kbuild - building a module/target from multiple directories

[John Levon <movement@marcelothewonderpenguin.com>]

With kbuild in 2.5, how do I specify that a module/target is to be built of
object files and sub-directories ?

The "obvious" approach :

obj-$(CONFIG_BLAH) := blah.o

blah-objs := blah_init.o blahstuff/

doesn't work. Is there an example of a module doing this ?

findall Makefile | xargs grep '+=' | grep -- -objs | awk -F: '{print $2}' | grep /
isn't promising ...

I'd like to avoid the awkwardness of multiple modules and the
unpleasantness of too many files in a single directory

thanks
john

-- 
"Of all manifestations of power, restraint impresses the most."
	- Thucydides