[LS1028a]: CAN TRANSCEIVER is not working ,when we are checking in loopback.

[Amit_Keshri]

Dear NXP Support Team,

We have ls1028a based custom board in which CAN TRANSCEIVER is connected directly to  processor.we want to check CAN TRANSCEIVER which is connected in loopback i.e CAN0_H is connected to CAN1_H,CAN0_L is connected to CAN1_L,CAN0_GND is connected to CAN1_GND.

We have created small application(can_test) to check CAN in loopback but when we are running application it is throwing below error:

ip: either "dev" is duplicate, or "type" is garbage
ip: either "dev" is duplicate, or "type" is garbage ,after  running below system() call in application :

system("ifconfig can0 down");
system("ip link set can0 up type can bitrate 112500");
system("ifconfig can1 down");
system("ip link set can1 up type can bitrate 112500");
system("ip link set can0 up type can bitrate 112500") 

Below is our dts file configuration for CAN0 & CAN1:

&can0 {
status = "okay";

can-transceiver {

max-bitrate = <5000000>;
};
};

&can1 {
status = "okay";

can-transceiver {

max-bitrate = <5000000>;
};
};

I have attached required information with this post.

Below are my question on this :

How we can test CAN TRANSCEIVER in loopback in linux ?

What modification is required in linux and in  .config files ?

Please help me on this.

Regards,

Amit Keshri

[yipingwang]

On ls1028ardb, 

Internal loopback mode of can0: pin2<->pin7

root@localhost:~# zcat /proc/config.gz | grep -i flexcan

CONFIG_CAN_FLEXCAN=y

root@localhost:~# ifconfig can0 down

root@localhost:~# ip link set can0 up type can bitrate 125000 loopback on

[   47.597118] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready

root@localhost:~# cat /proc/interrupts |grep can0

 20:          0          0     GICv3  53 Level     can0

root@localhost:~# candump can0 &

[1] 1804

root@localhost:~# echo ' SENSORCAN="can0"

> (1234567890.223344)  can0 123#1122

> (1234567890.223380)  can0 123#2223

> (1234567890.223400)  can0 123#3323

> (1234567890.223420)  can0 123#4423

> (1234567890.223460)  can0 123#5523

> '> can0data.txt

root@localhost:~# 

root@localhost:~# echo $?

0

root@localhost:~# cat can0data.txt

 SENSORCAN="can0"

(1234567890.223344)  can0 123#1122

(1234567890.223380)  can0 123#2223

(1234567890.223400)  can0 123#3323

(1234567890.223420)  can0 123#4423

(1234567890.223460)  can0 123#5523

root@localhost:~# canplayer -I can0data.txt

  can0  123   [2]  11 22

  can0  123   [2]  11 22

  can0  123   [2]  22 23

  can0  123   [2]  22 23

  can0  123   [2]  33 23

  can0  123   [2]  33 23

  can0  123   [2]  44 23

  can0  123   [2]  44 23

  can0  123   [2]  55 23

  can0  123   [2]  55 23

root@localhost:~# cat /proc/interrupts |grep can0

 20:         10          0     GICv3  53 Level     can0

root@localhost:~# ip -details -statistics link show can0

2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10

    link/can  promiscuity 0 minmtu 0 maxmtu 0

    can <LOOPBACK> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0

         bitrate 125000 sample-point 0.875

         tq 100 prop-seg 37 phase-seg1 32 phase-seg2 10 sjw 1

         flexcan: tseg1 2..96 tseg2 2..32 sjw 1..16 brp 1..1024 brp-inc 1

         flexcan: dtseg1 2..39 dtseg2 2..8 dsjw 1..4 dbrp 1..1024 dbrp-inc 1

         clock 200000000

         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  

    20         10       0       0       0       0      

    TX: bytes  packets  errors  dropped carrier collsns

    10         5        0       0       0       0        

Would you please try flexcan loopback mode on ls1028ardb first? 

[Amit_Keshri · Accepted solution]

Dear NXP Support Team,

Thank you for your reply.

After doing below things CAN loopback start working:

1.CONFIG_CAN_FLEXCAN=y in .config files

2.Install ip tool and copy in /usr/sbin directory in rootfs.

Regards,

Amit Keshri