gpm should have support for devices with absolute coordiantes (touchscreens), and should have a way to calibrate them.
Created attachment 122158 [details, diff] gpm-1.20.1-evabs.patch Patch for gentoo-patched gpm-1.20.1 to support devices with absolute coordinates and to calibrate them.
Created attachment 122159 [details] gpm-1.20.1-r5.ebuild ebuild that includes the evabs patch
Created attachment 122163 [details] gpm-1.20.1-evabs.patch fixed segfault on non-existant config-file
please bring this patch to the attention of upstream, we are not them.
yes, considering the current state of upstream gpm, enhancements should be sent to the gpm list