wmi-acer - Fix error test for ACPI bus register

[acer_acpi.git] / acer_acpi.c

/*
 *  Acer Laptop ACPI Extras
 *
 *  Copyright (C) 2005-2007     E.M. Smith
 *  Copyright (C) 2007          Carlos Corbacho <cathectic@gmail.com>
 *
 *  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 devolpment page for this driver is located at
 *  http://code.google.com/p/aceracpi
 *
 *  Credits:
 *
 *  John Belmonte - the Toshiba ACPI driver originally adapted for this module.
 *  Julien Lerouge & Karol Kozimor - ASUS Acpi driver authors.
 *  Olaf Tauber - developer of acerhk, the inspiration to solve the 64-bit
 *                driver problem for my Aspire 5024.
 *  Mathieu Segaud - solved the ACPI problem that needed a double-modprobe
 *                   in version 0.2 and below.
 *  Jim Ramsay - Figured out and added support for WMID interface
 */

#define ACER_ACPI_VERSION       "0.10.0"

/*
 * Comment the following line out to remove /proc support
 */
#define CONFIG_PROC

#ifdef CONFIG_PROC
#define PROC_ACER               "acer"
#include <linux/proc_fs.h>
#endif

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/version.h>

#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,17)
#include <asm/uaccess.h>
#else
#include <linux/uaccess.h>
#endif

#include <linux/io.h>
#include <linux/dmi.h>
#include <linux/backlight.h>
#include <linux/leds.h>
#include <linux/platform_device.h>

#include <acpi/acpi_drivers.h>

#include "wmi-acer.h"

/* Workaround needed for older kernels */
#ifndef bool
#define bool int
#endif

MODULE_AUTHOR("Mark Smith, Carlos Corbacho");
MODULE_DESCRIPTION("Acer Laptop ACPI Extras Driver");
MODULE_LICENSE("GPL");

MODULE_ALIAS("dmi:*:*Acer*:*:");

#define ACER_LOGPREFIX "acer_acpi: "
#define ACER_ERR KERN_ERR ACER_LOGPREFIX
#define ACER_NOTICE KERN_NOTICE ACER_LOGPREFIX
#define ACER_INFO KERN_INFO ACER_LOGPREFIX

#define DEBUG(level, message...) { \
        if (debug >= level) \
                printk(KERN_DEBUG ACER_LOGPREFIX message);\
}

/*
 * The maximum temperature one can set for fan control override.
 * Doesn't propably make much sense if over 80 degrees celsius though...
 */
#define ACER_MAX_TEMPERATURE_OVERRIDE 150

/*
 * The following defines quirks to get some specific functions to work
 * which are known to not be supported over ACPI (such as the mail LED
 * on WMID based Acer's)
 */
struct acer_quirks {
        const char *vendor;
        const char *model;
        u16 quirks;
};

/*
 * Keyboard controller ports
 */
#define ACER_KBD_STATUS_REG     0x64    /* Status register (R) */
#define ACER_KBD_CNTL_REG       0x64    /* Controller command register (W) */
#define ACER_KBD_DATA_REG       0x60    /* Keyboard data register (R/W) */

/*
 * Magic Number
 * Meaning is unknown - this number is required for writing to ACPI for AMW0
 * (it's also used in acerhk when directly accessing the EC)
 */
#define ACER_AMW0_WRITE 0x9610

/*
 * Bit masks for the old AMW0 interface
 */
#define ACER_AMW0_WIRELESS_MASK  0x35
#define ACER_AMW0_BLUETOOTH_MASK 0x34
#define ACER_AMW0_MAILLED_MASK   0x31

/*
 * Method IDs for new WMID interface
 */
#define ACER_WMID_GET_WIRELESS_METHODID         1
#define ACER_WMID_GET_BLUETOOTH_METHODID        2
#define ACER_WMID_GET_BRIGHTNESS_METHODID       3
#define ACER_WMID_SET_WIRELESS_METHODID         4
#define ACER_WMID_SET_BLUETOOTH_METHODID        5
#define ACER_WMID_SET_BRIGHTNESS_METHODID       6
#define ACER_WMID_GET_THREEG_METHODID           10
#define ACER_WMID_SET_THREEG_METHODID           11

/*
 * Acer ACPI method GUIDs
 */
#define AMW0_GUID1              "67C3371D-95A3-4C37-BB61-DD47B491DAAB"
#define WMID_GUID1              "6AF4F258-B401-42fd-BE91-3D4AC2D7C0D3"
#define WMID_GUID2              "95764E09-FB56-4e83-B31A-37761F60994A"

/*
 * Interface capability flags
 */
#define ACER_CAP_MAILLED                (1<<0)
#define ACER_CAP_WIRELESS               (1<<1)
#define ACER_CAP_BLUETOOTH              (1<<2)
#define ACER_CAP_BRIGHTNESS             (1<<3)
#define ACER_CAP_THREEG                 (1<<4)
#define ACER_CAP_TOUCHPAD_READ          (1<<5)
#define ACER_CAP_TEMPERATURE_OVERRIDE   (1<<6)
#define ACER_CAP_ANY                    (0xFFFFFFFF)

/*
 * Interface type flags
 */
enum interface_flags {
        ACER_AMW0,
        ACER_AMW0_V2,
        ACER_WMID,
};

/*
 * Presumed start states -
 * On some AMW0 laptops, we do not yet know how to get the device status from
 * the EC, so we must store this ourselves.
 *
 * Plus, we can't tell which features are enabled or disabled on a specific
 * model - e.g. The 5020 series can _support_ bluetooth; but the 5021 has no
 * bluetooth, whilst the 5024 does.  However, the BIOS identifies both laptops
 * as 5020, and you can add bluetooth later.
 *
 * Basically the code works like this:
 *   - On init, any values specified on the commandline are set.
 *   - For interfaces where the current values cannot be detected and which
 *     have not been set on the commandline, we set them to some sane default
 *     (disabled)
 *
 * See AMW0_init and acer_commandline_init
 */

#define ACER_DEFAULT_WIRELESS  0
#define ACER_DEFAULT_BLUETOOTH 0
#define ACER_DEFAULT_MAILLED   0
#define ACER_DEFAULT_THREEG    0

static int max_brightness = 0xF;

static int wireless = -1;
static int bluetooth = -1;
static int mailled = -1;
static int brightness = -1;
static int threeg = -1;
static int fan_temperature_override = -1;
static int debug = 0;
static int force_series;

module_param(mailled, int, 0444);
module_param(wireless, int, 0444);
module_param(bluetooth, int, 0444);
module_param(brightness, int, 0444);
module_param(threeg, int, 0444);
module_param(force_series, int, 0444);
module_param(fan_temperature_override, int, 0444);
module_param(debug, int, 0664);
MODULE_PARM_DESC(wireless, "Set initial state of Wireless hardware");
MODULE_PARM_DESC(bluetooth, "Set initial state of Bluetooth hardware");
MODULE_PARM_DESC(mailled, "Set initial state of Mail LED");
MODULE_PARM_DESC(brightness, "Set initial LCD backlight brightness");
MODULE_PARM_DESC(threeg, "Set initial state of 3G hardware");
MODULE_PARM_DESC(fan_temperature_override, "Set initial state of the 'FAN temperature-override'");
MODULE_PARM_DESC(debug, "Debugging verbosity level (0=least 2=most)");
MODULE_PARM_DESC(force_series, "Force a different laptop series for extra features (5020, 5720 or 2490)");

#ifdef CONFIG_PROC
struct ProcItem {
        const char *name;
        char *(*read_func) (char *, u32);
        unsigned long (*write_func) (const char *, unsigned long, u32);
        unsigned int capability;
};

static struct proc_dir_entry *acer_proc_dir;
#endif

/*
 * Wait for the keyboard controller to become ready
 */
static int wait_kbd_write(void)
{
        int i = 0;
        while ((inb(ACER_KBD_STATUS_REG) & 0x02) && (i < 10000)) {
                udelay(50);
                i++;
        }
        return -(i == 10000);
}

static void send_kbd_cmd(u8 cmd, u8 val)
{
        preempt_disable();
        if (!wait_kbd_write())
                outb(cmd, ACER_KBD_CNTL_REG);
        if (!wait_kbd_write())
                outb(val, ACER_KBD_DATA_REG);
        preempt_enable_no_resched();
}

static void set_keyboard_quirk(void)
{
        send_kbd_cmd(0x59, 0x90);
}

struct acer_data {
        int mailled;
        int wireless;
        int bluetooth;
        int threeg;
        int brightness;
};

/* Each low-level interface must define at least some of the following */
struct Interface {
        u32 type;               /* WMI device type */
        u32 capability;         /* The capabilities this interface provides */
        struct acer_data data;  /* Private data for interface */
};

/* The static interface pointer, points to the currently detected interface */
static struct Interface *interface;

/*
 * Embedded Controller quirks
 * Some laptops require us to directly access the EC to either enable or query
 * features that are not available through ACPI.
 */

struct quirk_entry {
        u8 wireless;
        u8 mailled;
        u8 brightness;
        u8 touchpad;
        u8 temperature_override;
        u8 mmkeys;
        u8 bluetooth;
};

static struct quirk_entry *quirks;

static void set_quirks(void)
{
        if (quirks->mailled != 0) {
                interface->capability |= ACER_CAP_MAILLED;
                DEBUG(1, "Using EC direct-access quirk for mail LED\n");
        }

        if (quirks->touchpad != 0) {
                interface->capability |= ACER_CAP_TOUCHPAD_READ;
                DEBUG(1, "Using EC direct-access quirk for reading touchpad status\n");
        }

        if (quirks->temperature_override != 0) {
                interface->capability |= ACER_CAP_TEMPERATURE_OVERRIDE;
                DEBUG(1, "Using EC direct-access quirk for temperature override setting (fan)\n");
        }

        if (quirks->brightness != 0) {
                interface->capability |= ACER_CAP_BRIGHTNESS;
                DEBUG(1, "Using EC direct-access quirk for backlight brightness\n");
        }

        if (quirks->mmkeys != 0) {
                set_keyboard_quirk();
                printk(ACER_INFO "Setting keyboard quirk to enable multimedia keys\n");
        }

        if (quirks->bluetooth != 0) {
                interface->capability |= ACER_CAP_BLUETOOTH;
                DEBUG(1, "Using EC direct-access quirk for bluetooth\n");
        }

        if (quirks->wireless != 0) {
                interface->capability |= ACER_CAP_WIRELESS;
                DEBUG(1, "Using EC direct-access quirk for wireless\n");
        }
}

static int dmi_matched(struct dmi_system_id *dmi)
{
        quirks = dmi->driver_data;
        return 0;
}

static struct quirk_entry quirk_unknown = {
};

/* Same Mail LED quirk as TM2490, but does not require keyboard quirk */
static struct quirk_entry quirk_acer_aspire_5100 = {
        .mailled = 1,
};

static struct quirk_entry quirk_acer_travelmate_2490 = {
        .mmkeys = 1,
        .mailled = 1,
        .temperature_override = 1,
        .touchpad = 1,
};

static struct quirk_entry quirk_acer_travelmate_5720 = {
        .touchpad = 2,
};

static struct dmi_system_id acer_quirks[] = {
        {
                .callback = dmi_matched,
                .ident = "Acer Aspire 3100",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 3100"),
                },
                .driver_data = &quirk_acer_aspire_5100,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer Aspire 5100",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5100"),
                },
                .driver_data = &quirk_acer_aspire_5100,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer Aspire 5630",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5630"),
                },
                .driver_data = &quirk_acer_travelmate_2490,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer Aspire 5650",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5650"),
                },
                .driver_data = &quirk_acer_travelmate_2490,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer Aspire 5680",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5680"),
                },
                .driver_data = &quirk_acer_travelmate_2490,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer Extensa 5220",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Extensa 5220"),
                },
                .driver_data = &quirk_acer_travelmate_5720,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer TravelMate 2490",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 2490"),
                },
                .driver_data = &quirk_acer_travelmate_2490,
        },
        {
                .callback = dmi_matched,
                .ident = "Acer TravelMate 5720",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5720"),
                },
                .driver_data = &quirk_acer_travelmate_5720,
        },
        {}
};

/* Find which quirks are needed for a particular vendor/ model pair */
static void find_quirks(void)
{
        DEBUG (1, "Looking for quirks\n");
        if (!force_series) {
                dmi_check_system(acer_quirks);
        } else if (force_series == 2490) {
                DEBUG(0, "Forcing Acer TravelMate 2490\n");
                quirks = &quirk_acer_travelmate_2490;
        }

        if (quirks == NULL) {
                DEBUG(1, "No quirks known for this laptop\n");
                quirks = &quirk_unknown;
        }
        set_quirks();
}

/*
 * General interface convenience methods
 */

static bool has_cap(u32 cap)
{
        if ((interface->capability & cap) != 0) {
                return 1;
        }
        return 0;
}

/*
 * Old interface (now known as the AMW0 interface)
 */
struct WMAB_args {
        u32 eax;
        u32 ebx;
        u32 ecx;
        u32 edx;
};

static acpi_status WMAB_execute(struct WMAB_args *regbuf, struct acpi_buffer *result)
{
        struct acpi_buffer input;
        acpi_status status;
        input.length = sizeof(struct WMAB_args);
        input.pointer = (u8*)regbuf;

        status = wmi_acer_evaluate_method(AMW0_GUID1, 1, 1, &input, result);
        DEBUG(2, "  Args: 0x%08x 0x%08x 0x%08x 0x%08x\n", regbuf->eax, regbuf->ebx, regbuf->ecx, regbuf->edx );

        return status;
}

static acpi_status AMW0_get_bool(bool *value, u32 cap, struct Interface *iface)
{
        u8 result;

        DEBUG(2, "  AMW0_get_bool: cap=%d\n", cap);
        switch (cap) {
        case ACER_CAP_MAILLED:
                switch (quirks->mailled) {
                default:
                        ec_read(0x0A, &result);
                        *value = (result >> 7) & 0x01;
                        return 0;
                }
                break;
        case ACER_CAP_WIRELESS:
                switch (quirks->wireless) {
                default:
                        ec_read(0x0A, &result);
                        *value = (result >> 2) & 0x01;
                        return 0;
                }
                break;
        case ACER_CAP_BLUETOOTH:
                switch (quirks->bluetooth) {
                default:
                        ec_read(0x0A, &result);
                        *value = (result >> 4) & 0x01;
                        return 0;
                }
                break;
        default:
                return AE_BAD_ADDRESS;
        }
        return AE_OK;
}

static acpi_status AMW0_set_bool(bool value, u32 cap, struct Interface *iface)
{
        struct WMAB_args args;

        args.eax = ACER_AMW0_WRITE;
        args.ebx = value ? (1<<8) : 0;
        args.ecx = args.edx = 0;

        switch (cap) {
        case ACER_CAP_MAILLED:
                args.ebx |= ACER_AMW0_MAILLED_MASK;
                break;
        case ACER_CAP_WIRELESS:
                args.ebx |= ACER_AMW0_WIRELESS_MASK;
                break;
        case ACER_CAP_BLUETOOTH:
                args.ebx |= ACER_AMW0_BLUETOOTH_MASK;
                break;
        default:
                return AE_BAD_ADDRESS;
        }

        /* Actually do the set */
        return WMAB_execute(&args, NULL);
}

static acpi_status AMW0_get_u8(u8 *value, u32 cap, struct Interface *iface) {
        switch (cap) {
        case ACER_CAP_BRIGHTNESS:
                switch (quirks->brightness) {
                default:
                        return ec_read(0x83, value);
                }
                break;
        default:
                return AE_BAD_ADDRESS;
        }
        return AE_OK;
}

static acpi_status AMW0_set_u8(u8 value, u32 cap, struct Interface *iface) {
        switch (cap) {
        case ACER_CAP_BRIGHTNESS:
                switch (quirks->brightness) {
                case 1:
                        return ec_write(0x83, value);
                default:
                        return AE_BAD_ADDRESS;
                break;
                }
        default:
                return AE_BAD_ADDRESS;
        }
        return AE_OK;
}

static struct Interface AMW0_interface = {
        .type = ACER_AMW0,
        .capability = (
                ACER_CAP_MAILLED |
                ACER_CAP_WIRELESS |
                ACER_CAP_BLUETOOTH
        ),
};

static struct Interface AMW0_V2_interface = {
        .type = ACER_AMW0_V2,
        .capability = (
                ACER_CAP_BRIGHTNESS |
                ACER_CAP_MAILLED
        ),
};

/*
 * New interface (The WMID interface)
 */
static acpi_status
WMI_execute_u32(u32 method_id, u32 in, u32 *out)
{
        struct acpi_buffer input = { (acpi_size) sizeof(u32), (void *)(&in) };
        struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *obj;
        u32 tmp;
        acpi_status status;

        DEBUG(2, "  WMI_execute_u32:\n");
        status = wmi_acer_evaluate_method(WMID_GUID1, 1, method_id, &input, &result);
        DEBUG(2, "  In: 0x%08x\n", in);

        if (ACPI_FAILURE(status))
                return status;

        obj = (union acpi_object *) result.pointer;
        if (obj && obj->type == ACPI_TYPE_BUFFER && obj->buffer.length == sizeof(u32)) {
                tmp = *((u32 *) obj->buffer.pointer);
                DEBUG(2, "  Out: 0x%08x\n", tmp);
        } else {
                tmp = 0;
                if (obj) {
                        DEBUG(2, "  Got unexpected result of type %d\n", obj->type);
                } else {
                        DEBUG(2, "  Got unexpected null result\n");
                }
        }

        if (out)
                *out = tmp;

        if (result.length > 0 && result.pointer)
                kfree(result.pointer);

        DEBUG(2, "  Returning from WMI_execute_u32:\n");
        return status;
}

static acpi_status WMID_get_u8(u8 *value, u32 cap, struct Interface *iface) {
        acpi_status status;
        u32 result;
        u32 method_id = 0;

        DEBUG(2, "  WMID_get_u8: cap=%d\n", cap);
        switch (cap) {
        case ACER_CAP_WIRELESS:
                method_id = ACER_WMID_GET_WIRELESS_METHODID;
                break;
        case ACER_CAP_BLUETOOTH:
                method_id = ACER_WMID_GET_BLUETOOTH_METHODID;
                break;
        case ACER_CAP_BRIGHTNESS:
                method_id = ACER_WMID_GET_BRIGHTNESS_METHODID;
                break;
        case ACER_CAP_THREEG:
                method_id = ACER_WMID_GET_THREEG_METHODID;
                break;
        case ACER_CAP_MAILLED:
                if (quirks->mailled == 1) {
                        ec_read(0x9f, value);
                        *value &= 0x01;
                        return 0;
                }
        case ACER_CAP_TOUCHPAD_READ:
                switch (quirks->touchpad) {
                case 1:
                        ec_read(0x9e, value);
                        *value = 1 - ((*value >> 3) & 0x01);
                        return 0;
                case 2:
                        ec_read(0x74, value);
                        *value = ((*value >> 3) & 0x01);
                        return 0;
                default:
                        break;
                }
        case ACER_CAP_TEMPERATURE_OVERRIDE:
                if (quirks->temperature_override == 1) {
                        ec_read(0xa9, value);
                        return 0;
                }
        default:
                return AE_BAD_ADDRESS;
        }
        status = WMI_execute_u32(method_id, 0, &result);
        DEBUG(2, "   WMI_execute_u32 status=%d:\n", status);

        if (ACPI_SUCCESS(status))
                *value = (u8)result;

        DEBUG(2, "  Returning from WMID_get_u8:\n");
        return status;
}

static acpi_status WMID_set_u8(u8 value, u32 cap, struct Interface *iface) {
        u32 method_id = 0;

        switch (cap) {
        case ACER_CAP_BRIGHTNESS:
                method_id = ACER_WMID_SET_BRIGHTNESS_METHODID;
                break;
        case ACER_CAP_WIRELESS:
                method_id = ACER_WMID_SET_WIRELESS_METHODID;
                break;
        case ACER_CAP_BLUETOOTH:
                method_id = ACER_WMID_SET_BLUETOOTH_METHODID;
                break;
        case ACER_CAP_THREEG:
                method_id = ACER_WMID_SET_THREEG_METHODID;
                break;
        case ACER_CAP_MAILLED:
                if (quirks->mailled == 1) {
                        send_kbd_cmd(0x59, value ? 0x92 : 0x93);
                        return 0;
                }
        case ACER_CAP_TEMPERATURE_OVERRIDE:
                if (quirks->temperature_override == 1) {
                        ec_write(0xa9, value);
                        return 0;
                }
        default:
                return AE_BAD_ADDRESS;
        }
        return WMI_execute_u32(method_id, (u32)value, NULL);
}

static acpi_status WMID_set_capabilities(void) {
        struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
        union acpi_object *obj;
        acpi_status status;
        u32 devices;

        status = wmi_acer_query_block(WMID_GUID2, 1, &out);
        if (ACPI_FAILURE(status))
                return status;

        obj = (union acpi_object *) out.pointer;
        if (obj && obj->type == ACPI_TYPE_BUFFER && obj->buffer.length == sizeof(u32)) {
                devices = *((u32 *) obj->buffer.pointer);
        } else {
                return AE_ERROR;
        }

        /* Not sure on the meaning of the relevant bits yet */
        interface->capability |= ACER_CAP_WIRELESS;
        interface->capability |= ACER_CAP_THREEG;

        if (devices & 0x10) {
                DEBUG(1, "Bluetooth hardware available - enabling\n");
                interface->capability |= ACER_CAP_BLUETOOTH;
        }
                
        if (!(devices & 0x20)) {
                DEBUG(1, "Maximum brightness quirk detected - enabling\n");
                max_brightness = 0x9;
        }
        
        return status;
}


static struct Interface WMID_interface = {
        .type = ACER_WMID,
        .capability = ACER_CAP_BRIGHTNESS,
};

#ifdef CONFIG_PROC
/*
 * High-level Procfs file handlers
 */

static int
dispatch_read(char *page, char **start, off_t off, int count, int *eof,
              struct ProcItem *item)
{
        char *p = page;
        int len;

        DEBUG(2, "  dispatch_read: \n");
        if (off == 0)
                p = item->read_func(p, item->capability);
        len = (p - page);
        if (len <= off + count)
                *eof = 1;
        *start = page + off;
        len -= off;
        if (len > count)
                len = count;
        if (len < 0)
                len = 0;
        return len;
}

static int
dispatch_write(struct file *file, const char __user *buffer,
               unsigned long count, struct ProcItem *item)
{
        int result;
        char *tmp_buffer;

        /*
         * Arg buffer points to userspace memory, which can't be accessed
         * directly.  Since we're making a copy, zero-terminate the
         * destination so that sscanf can be used on it safely.
         */
        tmp_buffer = kmalloc(count + 1, GFP_KERNEL);
        if (copy_from_user(tmp_buffer, buffer, count)) {
                result = -EFAULT;
        } else {
                tmp_buffer[count] = 0;
                result = item->write_func(tmp_buffer, count, item->capability);
        }
        kfree(tmp_buffer);
        return result;
}
#endif

/*
 * Generic Device (interface-independent)
 */

static acpi_status get_bool(bool *value, u32 cap) {
        acpi_status status = AE_BAD_ADDRESS;
        u8 tmp = 0;

        DEBUG(2, "  get_bool: cap=%d, interface type=%d\n",
                        cap, interface->type);
        switch (interface->type) {
        case ACER_AMW0:
                status = AMW0_get_bool(value, cap, interface);
                break;
        case ACER_AMW0_V2:
                if (cap == ACER_CAP_MAILLED) {
                        status = AMW0_get_bool(value, cap, interface);
                        break;
                }
        case ACER_WMID:
                status = WMID_get_u8(&tmp, cap, interface);
                *value = (tmp == 1) ? 1 : 0;
                break;
        }
        DEBUG(2, "  Returning from get_bool:\n");
        return status;
}

static acpi_status set_bool(int value, u32 cap) {
        acpi_status status = AE_BAD_PARAMETER;

        DEBUG(2, "  set_bool: cap=%d, interface type=%d, value=%d\n",
                        cap, interface->type, value);
        if ((value == 0 || value == 1) && (interface->capability & cap)) {
                switch (interface->type) {
                case ACER_AMW0:
                        status = AMW0_set_bool(value == 1, cap, interface);
                        break;
                case ACER_AMW0_V2:
                        if (cap == ACER_CAP_MAILLED) {
                                status = AMW0_set_bool(value == 1, cap,
                                        interface);
                                break;
                        }
                case ACER_WMID:
                        status = WMID_set_u8(value == 1, cap, interface);
                        break;
                }
        }
        return status;
}

static acpi_status get_u8(u8 *value, u32 cap) {
        DEBUG(2, "  get_u8: cap=%d\n", cap);
        switch (interface->type) {
        case ACER_AMW0:
                return AMW0_get_u8(value, cap, interface);
                break;
        case ACER_AMW0_V2:
        case ACER_WMID:
                return WMID_get_u8(value, cap, interface);
                break;
        default:
                return AE_BAD_ADDRESS;
        }
}

static acpi_status set_u8(u8 value, u8 min, u8 max, u32 cap) {

        DEBUG(2, "  set_u8: cap=%d, interface type=%d, value=%d\n",
                        cap, interface->type, value);

        if ((value >= min && value <= max) && (interface->capability & cap) ) {
                switch (interface->type) {
                case ACER_AMW0:
                        return AMW0_set_u8(value, cap, interface);
                case ACER_AMW0_V2:
                case ACER_WMID:
                        return WMID_set_u8(value, cap, interface);
                default:
                        return AE_BAD_PARAMETER;
                }
        }
        return AE_BAD_PARAMETER;
}

/* Each _u8 needs a small wrapper that sets the boundary values */
static acpi_status set_brightness(u8 value)
{
        return set_u8(value, 0, max_brightness, ACER_CAP_BRIGHTNESS);
}

static acpi_status set_temperature_override(u8 value)
{
        return set_u8(value, 0, ACER_MAX_TEMPERATURE_OVERRIDE, ACER_CAP_TEMPERATURE_OVERRIDE);
}

static void __init acer_commandline_init(void)
{
        DEBUG(1, "Commandline args: mailled(%d) wireless(%d) bluetooth(%d) brightness(%d)\n",
                mailled, wireless, bluetooth, brightness);

        /*
         * These will all fail silently if the value given is invalid, or the
         * capability isn't available on the given interface
         */
        set_bool(mailled, ACER_CAP_MAILLED);
        set_bool(wireless, ACER_CAP_WIRELESS);
        set_bool(bluetooth, ACER_CAP_BLUETOOTH);
        set_bool(threeg, ACER_CAP_THREEG);
        set_temperature_override(fan_temperature_override);
        set_brightness((u8)brightness);
}

#ifdef CONFIG_PROC
/*
 * Procfs interface (deprecated)
 */
static char *read_bool(char *p, u32 cap)
{
        bool result;
        acpi_status status;

        DEBUG(2, "  read_bool: cap=%d\n", cap);
        status = get_bool(&result, cap);
        if (ACPI_SUCCESS(status))
                p += sprintf(p, "%d\n", result);
        else
                p += sprintf(p, "Read error" );
        return p;
}

static unsigned long write_bool(const char *buffer, unsigned long count, u32 cap)
{
        int value;

        DEBUG(2, "  write_bool: cap=%d, interface type=%d\n buffer=%s\n",
                        cap, interface->type, buffer);

        if (sscanf(buffer, "%i", &value) == 1) {
                acpi_status status = set_bool(value, cap);
                if (ACPI_FAILURE(status))
                        return -EINVAL;
        } else {
                return -EINVAL;
        }
        return count;
}

static char *read_u8(char *p, u32 cap)
{
        u8 result;
        acpi_status status;

        DEBUG(2, "  read_u8: cap=%d\n", cap);
        status = get_u8(&result, cap);
        if (ACPI_SUCCESS(status))
                p += sprintf(p, "%u\n", result);
        else
                p += sprintf(p, "Read error" );
        return p;
}

static unsigned long write_u8(const char *buffer, unsigned long count, u32 cap)
{
        int value;
        acpi_status (*set_method)(u8);

        /* Choose the appropriate set_u8 wrapper here, based on the capability */
        switch (cap) {
        case ACER_CAP_BRIGHTNESS:
                set_method = set_brightness;
                break;
        case ACER_CAP_TEMPERATURE_OVERRIDE:
                set_method = set_temperature_override;
                break;
        default:
                return -EINVAL;
        };

        if (sscanf(buffer, "%i", &value) == 1) {
                acpi_status status = (*set_method)(value);
                if (ACPI_FAILURE(status))
                        return -EINVAL;
        } else {
                return -EINVAL;
        }
        return count;
}

static char *read_version(char *p, u32 cap)
{
        p += sprintf(p, "%s\n", ACER_ACPI_VERSION);
        return p;
}

static char *read_interface(char *p, u32 cap)
{
        p += sprintf(p, "%s\n", (interface->type == ACER_AMW0 ) ? "AMW0": "WMID");
        return p;
}

static struct ProcItem proc_items[] = {
        {"mailled", read_bool, write_bool, ACER_CAP_MAILLED},
        {"bluetooth", read_bool, write_bool, ACER_CAP_BLUETOOTH},
        {"wireless", read_bool, write_bool, ACER_CAP_WIRELESS},
        {"brightness", read_u8, write_u8, ACER_CAP_BRIGHTNESS},
        {"threeg", read_bool, write_bool, ACER_CAP_THREEG},
        {"touchpad", read_bool, NULL, ACER_CAP_TOUCHPAD_READ},
        {"fan_temperature_override", read_u8, write_u8, ACER_CAP_TEMPERATURE_OVERRIDE},
        {"version", read_version, NULL, ACER_CAP_ANY},
        {"interface", read_interface, NULL, ACER_CAP_ANY},
        {NULL}
};

static int __init add_proc_entries(void)
{
        struct proc_dir_entry *proc;
        struct ProcItem *item;

        for (item = proc_items; item->name; ++item) {
                /*
                 * Only add the proc file if the current interface actually
                 * supports it
                 */
                if (interface->capability & item->capability) {
                        proc = create_proc_read_entry(item->name,
                                        S_IFREG | S_IRUGO | S_IWUSR,
                                        acer_proc_dir,
                                        (read_proc_t *) dispatch_read,
                                        item);
                        if (proc)
                                proc->owner = THIS_MODULE;
                        if (proc && item->write_func)
                                proc->write_proc = (write_proc_t *) dispatch_write;
                }
        }

        return 0;
}

static int __exit remove_proc_entries(void)
{
        struct ProcItem *item;

        for (item = proc_items; item->name; ++item)
                remove_proc_entry(item->name, acer_proc_dir);
        return 0;
}
#endif

/*
 * LED device (Mail LED only, no other LEDs known yet)
 */
static void mail_led_set(struct led_classdev *led_cdev, enum led_brightness value)
{
        bool tmp = value;
        set_bool(tmp, ACER_CAP_MAILLED);
}

static struct led_classdev mail_led = {
        .name = "acer_acpi:mail",
        .brightness_set = mail_led_set,
};

static void acer_led_init(struct device *dev)
{
        led_classdev_register(dev, &mail_led);
}

static void acer_led_exit(void)
{
        led_classdev_unregister(&mail_led);
}

#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
/*
 * Backlight device
 */
static struct backlight_device *acer_backlight_device;

static int read_brightness(struct backlight_device *bd)
{
        u8 value;
        get_u8(&value, ACER_CAP_BRIGHTNESS);
        return value;
}

#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,20)
static int update_bl_status(struct backlight_device *bd)
{
        set_brightness(bd->props->brightness);
        return 0;
}

static struct backlight_properties acer_backlight_properties = {
        .get_brightness = read_brightness,
        .update_status = update_bl_status,
};

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

        DEBUG(1, "Loading backlight driver\n");
        bd = backlight_device_register("acer_acpi", dev, NULL, &acer_backlight_properties);
        if (IS_ERR(bd)) {
                printk(ACER_ERR "Could not register Acer backlight device\n");
                acer_backlight_device = NULL;
                return PTR_ERR(bd);
        }

        acer_backlight_device = bd;

        bd->props->max_brightness = max_brightness;
        return 0;
}
#else
static int update_bl_status(struct backlight_device *bd)
{
        set_brightness(bd->props.brightness);
        return 0;
}

static struct backlight_ops acer_backlight_ops = {
        .get_brightness = read_brightness,
        .update_status = update_bl_status,
};

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

        DEBUG(1, "Loading backlight driver\n");
        bd = backlight_device_register("acer_acpi", dev, NULL, &acer_backlight_ops);
        if (IS_ERR(bd)) {
                printk(ACER_ERR "Could not register Acer backlight device\n");
                acer_backlight_device = NULL;
                return PTR_ERR(bd);
        }

        acer_backlight_device = bd;

        bd->props.max_brightness = max_brightness;
        bd->props.brightness = read_brightness(NULL);
        backlight_update_status(bd);
        return 0;
}
#endif

static void __exit acer_backlight_exit(void)
{
        backlight_device_unregister(acer_backlight_device);
}
#endif

/*
 * Read/ write bool sysfs macro
 */
#define show_set_bool(value, cap) \
static ssize_t \
show_bool_##value(struct device *dev, struct device_attribute *attr, \
        char *buf) \
{ \
        bool result; \
        acpi_status status = get_bool(&result, cap); \
        if (ACPI_SUCCESS(status)) \
                return sprintf(buf, "%d\n", result); \
        return sprintf(buf, "Read error" ); \
} \
\
static ssize_t \
set_bool_##value(struct device *dev, struct device_attribute *attr, \
        const char *buf, size_t count) \
{ \
        bool tmp = simple_strtoul(buf, NULL, 10); \
        acpi_status status = set_bool(tmp, cap); \
                if (ACPI_FAILURE(status)) \
                        return -EINVAL; \
        return count; \
} \
static DEVICE_ATTR(value, S_IWUGO | S_IRUGO | S_IWUSR, \
        show_bool_##value, set_bool_##value);

show_set_bool(wireless, ACER_CAP_WIRELESS);
show_set_bool(bluetooth, ACER_CAP_BLUETOOTH);
show_set_bool(threeg, ACER_CAP_THREEG);
show_set_bool(fan_temperature_override, ACER_CAP_TEMPERATURE_OVERRIDE);

/*
 * Read-only bool sysfs macro
 */
#define show_bool(value, cap) \
static ssize_t \
show_bool_##value(struct device *dev, struct device_attribute *attr, \
        char *buf) \
{ \
        bool result; \
        acpi_status status = get_bool(&result, cap); \
        if (ACPI_SUCCESS(status)) \
                return sprintf(buf, "%d\n", result); \
        return sprintf(buf, "Read error" ); \
} \
static DEVICE_ATTR(value, S_IWUGO | S_IRUGO | S_IWUSR, \
        show_bool_##value, NULL);

show_bool(touchpad, ACER_CAP_TOUCHPAD_READ);

/*
 * Read interface sysfs macro
 */
static ssize_t show_interface(struct device *dev, struct device_attribute *attr,
        char *buf)
{
        switch (interface->type) {
        case ACER_AMW0:
                return sprintf(buf, "AMW0\n");
        case ACER_AMW0_V2:
                return sprintf(buf, "AMW0 v2\n");
        case ACER_WMID:
                return sprintf(buf, "WMID\n");
        default:
                return sprintf(buf, "Error!\n");
        }
}

static DEVICE_ATTR(interface, S_IWUGO | S_IRUGO | S_IWUSR, show_interface, NULL);

static ssize_t show_devices(struct device *dev, struct device_attribute *attr,
        char *buf)
{
        struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
        union acpi_object *obj;
        acpi_status status;
        u32 tmp;

        status = wmi_acer_query_block(WMID_GUID2, 1, &out);
        if (ACPI_FAILURE(status))
                return sprintf(buf, "Error\n");

        obj = (union acpi_object *) out.pointer;
        if (obj && obj->type == ACPI_TYPE_BUFFER && obj->buffer.length == sizeof(u32)) {
                tmp = *((u32 *) obj->buffer.pointer);
        } else {
                return sprintf(buf, "Error\n");
        }
        
        return sprintf(buf, "%u\n", tmp);
}

static DEVICE_ATTR(devices, S_IWUGO | S_IRUGO | S_IWUSR, show_devices, NULL);

/*
 * Platform device
 */
static int __devinit acer_platform_probe(struct platform_device *device)
{
        if (has_cap(ACER_CAP_MAILLED))
                acer_led_init(&device->dev);
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
        if (has_cap(ACER_CAP_BRIGHTNESS))
                acer_backlight_init(&device->dev);
#endif
        return 0;
}

static int acer_platform_remove(struct platform_device *device)
{
        if (has_cap(ACER_CAP_MAILLED))
                acer_led_exit();
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
        if (has_cap(ACER_CAP_BRIGHTNESS))
                acer_backlight_exit();
#endif
        return 0;
}

static int acer_platform_suspend(struct platform_device *device, pm_message_t state)
{
        /*
         * WMID fix for suspend-to-disk - save all current states now so we can
         * restore them on resume
         */
        bool value;
        u8 u8value;
        struct acer_data *data = &interface->data;

        #define save_bool_device(device, cap) \
        if (has_cap(cap)) {\
                get_bool(&value, cap);\
                data->device = value;\
        }

        #define save_u8_device(device, cap) \
        if (has_cap(cap)) {\
                get_u8(&u8value, cap);\
                data->device = u8value;\
        }

        save_bool_device(wireless, ACER_CAP_WIRELESS);
        save_bool_device(bluetooth, ACER_CAP_BLUETOOTH);
        save_bool_device(threeg, ACER_CAP_THREEG);
        save_bool_device(mailled, ACER_CAP_MAILLED);
        save_u8_device(brightness, ACER_CAP_BRIGHTNESS);

        return 0;
}

static int acer_platform_resume(struct platform_device *device)
{
        struct acer_data *data = &interface->data;

        #define restore_bool_device(device, cap) \
        if (has_cap(cap))\
                set_bool(data->device, cap);\

        restore_bool_device(wireless, ACER_CAP_WIRELESS);
        restore_bool_device(bluetooth, ACER_CAP_BLUETOOTH);
        restore_bool_device(threeg, ACER_CAP_THREEG);
        restore_bool_device(mailled, ACER_CAP_MAILLED);

        if (has_cap(ACER_CAP_BRIGHTNESS))
                set_brightness((u8)data->brightness);

        /* Check if this laptop requires the keyboard quirk */
        if (quirks->mmkeys != 0) {
                set_keyboard_quirk();
                printk(ACER_INFO "Setting keyboard quirk to enable multimedia keys\n");
        }

        return 0;
}

static struct platform_driver acer_platform_driver = {
        .driver = {
                .name = "acer_acpi",
                .owner = THIS_MODULE,
        },
        .probe = acer_platform_probe,
        .remove = acer_platform_remove,
        .suspend = acer_platform_suspend,
        .resume = acer_platform_resume,
};

static struct platform_device *acer_platform_device;

static int remove_sysfs(struct platform_device *device)
{
        #define remove_device_file(value, cap) \
        if (has_cap(cap)) \
                device_remove_file(&device->dev, &dev_attr_##value);

        if (wmi_acer_has_guid(WMID_GUID2)) {
                device_remove_file(&device->dev, &dev_attr_devices);
        }

        remove_device_file(wireless, ACER_CAP_WIRELESS);
        remove_device_file(bluetooth, ACER_CAP_BLUETOOTH);
        remove_device_file(threeg, ACER_CAP_THREEG);
        remove_device_file(interface, ACER_CAP_ANY);
        remove_device_file(fan_temperature_override, ACER_CAP_TEMPERATURE_OVERRIDE);
        remove_device_file(touchpad, ACER_CAP_TOUCHPAD_READ);
        return 0;
}

static int create_sysfs(void)
{
        int retval = -ENOMEM;

        #define add_device_file(value, cap) \
        if (has_cap(cap)) {\
                retval = device_create_file(&acer_platform_device->dev, &dev_attr_##value);\
                if (retval)\
                        goto error;\
        }

        if (wmi_acer_has_guid(WMID_GUID2)) {
                retval = device_create_file(&acer_platform_device->dev, &dev_attr_devices);
                if (retval)
                        goto error;
        }

        add_device_file(wireless, ACER_CAP_WIRELESS);
        add_device_file(bluetooth, ACER_CAP_BLUETOOTH);
        add_device_file(threeg, ACER_CAP_THREEG);
        add_device_file(interface, ACER_CAP_ANY);
        add_device_file(fan_temperature_override, ACER_CAP_TEMPERATURE_OVERRIDE);
        add_device_file(touchpad, ACER_CAP_TOUCHPAD_READ);

        return 0;

        error:
                remove_sysfs(acer_platform_device);
        return retval;
}

static int __init acer_acpi_init(void)
{
        printk(ACER_INFO "Acer Laptop ACPI Extras version %s\n",
                        ACER_ACPI_VERSION);

        /* Find if this laptop requires any quirks */
        DEBUG(1, "Finding quirks\n");
        find_quirks();

        /*
         * Detect which WMI interface we're using.
         */
        if (wmi_acer_has_guid(AMW0_GUID1)) {
                interface = &AMW0_interface;

                if (wmi_acer_has_guid(WMID_GUID1)) {
                        DEBUG(0, "Detected Acer AMW0 version 2 interface\n");
                        interface = &AMW0_V2_interface;
                } else {
                        DEBUG(0, "Detected Acer AMW0 version 1 interface\n");
                        if (!quirks->brightness) {
                                quirks->brightness = 1;
                                interface->capability |= ACER_CAP_BRIGHTNESS;
                        }
                }
        } else if (wmi_acer_has_guid(WMID_GUID1)) {
                DEBUG(0, "Detected Acer WMID interface\n");
                interface = &WMID_interface;
        } else {
                printk(ACER_ERR "No or unsupported WMI interface, unable to load.\n");
                return -ENODEV;
        }

        if (wmi_acer_has_guid(WMID_GUID2)) {
                if (ACPI_FAILURE(WMID_set_capabilities())) {
                        printk(ACER_ERR "Unable to detect available devices\n");
                        return -ENODEV;
                }
        }

#ifdef CONFIG_PROC
        /* Create the proc entries */
        acer_proc_dir = proc_mkdir(PROC_ACER, acpi_root_dir);
        if (!acer_proc_dir) {
                printk(ACER_ERR "Unable to create /proc entries, aborting.\n");
                goto error_proc_mkdir;
        }

        acer_proc_dir->owner = THIS_MODULE;
        if (add_proc_entries()) {
                printk(ACER_ERR "Unable to create /proc entries, aborting.\n");
                goto error_proc_add;
        }
#endif

        /*
         * Register the driver
         */
        if (platform_driver_register(&acer_platform_driver)) {
                printk(ACER_ERR "Unable to register platform driver, aborting.\n");
                goto error_platform_register;
        }
        acer_platform_device = platform_device_alloc("acer_acpi", -1);
        platform_device_add(acer_platform_device);

        create_sysfs();

        DEBUG(1, "Driver registered\n");

        /* Override any initial settings with values from the commandline */
        acer_commandline_init();

        return 0;

error_platform_register:
#ifdef CONFIG_PROC
        remove_proc_entries();
error_proc_add:
        if (acer_proc_dir)
                remove_proc_entry(PROC_ACER, acpi_root_dir);
error_proc_mkdir:
#endif
        return -ENODEV;
}

static void __exit acer_acpi_exit(void)
{
        remove_sysfs(acer_platform_device);
        platform_device_del(acer_platform_device);
        platform_driver_unregister(&acer_platform_driver);

#ifdef CONFIG_PROC
        remove_proc_entries();

        if (acer_proc_dir)
                remove_proc_entry(PROC_ACER, acpi_root_dir);
#endif
        printk(ACER_INFO "Acer Laptop ACPI Extras unloaded\n");
        return;
}

module_init(acer_acpi_init);
module_exit(acer_acpi_exit);