Use portal2 editor on Ubuntu 12.04

I have installed portal 2 on Steam as a native application not trough Wine. Is it possible to to use the editor trough Steam on Ubuntu 12.04? Somebody tried?

Found that my graphics card is still not supported by ATI with Linux drivers :D

Some useful links which I will probably not try to follow:

http://wiki.cchtml.com/index.php/Ubuntu_Saucy_Installation_Guide

http://wiki.cchtml.com/index.php/Hardware

https://help.ubuntu.com/community/BinaryDriverHowto/AMD

http://steamcommunity.com/app/221410/discussions/0/846938351012409765/#p7

https://launchpad.net/ubuntu/+source/fglrx-installer-experimental-13

I tried to install proprietary driver for Steam from System Settings -> Additional Drivers. All went well until I restarted. I saw the Ubuntu logo and then black screen.

I fixed this issue by restarting my laptop from the ACPI button and then booting to Ubuntu recovery mode. Enabled networking and then loaded root mode. Typed these commands:

sudo apt-get purge fglrx -y
sudo apt-get update
sudo apt-get dist-upgrade // this is not necessary but you can upgrade your system t0 latest updates

restart

I also downloaded AMD legacy driver from here: http://geeko.ioda.net/mirror/amd-fglrx-legacy/raw-src/

amd-driver-installer-catalyst-13.1-legacy-linux-x86.x86_64.run

in terminal I run:

sudo amd-driver-installer-catalyst-13.1-legacy-linux-x86.x86_64.run --buildpkg Ubuntu/precise

It will create three deb files. I installed the first one: fglrx_8.970-0ubuntu1_i386.deb

sudo dpkg -i fglrx_8.970-0ubuntu1_i386.deb

Then restart. And as I can see it works :D I can play Portal on my Ubuntu 12.04. But ok I see "AMD Unsupported hardware" icon on bottom right of screen.

Next thing is to install Portal 2 and Editor.