Adding rotation to xf86-video-omapfb

[Denis 'GNUtoo' Carikli]

Hi,

I've been trying to add rotation to the out of tree
xf86-video-omapfb(I'm aware of xf86-video-omap but I've an omap3, and
beside, it requires a staging kernel driver).

So far I got rotation working(xrandr -o 1 works).

But when I want to rotate back (xrandr -o 0) Xorg checks if the
requested X resolution is smaller or equals to the masimum allowed
Xresolution and it fails...

The thing is that I've been using a hack to make it work:
instead of keeping the same resolution and just making rotate the
display content, I've changed the resolution too.

My device is the GTA04 and it has a 480x640 display, so when rotating a
new mode is created(640x480):
root at om-gta04:~# xrandr -q
Screen 0: minimum 8 x 8, current 640 x 480, maximum 480 x 640
LCD connected 640x480+0+0 left (normal left inverted right x axis y
axis) 0mm x 0mm
   640x480        66.8 +
  480x640 (0x41)   22.2MHz
        h: width   480 start  504 end  512 total  520 skew    0 clock
42.6KHz
        v: height  640 start  644 end  646 total  648           clock
65.7Hz

This shouldn't happen and instead I should use the normal approach,
which is not to change the resolution...

But that fails too: My display is in portrait mode, and so when
rotating the image changes to 640x480, from the point 0.0 and isn't
rotated, which result in the image going over the physical screen
dimentions...

The code I've been developing is here:
https://gitorious.org/gnutoo-s-programs-for-shr/xf86-video-omapfb/commit/834a2b938cbff98e6f69ff66789cf422e3e2d483

I'd like to make the "correct way" work and rotate, but I've no idea of
how...

Denis.