[ACPI] Extensions for Display Adapters (Bruno Ducrot)

http://bugme.osdl.org/show_bug.cgi?id=1944Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/power/video_extension.txt

+This driver implement the ACPI Extensions For Display Adapters
+for integrated graphics devices on motherboard, as specified in
+ACPI 2.0 Specification, Appendix B, allowing to perform some basic
+control like defining the video POST device, retrieving EDID information
+or to setup a video output, etc.  Note that this is an ref. implementation only.
+It may or may not work for your integrated video device.
+
+Interfaces exposed to userland through /proc/acpi/video:
+
+VGA/info : display the supported video bus device capability like ,Video ROM, CRT/LCD/TV.
+VGA/ROM :  Used to get a copy of the display devices' ROM data (up to 4k).
+VGA/POST_info : Used to determine what options are implemented.
+VGA/POST : Used to get/set POST device.
+VGA/DOS : Used to get/set ownership of output switching:
+	Please refer ACPI spec B.4.1 _DOS
+VGA/CRT : CRT output
+VGA/LCD : LCD output
+VGA/TV : TV output 
+VGA/*/brightness : Used to get/set brightness of output device
+
+Notify event through /proc/acpi/event:
+
+#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      0x82
+#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x83
+#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x84
+#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x85
+#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x86
+

drivers/acpi/Kconfig

@@ -110,6 +110,20 @@ config ACPI_BUTTON
 	  down the system.  Until then, you can cat it, and see output when
 	  a button is pressed.
 
+config ACPI_VIDEO
+	tristate "Video"
+	depends on ACPI_INTERPRETER
+	depends on !IA64_SGI_SN
+	default m
+	help
+	  This driver implement the ACPI Extensions For Display Adapters
+	  for integrated graphics devices on motherboard, as specified in
+	  ACPI 2.0 Specification, Appendix B, allowing to perform some basic
+	  control like defining the video POST device, retrieving EDID information
+	  or to setup a video output, etc.
+	  Note that this is an ref. implementation only.  It may or may not work
+	  for your integrated video device.
+
 config ACPI_FAN
 	tristate "Fan"
 	depends on ACPI_INTERPRETER

drivers/acpi/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
 obj-$(CONFIG_ACPI_BUTTON)	+= button.o
 obj-$(CONFIG_ACPI_EC)		+= ec.o
 obj-$(CONFIG_ACPI_FAN)		+= fan.o
+obj-$(CONFIG_ACPI_VIDEO)	+= video.o
 obj-$(CONFIG_ACPI_PCI)		+= pci_root.o pci_link.o pci_irq.o pci_bind.o
 obj-$(CONFIG_ACPI_POWER)	+= power.o
 obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o

drivers/acpi/scan.c

@@ -312,7 +312,12 @@ acpi_bus_match (
 	struct acpi_device	*device,
 	struct acpi_driver	*driver)
 {
-	return acpi_match_ids(device, driver->ids);
+	int error = 0;
+
+	error = driver->ops.match ? driver->ops.match(device, driver) : 
+			acpi_match_ids(device, driver->ids) ;
+
+	return error;
 }
 
 

drivers/acpi/video.c

+/*
+ *  video.c - ACPI Video Driver ($Revision:$)
+ *
+ *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
+ *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <asm/uaccess.h>
+
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+#define ACPI_VIDEO_COMPONENT		0x08000000
+#define ACPI_VIDEO_CLASS		"video"
+#define ACPI_VIDEO_DRIVER_NAME		"ACPI Video Driver"
+#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	0x82
+#define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x83
+#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x84
+#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x85
+#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x86
+
+
+#define ACPI_VIDEO_HEAD_INVALID		(~0ul - 1)
+#define ACPI_VIDEO_HEAD_END		(~0ul)
+
+
+#define _COMPONENT		ACPI_VIDEO_COMPONENT
+ACPI_MODULE_NAME		("acpi_video")
+
+MODULE_AUTHOR("Bruno Ducrot");
+MODULE_DESCRIPTION(ACPI_VIDEO_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+
+static int acpi_video_bus_add (struct acpi_device *device);
+static int acpi_video_bus_remove (struct acpi_device *device, int type);
+static int acpi_video_bus_match (struct acpi_device *device, struct acpi_driver *driver);
+
+static struct acpi_driver acpi_video_bus = {
+	.name = ACPI_VIDEO_DRIVER_NAME,
+	.class = ACPI_VIDEO_CLASS,
+	.ops = {
+		.add = acpi_video_bus_add,
+		.remove = acpi_video_bus_remove,
+		.match = acpi_video_bus_match,
+	},
+};
+
+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 differenates displays type*/
+	u32	display_type:4;	/*Describe the specific type in use*/
+	u32	vendor_specific:4; /*Chipset Vendor Specifi*/ 
+	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 {
+	acpi_handle	handle;
+	u8	dos_setting;
+	struct acpi_video_enumerated_device *attached_array;
+	u8			attached_count;
+	struct acpi_video_bus_cap	cap;
+	struct acpi_video_bus_flags flags;
+	struct semaphore	sem;
+	struct list_head	video_device_list;
+	struct proc_dir_entry	*dir;
+};
+
+struct acpi_video_device_flags {
+	u8	crt:1;
+	u8	lcd:1;
+	u8	tvout:1;
+	u8	bios:1;
+	u8	unknown:1;
+	u8	reserved:3;
+};
+
+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	_DDC:1; /*Return the EDID for this device*/
+	u8	_DCS:1; /*Return status of output device*/
+	u8	_DGS:1; /*Query graphics state*/
+	u8	_DSS:1; /*Device state set*/
+	u8	_reserved:1;
+};
+
+struct acpi_video_device_brightness {
+	int	curr;
+	int	count;
+	int	*levels;
+};
+
+struct acpi_video_device {
+	acpi_handle		handle;
+	unsigned long		device_id;
+	struct acpi_video_device_flags	flags;
+	struct acpi_video_device_cap	cap;
+	struct list_head	entry;
+	struct acpi_video_bus	*video;
+	struct acpi_device	*dev;
+	struct acpi_video_device_brightness *brightness;
+};
+
+
+/* bus */
+static int acpi_video_bus_info_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_bus_info_fops = {
+	.open		= acpi_video_bus_info_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_bus_ROM_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_bus_ROM_fops = {
+	.open		= acpi_video_bus_ROM_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_bus_POST_info_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_bus_POST_info_fops = {
+	.open		= acpi_video_bus_POST_info_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_bus_POST_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_bus_POST_fops = {
+	.open		= acpi_video_bus_POST_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+
+static int acpi_video_bus_DOS_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_bus_DOS_fops = {
+	.open		= acpi_video_bus_DOS_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+/* device */
+static int acpi_video_device_info_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_device_info_fops = {
+	.open		= acpi_video_device_info_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_device_state_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_device_state_fops = {
+	.open		= acpi_video_device_state_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_device_brightness_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_device_brightness_fops = {
+	.open		= acpi_video_device_brightness_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int acpi_video_device_EDID_open_fs(struct inode *inode, struct file *file);
+static struct file_operations acpi_video_device_EDID_fops = {
+	.open		= acpi_video_device_EDID_open_fs,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+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_switch_output( struct acpi_video_bus *video, int	event);
+static int acpi_video_get_next_level( struct acpi_video_device *device, u32 level_current,u32 event);
+static void acpi_video_switch_brightness ( struct acpi_video_device *device, int event);
+
+
+/* --------------------------------------------------------------------------
+                               Video Management
+   -------------------------------------------------------------------------- */
+
+/* device */
+
+static int
+acpi_video_device_query (
+	struct acpi_video_device	*device,
+	unsigned long			*state)
+{
+	int			status;
+	ACPI_FUNCTION_TRACE("acpi_video_device_query");
+	status = acpi_evaluate_integer(device->handle, "_DGS", NULL, state);
+
+	return_VALUE(status);
+}
+
+static int
+acpi_video_device_get_state (
+	struct acpi_video_device	*device,
+	unsigned long 		*state)
+{
+	int			status;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_get_state");
+
+	status = acpi_evaluate_integer(device->handle, "_DCS", NULL, state);
+
+	return_VALUE(status);
+}
+
+static int
+acpi_video_device_set_state (
+	struct acpi_video_device	*device,
+	int			state)
+{
+	int			status;
+	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
+	struct acpi_object_list	args = {1, &arg0};
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_set_state");
+
+	arg0.integer.value = state;
+	status = acpi_evaluate_integer(device->handle, "_DSS", &args, NULL);
+
+	return_VALUE(status);
+}
+
+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;
+
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_query_levels");
+
+	*levels = NULL;
+
+	status = acpi_evaluate_object(device->handle, "_BCL", NULL, &buffer);
+	if (!ACPI_SUCCESS(status))
+		return_VALUE(status);
+	obj = (union acpi_object *) buffer.pointer;
+	if (!obj && (obj->type != ACPI_TYPE_PACKAGE)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _BCL data\n"));
+		status = -EFAULT;
+		goto err;
+	}
+
+	*levels = obj;
+
+	return_VALUE(0);
+
+err:
+	if (buffer.pointer)
+		kfree(buffer.pointer);
+
+	return_VALUE(status);
+}
+
+static int
+acpi_video_device_lcd_set_level (
+	struct acpi_video_device	*device,
+	int				level)
+{
+	int			status;
+	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
+	struct acpi_object_list	args = {1, &arg0};
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_set_level");
+
+	arg0.integer.value = level;
+	status = acpi_evaluate_object(device->handle, "_BCM", &args, NULL);
+
+	printk(KERN_DEBUG "set_level status: %x\n", status);
+	return_VALUE(status);
+}
+
+static int
+acpi_video_device_lcd_get_level_current (
+	struct acpi_video_device	*device,
+	unsigned long 	*level)
+{
+	int			status;
+	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_get_level_current");
+
+	status = acpi_evaluate_integer(device->handle, "_BQC", NULL, level);
+
+	return_VALUE(status);
+}
+
+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};
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_get_EDID");
+
+	*edid = NULL;
+
+	if (!device)
+		return_VALUE(-ENODEV);
+	if (length == 128)
+		arg0.integer.value = 1;
+	else if (length == 256)
+		arg0.integer.value = 2;
+	else
+		return_VALUE(-EINVAL);
+
+	status = acpi_evaluate_object(device->handle, "_DDC", &args, &buffer);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+
+	obj = (union acpi_object *) buffer.pointer;
+
+	if (obj && obj->type == ACPI_TYPE_BUFFER)
+		*edid = obj;
+	else {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DDC data\n"));
+		status = -EFAULT;
+		kfree(obj);
+	}
+
+	return_VALUE(status);
+}
+
+
+/* bus */
+
+static int
+acpi_video_bus_set_POST (
+	struct acpi_video_bus	*video,
+	unsigned long		option)
+{
+	int			status;
+	unsigned long		tmp;
+	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
+	struct acpi_object_list	args = {1, &arg0};
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_set_POST");
+
+	arg0.integer.value = option;
+
+	status = acpi_evaluate_integer(video->handle, "_SPD", &args, &tmp);
+	if (ACPI_SUCCESS(status))
+		status = tmp ? (-EINVAL):(AE_OK);
+
+	return_VALUE(status);
+}
+
+static int
+acpi_video_bus_get_POST (
+	struct acpi_video_bus	*video,
+	unsigned long		*id)
+{
+	int status;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_get_POST");
+
+	status = acpi_evaluate_integer(video->handle, "_GPD", NULL, id);
+
+	return_VALUE(status);
+}
+
+static int
+acpi_video_bus_POST_options (
+	struct acpi_video_bus	*video,
+	unsigned long		*options)
+{
+	int			status;
+	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_options");
+
+	status = acpi_evaluate_integer(video->handle, "_VPO", NULL, options);
+	*options &= 3;
+
+	return_VALUE(status);
+}
+
+/*
+ *  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 swich 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:
+ * 		-1	wrong arg.
+ */
+
+static int
+acpi_video_bus_DOS(
+	struct acpi_video_bus	*video,
+	int			bios_flag,
+	int			lcd_flag)
+{
+	acpi_integer		status = 0;
+	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
+	struct acpi_object_list	args = {1, &arg0};
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_DOS");
+
+	if (bios_flag < 0 || bios_flag >3 || lcd_flag < 0 || lcd_flag > 1){
+		status = -1;
+		goto Failed;
+	}
+	arg0.integer.value = (lcd_flag << 2) | bios_flag;
+	video->dos_setting = arg0.integer.value;
+	acpi_evaluate_object(video->handle, "_DOS", &args, NULL);
+
+Failed:
+	return_VALUE(status);
+}
+
+/*
+ *  Arg:	
+ *  	device	: video output device (LCD, CRT, ..)
+ *
+ *  Return Value:
+ *  	None
+ *
+ *  Find out all required AML method defined under the output
+ *  device.
+ */
+
+static void
+acpi_video_device_find_cap (struct acpi_video_device *device)
+{
+	acpi_integer		status;
+	acpi_handle h_dummy1;
+	int i;
+	union acpi_object *obj = NULL;
+	struct acpi_video_device_brightness *br = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_find_cap");
+
+	memset( &device->cap, 0, 4);
+
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_ADR", &h_dummy1))) {
+		device->cap._ADR = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_BCL", &h_dummy1))) {
+		device->cap._BCL= 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_BCM", &h_dummy1))) {
+		device->cap._BCM= 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DDC", &h_dummy1))) {
+		device->cap._DDC= 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DCS", &h_dummy1))) {
+		device->cap._DCS = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DGS", &h_dummy1))) {
+		device->cap._DGS = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DSS", &h_dummy1))) {
+		device->cap._DSS = 1;
+	}
+
+	status = acpi_video_device_lcd_query_levels(device, &obj);
+
+	if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count >= 2) {
+		int count = 0;
+		union acpi_object *o;
+		
+		br = kmalloc(sizeof &br, GFP_KERNEL);
+		if (!br) {
+			printk(KERN_ERR "can't allocate memory\n");
+		} else {
+			memset(br, 0, sizeof &br);
+			br->levels = kmalloc(obj->package.count * sizeof &br->levels, GFP_KERNEL);
+			if (!br->levels)
+				goto out;
+
+			for (i = 0; i < obj->package.count; i++) {
+				o = (union acpi_object *) &obj->package.elements[i];
+				if (o->type != ACPI_TYPE_INTEGER) {
+					ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data\n"));
+					continue;
+				}
+				br->levels[count] = (u32) o->integer.value;
+				count++;
+			}
+out:
+			if (count < 2) {
+				if (br->levels)
+					kfree(br->levels);
+				kfree(br);
+			} else {
+				br->count = count;
+				device->brightness = br;
+				ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count));
+			}
+		}
+	}
+
+	if (obj)
+		kfree(obj);
+
+	return_VOID;
+}
+
+/*
+ *  Arg:	
+ *  	device	: video output device (VGA)
+ *
+ *  Return Value:
+ *  	None
+ *
+ *  Find out all required AML method defined under the video bus device.
+ */
+
+static void 
+acpi_video_bus_find_cap (struct acpi_video_bus *video)
+{
+	acpi_handle	h_dummy1;
+
+	memset(&video->cap ,0, 4);
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_DOS", &h_dummy1))) {
+		video->cap._DOS = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_DOD", &h_dummy1))) {
+		video->cap._DOD = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_ROM", &h_dummy1))) {
+		video->cap._ROM = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_GPD", &h_dummy1))) {
+		video->cap._GPD = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_SPD", &h_dummy1))) {
+		video->cap._SPD = 1;
+	}
+    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_VPO", &h_dummy1))) {
+		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;
+
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_check");
+
+	if (!video)
+		return_VALUE(-EINVAL);
+
+	/* Since there is no HID, CID and so on for VGA driver, we have
+	 * to check well known required nodes.
+	 */
+
+	/* Does this device able to support video switching ? */
+	if(video->cap._DOS){
+		video->flags.multihead = 1;
+		status = 0;
+	}
+
+	/* Does this device able to retrieve a retrieve a video ROM ? */
+	if(video->cap._ROM){
+		video->flags.rom = 1;
+		status = 0;
+	}
+
+	/* Does this device able to configure which video device to POST ? */
+	if(video->cap._GPD && video->cap._SPD && video->cap._VPO){
+		video->flags.post = 1;
+		status = 0;
+	}
+
+	return_VALUE(status);
+}
+
+/* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+
+struct proc_dir_entry		*acpi_video_dir;
+
+/* video devices */
+
+static ssize_t
+acpi_video_device_info_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_info_seq_show");
+
+	if (!dev)
+		goto end;
+
+	seq_printf(seq, "device_id:    0x%04x\n", (u32) dev->device_id);
+	seq_printf(seq, "type:         ");
+	if (dev->flags.crt)
+		seq_printf(seq, "CRT\n");
+	else if (dev->flags.lcd)
+		seq_printf(seq, "LCD\n");
+	else if (dev->flags.tvout)
+		seq_printf(seq, "TVOUT\n");
+	else
+		seq_printf(seq, "UNKNOWN\n");
+
+	seq_printf(seq,"known by bios: %s\n",
+		   dev->flags.bios ? "yes":"no");
+
+end:
+	return_VALUE(0);
+}
+
+static int
+acpi_video_device_info_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_device_info_seq_show,
+			   PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_device_state_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	int			status;
+	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
+	unsigned long	state;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_state_seq_show");
+
+	if (!dev)
+		goto end;
+
+	status = acpi_video_device_get_state(dev, &state);
+	seq_printf(seq, "state:     ");
+	if (ACPI_SUCCESS(status))
+		seq_printf(seq, "0x%02lx\n", state);
+	else
+		seq_printf(seq, "<not supported>\n");
+
+	status = acpi_video_device_query(dev, &state);
+	seq_printf(seq, "query:     ");
+	if (ACPI_SUCCESS(status))
+		seq_printf(seq, "0x%02lx\n", state);
+	else
+		seq_printf(seq, "<not supported>\n");
+
+end:
+	return_VALUE(0);
+}
+
+static int
+acpi_video_device_state_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_device_state_seq_show,
+			   PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_device_write_state (
+	struct file		*file,
+	const char		__user *buffer,
+	size_t			count,
+	loff_t			*data)
+{
+	int			status;
+	struct seq_file		*m = (struct seq_file *) file->private_data;
+	struct acpi_video_device	*dev = (struct acpi_video_device *) m->private;
+	char			str[12] = {0};
+	u32			state = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_write_state");
+
+	if (!dev || count + 1 > sizeof str)
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(str, buffer, count))
+		return_VALUE(-EFAULT);
+
+	str[count] = 0;
+	state = simple_strtoul(str, NULL, 0);
+	state &= ((1ul<<31) | (1ul<<30) | (1ul<<0));
+
+	status = acpi_video_device_set_state(dev, state);
+
+	if (status)
+		return_VALUE(-EFAULT);
+
+	return_VALUE(count);
+}
+
+static ssize_t
+acpi_video_device_brightness_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
+	int			i;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_brightness_seq_show");
+
+	if (!dev || !dev->brightness) {
+		seq_printf(seq, "<not supported>\n");
+		return_VALUE(0);
+	}
+
+	seq_printf(seq, "levels: ");
+	for (i = 0; i < dev->brightness->count; i++)
+		seq_printf(seq, " %d", dev->brightness->levels[i]);
+	seq_printf(seq, "\ncurrent: %d\n", dev->brightness->curr);
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_device_brightness_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_device_brightness_seq_show,
+			   PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_device_write_brightness (
+	struct file		*file,
+	const char		__user *buffer,
+	size_t			count,
+	loff_t			*data)
+{
+	struct seq_file		*m = (struct seq_file *) file->private_data;
+	struct acpi_video_device	*dev = (struct acpi_video_device *) m->private;
+	char			str[4] = {0};
+	unsigned int		level = 0;
+	int			i;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_write_brightness");
+
+	if (!dev || count + 1 > sizeof str)
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(str, buffer, count))
+		return_VALUE(-EFAULT);
+
+	str[count] = 0;
+	level = simple_strtoul(str, NULL, 0);
+	
+	if (level > 100)
+		return_VALUE(-EFAULT);
+
+	/* validate though the list of available levels */
+	for (i = 0; i < dev->brightness->count; i++)
+		if (level == dev->brightness->levels[i]) {
+			if (ACPI_SUCCESS(acpi_video_device_lcd_set_level(dev, level)))
+				dev->brightness->curr = level;
+			break;
+		}
+
+	return_VALUE(count);
+}
+
+static ssize_t
+acpi_video_device_EDID_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
+	int			status;
+	int			i;
+	union acpi_object	*edid = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_EDID_seq_show");
+
+	if (!dev)
+		goto out;
+
+	status = acpi_video_device_EDID (dev, &edid, 128);
+	if (ACPI_FAILURE(status)) {
+		status = acpi_video_device_EDID (dev, &edid, 256);
+	}
+
+	if (ACPI_FAILURE(status)) {
+		goto out;
+	}
+
+	if (edid && edid->type == ACPI_TYPE_BUFFER) {
+		for (i = 0; i < edid->buffer.length; i++)
+			seq_putc(seq, edid->buffer.pointer[i]);
+	}
+
+out:
+	if (!edid)
+		seq_printf(seq, "<not supported>\n");
+	else
+		kfree(edid);
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_device_EDID_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_device_EDID_seq_show,
+			   PDE(inode)->data);
+}
+
+
+static int
+acpi_video_device_add_fs (
+	struct acpi_device	*device)
+{
+	struct proc_dir_entry	*entry = NULL;
+	struct acpi_video_device *vid_dev;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_add_fs");
+
+	if (!device)
+		return_VALUE(-ENODEV);
+
+	vid_dev = (struct acpi_video_device *) acpi_driver_data(device);
+	if (!vid_dev)
+		return_VALUE(-ENODEV);
+
+	if (!acpi_device_dir(device)) {
+		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+				vid_dev->video->dir);
+		if (!acpi_device_dir(device))
+			return_VALUE(-ENODEV);
+	}
+
+	/* 'info' [R] */
+	entry = create_proc_entry("info", S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create 'info' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_device_info_fops;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'state' [R/W] */
+	entry = create_proc_entry("state", S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create 'state' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_device_state_fops;
+		entry->proc_fops->write = acpi_video_device_write_state;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'brightness' [R/W] */
+	entry = create_proc_entry("brightness", S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create 'brightness' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_device_brightness_fops;
+		entry->proc_fops->write = acpi_video_device_write_brightness;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'EDID' [R] */
+	entry = create_proc_entry("EDID", S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create 'brightness' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_device_EDID_fops;
+		entry->data = acpi_driver_data(device);
+	}
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_device_remove_fs (
+	struct acpi_device	*device)
+{
+	struct acpi_video_device *vid_dev;
+	ACPI_FUNCTION_TRACE("acpi_video_device_remove_fs");
+
+	vid_dev = (struct acpi_video_device *) acpi_driver_data(device);
+	if (!vid_dev || !vid_dev->video || !vid_dev->video->dir)
+		return_VALUE(-ENODEV);
+
+	if (acpi_device_dir(device)) {
+		remove_proc_entry(acpi_device_bid(device), vid_dev->video->dir);
+		acpi_device_dir(device) = NULL;
+	}
+
+	return_VALUE(0);
+}
+
+
+/* video bus */
+static ssize_t
+acpi_video_bus_info_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_info_seq_show");
+
+	if (!video)
+		goto end;
+
+	seq_printf(seq, "Switching heads:              %s\n",
+			video->flags.multihead ? "yes":"no");
+	seq_printf(seq, "Video ROM:                    %s\n",
+			video->flags.rom ? "yes":"no");
+	seq_printf(seq, "Device to be POSTed on boot:  %s\n",
+			video->flags.post ? "yes":"no");
+
+end:
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_info_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_bus_info_seq_show, PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_bus_ROM_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_ROM_seq_show");
+
+	if (!video)
+		goto end;
+
+	printk(KERN_INFO PREFIX "Please implement %s\n", __FUNCTION__);
+	seq_printf(seq, "<TODO>\n");
+
+end:
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_ROM_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_bus_ROM_seq_show, PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_bus_POST_info_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
+	unsigned long		options;
+	int			status;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_info_seq_show");
+
+	if (!video)
+		goto end;
+
+	status = acpi_video_bus_POST_options(video, &options);
+	if (ACPI_SUCCESS(status)) {
+		if (!(options & 1)) {
+			printk(KERN_WARNING PREFIX "The motherboard VGA device is not listed as a possible POST device.\n");
+			printk(KERN_WARNING PREFIX "This indicate a BIOS bug.  Please contact the manufacturer.\n");
+		}
+		printk("%lx\n", options);
+		seq_printf(seq, "can POST: <intgrated video>");
+		if (options & 2)
+			seq_printf(seq, " <PCI video>");
+		if (options & 4)
+			seq_printf(seq, " <AGP video>");
+		seq_putc(seq, '\n');
+	} else
+		seq_printf(seq, "<not supported>\n");
+end:
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_POST_info_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_bus_POST_info_seq_show, PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_bus_POST_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
+	int			status;
+	unsigned long		id;
+	char			device_decode[][30] = {
+					"motherboard VGA device",
+					"PCI VGA device",
+					"AGP VGA device",
+					"UNKNOWN",
+	};
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_seq_show");
+
+	if (!video)
+		goto end;
+
+	status = acpi_video_bus_get_POST (video, &id);
+	if (!ACPI_SUCCESS(status)) {
+		seq_printf(seq, "<not supported>\n");
+		goto end;
+	}
+	seq_printf(seq, "device posted is <%s>\n",  device_decode[id & 3]);
+
+end:
+	return_VALUE(0);
+}
+
+static ssize_t
+acpi_video_bus_DOS_seq_show (
+	struct seq_file		*seq,
+	void			*offset)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_DOS_seq_show");
+
+	seq_printf(seq, "DOS setting: <%d>\n", video->dos_setting );
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_POST_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_bus_POST_seq_show, PDE(inode)->data);
+}
+
+static int
+acpi_video_bus_DOS_open_fs (
+	struct inode		*inode,
+	struct file		*file)
+{
+	return single_open(file, acpi_video_bus_DOS_seq_show, PDE(inode)->data);
+}
+
+static ssize_t
+acpi_video_bus_write_POST (
+	struct file		*file,
+	const char		__user *buffer,
+	size_t			count,
+	loff_t			*data)
+{
+	int			status;
+	struct seq_file		*m = (struct seq_file *) file->private_data;
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) m->private;
+	char			str[12] = {0};
+	unsigned long		opt, options;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_write_POST");
+
+
+	if (!video || count + 1 > sizeof str)
+		return_VALUE(-EINVAL);
+
+	status = acpi_video_bus_POST_options(video, &options);
+	if (!ACPI_SUCCESS(status))
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(str, buffer, count))
+		return_VALUE(-EFAULT);
+
+	str[count] = 0;
+	opt = strtoul(str, NULL, 0);
+	if (opt > 3)
+		return_VALUE(-EFAULT);
+
+	/* just in case an OEM 'forget' the motherboard... */
+	options |= 1;
+
+	if (options & (1ul << opt)) {
+		status = acpi_video_bus_set_POST (video, opt);
+		if (!ACPI_SUCCESS(status))
+			return_VALUE(-EFAULT);
+
+	}
+
+
+	return_VALUE(count);
+}
+
+static ssize_t
+acpi_video_bus_write_DOS (
+	struct file		*file,
+	const char		__user *buffer,
+	size_t			count,
+	loff_t			*data)
+{
+	int			status;
+	struct seq_file		*m = (struct seq_file *) file->private_data;
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) m->private;
+	char			str[12] = {0};
+	unsigned long		opt;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_write_DOS");
+
+
+	if (!video || count + 1 > sizeof str)
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(str, buffer, count))
+		return_VALUE(-EFAULT);
+
+	str[count] = 0;
+	opt = strtoul(str, NULL, 0);
+	if (opt > 7)
+		return_VALUE(-EFAULT);
+
+	status = acpi_video_bus_DOS (video, opt & 0x3, (opt & 0x4)>>2);
+
+	if (!ACPI_SUCCESS(status))
+		return_VALUE(-EFAULT);
+
+	return_VALUE(count);
+}
+
+static int
+acpi_video_bus_add_fs (
+	struct acpi_device	*device)
+{
+	struct proc_dir_entry	*entry = NULL;
+	struct acpi_video_bus	*video;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_add_fs");
+
+	video = (struct acpi_video_bus *) acpi_driver_data(device);
+
+	if (!acpi_device_dir(device)) {
+		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+				acpi_video_dir);
+		if (!acpi_device_dir(device))
+			return_VALUE(-ENODEV);
+	}
+
+	video->dir = acpi_device_dir(device);
+
+	/* 'info' [R] */
+	entry = create_proc_entry("info", S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'info' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_bus_info_fops;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'ROM' [R] */
+	entry = create_proc_entry("ROM", S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'ROM' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_bus_ROM_fops;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'POST_info' [R] */
+	entry = create_proc_entry("POST_info", S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'POST_info' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_bus_POST_info_fops;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'POST' [R/W] */
+	entry = create_proc_entry("POST", S_IFREG|S_IRUGO|S_IRUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'POST' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_bus_POST_fops;
+		entry->proc_fops->write = acpi_video_bus_write_POST;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'DOS' [R/W] */
+	entry = create_proc_entry("DOS", S_IFREG|S_IRUGO|S_IRUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'DOS' fs entry\n"));
+	else {
+		entry->proc_fops = &acpi_video_bus_DOS_fops;
+		entry->proc_fops->write = acpi_video_bus_write_DOS;
+		entry->data = acpi_driver_data(device);
+	}
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_remove_fs (
+	struct acpi_device	*device)
+{
+	ACPI_FUNCTION_TRACE("acpi_video_bus_remove_fs");
+
+	if (acpi_device_dir(device)) {
+		remove_proc_entry(acpi_device_bid(device), acpi_video_dir);
+		acpi_device_dir(device) = NULL;
+	}
+
+	return_VALUE(0);
+}
+
+/* --------------------------------------------------------------------------
+                                 Driver Interface
+   -------------------------------------------------------------------------- */
+
+/* device interface */
+
+static int
+acpi_video_bus_get_one_device (
+	struct acpi_device	*device,
+	struct acpi_video_bus	*video)
+{
+	unsigned long		device_id;
+	int			status, result;
+	struct acpi_video_device	*data;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_get_one_device");
+
+	if (!device || !video)
+		return_VALUE(-EINVAL);
+
+	status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
+	if (ACPI_SUCCESS(status)) {
+
+		data = kmalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
+		if (!data)
+			return_VALUE(-ENOMEM);
+
+		memset(data, 0, sizeof(struct acpi_video_device));
+
+		data->handle = device->handle;
+		strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
+		strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
+		acpi_driver_data(device) = data;
+
+		data->device_id = device_id;
+		data->video = video;
+		data->dev = device;
+
+		switch (device_id & 0xffff) {
+		case 0x0100:
+			data->flags.crt = 1;
+			break;
+		case 0x0400:
+			data->flags.lcd = 1;
+			break;
+		case 0x0200:
+			data->flags.tvout = 1;
+			break;
+		default:
+			data->flags.unknown = 1;
+			break;
+		}
+		
+		acpi_video_device_bind(video, data);
+		acpi_video_device_find_cap(data);
+
+		status = acpi_install_notify_handler(data->handle,
+			ACPI_DEVICE_NOTIFY, acpi_video_device_notify, data);
+		if (ACPI_FAILURE(status)) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				"Error installing notify handler\n"));
+			result = -ENODEV;
+			goto end;
+		}
+
+		down(&video->sem);
+		list_add_tail(&data->entry, &video->video_device_list);
+		up(&video->sem);
+
+		acpi_video_device_add_fs(device);
+
+		return_VALUE(0);
+	}
+
+end:
+	return_VALUE(-ENOENT);
+}
+
+/*
+ *  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 list_head * node, * next;
+	list_for_each_safe(node, next, &video->video_device_list) {
+		struct acpi_video_device * dev = container_of(node, struct acpi_video_device, entry);
+		acpi_video_device_bind( video, dev);
+	}
+}
+
+/*
+ *  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)
+{
+	int	i;
+	ACPI_FUNCTION_TRACE("acpi_video_device_bind");
+
+#define IDS_VAL(i) video->attached_array[i].value.int_val
+#define IDS_BIND(i) video->attached_array[i].bind_info
+	
+	for (i = 0; IDS_VAL(i) != ACPI_VIDEO_HEAD_INVALID && 
+		i < video->attached_count; i++) {
+		if (device->device_id == (IDS_VAL(i)& 0xffff)) {
+			IDS_BIND(i) = device;
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
+		}
+	}
+#undef IDS_VAL
+#undef IDS_BIND
+}
+
+/*
+ *  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_device_list;
+	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object	*dod = NULL;
+	union acpi_object	*obj;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_enumerate");
+
+	status = acpi_evaluate_object(video->handle, "_DOD", NULL, &buffer);
+	if (!ACPI_SUCCESS(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _DOD\n"));
+		return_VALUE(status);
+	}
+
+	dod = (union acpi_object *) buffer.pointer;
+	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DOD data\n"));
+		status = -EFAULT;
+		goto out;
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
+		dod->package.count));
+
+	active_device_list= kmalloc(
+ 		dod->package.count*sizeof(struct acpi_video_enumerated_device),
+	       	GFP_KERNEL);
+
+	if (!active_device_list) {
+		status = -ENOMEM;
+		goto out;
+	}
+
+	count = 0;
+	for (i = 0; i < dod->package.count; i++) {
+		obj = (union acpi_object *) &dod->package.elements[i];
+
+		if (obj->type != ACPI_TYPE_INTEGER) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DOD data\n"));
+			active_device_list[i].value.int_val = ACPI_VIDEO_HEAD_INVALID;
+		}
+		active_device_list[i].value.int_val = obj->integer.value;
+		active_device_list[i].bind_info = NULL;
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i, (int) obj->integer.value));
+		count++;
+	}
+	active_device_list[count].value.int_val = ACPI_VIDEO_HEAD_END;
+
+	if(video->attached_array)
+		kfree(video->attached_array);
+	
+	video->attached_array = active_device_list;
+	video->attached_count = count;
+out:
+	acpi_os_free(buffer.pointer);
+	return_VALUE(status);
+}
+
+/*
+ *  Arg:
+ *  	video	: video bus device 
+ *  	event	: Nontify Event
+ *
+ *  Return:
+ *  	< 0	: error
+ *  
+ *	1. Find out the current active output device.
+ *	2. Identify the next output device to switch
+ *	3. call _DSS to do actual switch.
+ */  
+
+static int 
+acpi_video_switch_output(
+	struct acpi_video_bus *video, 
+	int	event)
+{
+	struct list_head * node, * next;
+	struct acpi_video_device *dev=NULL;
+       	struct acpi_video_device *dev_next=NULL;
+	struct acpi_video_device *dev_prev=NULL;
+	unsigned long state;
+	int status = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_video_switch_output");
+
+	list_for_each_safe(node, next, &video->video_device_list) {
+		struct acpi_video_device * dev = container_of(node, struct acpi_video_device, entry);
+		status = acpi_video_device_get_state(dev, &state);
+		if (state & 0x2){
+			dev_next = container_of(node->next, struct acpi_video_device, entry);
+			dev_prev = container_of(node->prev, struct acpi_video_device, entry);
+			goto out;
+		}
+	}
+	dev_next = container_of(node->next, struct acpi_video_device, entry);
+	dev_prev = container_of(node->prev, struct acpi_video_device, entry);
+out:	
+	switch (event) {
+	case ACPI_VIDEO_NOTIFY_CYCLE:
+	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:
+		acpi_video_device_set_state(dev, 0);
+		acpi_video_device_set_state(dev_next, 0x80000001);
+		break;
+	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:
+		acpi_video_device_set_state(dev, 0);
+		acpi_video_device_set_state(dev_prev, 0x80000001);
+	default:
+		break;
+	}
+
+	return_VALUE(status);
+}
+
+static int 
+acpi_video_get_next_level(
+	struct acpi_video_device *device,
+	u32	level_current,
+	u32	event)
+{
+	/*Fix me*/
+	return level_current;
+}
+
+
+static void
+acpi_video_switch_brightness (
+	struct acpi_video_device *device, 
+	int	event)
+{
+	unsigned long level_current, level_next;
+	acpi_video_device_lcd_get_level_current(device, &level_current);
+	level_next = acpi_video_get_next_level(device, level_current, event);
+	acpi_video_device_lcd_set_level(device, level_next);
+}
+
+static int
+acpi_video_bus_get_devices (
+	struct acpi_video_bus	*video,
+	struct acpi_device	*device)
+{
+	int			status = 0;
+	struct list_head	*node, *next;
+
+	ACPI_FUNCTION_TRACE("acpi_video_get_devices");
+
+	acpi_video_device_enumerate(video);
+
+	list_for_each_safe(node, next, &device->children) {
+		struct acpi_device *dev = list_entry(node, struct acpi_device, node);
+
+		if (!dev)
+			continue;
+
+		status = acpi_video_bus_get_one_device(dev, video);
+		if (ACPI_FAILURE(status)) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Cant attach device\n"));
+			continue;
+		}
+
+	}
+	return_VALUE(status);
+}
+
+static int
+acpi_video_bus_put_one_device(
+	struct acpi_video_device	*device)
+{
+	struct acpi_video_bus *video;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_put_one_device");
+
+	if (!device || !device->video)
+		return (-ENOENT);
+
+	video = device->video;
+
+	down(&video->sem);
+	list_del(&device->entry);
+	up(&video->sem);
+	acpi_video_device_remove_fs(device->dev);
+
+	return_VALUE(0);
+}
+
+static int
+acpi_video_bus_put_devices (
+	struct acpi_video_bus	*video)
+{
+	int			status;
+	struct list_head	*node, *next;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_put_devices");
+
+	list_for_each_safe(node, next, &video->video_device_list) {
+		struct acpi_video_device *data = list_entry(node, struct acpi_video_device, entry);
+		if (!data)
+			continue;
+
+		status = acpi_video_bus_put_one_device(data);
+		if(ACPI_FAILURE(status))
+			printk(KERN_WARNING PREFIX "hhuuhhuu bug in acpi video driver.\n");
+
+		if (data->brightness)
+			kfree(data->brightness);
+
+		kfree(data);
+	}
+
+	return_VALUE(0);
+}
+
+/* acpi_video interface */
+
+static int
+acpi_video_bus_start_devices(
+	struct acpi_video_bus	*video)
+{
+	return acpi_video_bus_DOS(video, 1, 0);
+}
+
+static int
+acpi_video_bus_stop_devices(
+	struct acpi_video_bus	*video)
+{
+	return acpi_video_bus_DOS(video, 0, 1);
+}
+
+static void
+acpi_video_bus_notify (
+	acpi_handle		handle,
+	u32			event,
+	void			*data)
+{
+	struct acpi_video_bus	*video = (struct acpi_video_bus *) data;
+	struct acpi_device	*device = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_notify");
+	printk("video bus notify\n");
+
+	if (!video)
+		return_VOID;
+
+	if (acpi_bus_get_device(handle, &device))
+		return_VOID;
+
+	switch (event) {
+	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User request that a switch occur,
+					 * most likely via hotkey. */
+		acpi_bus_generate_event(device, event, 0);
+		break;
+
+	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plug or remove a video
+					 * connector. */
+		acpi_video_device_enumerate(video);
+		acpi_video_device_rebind(video);
+		acpi_video_switch_output(video, event);
+		acpi_bus_generate_event(device, event, 0);
+		break;
+
+	case ACPI_VIDEO_NOTIFY_CYCLE: /* Cycle Display output hotkey pressed.*/
+	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT: /* Next Display output hotkey pressed. */
+	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT: /* previous Display output hotkey pressed. */
+		acpi_video_switch_output(video, event);
+		acpi_bus_generate_event(device, event, 0);
+		break;
+
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			"Unsupported event [0x%x]\n", event));
+		break;
+	}
+
+	return_VOID;
+}
+
+static void
+acpi_video_device_notify (
+	acpi_handle		handle,
+	u32			event,
+	void			*data)
+{
+	struct acpi_video_device	*video_device = (struct acpi_video_device *) data;
+	struct acpi_device	*device = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_device_notify");
+
+	printk("video device notify\n");
+	if (!video_device)
+		return_VOID;
+
+	if (acpi_bus_get_device(handle, &device))
+		return_VOID;
+
+	switch (event) {
+	case ACPI_VIDEO_NOTIFY_SWITCH: /* change in status (cycle output device) */
+	case ACPI_VIDEO_NOTIFY_PROBE: /* change in status (output device status) */
+		acpi_bus_generate_event(device, event, 0);
+		break;
+	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
+	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
+	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
+	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightnesss */
+	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
+		acpi_video_switch_brightness (video_device, event);
+		acpi_bus_generate_event(device, event, 0);
+		break;
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			"Unsupported event [0x%x]\n", event));
+		break;
+	}
+	return_VOID;
+}
+
+static int
+acpi_video_bus_add (
+	struct acpi_device	*device)
+{
+	int			result = 0;
+	acpi_status		status = 0;
+	struct acpi_video_bus	*video = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_add");
+	
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	video = kmalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
+	if (!video)
+		return_VALUE(-ENOMEM);
+	memset(video, 0, sizeof(struct acpi_video_bus));
+
+	video->handle = device->handle;
+	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
+	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
+	acpi_driver_data(device) = video;
+
+	acpi_video_bus_find_cap(video);
+	result = acpi_video_bus_check(video);
+	if (result)
+		goto end;
+
+	result = acpi_video_bus_add_fs(device);
+	if (result)
+		goto end;
+
+	init_MUTEX(&video->sem);
+	INIT_LIST_HEAD(&video->video_device_list);
+
+	acpi_video_bus_get_devices(video, device);
+	acpi_video_bus_start_devices(video);
+
+	status = acpi_install_notify_handler(video->handle,
+		ACPI_DEVICE_NOTIFY, acpi_video_bus_notify, video);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Error installing notify handler\n"));
+		result = -ENODEV;
+		goto end;
+	}
+
+	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");
+
+end:
+	if (result) {
+		acpi_video_bus_remove_fs(device);
+		kfree(video);
+	}
+
+	return_VALUE(result);
+}
+
+static int
+acpi_video_bus_remove (
+	struct acpi_device	*device,
+	int			type)
+{
+	acpi_status		status = 0;
+	struct acpi_video_bus	*video = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_remove");
+
+	if (!device || !acpi_driver_data(device))
+		return_VALUE(-EINVAL);
+
+	video = (struct acpi_video_bus *) acpi_driver_data(device);
+
+	acpi_video_bus_stop_devices(video);
+
+	status = acpi_remove_notify_handler(video->handle,
+		ACPI_DEVICE_NOTIFY, acpi_video_bus_notify);
+	if (ACPI_FAILURE(status))
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Error removing notify handler\n"));
+
+	acpi_video_bus_put_devices(video);
+	acpi_video_bus_remove_fs(device);
+
+	if (video->attached_array)
+		kfree(video->attached_array);
+	kfree(video);
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_video_bus_match (
+	struct acpi_device	*device,
+	struct acpi_driver	*driver)
+{
+	acpi_handle		h_dummy1;
+	acpi_handle		h_dummy2;
+	acpi_handle		h_dummy3;
+
+	ACPI_FUNCTION_TRACE("acpi_video_bus_match");
+
+	if (!device || !driver)
+		return_VALUE(-EINVAL);
+
+	/* Since there is no HID, CID for ACPI Video drivers, we have
+	 * to check well known required nodes for each feature we support.
+	 */
+
+	/* Does this device able to support video switching ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy1)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy2)))
+		return_VALUE(0);
+
+	/* Does this device able to retrieve a video ROM ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy1)))
+		return_VALUE(0);
+
+	/* Does this device able to configure which video head to be POSTed ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy1)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy2)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy3)))
+		return_VALUE(0);
+
+
+	return_VALUE(-ENODEV);
+}
+
+
+static int __init
+acpi_video_init (void)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_video_init");
+
+	/*
+	acpi_dbg_level = 0xFFFFFFFF;
+	acpi_dbg_layer = 0x08000000;
+	*/
+
+	acpi_video_dir = proc_mkdir(ACPI_VIDEO_CLASS, acpi_root_dir);
+	if (!acpi_video_dir)
+		return_VALUE(-ENODEV);
+
+	result = acpi_bus_register_driver(&acpi_video_bus);
+	if (result < 0) {
+		remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+static void __exit
+acpi_video_exit (void)
+{
+	ACPI_FUNCTION_TRACE("acpi_video_exit");
+
+	acpi_bus_unregister_driver(&acpi_video_bus);
+
+	remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);
+
+	return_VOID;
+}
+
+module_init(acpi_video_init);
+module_exit(acpi_video_exit);

include/acpi/acpi_bus.h

@@ -104,6 +104,7 @@ typedef int (*acpi_op_suspend)	(struct acpi_device *device, int state);
 typedef int (*acpi_op_resume)	(struct acpi_device *device, int state);
 typedef int (*acpi_op_scan)	(struct acpi_device *device);
 typedef int (*acpi_op_bind)	(struct acpi_device *device);
+typedef int (*acpi_op_match)	(struct acpi_device *device, struct acpi_driver *driver);
 
 struct acpi_device_ops {
 	acpi_op_add		add;
@@ -115,6 +116,7 @@ struct acpi_device_ops {
 	acpi_op_resume		resume;
 	acpi_op_scan		scan;
 	acpi_op_bind		bind;
+	acpi_op_match		match;
 };
 
 struct acpi_driver {