The Surface Pro Type Cover has several non standard HID usages in it's
hid report descriptor.
I noticed that, upon folding the typecover back, a vendor specific range
of 4 32 bit integer hid usages is transmitted.
Only the first byte of the message seems to convey reliable information
about the keyboard state.
0x22 => Normal (keys enabled)
0x33 => Folded back (keys disabled)
0x53 => Rotated left/right side up (keys disabled)
0x13 => Cover closed (keys disabled)
0x43 => Folded back and Tablet upside down (keys disabled)
This list may not be exhaustive.
The tablet mode switch will be disabled for a value of 0x22 and enabled
on any other value.
The Surface Pro Type Cover has several non standard HID usages in it's hid report descriptor. I noticed that, upon folding the typecover back, a vendor specific range of 4 32 bit integer hid usages is transmitted. Only the first byte of the message seems to convey reliable information about the keyboard state.
0x22 => Normal (keys enabled) 0x33 => Folded back (keys disabled) 0x53 => Rotated left/right side up (keys disabled) 0x13 => Cover closed (keys disabled) 0x43 => Folded back and Tablet upside down (keys disabled) This list may not be exhaustive.
The tablet mode switch will be disabled for a value of 0x22 and enabled on any other value.