[PATCH synaptics] Add synaptics orientation support

[Aapo Rantalainen]

> On Fri, Mar 18, 2011 at 04:26:46PM +1000, Peter Hutterer wrote:
> Hi Aapo,
>
> I noticed this patch in the synaptics repo today. Unfortunately, it needs
> a bit more work, so I've reverted it for now. Please find my comments
> inline.
> fwiw, patches to synatics should go to the xorg-devel list first for public
> review.

Hi, this patch is extended (=longer) version of my patch, so I hope
Christoph would comment this too.

I made this patch (three years ago) because I thought there was need
for this missing feature.

User scenario:
User has laptop with touchpad. User rotates laptop (physical device)
to portrait. Display is rotated, automatically or manually.
Then user move finger on touchpad from top to bottom (real life coordinate)
( http://forum.eeeuser.com/viewtopic.php?pid=140403 )

Expected:
Mouse cursor is moving from top to bottom on the screen.
http://www.youtube.com/watch?v=VOQds5DfC60

Actual happens:
Mouse cursor is moving horizontally (left or right).

*
Today I know that wacom has same kind of feature, but I think only
drawing board is then rotated, not the display. (So it is not good
idea that display always know it's orientation and forces axes to all
interface device).

What is then common for wacom/synaptics/others? Is there a point to
tune this synaptics-patch or is this doable on server level? (Or some
other better way?)

> why not use degrees here?
> "left" doesn't have a clear meaning. -> "90 degrees clockwise"
> I'm more of a fan of the  "rotation",
> just because xrandr uses 0-3 doesn't make it a good idea ;)

If this patch is only for touchpad, is there really use for arbitrary degrees?

-Aapo Rantalainen