[嵌入式linux]CAN/CAN FD配置及测试

How to test CAN/CANFD in linuxThe Linux kernel supports CAN with the SocketCAN framework.Driver installation$ make linux-menuconfigNetworking support---><M>CAN bus subsystem...

Lenz's law

12195人浏览 · 2020-01-06 17:15:01

Lenz's law · 2020-01-06 17:15:01 发布

How to test CAN/CANFD in linux

The Linux kernel supports CAN with the SocketCAN framework.

Driver installation

$ make linux-menuconfig
Networking support  --->
    <M>   CAN bus subsystem support ---> 
        --- CAN bus subsystem support
        <M>   Raw CAN Protocol (raw access with CAN-ID filtering)
        <M>   Broadcast Manager CAN Protocol (with content filtering)
              CAN Device Drivers  --->
                  <M> Virtual Local CAN Interface (vcan)
                  <M> Platform CAN drivers with Netlink support
                  [*]   CAN bit-timing calculation   
                  <M> Microchip 251x series SPI CAN Controller

RootFs

You need to prepare 3 components for the root file system.

要在linux下面配置和测试CAN，需要安装以下三个组件。

iproute2 （配置CAN接口时需要）
libsocketcan（使用CAN必须）
can-utils (CAN的测试小工具，linux下测试CAN比较好用应用程序)

下面提供buildroot和源码安装两种方式，根据自己的情况取其一就可以了。

iproute2

buildroot

Package Selection for the target  --->
    Networking applications  --->
        [*] iproute2

Source install

Download:Index of /pub/linux/utils/net/iproute2/

Edit config.mk : Modify "AR" and "CC" according to the compiler you are using.

ifeq ("$(origin V)", "command line")
  VERBOSE = $(V)
endif
ifndef VERBOSE
  VERBOSE = 0
endif
ifeq ($(VERBOSE),1)
  Q =
else
  Q = @
endif

ifeq ($(VERBOSE), 0)
    QUIET_CC       = @echo '    CC       '$@;
    QUIET_AR       = @echo '    AR       '$@;
    QUIET_LINK     = @echo '    LINK     '$@;
    QUIET_YACC     = @echo '    YACC     '$@;
    QUIET_LEX      = @echo '    LEX      '$@;
endif
AR:=aarch64-linux-gnu-ar
CC:=aarch64-linux-gnu-gcc
TC_CONFIG_NO_XT:=y
IP_CONFIG_SETNS:=y
CFLAGS += -DHAVE_SETNS
CFLAGS += -DNEED_STRLCPY

%.o: %.c
	$(QUIET_CC)$(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(CPPFLAGS) -c -o $@ $<
TC_CONFIG_XT:=n

make&install

cd ${BR_BINARIES_DIR}/iproute2-4.20.0
make clean
make
make install DESTDIR=$TMP_ROOT_DIR

libsocktcan

buildroot

Target packages  --->
        Libraries  --->
            Networking  --->
                [*] libsocketcan

can-utils

buildroot

Target packages  --->
        Networking applications  --->
            [*] can-utils

Usage of can-utils

Link up
1. CAN 2.0 link up
```
ip link set can0 up type can bitrate 100000
```
2. CAN FD link up
```
ip link set can0 up type can bitrate 500000 dbitrate 2000000  fd on
```
- - If the following error occurs when you do the last instruction :
```
ip: either "dev" is duplicate, or "type" is garbage
```
    check that this command: # which ip return this message: /sbin/ip and not this one : /bin/ip If the binary is installed in /bin instead of /sbin, the executable file is a link to busybox and the command to set the bitrate doesn't work on busybox, so try the following instructions: $ make busybox-clean $ make busybox-dirclean $ make menuconfig Package Selection for the target ---> Networking applications ---> [*] iproute2 $ make Then, reflash your rootfs.

Send can frames

#The following command sends 3 bytes on the bus (0x1E, 0x10, 0x10) with the identifier 500.
cansend can0 500#1E.10.10

#You can send a remote request message
cansend can0 500#R 

#gen and send random frames
cangen can0 -I i -m -v -n 100 -g 10

cansen 后的帧数据格式详解如下

* Examples:
 *
 * 123# -> standard CAN-Id = 0x123, len = 0
 * 12345678# -> extended CAN-Id = 0x12345678, len = 0
 * 123#R -> standard CAN-Id = 0x123, len = 0, RTR-frame
 * 123#R0 -> standard CAN-Id = 0x123, len = 0, RTR-frame
 * 123#R7 -> standard CAN-Id = 0x123, len = 7, RTR-frame
 * 123#R8_9 -> standard CAN-Id = 0x123, len = 8, dlc = 9, RTR-frame
 * 7A1#r -> standard CAN-Id = 0x7A1, len = 0, RTR-frame
 *
 * 123#00 -> standard CAN-Id = 0x123, len = 1, data[0] = 0x00
 * 123#1122334455667788 -> standard CAN-Id = 0x123, len = 8
 * 123#1122334455667788_E -> standard CAN-Id = 0x123, len = 8, dlc = 14
 * 123#11.22.33.44.55.66.77.88 -> standard CAN-Id = 0x123, len = 8
 * 123#11.2233.44556677.88 -> standard CAN-Id = 0x123, len = 8
 * 32345678#112233 -> error frame with CAN_ERR_FLAG (0x2000000) set
 *
 * 123##0112233 -> CAN FD frame standard CAN-Id = 0x123, flags = 0, len = 3
 * 123##1112233 -> CAN FD frame, flags = CANFD_BRS, len = 3
 * 123##2112233 -> CAN FD frame, flags = CANFD_ESI, len = 3
 * 123##3 -> CAN FD frame, flags = (CANFD_ESI | CANFD_BRS), len = 0
 *     ^^
 *     CAN FD extension to handle the canfd_frame.flags content

例子：

cansend can0 1F334455##0112233445566778899aabbccdd

cansend can0 1F334455##1112233445566778899aabbccdd

cansend can0 1F334455##3112233445566778899aabbccdd

补充

can在linux下的配置，详细的内容还是参见：https://www.kernel.org/doc/Documentation/networking/can.txt

$ ip link set can0 type can help
Usage: ip link set DEVICE type can
[ bitrate BITRATE [ sample-point SAMPLE-POINT] ] |
[ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1
phase-seg2 PHASE-SEG2 [ sjw SJW ] ]

[ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] |
[ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1
dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ]

[ loopback { on | off } ]
[ listen-only { on | off } ]
[ triple-sampling { on | off } ]
[ one-shot { on | off } ]
[ berr-reporting { on | off } ]
[ fd { on | off } ]
[ fd-non-iso { on | off } ]
[ presume-ack { on | off } ]

[ restart-ms TIME-MS ]
[ restart ]

Where: BITRATE := { 1..1000000 }
SAMPLE-POINT := { 0.000..0.999 }
TQ := { NUMBER }
PROP-SEG := { 1..8 }
PHASE-SEG1 := { 1..8 }
PHASE-SEG2 := { 1..8 }
SJW := { 1..4 }
RESTART-MS := { 0 | NUMBER }

  Example configuring 500 kbit/s arbitration bitrate and 4 Mbit/s data bitrate:

    $ ip link set can0 up type can bitrate 500000 sample-point 0.75 \
                                   dbitrate 4000000 dsample-point 0.8 fd on
    $ ip -details link show can0
    5: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 72 qdisc pfifo_fast state UNKNOWN \
             mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can <FD> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
          bitrate 500000 sample-point 0.750
          tq 50 prop-seg 14 phase-seg1 15 phase-seg2 10 sjw 1
          pcan_usb_pro_fd: tseg1 1..64 tseg2 1..16 sjw 1..16 brp 1..1024 \
          brp-inc 1
          dbitrate 4000000 dsample-point 0.800
          dtq 12 dprop-seg 7 dphase-seg1 8 dphase-seg2 4 dsjw 1
          pcan_usb_pro_fd: dtseg1 1..16 dtseg2 1..8 dsjw 1..4 dbrp 1..1024 \
          dbrp-inc 1
          clock 80000000