README - chromiumos/third_party/modemmanager-next - Git at Google

 ModemManager.
 ModemManager provides a unified high level API for communicating with mobile
 broadband modems, regardless of the protocol used to communicate with the
 actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...).

 Using.
 ModemManager is a system daemon and is not meant to be used directly from
 the command line. However, since it provides a DBus API, it is possible to use
 'dbus-send' commands or the new 'mmcli' command line interface to control it
 from the terminal. The devices are queried from udev and automatically updated
 based on hardware events, although a manual re-scan can also be requested to
 look for RS232 modems.

 Implementation.
 ModemManager is a DBus system bus activated service (meaning it's started
 automatically when a request arrives). It is written in C, using glib and gio.
 Several GInterfaces specify different features that the modems support,
 including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provice basic
 operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given
 feature is not available in the modem, the specific interface will not be
 exported in DBus.

 Plugins.
 Plugins are loaded on startup, and must implement the MMPlugin interface. It
 consists of a couple of methods which tell the daemon whether the plugin
 supports a port and to create custom MMBroadbandModem implementations. It most
 likely makes sense to derive custom modem implementations from one of the
 generic classes and just add (or override) operations which are not standard.
 There are multiple fully working plugins in the plugins/ directory that can be
 used as an example for writing new plugins. Writing new plugins is highly
 encouraged! The plugin API is open for changes, so if you're writing a plugin
 and need to add or change some public method, feel free to suggest it!

 License.
 The ModemManager and mmcli binaries are both GPLv2+.
 The libmm-glib library is LGPLv2+.
	ModemManager.
	ModemManager provides a unified high level API for communicating with mobile
	broadband modems, regardless of the protocol used to communicate with the
	actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...).

	Using.
	ModemManager is a system daemon and is not meant to be used directly from
	the command line. However, since it provides a DBus API, it is possible to use
	'dbus-send' commands or the new 'mmcli' command line interface to control it
	from the terminal. The devices are queried from udev and automatically updated
	based on hardware events, although a manual re-scan can also be requested to
	look for RS232 modems.

	Implementation.
	ModemManager is a DBus system bus activated service (meaning it's started
	automatically when a request arrives). It is written in C, using glib and gio.
	Several GInterfaces specify different features that the modems support,
	including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provice basic
	operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given
	feature is not available in the modem, the specific interface will not be
	exported in DBus.

	Plugins.
	Plugins are loaded on startup, and must implement the MMPlugin interface. It
	consists of a couple of methods which tell the daemon whether the plugin
	supports a port and to create custom MMBroadbandModem implementations. It most
	likely makes sense to derive custom modem implementations from one of the
	generic classes and just add (or override) operations which are not standard.
	There are multiple fully working plugins in the plugins/ directory that can be
	used as an example for writing new plugins. Writing new plugins is highly
	encouraged! The plugin API is open for changes, so if you're writing a plugin
	and need to add or change some public method, feel free to suggest it!

	License.
	The ModemManager and mmcli binaries are both GPLv2+.
	The libmm-glib library is LGPLv2+.