backlight: Fix external uses of backlight internal semaphore

[linux-2.6/btrfs-unstable.git] / drivers / misc / asus-laptop.c

/*
 *  asus-laptop.c - Asus Laptop Support
 *
 *
 *  Copyright (C) 2002-2005 Julien Lerouge, 2003-2006 Karol Kozimor
 *  Copyright (C) 2006 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 helpfull
 *
 */

#include <linux/autoconf.h>
#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 <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <asm/uaccess.h>

#define ASUS_LAPTOP_VERSION "0.40"

#define ASUS_HOTK_NAME          "Asus Laptop Support"
#define ASUS_HOTK_CLASS         "hotkey"
#define ASUS_HOTK_DEVICE_NAME   "Hotkey"
#define ASUS_HOTK_HID           "ATK0100"
#define ASUS_HOTK_FILE          "asus-laptop"
#define ASUS_HOTK_PREFIX        "\\_SB.ATKD."

/*
 * Some events we use, same for all Asus
 */
#define ATKD_BR_UP       0x10
#define ATKD_BR_DOWN     0x20
#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_ON       0x01        //internal Wifi
#define BT_ON       0x02        //internal Bluetooth
#define MLED_ON     0x04        //mail LED
#define TLED_ON     0x08        //touchpad LED
#define RLED_ON     0x10        //Record LED
#define PLED_ON     0x20        //Phone LED
#define LCD_ON      0x40        //LCD backlight

#define ASUS_LOG    ASUS_HOTK_FILE ": "
#define ASUS_ERR    KERN_ERR    ASUS_LOG
#define ASUS_WARNING    KERN_WARNING    ASUS_LOG
#define ASUS_NOTICE KERN_NOTICE ASUS_LOG
#define ASUS_INFO   KERN_INFO   ASUS_LOG
#define ASUS_DEBUG  KERN_DEBUG  ASUS_LOG

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

#define ASUS_HANDLE(object, paths...)                                   \
        static acpi_handle  object##_handle = NULL;                     \
        static char *object##_paths[] = { paths }

/* LED */
ASUS_HANDLE(mled_set, ASUS_HOTK_PREFIX "MLED");
ASUS_HANDLE(tled_set, ASUS_HOTK_PREFIX "TLED");
ASUS_HANDLE(rled_set, ASUS_HOTK_PREFIX "RLED"); /* W1JC */
ASUS_HANDLE(pled_set, ASUS_HOTK_PREFIX "PLED"); /* A7J */

/* LEDD */
ASUS_HANDLE(ledd_set, ASUS_HOTK_PREFIX "SLCM");

/* Bluetooth and WLAN
 * WLED and BLED are not handled like other XLED, because in some dsdt
 * they also control the WLAN/Bluetooth device.
 */
ASUS_HANDLE(wl_switch, ASUS_HOTK_PREFIX "WLED");
ASUS_HANDLE(bt_switch, ASUS_HOTK_PREFIX "BLED");
ASUS_HANDLE(wireless_status, ASUS_HOTK_PREFIX "RSTS");  /* All new models */

/* Brightness */
ASUS_HANDLE(brightness_set, ASUS_HOTK_PREFIX "SPLV");
ASUS_HANDLE(brightness_get, ASUS_HOTK_PREFIX "GPLV");

/* Backlight */
ASUS_HANDLE(lcd_switch, "\\_SB.PCI0.SBRG.EC0._Q10",     /* All new models */
            "\\_SB.PCI0.ISA.EC0._Q10",  /* A1x */
            "\\_SB.PCI0.PX40.ECD0._Q10",        /* L3C */
            "\\_SB.PCI0.PX40.EC0.Q10",  /* M1A */
            "\\_SB.PCI0.LPCB.EC0._Q10", /* P30 */
            "\\_SB.PCI0.PX40.Q10",      /* S1x */
            "\\Q10");           /* A2x, L2D, L3D, M2E */

/* Display */
ASUS_HANDLE(display_set, ASUS_HOTK_PREFIX "SDSP");
ASUS_HANDLE(display_get, "\\_SB.PCI0.P0P1.VGA.GETD",    /*  A6B, A6K A6R A7D F3JM L4R M6R A3G
                                                           M6A M6V VX-1 V6J V6V W3Z */
            "\\_SB.PCI0.P0P2.VGA.GETD", /* A3E A4K, A4D A4L A6J A7J A8J Z71V M9V
                                           S5A M5A z33A W1Jc W2V */
            "\\_SB.PCI0.P0P3.VGA.GETD", /* A6V A6Q */
            "\\_SB.PCI0.P0PA.VGA.GETD", /* A6T, A6M */
            "\\_SB.PCI0.PCI1.VGAC.NMAP",        /* L3C */
            "\\_SB.PCI0.VGA.GETD",      /* Z96F */
            "\\ACTD",           /* A2D */
            "\\ADVG",           /* A4G Z71A W1N W5A W5F M2N M3N M5N M6N S1N S5N */
            "\\DNXT",           /* P30 */
            "\\INFB",           /* A2H D1 L2D L3D L3H L2E L5D L5C M1A M2E L4L W3V */
            "\\SSTE");          /* A3F A6F A3N A3L M6N W3N W6A */

ASUS_HANDLE(ls_switch, ASUS_HOTK_PREFIX "ALSC");        /* Z71A Z71V */
ASUS_HANDLE(ls_level, ASUS_HOTK_PREFIX "ALSL"); /* Z71A Z71V */

/*
 * This is the main structure, we can use it to store anything interesting
 * about the hotk device
 */
struct asus_hotk {
        char *name;             //laptop name
        struct acpi_device *device;     //the device we are in
        acpi_handle handle;     //the handle of the hotk device
        char status;            //status of the hotk, for LEDs, ...
        u32 ledd_status;        //status of the LED display
        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
};

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

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

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

/* The backlight device /sys/class/backlight */
static struct backlight_device *asus_backlight_device;

/*
 * The backlight class declaration
 */
static int read_brightness(struct backlight_device *bd);
static int update_bl_status(struct backlight_device *bd);
static struct backlight_properties asusbl_data = {
        .get_brightness = read_brightness,
        .update_status = update_bl_status,
        .max_brightness = 15,
};

/* These functions actually update the LED's, and 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. */
static struct workqueue_struct *led_workqueue;

#define ASUS_LED(object, ledname)                                       \
        static void object##_led_set(struct led_classdev *led_cdev,     \
                                     enum led_brightness value);        \
        static void object##_led_update(struct work_struct *ignored);   \
        static int object##_led_wk;                                     \
        DECLARE_WORK(object##_led_work, object##_led_update);           \
        static struct led_classdev object##_led = {                     \
                .name           = "asus:" ledname,                      \
                .brightness_set = object##_led_set,                     \
        }

ASUS_LED(mled, "mail");
ASUS_LED(tled, "touchpad");
ASUS_LED(rled, "record");
ASUS_LED(pled, "phone");

/*
 * 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_object_list *params)
{
        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, params, &output);
        *val = out_obj.integer.value;
        return (status == AE_OK) && (out_obj.type == ACPI_TYPE_INTEGER);
}

static int read_wireless_status(int mask)
{
        int status;

        if (!wireless_status_handle)
                return (hotk->status & mask) ? 1 : 0;

        if (read_acpi_int(wireless_status_handle, NULL, &status, NULL)) {
                return (status & mask) ? 1 : 0;
        } else
                printk(ASUS_WARNING "Error reading Wireless status\n");

        return (hotk->status & mask) ? 1 : 0;
}

/* Generic LED functions */
static int read_status(int mask)
{
        /* There is a special method for both wireless devices */
        if (mask == BT_ON || mask == WL_ON)
                return read_wireless_status(mask);

        return (hotk->status & mask) ? 1 : 0;
}

static void write_status(acpi_handle handle, int out, int mask, int invert)
{
        hotk->status = (out) ? (hotk->status | mask) : (hotk->status & ~mask);

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

        if (handle && !write_acpi_int(handle, NULL, out, NULL))
                printk(ASUS_WARNING " write failed\n");
}

/* /sys/class/led handlers */
#define ASUS_LED_HANDLER(object, mask, invert)                          \
        static void object##_led_set(struct led_classdev *led_cdev,     \
                                     enum led_brightness value)         \
        {                                                               \
                object##_led_wk = value;                                \
                queue_work(led_workqueue, &object##_led_work);          \
        }                                                               \
        static void object##_led_update(struct work_struct *ignored)    \
        {                                                               \
                int value = object##_led_wk;                            \
                write_status(object##_set_handle, value, (mask), (invert)); \
        }

ASUS_LED_HANDLER(mled, MLED_ON, 1);
ASUS_LED_HANDLER(pled, PLED_ON, 0);
ASUS_LED_HANDLER(rled, RLED_ON, 0);
ASUS_LED_HANDLER(tled, TLED_ON, 0);

static int get_lcd_state(void)
{
        return read_status(LCD_ON);
}

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

        lcd = value ? 1 : 0;

        if (lcd == get_lcd_state())
                return 0;

        if (lcd_switch_handle) {
                status = acpi_evaluate_object(lcd_switch_handle,
                                              NULL, NULL, NULL);

                if (ACPI_FAILURE(status))
                        printk(ASUS_WARNING "Error switching LCD\n");
        }

        write_status(NULL, lcd, LCD_ON, 0);
        return 0;
}

static void lcd_blank(int blank)
{
        struct backlight_device *bd = asus_backlight_device;

        if (bd) {
                bd->props->power = blank;
                backlight_update_status(bd);
        }
}

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

        if (!read_acpi_int(brightness_get_handle, NULL, &value, NULL))
                printk(ASUS_WARNING "Error reading brightness\n");

        return value;
}

static int set_brightness(struct backlight_device *bd, int value)
{
        int ret = 0;

        value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
        /* 0 <= value <= 15 */

        if (!write_acpi_int(brightness_set_handle, NULL, value, NULL)) {
                printk(ASUS_WARNING "Error changing brightness\n");
                ret = -EIO;
        }

        return ret;
}

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

        rv = set_brightness(bd, value);
        if (rv)
                return rv;

        value = (bd->props->power == FB_BLANK_UNBLANK) ? 1 : 0;
        return set_lcd_state(value);
}

/*
 * 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)
{
        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, ASUS_HOTK_NAME " " ASUS_LAPTOP_VERSION "\n");
        len += sprintf(page + len, "Model reference    : %s\n", hotk->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, NULL))
                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, NULL))
                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;
}

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 store_status(const char *buf, size_t count,
                            acpi_handle handle, int mask, int invert)
{
        int rv, value;
        int out = 0;

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

        write_status(handle, out, mask, invert);

        return rv;
}

/*
 * LEDD display
 */
static ssize_t show_ledd(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "0x%08x\n", hotk->ledd_status);
}

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

        rv = parse_arg(buf, count, &value);
        if (rv > 0) {
                if (!write_acpi_int(ledd_set_handle, NULL, value, NULL))
                        printk(ASUS_WARNING "LED display write failed\n");
                else
                        hotk->ledd_status = (u32) value;
        }
        return rv;
}

/*
 * WLAN
 */
static ssize_t show_wlan(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", read_status(WL_ON));
}

static ssize_t store_wlan(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        return store_status(buf, count, wl_switch_handle, WL_ON, 0);
}

/*
 * Bluetooth
 */
static ssize_t show_bluetooth(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", read_status(BT_ON));
}

static ssize_t store_bluetooth(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        return store_status(buf, count, bt_switch_handle, BT_ON, 0);
}

/*
 * Display
 */
static void set_display(int value)
{
        /* no sanity check needed for now */
        if (!write_acpi_int(display_set_handle, NULL, value, NULL))
                printk(ASUS_WARNING "Error setting display\n");
        return;
}

static int read_display(void)
{
        int value = 0;

        /* In most of the case, we know how to set the display, but sometime
           we can't read it */
        if (display_get_handle) {
                if (!read_acpi_int(display_get_handle, NULL, &value, NULL))
                        printk(ASUS_WARNING "Error reading display status\n");
        }

        value &= 0x0F;          /* needed for some models, shouldn't hurt others */

        return value;
}

/*
 * Now, *this* one could be more user-friendly, but so far, no-one has
 * complained. The significance of bits is the same as in store_disp()
 */
static ssize_t show_disp(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", read_display());
}

/*
 * 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)
{
        int rv, value;

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

/*
 * Light Sens
 */
static void set_light_sens_switch(int value)
{
        if (!write_acpi_int(ls_switch_handle, NULL, value, NULL))
                printk(ASUS_WARNING "Error setting light sensor switch\n");
        hotk->light_switch = value;
}

static ssize_t show_lssw(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", hotk->light_switch);
}

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

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

        return rv;
}

static void set_light_sens_level(int value)
{
        if (!write_acpi_int(ls_level_handle, NULL, value, NULL))
                printk(ASUS_WARNING "Error setting light sensor level\n");
        hotk->light_level = value;
}

static ssize_t show_lslvl(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", hotk->light_level);
}

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

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

        return rv;
}

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

        /*
         * We need to tell the backlight device when the backlight power is
         * switched
         */
        if (event == ATKD_LCD_ON) {
                write_status(NULL, 1, LCD_ON, 0);
                lcd_blank(FB_BLANK_UNBLANK);
        } else if (event == ATKD_LCD_OFF) {
                write_status(NULL, 0, LCD_ON, 0);
                lcd_blank(FB_BLANK_POWERDOWN);
        }

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

        return;
}

#define ASUS_CREATE_DEVICE_ATTR(_name)                                  \
        struct device_attribute dev_attr_##_name = {                    \
                .attr = {                                               \
                        .name = __stringify(_name),                     \
                        .mode = 0,                                      \
                        .owner = THIS_MODULE },                         \
                .show   = NULL,                                         \
                .store  = NULL,                                         \
        }

#define ASUS_SET_DEVICE_ATTR(_name, _mode, _show, _store)               \
        do {                                                            \
                dev_attr_##_name.attr.mode = _mode;                     \
                dev_attr_##_name.show = _show;                          \
                dev_attr_##_name.store = _store;                        \
        } while(0)

static ASUS_CREATE_DEVICE_ATTR(infos);
static ASUS_CREATE_DEVICE_ATTR(wlan);
static ASUS_CREATE_DEVICE_ATTR(bluetooth);
static ASUS_CREATE_DEVICE_ATTR(display);
static ASUS_CREATE_DEVICE_ATTR(ledd);
static ASUS_CREATE_DEVICE_ATTR(ls_switch);
static ASUS_CREATE_DEVICE_ATTR(ls_level);

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

static struct attribute_group asuspf_attribute_group = {
        .attrs = asuspf_attributes
};

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

static struct platform_device *asuspf_device;

static void asus_hotk_add_fs(void)
{
        ASUS_SET_DEVICE_ATTR(infos, 0444, show_infos, NULL);

        if (wl_switch_handle)
                ASUS_SET_DEVICE_ATTR(wlan, 0644, show_wlan, store_wlan);

        if (bt_switch_handle)
                ASUS_SET_DEVICE_ATTR(bluetooth, 0644,
                                     show_bluetooth, store_bluetooth);

        if (display_set_handle && display_get_handle)
                ASUS_SET_DEVICE_ATTR(display, 0644, show_disp, store_disp);
        else if (display_set_handle)
                ASUS_SET_DEVICE_ATTR(display, 0200, NULL, store_disp);

        if (ledd_set_handle)
                ASUS_SET_DEVICE_ATTR(ledd, 0644, show_ledd, store_ledd);

        if (ls_switch_handle && ls_level_handle) {
                ASUS_SET_DEVICE_ATTR(ls_level, 0644, show_lslvl, store_lslvl);
                ASUS_SET_DEVICE_ATTR(ls_switch, 0644, show_lssw, store_lssw);
        }
}

static int asus_handle_init(char *name, acpi_handle * handle,
                            char **paths, int num_paths)
{
        int i;
        acpi_status status;

        for (i = 0; i < num_paths; i++) {
                status = acpi_get_handle(NULL, paths[i], handle);
                if (ACPI_SUCCESS(status))
                        return 0;
        }

        *handle = NULL;
        return -ENODEV;
}

#define ASUS_HANDLE_INIT(object)                                        \
        asus_handle_init(#object, &object##_handle, object##_paths,     \
                         ARRAY_SIZE(object##_paths))

/*
 * This function is used to initialize the hotk with right values. In this
 * method, we can make all the detection we want, and modify the hotk struct
 */
static int asus_hotk_get_info(void)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *model = NULL;
        int bsts_result, 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. A global variable asus_info contains
         * the DSDT header.
         */
        status = acpi_get_table(ACPI_SIG_DSDT, 1, &asus_info);
        if (ACPI_FAILURE(status))
                printk(ASUS_WARNING "Couldn't get the DSDT table header\n");

        /* We have to write 0 on init this far for all ASUS models */
        if (!write_acpi_int(hotk->handle, "INIT", 0, &buffer)) {
                printk(ASUS_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, NULL))
                printk(ASUS_WARNING "Error calling BSTS\n");
        else if (bsts_result)
                printk(ASUS_NOTICE "BSTS called, 0x%02x returned\n",
                       bsts_result);

        /*
         * Try to match the object returned by INIT to the specific model.
         * Handle every possible object (or the lack of thereof) the DSDT
         * writers might throw at us. When in trouble, we pass NULL to
         * asus_model_match() and try something completely different.
         */
        if (buffer.pointer) {
                model = buffer.pointer;
                switch (model->type) {
                case ACPI_TYPE_STRING:
                        string = model->string.pointer;
                        break;
                case ACPI_TYPE_BUFFER:
                        string = model->buffer.pointer;
                        break;
                default:
                        string = "";
                        break;
                }
        }
        hotk->name = kstrdup(string, GFP_KERNEL);
        if (!hotk->name)
                return -ENOMEM;

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

        ASUS_HANDLE_INIT(mled_set);
        ASUS_HANDLE_INIT(tled_set);
        ASUS_HANDLE_INIT(rled_set);
        ASUS_HANDLE_INIT(pled_set);

        ASUS_HANDLE_INIT(ledd_set);

        /*
         * 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.
         */
        if (!read_acpi_int(hotk->handle, "HRWS", &hwrs_result, NULL))
                hwrs_result = WL_HWRS | BT_HWRS;

        if (hwrs_result & WL_HWRS)
                ASUS_HANDLE_INIT(wl_switch);
        if (hwrs_result & BT_HWRS)
                ASUS_HANDLE_INIT(bt_switch);

        ASUS_HANDLE_INIT(wireless_status);

        ASUS_HANDLE_INIT(brightness_set);
        ASUS_HANDLE_INIT(brightness_get);

        ASUS_HANDLE_INIT(lcd_switch);

        ASUS_HANDLE_INIT(display_set);
        ASUS_HANDLE_INIT(display_get);

        /* There is a lot of models with "ALSL", but a few get
           a real light sens, so we need to check it. */
        if (ASUS_HANDLE_INIT(ls_switch))
                ASUS_HANDLE_INIT(ls_level);

        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(ASUS_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(ASUS_NOTICE "Asus Laptop Support version %s\n",
               ASUS_LAPTOP_VERSION);

        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), ASUS_HOTK_DEVICE_NAME);
        strcpy(acpi_device_class(device), ASUS_HOTK_CLASS);
        acpi_driver_data(device) = hotk;
        hotk->device = device;

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

        asus_hotk_add_fs();

        /*
         * 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(ASUS_ERR "Error installing notify handler\n");

        asus_hotk_found = 1;

        /* WLED and BLED are on by default */
        write_status(bt_switch_handle, 1, BT_ON, 0);
        write_status(wl_switch_handle, 1, WL_ON, 0);

        /* LCD Backlight is on by default */
        write_status(NULL, 1, LCD_ON, 0);

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

        /* Set initial values of light sensor and level */
        hotk->light_switch = 1; /* Default to light sensor disabled */
        hotk->light_level = 0;  /* level 5 for sensor sensitivity */

        if (ls_switch_handle)
                set_light_sens_switch(hotk->light_switch);

        if (ls_level_handle)
                set_light_sens_level(hotk->light_level);

      end:
        if (result) {
                kfree(hotk->name);
                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(ASUS_ERR "Error removing notify handler\n");

        kfree(hotk->name);
        kfree(hotk);

        return 0;
}

static void asus_backlight_exit(void)
{
        if (asus_backlight_device)
                backlight_device_unregister(asus_backlight_device);
}

#define  ASUS_LED_UNREGISTER(object)                            \
        if(object##_led.class_dev                               \
           && !IS_ERR(object##_led.class_dev))                  \
                led_classdev_unregister(&object##_led)

static void asus_led_exit(void)
{
        ASUS_LED_UNREGISTER(mled);
        ASUS_LED_UNREGISTER(tled);
        ASUS_LED_UNREGISTER(pled);
        ASUS_LED_UNREGISTER(rled);

        destroy_workqueue(led_workqueue);
}

static void __exit asus_laptop_exit(void)
{
        asus_backlight_exit();
        asus_led_exit();

        acpi_bus_unregister_driver(&asus_hotk_driver);
        sysfs_remove_group(&asuspf_device->dev.kobj, &asuspf_attribute_group);
        platform_device_unregister(asuspf_device);
        platform_driver_unregister(&asuspf_driver);
}

static int asus_backlight_init(struct device *dev)
{
        struct backlight_device *bd;

        if (brightness_set_handle && lcd_switch_handle) {
                bd = backlight_device_register(ASUS_HOTK_FILE, dev,
                                               NULL, &asusbl_data);
                if (IS_ERR(bd)) {
                        printk(ASUS_ERR
                               "Could not register asus backlight device\n");
                        asus_backlight_device = NULL;
                        return PTR_ERR(bd);
                }

                asus_backlight_device = bd;

                bd->props->brightness = read_brightness(NULL);
                bd->props->power = FB_BLANK_UNBLANK;
                backlight_update_status(bd);
        }
        return 0;
}

static int asus_led_register(acpi_handle handle,
                             struct led_classdev *ldev, struct device *dev)
{
        if (!handle)
                return 0;

        return led_classdev_register(dev, ldev);
}

#define ASUS_LED_REGISTER(object, device)                               \
        asus_led_register(object##_set_handle, &object##_led, device)

static int asus_led_init(struct device *dev)
{
        int rv;

        rv = ASUS_LED_REGISTER(mled, dev);
        if (rv)
                return rv;

        rv = ASUS_LED_REGISTER(tled, dev);
        if (rv)
                return rv;

        rv = ASUS_LED_REGISTER(rled, dev);
        if (rv)
                return rv;

        rv = ASUS_LED_REGISTER(pled, dev);
        if (rv)
                return rv;

        led_workqueue = create_singlethread_workqueue("led_workqueue");
        if (!led_workqueue)
                return -ENOMEM;

        return 0;
}

static int __init asus_laptop_init(void)
{
        struct device *dev;
        int result;

        if (acpi_disabled)
                return -ENODEV;

        result = acpi_bus_register_driver(&asus_hotk_driver);
        if (result < 0)
                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);
                return -ENODEV;
        }

        dev = acpi_get_physical_device(hotk->device->handle);

        result = asus_backlight_init(dev);
        if (result)
                goto fail_backlight;

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

        /* Register platform stuff */
        result = platform_driver_register(&asuspf_driver);
        if (result)
                goto fail_platform_driver;

        asuspf_device = platform_device_alloc(ASUS_HOTK_FILE, -1);
        if (!asuspf_device) {
                result = -ENOMEM;
                goto fail_platform_device1;
        }

        result = platform_device_add(asuspf_device);
        if (result)
                goto fail_platform_device2;

        result = sysfs_create_group(&asuspf_device->dev.kobj,
                                    &asuspf_attribute_group);
        if (result)
                goto fail_sysfs;

        return 0;

      fail_sysfs:
        platform_device_del(asuspf_device);

      fail_platform_device2:
        platform_device_put(asuspf_device);

      fail_platform_device1:
        platform_driver_unregister(&asuspf_driver);

      fail_platform_driver:
        asus_led_exit();

      fail_led:
        asus_backlight_exit();

      fail_backlight:

        return result;
}

module_init(asus_laptop_init);
module_exit(asus_laptop_exit);