Hi I am working on Colibri iMX6ULL module and I want to use CAN peripheral. I used the below reference and edited the device tree source include file (.dtsi)
What should be my next step?
Hi, I’m the Toradex AI Assistant. I’m in early beta, and I would appreciate your feedback.
The Toradex Support team will follow up with you shortly!
Did you like my answer?
Hello,
After editing the device tree source file to enable the CAN peripheral by setting the status of the &can1 and/or &can2 node to okay, your next steps should involve recompiling the device tree and deploying it to your Colibri iMX6ULL module. Here’s a concise guide on what to do next:
-
Recompile the Device Tree: Use the appropriate commands to compile the device tree source files into a binary format (.dtb). This process typically involves using the
dtc(Device Tree Compiler) tool or executing a build process through a build system like Yocto Project or Buildroot, depending on how you manage your software development. -
Deploy the Compiled Device Tree: Copy the compiled device tree binary to the boot partition of your module or use the U-Boot environment to tell the bootloader where to find the new device tree file. The exact method may vary depending on your setup and whether you’re using a carrier board’s specific configurations.
-
Reboot the Module: After deploying the new device tree, reboot your Colibri iMX6ULL module to apply the changes. The system will use the updated device tree on boot, enabling the CAN peripheral as configured.
-
Verify the CAN Interface: Once the system is up, verify that the CAN interface is recognized and correctly configured by the kernel. You can use the
ip link showcommand to list all network interfaces, including CAN interfaces. If the CAN interface is correctly enabled, it should appear in the list. -
Configure the CAN Interface: Before using the CAN interface, you’ll need to configure it with the appropriate settings for your CAN network, such as bitrate. This can be done using the
iporifconfigcommand-line tools. -
Test the CAN Interface: Finally, test the CAN interface to ensure it’s working as expected. You can use can-utils, a collection of utilities for Linux designed to work with CAN networks, to send and receive CAN frames.
Remember, any changes to the device tree or system configuration should be thoroughly tested to ensure they do not adversely affect your system’s stability or functionality.
Best regards,
Toradex AI Assistant
Please, also check if these links can help you solve your problem:
Hi @kp_2024,
To enable can, do device tree modification as per article and make sure pins assigned to can node is not used elsewhere.
Best regards
Ritesh Kumar
yes, I made the modifications as mentioned. But I am confused that what should be my next step- Do I regenerate the image directly using $bitbake core-image-minimal or is there a step I am missing in between?
Hi @kp_2024,
At this moment I will suggest if you can work with source code outside oe build specially for device tree. Please check below article:
Once you verified your device tree, then you can move to oe/yocto to generate final image.
Best regards
Ritesh Kumar
Thanks! This will definitely help me…
Hello Ritesh,
I build the device tree binary (dtb) with the applied changes as mentioned in the https://developer.toradex.com/linux-bsp/application-development/peripheral-access/can-linux#kernel-support-colibri-imx6ull
Once the dtb file is build, I copied it and pasted it into my core-image-minimal tezi file (unzipped) replacing the imx6ull-colibri-eval-v3.dtb file (old).
I rebooted the module with the new image (containing new dtb file), but sill I cannot see any device of CAN using command: $ip link show or $ifconfig
Could you guild me here little bit as the above steps that I mentioned are correct or not?
Thanks
Krutarth Purohit
hi @kp_2024 ,
You must have forgotten to check whether the CAN pins are used somewhere else or not and to disable them.
In your case, looking into the imx6ull-colibri.dtsi file, can0 and can1 pins (pinctrl_gpio3 pinctrl_gpio7) are used in &iomux.
Please delete/comment out these pins , recompile the device tree and test.
If you did something wrong with pinmuxing, like pins assigned to different modules, then something like dmesg | grep iomux should reveal such issues.
If you enable some node in DT, or do other changes in DT, inspecting /sys/firmware could help confirming got your changes successfully applied or not. For example checking for can status=“okay” could look like this
# find /sys/firmware -name "*can*"
/sys/firmware/devicetree/base/soc/bus@40000000/iomuxc@40048000/vf610-colibri/can0grp
/sys/firmware/devicetree/base/soc/bus@40000000/iomuxc@40048000/vf610-colibri/can_int
/sys/firmware/devicetree/base/soc/bus@40000000/iomuxc@40048000/vf610-colibri/can1grp
/sys/firmware/devicetree/base/soc/bus@40000000/spi@4002d000/can@0
/sys/firmware/devicetree/base/soc/bus@40000000/spi@4002d000/mcp2518fd@0/microchip,txcan-open-drain
/sys/firmware/devicetree/base/soc/bus@40000000/can@40020000
/sys/firmware/devicetree/base/soc/bus@40080000/can@400d4000
/sys/firmware/devicetree/base/aliases/can0
/sys/firmware/devicetree/base/aliases/can1
# ls /sys/firmware/devicetree/base/soc/bus@40000000/can@40020000
clock-names compatible name pinctrl-names status
clocks interrupts pinctrl-0 reg
# cat /sys/firmware/devicetree/base/soc/bus@40000000/can@40020000/status
disabled
Hi thanks for replying, I have run the command and it seems like CAN-0 device is running.
root@localhost:~# find /sys/firmware/ -name "*can*"
/sys/firmware/devicetree/base/__symbols__/pinctrl_flexcan1
/sys/firmware/devicetree/base/__symbols__/can2
/sys/firmware/devicetree/base/__symbols__/pinctrl_flexcan2
/sys/firmware/devicetree/base/__symbols__/pinctrl_can_int
/sys/firmware/devicetree/base/__symbols__/can1
/sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2090000
/sys/firmware/devicetree/base/soc/aips-bus@2000000/spba-bus@2000000/spi@2008000/can@0
/sys/firmware/devicetree/base/soc/aips-bus@2000000/iomuxc@20e0000/imx6ull-colibri/flexcan2-grp
/sys/firmware/devicetree/base/soc/aips-bus@2000000/iomuxc@20e0000/imx6ull-colibri/flexcan1-grp
/sys/firmware/devicetree/base/soc/aips-bus@2000000/iomuxc@20e0000/imx6ull-colibri/canint-grp
/sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2094000
root@localhost:~#
root@localhost:~#
root@localhost:~# ls /sys/firmware/devicetree/base/soc/aips-bus@2000000/spba-bus@2000000/spi@2008000/can@0/
clocks name reg xceiver-supply
compatible phandle spi-max-frequency
interrupt-parent pinctrl-0 status
interrupts pinctrl-names vdd-supply
root@localhost:~# cat /sys/firmware/devicetree/base/soc/aips-bus@2000000/spba-bus@2000000/spi@2008000/can@0/status
okay
This is about MCP2515 SPI-CAN device on eval-v3 board, which is enabled by default in BSP. Your first message, at least the reference in it, was about SOC build-in FlexCAN devices, so you should check your DT flexcan instances:
cat /sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2090000/status
cat /sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2094000/status
hi,
I check the status of the flexcan, it was ‘disabled’ earlier, so I modified the device tree and change it’s status to ‘okay’.
**root@localhost:~#** cat /sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2090000/status
okay
**root@localhost:~#** cat /sys/firmware/devicetree/base/soc/aips-bus@2000000/flexcan@2094000/status
okay
Now, am I supposed to see any CAN device when I enter command: $ifconfig -a OR $ip link show? because I am not getting any CAN device.
root@localhost:~# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
link/ether 00:14:2d:6a:45:4f brd ff:ff:ff:ff:ff:ff
root@localhost:~# ifconfig -a
eth0: flags=4098<BROADCAST,MULTICAST> mtu 1500 metric 1
ether 00:14:2d:6a:45:4f txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 metric 1
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Kernel config should have FLEXCAN driver enabled. You may verify it with
# zcat /proc/config.gz | grep FLEXCAN
CONFIG_CAN_FLEXCAN=m
both =m and =y would be OK.
If flexcan is enabled, then dmesg should mention problems, which make driver probe fail. Try
dmesg | grep flexcan or dmesg | grep pinmux. If none finds something, then just try reading whole dmesg output. Some problems should be listed there
Hi I run the commands mentioned by you, here are the output:
root@localhost:~# zcat /proc/config.gz | grep FLEXCAN
CONFIG_CAN_FLEXCAN=m
root@localhost:~# dmesg | grep flexcan
root@localhost:~# dmesg | grep pinmux
The flexcan module is present but there is no mention of flexcan OR pinmux in the dmesg log.
Does lsmod list flexcan driver? Perhaps no loaded modules at all?
I noticed that there are no modules available for CAN when I checked using lsmod. However, I inserted CAN kernel modules - can.ko , can-dev.ko , can-raw.ko and flexcan.ko using insmod command.
Thank you both of you for your time and efforts.
Something is wrong on your side. Those modules should be autoloaded. Perhaps you have zImage from one compilation / config and modules from another one. You should compile both and populate both modules and kernel to target.
It seems that, minimal image do not auto-load the kernel module. I build the toradex the multimedia image and checked for the kernel modules that are present.
**root@colibri-imx6ull-06964559:~#** lsmod
Module Size Used by
rfcomm 69632 2
bnep 24576 2
usb_f_rndis 32768 2
u_ether 24576 1 usb_f_rndis
mcp251x 20480 0
can_dev 28672 1 mcp251x
mwifiex_sdio 36864 0
btmrvl_sdio 32768 0
btmrvl 24576 1 btmrvl_sdio
mwifiex 282624 1 mwifiex_sdio
bluetooth 491520 31 btmrvl_sdio,bnep,rfcomm,btmrvl
cfg80211 331776 1 mwifiex
imx_sdma 36864 2
virt_dma 16384 1 imx_sdma
secvio 16384 0
libcomposite 61440 10 usb_f_rndis
configfs 45056 3 usb_f_rndis,libcomposite
I believe that multimedia image autoloades the kernel module.
Looks like you are using colibri-imx6ull-wifi . Did you modify DT files for colibri-imx6ull or colibri-imx6ull-wifi? You wrote previously that you saw status=okay in /sys/firmware for flexcan instances, so looks like you modified right files? Anyway, with status=okay, enabled driver in config, you should see flexcan module loaded automatically. Even if driver fails to probe, since it was okay, module should be loaded.
Yes, earlier I was editing colibri-imx6ull-eval-v3.dts but later I found out that my image was using colibri-imx6ull-wifi-eval-v3.dtb to load the device tree. Apologies, I should have clarified this earlier in our conservation.
I downloaded the the source code of the kernel (kernel version that is compatible with my BSP 5.x.y) and generated the kernel image [zImage] (colibri-imx6ull_defconfig) along with CAN-enabled device tree binary. Then I replaced both the image into my unzipped Toradex-Image-Tezi folder present in my USB stick.