/*
 *  asus_acpi.c - Asus Laptop ACPI Extras
 *
 *
 *  Copyright (C) 2002-2005 Julien Lerouge, 2003-2006 Karol Kozimor
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 *  The development page for this driver is located at
 *  http://sourceforge.net/projects/acpi4asus/
 *
 *  Credits:
 *  Pontus Fuchs   - Helper functions, cleanup
 *  Johann Wiesner - Small compile fixes
 *  John Belmonte  - ACPI code for Toshiba laptop was a good starting point.
 *  �ic Burghard  - LED display support for W1N
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

#define ASUS_ACPI_VERSION "0.30"

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

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

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

/*
 * Flags for hotk status
 */
#define MLED_ON     0x01        /* Mail LED */
#define WLED_ON     0x02        /* Wireless LED */
#define TLED_ON     0x04        /* Touchpad LED */
#define BT_ON       0x08        /* Internal Bluetooth */

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

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

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

/*
 * This is the main structure, we can use it to store anything interesting
 * about the hotk device
 */
struct asus_hotk {
        struct acpi_device *device;     /* the device we are in */
        acpi_handle handle;             /* the handle of the hotk device */
        char status;                    /* status of the hotk, for LEDs */
        u32 ledd_status;                /* status of the LED display */
        struct model_data *methods;     /* methods available on the laptop */
        u8 brightness;                  /* brightness level */
        enum {
                A1x = 0,        /* A1340D, A1300F */
                A2x,            /* A2500H */
                A4G,            /* A4700G */
                D1x,            /* D1 */
                L2D,            /* L2000D */
                L3C,            /* L3800C */
                L3D,            /* L3400D */
                L3H,            /* L3H, L2000E, L5D */
                L4R,            /* L4500R */
                L5x,            /* L5800C */
                L8L,            /* L8400L */
                M1A,            /* M1300A */
                M2E,            /* M2400E, L4400L */
                M6N,            /* M6800N, W3400N */
                M6R,            /* M6700R, A3000G */
                P30,            /* Samsung P30 */
                S1x,            /* S1300A, but also L1400B and M2400A (L84F) */
                S2x,            /* S200 (J1 reported), Victor MP-XP7210 */
                W1N,            /* W1000N */
                W5A,            /* W5A */
                W3V,            /* W3030V */
                xxN,            /* M2400N, M3700N, M5200N, M6800N,
                                                         S1300N, S5200N*/
                A4S,            /* Z81sp */
                F3Sa,           /* (Centrino) */
                R1F,
                END_MODEL
        } model;                /* Models currently supported */
        u16 event_count[128];   /* Count for each event TODO make this better */
};

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        {
                .name           = "F3Sa",
                .mt_bt_switch   = "BLED",
                .mt_wled        = "WLED",
                .mt_mled        = "MLED",
                .brightness_get = "GPLV",
                .brightness_set = "SPLV",
                .mt_lcd_switch  = "\\_SB.PCI0.SBRG.EC0._Q10",
                .lcd_status     = "\\_SB.PCI0.SBRG.EC0.RPIN",
                .display_get    = "\\ADVG",
                .display_set    = "SDSP",
        },
        {
                .name = "R1F",
                .mt_bt_switch = "BLED",
                .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"
        }
};

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

static struct backlight_device *asus_backlight_device;

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

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

/*
 * The hotkey driver and autoloading declaration
 */
static int asus_hotk_add(struct acpi_device *device);
static int asus_hotk_remove(struct acpi_device *device, int type);
static void asus_hotk_notify(struct acpi_device *device, u32 event);

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

static struct acpi_driver asus_hotk_driver = {
        .name = "asus_acpi",
        .class = ACPI_HOTK_CLASS,
        .owner = THIS_MODULE,
        .ids = asus_device_ids,
        .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
        .ops = {
                .add = asus_hotk_add,
                .remove = asus_hotk_remove,
                .notify = asus_hotk_notify,
                },
};

/*
 * 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 (int) */
        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);
}

static int asus_info_proc_show(struct seq_file *m, void *v)
{
        int temp;

        seq_printf(m, ACPI_HOTK_NAME " " ASUS_ACPI_VERSION "\n");
        seq_printf(m, "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))
                seq_printf(m, "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))
                seq_printf(m, "ASYM value         : 0x%04x\n", temp);
        if (asus_info) {
                seq_printf(m, "DSDT length        : %d\n", asus_info->length);
                seq_printf(m, "DSDT checksum      : %d\n", asus_info->checksum);
                seq_printf(m, "DSDT revision      : %d\n", asus_info->revision);
                seq_printf(m, "OEM id             : %.*s\n", ACPI_OEM_ID_SIZE, asus_info->oem_id);
                seq_printf(m, "OEM table id       : %.*s\n", ACPI_OEM_TABLE_ID_SIZE, asus_info->oem_table_id);
                seq_printf(m, "OEM revision       : 0x%x\n", asus_info->oem_revision);
                seq_printf(m, "ASL comp vendor id : %.*s\n", ACPI_NAME_SIZE, asus_info->asl_compiler_id);
                seq_printf(m, "ASL comp revision  : 0x%x\n", asus_info->asl_compiler_revision);
        }

        return 0;
}

static int asus_info_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, asus_info_proc_show, NULL);
}

static const struct file_operations asus_info_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = asus_info_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

/*
 * /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
                        pr_warn("Error reading LED status\n");
        }
        return (hotk->status & ledmask) ? 1 : 0;
}

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

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

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

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

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

        if (!write_acpi_int(hotk->handle, ledname, led_out, NULL))
                pr_warn("LED (%s) write failed\n", ledname);

        return rv;
}

/*
 * Proc handlers for MLED
 */
static int mled_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", read_led(hotk->methods->mled_status, MLED_ON));
        return 0;
}

static int mled_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, mled_proc_show, NULL);
}

static ssize_t mled_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *pos)
{
        return write_led(buffer, count, hotk->methods->mt_mled, MLED_ON, 1);
}

static const struct file_operations mled_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = mled_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = mled_proc_write,
};

/*
 * Proc handlers for LED display
 */
static int ledd_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "0x%08x\n", hotk->ledd_status);
        return 0;
}

static int ledd_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, ledd_proc_show, NULL);
}

static ssize_t ledd_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *pos)
{
        int rv, value;

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

static const struct file_operations ledd_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = ledd_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = ledd_proc_write,
};

/*
 * Proc handlers for WLED
 */
static int wled_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", read_led(hotk->methods->wled_status, WLED_ON));
        return 0;
}

static int wled_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, wled_proc_show, NULL);
}

static ssize_t wled_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *pos)
{
        return write_led(buffer, count, hotk->methods->mt_wled, WLED_ON, 0);
}

static const struct file_operations wled_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = wled_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = wled_proc_write,
};

/*
 * Proc handlers for Bluetooth
 */
static int bluetooth_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", read_led(hotk->methods->bt_status, BT_ON));
        return 0;
}

static int bluetooth_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, bluetooth_proc_show, NULL);
}

static ssize_t bluetooth_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *pos)
{
        /* Note: mt_bt_switch controls both internal Bluetooth adapter's
           presence and its LED */
        return write_led(buffer, count, hotk->methods->mt_bt_switch, BT_ON, 0);
}

static const struct file_operations bluetooth_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = bluetooth_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = bluetooth_proc_write,
};

/*
 * Proc handlers for TLED
 */
static int tled_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", read_led(hotk->methods->tled_status, TLED_ON));
        return 0;
}

static int tled_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, tled_proc_show, NULL);
}

static ssize_t tled_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *pos)
{
        return write_led(buffer, count, hotk->methods->mt_tled, TLED_ON, 0);
}

static const struct file_operations tled_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = tled_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = tled_proc_write,
};

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

        if (hotk->model == L3H) {
                /* 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;
        } else if (hotk->model == F3Sa) {
                unsigned long long tmp;
                union acpi_object param;
                struct acpi_object_list input;
                acpi_status status;

                /* Read pin 11 */
                param.type = ACPI_TYPE_INTEGER;
                param.integer.value = 0x11;
                input.count = 1;
                input.pointer = &param;

                status = acpi_evaluate_integer(NULL, hotk->methods->lcd_status,
                                                &input, &tmp);
                if (status != AE_OK)
                        return -1;

                lcd = tmp;
        } else {
                /* We don't have to check anything if we are here */
                if (!read_acpi_int(NULL, hotk->methods->lcd_status, &lcd))
                        pr_warn("Error reading LCD status\n");

                if (hotk->model == L2D)
                        lcd = ~lcd;
        }

        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 must 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))
                        pr_warn("Error switching LCD\n");
        }
        return 0;

}

static int lcd_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", get_lcd_state());
        return 0;
}

static int lcd_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, lcd_proc_show, NULL);
}

static ssize_t lcd_proc_write(struct file *file, const char __user *buffer,
               size_t count, loff_t *pos)
{
        int rv, value;

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

static const struct file_operations lcd_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = lcd_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = lcd_proc_write,
};

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

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

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

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

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

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

static int brn_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", read_brightness(NULL));
        return 0;
}

static int brn_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, brn_proc_show, NULL);
}

static ssize_t brn_proc_write(struct file *file, const char __user *buffer,
               size_t count, loff_t *pos)
{
        int rv, value;

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

static const struct file_operations brn_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = brn_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = brn_proc_write,
};

static void set_display(int value)

{
        /* no sanity check needed for now */
        if (!write_acpi_int(hotk->handle, hotk->methods->display_set,
                            value, NULL))
                pr_warn("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 disp_proc_show(struct seq_file *m, void *v)
{
        int value = 0;

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

static int disp_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, disp_proc_show, NULL);
}

/*
 * 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 ssize_t disp_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *pos)
{
        int rv, value;

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

static const struct file_operations disp_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = disp_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = disp_proc_write,
};

static int
asus_proc_add(char *name, const struct file_operations *proc_fops, mode_t mode,
                     struct acpi_device *device)
{
        struct proc_dir_entry *proc;

        proc = proc_create_data(name, mode, acpi_device_dir(device),
                                proc_fops, acpi_driver_data(device));
        if (!proc) {
                pr_warn("  Unable to create %s fs entry\n", name);
                return -1;
        }
        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 ((asus_uid == 0) && (asus_gid == 0)) {
                mode = S_IFREG | S_IRUGO | S_IWUSR | S_IWGRP;
        } else {
                mode = S_IFREG | S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP;
                pr_warn("  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 = proc_create(PROC_INFO, mode, acpi_device_dir(device),
                           &asus_info_proc_fops);
        if (proc) {
                proc->uid = asus_uid;
                proc->gid = asus_gid;
        } else {
                pr_warn("  Unable to create " PROC_INFO " fs entry\n");
        }

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

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

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

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

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

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

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

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

        return 0;
}

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

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

        /*
         * The BIOS *should* be sending us device events, but apparently
         * Asus uses system events instead, so just ignore any device
         * events we get.
         */
        if (event > ACPI_MAX_SYS_NOTIFY)
                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_proc_event(hotk->device, event,
                                hotk->event_count[event % 128]++);

        return;
}

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

        if (strncmp(model, "L3D", 3) == 0)
                return L3D;
        else if (strncmp(model, "L2E", 3) == 0 ||
                 strncmp(model, "L3H", 3) == 0 || strncmp(model, "L5D", 3) == 0)
                return L3H;
        else if (strncmp(model, "L3", 2) == 0 || strncmp(model, "L2B", 3) == 0)
                return L3C;
        else if (strncmp(model, "L8L", 3) == 0)
                return L8L;
        else if (strncmp(model, "L4R", 3) == 0)
                return L4R;
        else if (strncmp(model, "M6N", 3) == 0 || strncmp(model, "W3N", 3) == 0)
                return M6N;
        else if (strncmp(model, "M6R", 3) == 0 || strncmp(model, "A3G", 3) == 0)
                return M6R;
        else if (strncmp(model, "M2N", 3) == 0 ||
                 strncmp(model, "M3N", 3) == 0 ||
                 strncmp(model, "M5N", 3) == 0 ||
                 strncmp(model, "S1N", 3) == 0 ||
                 strncmp(model, "S5N", 3) == 0)
                return xxN;
        else if (strncmp(model, "M1", 2) == 0)
                return M1A;
        else if (strncmp(model, "M2", 2) == 0 || strncmp(model, "L4E", 3) == 0)
                return M2E;
        else if (strncmp(model, "L2", 2) == 0)
                return L2D;
        else if (strncmp(model, "L8", 2) == 0)
                return S1x;
        else if (strncmp(model, "D1", 2) == 0)
                return D1x;
        else if (strncmp(model, "A1", 2) == 0)
                return A1x;
        else if (strncmp(model, "A2", 2) == 0)
                return A2x;
        else if (strncmp(model, "J1", 2) == 0)
                return S2x;
        else if (strncmp(model, "L5", 2) == 0)
                return L5x;
        else if (strncmp(model, "A4G", 3) == 0)
                return A4G;
        else if (strncmp(model, "W1N", 3) == 0)
                return W1N;
        else if (strncmp(model, "W3V", 3) == 0)
                return W3V;
        else if (strncmp(model, "W5A", 3) == 0)
                return W5A;
        else if (strncmp(model, "R1F", 3) == 0)
                return R1F;
        else if (strncmp(model, "A4S", 3) == 0)
                return A4S;
        else if (strncmp(model, "F3Sa", 4) == 0)
                return F3Sa;
        else
                return END_MODEL;
}

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

        /*
         * Get DSDT headers early enough to allow for differentiating between
         * models, but late enough to allow acpi_bus_register_driver() to fail
         * before doing anything ACPI-specific. Should we encounter a machine,
         * which needs special handling (i.e. its hotkey device has a different
         * HID), this bit will be moved. A global variable asus_info contains
         * the DSDT header.
         */
        status = acpi_get_table(ACPI_SIG_DSDT, 1, &asus_info);
        if (ACPI_FAILURE(status))
                pr_warn("  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)) {
                pr_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))
                pr_warn("  Error calling BSTS\n");
        else if (bsts_result)
                pr_notice("  BSTS called, 0x%02x returned\n", bsts_result);

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

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

        kfree(model);

        return 0;
}

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 {
                pr_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;

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

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

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

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

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

        /* 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))
                        pr_warn("  Error changing brightness\n");
                else {
                        status =
                            acpi_evaluate_object(NULL,
                                                 hotk->methods->brightness_up,
                                                 NULL, NULL);
                        if (ACPI_FAILURE(status))
                                pr_warn("  Strange, error changing brightness\n");
                }
        }

        asus_hotk_found = 1;

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

end:
        if (result)
                kfree(hotk);

        return result;
}

static int asus_hotk_remove(struct acpi_device *device, int type)
{
        asus_hotk_remove_fs(device);

        kfree(hotk);

        return 0;
}

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

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

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

        return;
}

static int __init asus_acpi_init(void)
{
        struct backlight_properties props;
        int result;

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

        asus_proc_dir = proc_mkdir(PROC_ASUS, acpi_root_dir);
        if (!asus_proc_dir) {
                pr_err("Unable to create /proc entry\n");
                acpi_bus_unregister_driver(&asus_hotk_driver);
                return -ENODEV;
        }

        /*
         * 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 -ENODEV;
        }

        memset(&props, 0, sizeof(struct backlight_properties));
        props.type = BACKLIGHT_PLATFORM;
        props.max_brightness = 15;
        asus_backlight_device = backlight_device_register("asus", NULL, NULL,
                                                          &asus_backlight_data,
                                                          &props);
        if (IS_ERR(asus_backlight_device)) {
                pr_err("Could not register asus backlight device\n");
                asus_backlight_device = NULL;
                asus_acpi_exit();
                return -ENODEV;
        }

        return 0;
}

module_init(asus_acpi_init);
module_exit(asus_acpi_exit);