The recent gpm package (version >=1.8, maybe earlier versions contain touchpad support, too) includes the above mentioned Synaptics touchpad device driver. This device driver has been developed by H. Davies <hdavies_AT_ameritech.net>. Instead of using the PS/2 compatibility mode of touchpad devices, you can now use native touchpad mode with some pretty impressive features.
In addition to translating finger motion into mouse motion and supporting the buttons, this support currently has several features (from the README):
a "tap" on the TouchPad causes a left mouse click
a "tap" followed quickly by a finger motion causes a left button drag type action.
a "tap" in one of the corners causes an action the default configuration is upper right causes middle mouse click and lower right causes right mouse click
more pressure on the touch pad speeds the motion of the cursor
a "tap" with a motion component (default > 2mm) initiates a toss and catch sequence. This is terminated by a finger touch on the pad (the toss also ends after 1 sec since that is the idle timeout period for the touchpad).
if the finger moves close to an edge then the mouse motion will be continued in that direction so that you don't need to pick up your finger and start moving again. This continued motion is pressure sensitive (more pressure is faster motion).
These features can be enabled/disabled and many of them have time and speed parameters which can be adjusted to the taste of the user.
It seems gpm is best known as a console biased tool. This is true, but you may use it as an X11 input device. gpm is used as a repeater device. In this way you can use both the built-in synaptics touchpad with all the features and at the same time a serial mouse (with three buttons). This all works smoothly together. X11 reads the mouse events from a named pipe /dev/gpmdata in a protocol it understands, which in my case is Mouse-Systems-Compatible (5bytes). Most 3-button mice use the default protocol. So a simple reconfiguration in XF86Config is all that is required, after starting gpm in an appropriate way, of course.
gpm could be started on your laptop with the following arguments : /usr/bin/gpm -t synps2 -M -t ms -m /dev/ttyS0 . Both touchpad and serial mouse work in console and X11 mode. You do have to create the named pipe /dev/gpmdata yourself.
Tapping with two fingers simultaneously to simulate a middle mouse button works on Logitech touchpads used in a few machines.
Thanks to Geert Van der Plas for most of the touchpad chapter.
