What is this how do i get and use it ?

[Kroltez]

This is the only thing with spi and dma support how to I get it and its surrounding files, how to I install it ?

http://lxr.free-electrons.com/source/dr ... -bcm2835.c

[mfa298]

At a quick glance that looks like the kernel module for spi which should already be on the Pi. You'll need to enable the spi device (either using raspi-config or editing /boot/config.txt) and then /dev/spidev* devices should appear after the next boot.

Edit: for the advanced information the kernel documentation https://www.kernel.org/doc/Documentation/spi/ might be useful.