ACPI: delete acpi_os_free(), use kfree() directly

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / asus_acpi.c

/*
 *  asus_acpi.c - Asus Laptop ACPI Extras
 *
 *
 *  Copyright (C) 2002, 2003, 2004 Julien Lerouge, 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.
 *
 *  TODO:
 *  add Fn key status
 *  Add mode selection on module loading (parameter) -> still necessary?
 *  Complete display switching -- may require dirty hacks or calling _DOS?
 */

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

#define ASUS_ACPI_VERSION "0.29"

#define PROC_ASUS       "asus"  //the directory
#define PROC_MLED       "mled"
#define PROC_WLED       "wled"
#define PROC_TLED       "tled"
#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"

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

/*
 * Flags for hotk status
 */
#define MLED_ON     0x01        //is MLED ON ?
#define WLED_ON     0x02
#define TLED_ON     0x04

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_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, ...
        struct model_data *methods;     //methods available on the laptop
        u8 brightness;          //brightness level
        enum {
                A1x = 0,        //A1340D, A1300F
                A2x,            //A2500H
                D1x,            //D1
                L2D,            //L2000D
                L3C,            //L3800C
                L3D,            //L3400D
                L3H,            //L3H, but also L2000E
                L4R,            //L4500R
                L5x,            //L5800C 
                L8L,            //L8400L
                M1A,            //M1300A
                M2E,            //M2400E, L4400L
                M6N,            //M6800N
                M6R,            //M6700R
                P30,            //Samsung P30
                S1x,            //S1300A, but also L1400B and M2400A (L84F)
                S2x,            //S200 (J1 reported), Victor MP-XP7210
                xxN,            //M2400N, M3700N, M5200N, S1300N, S5200N, W1OOON
                //(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] = {
        /*
         * Those pathnames are relative to the HOTK / ATKD device :
         *       - mt_mled
         *       - mt_wled
         *       - brightness_set
         *       - brightness_get
         *       - display_set
         *       - display_get
         *
         * 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 = "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 = "\\_SB.PCI0.P0P1.VGA.GETD"},
        {
         .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 = "\\SSTE"},

        {
         .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 = "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"}
};

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

/*
 * 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 = ACPI_HOTK_NAME,
        .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 value;
        int led_out = 0;

        count = parse_arg(buffer, count, &value);
        if (count > 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 count;
}

/*
 * 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 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 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 value;

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

static int read_brightness(void)
{
        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 void set_brightness(int value)
{
        acpi_status status = 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");
                return;
        }

        /* No SPLV method if we are here, act as appropriate */
        value -= read_brightness();
        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");
        }
        return;
}

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());
}

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

        count = parse_arg(buffer, count, &value);
        if (count > 0) {
                value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
                /* 0 <= value <= 15 */
                set_brightness(value);
        } else if (count < 0) {
                printk(KERN_WARNING "Asus ACPI: Error reading user input\n");
        }

        return count;
}

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 value;

        count = parse_arg(buffer, count, &value);
        if (count > 0)
                set_display(value);
        else if (count < 0)
                printk(KERN_WARNING "Asus ACPI: Error reading user input\n");

        return count;
}

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_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);
        }

        /* 
         * 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_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;
}

/*
 * 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 };
        struct acpi_buffer dsdt = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *model = NULL;
        int bsts_result;
        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_TABLE_ID_DSDT, 1, &dsdt);
        if (ACPI_FAILURE(status))
                printk(KERN_WARNING "  Couldn't get the DSDT table header\n");
        else
                asus_info = (struct acpi_table_header *)dsdt.pointer;

        /* 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);

        /* This is unlikely with implicit return */
        if (buffer.pointer == NULL)
                return -EINVAL;

        model = (union acpi_object *) buffer.pointer;
        /*
         * Samsung P30 has a device with a valid _HID whose INIT does not 
         * return anything. It used to be possible to catch this exception,
         * but the implicit return code will now happily confuse the 
         * driver. We assume that every ACPI_TYPE_STRING is a valid model
         * identifier but it's still possible to get completely bogus data.
         */
        if (model->type == ACPI_TYPE_STRING) {
                printk(KERN_NOTICE "  %s model detected, ", model->string.pointer);
        } else {
                if (asus_info &&        /* Samsung P30 */
                    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_WARNING "  no string returned by INIT\n");
                        printk(KERN_WARNING "  trying default values, supply "
                               "the developers with your DSDT\n");
                }
                hotk->methods = &model_conf[hotk->model];
                
                kfree(model);

                return AE_OK;
        }

        hotk->model = END_MODEL;
        if (strncmp(model->string.pointer, "L3D", 3) == 0)
                hotk->model = L3D;
        else if (strncmp(model->string.pointer, "L3H", 3) == 0 ||
                 strncmp(model->string.pointer, "L2E", 3) == 0)
                hotk->model = L3H;
        else if (strncmp(model->string.pointer, "L3", 2) == 0 ||
                 strncmp(model->string.pointer, "L2B", 3) == 0)
                hotk->model = L3C;
        else if (strncmp(model->string.pointer, "L8L", 3) == 0)
                hotk->model = L8L;
        else if (strncmp(model->string.pointer, "L4R", 3) == 0)
                hotk->model = L4R;
        else if (strncmp(model->string.pointer, "M6N", 3) == 0)
                hotk->model = M6N;
        else if (strncmp(model->string.pointer, "M6R", 3) == 0)
                hotk->model = M6R;
        else if (strncmp(model->string.pointer, "M2N", 3) == 0 ||
                 strncmp(model->string.pointer, "M3N", 3) == 0 ||
                 strncmp(model->string.pointer, "M5N", 3) == 0 ||
                 strncmp(model->string.pointer, "M6N", 3) == 0 ||
                 strncmp(model->string.pointer, "S1N", 3) == 0 ||
                 strncmp(model->string.pointer, "S5N", 3) == 0 ||
                 strncmp(model->string.pointer, "W1N", 3) == 0)
                hotk->model = xxN;
        else if (strncmp(model->string.pointer, "M1", 2) == 0)
                hotk->model = M1A;
        else if (strncmp(model->string.pointer, "M2", 2) == 0 ||
                 strncmp(model->string.pointer, "L4E", 3) == 0)
                hotk->model = M2E;
        else if (strncmp(model->string.pointer, "L2", 2) == 0)
                hotk->model = L2D;
        else if (strncmp(model->string.pointer, "L8", 2) == 0)
                hotk->model = S1x;
        else if (strncmp(model->string.pointer, "D1", 2) == 0)
                hotk->model = D1x;
        else if (strncmp(model->string.pointer, "A1", 2) == 0)
                hotk->model = A1x;
        else if (strncmp(model->string.pointer, "A2", 2) == 0)
                hotk->model = A2x;
        else if (strncmp(model->string.pointer, "J1", 2) == 0)
                hotk->model = S2x;
        else if (strncmp(model->string.pointer, "L5", 2) == 0)
                hotk->model = L5x;

        if (hotk->model == END_MODEL) {
                printk("unsupported, trying default values, supply the "
                       "developers with your DSDT\n");
                hotk->model = M2E;
        } else {
                printk("supported\n");
        }

        hotk->methods = &model_conf[hotk->model];

        /* Sort of per-model blacklist */
        if (strncmp(model->string.pointer, "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(model->string.pointer, "S5N", 3) == 0 ||
                 strncmp(model->string.pointer, "M5N", 3) == 0)
                hotk->methods->mt_mled = NULL;
        /* S5N and M5N have no MLED */
        else if (strncmp(model->string.pointer, "M2N", 3) == 0 ||
                 strncmp(model->string.pointer, "W1N", 3) == 0)
                hotk->methods->mt_wled = "WLED";
        /* M2N and W1N 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 =
            (struct asus_hotk *)kmalloc(sizeof(struct asus_hotk), GFP_KERNEL);
        if (!hotk)
                return -ENOMEM;
        memset(hotk, 0, sizeof(struct asus_hotk));

        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;

      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 int __init asus_acpi_init(void)
{
        int result;

        if (acpi_disabled)
                return -ENODEV;

        if (!acpi_specific_hotkey_enabled) {
                printk(KERN_ERR "Using generic hotkey driver\n");
                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;
        }

        return 0;
}

static void __exit asus_acpi_exit(void)
{
        acpi_bus_unregister_driver(&asus_hotk_driver);
        remove_proc_entry(PROC_ASUS, acpi_root_dir);

        kfree(asus_info);

        return;
}

module_init(asus_acpi_init);
module_exit(asus_acpi_exit);