// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * MSI WMI hotkeys
 *
 * Copyright (C) 2009 Novell <trenn@suse.de>
 *
 * Most stuff taken over from hp-wmi
 */

#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>
#include <acpi/video.h>

MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
MODULE_DESCRIPTION("MSI laptop WMI hotkeys driver");
MODULE_LICENSE("GPL");

#define DRV_NAME "msi-wmi"

#define MSIWMI_BIOS_GUID "551A1F84-FBDD-4125-91DB-3EA8F44F1D45"
#define MSIWMI_MSI_EVENT_GUID "B6F3EEF2-3D2F-49DC-9DE3-85BCE18C62F2"
#define MSIWMI_WIND_EVENT_GUID "5B3CC38A-40D9-7245-8AE6-1145B751BE3F"

MODULE_ALIAS("wmi:" MSIWMI_BIOS_GUID);
MODULE_ALIAS("wmi:" MSIWMI_MSI_EVENT_GUID);
MODULE_ALIAS("wmi:" MSIWMI_WIND_EVENT_GUID);

enum msi_scancodes {
        /* Generic MSI keys (not present on MSI Wind) */
        MSI_KEY_BRIGHTNESSUP    = 0xD0,
        MSI_KEY_BRIGHTNESSDOWN,
        MSI_KEY_VOLUMEUP,
        MSI_KEY_VOLUMEDOWN,
        MSI_KEY_MUTE,
        /* MSI Wind keys */
        WIND_KEY_TOUCHPAD       = 0x08, /* Fn+F3 touchpad toggle */
        WIND_KEY_BLUETOOTH      = 0x56, /* Fn+F11 Bluetooth toggle */
        WIND_KEY_CAMERA,                /* Fn+F6 webcam toggle */
        WIND_KEY_WLAN           = 0x5f, /* Fn+F11 Wi-Fi toggle */
        WIND_KEY_TURBO,                 /* Fn+F10 turbo mode toggle */
        WIND_KEY_ECO            = 0x69, /* Fn+F10 ECO mode toggle */
};
static struct key_entry msi_wmi_keymap[] = {
        { KE_KEY, MSI_KEY_BRIGHTNESSUP,         {KEY_BRIGHTNESSUP} },
        { KE_KEY, MSI_KEY_BRIGHTNESSDOWN,       {KEY_BRIGHTNESSDOWN} },
        { KE_KEY, MSI_KEY_VOLUMEUP,             {KEY_VOLUMEUP} },
        { KE_KEY, MSI_KEY_VOLUMEDOWN,           {KEY_VOLUMEDOWN} },
        { KE_KEY, MSI_KEY_MUTE,                 {KEY_MUTE} },

        /* These keys work without WMI. Ignore them to avoid double keycodes */
        { KE_IGNORE, WIND_KEY_TOUCHPAD,         {KEY_TOUCHPAD_TOGGLE} },
        { KE_IGNORE, WIND_KEY_BLUETOOTH,        {KEY_BLUETOOTH} },
        { KE_IGNORE, WIND_KEY_CAMERA,           {KEY_CAMERA} },
        { KE_IGNORE, WIND_KEY_WLAN,             {KEY_WLAN} },

        /* These are unknown WMI events found on MSI Wind */
        { KE_IGNORE, 0x00 },
        { KE_IGNORE, 0x62 },
        { KE_IGNORE, 0x63 },

        /* These are MSI Wind keys that should be handled via WMI */
        { KE_KEY, WIND_KEY_TURBO,               {KEY_PROG1} },
        { KE_KEY, WIND_KEY_ECO,                 {KEY_PROG2} },

        { KE_END, 0 }
};

static ktime_t last_pressed;

static const struct {
        const char *guid;
        bool quirk_last_pressed;
} *event_wmi, event_wmis[] = {
        { MSIWMI_MSI_EVENT_GUID, true },
        { MSIWMI_WIND_EVENT_GUID, false },
};

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);
        if (ACPI_FAILURE(status))
                return -EIO;

        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(union acpi_object *obj, void *context)
{
        struct key_entry *key;

        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) {
                        pr_info("Unknown key pressed - %x\n", eventcode);
                        return;
                }

                if (event_wmi->quirk_last_pressed) {
                        ktime_t cur = ktime_get_real();
                        ktime_t diff = ktime_sub(cur, last_pressed);
                        /* Ignore event if any 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 = cur;
                }

                if (key->type == KE_KEY &&
                /* Brightness is served via acpi video driver */
                (backlight ||
                (key->code != MSI_KEY_BRIGHTNESSUP &&
                key->code != MSI_KEY_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 event received\n");
}

static int __init msi_wmi_backlight_setup(void)
{
        int err;
        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))
                return PTR_ERR(backlight);

        err = bl_get(NULL);
        if (err < 0) {
                backlight_device_unregister(backlight);
                return err;
        }

        backlight->props.brightness = err;

        return 0;
}

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_dev;

        last_pressed = 0;

        return 0;

err_free_dev:
        input_free_device(msi_wmi_input_dev);
        return err;
}

static int __init msi_wmi_init(void)
{
        int err;
        int i;

        for (i = 0; i < ARRAY_SIZE(event_wmis); i++) {
                if (!wmi_has_guid(event_wmis[i].guid))
                        continue;

                err = msi_wmi_input_setup();
                if (err) {
                        pr_err("Unable to setup input device\n");
                        return err;
                }

                err = wmi_install_notify_handler(event_wmis[i].guid,
                        msi_wmi_notify, NULL);
                if (ACPI_FAILURE(err)) {
                        pr_err("Unable to setup WMI notify handler\n");
                        goto err_free_input;
                }

                pr_debug("Event handler installed\n");
                event_wmi = &event_wmis[i];
                break;
        }

        if (wmi_has_guid(MSIWMI_BIOS_GUID) &&
            acpi_video_get_backlight_type() == acpi_backlight_vendor) {
                err = msi_wmi_backlight_setup();
                if (err) {
                        pr_err("Unable to setup backlight device\n");
                        goto err_uninstall_handler;
                }
                pr_debug("Backlight device created\n");
        }

        if (!event_wmi && !backlight) {
                pr_err("This machine doesn't have neither MSI-hotkeys nor backlight through WMI\n");
                return -ENODEV;
        }

        return 0;

err_uninstall_handler:
        if (event_wmi)
                wmi_remove_notify_handler(event_wmi->guid);
err_free_input:
        if (event_wmi)
                input_unregister_device(msi_wmi_input_dev);
        return err;
}

static void __exit msi_wmi_exit(void)
{
        if (event_wmi) {
                wmi_remove_notify_handler(event_wmi->guid);
                input_unregister_device(msi_wmi_input_dev);
        }
        backlight_device_unregister(backlight);
}

module_init(msi_wmi_init);
module_exit(msi_wmi_exit);