Problem using MCP2515

Technical Support
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1

Hi

I’m using Colibri iMX6 Solo 256MB module in combination with the Colibri Evaluation Carrier Board. I have build kernel and rootfs using Yocto and “bitbake -k console-tdx-image” and repository toradex-bsp-platform and branch LinuxImageV2.7. The HW is up and running and now I try to use CAN using MCP2515 (will later switch to the build-in CAN module). I think that I’m unable to get it up and running correctly.

I have tried to follow the guide here without success: https://developer.toradex.com/knowledge-base/can-(linux)

At boot I can’t see the MCP2515 driver getting loaded like “mcp251x spi3.0: probed”. Some other CAN and SPI related things are still there:

[    1.164641] spi_imx 2014000.ecspi: probed
[    1.171547] vcan: Virtual CAN interface driver
[    1.178032] CAN device driver interface
[    1.183944] spi3.0 supply vdd not found, using dummy regulator
[    1.191762] spi3.0 supply xceiver not found, using dummy regulator
...
[    2.184205] can: controller area network core (rev 20120528 abi 9)
[    2.192296] NET: Registered protocol family 29
[    2.198696] can: raw protocol (rev 20120528)
[    2.204898] can: broadcast manager protocol (rev 20120528 t)
[    2.212469] can: netlink gateway (rev 20130117) max_hops=1

The driver might be there?

root@colibri-imx6:~# zcat /proc/config.gz | grep CONFIG_CAN_MCP251X
CONFIG_CAN_MCP251X=y

Try to start can0, the second command gives no reply

root@colibri-imx6:~# ip link set can0 type can bitrate 250000
root@colibri-imx6:~# ifconfig can0 up


root@colibri-imx6:~# ip -details link show can0
2: 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 restart-ms 0
    bitrate 250000 sample-point 0.875
    tq 250 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    mcp251x: tseg1 3..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000numtxqueues 1 numrxqueues 1

root@colibri-imx6:~# cat /proc/interrupts | grep mcp251x
130:          0  gpio-mxc  27 Edge      mcp251x

root@colibri-imx6:~# ip addr
2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN group default qlen 10
    link/can

I looked at the device tree file, ./tmp-glibc/work-shared/colibri-imx6/kernel-source/arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts, and found this.

&ecspi4 {
	status = "okay";

	mcp258x0: mcp258x@1 {
		compatible = "microchip,mcp2515";
		reg = <0>;
		clocks = <&clk16m>;
		interrupt-parent = <&gpio3>;
		interrupts = <27 0x2>;
		spi-max-frequency = <10000000>;
		status = "okay";
	};
	spidev0: spidev@1 {
		compatible = "toradex,evalspi";
		reg = <0>;
		spi-max-frequency = <23000000>;
		status = "disabled";
	};
};

According to the link above it should be can0:can@1, so I changed that, rebuild kernel and images (“bitbake -f -c compile virtual/kernel” and “bitbake -k console-tdx-image”) and used the new uImage, dtb-file and rootfs. No change.

  1. What is “mcp258x0: mcp258x@1” stand for? Is this right?
  2. What is wrong with my setup?
2

What exact hardware and software versions of things are you talking about?

3

Colibri iMX6 Solo 256MB v1.1A and Colibri Evaluation Carrier Board v3.2B.

According to https://developer.toradex.com/knowledge-base/can-(linux) MCP251x should be enabled from v2.6 and I’m using v2.7.

The SW is from the Yocto build described above. More details:

repo init -u http://git.toradex.com/toradex-bsp-platform.git -b LinuxImageV2.7
repo sync
. export

Edit conf/local.conf

MACHINE ?= "colibri-imx6"

Added to the end:

ACCEPT_FSL_EULA = "1"
DISTRO_FEATURES_remove = "x11 wayland"
IMAGE_INSTALL_remove = "eglinfo-x11"
IMAGE_INSTALL_append = " imx-gpu-viv kernel-module-imx-gpu-viv fsl-gpu-sdk packagegroup-fsl-tools-gpu mtdev tslib gstreamer gst-plugins-base gdb nano"

Build:

bitbake -k console-tdx-image
4

Have you tried it with any of our off-the-shelf images at all?

5

I have in a way “solved” the problem. I started using the “cansend” command (cansend can0 1F334455#1122334455667788) to send CAN data and it didn’t work, wrong identifier and data was the result.

Then I tried a c-code example (SocketCAN example | lnguin) instead and that worked. I also enabled the FlexCAN1 and tried cansend and my own application, same result, only my application transfered the correct data.

I have tried cansend both in Toradex v2.7 image (Colibri-iMX6_LXDE-Image 2.7b4 20171004) and my own Yocto build, same result.

The “ifconfig can0 up” command does not allways give a response, I have only seen it ones och twice. But the “ifconfig can1 up” does allways give you a responce.

6

Hi

Have you tried if you have cansend in the Pengutronix format? i.e.

cansend -e -i 0x1F334455   0x11 0x22 0x33 0x44 0x55 0x55 0x77 0x88

What is “mcp258x0: mcp258x@1” stand for? Is this right?

The mcp258x@1 is just a string naming that node. For a SPI bus one usually ends the string with ‘@X’ to denote which device it is. If that should start with ‘@0’ or ‘@1’ is debatable. The numbering of the CAN network interfaces have nothing to do with this.

Max