Say Y here if you have a Matrox G100, G200, G400, G450 or G550 based
video card. If you select "Advanced lowlevel driver options", you
should check 8 bpp packed pixel, 16 bpp packed pixel, 24 bpp packed
pixel and 32 bpp packed pixel. You can also use font widths
different from 8.

If you need support for G400 secondary head, you must say Y to
"Matrox I2C support" and "G400 second head support" right below.
G450/G550 secondary head and digital output are supported without
additional modules.

The driver starts in monitor mode. You must use the matroxset tool
(available at <ftp://platan.vc.cvut.cz/pub/linux/matrox-latest/>) to
swap primary and secondary head outputs, or to change output mode.
Secondary head driver always start in 640x480 resolution and you
must use fbset to change it.

Do not forget that second head supports only 16 and 32 bpp
packed pixels, so it is a good idea to compile them into the kernel
too. You can use only some font widths, as the driver uses generic
painting procedures (the secondary head does not use acceleration
engine).

G450/G550 hardware can display TV picture only from secondary CRTC,
and it performs no scaling, so picture must have 525 or 625 lines.

source code:

drivers/video/fbdev/matrox/