/*
 *  video.c - ACPI Video Driver ($Revision:$)
 *
 *  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/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/input.h>
#include <linux/backlight.h>
#include <linux/thermal.h>
#include <linux/video_output.h>
#include <linux/sort.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define ACPI_VIDEO_CLASS                "video"
#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 ACPI_VIDEO_DISPLAY_CRT  1
#define ACPI_VIDEO_DISPLAY_TV   2
#define ACPI_VIDEO_DISPLAY_DVI  3
#define ACPI_VIDEO_DISPLAY_LCD  4

#define _COMPONENT              ACPI_VIDEO_COMPONENT
ACPI_MODULE_NAME("video");

MODULE_AUTHOR("Bruno Ducrot");
MODULE_DESCRIPTION("ACPI Video Driver");
MODULE_LICENSE("GPL");

static int brightness_switch_enabled = 1;
module_param(brightness_switch_enabled, bool, 0644);

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_resume(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,
                .resume = acpi_video_resume,
                .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;
        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 list_head video_device_list;
        struct mutex device_list_lock;  /* protects video_device_list */
        struct proc_dir_entry *dir;
        struct input_dev *input;
        char phys[32];  /* for input device */
};

struct acpi_video_device_flags {
        u8 crt:1;
        u8 lcd:1;
        u8 tvout:1;
        u8 dvi:1;
        u8 bios:1;
        u8 unknown:1;
        u8 reserved:2;
};

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 */
        u8 _DCS:1;              /*Return status of output device */
        u8 _DGS:1;              /*Query graphics state */
        u8 _DSS:1;              /*Device state set */
};

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 _BCL_use_index:1;            /* levels in _BCL are index values */
        u8 _BCM_use_index:1;            /* input of _BCM is an index value */
        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 acpi_video_bus *video;
        struct acpi_device *dev;
        struct acpi_video_device_brightness *brightness;
        struct backlight_device *backlight;
        struct thermal_cooling_device *cdev;
        struct output_device *output_dev;
};

/* bus */
static int acpi_video_bus_info_open_fs(struct inode *inode, struct file *file);
static const struct file_operations acpi_video_bus_info_fops = {
        .owner = THIS_MODULE,
        .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 const struct file_operations acpi_video_bus_ROM_fops = {
        .owner = THIS_MODULE,
        .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 const struct file_operations acpi_video_bus_POST_info_fops = {
        .owner = THIS_MODULE,
        .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 ssize_t acpi_video_bus_write_POST(struct file *file,
        const char __user *buffer, size_t count, loff_t *data);
static const struct file_operations acpi_video_bus_POST_fops = {
        .owner = THIS_MODULE,
        .open = acpi_video_bus_POST_open_fs,
        .read = seq_read,
        .write = acpi_video_bus_write_POST,
        .llseek = seq_lseek,
        .release = single_release,
};

static int acpi_video_bus_DOS_open_fs(struct inode *inode, struct file *file);
static ssize_t acpi_video_bus_write_DOS(struct file *file,
        const char __user *buffer, size_t count, loff_t *data);
static const struct file_operations acpi_video_bus_DOS_fops = {
        .owner = THIS_MODULE,
        .open = acpi_video_bus_DOS_open_fs,
        .read = seq_read,
        .write = acpi_video_bus_write_DOS,
        .llseek = seq_lseek,
        .release = single_release,
};

/* device */
static int acpi_video_device_info_open_fs(struct inode *inode,
                                          struct file *file);
static const struct file_operations acpi_video_device_info_fops = {
        .owner = THIS_MODULE,
        .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 ssize_t acpi_video_device_write_state(struct file *file,
        const char __user *buffer, size_t count, loff_t *data);
static const struct file_operations acpi_video_device_state_fops = {
        .owner = THIS_MODULE,
        .open = acpi_video_device_state_open_fs,
        .read = seq_read,
        .write = acpi_video_device_write_state,
        .llseek = seq_lseek,
        .release = single_release,
};

static int acpi_video_device_brightness_open_fs(struct inode *inode,
                                                struct file *file);
static ssize_t acpi_video_device_write_brightness(struct file *file,
        const char __user *buffer, size_t count, loff_t *data);
static struct file_operations acpi_video_device_brightness_fops = {
        .owner = THIS_MODULE,
        .open = acpi_video_device_brightness_open_fs,
        .read = seq_read,
        .write = acpi_video_device_write_brightness,
        .llseek = seq_lseek,
        .release = single_release,
};

static int acpi_video_device_EDID_open_fs(struct inode *inode,
                                          struct file *file);
static const struct file_operations acpi_video_device_EDID_fops = {
        .owner = THIS_MODULE,
        .open = acpi_video_device_EDID_open_fs,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = single_release,
};

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);
static int acpi_video_get_next_level(struct acpi_video_device *device,
                                     u32 level_current, u32 event);
static int acpi_video_switch_brightness(struct acpi_video_device *device,
                                         int event);
static int acpi_video_device_get_state(struct acpi_video_device *device,
                            unsigned long long *state);
static int acpi_video_output_get(struct output_device *od);
static int acpi_video_device_set_state(struct acpi_video_device *device, int state);

/*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 =
                (struct acpi_video_device *)bl_get_data(bd);

        if (acpi_video_device_lcd_get_level_current(vd, &cur_level))
                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 =
                (struct acpi_video_device *)bl_get_data(bd);

        return acpi_video_device_lcd_set_level(vd,
                                vd->brightness->levels[request_level]);
}

static struct backlight_ops acpi_backlight_ops = {
        .get_brightness = acpi_video_get_brightness,
        .update_status  = acpi_video_set_brightness,
};

/*video output device sysfs support*/
static int acpi_video_output_get(struct output_device *od)
{
        unsigned long long state;
        struct acpi_video_device *vd =
                (struct acpi_video_device *)dev_get_drvdata(&od->dev);
        acpi_video_device_get_state(vd, &state);
        return (int)state;
}

static int acpi_video_output_set(struct output_device *od)
{
        unsigned long state = od->request_state;
        struct acpi_video_device *vd=
                (struct acpi_video_device *)dev_get_drvdata(&od->dev);
        return acpi_video_device_set_state(vd, state);
}

static struct output_properties acpi_output_properties = {
        .set_state = acpi_video_output_set,
        .get_status = acpi_video_output_get,
};


/* thermal cooling device callbacks */
static int video_get_max_state(struct thermal_cooling_device *cdev, unsigned
                               long *state)
{
        struct acpi_device *device = cdev->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 *cdev, unsigned
                               long *state)
{
        struct acpi_device *device = cdev->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))
                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 *cdev, unsigned long state)
{
        struct acpi_device *device = cdev->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 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
   -------------------------------------------------------------------------- */

/* device */

static int
acpi_video_device_query(struct acpi_video_device *device, unsigned long long *state)
{
        int status;

        status = acpi_evaluate_integer(device->dev->handle, "_DGS", NULL, state);

        return status;
}

static int
acpi_video_device_get_state(struct acpi_video_device *device,
                            unsigned long long *state)
{
        int status;

        status = acpi_evaluate_integer(device->dev->handle, "_DCS", NULL, state);

        return 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 };
        unsigned long long ret;


        arg0.integer.value = state;
        status = acpi_evaluate_integer(device->dev->handle, "_DSS", &args, &ret);

        return 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;


        *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;
        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
        struct acpi_object_list args = { 1, &arg0 };
        int state;

        arg0.integer.value = level;

        status = acpi_evaluate_object(device->dev->handle, "_BCM",
                                      &args, NULL);
        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 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"),
                },
        },
        {}
};

static int
acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
                                        unsigned long long *level)
{
        acpi_status status = AE_OK;

        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 (device->brightness->flags._BQC_use_index) {
                                if (device->brightness->flags._BCL_reversed)
                                        *level = device->brightness->count
                                                                 - 3 - (*level);
                                *level = device->brightness->levels[*level + 2];

                        }
                        *level += bqc_offset_aml_bug_workaround;
                        device->brightness->curr = *level;
                        return 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 */

static int
acpi_video_bus_set_POST(struct acpi_video_bus *video, unsigned long option)
{
        int status;
        unsigned long long tmp;
        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
        struct acpi_object_list args = { 1, &arg0 };


        arg0.integer.value = option;

        status = acpi_evaluate_integer(video->device->handle, "_SPD", &args, &tmp);
        if (ACPI_SUCCESS(status))
                status = tmp ? (-EINVAL) : (AE_OK);

        return status;
}

static int
acpi_video_bus_get_POST(struct acpi_video_bus *video, unsigned long long *id)
{
        int status;

        status = acpi_evaluate_integer(video->device->handle, "_GPD", NULL, id);

        return status;
}

static int
acpi_video_bus_POST_options(struct acpi_video_bus *video,
                            unsigned long long *options)
{
        int status;

        status = acpi_evaluate_integer(video->device->handle, "_VPO", NULL, options);
        *options &= 3;

        return 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 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:
 *              -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 };


        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->device->handle, "_DOS", &args, NULL);

      Failed:
        return status;
}

/*
 * 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;
}

/*
 *  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;

        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;
                }
                br->levels[count] = (u32) o->integer.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\n"));

        /* 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\n"));

        br->count = count;
        device->brightness = br;

        /* Check the input/output of _BQC/_BCL/_BCM */
        if ((max_level < 100) && (max_level <= (count - 2)))
                br->flags._BCL_use_index = 1;

        /*
         * _BCM is always consistent with _BCL,
         * at least for all the laptops we have ever seen.
         */
        br->flags._BCM_use_index = br->flags._BCL_use_index;

        /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
        br->curr = level_old = max_level;

        if (!device->cap._BQC)
                goto set_level;

        result = acpi_video_device_lcd_get_level_current(device, &level_old);
        if (result)
                goto out_free_levels;

        /*
         * Set the level to maximum and check if _BQC uses indexed value
         */
        result = acpi_video_device_lcd_set_level(device, max_level);
        if (result)
                goto out_free_levels;

        result = acpi_video_device_lcd_get_level_current(device, &level);
        if (result)
                goto out_free_levels;

        br->flags._BQC_use_index = (level == max_level ? 0 : 1);

        if (!br->flags._BQC_use_index)
                goto set_level;

        if (br->flags._BCL_reversed)
                level_old = (br->count - 1) - level_old;
        level_old = br->levels[level_old];

set_level:
        result = acpi_video_device_lcd_set_level(device, level_old);
        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)
{
        acpi_handle h_dummy1;


        memset(&device->cap, 0, sizeof(device->cap));

        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_ADR", &h_dummy1))) {
                device->cap._ADR = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCL", &h_dummy1))) {
                device->cap._BCL = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCM", &h_dummy1))) {
                device->cap._BCM = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle,"_BQC",&h_dummy1)))
                device->cap._BQC = 1;
        else if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCQ",
                                &h_dummy1))) {
                printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
                device->cap._BCQ = 1;
        }

        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DDC", &h_dummy1))) {
                device->cap._DDC = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DCS", &h_dummy1))) {
                device->cap._DCS = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DGS", &h_dummy1))) {
                device->cap._DGS = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DSS", &h_dummy1))) {
                device->cap._DSS = 1;
        }

        if (acpi_video_backlight_support()) {
                int result;
                static int count = 0;
                char *name;

                result = acpi_video_init_brightness(device);
                if (result)
                        return;
                name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
                if (!name)
                        return;

                sprintf(name, "acpi_video%d", count++);
                device->backlight = backlight_device_register(name,
                        NULL, device, &acpi_backlight_ops);
                device->backlight->props.max_brightness = device->brightness->count-3;
                kfree(name);

                device->cdev = thermal_cooling_device_register("LCD",
                                        device->dev, &video_cooling_ops);
                if (IS_ERR(device->cdev))
                        return;

                dev_info(&device->dev->dev, "registered as cooling_device%d\n",
                         device->cdev->id);
                result = sysfs_create_link(&device->dev->dev.kobj,
                                &device->cdev->device.kobj,
                                "thermal_cooling");
                if (result)
                        printk(KERN_ERR PREFIX "Create sysfs link\n");
                result = sysfs_create_link(&device->cdev->device.kobj,
                                &device->dev->dev.kobj, "device");
                if (result)
                        printk(KERN_ERR PREFIX "Create sysfs link\n");

        }

        if (acpi_video_display_switch_support()) {

                if (device->cap._DCS && device->cap._DSS) {

                        static int count;
                        char *name;
                        name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
                        if (!name)
                                return;
                        sprintf(name, "acpi_video%d", count++);
                        device->output_dev = video_output_register(name,
                                        NULL, device, &acpi_output_properties);
                        kfree(name);
                }
        }
}

/*
 *  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)
{
        acpi_handle h_dummy1;

        memset(&video->cap, 0, sizeof(video->cap));
        if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOS", &h_dummy1))) {
                video->cap._DOS = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOD", &h_dummy1))) {
                video->cap._DOD = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_ROM", &h_dummy1))) {
                video->cap._ROM = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_GPD", &h_dummy1))) {
                video->cap._GPD = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_SPD", &h_dummy1))) {
                video->cap._SPD = 1;
        }
        if (ACPI_SUCCESS(acpi_get_handle(video->device->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;
        struct device *dev;

        if (!video)
                return -EINVAL;

        dev = acpi_get_physical_pci_device(video->device->handle);
        if (!dev)
                return -ENODEV;
        put_device(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->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;
}

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static struct proc_dir_entry *acpi_video_dir;

/* video devices */

static int acpi_video_device_info_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_device *dev = seq->private;


        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 if (dev->flags.dvi)
                seq_printf(seq, "DVI\n");
        else
                seq_printf(seq, "UNKNOWN\n");

        seq_printf(seq, "known by bios: %s\n", dev->flags.bios ? "yes" : "no");

      end:
        return 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 int acpi_video_device_state_seq_show(struct seq_file *seq, void *offset)
{
        int status;
        struct acpi_video_device *dev = seq->private;
        unsigned long long state;


        if (!dev)
                goto end;

        status = acpi_video_device_get_state(dev, &state);
        seq_printf(seq, "state:     ");
        if (ACPI_SUCCESS(status))
                seq_printf(seq, "0x%02llx\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%02llx\n", state);
        else
                seq_printf(seq, "<not supported>\n");

      end:
        return 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 = file->private_data;
        struct acpi_video_device *dev = m->private;
        char str[12] = { 0 };
        u32 state = 0;


        if (!dev || count + 1 > sizeof str)
                return -EINVAL;

        if (copy_from_user(str, buffer, count))
                return -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 -EFAULT;

        return count;
}

static int
acpi_video_device_brightness_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_device *dev = seq->private;
        int i;


        if (!dev || !dev->brightness) {
                seq_printf(seq, "<not supported>\n");
                return 0;
        }

        seq_printf(seq, "levels: ");
        for (i = 2; i < dev->brightness->count; i++)
                seq_printf(seq, " %d", dev->brightness->levels[i]);
        seq_printf(seq, "\ncurrent: %d\n", dev->brightness->curr);

        return 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 = file->private_data;
        struct acpi_video_device *dev = m->private;
        char str[5] = { 0 };
        unsigned int level = 0;
        int i;


        if (!dev || !dev->brightness || count + 1 > sizeof str)
                return -EINVAL;

        if (copy_from_user(str, buffer, count))
                return -EFAULT;

        str[count] = 0;
        level = simple_strtoul(str, NULL, 0);

        if (level > 100)
                return -EFAULT;

        /* validate through the list of available levels */
        for (i = 2; i < dev->brightness->count; i++)
                if (level == dev->brightness->levels[i]) {
                        if (!acpi_video_device_lcd_set_level(dev, level))
                                return count;
                        break;
                }

        return -EINVAL;
}

static int acpi_video_device_EDID_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_device *dev = seq->private;
        int status;
        int i;
        union acpi_object *edid = NULL;


        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 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, *device_dir;
        struct acpi_video_device *vid_dev;

        vid_dev = acpi_driver_data(device);
        if (!vid_dev)
                return -ENODEV;

        device_dir = proc_mkdir(acpi_device_bid(device),
                                vid_dev->video->dir);
        if (!device_dir)
                return -ENOMEM;

        /* 'info' [R] */
        entry = proc_create_data("info", S_IRUGO, device_dir,
                        &acpi_video_device_info_fops, acpi_driver_data(device));
        if (!entry)
                goto err_remove_dir;

        /* 'state' [R/W] */
        entry = proc_create_data("state", S_IFREG | S_IRUGO | S_IWUSR,
                                 device_dir,
                                 &acpi_video_device_state_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_info;

        /* 'brightness' [R/W] */
        entry = proc_create_data("brightness", S_IFREG | S_IRUGO | S_IWUSR,
                                 device_dir,
                                 &acpi_video_device_brightness_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_state;

        /* 'EDID' [R] */
        entry = proc_create_data("EDID", S_IRUGO, device_dir,
                                 &acpi_video_device_EDID_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_brightness;

        acpi_device_dir(device) = device_dir;

        return 0;

 err_remove_brightness:
        remove_proc_entry("brightness", device_dir);
 err_remove_state:
        remove_proc_entry("state", device_dir);
 err_remove_info:
        remove_proc_entry("info", device_dir);
 err_remove_dir:
        remove_proc_entry(acpi_device_bid(device), vid_dev->video->dir);
        return -ENOMEM;
}

static int acpi_video_device_remove_fs(struct acpi_device *device)
{
        struct acpi_video_device *vid_dev;
        struct proc_dir_entry *device_dir;

        vid_dev = acpi_driver_data(device);
        if (!vid_dev || !vid_dev->video || !vid_dev->video->dir)
                return -ENODEV;

        device_dir = acpi_device_dir(device);
        if (device_dir) {
                remove_proc_entry("info", device_dir);
                remove_proc_entry("state", device_dir);
                remove_proc_entry("brightness", device_dir);
                remove_proc_entry("EDID", device_dir);
                remove_proc_entry(acpi_device_bid(device), vid_dev->video->dir);
                acpi_device_dir(device) = NULL;
        }

        return 0;
}

/* video bus */
static int acpi_video_bus_info_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_bus *video = seq->private;


        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 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 int acpi_video_bus_ROM_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_bus *video = seq->private;


        if (!video)
                goto end;

        printk(KERN_INFO PREFIX "Please implement %s\n", __func__);
        seq_printf(seq, "<TODO>\n");

      end:
        return 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 int acpi_video_bus_POST_info_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_bus *video = seq->private;
        unsigned long long options;
        int status;


        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 indicates a BIOS bug. Please contact the manufacturer.\n");
                }
                printk(KERN_WARNING "%llx\n", options);
                seq_printf(seq, "can POST: <integrated 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 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 int acpi_video_bus_POST_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_bus *video = seq->private;
        int status;
        unsigned long long id;


        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 0;
}

static int acpi_video_bus_DOS_seq_show(struct seq_file *seq, void *offset)
{
        struct acpi_video_bus *video = seq->private;


        seq_printf(seq, "DOS setting: <%d>\n", video->dos_setting);

        return 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 = file->private_data;
        struct acpi_video_bus *video = m->private;
        char str[12] = { 0 };
        unsigned long long opt, options;


        if (!video || count + 1 > sizeof str)
                return -EINVAL;

        status = acpi_video_bus_POST_options(video, &options);
        if (!ACPI_SUCCESS(status))
                return -EINVAL;

        if (copy_from_user(str, buffer, count))
                return -EFAULT;

        str[count] = 0;
        opt = strtoul(str, NULL, 0);
        if (opt > 3)
                return -EFAULT;

        /* just in case an OEM 'forgot' the motherboard... */
        options |= 1;

        if (options & (1ul << opt)) {
                status = acpi_video_bus_set_POST(video, opt);
                if (!ACPI_SUCCESS(status))
                        return -EFAULT;

        }

        return 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 = file->private_data;
        struct acpi_video_bus *video = m->private;
        char str[12] = { 0 };
        unsigned long opt;


        if (!video || count + 1 > sizeof str)
                return -EINVAL;

        if (copy_from_user(str, buffer, count))
                return -EFAULT;

        str[count] = 0;
        opt = strtoul(str, NULL, 0);
        if (opt > 7)
                return -EFAULT;

        status = acpi_video_bus_DOS(video, opt & 0x3, (opt & 0x4) >> 2);

        if (!ACPI_SUCCESS(status))
                return -EFAULT;

        return count;
}

static int acpi_video_bus_add_fs(struct acpi_device *device)
{
        struct acpi_video_bus *video = acpi_driver_data(device);
        struct proc_dir_entry *device_dir;
        struct proc_dir_entry *entry;

        device_dir = proc_mkdir(acpi_device_bid(device), acpi_video_dir);
        if (!device_dir)
                return -ENOMEM;

        /* 'info' [R] */
        entry = proc_create_data("info", S_IRUGO, device_dir,
                                 &acpi_video_bus_info_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_dir;

        /* 'ROM' [R] */
        entry = proc_create_data("ROM", S_IRUGO, device_dir,
                                 &acpi_video_bus_ROM_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_info;

        /* 'POST_info' [R] */
        entry = proc_create_data("POST_info", S_IRUGO, device_dir,
                                 &acpi_video_bus_POST_info_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_rom;

        /* 'POST' [R/W] */
        entry = proc_create_data("POST", S_IFREG | S_IRUGO | S_IWUSR,
                                 device_dir,
                                 &acpi_video_bus_POST_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_post_info;

        /* 'DOS' [R/W] */
        entry = proc_create_data("DOS", S_IFREG | S_IRUGO | S_IWUSR,
                                 device_dir,
                                 &acpi_video_bus_DOS_fops,
                                 acpi_driver_data(device));
        if (!entry)
                goto err_remove_post;

        video->dir = acpi_device_dir(device) = device_dir;
        return 0;

 err_remove_post:
        remove_proc_entry("POST", device_dir);
 err_remove_post_info:
        remove_proc_entry("POST_info", device_dir);
 err_remove_rom:
        remove_proc_entry("ROM", device_dir);
 err_remove_info:
        remove_proc_entry("info", device_dir);
 err_remove_dir:
        remove_proc_entry(acpi_device_bid(device), acpi_video_dir);
        return -ENOMEM;
}

static int acpi_video_bus_remove_fs(struct acpi_device *device)
{
        struct proc_dir_entry *device_dir = acpi_device_dir(device);

        if (device_dir) {
                remove_proc_entry("info", device_dir);
                remove_proc_entry("ROM", device_dir);
                remove_proc_entry("POST_info", device_dir);
                remove_proc_entry("POST", device_dir);
                remove_proc_entry("DOS", device_dir);
                remove_proc_entry(acpi_device_bid(device), acpi_video_dir);
                acpi_device_dir(device) = NULL;
        }

        return 0;
}

/* --------------------------------------------------------------------------
                                 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_bus_get_one_device(struct acpi_device *device,
                              struct acpi_video_bus *video)
{
        unsigned long long device_id;
        int status;
        struct acpi_video_device *data;
        struct acpi_video_device_attrib* attribute;

        if (!device || !video)
                return -EINVAL;

        status =
            acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
        if (ACPI_SUCCESS(status)) {

                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;

                attribute = acpi_video_get_device_attr(video, device_id);

                if((attribute != NULL) && 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
                        data->flags.unknown = 1;

                acpi_video_device_bind(video, data);
                acpi_video_device_find_cap(data);

                status = acpi_install_notify_handler(device->handle,
                                                     ACPI_DEVICE_NOTIFY,
                                                     acpi_video_device_notify,
                                                     data);
                if (ACPI_FAILURE(status)) {
                        printk(KERN_ERR PREFIX
                                          "Error installing notify handler\n");
                        if(data->brightness)
                                kfree(data->brightness->levels);
                        kfree(data->brightness);
                        kfree(data);
                        return -ENODEV;
                }

                mutex_lock(&video->device_list_lock);
                list_add_tail(&data->entry, &video->video_device_list);
                mutex_unlock(&video->device_list_lock);

                acpi_video_device_add_fs(device);

                return 0;
        }

        return -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 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));
                }
        }
}

/*
 *  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 int
acpi_video_switch_brightness(struct acpi_video_device *device, int event)
{
        unsigned long long level_current, level_next;
        int result = -EINVAL;

        if (!device->brightness)
                goto out;

        result = acpi_video_device_lcd_get_level_current(device,
                                                         &level_current);
        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);

out:
        if (result)
                printk(KERN_ERR PREFIX "Failed to switch the brightness\n");

        return result;
}

static int
acpi_video_bus_get_devices(struct acpi_video_bus *video,
                           struct acpi_device *device)
{
        int status = 0;
        struct acpi_device *dev;

        acpi_video_device_enumerate(video);

        list_for_each_entry(dev, &device->children, node) {

                status = acpi_video_bus_get_one_device(dev, video);
                if (ACPI_FAILURE(status)) {
                        printk(KERN_WARNING PREFIX
                                        "Cant attach device");
                        continue;
                }
        }
        return status;
}

static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
{
        acpi_status status;
        struct acpi_video_bus *video;


        if (!device || !device->video)
                return -ENOENT;

        video = device->video;

        acpi_video_device_remove_fs(device->dev);

        status = acpi_remove_notify_handler(device->dev->handle,
                                            ACPI_DEVICE_NOTIFY,
                                            acpi_video_device_notify);
        backlight_device_unregister(device->backlight);
        if (device->cdev) {
                sysfs_remove_link(&device->dev->dev.kobj,
                                  "thermal_cooling");
                sysfs_remove_link(&device->cdev->device.kobj,
                                  "device");
                thermal_cooling_device_unregister(device->cdev);
                device->cdev = NULL;