platform/x86: bitland-mifs-wmi: Add new Bitland MIFS WMI driver

Add a new driver for Bitland laptops that utilize the MIFS (MiInterface)
WMI interface.

The driver implements several features through the WMI interface:

- Platform Profile: Supports "Quiet", "Balanced", "Performance", and
  "Full Speed" modes. The "Full Speed" mode is intelligently restricted
  based on the AC adapter type (requires DC power, not supported on
  USB-C charging) as required by the hardware.
- Hwmon: Provides monitoring for CPU, GPU, and System fan speeds,
  as well as CPU temperature sensors.
- Keyboard Backlight: Integrated with the LED class device for
  brightness control and provides sysfs attributes for keyboard modes
  (cyclic, fixed, etc.).
- GPU Mode: Allows switching between Hybrid, Discrete, and UMA
  graphics modes via sysfs.
- Hotkeys: Handles WMI events for system hotkeys (Calculator, Browser,
  App launch) using sparse keymaps and reports status changes for
  Airplane mode, Touchpad, and CapsLock.
- Fan Boost: Provides a sysfs interface to force fans to maximum speed.

The driver registers two WMI GUIDs:
- B60BFB48-3E5B-49E4-A0E9-8CFFE1B3434B: Control methods
- 46C93E13-EE9B-4262-8488-563BCA757FEF: Event notifications

Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Mingyou Chen <qby140326@gmail.com>
Link: https://patch.msgid.link/20260323132218.444383-1-qby140326@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Documentation/wmi/devices/bitland-mifs-wmi.rst

@@ -0,0 +1,207 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+========================================
+Bitland MIFS driver (bitland-mifs-wmi)
+========================================
+
+Introduction
+============
+
+
+EC WMI interface description
+============================
+
+The EC WMI interface description can be decoded from the embedded binary MOF (bmof)
+data using the `bmfdec <https://github.com/pali/bmfdec>`_ utility:
+
+::
+
+  class WMIEvent : __ExtrinsicEvent {
+  };
+
+  [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x40A"), Description("Root WMI HID_EVENT20"), guid("{46c93e13-ee9b-4262-8488-563bca757fef}")]
+  class HID_EVENT20 : WmiEvent {
+    [key, read] string InstanceName;
+    [read] boolean Active;
+    [WmiDataId(1), read, write, Description("Package Data")] uint8 EventDetail[8];
+  };
+
+  [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x40A"), Description("Root WMI HID_EVENT21"), guid("{fa78e245-2c0f-4ca1-91cf-15f34e474850}")]
+  class HID_EVENT21 : WmiEvent {
+    [key, read] string InstanceName;
+    [read] boolean Active;
+    [WmiDataId(1), read, write, Description("Package Data")] uint8 EventDetail[8];
+  };
+
+  [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x40A"), Description("Root WMI HID_EVENT22"), guid("{1dceaf0a-4d63-44bb-bd0c-0d6281bfddc5}")]
+  class HID_EVENT22 : WmiEvent {
+    [key, read] string InstanceName;
+    [read] boolean Active;
+    [WmiDataId(1), read, write, Description("Package Data")] uint8 EventDetail[8];
+  };
+
+  [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x40A"), Description("Root WMI HID_EVENT23"), guid("{3f9e3c26-b077-4f86-91f5-37ff64d8c7ed}")]
+  class HID_EVENT23 : WmiEvent {
+    [key, read] string InstanceName;
+    [read] boolean Active;
+    [WmiDataId(1), read, write, Description("Package Data")] uint8 EventDetail[8];
+  };
+
+  [WMI, Dynamic, provider("WmiProv"), Locale("MS\\0x409"), Description("Class used to operate firmware interface"), guid("{b60bfb48-3e5b-49e4-a0e9-8cffe1b3434b}")]
+  class MICommonInterface {
+    [key, read] string InstanceName;
+    [read] boolean Active;
+
+    [WmiMethodId(1), Implemented, read, write, Description("Method used to support system functions.")] void MiInterface([in, Description("WMI Interface")] uint8 InData[32], [out] uint8 OutData[30], [out] uint16 Reserved);
+  };
+
+Reverse-Engineering the EC WMI interface
+========================================
+
+The OEM software can be download from `this link <https://iknow.lenovo.com.cn/detail/429447>`_
+
+Nothing is obfuscated, In this case, `ILSpy <https://github.com/icsharpcode/ILSpy>`_ could be helpful.
+
+WMI Methods (MICommonInterface)
+========================================
+
+The ``MICommonInterface`` class (GUID: ``{b60bfb48-3e5b-49e4-a0e9-8cffe1b3434b}``)
+is the primary control interface. It uses a 32-byte buffer for both input
+(``InData``) and output (``OutData``).
+
+Method Structure
+----------------
+
+The data packet follows a standardized format:
+
++----------+------------------------------------------------------------------+
+| Byte     | Description                                                      |
++==========+==================================================================+
+| 1        | Method Type: Get (0xFA / 250) or Set (0xFB / 251)                |
++----------+------------------------------------------------------------------+
+| 3        | Command ID (Method Name)                                         |
++----------+------------------------------------------------------------------+
+| 4 - 31   | Arguments (for Set) or Return Data (for Get)                     |
++----------+------------------------------------------------------------------+
+
+
+Command IDs
+-----------
+
+The following Command IDs are used in the third byte of the buffer:
+
++----------+-----------------------+------------------------------------------+
+| ID       | Name                  | Values / Description                     |
++==========+=======================+==========================================+
+| 8        | SystemPerMode         | 0: Balance, 1: Performance, 2: Quiet,    |
+|          |                       | 3: Full-speed                            |
++----------+-----------------------+------------------------------------------+
+| 9        | GPUMode               | 0: Hybrid, 1: Discrete, 2: UMA           |
++----------+-----------------------+------------------------------------------+
+| 10       | KeyboardType          | 0: White, 1: Single RGB, 2: Zone RGB     |
++----------+-----------------------+------------------------------------------+
+| 11       | FnLock                | 0: Off, 1: On                            |
++----------+-----------------------+------------------------------------------+
+| 12       | TPLock                | 0: Unlock, 1: Lock (Touchpad)            |
++----------+-----------------------+------------------------------------------+
+| 13       | CPUGPUSYSFanSpeed     | Returns 12 bytes of fan data:            |
+|          |                       | Bytes 4-5: CPU Fan RPM (Little Endian)   |
+|          |                       | Bytes 6-7: GPU Fan RPM (Little Endian)   |
+|          |                       | Bytes 10-11: SYS Fan RPM (Little Endian) |
++----------+-----------------------+------------------------------------------+
+| 16       | RGBKeyboardMode       | 0: Off, 1: Auto Cyclic, 2: Fixed,        |
+|          |                       | 3: Custom                                |
++----------+-----------------------+------------------------------------------+
+| 17       | RGBKeyboardColor      | Bytes 4, 5, 6: Red, Green, Blue values   |
++----------+-----------------------+------------------------------------------+
+| 18       | RGBKeyboardBrightness | 0-10: Brightness Levels, 128: Auto       |
++----------+-----------------------+------------------------------------------+
+| 19       | SystemAcType          | 1: Type-C, 2: Circular Hole (DC)         |
++----------+-----------------------+------------------------------------------+
+| 20       | MaxFanSpeedSwitch     | Byte 4: Fan Type (0: CPU/GPU, 1: SYS)    |
+|          |                       | Byte 5: State (0: Off, 1: On)            |
++----------+-----------------------+------------------------------------------+
+| 21       | MaxFanSpeed           | Sets manual fan speed duty cycle         |
++----------+-----------------------+------------------------------------------+
+| 22       | CPUThermometer        | Returns CPU Temperature                  |
++----------+-----------------------+------------------------------------------+
+
+WMI Events (HID_EVENT20)
+========================
+
+The driver listens for events from the ``HID_EVENT20`` class
+(GUID: ``{46c93e13-ee9b-4262-8488-563bca757fef}``). These events are triggered
+by hotkeys or system state changes (e.g., plugging in AC power).
+
+Event Structure
+---------------
+
+The event data is provided in an 8-byte array (``EventDetail``):
+
++----------+------------------------------------------------------------------+
+| Byte     | Description                                                      |
++==========+==================================================================+
+| 0        | Event Type (Always 0x01 for HotKey/Notification)                 |
++----------+------------------------------------------------------------------+
+| 1        | Event ID (Corresponds to the Command IDs above)                  |
++----------+------------------------------------------------------------------+
+| 2        | Value (The new state or value of the feature)                    |
++----------+------------------------------------------------------------------+
+
+Common Event IDs:
+-----------------
+
+Note: reserved event ids are not listed there
+
++----------+------------------------------------------------------------------+
+| Event Id | Description                                                      |
++==========+==================================================================+
+| 4        | AirPlane mode change                                             |
++----------+------------------------------------------------------------------+
+| 5        | Keyboard brightness change                                       |
++----------+------------------------------------------------------------------+
+| 6        | Touchpad state (enabled/disabled) change                         |
++----------+------------------------------------------------------------------+
+| 7        | FnLock state (enabled/disabled) change                           |
++----------+------------------------------------------------------------------+
+| 8        | Keyboard mode change                                             |
++----------+------------------------------------------------------------------+
+| 9        | CapsLock state change                                            |
++----------+------------------------------------------------------------------+
+| 13       | NumLock state change                                             |
++----------+------------------------------------------------------------------+
+| 14       | ScrollLock state change                                          |
++----------+------------------------------------------------------------------+
+| 15       | Performance plan change                                          |
++----------+------------------------------------------------------------------+
+| 25       | Display refresh rate change                                      |
++----------+------------------------------------------------------------------+
+| 33       | Super key lock state (enabled/disabled) change                   |
++----------+------------------------------------------------------------------+
+| 35       | Open control center key                                          |
++----------+------------------------------------------------------------------+
+
+Implementation Details
+======================
+
+Performance Modes
+-----------------
+Changing the performance mode via Command ID 0x08 (SystemPerMode) affects the
+power limits (PL1/PL2) and fan curves managed by the Embedded Controller (EC).
+Note that the "Full-speed" and "Performance" mode (1, 3) is typically only
+available when the system is connected to a DC power source (not USB-C/PD).
+
+In the driver implementation, switch to performance/full-speed mode without
+DC power connected will throw the EOPNOTSUPP error.
+
+Graphics Switching
+------------------
+The ``GPUMode`` (0x09) allows switching between Hybrid (Muxless) and Discrete
+(Muxed) graphics. Changing this value usually requires a system reboot to
+take effect in the BIOS/Firmware.
+
+Fan Control
+-----------
+The system supports both automatic EC control and manual overrides. Command ID
+0x14 (``MaxFanSpeedSwitch``) is used to toggle manual control, while ID 0x15
+sets the actual PWM duty cycle.

drivers/platform/x86/Kconfig

@@ -113,6 +113,24 @@ config GIGABYTE_WMI
 	  To compile this driver as a module, choose M here: the module will
 	  be called gigabyte-wmi.
 
+config BITLAND_MIFS_WMI
+	tristate "Bitland MIFS (MiInterface) WMI driver"
+	depends on ACPI_WMI
+	depends on HWMON
+	depends on INPUT
+	depends on POWER_SUPPLY
+	select ACPI_PLATFORM_PROFILE
+	select INPUT_SPARSEKMAP
+	help
+	  This is a driver for Bitland MiInterface based laptops.
+
+	  It provides the access to the temperature, fan speed, gpu
+	  control, keyboard backlight brightness and platform profile
+	  via hwmon and sysfs.
+
+	  To compile this driver as a module, choose M here: the module will
+          be called bitland-mifs-wmi.
+
 config ACERHDF
 	tristate "Acer Aspire One temperature and fan driver"
 	depends on ACPI_EC && THERMAL

drivers/platform/x86/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_NVIDIA_WMI_EC_BACKLIGHT)	+= nvidia-wmi-ec-backlight.o
 obj-$(CONFIG_XIAOMI_WMI)		+= xiaomi-wmi.o
 obj-$(CONFIG_REDMI_WMI)			+= redmi-wmi.o
 obj-$(CONFIG_GIGABYTE_WMI)		+= gigabyte-wmi.o
+obj-$(CONFIG_BITLAND_MIFS_WMI)		+= bitland-mifs-wmi.o
 
 # Acer
 obj-$(CONFIG_ACERHDF)		+= acerhdf.o