EOI in getting SPI going on the RPi5 solved read First post for updated info

The RPi5 has always had spi support via the /dev/spidevX interface. The hm2_spi will load and communicate with a 7c81, but is only in using halrun, once you add it to a servo thread it falls over, this is really to be expected, as the man page suggests it is really not suitable. This is the behavior I have witnessed.
The issue was never whether spi is available or works on the RPi5. The issue is register level access via the linuxcnc driver. The Hm2_rpspi driver is aimed at the RPi3/4, getting access to the SPI interface is well documented. The inclusion of the RP1 sitting on the PCIe bus is the game changer.

To sum it up.
1. The RPi5 has an SPI interface that is usable via the /dev/spidev* interface. Of course this needs to be enabled via the usual method.
2. Hardware & register level access, as used in the current hm2_rpsi driver, requires a new driver.
3. If the code includes the bcm2835 header the rule of thumb is that it is not compatible with the RPi5.

Maybe the heading of this thread is not exactly spot on.

Some work being done here by ScotA:
forum.linuxcnc.org/18-computer/54190-rp1...ver-for-the-rp1-chip

Yeah saw that, but to tell you the truth lost interest.
Got burnt out providing answers and on the rare occasions I had one getting SFA in return.
Tho the tipping point was the when I had a fix for the ipv6 thing and the missing icons on the lower panel.
Had some members pulling from the wrong repo and whinging that it didn’t work. Others saying the sources I was using were out of date and you couldn’t build a Debian iso in Mint. And a complete lack of anyone willing to help and. Even from the few locals that have my number and call me for help.
So I’ve quietly said fuck it.

There’s much smarter, patient and personable people around.

RANT, skip freely:
Welcome to the club!
I was OK with wasting hours to have any use from RPI3B as it was 35$ (65 Euro here), cheap enough to warrant a bit of tinkering, it was slow sluggish, cr@ppy,slow USB, even slower LAN, but it worked
RPI4 came out and the price went sky high, so the price to fun ratio went out the door.
Then came RPI5 and it's seven hardware versions in the first months and a price tag worthy of a kingdom, so i am out.
I blame people who buy it to a certain point, i absolutely blame youtubers in 3D printing for insisting you need RPI to run Klipper, a 30$ used SFF PC is much, much better at Klipper and does not stop mid print when doing timelapses, ruining time and material and nerves.
By now, my list of banned stuff has gotten really, really long, RPI is there, together with Microshaft, Adobe, Intel, BMW, MSI, etc, etc...
Not only RPI, any SBC lately is over 150$, add a screen and it gets to 300$ easily, i can buy new laptops for 200-250 Euro on sale here with 1 year warranty, they are cr@ppy laptops but magnificent RPI alternative, with day long battery life when screen if off!

SPI is now supported on the RPI5 so 7C80,7C81,7I90 will work with the RPI5.
Still need to add a force-8-bit option to Mesaflash as the kernel driver doesn't
support 32 bit transfers but seems to report that it can.

 

Sounds great Pete.
Will give it shot once the heat backs off.