[FROM-ML] platform/x86: msi-wmi-platform: Add support for fan control

Adds fan curve support for the MSI platform. These devices contain
support for two fans, where they are named CPU and GPU but in the
case of the Claw series just map to left and right fan.

Co-developed-by: Antheas Kapenekakis <lkml@antheas.dev>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Author: Wer-Wolf

Documentation/wmi/devices/msi-wmi-platform.rst

@@ -169,6 +169,32 @@ The fan RPM readings can be calculated with the following formula:
 
 If the fan speed reading is zero, then the fan RPM is zero too.
 
+The subfeature ``0x01`` is used to retrieve the fan speed table for the CPU fan. The output
+data contains the fan speed table and two bytes with unknown data. The fan speed table
+consists of six 8-bit entries, each containing a fan speed value in percent.
+
+The subfeature ``0x02`` is used tho retrieve the same data for the GPU fan.
+
+WMI method Set_Fan()
+--------------------
+
+The fan speed tables can be accessed using subfeature ``0x01`` (CPU fan) and subfeature ``0x02``
+(GPU fan). The input data has the same format as the output data of the ``Get_Fan`` WMI method.
+
+WMI method Get_AP()
+-------------------
+
+The current fan mode can be accessed using subfeature ``0x01``. The output data contains a flag
+byte and two bytes of unknown data. If the 7th bit inside the flag byte is cleared then all fans
+are operating in automatic mode, otherwise the fans operate based on the fan speed tables
+accessible thru the ``Get_Fan``/``Set_Fan`` WMI methods.
+
+WMI method Set_AP()
+-------------------
+
+The current fan mode can be changed using subfeature ``0x01``. The input data has the same format
+as the output data of the ``Get_AP`` WMI method.
+
 WMI method Get_WMI()
 --------------------