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   1/*
   2 *  video.c - ACPI Video Driver
   3 *
   4 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   5 *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   6 *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   7 *
   8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or (at
  13 *  your option) any later version.
  14 *
  15 *  This program is distributed in the hope that it will be useful, but
  16 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 *  General Public License for more details.
  19 *
  20 *  You should have received a copy of the GNU General Public License along
  21 *  with this program; if not, write to the Free Software Foundation, Inc.,
  22 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23 *
  24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25 */
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/init.h>
  30#include <linux/types.h>
  31#include <linux/list.h>
  32#include <linux/mutex.h>
  33#include <linux/input.h>
  34#include <linux/backlight.h>
  35#include <linux/thermal.h>
  36#include <linux/sort.h>
  37#include <linux/pci.h>
  38#include <linux/pci_ids.h>
  39#include <linux/slab.h>
  40#include <linux/dmi.h>
  41#include <linux/suspend.h>
  42#include <linux/acpi.h>
  43#include <acpi/video.h>
  44#include <asm/uaccess.h>
  45
  46#include "internal.h"
  47
  48#define ACPI_VIDEO_BUS_NAME		"Video Bus"
  49#define ACPI_VIDEO_DEVICE_NAME		"Video Device"
  50#define ACPI_VIDEO_NOTIFY_SWITCH	0x80
  51#define ACPI_VIDEO_NOTIFY_PROBE		0x81
  52#define ACPI_VIDEO_NOTIFY_CYCLE		0x82
  53#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT	0x83
  54#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT	0x84
  55
  56#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS	0x85
  57#define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x86
  58#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x87
  59#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x88
  60#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x89
  61
  62#define MAX_NAME_LEN	20
  63
  64#define _COMPONENT		ACPI_VIDEO_COMPONENT
  65ACPI_MODULE_NAME("video");
  66
  67MODULE_AUTHOR("Bruno Ducrot");
  68MODULE_DESCRIPTION("ACPI Video Driver");
  69MODULE_LICENSE("GPL");
  70
  71static bool brightness_switch_enabled = 1;
  72module_param(brightness_switch_enabled, bool, 0644);
  73
  74/*
  75 * By default, we don't allow duplicate ACPI video bus devices
  76 * under the same VGA controller
  77 */
  78static bool allow_duplicates;
  79module_param(allow_duplicates, bool, 0644);
  80
  81/*
  82 * For Windows 8 systems: used to decide if video module
  83 * should skip registering backlight interface of its own.
  84 */
  85static int use_native_backlight_param = -1;
  86module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
  87static bool use_native_backlight_dmi = false;
  88
  89static int register_count;
  90static struct mutex video_list_lock;
  91static struct list_head video_bus_head;
  92static int acpi_video_bus_add(struct acpi_device *device);
  93static int acpi_video_bus_remove(struct acpi_device *device);
  94static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  95
  96static const struct acpi_device_id video_device_ids[] = {
  97	{ACPI_VIDEO_HID, 0},
  98	{"", 0},
  99};
 100MODULE_DEVICE_TABLE(acpi, video_device_ids);
 101
 102static struct acpi_driver acpi_video_bus = {
 103	.name = "video",
 104	.class = ACPI_VIDEO_CLASS,
 105	.ids = video_device_ids,
 106	.ops = {
 107		.add = acpi_video_bus_add,
 108		.remove = acpi_video_bus_remove,
 109		.notify = acpi_video_bus_notify,
 110		},
 111};
 112
 113struct acpi_video_bus_flags {
 114	u8 multihead:1;		/* can switch video heads */
 115	u8 rom:1;		/* can retrieve a video rom */
 116	u8 post:1;		/* can configure the head to */
 117	u8 reserved:5;
 118};
 119
 120struct acpi_video_bus_cap {
 121	u8 _DOS:1;		/* Enable/Disable output switching */
 122	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
 123	u8 _ROM:1;		/* Get ROM Data */
 124	u8 _GPD:1;		/* Get POST Device */
 125	u8 _SPD:1;		/* Set POST Device */
 126	u8 _VPO:1;		/* Video POST Options */
 127	u8 reserved:2;
 128};
 129
 130struct acpi_video_device_attrib {
 131	u32 display_index:4;	/* A zero-based instance of the Display */
 132	u32 display_port_attachment:4;	/* This field differentiates the display type */
 133	u32 display_type:4;	/* Describe the specific type in use */
 134	u32 vendor_specific:4;	/* Chipset Vendor Specific */
 135	u32 bios_can_detect:1;	/* BIOS can detect the device */
 136	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
 137				   the VGA device. */
 138	u32 pipe_id:3;		/* For VGA multiple-head devices. */
 139	u32 reserved:10;	/* Must be 0 */
 140	u32 device_id_scheme:1;	/* Device ID Scheme */
 141};
 142
 143struct acpi_video_enumerated_device {
 144	union {
 145		u32 int_val;
 146		struct acpi_video_device_attrib attrib;
 147	} value;
 148	struct acpi_video_device *bind_info;
 149};
 150
 151struct acpi_video_bus {
 152	struct acpi_device *device;
 153	u8 dos_setting;
 154	struct acpi_video_enumerated_device *attached_array;
 155	u8 attached_count;
 156	struct acpi_video_bus_cap cap;
 157	struct acpi_video_bus_flags flags;
 158	struct list_head video_device_list;
 159	struct mutex device_list_lock;	/* protects video_device_list */
 160	struct list_head entry;
 161	struct input_dev *input;
 162	char phys[32];	/* for input device */
 163	struct notifier_block pm_nb;
 164};
 165
 166struct acpi_video_device_flags {
 167	u8 crt:1;
 168	u8 lcd:1;
 169	u8 tvout:1;
 170	u8 dvi:1;
 171	u8 bios:1;
 172	u8 unknown:1;
 173	u8 notify:1;
 174	u8 reserved:1;
 175};
 176
 177struct acpi_video_device_cap {
 178	u8 _ADR:1;		/* Return the unique ID */
 179	u8 _BCL:1;		/* Query list of brightness control levels supported */
 180	u8 _BCM:1;		/* Set the brightness level */
 181	u8 _BQC:1;		/* Get current brightness level */
 182	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
 183	u8 _DDC:1;		/* Return the EDID for this device */
 184};
 185
 186struct acpi_video_brightness_flags {
 187	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */
 188	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order */
 189	u8 _BQC_use_index:1;		/* _BQC returns an index value */
 190};
 191
 192struct acpi_video_device_brightness {
 193	int curr;
 194	int count;
 195	int *levels;
 196	struct acpi_video_brightness_flags flags;
 197};
 198
 199struct acpi_video_device {
 200	unsigned long device_id;
 201	struct acpi_video_device_flags flags;
 202	struct acpi_video_device_cap cap;
 203	struct list_head entry;
 204	struct acpi_video_bus *video;
 205	struct acpi_device *dev;
 206	struct acpi_video_device_brightness *brightness;
 207	struct backlight_device *backlight;
 208	struct thermal_cooling_device *cooling_dev;
 209};
 210
 211static const char device_decode[][30] = {
 212	"motherboard VGA device",
 213	"PCI VGA device",
 214	"AGP VGA device",
 215	"UNKNOWN",
 216};
 217
 218static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 219static void acpi_video_device_rebind(struct acpi_video_bus *video);
 220static void acpi_video_device_bind(struct acpi_video_bus *video,
 221				   struct acpi_video_device *device);
 222static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 223static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 224			int level);
 225static int acpi_video_device_lcd_get_level_current(
 226			struct acpi_video_device *device,
 227			unsigned long long *level, bool raw);
 228static int acpi_video_get_next_level(struct acpi_video_device *device,
 229				     u32 level_current, u32 event);
 230static int acpi_video_switch_brightness(struct acpi_video_device *device,
 231					 int event);
 232
 233static bool acpi_video_use_native_backlight(void)
 234{
 235	if (use_native_backlight_param != -1)
 236		return use_native_backlight_param;
 237	else
 238		return use_native_backlight_dmi;
 239}
 240
 241static bool acpi_video_verify_backlight_support(void)
 242{
 243	if (acpi_osi_is_win8() && acpi_video_use_native_backlight() &&
 244	    backlight_device_registered(BACKLIGHT_RAW))
 245		return false;
 246	return acpi_video_backlight_support();
 247}
 248
 249/* backlight device sysfs support */
 250static int acpi_video_get_brightness(struct backlight_device *bd)
 251{
 252	unsigned long long cur_level;
 253	int i;
 254	struct acpi_video_device *vd = bl_get_data(bd);
 255
 256	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 257		return -EINVAL;
 258	for (i = 2; i < vd->brightness->count; i++) {
 259		if (vd->brightness->levels[i] == cur_level)
 260			/*
 261			 * The first two entries are special - see page 575
 262			 * of the ACPI spec 3.0
 263			 */
 264			return i - 2;
 265	}
 266	return 0;
 267}
 268
 269static int acpi_video_set_brightness(struct backlight_device *bd)
 270{
 271	int request_level = bd->props.brightness + 2;
 272	struct acpi_video_device *vd = bl_get_data(bd);
 273
 274	return acpi_video_device_lcd_set_level(vd,
 275				vd->brightness->levels[request_level]);
 276}
 277
 278static const struct backlight_ops acpi_backlight_ops = {
 279	.get_brightness = acpi_video_get_brightness,
 280	.update_status  = acpi_video_set_brightness,
 281};
 282
 283/* thermal cooling device callbacks */
 284static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
 285			       long *state)
 286{
 287	struct acpi_device *device = cooling_dev->devdata;
 288	struct acpi_video_device *video = acpi_driver_data(device);
 289
 290	*state = video->brightness->count - 3;
 291	return 0;
 292}
 293
 294static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
 295			       long *state)
 296{
 297	struct acpi_device *device = cooling_dev->devdata;
 298	struct acpi_video_device *video = acpi_driver_data(device);
 299	unsigned long long level;
 300	int offset;
 301
 302	if (acpi_video_device_lcd_get_level_current(video, &level, false))
 303		return -EINVAL;
 304	for (offset = 2; offset < video->brightness->count; offset++)
 305		if (level == video->brightness->levels[offset]) {
 306			*state = video->brightness->count - offset - 1;
 307			return 0;
 308		}
 309
 310	return -EINVAL;
 311}
 312
 313static int
 314video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 315{
 316	struct acpi_device *device = cooling_dev->devdata;
 317	struct acpi_video_device *video = acpi_driver_data(device);
 318	int level;
 319
 320	if (state >= video->brightness->count - 2)
 321		return -EINVAL;
 322
 323	state = video->brightness->count - state;
 324	level = video->brightness->levels[state - 1];
 325	return acpi_video_device_lcd_set_level(video, level);
 326}
 327
 328static const struct thermal_cooling_device_ops video_cooling_ops = {
 329	.get_max_state = video_get_max_state,
 330	.get_cur_state = video_get_cur_state,
 331	.set_cur_state = video_set_cur_state,
 332};
 333
 334/*
 335 * --------------------------------------------------------------------------
 336 *                             Video Management
 337 * --------------------------------------------------------------------------
 338 */
 339
 340static int
 341acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
 342				   union acpi_object **levels)
 343{
 344	int status;
 345	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 346	union acpi_object *obj;
 347
 348
 349	*levels = NULL;
 350
 351	status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
 352	if (!ACPI_SUCCESS(status))
 353		return status;
 354	obj = (union acpi_object *)buffer.pointer;
 355	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 356		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 357		status = -EFAULT;
 358		goto err;
 359	}
 360
 361	*levels = obj;
 362
 363	return 0;
 364
 365err:
 366	kfree(buffer.pointer);
 367
 368	return status;
 369}
 370
 371static int
 372acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 373{
 374	int status;
 375	int state;
 376
 377	status = acpi_execute_simple_method(device->dev->handle,
 378					    "_BCM", level);
 379	if (ACPI_FAILURE(status)) {
 380		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 381		return -EIO;
 382	}
 383
 384	device->brightness->curr = level;
 385	for (state = 2; state < device->brightness->count; state++)
 386		if (level == device->brightness->levels[state]) {
 387			if (device->backlight)
 388				device->backlight->props.brightness = state - 2;
 389			return 0;
 390		}
 391
 392	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 393	return -EINVAL;
 394}
 395
 396/*
 397 * For some buggy _BQC methods, we need to add a constant value to
 398 * the _BQC return value to get the actual current brightness level
 399 */
 400
 401static int bqc_offset_aml_bug_workaround;
 402static int __init video_set_bqc_offset(const struct dmi_system_id *d)
 403{
 404	bqc_offset_aml_bug_workaround = 9;
 405	return 0;
 406}
 407
 408static int __init video_set_use_native_backlight(const struct dmi_system_id *d)
 409{
 410	use_native_backlight_dmi = true;
 411	return 0;
 412}
 413
 414static struct dmi_system_id video_dmi_table[] __initdata = {
 415	/*
 416	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 417	 */
 418	{
 419	 .callback = video_set_bqc_offset,
 420	 .ident = "Acer Aspire 5720",
 421	 .matches = {
 422		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 423		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 424		},
 425	},
 426	{
 427	 .callback = video_set_bqc_offset,
 428	 .ident = "Acer Aspire 5710Z",
 429	 .matches = {
 430		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 431		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 432		},
 433	},
 434	{
 435	 .callback = video_set_bqc_offset,
 436	 .ident = "eMachines E510",
 437	 .matches = {
 438		DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 439		DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 440		},
 441	},
 442	{
 443	 .callback = video_set_bqc_offset,
 444	 .ident = "Acer Aspire 5315",
 445	 .matches = {
 446		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 447		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 448		},
 449	},
 450	{
 451	 .callback = video_set_bqc_offset,
 452	 .ident = "Acer Aspire 7720",
 453	 .matches = {
 454		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 455		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 456		},
 457	},
 458	{
 459	 .callback = video_set_use_native_backlight,
 460	 .ident = "ThinkPad T430 and T430s",
 461	 .matches = {
 462		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 463		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T430"),
 464		},
 465	},
 466	{
 467	 .callback = video_set_use_native_backlight,
 468	 .ident = "ThinkPad X230",
 469	 .matches = {
 470		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 471		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X230"),
 472		},
 473	},
 474	{
 475	 .callback = video_set_use_native_backlight,
 476	.ident = "ThinkPad X1 Carbon",
 477	.matches = {
 478		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 479		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X1 Carbon"),
 480		},
 481	},
 482	{
 483	 .callback = video_set_use_native_backlight,
 484	 .ident = "Lenovo Yoga 13",
 485	 .matches = {
 486		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 487		DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Yoga 13"),
 488		},
 489	},
 490	{
 491	.callback = video_set_use_native_backlight,
 492	.ident = "Thinkpad Helix",
 493	.matches = {
 494		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 495		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad Helix"),
 496		},
 497	},
 498	{
 499	 .callback = video_set_use_native_backlight,
 500	 .ident = "Dell Inspiron 7520",
 501	 .matches = {
 502		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 503		DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7520"),
 504		},
 505	},
 506	{
 507	 .callback = video_set_use_native_backlight,
 508	 .ident = "Acer Aspire 5733Z",
 509	 .matches = {
 510		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 511		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5733Z"),
 512		},
 513	},
 514	{
 515	 .callback = video_set_use_native_backlight,
 516	 .ident = "Acer Aspire 5742G",
 517	 .matches = {
 518		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 519		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5742G"),
 520		},
 521	},
 522	{
 523	 .callback = video_set_use_native_backlight,
 524	 .ident = "Acer Aspire V5-431",
 525	 .matches = {
 526		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 527		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-431"),
 528		},
 529	},
 530	{
 531	.callback = video_set_use_native_backlight,
 532	.ident = "HP ProBook 4340s",
 533	.matches = {
 534		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 535		DMI_MATCH(DMI_PRODUCT_VERSION, "HP ProBook 4340s"),
 536		},
 537	},
 538	{
 539	.callback = video_set_use_native_backlight,
 540	.ident = "HP ProBook 2013 models",
 541	.matches = {
 542		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 543		DMI_MATCH(DMI_PRODUCT_NAME, "HP ProBook "),
 544		DMI_MATCH(DMI_PRODUCT_NAME, " G1"),
 545		},
 546	},
 547	{
 548	.callback = video_set_use_native_backlight,
 549	.ident = "HP EliteBook 2013 models",
 550	.matches = {
 551		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 552		DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook "),
 553		DMI_MATCH(DMI_PRODUCT_NAME, " G1"),
 554		},
 555	},
 556	{
 557	.callback = video_set_use_native_backlight,
 558	.ident = "HP ZBook 14",
 559	.matches = {
 560		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 561		DMI_MATCH(DMI_PRODUCT_NAME, "HP ZBook 14"),
 562		},
 563	},
 564	{
 565	.callback = video_set_use_native_backlight,
 566	.ident = "HP ZBook 15",
 567	.matches = {
 568		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 569		DMI_MATCH(DMI_PRODUCT_NAME, "HP ZBook 15"),
 570		},
 571	},
 572	{
 573	.callback = video_set_use_native_backlight,
 574	.ident = "HP ZBook 17",
 575	.matches = {
 576		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 577		DMI_MATCH(DMI_PRODUCT_NAME, "HP ZBook 17"),
 578		},
 579	},
 580	{
 581	.callback = video_set_use_native_backlight,
 582	.ident = "HP EliteBook 8780w",
 583	.matches = {
 584		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 585		DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8780w"),
 586		},
 587	},
 588	{}
 589};
 590
 591static unsigned long long
 592acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 593			      unsigned long long bqc_value)
 594{
 595	unsigned long long level;
 596
 597	if (device->brightness->flags._BQC_use_index) {
 598		/*
 599		 * _BQC returns an index that doesn't account for
 600		 * the first 2 items with special meaning, so we need
 601		 * to compensate for that by offsetting ourselves
 602		 */
 603		if (device->brightness->flags._BCL_reversed)
 604			bqc_value = device->brightness->count - 3 - bqc_value;
 605
 606		level = device->brightness->levels[bqc_value + 2];
 607	} else {
 608		level = bqc_value;
 609	}
 610
 611	level += bqc_offset_aml_bug_workaround;
 612
 613	return level;
 614}
 615
 616static int
 617acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 618					unsigned long long *level, bool raw)
 619{
 620	acpi_status status = AE_OK;
 621	int i;
 622
 623	if (device->cap._BQC || device->cap._BCQ) {
 624		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 625
 626		status = acpi_evaluate_integer(device->dev->handle, buf,
 627						NULL, level);
 628		if (ACPI_SUCCESS(status)) {
 629			if (raw) {
 630				/*
 631				 * Caller has indicated he wants the raw
 632				 * value returned by _BQC, so don't furtherly
 633				 * mess with the value.
 634				 */
 635				return 0;
 636			}
 637
 638			*level = acpi_video_bqc_value_to_level(device, *level);
 639
 640			for (i = 2; i < device->brightness->count; i++)
 641				if (device->brightness->levels[i] == *level) {
 642					device->brightness->curr = *level;
 643					return 0;
 644				}
 645			/*
 646			 * BQC returned an invalid level.
 647			 * Stop using it.
 648			 */
 649			ACPI_WARNING((AE_INFO,
 650				      "%s returned an invalid level",
 651				      buf));
 652			device->cap._BQC = device->cap._BCQ = 0;
 653		} else {
 654			/*
 655			 * Fixme:
 656			 * should we return an error or ignore this failure?
 657			 * dev->brightness->curr is a cached value which stores
 658			 * the correct current backlight level in most cases.
 659			 * ACPI video backlight still works w/ buggy _BQC.
 660			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 661			 */
 662			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 663			device->cap._BQC = device->cap._BCQ = 0;
 664		}
 665	}
 666
 667	*level = device->brightness->curr;
 668	return 0;
 669}
 670
 671static int
 672acpi_video_device_EDID(struct acpi_video_device *device,
 673		       union acpi_object **edid, ssize_t length)
 674{
 675	int status;
 676	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 677	union acpi_object *obj;
 678	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 679	struct acpi_object_list args = { 1, &arg0 };
 680
 681
 682	*edid = NULL;
 683
 684	if (!device)
 685		return -ENODEV;
 686	if (length == 128)
 687		arg0.integer.value = 1;
 688	else if (length == 256)
 689		arg0.integer.value = 2;
 690	else
 691		return -EINVAL;
 692
 693	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 694	if (ACPI_FAILURE(status))
 695		return -ENODEV;
 696
 697	obj = buffer.pointer;
 698
 699	if (obj && obj->type == ACPI_TYPE_BUFFER)
 700		*edid = obj;
 701	else {
 702		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 703		status = -EFAULT;
 704		kfree(obj);
 705	}
 706
 707	return status;
 708}
 709
 710/* bus */
 711
 712/*
 713 *  Arg:
 714 *	video		: video bus device pointer
 715 *	bios_flag	:
 716 *		0.	The system BIOS should NOT automatically switch(toggle)
 717 *			the active display output.
 718 *		1.	The system BIOS should automatically switch (toggle) the
 719 *			active display output. No switch event.
 720 *		2.	The _DGS value should be locked.
 721 *		3.	The system BIOS should not automatically switch (toggle) the
 722 *			active display output, but instead generate the display switch
 723 *			event notify code.
 724 *	lcd_flag	:
 725 *		0.	The system BIOS should automatically control the brightness level
 726 *			of the LCD when the power changes from AC to DC
 727 *		1.	The system BIOS should NOT automatically control the brightness
 728 *			level of the LCD when the power changes from AC to DC.
 729 *  Return Value:
 730 *		-EINVAL	wrong arg.
 731 */
 732
 733static int
 734acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 735{
 736	acpi_status status;
 737
 738	if (!video->cap._DOS)
 739		return 0;
 740
 741	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 742		return -EINVAL;
 743	video->dos_setting = (lcd_flag << 2) | bios_flag;
 744	status = acpi_execute_simple_method(video->device->handle, "_DOS",
 745					    (lcd_flag << 2) | bios_flag);
 746	if (ACPI_FAILURE(status))
 747		return -EIO;
 748
 749	return 0;
 750}
 751
 752/*
 753 * Simple comparison function used to sort backlight levels.
 754 */
 755
 756static int
 757acpi_video_cmp_level(const void *a, const void *b)
 758{
 759	return *(int *)a - *(int *)b;
 760}
 761
 762/*
 763 * Decides if _BQC/_BCQ for this system is usable
 764 *
 765 * We do this by changing the level first and then read out the current
 766 * brightness level, if the value does not match, find out if it is using
 767 * index. If not, clear the _BQC/_BCQ capability.
 768 */
 769static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 770				int max_level, int current_level)
 771{
 772	struct acpi_video_device_brightness *br = device->brightness;
 773	int result;
 774	unsigned long long level;
 775	int test_level;
 776
 777	/* don't mess with existing known broken systems */
 778	if (bqc_offset_aml_bug_workaround)
 779		return 0;
 780
 781	/*
 782	 * Some systems always report current brightness level as maximum
 783	 * through _BQC, we need to test another value for them.
 784	 */
 785	test_level = current_level == max_level ? br->levels[3] : max_level;
 786
 787	result = acpi_video_device_lcd_set_level(device, test_level);
 788	if (result)
 789		return result;
 790
 791	result = acpi_video_device_lcd_get_level_current(device, &level, true);
 792	if (result)
 793		return result;
 794
 795	if (level != test_level) {
 796		/* buggy _BQC found, need to find out if it uses index */
 797		if (level < br->count) {
 798			if (br->flags._BCL_reversed)
 799				level = br->count - 3 - level;
 800			if (br->levels[level + 2] == test_level)
 801				br->flags._BQC_use_index = 1;
 802		}
 803
 804		if (!br->flags._BQC_use_index)
 805			device->cap._BQC = device->cap._BCQ = 0;
 806	}
 807
 808	return 0;
 809}
 810
 811
 812/*
 813 *  Arg:
 814 *	device	: video output device (LCD, CRT, ..)
 815 *
 816 *  Return Value:
 817 *	Maximum brightness level
 818 *
 819 *  Allocate and initialize device->brightness.
 820 */
 821
 822static int
 823acpi_video_init_brightness(struct acpi_video_device *device)
 824{
 825	union acpi_object *obj = NULL;
 826	int i, max_level = 0, count = 0, level_ac_battery = 0;
 827	unsigned long long level, level_old;
 828	union acpi_object *o;
 829	struct acpi_video_device_brightness *br = NULL;
 830	int result = -EINVAL;
 831	u32 value;
 832
 833	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
 834		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 835						"LCD brightness level\n"));
 836		goto out;
 837	}
 838
 839	if (obj->package.count < 2)
 840		goto out;
 841
 842	br = kzalloc(sizeof(*br), GFP_KERNEL);
 843	if (!br) {
 844		printk(KERN_ERR "can't allocate memory\n");
 845		result = -ENOMEM;
 846		goto out;
 847	}
 848
 849	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 850				GFP_KERNEL);
 851	if (!br->levels) {
 852		result = -ENOMEM;
 853		goto out_free;
 854	}
 855
 856	for (i = 0; i < obj->package.count; i++) {
 857		o = (union acpi_object *)&obj->package.elements[i];
 858		if (o->type != ACPI_TYPE_INTEGER) {
 859			printk(KERN_ERR PREFIX "Invalid data\n");
 860			continue;
 861		}
 862		value = (u32) o->integer.value;
 863		/* Skip duplicate entries */
 864		if (count > 2 && br->levels[count - 1] == value)
 865			continue;
 866
 867		br->levels[count] = value;
 868
 869		if (br->levels[count] > max_level)
 870			max_level = br->levels[count];
 871		count++;
 872	}
 873
 874	/*
 875	 * some buggy BIOS don't export the levels
 876	 * when machine is on AC/Battery in _BCL package.
 877	 * In this case, the first two elements in _BCL packages
 878	 * are also supported brightness levels that OS should take care of.
 879	 */
 880	for (i = 2; i < count; i++) {
 881		if (br->levels[i] == br->levels[0])
 882			level_ac_battery++;
 883		if (br->levels[i] == br->levels[1])
 884			level_ac_battery++;
 885	}
 886
 887	if (level_ac_battery < 2) {
 888		level_ac_battery = 2 - level_ac_battery;
 889		br->flags._BCL_no_ac_battery_levels = 1;
 890		for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 891			br->levels[i] = br->levels[i - level_ac_battery];
 892		count += level_ac_battery;
 893	} else if (level_ac_battery > 2)
 894		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 895
 896	/* Check if the _BCL package is in a reversed order */
 897	if (max_level == br->levels[2]) {
 898		br->flags._BCL_reversed = 1;
 899		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 900			acpi_video_cmp_level, NULL);
 901	} else if (max_level != br->levels[count - 1])
 902		ACPI_ERROR((AE_INFO,
 903			    "Found unordered _BCL package"));
 904
 905	br->count = count;
 906	device->brightness = br;
 907
 908	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 909	br->curr = level = max_level;
 910
 911	if (!device->cap._BQC)
 912		goto set_level;
 913
 914	result = acpi_video_device_lcd_get_level_current(device,
 915							 &level_old, true);
 916	if (result)
 917		goto out_free_levels;
 918
 919	result = acpi_video_bqc_quirk(device, max_level, level_old);
 920	if (result)
 921		goto out_free_levels;
 922	/*
 923	 * cap._BQC may get cleared due to _BQC is found to be broken
 924	 * in acpi_video_bqc_quirk, so check again here.
 925	 */
 926	if (!device->cap._BQC)
 927		goto set_level;
 928
 929	level = acpi_video_bqc_value_to_level(device, level_old);
 930	/*
 931	 * On some buggy laptops, _BQC returns an uninitialized
 932	 * value when invoked for the first time, i.e.
 933	 * level_old is invalid (no matter whether it's a level
 934	 * or an index). Set the backlight to max_level in this case.
 935	 */
 936	for (i = 2; i < br->count; i++)
 937		if (level == br->levels[i])
 938			break;
 939	if (i == br->count || !level)
 940		level = max_level;
 941
 942set_level:
 943	result = acpi_video_device_lcd_set_level(device, level);
 944	if (result)
 945		goto out_free_levels;
 946
 947	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 948			  "found %d brightness levels\n", count - 2));
 949	kfree(obj);
 950	return result;
 951
 952out_free_levels:
 953	kfree(br->levels);
 954out_free:
 955	kfree(br);
 956out:
 957	device->brightness = NULL;
 958	kfree(obj);
 959	return result;
 960}
 961
 962/*
 963 *  Arg:
 964 *	device	: video output device (LCD, CRT, ..)
 965 *
 966 *  Return Value:
 967 *	None
 968 *
 969 *  Find out all required AML methods defined under the output
 970 *  device.
 971 */
 972
 973static void acpi_video_device_find_cap(struct acpi_video_device *device)
 974{
 975	if (acpi_has_method(device->dev->handle, "_ADR"))
 976		device->cap._ADR = 1;
 977	if (acpi_has_method(device->dev->handle, "_BCL"))
 978		device->cap._BCL = 1;
 979	if (acpi_has_method(device->dev->handle, "_BCM"))
 980		device->cap._BCM = 1;
 981	if (acpi_has_method(device->dev->handle, "_BQC")) {
 982		device->cap._BQC = 1;
 983	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 984		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 985		device->cap._BCQ = 1;
 986	}
 987
 988	if (acpi_has_method(device->dev->handle, "_DDC"))
 989		device->cap._DDC = 1;
 990}
 991
 992/*
 993 *  Arg:
 994 *	device	: video output device (VGA)
 995 *
 996 *  Return Value:
 997 *	None
 998 *
 999 *  Find out all required AML methods defined under the video bus device.
1000 */
1001
1002static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1003{
1004	if (acpi_has_method(video->device->handle, "_DOS"))
1005		video->cap._DOS = 1;
1006	if (acpi_has_method(video->device->handle, "_DOD"))
1007		video->cap._DOD = 1;
1008	if (acpi_has_method(video->device->handle, "_ROM"))
1009		video->cap._ROM = 1;
1010	if (acpi_has_method(video->device->handle, "_GPD"))
1011		video->cap._GPD = 1;
1012	if (acpi_has_method(video->device->handle, "_SPD"))
1013		video->cap._SPD = 1;
1014	if (acpi_has_method(video->device->handle, "_VPO"))
1015		video->cap._VPO = 1;
1016}
1017
1018/*
1019 * Check whether the video bus device has required AML method to
1020 * support the desired features
1021 */
1022
1023static int acpi_video_bus_check(struct acpi_video_bus *video)
1024{
1025	acpi_status status = -ENOENT;
1026	struct pci_dev *dev;
1027
1028	if (!video)
1029		return -EINVAL;
1030
1031	dev = acpi_get_pci_dev(video->device->handle);
1032	if (!dev)
1033		return -ENODEV;
1034	pci_dev_put(dev);
1035
1036	/*
1037	 * Since there is no HID, CID and so on for VGA driver, we have
1038	 * to check well known required nodes.
1039	 */
1040
1041	/* Does this device support video switching? */
1042	if (video->cap._DOS || video->cap._DOD) {
1043		if (!video->cap._DOS) {
1044			printk(KERN_WARNING FW_BUG
1045				"ACPI(%s) defines _DOD but not _DOS\n",
1046				acpi_device_bid(video->device));
1047		}
1048		video->flags.multihead = 1;
1049		status = 0;
1050	}
1051
1052	/* Does this device support retrieving a video ROM? */
1053	if (video->cap._ROM) {
1054		video->flags.rom = 1;
1055		status = 0;
1056	}
1057
1058	/* Does this device support configuring which video device to POST? */
1059	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1060		video->flags.post = 1;
1061		status = 0;
1062	}
1063
1064	return status;
1065}
1066
1067/*
1068 * --------------------------------------------------------------------------
1069 *                               Driver Interface
1070 * --------------------------------------------------------------------------
1071 */
1072
1073/* device interface */
1074static struct acpi_video_device_attrib *
1075acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1076{
1077	struct acpi_video_enumerated_device *ids;
1078	int i;
1079
1080	for (i = 0; i < video->attached_count; i++) {
1081		ids = &video->attached_array[i];
1082		if ((ids->value.int_val & 0xffff) == device_id)
1083			return &ids->value.attrib;
1084	}
1085
1086	return NULL;
1087}
1088
1089static int
1090acpi_video_get_device_type(struct acpi_video_bus *video,
1091			   unsigned long device_id)
1092{
1093	struct acpi_video_enumerated_device *ids;
1094	int i;
1095
1096	for (i = 0; i < video->attached_count; i++) {
1097		ids = &video->attached_array[i];
1098		if ((ids->value.int_val & 0xffff) == device_id)
1099			return ids->value.int_val;
1100	}
1101
1102	return 0;
1103}
1104
1105static int
1106acpi_video_bus_get_one_device(struct acpi_device *device,
1107			      struct acpi_video_bus *video)
1108{
1109	unsigned long long device_id;
1110	int status, device_type;
1111	struct acpi_video_device *data;
1112	struct acpi_video_device_attrib *attribute;
1113
1114	status =
1115	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1116	/* Some device omits _ADR, we skip them instead of fail */
1117	if (ACPI_FAILURE(status))
1118		return 0;
1119
1120	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1121	if (!data)
1122		return -ENOMEM;
1123
1124	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1125	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1126	device->driver_data = data;
1127
1128	data->device_id = device_id;
1129	data->video = video;
1130	data->dev = device;
1131
1132	attribute = acpi_video_get_device_attr(video, device_id);
1133
1134	if (attribute && attribute->device_id_scheme) {
1135		switch (attribute->display_type) {
1136		case ACPI_VIDEO_DISPLAY_CRT:
1137			data->flags.crt = 1;
1138			break;
1139		case ACPI_VIDEO_DISPLAY_TV:
1140			data->flags.tvout = 1;
1141			break;
1142		case ACPI_VIDEO_DISPLAY_DVI:
1143			data->flags.dvi = 1;
1144			break;
1145		case ACPI_VIDEO_DISPLAY_LCD:
1146			data->flags.lcd = 1;
1147			break;
1148		default:
1149			data->flags.unknown = 1;
1150			break;
1151		}
1152		if (attribute->bios_can_detect)
1153			data->flags.bios = 1;
1154	} else {
1155		/* Check for legacy IDs */
1156		device_type = acpi_video_get_device_type(video, device_id);
1157		/* Ignore bits 16 and 18-20 */
1158		switch (device_type & 0xffe2ffff) {
1159		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1160			data->flags.crt = 1;
1161			break;
1162		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1163			data->flags.lcd = 1;
1164			break;
1165		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1166			data->flags.tvout = 1;
1167			break;
1168		default:
1169			data->flags.unknown = 1;
1170		}
1171	}
1172
1173	acpi_video_device_bind(video, data);
1174	acpi_video_device_find_cap(data);
1175
1176	mutex_lock(&video->device_list_lock);
1177	list_add_tail(&data->entry, &video->video_device_list);
1178	mutex_unlock(&video->device_list_lock);
1179
1180	return status;
1181}
1182
1183/*
1184 *  Arg:
1185 *	video	: video bus device
1186 *
1187 *  Return:
1188 *	none
1189 *
1190 *  Enumerate the video device list of the video bus,
1191 *  bind the ids with the corresponding video devices
1192 *  under the video bus.
1193 */
1194
1195static void acpi_video_device_rebind(struct acpi_video_bus *video)
1196{
1197	struct acpi_video_device *dev;
1198
1199	mutex_lock(&video->device_list_lock);
1200
1201	list_for_each_entry(dev, &video->video_device_list, entry)
1202		acpi_video_device_bind(video, dev);
1203
1204	mutex_unlock(&video->device_list_lock);
1205}
1206
1207/*
1208 *  Arg:
1209 *	video	: video bus device
1210 *	device	: video output device under the video
1211 *		bus
1212 *
1213 *  Return:
1214 *	none
1215 *
1216 *  Bind the ids with the corresponding video devices
1217 *  under the video bus.
1218 */
1219
1220static void
1221acpi_video_device_bind(struct acpi_video_bus *video,
1222		       struct acpi_video_device *device)
1223{
1224	struct acpi_video_enumerated_device *ids;
1225	int i;
1226
1227	for (i = 0; i < video->attached_count; i++) {
1228		ids = &video->attached_array[i];
1229		if (device->device_id == (ids->value.int_val & 0xffff)) {
1230			ids->bind_info = device;
1231			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1232		}
1233	}
1234}
1235
1236/*
1237 *  Arg:
1238 *	video	: video bus device
1239 *
1240 *  Return:
1241 *	< 0	: error
1242 *
1243 *  Call _DOD to enumerate all devices attached to display adapter
1244 *
1245 */
1246
1247static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1248{
1249	int status;
1250	int count;
1251	int i;
1252	struct acpi_video_enumerated_device *active_list;
1253	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1254	union acpi_object *dod = NULL;
1255	union acpi_object *obj;
1256
1257	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1258	if (!ACPI_SUCCESS(status)) {
1259		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1260		return status;
1261	}
1262
1263	dod = buffer.pointer;
1264	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1265		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1266		status = -EFAULT;
1267		goto out;
1268	}
1269
1270	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1271			  dod->package.count));
1272
1273	active_list = kcalloc(1 + dod->package.count,
1274			      sizeof(struct acpi_video_enumerated_device),
1275			      GFP_KERNEL);
1276	if (!active_list) {
1277		status = -ENOMEM;
1278		goto out;
1279	}
1280
1281	count = 0;
1282	for (i = 0; i < dod->package.count; i++) {
1283		obj = &dod->package.elements[i];
1284
1285		if (obj->type != ACPI_TYPE_INTEGER) {
1286			printk(KERN_ERR PREFIX
1287				"Invalid _DOD data in element %d\n", i);
1288			continue;
1289		}
1290
1291		active_list[count].value.int_val = obj->integer.value;
1292		active_list[count].bind_info = NULL;
1293		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1294				  (int)obj->integer.value));
1295		count++;
1296	}
1297
1298	kfree(video->attached_array);
1299
1300	video->attached_array = active_list;
1301	video->attached_count = count;
1302
1303out:
1304	kfree(buffer.pointer);
1305	return status;
1306}
1307
1308static int
1309acpi_video_get_next_level(struct acpi_video_device *device,
1310			  u32 level_current, u32 event)
1311{
1312	int min, max, min_above, max_below, i, l, delta = 255;
1313	max = max_below = 0;
1314	min = min_above = 255;
1315	/* Find closest level to level_current */
1316	for (i = 2; i < device->brightness->count; i++) {
1317		l = device->brightness->levels[i];
1318		if (abs(l - level_current) < abs(delta)) {
1319			delta = l - level_current;
1320			if (!delta)
1321				break;
1322		}
1323	}
1324	/* Ajust level_current to closest available level */
1325	level_current += delta;
1326	for (i = 2; i < device->brightness->count; i++) {
1327		l = device->brightness->levels[i];
1328		if (l < min)
1329			min = l;
1330		if (l > max)
1331			max = l;
1332		if (l < min_above && l > level_current)
1333			min_above = l;
1334		if (l > max_below && l < level_current)
1335			max_below = l;
1336	}
1337
1338	switch (event) {
1339	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1340		return (level_current < max) ? min_above : min;
1341	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1342		return (level_current < max) ? min_above : max;
1343	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1344		return (level_current > min) ? max_below : min;
1345	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1346	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1347		return 0;
1348	default:
1349		return level_current;
1350	}
1351}
1352
1353static int
1354acpi_video_switch_brightness(struct acpi_video_device *device, int event)
1355{
1356	unsigned long long level_current, level_next;
1357	int result = -EINVAL;
1358
1359	/* no warning message if acpi_backlight=vendor or a quirk is used */
1360	if (!acpi_video_verify_backlight_support())
1361		return 0;
1362
1363	if (!device->brightness)
1364		goto out;
1365
1366	result = acpi_video_device_lcd_get_level_current(device,
1367							 &level_current,
1368							 false);
1369	if (result)
1370		goto out;
1371
1372	level_next = acpi_video_get_next_level(device, level_current, event);
1373
1374	result = acpi_video_device_lcd_set_level(device, level_next);
1375
1376	if (!result)
1377		backlight_force_update(device->backlight,
1378				       BACKLIGHT_UPDATE_HOTKEY);
1379
1380out:
1381	if (result)
1382		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1383
1384	return result;
1385}
1386
1387int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1388			void **edid)
1389{
1390	struct acpi_video_bus *video;
1391	struct acpi_video_device *video_device;
1392	union acpi_object *buffer = NULL;
1393	acpi_status status;
1394	int i, length;
1395
1396	if (!device || !acpi_driver_data(device))
1397		return -EINVAL;
1398
1399	video = acpi_driver_data(device);
1400
1401	for (i = 0; i < video->attached_count; i++) {
1402		video_device = video->attached_array[i].bind_info;
1403		length = 256;
1404
1405		if (!video_device)
1406			continue;
1407
1408		if (!video_device->cap._DDC)
1409			continue;
1410
1411		if (type) {
1412			switch (type) {
1413			case ACPI_VIDEO_DISPLAY_CRT:
1414				if (!video_device->flags.crt)
1415					continue;
1416				break;
1417			case ACPI_VIDEO_DISPLAY_TV:
1418				if (!video_device->flags.tvout)
1419					continue;
1420				break;
1421			case ACPI_VIDEO_DISPLAY_DVI:
1422				if (!video_device->flags.dvi)
1423					continue;
1424				break;
1425			case ACPI_VIDEO_DISPLAY_LCD:
1426				if (!video_device->flags.lcd)
1427					continue;
1428				break;
1429			}
1430		} else if (video_device->device_id != device_id) {
1431			continue;
1432		}
1433
1434		status = acpi_video_device_EDID(video_device, &buffer, length);
1435
1436		if (ACPI_FAILURE(status) || !buffer ||
1437		    buffer->type != ACPI_TYPE_BUFFER) {
1438			length = 128;
1439			status = acpi_video_device_EDID(video_device, &buffer,
1440							length);
1441			if (ACPI_FAILURE(status) || !buffer ||
1442			    buffer->type != ACPI_TYPE_BUFFER) {
1443				continue;
1444			}
1445		}
1446
1447		*edid = buffer->buffer.pointer;
1448		return length;
1449	}
1450
1451	return -ENODEV;
1452}
1453EXPORT_SYMBOL(acpi_video_get_edid);
1454
1455static int
1456acpi_video_bus_get_devices(struct acpi_video_bus *video,
1457			   struct acpi_device *device)
1458{
1459	int status = 0;
1460	struct acpi_device *dev;
1461
1462	/*
1463	 * There are systems where video module known to work fine regardless
1464	 * of broken _DOD and ignoring returned value here doesn't cause
1465	 * any issues later.
1466	 */
1467	acpi_video_device_enumerate(video);
1468
1469	list_for_each_entry(dev, &device->children, node) {
1470
1471		status = acpi_video_bus_get_one_device(dev, video);
1472		if (status) {
1473			dev_err(&dev->dev, "Can't attach device\n");
1474			break;
1475		}
1476	}
1477	return status;
1478}
1479
1480/* acpi_video interface */
1481
1482/*
1483 * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1484 * preform any automatic brightness change on receiving a notification.
1485 */
1486static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1487{
1488	return acpi_video_bus_DOS(video, 0,
1489				  acpi_osi_is_win8() ? 1 : 0);
1490}
1491
1492static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1493{
1494	return acpi_video_bus_DOS(video, 0,
1495				  acpi_osi_is_win8() ? 0 : 1);
1496}
1497
1498static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1499{
1500	struct acpi_video_bus *video = acpi_driver_data(device);
1501	struct input_dev *input;
1502	int keycode = 0;
1503
1504	if (!video || !video->input)
1505		return;
1506
1507	input = video->input;
1508
1509	switch (event) {
1510	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
1511					 * most likely via hotkey. */
1512		keycode = KEY_SWITCHVIDEOMODE;
1513		break;
1514
1515	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
1516					 * connector. */
1517		acpi_video_device_enumerate(video);
1518		acpi_video_device_rebind(video);
1519		keycode = KEY_SWITCHVIDEOMODE;
1520		break;
1521
1522	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
1523		keycode = KEY_SWITCHVIDEOMODE;
1524		break;
1525	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
1526		keycode = KEY_VIDEO_NEXT;
1527		break;
1528	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
1529		keycode = KEY_VIDEO_PREV;
1530		break;
1531
1532	default:
1533		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1534				  "Unsupported event [0x%x]\n", event));
1535		break;
1536	}
1537
1538	if (acpi_notifier_call_chain(device, event, 0))
1539		/* Something vetoed the keypress. */
1540		keycode = 0;
1541
1542	if (keycode) {
1543		input_report_key(input, keycode, 1);
1544		input_sync(input);
1545		input_report_key(input, keycode, 0);
1546		input_sync(input);
1547	}
1548
1549	return;
1550}
1551
1552static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1553{
1554	struct acpi_video_device *video_device = data;
1555	struct acpi_device *device = NULL;
1556	struct acpi_video_bus *bus;
1557	struct input_dev *input;
1558	int keycode = 0;
1559
1560	if (!video_device)
1561		return;
1562
1563	device = video_device->dev;
1564	bus = video_device->video;
1565	input = bus->input;
1566
1567	switch (event) {
1568	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
1569		if (brightness_switch_enabled)
1570			acpi_video_switch_brightness(video_device, event);
1571		keycode = KEY_BRIGHTNESS_CYCLE;
1572		break;
1573	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
1574		if (brightness_switch_enabled)
1575			acpi_video_switch_brightness(video_device, event);
1576		keycode = KEY_BRIGHTNESSUP;
1577		break;
1578	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
1579		if (brightness_switch_enabled)
1580			acpi_video_switch_brightness(video_device, event);
1581		keycode = KEY_BRIGHTNESSDOWN;
1582		break;
1583	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
1584		if (brightness_switch_enabled)
1585			acpi_video_switch_brightness(video_device, event);
1586		keycode = KEY_BRIGHTNESS_ZERO;
1587		break;
1588	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
1589		if (brightness_switch_enabled)
1590			acpi_video_switch_brightness(video_device, event);
1591		keycode = KEY_DISPLAY_OFF;
1592		break;
1593	default:
1594		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1595				  "Unsupported event [0x%x]\n", event));
1596		break;
1597	}
1598
1599	acpi_notifier_call_chain(device, event, 0);
1600
1601	if (keycode) {
1602		input_report_key(input, keycode, 1);
1603		input_sync(input);
1604		input_report_key(input, keycode, 0);
1605		input_sync(input);
1606	}
1607
1608	return;
1609}
1610
1611static int acpi_video_resume(struct notifier_block *nb,
1612				unsigned long val, void *ign)
1613{
1614	struct acpi_video_bus *video;
1615	struct acpi_video_device *video_device;
1616	int i;
1617
1618	switch (val) {
1619	case PM_HIBERNATION_PREPARE:
1620	case PM_SUSPEND_PREPARE:
1621	case PM_RESTORE_PREPARE:
1622		return NOTIFY_DONE;
1623	}
1624
1625	video = container_of(nb, struct acpi_video_bus, pm_nb);
1626
1627	dev_info(&video->device->dev, "Restoring backlight state\n");
1628
1629	for (i = 0; i < video->attached_count; i++) {
1630		video_device = video->attached_array[i].bind_info;
1631		if (video_device && video_device->backlight)
1632			acpi_video_set_brightness(video_device->backlight);
1633	}
1634
1635	return NOTIFY_OK;
1636}
1637
1638static acpi_status
1639acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1640			void **return_value)
1641{
1642	struct acpi_device *device = context;
1643	struct acpi_device *sibling;
1644	int result;
1645
1646	if (handle == device->handle)
1647		return AE_CTRL_TERMINATE;
1648
1649	result = acpi_bus_get_device(handle, &sibling);
1650	if (result)
1651		return AE_OK;
1652
1653	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1654			return AE_ALREADY_EXISTS;
1655
1656	return AE_OK;
1657}
1658
1659static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1660{
1661	if (acpi_video_verify_backlight_support()) {
1662		struct backlight_properties props;
1663		struct pci_dev *pdev;
1664		acpi_handle acpi_parent;
1665		struct device *parent = NULL;
1666		int result;
1667		static int count;
1668		char *name;
1669
1670		result = acpi_video_init_brightness(device);
1671		if (result)
1672			return;
1673		name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1674		if (!name)
1675			return;
1676		count++;
1677
1678		acpi_get_parent(device->dev->handle, &acpi_parent);
1679
1680		pdev = acpi_get_pci_dev(acpi_parent);
1681		if (pdev) {
1682			parent = &pdev->dev;
1683			pci_dev_put(pdev);
1684		}
1685
1686		memset(&props, 0, sizeof(struct backlight_properties));
1687		props.type = BACKLIGHT_FIRMWARE;
1688		props.max_brightness = device->brightness->count - 3;
1689		device->backlight = backlight_device_register(name,
1690							      parent,
1691							      device,
1692							      &acpi_backlight_ops,
1693							      &props);
1694		kfree(name);
1695		if (IS_ERR(device->backlight))
1696			return;
1697
1698		/*
1699		 * Save current brightness level in case we have to restore it
1700		 * before acpi_video_device_lcd_set_level() is called next time.
1701		 */
1702		device->backlight->props.brightness =
1703				acpi_video_get_brightness(device->backlight);
1704
1705		device->cooling_dev = thermal_cooling_device_register("LCD",
1706					device->dev, &video_cooling_ops);
1707		if (IS_ERR(device->cooling_dev)) {
1708			/*
1709			 * Set cooling_dev to NULL so we don't crash trying to
1710			 * free it.
1711			 * Also, why the hell we are returning early and
1712			 * not attempt to register video output if cooling
1713			 * device registration failed?
1714			 * -- dtor
1715			 */
1716			device->cooling_dev = NULL;
1717			return;
1718		}
1719
1720		dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1721			 device->cooling_dev->id);
1722		result = sysfs_create_link(&device->dev->dev.kobj,
1723				&device->cooling_dev->device.kobj,
1724				"thermal_cooling");
1725		if (result)
1726			printk(KERN_ERR PREFIX "Create sysfs link\n");
1727		result = sysfs_create_link(&device->cooling_dev->device.kobj,
1728				&device->dev->dev.kobj, "device");
1729		if (result)
1730			printk(KERN_ERR PREFIX "Create sysfs link\n");
1731	}
1732}
1733
1734static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1735{
1736	struct acpi_video_device *dev;
1737
1738	mutex_lock(&video->device_list_lock);
1739	list_for_each_entry(dev, &video->video_device_list, entry)
1740		acpi_video_dev_register_backlight(dev);
1741	mutex_unlock(&video->device_list_lock);
1742
1743	video->pm_nb.notifier_call = acpi_video_resume;
1744	video->pm_nb.priority = 0;
1745	return register_pm_notifier(&video->pm_nb);
1746}
1747
1748static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1749{
1750	if (device->backlight) {
1751		backlight_device_unregister(device->backlight);
1752		device->backlight = NULL;
1753	}
1754	if (device->brightness) {
1755		kfree(device->brightness->levels);
1756		kfree(device->brightness);
1757		device->brightness = NULL;
1758	}
1759	if (device->cooling_dev) {
1760		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1761		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1762		thermal_cooling_device_unregister(device->cooling_dev);
1763		device->cooling_dev = NULL;
1764	}
1765}
1766
1767static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1768{
1769	struct acpi_video_device *dev;
1770	int error = unregister_pm_notifier(&video->pm_nb);
1771
1772	mutex_lock(&video->device_list_lock);
1773	list_for_each_entry(dev, &video->video_device_list, entry)
1774		acpi_video_dev_unregister_backlight(dev);
1775	mutex_unlock(&video->device_list_lock);
1776
1777	return error;
1778}
1779
1780static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1781{
1782	acpi_status status;
1783	struct acpi_device *adev = device->dev;
1784
1785	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1786					     acpi_video_device_notify, device);
1787	if (ACPI_FAILURE(status))
1788		dev_err(&adev->dev, "Error installing notify handler\n");
1789	else
1790		device->flags.notify = 1;
1791}
1792
1793static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1794{
1795	struct input_dev *input;
1796	struct acpi_video_device *dev;
1797	int error;
1798
1799	video->input = input = input_allocate_device();
1800	if (!input) {
1801		error = -ENOMEM;
1802		goto out;
1803	}
1804
1805	error = acpi_video_bus_start_devices(video);
1806	if (error)
1807		goto err_free_input;
1808
1809	snprintf(video->phys, sizeof(video->phys),
1810			"%s/video/input0", acpi_device_hid(video->device));
1811
1812	input->name = acpi_device_name(video->device);
1813	input->phys = video->phys;
1814	input->id.bustype = BUS_HOST;
1815	input->id.product = 0x06;
1816	input->dev.parent = &video->device->dev;
1817	input->evbit[0] = BIT(EV_KEY);
1818	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1819	set_bit(KEY_VIDEO_NEXT, input->keybit);
1820	set_bit(KEY_VIDEO_PREV, input->keybit);
1821	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1822	set_bit(KEY_BRIGHTNESSUP, input->keybit);
1823	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1824	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1825	set_bit(KEY_DISPLAY_OFF, input->keybit);
1826
1827	error = input_register_device(input);
1828	if (error)
1829		goto err_stop_dev;
1830
1831	mutex_lock(&video->device_list_lock);
1832	list_for_each_entry(dev, &video->video_device_list, entry)
1833		acpi_video_dev_add_notify_handler(dev);
1834	mutex_unlock(&video->device_list_lock);
1835
1836	return 0;
1837
1838err_stop_dev:
1839	acpi_video_bus_stop_devices(video);
1840err_free_input:
1841	input_free_device(input);
1842	video->input = NULL;
1843out:
1844	return error;
1845}
1846
1847static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1848{
1849	if (dev->flags.notify) {
1850		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1851					   acpi_video_device_notify);
1852		dev->flags.notify = 0;
1853	}
1854}
1855
1856static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1857{
1858	struct acpi_video_device *dev;
1859
1860	mutex_lock(&video->device_list_lock);
1861	list_for_each_entry(dev, &video->video_device_list, entry)
1862		acpi_video_dev_remove_notify_handler(dev);
1863	mutex_unlock(&video->device_list_lock);
1864
1865	acpi_video_bus_stop_devices(video);
1866	input_unregister_device(video->input);
1867	video->input = NULL;
1868}
1869
1870static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1871{
1872	struct acpi_video_device *dev, *next;
1873
1874	mutex_lock(&video->device_list_lock);
1875	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1876		list_del(&dev->entry);
1877		kfree(dev);
1878	}
1879	mutex_unlock(&video->device_list_lock);
1880
1881	return 0;
1882}
1883
1884static int instance;
1885
1886static int acpi_video_bus_add(struct acpi_device *device)
1887{
1888	struct acpi_video_bus *video;
1889	int error;
1890	acpi_status status;
1891
1892	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1893				device->parent->handle, 1,
1894				acpi_video_bus_match, NULL,
1895				device, NULL);
1896	if (status == AE_ALREADY_EXISTS) {
1897		printk(KERN_WARNING FW_BUG
1898			"Duplicate ACPI video bus devices for the"
1899			" same VGA controller, please try module "
1900			"parameter \"video.allow_duplicates=1\""
1901			"if the current driver doesn't work.\n");
1902		if (!allow_duplicates)
1903			return -ENODEV;
1904	}
1905
1906	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1907	if (!video)
1908		return -ENOMEM;
1909
1910	/* a hack to fix the duplicate name "VID" problem on T61 */
1911	if (!strcmp(device->pnp.bus_id, "VID")) {
1912		if (instance)
1913			device->pnp.bus_id[3] = '0' + instance;
1914		instance++;
1915	}
1916	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1917	if (!strcmp(device->pnp.bus_id, "VGA")) {
1918		if (instance)
1919			device->pnp.bus_id[3] = '0' + instance;
1920		instance++;
1921	}
1922
1923	video->device = device;
1924	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1925	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1926	device->driver_data = video;
1927
1928	acpi_video_bus_find_cap(video);
1929	error = acpi_video_bus_check(video);
1930	if (error)
1931		goto err_free_video;
1932
1933	mutex_init(&video->device_list_lock);
1934	INIT_LIST_HEAD(&video->video_device_list);
1935
1936	error = acpi_video_bus_get_devices(video, device);
1937	if (error)
1938		goto err_put_video;
1939
1940	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1941	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1942	       video->flags.multihead ? "yes" : "no",
1943	       video->flags.rom ? "yes" : "no",
1944	       video->flags.post ? "yes" : "no");
1945	mutex_lock(&video_list_lock);
1946	list_add_tail(&video->entry, &video_bus_head);
1947	mutex_unlock(&video_list_lock);
1948
1949	acpi_video_bus_register_backlight(video);
1950	acpi_video_bus_add_notify_handler(video);
1951
1952	return 0;
1953
1954err_put_video:
1955	acpi_video_bus_put_devices(video);
1956	kfree(video->attached_array);
1957err_free_video:
1958	kfree(video);
1959	device->driver_data = NULL;
1960
1961	return error;
1962}
1963
1964static int acpi_video_bus_remove(struct acpi_device *device)
1965{
1966	struct acpi_video_bus *video = NULL;
1967
1968
1969	if (!device || !acpi_driver_data(device))
1970		return -EINVAL;
1971
1972	video = acpi_driver_data(device);
1973
1974	acpi_video_bus_remove_notify_handler(video);
1975	acpi_video_bus_unregister_backlight(video);
1976	acpi_video_bus_put_devices(video);
1977
1978	mutex_lock(&video_list_lock);
1979	list_del(&video->entry);
1980	mutex_unlock(&video_list_lock);
1981
1982	kfree(video->attached_array);
1983	kfree(video);
1984
1985	return 0;
1986}
1987
1988static int __init is_i740(struct pci_dev *dev)
1989{
1990	if (dev->device == 0x00D1)
1991		return 1;
1992	if (dev->device == 0x7000)
1993		return 1;
1994	return 0;
1995}
1996
1997static int __init intel_opregion_present(void)
1998{
1999	int opregion = 0;
2000	struct pci_dev *dev = NULL;
2001	u32 address;
2002
2003	for_each_pci_dev(dev) {
2004		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2005			continue;
2006		if (dev->vendor != PCI_VENDOR_ID_INTEL)
2007			continue;
2008		/* We don't want to poke around undefined i740 registers */
2009		if (is_i740(dev))
2010			continue;
2011		pci_read_config_dword(dev, 0xfc, &address);
2012		if (!address)
2013			continue;
2014		opregion = 1;
2015	}
2016	return opregion;
2017}
2018
2019int acpi_video_register(void)
2020{
2021	int result = 0;
2022	if (register_count) {
2023		/*
2024		 * if the function of acpi_video_register is already called,
2025		 * don't register the acpi_vide_bus again and return no error.
2026		 */
2027		return 0;
2028	}
2029
2030	mutex_init(&video_list_lock);
2031	INIT_LIST_HEAD(&video_bus_head);
2032
2033	result = acpi_bus_register_driver(&acpi_video_bus);
2034	if (result < 0)
2035		return -ENODEV;
2036
2037	/*
2038	 * When the acpi_video_bus is loaded successfully, increase
2039	 * the counter reference.
2040	 */
2041	register_count = 1;
2042
2043	return 0;
2044}
2045EXPORT_SYMBOL(acpi_video_register);
2046
2047void acpi_video_unregister(void)
2048{
2049	if (!register_count) {
2050		/*
2051		 * If the acpi video bus is already unloaded, don't
2052		 * unload it again and return directly.
2053		 */
2054		return;
2055	}
2056	acpi_bus_unregister_driver(&acpi_video_bus);
2057
2058	register_count = 0;
2059
2060	return;
2061}
2062EXPORT_SYMBOL(acpi_video_unregister);
2063
2064/*
2065 * This is kind of nasty. Hardware using Intel chipsets may require
2066 * the video opregion code to be run first in order to initialise
2067 * state before any ACPI video calls are made. To handle this we defer
2068 * registration of the video class until the opregion code has run.
2069 */
2070
2071static int __init acpi_video_init(void)
2072{
2073	dmi_check_system(video_dmi_table);
2074
2075	if (intel_opregion_present())
2076		return 0;
2077
2078	return acpi_video_register();
2079}
2080
2081static void __exit acpi_video_exit(void)
2082{
2083	acpi_video_unregister();
2084
2085	return;
2086}
2087
2088module_init(acpi_video_init);
2089module_exit(acpi_video_exit);