My attempt at Haskell USB

[Maurí­cio]

 >> (...)

> foreign import ccall "libusb_get_device_address"
>  libusb_get_device_address
>     :: Ptr libusb_device -> IO Word8
> 
> is it normal libusb_device is written in lower case, not Libusb_device ?

No!

Could this make a case for requiring explicit foralls?

I think not :) My mistake, just corrected, cabal will generate
documentation again after some time.

Thanks,
Maurício