xref: /openbmc/linux/drivers/acpi/acpi_video.c (revision b9b77222)
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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/types.h>
27 #include <linux/list.h>
28 #include <linux/mutex.h>
29 #include <linux/input.h>
30 #include <linux/backlight.h>
31 #include <linux/thermal.h>
32 #include <linux/sort.h>
33 #include <linux/pci.h>
34 #include <linux/pci_ids.h>
35 #include <linux/slab.h>
36 #include <linux/dmi.h>
37 #include <linux/suspend.h>
38 #include <linux/acpi.h>
39 #include <acpi/video.h>
40 #include <linux/uaccess.h>
41 
42 #define PREFIX "ACPI: "
43 
44 #define ACPI_VIDEO_BUS_NAME		"Video Bus"
45 #define ACPI_VIDEO_DEVICE_NAME		"Video Device"
46 
47 #define MAX_NAME_LEN	20
48 
49 #define _COMPONENT		ACPI_VIDEO_COMPONENT
50 ACPI_MODULE_NAME("video");
51 
52 MODULE_AUTHOR("Bruno Ducrot");
53 MODULE_DESCRIPTION("ACPI Video Driver");
54 MODULE_LICENSE("GPL");
55 
56 static bool brightness_switch_enabled = true;
57 module_param(brightness_switch_enabled, bool, 0644);
58 
59 /*
60  * By default, we don't allow duplicate ACPI video bus devices
61  * under the same VGA controller
62  */
63 static bool allow_duplicates;
64 module_param(allow_duplicates, bool, 0644);
65 
66 static int disable_backlight_sysfs_if = -1;
67 module_param(disable_backlight_sysfs_if, int, 0444);
68 
69 #define REPORT_OUTPUT_KEY_EVENTS		0x01
70 #define REPORT_BRIGHTNESS_KEY_EVENTS		0x02
71 static int report_key_events = -1;
72 module_param(report_key_events, int, 0644);
73 MODULE_PARM_DESC(report_key_events,
74 	"0: none, 1: output changes, 2: brightness changes, 3: all");
75 
76 /*
77  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
78  * assumed even if not actually set.
79  */
80 static bool device_id_scheme = false;
81 module_param(device_id_scheme, bool, 0444);
82 
83 static int only_lcd = -1;
84 module_param(only_lcd, int, 0444);
85 
86 static int register_count;
87 static DEFINE_MUTEX(register_count_mutex);
88 static DEFINE_MUTEX(video_list_lock);
89 static LIST_HEAD(video_bus_head);
90 static int acpi_video_bus_add(struct acpi_device *device);
91 static int acpi_video_bus_remove(struct acpi_device *device);
92 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
93 void acpi_video_detect_exit(void);
94 
95 /*
96  * Indices in the _BCL method response: the first two items are special,
97  * the rest are all supported levels.
98  *
99  * See page 575 of the ACPI spec 3.0
100  */
101 enum acpi_video_level_idx {
102 	ACPI_VIDEO_AC_LEVEL,		/* level when machine has full power */
103 	ACPI_VIDEO_BATTERY_LEVEL,	/* level when machine is on batteries */
104 	ACPI_VIDEO_FIRST_LEVEL,		/* actual supported levels begin here */
105 };
106 
107 static const struct acpi_device_id video_device_ids[] = {
108 	{ACPI_VIDEO_HID, 0},
109 	{"", 0},
110 };
111 MODULE_DEVICE_TABLE(acpi, video_device_ids);
112 
113 static struct acpi_driver acpi_video_bus = {
114 	.name = "video",
115 	.class = ACPI_VIDEO_CLASS,
116 	.ids = video_device_ids,
117 	.ops = {
118 		.add = acpi_video_bus_add,
119 		.remove = acpi_video_bus_remove,
120 		.notify = acpi_video_bus_notify,
121 		},
122 };
123 
124 struct acpi_video_bus_flags {
125 	u8 multihead:1;		/* can switch video heads */
126 	u8 rom:1;		/* can retrieve a video rom */
127 	u8 post:1;		/* can configure the head to */
128 	u8 reserved:5;
129 };
130 
131 struct acpi_video_bus_cap {
132 	u8 _DOS:1;		/* Enable/Disable output switching */
133 	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
134 	u8 _ROM:1;		/* Get ROM Data */
135 	u8 _GPD:1;		/* Get POST Device */
136 	u8 _SPD:1;		/* Set POST Device */
137 	u8 _VPO:1;		/* Video POST Options */
138 	u8 reserved:2;
139 };
140 
141 struct acpi_video_device_attrib {
142 	u32 display_index:4;	/* A zero-based instance of the Display */
143 	u32 display_port_attachment:4;	/* This field differentiates the display type */
144 	u32 display_type:4;	/* Describe the specific type in use */
145 	u32 vendor_specific:4;	/* Chipset Vendor Specific */
146 	u32 bios_can_detect:1;	/* BIOS can detect the device */
147 	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
148 				   the VGA device. */
149 	u32 pipe_id:3;		/* For VGA multiple-head devices. */
150 	u32 reserved:10;	/* Must be 0 */
151 
152 	/*
153 	 * The device ID might not actually follow the scheme described by this
154 	 * struct acpi_video_device_attrib. If it does, then this bit
155 	 * device_id_scheme is set; otherwise, other fields should be ignored.
156 	 *
157 	 * (but also see the global flag device_id_scheme)
158 	 */
159 	u32 device_id_scheme:1;
160 };
161 
162 struct acpi_video_enumerated_device {
163 	union {
164 		u32 int_val;
165 		struct acpi_video_device_attrib attrib;
166 	} value;
167 	struct acpi_video_device *bind_info;
168 };
169 
170 struct acpi_video_bus {
171 	struct acpi_device *device;
172 	bool backlight_registered;
173 	u8 dos_setting;
174 	struct acpi_video_enumerated_device *attached_array;
175 	u8 attached_count;
176 	u8 child_count;
177 	struct acpi_video_bus_cap cap;
178 	struct acpi_video_bus_flags flags;
179 	struct list_head video_device_list;
180 	struct mutex device_list_lock;	/* protects video_device_list */
181 	struct list_head entry;
182 	struct input_dev *input;
183 	char phys[32];	/* for input device */
184 	struct notifier_block pm_nb;
185 };
186 
187 struct acpi_video_device_flags {
188 	u8 crt:1;
189 	u8 lcd:1;
190 	u8 tvout:1;
191 	u8 dvi:1;
192 	u8 bios:1;
193 	u8 unknown:1;
194 	u8 notify:1;
195 	u8 reserved:1;
196 };
197 
198 struct acpi_video_device_cap {
199 	u8 _ADR:1;		/* Return the unique ID */
200 	u8 _BCL:1;		/* Query list of brightness control levels supported */
201 	u8 _BCM:1;		/* Set the brightness level */
202 	u8 _BQC:1;		/* Get current brightness level */
203 	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
204 	u8 _DDC:1;		/* Return the EDID for this device */
205 };
206 
207 struct acpi_video_device {
208 	unsigned long device_id;
209 	struct acpi_video_device_flags flags;
210 	struct acpi_video_device_cap cap;
211 	struct list_head entry;
212 	struct delayed_work switch_brightness_work;
213 	int switch_brightness_event;
214 	struct acpi_video_bus *video;
215 	struct acpi_device *dev;
216 	struct acpi_video_device_brightness *brightness;
217 	struct backlight_device *backlight;
218 	struct thermal_cooling_device *cooling_dev;
219 };
220 
221 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
222 static void acpi_video_device_rebind(struct acpi_video_bus *video);
223 static void acpi_video_device_bind(struct acpi_video_bus *video,
224 				   struct acpi_video_device *device);
225 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
226 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
227 			int level);
228 static int acpi_video_device_lcd_get_level_current(
229 			struct acpi_video_device *device,
230 			unsigned long long *level, bool raw);
231 static int acpi_video_get_next_level(struct acpi_video_device *device,
232 				     u32 level_current, u32 event);
233 static void acpi_video_switch_brightness(struct work_struct *work);
234 
235 /* backlight device sysfs support */
236 static int acpi_video_get_brightness(struct backlight_device *bd)
237 {
238 	unsigned long long cur_level;
239 	int i;
240 	struct acpi_video_device *vd = bl_get_data(bd);
241 
242 	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
243 		return -EINVAL;
244 	for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
245 		if (vd->brightness->levels[i] == cur_level)
246 			return i - ACPI_VIDEO_FIRST_LEVEL;
247 	}
248 	return 0;
249 }
250 
251 static int acpi_video_set_brightness(struct backlight_device *bd)
252 {
253 	int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
254 	struct acpi_video_device *vd = bl_get_data(bd);
255 
256 	cancel_delayed_work(&vd->switch_brightness_work);
257 	return acpi_video_device_lcd_set_level(vd,
258 				vd->brightness->levels[request_level]);
259 }
260 
261 static const struct backlight_ops acpi_backlight_ops = {
262 	.get_brightness = acpi_video_get_brightness,
263 	.update_status  = acpi_video_set_brightness,
264 };
265 
266 /* thermal cooling device callbacks */
267 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
268 			       unsigned long *state)
269 {
270 	struct acpi_device *device = cooling_dev->devdata;
271 	struct acpi_video_device *video = acpi_driver_data(device);
272 
273 	*state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
274 	return 0;
275 }
276 
277 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
278 			       unsigned long *state)
279 {
280 	struct acpi_device *device = cooling_dev->devdata;
281 	struct acpi_video_device *video = acpi_driver_data(device);
282 	unsigned long long level;
283 	int offset;
284 
285 	if (acpi_video_device_lcd_get_level_current(video, &level, false))
286 		return -EINVAL;
287 	for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
288 	     offset++)
289 		if (level == video->brightness->levels[offset]) {
290 			*state = video->brightness->count - offset - 1;
291 			return 0;
292 		}
293 
294 	return -EINVAL;
295 }
296 
297 static int
298 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
299 {
300 	struct acpi_device *device = cooling_dev->devdata;
301 	struct acpi_video_device *video = acpi_driver_data(device);
302 	int level;
303 
304 	if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
305 		return -EINVAL;
306 
307 	state = video->brightness->count - state;
308 	level = video->brightness->levels[state - 1];
309 	return acpi_video_device_lcd_set_level(video, level);
310 }
311 
312 static const struct thermal_cooling_device_ops video_cooling_ops = {
313 	.get_max_state = video_get_max_state,
314 	.get_cur_state = video_get_cur_state,
315 	.set_cur_state = video_set_cur_state,
316 };
317 
318 /*
319  * --------------------------------------------------------------------------
320  *                             Video Management
321  * --------------------------------------------------------------------------
322  */
323 
324 static int
325 acpi_video_device_lcd_query_levels(acpi_handle handle,
326 				   union acpi_object **levels)
327 {
328 	int status;
329 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
330 	union acpi_object *obj;
331 
332 
333 	*levels = NULL;
334 
335 	status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
336 	if (!ACPI_SUCCESS(status))
337 		return status;
338 	obj = (union acpi_object *)buffer.pointer;
339 	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
340 		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
341 		status = -EFAULT;
342 		goto err;
343 	}
344 
345 	*levels = obj;
346 
347 	return 0;
348 
349 err:
350 	kfree(buffer.pointer);
351 
352 	return status;
353 }
354 
355 static int
356 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
357 {
358 	int status;
359 	int state;
360 
361 	status = acpi_execute_simple_method(device->dev->handle,
362 					    "_BCM", level);
363 	if (ACPI_FAILURE(status)) {
364 		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
365 		return -EIO;
366 	}
367 
368 	device->brightness->curr = level;
369 	for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
370 	     state++)
371 		if (level == device->brightness->levels[state]) {
372 			if (device->backlight)
373 				device->backlight->props.brightness =
374 					state - ACPI_VIDEO_FIRST_LEVEL;
375 			return 0;
376 		}
377 
378 	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
379 	return -EINVAL;
380 }
381 
382 /*
383  * For some buggy _BQC methods, we need to add a constant value to
384  * the _BQC return value to get the actual current brightness level
385  */
386 
387 static int bqc_offset_aml_bug_workaround;
388 static int video_set_bqc_offset(const struct dmi_system_id *d)
389 {
390 	bqc_offset_aml_bug_workaround = 9;
391 	return 0;
392 }
393 
394 static int video_disable_backlight_sysfs_if(
395 	const struct dmi_system_id *d)
396 {
397 	if (disable_backlight_sysfs_if == -1)
398 		disable_backlight_sysfs_if = 1;
399 	return 0;
400 }
401 
402 static int video_set_device_id_scheme(const struct dmi_system_id *d)
403 {
404 	device_id_scheme = true;
405 	return 0;
406 }
407 
408 static int video_enable_only_lcd(const struct dmi_system_id *d)
409 {
410 	only_lcd = true;
411 	return 0;
412 }
413 
414 static int video_set_report_key_events(const struct dmi_system_id *id)
415 {
416 	if (report_key_events == -1)
417 		report_key_events = (uintptr_t)id->driver_data;
418 	return 0;
419 }
420 
421 static const struct dmi_system_id video_dmi_table[] = {
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 	 * Some machines have a broken acpi-video interface for brightness
468 	 * control, but still need an acpi_video_device_lcd_set_level() call
469 	 * on resume to turn the backlight power on.  We Enable backlight
470 	 * control on these systems, but do not register a backlight sysfs
471 	 * as brightness control does not work.
472 	 */
473 	{
474 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
475 	 .callback = video_disable_backlight_sysfs_if,
476 	 .ident = "Toshiba Portege R700",
477 	 .matches = {
478 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
479 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
480 		},
481 	},
482 	{
483 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
484 	 .callback = video_disable_backlight_sysfs_if,
485 	 .ident = "Toshiba Portege R830",
486 	 .matches = {
487 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
488 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
489 		},
490 	},
491 	{
492 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
493 	 .callback = video_disable_backlight_sysfs_if,
494 	 .ident = "Toshiba Satellite R830",
495 	 .matches = {
496 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
497 		DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
498 		},
499 	},
500 	/*
501 	 * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
502 	 * but the IDs actually follow the Device ID Scheme.
503 	 */
504 	{
505 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
506 	 .callback = video_set_device_id_scheme,
507 	 .ident = "ESPRIMO Mobile M9410",
508 	 .matches = {
509 		DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
510 		DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
511 		},
512 	},
513 	/*
514 	 * Some machines have multiple video output devices, but only the one
515 	 * that is the type of LCD can do the backlight control so we should not
516 	 * register backlight interface for other video output devices.
517 	 */
518 	{
519 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
520 	 .callback = video_enable_only_lcd,
521 	 .ident = "ESPRIMO Mobile M9410",
522 	 .matches = {
523 		DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
524 		DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
525 		},
526 	},
527 	/*
528 	 * Some machines report wrong key events on the acpi-bus, suppress
529 	 * key event reporting on these.  Note this is only intended to work
530 	 * around events which are plain wrong. In some cases we get double
531 	 * events, in this case acpi-video is considered the canonical source
532 	 * and the events from the other source should be filtered. E.g.
533 	 * by calling acpi_video_handles_brightness_key_presses() from the
534 	 * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
535 	 */
536 	{
537 	 .callback = video_set_report_key_events,
538 	 .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
539 	 .ident = "Dell Vostro V131",
540 	 .matches = {
541 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
542 		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
543 		},
544 	},
545 	{}
546 };
547 
548 static unsigned long long
549 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
550 			      unsigned long long bqc_value)
551 {
552 	unsigned long long level;
553 
554 	if (device->brightness->flags._BQC_use_index) {
555 		/*
556 		 * _BQC returns an index that doesn't account for the first 2
557 		 * items with special meaning (see enum acpi_video_level_idx),
558 		 * so we need to compensate for that by offsetting ourselves
559 		 */
560 		if (device->brightness->flags._BCL_reversed)
561 			bqc_value = device->brightness->count -
562 				ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
563 
564 		level = device->brightness->levels[bqc_value +
565 		                                   ACPI_VIDEO_FIRST_LEVEL];
566 	} else {
567 		level = bqc_value;
568 	}
569 
570 	level += bqc_offset_aml_bug_workaround;
571 
572 	return level;
573 }
574 
575 static int
576 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
577 					unsigned long long *level, bool raw)
578 {
579 	acpi_status status = AE_OK;
580 	int i;
581 
582 	if (device->cap._BQC || device->cap._BCQ) {
583 		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
584 
585 		status = acpi_evaluate_integer(device->dev->handle, buf,
586 						NULL, level);
587 		if (ACPI_SUCCESS(status)) {
588 			if (raw) {
589 				/*
590 				 * Caller has indicated he wants the raw
591 				 * value returned by _BQC, so don't furtherly
592 				 * mess with the value.
593 				 */
594 				return 0;
595 			}
596 
597 			*level = acpi_video_bqc_value_to_level(device, *level);
598 
599 			for (i = ACPI_VIDEO_FIRST_LEVEL;
600 			     i < device->brightness->count; i++)
601 				if (device->brightness->levels[i] == *level) {
602 					device->brightness->curr = *level;
603 					return 0;
604 				}
605 			/*
606 			 * BQC returned an invalid level.
607 			 * Stop using it.
608 			 */
609 			ACPI_WARNING((AE_INFO,
610 				      "%s returned an invalid level",
611 				      buf));
612 			device->cap._BQC = device->cap._BCQ = 0;
613 		} else {
614 			/*
615 			 * Fixme:
616 			 * should we return an error or ignore this failure?
617 			 * dev->brightness->curr is a cached value which stores
618 			 * the correct current backlight level in most cases.
619 			 * ACPI video backlight still works w/ buggy _BQC.
620 			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
621 			 */
622 			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
623 			device->cap._BQC = device->cap._BCQ = 0;
624 		}
625 	}
626 
627 	*level = device->brightness->curr;
628 	return 0;
629 }
630 
631 static int
632 acpi_video_device_EDID(struct acpi_video_device *device,
633 		       union acpi_object **edid, ssize_t length)
634 {
635 	int status;
636 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
637 	union acpi_object *obj;
638 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
639 	struct acpi_object_list args = { 1, &arg0 };
640 
641 
642 	*edid = NULL;
643 
644 	if (!device)
645 		return -ENODEV;
646 	if (length == 128)
647 		arg0.integer.value = 1;
648 	else if (length == 256)
649 		arg0.integer.value = 2;
650 	else
651 		return -EINVAL;
652 
653 	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
654 	if (ACPI_FAILURE(status))
655 		return -ENODEV;
656 
657 	obj = buffer.pointer;
658 
659 	if (obj && obj->type == ACPI_TYPE_BUFFER)
660 		*edid = obj;
661 	else {
662 		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
663 		status = -EFAULT;
664 		kfree(obj);
665 	}
666 
667 	return status;
668 }
669 
670 /* bus */
671 
672 /*
673  *  Arg:
674  *	video		: video bus device pointer
675  *	bios_flag	:
676  *		0.	The system BIOS should NOT automatically switch(toggle)
677  *			the active display output.
678  *		1.	The system BIOS should automatically switch (toggle) the
679  *			active display output. No switch event.
680  *		2.	The _DGS value should be locked.
681  *		3.	The system BIOS should not automatically switch (toggle) the
682  *			active display output, but instead generate the display switch
683  *			event notify code.
684  *	lcd_flag	:
685  *		0.	The system BIOS should automatically control the brightness level
686  *			of the LCD when the power changes from AC to DC
687  *		1.	The system BIOS should NOT automatically control the brightness
688  *			level of the LCD when the power changes from AC to DC.
689  *  Return Value:
690  *		-EINVAL	wrong arg.
691  */
692 
693 static int
694 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
695 {
696 	acpi_status status;
697 
698 	if (!video->cap._DOS)
699 		return 0;
700 
701 	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
702 		return -EINVAL;
703 	video->dos_setting = (lcd_flag << 2) | bios_flag;
704 	status = acpi_execute_simple_method(video->device->handle, "_DOS",
705 					    (lcd_flag << 2) | bios_flag);
706 	if (ACPI_FAILURE(status))
707 		return -EIO;
708 
709 	return 0;
710 }
711 
712 /*
713  * Simple comparison function used to sort backlight levels.
714  */
715 
716 static int
717 acpi_video_cmp_level(const void *a, const void *b)
718 {
719 	return *(int *)a - *(int *)b;
720 }
721 
722 /*
723  * Decides if _BQC/_BCQ for this system is usable
724  *
725  * We do this by changing the level first and then read out the current
726  * brightness level, if the value does not match, find out if it is using
727  * index. If not, clear the _BQC/_BCQ capability.
728  */
729 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
730 				int max_level, int current_level)
731 {
732 	struct acpi_video_device_brightness *br = device->brightness;
733 	int result;
734 	unsigned long long level;
735 	int test_level;
736 
737 	/* don't mess with existing known broken systems */
738 	if (bqc_offset_aml_bug_workaround)
739 		return 0;
740 
741 	/*
742 	 * Some systems always report current brightness level as maximum
743 	 * through _BQC, we need to test another value for them. However,
744 	 * there is a subtlety:
745 	 *
746 	 * If the _BCL package ordering is descending, the first level
747 	 * (br->levels[2]) is likely to be 0, and if the number of levels
748 	 * matches the number of steps, we might confuse a returned level to
749 	 * mean the index.
750 	 *
751 	 * For example:
752 	 *
753 	 *     current_level = max_level = 100
754 	 *     test_level = 0
755 	 *     returned level = 100
756 	 *
757 	 * In this case 100 means the level, not the index, and _BCM failed.
758 	 * Still, if the _BCL package ordering is descending, the index of
759 	 * level 0 is also 100, so we assume _BQC is indexed, when it's not.
760 	 *
761 	 * This causes all _BQC calls to return bogus values causing weird
762 	 * behavior from the user's perspective.  For example:
763 	 *
764 	 * xbacklight -set 10; xbacklight -set 20;
765 	 *
766 	 * would flash to 90% and then slowly down to the desired level (20).
767 	 *
768 	 * The solution is simple; test anything other than the first level
769 	 * (e.g. 1).
770 	 */
771 	test_level = current_level == max_level
772 		? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
773 		: max_level;
774 
775 	result = acpi_video_device_lcd_set_level(device, test_level);
776 	if (result)
777 		return result;
778 
779 	result = acpi_video_device_lcd_get_level_current(device, &level, true);
780 	if (result)
781 		return result;
782 
783 	if (level != test_level) {
784 		/* buggy _BQC found, need to find out if it uses index */
785 		if (level < br->count) {
786 			if (br->flags._BCL_reversed)
787 				level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
788 			if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
789 				br->flags._BQC_use_index = 1;
790 		}
791 
792 		if (!br->flags._BQC_use_index)
793 			device->cap._BQC = device->cap._BCQ = 0;
794 	}
795 
796 	return 0;
797 }
798 
799 int acpi_video_get_levels(struct acpi_device *device,
800 			  struct acpi_video_device_brightness **dev_br,
801 			  int *pmax_level)
802 {
803 	union acpi_object *obj = NULL;
804 	int i, max_level = 0, count = 0, level_ac_battery = 0;
805 	union acpi_object *o;
806 	struct acpi_video_device_brightness *br = NULL;
807 	int result = 0;
808 	u32 value;
809 
810 	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
811 								&obj))) {
812 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
813 						"LCD brightness level\n"));
814 		result = -ENODEV;
815 		goto out;
816 	}
817 
818 	if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
819 		result = -EINVAL;
820 		goto out;
821 	}
822 
823 	br = kzalloc(sizeof(*br), GFP_KERNEL);
824 	if (!br) {
825 		printk(KERN_ERR "can't allocate memory\n");
826 		result = -ENOMEM;
827 		goto out;
828 	}
829 
830 	/*
831 	 * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
832 	 * in order to account for buggy BIOS which don't export the first two
833 	 * special levels (see below)
834 	 */
835 	br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
836 				   sizeof(*br->levels),
837 				   GFP_KERNEL);
838 	if (!br->levels) {
839 		result = -ENOMEM;
840 		goto out_free;
841 	}
842 
843 	for (i = 0; i < obj->package.count; i++) {
844 		o = (union acpi_object *)&obj->package.elements[i];
845 		if (o->type != ACPI_TYPE_INTEGER) {
846 			printk(KERN_ERR PREFIX "Invalid data\n");
847 			continue;
848 		}
849 		value = (u32) o->integer.value;
850 		/* Skip duplicate entries */
851 		if (count > ACPI_VIDEO_FIRST_LEVEL
852 		    && br->levels[count - 1] == value)
853 			continue;
854 
855 		br->levels[count] = value;
856 
857 		if (br->levels[count] > max_level)
858 			max_level = br->levels[count];
859 		count++;
860 	}
861 
862 	/*
863 	 * some buggy BIOS don't export the levels
864 	 * when machine is on AC/Battery in _BCL package.
865 	 * In this case, the first two elements in _BCL packages
866 	 * are also supported brightness levels that OS should take care of.
867 	 */
868 	for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
869 		if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
870 			level_ac_battery++;
871 		if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
872 			level_ac_battery++;
873 	}
874 
875 	if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
876 		level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
877 		br->flags._BCL_no_ac_battery_levels = 1;
878 		for (i = (count - 1 + level_ac_battery);
879 		     i >= ACPI_VIDEO_FIRST_LEVEL; i--)
880 			br->levels[i] = br->levels[i - level_ac_battery];
881 		count += level_ac_battery;
882 	} else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
883 		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
884 
885 	/* Check if the _BCL package is in a reversed order */
886 	if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
887 		br->flags._BCL_reversed = 1;
888 		sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
889 		     count - ACPI_VIDEO_FIRST_LEVEL,
890 		     sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
891 		     acpi_video_cmp_level, NULL);
892 	} else if (max_level != br->levels[count - 1])
893 		ACPI_ERROR((AE_INFO,
894 			    "Found unordered _BCL package"));
895 
896 	br->count = count;
897 	*dev_br = br;
898 	if (pmax_level)
899 		*pmax_level = max_level;
900 
901 out:
902 	kfree(obj);
903 	return result;
904 out_free:
905 	kfree(br);
906 	goto out;
907 }
908 EXPORT_SYMBOL(acpi_video_get_levels);
909 
910 /*
911  *  Arg:
912  *	device	: video output device (LCD, CRT, ..)
913  *
914  *  Return Value:
915  *	Maximum brightness level
916  *
917  *  Allocate and initialize device->brightness.
918  */
919 
920 static int
921 acpi_video_init_brightness(struct acpi_video_device *device)
922 {
923 	int i, max_level = 0;
924 	unsigned long long level, level_old;
925 	struct acpi_video_device_brightness *br = NULL;
926 	int result = -EINVAL;
927 
928 	result = acpi_video_get_levels(device->dev, &br, &max_level);
929 	if (result)
930 		return result;
931 	device->brightness = br;
932 
933 	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
934 	br->curr = level = max_level;
935 
936 	if (!device->cap._BQC)
937 		goto set_level;
938 
939 	result = acpi_video_device_lcd_get_level_current(device,
940 							 &level_old, true);
941 	if (result)
942 		goto out_free_levels;
943 
944 	result = acpi_video_bqc_quirk(device, max_level, level_old);
945 	if (result)
946 		goto out_free_levels;
947 	/*
948 	 * cap._BQC may get cleared due to _BQC is found to be broken
949 	 * in acpi_video_bqc_quirk, so check again here.
950 	 */
951 	if (!device->cap._BQC)
952 		goto set_level;
953 
954 	level = acpi_video_bqc_value_to_level(device, level_old);
955 	/*
956 	 * On some buggy laptops, _BQC returns an uninitialized
957 	 * value when invoked for the first time, i.e.
958 	 * level_old is invalid (no matter whether it's a level
959 	 * or an index). Set the backlight to max_level in this case.
960 	 */
961 	for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
962 		if (level == br->levels[i])
963 			break;
964 	if (i == br->count || !level)
965 		level = max_level;
966 
967 set_level:
968 	result = acpi_video_device_lcd_set_level(device, level);
969 	if (result)
970 		goto out_free_levels;
971 
972 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
973 	                  "found %d brightness levels\n",
974 	                  br->count - ACPI_VIDEO_FIRST_LEVEL));
975 	return 0;
976 
977 out_free_levels:
978 	kfree(br->levels);
979 	kfree(br);
980 	device->brightness = NULL;
981 	return result;
982 }
983 
984 /*
985  *  Arg:
986  *	device	: video output device (LCD, CRT, ..)
987  *
988  *  Return Value:
989  *	None
990  *
991  *  Find out all required AML methods defined under the output
992  *  device.
993  */
994 
995 static void acpi_video_device_find_cap(struct acpi_video_device *device)
996 {
997 	if (acpi_has_method(device->dev->handle, "_ADR"))
998 		device->cap._ADR = 1;
999 	if (acpi_has_method(device->dev->handle, "_BCL"))
1000 		device->cap._BCL = 1;
1001 	if (acpi_has_method(device->dev->handle, "_BCM"))
1002 		device->cap._BCM = 1;
1003 	if (acpi_has_method(device->dev->handle, "_BQC")) {
1004 		device->cap._BQC = 1;
1005 	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1006 		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1007 		device->cap._BCQ = 1;
1008 	}
1009 
1010 	if (acpi_has_method(device->dev->handle, "_DDC"))
1011 		device->cap._DDC = 1;
1012 }
1013 
1014 /*
1015  *  Arg:
1016  *	device	: video output device (VGA)
1017  *
1018  *  Return Value:
1019  *	None
1020  *
1021  *  Find out all required AML methods defined under the video bus device.
1022  */
1023 
1024 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1025 {
1026 	if (acpi_has_method(video->device->handle, "_DOS"))
1027 		video->cap._DOS = 1;
1028 	if (acpi_has_method(video->device->handle, "_DOD"))
1029 		video->cap._DOD = 1;
1030 	if (acpi_has_method(video->device->handle, "_ROM"))
1031 		video->cap._ROM = 1;
1032 	if (acpi_has_method(video->device->handle, "_GPD"))
1033 		video->cap._GPD = 1;
1034 	if (acpi_has_method(video->device->handle, "_SPD"))
1035 		video->cap._SPD = 1;
1036 	if (acpi_has_method(video->device->handle, "_VPO"))
1037 		video->cap._VPO = 1;
1038 }
1039 
1040 /*
1041  * Check whether the video bus device has required AML method to
1042  * support the desired features
1043  */
1044 
1045 static int acpi_video_bus_check(struct acpi_video_bus *video)
1046 {
1047 	acpi_status status = -ENOENT;
1048 	struct pci_dev *dev;
1049 
1050 	if (!video)
1051 		return -EINVAL;
1052 
1053 	dev = acpi_get_pci_dev(video->device->handle);
1054 	if (!dev)
1055 		return -ENODEV;
1056 	pci_dev_put(dev);
1057 
1058 	/*
1059 	 * Since there is no HID, CID and so on for VGA driver, we have
1060 	 * to check well known required nodes.
1061 	 */
1062 
1063 	/* Does this device support video switching? */
1064 	if (video->cap._DOS || video->cap._DOD) {
1065 		if (!video->cap._DOS) {
1066 			printk(KERN_WARNING FW_BUG
1067 				"ACPI(%s) defines _DOD but not _DOS\n",
1068 				acpi_device_bid(video->device));
1069 		}
1070 		video->flags.multihead = 1;
1071 		status = 0;
1072 	}
1073 
1074 	/* Does this device support retrieving a video ROM? */
1075 	if (video->cap._ROM) {
1076 		video->flags.rom = 1;
1077 		status = 0;
1078 	}
1079 
1080 	/* Does this device support configuring which video device to POST? */
1081 	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1082 		video->flags.post = 1;
1083 		status = 0;
1084 	}
1085 
1086 	return status;
1087 }
1088 
1089 /*
1090  * --------------------------------------------------------------------------
1091  *                               Driver Interface
1092  * --------------------------------------------------------------------------
1093  */
1094 
1095 /* device interface */
1096 static struct acpi_video_device_attrib *
1097 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1098 {
1099 	struct acpi_video_enumerated_device *ids;
1100 	int i;
1101 
1102 	for (i = 0; i < video->attached_count; i++) {
1103 		ids = &video->attached_array[i];
1104 		if ((ids->value.int_val & 0xffff) == device_id)
1105 			return &ids->value.attrib;
1106 	}
1107 
1108 	return NULL;
1109 }
1110 
1111 static int
1112 acpi_video_get_device_type(struct acpi_video_bus *video,
1113 			   unsigned long device_id)
1114 {
1115 	struct acpi_video_enumerated_device *ids;
1116 	int i;
1117 
1118 	for (i = 0; i < video->attached_count; i++) {
1119 		ids = &video->attached_array[i];
1120 		if ((ids->value.int_val & 0xffff) == device_id)
1121 			return ids->value.int_val;
1122 	}
1123 
1124 	return 0;
1125 }
1126 
1127 static int
1128 acpi_video_bus_get_one_device(struct acpi_device *device,
1129 			      struct acpi_video_bus *video)
1130 {
1131 	unsigned long long device_id;
1132 	int status, device_type;
1133 	struct acpi_video_device *data;
1134 	struct acpi_video_device_attrib *attribute;
1135 
1136 	status =
1137 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1138 	/* Some device omits _ADR, we skip them instead of fail */
1139 	if (ACPI_FAILURE(status))
1140 		return 0;
1141 
1142 	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1143 	if (!data)
1144 		return -ENOMEM;
1145 
1146 	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1147 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1148 	device->driver_data = data;
1149 
1150 	data->device_id = device_id;
1151 	data->video = video;
1152 	data->dev = device;
1153 	INIT_DELAYED_WORK(&data->switch_brightness_work,
1154 			  acpi_video_switch_brightness);
1155 
1156 	attribute = acpi_video_get_device_attr(video, device_id);
1157 
1158 	if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1159 		switch (attribute->display_type) {
1160 		case ACPI_VIDEO_DISPLAY_CRT:
1161 			data->flags.crt = 1;
1162 			break;
1163 		case ACPI_VIDEO_DISPLAY_TV:
1164 			data->flags.tvout = 1;
1165 			break;
1166 		case ACPI_VIDEO_DISPLAY_DVI:
1167 			data->flags.dvi = 1;
1168 			break;
1169 		case ACPI_VIDEO_DISPLAY_LCD:
1170 			data->flags.lcd = 1;
1171 			break;
1172 		default:
1173 			data->flags.unknown = 1;
1174 			break;
1175 		}
1176 		if (attribute->bios_can_detect)
1177 			data->flags.bios = 1;
1178 	} else {
1179 		/* Check for legacy IDs */
1180 		device_type = acpi_video_get_device_type(video, device_id);
1181 		/* Ignore bits 16 and 18-20 */
1182 		switch (device_type & 0xffe2ffff) {
1183 		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1184 			data->flags.crt = 1;
1185 			break;
1186 		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1187 			data->flags.lcd = 1;
1188 			break;
1189 		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1190 			data->flags.tvout = 1;
1191 			break;
1192 		default:
1193 			data->flags.unknown = 1;
1194 		}
1195 	}
1196 
1197 	acpi_video_device_bind(video, data);
1198 	acpi_video_device_find_cap(data);
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 
1204 	return status;
1205 }
1206 
1207 /*
1208  *  Arg:
1209  *	video	: video bus device
1210  *
1211  *  Return:
1212  *	none
1213  *
1214  *  Enumerate the video device list of the video bus,
1215  *  bind the ids with the corresponding video devices
1216  *  under the video bus.
1217  */
1218 
1219 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1220 {
1221 	struct acpi_video_device *dev;
1222 
1223 	mutex_lock(&video->device_list_lock);
1224 
1225 	list_for_each_entry(dev, &video->video_device_list, entry)
1226 		acpi_video_device_bind(video, dev);
1227 
1228 	mutex_unlock(&video->device_list_lock);
1229 }
1230 
1231 /*
1232  *  Arg:
1233  *	video	: video bus device
1234  *	device	: video output device under the video
1235  *		bus
1236  *
1237  *  Return:
1238  *	none
1239  *
1240  *  Bind the ids with the corresponding video devices
1241  *  under the video bus.
1242  */
1243 
1244 static void
1245 acpi_video_device_bind(struct acpi_video_bus *video,
1246 		       struct acpi_video_device *device)
1247 {
1248 	struct acpi_video_enumerated_device *ids;
1249 	int i;
1250 
1251 	for (i = 0; i < video->attached_count; i++) {
1252 		ids = &video->attached_array[i];
1253 		if (device->device_id == (ids->value.int_val & 0xffff)) {
1254 			ids->bind_info = device;
1255 			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1256 		}
1257 	}
1258 }
1259 
1260 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1261 {
1262 	struct acpi_video_bus *video = device->video;
1263 	int i;
1264 
1265 	/*
1266 	 * If we have a broken _DOD or we have more than 8 output devices
1267 	 * under the graphics controller node that we can't proper deal with
1268 	 * in the operation region code currently, no need to test.
1269 	 */
1270 	if (!video->attached_count || video->child_count > 8)
1271 		return true;
1272 
1273 	for (i = 0; i < video->attached_count; i++) {
1274 		if ((video->attached_array[i].value.int_val & 0xfff) ==
1275 		    (device->device_id & 0xfff))
1276 			return true;
1277 	}
1278 
1279 	return false;
1280 }
1281 
1282 /*
1283  *  Arg:
1284  *	video	: video bus device
1285  *
1286  *  Return:
1287  *	< 0	: error
1288  *
1289  *  Call _DOD to enumerate all devices attached to display adapter
1290  *
1291  */
1292 
1293 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1294 {
1295 	int status;
1296 	int count;
1297 	int i;
1298 	struct acpi_video_enumerated_device *active_list;
1299 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1300 	union acpi_object *dod = NULL;
1301 	union acpi_object *obj;
1302 
1303 	if (!video->cap._DOD)
1304 		return AE_NOT_EXIST;
1305 
1306 	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1307 	if (!ACPI_SUCCESS(status)) {
1308 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1309 		return status;
1310 	}
1311 
1312 	dod = buffer.pointer;
1313 	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1314 		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1315 		status = -EFAULT;
1316 		goto out;
1317 	}
1318 
1319 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1320 			  dod->package.count));
1321 
1322 	active_list = kcalloc(1 + dod->package.count,
1323 			      sizeof(struct acpi_video_enumerated_device),
1324 			      GFP_KERNEL);
1325 	if (!active_list) {
1326 		status = -ENOMEM;
1327 		goto out;
1328 	}
1329 
1330 	count = 0;
1331 	for (i = 0; i < dod->package.count; i++) {
1332 		obj = &dod->package.elements[i];
1333 
1334 		if (obj->type != ACPI_TYPE_INTEGER) {
1335 			printk(KERN_ERR PREFIX
1336 				"Invalid _DOD data in element %d\n", i);
1337 			continue;
1338 		}
1339 
1340 		active_list[count].value.int_val = obj->integer.value;
1341 		active_list[count].bind_info = NULL;
1342 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1343 				  (int)obj->integer.value));
1344 		count++;
1345 	}
1346 
1347 	kfree(video->attached_array);
1348 
1349 	video->attached_array = active_list;
1350 	video->attached_count = count;
1351 
1352 out:
1353 	kfree(buffer.pointer);
1354 	return status;
1355 }
1356 
1357 static int
1358 acpi_video_get_next_level(struct acpi_video_device *device,
1359 			  u32 level_current, u32 event)
1360 {
1361 	int min, max, min_above, max_below, i, l, delta = 255;
1362 	max = max_below = 0;
1363 	min = min_above = 255;
1364 	/* Find closest level to level_current */
1365 	for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1366 		l = device->brightness->levels[i];
1367 		if (abs(l - level_current) < abs(delta)) {
1368 			delta = l - level_current;
1369 			if (!delta)
1370 				break;
1371 		}
1372 	}
1373 	/* Ajust level_current to closest available level */
1374 	level_current += delta;
1375 	for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1376 		l = device->brightness->levels[i];
1377 		if (l < min)
1378 			min = l;
1379 		if (l > max)
1380 			max = l;
1381 		if (l < min_above && l > level_current)
1382 			min_above = l;
1383 		if (l > max_below && l < level_current)
1384 			max_below = l;
1385 	}
1386 
1387 	switch (event) {
1388 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1389 		return (level_current < max) ? min_above : min;
1390 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1391 		return (level_current < max) ? min_above : max;
1392 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1393 		return (level_current > min) ? max_below : min;
1394 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1395 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1396 		return 0;
1397 	default:
1398 		return level_current;
1399 	}
1400 }
1401 
1402 static void
1403 acpi_video_switch_brightness(struct work_struct *work)
1404 {
1405 	struct acpi_video_device *device = container_of(to_delayed_work(work),
1406 			     struct acpi_video_device, switch_brightness_work);
1407 	unsigned long long level_current, level_next;
1408 	int event = device->switch_brightness_event;
1409 	int result = -EINVAL;
1410 
1411 	/* no warning message if acpi_backlight=vendor or a quirk is used */
1412 	if (!device->backlight)
1413 		return;
1414 
1415 	if (!device->brightness)
1416 		goto out;
1417 
1418 	result = acpi_video_device_lcd_get_level_current(device,
1419 							 &level_current,
1420 							 false);
1421 	if (result)
1422 		goto out;
1423 
1424 	level_next = acpi_video_get_next_level(device, level_current, event);
1425 
1426 	result = acpi_video_device_lcd_set_level(device, level_next);
1427 
1428 	if (!result)
1429 		backlight_force_update(device->backlight,
1430 				       BACKLIGHT_UPDATE_HOTKEY);
1431 
1432 out:
1433 	if (result)
1434 		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1435 }
1436 
1437 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1438 			void **edid)
1439 {
1440 	struct acpi_video_bus *video;
1441 	struct acpi_video_device *video_device;
1442 	union acpi_object *buffer = NULL;
1443 	acpi_status status;
1444 	int i, length;
1445 
1446 	if (!device || !acpi_driver_data(device))
1447 		return -EINVAL;
1448 
1449 	video = acpi_driver_data(device);
1450 
1451 	for (i = 0; i < video->attached_count; i++) {
1452 		video_device = video->attached_array[i].bind_info;
1453 		length = 256;
1454 
1455 		if (!video_device)
1456 			continue;
1457 
1458 		if (!video_device->cap._DDC)
1459 			continue;
1460 
1461 		if (type) {
1462 			switch (type) {
1463 			case ACPI_VIDEO_DISPLAY_CRT:
1464 				if (!video_device->flags.crt)
1465 					continue;
1466 				break;
1467 			case ACPI_VIDEO_DISPLAY_TV:
1468 				if (!video_device->flags.tvout)
1469 					continue;
1470 				break;
1471 			case ACPI_VIDEO_DISPLAY_DVI:
1472 				if (!video_device->flags.dvi)
1473 					continue;
1474 				break;
1475 			case ACPI_VIDEO_DISPLAY_LCD:
1476 				if (!video_device->flags.lcd)
1477 					continue;
1478 				break;
1479 			}
1480 		} else if (video_device->device_id != device_id) {
1481 			continue;
1482 		}
1483 
1484 		status = acpi_video_device_EDID(video_device, &buffer, length);
1485 
1486 		if (ACPI_FAILURE(status) || !buffer ||
1487 		    buffer->type != ACPI_TYPE_BUFFER) {
1488 			length = 128;
1489 			status = acpi_video_device_EDID(video_device, &buffer,
1490 							length);
1491 			if (ACPI_FAILURE(status) || !buffer ||
1492 			    buffer->type != ACPI_TYPE_BUFFER) {
1493 				continue;
1494 			}
1495 		}
1496 
1497 		*edid = buffer->buffer.pointer;
1498 		return length;
1499 	}
1500 
1501 	return -ENODEV;
1502 }
1503 EXPORT_SYMBOL(acpi_video_get_edid);
1504 
1505 static int
1506 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1507 			   struct acpi_device *device)
1508 {
1509 	int status = 0;
1510 	struct acpi_device *dev;
1511 
1512 	/*
1513 	 * There are systems where video module known to work fine regardless
1514 	 * of broken _DOD and ignoring returned value here doesn't cause
1515 	 * any issues later.
1516 	 */
1517 	acpi_video_device_enumerate(video);
1518 
1519 	list_for_each_entry(dev, &device->children, node) {
1520 
1521 		status = acpi_video_bus_get_one_device(dev, video);
1522 		if (status) {
1523 			dev_err(&dev->dev, "Can't attach device\n");
1524 			break;
1525 		}
1526 		video->child_count++;
1527 	}
1528 	return status;
1529 }
1530 
1531 /* acpi_video interface */
1532 
1533 /*
1534  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1535  * preform any automatic brightness change on receiving a notification.
1536  */
1537 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1538 {
1539 	return acpi_video_bus_DOS(video, 0,
1540 				  acpi_osi_is_win8() ? 1 : 0);
1541 }
1542 
1543 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1544 {
1545 	return acpi_video_bus_DOS(video, 0,
1546 				  acpi_osi_is_win8() ? 0 : 1);
1547 }
1548 
1549 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1550 {
1551 	struct acpi_video_bus *video = acpi_driver_data(device);
1552 	struct input_dev *input;
1553 	int keycode = 0;
1554 
1555 	if (!video || !video->input)
1556 		return;
1557 
1558 	input = video->input;
1559 
1560 	switch (event) {
1561 	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
1562 					 * most likely via hotkey. */
1563 		keycode = KEY_SWITCHVIDEOMODE;
1564 		break;
1565 
1566 	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
1567 					 * connector. */
1568 		acpi_video_device_enumerate(video);
1569 		acpi_video_device_rebind(video);
1570 		keycode = KEY_SWITCHVIDEOMODE;
1571 		break;
1572 
1573 	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
1574 		keycode = KEY_SWITCHVIDEOMODE;
1575 		break;
1576 	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
1577 		keycode = KEY_VIDEO_NEXT;
1578 		break;
1579 	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
1580 		keycode = KEY_VIDEO_PREV;
1581 		break;
1582 
1583 	default:
1584 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1585 				  "Unsupported event [0x%x]\n", event));
1586 		break;
1587 	}
1588 
1589 	if (acpi_notifier_call_chain(device, event, 0))
1590 		/* Something vetoed the keypress. */
1591 		keycode = 0;
1592 
1593 	if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1594 		input_report_key(input, keycode, 1);
1595 		input_sync(input);
1596 		input_report_key(input, keycode, 0);
1597 		input_sync(input);
1598 	}
1599 
1600 	return;
1601 }
1602 
1603 static void brightness_switch_event(struct acpi_video_device *video_device,
1604 				    u32 event)
1605 {
1606 	if (!brightness_switch_enabled)
1607 		return;
1608 
1609 	video_device->switch_brightness_event = event;
1610 	schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1611 }
1612 
1613 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1614 {
1615 	struct acpi_video_device *video_device = data;
1616 	struct acpi_device *device = NULL;
1617 	struct acpi_video_bus *bus;
1618 	struct input_dev *input;
1619 	int keycode = 0;
1620 
1621 	if (!video_device)
1622 		return;
1623 
1624 	device = video_device->dev;
1625 	bus = video_device->video;
1626 	input = bus->input;
1627 
1628 	switch (event) {
1629 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
1630 		brightness_switch_event(video_device, event);
1631 		keycode = KEY_BRIGHTNESS_CYCLE;
1632 		break;
1633 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
1634 		brightness_switch_event(video_device, event);
1635 		keycode = KEY_BRIGHTNESSUP;
1636 		break;
1637 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
1638 		brightness_switch_event(video_device, event);
1639 		keycode = KEY_BRIGHTNESSDOWN;
1640 		break;
1641 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
1642 		brightness_switch_event(video_device, event);
1643 		keycode = KEY_BRIGHTNESS_ZERO;
1644 		break;
1645 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
1646 		brightness_switch_event(video_device, event);
1647 		keycode = KEY_DISPLAY_OFF;
1648 		break;
1649 	default:
1650 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1651 				  "Unsupported event [0x%x]\n", event));
1652 		break;
1653 	}
1654 
1655 	acpi_notifier_call_chain(device, event, 0);
1656 
1657 	if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1658 		input_report_key(input, keycode, 1);
1659 		input_sync(input);
1660 		input_report_key(input, keycode, 0);
1661 		input_sync(input);
1662 	}
1663 
1664 	return;
1665 }
1666 
1667 static int acpi_video_resume(struct notifier_block *nb,
1668 				unsigned long val, void *ign)
1669 {
1670 	struct acpi_video_bus *video;
1671 	struct acpi_video_device *video_device;
1672 	int i;
1673 
1674 	switch (val) {
1675 	case PM_HIBERNATION_PREPARE:
1676 	case PM_SUSPEND_PREPARE:
1677 	case PM_RESTORE_PREPARE:
1678 		return NOTIFY_DONE;
1679 	}
1680 
1681 	video = container_of(nb, struct acpi_video_bus, pm_nb);
1682 
1683 	dev_info(&video->device->dev, "Restoring backlight state\n");
1684 
1685 	for (i = 0; i < video->attached_count; i++) {
1686 		video_device = video->attached_array[i].bind_info;
1687 		if (video_device && video_device->brightness)
1688 			acpi_video_device_lcd_set_level(video_device,
1689 					video_device->brightness->curr);
1690 	}
1691 
1692 	return NOTIFY_OK;
1693 }
1694 
1695 static acpi_status
1696 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1697 			void **return_value)
1698 {
1699 	struct acpi_device *device = context;
1700 	struct acpi_device *sibling;
1701 	int result;
1702 
1703 	if (handle == device->handle)
1704 		return AE_CTRL_TERMINATE;
1705 
1706 	result = acpi_bus_get_device(handle, &sibling);
1707 	if (result)
1708 		return AE_OK;
1709 
1710 	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1711 			return AE_ALREADY_EXISTS;
1712 
1713 	return AE_OK;
1714 }
1715 
1716 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1717 {
1718 	struct backlight_properties props;
1719 	struct pci_dev *pdev;
1720 	acpi_handle acpi_parent;
1721 	struct device *parent = NULL;
1722 	int result;
1723 	static int count;
1724 	char *name;
1725 
1726 	result = acpi_video_init_brightness(device);
1727 	if (result)
1728 		return;
1729 
1730 	if (disable_backlight_sysfs_if > 0)
1731 		return;
1732 
1733 	name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1734 	if (!name)
1735 		return;
1736 	count++;
1737 
1738 	acpi_get_parent(device->dev->handle, &acpi_parent);
1739 
1740 	pdev = acpi_get_pci_dev(acpi_parent);
1741 	if (pdev) {
1742 		parent = &pdev->dev;
1743 		pci_dev_put(pdev);
1744 	}
1745 
1746 	memset(&props, 0, sizeof(struct backlight_properties));
1747 	props.type = BACKLIGHT_FIRMWARE;
1748 	props.max_brightness =
1749 		device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1750 	device->backlight = backlight_device_register(name,
1751 						      parent,
1752 						      device,
1753 						      &acpi_backlight_ops,
1754 						      &props);
1755 	kfree(name);
1756 	if (IS_ERR(device->backlight)) {
1757 		device->backlight = NULL;
1758 		return;
1759 	}
1760 
1761 	/*
1762 	 * Save current brightness level in case we have to restore it
1763 	 * before acpi_video_device_lcd_set_level() is called next time.
1764 	 */
1765 	device->backlight->props.brightness =
1766 			acpi_video_get_brightness(device->backlight);
1767 
1768 	device->cooling_dev = thermal_cooling_device_register("LCD",
1769 				device->dev, &video_cooling_ops);
1770 	if (IS_ERR(device->cooling_dev)) {
1771 		/*
1772 		 * Set cooling_dev to NULL so we don't crash trying to free it.
1773 		 * Also, why the hell we are returning early and not attempt to
1774 		 * register video output if cooling device registration failed?
1775 		 * -- dtor
1776 		 */
1777 		device->cooling_dev = NULL;
1778 		return;
1779 	}
1780 
1781 	dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1782 		 device->cooling_dev->id);
1783 	result = sysfs_create_link(&device->dev->dev.kobj,
1784 			&device->cooling_dev->device.kobj,
1785 			"thermal_cooling");
1786 	if (result)
1787 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1788 	result = sysfs_create_link(&device->cooling_dev->device.kobj,
1789 			&device->dev->dev.kobj, "device");
1790 	if (result)
1791 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1792 }
1793 
1794 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1795 {
1796 	struct acpi_video_device *dev;
1797 	union acpi_object *levels;
1798 
1799 	mutex_lock(&video->device_list_lock);
1800 	list_for_each_entry(dev, &video->video_device_list, entry) {
1801 		if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1802 			kfree(levels);
1803 	}
1804 	mutex_unlock(&video->device_list_lock);
1805 }
1806 
1807 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1808 {
1809 	/*
1810 	 * Do not create backlight device for video output
1811 	 * device that is not in the enumerated list.
1812 	 */
1813 	if (!acpi_video_device_in_dod(dev)) {
1814 		dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1815 		return false;
1816 	}
1817 
1818 	if (only_lcd)
1819 		return dev->flags.lcd;
1820 	return true;
1821 }
1822 
1823 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1824 {
1825 	struct acpi_video_device *dev;
1826 
1827 	if (video->backlight_registered)
1828 		return 0;
1829 
1830 	acpi_video_run_bcl_for_osi(video);
1831 
1832 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
1833 		return 0;
1834 
1835 	mutex_lock(&video->device_list_lock);
1836 	list_for_each_entry(dev, &video->video_device_list, entry) {
1837 		if (acpi_video_should_register_backlight(dev))
1838 			acpi_video_dev_register_backlight(dev);
1839 	}
1840 	mutex_unlock(&video->device_list_lock);
1841 
1842 	video->backlight_registered = true;
1843 
1844 	video->pm_nb.notifier_call = acpi_video_resume;
1845 	video->pm_nb.priority = 0;
1846 	return register_pm_notifier(&video->pm_nb);
1847 }
1848 
1849 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1850 {
1851 	if (device->backlight) {
1852 		backlight_device_unregister(device->backlight);
1853 		device->backlight = NULL;
1854 	}
1855 	if (device->brightness) {
1856 		kfree(device->brightness->levels);
1857 		kfree(device->brightness);
1858 		device->brightness = NULL;
1859 	}
1860 	if (device->cooling_dev) {
1861 		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1862 		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1863 		thermal_cooling_device_unregister(device->cooling_dev);
1864 		device->cooling_dev = NULL;
1865 	}
1866 }
1867 
1868 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1869 {
1870 	struct acpi_video_device *dev;
1871 	int error;
1872 
1873 	if (!video->backlight_registered)
1874 		return 0;
1875 
1876 	error = unregister_pm_notifier(&video->pm_nb);
1877 
1878 	mutex_lock(&video->device_list_lock);
1879 	list_for_each_entry(dev, &video->video_device_list, entry)
1880 		acpi_video_dev_unregister_backlight(dev);
1881 	mutex_unlock(&video->device_list_lock);
1882 
1883 	video->backlight_registered = false;
1884 
1885 	return error;
1886 }
1887 
1888 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1889 {
1890 	acpi_status status;
1891 	struct acpi_device *adev = device->dev;
1892 
1893 	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1894 					     acpi_video_device_notify, device);
1895 	if (ACPI_FAILURE(status))
1896 		dev_err(&adev->dev, "Error installing notify handler\n");
1897 	else
1898 		device->flags.notify = 1;
1899 }
1900 
1901 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1902 {
1903 	struct input_dev *input;
1904 	struct acpi_video_device *dev;
1905 	int error;
1906 
1907 	video->input = input = input_allocate_device();
1908 	if (!input) {
1909 		error = -ENOMEM;
1910 		goto out;
1911 	}
1912 
1913 	error = acpi_video_bus_start_devices(video);
1914 	if (error)
1915 		goto err_free_input;
1916 
1917 	snprintf(video->phys, sizeof(video->phys),
1918 			"%s/video/input0", acpi_device_hid(video->device));
1919 
1920 	input->name = acpi_device_name(video->device);
1921 	input->phys = video->phys;
1922 	input->id.bustype = BUS_HOST;
1923 	input->id.product = 0x06;
1924 	input->dev.parent = &video->device->dev;
1925 	input->evbit[0] = BIT(EV_KEY);
1926 	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1927 	set_bit(KEY_VIDEO_NEXT, input->keybit);
1928 	set_bit(KEY_VIDEO_PREV, input->keybit);
1929 	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1930 	set_bit(KEY_BRIGHTNESSUP, input->keybit);
1931 	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1932 	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1933 	set_bit(KEY_DISPLAY_OFF, input->keybit);
1934 
1935 	error = input_register_device(input);
1936 	if (error)
1937 		goto err_stop_dev;
1938 
1939 	mutex_lock(&video->device_list_lock);
1940 	list_for_each_entry(dev, &video->video_device_list, entry)
1941 		acpi_video_dev_add_notify_handler(dev);
1942 	mutex_unlock(&video->device_list_lock);
1943 
1944 	return 0;
1945 
1946 err_stop_dev:
1947 	acpi_video_bus_stop_devices(video);
1948 err_free_input:
1949 	input_free_device(input);
1950 	video->input = NULL;
1951 out:
1952 	return error;
1953 }
1954 
1955 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1956 {
1957 	if (dev->flags.notify) {
1958 		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1959 					   acpi_video_device_notify);
1960 		dev->flags.notify = 0;
1961 	}
1962 }
1963 
1964 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1965 {
1966 	struct acpi_video_device *dev;
1967 
1968 	mutex_lock(&video->device_list_lock);
1969 	list_for_each_entry(dev, &video->video_device_list, entry)
1970 		acpi_video_dev_remove_notify_handler(dev);
1971 	mutex_unlock(&video->device_list_lock);
1972 
1973 	acpi_video_bus_stop_devices(video);
1974 	input_unregister_device(video->input);
1975 	video->input = NULL;
1976 }
1977 
1978 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1979 {
1980 	struct acpi_video_device *dev, *next;
1981 
1982 	mutex_lock(&video->device_list_lock);
1983 	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1984 		list_del(&dev->entry);
1985 		kfree(dev);
1986 	}
1987 	mutex_unlock(&video->device_list_lock);
1988 
1989 	return 0;
1990 }
1991 
1992 static int instance;
1993 
1994 static int acpi_video_bus_add(struct acpi_device *device)
1995 {
1996 	struct acpi_video_bus *video;
1997 	int error;
1998 	acpi_status status;
1999 
2000 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2001 				device->parent->handle, 1,
2002 				acpi_video_bus_match, NULL,
2003 				device, NULL);
2004 	if (status == AE_ALREADY_EXISTS) {
2005 		printk(KERN_WARNING FW_BUG
2006 			"Duplicate ACPI video bus devices for the"
2007 			" same VGA controller, please try module "
2008 			"parameter \"video.allow_duplicates=1\""
2009 			"if the current driver doesn't work.\n");
2010 		if (!allow_duplicates)
2011 			return -ENODEV;
2012 	}
2013 
2014 	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2015 	if (!video)
2016 		return -ENOMEM;
2017 
2018 	/* a hack to fix the duplicate name "VID" problem on T61 */
2019 	if (!strcmp(device->pnp.bus_id, "VID")) {
2020 		if (instance)
2021 			device->pnp.bus_id[3] = '0' + instance;
2022 		instance++;
2023 	}
2024 	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2025 	if (!strcmp(device->pnp.bus_id, "VGA")) {
2026 		if (instance)
2027 			device->pnp.bus_id[3] = '0' + instance;
2028 		instance++;
2029 	}
2030 
2031 	video->device = device;
2032 	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2033 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2034 	device->driver_data = video;
2035 
2036 	acpi_video_bus_find_cap(video);
2037 	error = acpi_video_bus_check(video);
2038 	if (error)
2039 		goto err_free_video;
2040 
2041 	mutex_init(&video->device_list_lock);
2042 	INIT_LIST_HEAD(&video->video_device_list);
2043 
2044 	error = acpi_video_bus_get_devices(video, device);
2045 	if (error)
2046 		goto err_put_video;
2047 
2048 	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2049 	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2050 	       video->flags.multihead ? "yes" : "no",
2051 	       video->flags.rom ? "yes" : "no",
2052 	       video->flags.post ? "yes" : "no");
2053 	mutex_lock(&video_list_lock);
2054 	list_add_tail(&video->entry, &video_bus_head);
2055 	mutex_unlock(&video_list_lock);
2056 
2057 	acpi_video_bus_register_backlight(video);
2058 	acpi_video_bus_add_notify_handler(video);
2059 
2060 	return 0;
2061 
2062 err_put_video:
2063 	acpi_video_bus_put_devices(video);
2064 	kfree(video->attached_array);
2065 err_free_video:
2066 	kfree(video);
2067 	device->driver_data = NULL;
2068 
2069 	return error;
2070 }
2071 
2072 static int acpi_video_bus_remove(struct acpi_device *device)
2073 {
2074 	struct acpi_video_bus *video = NULL;
2075 
2076 
2077 	if (!device || !acpi_driver_data(device))
2078 		return -EINVAL;
2079 
2080 	video = acpi_driver_data(device);
2081 
2082 	acpi_video_bus_remove_notify_handler(video);
2083 	acpi_video_bus_unregister_backlight(video);
2084 	acpi_video_bus_put_devices(video);
2085 
2086 	mutex_lock(&video_list_lock);
2087 	list_del(&video->entry);
2088 	mutex_unlock(&video_list_lock);
2089 
2090 	kfree(video->attached_array);
2091 	kfree(video);
2092 
2093 	return 0;
2094 }
2095 
2096 static int __init is_i740(struct pci_dev *dev)
2097 {
2098 	if (dev->device == 0x00D1)
2099 		return 1;
2100 	if (dev->device == 0x7000)
2101 		return 1;
2102 	return 0;
2103 }
2104 
2105 static int __init intel_opregion_present(void)
2106 {
2107 	int opregion = 0;
2108 	struct pci_dev *dev = NULL;
2109 	u32 address;
2110 
2111 	for_each_pci_dev(dev) {
2112 		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2113 			continue;
2114 		if (dev->vendor != PCI_VENDOR_ID_INTEL)
2115 			continue;
2116 		/* We don't want to poke around undefined i740 registers */
2117 		if (is_i740(dev))
2118 			continue;
2119 		pci_read_config_dword(dev, 0xfc, &address);
2120 		if (!address)
2121 			continue;
2122 		opregion = 1;
2123 	}
2124 	return opregion;
2125 }
2126 
2127 static bool dmi_is_desktop(void)
2128 {
2129 	const char *chassis_type;
2130 
2131 	chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2132 	if (!chassis_type)
2133 		return false;
2134 
2135 	if (!strcmp(chassis_type, "3") || /*  3: Desktop */
2136 	    !strcmp(chassis_type, "4") || /*  4: Low Profile Desktop */
2137 	    !strcmp(chassis_type, "5") || /*  5: Pizza Box */
2138 	    !strcmp(chassis_type, "6") || /*  6: Mini Tower */
2139 	    !strcmp(chassis_type, "7") || /*  7: Tower */
2140 	    !strcmp(chassis_type, "11"))  /* 11: Main Server Chassis */
2141 		return true;
2142 
2143 	return false;
2144 }
2145 
2146 int acpi_video_register(void)
2147 {
2148 	int ret = 0;
2149 
2150 	mutex_lock(&register_count_mutex);
2151 	if (register_count) {
2152 		/*
2153 		 * if the function of acpi_video_register is already called,
2154 		 * don't register the acpi_vide_bus again and return no error.
2155 		 */
2156 		goto leave;
2157 	}
2158 
2159 	/*
2160 	 * We're seeing a lot of bogus backlight interfaces on newer machines
2161 	 * without a LCD such as desktops, servers and HDMI sticks. Checking
2162 	 * the lcd flag fixes this, so enable this on any machines which are
2163 	 * win8 ready (where we also prefer the native backlight driver, so
2164 	 * normally the acpi_video code should not register there anyways).
2165 	 */
2166 	if (only_lcd == -1) {
2167 		if (dmi_is_desktop() && acpi_osi_is_win8())
2168 			only_lcd = true;
2169 		else
2170 			only_lcd = false;
2171 	}
2172 
2173 	dmi_check_system(video_dmi_table);
2174 
2175 	ret = acpi_bus_register_driver(&acpi_video_bus);
2176 	if (ret)
2177 		goto leave;
2178 
2179 	/*
2180 	 * When the acpi_video_bus is loaded successfully, increase
2181 	 * the counter reference.
2182 	 */
2183 	register_count = 1;
2184 
2185 leave:
2186 	mutex_unlock(&register_count_mutex);
2187 	return ret;
2188 }
2189 EXPORT_SYMBOL(acpi_video_register);
2190 
2191 void acpi_video_unregister(void)
2192 {
2193 	mutex_lock(&register_count_mutex);
2194 	if (register_count) {
2195 		acpi_bus_unregister_driver(&acpi_video_bus);
2196 		register_count = 0;
2197 	}
2198 	mutex_unlock(&register_count_mutex);
2199 }
2200 EXPORT_SYMBOL(acpi_video_unregister);
2201 
2202 void acpi_video_unregister_backlight(void)
2203 {
2204 	struct acpi_video_bus *video;
2205 
2206 	mutex_lock(&register_count_mutex);
2207 	if (register_count) {
2208 		mutex_lock(&video_list_lock);
2209 		list_for_each_entry(video, &video_bus_head, entry)
2210 			acpi_video_bus_unregister_backlight(video);
2211 		mutex_unlock(&video_list_lock);
2212 	}
2213 	mutex_unlock(&register_count_mutex);
2214 }
2215 
2216 bool acpi_video_handles_brightness_key_presses(void)
2217 {
2218 	bool have_video_busses;
2219 
2220 	mutex_lock(&video_list_lock);
2221 	have_video_busses = !list_empty(&video_bus_head);
2222 	mutex_unlock(&video_list_lock);
2223 
2224 	return have_video_busses &&
2225 	       (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2226 }
2227 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2228 
2229 /*
2230  * This is kind of nasty. Hardware using Intel chipsets may require
2231  * the video opregion code to be run first in order to initialise
2232  * state before any ACPI video calls are made. To handle this we defer
2233  * registration of the video class until the opregion code has run.
2234  */
2235 
2236 static int __init acpi_video_init(void)
2237 {
2238 	/*
2239 	 * Let the module load even if ACPI is disabled (e.g. due to
2240 	 * a broken BIOS) so that i915.ko can still be loaded on such
2241 	 * old systems without an AcpiOpRegion.
2242 	 *
2243 	 * acpi_video_register() will report -ENODEV later as well due
2244 	 * to acpi_disabled when i915.ko tries to register itself afterwards.
2245 	 */
2246 	if (acpi_disabled)
2247 		return 0;
2248 
2249 	if (intel_opregion_present())
2250 		return 0;
2251 
2252 	return acpi_video_register();
2253 }
2254 
2255 static void __exit acpi_video_exit(void)
2256 {
2257 	acpi_video_detect_exit();
2258 	acpi_video_unregister();
2259 
2260 	return;
2261 }
2262 
2263 module_init(acpi_video_init);
2264 module_exit(acpi_video_exit);
2265