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 void acpi_video_unregister_backlight(void);
39
40 static bool backlight_notifier_registered;
41 static struct notifier_block backlight_nb;
42 static struct work_struct backlight_notify_work;
43
44 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
45 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
46
acpi_video_parse_cmdline(void)47 static 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
59 static acpi_status
find_video(acpi_handle handle,u32 lvl,void * context,void ** rv)60 find_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 */
video_detect_force_vendor(const struct dmi_system_id * d)85 static int video_detect_force_vendor(const struct dmi_system_id *d)
86 {
87 acpi_backlight_dmi = acpi_backlight_vendor;
88 return 0;
89 }
90
video_detect_force_video(const struct dmi_system_id * d)91 static int video_detect_force_video(const struct dmi_system_id *d)
92 {
93 acpi_backlight_dmi = acpi_backlight_video;
94 return 0;
95 }
96
video_detect_force_native(const struct dmi_system_id * d)97 static int video_detect_force_native(const struct dmi_system_id *d)
98 {
99 acpi_backlight_dmi = acpi_backlight_native;
100 return 0;
101 }
102
video_detect_force_none(const struct dmi_system_id * d)103 static int video_detect_force_none(const struct dmi_system_id *d)
104 {
105 acpi_backlight_dmi = acpi_backlight_none;
106 return 0;
107 }
108
109 static 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.redhat.com/show_bug.cgi?id=1187004 */
312 .callback = video_detect_force_native,
313 .ident = "Lenovo Ideapad Z570",
314 .matches = {
315 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
316 DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
317 },
318 },
319 {
320 .callback = video_detect_force_native,
321 .ident = "Lenovo E41-25",
322 .matches = {
323 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
324 DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
325 },
326 },
327 {
328 .callback = video_detect_force_native,
329 .ident = "Lenovo E41-45",
330 .matches = {
331 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
332 DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
333 },
334 },
335 {
336 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
337 .callback = video_detect_force_native,
338 .ident = "Apple MacBook Pro 12,1",
339 .matches = {
340 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
341 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
342 },
343 },
344 {
345 .callback = video_detect_force_native,
346 .ident = "Dell Vostro V131",
347 .matches = {
348 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
349 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
350 },
351 },
352 {
353 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
354 .callback = video_detect_force_native,
355 .ident = "Dell XPS 17 L702X",
356 .matches = {
357 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
358 DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
359 },
360 },
361 {
362 .callback = video_detect_force_native,
363 .ident = "Dell Precision 7510",
364 .matches = {
365 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
366 DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
367 },
368 },
369 {
370 .callback = video_detect_force_native,
371 .ident = "Acer Aspire 5738z",
372 .matches = {
373 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
374 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
375 DMI_MATCH(DMI_BOARD_NAME, "JV50"),
376 },
377 },
378 {
379 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
380 .callback = video_detect_force_native,
381 .ident = "Acer TravelMate 5735Z",
382 .matches = {
383 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
384 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
385 DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
386 },
387 },
388 {
389 .callback = video_detect_force_native,
390 .ident = "ASUSTeK COMPUTER INC. GA401",
391 .matches = {
392 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
393 DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
394 },
395 },
396 {
397 .callback = video_detect_force_native,
398 .ident = "ASUSTeK COMPUTER INC. GA502",
399 .matches = {
400 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
401 DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
402 },
403 },
404 {
405 .callback = video_detect_force_native,
406 .ident = "ASUSTeK COMPUTER INC. GA503",
407 .matches = {
408 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
409 DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
410 },
411 },
412 /*
413 * Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a
414 * working native and video interface. However the default detection
415 * mechanism first registers the video interface before unregistering
416 * it again and switching to the native interface during boot. This
417 * results in a dangling SBIOS request for backlight change for some
418 * reason, causing the backlight to switch to ~2% once per boot on the
419 * first power cord connect or disconnect event. Setting the native
420 * interface explicitly circumvents this buggy behaviour, by avoiding
421 * the unregistering process.
422 */
423 {
424 .callback = video_detect_force_native,
425 .ident = "Clevo NL5xRU",
426 .matches = {
427 DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
428 },
429 },
430 {
431 .callback = video_detect_force_native,
432 .ident = "Clevo NL5xRU",
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
435 DMI_MATCH(DMI_BOARD_NAME, "AURA1501"),
436 },
437 },
438 {
439 .callback = video_detect_force_native,
440 .ident = "Clevo NL5xRU",
441 .matches = {
442 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
443 DMI_MATCH(DMI_BOARD_NAME, "EDUBOOK1502"),
444 },
445 },
446 {
447 .callback = video_detect_force_native,
448 .ident = "Clevo NL5xNU",
449 .matches = {
450 DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
451 },
452 },
453 /*
454 * The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
455 * Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
456 * NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description
457 * above.
458 */
459 {
460 .callback = video_detect_force_native,
461 .ident = "TongFang PF5PU1G",
462 .matches = {
463 DMI_MATCH(DMI_BOARD_NAME, "PF5PU1G"),
464 },
465 },
466 {
467 .callback = video_detect_force_native,
468 .ident = "TongFang PF4NU1F",
469 .matches = {
470 DMI_MATCH(DMI_BOARD_NAME, "PF4NU1F"),
471 },
472 },
473 {
474 .callback = video_detect_force_native,
475 .ident = "TongFang PF4NU1F",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
478 DMI_MATCH(DMI_BOARD_NAME, "PULSE1401"),
479 },
480 },
481 {
482 .callback = video_detect_force_native,
483 .ident = "TongFang PF5NU1G",
484 .matches = {
485 DMI_MATCH(DMI_BOARD_NAME, "PF5NU1G"),
486 },
487 },
488 {
489 .callback = video_detect_force_native,
490 .ident = "TongFang PF5NU1G",
491 .matches = {
492 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
493 DMI_MATCH(DMI_BOARD_NAME, "PULSE1501"),
494 },
495 },
496 {
497 .callback = video_detect_force_native,
498 .ident = "TongFang PF5LUXG",
499 .matches = {
500 DMI_MATCH(DMI_BOARD_NAME, "PF5LUXG"),
501 },
502 },
503 /*
504 * More Tongfang devices with the same issue as the Clevo NL5xRU and
505 * NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description above.
506 */
507 {
508 .callback = video_detect_force_native,
509 .ident = "TongFang GKxNRxx",
510 .matches = {
511 DMI_MATCH(DMI_BOARD_NAME, "GKxNRxx"),
512 },
513 },
514 {
515 .callback = video_detect_force_native,
516 .ident = "TongFang GKxNRxx",
517 .matches = {
518 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
519 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A1650TI"),
520 },
521 },
522 {
523 .callback = video_detect_force_native,
524 .ident = "TongFang GKxNRxx",
525 .matches = {
526 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
527 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1501A2060"),
528 },
529 },
530 {
531 .callback = video_detect_force_native,
532 .ident = "TongFang GKxNRxx",
533 .matches = {
534 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
535 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A1650TI"),
536 },
537 },
538 {
539 .callback = video_detect_force_native,
540 .ident = "TongFang GKxNRxx",
541 .matches = {
542 DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
543 DMI_MATCH(DMI_BOARD_NAME, "POLARIS1701A2060"),
544 },
545 },
546 {
547 .callback = video_detect_force_native,
548 .ident = "TongFang GMxNGxx",
549 .matches = {
550 DMI_MATCH(DMI_BOARD_NAME, "GMxNGxx"),
551 },
552 },
553 {
554 .callback = video_detect_force_native,
555 .ident = "TongFang GMxZGxx",
556 .matches = {
557 DMI_MATCH(DMI_BOARD_NAME, "GMxZGxx"),
558 },
559 },
560 {
561 .callback = video_detect_force_native,
562 .ident = "TongFang GMxRGxx",
563 .matches = {
564 DMI_MATCH(DMI_BOARD_NAME, "GMxRGxx"),
565 },
566 },
567 /*
568 * Desktops which falsely report a backlight and which our heuristics
569 * for this do not catch.
570 */
571 {
572 .callback = video_detect_force_none,
573 .ident = "Dell OptiPlex 9020M",
574 .matches = {
575 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
576 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
577 },
578 },
579 {
580 .callback = video_detect_force_none,
581 .ident = "MSI MS-7721",
582 .matches = {
583 DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
584 DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
585 },
586 },
587 { },
588 };
589
590 /* This uses a workqueue to avoid various locking ordering issues */
acpi_video_backlight_notify_work(struct work_struct * work)591 static void acpi_video_backlight_notify_work(struct work_struct *work)
592 {
593 if (acpi_video_get_backlight_type() != acpi_backlight_video)
594 acpi_video_unregister_backlight();
595 }
596
acpi_video_backlight_notify(struct notifier_block * nb,unsigned long val,void * bd)597 static int acpi_video_backlight_notify(struct notifier_block *nb,
598 unsigned long val, void *bd)
599 {
600 struct backlight_device *backlight = bd;
601
602 /* A raw bl registering may change video -> native */
603 if (backlight->props.type == BACKLIGHT_RAW &&
604 val == BACKLIGHT_REGISTERED)
605 schedule_work(&backlight_notify_work);
606
607 return NOTIFY_OK;
608 }
609
610 /*
611 * Determine which type of backlight interface to use on this system,
612 * First check cmdline, then dmi quirks, then do autodetect.
613 *
614 * The autodetect order is:
615 * 1) Is the acpi-video backlight interface supported ->
616 * no, use a vendor interface
617 * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
618 * yes, use a native interface
619 * 3) Else use the acpi-video interface
620 *
621 * Arguably the native on win8 check should be done first, but that would
622 * be a behavior change, which may causes issues.
623 */
acpi_video_get_backlight_type(void)624 enum acpi_backlight_type acpi_video_get_backlight_type(void)
625 {
626 static DEFINE_MUTEX(init_mutex);
627 static bool init_done;
628 static long video_caps;
629
630 /* Parse cmdline, dmi and acpi only once */
631 mutex_lock(&init_mutex);
632 if (!init_done) {
633 acpi_video_parse_cmdline();
634 dmi_check_system(video_detect_dmi_table);
635 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
636 ACPI_UINT32_MAX, find_video, NULL,
637 &video_caps, NULL);
638 INIT_WORK(&backlight_notify_work,
639 acpi_video_backlight_notify_work);
640 backlight_nb.notifier_call = acpi_video_backlight_notify;
641 backlight_nb.priority = 0;
642 if (backlight_register_notifier(&backlight_nb) == 0)
643 backlight_notifier_registered = true;
644 init_done = true;
645 }
646 mutex_unlock(&init_mutex);
647
648 if (acpi_backlight_cmdline != acpi_backlight_undef)
649 return acpi_backlight_cmdline;
650
651 if (acpi_backlight_dmi != acpi_backlight_undef)
652 return acpi_backlight_dmi;
653
654 if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
655 return acpi_backlight_vendor;
656
657 if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW))
658 return acpi_backlight_native;
659
660 return acpi_backlight_video;
661 }
662 EXPORT_SYMBOL(acpi_video_get_backlight_type);
663
664 /*
665 * Set the preferred backlight interface type based on DMI info.
666 * This function allows DMI blacklists to be implemented by external
667 * platform drivers instead of putting a big blacklist in video_detect.c
668 */
acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)669 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
670 {
671 acpi_backlight_dmi = type;
672 /* Remove acpi-video backlight interface if it is no longer desired */
673 if (acpi_video_get_backlight_type() != acpi_backlight_video)
674 acpi_video_unregister_backlight();
675 }
676 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
677
acpi_video_detect_exit(void)678 void __exit acpi_video_detect_exit(void)
679 {
680 if (backlight_notifier_registered)
681 backlight_unregister_notifier(&backlight_nb);
682 }
683