pi@raspberrypi ~ $ sudo su
# Enable the spi-bcm2708 driver and blacklist the mcp251x driver
root@raspberrypi:/home/pi# nano /etc/modprobe.d/raspi-blacklist.conf
# add the spi-config and the new mcp2515 modules in file /etc/modules
root@raspberrypi:/home/pi# nano /etc/modules
# the network can0 auto connect.
root@raspberrypi:/home/pi# nano /etc/network/interfaces
root@raspberrypi:/home/pi# cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
# Parameters can be specified after the module name.

snd-bcm2835
# MCP2515 configuration with /INT on GPIO25 and 16MHz clock
spi-config devices=\
bus=0:cs=0:modalias=mcp2515:speed=10000000:gpioirq=25:pd=20:pds32-0=16000000:pdu32-4=0x2002:force_release

#and of course the mcp2515 driver
mcp2515

root@raspberrypi:/home/pi# cat /etc/network/interfaces
auto lo

iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

auto can0
iface can0 inet manual
pre-up /sbin/ip link set can0 type can bitrate 125000
up /sbin/ifconfig can0 up
down /sbin/ifconfig can0 down
root@raspberrypi:/home/pi# reboot