[Buildroot] Fwd: Use the CAN0 device on beaglebone black

[Andy Bergh]

Looks like I never sent the answer to the buildroot group. Quickly
correcting that as it solved my problem.

---------- Forwarded message ---------
From: Andy Bergh <allmyaddmin at gmail.com>
Date: Fri, May 14, 2021 at 5:52 PM
Subject: Re: [Buildroot] Use the CAN0 device on beaglebone black
To: Robert Nelson <robertcnelson at gmail.com>


Hi Robert,

This did the trick, thank you very much! I appreciate your time to answer
my question!





*ls -ls /sys/class/net/total 0     0 lrwxrwxrwx    1 root     root
    0 Jan  1 00:04 can0 ->
../../devices/platform/ocp/481cc000.can/net/can0     0 lrwxrwxrwx    1 root
    root             0 Jan  1 00:00 eth0 ->
../../devices/platform/ocp/4a100000.ethernet/net/eth0     0 lrwxrwxrwx    1
root     root             0 Jan  1 00:00 lo ->
../../devices/virtual/net/lo     0 lrwxrwxrwx    1 root     root
  0 Jan  1 00:04 sit0 -> ../../devices/virtual/net/sit0*

Regards

On Fri, May 14, 2021 at 3:49 PM Robert Nelson <robertcnelson at gmail.com>
wrote:

> On Fri, May 14, 2021 at 2:37 AM Andy Bergh <allmyaddmin at gmail.com> wrote:
> >
> > Hi,
> >
> > How can I use the CAN0 device with a Buildroot image?
> >
> > I have a Beaglebone black rev C and have built an image using Buildroot.
> I used the standard beaglebone_defconfig and installed can-utils as well as
> iproute2.
> >
> > My understanding is that the i2c2 pins should be reconfigured to be able
> to use the CAN0 device. In order to keep things simple (and avoid overlays)
> I edit the "am335x-bone-common.dtsi" file in two ways.
> >
> > 1) Comment out the i2c2 and insert the CAN0 pin setup:
> >
> > //    i2c2_pins: pinmux_i2c2_pins {
> > //        pinctrl-single,pins = <
> > //            0x178 (PIN_INPUT_PULLUP | MUX_MODE3)    /*
> uart1_ctsn.i2c2_sda */
> > //            0x17c (PIN_INPUT_PULLUP | MUX_MODE3)    /*
> uart1_rtsn.i2c2_scl */
> > //        >;
> > //    };
> >
> > dcan0_pins: pinmux_dcan0_pins {
> >         pinctrl-single,pins = <
> >             0x178 (PIN_OUTPUT_PULLUP | MUX_MODE2)  /* P9.20 (0x178),
> ddcan0_tx */
> >             0x17c (PIN_INPUT_PULLUP | MUX_MODE2)   /* P9.19 (0x17c),
> ddcan0_rx */
> >         >;
> >     };
> >
> > 2) Replace i2c2 with
> > &dcan0 {
> >     #address-cells = <1>;
> >     #size-cells = <1>;
> >     status = "okay";
> >     pinctrl-names = "default";
> >     pinctrl-0 = <&dcan0_pins>;
> >
> > };
> >
> > Once I log in I can not get any CAN device going anywhere:
> > # ifup can0
> > Cannot find device "can0"
> > # ifconfig can0 up
> > ifconfig: SIOCGIFFLAGS: No such device
> >
> > And looking at the available networks
> >
> > # ls -al /sys/class/net/
> > total 0
> > drwxr-xr-x    2 root     root             0 Jan  1 00:00 .
> > drwxr-xr-x   43 root     root             0 Jan  1 00:00 ..
> > lrwxrwxrwx    1 root     root             0 Jan  1 00:00 eth0 ->
> ../../devices/platform/ocp/4a100000.ethernet/net/eth0
> > lrwxrwxrwx    1 root     root             0 Jan  1 00:00 lo ->
> ../../devices/virtual/net/lo
> > lrwxrwxrwx    1 root     root             0 Jan  1 00:02 sit0 ->
> ../../devices/virtual/net/sit0
> >
> > I have exhausted all resources and am truly stuck. Any information which
> may help will be greatly appreciated.
>
> Double check your kernel config:
>
> CONFIG_CAN_C_CAN=y
> CONFIG_CAN_C_CAN_PLATFORM=y
>
> Regards,
>
> --
> Robert Nelson
> https://rcn-ee.com/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.busybox.net/pipermail/buildroot/attachments/20210515/54c6b1a7/attachment-0002.html>