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Merge tag 'cris-for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper...
[deliverable/linux.git] / drivers / acpi / video.c
1 /*
2 * video.c - ACPI Video Driver
3 *
4 * Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
5 * Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
6 * Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or (at
13 * your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23 *
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 */
26
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/list.h>
32 #include <linux/mutex.h>
33 #include <linux/input.h>
34 #include <linux/backlight.h>
35 #include <linux/thermal.h>
36 #include <linux/sort.h>
37 #include <linux/pci.h>
38 #include <linux/pci_ids.h>
39 #include <linux/slab.h>
40 #include <linux/dmi.h>
41 #include <linux/suspend.h>
42 #include <linux/acpi.h>
43 #include <acpi/video.h>
44 #include <asm/uaccess.h>
45
46 #include "internal.h"
47
48 #define ACPI_VIDEO_BUS_NAME "Video Bus"
49 #define ACPI_VIDEO_DEVICE_NAME "Video Device"
50 #define ACPI_VIDEO_NOTIFY_SWITCH 0x80
51 #define ACPI_VIDEO_NOTIFY_PROBE 0x81
52 #define ACPI_VIDEO_NOTIFY_CYCLE 0x82
53 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
54 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
55
56 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x85
57 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x86
58 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x87
59 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x88
60 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x89
61
62 #define MAX_NAME_LEN 20
63
64 #define _COMPONENT ACPI_VIDEO_COMPONENT
65 ACPI_MODULE_NAME("video");
66
67 MODULE_AUTHOR("Bruno Ducrot");
68 MODULE_DESCRIPTION("ACPI Video Driver");
69 MODULE_LICENSE("GPL");
70
71 static bool brightness_switch_enabled = 1;
72 module_param(brightness_switch_enabled, bool, 0644);
73
74 /*
75 * By default, we don't allow duplicate ACPI video bus devices
76 * under the same VGA controller
77 */
78 static bool allow_duplicates;
79 module_param(allow_duplicates, bool, 0644);
80
81 /*
82 * For Windows 8 systems: used to decide if video module
83 * should skip registering backlight interface of its own.
84 */
85 static int use_native_backlight_param = -1;
86 module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
87 static bool use_native_backlight_dmi = true;
88
89 static int register_count;
90 static struct mutex video_list_lock;
91 static struct list_head video_bus_head;
92 static int acpi_video_bus_add(struct acpi_device *device);
93 static int acpi_video_bus_remove(struct acpi_device *device);
94 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
95
96 static const struct acpi_device_id video_device_ids[] = {
97 {ACPI_VIDEO_HID, 0},
98 {"", 0},
99 };
100 MODULE_DEVICE_TABLE(acpi, video_device_ids);
101
102 static struct acpi_driver acpi_video_bus = {
103 .name = "video",
104 .class = ACPI_VIDEO_CLASS,
105 .ids = video_device_ids,
106 .ops = {
107 .add = acpi_video_bus_add,
108 .remove = acpi_video_bus_remove,
109 .notify = acpi_video_bus_notify,
110 },
111 };
112
113 struct acpi_video_bus_flags {
114 u8 multihead:1; /* can switch video heads */
115 u8 rom:1; /* can retrieve a video rom */
116 u8 post:1; /* can configure the head to */
117 u8 reserved:5;
118 };
119
120 struct acpi_video_bus_cap {
121 u8 _DOS:1; /* Enable/Disable output switching */
122 u8 _DOD:1; /* Enumerate all devices attached to display adapter */
123 u8 _ROM:1; /* Get ROM Data */
124 u8 _GPD:1; /* Get POST Device */
125 u8 _SPD:1; /* Set POST Device */
126 u8 _VPO:1; /* Video POST Options */
127 u8 reserved:2;
128 };
129
130 struct acpi_video_device_attrib {
131 u32 display_index:4; /* A zero-based instance of the Display */
132 u32 display_port_attachment:4; /* This field differentiates the display type */
133 u32 display_type:4; /* Describe the specific type in use */
134 u32 vendor_specific:4; /* Chipset Vendor Specific */
135 u32 bios_can_detect:1; /* BIOS can detect the device */
136 u32 depend_on_vga:1; /* Non-VGA output device whose power is related to
137 the VGA device. */
138 u32 pipe_id:3; /* For VGA multiple-head devices. */
139 u32 reserved:10; /* Must be 0 */
140 u32 device_id_scheme:1; /* Device ID Scheme */
141 };
142
143 struct acpi_video_enumerated_device {
144 union {
145 u32 int_val;
146 struct acpi_video_device_attrib attrib;
147 } value;
148 struct acpi_video_device *bind_info;
149 };
150
151 struct acpi_video_bus {
152 struct acpi_device *device;
153 bool backlight_registered;
154 bool backlight_notifier_registered;
155 u8 dos_setting;
156 struct acpi_video_enumerated_device *attached_array;
157 u8 attached_count;
158 u8 child_count;
159 struct acpi_video_bus_cap cap;
160 struct acpi_video_bus_flags flags;
161 struct list_head video_device_list;
162 struct mutex device_list_lock; /* protects video_device_list */
163 struct list_head entry;
164 struct input_dev *input;
165 char phys[32]; /* for input device */
166 struct notifier_block pm_nb;
167 struct notifier_block backlight_nb;
168 };
169
170 struct acpi_video_device_flags {
171 u8 crt:1;
172 u8 lcd:1;
173 u8 tvout:1;
174 u8 dvi:1;
175 u8 bios:1;
176 u8 unknown:1;
177 u8 notify:1;
178 u8 reserved:1;
179 };
180
181 struct acpi_video_device_cap {
182 u8 _ADR:1; /* Return the unique ID */
183 u8 _BCL:1; /* Query list of brightness control levels supported */
184 u8 _BCM:1; /* Set the brightness level */
185 u8 _BQC:1; /* Get current brightness level */
186 u8 _BCQ:1; /* Some buggy BIOS uses _BCQ instead of _BQC */
187 u8 _DDC:1; /* Return the EDID for this device */
188 };
189
190 struct acpi_video_brightness_flags {
191 u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
192 u8 _BCL_reversed:1; /* _BCL package is in a reversed order */
193 u8 _BQC_use_index:1; /* _BQC returns an index value */
194 };
195
196 struct acpi_video_device_brightness {
197 int curr;
198 int count;
199 int *levels;
200 struct acpi_video_brightness_flags flags;
201 };
202
203 struct acpi_video_device {
204 unsigned long device_id;
205 struct acpi_video_device_flags flags;
206 struct acpi_video_device_cap cap;
207 struct list_head entry;
208 struct delayed_work switch_brightness_work;
209 int switch_brightness_event;
210 struct acpi_video_bus *video;
211 struct acpi_device *dev;
212 struct acpi_video_device_brightness *brightness;
213 struct backlight_device *backlight;
214 struct thermal_cooling_device *cooling_dev;
215 };
216
217 static const char device_decode[][30] = {
218 "motherboard VGA device",
219 "PCI VGA device",
220 "AGP VGA device",
221 "UNKNOWN",
222 };
223
224 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
225 static void acpi_video_device_rebind(struct acpi_video_bus *video);
226 static void acpi_video_device_bind(struct acpi_video_bus *video,
227 struct acpi_video_device *device);
228 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
229 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
230 int level);
231 static int acpi_video_device_lcd_get_level_current(
232 struct acpi_video_device *device,
233 unsigned long long *level, bool raw);
234 static int acpi_video_get_next_level(struct acpi_video_device *device,
235 u32 level_current, u32 event);
236 static void acpi_video_switch_brightness(struct work_struct *work);
237
238 static bool acpi_video_use_native_backlight(void)
239 {
240 if (use_native_backlight_param != -1)
241 return use_native_backlight_param;
242 else
243 return use_native_backlight_dmi;
244 }
245
246 bool acpi_video_verify_backlight_support(void)
247 {
248 if (acpi_osi_is_win8() && acpi_video_use_native_backlight() &&
249 backlight_device_registered(BACKLIGHT_RAW))
250 return false;
251 return acpi_video_backlight_support();
252 }
253 EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support);
254
255 /* backlight device sysfs support */
256 static int acpi_video_get_brightness(struct backlight_device *bd)
257 {
258 unsigned long long cur_level;
259 int i;
260 struct acpi_video_device *vd = bl_get_data(bd);
261
262 if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
263 return -EINVAL;
264 for (i = 2; i < vd->brightness->count; i++) {
265 if (vd->brightness->levels[i] == cur_level)
266 /*
267 * The first two entries are special - see page 575
268 * of the ACPI spec 3.0
269 */
270 return i - 2;
271 }
272 return 0;
273 }
274
275 static int acpi_video_set_brightness(struct backlight_device *bd)
276 {
277 int request_level = bd->props.brightness + 2;
278 struct acpi_video_device *vd = bl_get_data(bd);
279
280 cancel_delayed_work(&vd->switch_brightness_work);
281 return acpi_video_device_lcd_set_level(vd,
282 vd->brightness->levels[request_level]);
283 }
284
285 static const struct backlight_ops acpi_backlight_ops = {
286 .get_brightness = acpi_video_get_brightness,
287 .update_status = acpi_video_set_brightness,
288 };
289
290 /* thermal cooling device callbacks */
291 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
292 long *state)
293 {
294 struct acpi_device *device = cooling_dev->devdata;
295 struct acpi_video_device *video = acpi_driver_data(device);
296
297 *state = video->brightness->count - 3;
298 return 0;
299 }
300
301 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
302 long *state)
303 {
304 struct acpi_device *device = cooling_dev->devdata;
305 struct acpi_video_device *video = acpi_driver_data(device);
306 unsigned long long level;
307 int offset;
308
309 if (acpi_video_device_lcd_get_level_current(video, &level, false))
310 return -EINVAL;
311 for (offset = 2; offset < video->brightness->count; offset++)
312 if (level == video->brightness->levels[offset]) {
313 *state = video->brightness->count - offset - 1;
314 return 0;
315 }
316
317 return -EINVAL;
318 }
319
320 static int
321 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
322 {
323 struct acpi_device *device = cooling_dev->devdata;
324 struct acpi_video_device *video = acpi_driver_data(device);
325 int level;
326
327 if (state >= video->brightness->count - 2)
328 return -EINVAL;
329
330 state = video->brightness->count - state;
331 level = video->brightness->levels[state - 1];
332 return acpi_video_device_lcd_set_level(video, level);
333 }
334
335 static const struct thermal_cooling_device_ops video_cooling_ops = {
336 .get_max_state = video_get_max_state,
337 .get_cur_state = video_get_cur_state,
338 .set_cur_state = video_set_cur_state,
339 };
340
341 /*
342 * --------------------------------------------------------------------------
343 * Video Management
344 * --------------------------------------------------------------------------
345 */
346
347 static int
348 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
349 union acpi_object **levels)
350 {
351 int status;
352 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
353 union acpi_object *obj;
354
355
356 *levels = NULL;
357
358 status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
359 if (!ACPI_SUCCESS(status))
360 return status;
361 obj = (union acpi_object *)buffer.pointer;
362 if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
363 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
364 status = -EFAULT;
365 goto err;
366 }
367
368 *levels = obj;
369
370 return 0;
371
372 err:
373 kfree(buffer.pointer);
374
375 return status;
376 }
377
378 static int
379 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
380 {
381 int status;
382 int state;
383
384 status = acpi_execute_simple_method(device->dev->handle,
385 "_BCM", level);
386 if (ACPI_FAILURE(status)) {
387 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
388 return -EIO;
389 }
390
391 device->brightness->curr = level;
392 for (state = 2; state < device->brightness->count; state++)
393 if (level == device->brightness->levels[state]) {
394 if (device->backlight)
395 device->backlight->props.brightness = state - 2;
396 return 0;
397 }
398
399 ACPI_ERROR((AE_INFO, "Current brightness invalid"));
400 return -EINVAL;
401 }
402
403 /*
404 * For some buggy _BQC methods, we need to add a constant value to
405 * the _BQC return value to get the actual current brightness level
406 */
407
408 static int bqc_offset_aml_bug_workaround;
409 static int __init video_set_bqc_offset(const struct dmi_system_id *d)
410 {
411 bqc_offset_aml_bug_workaround = 9;
412 return 0;
413 }
414
415 static int __init video_disable_native_backlight(const struct dmi_system_id *d)
416 {
417 use_native_backlight_dmi = false;
418 return 0;
419 }
420
421 static struct dmi_system_id video_dmi_table[] __initdata = {
422 /*
423 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
424 */
425 {
426 .callback = video_set_bqc_offset,
427 .ident = "Acer Aspire 5720",
428 .matches = {
429 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
430 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
431 },
432 },
433 {
434 .callback = video_set_bqc_offset,
435 .ident = "Acer Aspire 5710Z",
436 .matches = {
437 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
438 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
439 },
440 },
441 {
442 .callback = video_set_bqc_offset,
443 .ident = "eMachines E510",
444 .matches = {
445 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
446 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
447 },
448 },
449 {
450 .callback = video_set_bqc_offset,
451 .ident = "Acer Aspire 5315",
452 .matches = {
453 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
454 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
455 },
456 },
457 {
458 .callback = video_set_bqc_offset,
459 .ident = "Acer Aspire 7720",
460 .matches = {
461 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
462 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
463 },
464 },
465
466 /*
467 * These models have a working acpi_video backlight control, and using
468 * native backlight causes a regression where backlight does not work
469 * when userspace is not handling brightness key events. Disable
470 * native_backlight on these to fix this:
471 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
472 */
473 {
474 .callback = video_disable_native_backlight,
475 .ident = "ThinkPad T420",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
478 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
479 },
480 },
481 {
482 .callback = video_disable_native_backlight,
483 .ident = "ThinkPad T520",
484 .matches = {
485 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
486 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
487 },
488 },
489 {
490 .callback = video_disable_native_backlight,
491 .ident = "ThinkPad X201s",
492 .matches = {
493 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
494 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
495 },
496 },
497
498 /* The native backlight controls do not work on some older machines */
499 {
500 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
501 .callback = video_disable_native_backlight,
502 .ident = "HP ENVY 15 Notebook",
503 .matches = {
504 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
505 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
506 },
507 },
508
509 {
510 .callback = video_disable_native_backlight,
511 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
512 .matches = {
513 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
514 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
515 },
516 },
517 {
518 .callback = video_disable_native_backlight,
519 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
520 .matches = {
521 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
522 DMI_MATCH(DMI_PRODUCT_NAME, "370R4E/370R4V/370R5E/3570RE/370R5V"),
523 },
524 },
525 {
526 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
527 .callback = video_disable_native_backlight,
528 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
529 .matches = {
530 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
531 DMI_MATCH(DMI_PRODUCT_NAME, "3570R/370R/470R/450R/510R/4450RV"),
532 },
533 },
534 {
535 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
536 .callback = video_disable_native_backlight,
537 .ident = "SAMSUNG 730U3E/740U3E",
538 .matches = {
539 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
540 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
541 },
542 },
543
544 {
545 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
546 .callback = video_disable_native_backlight,
547 .ident = "Dell XPS15 L521X",
548 .matches = {
549 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
550 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
551 },
552 },
553 {}
554 };
555
556 static unsigned long long
557 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
558 unsigned long long bqc_value)
559 {
560 unsigned long long level;
561
562 if (device->brightness->flags._BQC_use_index) {
563 /*
564 * _BQC returns an index that doesn't account for
565 * the first 2 items with special meaning, so we need
566 * to compensate for that by offsetting ourselves
567 */
568 if (device->brightness->flags._BCL_reversed)
569 bqc_value = device->brightness->count - 3 - bqc_value;
570
571 level = device->brightness->levels[bqc_value + 2];
572 } else {
573 level = bqc_value;
574 }
575
576 level += bqc_offset_aml_bug_workaround;
577
578 return level;
579 }
580
581 static int
582 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
583 unsigned long long *level, bool raw)
584 {
585 acpi_status status = AE_OK;
586 int i;
587
588 if (device->cap._BQC || device->cap._BCQ) {
589 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
590
591 status = acpi_evaluate_integer(device->dev->handle, buf,
592 NULL, level);
593 if (ACPI_SUCCESS(status)) {
594 if (raw) {
595 /*
596 * Caller has indicated he wants the raw
597 * value returned by _BQC, so don't furtherly
598 * mess with the value.
599 */
600 return 0;
601 }
602
603 *level = acpi_video_bqc_value_to_level(device, *level);
604
605 for (i = 2; i < device->brightness->count; i++)
606 if (device->brightness->levels[i] == *level) {
607 device->brightness->curr = *level;
608 return 0;
609 }
610 /*
611 * BQC returned an invalid level.
612 * Stop using it.
613 */
614 ACPI_WARNING((AE_INFO,
615 "%s returned an invalid level",
616 buf));
617 device->cap._BQC = device->cap._BCQ = 0;
618 } else {
619 /*
620 * Fixme:
621 * should we return an error or ignore this failure?
622 * dev->brightness->curr is a cached value which stores
623 * the correct current backlight level in most cases.
624 * ACPI video backlight still works w/ buggy _BQC.
625 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
626 */
627 ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
628 device->cap._BQC = device->cap._BCQ = 0;
629 }
630 }
631
632 *level = device->brightness->curr;
633 return 0;
634 }
635
636 static int
637 acpi_video_device_EDID(struct acpi_video_device *device,
638 union acpi_object **edid, ssize_t length)
639 {
640 int status;
641 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
642 union acpi_object *obj;
643 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
644 struct acpi_object_list args = { 1, &arg0 };
645
646
647 *edid = NULL;
648
649 if (!device)
650 return -ENODEV;
651 if (length == 128)
652 arg0.integer.value = 1;
653 else if (length == 256)
654 arg0.integer.value = 2;
655 else
656 return -EINVAL;
657
658 status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
659 if (ACPI_FAILURE(status))
660 return -ENODEV;
661
662 obj = buffer.pointer;
663
664 if (obj && obj->type == ACPI_TYPE_BUFFER)
665 *edid = obj;
666 else {
667 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
668 status = -EFAULT;
669 kfree(obj);
670 }
671
672 return status;
673 }
674
675 /* bus */
676
677 /*
678 * Arg:
679 * video : video bus device pointer
680 * bios_flag :
681 * 0. The system BIOS should NOT automatically switch(toggle)
682 * the active display output.
683 * 1. The system BIOS should automatically switch (toggle) the
684 * active display output. No switch event.
685 * 2. The _DGS value should be locked.
686 * 3. The system BIOS should not automatically switch (toggle) the
687 * active display output, but instead generate the display switch
688 * event notify code.
689 * lcd_flag :
690 * 0. The system BIOS should automatically control the brightness level
691 * of the LCD when the power changes from AC to DC
692 * 1. The system BIOS should NOT automatically control the brightness
693 * level of the LCD when the power changes from AC to DC.
694 * Return Value:
695 * -EINVAL wrong arg.
696 */
697
698 static int
699 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
700 {
701 acpi_status status;
702
703 if (!video->cap._DOS)
704 return 0;
705
706 if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
707 return -EINVAL;
708 video->dos_setting = (lcd_flag << 2) | bios_flag;
709 status = acpi_execute_simple_method(video->device->handle, "_DOS",
710 (lcd_flag << 2) | bios_flag);
711 if (ACPI_FAILURE(status))
712 return -EIO;
713
714 return 0;
715 }
716
717 /*
718 * Simple comparison function used to sort backlight levels.
719 */
720
721 static int
722 acpi_video_cmp_level(const void *a, const void *b)
723 {
724 return *(int *)a - *(int *)b;
725 }
726
727 /*
728 * Decides if _BQC/_BCQ for this system is usable
729 *
730 * We do this by changing the level first and then read out the current
731 * brightness level, if the value does not match, find out if it is using
732 * index. If not, clear the _BQC/_BCQ capability.
733 */
734 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
735 int max_level, int current_level)
736 {
737 struct acpi_video_device_brightness *br = device->brightness;
738 int result;
739 unsigned long long level;
740 int test_level;
741
742 /* don't mess with existing known broken systems */
743 if (bqc_offset_aml_bug_workaround)
744 return 0;
745
746 /*
747 * Some systems always report current brightness level as maximum
748 * through _BQC, we need to test another value for them.
749 */
750 test_level = current_level == max_level ? br->levels[3] : max_level;
751
752 result = acpi_video_device_lcd_set_level(device, test_level);
753 if (result)
754 return result;
755
756 result = acpi_video_device_lcd_get_level_current(device, &level, true);
757 if (result)
758 return result;
759
760 if (level != test_level) {
761 /* buggy _BQC found, need to find out if it uses index */
762 if (level < br->count) {
763 if (br->flags._BCL_reversed)
764 level = br->count - 3 - level;
765 if (br->levels[level + 2] == test_level)
766 br->flags._BQC_use_index = 1;
767 }
768
769 if (!br->flags._BQC_use_index)
770 device->cap._BQC = device->cap._BCQ = 0;
771 }
772
773 return 0;
774 }
775
776
777 /*
778 * Arg:
779 * device : video output device (LCD, CRT, ..)
780 *
781 * Return Value:
782 * Maximum brightness level
783 *
784 * Allocate and initialize device->brightness.
785 */
786
787 static int
788 acpi_video_init_brightness(struct acpi_video_device *device)
789 {
790 union acpi_object *obj = NULL;
791 int i, max_level = 0, count = 0, level_ac_battery = 0;
792 unsigned long long level, level_old;
793 union acpi_object *o;
794 struct acpi_video_device_brightness *br = NULL;
795 int result = -EINVAL;
796 u32 value;
797
798 if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
799 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
800 "LCD brightness level\n"));
801 goto out;
802 }
803
804 if (obj->package.count < 2)
805 goto out;
806
807 br = kzalloc(sizeof(*br), GFP_KERNEL);
808 if (!br) {
809 printk(KERN_ERR "can't allocate memory\n");
810 result = -ENOMEM;
811 goto out;
812 }
813
814 br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
815 GFP_KERNEL);
816 if (!br->levels) {
817 result = -ENOMEM;
818 goto out_free;
819 }
820
821 for (i = 0; i < obj->package.count; i++) {
822 o = (union acpi_object *)&obj->package.elements[i];
823 if (o->type != ACPI_TYPE_INTEGER) {
824 printk(KERN_ERR PREFIX "Invalid data\n");
825 continue;
826 }
827 value = (u32) o->integer.value;
828 /* Skip duplicate entries */
829 if (count > 2 && br->levels[count - 1] == value)
830 continue;
831
832 br->levels[count] = value;
833
834 if (br->levels[count] > max_level)
835 max_level = br->levels[count];
836 count++;
837 }
838
839 /*
840 * some buggy BIOS don't export the levels
841 * when machine is on AC/Battery in _BCL package.
842 * In this case, the first two elements in _BCL packages
843 * are also supported brightness levels that OS should take care of.
844 */
845 for (i = 2; i < count; i++) {
846 if (br->levels[i] == br->levels[0])
847 level_ac_battery++;
848 if (br->levels[i] == br->levels[1])
849 level_ac_battery++;
850 }
851
852 if (level_ac_battery < 2) {
853 level_ac_battery = 2 - level_ac_battery;
854 br->flags._BCL_no_ac_battery_levels = 1;
855 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
856 br->levels[i] = br->levels[i - level_ac_battery];
857 count += level_ac_battery;
858 } else if (level_ac_battery > 2)
859 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
860
861 /* Check if the _BCL package is in a reversed order */
862 if (max_level == br->levels[2]) {
863 br->flags._BCL_reversed = 1;
864 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
865 acpi_video_cmp_level, NULL);
866 } else if (max_level != br->levels[count - 1])
867 ACPI_ERROR((AE_INFO,
868 "Found unordered _BCL package"));
869
870 br->count = count;
871 device->brightness = br;
872
873 /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
874 br->curr = level = max_level;
875
876 if (!device->cap._BQC)
877 goto set_level;
878
879 result = acpi_video_device_lcd_get_level_current(device,
880 &level_old, true);
881 if (result)
882 goto out_free_levels;
883
884 result = acpi_video_bqc_quirk(device, max_level, level_old);
885 if (result)
886 goto out_free_levels;
887 /*
888 * cap._BQC may get cleared due to _BQC is found to be broken
889 * in acpi_video_bqc_quirk, so check again here.
890 */
891 if (!device->cap._BQC)
892 goto set_level;
893
894 level = acpi_video_bqc_value_to_level(device, level_old);
895 /*
896 * On some buggy laptops, _BQC returns an uninitialized
897 * value when invoked for the first time, i.e.
898 * level_old is invalid (no matter whether it's a level
899 * or an index). Set the backlight to max_level in this case.
900 */
901 for (i = 2; i < br->count; i++)
902 if (level == br->levels[i])
903 break;
904 if (i == br->count || !level)
905 level = max_level;
906
907 set_level:
908 result = acpi_video_device_lcd_set_level(device, level);
909 if (result)
910 goto out_free_levels;
911
912 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
913 "found %d brightness levels\n", count - 2));
914 kfree(obj);
915 return result;
916
917 out_free_levels:
918 kfree(br->levels);
919 out_free:
920 kfree(br);
921 out:
922 device->brightness = NULL;
923 kfree(obj);
924 return result;
925 }
926
927 /*
928 * Arg:
929 * device : video output device (LCD, CRT, ..)
930 *
931 * Return Value:
932 * None
933 *
934 * Find out all required AML methods defined under the output
935 * device.
936 */
937
938 static void acpi_video_device_find_cap(struct acpi_video_device *device)
939 {
940 if (acpi_has_method(device->dev->handle, "_ADR"))
941 device->cap._ADR = 1;
942 if (acpi_has_method(device->dev->handle, "_BCL"))
943 device->cap._BCL = 1;
944 if (acpi_has_method(device->dev->handle, "_BCM"))
945 device->cap._BCM = 1;
946 if (acpi_has_method(device->dev->handle, "_BQC")) {
947 device->cap._BQC = 1;
948 } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
949 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
950 device->cap._BCQ = 1;
951 }
952
953 if (acpi_has_method(device->dev->handle, "_DDC"))
954 device->cap._DDC = 1;
955 }
956
957 /*
958 * Arg:
959 * device : video output device (VGA)
960 *
961 * Return Value:
962 * None
963 *
964 * Find out all required AML methods defined under the video bus device.
965 */
966
967 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
968 {
969 if (acpi_has_method(video->device->handle, "_DOS"))
970 video->cap._DOS = 1;
971 if (acpi_has_method(video->device->handle, "_DOD"))
972 video->cap._DOD = 1;
973 if (acpi_has_method(video->device->handle, "_ROM"))
974 video->cap._ROM = 1;
975 if (acpi_has_method(video->device->handle, "_GPD"))
976 video->cap._GPD = 1;
977 if (acpi_has_method(video->device->handle, "_SPD"))
978 video->cap._SPD = 1;
979 if (acpi_has_method(video->device->handle, "_VPO"))
980 video->cap._VPO = 1;
981 }
982
983 /*
984 * Check whether the video bus device has required AML method to
985 * support the desired features
986 */
987
988 static int acpi_video_bus_check(struct acpi_video_bus *video)
989 {
990 acpi_status status = -ENOENT;
991 struct pci_dev *dev;
992
993 if (!video)
994 return -EINVAL;
995
996 dev = acpi_get_pci_dev(video->device->handle);
997 if (!dev)
998 return -ENODEV;
999 pci_dev_put(dev);
1000
1001 /*
1002 * Since there is no HID, CID and so on for VGA driver, we have
1003 * to check well known required nodes.
1004 */
1005
1006 /* Does this device support video switching? */
1007 if (video->cap._DOS || video->cap._DOD) {
1008 if (!video->cap._DOS) {
1009 printk(KERN_WARNING FW_BUG
1010 "ACPI(%s) defines _DOD but not _DOS\n",
1011 acpi_device_bid(video->device));
1012 }
1013 video->flags.multihead = 1;
1014 status = 0;
1015 }
1016
1017 /* Does this device support retrieving a video ROM? */
1018 if (video->cap._ROM) {
1019 video->flags.rom = 1;
1020 status = 0;
1021 }
1022
1023 /* Does this device support configuring which video device to POST? */
1024 if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1025 video->flags.post = 1;
1026 status = 0;
1027 }
1028
1029 return status;
1030 }
1031
1032 /*
1033 * --------------------------------------------------------------------------
1034 * Driver Interface
1035 * --------------------------------------------------------------------------
1036 */
1037
1038 /* device interface */
1039 static struct acpi_video_device_attrib *
1040 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1041 {
1042 struct acpi_video_enumerated_device *ids;
1043 int i;
1044
1045 for (i = 0; i < video->attached_count; i++) {
1046 ids = &video->attached_array[i];
1047 if ((ids->value.int_val & 0xffff) == device_id)
1048 return &ids->value.attrib;
1049 }
1050
1051 return NULL;
1052 }
1053
1054 static int
1055 acpi_video_get_device_type(struct acpi_video_bus *video,
1056 unsigned long device_id)
1057 {
1058 struct acpi_video_enumerated_device *ids;
1059 int i;
1060
1061 for (i = 0; i < video->attached_count; i++) {
1062 ids = &video->attached_array[i];
1063 if ((ids->value.int_val & 0xffff) == device_id)
1064 return ids->value.int_val;
1065 }
1066
1067 return 0;
1068 }
1069
1070 static int
1071 acpi_video_bus_get_one_device(struct acpi_device *device,
1072 struct acpi_video_bus *video)
1073 {
1074 unsigned long long device_id;
1075 int status, device_type;
1076 struct acpi_video_device *data;
1077 struct acpi_video_device_attrib *attribute;
1078
1079 status =
1080 acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1081 /* Some device omits _ADR, we skip them instead of fail */
1082 if (ACPI_FAILURE(status))
1083 return 0;
1084
1085 data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1086 if (!data)
1087 return -ENOMEM;
1088
1089 strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1090 strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1091 device->driver_data = data;
1092
1093 data->device_id = device_id;
1094 data->video = video;
1095 data->dev = device;
1096 INIT_DELAYED_WORK(&data->switch_brightness_work,
1097 acpi_video_switch_brightness);
1098
1099 attribute = acpi_video_get_device_attr(video, device_id);
1100
1101 if (attribute && attribute->device_id_scheme) {
1102 switch (attribute->display_type) {
1103 case ACPI_VIDEO_DISPLAY_CRT:
1104 data->flags.crt = 1;
1105 break;
1106 case ACPI_VIDEO_DISPLAY_TV:
1107 data->flags.tvout = 1;
1108 break;
1109 case ACPI_VIDEO_DISPLAY_DVI:
1110 data->flags.dvi = 1;
1111 break;
1112 case ACPI_VIDEO_DISPLAY_LCD:
1113 data->flags.lcd = 1;
1114 break;
1115 default:
1116 data->flags.unknown = 1;
1117 break;
1118 }
1119 if (attribute->bios_can_detect)
1120 data->flags.bios = 1;
1121 } else {
1122 /* Check for legacy IDs */
1123 device_type = acpi_video_get_device_type(video, device_id);
1124 /* Ignore bits 16 and 18-20 */
1125 switch (device_type & 0xffe2ffff) {
1126 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1127 data->flags.crt = 1;
1128 break;
1129 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1130 data->flags.lcd = 1;
1131 break;
1132 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1133 data->flags.tvout = 1;
1134 break;
1135 default:
1136 data->flags.unknown = 1;
1137 }
1138 }
1139
1140 acpi_video_device_bind(video, data);
1141 acpi_video_device_find_cap(data);
1142
1143 mutex_lock(&video->device_list_lock);
1144 list_add_tail(&data->entry, &video->video_device_list);
1145 mutex_unlock(&video->device_list_lock);
1146
1147 return status;
1148 }
1149
1150 /*
1151 * Arg:
1152 * video : video bus device
1153 *
1154 * Return:
1155 * none
1156 *
1157 * Enumerate the video device list of the video bus,
1158 * bind the ids with the corresponding video devices
1159 * under the video bus.
1160 */
1161
1162 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1163 {
1164 struct acpi_video_device *dev;
1165
1166 mutex_lock(&video->device_list_lock);
1167
1168 list_for_each_entry(dev, &video->video_device_list, entry)
1169 acpi_video_device_bind(video, dev);
1170
1171 mutex_unlock(&video->device_list_lock);
1172 }
1173
1174 /*
1175 * Arg:
1176 * video : video bus device
1177 * device : video output device under the video
1178 * bus
1179 *
1180 * Return:
1181 * none
1182 *
1183 * Bind the ids with the corresponding video devices
1184 * under the video bus.
1185 */
1186
1187 static void
1188 acpi_video_device_bind(struct acpi_video_bus *video,
1189 struct acpi_video_device *device)
1190 {
1191 struct acpi_video_enumerated_device *ids;
1192 int i;
1193
1194 for (i = 0; i < video->attached_count; i++) {
1195 ids = &video->attached_array[i];
1196 if (device->device_id == (ids->value.int_val & 0xffff)) {
1197 ids->bind_info = device;
1198 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1199 }
1200 }
1201 }
1202
1203 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1204 {
1205 struct acpi_video_bus *video = device->video;
1206 int i;
1207
1208 /*
1209 * If we have a broken _DOD or we have more than 8 output devices
1210 * under the graphics controller node that we can't proper deal with
1211 * in the operation region code currently, no need to test.
1212 */
1213 if (!video->attached_count || video->child_count > 8)
1214 return true;
1215
1216 for (i = 0; i < video->attached_count; i++) {
1217 if ((video->attached_array[i].value.int_val & 0xfff) ==
1218 (device->device_id & 0xfff))
1219 return true;
1220 }
1221
1222 return false;
1223 }
1224
1225 /*
1226 * Arg:
1227 * video : video bus device
1228 *
1229 * Return:
1230 * < 0 : error
1231 *
1232 * Call _DOD to enumerate all devices attached to display adapter
1233 *
1234 */
1235
1236 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1237 {
1238 int status;
1239 int count;
1240 int i;
1241 struct acpi_video_enumerated_device *active_list;
1242 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1243 union acpi_object *dod = NULL;
1244 union acpi_object *obj;
1245
1246 status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1247 if (!ACPI_SUCCESS(status)) {
1248 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1249 return status;
1250 }
1251
1252 dod = buffer.pointer;
1253 if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1254 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1255 status = -EFAULT;
1256 goto out;
1257 }
1258
1259 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1260 dod->package.count));
1261
1262 active_list = kcalloc(1 + dod->package.count,
1263 sizeof(struct acpi_video_enumerated_device),
1264 GFP_KERNEL);
1265 if (!active_list) {
1266 status = -ENOMEM;
1267 goto out;
1268 }
1269
1270 count = 0;
1271 for (i = 0; i < dod->package.count; i++) {
1272 obj = &dod->package.elements[i];
1273
1274 if (obj->type != ACPI_TYPE_INTEGER) {
1275 printk(KERN_ERR PREFIX
1276 "Invalid _DOD data in element %d\n", i);
1277 continue;
1278 }
1279
1280 active_list[count].value.int_val = obj->integer.value;
1281 active_list[count].bind_info = NULL;
1282 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1283 (int)obj->integer.value));
1284 count++;
1285 }
1286
1287 kfree(video->attached_array);
1288
1289 video->attached_array = active_list;
1290 video->attached_count = count;
1291
1292 out:
1293 kfree(buffer.pointer);
1294 return status;
1295 }
1296
1297 static int
1298 acpi_video_get_next_level(struct acpi_video_device *device,
1299 u32 level_current, u32 event)
1300 {
1301 int min, max, min_above, max_below, i, l, delta = 255;
1302 max = max_below = 0;
1303 min = min_above = 255;
1304 /* Find closest level to level_current */
1305 for (i = 2; i < device->brightness->count; i++) {
1306 l = device->brightness->levels[i];
1307 if (abs(l - level_current) < abs(delta)) {
1308 delta = l - level_current;
1309 if (!delta)
1310 break;
1311 }
1312 }
1313 /* Ajust level_current to closest available level */
1314 level_current += delta;
1315 for (i = 2; i < device->brightness->count; i++) {
1316 l = device->brightness->levels[i];
1317 if (l < min)
1318 min = l;
1319 if (l > max)
1320 max = l;
1321 if (l < min_above && l > level_current)
1322 min_above = l;
1323 if (l > max_below && l < level_current)
1324 max_below = l;
1325 }
1326
1327 switch (event) {
1328 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1329 return (level_current < max) ? min_above : min;
1330 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1331 return (level_current < max) ? min_above : max;
1332 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1333 return (level_current > min) ? max_below : min;
1334 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1335 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1336 return 0;
1337 default:
1338 return level_current;
1339 }
1340 }
1341
1342 static void
1343 acpi_video_switch_brightness(struct work_struct *work)
1344 {
1345 struct acpi_video_device *device = container_of(to_delayed_work(work),
1346 struct acpi_video_device, switch_brightness_work);
1347 unsigned long long level_current, level_next;
1348 int event = device->switch_brightness_event;
1349 int result = -EINVAL;
1350
1351 /* no warning message if acpi_backlight=vendor or a quirk is used */
1352 if (!acpi_video_verify_backlight_support())
1353 return;
1354
1355 if (!device->brightness)
1356 goto out;
1357
1358 result = acpi_video_device_lcd_get_level_current(device,
1359 &level_current,
1360 false);
1361 if (result)
1362 goto out;
1363
1364 level_next = acpi_video_get_next_level(device, level_current, event);
1365
1366 result = acpi_video_device_lcd_set_level(device, level_next);
1367
1368 if (!result)
1369 backlight_force_update(device->backlight,
1370 BACKLIGHT_UPDATE_HOTKEY);
1371
1372 out:
1373 if (result)
1374 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1375 }
1376
1377 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1378 void **edid)
1379 {
1380 struct acpi_video_bus *video;
1381 struct acpi_video_device *video_device;
1382 union acpi_object *buffer = NULL;
1383 acpi_status status;
1384 int i, length;
1385
1386 if (!device || !acpi_driver_data(device))
1387 return -EINVAL;
1388
1389 video = acpi_driver_data(device);
1390
1391 for (i = 0; i < video->attached_count; i++) {
1392 video_device = video->attached_array[i].bind_info;
1393 length = 256;
1394
1395 if (!video_device)
1396 continue;
1397
1398 if (!video_device->cap._DDC)
1399 continue;
1400
1401 if (type) {
1402 switch (type) {
1403 case ACPI_VIDEO_DISPLAY_CRT:
1404 if (!video_device->flags.crt)
1405 continue;
1406 break;
1407 case ACPI_VIDEO_DISPLAY_TV:
1408 if (!video_device->flags.tvout)
1409 continue;
1410 break;
1411 case ACPI_VIDEO_DISPLAY_DVI:
1412 if (!video_device->flags.dvi)
1413 continue;
1414 break;
1415 case ACPI_VIDEO_DISPLAY_LCD:
1416 if (!video_device->flags.lcd)
1417 continue;
1418 break;
1419 }
1420 } else if (video_device->device_id != device_id) {
1421 continue;
1422 }
1423
1424 status = acpi_video_device_EDID(video_device, &buffer, length);
1425
1426 if (ACPI_FAILURE(status) || !buffer ||
1427 buffer->type != ACPI_TYPE_BUFFER) {
1428 length = 128;
1429 status = acpi_video_device_EDID(video_device, &buffer,
1430 length);
1431 if (ACPI_FAILURE(status) || !buffer ||
1432 buffer->type != ACPI_TYPE_BUFFER) {
1433 continue;
1434 }
1435 }
1436
1437 *edid = buffer->buffer.pointer;
1438 return length;
1439 }
1440
1441 return -ENODEV;
1442 }
1443 EXPORT_SYMBOL(acpi_video_get_edid);
1444
1445 static int
1446 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1447 struct acpi_device *device)
1448 {
1449 int status = 0;
1450 struct acpi_device *dev;
1451
1452 /*
1453 * There are systems where video module known to work fine regardless
1454 * of broken _DOD and ignoring returned value here doesn't cause
1455 * any issues later.
1456 */
1457 acpi_video_device_enumerate(video);
1458
1459 list_for_each_entry(dev, &device->children, node) {
1460
1461 status = acpi_video_bus_get_one_device(dev, video);
1462 if (status) {
1463 dev_err(&dev->dev, "Can't attach device\n");
1464 break;
1465 }
1466 video->child_count++;
1467 }
1468 return status;
1469 }
1470
1471 /* acpi_video interface */
1472
1473 /*
1474 * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1475 * preform any automatic brightness change on receiving a notification.
1476 */
1477 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1478 {
1479 return acpi_video_bus_DOS(video, 0,
1480 acpi_osi_is_win8() ? 1 : 0);
1481 }
1482
1483 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1484 {
1485 return acpi_video_bus_DOS(video, 0,
1486 acpi_osi_is_win8() ? 0 : 1);
1487 }
1488
1489 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1490 {
1491 struct acpi_video_bus *video = acpi_driver_data(device);
1492 struct input_dev *input;
1493 int keycode = 0;
1494
1495 if (!video || !video->input)
1496 return;
1497
1498 input = video->input;
1499
1500 switch (event) {
1501 case ACPI_VIDEO_NOTIFY_SWITCH: /* User requested a switch,
1502 * most likely via hotkey. */
1503 keycode = KEY_SWITCHVIDEOMODE;
1504 break;
1505
1506 case ACPI_VIDEO_NOTIFY_PROBE: /* User plugged in or removed a video
1507 * connector. */
1508 acpi_video_device_enumerate(video);
1509 acpi_video_device_rebind(video);
1510 keycode = KEY_SWITCHVIDEOMODE;
1511 break;
1512
1513 case ACPI_VIDEO_NOTIFY_CYCLE: /* Cycle Display output hotkey pressed. */
1514 keycode = KEY_SWITCHVIDEOMODE;
1515 break;
1516 case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT: /* Next Display output hotkey pressed. */
1517 keycode = KEY_VIDEO_NEXT;
1518 break;
1519 case ACPI_VIDEO_NOTIFY_PREV_OUTPUT: /* previous Display output hotkey pressed. */
1520 keycode = KEY_VIDEO_PREV;
1521 break;
1522
1523 default:
1524 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1525 "Unsupported event [0x%x]\n", event));
1526 break;
1527 }
1528
1529 if (acpi_notifier_call_chain(device, event, 0))
1530 /* Something vetoed the keypress. */
1531 keycode = 0;
1532
1533 if (keycode) {
1534 input_report_key(input, keycode, 1);
1535 input_sync(input);
1536 input_report_key(input, keycode, 0);
1537 input_sync(input);
1538 }
1539
1540 return;
1541 }
1542
1543 static void brightness_switch_event(struct acpi_video_device *video_device,
1544 u32 event)
1545 {
1546 if (!brightness_switch_enabled)
1547 return;
1548
1549 video_device->switch_brightness_event = event;
1550 schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1551 }
1552
1553 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1554 {
1555 struct acpi_video_device *video_device = data;
1556 struct acpi_device *device = NULL;
1557 struct acpi_video_bus *bus;
1558 struct input_dev *input;
1559 int keycode = 0;
1560
1561 if (!video_device)
1562 return;
1563
1564 device = video_device->dev;
1565 bus = video_device->video;
1566 input = bus->input;
1567
1568 switch (event) {
1569 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
1570 brightness_switch_event(video_device, event);
1571 keycode = KEY_BRIGHTNESS_CYCLE;
1572 break;
1573 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
1574 brightness_switch_event(video_device, event);
1575 keycode = KEY_BRIGHTNESSUP;
1576 break;
1577 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
1578 brightness_switch_event(video_device, event);
1579 keycode = KEY_BRIGHTNESSDOWN;
1580 break;
1581 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1582 brightness_switch_event(video_device, event);
1583 keycode = KEY_BRIGHTNESS_ZERO;
1584 break;
1585 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
1586 brightness_switch_event(video_device, event);
1587 keycode = KEY_DISPLAY_OFF;
1588 break;
1589 default:
1590 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1591 "Unsupported event [0x%x]\n", event));
1592 break;
1593 }
1594
1595 acpi_notifier_call_chain(device, event, 0);
1596
1597 if (keycode) {
1598 input_report_key(input, keycode, 1);
1599 input_sync(input);
1600 input_report_key(input, keycode, 0);
1601 input_sync(input);
1602 }
1603
1604 return;
1605 }
1606
1607 static int acpi_video_resume(struct notifier_block *nb,
1608 unsigned long val, void *ign)
1609 {
1610 struct acpi_video_bus *video;
1611 struct acpi_video_device *video_device;
1612 int i;
1613
1614 switch (val) {
1615 case PM_HIBERNATION_PREPARE:
1616 case PM_SUSPEND_PREPARE:
1617 case PM_RESTORE_PREPARE:
1618 return NOTIFY_DONE;
1619 }
1620
1621 video = container_of(nb, struct acpi_video_bus, pm_nb);
1622
1623 dev_info(&video->device->dev, "Restoring backlight state\n");
1624
1625 for (i = 0; i < video->attached_count; i++) {
1626 video_device = video->attached_array[i].bind_info;
1627 if (video_device && video_device->backlight)
1628 acpi_video_set_brightness(video_device->backlight);
1629 }
1630
1631 return NOTIFY_OK;
1632 }
1633
1634 static acpi_status
1635 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1636 void **return_value)
1637 {
1638 struct acpi_device *device = context;
1639 struct acpi_device *sibling;
1640 int result;
1641
1642 if (handle == device->handle)
1643 return AE_CTRL_TERMINATE;
1644
1645 result = acpi_bus_get_device(handle, &sibling);
1646 if (result)
1647 return AE_OK;
1648
1649 if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1650 return AE_ALREADY_EXISTS;
1651
1652 return AE_OK;
1653 }
1654
1655 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1656 {
1657 struct backlight_properties props;
1658 struct pci_dev *pdev;
1659 acpi_handle acpi_parent;
1660 struct device *parent = NULL;
1661 int result;
1662 static int count;
1663 char *name;
1664
1665 /*
1666 * Do not create backlight device for video output
1667 * device that is not in the enumerated list.
1668 */
1669 if (!acpi_video_device_in_dod(device)) {
1670 dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1671 return;
1672 }
1673
1674 result = acpi_video_init_brightness(device);
1675 if (result)
1676 return;
1677 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1678 if (!name)
1679 return;
1680 count++;
1681
1682 acpi_get_parent(device->dev->handle, &acpi_parent);
1683
1684 pdev = acpi_get_pci_dev(acpi_parent);
1685 if (pdev) {
1686 parent = &pdev->dev;
1687 pci_dev_put(pdev);
1688 }
1689
1690 memset(&props, 0, sizeof(struct backlight_properties));
1691 props.type = BACKLIGHT_FIRMWARE;
1692 props.max_brightness = device->brightness->count - 3;
1693 device->backlight = backlight_device_register(name,
1694 parent,
1695 device,
1696 &acpi_backlight_ops,
1697 &props);
1698 kfree(name);
1699 if (IS_ERR(device->backlight))
1700 return;
1701
1702 /*
1703 * Save current brightness level in case we have to restore it
1704 * before acpi_video_device_lcd_set_level() is called next time.
1705 */
1706 device->backlight->props.brightness =
1707 acpi_video_get_brightness(device->backlight);
1708
1709 device->cooling_dev = thermal_cooling_device_register("LCD",
1710 device->dev, &video_cooling_ops);
1711 if (IS_ERR(device->cooling_dev)) {
1712 /*
1713 * Set cooling_dev to NULL so we don't crash trying to free it.
1714 * Also, why the hell we are returning early and not attempt to
1715 * register video output if cooling device registration failed?
1716 * -- dtor
1717 */
1718 device->cooling_dev = NULL;
1719 return;
1720 }
1721
1722 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1723 device->cooling_dev->id);
1724 result = sysfs_create_link(&device->dev->dev.kobj,
1725 &device->cooling_dev->device.kobj,
1726 "thermal_cooling");
1727 if (result)
1728 printk(KERN_ERR PREFIX "Create sysfs link\n");
1729 result = sysfs_create_link(&device->cooling_dev->device.kobj,
1730 &device->dev->dev.kobj, "device");
1731 if (result)
1732 printk(KERN_ERR PREFIX "Create sysfs link\n");
1733 }
1734
1735 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1736 {
1737 struct acpi_video_device *dev;
1738 union acpi_object *levels;
1739
1740 mutex_lock(&video->device_list_lock);
1741 list_for_each_entry(dev, &video->video_device_list, entry) {
1742 if (!acpi_video_device_lcd_query_levels(dev, &levels))
1743 kfree(levels);
1744 }
1745 mutex_unlock(&video->device_list_lock);
1746 }
1747
1748 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1749 {
1750 struct acpi_video_device *dev;
1751
1752 if (video->backlight_registered)
1753 return 0;
1754
1755 acpi_video_run_bcl_for_osi(video);
1756
1757 if (!acpi_video_verify_backlight_support())
1758 return 0;
1759
1760 mutex_lock(&video->device_list_lock);
1761 list_for_each_entry(dev, &video->video_device_list, entry)
1762 acpi_video_dev_register_backlight(dev);
1763 mutex_unlock(&video->device_list_lock);
1764
1765 video->backlight_registered = true;
1766
1767 video->pm_nb.notifier_call = acpi_video_resume;
1768 video->pm_nb.priority = 0;
1769 return register_pm_notifier(&video->pm_nb);
1770 }
1771
1772 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1773 {
1774 if (device->backlight) {
1775 backlight_device_unregister(device->backlight);
1776 device->backlight = NULL;
1777 }
1778 if (device->brightness) {
1779 kfree(device->brightness->levels);
1780 kfree(device->brightness);
1781 device->brightness = NULL;
1782 }
1783 if (device->cooling_dev) {
1784 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1785 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1786 thermal_cooling_device_unregister(device->cooling_dev);
1787 device->cooling_dev = NULL;
1788 }
1789 }
1790
1791 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1792 {
1793 struct acpi_video_device *dev;
1794 int error;
1795
1796 if (!video->backlight_registered)
1797 return 0;
1798
1799 error = unregister_pm_notifier(&video->pm_nb);
1800
1801 mutex_lock(&video->device_list_lock);
1802 list_for_each_entry(dev, &video->video_device_list, entry)
1803 acpi_video_dev_unregister_backlight(dev);
1804 mutex_unlock(&video->device_list_lock);
1805
1806 video->backlight_registered = false;
1807
1808 return error;
1809 }
1810
1811 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1812 {
1813 acpi_status status;
1814 struct acpi_device *adev = device->dev;
1815
1816 status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1817 acpi_video_device_notify, device);
1818 if (ACPI_FAILURE(status))
1819 dev_err(&adev->dev, "Error installing notify handler\n");
1820 else
1821 device->flags.notify = 1;
1822 }
1823
1824 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1825 {
1826 struct input_dev *input;
1827 struct acpi_video_device *dev;
1828 int error;
1829
1830 video->input = input = input_allocate_device();
1831 if (!input) {
1832 error = -ENOMEM;
1833 goto out;
1834 }
1835
1836 error = acpi_video_bus_start_devices(video);
1837 if (error)
1838 goto err_free_input;
1839
1840 snprintf(video->phys, sizeof(video->phys),
1841 "%s/video/input0", acpi_device_hid(video->device));
1842
1843 input->name = acpi_device_name(video->device);
1844 input->phys = video->phys;
1845 input->id.bustype = BUS_HOST;
1846 input->id.product = 0x06;
1847 input->dev.parent = &video->device->dev;
1848 input->evbit[0] = BIT(EV_KEY);
1849 set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1850 set_bit(KEY_VIDEO_NEXT, input->keybit);
1851 set_bit(KEY_VIDEO_PREV, input->keybit);
1852 set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1853 set_bit(KEY_BRIGHTNESSUP, input->keybit);
1854 set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1855 set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1856 set_bit(KEY_DISPLAY_OFF, input->keybit);
1857
1858 error = input_register_device(input);
1859 if (error)
1860 goto err_stop_dev;
1861
1862 mutex_lock(&video->device_list_lock);
1863 list_for_each_entry(dev, &video->video_device_list, entry)
1864 acpi_video_dev_add_notify_handler(dev);
1865 mutex_unlock(&video->device_list_lock);
1866
1867 return 0;
1868
1869 err_stop_dev:
1870 acpi_video_bus_stop_devices(video);
1871 err_free_input:
1872 input_free_device(input);
1873 video->input = NULL;
1874 out:
1875 return error;
1876 }
1877
1878 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1879 {
1880 if (dev->flags.notify) {
1881 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1882 acpi_video_device_notify);
1883 dev->flags.notify = 0;
1884 }
1885 }
1886
1887 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1888 {
1889 struct acpi_video_device *dev;
1890
1891 mutex_lock(&video->device_list_lock);
1892 list_for_each_entry(dev, &video->video_device_list, entry)
1893 acpi_video_dev_remove_notify_handler(dev);
1894 mutex_unlock(&video->device_list_lock);
1895
1896 acpi_video_bus_stop_devices(video);
1897 input_unregister_device(video->input);
1898 video->input = NULL;
1899 }
1900
1901 static int acpi_video_backlight_notify(struct notifier_block *nb,
1902 unsigned long val, void *bd)
1903 {
1904 struct backlight_device *backlight = bd;
1905 struct acpi_video_bus *video;
1906
1907 /* acpi_video_verify_backlight_support only cares about raw devices */
1908 if (backlight->props.type != BACKLIGHT_RAW)
1909 return NOTIFY_DONE;
1910
1911 video = container_of(nb, struct acpi_video_bus, backlight_nb);
1912
1913 switch (val) {
1914 case BACKLIGHT_REGISTERED:
1915 if (!acpi_video_verify_backlight_support())
1916 acpi_video_bus_unregister_backlight(video);
1917 break;
1918 case BACKLIGHT_UNREGISTERED:
1919 acpi_video_bus_register_backlight(video);
1920 break;
1921 }
1922
1923 return NOTIFY_OK;
1924 }
1925
1926 static int acpi_video_bus_add_backlight_notify_handler(
1927 struct acpi_video_bus *video)
1928 {
1929 int error;
1930
1931 video->backlight_nb.notifier_call = acpi_video_backlight_notify;
1932 video->backlight_nb.priority = 0;
1933 error = backlight_register_notifier(&video->backlight_nb);
1934 if (error == 0)
1935 video->backlight_notifier_registered = true;
1936
1937 return error;
1938 }
1939
1940 static int acpi_video_bus_remove_backlight_notify_handler(
1941 struct acpi_video_bus *video)
1942 {
1943 if (!video->backlight_notifier_registered)
1944 return 0;
1945
1946 video->backlight_notifier_registered = false;
1947
1948 return backlight_unregister_notifier(&video->backlight_nb);
1949 }
1950
1951 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1952 {
1953 struct acpi_video_device *dev, *next;
1954
1955 mutex_lock(&video->device_list_lock);
1956 list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1957 list_del(&dev->entry);
1958 kfree(dev);
1959 }
1960 mutex_unlock(&video->device_list_lock);
1961
1962 return 0;
1963 }
1964
1965 static int instance;
1966
1967 static int acpi_video_bus_add(struct acpi_device *device)
1968 {
1969 struct acpi_video_bus *video;
1970 int error;
1971 acpi_status status;
1972
1973 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1974 device->parent->handle, 1,
1975 acpi_video_bus_match, NULL,
1976 device, NULL);
1977 if (status == AE_ALREADY_EXISTS) {
1978 printk(KERN_WARNING FW_BUG
1979 "Duplicate ACPI video bus devices for the"
1980 " same VGA controller, please try module "
1981 "parameter \"video.allow_duplicates=1\""
1982 "if the current driver doesn't work.\n");
1983 if (!allow_duplicates)
1984 return -ENODEV;
1985 }
1986
1987 video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1988 if (!video)
1989 return -ENOMEM;
1990
1991 /* a hack to fix the duplicate name "VID" problem on T61 */
1992 if (!strcmp(device->pnp.bus_id, "VID")) {
1993 if (instance)
1994 device->pnp.bus_id[3] = '0' + instance;
1995 instance++;
1996 }
1997 /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1998 if (!strcmp(device->pnp.bus_id, "VGA")) {
1999 if (instance)
2000 device->pnp.bus_id[3] = '0' + instance;
2001 instance++;
2002 }
2003
2004 video->device = device;
2005 strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2006 strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2007 device->driver_data = video;
2008
2009 acpi_video_bus_find_cap(video);
2010 error = acpi_video_bus_check(video);
2011 if (error)
2012 goto err_free_video;
2013
2014 mutex_init(&video->device_list_lock);
2015 INIT_LIST_HEAD(&video->video_device_list);
2016
2017 error = acpi_video_bus_get_devices(video, device);
2018 if (error)
2019 goto err_put_video;
2020
2021 printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s rom: %s post: %s)\n",
2022 ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2023 video->flags.multihead ? "yes" : "no",
2024 video->flags.rom ? "yes" : "no",
2025 video->flags.post ? "yes" : "no");
2026 mutex_lock(&video_list_lock);
2027 list_add_tail(&video->entry, &video_bus_head);
2028 mutex_unlock(&video_list_lock);
2029
2030 acpi_video_bus_register_backlight(video);
2031 acpi_video_bus_add_notify_handler(video);
2032 acpi_video_bus_add_backlight_notify_handler(video);
2033
2034 return 0;
2035
2036 err_put_video:
2037 acpi_video_bus_put_devices(video);
2038 kfree(video->attached_array);
2039 err_free_video:
2040 kfree(video);
2041 device->driver_data = NULL;
2042
2043 return error;
2044 }
2045
2046 static int acpi_video_bus_remove(struct acpi_device *device)
2047 {
2048 struct acpi_video_bus *video = NULL;
2049
2050
2051 if (!device || !acpi_driver_data(device))
2052 return -EINVAL;
2053
2054 video = acpi_driver_data(device);
2055
2056 acpi_video_bus_remove_backlight_notify_handler(video);
2057 acpi_video_bus_remove_notify_handler(video);
2058 acpi_video_bus_unregister_backlight(video);
2059 acpi_video_bus_put_devices(video);
2060
2061 mutex_lock(&video_list_lock);
2062 list_del(&video->entry);
2063 mutex_unlock(&video_list_lock);
2064
2065 kfree(video->attached_array);
2066 kfree(video);
2067
2068 return 0;
2069 }
2070
2071 static int __init is_i740(struct pci_dev *dev)
2072 {
2073 if (dev->device == 0x00D1)
2074 return 1;
2075 if (dev->device == 0x7000)
2076 return 1;
2077 return 0;
2078 }
2079
2080 static int __init intel_opregion_present(void)
2081 {
2082 int opregion = 0;
2083 struct pci_dev *dev = NULL;
2084 u32 address;
2085
2086 for_each_pci_dev(dev) {
2087 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2088 continue;
2089 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2090 continue;
2091 /* We don't want to poke around undefined i740 registers */
2092 if (is_i740(dev))
2093 continue;
2094 pci_read_config_dword(dev, 0xfc, &address);
2095 if (!address)
2096 continue;
2097 opregion = 1;
2098 }
2099 return opregion;
2100 }
2101
2102 int acpi_video_register(void)
2103 {
2104 int result = 0;
2105 if (register_count) {
2106 /*
2107 * if the function of acpi_video_register is already called,
2108 * don't register the acpi_vide_bus again and return no error.
2109 */
2110 return 0;
2111 }
2112
2113 mutex_init(&video_list_lock);
2114 INIT_LIST_HEAD(&video_bus_head);
2115
2116 result = acpi_bus_register_driver(&acpi_video_bus);
2117 if (result < 0)
2118 return -ENODEV;
2119
2120 /*
2121 * When the acpi_video_bus is loaded successfully, increase
2122 * the counter reference.
2123 */
2124 register_count = 1;
2125
2126 return 0;
2127 }
2128 EXPORT_SYMBOL(acpi_video_register);
2129
2130 void acpi_video_unregister(void)
2131 {
2132 if (!register_count) {
2133 /*
2134 * If the acpi video bus is already unloaded, don't
2135 * unload it again and return directly.
2136 */
2137 return;
2138 }
2139 acpi_bus_unregister_driver(&acpi_video_bus);
2140
2141 register_count = 0;
2142
2143 return;
2144 }
2145 EXPORT_SYMBOL(acpi_video_unregister);
2146
2147 void acpi_video_unregister_backlight(void)
2148 {
2149 struct acpi_video_bus *video;
2150
2151 if (!register_count)
2152 return;
2153
2154 mutex_lock(&video_list_lock);
2155 list_for_each_entry(video, &video_bus_head, entry)
2156 acpi_video_bus_unregister_backlight(video);
2157 mutex_unlock(&video_list_lock);
2158 }
2159 EXPORT_SYMBOL(acpi_video_unregister_backlight);
2160
2161 /*
2162 * This is kind of nasty. Hardware using Intel chipsets may require
2163 * the video opregion code to be run first in order to initialise
2164 * state before any ACPI video calls are made. To handle this we defer
2165 * registration of the video class until the opregion code has run.
2166 */
2167
2168 static int __init acpi_video_init(void)
2169 {
2170 dmi_check_system(video_dmi_table);
2171
2172 if (intel_opregion_present())
2173 return 0;
2174
2175 return acpi_video_register();
2176 }
2177
2178 static void __exit acpi_video_exit(void)
2179 {
2180 acpi_video_unregister();
2181
2182 return;
2183 }
2184
2185 module_init(acpi_video_init);
2186 module_exit(acpi_video_exit);
Linux kernel - Deliverables
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