finding my way among my el files

[Rustom Mody]

My emacs comes with orgmode 7.4
The org which I use is the later one 7.7 (which resides say under my
.emacs/myelisp)

But when I do (info "org") I get 7.4 not 7.7's docs

I can of course write my own function info-org which hardcodes my path.
But I wonder how hard it is to find my way using relative paths.

In particular C-h f foo
emacs knows where foo's def is because I can click through to the file
having foo's definition

If say that were available in a variable func-file-name then I could
info-open (file-name-directory func-file-name)/../doc/org

How to get func-file-name?