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
38 ACPI_MODULE_NAME("video");
39 #define _COMPONENT ACPI_VIDEO_COMPONENT
40
41 void acpi_video_unregister_backlight(void);
42
43 static bool backlight_notifier_registered;
44 static struct notifier_block backlight_nb;
45 static struct work_struct backlight_notify_work;
46
47 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
48 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
49
acpi_video_parse_cmdline(void)50 static void acpi_video_parse_cmdline(void)
51 {
52 if (!strcmp("vendor", acpi_video_backlight_string))
53 acpi_backlight_cmdline = acpi_backlight_vendor;
54 if (!strcmp("video", acpi_video_backlight_string))
55 acpi_backlight_cmdline = acpi_backlight_video;
56 if (!strcmp("native", acpi_video_backlight_string))
57 acpi_backlight_cmdline = acpi_backlight_native;
58 if (!strcmp("none", acpi_video_backlight_string))
59 acpi_backlight_cmdline = acpi_backlight_none;
60 }
61
62 static acpi_status
find_video(acpi_handle handle,u32 lvl,void * context,void ** rv)63 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
64 {
65 long *cap = context;
66 struct pci_dev *dev;
67 struct acpi_device *acpi_dev;
68
69 static const struct acpi_device_id video_ids[] = {
70 {ACPI_VIDEO_HID, 0},
71 {"", 0},
72 };
73 if (acpi_bus_get_device(handle, &acpi_dev))
74 return AE_OK;
75
76 if (!acpi_match_device_ids(acpi_dev, video_ids)) {
77 dev = acpi_get_pci_dev(handle);
78 if (!dev)
79 return AE_OK;
80 pci_dev_put(dev);
81 *cap |= acpi_is_video_device(handle);
82 }
83 return AE_OK;
84 }
85
86 /* Force to use vendor driver when the ACPI device is known to be
87 * buggy */
video_detect_force_vendor(const struct dmi_system_id * d)88 static int video_detect_force_vendor(const struct dmi_system_id *d)
89 {
90 acpi_backlight_dmi = acpi_backlight_vendor;
91 return 0;
92 }
93
video_detect_force_video(const struct dmi_system_id * d)94 static int video_detect_force_video(const struct dmi_system_id *d)
95 {
96 acpi_backlight_dmi = acpi_backlight_video;
97 return 0;
98 }
99
video_detect_force_native(const struct dmi_system_id * d)100 static int video_detect_force_native(const struct dmi_system_id *d)
101 {
102 acpi_backlight_dmi = acpi_backlight_native;
103 return 0;
104 }
105
video_detect_force_none(const struct dmi_system_id * d)106 static int video_detect_force_none(const struct dmi_system_id *d)
107 {
108 acpi_backlight_dmi = acpi_backlight_none;
109 return 0;
110 }
111
112 static const struct dmi_system_id video_detect_dmi_table[] = {
113 /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
114 * ACPI backlight device is used. This flag will definitively break
115 * the backlight interface (even the vendor interface) until next
116 * reboot. It's why we should prevent video.ko from being used here
117 * and we can't rely on a later call to acpi_video_unregister().
118 */
119 {
120 .callback = video_detect_force_vendor,
121 .ident = "X360",
122 .matches = {
123 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
124 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
125 DMI_MATCH(DMI_BOARD_NAME, "X360"),
126 },
127 },
128 {
129 .callback = video_detect_force_vendor,
130 .ident = "Asus UL30VT",
131 .matches = {
132 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
133 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
134 },
135 },
136 {
137 .callback = video_detect_force_vendor,
138 .ident = "Asus UL30A",
139 .matches = {
140 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
141 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
142 },
143 },
144 {
145 .callback = video_detect_force_vendor,
146 .ident = "GIGABYTE GB-BXBT-2807",
147 .matches = {
148 DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
149 DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
150 },
151 },
152 {
153 .callback = video_detect_force_vendor,
154 .ident = "Sony VPCEH3U1E",
155 .matches = {
156 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
157 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
158 },
159 },
160
161 /*
162 * These models have a working acpi_video backlight control, and using
163 * native backlight causes a regression where backlight does not work
164 * when userspace is not handling brightness key events. Disable
165 * native_backlight on these to fix this:
166 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
167 */
168 {
169 .callback = video_detect_force_video,
170 .ident = "ThinkPad T420",
171 .matches = {
172 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
173 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
174 },
175 },
176 {
177 .callback = video_detect_force_video,
178 .ident = "ThinkPad T520",
179 .matches = {
180 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
181 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
182 },
183 },
184 {
185 .callback = video_detect_force_video,
186 .ident = "ThinkPad X201s",
187 .matches = {
188 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
189 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
190 },
191 },
192 {
193 .callback = video_detect_force_video,
194 .ident = "ThinkPad X201T",
195 .matches = {
196 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
197 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
198 },
199 },
200
201 /* The native backlight controls do not work on some older machines */
202 {
203 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
204 .callback = video_detect_force_video,
205 .ident = "HP ENVY 15 Notebook",
206 .matches = {
207 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
208 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
209 },
210 },
211 {
212 .callback = video_detect_force_video,
213 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
214 .matches = {
215 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
216 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
217 },
218 },
219 {
220 .callback = video_detect_force_video,
221 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
222 .matches = {
223 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
224 DMI_MATCH(DMI_PRODUCT_NAME,
225 "370R4E/370R4V/370R5E/3570RE/370R5V"),
226 },
227 },
228 {
229 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
230 .callback = video_detect_force_video,
231 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
232 .matches = {
233 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
234 DMI_MATCH(DMI_PRODUCT_NAME,
235 "3570R/370R/470R/450R/510R/4450RV"),
236 },
237 },
238 {
239 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
240 .callback = video_detect_force_video,
241 .ident = "SAMSUNG 670Z5E",
242 .matches = {
243 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
244 DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
245 },
246 },
247 {
248 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
249 .callback = video_detect_force_video,
250 .ident = "SAMSUNG 730U3E/740U3E",
251 .matches = {
252 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
253 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
254 },
255 },
256 {
257 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
258 .callback = video_detect_force_video,
259 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
260 .matches = {
261 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
262 DMI_MATCH(DMI_PRODUCT_NAME,
263 "900X3C/900X3D/900X3E/900X4C/900X4D"),
264 },
265 },
266 {
267 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
268 .callback = video_detect_force_video,
269 .ident = "Dell XPS14 L421X",
270 .matches = {
271 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
272 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
273 },
274 },
275 {
276 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
277 .callback = video_detect_force_video,
278 .ident = "Dell XPS15 L521X",
279 .matches = {
280 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
281 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
282 },
283 },
284 {
285 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
286 .callback = video_detect_force_video,
287 .ident = "SAMSUNG 530U4E/540U4E",
288 .matches = {
289 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
290 DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
291 },
292 },
293 /* https://bugs.launchpad.net/bugs/1894667 */
294 {
295 .callback = video_detect_force_video,
296 .ident = "HP 635 Notebook",
297 .matches = {
298 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
299 DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
300 },
301 },
302
303 /* Non win8 machines which need native backlight nevertheless */
304 {
305 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
306 .callback = video_detect_force_native,
307 .ident = "Lenovo Ideapad S405",
308 .matches = {
309 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
310 DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
311 },
312 },
313 {
314 /* https://bugzilla.suse.com/show_bug.cgi?id=1208724 */
315 .callback = video_detect_force_native,
316 /* Lenovo Ideapad Z470 */
317 .matches = {
318 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
319 DMI_MATCH(DMI_PRODUCT_VERSION, "IdeaPad Z470"),
320 },
321 },
322 {
323 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
324 .callback = video_detect_force_native,
325 .ident = "Lenovo Ideapad Z570",
326 .matches = {
327 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
328 DMI_MATCH(DMI_PRODUCT_VERSION, "Ideapad Z570"),
329 },
330 },
331 {
332 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
333 .callback = video_detect_force_native,
334 .ident = "Apple MacBook Pro 12,1",
335 .matches = {
336 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
337 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
338 },
339 },
340 {
341 .callback = video_detect_force_native,
342 .ident = "Dell Vostro V131",
343 .matches = {
344 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
345 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
346 },
347 },
348 {
349 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
350 .callback = video_detect_force_native,
351 .ident = "Dell XPS 17 L702X",
352 .matches = {
353 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
354 DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
355 },
356 },
357 {
358 .callback = video_detect_force_native,
359 .ident = "Dell Precision 7510",
360 .matches = {
361 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
362 DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
363 },
364 },
365 {
366 .callback = video_detect_force_native,
367 .ident = "Acer Aspire 5738z",
368 .matches = {
369 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
370 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
371 DMI_MATCH(DMI_BOARD_NAME, "JV50"),
372 },
373 },
374 {
375 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
376 .callback = video_detect_force_native,
377 .ident = "Acer TravelMate 5735Z",
378 .matches = {
379 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
380 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
381 DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
382 },
383 },
384 /*
385 * Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a
386 * working native and video interface. However the default detection
387 * mechanism first registers the video interface before unregistering
388 * it again and switching to the native interface during boot. This
389 * results in a dangling SBIOS request for backlight change for some
390 * reason, causing the backlight to switch to ~2% once per boot on the
391 * first power cord connect or disconnect event. Setting the native
392 * interface explicitly circumvents this buggy behaviour, by avoiding
393 * the unregistering process.
394 */
395 {
396 .callback = video_detect_force_native,
397 .ident = "Clevo NL5xRU",
398 .matches = {
399 DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
400 },
401 },
402 {
403 .callback = video_detect_force_native,
404 .ident = "Clevo NL5xRU",
405 .matches = {
406 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
407 DMI_MATCH(DMI_BOARD_NAME, "AURA1501"),
408 },
409 },
410 {
411 .callback = video_detect_force_native,
412 .ident = "Clevo NL5xRU",
413 .matches = {
414 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
415 DMI_MATCH(DMI_BOARD_NAME, "EDUBOOK1502"),
416 },
417 },
418 {
419 .callback = video_detect_force_native,
420 .ident = "Clevo NL5xNU",
421 .matches = {
422 DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
423 },
424 },
425 /*
426 * The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
427 * Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
428 * NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description
429 * above.
430 */
431 {
432 .callback = video_detect_force_native,
433 .ident = "TongFang PF5PU1G",
434 .matches = {
435 DMI_MATCH(DMI_BOARD_NAME, "PF5PU1G"),
436 },
437 },
438 {
439 .callback = video_detect_force_native,
440 .ident = "TongFang PF4NU1F",
441 .matches = {
442 DMI_MATCH(DMI_BOARD_NAME, "PF4NU1F"),
443 },
444 },
445 {
446 .callback = video_detect_force_native,
447 .ident = "TongFang PF4NU1F",
448 .matches = {
449 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
450 DMI_MATCH(DMI_BOARD_NAME, "PULSE1401"),
451 },
452 },
453 {
454 .callback = video_detect_force_native,
455 .ident = "TongFang PF5NU1G",
456 .matches = {
457 DMI_MATCH(DMI_BOARD_NAME, "PF5NU1G"),
458 },
459 },
460 {
461 .callback = video_detect_force_native,
462 .ident = "TongFang PF5NU1G",
463 .matches = {
464 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
465 DMI_MATCH(DMI_BOARD_NAME, "PULSE1501"),
466 },
467 },
468 {
469 .callback = video_detect_force_native,
470 .ident = "TongFang PF5LUXG",
471 .matches = {
472 DMI_MATCH(DMI_BOARD_NAME, "PF5LUXG"),
473 },
474 },
475 /*
476 * More Tongfang devices with the same issue as the Clevo NL5xRU and
477 * NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description above.
478 */
479 {
480 .callback = video_detect_force_native,
481 .ident = "TongFang GKxNRxx",
482 .matches = {
483 DMI_MATCH(DMI_BOARD_NAME, "GKxNRxx"),
484 },
485 },
486 {
487 .callback = video_detect_force_native,
488 .ident = "TongFang GKxNRxx",
489 .matches = {
490 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
491 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A1650TI"),
492 },
493 },
494 {
495 .callback = video_detect_force_native,
496 .ident = "TongFang GKxNRxx",
497 .matches = {
498 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
499 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A2060"),
500 },
501 },
502 {
503 .callback = video_detect_force_native,
504 .ident = "TongFang GKxNRxx",
505 .matches = {
506 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
507 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A1650TI"),
508 },
509 },
510 {
511 .callback = video_detect_force_native,
512 .ident = "TongFang GKxNRxx",
513 .matches = {
514 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
515 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A2060"),
516 },
517 },
518 {
519 .callback = video_detect_force_native,
520 .ident = "TongFang GMxNGxx",
521 .matches = {
522 DMI_MATCH(DMI_BOARD_NAME, "GMxNGxx"),
523 },
524 },
525 {
526 .callback = video_detect_force_native,
527 .ident = "TongFang GMxZGxx",
528 .matches = {
529 DMI_MATCH(DMI_BOARD_NAME, "GMxZGxx"),
530 },
531 },
532 {
533 .callback = video_detect_force_native,
534 .ident = "TongFang GMxRGxx",
535 .matches = {
536 DMI_MATCH(DMI_BOARD_NAME, "GMxRGxx"),
537 },
538 },
539 /*
540 * Desktops which falsely report a backlight and which our heuristics
541 * for this do not catch.
542 */
543 {
544 .callback = video_detect_force_none,
545 .ident = "Dell OptiPlex 9020M",
546 .matches = {
547 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
548 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
549 },
550 },
551 {
552 .callback = video_detect_force_none,
553 .ident = "MSI MS-7721",
554 .matches = {
555 DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
556 DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
557 },
558 },
559 { },
560 };
561
562 /* This uses a workqueue to avoid various locking ordering issues */
acpi_video_backlight_notify_work(struct work_struct * work)563 static void acpi_video_backlight_notify_work(struct work_struct *work)
564 {
565 if (acpi_video_get_backlight_type() != acpi_backlight_video)
566 acpi_video_unregister_backlight();
567 }
568
acpi_video_backlight_notify(struct notifier_block * nb,unsigned long val,void * bd)569 static int acpi_video_backlight_notify(struct notifier_block *nb,
570 unsigned long val, void *bd)
571 {
572 struct backlight_device *backlight = bd;
573
574 /* A raw bl registering may change video -> native */
575 if (backlight->props.type == BACKLIGHT_RAW &&
576 val == BACKLIGHT_REGISTERED)
577 schedule_work(&backlight_notify_work);
578
579 return NOTIFY_OK;
580 }
581
582 /*
583 * Determine which type of backlight interface to use on this system,
584 * First check cmdline, then dmi quirks, then do autodetect.
585 *
586 * The autodetect order is:
587 * 1) Is the acpi-video backlight interface supported ->
588 * no, use a vendor interface
589 * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
590 * yes, use a native interface
591 * 3) Else use the acpi-video interface
592 *
593 * Arguably the native on win8 check should be done first, but that would
594 * be a behavior change, which may causes issues.
595 */
acpi_video_get_backlight_type(void)596 enum acpi_backlight_type acpi_video_get_backlight_type(void)
597 {
598 static DEFINE_MUTEX(init_mutex);
599 static bool init_done;
600 static long video_caps;
601
602 /* Parse cmdline, dmi and acpi only once */
603 mutex_lock(&init_mutex);
604 if (!init_done) {
605 acpi_video_parse_cmdline();
606 dmi_check_system(video_detect_dmi_table);
607 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
608 ACPI_UINT32_MAX, find_video, NULL,
609 &video_caps, NULL);
610 INIT_WORK(&backlight_notify_work,
611 acpi_video_backlight_notify_work);
612 backlight_nb.notifier_call = acpi_video_backlight_notify;
613 backlight_nb.priority = 0;
614 if (backlight_register_notifier(&backlight_nb) == 0)
615 backlight_notifier_registered = true;
616 init_done = true;
617 }
618 mutex_unlock(&init_mutex);
619
620 if (acpi_backlight_cmdline != acpi_backlight_undef)
621 return acpi_backlight_cmdline;
622
623 if (acpi_backlight_dmi != acpi_backlight_undef)
624 return acpi_backlight_dmi;
625
626 if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
627 return acpi_backlight_vendor;
628
629 if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW))
630 return acpi_backlight_native;
631
632 return acpi_backlight_video;
633 }
634 EXPORT_SYMBOL(acpi_video_get_backlight_type);
635
636 /*
637 * Set the preferred backlight interface type based on DMI info.
638 * This function allows DMI blacklists to be implemented by external
639 * platform drivers instead of putting a big blacklist in video_detect.c
640 */
acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)641 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
642 {
643 acpi_backlight_dmi = type;
644 /* Remove acpi-video backlight interface if it is no longer desired */
645 if (acpi_video_get_backlight_type() != acpi_backlight_video)
646 acpi_video_unregister_backlight();
647 }
648 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
649
acpi_video_detect_exit(void)650 void __exit acpi_video_detect_exit(void)
651 {
652 if (backlight_notifier_registered)
653 backlight_unregister_notifier(&backlight_nb);
654 }
655