Raspberry Pi - driver and overlay available for seeed-can-fd-hat

[menschel]

Hi,

there is now support for seeed-can-fd-hat in regular raspberry pi kernel.

raspberrypi/linux#4034

Please update your readme.md
and the wiki page.

Thanks.

[Pillar1989]

Thank you very much for the PR, we will revise the document as soon as possible, thanks.

[marckleinebudde]

Hey @Pillar1989,

just a quick update, we've renamed the overlays, it's now -v1 for the old mcp2517fd hat and -v2 for the mcp2518fd.

	seeed-can-fd-hat-v1
	seeed-can-fd-hat-v2

[Pillar1989]

@menschel Thank you for the reminder, it is very much appreciated.

[menschel]

Thank you but actually, most of the credit goes to @marckleinebudde .

[marckleinebudde]

We all stand on the shoulders of giants. @menschel had the idea to create a single overlay for the board.

[JakeSays]

Hey @Pillar1989,

just a quick update, we've renamed the overlays, it's now -v1 for the old mcp2517fd hat and -v2 for the mcp2518fd.

	seeed-can-fd-hat-v1
	seeed-can-fd-hat-v2

@marckleinebudde You missed one - the mcp2518fd with the rtc.

[marckleinebudde]

Hey @JakeSays,

the -v2 does include the rtc:

https://github.com/raspberrypi/linux/blob/abdf918004f2a4c203891e94328b8cf76fbae45f/arch/arm/boot/dts/overlays/seeed-can-fd-hat-v2-overlay.dts#L100-L116

	fragment@8 {
		target = <&i2cbus>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;
			pcf85063@51 {
				compatible = "nxp,pcf85063";
				reg = <0x51>;
			};
		};
	};
	fragment@9 {
		target = <&i2c_arm>;
		i2cbus: __overlay__ {
			status = "okay";
		};
	};

Is there a HAT with two mcp2518fd and no RTC?

[menschel]

This list indicates there may have been a second batch of the first design populated with mcp2518fd instead.

https://wiki.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi/#versions-declare

And the first design is missing the RTC.

[marckleinebudde]

Hmmm, ok. If they have the old board populated with a mcp2518fd instead (no RTC) and are using spi1-0 as on the mcp2517fd, then just use the -v1 overlay. All overlays use mcp251xfd as compatible, which auto-detects the exact variant.

Let's wait for Seeed Studio to clarify.

[JakeSays]

@marckleinebudde yeah there is unfortunately. I have two.

[marckleinebudde]

Ok, the we have to clarify the readme.

[marckleinebudde]

What about:

Name:   seeed-can-fd-hat-v1
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD channels
        (based on the mcp2517fd or mcp2518fd), without RTC.
        https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
Load:   dtoverlay=seeed-can-fd-hat-v1
Params: <None>


Name:   seeed-can-fd-hat-v2
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD channels
        (based on the mcp2518fd) and an RTC.
        https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
Load:   dtoverlay=seeed-can-fd-hat-v2
Params: <None>

[menschel]

I believe the battery holder is the "indicator" to distinguish v1 and v2.

The first design has spi0-0 and spi1-0 and no battery holder / RTC.

The second design has the battery holder / RTC and spi0-0 , spi0-1 combination.

So i would drop the (based on .*) entry in favor of a clause to look for the battery holder.

I also believe your

2-Channel CAN FD Master
HAT for Raspberry Pi
www.seeedstudio.com
v1.0 2/28/2020

is hardware identical to my

CAN-BUS(FD) HAT for Raspberry Pi
www.seeedstudio.com
v1.0 6/20/2020

[marckleinebudde]

That all makes sense :)

What about:

Name:   seeed-can-fd-hat-v1
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD channels without RTC. Use this overlay if your HAT has no battery holder.
        https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
Load:   dtoverlay=seeed-can-fd-hat-v1
Params: <None>


Name:   seeed-can-fd-hat-v2
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD channels and an RTC. Use this overlay if your HAT has a battery holder.
        https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
Load:   dtoverlay=seeed-can-fd-hat-v2
Params: <None>

[menschel]

Perfect, don't forget to limit the lines to 80 chars.
Thanks.

[marckleinebudde]

Sure. I was to lazy to copy form here to editor and back here. :)

[marckleinebudde]

rewrapped to 80 chars:

Name:   seeed-can-fd-hat-v1
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
        channels without RTC. Use this overlay if your HAT has no
        battery holder.
        https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
Load:   dtoverlay=seeed-can-fd-hat-v1
Params: <None>


Name:   seeed-can-fd-hat-v2
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
        channels and an RTC. Use this overlay if your HAT has a
        battery holder.
        https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
Load:   dtoverlay=seeed-can-fd-hat-v2
Params: <None>

[dav2dg]

I am trying to get the Seeed CAN HAT (with RTC) working.
Is there a convenient way to get seeed-can-fd-hat-v2.dtbo without doing an rpi-update? This seems like going a bit too far over the bleeding edge.

I used the Image tool and have the following rpi version:
pi@raspberrypi:~ $ uname -a
Linux raspberrypi 5.4.83-v7+ #1379 SMP Mon Dec 14 13:08:57 GMT 2020 armv7l GNU/Linux

but this does not have the dtbo in /boot/overlays which is where I understand they should be.

Assuming I can get a dtbo is all I need to do is update /boot/config.txt
and add...
dtoverlay=seeed-can-fd-hat-v2

Thanks
David

[dav2dg]

I did the rpi-update to
Linux raspberrypi 5.10.20-v7+ #1404 SMP Thu Mar 4 19:40:23 GMT 2021 armv7l GNU/Linux

sudo reboot

then followed the tests on Seed. It all worked.

Thanks