CAN Bus

Note: The configuration mentioned in this chapter is already enabled in the run-leda.sh script.

QEMU

General documentation about using CAN-Bus in Qemu: https://www.qemu.org/docs/master/system/devices/can.html

Enabling Virtual CAN Bus interfaces (vcan)

No special parameters are necessary for qemu, as vcan is virtual:

runqemu qemux86-64 nographic slirp qemuparams="-m 2048"

Bring interface up:

ip link add dev vcan0 type vcan
ip link set vcan0 up

Enabling CAN Bus interfaces (can)

Standalone CAN within Qemu

To run a standalone CAN setup, qemu must be instructed to emulate a specific CAN hardware device. We will be using the kvaser_pci device in this example:

runqemu qemux86-64 nographic slirp qemuparams="-m 2048 -object can-bus,id=canbus0 -device kvaser_pci,canbus=canbus0"

After the image has booted, load the Linux Kernel Module kvaser_pci device driver and configure the CAN-Bus device (eg bitrate) before bringing the interface up:

root@qemux86-64:~# modprobe kvaser_pci

root@qemux86-64:~# dmesg | grep kvaser
[    9.565149] kvaser_pci 0000:00:04.0: initializing device 10e8:8406
[    9.569308] kvaser_pci 0000:00:04.0: reg_base=00000000d5a68095 conf_addr=000000002b3c7ef6 irq=20
[    9.596942] kvaser_pci 0000:00:04.0: xilinx version=13 number of channels=0

root@qemux86-64:~# ip link show type can
4: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can

Configure the interface:

root@qemux86-64:~# ip link set can0 type can bitrate 1000000
[  165.519919] kvaser_pci 0000:00:04.0 can0: setting BTR0=0x00 BTR1=0x14

root@qemux86-64:~# ip link set can0 up
[  186.906065] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready

root@qemux86-64:~# ip link show type can
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10
    link/can

Tunneling a CAN Interface from the Host

runqemu qemux86-64 nographic slirp qemuparams="-m 2048 -object can-bus,id=canbus0 -object can-host-socketcan,id=canhost0,if=can0,canbus=canbus0 -device kvaser_pci,canbus=canbus0"

Bring interface up:

ip link add dev can0 type can
ip link set can0 type can bitrate 1000000
ip link set can0 up
ip link show type can

Raspberry Pi CAN HAT Extensions

Supported boards:

  • Boards with a Microchip MCP251x based CAN chip, such as Waveshare CAN HAT or PiCAN 2

Verify driver is loaded:

# dmesg | grep mcp
[    8.23543] mcp251x spi0.0 can0: MCP2515 successfully initialized

Verify SocketCAN network interface shows up:

# ip link show type can
3: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT roup default qlen 10

Continue with configuring the CAN chip and bring up the SocketCAN network interface:

# ip link set can0 type can bitrate 1000000
# ip link set can0 up
# ip link show type can

Linux Kernel Modules

The following Linux Kernel modules are available on the quickstart images:

Note: For QEMU, only kvaser_pci is used

Leda main Kernel

  • peak_pciefd - Socket-CAN driver for PEAK PCAN PCIe/M.2 FD family cards
  • m_can - CAN bus driver for Bosch M_CAN controller
  • m_can_pci - CAN bus driver for Bosch M_CAN controller on PCI bus
  • m_can_platform - M_CAN driver for IO Mapped Bosch controllers
  • softing - Softing DPRAM CAN driver
  • cc770_platform - Socket-CAN driver for CC770 on the platform bus
  • cc770_isa - Socket-CAN driver for CC770 on the ISA bus
  • cc770 - cc770CAN netdevice driver
  • ifi_canfd - CAN bus driver for IFI CANFD controller
  • kvaser_usb - CAN driver for Kvaser CAN/USB devices
  • etas_es58x - Socket CAN driver for ETAS ES58X USB adapters
  • ucan - Driver for Theobroma Systems UCAN devices
  • peak_usb - CAN driver for PEAK-System USB adapters
  • kvaser_pciefd - CAN driver for Kvaser CAN/PCIe devices
  • kvaser_pci - Socket-CAN driver for KVASER PCAN PCI cards
  • f81601 - Fintek F81601 PCIE to 2 CANBUS adaptor driver
  • sja1000_isa - Socket-CAN driver for SJA1000 on the ISA bus
  • plx_pci - Socket-CAN driver for PLX90xx PCI-bridge cards with the SJA1000 chips
  • sja1000 - sja1000CAN netdevice driver
  • ems_pci - Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards
  • peak_pci - Socket-CAN driver for PEAK PCAN PCI family cards
  • sja1000_platform - Socket-CAN driver for SJA1000 on the platform bus
  • vxcan - Virtual CAN Tunnel
  • c_can_platform - Platform CAN bus driver for Bosch C_CAN controller
  • c_can - CAN bus driver for Bosch C_CAN controller
  • c_can_pci - PCI CAN bus driver for Bosch C_CAN/D_CAN controller
  • slcan - serial line CAN interface
  • can_dev - CAN device driver interface
  • vcan - virtual CAN interface
  • can-isotop - PF_CAN isotp 15765-2:2016 protocol
  • can-gw - PF_CAN netlink gateway
  • can-j1939 - PF_CAN SAE J1939
  • can-raw - PF_CAN raw protocol
  • can-bcm - PF_CAN broadcast manager protocol
  • can - Controller Area Network PF_CAN core

Raspberry Pi

The following Linux Kernel modules are available on the quickstart image for Raspberry Pi:

  • can - Controller Area Network PF_CAN core
  • vxcan - Virtual CAN Tunnel
  • can-dev - CAN device driver interface
  • can-bcm - PF_CAN broadcast manager protocol
  • can-gw - PF_CAN netlink gateway
  • can-raw - PF_CAN raw protocol
  • can-isotop - PF_CAN isotp 15765-2:2016 protocol
  • can-j1939 - PF_CAN SAE J1939
  • vcan - virtual CAN interface
  • slcan - serial line CAN interface
  • mcp251x - Microchip 251x/25625 CAN driver
  • mcp251xfd - Microchip 251xFD Family CAN controller driver
  • ems_usb - CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces
  • gs_usb - Socket CAN device driver for Geschwister Schneider UG
  • peak_usb - CAN driver for PEAK-System USB adapters