Suppose you have a Microsoft Surface Pro running Linux with all the Linux Surface patches and IPTS daemon running for your stylus.

To rotate the display left, first find your screen by executing xrandr --listmonitors, which will have output looking like this:

Monitors: 1
 0: +*eDP-1 2736/260x1824/173+0+0  eDP-1

Then, you execute the following (in my case I would use display_name=eDP-1):

xrandr --output $display_name --rotate left

However, this isn’t enough, because the stylus’s coordinate system did not rotate. Your pen’s coordinates will look like they’ve been reflected across a diagonal line.

Find your stylus by running xinput:

⎡ Virtual core pointer                    	id=2	[master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer              	id=4	[slave  pointer  (2)]
⎜   ↳ IPTS 045E:001F Touchscreen              	id=7	[slave  pointer  (2)]
⎜   ↳ Microsoft Surface Type Cover Mouse      	id=9	[slave  pointer  (2)]
⎜   ↳ Microsoft Surface Type Cover Keyboard   	id=10	[slave  pointer  (2)]
⎜   ↳ Microsoft Surface Type Cover Touchpad   	id=15	[slave  pointer  (2)]
⎜   ↳ IPTS Touch                              	id=12	[slave  pointer  (2)]
⎜   ↳ IPTS Stylus Pen (0)                     	id=13	[slave  pointer  (2)]
⎜   ↳ IPTS Stylus Eraser (0)                  	id=14	[slave  pointer  (2)]
⎣ Virtual core keyboard                   	id=3	[master keyboard (2)]
    ↳ Virtual core XTEST keyboard             	id=5	[slave  keyboard (3)]
    ↳ Video Bus                               	id=6	[slave  keyboard (3)]
    ↳ Microsoft Surface Type Cover Keyboard   	id=11	[slave  keyboard (3)]
    ↳ IPTS Stylus                             	id=8	[slave  keyboard (3)]

Notice that there may be multiple IDs associated with the stylus. You will have to execute the following command for all of them:

xinput set-prop $xinput_id 191 0 -1 1 1 0 0 0 0 1

To reverse the process, you run the following (again, over all $xinput_ids):

xrandr --output $display_name --rotate left
xinput set-prop $xinput_id 191 1 0 0 0 1 0 0 0 1

A wrapper script

Instead of calling that directly, here’s a fairly janky but working Python script I wrote that wraps those commands:

#!/usr/bin/env python3

import os
import re
import subprocess
import sys


MATRICES = {
    'normal': '1 0 0 0 1 0 0 0 1',
    'left': '0 -1 1 1 0 0 0 0 1',
}

COORDINATE_TRANFORM_ATTR = 191


def main():
    if len(sys.argv) != 2 or sys.argv[1] not in MATRICES:
        display_help()
        exit(1)

    for input_id in find_ipts_ids():
        rotate_input_by_id(input_id, sys.argv[1])
    rotate_primary_screen(sys.argv[1])


def rotate_input_by_id(xinput_id: int, rotation: str):
    matrix = MATRICES[rotation]
    cmd = f"xinput set-prop {xinput_id} {COORDINATE_TRANFORM_ATTR} {matrix}"
    os.system(cmd)


def rotate_primary_screen(rotation: str):
    os.system(f'xrandr --output eDP-1 --primary --mode 2736x1824 --pos 0x0 --rotate {rotation}')


def find_ipts_ids():
    xinput_result = subprocess.check_output('xinput', shell=True).decode()
    for l in xinput_result.splitlines():
        if 'IPTS' in l and 'pointer' in l:
            yield int(re.search(r'id=(\d+)', l).group(1))


def display_help():
    print("simple script for rotating the surface's screen")
    print(f"usage: {sys.argv[0]} <normal | left>")


if __name__ == '__main__':
    main()

Ignore the inconsistency between os.system and subprocess.run and the whole “running code in a shell” thing we’re doing, it was hacked together on a plane, give me some slack :)

Explanation

What’s going on with these values?

MATRICES = {
    'normal': '1 0 0 0 1 0 0 0 1',
    'left': '0 -1 1 1 0 0 0 0 1',
}

These are transformation matrices. Your touchscreen digitizer puts inputs into a specific coordinate space, and these matrices can be applied to that coordinate space to tweak it. For more explanation, see this page from the Ubuntu wiki.