Handing Control of Sentelic Touchpads to Synaptics

Éric Piel E.A.B.Piel at tudelft.nl
Mon Jul 19 07:43:00 PDT 2010

Op 19-07-10 16:03, David Regev schreef:
> I have an MSI Wind U100, which comes with a Sentelic touchpad.
> Apparently, its driver is already in the kernel.[1] Unfortunately, the
> driver does not provide any of the typical features you would expect
> from a touchpad, most notably edge scrolling. Instead, it uses hot zones
> that are mapped to buttons 4–7. From what I can tell, the Synaptics
> driver is meant to provide these features for non-Synaptics as well.
> This was confirmed by Peter Hutterer, who suggested I bring up this
> issue here.[2]
> So, my question is: Would it be possible to have Synpatics handle this
> touchpad and, thus, provide some of the standard touchpad features? I
> would like to help in whatever way I can.
Looking at the kernel driver code, the problem is that it only reports
position in relative mode. The X touchpad driver (aka synaptics)
requires absolute position reports to work.

That said, it seems that the original driver [1] had both relative and
absolute mode (cf fsp_onpad_icon()). It would be interesting to find out
why in the kernel merge, it was the relative mode which was kept,
although absolute mode looks much more obvious for a touchpad.

If this is just a wrong decision (ie: absolute mode works fine with the
hardware), you just need to patch the kernel driver, and it should work
automagically with the X.org driver :-) I don't have the hardware, but I
can help you with kernel driver hacking if you need guidance :-)

See you,


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