SpiDev on 21.12

Hello,

I can’t activate SpiDev with debian version 21.12 on the dragonboard 410c. I followed the whole procedure described here:

Enabling SPI on Dragonboard 410c with SPIDEV

I checked in the configuration file and found:

CONFIG_SPIDEV=m

The procedure goes smoothly but after restarting SpiDev is not present in /dev. I also tried doing modprobe spidev, without success.

I then returned to version 21.03 and the enabling of SpiDev works perfectly with the same procedure.

Thanks in Advance.

The technique described in that guide cannot be applied on recent kernels because it is (deliberately) no longer supported. See [PATCH] spidev: Make probe to fail early if a spidev compatible is used - Javier Martinez Canillas for more details.

Some users have reported that a small source code change can reenable spidev support: SPIDEV not available on top of LS interface SPI2 - #6 by reda_zaiti ).

Alternatively you could set up a DT uses a real compatible string instead of “spidev”. If that new “correct” compatible string is unknown to the spidev driver then you should be able to force it to bind regardless (or alternatively add a suitable compatible string to the spidev driver):

echo spidev > /sys/bus/spi/devices/spiX.Y/driver_override
echo spiX.Y > /sys/bus/spi/drivers/spidev/bind

PS depending on what hardware you are connecting it might be better to enable one of the kernel drivers instead of using spidev…

Thank you for your reply.
I think I will rather stop using spidev if it is no longer supported.