Screen tilting support on the thinkpad x200 tablet

I haven't set it up before, and never learned about it how it works, until researching the answer to your post.

Apparently support for touch screens is built into the linux kernel now, and certain desktop environments have support for it.

Generally that is how things go, the hardware has it's own support facilities, the kernel may or may not, and then the higher level operating system itself may or may not have support for different features. Ideally these things all line up to have true "support"

https://www.maketecheasier.com/best-linux-desktop-touch-enabled-monitor/
"1. GNOME

As one of the most popular desktops available for Linux, it shouldn’t come as a surprise that GNOME works well with a touchscreen. Since version 3.14, the desktop introduced support for touchscreen gestures, which lets you get even more done with your touchscreen monitor.

GNOME 40’s release in late 2021 further integrated the ability to switch between workspaces and access the application overview with touch gestures out of the box.
Touchdesktop Gnome"

So apparently, Gnome, KDE, cinnamon, deepin, and budgie, the desktop environments each have varying levels of touch screen support.

The drivers themselves are built into the standard linux kernel now, and as to whether or not they are "free software" or "open source" or contain "proprietary bits" I couldn't say, without doing more research and discovering the specific drivers that support using a touchscreen.

I would recommend looking into those desktop environments if you want to get it to work, and I'm not sure about the exact model of your PC, but you will mostly likely want to take advantage of an older version. The best way to find out their level of support right now, is to go to their websites directly, the search engines directed me to a post on a webpage that is three years old, which might be related to it's own for-profit motives...(directing people away from free operating systems in effect)

Lastly, you will have to find out how the support is built into the kernel, and you may have to recompile it to add support for different features.

I can try to reference the libre-kernel if see if any of the supporting drivers are marked as problematic...and it's general configuration to see if adding support for different features is built-in (that's generally the case)

I do know from experience however, that, looking at this subject from this perspective, here on trisquel, you effectively enjoy layers of support for "freedom" and "security" given that the linux kernel team itself supports ethical software to some degree, and then the libre-kernel takes that ethical support to a higher level, similarly to gnu->debian->ubuntu->trisquel, the software we end up using at the end, has layers of support, and oversight.

Okay, so here's what the kernel configuration shows

(still havent referenced libre-kernel docs)
(still havent referenced upstream desktop environment docs)

.config - Linux/x86 6.16.1-gnu Kernel Configuration
> Device Drivers > Input device support > Touchscreens

The kernel has built in support for a variety of different devices, that look like this:

< > Marvell 88PM860x touchscreen
< > ADS7846/TSC2046/AD7873 and AD(S)7843 based touchscreens
< > AD7877 based touchscreens
< > Analog Devices AD7879-1/AD7889-1 touchscreen interface
< > Atmel mXT I2C Touchscreen
< > AUO in-cell touchscreen using Pixcir ICs
< > BU21013 based touch panel controllers
< > Rohm BU21029 based touch panel controllers
< > chipone icn8505 touchscreen controller
< > cy8ctma140 touchscreen
< > cy8ctmg110 touchscreen
< > Cypress TTSP touchscreen
< > Cypress TrueTouch Gen5 Touchscreen Driver
< > Touchscreen support for Dialog Semiconductor DA9034
< > Dialog DA9052/DA9053 TSI
< > Dynapro serial touchscreen
< > Hampshire serial touchscreen
< > EETI touchscreen panel support
< > EETI eGalax serial touchscreen
< > EETI EXC3000 multi-touch panel support
< > Fujitsu serial touchscreen
< > Goodix I2C touchscreen
< > Goodix Berlin I2C touchscreen
< > Goodix Berlin SPI touchscreen
< > HiDeep Touch IC
< > Hycon hy46xx touchscreen support
< > Hynitron touchscreen support
< > Ilitek ILI210X based touchscreen
< > Ilitek I2C 213X/23XX/25XX/Lego Series Touch ICs
< > Samsung S6SY761 Touchscreen driver
< > Gunze AHL-51S touchscreen
< > Elan eKTF2127 I2C touchscreen
<*> Elan eKTH I2C touchscreen
< > Elo serial touchscreens
< > Wacom W8001 penabled serial touchscreen
< > Wacom Tablet support (I2C)
< > MAX11801 based touchscreens
< > MELFAS MMS114 touchscreen
< > MELFAS MIP4 Touchscreen
< > MStar msg2638 touchscreen support < > MicroTouch serial touchscreens
< > Novatek NT11205 touchscreen support
< > Imagis touchscreen support
< > iNexio serial touchscreens
< > Penmount serial touchscreen
< > Touchright serial touchscreen
< > Touchwin serial touchscreen
< > PIXCIR I2C touchscreens
< > Weida HiTech I2C touchscreen < > Support for WM831x touchscreen controllers
< > USB Touchscreen Driver
< > Sahara TouchIT-213 touchscreen
< > TSC-10/25/40 serial touchscreen support
< > TSC2004 based touchscreens
< > TSC2005 based touchscreens
< > TSC2007 based touchscreens
< > Motorola PCAP touchscreen
< > Raydium I2C Touchscreen
< > Silead I2C touchscreen
< > SiS 9200 family I2C touchscreen
< > Sitronix ST1232 or ST1633 touchscreen controllers
< > STMicroelectronics STMFTS touchscreen
< > Samsung SUR40 (Surface 2.0/PixelSense) touchscreen
< > Ntrig/Microsoft Surface 3 SPI touchscreen
< > Semtech SX8654 touchscreen
< > TPS6507x based touchscreens
< > Zeitec ZET6223 touchscreen driver
< > Neonode zForce infrared touchscreens
< > ROHM BU21023/24 Dual touch support resistive touchscreens
< > Azoteq IQS550/572/525 trackpad/touchscreen controller
< > Azoteq IQS7210A/7211A/E
< > Zinitix touchscreen support
< > Himax hx83112b touchscreen driver

thats the configuration menu in my own personal libre-kernel compiled with the upstream fsfla .config, and make localmodconfig, I don't have a touch screen, but the facillities for building the kernel are imperfect, and so weird things get stuck in there like this for me: " <*> Elan eKTH I2C touchscreen "

My kernel has support for that driver built into it, and I don't even have a touch screen...

This is also the libre-kernel config, so if any drivers are removed completely from the libre-kernel they don't show up in my configuration menu. (that's my understanding, Im sure technically it is more different)

Anyways, that is how you fix the problem, you have to discover whether or the kernel has support for your specific device, and whether or not different desktop environments have support for your specific device.

Generally speaking all of this stuff is very much proprietary technology, just looking at these drivers, but so is anything else, that's how the world is made, as to whether or not they respect/support people's freedom/security I do not know.

and the tablets menu in the same config.. (for the libre-kernel, the standard kernel may be different, I do not know yet)

--- Tablets
< > Acecad Flair tablet support (USB)
< > Aiptek 6000U/8000U and Genius G_PEN tablet support (USB)
< > Hanwang Art Master III tablet support (USB)
< > KB Gear JamStudio tablet support (USB)
< > Pegasus Mobile Notetaker Pen i
< > Wacom protocol 4 serial tablet support