What needs to happen is to write the device name to the spidev driver's
bind attribute to manually attach. Because of driver_override, this
will work, rather than fail as it does without.
Unfortunately, "bind" is an attribute of the driver while udev is
responding to a uevent for the device. So there's no handy ATTR{bind}
to use.
I don't recall the exact udev magic, but I did verify it can be done.
I think it needed udev to run a command, something like:
RUN+="echo %k > %S/%p/subsystem/drivers/spidev/bind"
Thanks. It turned out to be a bit more complicated because attributes set
by ATTR{driver_override}+="spidev" only take effect after the rule has been
processed, apparently. It's quite easy to hack around this. Here's a
complete rule which works for me:
# cannot use ATTR{driver_override}+="spidev" because it apparently only
runs after the PROGRAM
ACTION=="add|change", SUBSYSTEM=="spi",
ENV{MODALIAS}=="spi:my-device-from-device-tree", PROGRAM+="/bin/sh -c 'echo
spidev > %S%p/driver_override && echo %k >
%S%p/subsystem/drivers/spidev/bind'"
Thanks for pointing me in the right direction, Trent and Geert.
With kind regards,
Jan
