Contributors: 3
Author Tokens Token Proportion Commits Commit Proportion
Mingyou Chen 3471 98.78% 1 20.00%
Armin Wolf 37 1.05% 3 60.00%
Mario Limonciello 6 0.17% 1 20.00%
Total 3514 5 


// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Linux driver for Bitland notebooks.
 *
 * Copyright (C) 2026 2 Mingyou Chen <qby140326@gmail.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/acpi.h>
#include <linux/array_size.h>
#include <linux/bits.h>
#include <linux/container_of.h>
#include <linux/dev_printk.h>
#include <linux/device.h>
#include <linux/device/devres.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/input-event-codes.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/platform_profile.h>
#include <linux/pm.h>
#include <linux/power_supply.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/unaligned.h>
#include <linux/units.h>
#include <linux/wmi.h>

#define DRV_NAME		"bitland-mifs-wmi"
#define BITLAND_MIFS_GUID	"B60BFB48-3E5B-49E4-A0E9-8CFFE1B3434B"
#define BITLAND_EVENT_GUID	"46C93E13-EE9B-4262-8488-563BCA757FEF"

enum bitland_mifs_operation {
	WMI_METHOD_GET	= 250,
	WMI_METHOD_SET	= 251,
};

enum bitland_mifs_function {
	WMI_FN_SYSTEM_PER_MODE		= 8,
	WMI_FN_GPU_MODE			= 9,
	WMI_FN_KBD_TYPE			= 10,
	WMI_FN_FN_LOCK			= 11,
	WMI_FN_TP_LOCK			= 12,
	WMI_FN_FAN_SPEEDS		= 13,
	WMI_FN_RGB_KB_MODE		= 16,
	WMI_FN_RGB_KB_COLOR		= 17,
	WMI_FN_RGB_KB_BRIGHTNESS	= 18,
	WMI_FN_SYSTEM_AC_TYPE		= 19,
	WMI_FN_MAX_FAN_SWITCH		= 20,
	WMI_FN_MAX_FAN_SPEED		= 21,
	WMI_FN_CPU_THERMOMETER		= 22,
	WMI_FN_CPU_POWER		= 23,
};

enum bitland_system_ac_mode {
	WMI_SYSTEM_AC_TYPEC		= 1,
	/* Unknown type, this is unused in the original driver */
	WMI_SYSTEM_AC_CIRCULARHOLE	= 2,
};

enum bitland_mifs_power_profile {
	WMI_PP_BALANCED		= 0,
	WMI_PP_PERFORMANCE	= 1,
	WMI_PP_QUIET		= 2,
	WMI_PP_FULL_SPEED	= 3,
};

enum bitland_mifs_event_id {
	WMI_EVENT_RESERVED_1		= 1,
	WMI_EVENT_RESERVED_2		= 2,
	WMI_EVENT_RESERVED_3		= 3,
	WMI_EVENT_AIRPLANE_MODE		= 4,
	WMI_EVENT_KBD_BRIGHTNESS	= 5,
	WMI_EVENT_TOUCHPAD_STATE	= 6,
	WMI_EVENT_FNLOCK_STATE		= 7,
	WMI_EVENT_KBD_MODE		= 8,
	WMI_EVENT_CAPSLOCK_STATE	= 9,
	WMI_EVENT_CALCULATOR_START	= 11,
	WMI_EVENT_BROWSER_START		= 12,
	WMI_EVENT_NUMLOCK_STATE		= 13,
	WMI_EVENT_SCROLLLOCK_STATE	= 14,
	WMI_EVENT_PERFORMANCE_PLAN	= 15,
	WMI_EVENT_FN_J			= 16,
	WMI_EVENT_FN_F			= 17,
	WMI_EVENT_FN_0			= 18,
	WMI_EVENT_FN_1			= 19,
	WMI_EVENT_FN_2			= 20,
	WMI_EVENT_FN_3			= 21,
	WMI_EVENT_FN_4			= 22,
	WMI_EVENT_FN_5			= 24,
	WMI_EVENT_REFRESH_RATE		= 25,
	WMI_EVENT_CPU_FAN_SPEED		= 26,
	WMI_EVENT_GPU_FAN_SPEED		= 32,
	WMI_EVENT_WIN_KEY_LOCK		= 33,
	WMI_EVENT_RESERVED_23		= 34,
	WMI_EVENT_OPEN_APP		= 35,
};

enum bitland_mifs_event_type {
	WMI_EVENT_TYPE_HOTKEY	= 1,
};

enum bitland_wmi_device_type {
	BITLAND_WMI_CONTROL	= 0,
	BITLAND_WMI_EVENT	= 1,
};

struct bitland_mifs_input {
	u8 reserved1;
	u8 operation;
	u8 reserved2;
	u8 function;
	u8 payload[28];
} __packed;

struct bitland_mifs_output {
	u8 reserved1;
	u8 operation;
	u8 reserved2;
	u8 function;
	u8 data[28];
} __packed;

struct bitland_mifs_event {
	u8 event_type;
	u8 event_id;
	u8 value_low;	/* For most events, this is the value */
	u8 value_high;	/* For fan speed events, combined with value_low */
	u8 reserved[4];
} __packed;

static BLOCKING_NOTIFIER_HEAD(bitland_notifier_list);

enum bitland_notifier_actions {
	BITLAND_NOTIFY_KBD_BRIGHTNESS,
	BITLAND_NOTIFY_PLATFORM_PROFILE,
	BITLAND_NOTIFY_HWMON,
};

struct bitland_fan_notify_data {
	int channel; /* 0 = CPU, 1 = GPU */
	u16 speed;
};

struct bitland_mifs_wmi_data {
	struct wmi_device *wdev;
	struct mutex lock;		/* Protects WMI calls */
	struct led_classdev kbd_led;
	struct notifier_block notifier;
	struct input_dev *input_dev;
	struct device *hwmon_dev;
	struct device *pp_dev;
	enum platform_profile_option saved_profile;
};

static int bitland_mifs_wmi_call(struct bitland_mifs_wmi_data *data,
				 const struct bitland_mifs_input *input,
				 struct bitland_mifs_output *output)
{
	struct wmi_buffer in_buf = { .length = sizeof(*input), .data = (void *)input };
	struct wmi_buffer out_buf = { 0 };
	int ret;

	guard(mutex)(&data->lock);

	if (!output)
		return wmidev_invoke_procedure(data->wdev, 0, 1, &in_buf);

	ret = wmidev_invoke_method(data->wdev, 0, 1, &in_buf, &out_buf, sizeof(*output));
	if (ret)
		return ret;

	memcpy(output, out_buf.data, sizeof(*output));
	kfree(out_buf.data);

	return 0;
}

static int laptop_profile_get(struct device *dev,
			      enum platform_profile_option *profile)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_GET,
		.reserved2 = 0,
		.function = WMI_FN_SYSTEM_PER_MODE,
	};
	struct bitland_mifs_output result;
	int ret;

	ret = bitland_mifs_wmi_call(data, &input, &result);
	if (ret)
		return ret;

	switch (result.data[0]) {
	case WMI_PP_BALANCED:
		*profile = PLATFORM_PROFILE_BALANCED;
		break;
	case WMI_PP_PERFORMANCE:
		*profile = PLATFORM_PROFILE_BALANCED_PERFORMANCE;
		break;
	case WMI_PP_QUIET:
		*profile = PLATFORM_PROFILE_LOW_POWER;
		break;
	case WMI_PP_FULL_SPEED:
		*profile = PLATFORM_PROFILE_PERFORMANCE;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int bitland_check_performance_capability(struct bitland_mifs_wmi_data *data)
{
	struct bitland_mifs_input input = {
		.operation = WMI_METHOD_GET,
		.function = WMI_FN_SYSTEM_AC_TYPE,
	};
	struct bitland_mifs_output output;
	int ret;

	/* Full-speed/performance mode requires DC power (not USB-C) */
	if (!power_supply_is_system_supplied())
		return -EOPNOTSUPP;

	ret = bitland_mifs_wmi_call(data, &input, &output);
	if (ret)
		return ret;

	if (output.data[0] != WMI_SYSTEM_AC_CIRCULARHOLE)
		return -EOPNOTSUPP;

	return 0;
}

static int laptop_profile_set(struct device *dev,
			      enum platform_profile_option profile)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_SET,
		.reserved2 = 0,
		.function = WMI_FN_SYSTEM_PER_MODE,
	};
	int ret;
	u8 val;

	switch (profile) {
	case PLATFORM_PROFILE_LOW_POWER:
		val = WMI_PP_QUIET;
		break;
	case PLATFORM_PROFILE_BALANCED:
		val = WMI_PP_BALANCED;
		break;
	case PLATFORM_PROFILE_BALANCED_PERFORMANCE:
		ret = bitland_check_performance_capability(data);
		if (ret)
			return ret;
		val = WMI_PP_PERFORMANCE;
		break;
	case PLATFORM_PROFILE_PERFORMANCE:
		ret = bitland_check_performance_capability(data);
		if (ret)
			return ret;
		val = WMI_PP_FULL_SPEED;
		break;
	default:
		return -EOPNOTSUPP;
	}

	input.payload[0] = val;

	return bitland_mifs_wmi_call(data, &input, NULL);
}

static int platform_profile_probe(void *drvdata, unsigned long *choices)
{
	set_bit(PLATFORM_PROFILE_LOW_POWER, choices);
	set_bit(PLATFORM_PROFILE_BALANCED, choices);
	set_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE, choices);
	set_bit(PLATFORM_PROFILE_PERFORMANCE, choices);

	return 0;
}

static int bitland_mifs_wmi_suspend(struct device *dev)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	enum platform_profile_option profile;
	int ret;

	ret = laptop_profile_get(data->pp_dev, &profile);
	if (ret == 0)
		data->saved_profile = profile;

	return ret;
}

static int bitland_mifs_wmi_resume(struct device *dev)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);

	dev_dbg(dev, "Resuming, restoring profile %d\n", data->saved_profile);
	return laptop_profile_set(dev, data->saved_profile);
}

static DEFINE_SIMPLE_DEV_PM_OPS(bitland_mifs_wmi_pm_ops,
				bitland_mifs_wmi_suspend,
				bitland_mifs_wmi_resume);

static const struct platform_profile_ops laptop_profile_ops = {
	.probe = platform_profile_probe,
	.profile_get = laptop_profile_get,
	.profile_set = laptop_profile_set,
};

static const char *const fan_labels[] = {
	"CPU", /* 0 */
	"GPU", /* 1 */
	"SYS", /* 2 */
};

static int laptop_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
			     u32 attr, int channel, long *val)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_GET,
		.reserved2 = 0,
	};
	struct bitland_mifs_output res;
	int ret;

	switch (type) {
	case hwmon_temp:
		input.function = WMI_FN_CPU_THERMOMETER;
		ret = bitland_mifs_wmi_call(data, &input, &res);
		if (!ret)
			*val = res.data[0] * MILLIDEGREE_PER_DEGREE;
		return ret;
	case hwmon_fan:
		input.function = WMI_FN_FAN_SPEEDS;
		ret = bitland_mifs_wmi_call(data, &input, &res);
		if (ret)
			return ret;

		switch (channel) {
		case 0: /* CPU */
			*val = get_unaligned_le16(&res.data[0]);
			return 0;
		case 1: /* GPU */
			*val = get_unaligned_le16(&res.data[2]);
			return 0;
		case 2: /* SYS */
			*val = get_unaligned_le16(&res.data[6]);
			return 0;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static int laptop_hwmon_read_string(struct device *dev,
				    enum hwmon_sensor_types type, u32 attr,
				    int channel, const char **str)
{
	if (type == hwmon_fan && attr == hwmon_fan_label) {
		if (channel >= 0 && channel < ARRAY_SIZE(fan_labels)) {
			*str = fan_labels[channel];
			return 0;
		}
	}
	return -EINVAL;
}

static const struct hwmon_channel_info *laptop_hwmon_info[] = {
	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_LABEL,
				HWMON_F_INPUT | HWMON_F_LABEL,
				HWMON_F_INPUT | HWMON_F_LABEL),
	NULL
};

static const struct hwmon_ops laptop_hwmon_ops = {
	.visible = 0444,
	.read = laptop_hwmon_read,
	.read_string = laptop_hwmon_read_string,
};

static const struct hwmon_chip_info laptop_chip_info = {
	.ops = &laptop_hwmon_ops,
	.info = laptop_hwmon_info,
};

static int laptop_kbd_led_set(struct led_classdev *led_cdev,
			      enum led_brightness value)
{
	struct bitland_mifs_wmi_data *data =
		container_of(led_cdev, struct bitland_mifs_wmi_data, kbd_led);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_SET,
		.reserved2 = 0,
		.function = WMI_FN_RGB_KB_BRIGHTNESS,
	};

	input.payload[0] = (u8)value;

	return bitland_mifs_wmi_call(data, &input, NULL);
}

static enum led_brightness laptop_kbd_led_get(struct led_classdev *led_cdev)
{
	struct bitland_mifs_wmi_data *data =
		container_of(led_cdev, struct bitland_mifs_wmi_data, kbd_led);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_GET,
		.reserved2 = 0,
		.function = WMI_FN_RGB_KB_BRIGHTNESS,
	};
	struct bitland_mifs_output res;
	int ret;

	ret = bitland_mifs_wmi_call(data, &input, &res);
	if (ret)
		return ret;

	return res.data[0];
}

static const char *const gpu_mode_strings[] = {
	"hybrid",
	"discrete",
	"uma",
};

/* GPU Mode: 0:Hybrid, 1:Discrete, 2:UMA */
static ssize_t gpu_mode_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_GET,
		.reserved2 = 0,
		.function = WMI_FN_GPU_MODE,
	};
	struct bitland_mifs_output res;
	u8 mode_val;
	int ret;

	ret = bitland_mifs_wmi_call(data, &input, &res);
	if (ret)
		return ret;

	mode_val = res.data[0];
	if (mode_val >= ARRAY_SIZE(gpu_mode_strings))
		return -EPROTO;

	return sysfs_emit(buf, "%s\n", gpu_mode_strings[mode_val]);
}

static ssize_t gpu_mode_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_SET,
		.reserved2 = 0,
		.function = WMI_FN_GPU_MODE,
	};
	int val;
	int ret;

	val = sysfs_match_string(gpu_mode_strings, buf);
	if (val < 0)
		return -EINVAL;

	input.payload[0] = (u8)val;

	ret = bitland_mifs_wmi_call(data, &input, NULL);
	if (ret)
		return ret;

	return count;
}

static const char *const kb_mode_strings[] = {
	"off",		/* 0 */
	"cyclic",	/* 1 */
	"fixed",	/* 2 */
	"custom",	/* 3 */
};

static ssize_t kb_mode_show(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_GET,
		.reserved2 = 0,
		.function = WMI_FN_RGB_KB_MODE,
	};
	struct bitland_mifs_output res;
	u8 mode_val;
	int ret;

	ret = bitland_mifs_wmi_call(data, &input, &res);
	if (ret)
		return ret;

	mode_val = res.data[0];
	if (mode_val >= ARRAY_SIZE(kb_mode_strings))
		return -EPROTO;

	return sysfs_emit(buf, "%s\n", kb_mode_strings[mode_val]);
}

static ssize_t kb_mode_store(struct device *dev, struct device_attribute *attr,
			     const char *buf, size_t count)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_SET,
		.reserved2 = 0,
		.function = WMI_FN_RGB_KB_MODE,
	};
	// the wmi value (0, 1, 2 or 3)
	int val;
	int ret;

	val = sysfs_match_string(kb_mode_strings, buf);
	if (val < 0)
		return -EINVAL;

	input.payload[0] = (u8)val;

	ret = bitland_mifs_wmi_call(data, &input, NULL);
	if (ret)
		return ret;

	return count;
}

/* Fan Boost: 0:Normal, 1:Max Speed */
static ssize_t fan_boost_store(struct device *dev,
			       struct device_attribute *attr, const char *buf,
			       size_t count)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
	struct bitland_mifs_input input = {
		.reserved1 = 0,
		.operation = WMI_METHOD_SET,
		.reserved2 = 0,
		.function = WMI_FN_MAX_FAN_SWITCH,
	};
	bool val;
	int ret;

	if (kstrtobool(buf, &val))
		return -EINVAL;

	input.payload[0] = 0;	/* CPU/GPU Fan */
	input.payload[1] = val;

	ret = bitland_mifs_wmi_call(data, &input, NULL);
	if (ret)
		return ret;

	return count;
}

static const DEVICE_ATTR_RW(gpu_mode);
static const DEVICE_ATTR_RW(kb_mode);
static const DEVICE_ATTR_WO(fan_boost);

static const struct attribute *const laptop_attrs[] = {
	&dev_attr_gpu_mode.attr,
	&dev_attr_kb_mode.attr,
	&dev_attr_fan_boost.attr,
	NULL,
};
ATTRIBUTE_GROUPS(laptop);

static const struct key_entry bitland_mifs_wmi_keymap[] = {
	{ KE_KEY, WMI_EVENT_OPEN_APP, { KEY_PROG1 } },
	{ KE_KEY, WMI_EVENT_CALCULATOR_START, { KEY_CALC } },
	{ KE_KEY, WMI_EVENT_BROWSER_START, { KEY_WWW } },
	{ KE_IGNORE, WMI_EVENT_FN_J, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_F, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_0, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_1, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_2, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_3, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_4, { KEY_RESERVED } },
	{ KE_IGNORE, WMI_EVENT_FN_5, { KEY_RESERVED } },
	{ KE_END, 0 }
};

static void bitland_notifier_unregister(void *data)
{
	struct notifier_block *nb = data;

	blocking_notifier_chain_unregister(&bitland_notifier_list, nb);
}

static int bitland_notifier_callback(struct notifier_block *nb,
				     unsigned long action, void *data)
{
	struct bitland_mifs_wmi_data *data_ctx =
		container_of(nb, struct bitland_mifs_wmi_data, notifier);
	struct bitland_fan_notify_data *fan_info;
	u8 *brightness;

	switch (action) {
	case BITLAND_NOTIFY_KBD_BRIGHTNESS:
		brightness = data;
		led_classdev_notify_brightness_hw_changed(&data_ctx->kbd_led,
							  *brightness);
		break;
	case BITLAND_NOTIFY_PLATFORM_PROFILE:
		platform_profile_notify(data_ctx->pp_dev);
		break;
	case BITLAND_NOTIFY_HWMON:
		fan_info = data;

		hwmon_notify_event(data_ctx->hwmon_dev, hwmon_fan,
				   hwmon_fan_input, fan_info->channel);
		break;
	}

	return NOTIFY_OK;
}

static int bitland_mifs_wmi_probe(struct wmi_device *wdev, const void *context)
{
	struct bitland_mifs_wmi_data *drv_data;
	enum bitland_wmi_device_type dev_type =
		(enum bitland_wmi_device_type)(unsigned long)context;
	struct led_init_data init_data = {
		.devicename = DRV_NAME,
		.default_label = ":" LED_FUNCTION_KBD_BACKLIGHT,
		.devname_mandatory = true,
	};
	int ret;

	drv_data = devm_kzalloc(&wdev->dev, sizeof(*drv_data), GFP_KERNEL);
	if (!drv_data)
		return -ENOMEM;

	drv_data->wdev = wdev;

	ret = devm_mutex_init(&wdev->dev, &drv_data->lock);
	if (ret)
		return ret;

	dev_set_drvdata(&wdev->dev, drv_data);

	if (dev_type == BITLAND_WMI_EVENT) {
		/* Register input device for hotkeys */
		drv_data->input_dev = devm_input_allocate_device(&wdev->dev);
		if (!drv_data->input_dev)
			return -ENOMEM;

		drv_data->input_dev->name = "Bitland MIFS WMI hotkeys";
		drv_data->input_dev->phys = "wmi/input0";
		drv_data->input_dev->id.bustype = BUS_HOST;
		drv_data->input_dev->dev.parent = &wdev->dev;

		ret = sparse_keymap_setup(drv_data->input_dev,
					  bitland_mifs_wmi_keymap, NULL);
		if (ret)
			return ret;

		return input_register_device(drv_data->input_dev);
	}

	/* Register platform profile */
	drv_data->pp_dev = devm_platform_profile_register(&wdev->dev, DRV_NAME, drv_data,
							  &laptop_profile_ops);
	if (IS_ERR(drv_data->pp_dev))
		return PTR_ERR(drv_data->pp_dev);

	/* Register hwmon */
	drv_data->hwmon_dev = devm_hwmon_device_register_with_info(&wdev->dev,
								   "bitland_mifs",
								   drv_data,
								   &laptop_chip_info,
								   NULL);
	if (IS_ERR(drv_data->hwmon_dev))
		return PTR_ERR(drv_data->hwmon_dev);

	/* Register keyboard LED */
	drv_data->kbd_led.max_brightness = 3;
	drv_data->kbd_led.brightness_set_blocking = laptop_kbd_led_set;
	drv_data->kbd_led.brightness_get = laptop_kbd_led_get;
	drv_data->kbd_led.brightness = laptop_kbd_led_get(&drv_data->kbd_led);
	drv_data->kbd_led.flags = LED_CORE_SUSPENDRESUME |
				  LED_BRIGHT_HW_CHANGED |
				  LED_REJECT_NAME_CONFLICT;
	ret = devm_led_classdev_register_ext(&wdev->dev, &drv_data->kbd_led, &init_data);
	if (ret)
		return ret;

	drv_data->notifier.notifier_call = bitland_notifier_callback;
	ret = blocking_notifier_chain_register(&bitland_notifier_list, &drv_data->notifier);
	if (ret)
		return ret;

	return devm_add_action_or_reset(&wdev->dev,
				       bitland_notifier_unregister,
				       &drv_data->notifier);
}

static void bitland_mifs_wmi_notify(struct wmi_device *wdev,
				    const struct wmi_buffer *buffer)
{
	struct bitland_mifs_wmi_data *data = dev_get_drvdata(&wdev->dev);
	const struct bitland_mifs_event *event = buffer->data;
	struct bitland_fan_notify_data fan_data;
	u8 brightness;

	/* Validate event type */
	if (event->event_type != WMI_EVENT_TYPE_HOTKEY)
		return;

	dev_dbg(&wdev->dev,
		"WMI event: id=0x%02x value_low=0x%02x value_high=0x%02x\n",
		event->event_id, event->value_low, event->value_high);

	switch (event->event_id) {
	case WMI_EVENT_KBD_BRIGHTNESS:
		brightness = event->value_low;
		blocking_notifier_call_chain(&bitland_notifier_list,
					     BITLAND_NOTIFY_KBD_BRIGHTNESS,
					     &brightness);
		break;

	case WMI_EVENT_PERFORMANCE_PLAN:
		blocking_notifier_call_chain(&bitland_notifier_list,
					     BITLAND_NOTIFY_PLATFORM_PROFILE,
					     NULL);
		break;

	case WMI_EVENT_OPEN_APP:
	case WMI_EVENT_CALCULATOR_START:
	case WMI_EVENT_BROWSER_START: {
		guard(mutex)(&data->lock);
		if (!sparse_keymap_report_event(data->input_dev,
						event->event_id, 1, true))
			dev_warn(&wdev->dev, "Unknown key pressed: 0x%02x\n",
				 event->event_id);
		break;
	}

	/*
	 * The device has 3 fans (CPU, GPU, SYS),
	 * but there are only the CPU and GPU fan has events
	 */
	case WMI_EVENT_CPU_FAN_SPEED:
	case WMI_EVENT_GPU_FAN_SPEED:
		if (event->event_id == WMI_EVENT_CPU_FAN_SPEED)
			fan_data.channel = 0;
		else
			fan_data.channel = 1;

		/* Fan speed is 16-bit value (value_low is LSB, value_high is MSB) */
		fan_data.speed = (event->value_high << 8) | event->value_low;
		blocking_notifier_call_chain(&bitland_notifier_list,
					     BITLAND_NOTIFY_HWMON,
					     &fan_data);
		break;

	case WMI_EVENT_AIRPLANE_MODE:
	case WMI_EVENT_TOUCHPAD_STATE:
	case WMI_EVENT_FNLOCK_STATE:
	case WMI_EVENT_KBD_MODE:
	case WMI_EVENT_CAPSLOCK_STATE:
	case WMI_EVENT_NUMLOCK_STATE:
	case WMI_EVENT_SCROLLLOCK_STATE:
	case WMI_EVENT_REFRESH_RATE:
	case WMI_EVENT_WIN_KEY_LOCK:
		/* These events are informational or handled by firmware */
		dev_dbg(&wdev->dev, "State change event: id=%d value=%d\n",
			event->event_id, event->value_low);
		break;

	default:
		dev_dbg(&wdev->dev, "Unknown event: id=0x%02x value=0x%02x\n",
			event->event_id, event->value_low);
		break;
	}
}

static const struct wmi_device_id bitland_mifs_wmi_id_table[] = {
	{ BITLAND_MIFS_GUID, (void *)BITLAND_WMI_CONTROL },
	{ BITLAND_EVENT_GUID, (void *)BITLAND_WMI_EVENT },
	{}
};
MODULE_DEVICE_TABLE(wmi, bitland_mifs_wmi_id_table);

static struct wmi_driver bitland_mifs_wmi_driver = {
	.no_singleton = true,
	.driver = {
		.name = DRV_NAME,
		.dev_groups = laptop_groups,
		.pm = pm_sleep_ptr(&bitland_mifs_wmi_pm_ops),
	},
	.id_table = bitland_mifs_wmi_id_table,
	.min_event_size = sizeof(struct bitland_mifs_event),
	.probe = bitland_mifs_wmi_probe,
	.notify_new = bitland_mifs_wmi_notify,
};

module_wmi_driver(bitland_mifs_wmi_driver);

MODULE_AUTHOR("Mingyou Chen <qby140326@gmail.com>");
MODULE_DESCRIPTION("Bitland MIFS (MiInterface) WMI driver");
MODULE_LICENSE("GPL");