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Merge tag 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux...
[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 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
545 .callback = video_disable_native_backlight,
546 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
547 .matches = {
548 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
549 DMI_MATCH(DMI_PRODUCT_NAME, "900X3C/900X3D/900X3E/900X4C/900X4D"),
550 },
551 },
552
553 {
554 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
555 .callback = video_disable_native_backlight,
556 .ident = "Dell XPS15 L521X",
557 .matches = {
558 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
559 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
560 },
561 },
562 {}
563 };
564
565 static unsigned long long
566 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
567 unsigned long long bqc_value)
568 {
569 unsigned long long level;
570
571 if (device->brightness->flags._BQC_use_index) {
572 /*
573 * _BQC returns an index that doesn't account for
574 * the first 2 items with special meaning, so we need
575 * to compensate for that by offsetting ourselves
576 */
577 if (device->brightness->flags._BCL_reversed)
578 bqc_value = device->brightness->count - 3 - bqc_value;
579
580 level = device->brightness->levels[bqc_value + 2];
581 } else {
582 level = bqc_value;
583 }
584
585 level += bqc_offset_aml_bug_workaround;
586
587 return level;
588 }
589
590 static int
591 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
592 unsigned long long *level, bool raw)
593 {
594 acpi_status status = AE_OK;
595 int i;
596
597 if (device->cap._BQC || device->cap._BCQ) {
598 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
599
600 status = acpi_evaluate_integer(device->dev->handle, buf,
601 NULL, level);
602 if (ACPI_SUCCESS(status)) {
603 if (raw) {
604 /*
605 * Caller has indicated he wants the raw
606 * value returned by _BQC, so don't furtherly
607 * mess with the value.
608 */
609 return 0;
610 }
611
612 *level = acpi_video_bqc_value_to_level(device, *level);
613
614 for (i = 2; i < device->brightness->count; i++)
615 if (device->brightness->levels[i] == *level) {
616 device->brightness->curr = *level;
617 return 0;
618 }
619 /*
620 * BQC returned an invalid level.
621 * Stop using it.
622 */
623 ACPI_WARNING((AE_INFO,
624 "%s returned an invalid level",
625 buf));
626 device->cap._BQC = device->cap._BCQ = 0;
627 } else {
628 /*
629 * Fixme:
630 * should we return an error or ignore this failure?
631 * dev->brightness->curr is a cached value which stores
632 * the correct current backlight level in most cases.
633 * ACPI video backlight still works w/ buggy _BQC.
634 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
635 */
636 ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
637 device->cap._BQC = device->cap._BCQ = 0;
638 }
639 }
640
641 *level = device->brightness->curr;
642 return 0;
643 }
644
645 static int
646 acpi_video_device_EDID(struct acpi_video_device *device,
647 union acpi_object **edid, ssize_t length)
648 {
649 int status;
650 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
651 union acpi_object *obj;
652 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
653 struct acpi_object_list args = { 1, &arg0 };
654
655
656 *edid = NULL;
657
658 if (!device)
659 return -ENODEV;
660 if (length == 128)
661 arg0.integer.value = 1;
662 else if (length == 256)
663 arg0.integer.value = 2;
664 else
665 return -EINVAL;
666
667 status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
668 if (ACPI_FAILURE(status))
669 return -ENODEV;
670
671 obj = buffer.pointer;
672
673 if (obj && obj->type == ACPI_TYPE_BUFFER)
674 *edid = obj;
675 else {
676 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
677 status = -EFAULT;
678 kfree(obj);
679 }
680
681 return status;
682 }
683
684 /* bus */
685
686 /*
687 * Arg:
688 * video : video bus device pointer
689 * bios_flag :
690 * 0. The system BIOS should NOT automatically switch(toggle)
691 * the active display output.
692 * 1. The system BIOS should automatically switch (toggle) the
693 * active display output. No switch event.
694 * 2. The _DGS value should be locked.
695 * 3. The system BIOS should not automatically switch (toggle) the
696 * active display output, but instead generate the display switch
697 * event notify code.
698 * lcd_flag :
699 * 0. The system BIOS should automatically control the brightness level
700 * of the LCD when the power changes from AC to DC
701 * 1. The system BIOS should NOT automatically control the brightness
702 * level of the LCD when the power changes from AC to DC.
703 * Return Value:
704 * -EINVAL wrong arg.
705 */
706
707 static int
708 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
709 {
710 acpi_status status;
711
712 if (!video->cap._DOS)
713 return 0;
714
715 if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
716 return -EINVAL;
717 video->dos_setting = (lcd_flag << 2) | bios_flag;
718 status = acpi_execute_simple_method(video->device->handle, "_DOS",
719 (lcd_flag << 2) | bios_flag);
720 if (ACPI_FAILURE(status))
721 return -EIO;
722
723 return 0;
724 }
725
726 /*
727 * Simple comparison function used to sort backlight levels.
728 */
729
730 static int
731 acpi_video_cmp_level(const void *a, const void *b)
732 {
733 return *(int *)a - *(int *)b;
734 }
735
736 /*
737 * Decides if _BQC/_BCQ for this system is usable
738 *
739 * We do this by changing the level first and then read out the current
740 * brightness level, if the value does not match, find out if it is using
741 * index. If not, clear the _BQC/_BCQ capability.
742 */
743 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
744 int max_level, int current_level)
745 {
746 struct acpi_video_device_brightness *br = device->brightness;
747 int result;
748 unsigned long long level;
749 int test_level;
750
751 /* don't mess with existing known broken systems */
752 if (bqc_offset_aml_bug_workaround)
753 return 0;
754
755 /*
756 * Some systems always report current brightness level as maximum
757 * through _BQC, we need to test another value for them.
758 */
759 test_level = current_level == max_level ? br->levels[3] : max_level;
760
761 result = acpi_video_device_lcd_set_level(device, test_level);
762 if (result)
763 return result;
764
765 result = acpi_video_device_lcd_get_level_current(device, &level, true);
766 if (result)
767 return result;
768
769 if (level != test_level) {
770 /* buggy _BQC found, need to find out if it uses index */
771 if (level < br->count) {
772 if (br->flags._BCL_reversed)
773 level = br->count - 3 - level;
774 if (br->levels[level + 2] == test_level)
775 br->flags._BQC_use_index = 1;
776 }
777
778 if (!br->flags._BQC_use_index)
779 device->cap._BQC = device->cap._BCQ = 0;
780 }
781
782 return 0;
783 }
784
785
786 /*
787 * Arg:
788 * device : video output device (LCD, CRT, ..)
789 *
790 * Return Value:
791 * Maximum brightness level
792 *
793 * Allocate and initialize device->brightness.
794 */
795
796 static int
797 acpi_video_init_brightness(struct acpi_video_device *device)
798 {
799 union acpi_object *obj = NULL;
800 int i, max_level = 0, count = 0, level_ac_battery = 0;
801 unsigned long long level, level_old;
802 union acpi_object *o;
803 struct acpi_video_device_brightness *br = NULL;
804 int result = -EINVAL;
805 u32 value;
806
807 if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
808 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
809 "LCD brightness level\n"));
810 goto out;
811 }
812
813 if (obj->package.count < 2)
814 goto out;
815
816 br = kzalloc(sizeof(*br), GFP_KERNEL);
817 if (!br) {
818 printk(KERN_ERR "can't allocate memory\n");
819 result = -ENOMEM;
820 goto out;
821 }
822
823 br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
824 GFP_KERNEL);
825 if (!br->levels) {
826 result = -ENOMEM;
827 goto out_free;
828 }
829
830 for (i = 0; i < obj->package.count; i++) {
831 o = (union acpi_object *)&obj->package.elements[i];
832 if (o->type != ACPI_TYPE_INTEGER) {
833 printk(KERN_ERR PREFIX "Invalid data\n");
834 continue;
835 }
836 value = (u32) o->integer.value;
837 /* Skip duplicate entries */
838 if (count > 2 && br->levels[count - 1] == value)
839 continue;
840
841 br->levels[count] = value;
842
843 if (br->levels[count] > max_level)
844 max_level = br->levels[count];
845 count++;
846 }
847
848 /*
849 * some buggy BIOS don't export the levels
850 * when machine is on AC/Battery in _BCL package.
851 * In this case, the first two elements in _BCL packages
852 * are also supported brightness levels that OS should take care of.
853 */
854 for (i = 2; i < count; i++) {
855 if (br->levels[i] == br->levels[0])
856 level_ac_battery++;
857 if (br->levels[i] == br->levels[1])
858 level_ac_battery++;
859 }
860
861 if (level_ac_battery < 2) {
862 level_ac_battery = 2 - level_ac_battery;
863 br->flags._BCL_no_ac_battery_levels = 1;
864 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
865 br->levels[i] = br->levels[i - level_ac_battery];
866 count += level_ac_battery;
867 } else if (level_ac_battery > 2)
868 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
869
870 /* Check if the _BCL package is in a reversed order */
871 if (max_level == br->levels[2]) {
872 br->flags._BCL_reversed = 1;
873 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
874 acpi_video_cmp_level, NULL);
875 } else if (max_level != br->levels[count - 1])
876 ACPI_ERROR((AE_INFO,
877 "Found unordered _BCL package"));
878
879 br->count = count;
880 device->brightness = br;
881
882 /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
883 br->curr = level = max_level;
884
885 if (!device->cap._BQC)
886 goto set_level;
887
888 result = acpi_video_device_lcd_get_level_current(device,
889 &level_old, true);
890 if (result)
891 goto out_free_levels;
892
893 result = acpi_video_bqc_quirk(device, max_level, level_old);
894 if (result)
895 goto out_free_levels;
896 /*
897 * cap._BQC may get cleared due to _BQC is found to be broken
898 * in acpi_video_bqc_quirk, so check again here.
899 */
900 if (!device->cap._BQC)
901 goto set_level;
902
903 level = acpi_video_bqc_value_to_level(device, level_old);
904 /*
905 * On some buggy laptops, _BQC returns an uninitialized
906 * value when invoked for the first time, i.e.
907 * level_old is invalid (no matter whether it's a level
908 * or an index). Set the backlight to max_level in this case.
909 */
910 for (i = 2; i < br->count; i++)
911 if (level == br->levels[i])
912 break;
913 if (i == br->count || !level)
914 level = max_level;
915
916 set_level:
917 result = acpi_video_device_lcd_set_level(device, level);
918 if (result)
919 goto out_free_levels;
920
921 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
922 "found %d brightness levels\n", count - 2));
923 kfree(obj);
924 return result;
925
926 out_free_levels:
927 kfree(br->levels);
928 out_free:
929 kfree(br);
930 out:
931 device->brightness = NULL;
932 kfree(obj);
933 return result;
934 }
935
936 /*
937 * Arg:
938 * device : video output device (LCD, CRT, ..)
939 *
940 * Return Value:
941 * None
942 *
943 * Find out all required AML methods defined under the output
944 * device.
945 */
946
947 static void acpi_video_device_find_cap(struct acpi_video_device *device)
948 {
949 if (acpi_has_method(device->dev->handle, "_ADR"))
950 device->cap._ADR = 1;
951 if (acpi_has_method(device->dev->handle, "_BCL"))
952 device->cap._BCL = 1;
953 if (acpi_has_method(device->dev->handle, "_BCM"))
954 device->cap._BCM = 1;
955 if (acpi_has_method(device->dev->handle, "_BQC")) {
956 device->cap._BQC = 1;
957 } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
958 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
959 device->cap._BCQ = 1;
960 }
961
962 if (acpi_has_method(device->dev->handle, "_DDC"))
963 device->cap._DDC = 1;
964 }
965
966 /*
967 * Arg:
968 * device : video output device (VGA)
969 *
970 * Return Value:
971 * None
972 *
973 * Find out all required AML methods defined under the video bus device.
974 */
975
976 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
977 {
978 if (acpi_has_method(video->device->handle, "_DOS"))
979 video->cap._DOS = 1;
980 if (acpi_has_method(video->device->handle, "_DOD"))
981 video->cap._DOD = 1;
982 if (acpi_has_method(video->device->handle, "_ROM"))
983 video->cap._ROM = 1;
984 if (acpi_has_method(video->device->handle, "_GPD"))
985 video->cap._GPD = 1;
986 if (acpi_has_method(video->device->handle, "_SPD"))
987 video->cap._SPD = 1;
988 if (acpi_has_method(video->device->handle, "_VPO"))
989 video->cap._VPO = 1;
990 }
991
992 /*
993 * Check whether the video bus device has required AML method to
994 * support the desired features
995 */
996
997 static int acpi_video_bus_check(struct acpi_video_bus *video)
998 {
999 acpi_status status = -ENOENT;
1000 struct pci_dev *dev;
1001
1002 if (!video)
1003 return -EINVAL;
1004
1005 dev = acpi_get_pci_dev(video->device->handle);
1006 if (!dev)
1007 return -ENODEV;
1008 pci_dev_put(dev);
1009
1010 /*
1011 * Since there is no HID, CID and so on for VGA driver, we have
1012 * to check well known required nodes.
1013 */
1014
1015 /* Does this device support video switching? */
1016 if (video->cap._DOS || video->cap._DOD) {
1017 if (!video->cap._DOS) {
1018 printk(KERN_WARNING FW_BUG
1019 "ACPI(%s) defines _DOD but not _DOS\n",
1020 acpi_device_bid(video->device));
1021 }
1022 video->flags.multihead = 1;
1023 status = 0;
1024 }
1025
1026 /* Does this device support retrieving a video ROM? */
1027 if (video->cap._ROM) {
1028 video->flags.rom = 1;
1029 status = 0;
1030 }
1031
1032 /* Does this device support configuring which video device to POST? */
1033 if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1034 video->flags.post = 1;
1035 status = 0;
1036 }
1037
1038 return status;
1039 }
1040
1041 /*
1042 * --------------------------------------------------------------------------
1043 * Driver Interface
1044 * --------------------------------------------------------------------------
1045 */
1046
1047 /* device interface */
1048 static struct acpi_video_device_attrib *
1049 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1050 {
1051 struct acpi_video_enumerated_device *ids;
1052 int i;
1053
1054 for (i = 0; i < video->attached_count; i++) {
1055 ids = &video->attached_array[i];
1056 if ((ids->value.int_val & 0xffff) == device_id)
1057 return &ids->value.attrib;
1058 }
1059
1060 return NULL;
1061 }
1062
1063 static int
1064 acpi_video_get_device_type(struct acpi_video_bus *video,
1065 unsigned long device_id)
1066 {
1067 struct acpi_video_enumerated_device *ids;
1068 int i;
1069
1070 for (i = 0; i < video->attached_count; i++) {
1071 ids = &video->attached_array[i];
1072 if ((ids->value.int_val & 0xffff) == device_id)
1073 return ids->value.int_val;
1074 }
1075
1076 return 0;
1077 }
1078
1079 static int
1080 acpi_video_bus_get_one_device(struct acpi_device *device,
1081 struct acpi_video_bus *video)
1082 {
1083 unsigned long long device_id;
1084 int status, device_type;
1085 struct acpi_video_device *data;
1086 struct acpi_video_device_attrib *attribute;
1087
1088 status =
1089 acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1090 /* Some device omits _ADR, we skip them instead of fail */
1091 if (ACPI_FAILURE(status))
1092 return 0;
1093
1094 data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1095 if (!data)
1096 return -ENOMEM;
1097
1098 strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1099 strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1100 device->driver_data = data;
1101
1102 data->device_id = device_id;
1103 data->video = video;
1104 data->dev = device;
1105 INIT_DELAYED_WORK(&data->switch_brightness_work,
1106 acpi_video_switch_brightness);
1107
1108 attribute = acpi_video_get_device_attr(video, device_id);
1109
1110 if (attribute && attribute->device_id_scheme) {
1111 switch (attribute->display_type) {
1112 case ACPI_VIDEO_DISPLAY_CRT:
1113 data->flags.crt = 1;
1114 break;
1115 case ACPI_VIDEO_DISPLAY_TV:
1116 data->flags.tvout = 1;
1117 break;
1118 case ACPI_VIDEO_DISPLAY_DVI:
1119 data->flags.dvi = 1;
1120 break;
1121 case ACPI_VIDEO_DISPLAY_LCD:
1122 data->flags.lcd = 1;
1123 break;
1124 default:
1125 data->flags.unknown = 1;
1126 break;
1127 }
1128 if (attribute->bios_can_detect)
1129 data->flags.bios = 1;
1130 } else {
1131 /* Check for legacy IDs */
1132 device_type = acpi_video_get_device_type(video, device_id);
1133 /* Ignore bits 16 and 18-20 */
1134 switch (device_type & 0xffe2ffff) {
1135 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1136 data->flags.crt = 1;
1137 break;
1138 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1139 data->flags.lcd = 1;
1140 break;
1141 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1142 data->flags.tvout = 1;
1143 break;
1144 default:
1145 data->flags.unknown = 1;
1146 }
1147 }
1148
1149 acpi_video_device_bind(video, data);
1150 acpi_video_device_find_cap(data);
1151
1152 mutex_lock(&video->device_list_lock);
1153 list_add_tail(&data->entry, &video->video_device_list);
1154 mutex_unlock(&video->device_list_lock);
1155
1156 return status;
1157 }
1158
1159 /*
1160 * Arg:
1161 * video : video bus device
1162 *
1163 * Return:
1164 * none
1165 *
1166 * Enumerate the video device list of the video bus,
1167 * bind the ids with the corresponding video devices
1168 * under the video bus.
1169 */
1170
1171 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1172 {
1173 struct acpi_video_device *dev;
1174
1175 mutex_lock(&video->device_list_lock);
1176
1177 list_for_each_entry(dev, &video->video_device_list, entry)
1178 acpi_video_device_bind(video, dev);
1179
1180 mutex_unlock(&video->device_list_lock);
1181 }
1182
1183 /*
1184 * Arg:
1185 * video : video bus device
1186 * device : video output device under the video
1187 * bus
1188 *
1189 * Return:
1190 * none
1191 *
1192 * Bind the ids with the corresponding video devices
1193 * under the video bus.
1194 */
1195
1196 static void
1197 acpi_video_device_bind(struct acpi_video_bus *video,
1198 struct acpi_video_device *device)
1199 {
1200 struct acpi_video_enumerated_device *ids;
1201 int i;
1202
1203 for (i = 0; i < video->attached_count; i++) {
1204 ids = &video->attached_array[i];
1205 if (device->device_id == (ids->value.int_val & 0xffff)) {
1206 ids->bind_info = device;
1207 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1208 }
1209 }
1210 }
1211
1212 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1213 {
1214 struct acpi_video_bus *video = device->video;
1215 int i;
1216
1217 /*
1218 * If we have a broken _DOD or we have more than 8 output devices
1219 * under the graphics controller node that we can't proper deal with
1220 * in the operation region code currently, no need to test.
1221 */
1222 if (!video->attached_count || video->child_count > 8)
1223 return true;
1224
1225 for (i = 0; i < video->attached_count; i++) {
1226 if ((video->attached_array[i].value.int_val & 0xfff) ==
1227 (device->device_id & 0xfff))
1228 return true;
1229 }
1230
1231 return false;
1232 }
1233
1234 /*
1235 * Arg:
1236 * video : video bus device
1237 *
1238 * Return:
1239 * < 0 : error
1240 *
1241 * Call _DOD to enumerate all devices attached to display adapter
1242 *
1243 */
1244
1245 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1246 {
1247 int status;
1248 int count;
1249 int i;
1250 struct acpi_video_enumerated_device *active_list;
1251 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1252 union acpi_object *dod = NULL;
1253 union acpi_object *obj;
1254
1255 status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1256 if (!ACPI_SUCCESS(status)) {
1257 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1258 return status;
1259 }
1260
1261 dod = buffer.pointer;
1262 if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1263 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1264 status = -EFAULT;
1265 goto out;
1266 }
1267
1268 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1269 dod->package.count));
1270
1271 active_list = kcalloc(1 + dod->package.count,
1272 sizeof(struct acpi_video_enumerated_device),
1273 GFP_KERNEL);
1274 if (!active_list) {
1275 status = -ENOMEM;
1276 goto out;
1277 }
1278
1279 count = 0;
1280 for (i = 0; i < dod->package.count; i++) {
1281 obj = &dod->package.elements[i];
1282
1283 if (obj->type != ACPI_TYPE_INTEGER) {
1284 printk(KERN_ERR PREFIX
1285 "Invalid _DOD data in element %d\n", i);
1286 continue;
1287 }
1288
1289 active_list[count].value.int_val = obj->integer.value;
1290 active_list[count].bind_info = NULL;
1291 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1292 (int)obj->integer.value));
1293 count++;
1294 }
1295
1296 kfree(video->attached_array);
1297
1298 video->attached_array = active_list;
1299 video->attached_count = count;
1300
1301 out:
1302 kfree(buffer.pointer);
1303 return status;
1304 }
1305
1306 static int
1307 acpi_video_get_next_level(struct acpi_video_device *device,
1308 u32 level_current, u32 event)
1309 {
1310 int min, max, min_above, max_below, i, l, delta = 255;
1311 max = max_below = 0;
1312 min = min_above = 255;
1313 /* Find closest level to level_current */
1314 for (i = 2; i < device->brightness->count; i++) {
1315 l = device->brightness->levels[i];
1316 if (abs(l - level_current) < abs(delta)) {
1317 delta = l - level_current;
1318 if (!delta)
1319 break;
1320 }
1321 }
1322 /* Ajust level_current to closest available level */
1323 level_current += delta;
1324 for (i = 2; i < device->brightness->count; i++) {
1325 l = device->brightness->levels[i];
1326 if (l < min)
1327 min = l;
1328 if (l > max)
1329 max = l;
1330 if (l < min_above && l > level_current)
1331 min_above = l;
1332 if (l > max_below && l < level_current)
1333 max_below = l;
1334 }
1335
1336 switch (event) {
1337 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1338 return (level_current < max) ? min_above : min;
1339 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1340 return (level_current < max) ? min_above : max;
1341 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1342 return (level_current > min) ? max_below : min;
1343 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1344 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1345 return 0;
1346 default:
1347 return level_current;
1348 }
1349 }
1350
1351 static void
1352 acpi_video_switch_brightness(struct work_struct *work)
1353 {
1354 struct acpi_video_device *device = container_of(to_delayed_work(work),
1355 struct acpi_video_device, switch_brightness_work);
1356 unsigned long long level_current, level_next;
1357 int event = device->switch_brightness_event;
1358 int result = -EINVAL;
1359
1360 /* no warning message if acpi_backlight=vendor or a quirk is used */
1361 if (!acpi_video_verify_backlight_support())
1362 return;
1363
1364 if (!device->brightness)
1365 goto out;
1366
1367 result = acpi_video_device_lcd_get_level_current(device,
1368 &level_current,
1369 false);
1370 if (result)
1371 goto out;
1372
1373 level_next = acpi_video_get_next_level(device, level_current, event);
1374
1375 result = acpi_video_device_lcd_set_level(device, level_next);
1376
1377 if (!result)
1378 backlight_force_update(device->backlight,
1379 BACKLIGHT_UPDATE_HOTKEY);
1380
1381 out:
1382 if (result)
1383 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1384 }
1385
1386 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1387 void **edid)
1388 {
1389 struct acpi_video_bus *video;
1390 struct acpi_video_device *video_device;
1391 union acpi_object *buffer = NULL;
1392 acpi_status status;
1393 int i, length;
1394
1395 if (!device || !acpi_driver_data(device))
1396 return -EINVAL;
1397
1398 video = acpi_driver_data(device);
1399
1400 for (i = 0; i < video->attached_count; i++) {
1401 video_device = video->attached_array[i].bind_info;
1402 length = 256;
1403
1404 if (!video_device)
1405 continue;
1406
1407 if (!video_device->cap._DDC)
1408 continue;
1409
1410 if (type) {
1411 switch (type) {
1412 case ACPI_VIDEO_DISPLAY_CRT:
1413 if (!video_device->flags.crt)
1414 continue;
1415 break;
1416 case ACPI_VIDEO_DISPLAY_TV:
1417 if (!video_device->flags.tvout)
1418 continue;
1419 break;
1420 case ACPI_VIDEO_DISPLAY_DVI:
1421 if (!video_device->flags.dvi)
1422 continue;
1423 break;
1424 case ACPI_VIDEO_DISPLAY_LCD:
1425 if (!video_device->flags.lcd)
1426 continue;
1427 break;
1428 }
1429 } else if (video_device->device_id != device_id) {
1430 continue;
1431 }
1432
1433 status = acpi_video_device_EDID(video_device, &buffer, length);
1434
1435 if (ACPI_FAILURE(status) || !buffer ||
1436 buffer->type != ACPI_TYPE_BUFFER) {
1437 length = 128;
1438 status = acpi_video_device_EDID(video_device, &buffer,
1439 length);
1440 if (ACPI_FAILURE(status) || !buffer ||
1441 buffer->type != ACPI_TYPE_BUFFER) {
1442 continue;
1443 }
1444 }
1445
1446 *edid = buffer->buffer.pointer;
1447 return length;
1448 }
1449
1450 return -ENODEV;
1451 }
1452 EXPORT_SYMBOL(acpi_video_get_edid);
1453
1454 static int
1455 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1456 struct acpi_device *device)
1457 {
1458 int status = 0;
1459 struct acpi_device *dev;
1460
1461 /*
1462 * There are systems where video module known to work fine regardless
1463 * of broken _DOD and ignoring returned value here doesn't cause
1464 * any issues later.
1465 */
1466 acpi_video_device_enumerate(video);
1467
1468 list_for_each_entry(dev, &device->children, node) {
1469
1470 status = acpi_video_bus_get_one_device(dev, video);
1471 if (status) {
1472 dev_err(&dev->dev, "Can't attach device\n");
1473 break;
1474 }
1475 video->child_count++;
1476 }
1477 return status;
1478 }
1479
1480 /* acpi_video interface */
1481
1482 /*
1483 * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1484 * preform any automatic brightness change on receiving a notification.
1485 */
1486 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1487 {
1488 return acpi_video_bus_DOS(video, 0,
1489 acpi_osi_is_win8() ? 1 : 0);
1490 }
1491
1492 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1493 {
1494 return acpi_video_bus_DOS(video, 0,
1495 acpi_osi_is_win8() ? 0 : 1);
1496 }
1497
1498 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1499 {
1500 struct acpi_video_bus *video = acpi_driver_data(device);
1501 struct input_dev *input;
1502 int keycode = 0;
1503
1504 if (!video || !video->input)
1505 return;
1506
1507 input = video->input;
1508
1509 switch (event) {
1510 case ACPI_VIDEO_NOTIFY_SWITCH: /* User requested a switch,
1511 * most likely via hotkey. */
1512 keycode = KEY_SWITCHVIDEOMODE;
1513 break;
1514
1515 case ACPI_VIDEO_NOTIFY_PROBE: /* User plugged in or removed a video
1516 * connector. */
1517 acpi_video_device_enumerate(video);
1518 acpi_video_device_rebind(video);
1519 keycode = KEY_SWITCHVIDEOMODE;
1520 break;
1521
1522 case ACPI_VIDEO_NOTIFY_CYCLE: /* Cycle Display output hotkey pressed. */
1523 keycode = KEY_SWITCHVIDEOMODE;
1524 break;
1525 case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT: /* Next Display output hotkey pressed. */
1526 keycode = KEY_VIDEO_NEXT;
1527 break;
1528 case ACPI_VIDEO_NOTIFY_PREV_OUTPUT: /* previous Display output hotkey pressed. */
1529 keycode = KEY_VIDEO_PREV;
1530 break;
1531
1532 default:
1533 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1534 "Unsupported event [0x%x]\n", event));
1535 break;
1536 }
1537
1538 if (acpi_notifier_call_chain(device, event, 0))
1539 /* Something vetoed the keypress. */
1540 keycode = 0;
1541
1542 if (keycode) {
1543 input_report_key(input, keycode, 1);
1544 input_sync(input);
1545 input_report_key(input, keycode, 0);
1546 input_sync(input);
1547 }
1548
1549 return;
1550 }
1551
1552 static void brightness_switch_event(struct acpi_video_device *video_device,
1553 u32 event)
1554 {
1555 if (!brightness_switch_enabled)
1556 return;
1557
1558 video_device->switch_brightness_event = event;
1559 schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1560 }
1561
1562 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1563 {
1564 struct acpi_video_device *video_device = data;
1565 struct acpi_device *device = NULL;
1566 struct acpi_video_bus *bus;
1567 struct input_dev *input;
1568 int keycode = 0;
1569
1570 if (!video_device)
1571 return;
1572
1573 device = video_device->dev;
1574 bus = video_device->video;
1575 input = bus->input;
1576
1577 switch (event) {
1578 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
1579 brightness_switch_event(video_device, event);
1580 keycode = KEY_BRIGHTNESS_CYCLE;
1581 break;
1582 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
1583 brightness_switch_event(video_device, event);
1584 keycode = KEY_BRIGHTNESSUP;
1585 break;
1586 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
1587 brightness_switch_event(video_device, event);
1588 keycode = KEY_BRIGHTNESSDOWN;
1589 break;
1590 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1591 brightness_switch_event(video_device, event);
1592 keycode = KEY_BRIGHTNESS_ZERO;
1593 break;
1594 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
1595 brightness_switch_event(video_device, event);
1596 keycode = KEY_DISPLAY_OFF;
1597 break;
1598 default:
1599 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1600 "Unsupported event [0x%x]\n", event));
1601 break;
1602 }
1603
1604 acpi_notifier_call_chain(device, event, 0);
1605
1606 if (keycode) {
1607 input_report_key(input, keycode, 1);
1608 input_sync(input);
1609 input_report_key(input, keycode, 0);
1610 input_sync(input);
1611 }
1612
1613 return;
1614 }
1615
1616 static int acpi_video_resume(struct notifier_block *nb,
1617 unsigned long val, void *ign)
1618 {
1619 struct acpi_video_bus *video;
1620 struct acpi_video_device *video_device;
1621 int i;
1622
1623 switch (val) {
1624 case PM_HIBERNATION_PREPARE:
1625 case PM_SUSPEND_PREPARE:
1626 case PM_RESTORE_PREPARE:
1627 return NOTIFY_DONE;
1628 }
1629
1630 video = container_of(nb, struct acpi_video_bus, pm_nb);
1631
1632 dev_info(&video->device->dev, "Restoring backlight state\n");
1633
1634 for (i = 0; i < video->attached_count; i++) {
1635 video_device = video->attached_array[i].bind_info;
1636 if (video_device && video_device->backlight)
1637 acpi_video_set_brightness(video_device->backlight);
1638 }
1639
1640 return NOTIFY_OK;
1641 }
1642
1643 static acpi_status
1644 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1645 void **return_value)
1646 {
1647 struct acpi_device *device = context;
1648 struct acpi_device *sibling;
1649 int result;
1650
1651 if (handle == device->handle)
1652 return AE_CTRL_TERMINATE;
1653
1654 result = acpi_bus_get_device(handle, &sibling);
1655 if (result)
1656 return AE_OK;
1657
1658 if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1659 return AE_ALREADY_EXISTS;
1660
1661 return AE_OK;
1662 }
1663
1664 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1665 {
1666 struct backlight_properties props;
1667 struct pci_dev *pdev;
1668 acpi_handle acpi_parent;
1669 struct device *parent = NULL;
1670 int result;
1671 static int count;
1672 char *name;
1673
1674 /*
1675 * Do not create backlight device for video output
1676 * device that is not in the enumerated list.
1677 */
1678 if (!acpi_video_device_in_dod(device)) {
1679 dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1680 return;
1681 }
1682
1683 result = acpi_video_init_brightness(device);
1684 if (result)
1685 return;
1686 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1687 if (!name)
1688 return;
1689 count++;
1690
1691 acpi_get_parent(device->dev->handle, &acpi_parent);
1692
1693 pdev = acpi_get_pci_dev(acpi_parent);
1694 if (pdev) {
1695 parent = &pdev->dev;
1696 pci_dev_put(pdev);
1697 }
1698
1699 memset(&props, 0, sizeof(struct backlight_properties));
1700 props.type = BACKLIGHT_FIRMWARE;
1701 props.max_brightness = device->brightness->count - 3;
1702 device->backlight = backlight_device_register(name,
1703 parent,
1704 device,
1705 &acpi_backlight_ops,
1706 &props);
1707 kfree(name);
1708 if (IS_ERR(device->backlight))
1709 return;
1710
1711 /*
1712 * Save current brightness level in case we have to restore it
1713 * before acpi_video_device_lcd_set_level() is called next time.
1714 */
1715 device->backlight->props.brightness =
1716 acpi_video_get_brightness(device->backlight);
1717
1718 device->cooling_dev = thermal_cooling_device_register("LCD",
1719 device->dev, &video_cooling_ops);
1720 if (IS_ERR(device->cooling_dev)) {
1721 /*
1722 * Set cooling_dev to NULL so we don't crash trying to free it.
1723 * Also, why the hell we are returning early and not attempt to
1724 * register video output if cooling device registration failed?
1725 * -- dtor
1726 */
1727 device->cooling_dev = NULL;
1728 return;
1729 }
1730
1731 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1732 device->cooling_dev->id);
1733 result = sysfs_create_link(&device->dev->dev.kobj,
1734 &device->cooling_dev->device.kobj,
1735 "thermal_cooling");
1736 if (result)
1737 printk(KERN_ERR PREFIX "Create sysfs link\n");
1738 result = sysfs_create_link(&device->cooling_dev->device.kobj,
1739 &device->dev->dev.kobj, "device");
1740 if (result)
1741 printk(KERN_ERR PREFIX "Create sysfs link\n");
1742 }
1743
1744 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1745 {
1746 struct acpi_video_device *dev;
1747 union acpi_object *levels;
1748
1749 mutex_lock(&video->device_list_lock);
1750 list_for_each_entry(dev, &video->video_device_list, entry) {
1751 if (!acpi_video_device_lcd_query_levels(dev, &levels))
1752 kfree(levels);
1753 }
1754 mutex_unlock(&video->device_list_lock);
1755 }
1756
1757 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1758 {
1759 struct acpi_video_device *dev;
1760
1761 if (video->backlight_registered)
1762 return 0;
1763
1764 acpi_video_run_bcl_for_osi(video);
1765
1766 if (!acpi_video_verify_backlight_support())
1767 return 0;
1768
1769 mutex_lock(&video->device_list_lock);
1770 list_for_each_entry(dev, &video->video_device_list, entry)
1771 acpi_video_dev_register_backlight(dev);
1772 mutex_unlock(&video->device_list_lock);
1773
1774 video->backlight_registered = true;
1775
1776 video->pm_nb.notifier_call = acpi_video_resume;
1777 video->pm_nb.priority = 0;
1778 return register_pm_notifier(&video->pm_nb);
1779 }
1780
1781 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1782 {
1783 if (device->backlight) {
1784 backlight_device_unregister(device->backlight);
1785 device->backlight = NULL;
1786 }
1787 if (device->brightness) {
1788 kfree(device->brightness->levels);
1789 kfree(device->brightness);
1790 device->brightness = NULL;
1791 }
1792 if (device->cooling_dev) {
1793 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1794 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1795 thermal_cooling_device_unregister(device->cooling_dev);
1796 device->cooling_dev = NULL;
1797 }
1798 }
1799
1800 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1801 {
1802 struct acpi_video_device *dev;
1803 int error;
1804
1805 if (!video->backlight_registered)
1806 return 0;
1807
1808 error = unregister_pm_notifier(&video->pm_nb);
1809
1810 mutex_lock(&video->device_list_lock);
1811 list_for_each_entry(dev, &video->video_device_list, entry)
1812 acpi_video_dev_unregister_backlight(dev);
1813 mutex_unlock(&video->device_list_lock);
1814
1815 video->backlight_registered = false;
1816
1817 return error;
1818 }
1819
1820 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1821 {
1822 acpi_status status;
1823 struct acpi_device *adev = device->dev;
1824
1825 status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1826 acpi_video_device_notify, device);
1827 if (ACPI_FAILURE(status))
1828 dev_err(&adev->dev, "Error installing notify handler\n");
1829 else
1830 device->flags.notify = 1;
1831 }
1832
1833 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1834 {
1835 struct input_dev *input;
1836 struct acpi_video_device *dev;
1837 int error;
1838
1839 video->input = input = input_allocate_device();
1840 if (!input) {
1841 error = -ENOMEM;
1842 goto out;
1843 }
1844
1845 error = acpi_video_bus_start_devices(video);
1846 if (error)
1847 goto err_free_input;
1848
1849 snprintf(video->phys, sizeof(video->phys),
1850 "%s/video/input0", acpi_device_hid(video->device));
1851
1852 input->name = acpi_device_name(video->device);
1853 input->phys = video->phys;
1854 input->id.bustype = BUS_HOST;
1855 input->id.product = 0x06;
1856 input->dev.parent = &video->device->dev;
1857 input->evbit[0] = BIT(EV_KEY);
1858 set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1859 set_bit(KEY_VIDEO_NEXT, input->keybit);
1860 set_bit(KEY_VIDEO_PREV, input->keybit);
1861 set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1862 set_bit(KEY_BRIGHTNESSUP, input->keybit);
1863 set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1864 set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1865 set_bit(KEY_DISPLAY_OFF, input->keybit);
1866
1867 error = input_register_device(input);
1868 if (error)
1869 goto err_stop_dev;
1870
1871 mutex_lock(&video->device_list_lock);
1872 list_for_each_entry(dev, &video->video_device_list, entry)
1873 acpi_video_dev_add_notify_handler(dev);
1874 mutex_unlock(&video->device_list_lock);
1875
1876 return 0;
1877
1878 err_stop_dev:
1879 acpi_video_bus_stop_devices(video);
1880 err_free_input:
1881 input_free_device(input);
1882 video->input = NULL;
1883 out:
1884 return error;
1885 }
1886
1887 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1888 {
1889 if (dev->flags.notify) {
1890 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1891 acpi_video_device_notify);
1892 dev->flags.notify = 0;
1893 }
1894 }
1895
1896 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1897 {
1898 struct acpi_video_device *dev;
1899
1900 mutex_lock(&video->device_list_lock);
1901 list_for_each_entry(dev, &video->video_device_list, entry)
1902 acpi_video_dev_remove_notify_handler(dev);
1903 mutex_unlock(&video->device_list_lock);
1904
1905 acpi_video_bus_stop_devices(video);
1906 input_unregister_device(video->input);
1907 video->input = NULL;
1908 }
1909
1910 static int acpi_video_backlight_notify(struct notifier_block *nb,
1911 unsigned long val, void *bd)
1912 {
1913 struct backlight_device *backlight = bd;
1914 struct acpi_video_bus *video;
1915
1916 /* acpi_video_verify_backlight_support only cares about raw devices */
1917 if (backlight->props.type != BACKLIGHT_RAW)
1918 return NOTIFY_DONE;
1919
1920 video = container_of(nb, struct acpi_video_bus, backlight_nb);
1921
1922 switch (val) {
1923 case BACKLIGHT_REGISTERED:
1924 if (!acpi_video_verify_backlight_support())
1925 acpi_video_bus_unregister_backlight(video);
1926 break;
1927 case BACKLIGHT_UNREGISTERED:
1928 acpi_video_bus_register_backlight(video);
1929 break;
1930 }
1931
1932 return NOTIFY_OK;
1933 }
1934
1935 static int acpi_video_bus_add_backlight_notify_handler(
1936 struct acpi_video_bus *video)
1937 {
1938 int error;
1939
1940 video->backlight_nb.notifier_call = acpi_video_backlight_notify;
1941 video->backlight_nb.priority = 0;
1942 error = backlight_register_notifier(&video->backlight_nb);
1943 if (error == 0)
1944 video->backlight_notifier_registered = true;
1945
1946 return error;
1947 }
1948
1949 static int acpi_video_bus_remove_backlight_notify_handler(
1950 struct acpi_video_bus *video)
1951 {
1952 if (!video->backlight_notifier_registered)
1953 return 0;
1954
1955 video->backlight_notifier_registered = false;
1956
1957 return backlight_unregister_notifier(&video->backlight_nb);
1958 }
1959
1960 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1961 {
1962 struct acpi_video_device *dev, *next;
1963
1964 mutex_lock(&video->device_list_lock);
1965 list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1966 list_del(&dev->entry);
1967 kfree(dev);
1968 }
1969 mutex_unlock(&video->device_list_lock);
1970
1971 return 0;
1972 }
1973
1974 static int instance;
1975
1976 static int acpi_video_bus_add(struct acpi_device *device)
1977 {
1978 struct acpi_video_bus *video;
1979 int error;
1980 acpi_status status;
1981
1982 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1983 device->parent->handle, 1,
1984 acpi_video_bus_match, NULL,
1985 device, NULL);
1986 if (status == AE_ALREADY_EXISTS) {
1987 printk(KERN_WARNING FW_BUG
1988 "Duplicate ACPI video bus devices for the"
1989 " same VGA controller, please try module "
1990 "parameter \"video.allow_duplicates=1\""
1991 "if the current driver doesn't work.\n");
1992 if (!allow_duplicates)
1993 return -ENODEV;
1994 }
1995
1996 video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1997 if (!video)
1998 return -ENOMEM;
1999
2000 /* a hack to fix the duplicate name "VID" problem on T61 */
2001 if (!strcmp(device->pnp.bus_id, "VID")) {
2002 if (instance)
2003 device->pnp.bus_id[3] = '0' + instance;
2004 instance++;
2005 }
2006 /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2007 if (!strcmp(device->pnp.bus_id, "VGA")) {
2008 if (instance)
2009 device->pnp.bus_id[3] = '0' + instance;
2010 instance++;
2011 }
2012
2013 video->device = device;
2014 strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2015 strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2016 device->driver_data = video;
2017
2018 acpi_video_bus_find_cap(video);
2019 error = acpi_video_bus_check(video);
2020 if (error)
2021 goto err_free_video;
2022
2023 mutex_init(&video->device_list_lock);
2024 INIT_LIST_HEAD(&video->video_device_list);
2025
2026 error = acpi_video_bus_get_devices(video, device);
2027 if (error)
2028 goto err_put_video;
2029
2030 printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s rom: %s post: %s)\n",
2031 ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2032 video->flags.multihead ? "yes" : "no",
2033 video->flags.rom ? "yes" : "no",
2034 video->flags.post ? "yes" : "no");
2035 mutex_lock(&video_list_lock);
2036 list_add_tail(&video->entry, &video_bus_head);
2037 mutex_unlock(&video_list_lock);
2038
2039 acpi_video_bus_register_backlight(video);
2040 acpi_video_bus_add_notify_handler(video);
2041 acpi_video_bus_add_backlight_notify_handler(video);
2042
2043 return 0;
2044
2045 err_put_video:
2046 acpi_video_bus_put_devices(video);
2047 kfree(video->attached_array);
2048 err_free_video:
2049 kfree(video);
2050 device->driver_data = NULL;
2051
2052 return error;
2053 }
2054
2055 static int acpi_video_bus_remove(struct acpi_device *device)
2056 {
2057 struct acpi_video_bus *video = NULL;
2058
2059
2060 if (!device || !acpi_driver_data(device))
2061 return -EINVAL;
2062
2063 video = acpi_driver_data(device);
2064
2065 acpi_video_bus_remove_backlight_notify_handler(video);
2066 acpi_video_bus_remove_notify_handler(video);
2067 acpi_video_bus_unregister_backlight(video);
2068 acpi_video_bus_put_devices(video);
2069
2070 mutex_lock(&video_list_lock);
2071 list_del(&video->entry);
2072 mutex_unlock(&video_list_lock);
2073
2074 kfree(video->attached_array);
2075 kfree(video);
2076
2077 return 0;
2078 }
2079
2080 static int __init is_i740(struct pci_dev *dev)
2081 {
2082 if (dev->device == 0x00D1)
2083 return 1;
2084 if (dev->device == 0x7000)
2085 return 1;
2086 return 0;
2087 }
2088
2089 static int __init intel_opregion_present(void)
2090 {
2091 int opregion = 0;
2092 struct pci_dev *dev = NULL;
2093 u32 address;
2094
2095 for_each_pci_dev(dev) {
2096 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2097 continue;
2098 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2099 continue;
2100 /* We don't want to poke around undefined i740 registers */
2101 if (is_i740(dev))
2102 continue;
2103 pci_read_config_dword(dev, 0xfc, &address);
2104 if (!address)
2105 continue;
2106 opregion = 1;
2107 }
2108 return opregion;
2109 }
2110
2111 int acpi_video_register(void)
2112 {
2113 int ret;
2114
2115 if (register_count) {
2116 /*
2117 * if the function of acpi_video_register is already called,
2118 * don't register the acpi_vide_bus again and return no error.
2119 */
2120 return 0;
2121 }
2122
2123 mutex_init(&video_list_lock);
2124 INIT_LIST_HEAD(&video_bus_head);
2125
2126 ret = acpi_bus_register_driver(&acpi_video_bus);
2127 if (ret)
2128 return ret;
2129
2130 /*
2131 * When the acpi_video_bus is loaded successfully, increase
2132 * the counter reference.
2133 */
2134 register_count = 1;
2135
2136 return 0;
2137 }
2138 EXPORT_SYMBOL(acpi_video_register);
2139
2140 void acpi_video_unregister(void)
2141 {
2142 if (!register_count) {
2143 /*
2144 * If the acpi video bus is already unloaded, don't
2145 * unload it again and return directly.
2146 */
2147 return;
2148 }
2149 acpi_bus_unregister_driver(&acpi_video_bus);
2150
2151 register_count = 0;
2152
2153 return;
2154 }
2155 EXPORT_SYMBOL(acpi_video_unregister);
2156
2157 void acpi_video_unregister_backlight(void)
2158 {
2159 struct acpi_video_bus *video;
2160
2161 if (!register_count)
2162 return;
2163
2164 mutex_lock(&video_list_lock);
2165 list_for_each_entry(video, &video_bus_head, entry)
2166 acpi_video_bus_unregister_backlight(video);
2167 mutex_unlock(&video_list_lock);
2168 }
2169 EXPORT_SYMBOL(acpi_video_unregister_backlight);
2170
2171 /*
2172 * This is kind of nasty. Hardware using Intel chipsets may require
2173 * the video opregion code to be run first in order to initialise
2174 * state before any ACPI video calls are made. To handle this we defer
2175 * registration of the video class until the opregion code has run.
2176 */
2177
2178 static int __init acpi_video_init(void)
2179 {
2180 /*
2181 * Let the module load even if ACPI is disabled (e.g. due to
2182 * a broken BIOS) so that i915.ko can still be loaded on such
2183 * old systems without an AcpiOpRegion.
2184 *
2185 * acpi_video_register() will report -ENODEV later as well due
2186 * to acpi_disabled when i915.ko tries to register itself afterwards.
2187 */
2188 if (acpi_disabled)
2189 return 0;
2190
2191 dmi_check_system(video_dmi_table);
2192
2193 if (intel_opregion_present())
2194 return 0;
2195
2196 return acpi_video_register();
2197 }
2198
2199 static void __exit acpi_video_exit(void)
2200 {
2201 acpi_video_unregister();
2202
2203 return;
2204 }
2205
2206 module_init(acpi_video_init);
2207 module_exit(acpi_video_exit);
Linux kernel - Deliverables
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