msi-wmi.c

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/*
 * MSI WMI hotkeys
 *
 * Copyright (C) 2009 Novell <[email protected]>
 *
 * Most stuff taken over from hp-wmi
 *
 *  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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/acpi.h>
#include <linux/backlight.h>
#include <linux/slab.h>
#include <linux/module.h>

MODULE_AUTHOR("Thomas Renninger <[email protected]>");
MODULE_DESCRIPTION("MSI laptop WMI hotkeys driver");
MODULE_LICENSE("GPL");

MODULE_ALIAS("wmi:551A1F84-FBDD-4125-91DB-3EA8F44F1D45");
MODULE_ALIAS("wmi:B6F3EEF2-3D2F-49DC-9DE3-85BCE18C62F2");

#define DRV_NAME "msi-wmi"

#define MSIWMI_BIOS_GUID "551A1F84-FBDD-4125-91DB-3EA8F44F1D45"
#define MSIWMI_EVENT_GUID "B6F3EEF2-3D2F-49DC-9DE3-85BCE18C62F2"

#define SCANCODE_BASE 0xD0
#define MSI_WMI_BRIGHTNESSUP   SCANCODE_BASE
#define MSI_WMI_BRIGHTNESSDOWN (SCANCODE_BASE + 1)
#define MSI_WMI_VOLUMEUP       (SCANCODE_BASE + 2)
#define MSI_WMI_VOLUMEDOWN     (SCANCODE_BASE + 3)
#define MSI_WMI_MUTE           (SCANCODE_BASE + 4)
static struct key_entry msi_wmi_keymap[] = {
    { KE_KEY, MSI_WMI_BRIGHTNESSUP,   {KEY_BRIGHTNESSUP} },
    { KE_KEY, MSI_WMI_BRIGHTNESSDOWN, {KEY_BRIGHTNESSDOWN} },
    { KE_KEY, MSI_WMI_VOLUMEUP,       {KEY_VOLUMEUP} },
    { KE_KEY, MSI_WMI_VOLUMEDOWN,     {KEY_VOLUMEDOWN} },
    { KE_KEY, MSI_WMI_MUTE,           {KEY_MUTE} },
    { KE_END, 0}
};
static ktime_t last_pressed[ARRAY_SIZE(msi_wmi_keymap) - 1];

static struct backlight_device *backlight;

static int backlight_map[] = { 0x00, 0x33, 0x66, 0x99, 0xCC, 0xFF };

static struct input_dev *msi_wmi_input_dev;

static int msi_wmi_query_block(int instance, int *ret)
{
    acpi_status status;
    union acpi_object *obj;

    struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };

    status = wmi_query_block(MSIWMI_BIOS_GUID, instance, &output);

    obj = output.pointer;

    if (!obj || obj->type != ACPI_TYPE_INTEGER) {
        if (obj) {
            pr_err("query block returned object "
                   "type: %d - buffer length:%d\n", obj->type,
                   obj->type == ACPI_TYPE_BUFFER ?
                   obj->buffer.length : 0);
        }
        kfree(obj);
        return -EINVAL;
    }
    *ret = obj->integer.value;
    kfree(obj);
    return 0;
}

static int msi_wmi_set_block(int instance, int value)
{
    acpi_status status;

    struct acpi_buffer input = { sizeof(int), &value };

    pr_debug("Going to set block of instance: %d - value: %d\n",
         instance, value);

    status = wmi_set_block(MSIWMI_BIOS_GUID, instance, &input);

    return ACPI_SUCCESS(status) ? 0 : 1;
}

static int bl_get(struct backlight_device *bd)
{
    int level, err, ret;

    /* Instance 1 is "get backlight", cmp with DSDT */
    err = msi_wmi_query_block(1, &ret);
    if (err) {
        pr_err("Could not query backlight: %d\n", err);
        return -EINVAL;
    }
    pr_debug("Get: Query block returned: %d\n", ret);
    for (level = 0; level < ARRAY_SIZE(backlight_map); level++) {
        if (backlight_map[level] == ret) {
            pr_debug("Current backlight level: 0x%X - index: %d\n",
                 backlight_map[level], level);
            break;
        }
    }
    if (level == ARRAY_SIZE(backlight_map)) {
        pr_err("get: Invalid brightness value: 0x%X\n", ret);
        return -EINVAL;
    }
    return level;
}

static int bl_set_status(struct backlight_device *bd)
{
    int bright = bd->props.brightness;
    if (bright >= ARRAY_SIZE(backlight_map) || bright < 0)
        return -EINVAL;

    /* Instance 0 is "set backlight" */
    return msi_wmi_set_block(0, backlight_map[bright]);
}

static const struct backlight_ops msi_backlight_ops = {
    .get_brightness = bl_get,
    .update_status  = bl_set_status,
};

static void msi_wmi_notify(u32 value, void *context)
{
    struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
    static struct key_entry *key;
    union acpi_object *obj;
    ktime_t cur;
    acpi_status status;

    status = wmi_get_event_data(value, &response);
    if (status != AE_OK) {
        pr_info("bad event status 0x%x\n", status);
        return;
    }

    obj = (union acpi_object *)response.pointer;

    if (obj && obj->type == ACPI_TYPE_INTEGER) {
        int eventcode = obj->integer.value;
        pr_debug("Eventcode: 0x%x\n", eventcode);
        key = sparse_keymap_entry_from_scancode(msi_wmi_input_dev,
                eventcode);
        if (key) {
            ktime_t diff;
            cur = ktime_get_real();
            diff = ktime_sub(cur, last_pressed[key->code -
                    SCANCODE_BASE]);
            /* Ignore event if the same event happened in a 50 ms
               timeframe -> Key press may result in 10-20 GPEs */
            if (ktime_to_us(diff) < 1000 * 50) {
                pr_debug("Suppressed key event 0x%X - "
                     "Last press was %lld us ago\n",
                     key->code, ktime_to_us(diff));
                return;
            }
            last_pressed[key->code - SCANCODE_BASE] = cur;

            if (key->type == KE_KEY &&
            /* Brightness is served via acpi video driver */
            (!acpi_video_backlight_support() ||
            (key->code != MSI_WMI_BRIGHTNESSUP &&
            key->code != MSI_WMI_BRIGHTNESSDOWN))) {
                pr_debug("Send key: 0x%X - "
                     "Input layer keycode: %d\n",
                     key->code, key->keycode);
                sparse_keymap_report_entry(msi_wmi_input_dev,
                        key, 1, true);
            }
        } else
            pr_info("Unknown key pressed - %x\n", eventcode);
    } else
        pr_info("Unknown event received\n");
    kfree(response.pointer);
}

static int __init msi_wmi_input_setup(void)
{
    int err;

    msi_wmi_input_dev = input_allocate_device();
    if (!msi_wmi_input_dev)
        return -ENOMEM;

    msi_wmi_input_dev->name = "MSI WMI hotkeys";
    msi_wmi_input_dev->phys = "wmi/input0";
    msi_wmi_input_dev->id.bustype = BUS_HOST;

    err = sparse_keymap_setup(msi_wmi_input_dev, msi_wmi_keymap, NULL);
    if (err)
        goto err_free_dev;

    err = input_register_device(msi_wmi_input_dev);

    if (err)
        goto err_free_keymap;

    memset(last_pressed, 0, sizeof(last_pressed));

    return 0;

err_free_keymap:
    sparse_keymap_free(msi_wmi_input_dev);
err_free_dev:
    input_free_device(msi_wmi_input_dev);
    return err;
}

static int __init msi_wmi_init(void)
{
    int err;

    if (!wmi_has_guid(MSIWMI_EVENT_GUID)) {
        pr_err("This machine doesn't have MSI-hotkeys through WMI\n");
        return -ENODEV;
    }
    err = wmi_install_notify_handler(MSIWMI_EVENT_GUID,
            msi_wmi_notify, NULL);
    if (ACPI_FAILURE(err))
        return -EINVAL;

    err = msi_wmi_input_setup();
    if (err)
        goto err_uninstall_notifier;

    if (!acpi_video_backlight_support()) {
        struct backlight_properties props;
        memset(&props, 0, sizeof(struct backlight_properties));
        props.type = BACKLIGHT_PLATFORM;
        props.max_brightness = ARRAY_SIZE(backlight_map) - 1;
        backlight = backlight_device_register(DRV_NAME, NULL, NULL,
                              &msi_backlight_ops,
                              &props);
        if (IS_ERR(backlight)) {
            err = PTR_ERR(backlight);
            goto err_free_input;
        }

        err = bl_get(NULL);
        if (err < 0)
            goto err_free_backlight;

        backlight->props.brightness = err;
    }
    pr_debug("Event handler installed\n");

    return 0;

err_free_backlight:
    backlight_device_unregister(backlight);
err_free_input:
    sparse_keymap_free(msi_wmi_input_dev);
    input_unregister_device(msi_wmi_input_dev);
err_uninstall_notifier:
    wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
    return err;
}

static void __exit msi_wmi_exit(void)
{
    if (wmi_has_guid(MSIWMI_EVENT_GUID)) {
        wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
        sparse_keymap_free(msi_wmi_input_dev);
        input_unregister_device(msi_wmi_input_dev);
        backlight_device_unregister(backlight);
    }
}

module_init(msi_wmi_init);
module_exit(msi_wmi_exit);