This is inside of my SK8855, which is early revision(rev R00) of the product and has a firmware bug on keyboard part that they fixed it in later revision.

And this is HID report descriptor of the keyboard, just for people intrested. It defines feature report in last part, I guess TrackPoint driver uses this report to configure the device, and I think you can emulate this interface to deceive the driver.
Bus 001 Device 054: ID 17ef:6009 Lenovo ThinkPad Keyboard with TrackPoint
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x17ef Lenovo
idProduct 0x6009 ThinkPad Keyboard with TrackPoint
bcdDevice 1.22
iManufacturer 1 Lite-On Technology Corp.
iProduct 2 ThinkPad USB Keyboard with TrackPoint
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 59
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 1 Boot Interface Subclass
bInterfaceProtocol 1 Keyboard
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.10
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 65
Report Descriptor: (length is 65)
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x06 ] 6
Keyboard
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0xe0 ] 224
Control Left
Item(Local ): Usage Maximum, data= [ 0xe7 ] 231
GUI Right
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x08 ] 8
LEDs
Item(Local ): Usage Minimum, data= [ 0x01 ] 1
NumLock
Item(Local ): Usage Maximum, data= [ 0x03 ] 3
Scroll Lock
Item(Global): Report Count, data= [ 0x03 ] 3
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x05 ] 5
Item(Main ): Output, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0x00 ] 0
No Event
Item(Local ): Usage Maximum, data= [ 0xff 0x00 ] 255
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Global): Report Count, data= [ 0x06 ] 6
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x00 ] 0
Data Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 10
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 0 No Subclass
bInterfaceProtocol 0 None
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.10
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 185
Report Descriptor: (length is 185)
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x02 ] 2
Mouse
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x01 ] 1
Item(Local ): Usage, data= [ 0x01 ] 1
Pointer
Item(Main ): Collection, data= [ 0x00 ] 0
Physical
Item(Global): Usage Page, data= [ 0x09 ] 9
Buttons
Item(Local ): Usage Minimum, data= [ 0x01 ] 1
Button 1 (Primary)
Item(Local ): Usage Maximum, data= [ 0x03 ] 3
Button 3 (Tertiary)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x03 ] 3
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x05 ] 5
Item(Main ): Input, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x30 ] 48
Direction-X
Item(Local ): Usage, data= [ 0x31 ] 49
Direction-Y
Item(Global): Logical Minimum, data= [ 0x81 ] 129
Item(Global): Logical Maximum, data= [ 0x7f ] 127
Item(Global): Report Count, data= [ 0x02 ] 2
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x06 ] 6
Data Variable Relative No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x80 ] 128
System Control
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x02 ] 2
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Local ): Usage Minimum, data= [ 0x81 ] 129
System Power Down
Item(Local ): Usage Maximum, data= [ 0x88 ] 136
System Menu Exit
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x0c ] 12
Consumer
Item(Local ): Usage, data= [ 0x01 ] 1
Consumer Control
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x03 ] 3
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Local ): Usage, data= [ 0xe9 ] 233
Volume Increment
Item(Local ): Usage, data= [ 0xea ] 234
Volume Decrement
Item(Local ): Usage, data= [ 0xe2 ] 226
Mute
Item(Local ): Usage, data= [ 0xb7 ] 183
Stop
Item(Local ): Usage, data= [ 0xcd ] 205
Play/Pause
Item(Local ): Usage, data= [ 0xb5 ] 181
Scan Next Track
Item(Local ): Usage, data= [ 0xb6 ] 182
Scan Previous Track
Item(Local ): Usage, data= [ 0x94 0x01 ] 404
AL Local Machine Browser
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x03 ] 3
Programmable Buttons
Item(Main ): Collection, data= [ 0x02 ] 2
Logical
Item(Global): Usage Page, data= [ 0x09 ] 9
Buttons
Item(Local ): Usage Minimum, data= [ 0x10 ] 16
(null)
Item(Local ): Usage Maximum, data= [ 0x17 ] 23
(null)
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x09 ] 9
Buttons
Item(Local ): Usage Minimum, data= [ 0x18 ] 24
(null)
Item(Local ): Usage Maximum, data= [ 0x1f ] 31
(null)
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x08 ] 8
LEDs
Item(Global): Report Count, data= [ 0x02 ] 2
Item(Local ): Usage, data= [ 0x09 ] 9
Mute
Item(Local ): Usage, data= [ 0x21 ] 33
Microphone
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x06 ] 6
Item(Main ): Output, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Item(Global): Usage Page, data= [ 0x01 0xff ] 65281
(null)
Item(Local ): Usage, data= [ 0x01 ] 1
(null)
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x04 ] 4
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Local ): Usage, data= [ 0x20 ] 32
(null)
Item(Main ): Feature, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x21 ] 33
(null)
Item(Main ): Feature, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x22 ] 34
(null)
Item(Main ): Feature, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x23 ] 35
(null)
Item(Main ): Feature, data= [ 0x03 ] 3
Constant Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 10
Device Status: 0x0000
(Bus Powered)