Hi,

after a long time I started up my C4 and tried both the standard download kernel as well as a home compiled one.

I need SPI on the C4, so I changed the device tree to meson-sm1-odroid-c4-spidev.dtb, and see spidev kernel modul loaded, but no driver, and I don't get any signals on the corresponding pins.

Any help is appreciated - would be great to have SPI working again...

See you, Michael

Hello Michael,

 

Unfortunately I am bit late to the party, but it seems that you have to specify fdtfile in armbianEnv.txt. The path needs to be amlogic/..., exactly like discovered in

Otherwise you won't be able to boot and need to edit the file with another linux/unix. Add this to your /boot/armbianEnv.txt

# Add to /boot/armbianEnv.txt
fdtfile=amlogic/meson-sm1-odroid-c4-spidev.dtb
overlays=spi0 spi-spidev spidev # TODO check which one is the right one ;)
#param_spidev_spi_bus=0 # Not needed at least for spidev0.x

 

Changing the status to "okay" in meson-sm1-odroid-c4.dtb does not do the trick, despite getting high hopes reading https://wiki.odroid.com/odroid-c4/application_note/gpio/spi#tab__odroid-c4.

 

Nevertheless it can't hurt to check the status in meson-sm1-odroid-c4-spidev.dtd:

fdtget /boot/dtb/amlogic/meson-sm1-odroid-c4-spidev.dtb /soc/bus@ffd00000/spi@15000 status
fdtget /boot/dtb/amlogic/meson-sm1-odroid-c4-spidev.dtb /soc/bus@ffd00000/spi@15000/spidev@0 status

 

Make sure to load the spidev kernel module at startup, i.e. by adding to /etc/modules

# Append /etc/modules
spidev

 

Note: I did a diff between both de-compiled dtb files, but haven't checked yet, if something else could be affected by using the spidev variant.

 

Hope this helps! I would highly appreciate it, if you could have a look into the overlays= / param_spidev_bus= and report your findings. Thanks in advance!

 

Best,
Daniel G.

Will check after some other issues, thanks for your input! We use an Odroid C2 meanwhile, it is slow, but works.

Let me revive this thread, finally I found time to get into the issue again.
I use the latest C4 server image (Ubuntu 24.04).
Changes made so far: I added a line
 

fdtfile=amlogic/meson-sm1-odroid-c4-spidev.dtb

into the armbianEnv.txt, which seems at least to load the spidev kernel module.
A /dev/spidev0.0 is created, and I can use the standard test program found on https://github.com/KnCMiner/spi-test/blob/master/spi-test.c

It seems to work, there are no errors invoking the program, but the I/Os of SPI stay inactive, no matter what I do.

gpioinfo shows the lines on PIN_19, PIN_21, PIN_23 and PIN_24 as "unused":

Seem that basically the SPI controller is working, but the I/O mux is not setup correctly.

 

Anyone who can contribute here? I can test with logic analyzer, in case some input is given to me

 

Thanks to Igor, I have a patch now in the build system (own branch - fix-spi-c4). Would be nice if someone could countercheck if that one also works in other place than mine.