TCAN4550EVM: TCAN4550EVM Linux DTS overlay problem

Hello Mattia,

I'm sorry to hear you are having difficulties.  I'm unfortunately not a Linux expert and my expertise is with the TCAN4550 device level register configuration and physical layer properties.  The Linux Developer that created the driver that I was communicating with during the post you referenced is also no longer with the company and this driver has been upstreamed into the Linux Kernel and supported by the Linux community for many years now.

The TCAN4x5x driver is essentially a wrapper around the MCAN driver that was already in Linux to handle the custom SPI register read/write interface.  I believe the can0 interface is really part of the MCAN driver.

I don't really have any specific information to share about what steps you specifically need to follow or may have missed and would suggest trying to locate a more Linux or Raspberry Pi oriented forum that has more Linux based experts that could help. 

Since you have SPI communication established, if you have any device register related questions I can certainly willing an capable of helping you with those, now or in the future.

Regards,

Jonathan

Hi Jonathan,

Thank you for your reply. We managed to figure out what was wrong and solve our issue!

This is the overlay file for the RaspberryPi 4B that we compiled to use the TCAN4x5x over the can0 interface:

# tcan4x5x-overlay.dts

/dts-v1/;
/plugin/;

/ {
    compatible = "brcm,bcm2711";

    fragment@0 {
        target = <&spidev0>;
        __overlay__ {
            status = "disabled";
        };
    };


    fragment@1 {
        target = <&spi0>;
        __overlay__ {
            /* needed to avoid dtc warning */
            #address-cells = <1>;
            #size-cells = <0>;
            tcan4x5x: tcan4x5x@0 {
                compatible = "ti,tcan4x5x";
                reg = <0>;
                spi-max-frequency = <10000000>;
                bosch,mram-cfg = <0x0 30 0 7 7 0 10 10>;                
                interrupt-parent = <&gpio>;
                interrupts = <25 0x2>;
                wakeup-source;
            };
        };
    };

};

Compile and install with:

dtc -@ -I dts -O dtb -o tcan4x5x-overlay.dtbo tcan4x5x-overlay.dts

sudo cp tcan4x5x-overlay.dtbo /boot/firmware/overlays/

Then, in /boot/firmware/config.txt, we added these lines:

dtparam=spi=on
dtoverlay=spi-bcm2711
dtoverlay=tcan4x5x-overlay

Reboot and ifconfig can0 should show the interface!

Hope this is helpful for someone in the future

Mattia