CAN總線
CAN是控制器局域網絡(Controller Area Network, CAN)的簡稱，是由以研發和生產汽車電子產品著稱的德國BOSCH公司開發的，並最終成爲國際標準（ISO 11898），是國際上應用最廣泛的現場總線之一。 在北美和西歐，CAN總線協議已經成爲汽車計算機控制系統和嵌入式工業控制局域網的標準總線，並且擁有以CAN爲底層協議專爲大型貨車和重工機械車輛設計的J1939協議。
配置can
user@server:~$ cat /etc/can_setup.sh
#!/bin/sh
modprobe can
modprobe can_raw
modprobe mttcan
ip link set can0 up type can bitrate 500000 restart-ms 5000
ip link set can1 up type can bitrate 500000 restart-ms 5000
驗證can
user@server:~$ ip -details -statistics link show can0
8: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
link/can promiscuity 0
can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 5000
bitrate 498701 sample-point 0.870
tq 26 prop-seg 33 phase-seg1 33 phase-seg2 10 sjw 1
mttcan: tseg1 2..255 tseg2 0..127 sjw 1..127 brp 1..511 brp-inc 1
mttcan: dtseg1 1..31 dtseg2 0..15 dsjw 1..15 dbrp 1..15 dbrp-inc 1
clock 38400000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 0 0 0 0 0 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
RX: bytes packets errors dropped overrun mcast
2984408 373051 0 0 0 0
TX: bytes packets errors dropped carrier collsns
210824 26870 0 0 0 0
檢查dmesg消息
user@server:~$ dmesg |grep can
[ 0.000000] OF: fdt:memory scan node memory, reg size 48,
[ 1.521230] tegra-pwm 3280000.pwm: PWM clk can sleep in ops
[ 1.521649] tegra-pwm c340000.pwm: PWM clk can sleep in ops
[ 1.522360] tegra-pwm 32c0000.pwm: PWM clk can sleep in ops
[ 1.522751] tegra-pwm 32f0000.pwm: PWM clk can sleep in ops
[ 6.330840] FAN: can't find tach_gpio
[ 21.855925] can: controller area network core (rev 20120528 abi 9)
[ 21.868303] can: raw protocol (rev 20120528)
[ 21.912229] net can0: mttcan device registered (regs=ffffff800d141000, irq=69)
[ 21.926728] net can1: mttcan device registered (regs=ffffff800d147000, irq=70)
[ 21.934051] mttcan c310000.mttcan can0: bitrate error 0.2%
[ 21.934179] mttcan c310000.mttcan can0: Bitrate set
[ 21.934238] mttcan_controller_config: ctrlmode 0
[ 21.934252] mttcan c310000.mttcan can0: Bitrate set
[ 21.934310] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
[ 21.949344] mttcan c320000.mttcan can1: bitrate error 0.2%
[ 21.949478] mttcan c320000.mttcan can1: Bitrate set
[ 21.949546] mttcan_controller_config: ctrlmode 0
[ 21.949563] mttcan c320000.mttcan can1: Bitrate set
[ 21.949621] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready
檢查candump輸出
user@server:~$ candump can0 |head
can0 607 [8] 61 00 00 00 0F A0 06 C8
can0 601 [8] 00 3C 00 02 01 01 44 0B
can0 602 [8] 00 00 00 00 00 00 00 00
can0 605 [8] 1F C8 4D 40 00 2C F6 00
can0 606 [8] 80 01 37 E0 00 39 00 00
can0 602 [8] 00 00 00 00 00 00 00 00
can0 601 [8] 00 3C 00 02 01 01 44 0C
can0 605 [8] 1F BA 4C F0 00 30 29 00
can0 606 [8] 80 01 37 E0 00 39 00 00
can0 607 [8] 61 00 00 00 0F A0 07 C9