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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * video.c - ACPI Video Driver
4 *
5 * Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
6 * Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
7 * Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
8 */
9
10#define pr_fmt(fmt) "ACPI: video: " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/list.h>
17#include <linux/mutex.h>
18#include <linux/input.h>
19#include <linux/backlight.h>
20#include <linux/thermal.h>
21#include <linux/sort.h>
22#include <linux/pci.h>
23#include <linux/pci_ids.h>
24#include <linux/slab.h>
25#include <linux/dmi.h>
26#include <linux/suspend.h>
27#include <linux/acpi.h>
28#include <acpi/video.h>
29#include <linux/uaccess.h>
30
31#define ACPI_VIDEO_BUS_NAME "Video Bus"
32#define ACPI_VIDEO_DEVICE_NAME "Video Device"
33
34#define MAX_NAME_LEN 20
35
36MODULE_AUTHOR("Bruno Ducrot");
37MODULE_DESCRIPTION("ACPI Video Driver");
38MODULE_LICENSE("GPL");
39
40static bool brightness_switch_enabled = true;
41module_param(brightness_switch_enabled, bool, 0644);
42
43/*
44 * By default, we don't allow duplicate ACPI video bus devices
45 * under the same VGA controller
46 */
47static bool allow_duplicates;
48module_param(allow_duplicates, bool, 0644);
49
50#define REPORT_OUTPUT_KEY_EVENTS 0x01
51#define REPORT_BRIGHTNESS_KEY_EVENTS 0x02
52static int report_key_events = -1;
53module_param(report_key_events, int, 0644);
54MODULE_PARM_DESC(report_key_events,
55 "0: none, 1: output changes, 2: brightness changes, 3: all");
56
57static int hw_changes_brightness = -1;
58module_param(hw_changes_brightness, int, 0644);
59MODULE_PARM_DESC(hw_changes_brightness,
60 "Set this to 1 on buggy hw which changes the brightness itself when "
61 "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
62
63/*
64 * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
65 * assumed even if not actually set.
66 */
67static bool device_id_scheme = false;
68module_param(device_id_scheme, bool, 0444);
69
70static int only_lcd;
71module_param(only_lcd, int, 0444);
72
73static bool may_report_brightness_keys;
74static int register_count;
75static DEFINE_MUTEX(register_count_mutex);
76static DEFINE_MUTEX(video_list_lock);
77static LIST_HEAD(video_bus_head);
78static int acpi_video_bus_add(struct acpi_device *device);
79static void acpi_video_bus_remove(struct acpi_device *device);
80static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data);
81
82/*
83 * Indices in the _BCL method response: the first two items are special,
84 * the rest are all supported levels.
85 *
86 * See page 575 of the ACPI spec 3.0
87 */
88enum acpi_video_level_idx {
89 ACPI_VIDEO_AC_LEVEL, /* level when machine has full power */
90 ACPI_VIDEO_BATTERY_LEVEL, /* level when machine is on batteries */
91 ACPI_VIDEO_FIRST_LEVEL, /* actual supported levels begin here */
92};
93
94static const struct acpi_device_id video_device_ids[] = {
95 {ACPI_VIDEO_HID, 0},
96 {"", 0},
97};
98MODULE_DEVICE_TABLE(acpi, video_device_ids);
99
100static struct acpi_driver acpi_video_bus = {
101 .name = "video",
102 .class = ACPI_VIDEO_CLASS,
103 .ids = video_device_ids,
104 .ops = {
105 .add = acpi_video_bus_add,
106 .remove = acpi_video_bus_remove,
107 },
108};
109
110struct acpi_video_bus_flags {
111 u8 multihead:1; /* can switch video heads */
112 u8 rom:1; /* can retrieve a video rom */
113 u8 post:1; /* can configure the head to */
114 u8 reserved:5;
115};
116
117struct acpi_video_bus_cap {
118 u8 _DOS:1; /* Enable/Disable output switching */
119 u8 _DOD:1; /* Enumerate all devices attached to display adapter */
120 u8 _ROM:1; /* Get ROM Data */
121 u8 _GPD:1; /* Get POST Device */
122 u8 _SPD:1; /* Set POST Device */
123 u8 _VPO:1; /* Video POST Options */
124 u8 reserved:2;
125};
126
127struct acpi_video_device_attrib {
128 u32 display_index:4; /* A zero-based instance of the Display */
129 u32 display_port_attachment:4; /* This field differentiates the display type */
130 u32 display_type:4; /* Describe the specific type in use */
131 u32 vendor_specific:4; /* Chipset Vendor Specific */
132 u32 bios_can_detect:1; /* BIOS can detect the device */
133 u32 depend_on_vga:1; /* Non-VGA output device whose power is related to
134 the VGA device. */
135 u32 pipe_id:3; /* For VGA multiple-head devices. */
136 u32 reserved:10; /* Must be 0 */
137
138 /*
139 * The device ID might not actually follow the scheme described by this
140 * struct acpi_video_device_attrib. If it does, then this bit
141 * device_id_scheme is set; otherwise, other fields should be ignored.
142 *
143 * (but also see the global flag device_id_scheme)
144 */
145 u32 device_id_scheme:1;
146};
147
148struct acpi_video_enumerated_device {
149 union {
150 u32 int_val;
151 struct acpi_video_device_attrib attrib;
152 } value;
153 struct acpi_video_device *bind_info;
154};
155
156struct acpi_video_bus {
157 struct acpi_device *device;
158 bool backlight_registered;
159 u8 dos_setting;
160 struct acpi_video_enumerated_device *attached_array;
161 u8 attached_count;
162 u8 child_count;
163 struct acpi_video_bus_cap cap;
164 struct acpi_video_bus_flags flags;
165 struct list_head video_device_list;
166 struct mutex device_list_lock; /* protects video_device_list */
167 struct list_head entry;
168 struct input_dev *input;
169 char phys[32]; /* for input device */
170 struct notifier_block pm_nb;
171};
172
173struct acpi_video_device_flags {
174 u8 crt:1;
175 u8 lcd:1;
176 u8 tvout:1;
177 u8 dvi:1;
178 u8 bios:1;
179 u8 unknown:1;
180 u8 notify:1;
181 u8 reserved:1;
182};
183
184struct acpi_video_device_cap {
185 u8 _ADR:1; /* Return the unique ID */
186 u8 _BCL:1; /* Query list of brightness control levels supported */
187 u8 _BCM:1; /* Set the brightness level */
188 u8 _BQC:1; /* Get current brightness level */
189 u8 _BCQ:1; /* Some buggy BIOS uses _BCQ instead of _BQC */
190 u8 _DDC:1; /* Return the EDID for this device */
191};
192
193struct acpi_video_device {
194 unsigned long device_id;
195 struct acpi_video_device_flags flags;
196 struct acpi_video_device_cap cap;
197 struct list_head entry;
198 struct delayed_work switch_brightness_work;
199 int switch_brightness_event;
200 struct acpi_video_bus *video;
201 struct acpi_device *dev;
202 struct acpi_video_device_brightness *brightness;
203 struct backlight_device *backlight;
204 struct thermal_cooling_device *cooling_dev;
205};
206
207static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
208static void acpi_video_device_rebind(struct acpi_video_bus *video);
209static void acpi_video_device_bind(struct acpi_video_bus *video,
210 struct acpi_video_device *device);
211static int acpi_video_device_enumerate(struct acpi_video_bus *video);
212static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
213 int level);
214static int acpi_video_device_lcd_get_level_current(
215 struct acpi_video_device *device,
216 unsigned long long *level, bool raw);
217static int acpi_video_get_next_level(struct acpi_video_device *device,
218 u32 level_current, u32 event);
219static void acpi_video_switch_brightness(struct work_struct *work);
220
221/* backlight device sysfs support */
222static int acpi_video_get_brightness(struct backlight_device *bd)
223{
224 unsigned long long cur_level;
225 int i;
226 struct acpi_video_device *vd = bl_get_data(bd);
227
228 if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
229 return -EINVAL;
230 for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
231 if (vd->brightness->levels[i] == cur_level)
232 return i - ACPI_VIDEO_FIRST_LEVEL;
233 }
234 return 0;
235}
236
237static int acpi_video_set_brightness(struct backlight_device *bd)
238{
239 int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
240 struct acpi_video_device *vd = bl_get_data(bd);
241
242 cancel_delayed_work(&vd->switch_brightness_work);
243 return acpi_video_device_lcd_set_level(vd,
244 vd->brightness->levels[request_level]);
245}
246
247static const struct backlight_ops acpi_backlight_ops = {
248 .get_brightness = acpi_video_get_brightness,
249 .update_status = acpi_video_set_brightness,
250};
251
252/* thermal cooling device callbacks */
253static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
254 unsigned long *state)
255{
256 struct acpi_video_device *video = cooling_dev->devdata;
257
258 *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
259 return 0;
260}
261
262static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
263 unsigned long *state)
264{
265 struct acpi_video_device *video = cooling_dev->devdata;
266 unsigned long long level;
267 int offset;
268
269 if (acpi_video_device_lcd_get_level_current(video, &level, false))
270 return -EINVAL;
271 for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
272 offset++)
273 if (level == video->brightness->levels[offset]) {
274 *state = video->brightness->count - offset - 1;
275 return 0;
276 }
277
278 return -EINVAL;
279}
280
281static int
282video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
283{
284 struct acpi_video_device *video = cooling_dev->devdata;
285 int level;
286
287 if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
288 return -EINVAL;
289
290 state = video->brightness->count - state;
291 level = video->brightness->levels[state - 1];
292 return acpi_video_device_lcd_set_level(video, level);
293}
294
295static const struct thermal_cooling_device_ops video_cooling_ops = {
296 .get_max_state = video_get_max_state,
297 .get_cur_state = video_get_cur_state,
298 .set_cur_state = video_set_cur_state,
299};
300
301/*
302 * --------------------------------------------------------------------------
303 * Video Management
304 * --------------------------------------------------------------------------
305 */
306
307static int
308acpi_video_device_lcd_query_levels(acpi_handle handle,
309 union acpi_object **levels)
310{
311 int status;
312 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
313 union acpi_object *obj;
314
315
316 *levels = NULL;
317
318 status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
319 if (ACPI_FAILURE(status))
320 return status;
321 obj = (union acpi_object *)buffer.pointer;
322 if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
323 acpi_handle_info(handle, "Invalid _BCL data\n");
324 status = -EFAULT;
325 goto err;
326 }
327
328 *levels = obj;
329
330 return 0;
331
332err:
333 kfree(buffer.pointer);
334
335 return status;
336}
337
338static int
339acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
340{
341 int status;
342 int state;
343
344 status = acpi_execute_simple_method(device->dev->handle,
345 "_BCM", level);
346 if (ACPI_FAILURE(status)) {
347 acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
348 return -EIO;
349 }
350
351 device->brightness->curr = level;
352 for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
353 state++)
354 if (level == device->brightness->levels[state]) {
355 if (device->backlight)
356 device->backlight->props.brightness =
357 state - ACPI_VIDEO_FIRST_LEVEL;
358 return 0;
359 }
360
361 acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
362 return -EINVAL;
363}
364
365/*
366 * For some buggy _BQC methods, we need to add a constant value to
367 * the _BQC return value to get the actual current brightness level
368 */
369
370static int bqc_offset_aml_bug_workaround;
371static int video_set_bqc_offset(const struct dmi_system_id *d)
372{
373 bqc_offset_aml_bug_workaround = 9;
374 return 0;
375}
376
377static int video_set_device_id_scheme(const struct dmi_system_id *d)
378{
379 device_id_scheme = true;
380 return 0;
381}
382
383static int video_enable_only_lcd(const struct dmi_system_id *d)
384{
385 only_lcd = true;
386 return 0;
387}
388
389static int video_set_report_key_events(const struct dmi_system_id *id)
390{
391 if (report_key_events == -1)
392 report_key_events = (uintptr_t)id->driver_data;
393 return 0;
394}
395
396static int video_hw_changes_brightness(
397 const struct dmi_system_id *d)
398{
399 if (hw_changes_brightness == -1)
400 hw_changes_brightness = 1;
401 return 0;
402}
403
404static const struct dmi_system_id video_dmi_table[] = {
405 /*
406 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
407 */
408 {
409 .callback = video_set_bqc_offset,
410 .ident = "Acer Aspire 5720",
411 .matches = {
412 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
413 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
414 },
415 },
416 {
417 .callback = video_set_bqc_offset,
418 .ident = "Acer Aspire 5710Z",
419 .matches = {
420 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
421 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
422 },
423 },
424 {
425 .callback = video_set_bqc_offset,
426 .ident = "eMachines E510",
427 .matches = {
428 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
429 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
430 },
431 },
432 {
433 .callback = video_set_bqc_offset,
434 .ident = "Acer Aspire 5315",
435 .matches = {
436 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
437 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
438 },
439 },
440 {
441 .callback = video_set_bqc_offset,
442 .ident = "Acer Aspire 7720",
443 .matches = {
444 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
445 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
446 },
447 },
448
449 /*
450 * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
451 * but the IDs actually follow the Device ID Scheme.
452 */
453 {
454 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
455 .callback = video_set_device_id_scheme,
456 .ident = "ESPRIMO Mobile M9410",
457 .matches = {
458 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
459 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
460 },
461 },
462 /*
463 * Some machines have multiple video output devices, but only the one
464 * that is the type of LCD can do the backlight control so we should not
465 * register backlight interface for other video output devices.
466 */
467 {
468 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
469 .callback = video_enable_only_lcd,
470 .ident = "ESPRIMO Mobile M9410",
471 .matches = {
472 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
473 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
474 },
475 },
476 /*
477 * Some machines report wrong key events on the acpi-bus, suppress
478 * key event reporting on these. Note this is only intended to work
479 * around events which are plain wrong. In some cases we get double
480 * events, in this case acpi-video is considered the canonical source
481 * and the events from the other source should be filtered. E.g.
482 * by calling acpi_video_handles_brightness_key_presses() from the
483 * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
484 */
485 {
486 .callback = video_set_report_key_events,
487 .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
488 .ident = "Dell Vostro V131",
489 .matches = {
490 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
491 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
492 },
493 },
494 {
495 .callback = video_set_report_key_events,
496 .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
497 .ident = "Dell Vostro 3350",
498 .matches = {
499 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
500 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
501 },
502 },
503 {
504 .callback = video_set_report_key_events,
505 .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
506 .ident = "COLORFUL X15 AT 23",
507 .matches = {
508 DMI_MATCH(DMI_SYS_VENDOR, "COLORFUL"),
509 DMI_MATCH(DMI_PRODUCT_NAME, "X15 AT 23"),
510 },
511 },
512 /*
513 * Some machines change the brightness themselves when a brightness
514 * hotkey gets pressed, despite us telling them not to. In this case
515 * acpi_video_device_notify() should only call backlight_force_update(
516 * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
517 */
518 {
519 /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
520 .callback = video_hw_changes_brightness,
521 .ident = "Packard Bell EasyNote MZ35",
522 .matches = {
523 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
524 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
525 },
526 },
527 {}
528};
529
530static unsigned long long
531acpi_video_bqc_value_to_level(struct acpi_video_device *device,
532 unsigned long long bqc_value)
533{
534 unsigned long long level;
535
536 if (device->brightness->flags._BQC_use_index) {
537 /*
538 * _BQC returns an index that doesn't account for the first 2
539 * items with special meaning (see enum acpi_video_level_idx),
540 * so we need to compensate for that by offsetting ourselves
541 */
542 if (device->brightness->flags._BCL_reversed)
543 bqc_value = device->brightness->count -
544 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
545
546 level = device->brightness->levels[bqc_value +
547 ACPI_VIDEO_FIRST_LEVEL];
548 } else {
549 level = bqc_value;
550 }
551
552 level += bqc_offset_aml_bug_workaround;
553
554 return level;
555}
556
557static int
558acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
559 unsigned long long *level, bool raw)
560{
561 acpi_status status = AE_OK;
562 int i;
563
564 if (device->cap._BQC || device->cap._BCQ) {
565 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
566
567 status = acpi_evaluate_integer(device->dev->handle, buf,
568 NULL, level);
569 if (ACPI_SUCCESS(status)) {
570 if (raw) {
571 /*
572 * Caller has indicated he wants the raw
573 * value returned by _BQC, so don't furtherly
574 * mess with the value.
575 */
576 return 0;
577 }
578
579 *level = acpi_video_bqc_value_to_level(device, *level);
580
581 for (i = ACPI_VIDEO_FIRST_LEVEL;
582 i < device->brightness->count; i++)
583 if (device->brightness->levels[i] == *level) {
584 device->brightness->curr = *level;
585 return 0;
586 }
587 /*
588 * BQC returned an invalid level.
589 * Stop using it.
590 */
591 acpi_handle_info(device->dev->handle,
592 "%s returned an invalid level", buf);
593 device->cap._BQC = device->cap._BCQ = 0;
594 } else {
595 /*
596 * Fixme:
597 * should we return an error or ignore this failure?
598 * dev->brightness->curr is a cached value which stores
599 * the correct current backlight level in most cases.
600 * ACPI video backlight still works w/ buggy _BQC.
601 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
602 */
603 acpi_handle_info(device->dev->handle,
604 "%s evaluation failed", buf);
605 device->cap._BQC = device->cap._BCQ = 0;
606 }
607 }
608
609 *level = device->brightness->curr;
610 return 0;
611}
612
613/**
614 * acpi_video_device_EDID() - Get EDID from ACPI _DDC
615 * @device: video output device (LCD, CRT, ..)
616 * @edid: address for returned EDID pointer
617 * @length: _DDC length to request (must be a multiple of 128)
618 *
619 * Get EDID from ACPI _DDC. On success, a pointer to the EDID data is written
620 * to the @edid address, and the length of the EDID is returned. The caller is
621 * responsible for freeing the edid pointer.
622 *
623 * Return the length of EDID (positive value) on success or error (negative
624 * value).
625 */
626static int
627acpi_video_device_EDID(struct acpi_video_device *device, void **edid, int length)
628{
629 acpi_status status;
630 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
631 union acpi_object *obj;
632 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
633 struct acpi_object_list args = { 1, &arg0 };
634 int ret;
635
636 *edid = NULL;
637
638 if (!device)
639 return -ENODEV;
640 if (!length || (length % 128))
641 return -EINVAL;
642
643 arg0.integer.value = length / 128;
644
645 status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
646 if (ACPI_FAILURE(status))
647 return -ENODEV;
648
649 obj = buffer.pointer;
650
651 if (obj && obj->type == ACPI_TYPE_BUFFER) {
652 *edid = kmemdup(obj->buffer.pointer, obj->buffer.length, GFP_KERNEL);
653 ret = *edid ? obj->buffer.length : -ENOMEM;
654 } else {
655 acpi_handle_debug(device->dev->handle,
656 "Invalid _DDC data for length %d\n", length);
657 ret = -EFAULT;
658 }
659
660 kfree(obj);
661 return ret;
662}
663
664/* bus */
665
666/*
667 * Arg:
668 * video : video bus device pointer
669 * bios_flag :
670 * 0. The system BIOS should NOT automatically switch(toggle)
671 * the active display output.
672 * 1. The system BIOS should automatically switch (toggle) the
673 * active display output. No switch event.
674 * 2. The _DGS value should be locked.
675 * 3. The system BIOS should not automatically switch (toggle) the
676 * active display output, but instead generate the display switch
677 * event notify code.
678 * lcd_flag :
679 * 0. The system BIOS should automatically control the brightness level
680 * of the LCD when:
681 * - the power changes from AC to DC (ACPI appendix B)
682 * - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
683 * 1. The system BIOS should NOT automatically control the brightness
684 * level of the LCD when:
685 * - the power changes from AC to DC (ACPI appendix B)
686 * - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
687 * Return Value:
688 * -EINVAL wrong arg.
689 */
690
691static int
692acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
693{
694 acpi_status status;
695
696 if (!video->cap._DOS)
697 return 0;
698
699 if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
700 return -EINVAL;
701 video->dos_setting = (lcd_flag << 2) | bios_flag;
702 status = acpi_execute_simple_method(video->device->handle, "_DOS",
703 (lcd_flag << 2) | bios_flag);
704 if (ACPI_FAILURE(status))
705 return -EIO;
706
707 return 0;
708}
709
710/*
711 * Simple comparison function used to sort backlight levels.
712 */
713
714static int
715acpi_video_cmp_level(const void *a, const void *b)
716{
717 return *(int *)a - *(int *)b;
718}
719
720/*
721 * Decides if _BQC/_BCQ for this system is usable
722 *
723 * We do this by changing the level first and then read out the current
724 * brightness level, if the value does not match, find out if it is using
725 * index. If not, clear the _BQC/_BCQ capability.
726 */
727static int acpi_video_bqc_quirk(struct acpi_video_device *device,
728 int max_level, int current_level)
729{
730 struct acpi_video_device_brightness *br = device->brightness;
731 int result;
732 unsigned long long level;
733 int test_level;
734
735 /* don't mess with existing known broken systems */
736 if (bqc_offset_aml_bug_workaround)
737 return 0;
738
739 /*
740 * Some systems always report current brightness level as maximum
741 * through _BQC, we need to test another value for them. However,
742 * there is a subtlety:
743 *
744 * If the _BCL package ordering is descending, the first level
745 * (br->levels[2]) is likely to be 0, and if the number of levels
746 * matches the number of steps, we might confuse a returned level to
747 * mean the index.
748 *
749 * For example:
750 *
751 * current_level = max_level = 100
752 * test_level = 0
753 * returned level = 100
754 *
755 * In this case 100 means the level, not the index, and _BCM failed.
756 * Still, if the _BCL package ordering is descending, the index of
757 * level 0 is also 100, so we assume _BQC is indexed, when it's not.
758 *
759 * This causes all _BQC calls to return bogus values causing weird
760 * behavior from the user's perspective. For example:
761 *
762 * xbacklight -set 10; xbacklight -set 20;
763 *
764 * would flash to 90% and then slowly down to the desired level (20).
765 *
766 * The solution is simple; test anything other than the first level
767 * (e.g. 1).
768 */
769 test_level = current_level == max_level
770 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
771 : max_level;
772
773 result = acpi_video_device_lcd_set_level(device, test_level);
774 if (result)
775 return result;
776
777 result = acpi_video_device_lcd_get_level_current(device, &level, true);
778 if (result)
779 return result;
780
781 if (level != test_level) {
782 /* buggy _BQC found, need to find out if it uses index */
783 if (level < br->count) {
784 if (br->flags._BCL_reversed)
785 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
786 if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
787 br->flags._BQC_use_index = 1;
788 }
789
790 if (!br->flags._BQC_use_index)
791 device->cap._BQC = device->cap._BCQ = 0;
792 }
793
794 return 0;
795}
796
797int acpi_video_get_levels(struct acpi_device *device,
798 struct acpi_video_device_brightness **dev_br,
799 int *pmax_level)
800{
801 union acpi_object *obj = NULL;
802 int i, max_level = 0, count = 0, level_ac_battery = 0;
803 union acpi_object *o;
804 struct acpi_video_device_brightness *br = NULL;
805 int result = 0;
806 u32 value;
807
808 if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
809 acpi_handle_debug(device->handle,
810 "Could not query available LCD brightness level\n");
811 result = -ENODEV;
812 goto out;
813 }
814
815 if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
816 result = -EINVAL;
817 goto out;
818 }
819
820 br = kzalloc(sizeof(*br), GFP_KERNEL);
821 if (!br) {
822 result = -ENOMEM;
823 goto out;
824 }
825
826 /*
827 * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
828 * in order to account for buggy BIOS which don't export the first two
829 * special levels (see below)
830 */
831 br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
832 sizeof(*br->levels),
833 GFP_KERNEL);
834 if (!br->levels) {
835 result = -ENOMEM;
836 goto out_free;
837 }
838
839 for (i = 0; i < obj->package.count; i++) {
840 o = (union acpi_object *)&obj->package.elements[i];
841 if (o->type != ACPI_TYPE_INTEGER) {
842 acpi_handle_info(device->handle, "Invalid data\n");
843 continue;
844 }
845 value = (u32) o->integer.value;
846 /* Skip duplicate entries */
847 if (count > ACPI_VIDEO_FIRST_LEVEL
848 && br->levels[count - 1] == value)
849 continue;
850
851 br->levels[count] = value;
852
853 if (br->levels[count] > max_level)
854 max_level = br->levels[count];
855 count++;
856 }
857
858 /*
859 * some buggy BIOS don't export the levels
860 * when machine is on AC/Battery in _BCL package.
861 * In this case, the first two elements in _BCL packages
862 * are also supported brightness levels that OS should take care of.
863 */
864 for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
865 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
866 level_ac_battery++;
867 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
868 level_ac_battery++;
869 }
870
871 if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
872 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
873 br->flags._BCL_no_ac_battery_levels = 1;
874 for (i = (count - 1 + level_ac_battery);
875 i >= ACPI_VIDEO_FIRST_LEVEL; i--)
876 br->levels[i] = br->levels[i - level_ac_battery];
877 count += level_ac_battery;
878 } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
879 acpi_handle_info(device->handle,
880 "Too many duplicates in _BCL package");
881
882 /* Check if the _BCL package is in a reversed order */
883 if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
884 br->flags._BCL_reversed = 1;
885 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
886 count - ACPI_VIDEO_FIRST_LEVEL,
887 sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
888 acpi_video_cmp_level, NULL);
889 } else if (max_level != br->levels[count - 1])
890 acpi_handle_info(device->handle,
891 "Found unordered _BCL package");
892
893 br->count = count;
894 *dev_br = br;
895 if (pmax_level)
896 *pmax_level = max_level;
897
898out:
899 kfree(obj);
900 return result;
901out_free:
902 kfree(br);
903 goto out;
904}
905EXPORT_SYMBOL(acpi_video_get_levels);
906
907/*
908 * Arg:
909 * device : video output device (LCD, CRT, ..)
910 *
911 * Return Value:
912 * Maximum brightness level
913 *
914 * Allocate and initialize device->brightness.
915 */
916
917static int
918acpi_video_init_brightness(struct acpi_video_device *device)
919{
920 int i, max_level = 0;
921 unsigned long long level, level_old;
922 struct acpi_video_device_brightness *br = NULL;
923 int result;
924
925 result = acpi_video_get_levels(device->dev, &br, &max_level);
926 if (result)
927 return result;
928 device->brightness = br;
929
930 /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
931 br->curr = level = max_level;
932
933 if (!device->cap._BQC)
934 goto set_level;
935
936 result = acpi_video_device_lcd_get_level_current(device,
937 &level_old, true);
938 if (result)
939 goto out_free_levels;
940
941 result = acpi_video_bqc_quirk(device, max_level, level_old);
942 if (result)
943 goto out_free_levels;
944 /*
945 * cap._BQC may get cleared due to _BQC is found to be broken
946 * in acpi_video_bqc_quirk, so check again here.
947 */
948 if (!device->cap._BQC)
949 goto set_level;
950
951 level = acpi_video_bqc_value_to_level(device, level_old);
952 /*
953 * On some buggy laptops, _BQC returns an uninitialized
954 * value when invoked for the first time, i.e.
955 * level_old is invalid (no matter whether it's a level
956 * or an index). Set the backlight to max_level in this case.
957 */
958 for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
959 if (level == br->levels[i])
960 break;
961 if (i == br->count || !level)
962 level = max_level;
963
964set_level:
965 result = acpi_video_device_lcd_set_level(device, level);
966 if (result)
967 goto out_free_levels;
968
969 acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
970 br->count - ACPI_VIDEO_FIRST_LEVEL);
971
972 return 0;
973
974out_free_levels:
975 kfree(br->levels);
976 kfree(br);
977 device->brightness = NULL;
978 return result;
979}
980
981/*
982 * Arg:
983 * device : video output device (LCD, CRT, ..)
984 *
985 * Return Value:
986 * None
987 *
988 * Find out all required AML methods defined under the output
989 * device.
990 */
991
992static void acpi_video_device_find_cap(struct acpi_video_device *device)
993{
994 if (acpi_has_method(device->dev->handle, "_ADR"))
995 device->cap._ADR = 1;
996 if (acpi_has_method(device->dev->handle, "_BCL"))
997 device->cap._BCL = 1;
998 if (acpi_has_method(device->dev->handle, "_BCM"))
999 device->cap._BCM = 1;
1000 if (acpi_has_method(device->dev->handle, "_BQC")) {
1001 device->cap._BQC = 1;
1002 } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1003 acpi_handle_info(device->dev->handle,
1004 "_BCQ is used instead of _BQC\n");
1005 device->cap._BCQ = 1;
1006 }
1007
1008 if (acpi_has_method(device->dev->handle, "_DDC"))
1009 device->cap._DDC = 1;
1010}
1011
1012/*
1013 * Arg:
1014 * device : video output device (VGA)
1015 *
1016 * Return Value:
1017 * None
1018 *
1019 * Find out all required AML methods defined under the video bus device.
1020 */
1021
1022static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1023{
1024 if (acpi_has_method(video->device->handle, "_DOS"))
1025 video->cap._DOS = 1;
1026 if (acpi_has_method(video->device->handle, "_DOD"))
1027 video->cap._DOD = 1;
1028 if (acpi_has_method(video->device->handle, "_ROM"))
1029 video->cap._ROM = 1;
1030 if (acpi_has_method(video->device->handle, "_GPD"))
1031 video->cap._GPD = 1;
1032 if (acpi_has_method(video->device->handle, "_SPD"))
1033 video->cap._SPD = 1;
1034 if (acpi_has_method(video->device->handle, "_VPO"))
1035 video->cap._VPO = 1;
1036}
1037
1038/*
1039 * Check whether the video bus device has required AML method to
1040 * support the desired features
1041 */
1042
1043static int acpi_video_bus_check(struct acpi_video_bus *video)
1044{
1045 acpi_status status = -ENOENT;
1046 struct pci_dev *dev;
1047
1048 if (!video)
1049 return -EINVAL;
1050
1051 dev = acpi_get_pci_dev(video->device->handle);
1052 if (!dev)
1053 return -ENODEV;
1054 pci_dev_put(dev);
1055
1056 /*
1057 * Since there is no HID, CID and so on for VGA driver, we have
1058 * to check well known required nodes.
1059 */
1060
1061 /* Does this device support video switching? */
1062 if (video->cap._DOS || video->cap._DOD) {
1063 if (!video->cap._DOS) {
1064 pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1065 acpi_device_bid(video->device));
1066 }
1067 video->flags.multihead = 1;
1068 status = 0;
1069 }
1070
1071 /* Does this device support retrieving a video ROM? */
1072 if (video->cap._ROM) {
1073 video->flags.rom = 1;
1074 status = 0;
1075 }
1076
1077 /* Does this device support configuring which video device to POST? */
1078 if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1079 video->flags.post = 1;
1080 status = 0;
1081 }
1082
1083 return status;
1084}
1085
1086/*
1087 * --------------------------------------------------------------------------
1088 * Driver Interface
1089 * --------------------------------------------------------------------------
1090 */
1091
1092/* device interface */
1093static struct acpi_video_device_attrib *
1094acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1095{
1096 struct acpi_video_enumerated_device *ids;
1097 int i;
1098
1099 for (i = 0; i < video->attached_count; i++) {
1100 ids = &video->attached_array[i];
1101 if ((ids->value.int_val & 0xffff) == device_id)
1102 return &ids->value.attrib;
1103 }
1104
1105 return NULL;
1106}
1107
1108static int
1109acpi_video_get_device_type(struct acpi_video_bus *video,
1110 unsigned long device_id)
1111{
1112 struct acpi_video_enumerated_device *ids;
1113 int i;
1114
1115 for (i = 0; i < video->attached_count; i++) {
1116 ids = &video->attached_array[i];
1117 if ((ids->value.int_val & 0xffff) == device_id)
1118 return ids->value.int_val;
1119 }
1120
1121 return 0;
1122}
1123
1124static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg)
1125{
1126 struct acpi_video_bus *video = arg;
1127 struct acpi_video_device_attrib *attribute;
1128 struct acpi_video_device *data;
1129 unsigned long long device_id;
1130 acpi_status status;
1131 int device_type;
1132
1133 status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1134 /* Skip devices without _ADR instead of failing. */
1135 if (ACPI_FAILURE(status))
1136 goto exit;
1137
1138 data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1139 if (!data) {
1140 dev_dbg(&device->dev, "Cannot attach\n");
1141 return -ENOMEM;
1142 }
1143
1144 strscpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1145 strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1146
1147 data->device_id = device_id;
1148 data->video = video;
1149 data->dev = device;
1150 INIT_DELAYED_WORK(&data->switch_brightness_work,
1151 acpi_video_switch_brightness);
1152
1153 attribute = acpi_video_get_device_attr(video, device_id);
1154
1155 if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1156 switch (attribute->display_type) {
1157 case ACPI_VIDEO_DISPLAY_CRT:
1158 data->flags.crt = 1;
1159 break;
1160 case ACPI_VIDEO_DISPLAY_TV:
1161 data->flags.tvout = 1;
1162 break;
1163 case ACPI_VIDEO_DISPLAY_DVI:
1164 data->flags.dvi = 1;
1165 break;
1166 case ACPI_VIDEO_DISPLAY_LCD:
1167 data->flags.lcd = 1;
1168 break;
1169 default:
1170 data->flags.unknown = 1;
1171 break;
1172 }
1173 if (attribute->bios_can_detect)
1174 data->flags.bios = 1;
1175 } else {
1176 /* Check for legacy IDs */
1177 device_type = acpi_video_get_device_type(video, device_id);
1178 /* Ignore bits 16 and 18-20 */
1179 switch (device_type & 0xffe2ffff) {
1180 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1181 data->flags.crt = 1;
1182 break;
1183 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1184 data->flags.lcd = 1;
1185 break;
1186 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1187 data->flags.tvout = 1;
1188 break;
1189 default:
1190 data->flags.unknown = 1;
1191 }
1192 }
1193
1194 acpi_video_device_bind(video, data);
1195 acpi_video_device_find_cap(data);
1196
1197 if (data->cap._BCM && data->cap._BCL)
1198 may_report_brightness_keys = true;
1199
1200 mutex_lock(&video->device_list_lock);
1201 list_add_tail(&data->entry, &video->video_device_list);
1202 mutex_unlock(&video->device_list_lock);
1203
1204exit:
1205 video->child_count++;
1206 return 0;
1207}
1208
1209/*
1210 * Arg:
1211 * video : video bus device
1212 *
1213 * Return:
1214 * none
1215 *
1216 * Enumerate the video device list of the video bus,
1217 * bind the ids with the corresponding video devices
1218 * under the video bus.
1219 */
1220
1221static void acpi_video_device_rebind(struct acpi_video_bus *video)
1222{
1223 struct acpi_video_device *dev;
1224
1225 mutex_lock(&video->device_list_lock);
1226
1227 list_for_each_entry(dev, &video->video_device_list, entry)
1228 acpi_video_device_bind(video, dev);
1229
1230 mutex_unlock(&video->device_list_lock);
1231}
1232
1233/*
1234 * Arg:
1235 * video : video bus device
1236 * device : video output device under the video
1237 * bus
1238 *
1239 * Return:
1240 * none
1241 *
1242 * Bind the ids with the corresponding video devices
1243 * under the video bus.
1244 */
1245
1246static void
1247acpi_video_device_bind(struct acpi_video_bus *video,
1248 struct acpi_video_device *device)
1249{
1250 struct acpi_video_enumerated_device *ids;
1251 int i;
1252
1253 for (i = 0; i < video->attached_count; i++) {
1254 ids = &video->attached_array[i];
1255 if (device->device_id == (ids->value.int_val & 0xffff)) {
1256 ids->bind_info = device;
1257 acpi_handle_debug(video->device->handle, "%s: %d\n",
1258 __func__, i);
1259 }
1260 }
1261}
1262
1263static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1264{
1265 struct acpi_video_bus *video = device->video;
1266 int i;
1267
1268 /*
1269 * If we have a broken _DOD or we have more than 8 output devices
1270 * under the graphics controller node that we can't proper deal with
1271 * in the operation region code currently, no need to test.
1272 */
1273 if (!video->attached_count || video->child_count > 8)
1274 return true;
1275
1276 for (i = 0; i < video->attached_count; i++) {
1277 if ((video->attached_array[i].value.int_val & 0xfff) ==
1278 (device->device_id & 0xfff))
1279 return true;
1280 }
1281
1282 return false;
1283}
1284
1285/*
1286 * Arg:
1287 * video : video bus device
1288 *
1289 * Return:
1290 * < 0 : error
1291 *
1292 * Call _DOD to enumerate all devices attached to display adapter
1293 *
1294 */
1295
1296static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1297{
1298 int status;
1299 int count;
1300 int i;
1301 struct acpi_video_enumerated_device *active_list;
1302 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1303 union acpi_object *dod = NULL;
1304 union acpi_object *obj;
1305
1306 if (!video->cap._DOD)
1307 return AE_NOT_EXIST;
1308
1309 status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1310 if (ACPI_FAILURE(status)) {
1311 acpi_handle_info(video->device->handle,
1312 "_DOD evaluation failed: %s\n",
1313 acpi_format_exception(status));
1314 return status;
1315 }
1316
1317 dod = buffer.pointer;
1318 if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1319 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1320 status = -EFAULT;
1321 goto out;
1322 }
1323
1324 acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1325 dod->package.count);
1326
1327 active_list = kcalloc(1 + dod->package.count,
1328 sizeof(struct acpi_video_enumerated_device),
1329 GFP_KERNEL);
1330 if (!active_list) {
1331 status = -ENOMEM;
1332 goto out;
1333 }
1334
1335 count = 0;
1336 for (i = 0; i < dod->package.count; i++) {
1337 obj = &dod->package.elements[i];
1338
1339 if (obj->type != ACPI_TYPE_INTEGER) {
1340 acpi_handle_info(video->device->handle,
1341 "Invalid _DOD data in element %d\n", i);
1342 continue;
1343 }
1344
1345 active_list[count].value.int_val = obj->integer.value;
1346 active_list[count].bind_info = NULL;
1347
1348 acpi_handle_debug(video->device->handle,
1349 "_DOD element[%d] = %d\n", i,
1350 (int)obj->integer.value);
1351
1352 count++;
1353 }
1354
1355 kfree(video->attached_array);
1356
1357 video->attached_array = active_list;
1358 video->attached_count = count;
1359
1360out:
1361 kfree(buffer.pointer);
1362 return status;
1363}
1364
1365static int
1366acpi_video_get_next_level(struct acpi_video_device *device,
1367 u32 level_current, u32 event)
1368{
1369 int min, max, min_above, max_below, i, l, delta = 255;
1370 max = max_below = 0;
1371 min = min_above = 255;
1372 /* Find closest level to level_current */
1373 for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1374 l = device->brightness->levels[i];
1375 if (abs(l - level_current) < abs(delta)) {
1376 delta = l - level_current;
1377 if (!delta)
1378 break;
1379 }
1380 }
1381 /* Adjust level_current to closest available level */
1382 level_current += delta;
1383 for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1384 l = device->brightness->levels[i];
1385 if (l < min)
1386 min = l;
1387 if (l > max)
1388 max = l;
1389 if (l < min_above && l > level_current)
1390 min_above = l;
1391 if (l > max_below && l < level_current)
1392 max_below = l;
1393 }
1394
1395 switch (event) {
1396 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1397 return (level_current < max) ? min_above : min;
1398 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1399 return (level_current < max) ? min_above : max;
1400 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1401 return (level_current > min) ? max_below : min;
1402 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1403 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1404 return 0;
1405 default:
1406 return level_current;
1407 }
1408}
1409
1410static void
1411acpi_video_switch_brightness(struct work_struct *work)
1412{
1413 struct acpi_video_device *device = container_of(to_delayed_work(work),
1414 struct acpi_video_device, switch_brightness_work);
1415 unsigned long long level_current, level_next;
1416 int event = device->switch_brightness_event;
1417 int result = -EINVAL;
1418
1419 /* no warning message if acpi_backlight=vendor or a quirk is used */
1420 if (!device->backlight)
1421 return;
1422
1423 if (!device->brightness)
1424 goto out;
1425
1426 result = acpi_video_device_lcd_get_level_current(device,
1427 &level_current,
1428 false);
1429 if (result)
1430 goto out;
1431
1432 level_next = acpi_video_get_next_level(device, level_current, event);
1433
1434 result = acpi_video_device_lcd_set_level(device, level_next);
1435
1436 if (!result)
1437 backlight_force_update(device->backlight,
1438 BACKLIGHT_UPDATE_HOTKEY);
1439
1440out:
1441 if (result)
1442 acpi_handle_info(device->dev->handle,
1443 "Failed to switch brightness\n");
1444}
1445
1446int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1447 void **edid)
1448{
1449 struct acpi_video_bus *video;
1450 struct acpi_video_device *video_device;
1451 int i, length, ret;
1452
1453 if (!device || !acpi_driver_data(device))
1454 return -EINVAL;
1455
1456 video = acpi_driver_data(device);
1457
1458 for (i = 0; i < video->attached_count; i++) {
1459 video_device = video->attached_array[i].bind_info;
1460
1461 if (!video_device)
1462 continue;
1463
1464 if (!video_device->cap._DDC)
1465 continue;
1466
1467 if (type) {
1468 switch (type) {
1469 case ACPI_VIDEO_DISPLAY_CRT:
1470 if (!video_device->flags.crt)
1471 continue;
1472 break;
1473 case ACPI_VIDEO_DISPLAY_TV:
1474 if (!video_device->flags.tvout)
1475 continue;
1476 break;
1477 case ACPI_VIDEO_DISPLAY_DVI:
1478 if (!video_device->flags.dvi)
1479 continue;
1480 break;
1481 case ACPI_VIDEO_DISPLAY_LCD:
1482 if (!video_device->flags.lcd)
1483 continue;
1484 break;
1485 }
1486 } else if (video_device->device_id != device_id) {
1487 continue;
1488 }
1489
1490 for (length = 512; length > 0; length -= 128) {
1491 ret = acpi_video_device_EDID(video_device, edid, length);
1492 if (ret > 0)
1493 return ret;
1494 }
1495 }
1496
1497 return -ENODEV;
1498}
1499EXPORT_SYMBOL(acpi_video_get_edid);
1500
1501static int
1502acpi_video_bus_get_devices(struct acpi_video_bus *video,
1503 struct acpi_device *device)
1504{
1505 /*
1506 * There are systems where video module known to work fine regardless
1507 * of broken _DOD and ignoring returned value here doesn't cause
1508 * any issues later.
1509 */
1510 acpi_video_device_enumerate(video);
1511
1512 return acpi_dev_for_each_child(device, acpi_video_bus_get_one_device, video);
1513}
1514
1515/* acpi_video interface */
1516
1517/*
1518 * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1519 * perform any automatic brightness change on receiving a notification.
1520 */
1521static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1522{
1523 return acpi_video_bus_DOS(video, 0,
1524 acpi_osi_is_win8() ? 1 : 0);
1525}
1526
1527static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1528{
1529 return acpi_video_bus_DOS(video, 0,
1530 acpi_osi_is_win8() ? 0 : 1);
1531}
1532
1533static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data)
1534{
1535 struct acpi_device *device = data;
1536 struct acpi_video_bus *video = acpi_driver_data(device);
1537 struct input_dev *input;
1538 int keycode = 0;
1539
1540 if (!video || !video->input)
1541 return;
1542
1543 input = video->input;
1544
1545 switch (event) {
1546 case ACPI_VIDEO_NOTIFY_SWITCH: /* User requested a switch,
1547 * most likely via hotkey. */
1548 keycode = KEY_SWITCHVIDEOMODE;
1549 break;
1550
1551 case ACPI_VIDEO_NOTIFY_PROBE: /* User plugged in or removed a video
1552 * connector. */
1553 acpi_video_device_enumerate(video);
1554 acpi_video_device_rebind(video);
1555 keycode = KEY_SWITCHVIDEOMODE;
1556 break;
1557
1558 case ACPI_VIDEO_NOTIFY_CYCLE: /* Cycle Display output hotkey pressed. */
1559 keycode = KEY_SWITCHVIDEOMODE;
1560 break;
1561 case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT: /* Next Display output hotkey pressed. */
1562 keycode = KEY_VIDEO_NEXT;
1563 break;
1564 case ACPI_VIDEO_NOTIFY_PREV_OUTPUT: /* previous Display output hotkey pressed. */
1565 keycode = KEY_VIDEO_PREV;
1566 break;
1567
1568 default:
1569 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1570 event);
1571 break;
1572 }
1573
1574 if (acpi_notifier_call_chain(device, event, 0))
1575 /* Something vetoed the keypress. */
1576 keycode = 0;
1577
1578 if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1579 input_report_key(input, keycode, 1);
1580 input_sync(input);
1581 input_report_key(input, keycode, 0);
1582 input_sync(input);
1583 }
1584}
1585
1586static void brightness_switch_event(struct acpi_video_device *video_device,
1587 u32 event)
1588{
1589 if (!brightness_switch_enabled)
1590 return;
1591
1592 video_device->switch_brightness_event = event;
1593 schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1594}
1595
1596static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1597{
1598 struct acpi_video_device *video_device = data;
1599 struct acpi_device *device = NULL;
1600 struct acpi_video_bus *bus;
1601 struct input_dev *input;
1602 int keycode = 0;
1603
1604 if (!video_device)
1605 return;
1606
1607 device = video_device->dev;
1608 bus = video_device->video;
1609 input = bus->input;
1610
1611 if (hw_changes_brightness > 0) {
1612 if (video_device->backlight)
1613 backlight_force_update(video_device->backlight,
1614 BACKLIGHT_UPDATE_HOTKEY);
1615 acpi_notifier_call_chain(device, event, 0);
1616 return;
1617 }
1618
1619 switch (event) {
1620 case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
1621 brightness_switch_event(video_device, event);
1622 keycode = KEY_BRIGHTNESS_CYCLE;
1623 break;
1624 case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
1625 brightness_switch_event(video_device, event);
1626 keycode = KEY_BRIGHTNESSUP;
1627 break;
1628 case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
1629 brightness_switch_event(video_device, event);
1630 keycode = KEY_BRIGHTNESSDOWN;
1631 break;
1632 case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1633 brightness_switch_event(video_device, event);
1634 keycode = KEY_BRIGHTNESS_ZERO;
1635 break;
1636 case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
1637 brightness_switch_event(video_device, event);
1638 keycode = KEY_DISPLAY_OFF;
1639 break;
1640 default:
1641 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1642 break;
1643 }
1644
1645 if (keycode)
1646 may_report_brightness_keys = true;
1647
1648 acpi_notifier_call_chain(device, event, 0);
1649
1650 if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1651 input_report_key(input, keycode, 1);
1652 input_sync(input);
1653 input_report_key(input, keycode, 0);
1654 input_sync(input);
1655 }
1656}
1657
1658static int acpi_video_resume(struct notifier_block *nb,
1659 unsigned long val, void *ign)
1660{
1661 struct acpi_video_bus *video;
1662 struct acpi_video_device *video_device;
1663 int i;
1664
1665 switch (val) {
1666 case PM_POST_HIBERNATION:
1667 case PM_POST_SUSPEND:
1668 case PM_POST_RESTORE:
1669 video = container_of(nb, struct acpi_video_bus, pm_nb);
1670
1671 dev_info(&video->device->dev, "Restoring backlight state\n");
1672
1673 for (i = 0; i < video->attached_count; i++) {
1674 video_device = video->attached_array[i].bind_info;
1675 if (video_device && video_device->brightness)
1676 acpi_video_device_lcd_set_level(video_device,
1677 video_device->brightness->curr);
1678 }
1679
1680 return NOTIFY_OK;
1681 }
1682 return NOTIFY_DONE;
1683}
1684
1685static acpi_status
1686acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1687 void **return_value)
1688{
1689 struct acpi_device *device = context;
1690 struct acpi_device *sibling;
1691
1692 if (handle == device->handle)
1693 return AE_CTRL_TERMINATE;
1694
1695 sibling = acpi_fetch_acpi_dev(handle);
1696 if (!sibling)
1697 return AE_OK;
1698
1699 if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1700 return AE_ALREADY_EXISTS;
1701
1702 return AE_OK;
1703}
1704
1705static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1706{
1707 struct backlight_properties props;
1708 struct pci_dev *pdev;
1709 acpi_handle acpi_parent;
1710 struct device *parent = NULL;
1711 int result;
1712 static int count;
1713 char *name;
1714
1715 result = acpi_video_init_brightness(device);
1716 if (result)
1717 return;
1718
1719 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1720 if (!name)
1721 return;
1722 count++;
1723
1724 if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
1725 pdev = acpi_get_pci_dev(acpi_parent);
1726 if (pdev) {
1727 parent = &pdev->dev;
1728 pci_dev_put(pdev);
1729 }
1730 }
1731
1732 memset(&props, 0, sizeof(struct backlight_properties));
1733 props.type = BACKLIGHT_FIRMWARE;
1734 props.max_brightness =
1735 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1736 device->backlight = backlight_device_register(name,
1737 parent,
1738 device,
1739 &acpi_backlight_ops,
1740 &props);
1741 kfree(name);
1742 if (IS_ERR(device->backlight)) {
1743 device->backlight = NULL;
1744 return;
1745 }
1746
1747 /*
1748 * Save current brightness level in case we have to restore it
1749 * before acpi_video_device_lcd_set_level() is called next time.
1750 */
1751 device->backlight->props.brightness =
1752 acpi_video_get_brightness(device->backlight);
1753
1754 device->cooling_dev = thermal_cooling_device_register("LCD", device,
1755 &video_cooling_ops);
1756 if (IS_ERR(device->cooling_dev)) {
1757 /*
1758 * Set cooling_dev to NULL so we don't crash trying to free it.
1759 * Also, why the hell we are returning early and not attempt to
1760 * register video output if cooling device registration failed?
1761 * -- dtor
1762 */
1763 device->cooling_dev = NULL;
1764 return;
1765 }
1766
1767 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1768 device->cooling_dev->id);
1769 result = sysfs_create_link(&device->dev->dev.kobj,
1770 &device->cooling_dev->device.kobj,
1771 "thermal_cooling");
1772 if (result)
1773 pr_info("sysfs link creation failed\n");
1774
1775 result = sysfs_create_link(&device->cooling_dev->device.kobj,
1776 &device->dev->dev.kobj, "device");
1777 if (result)
1778 pr_info("Reverse sysfs link creation failed\n");
1779}
1780
1781static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1782{
1783 struct acpi_video_device *dev;
1784 union acpi_object *levels;
1785
1786 mutex_lock(&video->device_list_lock);
1787 list_for_each_entry(dev, &video->video_device_list, entry) {
1788 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1789 kfree(levels);
1790 }
1791 mutex_unlock(&video->device_list_lock);
1792}
1793
1794static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1795{
1796 /*
1797 * Do not create backlight device for video output
1798 * device that is not in the enumerated list.
1799 */
1800 if (!acpi_video_device_in_dod(dev)) {
1801 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1802 return false;
1803 }
1804
1805 if (only_lcd)
1806 return dev->flags.lcd;
1807 return true;
1808}
1809
1810static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1811{
1812 struct acpi_video_device *dev;
1813
1814 if (video->backlight_registered)
1815 return 0;
1816
1817 if (acpi_video_get_backlight_type() != acpi_backlight_video)
1818 return 0;
1819
1820 mutex_lock(&video->device_list_lock);
1821 list_for_each_entry(dev, &video->video_device_list, entry) {
1822 if (acpi_video_should_register_backlight(dev))
1823 acpi_video_dev_register_backlight(dev);
1824 }
1825 mutex_unlock(&video->device_list_lock);
1826
1827 video->backlight_registered = true;
1828
1829 video->pm_nb.notifier_call = acpi_video_resume;
1830 video->pm_nb.priority = 0;
1831 return register_pm_notifier(&video->pm_nb);
1832}
1833
1834static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1835{
1836 if (device->backlight) {
1837 backlight_device_unregister(device->backlight);
1838 device->backlight = NULL;
1839 }
1840 if (device->brightness) {
1841 kfree(device->brightness->levels);
1842 kfree(device->brightness);
1843 device->brightness = NULL;
1844 }
1845 if (device->cooling_dev) {
1846 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1847 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1848 thermal_cooling_device_unregister(device->cooling_dev);
1849 device->cooling_dev = NULL;
1850 }
1851}
1852
1853static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1854{
1855 struct acpi_video_device *dev;
1856 int error;
1857
1858 if (!video->backlight_registered)
1859 return 0;
1860
1861 error = unregister_pm_notifier(&video->pm_nb);
1862
1863 mutex_lock(&video->device_list_lock);
1864 list_for_each_entry(dev, &video->video_device_list, entry)
1865 acpi_video_dev_unregister_backlight(dev);
1866 mutex_unlock(&video->device_list_lock);
1867
1868 video->backlight_registered = false;
1869
1870 return error;
1871}
1872
1873static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1874{
1875 acpi_status status;
1876 struct acpi_device *adev = device->dev;
1877
1878 status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1879 acpi_video_device_notify, device);
1880 if (ACPI_FAILURE(status))
1881 dev_err(&adev->dev, "Error installing notify handler\n");
1882 else
1883 device->flags.notify = 1;
1884}
1885
1886static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1887{
1888 struct input_dev *input;
1889 struct acpi_video_device *dev;
1890 int error;
1891
1892 video->input = input = input_allocate_device();
1893 if (!input) {
1894 error = -ENOMEM;
1895 goto out;
1896 }
1897
1898 error = acpi_video_bus_start_devices(video);
1899 if (error)
1900 goto err_free_input;
1901
1902 snprintf(video->phys, sizeof(video->phys),
1903 "%s/video/input0", acpi_device_hid(video->device));
1904
1905 input->name = acpi_device_name(video->device);
1906 input->phys = video->phys;
1907 input->id.bustype = BUS_HOST;
1908 input->id.product = 0x06;
1909 input->dev.parent = &video->device->dev;
1910 input->evbit[0] = BIT(EV_KEY);
1911 set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1912 set_bit(KEY_VIDEO_NEXT, input->keybit);
1913 set_bit(KEY_VIDEO_PREV, input->keybit);
1914 set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1915 set_bit(KEY_BRIGHTNESSUP, input->keybit);
1916 set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1917 set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1918 set_bit(KEY_DISPLAY_OFF, input->keybit);
1919
1920 error = input_register_device(input);
1921 if (error)
1922 goto err_stop_dev;
1923
1924 mutex_lock(&video->device_list_lock);
1925 list_for_each_entry(dev, &video->video_device_list, entry)
1926 acpi_video_dev_add_notify_handler(dev);
1927 mutex_unlock(&video->device_list_lock);
1928
1929 return 0;
1930
1931err_stop_dev:
1932 acpi_video_bus_stop_devices(video);
1933err_free_input:
1934 input_free_device(input);
1935 video->input = NULL;
1936out:
1937 return error;
1938}
1939
1940static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1941{
1942 if (dev->flags.notify) {
1943 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1944 acpi_video_device_notify);
1945 dev->flags.notify = 0;
1946 }
1947}
1948
1949static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1950{
1951 struct acpi_video_device *dev;
1952
1953 mutex_lock(&video->device_list_lock);
1954 list_for_each_entry(dev, &video->video_device_list, entry)
1955 acpi_video_dev_remove_notify_handler(dev);
1956 mutex_unlock(&video->device_list_lock);
1957
1958 acpi_video_bus_stop_devices(video);
1959 input_unregister_device(video->input);
1960 video->input = NULL;
1961}
1962
1963static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1964{
1965 struct acpi_video_device *dev, *next;
1966
1967 mutex_lock(&video->device_list_lock);
1968 list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1969 list_del(&dev->entry);
1970 kfree(dev);
1971 }
1972 mutex_unlock(&video->device_list_lock);
1973
1974 return 0;
1975}
1976
1977static int instance;
1978
1979static int acpi_video_bus_add(struct acpi_device *device)
1980{
1981 struct acpi_video_bus *video;
1982 bool auto_detect;
1983 int error;
1984 acpi_status status;
1985
1986 status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1987 acpi_dev_parent(device)->handle, 1,
1988 acpi_video_bus_match, NULL,
1989 device, NULL);
1990 if (status == AE_ALREADY_EXISTS) {
1991 pr_info(FW_BUG
1992 "Duplicate ACPI video bus devices for the"
1993 " same VGA controller, please try module "
1994 "parameter \"video.allow_duplicates=1\""
1995 "if the current driver doesn't work.\n");
1996 if (!allow_duplicates)
1997 return -ENODEV;
1998 }
1999
2000 video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2001 if (!video)
2002 return -ENOMEM;
2003
2004 /* a hack to fix the duplicate name "VID" problem on T61 */
2005 if (!strcmp(device->pnp.bus_id, "VID")) {
2006 if (instance)
2007 device->pnp.bus_id[3] = '0' + instance;
2008 instance++;
2009 }
2010 /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2011 if (!strcmp(device->pnp.bus_id, "VGA")) {
2012 if (instance)
2013 device->pnp.bus_id[3] = '0' + instance;
2014 instance++;
2015 }
2016
2017 video->device = device;
2018 strscpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2019 strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2020 device->driver_data = video;
2021
2022 acpi_video_bus_find_cap(video);
2023 error = acpi_video_bus_check(video);
2024 if (error)
2025 goto err_free_video;
2026
2027 mutex_init(&video->device_list_lock);
2028 INIT_LIST_HEAD(&video->video_device_list);
2029
2030 error = acpi_video_bus_get_devices(video, device);
2031 if (error)
2032 goto err_put_video;
2033
2034 /*
2035 * HP ZBook Fury 16 G10 requires ACPI video's child devices have _PS0
2036 * evaluated to have functional panel brightness control.
2037 */
2038 acpi_device_fix_up_power_children(device);
2039
2040 pr_info("%s [%s] (multi-head: %s rom: %s post: %s)\n",
2041 ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2042 video->flags.multihead ? "yes" : "no",
2043 video->flags.rom ? "yes" : "no",
2044 video->flags.post ? "yes" : "no");
2045 mutex_lock(&video_list_lock);
2046 list_add_tail(&video->entry, &video_bus_head);
2047 mutex_unlock(&video_list_lock);
2048
2049 /*
2050 * If backlight-type auto-detection is used then a native backlight may
2051 * show up later and this may change the result from video to native.
2052 * Therefor normally the userspace visible /sys/class/backlight device
2053 * gets registered separately by the GPU driver calling
2054 * acpi_video_register_backlight() when an internal panel is detected.
2055 * Register the backlight now when not using auto-detection, so that
2056 * when the kernel cmdline or DMI-quirks are used the backlight will
2057 * get registered even if acpi_video_register_backlight() is not called.
2058 */
2059 acpi_video_run_bcl_for_osi(video);
2060 if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
2061 !auto_detect)
2062 acpi_video_bus_register_backlight(video);
2063
2064 error = acpi_video_bus_add_notify_handler(video);
2065 if (error)
2066 goto err_del;
2067
2068 error = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
2069 acpi_video_bus_notify, device);
2070 if (error)
2071 goto err_remove;
2072
2073 return 0;
2074
2075err_remove:
2076 acpi_video_bus_remove_notify_handler(video);
2077err_del:
2078 mutex_lock(&video_list_lock);
2079 list_del(&video->entry);
2080 mutex_unlock(&video_list_lock);
2081 acpi_video_bus_unregister_backlight(video);
2082err_put_video:
2083 acpi_video_bus_put_devices(video);
2084 kfree(video->attached_array);
2085err_free_video:
2086 kfree(video);
2087 device->driver_data = NULL;
2088
2089 return error;
2090}
2091
2092static void acpi_video_bus_remove(struct acpi_device *device)
2093{
2094 struct acpi_video_bus *video = NULL;
2095
2096
2097 if (!device || !acpi_driver_data(device))
2098 return;
2099
2100 video = acpi_driver_data(device);
2101
2102 acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
2103 acpi_video_bus_notify);
2104
2105 mutex_lock(&video_list_lock);
2106 list_del(&video->entry);
2107 mutex_unlock(&video_list_lock);
2108
2109 acpi_video_bus_remove_notify_handler(video);
2110 acpi_video_bus_unregister_backlight(video);
2111 acpi_video_bus_put_devices(video);
2112
2113 kfree(video->attached_array);
2114 kfree(video);
2115}
2116
2117static int __init is_i740(struct pci_dev *dev)
2118{
2119 if (dev->device == 0x00D1)
2120 return 1;
2121 if (dev->device == 0x7000)
2122 return 1;
2123 return 0;
2124}
2125
2126static int __init intel_opregion_present(void)
2127{
2128 int opregion = 0;
2129 struct pci_dev *dev = NULL;
2130 u32 address;
2131
2132 for_each_pci_dev(dev) {
2133 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2134 continue;
2135 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2136 continue;
2137 /* We don't want to poke around undefined i740 registers */
2138 if (is_i740(dev))
2139 continue;
2140 pci_read_config_dword(dev, 0xfc, &address);
2141 if (!address)
2142 continue;
2143 opregion = 1;
2144 }
2145 return opregion;
2146}
2147
2148int acpi_video_register(void)
2149{
2150 int ret = 0;
2151
2152 mutex_lock(®ister_count_mutex);
2153 if (register_count) {
2154 /*
2155 * if the function of acpi_video_register is already called,
2156 * don't register the acpi_video_bus again and return no error.
2157 */
2158 goto leave;
2159 }
2160
2161 dmi_check_system(video_dmi_table);
2162
2163 ret = acpi_bus_register_driver(&acpi_video_bus);
2164 if (ret)
2165 goto leave;
2166
2167 /*
2168 * When the acpi_video_bus is loaded successfully, increase
2169 * the counter reference.
2170 */
2171 register_count = 1;
2172
2173leave:
2174 mutex_unlock(®ister_count_mutex);
2175 return ret;
2176}
2177EXPORT_SYMBOL(acpi_video_register);
2178
2179void acpi_video_unregister(void)
2180{
2181 mutex_lock(®ister_count_mutex);
2182 if (register_count) {
2183 acpi_bus_unregister_driver(&acpi_video_bus);
2184 register_count = 0;
2185 may_report_brightness_keys = false;
2186 }
2187 mutex_unlock(®ister_count_mutex);
2188}
2189EXPORT_SYMBOL(acpi_video_unregister);
2190
2191void acpi_video_register_backlight(void)
2192{
2193 struct acpi_video_bus *video;
2194
2195 mutex_lock(&video_list_lock);
2196 list_for_each_entry(video, &video_bus_head, entry)
2197 acpi_video_bus_register_backlight(video);
2198 mutex_unlock(&video_list_lock);
2199}
2200EXPORT_SYMBOL(acpi_video_register_backlight);
2201
2202bool acpi_video_handles_brightness_key_presses(void)
2203{
2204 return may_report_brightness_keys &&
2205 (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2206}
2207EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2208
2209/*
2210 * This is kind of nasty. Hardware using Intel chipsets may require
2211 * the video opregion code to be run first in order to initialise
2212 * state before any ACPI video calls are made. To handle this we defer
2213 * registration of the video class until the opregion code has run.
2214 */
2215
2216static int __init acpi_video_init(void)
2217{
2218 /*
2219 * Let the module load even if ACPI is disabled (e.g. due to
2220 * a broken BIOS) so that i915.ko can still be loaded on such
2221 * old systems without an AcpiOpRegion.
2222 *
2223 * acpi_video_register() will report -ENODEV later as well due
2224 * to acpi_disabled when i915.ko tries to register itself afterwards.
2225 */
2226 if (acpi_disabled)
2227 return 0;
2228
2229 if (intel_opregion_present())
2230 return 0;
2231
2232 return acpi_video_register();
2233}
2234
2235static void __exit acpi_video_exit(void)
2236{
2237 acpi_video_unregister();
2238}
2239
2240module_init(acpi_video_init);
2241module_exit(acpi_video_exit);