Create parallel helper functions that use libmtp to walk the file tree on the
device and to then read a specific file from the device into our dc_buffer.
MTP is not a file system, it's an object storage, that just happens to allow
object names and parent/child relationships between objects. As a result we
need to remember those file ids for MTP downloads.
The mtp_get_file_list function is rather complex as it includes both the
initial communication with the device and the code to walk the object tree and
then create the list of file.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This ends up being just a file interface for dive computers that expose
their data as a filesystem that can be mounted.
Right now that's only the Garmin Descent Mk1, although technically the
Uemis Zurich also did that (but oddly, and the backend was never merged
into libdivecomputer).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
