libqmi is a library for talking to devices that speak the QMI protocol, like
Qualcomm Gobi cellular modems.

References:

In the code, there are references to some of Qualcomm's open-source code that
documents portions of the QMI protocol.  Here is a guide to where to find
that code:

[Gobi]: https://www.codeaurora.org/patches/quic/gobi/Gobi/Gobi_2012-01-12-1106.tar.gz
[Gobi3000Net]: https://www.codeaurora.org/patches/quic/gobi/Gobi3000/GobiNet_2011-07-29-1026.tar.gz
[Gobi3000API]: https://www.codeaurora.org/patches/quic/gobi/Gobi3000/GobiAPI_2011-07-29-1026.tar.gz

In addition, there are some references to Chromium OS's old rewrite of the
GobiNet kernel driver:

[cros-kernel]: http://git.chromium.org/gitweb/?p=chromiumos/third_party/kernel.git