight_notify(struct notifier_block *nb,
641				       unsigned long val, void *bd)
642{
643	struct backlight_device *backlight = bd;
644
645	/* A raw bl registering may change video -> native */
646	if (backlight->props.type == BACKLIGHT_RAW &&
647	    val == BACKLIGHT_REGISTERED)
648		schedule_work(&backlight_notify_work);
649
650	return NOTIFY_OK;
651}
652
653/*
654 * Determine which type of backlight interface to use on this system,
655 * First check cmdline, then dmi quirks, then do autodetect.
656 *
657 * The autodetect order is:
658 * 1) Is the acpi-video backlight interface supported ->
659 *  no, use a vendor interface
660 * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
661 *  yes, use a native interface
662 * 3) Else use the acpi-video interface
663 *
664 * Arguably the native on win8 check should be done first, but that would
665 * be a behavior change, which may causes issues.
666 */
667enum acpi_backlight_type acpi_video_get_backlight_type(void)
668{
669	static DEFINE_MUTEX(init_mutex);
670	static bool init_done;
671	static long video_caps;
672
673	/* Parse cmdline, dmi and acpi only once */
674	mutex_lock(&init_mutex);
675	if (!init_done) {
676		acpi_video_parse_cmdline();
677		dmi_check_system(video_detect_dmi_table);
678		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
679				    ACPI_UINT32_MAX, find_video, NULL,
680				    &video_caps, NULL);
681		INIT_WORK(&backlight_notify_work,
682			  acpi_video_backlight_notify_work);
683		backlight_nb.notifier_call = acpi_video_backlight_notify;
684		backlight_nb.priority = 0;
685		if (backlight_register_notifier(&backlight_nb) == 0)
686			backlight_notifier_registered = true;
687		init_done = true;
688	}
689	mutex_unlock(&init_mutex);
690
691	if (acpi_backlight_cmdline != acpi_backlight_undef)
692		return acpi_backlight_cmdline;
693
694	if (acpi_backlight_dmi != acpi_backlight_undef)
695		return acpi_backlight_dmi;
696
697	if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
698		return acpi_backlight_vendor;
699
700	if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW))
701		return acpi_backlight_native;
702
703	return acpi_backlight_video;
704}
705EXPORT_SYMBOL(acpi_video_get_backlight_type);
706
707/*
708 * Set the preferred backlight interface type based on DMI info.
709 * This function allows DMI blacklists to be implemented by external
710 * platform drivers instead of putting a big blacklist in video_detect.c
711 */
712void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
713{
714	acpi_backlight_dmi = type;
715	/* Remove acpi-video backlight interface if it is no longer desired */
716	if (acpi_video_get_backlight_type() != acpi_backlight_video)
717		acpi_video_unregister_backlight();
718}
719EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
720
721void __exit acpi_video_detect_exit(void)
722{
723	if (backlight_notifier_registered)
724		backlight_unregister_notifier(&backlight_nb);
725}
726