Waveshare CAN 2CH FD HAT - Overlay spi1-3cs conflict with RpiGpioSetup GPIO16

[dersch81]

As written at the RpiGpioSetup issue we need to replace spi1-3cs with spi1-1cs:

#### begin CAN overlay
# Waveshare 2-channel Isolated CANbus FD Hat
# instantiates as can0 and can1 ONLY !!!
# use udev rules to rename
[all]
dtoverlay=spi1-1cs
dtoverlay=mcp251xfd,spi0-0,interrupt=25
dtoverlay=mcp251xfd,spi1-0,interrupt=24
#### end CAN overlay

You already deliver this overlay at /data/VeCanSetup/spi1-1cs.dtbo

This file has to move to /u-boot/overlays as well.

[dersch81]

As a side note. spi1-3cs is only neccessary in case of two 2CH FD CAN Hats in a stack. So nearly nobody will use that on the Venus side, i guess.

That's why we can go in general with the spi1-1cs setting. In case of a stack there will not be any gpio free to use with RpiGpio and this will be a special individual case.

[dersch81]

Hi, can you merge this request?

[kwindrem]

Sorry, thought I'd done this already, but not. I'll get on it.

[kwindrem]

Done

[dersch81]

Many thanks. BTW: i just noticed that the FD HAT is also working with that entry in u-boot/config.txt without VeCanSetup installed out of the box ;)

[kwindrem]

Yes, I don't doubt that it works without VeCanSetup. There will of course be conflicts with using GPIO pins for digital inputs and relay outputs set up in RpiGpioSetup and the spi1-3cs that's included in the Venus OS image.

The other issue is some CANbus hats randomly switch channels on can0 and can1 even though those are specified in confit.txt. And there would be conflicts with any USB CANbus adapters installed at the same time. VeCanSetup addresses these issues.

[dersch81]

But the conflicts with RpiGpio are adressed from the RpiGpio side with specific mapping (on what we worked together)?

What we also found is, that for this specific HAT in combination with RpiGpio the spi1-1cs is the right choice to use.

Anyway. Many thanks for your support. Now we have a full functional 2CH FD HAT without any issue with RpiGpio AND ShutdownPin anymore. We can use now everything together without any compromise.

[kwindrem]

Are you saying that if you specify spi1-1cs in config.txt that spi1-3cs.dtbo doesn't enable conflicting pins? And that the hat works without RpiGpio conflicts?

If so, do I need to install spi1-1cs.dtbo? This would be good if so.

[dersch81]

Yes, because spi1-3cs is occupying pins used by RpiGpio alternate GPIO List (17 & 16). Even they are not in use for the HAT. The additional pins are used to use 2x FD Hats in a stack.

spi1-1cs is not occupying pins 17 & 16.

https://github.com/Ysurac/raspberry_kernel_mptcp/blob/master/arch/arm/boot/dts/overlays/spi1-1cs-overlay.dts

https://github.com/Ysurac/raspberry_kernel_mptcp/blob/master/arch/arm/boot/dts/overlays/spi1-3cs-overlay.dts

Therefore to use spi1-1cs in general is the right choice. Only users with two FD Hats in a stack will need spi1-3cs, but that's a rare case, i guess.

I'm using RPIGpio with alternate GPIO List, Shutdown PIN and the FD HAT with 2CH with spi1-1cs at the same time now and it is working fine. As you remember we had to change a lot but now it is solved.

[kwindrem]

OK, thanks. Yes adding additional CANbus hats is not something VeCanSetup supports.

So I'll leave things as they are now.

[dersch81]

Here is the PIN List of the HAT for your reference