/*
*  asus_acpi.c - Asus Laptop ACPI Extras
*
*
*  Copyright (C) 2002-2005 Julien Lerouge, 2003-2006 Karol Kozimor
*
*  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
*
*
*  The development page for this driver is located at
*  http://sourceforge.net/projects/acpi4asus/
*
*  Credits:
*  Pontus Fuchs   - Helper functions, cleanup
*  Johann Wiesner - Small compile fixes
*  John Belmonte  - ACPI code for Toshiba laptop was a good starting point.
*  �ic Burghard  - LED display support for W1N
*
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <asm/uaccess.h>

#define ASUS_ACPI_VERSION "0.30"

#define PROC_ASUS       "asus"  //the directory
#define PROC_MLED       "mled"
#define PROC_WLED       "wled"
#define PROC_TLED       "tled"
#define PROC_BT         "bluetooth"
#define PROC_LEDD       "ledd"
#define PROC_INFO       "info"
#define PROC_LCD        "lcd"
#define PROC_BRN        "brn"
#define PROC_DISP       "disp"

#define ACPI_HOTK_NAME          "Asus Laptop ACPI Extras Driver"
#define ACPI_HOTK_CLASS         "hotkey"
#define ACPI_HOTK_DEVICE_NAME   "Hotkey"
#define ACPI_HOTK_HID           "ATK0100"

/*
* Definitions for Asus EeePC : begin
*/
#define PROC_INIT       "init"
#define PROC_CAMERA     "camera"
#define PROC_CARDR      "cardr"
#define PROC_CPUFV      "cpufv"
#define PROC_HDPS       "hdps"
#define PROC_MODEM      "modem"
#define PROC_WLAN       "wlan"
#define PROC_USB        "usb"

#define NOTIFY_WLAN_ON  0x10

#define EEEPC_HOTK_NAME          "Asus EEEPC Hotkey Driver"
#define EEEPC_HOTK_CLASS         "hotkey"
#define EEEPC_HOTK_DEVICE_NAME   "Hotkey"
#define EEEPC_HOTK_HID           "ASUS010"

enum {
       DISABLE_ASL_WLAN = 0x0001,
       DISABLE_ASL_BLUETOOTH = 0x0002,
       DISABLE_ASL_IRDA = 0x0004,
       DISABLE_ASL_CAMERA = 0x0008,
       DISABLE_ASL_TV = 0x0010,
       DISABLE_ASL_GPS = 0x0020,
       DISABLE_ASL_DISPLAYSWITCH = 0x0040,
       DISABLE_ASL_MODEM = 0x0080,
       DISABLE_ASL_CARDREADER = 0x0100
       };

typedef enum {
       CM_ASL_WLAN = 0,
       CM_ASL_BLUETOOTH,
       CM_ASL_IRDA,
       CM_ASL_1394,
       CM_ASL_CAMERA,
       CM_ASL_TV,
       CM_ASL_GPS,
       CM_ASL_DVDROM,
       CM_ASL_DISPLAYSWITCH,
       CM_ASL_PANELBRIGHT,
       CM_ASL_BIOSFLASH,
       CM_ASL_ACPIFLASH,
       CM_ASL_CPUFV,
       CM_ASL_CPUTEMPERATURE,
       CM_ASL_FANCPU,
       CM_ASL_FANCHASSIS,
       CM_ASL_USBPORT1,
       CM_ASL_USBPORT2,
       CM_ASL_USBPORT3,
       CM_ASL_MODEM,
       CM_ASL_CARDREADER,
       CM_ASL_LID
       } cm_asl_t;

const char *cm_getv[]= {"WLDG",   NULL,   NULL,   NULL,
                       "CAMG",   NULL,   NULL,   NULL,
                         NULL, "PBLG",   NULL,   NULL,
                       "CFVG",   NULL,   NULL,   NULL,
                       "USBG",   NULL,   NULL, "MODG",
                       "CRDG", "LIDG"};

const char *cm_setv[]= {"WLDS",   NULL,   NULL,   NULL,
                       "CAMS",   NULL,   NULL,   NULL,
                       "SDSP", "PBLS", "HDPS",   NULL,
                       "CFVS",   NULL,   NULL,   NULL,
                       "USBG",   NULL,   NULL, "MODS",
                       "CRDS",   NULL};

static uid_t eeepc_uid;
static gid_t eeepc_gid;
module_param(eeepc_uid, uint, 0);
MODULE_PARM_DESC(eeepc_uid, "UID for entries in /proc/acpi/eeepc.\n");
module_param(eeepc_gid, uint, 0);
MODULE_PARM_DESC(eeepc_gid, "GID for entries in /proc/acpi/eeepc.\n");

static unsigned int init_flag;
static struct proc_dir_entry *eeepc_proc_dir;

/*
* This is the main structure, we can use it to store useful information
* about the hotk device
*/
struct eeepc_hotk {
       struct acpi_device      *device;        //the device we are in
       acpi_handle             handle;         //the handle of the hotk device
       unsigned int            cm_supported;   //the control method supported status of this BIOS.
       unsigned short          event_count[128];       //count for each event
};

/* The actual device the driver binds to */
static struct eeepc_hotk *ehotk;

/*
* The hotkey driver declaration
*/
static int eeepc_hotk_add(struct acpi_device *device);
static int eeepc_hotk_remove(struct acpi_device *device, int type);

static struct acpi_driver eeepc_hotk_driver = {
       .name = "eeepc_acpi",
       .class = EEEPC_HOTK_CLASS,
       .ids = EEEPC_HOTK_HID,
       .ops = {
               .add = eeepc_hotk_add,
               .remove = eeepc_hotk_remove,
       },
};

/*
* Definitions for Asus EeePC : end
*/

/*
* Some events we use, same for all Asus
*/
#define BR_UP       0x10
#define BR_DOWN     0x20

/*
* Flags for hotk status
*/
#define MLED_ON     0x01        //mail LED
#define WLED_ON     0x02        //wireless LED
#define TLED_ON     0x04        //touchpad LED
#define BT_ON       0x08        //internal Bluetooth

MODULE_AUTHOR("Julien Lerouge, Karol Kozimor");
MODULE_DESCRIPTION(ACPI_HOTK_NAME);
MODULE_LICENSE("GPL");

static uid_t asus_uid;
static gid_t asus_gid;
module_param(asus_uid, uint, 0);
MODULE_PARM_DESC(asus_uid, "UID for entries in /proc/acpi/asus.\n");
module_param(asus_gid, uint, 0);
MODULE_PARM_DESC(asus_gid, "GID for entries in /proc/acpi/asus.\n");

/* For each model, all features implemented,
* those marked with R are relative to HOTK, A for absolute */
struct model_data {
       char *name;             //name of the laptop________________A
       char *mt_mled;          //method to handle mled_____________R
       char *mled_status;      //node to handle mled reading_______A
       char *mt_wled;          //method to handle wled_____________R
       char *wled_status;      //node to handle wled reading_______A
       char *mt_tled;          //method to handle tled_____________R
       char *tled_status;      //node to handle tled reading_______A
       char *mt_ledd;          //method to handle LED display______R
       char *mt_bt_switch;     //method to switch Bluetooth on/off_R
       char *bt_status;        //no model currently supports this__?
       char *mt_lcd_switch;    //method to turn LCD on/off_________A
       char *lcd_status;       //node to read LCD panel state______A
       char *brightness_up;    //method to set brightness up_______A
       char *brightness_down;  //guess what ?______________________A
       char *brightness_set;   //method to set absolute brightness_R
       char *brightness_get;   //method to get absolute brightness_R
       char *brightness_status;        //node to get brightness____________A
       char *display_set;      //method to set video output________R
       char *display_get;      //method to get video output________R
};

/*
* This is the main structure, we can use it to store anything interesting
* about the hotk device
*/
struct asus_hotk {
       struct acpi_device *device;     //the device we are in
       acpi_handle handle;     //the handle of the hotk device
       char status;            //status of the hotk, for LEDs, ...
       u32 ledd_status;        //status of the LED display
       struct model_data *methods;     //methods available on the laptop
       u8 brightness;          //brightness level
       enum {
               A1x = 0,        //A1340D, A1300F
               A2x,            //A2500H
               A4G,            //A4700G
               D1x,            //D1
               L2D,            //L2000D
               L3C,            //L3800C
               L3D,            //L3400D
               L3H,            //L3H, L2000E, L5D
               L4R,            //L4500R
               L5x,            //L5800C
               L8L,            //L8400L
               M1A,            //M1300A
               M2E,            //M2400E, L4400L
               M6N,            //M6800N, W3400N
               M6R,            //M6700R, A3000G
               P30,            //Samsung P30
               S1x,            //S1300A, but also L1400B and M2400A (L84F)
               S2x,            //S200 (J1 reported), Victor MP-XP7210
               W1N,            //W1000N
               W5A,            //W5A
               W3V,            //W3030V
               xxN,            //M2400N, M3700N, M5200N, M6800N, S1300N, S5200N
               A4S,            //Z81sp
               //(Centrino)
               END_MODEL
       } model;                //Models currently supported
       u16 event_count[128];   //count for each event TODO make this better
};

/* Here we go */
#define A1x_PREFIX "\\_SB.PCI0.ISA.EC0."
#define L3C_PREFIX "\\_SB.PCI0.PX40.ECD0."
#define M1A_PREFIX "\\_SB.PCI0.PX40.EC0."
#define P30_PREFIX "\\_SB.PCI0.LPCB.EC0."
#define S1x_PREFIX "\\_SB.PCI0.PX40."
#define S2x_PREFIX A1x_PREFIX
#define xxN_PREFIX "\\_SB.PCI0.SBRG.EC0."

static struct model_data model_conf[END_MODEL] = {
       /*
        * TODO I have seen a SWBX and AIBX method on some models, like L1400B,
        * it seems to be a kind of switch, but what for ?
        */

       {
        .name = "A1x",
        .mt_mled = "MLED",
        .mled_status = "\\MAIL",
        .mt_lcd_switch = A1x_PREFIX "_Q10",
        .lcd_status = "\\BKLI",
        .brightness_up = A1x_PREFIX "_Q0E",
        .brightness_down = A1x_PREFIX "_Q0F"},

       {
        .name = "A2x",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .wled_status = "\\SG66",
        .mt_lcd_switch = "\\Q10",
        .lcd_status = "\\BAOF",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "A4G",
        .mt_mled = "MLED",
/* WLED present, but not controlled by ACPI */
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\ADVG"},

       {
        .name = "D1x",
        .mt_mled = "MLED",
        .mt_lcd_switch = "\\Q0D",
        .lcd_status = "\\GP11",
        .brightness_up = "\\Q0C",
        .brightness_down = "\\Q0B",
        .brightness_status = "\\BLVL",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "L2D",
        .mt_mled = "MLED",
        .mled_status = "\\SGP6",
        .mt_wled = "WLED",
        .wled_status = "\\RCP3",
        .mt_lcd_switch = "\\Q10",
        .lcd_status = "\\SGP0",
        .brightness_up = "\\Q0E",
        .brightness_down = "\\Q0F",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "L3C",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = L3C_PREFIX "_Q10",
        .lcd_status = "\\GL32",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\_SB.PCI0.PCI1.VGAC.NMAP"},

       {
        .name = "L3D",
        .mt_mled = "MLED",
        .mled_status = "\\MALD",
        .mt_wled = "WLED",
        .mt_lcd_switch = "\\Q10",
        .lcd_status = "\\BKLG",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "L3H",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = "EHK",
        .lcd_status = "\\_SB.PCI0.PM.PBC",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "L4R",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .wled_status = "\\_SB.PCI0.SBRG.SG13",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\_SB.PCI0.SBSM.SEO4",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\_SB.PCI0.P0P1.VGA.GETD"},

       {
        .name = "L5x",
        .mt_mled = "MLED",
/* WLED present, but not controlled by ACPI */
        .mt_tled = "TLED",
        .mt_lcd_switch = "\\Q0D",
        .lcd_status = "\\BAOF",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "L8L"
/* No features, but at least support the hotkeys */
        },

       {
        .name = "M1A",
        .mt_mled = "MLED",
        .mt_lcd_switch = M1A_PREFIX "Q10",
        .lcd_status = "\\PNOF",
        .brightness_up = M1A_PREFIX "Q0E",
        .brightness_down = M1A_PREFIX "Q0F",
        .brightness_status = "\\BRIT",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "M2E",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = "\\Q10",
        .lcd_status = "\\GP06",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

       {
        .name = "M6N",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .wled_status = "\\_SB.PCI0.SBRG.SG13",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\_SB.BKLT",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\SSTE"},

       {
        .name = "M6R",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\_SB.PCI0.SBSM.SEO4",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\_SB.PCI0.P0P1.VGA.GETD"},

       {
        .name = "P30",
        .mt_wled = "WLED",
        .mt_lcd_switch = P30_PREFIX "_Q0E",
        .lcd_status = "\\BKLT",
        .brightness_up = P30_PREFIX "_Q68",
        .brightness_down = P30_PREFIX "_Q69",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\DNXT"},

       {
        .name = "S1x",
        .mt_mled = "MLED",
        .mled_status = "\\EMLE",
        .mt_wled = "WLED",
        .mt_lcd_switch = S1x_PREFIX "Q10",
        .lcd_status = "\\PNOF",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV"},

       {
        .name = "S2x",
        .mt_mled = "MLED",
        .mled_status = "\\MAIL",
        .mt_lcd_switch = S2x_PREFIX "_Q10",
        .lcd_status = "\\BKLI",
        .brightness_up = S2x_PREFIX "_Q0B",
        .brightness_down = S2x_PREFIX "_Q0A"},

       {
        .name = "W1N",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_ledd = "SLCM",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\BKLT",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\ADVG"},

       {
        .name = "W5A",
        .mt_bt_switch = "BLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\ADVG"},

       {
        .name = "W3V",
        .mt_mled = "MLED",
        .mt_wled = "WLED",
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\BKLT",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
        .display_get = "\\INFB"},

      {
        .name = "xxN",
        .mt_mled = "MLED",
/* WLED present, but not controlled by ACPI */
        .mt_lcd_switch = xxN_PREFIX "_Q10",
        .lcd_status = "\\BKLT",
        .brightness_set = "SPLV",
        .brightness_get = "GPLV",
        .display_set = "SDSP",
       .display_get = "\\ADVG"},

       {
               .name              = "A4S",
               .brightness_set    = "SPLV",
               .brightness_get    = "GPLV",
               .mt_bt_switch      = "BLED",
               .mt_wled           = "WLED"
       }

};

/* procdir we use */
static struct proc_dir_entry *asus_proc_dir;

static struct backlight_device *asus_backlight_device;

/*
* This header is made available to allow proper configuration given model,
* revision number , ... this info cannot go in struct asus_hotk because it is
* available before the hotk
*/
static struct acpi_table_header *asus_info;

/* The actual device the driver binds to */
static struct asus_hotk *hotk;

/*
* The hotkey driver declaration
*/
static int asus_hotk_add(struct acpi_device *device);
static int asus_hotk_remove(struct acpi_device *device, int type);
static struct acpi_driver asus_hotk_driver = {
       .name = "asus_acpi",
       .class = ACPI_HOTK_CLASS,
       .ids = ACPI_HOTK_HID,
       .ops = {
               .add = asus_hotk_add,
               .remove = asus_hotk_remove,
               },
};

/*
* This function evaluates an ACPI method, given an int as parameter, the
* method is searched within the scope of the handle, can be NULL. The output
* of the method is written is output, which can also be NULL
*
* returns 1 if write is successful, 0 else.
*/
static int write_acpi_int(acpi_handle handle, const char *method, int val,
                         struct acpi_buffer *output)
{
       struct acpi_object_list params; //list of input parameters (an int here)
       union acpi_object in_obj;       //the only param we use
       acpi_status status;

       params.count = 1;
       params.pointer = &in_obj;
       in_obj.type = ACPI_TYPE_INTEGER;
       in_obj.integer.value = val;

       status = acpi_evaluate_object(handle, (char *)method, &params, output);
       return (status == AE_OK);
}

static int read_acpi_int(acpi_handle handle, const char *method, int *val)
{
       struct acpi_buffer output;
       union acpi_object out_obj;
       acpi_status status;

       output.length = sizeof(out_obj);
       output.pointer = &out_obj;

       status = acpi_evaluate_object(handle, (char *)method, NULL, &output);
       *val = out_obj.integer.value;
       return (status == AE_OK) && (out_obj.type == ACPI_TYPE_INTEGER);
}

/*
* We write our info in page, we begin at offset off and cannot write more
* than count bytes. We set eof to 1 if we handle those 2 values. We return the
* number of bytes written in page
*/
static int
proc_read_info(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       int len = 0;
       int temp;
       char buf[16];           //enough for all info
       /*
        * We use the easy way, we don't care of off and count, so we don't set eof
        * to 1
        */

       len += sprintf(page, ACPI_HOTK_NAME " " ASUS_ACPI_VERSION "\n");
       len += sprintf(page + len, "Model reference    : %s\n",
                      hotk->methods->name);
       /*
        * The SFUN method probably allows the original driver to get the list
        * of features supported by a given model. For now, 0x0100 or 0x0800
        * bit signifies that the laptop is equipped with a Wi-Fi MiniPCI card.
        * The significance of others is yet to be found.
        */
       if (read_acpi_int(hotk->handle, "SFUN", &temp))
               len +=
                   sprintf(page + len, "SFUN value         : 0x%04x\n", temp);
       /*
        * Another value for userspace: the ASYM method returns 0x02 for
        * battery low and 0x04 for battery critical, its readings tend to be
        * more accurate than those provided by _BST.
        * Note: since not all the laptops provide this method, errors are
        * silently ignored.
        */
       if (read_acpi_int(hotk->handle, "ASYM", &temp))
               len +=
                   sprintf(page + len, "ASYM value         : 0x%04x\n", temp);
       if (asus_info) {
               snprintf(buf, 16, "%d", asus_info->length);
               len += sprintf(page + len, "DSDT length        : %s\n", buf);
               snprintf(buf, 16, "%d", asus_info->checksum);
               len += sprintf(page + len, "DSDT checksum      : %s\n", buf);
               snprintf(buf, 16, "%d", asus_info->revision);
               len += sprintf(page + len, "DSDT revision      : %s\n", buf);
               snprintf(buf, 7, "%s", asus_info->oem_id);
               len += sprintf(page + len, "OEM id             : %s\n", buf);
               snprintf(buf, 9, "%s", asus_info->oem_table_id);
               len += sprintf(page + len, "OEM table id       : %s\n", buf);
               snprintf(buf, 16, "%x", asus_info->oem_revision);
               len += sprintf(page + len, "OEM revision       : 0x%s\n", buf);
               snprintf(buf, 5, "%s", asus_info->asl_compiler_id);
               len += sprintf(page + len, "ASL comp vendor id : %s\n", buf);
               snprintf(buf, 16, "%x", asus_info->asl_compiler_revision);
               len += sprintf(page + len, "ASL comp revision  : 0x%s\n", buf);
       }

       return len;
}

/*
* /proc handlers
* We write our info in page, we begin at offset off and cannot write more
* than count bytes. We set eof to 1 if we handle those 2 values. We return the
* number of bytes written in page
*/

/* Generic LED functions */
static int read_led(const char *ledname, int ledmask)
{
       if (ledname) {
               int led_status;

               if (read_acpi_int(NULL, ledname, &led_status))
                       return led_status;
               else
                       printk(KERN_WARNING "Asus ACPI: Error reading LED "
                              "status\n");
       }
       return (hotk->status & ledmask) ? 1 : 0;
}

static int parse_arg(const char __user * buf, unsigned long count, int *val)
{
       char s[32];
       if (!count)
               return 0;
       if (count > 31)
               return -EINVAL;
       if (copy_from_user(s, buf, count))
               return -EFAULT;
       s[count] = 0;
       if (sscanf(s, "%i", val) != 1)
               return -EINVAL;
       return count;
}

/* FIXME: kill extraneous args so it can be called independently */
static int
write_led(const char __user * buffer, unsigned long count,
         char *ledname, int ledmask, int invert)
{
       int rv, value;
       int led_out = 0;

       rv = parse_arg(buffer, count, &value);
       if (rv > 0)
               led_out = value ? 1 : 0;

       hotk->status =
           (led_out) ? (hotk->status | ledmask) : (hotk->status & ~ledmask);

       if (invert)             /* invert target value */
               led_out = !led_out & 0x1;

       if (!write_acpi_int(hotk->handle, ledname, led_out, NULL))
               printk(KERN_WARNING "Asus ACPI: LED (%s) write failed\n",
                      ledname);

       return rv;
}

/*
* Proc handlers for MLED
*/
static int
proc_read_mled(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       return sprintf(page, "%d\n",
                      read_led(hotk->methods->mled_status, MLED_ON));
}

static int
proc_write_mled(struct file *file, const char __user * buffer,
               unsigned long count, void *data)
{
       return write_led(buffer, count, hotk->methods->mt_mled, MLED_ON, 1);
}

/*
* Proc handlers for LED display
*/
static int
proc_read_ledd(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       return sprintf(page, "0x%08x\n", hotk->ledd_status);
}

static int
proc_write_ledd(struct file *file, const char __user * buffer,
               unsigned long count, void *data)
{
       int rv, value;

       rv = parse_arg(buffer, count, &value);
       if (rv > 0) {
               if (!write_acpi_int
                   (hotk->handle, hotk->methods->mt_ledd, value, NULL))
                       printk(KERN_WARNING
                              "Asus ACPI: LED display write failed\n");
               else
                       hotk->ledd_status = (u32) value;
       }
       return rv;
}

/*
* Proc handlers for WLED
*/
static int
proc_read_wled(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       return sprintf(page, "%d\n",
                      read_led(hotk->methods->wled_status, WLED_ON));
}

static int
proc_write_wled(struct file *file, const char __user * buffer,
               unsigned long count, void *data)
{
       return write_led(buffer, count, hotk->methods->mt_wled, WLED_ON, 0);
}

/*
* Proc handlers for Bluetooth
*/
static int
proc_read_bluetooth(char *page, char **start, off_t off, int count, int *eof,
                   void *data)
{
       return sprintf(page, "%d\n", read_led(hotk->methods->bt_status, BT_ON));
}

static int
proc_write_bluetooth(struct file *file, const char __user * buffer,
                    unsigned long count, void *data)
{
       /* Note: mt_bt_switch controls both internal Bluetooth adapter's
          presence and its LED */
       return write_led(buffer, count, hotk->methods->mt_bt_switch, BT_ON, 0);
}

/*
* Proc handlers for TLED
*/
static int
proc_read_tled(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       return sprintf(page, "%d\n",
                      read_led(hotk->methods->tled_status, TLED_ON));
}

static int
proc_write_tled(struct file *file, const char __user * buffer,
               unsigned long count, void *data)
{
       return write_led(buffer, count, hotk->methods->mt_tled, TLED_ON, 0);
}

static int get_lcd_state(void)
{
       int lcd = 0;

       if (hotk->model != L3H) {
               /* We don't have to check anything if we are here */
               if (!read_acpi_int(NULL, hotk->methods->lcd_status, &lcd))
                       printk(KERN_WARNING
                              "Asus ACPI: Error reading LCD status\n");

               if (hotk->model == L2D)
                       lcd = ~lcd;
       } else {                /* L3H and the like have to be handled differently */
               acpi_status status = 0;
               struct acpi_object_list input;
               union acpi_object mt_params[2];
               struct acpi_buffer output;
               union acpi_object out_obj;

               input.count = 2;
               input.pointer = mt_params;
               /* Note: the following values are partly guessed up, but
                  otherwise they seem to work */
               mt_params[0].type = ACPI_TYPE_INTEGER;
               mt_params[0].integer.value = 0x02;
               mt_params[1].type = ACPI_TYPE_INTEGER;
               mt_params[1].integer.value = 0x02;

               output.length = sizeof(out_obj);
               output.pointer = &out_obj;

               status =
                   acpi_evaluate_object(NULL, hotk->methods->lcd_status,
                                        &input, &output);
               if (status != AE_OK)
                       return -1;
               if (out_obj.type == ACPI_TYPE_INTEGER)
                       /* That's what the AML code does */
                       lcd = out_obj.integer.value >> 8;
       }

       return (lcd & 1);
}

static int set_lcd_state(int value)
{
       int lcd = 0;
       acpi_status status = 0;

       lcd = value ? 1 : 0;
       if (lcd != get_lcd_state()) {
               /* switch */
               if (hotk->model != L3H) {
                       status =
                           acpi_evaluate_object(NULL,
                                                hotk->methods->mt_lcd_switch,
                                                NULL, NULL);
               } else {        /* L3H and the like have to be handled differently */
                       if (!write_acpi_int
                           (hotk->handle, hotk->methods->mt_lcd_switch, 0x07,
                            NULL))
                               status = AE_ERROR;
                       /* L3H's AML executes EHK (0x07) upon Fn+F7 keypress,
                          the exact behaviour is simulated here */
               }
               if (ACPI_FAILURE(status))
                       printk(KERN_WARNING "Asus ACPI: Error switching LCD\n");
       }
       return 0;

}

static int
proc_read_lcd(char *page, char **start, off_t off, int count, int *eof,
             void *data)
{
       return sprintf(page, "%d\n", get_lcd_state());
}

static int
proc_write_lcd(struct file *file, const char __user * buffer,
              unsigned long count, void *data)
{
       int rv, value;

       rv = parse_arg(buffer, count, &value);
       if (rv > 0)
               set_lcd_state(value);
       return rv;
}

static int read_brightness(struct backlight_device *bd)
{
       int value;

       if (hotk->methods->brightness_get) {    /* SPLV/GPLV laptop */
               if (!read_acpi_int(hotk->handle, hotk->methods->brightness_get,
                                  &value))
                       printk(KERN_WARNING
                              "Asus ACPI: Error reading brightness\n");
       } else if (hotk->methods->brightness_status) {  /* For D1 for example */
               if (!read_acpi_int(NULL, hotk->methods->brightness_status,
                                  &value))
                       printk(KERN_WARNING
                              "Asus ACPI: Error reading brightness\n");
       } else                  /* No GPLV method */
               value = hotk->brightness;
       return value;
}

/*
* Change the brightness level
*/
static int set_brightness(int value)
{
       acpi_status status = 0;
       int ret = 0;

       /* SPLV laptop */
       if (hotk->methods->brightness_set) {
               if (!write_acpi_int(hotk->handle, hotk->methods->brightness_set,
                                   value, NULL))
                       printk(KERN_WARNING
                              "Asus ACPI: Error changing brightness\n");
                       ret = -EIO;
               goto out;
       }

       /* No SPLV method if we are here, act as appropriate */
       value -= read_brightness(NULL);
       while (value != 0) {
               status = acpi_evaluate_object(NULL, (value > 0) ?
                                             hotk->methods->brightness_up :
                                             hotk->methods->brightness_down,
                                             NULL, NULL);
               (value > 0) ? value-- : value++;
               if (ACPI_FAILURE(status))
                       printk(KERN_WARNING
                              "Asus ACPI: Error changing brightness\n");
                       ret = -EIO;
       }
out:
       return ret;
}

static int set_brightness_status(struct backlight_device *bd)
{
       return set_brightness(bd->props.brightness);
}

static int
proc_read_brn(char *page, char **start, off_t off, int count, int *eof,
             void *data)
{
       return sprintf(page, "%d\n", read_brightness(NULL));
}

static int
proc_write_brn(struct file *file, const char __user * buffer,
              unsigned long count, void *data)
{
       int rv, value;

       rv = parse_arg(buffer, count, &value);
       if (rv > 0) {
               value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
               /* 0 <= value <= 15 */
               set_brightness(value);
       }
       return rv;
}

static void set_display(int value)
{
       /* no sanity check needed for now */
       if (!write_acpi_int(hotk->handle, hotk->methods->display_set,
                           value, NULL))
               printk(KERN_WARNING "Asus ACPI: Error setting display\n");
       return;
}

/*
* Now, *this* one could be more user-friendly, but so far, no-one has
* complained. The significance of bits is the same as in proc_write_disp()
*/
static int
proc_read_disp(char *page, char **start, off_t off, int count, int *eof,
              void *data)
{
       int value = 0;

       if (!read_acpi_int(hotk->handle, hotk->methods->display_get, &value))
               printk(KERN_WARNING
                      "Asus ACPI: Error reading display status\n");
       value &= 0x07;          /* needed for some models, shouldn't hurt others */
       return sprintf(page, "%d\n", value);
}

/*
* Experimental support for display switching. As of now: 1 should activate
* the LCD output, 2 should do for CRT, and 4 for TV-Out. Any combination
* (bitwise) of these will suffice. I never actually tested 3 displays hooked up
* simultaneously, so be warned. See the acpi4asus README for more info.
*/
static int
proc_write_disp(struct file *file, const char __user * buffer,
               unsigned long count, void *data)
{
       int rv, value;

       rv = parse_arg(buffer, count, &value);
       if (rv > 0)
               set_display(value);
       return rv;
}

typedef int (proc_readfunc) (char *page, char **start, off_t off, int count,
                            int *eof, void *data);
typedef int (proc_writefunc) (struct file * file, const char __user * buffer,
                             unsigned long count, void *data);

static int
asus_proc_add(char *name, proc_writefunc * writefunc,
                    proc_readfunc * readfunc, mode_t mode,
                    struct acpi_device *device)
{
       struct proc_dir_entry *proc =
           create_proc_entry(name, mode, acpi_device_dir(device));
       if (!proc) {
               printk(KERN_WARNING "  Unable to create %s fs entry\n", name);
               return -1;
       }
       proc->write_proc = writefunc;
       proc->read_proc = readfunc;
       proc->data = acpi_driver_data(device);
       proc->owner = THIS_MODULE;
       proc->uid = asus_uid;
       proc->gid = asus_gid;
       return 0;
}

static int asus_hotk_add_fs(struct acpi_device *device)
{
       struct proc_dir_entry *proc;
       mode_t mode;

       /*
        * If parameter uid or gid is not changed, keep the default setting for
        * our proc entries (-rw-rw-rw-) else, it means we care about security,
        * and then set to -rw-rw----
        */

       if ((asus_uid == 0) && (asus_gid == 0)) {
               mode = S_IFREG | S_IRUGO | S_IWUGO;
       } else {
               mode = S_IFREG | S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP;
               printk(KERN_WARNING "  asus_uid and asus_gid parameters are "
                      "deprecated, use chown and chmod instead!\n");
       }

       acpi_device_dir(device) = asus_proc_dir;
       if (!acpi_device_dir(device))
               return -ENODEV;

       proc = create_proc_entry(PROC_INFO, mode, acpi_device_dir(device));
       if (proc) {
               proc->read_proc = proc_read_info;
               proc->data = acpi_driver_data(device);
               proc->owner = THIS_MODULE;
               proc->uid = asus_uid;
               proc->gid = asus_gid;
       } else {
               printk(KERN_WARNING "  Unable to create " PROC_INFO
                      " fs entry\n");
       }

       if (hotk->methods->mt_wled) {
               asus_proc_add(PROC_WLED, &proc_write_wled, &proc_read_wled,
                             mode, device);
       }

       if (hotk->methods->mt_ledd) {
               asus_proc_add(PROC_LEDD, &proc_write_ledd, &proc_read_ledd,
                             mode, device);
       }

       if (hotk->methods->mt_mled) {
               asus_proc_add(PROC_MLED, &proc_write_mled, &proc_read_mled,
                             mode, device);
       }

       if (hotk->methods->mt_tled) {
               asus_proc_add(PROC_TLED, &proc_write_tled, &proc_read_tled,
                             mode, device);
       }

       if (hotk->methods->mt_bt_switch) {
               asus_proc_add(PROC_BT, &proc_write_bluetooth,
                             &proc_read_bluetooth, mode, device);
       }

       /*
        * We need both read node and write method as LCD switch is also accessible
        * from keyboard
        */
       if (hotk->methods->mt_lcd_switch && hotk->methods->lcd_status) {
               asus_proc_add(PROC_LCD, &proc_write_lcd, &proc_read_lcd, mode,
                             device);
       }

       if ((hotk->methods->brightness_up && hotk->methods->brightness_down) ||
           (hotk->methods->brightness_get && hotk->methods->brightness_set)) {
               asus_proc_add(PROC_BRN, &proc_write_brn, &proc_read_brn, mode,
                             device);
       }

       if (hotk->methods->display_set) {
               asus_proc_add(PROC_DISP, &proc_write_disp, &proc_read_disp,
                             mode, device);
       }

       return 0;
}

static int asus_hotk_remove_fs(struct acpi_device *device)
{
       if (acpi_device_dir(device)) {
               remove_proc_entry(PROC_INFO, acpi_device_dir(device));
               if (hotk->methods->mt_wled)
                       remove_proc_entry(PROC_WLED, acpi_device_dir(device));
               if (hotk->methods->mt_mled)
                       remove_proc_entry(PROC_MLED, acpi_device_dir(device));
               if (hotk->methods->mt_tled)
                       remove_proc_entry(PROC_TLED, acpi_device_dir(device));
               if (hotk->methods->mt_ledd)
                       remove_proc_entry(PROC_LEDD, acpi_device_dir(device));
               if (hotk->methods->mt_bt_switch)
                       remove_proc_entry(PROC_BT, acpi_device_dir(device));
               if (hotk->methods->mt_lcd_switch && hotk->methods->lcd_status)
                       remove_proc_entry(PROC_LCD, acpi_device_dir(device));
               if ((hotk->methods->brightness_up
                    && hotk->methods->brightness_down)
                   || (hotk->methods->brightness_get
                       && hotk->methods->brightness_set))
                       remove_proc_entry(PROC_BRN, acpi_device_dir(device));
               if (hotk->methods->display_set)
                       remove_proc_entry(PROC_DISP, acpi_device_dir(device));
       }
       return 0;
}

static void asus_hotk_notify(acpi_handle handle, u32 event, void *data)
{
       /* TODO Find a better way to handle events count. */
       if (!hotk)
               return;

       if ((event & ~((u32) BR_UP)) < 16) {
               hotk->brightness = (event & ~((u32) BR_UP));
       } else if ((event & ~((u32) BR_DOWN)) < 16) {
               hotk->brightness = (event & ~((u32) BR_DOWN));
       }

       acpi_bus_generate_event(hotk->device, event,
                               hotk->event_count[event % 128]++);

       return;
}

/*
* Match the model string to the list of supported models. Return END_MODEL if
* no match or model is NULL.
*/
static int asus_model_match(char *model)
{
       if (model == NULL)
               return END_MODEL;

       if (strncmp(model, "L3D", 3) == 0)
               return L3D;
       else if (strncmp(model, "L2E", 3) == 0 ||
                strncmp(model, "L3H", 3) == 0 || strncmp(model, "L5D", 3) == 0)
               return L3H;
       else if (strncmp(model, "L3", 2) == 0 || strncmp(model, "L2B", 3) == 0)
               return L3C;
       else if (strncmp(model, "L8L", 3) == 0)
               return L8L;
       else if (strncmp(model, "L4R", 3) == 0)
               return L4R;
       else if (strncmp(model, "M6N", 3) == 0 || strncmp(model, "W3N", 3) == 0)
               return M6N;
       else if (strncmp(model, "M6R", 3) == 0 || strncmp(model, "A3G", 3) == 0)
               return M6R;
       else if (strncmp(model, "M2N", 3) == 0 ||
                strncmp(model, "M3N", 3) == 0 ||
                strncmp(model, "M5N", 3) == 0 ||
                strncmp(model, "M6N", 3) == 0 ||
                strncmp(model, "S1N", 3) == 0 ||
                strncmp(model, "S5N", 3) == 0 || strncmp(model, "W1N", 3) == 0)
               return xxN;
       else if (strncmp(model, "M1", 2) == 0)
               return M1A;
       else if (strncmp(model, "M2", 2) == 0 || strncmp(model, "L4E", 3) == 0)
               return M2E;
       else if (strncmp(model, "L2", 2) == 0)
               return L2D;
       else if (strncmp(model, "L8", 2) == 0)
               return S1x;
       else if (strncmp(model, "D1", 2) == 0)
               return D1x;
       else if (strncmp(model, "A1", 2) == 0)
               return A1x;
       else if (strncmp(model, "A2", 2) == 0)
               return A2x;
       else if (strncmp(model, "J1", 2) == 0)
               return S2x;
       else if (strncmp(model, "L5", 2) == 0)
               return L5x;
       else if (strncmp(model, "A4G", 3) == 0)
               return A4G;
       else if (strncmp(model, "W1N", 3) == 0)
               return W1N;
       else if (strncmp(model, "W3V", 3) == 0)
               return W3V;
       else if (strncmp(model, "W5A", 3) == 0)
               return W5A;
       else if (strncmp(model, "A4S", 3) == 0)
               return A4S;
       else
               return END_MODEL;
}

/*
* This function is used to initialize the hotk with right values. In this
* method, we can make all the detection we want, and modify the hotk struct
*/
static int asus_hotk_get_info(void)
{
       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
       union acpi_object *model = NULL;
       int bsts_result;
       char *string = NULL;
       acpi_status status;

       /*
        * Get DSDT headers early enough to allow for differentiating between
        * models, but late enough to allow acpi_bus_register_driver() to fail
        * before doing anything ACPI-specific. Should we encounter a machine,
        * which needs special handling (i.e. its hotkey device has a different
        * HID), this bit will be moved. A global variable asus_info contains
        * the DSDT header.
        */
       status = acpi_get_table(ACPI_SIG_DSDT, 1, &asus_info);
       if (ACPI_FAILURE(status))
               printk(KERN_WARNING "  Couldn't get the DSDT table header\n");

       /* We have to write 0 on init this far for all ASUS models */
       if (!write_acpi_int(hotk->handle, "INIT", 0, &buffer)) {
               printk(KERN_ERR "  Hotkey initialization failed\n");
               return -ENODEV;
       }

       /* This needs to be called for some laptops to init properly */
       if (!read_acpi_int(hotk->handle, "BSTS", &bsts_result))
               printk(KERN_WARNING "  Error calling BSTS\n");
       else if (bsts_result)
               printk(KERN_NOTICE "  BSTS called, 0x%02x returned\n",
                      bsts_result);

       /*
        * Try to match the object returned by INIT to the specific model.
        * Handle every possible object (or the lack of thereof) the DSDT
        * writers might throw at us. When in trouble, we pass NULL to
        * asus_model_match() and try something completely different.
        */
       if (buffer.pointer) {
               model = buffer.pointer;
               switch (model->type) {
               case ACPI_TYPE_STRING:
                       string = model->string.pointer;
                       break;
               case ACPI_TYPE_BUFFER:
                       string = model->buffer.pointer;
                       break;
               default:
                       kfree(model);
                       break;
               }
       }
       hotk->model = asus_model_match(string);
       if (hotk->model == END_MODEL) { /* match failed */
               if (asus_info &&
                   strncmp(asus_info->oem_table_id, "ODEM", 4) == 0) {
                       hotk->model = P30;
                       printk(KERN_NOTICE
                              "  Samsung P30 detected, supported\n");
               } else {
                       hotk->model = M2E;
                       printk(KERN_NOTICE "  unsupported model %s, trying "
                              "default values\n", string);
                       printk(KERN_NOTICE
                              "  send /proc/acpi/dsdt to the developers\n");
               }
               hotk->methods = &model_conf[hotk->model];
               return AE_OK;
       }
       hotk->methods = &model_conf[hotk->model];
       printk(KERN_NOTICE "  %s model detected, supported\n", string);

       /* Sort of per-model blacklist */
       if (strncmp(string, "L2B", 3) == 0)
               hotk->methods->lcd_status = NULL;
       /* L2B is similar enough to L3C to use its settings, with this only
          exception */
       else if (strncmp(string, "A3G", 3) == 0)
               hotk->methods->lcd_status = "\\BLFG";
       /* A3G is like M6R */
       else if (strncmp(string, "S5N", 3) == 0 ||
                strncmp(string, "M5N", 3) == 0 ||
                strncmp(string, "W3N", 3) == 0)
               hotk->methods->mt_mled = NULL;
       /* S5N, M5N and W3N have no MLED */
       else if (strncmp(string, "L5D", 3) == 0)
               hotk->methods->mt_wled = NULL;
       /* L5D's WLED is not controlled by ACPI */
       else if (strncmp(string, "M2N", 3) == 0 ||
                strncmp(string, "W3V", 3) == 0 ||
                strncmp(string, "S1N", 3) == 0)
               hotk->methods->mt_wled = "WLED";
       /* M2N, S1N and W3V have a usable WLED */
       else if (asus_info) {
               if (strncmp(asus_info->oem_table_id, "L1", 2) == 0)
                       hotk->methods->mled_status = NULL;
               /* S1300A reports L84F, but L1400B too, account for that */
       }

       kfree(model);

       return AE_OK;
}

static int asus_hotk_check(void)
{
       int result = 0;

       result = acpi_bus_get_status(hotk->device);
       if (result)
               return result;

       if (hotk->device->status.present) {
               result = asus_hotk_get_info();
       } else {
               printk(KERN_ERR "  Hotkey device not present, aborting\n");
               return -EINVAL;
       }

       return result;
}

static int asus_hotk_found;

static int asus_hotk_add(struct acpi_device *device)
{
       acpi_status status = AE_OK;
       int result;

       if (!device)
               return -EINVAL;

       printk(KERN_NOTICE "Asus Laptop ACPI Extras version %s\n",
              ASUS_ACPI_VERSION);

       hotk = kzalloc(sizeof(struct asus_hotk), GFP_KERNEL);
       if (!hotk)
               return -ENOMEM;

       hotk->handle = device->handle;
       strcpy(acpi_device_name(device), ACPI_HOTK_DEVICE_NAME);
       strcpy(acpi_device_class(device), ACPI_HOTK_CLASS);
       acpi_driver_data(device) = hotk;
       hotk->device = device;

       result = asus_hotk_check();
       if (result)
               goto end;

       result = asus_hotk_add_fs(device);
       if (result)
               goto end;

       /*
        * We install the handler, it will receive the hotk in parameter, so, we
        * could add other data to the hotk struct
        */
       status = acpi_install_notify_handler(hotk->handle, ACPI_SYSTEM_NOTIFY,
                                            asus_hotk_notify, hotk);
       if (ACPI_FAILURE(status))
               printk(KERN_ERR "  Error installing notify handler\n");

       /* For laptops without GPLV: init the hotk->brightness value */
       if ((!hotk->methods->brightness_get)
           && (!hotk->methods->brightness_status)
           && (hotk->methods->brightness_up && hotk->methods->brightness_down)) {
               status =
                   acpi_evaluate_object(NULL, hotk->methods->brightness_down,
                                        NULL, NULL);
               if (ACPI_FAILURE(status))
                       printk(KERN_WARNING "  Error changing brightness\n");
               else {
                       status =
                           acpi_evaluate_object(NULL,
                                                hotk->methods->brightness_up,
                                                NULL, NULL);
                       if (ACPI_FAILURE(status))
                               printk(KERN_WARNING "  Strange, error changing"
                                      " brightness\n");
               }
       }

       asus_hotk_found = 1;

       /* LED display is off by default */
       hotk->ledd_status = 0xFFF;

     end:
       if (result) {
               kfree(hotk);
       }

       return result;
}

static int asus_hotk_remove(struct acpi_device *device, int type)
{
       acpi_status status = 0;

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

       status = acpi_remove_notify_handler(hotk->handle, ACPI_SYSTEM_NOTIFY,
                                           asus_hotk_notify);
       if (ACPI_FAILURE(status))
               printk(KERN_ERR "Asus ACPI: Error removing notify handler\n");

       asus_hotk_remove_fs(device);

       kfree(hotk);

       return 0;
}

static struct backlight_ops asus_backlight_data = {
       .get_brightness = read_brightness,
       .update_status  = set_brightness_status,
};

static void __exit asus_acpi_exit(void)
{
       if (asus_backlight_device)
               backlight_device_unregister(asus_backlight_device);

       acpi_bus_unregister_driver(&asus_hotk_driver);
       remove_proc_entry(PROC_ASUS, acpi_root_dir);

       return;
}

static int __init asus_acpi_init(void)
{
       int result;

       if (acpi_disabled)
               return -ENODEV;

       asus_proc_dir = proc_mkdir(PROC_ASUS, acpi_root_dir);
       if (!asus_proc_dir) {
               printk(KERN_ERR "Asus ACPI: Unable to create /proc entry\n");
               return -ENODEV;
       }
       asus_proc_dir->owner = THIS_MODULE;

       result = acpi_bus_register_driver(&asus_hotk_driver);
       if (result < 0) {
               remove_proc_entry(PROC_ASUS, acpi_root_dir);
               return result;
       }

       /*
        * This is a bit of a kludge.  We only want this module loaded
        * for ASUS systems, but there's currently no way to probe the
        * ACPI namespace for ASUS HIDs.  So we just return failure if
        * we didn't find one, which will cause the module to be
        * unloaded.
        */
       if (!asus_hotk_found) {
               acpi_bus_unregister_driver(&asus_hotk_driver);
               remove_proc_entry(PROC_ASUS, acpi_root_dir);
               return result;
       }

       asus_backlight_device = backlight_device_register("asus",NULL,NULL,
                                                         &asus_backlight_data);
       if (IS_ERR(asus_backlight_device)) {
               printk(KERN_ERR "Could not register asus backlight device\n");
               asus_backlight_device = NULL;
               asus_acpi_exit();
       }
       asus_backlight_device->props.max_brightness = 15;

       return 0;
}
/*
* Replaced with eeepc_hotk_init
*/
//module_init(asus_acpi_init);
/*
* Replaced with eeepc_hotk_exit
*/
//module_exit(asus_acpi_exit);

/*
* returns 1 if write is successful, 0 else.
*/
static int
write_eeepc_acpi_int(acpi_handle handle, const char *method, int val, struct acpi_buffer *output)
{
       struct acpi_object_list params;
       union acpi_object in_obj;
       acpi_status status;

       params.count = 1;
       params.pointer = &in_obj;
       in_obj.type = ACPI_TYPE_INTEGER;
       in_obj.integer.value = val;

       status = acpi_evaluate_object(handle, (char *)method, &params, output);
       return (status == AE_OK);
}

static int
read_eeepc_acpi_int(acpi_handle handle, const char *method, int *val)
{
       struct acpi_buffer output;
       union acpi_object out_obj;
       acpi_status status;

       output.length = sizeof(out_obj);
       output.pointer = &out_obj;

       status = acpi_evaluate_object(handle, (char *)method, NULL, &output);
       *val = out_obj.integer.value;
       return (status == AE_OK) && (out_obj.type == ACPI_TYPE_INTEGER);
}

static int
eeepc_hotk_write_proc(struct file *file, const char __user * buffer, unsigned long count, void *data)
{
       int     value, rv;
       cm_asl_t cm;

       rv = parse_arg(buffer, count, &value);
       cm = (unsigned int)data;
       if((ehotk->cm_supported & (0x1<<cm)) && (0 < rv))
       {
               if (!write_eeepc_acpi_int(ehotk->handle, cm_setv[cm], value, NULL))
                       printk(KERN_WARNING "[eeepc hotk] Error writing %s.\n", cm_setv[cm]);
       }
       return rv;
}

static int
eeepc_hotk_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
{
       int     value;
       cm_asl_t cm;

       cm = (unsigned int)data;

       if((ehotk->cm_supported & (0x1<<cm))) {
               if (!cm_getv[cm]) return 0;
               if (!read_eeepc_acpi_int(ehotk->handle, cm_getv[cm], &value))
                       printk(KERN_WARNING "[eeepc hotk] Error reading %s.\n", cm_getv[cm]);
       }
       else    value = -1;
       return sprintf(page, "%d\n", value);
}

static int
eeepc_hotk_reset_init(struct file *file, const char __user * buffer, unsigned long count, void *data)
{
       int     value, rv;

       rv = parse_arg(buffer, count, &value);
       if (!write_eeepc_acpi_int(ehotk->handle, "INIT", value, NULL))
               printk(KERN_ERR "[eeepc hotk] Hotkey initialization failed\n");
       else    printk(KERN_INFO "[eeepc hotk] reset init flag 0x%x\n", value);
       return rv;
}

static int
eeepc_hotk_init_proc(char* name, mode_t mode, struct acpi_device *device)
{
       struct proc_dir_entry *proc = create_proc_entry(name, mode, acpi_device_dir(device));

       if (!proc) {
               printk(KERN_WARNING "[eeepc hotk] Unable to create init fs entry\n");
               return -1;
       }
       proc->write_proc = eeepc_hotk_reset_init;
       proc->read_proc = NULL;
       proc->data = NULL;
       proc->owner = THIS_MODULE;
       proc->uid = eeepc_uid;
       proc->gid = eeepc_gid;
       return 0;
}

static int
eeepc_hotk_new_proc(char *name, cm_asl_t cm , mode_t mode,  struct acpi_device *device)
{
       struct proc_dir_entry *proc = create_proc_entry(name, mode, acpi_device_dir(device));

       if (!proc) {
               printk(KERN_WARNING "[eeepc hotk] Unable to create %s fs entry\n", name);
               return -1;
       }
       proc->write_proc = eeepc_hotk_write_proc;
       proc->read_proc = eeepc_hotk_read_proc;
       proc->data = (void*)cm;
       proc->owner = THIS_MODULE;
       proc->uid = eeepc_uid;
       proc->gid = eeepc_gid;
       return 0;
}

static int
eeepc_hotk_add_fs(struct acpi_device *device)
{
       mode_t mode;

       if ((eeepc_uid == 0) && (eeepc_gid == 0))
               mode = S_IFREG | S_IRUGO | S_IWUGO;
       else
       {
               mode = S_IFREG | S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP;
               printk(KERN_WARNING "  eeepc_uid and eeepc_gid parameters are "
                      "deprecated, use chown and chmod instead!\n");
       }

       acpi_device_dir(device) = eeepc_proc_dir;
       if (!acpi_device_dir(device))
               return -ENODEV;

       if(ehotk->cm_supported & (0x1 << CM_ASL_WLAN))
               eeepc_hotk_new_proc(PROC_WLAN, CM_ASL_WLAN , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_CAMERA))
               eeepc_hotk_new_proc(PROC_CAMERA, CM_ASL_CAMERA , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_DISPLAYSWITCH))
               eeepc_hotk_new_proc(PROC_DISP, CM_ASL_DISPLAYSWITCH , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_PANELBRIGHT))
               eeepc_hotk_new_proc(PROC_BRN, CM_ASL_PANELBRIGHT , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_BIOSFLASH))
               eeepc_hotk_new_proc(PROC_HDPS, CM_ASL_BIOSFLASH , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_CPUFV))
               eeepc_hotk_new_proc(PROC_CPUFV, CM_ASL_CPUFV , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_MODEM))
               eeepc_hotk_new_proc(PROC_MODEM, CM_ASL_MODEM , mode, device);

       if(ehotk->cm_supported & (0x1 << CM_ASL_CARDREADER))
               eeepc_hotk_new_proc(PROC_CARDR, CM_ASL_CARDREADER , mode, device);

       eeepc_hotk_init_proc(PROC_INIT, mode, device);

       return 0;
}

static int
eeepc_hotk_remove_fs(struct acpi_device *device)
{
       if (acpi_device_dir(device))
       {
               if(ehotk->cm_supported & (0x1 << CM_ASL_WLAN))
                       remove_proc_entry(PROC_WLAN, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_CAMERA))
                       remove_proc_entry(PROC_CAMERA, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_DISPLAYSWITCH))
                       remove_proc_entry(PROC_DISP, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_PANELBRIGHT))
                       remove_proc_entry(PROC_BRN, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_BIOSFLASH))
                       remove_proc_entry(PROC_HDPS, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_CPUFV))
                       remove_proc_entry(PROC_CPUFV, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_MODEM))
                       remove_proc_entry(PROC_MODEM, acpi_device_dir(device));

               if(ehotk->cm_supported & (0x1 << CM_ASL_CARDREADER))
                       remove_proc_entry(PROC_CARDR, acpi_device_dir(device));

               remove_proc_entry(PROC_INIT, acpi_device_dir(device));
       }
       return 0;
}

static int
eeepc_hotk_check(void)
{
       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
       int result = AE_OK;

       result = acpi_bus_get_status(ehotk->device);
       if(result)
               return result;
       if(ehotk->device->status.present)
       {
               if (!write_eeepc_acpi_int(ehotk->handle, "INIT", init_flag, &buffer))
               {
                       printk(KERN_ERR "[eeepc hotk] Hotkey initialization failed\n");
                       return -ENODEV;
               }
               else    printk(KERN_NOTICE "[eeepc hotk] Hotkey init flags 0x%x.\n", init_flag);

               // get control methods supported.
               if(!read_eeepc_acpi_int(ehotk->handle, "CMSG", &ehotk->cm_supported))
               {
                       printk(KERN_ERR "[eeepc hotk] Get control methods supported failed\n");
                       return -ENODEV;
               }
               else    printk(KERN_INFO "[eeepc hotk] Get control methods supported : 0x%x\n", ehotk->cm_supported);
               ehotk->cm_supported = ehotk->cm_supported | (0x01 << CM_ASL_LID);
       }
       else
       {
               printk(KERN_ERR "[eeepc hotk] Hotkey device not present, aborting\n");
               return -EINVAL;
       }

       return result;
}

static void
eeepc_hotk_notify(acpi_handle handle, u32 event, void *data)
{
       int value;
       if (!ehotk)
               return;

       // if DISABLE_ASL_WLAN is set, the notify code for fn+f2 will always be 0x10
       if((DISABLE_ASL_WLAN&init_flag) && (event==NOTIFY_WLAN_ON))
       {
               if(ehotk->cm_supported & (0x1 << CM_ASL_WLAN))
               {
                       if(!(read_eeepc_acpi_int(ehotk->handle, cm_getv[CM_ASL_WLAN], &value)))
                               printk(KERN_WARNING "[eeepc hotk] Error reading %s\n", cm_getv[CM_ASL_WLAN]);
                       else if(value == 1)
                               event = 0x11;
               }
       }
       acpi_bus_generate_event(ehotk->device, event, ehotk->event_count[event % 128]++);

       return;
}

static int ehotk_found;

static int eeepc_hotk_add(struct acpi_device *device)
{
       acpi_status status = AE_OK;
       int     result;

       if(!device)
               return -EINVAL;

       printk(KERN_NOTICE "Asus EEEPC HOTKEY\n");

       ehotk = kzalloc(sizeof(struct eeepc_hotk), GFP_KERNEL);
       if(!ehotk)
               return -ENOMEM;

       ehotk->handle = device->handle;
       strcpy(acpi_device_name(device), EEEPC_HOTK_DEVICE_NAME);
       strcpy(acpi_device_class(device), EEEPC_HOTK_CLASS);
       acpi_driver_data(device) = ehotk;
       ehotk->device = device;

       result = eeepc_hotk_check();
       if (result)
               goto end;

       result = eeepc_hotk_add_fs(device);
       if (result)
               goto end;

       status = acpi_install_notify_handler(ehotk->handle, ACPI_SYSTEM_NOTIFY,
                                            eeepc_hotk_notify, ehotk);
       if (ACPI_FAILURE(status))
               printk(KERN_ERR "  Error installing notify handler\n");

       ehotk_found = 1;

end:
       if (result) {
               kfree(ehotk);

       }

       return result;

}

static int eeepc_hotk_remove(struct acpi_device *device, int type)
{
       acpi_status status = 0;

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

       status = acpi_remove_notify_handler(ehotk->handle, ACPI_SYSTEM_NOTIFY, eeepc_hotk_notify);

       if (ACPI_FAILURE(status))
               printk(KERN_ERR "[eeepc hotk] Error removing notify handler\n");

       eeepc_hotk_remove_fs(device);

       kfree(ehotk);

       return 0;
}

static void __exit eeepc_hotk_exit(void)
{
       acpi_bus_unregister_driver(&eeepc_hotk_driver);
       remove_proc_entry(PROC_ASUS, acpi_root_dir);

       return;
}

static int __init eeepc_hotk_init(void)
{
       int result;

       if (acpi_disabled)
               return -ENODEV;

       eeepc_proc_dir = proc_mkdir(PROC_ASUS, acpi_root_dir);
       if (!eeepc_proc_dir)
       {
               printk(KERN_ERR "Asus ACPI: Unable to create /proc entry\n");
               return -ENODEV;
       }
       eeepc_proc_dir->owner = THIS_MODULE;

       init_flag = DISABLE_ASL_WLAN|DISABLE_ASL_DISPLAYSWITCH;

       result = acpi_bus_register_driver(&eeepc_hotk_driver);
       if (result < 0)
       {
               remove_proc_entry(PROC_ASUS, acpi_root_dir);
               return result;
       }

       if (!ehotk_found)
       {
               acpi_bus_unregister_driver(&eeepc_hotk_driver);
               remove_proc_entry(PROC_ASUS, acpi_root_dir);
               return result;
       }
       return 0;
}

module_init(eeepc_hotk_init);
module_exit(eeepc_hotk_exit);