TDA4VM: CAN access from Linux - using TDA4VM SK

Stefan_Haas

Mastermind 25482 points

Part Number: TDA4VM

(on behalf of a customer)

Hello,

Is there a solution to directly access CAN ports from TDA4VM SK A72/Linux side?

Ideally Linux accessing the CAN peripheral directly, alternatively communicating to MCUSW from Linux.

This needs to be usable for the TDA4VM Starter Kit board, i.e. the TDA4VM SK SDK needs to be used.

Thanks, Stefan

over 3 years ago

0 Karan Saxena over 3 years ago

TI__Guru* 77985 points

Hi Stefan,

I tested internal loopback for CAN on the SK EVM, please see the below logs.

tda4vm-sk login: [   25.339217] process 'docker/tmp/qemu-check010933481/check' started with executable stack

tda4vm-sk login: root
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# dmesg | grep -i can
[    0.659909] sysfs: cannot create duplicate filename '/devices/platform/dma_buf_phys'
[    7.718414] CAN device driver interface
[    8.099101] tidss 4a00000.dss: [drm] Cannot find any crtc or sizes
[    9.581775] m_can_platform 40528000.can: m_can device registered (irq=20, version=32)
[    9.595913] m_can_platform 2701000.can: m_can device registered (irq=42, version=32)
[    9.611884] m_can_platform 2751000.can: m_can device registered (irq=44, version=32)
[    9.627052] m_can_platform 2791000.can: m_can device registered (irq=46, version=32)
root@tda4vm-sk:/opt/edge_ai_apps# ip link set can0 type can bitrate 1000000 dbitrate 5000000 fd on loopback on
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# ip link set can0 up
[  477.749173] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# candump can0 &
[1] 1398
[  485.846762] can: controller area network core
[  485.851167] NET: Registered protocol family 29
root@tda4vm-sk:/opt/edge_ai_apps# [  485.861522] can: raw protocol

root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# cansend can0 113##2AAAAAAAA
  can0  113  [04]  AA AA AA AA
  can0  113  [04]  AA AA AA AA
root@tda4vm-sk:/opt/edge_ai_apps# cansend can0 113##2AAAAAAAA
  can0  113  [04]  AA AA AA AA
  can0  113  [04]  AA AA AA AA
root@tda4vm-sk:/opt/edge_ai_apps# cansend can0 113##2AAAAAABB
  can0  113  [04]  AA AA AA BB
  can0  113  [04]  AA AA AA BB

I am yet to test Tx and Rx from the board for which I would need to make sure the CAN transceiver configuration is correct for the SK.

As far as the driver is concerned with internal loopback working fine, that piece is flow flushed and you can use CAN directly from A72 running Linux.

I will post back with the patches to enable the CAN transceiver and pinmux for the CAN on this thread.

Regards

Karan

0 Karan Saxena over 3 years ago in reply to Karan Saxena

TI__Guru* 77985 points

Hi Stefan,

I tested Tx from the SK and that works fine too. Essentially the transceiver configuration was already taken care of by the DTB in the SDK.

Please find the below logs:

tda4vm-sk login: [   21.820376] Initializing XFRM netlink socket
root
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# [   25.158189] process 'docker/tmp/qemu-check694855289/check' started with executable stack
rate 5000000 fd onype can bitrate 1000000 dbitr
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# ip link set can0 type can bitrate 1000000 dbitrate 5000000 fd on
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# ip link set can0 up
[   67.103316] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps#
root@tda4vm-sk:/opt/edge_ai_apps# cansend can0 113##2AAAAAAAA
[   75.662276] can: controller area network core
[   75.666667] NET: Registered protocol family 29
[   75.678134] can: raw protocol
root@tda4vm-sk:/opt/edge_ai_apps# cansend can0 113##2AAAAAAAB
root@tda4vm-sk:/opt/edge_ai_apps#

Reception on PCAN tool: