/*
 *  toshiba_acpi.c - Toshiba Laptop ACPI Extras
 *
 *
 *  Copyright (C) 2002-2004 John Belmonte
 *  Copyright (C) 2008 Philip Langdale
 *  Copyright (C) 2010 Pierre Ducroquet
 *
 *  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://memebeam.org/toys/ToshibaAcpiDriver.
 *
 *  Credits:
 *      Jonathan A. Buzzard - Toshiba HCI info, and critical tips on reverse
 *              engineering the Windows drivers
 *      Yasushi Nagato - changes for linux kernel 2.4 -> 2.5
 *      Rob Miller - TV out and hotkeys help
 *
 *
 *  TODO
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define TOSHIBA_ACPI_VERSION    "0.19"
#define PROC_INTERFACE_VERSION  1

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/backlight.h>
#include <linux/rfkill.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/i8042.h>

#include <asm/uaccess.h>

#include <acpi/acpi_drivers.h>

MODULE_AUTHOR("John Belmonte");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Extras Driver");
MODULE_LICENSE("GPL");

#define TOSHIBA_WMI_EVENT_GUID "59142400-C6A3-40FA-BADB-8A2652834100"

/* Scan code for Fn key on TOS1900 models */
#define TOS1900_FN_SCAN         0x6e

/* Toshiba ACPI method paths */
#define METHOD_VIDEO_OUT        "\\_SB_.VALX.DSSX"

/* Toshiba HCI interface definitions
 *
 * HCI is Toshiba's "Hardware Control Interface" which is supposed to
 * be uniform across all their models.  Ideally we would just call
 * dedicated ACPI methods instead of using this primitive interface.
 * However the ACPI methods seem to be incomplete in some areas (for
 * example they allow setting, but not reading, the LCD brightness value),
 * so this is still useful.
 */

#define HCI_WORDS                       6

/* operations */
#define HCI_SET                         0xff00
#define HCI_GET                         0xfe00

/* return codes */
#define HCI_SUCCESS                     0x0000
#define HCI_FAILURE                     0x1000
#define HCI_NOT_SUPPORTED               0x8000
#define HCI_EMPTY                       0x8c00

/* registers */
#define HCI_FAN                         0x0004
#define HCI_TR_BACKLIGHT                0x0005
#define HCI_SYSTEM_EVENT                0x0016
#define HCI_VIDEO_OUT                   0x001c
#define HCI_HOTKEY_EVENT                0x001e
#define HCI_LCD_BRIGHTNESS              0x002a
#define HCI_WIRELESS                    0x0056

/* field definitions */
#define HCI_HOTKEY_DISABLE              0x0b
#define HCI_HOTKEY_ENABLE               0x09
#define HCI_LCD_BRIGHTNESS_BITS         3
#define HCI_LCD_BRIGHTNESS_SHIFT        (16-HCI_LCD_BRIGHTNESS_BITS)
#define HCI_LCD_BRIGHTNESS_LEVELS       (1 << HCI_LCD_BRIGHTNESS_BITS)
#define HCI_VIDEO_OUT_LCD               0x1
#define HCI_VIDEO_OUT_CRT               0x2
#define HCI_VIDEO_OUT_TV                0x4
#define HCI_WIRELESS_KILL_SWITCH        0x01
#define HCI_WIRELESS_BT_PRESENT         0x0f
#define HCI_WIRELESS_BT_ATTACH          0x40
#define HCI_WIRELESS_BT_POWER           0x80

struct toshiba_acpi_dev {
        struct acpi_device *acpi_dev;
        const char *method_hci;
        struct rfkill *bt_rfk;
        struct input_dev *hotkey_dev;
        struct work_struct hotkey_work;
        struct backlight_device *backlight_dev;
        struct led_classdev led_dev;

        int force_fan;
        int last_key_event;
        int key_event_valid;

        unsigned int illumination_supported:1;
        unsigned int video_supported:1;
        unsigned int fan_supported:1;
        unsigned int system_event_supported:1;
        unsigned int ntfy_supported:1;
        unsigned int info_supported:1;
        unsigned int tr_backlight_supported:1;

        struct mutex mutex;
};

static struct toshiba_acpi_dev *toshiba_acpi;

static const struct acpi_device_id toshiba_device_ids[] = {
        {"TOS6200", 0},
        {"TOS6208", 0},
        {"TOS1900", 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, toshiba_device_ids);

static const struct key_entry toshiba_acpi_keymap[] = {
        { KE_KEY, 0x101, { KEY_MUTE } },
        { KE_KEY, 0x102, { KEY_ZOOMOUT } },
        { KE_KEY, 0x103, { KEY_ZOOMIN } },
        { KE_KEY, 0x12c, { KEY_KBDILLUMTOGGLE } },
        { KE_KEY, 0x139, { KEY_ZOOMRESET } },
        { KE_KEY, 0x13b, { KEY_COFFEE } },
        { KE_KEY, 0x13c, { KEY_BATTERY } },
        { KE_KEY, 0x13d, { KEY_SLEEP } },
        { KE_KEY, 0x13e, { KEY_SUSPEND } },
        { KE_KEY, 0x13f, { KEY_SWITCHVIDEOMODE } },
        { KE_KEY, 0x140, { KEY_BRIGHTNESSDOWN } },
        { KE_KEY, 0x141, { KEY_BRIGHTNESSUP } },
        { KE_KEY, 0x142, { KEY_WLAN } },
        { KE_KEY, 0x143, { KEY_TOUCHPAD_TOGGLE } },
        { KE_KEY, 0x17f, { KEY_FN } },
        { KE_KEY, 0xb05, { KEY_PROG2 } },
        { KE_KEY, 0xb06, { KEY_WWW } },
        { KE_KEY, 0xb07, { KEY_MAIL } },
        { KE_KEY, 0xb30, { KEY_STOP } },
        { KE_KEY, 0xb31, { KEY_PREVIOUSSONG } },
        { KE_KEY, 0xb32, { KEY_NEXTSONG } },
        { KE_KEY, 0xb33, { KEY_PLAYPAUSE } },
        { KE_KEY, 0xb5a, { KEY_MEDIA } },
        { KE_IGNORE, 0x1430, { KEY_RESERVED } },
        { KE_END, 0 },
};

/* utility
 */

static __inline__ void _set_bit(u32 * word, u32 mask, int value)
{
        *word = (*word & ~mask) | (mask * value);
}

/* acpi interface wrappers
 */

static int write_acpi_int(const char *methodName, int val)
{
        struct acpi_object_list params;
        union acpi_object in_objs[1];
        acpi_status status;

        params.count = ARRAY_SIZE(in_objs);
        params.pointer = in_objs;
        in_objs[0].type = ACPI_TYPE_INTEGER;
        in_objs[0].integer.value = val;

        status = acpi_evaluate_object(NULL, (char *)methodName, &params, NULL);
        return (status == AE_OK) ? 0 : -EIO;
}

/* Perform a raw HCI call.  Here we don't care about input or output buffer
 * format.
 */
static acpi_status hci_raw(struct toshiba_acpi_dev *dev,
                           const u32 in[HCI_WORDS], u32 out[HCI_WORDS])
{
        struct acpi_object_list params;
        union acpi_object in_objs[HCI_WORDS];
        struct acpi_buffer results;
        union acpi_object out_objs[HCI_WORDS + 1];
        acpi_status status;
        int i;

        params.count = HCI_WORDS;
        params.pointer = in_objs;
        for (i = 0; i < HCI_WORDS; ++i) {
                in_objs[i].type = ACPI_TYPE_INTEGER;
                in_objs[i].integer.value = in[i];
        }

        results.length = sizeof(out_objs);
        results.pointer = out_objs;

        status = acpi_evaluate_object(dev->acpi_dev->handle,
                                      (char *)dev->method_hci, &params,
                                      &results);
        if ((status == AE_OK) && (out_objs->package.count <= HCI_WORDS)) {
                for (i = 0; i < out_objs->package.count; ++i) {
                        out[i] = out_objs->package.elements[i].integer.value;
                }
        }

        return status;
}

/* common hci tasks (get or set one or two value)
 *
 * In addition to the ACPI status, the HCI system returns a result which
 * may be useful (such as "not supported").
 */

static acpi_status hci_write1(struct toshiba_acpi_dev *dev, u32 reg,
                              u32 in1, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_SET, reg, in1, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(dev, in, out);
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_read1(struct toshiba_acpi_dev *dev, u32 reg,
                             u32 *out1, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_GET, reg, 0, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(dev, in, out);
        *out1 = out[2];
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_write2(struct toshiba_acpi_dev *dev, u32 reg,
                              u32 in1, u32 in2, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_SET, reg, in1, in2, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(dev, in, out);
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_read2(struct toshiba_acpi_dev *dev, u32 reg,
                             u32 *out1, u32 *out2, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_GET, reg, *out1, *out2, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(dev, in, out);
        *out1 = out[2];
        *out2 = out[3];
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

/* Illumination support */
static int toshiba_illumination_available(struct toshiba_acpi_dev *dev)
{
        u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status;

        in[0] = 0xf100;
        status = hci_raw(dev, in, out);
        if (ACPI_FAILURE(status)) {
                pr_info("Illumination device not available\n");
                return 0;
        }
        in[0] = 0xf400;
        status = hci_raw(dev, in, out);
        return 1;
}

static void toshiba_illumination_set(struct led_classdev *cdev,
                                     enum led_brightness brightness)
{
        struct toshiba_acpi_dev *dev = container_of(cdev,
                        struct toshiba_acpi_dev, led_dev);
        u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status;

        /* First request : initialize communication. */
        in[0] = 0xf100;
        status = hci_raw(dev, in, out);
        if (ACPI_FAILURE(status)) {
                pr_info("Illumination device not available\n");
                return;
        }

        if (brightness) {
                /* Switch the illumination on */
                in[0] = 0xf400;
                in[1] = 0x14e;
                in[2] = 1;
                status = hci_raw(dev, in, out);
                if (ACPI_FAILURE(status)) {
                        pr_info("ACPI call for illumination failed\n");
                        return;
                }
        } else {
                /* Switch the illumination off */
                in[0] = 0xf400;
                in[1] = 0x14e;
                in[2] = 0;
                status = hci_raw(dev, in, out);
                if (ACPI_FAILURE(status)) {
                        pr_info("ACPI call for illumination failed.\n");
                        return;
                }
        }

        /* Last request : close communication. */
        in[0] = 0xf200;
        in[1] = 0;
        in[2] = 0;
        hci_raw(dev, in, out);
}

static enum led_brightness toshiba_illumination_get(struct led_classdev *cdev)
{
        struct toshiba_acpi_dev *dev = container_of(cdev,
                        struct toshiba_acpi_dev, led_dev);
        u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status;
        enum led_brightness result;

        /* First request : initialize communication. */
        in[0] = 0xf100;
        status = hci_raw(dev, in, out);
        if (ACPI_FAILURE(status)) {
                pr_info("Illumination device not available\n");
                return LED_OFF;
        }

        /* Check the illumination */
        in[0] = 0xf300;
        in[1] = 0x14e;
        status = hci_raw(dev, in, out);
        if (ACPI_FAILURE(status)) {
                pr_info("ACPI call for illumination failed.\n");
                return LED_OFF;
        }

        result = out[2] ? LED_FULL : LED_OFF;

        /* Last request : close communication. */
        in[0] = 0xf200;
        in[1] = 0;
        in[2] = 0;
        hci_raw(dev, in, out);

        return result;
}

/* Bluetooth rfkill handlers */

static u32 hci_get_bt_present(struct toshiba_acpi_dev *dev, bool *present)
{
        u32 hci_result;
        u32 value, value2;

        value = 0;
        value2 = 0;
        hci_read2(dev, HCI_WIRELESS, &value, &value2, &hci_result);
        if (hci_result == HCI_SUCCESS)
                *present = (value & HCI_WIRELESS_BT_PRESENT) ? true : false;

        return hci_result;
}

static u32 hci_get_radio_state(struct toshiba_acpi_dev *dev, bool *radio_state)
{
        u32 hci_result;
        u32 value, value2;

        value = 0;
        value2 = 0x0001;
        hci_read2(dev, HCI_WIRELESS, &value, &value2, &hci_result);

        *radio_state = value & HCI_WIRELESS_KILL_SWITCH;
        return hci_result;
}

static int bt_rfkill_set_block(void *data, bool blocked)
{
        struct toshiba_acpi_dev *dev = data;
        u32 result1, result2;
        u32 value;
        int err;
        bool radio_state;

        value = (blocked == false);

        mutex_lock(&dev->mutex);
        if (hci_get_radio_state(dev, &radio_state) != HCI_SUCCESS) {
                err = -EIO;
                goto out;
        }

        if (!radio_state) {
                err = 0;
                goto out;
        }

        hci_write2(dev, HCI_WIRELESS, value, HCI_WIRELESS_BT_POWER, &result1);
        hci_write2(dev, HCI_WIRELESS, value, HCI_WIRELESS_BT_ATTACH, &result2);

        if (result1 != HCI_SUCCESS || result2 != HCI_SUCCESS)
                err = -EIO;
        else
                err = 0;
 out:
        mutex_unlock(&dev->mutex);
        return err;
}

static void bt_rfkill_poll(struct rfkill *rfkill, void *data)
{
        bool new_rfk_state;
        bool value;
        u32 hci_result;
        struct toshiba_acpi_dev *dev = data;

        mutex_lock(&dev->mutex);

        hci_result = hci_get_radio_state(dev, &value);
        if (hci_result != HCI_SUCCESS) {
                /* Can't do anything useful */
                mutex_unlock(&dev->mutex);
                return;
        }

        new_rfk_state = value;

        mutex_unlock(&dev->mutex);

        if (rfkill_set_hw_state(rfkill, !new_rfk_state))
                bt_rfkill_set_block(data, true);
}

static const struct rfkill_ops toshiba_rfk_ops = {
        .set_block = bt_rfkill_set_block,
        .poll = bt_rfkill_poll,
};

static int get_tr_backlight_status(struct toshiba_acpi_dev *dev, bool *enabled)
{
        u32 hci_result;
        u32 status;

        hci_read1(dev, HCI_TR_BACKLIGHT, &status, &hci_result);
        *enabled = !status;
        return hci_result == HCI_SUCCESS ? 0 : -EIO;
}

static int set_tr_backlight_status(struct toshiba_acpi_dev *dev, bool enable)
{
        u32 hci_result;
        u32 value = !enable;

        hci_write1(dev, HCI_TR_BACKLIGHT, value, &hci_result);
        return hci_result == HCI_SUCCESS ? 0 : -EIO;
}

static struct proc_dir_entry *toshiba_proc_dir /*= 0*/ ;

static int __get_lcd_brightness(struct toshiba_acpi_dev *dev)
{
        u32 hci_result;
        u32 value;
        int brightness = 0;

        if (dev->tr_backlight_supported) {
                bool enabled;
                int ret = get_tr_backlight_status(dev, &enabled);
                if (ret)
                        return ret;
                if (enabled)
                        return 0;
                brightness++;
        }

        hci_read1(dev, HCI_LCD_BRIGHTNESS, &value, &hci_result);
        if (hci_result == HCI_SUCCESS)
                return brightness + (value >> HCI_LCD_BRIGHTNESS_SHIFT);

        return -EIO;
}

static int get_lcd_brightness(struct backlight_device *bd)
{
        struct toshiba_acpi_dev *dev = bl_get_data(bd);
        return __get_lcd_brightness(dev);
}

static int lcd_proc_show(struct seq_file *m, void *v)
{
        struct toshiba_acpi_dev *dev = m->private;
        int value;
        int levels;

        if (!dev->backlight_dev)
                return -ENODEV;

        levels = dev->backlight_dev->props.max_brightness + 1;
        value = get_lcd_brightness(dev->backlight_dev);
        if (value >= 0) {
                seq_printf(m, "brightness:              %d\n", value);
                seq_printf(m, "brightness_levels:       %d\n", levels);
                return 0;
        }

        pr_err("Error reading LCD brightness\n");
        return -EIO;
}

static int lcd_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, lcd_proc_show, PDE(inode)->data);
}

static int set_lcd_brightness(struct toshiba_acpi_dev *dev, int value)
{
        u32 hci_result;

        if (dev->tr_backlight_supported) {
                bool enable = !value;
                int ret = set_tr_backlight_status(dev, enable);
                if (ret)
                        return ret;
                if (value)
                        value--;
        }

        value = value << HCI_LCD_BRIGHTNESS_SHIFT;
        hci_write1(dev, HCI_LCD_BRIGHTNESS, value, &hci_result);
        return hci_result == HCI_SUCCESS ? 0 : -EIO;
}

static int set_lcd_status(struct backlight_device *bd)
{
        struct toshiba_acpi_dev *dev = bl_get_data(bd);
        return set_lcd_brightness(dev, bd->props.brightness);
}

static ssize_t lcd_proc_write(struct file *file, const char __user *buf,
                              size_t count, loff_t *pos)
{
        struct toshiba_acpi_dev *dev = PDE(file->f_path.dentry->d_inode)->data;
        char cmd[42];
        size_t len;
        int value;
        int ret;
        int levels = dev->backlight_dev->props.max_brightness + 1;

        len = min(count, sizeof(cmd) - 1);
        if (copy_from_user(cmd, buf, len))
                return -EFAULT;
        cmd[len] = '\0';

        if (sscanf(cmd, " brightness : %i", &value) == 1 &&
            value >= 0 && value < levels) {
                ret = set_lcd_brightness(dev, value);
                if (ret == 0)
                        ret = count;
        } else {
                ret = -EINVAL;
        }
        return ret;
}

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 get_video_status(struct toshiba_acpi_dev *dev, u32 *status)
{
        u32 hci_result;

        hci_read1(dev, HCI_VIDEO_OUT, status, &hci_result);
        return hci_result == HCI_SUCCESS ? 0 : -EIO;
}

static int video_proc_show(struct seq_file *m, void *v)
{
        struct toshiba_acpi_dev *dev = m->private;
        u32 value;
        int ret;

        ret = get_video_status(dev, &value);
        if (!ret) {
                int is_lcd = (value & HCI_VIDEO_OUT_LCD) ? 1 : 0;
                int is_crt = (value & HCI_VIDEO_OUT_CRT) ? 1 : 0;
                int is_tv = (value & HCI_VIDEO_OUT_TV) ? 1 : 0;
                seq_printf(m, "lcd_out:                 %d\n", is_lcd);
                seq_printf(m, "crt_out:                 %d\n", is_crt);
                seq_printf(m, "tv_out:                  %d\n", is_tv);
        }

        return ret;
}

static int video_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, video_proc_show, PDE(inode)->data);
}

static ssize_t video_proc_write(struct file *file, const char __user *buf,
                                size_t count, loff_t *pos)
{
        struct toshiba_acpi_dev *dev = PDE(file->f_path.dentry->d_inode)->data;
        char *cmd, *buffer;
        int ret;
        int value;
        int remain = count;
        int lcd_out = -1;
        int crt_out = -1;
        int tv_out = -1;
        u32 video_out;

        cmd = kmalloc(count + 1, GFP_KERNEL);
        if (!cmd)
                return -ENOMEM;
        if (copy_from_user(cmd, buf, count)) {
                kfree(cmd);
                return -EFAULT;
        }
        cmd[count] = '\0';

        buffer = cmd;

        /* scan expression.  Multiple expressions may be delimited with ;
         *
         *  NOTE: to keep scanning simple, invalid fields are ignored
         */
        while (remain) {
                if (sscanf(buffer, " lcd_out : %i", &value) == 1)
                        lcd_out = value & 1;
                else if (sscanf(buffer, " crt_out : %i", &value) == 1)
                        crt_out = value & 1;
                else if (sscanf(buffer, " tv_out : %i", &value) == 1)
                        tv_out = value & 1;
                /* advance to one character past the next ; */
                do {
                        ++buffer;
                        --remain;
                }
                while (remain && *(buffer - 1) != ';');
        }

        kfree(cmd);

        ret = get_video_status(dev, &video_out);
        if (!ret) {
                unsigned int new_video_out = video_out;
                if (lcd_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_LCD, lcd_out);
                if (crt_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_CRT, crt_out);
                if (tv_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_TV, tv_out);
                /* To avoid unnecessary video disruption, only write the new
                 * video setting if something changed. */
                if (new_video_out != video_out)
                        ret = write_acpi_int(METHOD_VIDEO_OUT, new_video_out);
        }

        return ret ? ret : count;
}

static const struct file_operations video_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = video_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = video_proc_write,
};

static int get_fan_status(struct toshiba_acpi_dev *dev, u32 *status)
{
        u32 hci_result;

        hci_read1(dev, HCI_FAN, status, &hci_result);
        return hci_result == HCI_SUCCESS ? 0 : -EIO;
}

static int fan_proc_show(struct seq_file *m, void *v)
{
        struct toshiba_acpi_dev *dev = m->private;
        int ret;
        u32 value;

        ret = get_fan_status(dev, &value);
        if (!ret) {
                seq_printf(m, "running:                 %d\n", (value > 0));
                seq_printf(m, "force_on:                %d\n", dev->force_fan);
        }

        return ret;
}

static int fan_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, fan_proc_show, PDE(inode)->data);
}

static ssize_t fan_proc_write(struct file *file, const char __user *buf,
                              size_t count, loff_t *pos)
{
        struct toshiba_acpi_dev *dev = PDE(file->f_path.dentry->d_inode)->data;
        char cmd[42];
        size_t len;
        int value;
        u32 hci_result;

        len = min(count, sizeof(cmd) - 1);
        if (copy_from_user(cmd, buf, len))
                return -EFAULT;
        cmd[len] = '\0';

        if (sscanf(cmd, " force_on : %i", &value) == 1 &&
            value >= 0 && value <= 1) {
                hci_write1(dev, HCI_FAN, value, &hci_result);
                if (hci_result != HCI_SUCCESS)
                        return -EIO;
                else
                        dev->force_fan = value;
        } else {
                return -EINVAL;
        }

        return count;
}

static const struct file_operations fan_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = fan_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = fan_proc_write,
};

static int keys_proc_show(struct seq_file *m, void *v)
{
        struct toshiba_acpi_dev *dev = m->private;
        u32 hci_result;
        u32 value;

        if (!dev->key_event_valid && dev->system_event_supported) {
                hci_read1(dev, HCI_SYSTEM_EVENT, &value, &hci_result);
                if (hci_result == HCI_SUCCESS) {
                        dev->key_event_valid = 1;
                        dev->last_key_event = value;
                } else if (hci_result == HCI_EMPTY) {
                        /* better luck next time */
                } else if (hci_result == HCI_NOT_SUPPORTED) {
                        /* This is a workaround for an unresolved issue on
                         * some machines where system events sporadically
                         * become disabled. */
                        hci_write1(dev, HCI_SYSTEM_EVENT, 1, &hci_result);
                        pr_notice("Re-enabled hotkeys\n");
                } else {
                        pr_err("Error reading hotkey status\n");
                        return -EIO;
                }
        }

        seq_printf(m, "hotkey_ready:            %d\n", dev->key_event_valid);
        seq_printf(m, "hotkey:                  0x%04x\n", dev->last_key_event);
        return 0;
}

static int keys_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, keys_proc_show, PDE(inode)->data);
}

static ssize_t keys_proc_write(struct file *file, const char __user *buf,
                               size_t count, loff_t *pos)
{
        struct toshiba_acpi_dev *dev = PDE(file->f_path.dentry->d_inode)->data;
        char cmd[42];
        size_t len;
        int value;

        len = min(count, sizeof(cmd) - 1);
        if (copy_from_user(cmd, buf, len))
                return -EFAULT;
        cmd[len] = '\0';

        if (sscanf(cmd, " hotkey_ready : %i", &value) == 1 && value == 0) {
                dev->key_event_valid = 0;
        } else {
                return -EINVAL;
        }

        return count;
}

static const struct file_operations keys_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = keys_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = keys_proc_write,
};

static int version_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "driver:                  %s\n", TOSHIBA_ACPI_VERSION);
        seq_printf(m, "proc_interface:          %d\n", PROC_INTERFACE_VERSION);
        return 0;
}

static int version_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, version_proc_show, PDE(inode)->data);
}

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

/* proc and module init
 */

#define PROC_TOSHIBA            "toshiba"

static void create_toshiba_proc_entries(struct toshiba_acpi_dev *dev)
{
        if (dev->backlight_dev)
                proc_create_data("lcd", S_IRUGO | S_IWUSR, toshiba_proc_dir,
                                 &lcd_proc_fops, dev);
        if (dev->video_supported)
                proc_create_data("video", S_IRUGO | S_IWUSR, toshiba_proc_dir,
                                 &video_proc_fops, dev);
        if (dev->fan_supported)
                proc_create_data("fan", S_IRUGO | S_IWUSR, toshiba_proc_dir,
                                 &fan_proc_fops, dev);
        if (dev->hotkey_dev)
                proc_create_data("keys", S_IRUGO | S_IWUSR, toshiba_proc_dir,
                                 &keys_proc_fops, dev);
        proc_create_data("version", S_IRUGO, toshiba_proc_dir,
                         &version_proc_fops, dev);
}

static void remove_toshiba_proc_entries(struct toshiba_acpi_dev *dev)
{
        if (dev->backlight_dev)
                remove_proc_entry("lcd", toshiba_proc_dir);
        if (dev->video_supported)
                remove_proc_entry("video", toshiba_proc_dir);
        if (dev->fan_supported)
                remove_proc_entry("fan", toshiba_proc_dir);
        if (dev->hotkey_dev)
                remove_proc_entry("keys", toshiba_proc_dir);
        remove_proc_entry("version", toshiba_proc_dir);
}

static const struct backlight_ops toshiba_backlight_data = {
        .options = BL_CORE_SUSPENDRESUME,
        .get_brightness = get_lcd_brightness,
        .update_status  = set_lcd_status,
};

static bool toshiba_acpi_i8042_filter(unsigned char data, unsigned char str,
                                      struct serio *port)
{
        if (str & 0x20)
                return false;

        if (unlikely(data == 0xe0))
                return false;

        if ((data & 0x7f) == TOS1900_FN_SCAN) {
                schedule_work(&toshiba_acpi->hotkey_work);
                return true;
        }

        return false;
}

static void toshiba_acpi_hotkey_work(struct work_struct *work)
{
        acpi_handle ec_handle = ec_get_handle();
        acpi_status status;

        if (!ec_handle)
                return;

        status = acpi_evaluate_object(ec_handle, "NTFY", NULL, NULL);
        if (ACPI_FAILURE(status))
                pr_err("ACPI NTFY method execution failed\n");
}

/*
 * Returns hotkey scancode, or < 0 on failure.
 */
static int toshiba_acpi_query_hotkey(struct toshiba_acpi_dev *dev)
{
        struct acpi_buffer buf;
        union acpi_object out_obj;
        acpi_status status;

        buf.pointer = &out_obj;
        buf.length = sizeof(out_obj);

        status = acpi_evaluate_object(dev->acpi_dev->handle, "INFO",
                                      NULL, &buf);
        if (ACPI_FAILURE(status) || out_obj.type != ACPI_TYPE_INTEGER) {
                pr_err("ACPI INFO method execution failed\n");
                return -EIO;
        }

        return out_obj.integer.value;
}

static void toshiba_acpi_report_hotkey(struct toshiba_acpi_dev *dev,
                                       int scancode)
{
        if (scancode == 0x100)
                return;

        /* act on key press; ignore key release */
        if (scancode & 0x80)
                return;

        if (!sparse_keymap_report_event(dev->hotkey_dev, scancode, 1, true))
                pr_info("Unknown key %x\n", scancode);
}

static int toshiba_acpi_setup_keyboard(struct toshiba_acpi_dev *dev)
{
        acpi_status status;
        acpi_handle ec_handle, handle;
        int error;
        u32 hci_result;

        dev->hotkey_dev = input_allocate_device();
        if (!dev->hotkey_dev) {
                pr_info("Unable to register input device\n");
                return -ENOMEM;
        }

        dev->hotkey_dev->name = "Toshiba input device";
        dev->hotkey_dev->phys = "toshiba_acpi/input0";
        dev->hotkey_dev->id.bustype = BUS_HOST;

        error = sparse_keymap_setup(dev->hotkey_dev, toshiba_acpi_keymap, NULL);
        if (error)
                goto err_free_dev;

        /*
         * For some machines the SCI responsible for providing hotkey
         * notification doesn't fire. We can trigger the notification
         * whenever the Fn key is pressed using the NTFY method, if
         * supported, so if it's present set up an i8042 key filter
         * for this purpose.
         */
        status = AE_ERROR;
        ec_handle = ec_get_handle();
        if (ec_handle)
                status = acpi_get_handle(ec_handle, "NTFY", &handle);

        if (ACPI_SUCCESS(status)) {
                INIT_WORK(&dev->hotkey_work, toshiba_acpi_hotkey_work);

                error = i8042_install_filter(toshiba_acpi_i8042_filter);
                if (error) {
                        pr_err("Error installing key filter\n");
                        goto err_free_keymap;
                }

                dev->ntfy_supported = 1;
        }

        /*
         * Determine hotkey query interface. Prefer using the INFO
         * method when it is available.
         */
        status = acpi_get_handle(dev->acpi_dev->handle, "INFO", &handle);
        if (ACPI_SUCCESS(status)) {
                dev->info_supported = 1;
        } else {
                hci_write1(dev, HCI_SYSTEM_EVENT, 1, &hci_result);
                if (hci_result == HCI_SUCCESS)
                        dev->system_event_supported = 1;
        }

        if (!dev->info_supported && !dev->system_event_supported) {
                pr_warn("No hotkey query interface found\n");
                goto err_remove_filter;
        }

        status = acpi_evaluate_object(dev->acpi_dev->handle, "ENAB", NULL, NULL);
        if (ACPI_FAILURE(status)) {
                pr_info("Unable to enable hotkeys\n");
                error = -ENODEV;
                goto err_remove_filter;
        }

        error = input_register_device(dev->hotkey_dev);
        if (error) {
                pr_info("Unable to register input device\n");
                goto err_remove_filter;
        }

        hci_write1(dev, HCI_HOTKEY_EVENT, HCI_HOTKEY_ENABLE, &hci_result);
        return 0;

 err_remove_filter:
        if (dev->ntfy_supported)
                i8042_remove_filter(toshiba_acpi_i8042_filter);
 err_free_keymap:
        sparse_keymap_free(dev->hotkey_dev);
 err_free_dev:
        input_free_device(dev->hotkey_dev);
        dev->hotkey_dev = NULL;
        return error;
}

static int toshiba_acpi_setup_backlight(struct toshiba_acpi_dev *dev)
{
        struct backlight_properties props;
        int brightness;
        int ret;
        bool enabled;

        /*
         * Some machines don't support the backlight methods at all, and
         * others support it read-only. Either of these is pretty useless,
         * so only register the backlight device if the backlight method
         * supports both reads and writes.
         */
        brightness = __get_lcd_brightness(dev);
        if (brightness < 0)
                return 0;
        ret = set_lcd_brightness(dev, brightness);
        if (ret) {
                pr_debug("Backlight method is read-only, disabling backlight support\n");
                return 0;
        }

        /* Determine whether or not BIOS supports transflective backlight */
        ret = get_tr_backlight_status(dev, &enabled);
        dev->tr_backlight_supported = !ret;

        memset(&props, 0, sizeof(props));
        props.type = BACKLIGHT_PLATFORM;
        props.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1;

        /* adding an extra level and having 0 change to transflective mode */
        if (dev->tr_backlight_supported)
                props.max_brightness++;

        dev->backlight_dev = backlight_device_register("toshiba",
                                                       &dev->acpi_dev->dev,
                                                       dev,
                                                       &toshiba_backlight_data,
                                                       &props);
        if (IS_ERR(dev->backlight_dev)) {
                ret = PTR_ERR(dev->backlight_dev);
                pr_err("Could not register toshiba backlight device\n");
                dev->backlight_dev = NULL;
                return ret;
        }

        dev->backlight_dev->props.brightness = brightness;
        return 0;
}

static int toshiba_acpi_remove(struct acpi_device *acpi_dev, int type)
{
        struct toshiba_acpi_dev *dev = acpi_driver_data(acpi_dev);

        remove_toshiba_proc_entries(dev);

        if (dev->ntfy_supported) {
                i8042_remove_filter(toshiba_acpi_i8042_filter);
                cancel_work_sync(&dev->hotkey_work);
        }

        if (dev->hotkey_dev) {
                input_unregister_device(dev->hotkey_dev);
                sparse_keymap_free(dev->hotkey_dev);
        }

        if (dev->bt_rfk) {
                rfkill_unregister(dev->bt_rfk);
                rfkill_destroy(dev->bt_rfk);
        }

        if (dev->backlight_dev)
                backlight_device_unregister(dev->backlight_dev);

        if (dev->illumination_supported)
                led_classdev_unregister(&dev->led_dev);

        if (toshiba_acpi)
                toshiba_acpi = NULL;

        kfree(dev);

        return 0;
}

static const char *find_hci_method(acpi_handle handle)
{
        acpi_status status;
        acpi_handle hci_handle;

        status = acpi_get_handle(handle, "GHCI", &hci_handle);
        if (ACPI_SUCCESS(status))
                return "GHCI";

        status = acpi_get_handle(handle, "SPFC", &hci_handle);
        if (ACPI_SUCCESS(status))
                return "SPFC";

        return NULL;
}

static int toshiba_acpi_add(struct acpi_device *acpi_dev)
{
        struct toshiba_acpi_dev *dev;
        const char *hci_method;
        u32 dummy;
        bool bt_present;
        int ret = 0;

        if (toshiba_acpi)
                return -EBUSY;

        pr_info("Toshiba Laptop ACPI Extras version %s\n",
               TOSHIBA_ACPI_VERSION);

        hci_method = find_hci_method(acpi_dev->handle);
        if (!hci_method) {
                pr_err("HCI interface not found\n");
                return -ENODEV;
        }

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;
        dev->acpi_dev = acpi_dev;
        dev->method_hci = hci_method;
        acpi_dev->driver_data = dev;

        if (toshiba_acpi_setup_keyboard(dev))
                pr_info("Unable to activate hotkeys\n");

        mutex_init(&dev->mutex);

        ret = toshiba_acpi_setup_backlight(dev);
        if (ret)
                goto error;

        /* Register rfkill switch for Bluetooth */
        if (hci_get_bt_present(dev, &bt_present) == HCI_SUCCESS && bt_present) {
                dev->bt_rfk = rfkill_alloc("Toshiba Bluetooth",
                                           &acpi_dev->dev,
                                           RFKILL_TYPE_BLUETOOTH,
                                           &toshiba_rfk_ops,
                                           dev);
                if (!dev->bt_rfk) {
                        pr_err("unable to allocate rfkill device\n");
                        ret = -ENOMEM;
                        goto error;
                }

                ret = rfkill_register(dev->bt_rfk);
                if (ret) {
                        pr_err("unable to register rfkill device\n");
                        rfkill_destroy(dev->bt_rfk);
                        goto error;
                }
        }

        if (toshiba_illumination_available(dev)) {
                dev->led_dev.name = "toshiba::illumination";
                dev->led_dev.max_brightness = 1;
                dev->led_dev.brightness_set = toshiba_illumination_set;
                dev->led_dev.brightness_get = toshiba_illumination_get;
                if (!led_classdev_register(&acpi_dev->dev, &dev->led_dev))
                        dev->illumination_supported = 1;
        }

        /* Determine whether or not BIOS supports fan and video interfaces */

        ret = get_video_status(dev, &dummy);
        dev->video_supported = !ret;

        ret = get_fan_status(dev, &dummy);
        dev->fan_supported = !ret;

        create_toshiba_proc_entries(dev);

        toshiba_acpi = dev;

        return 0;

error:
        toshiba_acpi_remove(acpi_dev, 0);
        return ret;
}

static void toshiba_acpi_notify(struct acpi_device *acpi_dev, u32 event)
{
        struct toshiba_acpi_dev *dev = acpi_driver_data(acpi_dev);
        u32 hci_result, value;
        int retries = 3;
        int scancode;

        if (event != 0x80)
                return;

        if (dev->info_supported) {
                scancode = toshiba_acpi_query_hotkey(dev);
                if (scancode < 0)
                        pr_err("Failed to query hotkey event\n");
                else if (scancode != 0)
                        toshiba_acpi_report_hotkey(dev, scancode);
        } else if (dev->system_event_supported) {
                do {
                        hci_read1(dev, HCI_SYSTEM_EVENT, &value, &hci_result);
                        switch (hci_result) {
                        case HCI_SUCCESS:
                                toshiba_acpi_report_hotkey(dev, (int)value);
                                break;
                        case HCI_NOT_SUPPORTED:
                                /*
                                 * This is a workaround for an unresolved
                                 * issue on some machines where system events
                                 * sporadically become disabled.
                                 */
                                hci_write1(dev, HCI_SYSTEM_EVENT, 1,
                                           &hci_result);
                                pr_notice("Re-enabled hotkeys\n");
                                /* fall through */
                        default:
                                retries--;
                                break;
                        }
                } while (retries && hci_result != HCI_EMPTY);
        }
}

#ifdef CONFIG_PM_SLEEP
static int toshiba_acpi_suspend(struct device *device)
{
        struct toshiba_acpi_dev *dev = acpi_driver_data(to_acpi_device(device));
        u32 result;

        if (dev->hotkey_dev)
                hci_write1(dev, HCI_HOTKEY_EVENT, HCI_HOTKEY_DISABLE, &result);

        return 0;
}

static int toshiba_acpi_resume(struct device *device)
{
        struct toshiba_acpi_dev *dev = acpi_driver_data(to_acpi_device(device));
        u32 result;

        if (dev->hotkey_dev)
                hci_write1(dev, HCI_HOTKEY_EVENT, HCI_HOTKEY_ENABLE, &result);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(toshiba_acpi_pm,
                         toshiba_acpi_suspend, toshiba_acpi_resume);

static struct acpi_driver toshiba_acpi_driver = {
        .name   = "Toshiba ACPI driver",
        .owner  = THIS_MODULE,
        .ids    = toshiba_device_ids,
        .flags  = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
        .ops    = {
                .add            = toshiba_acpi_add,
                .remove         = toshiba_acpi_remove,
                .notify         = toshiba_acpi_notify,
        },
        .drv.pm = &toshiba_acpi_pm,
};

static int __init toshiba_acpi_init(void)
{
        int ret;

        /*
         * Machines with this WMI guid aren't supported due to bugs in
         * their AML. This check relies on wmi initializing before
         * toshiba_acpi to guarantee guids have been identified.
         */
        if (wmi_has_guid(TOSHIBA_WMI_EVENT_GUID))
                return -ENODEV;

        toshiba_proc_dir = proc_mkdir(PROC_TOSHIBA, acpi_root_dir);
        if (!toshiba_proc_dir) {
                pr_err("Unable to create proc dir " PROC_TOSHIBA "\n");
                return -ENODEV;
        }

        ret = acpi_bus_register_driver(&toshiba_acpi_driver);
        if (ret) {
                pr_err("Failed to register ACPI driver: %d\n", ret);
                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
        }

        return ret;
}

static void __exit toshiba_acpi_exit(void)
{
        acpi_bus_unregister_driver(&toshiba_acpi_driver);
        if (toshiba_proc_dir)
                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
}

module_init(toshiba_acpi_init);
module_exit(toshiba_acpi_exit);