acpi-video-detect: video: Make video_detect code part of the video module

This is a preparation patch for the backlight interface selection logic
cleanup, there are 2 reasons to not always build the video_detect code
into the kernel:

1) In order for the video_detect.c to also deal with / select native
backlight interfaces on win8 systems, instead of doing this in video.c
where it does not belong, video_detect.c needs to call into the backlight
class code. Which cannot be done if it is builtin and the blacklight class
is not.

2) Currently all the platform/x86 drivers which have quirks to prefer
the vendor driver over acpi-video call acpi_video_unregister_backlight()
to remove the acpi-video backlight interface, this logic really belongs
in video_detect.c, which will cause video_detect.c to depend on symbols of
video.c and video.c already depends on video_detect.c symbols, so they
really need to be a single module.

Note that this commits make 2 changes so as to maintain 100% kernel
commandline compatibility:

1) The __setup call for the acpi_backlight= handling is moved to
   acpi/util.c as __setup may only be used by code which is alwasy builtin
2) video.c is renamed to acpi_video.c so that it can be combined with
   video_detect.c into video.ko

This commit also makes changes to drivers/platform/x86/Kconfig to ensure
that drivers which use acpi_video_backlight_support() from video_detect.c,
will not be built-in when acpi_video is not built in. This also changes
some "select" uses to "depends on" to avoid dependency loops.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 0 insertions, 2275 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
deleted file mode 100644
index 3bc4c68..0000000
--- a/drivers/acpi/video.c
+++ /dev/null
@@ -1,2275 +0,0 @@
-/*
- *  video.c - ACPI Video Driver
- *
- *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
- *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
- *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or (at
- *  your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful, but
- *  WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- *  General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along
- *  with this program; if not, write to the Free Software Foundation, Inc.,
- *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/list.h>
-#include <linux/mutex.h>
-#include <linux/input.h>
-#include <linux/backlight.h>
-#include <linux/thermal.h>
-#include <linux/sort.h>
-#include <linux/pci.h>
-#include <linux/pci_ids.h>
-#include <linux/slab.h>
-#include <linux/dmi.h>
-#include <linux/suspend.h>
-#include <linux/acpi.h>
-#include <acpi/video.h>
-#include <asm/uaccess.h>
-
-#include "internal.h"
-
-#define ACPI_VIDEO_BUS_NAME		"Video Bus"
-#define ACPI_VIDEO_DEVICE_NAME		"Video Device"
-#define ACPI_VIDEO_NOTIFY_SWITCH	0x80
-#define ACPI_VIDEO_NOTIFY_PROBE		0x81
-#define ACPI_VIDEO_NOTIFY_CYCLE		0x82
-#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT	0x83
-#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT	0x84
-
-#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS	0x85
-#define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x86
-#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x87
-#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x88
-#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x89
-
-#define MAX_NAME_LEN	20
-
-#define _COMPONENT		ACPI_VIDEO_COMPONENT
-ACPI_MODULE_NAME("video");
-
-MODULE_AUTHOR("Bruno Ducrot");
-MODULE_DESCRIPTION("ACPI Video Driver");
-MODULE_LICENSE("GPL");
-
-static bool brightness_switch_enabled = 1;
-module_param(brightness_switch_enabled, bool, 0644);
-
-/*
- * By default, we don't allow duplicate ACPI video bus devices
- * under the same VGA controller
- */
-static bool allow_duplicates;
-module_param(allow_duplicates, bool, 0644);
-
-/*
- * For Windows 8 systems: used to decide if video module
- * should skip registering backlight interface of its own.
- */
-enum {
-	NATIVE_BACKLIGHT_NOT_SET = -1,
-	NATIVE_BACKLIGHT_OFF,
-	NATIVE_BACKLIGHT_ON,
-};
-
-static int use_native_backlight_param = NATIVE_BACKLIGHT_NOT_SET;
-module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
-static int use_native_backlight_dmi = NATIVE_BACKLIGHT_NOT_SET;
-
-static int disable_backlight_sysfs_if = -1;
-module_param(disable_backlight_sysfs_if, int, 0444);
-
-static int register_count;
-static struct mutex video_list_lock;
-static struct list_head video_bus_head;
-static int acpi_video_bus_add(struct acpi_device *device);
-static int acpi_video_bus_remove(struct acpi_device *device);
-static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
-
-static const struct acpi_device_id video_device_ids[] = {
-	{ACPI_VIDEO_HID, 0},
-	{"", 0},
-};
-MODULE_DEVICE_TABLE(acpi, video_device_ids);
-
-static struct acpi_driver acpi_video_bus = {
-	.name = "video",
-	.class = ACPI_VIDEO_CLASS,
-	.ids = video_device_ids,
-	.ops = {
-		.add = acpi_video_bus_add,
-		.remove = acpi_video_bus_remove,
-		.notify = acpi_video_bus_notify,
-		},
-};
-
-struct acpi_video_bus_flags {
-	u8 multihead:1;		/* can switch video heads */
-	u8 rom:1;		/* can retrieve a video rom */
-	u8 post:1;		/* can configure the head to */
-	u8 reserved:5;
-};
-
-struct acpi_video_bus_cap {
-	u8 _DOS:1;		/* Enable/Disable output switching */
-	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
-	u8 _ROM:1;		/* Get ROM Data */
-	u8 _GPD:1;		/* Get POST Device */
-	u8 _SPD:1;		/* Set POST Device */
-	u8 _VPO:1;		/* Video POST Options */
-	u8 reserved:2;
-};
-
-struct acpi_video_device_attrib {
-	u32 display_index:4;	/* A zero-based instance of the Display */
-	u32 display_port_attachment:4;	/* This field differentiates the display type */
-	u32 display_type:4;	/* Describe the specific type in use */
-	u32 vendor_specific:4;	/* Chipset Vendor Specific */
-	u32 bios_can_detect:1;	/* BIOS can detect the device */
-	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
-				   the VGA device. */
-	u32 pipe_id:3;		/* For VGA multiple-head devices. */
-	u32 reserved:10;	/* Must be 0 */
-	u32 device_id_scheme:1;	/* Device ID Scheme */
-};
-
-struct acpi_video_enumerated_device {
-	union {
-		u32 int_val;
-		struct acpi_video_device_attrib attrib;
-	} value;
-	struct acpi_video_device *bind_info;
-};
-
-struct acpi_video_bus {
-	struct acpi_device *device;
-	bool backlight_registered;
-	bool backlight_notifier_registered;
-	u8 dos_setting;
-	struct acpi_video_enumerated_device *attached_array;
-	u8 attached_count;
-	u8 child_count;
-	struct acpi_video_bus_cap cap;
-	struct acpi_video_bus_flags flags;
-	struct list_head video_device_list;
-	struct mutex device_list_lock;	/* protects video_device_list */
-	struct list_head entry;
-	struct input_dev *input;
-	char phys[32];	/* for input device */
-	struct notifier_block pm_nb;
-	struct notifier_block backlight_nb;
-};
-
-struct acpi_video_device_flags {
-	u8 crt:1;
-	u8 lcd:1;
-	u8 tvout:1;
-	u8 dvi:1;
-	u8 bios:1;
-	u8 unknown:1;
-	u8 notify:1;
-	u8 reserved:1;
-};
-
-struct acpi_video_device_cap {
-	u8 _ADR:1;		/* Return the unique ID */
-	u8 _BCL:1;		/* Query list of brightness control levels supported */
-	u8 _BCM:1;		/* Set the brightness level */
-	u8 _BQC:1;		/* Get current brightness level */
-	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
-	u8 _DDC:1;		/* Return the EDID for this device */
-};
-
-struct acpi_video_brightness_flags {
-	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */
-	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order */
-	u8 _BQC_use_index:1;		/* _BQC returns an index value */
-};
-
-struct acpi_video_device_brightness {
-	int curr;
-	int count;
-	int *levels;
-	struct acpi_video_brightness_flags flags;
-};
-
-struct acpi_video_device {
-	unsigned long device_id;
-	struct acpi_video_device_flags flags;
-	struct acpi_video_device_cap cap;
-	struct list_head entry;
-	struct delayed_work switch_brightness_work;
-	int switch_brightness_event;
-	struct acpi_video_bus *video;
-	struct acpi_device *dev;
-	struct acpi_video_device_brightness *brightness;
-	struct backlight_device *backlight;
-	struct thermal_cooling_device *cooling_dev;
-};
-
-static const char device_decode[][30] = {
-	"motherboard VGA device",
-	"PCI VGA device",
-	"AGP VGA device",
-	"UNKNOWN",
-};
-
-static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
-static void acpi_video_device_rebind(struct acpi_video_bus *video);
-static void acpi_video_device_bind(struct acpi_video_bus *video,
-				   struct acpi_video_device *device);
-static int acpi_video_device_enumerate(struct acpi_video_bus *video);
-static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
-			int level);
-static int acpi_video_device_lcd_get_level_current(
-			struct acpi_video_device *device,
-			unsigned long long *level, bool raw);
-static int acpi_video_get_next_level(struct acpi_video_device *device,
-				     u32 level_current, u32 event);
-static void acpi_video_switch_brightness(struct work_struct *work);
-
-static bool acpi_video_use_native_backlight(void)
-{
-	if (use_native_backlight_param != NATIVE_BACKLIGHT_NOT_SET)
-		return use_native_backlight_param;
-	else if (use_native_backlight_dmi != NATIVE_BACKLIGHT_NOT_SET)
-		return use_native_backlight_dmi;
-	return acpi_osi_is_win8();
-}
-
-bool acpi_video_verify_backlight_support(void)
-{
-	if (acpi_video_use_native_backlight() &&
-	    backlight_device_registered(BACKLIGHT_RAW))
-		return false;
-	return acpi_video_backlight_support();
-}
-EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support);
-
-/* backlight device sysfs support */
-static int acpi_video_get_brightness(struct backlight_device *bd)
-{
-	unsigned long long cur_level;
-	int i;
-	struct acpi_video_device *vd = bl_get_data(bd);
-
-	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
-		return -EINVAL;
-	for (i = 2; i < vd->brightness->count; i++) {
-		if (vd->brightness->levels[i] == cur_level)
-			/*
-			 * The first two entries are special - see page 575
-			 * of the ACPI spec 3.0
-			 */
-			return i - 2;
-	}
-	return 0;
-}
-
-static int acpi_video_set_brightness(struct backlight_device *bd)
-{
-	int request_level = bd->props.brightness + 2;
-	struct acpi_video_device *vd = bl_get_data(bd);
-
-	cancel_delayed_work(&vd->switch_brightness_work);
-	return acpi_video_device_lcd_set_level(vd,
-				vd->brightness->levels[request_level]);
-}
-
-static const struct backlight_ops acpi_backlight_ops = {
-	.get_brightness = acpi_video_get_brightness,
-	.update_status  = acpi_video_set_brightness,
-};
-
-/* thermal cooling device callbacks */
-static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
-			       long *state)
-{
-	struct acpi_device *device = cooling_dev->devdata;
-	struct acpi_video_device *video = acpi_driver_data(device);
-
-	*state = video->brightness->count - 3;
-	return 0;
-}
-
-static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
-			       long *state)
-{
-	struct acpi_device *device = cooling_dev->devdata;
-	struct acpi_video_device *video = acpi_driver_data(device);
-	unsigned long long level;
-	int offset;
-
-	if (acpi_video_device_lcd_get_level_current(video, &level, false))
-		return -EINVAL;
-	for (offset = 2; offset < video->brightness->count; offset++)
-		if (level == video->brightness->levels[offset]) {
-			*state = video->brightness->count - offset - 1;
-			return 0;
-		}
-
-	return -EINVAL;
-}
-
-static int
-video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
-{
-	struct acpi_device *device = cooling_dev->devdata;
-	struct acpi_video_device *video = acpi_driver_data(device);
-	int level;
-
-	if (state >= video->brightness->count - 2)
-		return -EINVAL;
-
-	state = video->brightness->count - state;
-	level = video->brightness->levels[state - 1];
-	return acpi_video_device_lcd_set_level(video, level);
-}
-
-static const struct thermal_cooling_device_ops video_cooling_ops = {
-	.get_max_state = video_get_max_state,
-	.get_cur_state = video_get_cur_state,
-	.set_cur_state = video_set_cur_state,
-};
-
-/*
- * --------------------------------------------------------------------------
- *                             Video Management
- * --------------------------------------------------------------------------
- */
-
-static int
-acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
-				   union acpi_object **levels)
-{
-	int status;
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-
-
-	*levels = NULL;
-
-	status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
-	if (!ACPI_SUCCESS(status))
-		return status;
-	obj = (union acpi_object *)buffer.pointer;
-	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
-		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
-		status = -EFAULT;
-		goto err;
-	}
-
-	*levels = obj;
-
-	return 0;
-
-err:
-	kfree(buffer.pointer);
-
-	return status;
-}
-
-static int
-acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
-{
-	int status;
-	int state;
-
-	status = acpi_execute_simple_method(device->dev->handle,
-					    "_BCM", level);
-	if (ACPI_FAILURE(status)) {
-		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
-		return -EIO;
-	}
-
-	device->brightness->curr = level;
-	for (state = 2; state < device->brightness->count; state++)
-		if (level == device->brightness->levels[state]) {
-			if (device->backlight)
-				device->backlight->props.brightness = state - 2;
-			return 0;
-		}
-
-	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
-	return -EINVAL;
-}
-
-/*
- * For some buggy _BQC methods, we need to add a constant value to
- * the _BQC return value to get the actual current brightness level
- */
-
-static int bqc_offset_aml_bug_workaround;
-static int __init video_set_bqc_offset(const struct dmi_system_id *d)
-{
-	bqc_offset_aml_bug_workaround = 9;
-	return 0;
-}
-
-static int __init video_disable_native_backlight(const struct dmi_system_id *d)
-{
-	use_native_backlight_dmi = NATIVE_BACKLIGHT_OFF;
-	return 0;
-}
-
-static int __init video_enable_native_backlight(const struct dmi_system_id *d)
-{
-	use_native_backlight_dmi = NATIVE_BACKLIGHT_ON;
-	return 0;
-}
-
-static int __init video_disable_backlight_sysfs_if(
-	const struct dmi_system_id *d)
-{
-	if (disable_backlight_sysfs_if == -1)
-		disable_backlight_sysfs_if = 1;
-	return 0;
-}
-
-static struct dmi_system_id video_dmi_table[] __initdata = {
-	/*
-	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
-	 */
-	{
-	 .callback = video_set_bqc_offset,
-	 .ident = "Acer Aspire 5720",
-	 .matches = {
-		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
-		},
-	},
-	{
-	 .callback = video_set_bqc_offset,
-	 .ident = "Acer Aspire 5710Z",
-	 .matches = {
-		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
-		},
-	},
-	{
-	 .callback = video_set_bqc_offset,
-	 .ident = "eMachines E510",
-	 .matches = {
-		DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
-		},
-	},
-	{
-	 .callback = video_set_bqc_offset,
-	 .ident = "Acer Aspire 5315",
-	 .matches = {
-		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
-		},
-	},
-	{
-	 .callback = video_set_bqc_offset,
-	 .ident = "Acer Aspire 7720",
-	 .matches = {
-		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
-		},
-	},
-
-	/*
-	 * These models have a working acpi_video backlight control, and using
-	 * native backlight causes a regression where backlight does not work
-	 * when userspace is not handling brightness key events. Disable
-	 * native_backlight on these to fix this:
-	 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
-	 */
-	{
-	 .callback = video_disable_native_backlight,
-	 .ident = "ThinkPad T420",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
-		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
-		},
-	},
-	{
-	 .callback = video_disable_native_backlight,
-	 .ident = "ThinkPad T520",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
-		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
-		},
-	},
-	{
-	 .callback = video_disable_native_backlight,
-	 .ident = "ThinkPad X201s",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
-		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
-		},
-	},
-
-	/* The native backlight controls do not work on some older machines */
-	{
-	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
-	 .callback = video_disable_native_backlight,
-	 .ident = "HP ENVY 15 Notebook",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
-		},
-	},
-
-	{
-	 .callback = video_disable_native_backlight,
-	 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
-		},
-	},
-	{
-	 .callback = video_disable_native_backlight,
-	 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "370R4E/370R4V/370R5E/3570RE/370R5V"),
-		},
-	},
-	{
-	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
-	 .callback = video_disable_native_backlight,
-	 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "3570R/370R/470R/450R/510R/4450RV"),
-		},
-	},
-	{
-	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
-	 .callback = video_disable_native_backlight,
-	 .ident = "SAMSUNG 730U3E/740U3E",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
-		},
-	},
-	{
-	 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
-	 .callback = video_disable_native_backlight,
-	 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "900X3C/900X3D/900X3E/900X4C/900X4D"),
-		},
-	},
-
-	{
-	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
-	 .callback = video_disable_native_backlight,
-	 .ident = "Dell XPS15 L521X",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
-		},
-	},
-
-	/* Non win8 machines which need native backlight nevertheless */
-	{
-	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
-	 .callback = video_enable_native_backlight,
-	 .ident = "Lenovo Ideapad Z570",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
-		},
-	},
-	{
-	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
-	 .callback = video_enable_native_backlight,
-	 .ident = "Apple MacBook Pro 12,1",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
-		},
-	},
-
-	/*
-	 * Some machines have a broken acpi-video interface for brightness
-	 * control, but still need an acpi_video_device_lcd_set_level() call
-	 * on resume to turn the backlight power on.  We Enable backlight
-	 * control on these systems, but do not register a backlight sysfs
-	 * as brightness control does not work.
-	 */
-	{
-	 /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
-	 .callback = video_disable_backlight_sysfs_if,
-	 .ident = "Toshiba Portege R830",
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
-		},
-	},
-	{}
-};
-
-static unsigned long long
-acpi_video_bqc_value_to_level(struct acpi_video_device *device,
-			      unsigned long long bqc_value)
-{
-	unsigned long long level;
-
-	if (device->brightness->flags._BQC_use_index) {
-		/*
-		 * _BQC returns an index that doesn't account for
-		 * the first 2 items with special meaning, so we need
-		 * to compensate for that by offsetting ourselves
-		 */
-		if (device->brightness->flags._BCL_reversed)
-			bqc_value = device->brightness->count - 3 - bqc_value;
-
-		level = device->brightness->levels[bqc_value + 2];
-	} else {
-		level = bqc_value;
-	}
-
-	level += bqc_offset_aml_bug_workaround;
-
-	return level;
-}
-
-static int
-acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
-					unsigned long long *level, bool raw)
-{
-	acpi_status status = AE_OK;
-	int i;
-
-	if (device->cap._BQC || device->cap._BCQ) {
-		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
-
-		status = acpi_evaluate_integer(device->dev->handle, buf,
-						NULL, level);
-		if (ACPI_SUCCESS(status)) {
-			if (raw) {
-				/*
-				 * Caller has indicated he wants the raw
-				 * value returned by _BQC, so don't furtherly
-				 * mess with the value.
-				 */
-				return 0;
-			}
-
-			*level = acpi_video_bqc_value_to_level(device, *level);
-
-			for (i = 2; i < device->brightness->count; i++)
-				if (device->brightness->levels[i] == *level) {
-					device->brightness->curr = *level;
-					return 0;
-				}
-			/*
-			 * BQC returned an invalid level.
-			 * Stop using it.
-			 */
-			ACPI_WARNING((AE_INFO,
-				      "%s returned an invalid level",
-				      buf));
-			device->cap._BQC = device->cap._BCQ = 0;
-		} else {
-			/*
-			 * Fixme:
-			 * should we return an error or ignore this failure?
-			 * dev->brightness->curr is a cached value which stores
-			 * the correct current backlight level in most cases.
-			 * ACPI video backlight still works w/ buggy _BQC.
-			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
-			 */
-			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
-			device->cap._BQC = device->cap._BCQ = 0;
-		}
-	}
-
-	*level = device->brightness->curr;
-	return 0;
-}
-
-static int
-acpi_video_device_EDID(struct acpi_video_device *device,
-		       union acpi_object **edid, ssize_t length)
-{
-	int status;
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
-	struct acpi_object_list args = { 1, &arg0 };
-
-
-	*edid = NULL;
-
-	if (!device)
-		return -ENODEV;
-	if (length == 128)
-		arg0.integer.value = 1;
-	else if (length == 256)
-		arg0.integer.value = 2;
-	else
-		return -EINVAL;
-
-	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
-
-	obj = buffer.pointer;
-
-	if (obj && obj->type == ACPI_TYPE_BUFFER)
-		*edid = obj;
-	else {
-		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
-		status = -EFAULT;
-		kfree(obj);
-	}
-
-	return status;
-}
-
-/* bus */
-
-/*
- *  Arg:
- *	video		: video bus device pointer
- *	bios_flag	:
- *		0.	The system BIOS should NOT automatically switch(toggle)
- *			the active display output.
- *		1.	The system BIOS should automatically switch (toggle) the
- *			active display output. No switch event.
- *		2.	The _DGS value should be locked.
- *		3.	The system BIOS should not automatically switch (toggle) the
- *			active display output, but instead generate the display switch
- *			event notify code.
- *	lcd_flag	:
- *		0.	The system BIOS should automatically control the brightness level
- *			of the LCD when the power changes from AC to DC
- *		1.	The system BIOS should NOT automatically control the brightness
- *			level of the LCD when the power changes from AC to DC.
- *  Return Value:
- *		-EINVAL	wrong arg.
- */
-
-static int
-acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
-{
-	acpi_status status;
-
-	if (!video->cap._DOS)
-		return 0;
-
-	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
-		return -EINVAL;
-	video->dos_setting = (lcd_flag << 2) | bios_flag;
-	status = acpi_execute_simple_method(video->device->handle, "_DOS",
-					    (lcd_flag << 2) | bios_flag);
-	if (ACPI_FAILURE(status))
-		return -EIO;
-
-	return 0;
-}
-
-/*
- * Simple comparison function used to sort backlight levels.
- */
-
-static int
-acpi_video_cmp_level(const void *a, const void *b)
-{
-	return *(int *)a - *(int *)b;
-}
-
-/*
- * Decides if _BQC/_BCQ for this system is usable
- *
- * We do this by changing the level first and then read out the current
- * brightness level, if the value does not match, find out if it is using
- * index. If not, clear the _BQC/_BCQ capability.
- */
-static int acpi_video_bqc_quirk(struct acpi_video_device *device,
-				int max_level, int current_level)
-{
-	struct acpi_video_device_brightness *br = device->brightness;
-	int result;
-	unsigned long long level;
-	int test_level;
-
-	/* don't mess with existing known broken systems */
-	if (bqc_offset_aml_bug_workaround)
-		return 0;
-
-	/*
-	 * Some systems always report current brightness level as maximum
-	 * through _BQC, we need to test another value for them.
-	 */
-	test_level = current_level == max_level ? br->levels[3] : max_level;
-
-	result = acpi_video_device_lcd_set_level(device, test_level);
-	if (result)
-		return result;
-
-	result = acpi_video_device_lcd_get_level_current(device, &level, true);
-	if (result)
-		return result;
-
-	if (level != test_level) {
-		/* buggy _BQC found, need to find out if it uses index */
-		if (level < br->count) {
-			if (br->flags._BCL_reversed)
-				level = br->count - 3 - level;
-			if (br->levels[level + 2] == test_level)
-				br->flags._BQC_use_index = 1;
-		}
-
-		if (!br->flags._BQC_use_index)
-			device->cap._BQC = device->cap._BCQ = 0;
-	}
-
-	return 0;
-}
-
-
-/*
- *  Arg:
- *	device	: video output device (LCD, CRT, ..)
- *
- *  Return Value:
- *	Maximum brightness level
- *
- *  Allocate and initialize device->brightness.
- */
-
-static int
-acpi_video_init_brightness(struct acpi_video_device *device)
-{
-	union acpi_object *obj = NULL;
-	int i, max_level = 0, count = 0, level_ac_battery = 0;
-	unsigned long long level, level_old;
-	union acpi_object *o;
-	struct acpi_video_device_brightness *br = NULL;
-	int result = -EINVAL;
-	u32 value;
-
-	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
-						"LCD brightness level\n"));
-		goto out;
-	}
-
-	if (obj->package.count < 2)
-		goto out;
-
-	br = kzalloc(sizeof(*br), GFP_KERNEL);
-	if (!br) {
-		printk(KERN_ERR "can't allocate memory\n");
-		result = -ENOMEM;
-		goto out;
-	}
-
-	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
-				GFP_KERNEL);
-	if (!br->levels) {
-		result = -ENOMEM;
-		goto out_free;
-	}
-
-	for (i = 0; i < obj->package.count; i++) {
-		o = (union acpi_object *)&obj->package.elements[i];
-		if (o->type != ACPI_TYPE_INTEGER) {
-			printk(KERN_ERR PREFIX "Invalid data\n");
-			continue;
-		}
-		value = (u32) o->integer.value;
-		/* Skip duplicate entries */
-		if (count > 2 && br->levels[count - 1] == value)
-			continue;
-
-		br->levels[count] = value;
-
-		if (br->levels[count] > max_level)
-			max_level = br->levels[count];
-		count++;
-	}
-
-	/*
-	 * some buggy BIOS don't export the levels
-	 * when machine is on AC/Battery in _BCL package.
-	 * In this case, the first two elements in _BCL packages
-	 * are also supported brightness levels that OS should take care of.
-	 */
-	for (i = 2; i < count; i++) {
-		if (br->levels[i] == br->levels[0])
-			level_ac_battery++;
-		if (br->levels[i] == br->levels[1])
-			level_ac_battery++;
-	}
-
-	if (level_ac_battery < 2) {
-		level_ac_battery = 2 - level_ac_battery;
-		br->flags._BCL_no_ac_battery_levels = 1;
-		for (i = (count - 1 + level_ac_battery); i >= 2; i--)
-			br->levels[i] = br->levels[i - level_ac_battery];
-		count += level_ac_battery;
-	} else if (level_ac_battery > 2)
-		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
-
-	/* Check if the _BCL package is in a reversed order */
-	if (max_level == br->levels[2]) {
-		br->flags._BCL_reversed = 1;
-		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
-			acpi_video_cmp_level, NULL);
-	} else if (max_level != br->levels[count - 1])
-		ACPI_ERROR((AE_INFO,
-			    "Found unordered _BCL package"));
-
-	br->count = count;
-	device->brightness = br;
-
-	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
-	br->curr = level = max_level;
-
-	if (!device->cap._BQC)
-		goto set_level;
-
-	result = acpi_video_device_lcd_get_level_current(device,
-							 &level_old, true);
-	if (result)
-		goto out_free_levels;
-
-	result = acpi_video_bqc_quirk(device, max_level, level_old);
-	if (result)
-		goto out_free_levels;
-	/*
-	 * cap._BQC may get cleared due to _BQC is found to be broken
-	 * in acpi_video_bqc_quirk, so check again here.
-	 */
-	if (!device->cap._BQC)
-		goto set_level;
-
-	level = acpi_video_bqc_value_to_level(device, level_old);
-	/*
-	 * On some buggy laptops, _BQC returns an uninitialized
-	 * value when invoked for the first time, i.e.
-	 * level_old is invalid (no matter whether it's a level
-	 * or an index). Set the backlight to max_level in this case.
-	 */
-	for (i = 2; i < br->count; i++)
-		if (level == br->levels[i])
-			break;
-	if (i == br->count || !level)
-		level = max_level;
-
-set_level:
-	result = acpi_video_device_lcd_set_level(device, level);
-	if (result)
-		goto out_free_levels;
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-			  "found %d brightness levels\n", count - 2));
-	kfree(obj);
-	return result;
-
-out_free_levels:
-	kfree(br->levels);
-out_free:
-	kfree(br);
-out:
-	device->brightness = NULL;
-	kfree(obj);
-	return result;
-}
-
-/*
- *  Arg:
- *	device	: video output device (LCD, CRT, ..)
- *
- *  Return Value:
- *	None
- *
- *  Find out all required AML methods defined under the output
- *  device.
- */
-
-static void acpi_video_device_find_cap(struct acpi_video_device *device)
-{
-	if (acpi_has_method(device->dev->handle, "_ADR"))
-		device->cap._ADR = 1;
-	if (acpi_has_method(device->dev->handle, "_BCL"))
-		device->cap._BCL = 1;
-	if (acpi_has_method(device->dev->handle, "_BCM"))
-		device->cap._BCM = 1;
-	if (acpi_has_method(device->dev->handle, "_BQC")) {
-		device->cap._BQC = 1;
-	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
-		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
-		device->cap._BCQ = 1;
-	}
-
-	if (acpi_has_method(device->dev->handle, "_DDC"))
-		device->cap._DDC = 1;
-}
-
-/*
- *  Arg:
- *	device	: video output device (VGA)
- *
- *  Return Value:
- *	None
- *
- *  Find out all required AML methods defined under the video bus device.
- */
-
-static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
-{
-	if (acpi_has_method(video->device->handle, "_DOS"))
-		video->cap._DOS = 1;
-	if (acpi_has_method(video->device->handle, "_DOD"))
-		video->cap._DOD = 1;
-	if (acpi_has_method(video->device->handle, "_ROM"))
-		video->cap._ROM = 1;
-	if (acpi_has_method(video->device->handle, "_GPD"))
-		video->cap._GPD = 1;
-	if (acpi_has_method(video->device->handle, "_SPD"))
-		video->cap._SPD = 1;
-	if (acpi_has_method(video->device->handle, "_VPO"))
-		video->cap._VPO = 1;
-}
-
-/*
- * Check whether the video bus device has required AML method to
- * support the desired features
- */
-
-static int acpi_video_bus_check(struct acpi_video_bus *video)
-{
-	acpi_status status = -ENOENT;
-	struct pci_dev *dev;
-
-	if (!video)
-		return -EINVAL;
-
-	dev = acpi_get_pci_dev(video->device->handle);
-	if (!dev)
-		return -ENODEV;
-	pci_dev_put(dev);
-
-	/*
-	 * Since there is no HID, CID and so on for VGA driver, we have
-	 * to check well known required nodes.
-	 */
-
-	/* Does this device support video switching? */
-	if (video->cap._DOS || video->cap._DOD) {
-		if (!video->cap._DOS) {
-			printk(KERN_WARNING FW_BUG
-				"ACPI(%s) defines _DOD but not _DOS\n",
-				acpi_device_bid(video->device));
-		}
-		video->flags.multihead = 1;
-		status = 0;
-	}
-
-	/* Does this device support retrieving a video ROM? */
-	if (video->cap._ROM) {
-		video->flags.rom = 1;
-		status = 0;
-	}
-
-	/* Does this device support configuring which video device to POST? */
-	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
-		video->flags.post = 1;
-		status = 0;
-	}
-
-	return status;
-}
-
-/*
- * --------------------------------------------------------------------------
- *                               Driver Interface
- * --------------------------------------------------------------------------
- */
-
-/* device interface */
-static struct acpi_video_device_attrib *
-acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
-{
-	struct acpi_video_enumerated_device *ids;
-	int i;
-
-	for (i = 0; i < video->attached_count; i++) {
-		ids = &video->attached_array[i];
-		if ((ids->value.int_val & 0xffff) == device_id)
-			return &ids->value.attrib;
-	}
-
-	return NULL;
-}
-
-static int
-acpi_video_get_device_type(struct acpi_video_bus *video,
-			   unsigned long device_id)
-{
-	struct acpi_video_enumerated_device *ids;
-	int i;
-
-	for (i = 0; i < video->attached_count; i++) {
-		ids = &video->attached_array[i];
-		if ((ids->value.int_val & 0xffff) == device_id)
-			return ids->value.int_val;
-	}
-
-	return 0;
-}
-
-static int
-acpi_video_bus_get_one_device(struct acpi_device *device,
-			      struct acpi_video_bus *video)
-{
-	unsigned long long device_id;
-	int status, device_type;
-	struct acpi_video_device *data;
-	struct acpi_video_device_attrib *attribute;
-
-	status =
-	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
-	/* Some device omits _ADR, we skip them instead of fail */
-	if (ACPI_FAILURE(status))
-		return 0;
-
-	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
-	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
-	device->driver_data = data;
-
-	data->device_id = device_id;
-	data->video = video;
-	data->dev = device;
-	INIT_DELAYED_WORK(&data->switch_brightness_work,
-			  acpi_video_switch_brightness);
-
-	attribute = acpi_video_get_device_attr(video, device_id);
-
-	if (attribute && attribute->device_id_scheme) {
-		switch (attribute->display_type) {
-		case ACPI_VIDEO_DISPLAY_CRT:
-			data->flags.crt = 1;
-			break;
-		case ACPI_VIDEO_DISPLAY_TV:
-			data->flags.tvout = 1;
-			break;
-		case ACPI_VIDEO_DISPLAY_DVI:
-			data->flags.dvi = 1;
-			break;
-		case ACPI_VIDEO_DISPLAY_LCD:
-			data->flags.lcd = 1;
-			break;
-		default:
-			data->flags.unknown = 1;
-			break;
-		}
-		if (attribute->bios_can_detect)
-			data->flags.bios = 1;
-	} else {
-		/* Check for legacy IDs */
-		device_type = acpi_video_get_device_type(video, device_id);
-		/* Ignore bits 16 and 18-20 */
-		switch (device_type & 0xffe2ffff) {
-		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
-			data->flags.crt = 1;
-			break;
-		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
-			data->flags.lcd = 1;
-			break;
-		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
-			data->flags.tvout = 1;
-			break;
-		default:
-			data->flags.unknown = 1;
-		}
-	}
-
-	acpi_video_device_bind(video, data);
-	acpi_video_device_find_cap(data);
-
-	mutex_lock(&video->device_list_lock);
-	list_add_tail(&data->entry, &video->video_device_list);
-	mutex_unlock(&video->device_list_lock);
-
-	return status;
-}
-
-/*
- *  Arg:
- *	video	: video bus device
- *
- *  Return:
- *	none
- *
- *  Enumerate the video device list of the video bus,
- *  bind the ids with the corresponding video devices
- *  under the video bus.
- */
-
-static void acpi_video_device_rebind(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev;
-
-	mutex_lock(&video->device_list_lock);
-
-	list_for_each_entry(dev, &video->video_device_list, entry)
-		acpi_video_device_bind(video, dev);
-
-	mutex_unlock(&video->device_list_lock);
-}
-
-/*
- *  Arg:
- *	video	: video bus device
- *	device	: video output device under the video
- *		bus
- *
- *  Return:
- *	none
- *
- *  Bind the ids with the corresponding video devices
- *  under the video bus.
- */
-
-static void
-acpi_video_device_bind(struct acpi_video_bus *video,
-		       struct acpi_video_device *device)
-{
-	struct acpi_video_enumerated_device *ids;
-	int i;
-
-	for (i = 0; i < video->attached_count; i++) {
-		ids = &video->attached_array[i];
-		if (device->device_id == (ids->value.int_val & 0xffff)) {
-			ids->bind_info = device;
-			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
-		}
-	}
-}
-
-static bool acpi_video_device_in_dod(struct acpi_video_device *device)
-{
-	struct acpi_video_bus *video = device->video;
-	int i;
-
-	/*
-	 * If we have a broken _DOD or we have more than 8 output devices
-	 * under the graphics controller node that we can't proper deal with
-	 * in the operation region code currently, no need to test.
-	 */
-	if (!video->attached_count || video->child_count > 8)
-		return true;
-
-	for (i = 0; i < video->attached_count; i++) {
-		if ((video->attached_array[i].value.int_val & 0xfff) ==
-		    (device->device_id & 0xfff))
-			return true;
-	}
-
-	return false;
-}
-
-/*
- *  Arg:
- *	video	: video bus device
- *
- *  Return:
- *	< 0	: error
- *
- *  Call _DOD to enumerate all devices attached to display adapter
- *
- */
-
-static int acpi_video_device_enumerate(struct acpi_video_bus *video)
-{
-	int status;
-	int count;
-	int i;
-	struct acpi_video_enumerated_device *active_list;
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *dod = NULL;
-	union acpi_object *obj;
-
-	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
-	if (!ACPI_SUCCESS(status)) {
-		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
-		return status;
-	}
-
-	dod = buffer.pointer;
-	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
-		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
-		status = -EFAULT;
-		goto out;
-	}
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
-			  dod->package.count));
-
-	active_list = kcalloc(1 + dod->package.count,
-			      sizeof(struct acpi_video_enumerated_device),
-			      GFP_KERNEL);
-	if (!active_list) {
-		status = -ENOMEM;
-		goto out;
-	}
-
-	count = 0;
-	for (i = 0; i < dod->package.count; i++) {
-		obj = &dod->package.elements[i];
-
-		if (obj->type != ACPI_TYPE_INTEGER) {
-			printk(KERN_ERR PREFIX
-				"Invalid _DOD data in element %d\n", i);
-			continue;
-		}
-
-		active_list[count].value.int_val = obj->integer.value;
-		active_list[count].bind_info = NULL;
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
-				  (int)obj->integer.value));
-		count++;
-	}
-
-	kfree(video->attached_array);
-
-	video->attached_array = active_list;
-	video->attached_count = count;
-
-out:
-	kfree(buffer.pointer);
-	return status;
-}
-
-static int
-acpi_video_get_next_level(struct acpi_video_device *device,
-			  u32 level_current, u32 event)
-{
-	int min, max, min_above, max_below, i, l, delta = 255;
-	max = max_below = 0;
-	min = min_above = 255;
-	/* Find closest level to level_current */
-	for (i = 2; i < device->brightness->count; i++) {
-		l = device->brightness->levels[i];
-		if (abs(l - level_current) < abs(delta)) {
-			delta = l - level_current;
-			if (!delta)
-				break;
-		}
-	}
-	/* Ajust level_current to closest available level */
-	level_current += delta;
-	for (i = 2; i < device->brightness->count; i++) {
-		l = device->brightness->levels[i];
-		if (l < min)
-			min = l;
-		if (l > max)
-			max = l;
-		if (l < min_above && l > level_current)
-			min_above = l;
-		if (l > max_below && l < level_current)
-			max_below = l;
-	}
-
-	switch (event) {
-	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
-		return (level_current < max) ? min_above : min;
-	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
-		return (level_current < max) ? min_above : max;
-	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
-		return (level_current > min) ? max_below : min;
-	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
-	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
-		return 0;
-	default:
-		return level_current;
-	}
-}
-
-static void
-acpi_video_switch_brightness(struct work_struct *work)
-{
-	struct acpi_video_device *device = container_of(to_delayed_work(work),
-			     struct acpi_video_device, switch_brightness_work);
-	unsigned long long level_current, level_next;
-	int event = device->switch_brightness_event;
-	int result = -EINVAL;
-
-	/* no warning message if acpi_backlight=vendor or a quirk is used */
-	if (!device->backlight)
-		return;
-
-	if (!device->brightness)
-		goto out;
-
-	result = acpi_video_device_lcd_get_level_current(device,
-							 &level_current,
-							 false);
-	if (result)
-		goto out;
-
-	level_next = acpi_video_get_next_level(device, level_current, event);
-
-	result = acpi_video_device_lcd_set_level(device, level_next);
-
-	if (!result)
-		backlight_force_update(device->backlight,
-				       BACKLIGHT_UPDATE_HOTKEY);
-
-out:
-	if (result)
-		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
-}
-
-int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
-			void **edid)
-{
-	struct acpi_video_bus *video;
-	struct acpi_video_device *video_device;
-	union acpi_object *buffer = NULL;
-	acpi_status status;
-	int i, length;
-
-	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
-
-	video = acpi_driver_data(device);
-
-	for (i = 0; i < video->attached_count; i++) {
-		video_device = video->attached_array[i].bind_info;
-		length = 256;
-
-		if (!video_device)
-			continue;
-
-		if (!video_device->cap._DDC)
-			continue;
-
-		if (type) {
-			switch (type) {
-			case ACPI_VIDEO_DISPLAY_CRT:
-				if (!video_device->flags.crt)
-					continue;
-				break;
-			case ACPI_VIDEO_DISPLAY_TV:
-				if (!video_device->flags.tvout)
-					continue;
-				break;
-			case ACPI_VIDEO_DISPLAY_DVI:
-				if (!video_device->flags.dvi)
-					continue;
-				break;
-			case ACPI_VIDEO_DISPLAY_LCD:
-				if (!video_device->flags.lcd)
-					continue;
-				break;
-			}
-		} else if (video_device->device_id != device_id) {
-			continue;
-		}
-
-		status = acpi_video_device_EDID(video_device, &buffer, length);
-
-		if (ACPI_FAILURE(status) || !buffer ||
-		    buffer->type != ACPI_TYPE_BUFFER) {
-			length = 128;
-			status = acpi_video_device_EDID(video_device, &buffer,
-							length);
-			if (ACPI_FAILURE(status) || !buffer ||
-			    buffer->type != ACPI_TYPE_BUFFER) {
-				continue;
-			}
-		}
-
-		*edid = buffer->buffer.pointer;
-		return length;
-	}
-
-	return -ENODEV;
-}
-EXPORT_SYMBOL(acpi_video_get_edid);
-
-static int
-acpi_video_bus_get_devices(struct acpi_video_bus *video,
-			   struct acpi_device *device)
-{
-	int status = 0;
-	struct acpi_device *dev;
-
-	/*
-	 * There are systems where video module known to work fine regardless
-	 * of broken _DOD and ignoring returned value here doesn't cause
-	 * any issues later.
-	 */
-	acpi_video_device_enumerate(video);
-
-	list_for_each_entry(dev, &device->children, node) {
-
-		status = acpi_video_bus_get_one_device(dev, video);
-		if (status) {
-			dev_err(&dev->dev, "Can't attach device\n");
-			break;
-		}
-		video->child_count++;
-	}
-	return status;
-}
-
-/* acpi_video interface */
-
-/*
- * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
- * preform any automatic brightness change on receiving a notification.
- */
-static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
-{
-	return acpi_video_bus_DOS(video, 0,
-				  acpi_osi_is_win8() ? 1 : 0);
-}
-
-static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
-{
-	return acpi_video_bus_DOS(video, 0,
-				  acpi_osi_is_win8() ? 0 : 1);
-}
-
-static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
-{
-	struct acpi_video_bus *video = acpi_driver_data(device);
-	struct input_dev *input;
-	int keycode = 0;
-
-	if (!video || !video->input)
-		return;
-
-	input = video->input;
-
-	switch (event) {
-	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
-					 * most likely via hotkey. */
-		keycode = KEY_SWITCHVIDEOMODE;
-		break;
-
-	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
-					 * connector. */
-		acpi_video_device_enumerate(video);
-		acpi_video_device_rebind(video);
-		keycode = KEY_SWITCHVIDEOMODE;
-		break;
-
-	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
-		keycode = KEY_SWITCHVIDEOMODE;
-		break;
-	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
-		keycode = KEY_VIDEO_NEXT;
-		break;
-	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
-		keycode = KEY_VIDEO_PREV;
-		break;
-
-	default:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Unsupported event [0x%x]\n", event));
-		break;
-	}
-
-	if (acpi_notifier_call_chain(device, event, 0))
-		/* Something vetoed the keypress. */
-		keycode = 0;
-
-	if (keycode) {
-		input_report_key(input, keycode, 1);
-		input_sync(input);
-		input_report_key(input, keycode, 0);
-		input_sync(input);
-	}
-
-	return;
-}
-
-static void brightness_switch_event(struct acpi_video_device *video_device,
-				    u32 event)
-{
-	if (!brightness_switch_enabled)
-		return;
-
-	video_device->switch_brightness_event = event;
-	schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
-}
-
-static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
-{
-	struct acpi_video_device *video_device = data;
-	struct acpi_device *device = NULL;
-	struct acpi_video_bus *bus;
-	struct input_dev *input;
-	int keycode = 0;
-
-	if (!video_device)
-		return;
-
-	device = video_device->dev;
-	bus = video_device->video;
-	input = bus->input;
-
-	switch (event) {
-	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
-		brightness_switch_event(video_device, event);
-		keycode = KEY_BRIGHTNESS_CYCLE;
-		break;
-	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
-		brightness_switch_event(video_device, event);
-		keycode = KEY_BRIGHTNESSUP;
-		break;
-	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
-		brightness_switch_event(video_device, event);
-		keycode = KEY_BRIGHTNESSDOWN;
-		break;
-	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
-		brightness_switch_event(video_device, event);
-		keycode = KEY_BRIGHTNESS_ZERO;
-		break;
-	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
-		brightness_switch_event(video_device, event);
-		keycode = KEY_DISPLAY_OFF;
-		break;
-	default:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Unsupported event [0x%x]\n", event));
-		break;
-	}
-
-	acpi_notifier_call_chain(device, event, 0);
-
-	if (keycode) {
-		input_report_key(input, keycode, 1);
-		input_sync(input);
-		input_report_key(input, keycode, 0);
-		input_sync(input);
-	}
-
-	return;
-}
-
-static int acpi_video_resume(struct notifier_block *nb,
-				unsigned long val, void *ign)
-{
-	struct acpi_video_bus *video;
-	struct acpi_video_device *video_device;
-	int i;
-
-	switch (val) {
-	case PM_HIBERNATION_PREPARE:
-	case PM_SUSPEND_PREPARE:
-	case PM_RESTORE_PREPARE:
-		return NOTIFY_DONE;
-	}
-
-	video = container_of(nb, struct acpi_video_bus, pm_nb);
-
-	dev_info(&video->device->dev, "Restoring backlight state\n");
-
-	for (i = 0; i < video->attached_count; i++) {
-		video_device = video->attached_array[i].bind_info;
-		if (video_device && video_device->brightness)
-			acpi_video_device_lcd_set_level(video_device,
-					video_device->brightness->curr);
-	}
-
-	return NOTIFY_OK;
-}
-
-static acpi_status
-acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
-			void **return_value)
-{
-	struct acpi_device *device = context;
-	struct acpi_device *sibling;
-	int result;
-
-	if (handle == device->handle)
-		return AE_CTRL_TERMINATE;
-
-	result = acpi_bus_get_device(handle, &sibling);
-	if (result)
-		return AE_OK;
-
-	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
-			return AE_ALREADY_EXISTS;
-
-	return AE_OK;
-}
-
-static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
-{
-	struct backlight_properties props;
-	struct pci_dev *pdev;
-	acpi_handle acpi_parent;
-	struct device *parent = NULL;
-	int result;
-	static int count;
-	char *name;
-
-	/*
-	 * Do not create backlight device for video output
-	 * device that is not in the enumerated list.
-	 */
-	if (!acpi_video_device_in_dod(device)) {
-		dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
-		return;
-	}
-
-	result = acpi_video_init_brightness(device);
-	if (result)
-		return;
-
-	if (disable_backlight_sysfs_if > 0)
-		return;
-
-	name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
-	if (!name)
-		return;
-	count++;
-
-	acpi_get_parent(device->dev->handle, &acpi_parent);
-
-	pdev = acpi_get_pci_dev(acpi_parent);
-	if (pdev) {
-		parent = &pdev->dev;
-		pci_dev_put(pdev);
-	}
-
-	memset(&props, 0, sizeof(struct backlight_properties));
-	props.type = BACKLIGHT_FIRMWARE;
-	props.max_brightness = device->brightness->count - 3;
-	device->backlight = backlight_device_register(name,
-						      parent,
-						      device,
-						      &acpi_backlight_ops,
-						      &props);
-	kfree(name);
-	if (IS_ERR(device->backlight)) {
-		device->backlight = NULL;
-		return;
-	}
-
-	/*
-	 * Save current brightness level in case we have to restore it
-	 * before acpi_video_device_lcd_set_level() is called next time.
-	 */
-	device->backlight->props.brightness =
-			acpi_video_get_brightness(device->backlight);
-
-	device->cooling_dev = thermal_cooling_device_register("LCD",
-				device->dev, &video_cooling_ops);
-	if (IS_ERR(device->cooling_dev)) {
-		/*
-		 * Set cooling_dev to NULL so we don't crash trying to free it.
-		 * Also, why the hell we are returning early and not attempt to
-		 * register video output if cooling device registration failed?
-		 * -- dtor
-		 */
-		device->cooling_dev = NULL;
-		return;
-	}
-
-	dev_info(&device->dev->dev, "registered as cooling_device%d\n",
-		 device->cooling_dev->id);
-	result = sysfs_create_link(&device->dev->dev.kobj,
-			&device->cooling_dev->device.kobj,
-			"thermal_cooling");
-	if (result)
-		printk(KERN_ERR PREFIX "Create sysfs link\n");
-	result = sysfs_create_link(&device->cooling_dev->device.kobj,
-			&device->dev->dev.kobj, "device");
-	if (result)
-		printk(KERN_ERR PREFIX "Create sysfs link\n");
-}
-
-static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev;
-	union acpi_object *levels;
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry(dev, &video->video_device_list, entry) {
-		if (!acpi_video_device_lcd_query_levels(dev, &levels))
-			kfree(levels);
-	}
-	mutex_unlock(&video->device_list_lock);
-}
-
-static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev;
-
-	if (video->backlight_registered)
-		return 0;
-
-	acpi_video_run_bcl_for_osi(video);
-
-	if (!acpi_video_verify_backlight_support())
-		return 0;
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry(dev, &video->video_device_list, entry)
-		acpi_video_dev_register_backlight(dev);
-	mutex_unlock(&video->device_list_lock);
-
-	video->backlight_registered = true;
-
-	video->pm_nb.notifier_call = acpi_video_resume;
-	video->pm_nb.priority = 0;
-	return register_pm_notifier(&video->pm_nb);
-}
-
-static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
-{
-	if (device->backlight) {
-		backlight_device_unregister(device->backlight);
-		device->backlight = NULL;
-	}
-	if (device->brightness) {
-		kfree(device->brightness->levels);
-		kfree(device->brightness);
-		device->brightness = NULL;
-	}
-	if (device->cooling_dev) {
-		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
-		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
-		thermal_cooling_device_unregister(device->cooling_dev);
-		device->cooling_dev = NULL;
-	}
-}
-
-static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev;
-	int error;
-
-	if (!video->backlight_registered)
-		return 0;
-
-	error = unregister_pm_notifier(&video->pm_nb);
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry(dev, &video->video_device_list, entry)
-		acpi_video_dev_unregister_backlight(dev);
-	mutex_unlock(&video->device_list_lock);
-
-	video->backlight_registered = false;
-
-	return error;
-}
-
-static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
-{
-	acpi_status status;
-	struct acpi_device *adev = device->dev;
-
-	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
-					     acpi_video_device_notify, device);
-	if (ACPI_FAILURE(status))
-		dev_err(&adev->dev, "Error installing notify handler\n");
-	else
-		device->flags.notify = 1;
-}
-
-static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
-{
-	struct input_dev *input;
-	struct acpi_video_device *dev;
-	int error;
-
-	video->input = input = input_allocate_device();
-	if (!input) {
-		error = -ENOMEM;
-		goto out;
-	}
-
-	error = acpi_video_bus_start_devices(video);
-	if (error)
-		goto err_free_input;
-
-	snprintf(video->phys, sizeof(video->phys),
-			"%s/video/input0", acpi_device_hid(video->device));
-
-	input->name = acpi_device_name(video->device);
-	input->phys = video->phys;
-	input->id.bustype = BUS_HOST;
-	input->id.product = 0x06;
-	input->dev.parent = &video->device->dev;
-	input->evbit[0] = BIT(EV_KEY);
-	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
-	set_bit(KEY_VIDEO_NEXT, input->keybit);
-	set_bit(KEY_VIDEO_PREV, input->keybit);
-	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
-	set_bit(KEY_BRIGHTNESSUP, input->keybit);
-	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
-	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
-	set_bit(KEY_DISPLAY_OFF, input->keybit);
-
-	error = input_register_device(input);
-	if (error)
-		goto err_stop_dev;
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry(dev, &video->video_device_list, entry)
-		acpi_video_dev_add_notify_handler(dev);
-	mutex_unlock(&video->device_list_lock);
-
-	return 0;
-
-err_stop_dev:
-	acpi_video_bus_stop_devices(video);
-err_free_input:
-	input_free_device(input);
-	video->input = NULL;
-out:
-	return error;
-}
-
-static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
-{
-	if (dev->flags.notify) {
-		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
-					   acpi_video_device_notify);
-		dev->flags.notify = 0;
-	}
-}
-
-static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev;
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry(dev, &video->video_device_list, entry)
-		acpi_video_dev_remove_notify_handler(dev);
-	mutex_unlock(&video->device_list_lock);
-
-	acpi_video_bus_stop_devices(video);
-	input_unregister_device(video->input);
-	video->input = NULL;
-}
-
-static int acpi_video_backlight_notify(struct notifier_block *nb,
-					unsigned long val, void *bd)
-{
-	struct backlight_device *backlight = bd;
-	struct acpi_video_bus *video;
-
-	/* acpi_video_verify_backlight_support only cares about raw devices */
-	if (backlight->props.type != BACKLIGHT_RAW)
-		return NOTIFY_DONE;
-
-	video = container_of(nb, struct acpi_video_bus, backlight_nb);
-
-	switch (val) {
-	case BACKLIGHT_REGISTERED:
-		if (!acpi_video_verify_backlight_support())
-			acpi_video_bus_unregister_backlight(video);
-		break;
-	case BACKLIGHT_UNREGISTERED:
-		acpi_video_bus_register_backlight(video);
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-static int acpi_video_bus_add_backlight_notify_handler(
-						struct acpi_video_bus *video)
-{
-	int error;
-
-	video->backlight_nb.notifier_call = acpi_video_backlight_notify;
-	video->backlight_nb.priority = 0;
-	error = backlight_register_notifier(&video->backlight_nb);
-	if (error == 0)
-		video->backlight_notifier_registered = true;
-
-	return error;
-}
-
-static int acpi_video_bus_remove_backlight_notify_handler(
-						struct acpi_video_bus *video)
-{
-	if (!video->backlight_notifier_registered)
-		return 0;
-
-	video->backlight_notifier_registered = false;
-
-	return backlight_unregister_notifier(&video->backlight_nb);
-}
-
-static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
-{
-	struct acpi_video_device *dev, *next;
-
-	mutex_lock(&video->device_list_lock);
-	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
-		list_del(&dev->entry);
-		kfree(dev);
-	}
-	mutex_unlock(&video->device_list_lock);
-
-	return 0;
-}
-
-static int instance;
-
-static int acpi_video_bus_add(struct acpi_device *device)
-{
-	struct acpi_video_bus *video;
-	int error;
-	acpi_status status;
-
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
-				device->parent->handle, 1,
-				acpi_video_bus_match, NULL,
-				device, NULL);
-	if (status == AE_ALREADY_EXISTS) {
-		printk(KERN_WARNING FW_BUG
-			"Duplicate ACPI video bus devices for the"
-			" same VGA controller, please try module "
-			"parameter \"video.allow_duplicates=1\""
-			"if the current driver doesn't work.\n");
-		if (!allow_duplicates)
-			return -ENODEV;
-	}
-
-	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
-	if (!video)
-		return -ENOMEM;
-
-	/* a hack to fix the duplicate name "VID" problem on T61 */
-	if (!strcmp(device->pnp.bus_id, "VID")) {
-		if (instance)
-			device->pnp.bus_id[3] = '0' + instance;
-		instance++;
-	}
-	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
-	if (!strcmp(device->pnp.bus_id, "VGA")) {
-		if (instance)
-			device->pnp.bus_id[3] = '0' + instance;
-		instance++;
-	}
-
-	video->device = device;
-	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
-	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
-	device->driver_data = video;
-
-	acpi_video_bus_find_cap(video);
-	error = acpi_video_bus_check(video);
-	if (error)
-		goto err_free_video;
-
-	mutex_init(&video->device_list_lock);
-	INIT_LIST_HEAD(&video->video_device_list);
-
-	error = acpi_video_bus_get_devices(video, device);
-	if (error)
-		goto err_put_video;
-
-	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
-	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
-	       video->flags.multihead ? "yes" : "no",
-	       video->flags.rom ? "yes" : "no",
-	       video->flags.post ? "yes" : "no");
-	mutex_lock(&video_list_lock);
-	list_add_tail(&video->entry, &video_bus_head);
-	mutex_unlock(&video_list_lock);
-
-	acpi_video_bus_register_backlight(video);
-	acpi_video_bus_add_notify_handler(video);
-	acpi_video_bus_add_backlight_notify_handler(video);
-
-	return 0;
-
-err_put_video:
-	acpi_video_bus_put_devices(video);
-	kfree(video->attached_array);
-err_free_video:
-	kfree(video);
-	device->driver_data = NULL;
-
-	return error;
-}
-
-static int acpi_video_bus_remove(struct acpi_device *device)
-{
-	struct acpi_video_bus *video = NULL;
-
-
-	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
-
-	video = acpi_driver_data(device);
-
-	acpi_video_bus_remove_backlight_notify_handler(video);
-	acpi_video_bus_remove_notify_handler(video);
-	acpi_video_bus_unregister_backlight(video);
-	acpi_video_bus_put_devices(video);
-
-	mutex_lock(&video_list_lock);
-	list_del(&video->entry);
-	mutex_unlock(&video_list_lock);
-
-	kfree(video->attached_array);
-	kfree(video);
-
-	return 0;
-}
-
-static int __init is_i740(struct pci_dev *dev)
-{
-	if (dev->device == 0x00D1)
-		return 1;
-	if (dev->device == 0x7000)
-		return 1;
-	return 0;
-}
-
-static int __init intel_opregion_present(void)
-{
-	int opregion = 0;
-	struct pci_dev *dev = NULL;
-	u32 address;
-
-	for_each_pci_dev(dev) {
-		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
-			continue;
-		if (dev->vendor != PCI_VENDOR_ID_INTEL)
-			continue;
-		/* We don't want to poke around undefined i740 registers */
-		if (is_i740(dev))
-			continue;
-		pci_read_config_dword(dev, 0xfc, &address);
-		if (!address)
-			continue;
-		opregion = 1;
-	}
-	return opregion;
-}
-
-int acpi_video_register(void)
-{
-	int ret;
-
-	if (register_count) {
-		/*
-		 * if the function of acpi_video_register is already called,
-		 * don't register the acpi_vide_bus again and return no error.
-		 */
-		return 0;
-	}
-
-	mutex_init(&video_list_lock);
-	INIT_LIST_HEAD(&video_bus_head);
-
-	ret = acpi_bus_register_driver(&acpi_video_bus);
-	if (ret)
-		return ret;
-
-	/*
-	 * When the acpi_video_bus is loaded successfully, increase
-	 * the counter reference.
-	 */
-	register_count = 1;
-
-	return 0;
-}
-EXPORT_SYMBOL(acpi_video_register);
-
-void acpi_video_unregister(void)
-{
-	if (!register_count) {
-		/*
-		 * If the acpi video bus is already unloaded, don't
-		 * unload it again and return directly.
-		 */
-		return;
-	}
-	acpi_bus_unregister_driver(&acpi_video_bus);
-
-	register_count = 0;
-
-	return;
-}
-EXPORT_SYMBOL(acpi_video_unregister);
-
-void acpi_video_unregister_backlight(void)
-{
-	struct acpi_video_bus *video;
-
-	if (!register_count)
-		return;
-
-	mutex_lock(&video_list_lock);
-	list_for_each_entry(video, &video_bus_head, entry)
-		acpi_video_bus_unregister_backlight(video);
-	mutex_unlock(&video_list_lock);
-}
-EXPORT_SYMBOL(acpi_video_unregister_backlight);
-
-/*
- * This is kind of nasty. Hardware using Intel chipsets may require
- * the video opregion code to be run first in order to initialise
- * state before any ACPI video calls are made. To handle this we defer
- * registration of the video class until the opregion code has run.
- */
-
-static int __init acpi_video_init(void)
-{
-	/*
-	 * Let the module load even if ACPI is disabled (e.g. due to
-	 * a broken BIOS) so that i915.ko can still be loaded on such
-	 * old systems without an AcpiOpRegion.
-	 *
-	 * acpi_video_register() will report -ENODEV later as well due
-	 * to acpi_disabled when i915.ko tries to register itself afterwards.
-	 */
-	if (acpi_disabled)
-		return 0;
-
-	dmi_check_system(video_dmi_table);
-
-	if (intel_opregion_present())
-		return 0;
-
-	return acpi_video_register();
-}
-
-static void __exit acpi_video_exit(void)
-{
-	acpi_video_unregister();
-
-	return;
-}
-
-module_init(acpi_video_init);
-module_exit(acpi_video_exit);