platform-drivers: x86: fix common misspellings

[deliverable/linux.git] / drivers / platform / x86 / asus-laptop.c

/*
 *  asus-laptop.c - Asus Laptop Support
 *
 *
 *  Copyright (C) 2002-2005 Julien Lerouge, 2003-2006 Karol Kozimor
 *  Copyright (C) 2006-2007 Corentin Chary
 *
 *  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.
 *  Eric Burghard  - LED display support for W1N
 *  Josh Green     - Light Sens support
 *  Thomas Tuttle  - His first patch for led support was very helpful
 *  Sam Lin        - GPS support
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <linux/fb.h>
#include <linux/leds.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/rfkill.h>
#include <linux/slab.h>
#include <linux/dmi.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>

#define ASUS_LAPTOP_VERSION     "0.42"

#define ASUS_LAPTOP_NAME        "Asus Laptop Support"
#define ASUS_LAPTOP_CLASS       "hotkey"
#define ASUS_LAPTOP_DEVICE_NAME "Hotkey"
#define ASUS_LAPTOP_FILE        KBUILD_MODNAME
#define ASUS_LAPTOP_PREFIX      "\\_SB.ATKD."

MODULE_AUTHOR("Julien Lerouge, Karol Kozimor, Corentin Chary");
MODULE_DESCRIPTION(ASUS_LAPTOP_NAME);
MODULE_LICENSE("GPL");

/*
 * WAPF defines the behavior of the Fn+Fx wlan key
 * The significance of values is yet to be found, but
 * most of the time:
 * 0x0 will do nothing
 * 0x1 will allow to control the device with Fn+Fx key.
 * 0x4 will send an ACPI event (0x88) while pressing the Fn+Fx key
 * 0x5 like 0x1 or 0x4
 * So, if something doesn't work as you want, just try other values =)
 */
static uint wapf = 1;
module_param(wapf, uint, 0444);
MODULE_PARM_DESC(wapf, "WAPF value");

static int wlan_status = 1;
static int bluetooth_status = 1;
static int wimax_status = -1;
static int wwan_status = -1;

module_param(wlan_status, int, 0444);
MODULE_PARM_DESC(wlan_status, "Set the wireless status on boot "
                 "(0 = disabled, 1 = enabled, -1 = don't do anything). "
                 "default is 1");

module_param(bluetooth_status, int, 0444);
MODULE_PARM_DESC(bluetooth_status, "Set the wireless status on boot "
                 "(0 = disabled, 1 = enabled, -1 = don't do anything). "
                 "default is 1");

module_param(wimax_status, int, 0444);
MODULE_PARM_DESC(wimax_status, "Set the wireless status on boot "
                 "(0 = disabled, 1 = enabled, -1 = don't do anything). "
                 "default is 1");

module_param(wwan_status, int, 0444);
MODULE_PARM_DESC(wwan_status, "Set the wireless status on boot "
                 "(0 = disabled, 1 = enabled, -1 = don't do anything). "
                 "default is 1");

/*
 * Some events we use, same for all Asus
 */
#define ATKD_BR_UP      0x10    /* (event & ~ATKD_BR_UP) = brightness level */
#define ATKD_BR_DOWN    0x20    /* (event & ~ATKD_BR_DOWN) = britghness level */
#define ATKD_BR_MIN     ATKD_BR_UP
#define ATKD_BR_MAX     (ATKD_BR_DOWN | 0xF)    /* 0x2f */
#define ATKD_LCD_ON     0x33
#define ATKD_LCD_OFF    0x34

/*
 * Known bits returned by \_SB.ATKD.HWRS
 */
#define WL_HWRS         0x80
#define BT_HWRS         0x100

/*
 * Flags for hotk status
 * WL_ON and BT_ON are also used for wireless_status()
 */
#define WL_RSTS         0x01    /* internal Wifi */
#define BT_RSTS         0x02    /* internal Bluetooth */
#define WM_RSTS         0x08    /* internal wimax */
#define WW_RSTS         0x20    /* internal wwan */

/* LED */
#define METHOD_MLED             "MLED"
#define METHOD_TLED             "TLED"
#define METHOD_RLED             "RLED"  /* W1JC */
#define METHOD_PLED             "PLED"  /* A7J */
#define METHOD_GLED             "GLED"  /* G1, G2 (probably) */

/* LEDD */
#define METHOD_LEDD             "SLCM"

/*
 * Bluetooth and WLAN
 * WLED and BLED are not handled like other XLED, because in some dsdt
 * they also control the WLAN/Bluetooth device.
 */
#define METHOD_WLAN             "WLED"
#define METHOD_BLUETOOTH        "BLED"

/* WWAN and WIMAX */
#define METHOD_WWAN             "GSMC"
#define METHOD_WIMAX            "WMXC"

#define METHOD_WL_STATUS        "RSTS"

/* Brightness */
#define METHOD_BRIGHTNESS_SET   "SPLV"
#define METHOD_BRIGHTNESS_GET   "GPLV"

/* Display */
#define METHOD_SWITCH_DISPLAY   "SDSP"

#define METHOD_ALS_CONTROL      "ALSC" /* Z71A Z71V */
#define METHOD_ALS_LEVEL        "ALSL" /* Z71A Z71V */

/* GPS */
/* R2H use different handle for GPS on/off */
#define METHOD_GPS_ON           "SDON"
#define METHOD_GPS_OFF          "SDOF"
#define METHOD_GPS_STATUS       "GPST"

/* Keyboard light */
#define METHOD_KBD_LIGHT_SET    "SLKB"
#define METHOD_KBD_LIGHT_GET    "GLKB"

/*
 * Define a specific led structure to keep the main structure clean
 */
struct asus_led {
        int wk;
        struct work_struct work;
        struct led_classdev led;
        struct asus_laptop *asus;
        const char *method;
};

/*
 * This is the main structure, we can use it to store anything interesting
 * about the hotk device
 */
struct asus_laptop {
        char *name;             /* laptop name */

        struct acpi_table_header *dsdt_info;
        struct platform_device *platform_device;
        struct acpi_device *device;             /* the device we are in */
        struct backlight_device *backlight_device;

        struct input_dev *inputdev;
        struct key_entry *keymap;

        struct asus_led mled;
        struct asus_led tled;
        struct asus_led rled;
        struct asus_led pled;
        struct asus_led gled;
        struct asus_led kled;
        struct workqueue_struct *led_workqueue;

        int wireless_status;
        bool have_rsts;

        struct rfkill *gps_rfkill;

        acpi_handle handle;     /* the handle of the hotk device */
        u32 ledd_status;        /* status of the LED display */
        u8 light_level;         /* light sensor level */
        u8 light_switch;        /* light sensor switch value */
        u16 event_count[128];   /* count for each event TODO make this better */
};

static const struct key_entry asus_keymap[] = {
        /* Lenovo SL Specific keycodes */
        {KE_KEY, 0x02, { KEY_SCREENLOCK } },
        {KE_KEY, 0x05, { KEY_WLAN } },
        {KE_KEY, 0x08, { KEY_F13 } },
        {KE_KEY, 0x17, { KEY_ZOOM } },
        {KE_KEY, 0x1f, { KEY_BATTERY } },
        /* End of Lenovo SL Specific keycodes */
        {KE_KEY, 0x30, { KEY_VOLUMEUP } },
        {KE_KEY, 0x31, { KEY_VOLUMEDOWN } },
        {KE_KEY, 0x32, { KEY_MUTE } },
        {KE_KEY, 0x33, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x34, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x40, { KEY_PREVIOUSSONG } },
        {KE_KEY, 0x41, { KEY_NEXTSONG } },
        {KE_KEY, 0x43, { KEY_STOPCD } },
        {KE_KEY, 0x45, { KEY_PLAYPAUSE } },
        {KE_KEY, 0x4c, { KEY_MEDIA } },
        {KE_KEY, 0x50, { KEY_EMAIL } },
        {KE_KEY, 0x51, { KEY_WWW } },
        {KE_KEY, 0x55, { KEY_CALC } },
        {KE_KEY, 0x5C, { KEY_SCREENLOCK } },  /* Screenlock */
        {KE_KEY, 0x5D, { KEY_WLAN } },
        {KE_KEY, 0x5E, { KEY_WLAN } },
        {KE_KEY, 0x5F, { KEY_WLAN } },
        {KE_KEY, 0x60, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x61, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x62, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x63, { KEY_SWITCHVIDEOMODE } },
        {KE_KEY, 0x6B, { KEY_F13 } }, /* Lock Touchpad */
        {KE_KEY, 0x7E, { KEY_BLUETOOTH } },
        {KE_KEY, 0x7D, { KEY_BLUETOOTH } },
        {KE_KEY, 0x82, { KEY_CAMERA } },
        {KE_KEY, 0x88, { KEY_WLAN  } },
        {KE_KEY, 0x8A, { KEY_PROG1 } },
        {KE_KEY, 0x95, { KEY_MEDIA } },
        {KE_KEY, 0x99, { KEY_PHONE } },
        {KE_KEY, 0xc4, { KEY_KBDILLUMUP } },
        {KE_KEY, 0xc5, { KEY_KBDILLUMDOWN } },
        {KE_KEY, 0xb5, { KEY_CALC } },
        {KE_END, 0},
};


/*
 * 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 0 if write is successful, -1 else.
 */
static int write_acpi_int_ret(acpi_handle handle, const char *method, int val,
                              struct acpi_buffer *output)
{
        struct acpi_object_list params; /* list of input parameters (an int) */
        union acpi_object in_obj;       /* the only param we use */
        acpi_status status;

        if (!handle)
                return -1;

        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);
        if (status == AE_OK)
                return 0;
        else
                return -1;
}

static int write_acpi_int(acpi_handle handle, const char *method, int val)
{
        return write_acpi_int_ret(handle, method, val, NULL);
}

static int acpi_check_handle(acpi_handle handle, const char *method,
                             acpi_handle *ret)
{
        acpi_status status;

        if (method == NULL)
                return -ENODEV;

        if (ret)
                status = acpi_get_handle(handle, (char *)method,
                                         ret);
        else {
                acpi_handle dummy;

                status = acpi_get_handle(handle, (char *)method,
                                         &dummy);
        }

        if (status != AE_OK) {
                if (ret)
                        pr_warning("Error finding %s\n", method);
                return -ENODEV;
        }
        return 0;
}

/* Generic LED function */
static int asus_led_set(struct asus_laptop *asus, const char *method,
                         int value)
{
        if (!strcmp(method, METHOD_MLED))
                value = !value;
        else if (!strcmp(method, METHOD_GLED))
                value = !value + 1;
        else
                value = !!value;

        return write_acpi_int(asus->handle, method, value);
}

/*
 * LEDs
 */
/* /sys/class/led handlers */
static void asus_led_cdev_set(struct led_classdev *led_cdev,
                         enum led_brightness value)
{
        struct asus_led *led = container_of(led_cdev, struct asus_led, led);
        struct asus_laptop *asus = led->asus;

        led->wk = !!value;
        queue_work(asus->led_workqueue, &led->work);
}

static void asus_led_cdev_update(struct work_struct *work)
{
        struct asus_led *led = container_of(work, struct asus_led, work);
        struct asus_laptop *asus = led->asus;

        asus_led_set(asus, led->method, led->wk);
}

static enum led_brightness asus_led_cdev_get(struct led_classdev *led_cdev)
{
        return led_cdev->brightness;
}

/*
 * Keyboard backlight (also a LED)
 */
static int asus_kled_lvl(struct asus_laptop *asus)
{
        unsigned long long kblv;
        struct acpi_object_list params;
        union acpi_object in_obj;
        acpi_status rv;

        params.count = 1;
        params.pointer = &in_obj;
        in_obj.type = ACPI_TYPE_INTEGER;
        in_obj.integer.value = 2;

        rv = acpi_evaluate_integer(asus->handle, METHOD_KBD_LIGHT_GET,
                                   &params, &kblv);
        if (ACPI_FAILURE(rv)) {
                pr_warning("Error reading kled level\n");
                return -ENODEV;
        }
        return kblv;
}

static int asus_kled_set(struct asus_laptop *asus, int kblv)
{
        if (kblv > 0)
                kblv = (1 << 7) | (kblv & 0x7F);
        else
                kblv = 0;

        if (write_acpi_int(asus->handle, METHOD_KBD_LIGHT_SET, kblv)) {
                pr_warning("Keyboard LED display write failed\n");
                return -EINVAL;
        }
        return 0;
}

static void asus_kled_cdev_set(struct led_classdev *led_cdev,
                              enum led_brightness value)
{
        struct asus_led *led = container_of(led_cdev, struct asus_led, led);
        struct asus_laptop *asus = led->asus;

        led->wk = value;
        queue_work(asus->led_workqueue, &led->work);
}

static void asus_kled_cdev_update(struct work_struct *work)
{
        struct asus_led *led = container_of(work, struct asus_led, work);
        struct asus_laptop *asus = led->asus;

        asus_kled_set(asus, led->wk);
}

static enum led_brightness asus_kled_cdev_get(struct led_classdev *led_cdev)
{
        struct asus_led *led = container_of(led_cdev, struct asus_led, led);
        struct asus_laptop *asus = led->asus;

        return asus_kled_lvl(asus);
}

static void asus_led_exit(struct asus_laptop *asus)
{
        if (asus->mled.led.dev)
                led_classdev_unregister(&asus->mled.led);
        if (asus->tled.led.dev)
                led_classdev_unregister(&asus->tled.led);
        if (asus->pled.led.dev)
                led_classdev_unregister(&asus->pled.led);
        if (asus->rled.led.dev)
                led_classdev_unregister(&asus->rled.led);
        if (asus->gled.led.dev)
                led_classdev_unregister(&asus->gled.led);
        if (asus->kled.led.dev)
                led_classdev_unregister(&asus->kled.led);
        if (asus->led_workqueue) {
                destroy_workqueue(asus->led_workqueue);
                asus->led_workqueue = NULL;
        }
}

/*  Ugly macro, need to fix that later */
static int asus_led_register(struct asus_laptop *asus,
                             struct asus_led *led,
                             const char *name, const char *method)
{
        struct led_classdev *led_cdev = &led->led;

        if (!method || acpi_check_handle(asus->handle, method, NULL))
                return 0; /* Led not present */

        led->asus = asus;
        led->method = method;

        INIT_WORK(&led->work, asus_led_cdev_update);
        led_cdev->name = name;
        led_cdev->brightness_set = asus_led_cdev_set;
        led_cdev->brightness_get = asus_led_cdev_get;
        led_cdev->max_brightness = 1;
        return led_classdev_register(&asus->platform_device->dev, led_cdev);
}

static int asus_led_init(struct asus_laptop *asus)
{
        int r;

        /*
         * Functions that actually update the LED's are called from a
         * workqueue. By doing this as separate work rather than when the LED
         * subsystem asks, we avoid messing with the Asus ACPI stuff during a
         * potentially bad time, such as a timer interrupt.
         */
        asus->led_workqueue = create_singlethread_workqueue("led_workqueue");
        if (!asus->led_workqueue)
                return -ENOMEM;

        r = asus_led_register(asus, &asus->mled, "asus::mail", METHOD_MLED);
        if (r)
                goto error;
        r = asus_led_register(asus, &asus->tled, "asus::touchpad", METHOD_TLED);
        if (r)
                goto error;
        r = asus_led_register(asus, &asus->rled, "asus::record", METHOD_RLED);
        if (r)
                goto error;
        r = asus_led_register(asus, &asus->pled, "asus::phone", METHOD_PLED);
        if (r)
                goto error;
        r = asus_led_register(asus, &asus->gled, "asus::gaming", METHOD_GLED);
        if (r)
                goto error;
        if (!acpi_check_handle(asus->handle, METHOD_KBD_LIGHT_SET, NULL) &&
            !acpi_check_handle(asus->handle, METHOD_KBD_LIGHT_GET, NULL)) {
                struct asus_led *led = &asus->kled;
                struct led_classdev *cdev = &led->led;

                led->asus = asus;

                INIT_WORK(&led->work, asus_kled_cdev_update);
                cdev->name = "asus::kbd_backlight";
                cdev->brightness_set = asus_kled_cdev_set;
                cdev->brightness_get = asus_kled_cdev_get;
                cdev->max_brightness = 3;
                r = led_classdev_register(&asus->platform_device->dev, cdev);
        }
error:
        if (r)
                asus_led_exit(asus);
        return r;
}

/*
 * Backlight device
 */
static int asus_read_brightness(struct backlight_device *bd)
{
        struct asus_laptop *asus = bl_get_data(bd);
        unsigned long long value;
        acpi_status rv = AE_OK;

        rv = acpi_evaluate_integer(asus->handle, METHOD_BRIGHTNESS_GET,
                                   NULL, &value);
        if (ACPI_FAILURE(rv))
                pr_warning("Error reading brightness\n");

        return value;
}

static int asus_set_brightness(struct backlight_device *bd, int value)
{
        struct asus_laptop *asus = bl_get_data(bd);

        if (write_acpi_int(asus->handle, METHOD_BRIGHTNESS_SET, value)) {
                pr_warning("Error changing brightness\n");
                return -EIO;
        }
        return 0;
}

static int update_bl_status(struct backlight_device *bd)
{
        int value = bd->props.brightness;

        return asus_set_brightness(bd, value);
}

static const struct backlight_ops asusbl_ops = {
        .get_brightness = asus_read_brightness,
        .update_status = update_bl_status,
};

static int asus_backlight_notify(struct asus_laptop *asus)
{
        struct backlight_device *bd = asus->backlight_device;
        int old = bd->props.brightness;

        backlight_force_update(bd, BACKLIGHT_UPDATE_HOTKEY);

        return old;
}

static int asus_backlight_init(struct asus_laptop *asus)
{
        struct backlight_device *bd;
        struct backlight_properties props;

        if (acpi_check_handle(asus->handle, METHOD_BRIGHTNESS_GET, NULL) ||
            acpi_check_handle(asus->handle, METHOD_BRIGHTNESS_SET, NULL))
                return 0;

        memset(&props, 0, sizeof(struct backlight_properties));
        props.max_brightness = 15;
        props.type = BACKLIGHT_PLATFORM;

        bd = backlight_device_register(ASUS_LAPTOP_FILE,
                                       &asus->platform_device->dev, asus,
                                       &asusbl_ops, &props);
        if (IS_ERR(bd)) {
                pr_err("Could not register asus backlight device\n");
                asus->backlight_device = NULL;
                return PTR_ERR(bd);
        }

        asus->backlight_device = bd;
        bd->props.brightness = asus_read_brightness(bd);
        bd->props.power = FB_BLANK_UNBLANK;
        backlight_update_status(bd);
        return 0;
}

static void asus_backlight_exit(struct asus_laptop *asus)
{
        if (asus->backlight_device)
                backlight_device_unregister(asus->backlight_device);
        asus->backlight_device = NULL;
}

/*
 * Platform device 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
 */
static ssize_t show_infos(struct device *dev,
                          struct device_attribute *attr, char *page)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int len = 0;
        unsigned long long temp;
        char buf[16];           /* enough for all info */
        acpi_status rv = AE_OK;

        /*
         * We use the easy way, we don't care of off and count,
         * so we don't set eof to 1
         */

        len += sprintf(page, ASUS_LAPTOP_NAME " " ASUS_LAPTOP_VERSION "\n");
        len += sprintf(page + len, "Model reference    : %s\n", asus->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.
         */
        rv = acpi_evaluate_integer(asus->handle, "SFUN", NULL, &temp);
        if (!ACPI_FAILURE(rv))
                len += sprintf(page + len, "SFUN value         : %#x\n",
                               (uint) temp);
        /*
         * The HWRS method return informations about the hardware.
         * 0x80 bit is for WLAN, 0x100 for Bluetooth.
         * The significance of others is yet to be found.
         * If we don't find the method, we assume the device are present.
         */
        rv = acpi_evaluate_integer(asus->handle, "HRWS", NULL, &temp);
        if (!ACPI_FAILURE(rv))
                len += sprintf(page + len, "HRWS value         : %#x\n",
                               (uint) 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.
         */
        rv = acpi_evaluate_integer(asus->handle, "ASYM", NULL, &temp);
        if (!ACPI_FAILURE(rv))
                len += sprintf(page + len, "ASYM value         : %#x\n",
                               (uint) temp);
        if (asus->dsdt_info) {
                snprintf(buf, 16, "%d", asus->dsdt_info->length);
                len += sprintf(page + len, "DSDT length        : %s\n", buf);
                snprintf(buf, 16, "%d", asus->dsdt_info->checksum);
                len += sprintf(page + len, "DSDT checksum      : %s\n", buf);
                snprintf(buf, 16, "%d", asus->dsdt_info->revision);
                len += sprintf(page + len, "DSDT revision      : %s\n", buf);
                snprintf(buf, 7, "%s", asus->dsdt_info->oem_id);
                len += sprintf(page + len, "OEM id             : %s\n", buf);
                snprintf(buf, 9, "%s", asus->dsdt_info->oem_table_id);
                len += sprintf(page + len, "OEM table id       : %s\n", buf);
                snprintf(buf, 16, "%x", asus->dsdt_info->oem_revision);
                len += sprintf(page + len, "OEM revision       : 0x%s\n", buf);
                snprintf(buf, 5, "%s", asus->dsdt_info->asl_compiler_id);
                len += sprintf(page + len, "ASL comp vendor id : %s\n", buf);
                snprintf(buf, 16, "%x", asus->dsdt_info->asl_compiler_revision);
                len += sprintf(page + len, "ASL comp revision  : 0x%s\n", buf);
        }

        return len;
}

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

static ssize_t sysfs_acpi_set(struct asus_laptop *asus,
                              const char *buf, size_t count,
                              const char *method)
{
        int rv, value;
        int out = 0;

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

        if (write_acpi_int(asus->handle, method, value))
                return -ENODEV;
        return rv;
}

/*
 * LEDD display
 */
static ssize_t show_ledd(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "0x%08x\n", asus->ledd_status);
}

static ssize_t store_ledd(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int rv, value;

        rv = parse_arg(buf, count, &value);
        if (rv > 0) {
                if (write_acpi_int(asus->handle, METHOD_LEDD, value)) {
                        pr_warning("LED display write failed\n");
                        return -ENODEV;
                }
                asus->ledd_status = (u32) value;
        }
        return rv;
}

/*
 * Wireless
 */
static int asus_wireless_status(struct asus_laptop *asus, int mask)
{
        unsigned long long status;
        acpi_status rv = AE_OK;

        if (!asus->have_rsts)
                return (asus->wireless_status & mask) ? 1 : 0;

        rv = acpi_evaluate_integer(asus->handle, METHOD_WL_STATUS,
                                   NULL, &status);
        if (ACPI_FAILURE(rv)) {
                pr_warning("Error reading Wireless status\n");
                return -EINVAL;
        }
        return !!(status & mask);
}

/*
 * WLAN
 */
static int asus_wlan_set(struct asus_laptop *asus, int status)
{
        if (write_acpi_int(asus->handle, METHOD_WLAN, !!status)) {
                pr_warning("Error setting wlan status to %d", status);
                return -EIO;
        }
        return 0;
}

static ssize_t show_wlan(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus_wireless_status(asus, WL_RSTS));
}

static ssize_t store_wlan(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sysfs_acpi_set(asus, buf, count, METHOD_WLAN);
}

/*
 * Bluetooth
 */
static int asus_bluetooth_set(struct asus_laptop *asus, int status)
{
        if (write_acpi_int(asus->handle, METHOD_BLUETOOTH, !!status)) {
                pr_warning("Error setting bluetooth status to %d", status);
                return -EIO;
        }
        return 0;
}

static ssize_t show_bluetooth(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus_wireless_status(asus, BT_RSTS));
}

static ssize_t store_bluetooth(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sysfs_acpi_set(asus, buf, count, METHOD_BLUETOOTH);
}

/*
 * Wimax
 */
static int asus_wimax_set(struct asus_laptop *asus, int status)
{
        if (write_acpi_int(asus->handle, METHOD_WIMAX, !!status)) {
                pr_warning("Error setting wimax status to %d", status);
                return -EIO;
        }
        return 0;
}

static ssize_t show_wimax(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus_wireless_status(asus, WM_RSTS));
}

static ssize_t store_wimax(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sysfs_acpi_set(asus, buf, count, METHOD_WIMAX);
}

/*
 * Wwan
 */
static int asus_wwan_set(struct asus_laptop *asus, int status)
{
        if (write_acpi_int(asus->handle, METHOD_WWAN, !!status)) {
                pr_warning("Error setting wwan status to %d", status);
                return -EIO;
        }
        return 0;
}

static ssize_t show_wwan(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus_wireless_status(asus, WW_RSTS));
}

static ssize_t store_wwan(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sysfs_acpi_set(asus, buf, count, METHOD_WWAN);
}

/*
 * Display
 */
static void asus_set_display(struct asus_laptop *asus, int value)
{
        /* no sanity check needed for now */
        if (write_acpi_int(asus->handle, METHOD_SWITCH_DISPLAY, value))
                pr_warning("Error setting display\n");
        return;
}

/*
 * Experimental support for display switching. As of now: 1 should activate
 * the LCD output, 2 should do for CRT, 4 for TV-Out and 8 for DVI.
 * Any combination (bitwise) of these will suffice. I never actually tested 4
 * displays hooked up simultaneously, so be warned. See the acpi4asus README
 * for more info.
 */
static ssize_t store_disp(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int rv, value;

        rv = parse_arg(buf, count, &value);
        if (rv > 0)
                asus_set_display(asus, value);
        return rv;
}

/*
 * Light Sens
 */
static void asus_als_switch(struct asus_laptop *asus, int value)
{
        if (write_acpi_int(asus->handle, METHOD_ALS_CONTROL, value))
                pr_warning("Error setting light sensor switch\n");
        asus->light_switch = value;
}

static ssize_t show_lssw(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus->light_switch);
}

static ssize_t store_lssw(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int rv, value;

        rv = parse_arg(buf, count, &value);
        if (rv > 0)
                asus_als_switch(asus, value ? 1 : 0);

        return rv;
}

static void asus_als_level(struct asus_laptop *asus, int value)
{
        if (write_acpi_int(asus->handle, METHOD_ALS_LEVEL, value))
                pr_warning("Error setting light sensor level\n");
        asus->light_level = value;
}

static ssize_t show_lslvl(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus->light_level);
}

static ssize_t store_lslvl(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int rv, value;

        rv = parse_arg(buf, count, &value);
        if (rv > 0) {
                value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
                /* 0 <= value <= 15 */
                asus_als_level(asus, value);
        }

        return rv;
}

/*
 * GPS
 */
static int asus_gps_status(struct asus_laptop *asus)
{
        unsigned long long status;
        acpi_status rv = AE_OK;

        rv = acpi_evaluate_integer(asus->handle, METHOD_GPS_STATUS,
                                   NULL, &status);
        if (ACPI_FAILURE(rv)) {
                pr_warning("Error reading GPS status\n");
                return -ENODEV;
        }
        return !!status;
}

static int asus_gps_switch(struct asus_laptop *asus, int status)
{
        const char *meth = status ? METHOD_GPS_ON : METHOD_GPS_OFF;

        if (write_acpi_int(asus->handle, meth, 0x02))
                return -ENODEV;
        return 0;
}

static ssize_t show_gps(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);

        return sprintf(buf, "%d\n", asus_gps_status(asus));
}

static ssize_t store_gps(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count)
{
        struct asus_laptop *asus = dev_get_drvdata(dev);
        int rv, value;
        int ret;

        rv = parse_arg(buf, count, &value);
        if (rv <= 0)
                return -EINVAL;
        ret = asus_gps_switch(asus, !!value);
        if (ret)
                return ret;
        rfkill_set_sw_state(asus->gps_rfkill, !value);
        return rv;
}

/*
 * rfkill
 */
static int asus_gps_rfkill_set(void *data, bool blocked)
{
        struct asus_laptop *asus = data;

        return asus_gps_switch(asus, !blocked);
}

static const struct rfkill_ops asus_gps_rfkill_ops = {
        .set_block = asus_gps_rfkill_set,
};

static void asus_rfkill_exit(struct asus_laptop *asus)
{
        if (asus->gps_rfkill) {
                rfkill_unregister(asus->gps_rfkill);
                rfkill_destroy(asus->gps_rfkill);
                asus->gps_rfkill = NULL;
        }
}

static int asus_rfkill_init(struct asus_laptop *asus)
{
        int result;

        if (acpi_check_handle(asus->handle, METHOD_GPS_ON, NULL) ||
            acpi_check_handle(asus->handle, METHOD_GPS_OFF, NULL) ||
            acpi_check_handle(asus->handle, METHOD_GPS_STATUS, NULL))
                return 0;

        asus->gps_rfkill = rfkill_alloc("asus-gps", &asus->platform_device->dev,
                                        RFKILL_TYPE_GPS,
                                        &asus_gps_rfkill_ops, asus);
        if (!asus->gps_rfkill)
                return -EINVAL;

        result = rfkill_register(asus->gps_rfkill);
        if (result) {
                rfkill_destroy(asus->gps_rfkill);
                asus->gps_rfkill = NULL;
        }

        return result;
}

/*
 * Input device (i.e. hotkeys)
 */
static void asus_input_notify(struct asus_laptop *asus, int event)
{
        if (asus->inputdev)
                sparse_keymap_report_event(asus->inputdev, event, 1, true);
}

static int asus_input_init(struct asus_laptop *asus)
{
        struct input_dev *input;
        int error;

        input = input_allocate_device();
        if (!input) {
                pr_info("Unable to allocate input device\n");
                return -ENOMEM;
        }
        input->name = "Asus Laptop extra buttons";
        input->phys = ASUS_LAPTOP_FILE "/input0";
        input->id.bustype = BUS_HOST;
        input->dev.parent = &asus->platform_device->dev;

        error = sparse_keymap_setup(input, asus_keymap, NULL);
        if (error) {
                pr_err("Unable to setup input device keymap\n");
                goto err_free_dev;
        }
        error = input_register_device(input);
        if (error) {
                pr_info("Unable to register input device\n");
                goto err_free_keymap;
        }

        asus->inputdev = input;
        return 0;

err_free_keymap:
        sparse_keymap_free(input);
err_free_dev:
        input_free_device(input);
        return error;
}

static void asus_input_exit(struct asus_laptop *asus)
{
        if (asus->inputdev) {
                sparse_keymap_free(asus->inputdev);
                input_unregister_device(asus->inputdev);
        }
        asus->inputdev = NULL;
}

/*
 * ACPI driver
 */
static void asus_acpi_notify(struct acpi_device *device, u32 event)
{
        struct asus_laptop *asus = acpi_driver_data(device);
        u16 count;

        /* TODO Find a better way to handle events count. */
        count = asus->event_count[event % 128]++;
        acpi_bus_generate_proc_event(asus->device, event, count);
        acpi_bus_generate_netlink_event(asus->device->pnp.device_class,
                                        dev_name(&asus->device->dev), event,
                                        count);

        /* Brightness events are special */
        if (event >= ATKD_BR_MIN && event <= ATKD_BR_MAX) {

                /* Ignore them completely if the acpi video driver is used */
                if (asus->backlight_device != NULL) {
                        /* Update the backlight device. */
                        asus_backlight_notify(asus);
                }
                return ;
        }
        asus_input_notify(asus, event);
}

static DEVICE_ATTR(infos, S_IRUGO, show_infos, NULL);
static DEVICE_ATTR(wlan, S_IRUGO | S_IWUSR, show_wlan, store_wlan);
static DEVICE_ATTR(bluetooth, S_IRUGO | S_IWUSR,
                   show_bluetooth, store_bluetooth);
static DEVICE_ATTR(wimax, S_IRUGO | S_IWUSR, show_wimax, store_wimax);
static DEVICE_ATTR(wwan, S_IRUGO | S_IWUSR, show_wwan, store_wwan);
static DEVICE_ATTR(display, S_IWUSR, NULL, store_disp);
static DEVICE_ATTR(ledd, S_IRUGO | S_IWUSR, show_ledd, store_ledd);
static DEVICE_ATTR(ls_level, S_IRUGO | S_IWUSR, show_lslvl, store_lslvl);
static DEVICE_ATTR(ls_switch, S_IRUGO | S_IWUSR, show_lssw, store_lssw);
static DEVICE_ATTR(gps, S_IRUGO | S_IWUSR, show_gps, store_gps);

static struct attribute *asus_attributes[] = {
        &dev_attr_infos.attr,
        &dev_attr_wlan.attr,
        &dev_attr_bluetooth.attr,
        &dev_attr_wimax.attr,
        &dev_attr_wwan.attr,
        &dev_attr_display.attr,
        &dev_attr_ledd.attr,
        &dev_attr_ls_level.attr,
        &dev_attr_ls_switch.attr,
        &dev_attr_gps.attr,
        NULL
};

static mode_t asus_sysfs_is_visible(struct kobject *kobj,
                                    struct attribute *attr,
                                    int idx)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct platform_device *pdev = to_platform_device(dev);
        struct asus_laptop *asus = platform_get_drvdata(pdev);
        acpi_handle handle = asus->handle;
        bool supported;

        if (attr == &dev_attr_wlan.attr) {
                supported = !acpi_check_handle(handle, METHOD_WLAN, NULL);

        } else if (attr == &dev_attr_bluetooth.attr) {
                supported = !acpi_check_handle(handle, METHOD_BLUETOOTH, NULL);

        } else if (attr == &dev_attr_display.attr) {
                supported = !acpi_check_handle(handle, METHOD_SWITCH_DISPLAY, NULL);

        } else if (attr == &dev_attr_wimax.attr) {
                supported =
                        !acpi_check_handle(asus->handle, METHOD_WIMAX, NULL);

        } else if (attr == &dev_attr_wwan.attr) {
                supported = !acpi_check_handle(asus->handle, METHOD_WWAN, NULL);

        } else if (attr == &dev_attr_ledd.attr) {
                supported = !acpi_check_handle(handle, METHOD_LEDD, NULL);

        } else if (attr == &dev_attr_ls_switch.attr ||
                   attr == &dev_attr_ls_level.attr) {
                supported = !acpi_check_handle(handle, METHOD_ALS_CONTROL, NULL) &&
                            !acpi_check_handle(handle, METHOD_ALS_LEVEL, NULL);

        } else if (attr == &dev_attr_gps.attr) {
                supported = !acpi_check_handle(handle, METHOD_GPS_ON, NULL) &&
                            !acpi_check_handle(handle, METHOD_GPS_OFF, NULL) &&
                            !acpi_check_handle(handle, METHOD_GPS_STATUS, NULL);
        } else {
                supported = true;
        }

        return supported ? attr->mode : 0;
}


static const struct attribute_group asus_attr_group = {
        .is_visible     = asus_sysfs_is_visible,
        .attrs          = asus_attributes,
};

static int asus_platform_init(struct asus_laptop *asus)
{
        int result;

        asus->platform_device = platform_device_alloc(ASUS_LAPTOP_FILE, -1);
        if (!asus->platform_device)
                return -ENOMEM;
        platform_set_drvdata(asus->platform_device, asus);

        result = platform_device_add(asus->platform_device);
        if (result)
                goto fail_platform_device;

        result = sysfs_create_group(&asus->platform_device->dev.kobj,
                                    &asus_attr_group);
        if (result)
                goto fail_sysfs;

        return 0;

fail_sysfs:
        platform_device_del(asus->platform_device);
fail_platform_device:
        platform_device_put(asus->platform_device);
        return result;
}

static void asus_platform_exit(struct asus_laptop *asus)
{
        sysfs_remove_group(&asus->platform_device->dev.kobj, &asus_attr_group);
        platform_device_unregister(asus->platform_device);
}

static struct platform_driver platform_driver = {
        .driver = {
                .name = ASUS_LAPTOP_FILE,
                .owner = THIS_MODULE,
        }
};

/*
 * This function is used to initialize the context with right values. In this
 * method, we can make all the detection we want, and modify the asus_laptop
 * struct
 */
static int asus_laptop_get_info(struct asus_laptop *asus)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *model = NULL;
        unsigned long long bsts_result, hwrs_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.
         */
        status = acpi_get_table(ACPI_SIG_DSDT, 1, &asus->dsdt_info);
        if (ACPI_FAILURE(status))
                pr_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_ret(asus->handle, "INIT", 0, &buffer)) {
                pr_err("Hotkey initialization failed\n");
                return -ENODEV;
        }

        /* This needs to be called for some laptops to init properly */
        status =
            acpi_evaluate_integer(asus->handle, "BSTS", NULL, &bsts_result);
        if (ACPI_FAILURE(status))
                pr_warning("Error calling BSTS\n");
        else if (bsts_result)
                pr_notice("BSTS called, 0x%02x returned\n",
                       (uint) bsts_result);

        /* This too ... */
        if (write_acpi_int(asus->handle, "CWAP", wapf))
                pr_err("Error calling CWAP(%d)\n", wapf);
        /*
         * 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:
                        string = "";
                        break;
                }
        }
        asus->name = kstrdup(string, GFP_KERNEL);
        if (!asus->name) {
                kfree(buffer.pointer);
                return -ENOMEM;
        }

        if (*string)
                pr_notice("  %s model detected\n", string);

        /*
         * The HWRS method return informations about the hardware.
         * 0x80 bit is for WLAN, 0x100 for Bluetooth,
         * 0x40 for WWAN, 0x10 for WIMAX.
         * The significance of others is yet to be found.
         */
        status =
            acpi_evaluate_integer(asus->handle, "HRWS", NULL, &hwrs_result);
        if (!ACPI_FAILURE(status))
                pr_notice("  HRWS returned %x", (int)hwrs_result);

        if (!acpi_check_handle(asus->handle, METHOD_WL_STATUS, NULL))
                asus->have_rsts = true;

        kfree(model);

        return AE_OK;
}

static int __devinit asus_acpi_init(struct asus_laptop *asus)
{
        int result = 0;

        result = acpi_bus_get_status(asus->device);
        if (result)
                return result;
        if (!asus->device->status.present) {
                pr_err("Hotkey device not present, aborting\n");
                return -ENODEV;
        }

        result = asus_laptop_get_info(asus);
        if (result)
                return result;

        /* WLED and BLED are on by default */
        if (bluetooth_status >= 0)
                asus_bluetooth_set(asus, !!bluetooth_status);

        if (wlan_status >= 0)
                asus_wlan_set(asus, !!wlan_status);

        if (wimax_status >= 0)
                asus_wimax_set(asus, !!wimax_status);

        if (wwan_status >= 0)
                asus_wwan_set(asus, !!wwan_status);

        /* Keyboard Backlight is on by default */
        if (!acpi_check_handle(asus->handle, METHOD_KBD_LIGHT_SET, NULL))
                asus_kled_set(asus, 1);

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

        /* Set initial values of light sensor and level */
        asus->light_switch = 0; /* Default to light sensor disabled */
        asus->light_level = 5;  /* level 5 for sensor sensitivity */

        if (!acpi_check_handle(asus->handle, METHOD_ALS_CONTROL, NULL) &&
            !acpi_check_handle(asus->handle, METHOD_ALS_LEVEL, NULL)) {
                asus_als_switch(asus, asus->light_switch);
                asus_als_level(asus, asus->light_level);
        }

        return result;
}

static void __devinit asus_dmi_check(void)
{
        const char *model;

        model = dmi_get_system_info(DMI_PRODUCT_NAME);
        if (!model)
                return;

        /* On L1400B WLED control the sound card, don't mess with it ... */
        if (strncmp(model, "L1400B", 6) == 0) {
                wlan_status = -1;
        }
}

static bool asus_device_present;

static int __devinit asus_acpi_add(struct acpi_device *device)
{
        struct asus_laptop *asus;
        int result;

        pr_notice("Asus Laptop Support version %s\n",
                  ASUS_LAPTOP_VERSION);
        asus = kzalloc(sizeof(struct asus_laptop), GFP_KERNEL);
        if (!asus)
                return -ENOMEM;
        asus->handle = device->handle;
        strcpy(acpi_device_name(device), ASUS_LAPTOP_DEVICE_NAME);
        strcpy(acpi_device_class(device), ASUS_LAPTOP_CLASS);
        device->driver_data = asus;
        asus->device = device;

        asus_dmi_check();

        result = asus_acpi_init(asus);
        if (result)
                goto fail_platform;

        /*
         * Register the platform device first.  It is used as a parent for the
         * sub-devices below.
         */
        result = asus_platform_init(asus);
        if (result)
                goto fail_platform;

        if (!acpi_video_backlight_support()) {
                result = asus_backlight_init(asus);
                if (result)
                        goto fail_backlight;
        } else
                pr_info("Backlight controlled by ACPI video driver\n");

        result = asus_input_init(asus);
        if (result)
                goto fail_input;

        result = asus_led_init(asus);
        if (result)
                goto fail_led;

        result = asus_rfkill_init(asus);
        if (result)
                goto fail_rfkill;

        asus_device_present = true;
        return 0;

fail_rfkill:
        asus_led_exit(asus);
fail_led:
        asus_input_exit(asus);
fail_input:
        asus_backlight_exit(asus);
fail_backlight:
        asus_platform_exit(asus);
fail_platform:
        kfree(asus->name);
        kfree(asus);

        return result;
}

static int asus_acpi_remove(struct acpi_device *device, int type)
{
        struct asus_laptop *asus = acpi_driver_data(device);

        asus_backlight_exit(asus);
        asus_rfkill_exit(asus);
        asus_led_exit(asus);
        asus_input_exit(asus);
        asus_platform_exit(asus);

        kfree(asus->name);
        kfree(asus);
        return 0;
}

static const struct acpi_device_id asus_device_ids[] = {
        {"ATK0100", 0},
        {"ATK0101", 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, asus_device_ids);

static struct acpi_driver asus_acpi_driver = {
        .name = ASUS_LAPTOP_NAME,
        .class = ASUS_LAPTOP_CLASS,
        .owner = THIS_MODULE,
        .ids = asus_device_ids,
        .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
        .ops = {
                .add = asus_acpi_add,
                .remove = asus_acpi_remove,
                .notify = asus_acpi_notify,
                },
};

static int __init asus_laptop_init(void)
{
        int result;

        result = platform_driver_register(&platform_driver);
        if (result < 0)
                return result;

        result = acpi_bus_register_driver(&asus_acpi_driver);
        if (result < 0)
                goto fail_acpi_driver;
        if (!asus_device_present) {
                result = -ENODEV;
                goto fail_no_device;
        }
        return 0;

fail_no_device:
        acpi_bus_unregister_driver(&asus_acpi_driver);
fail_acpi_driver:
        platform_driver_unregister(&platform_driver);
        return result;
}

static void __exit asus_laptop_exit(void)
{
        acpi_bus_unregister_driver(&asus_acpi_driver);
        platform_driver_unregister(&platform_driver);
}

module_init(asus_laptop_init);
module_exit(asus_laptop_exit);