7e0663f922
Users with QMI or MBIM capable modems may want to ensure that these
are never managed using plain AT commands, as that also involves using
PPP. This fallback to AT could happen if the QMI or MBIM port probing
fails for whatever reason.
The new `ID_MM_REQUIRED` udev tag allows specifying that a given port
MUST be successfully grabbed when creating a new modem object, or
otherwise the modem object will not be created at all (even if there
are other fallback control ports like AT that could have been used).
Use this tag with caution.
It is assumed that when this tag is used some other external process
may be monitoring the existence of the modem object in DBus as exposed
by ModemManager, and if it does not appear for any reason then the
modem would be reseted with some other mechanism (e.g. GPIOs, if
available). If no such mechanism to autorecover the modem is in place,
using this tag may leave the modem exposed in the kernel but ignored
by ModemManager.
This tag must be applied on the specific port for which the existence
and usability must be ensured.
E.g. flagging the MBIM port of the Fibocom L850 module as required:
$ vim /lib/udev/rules.d/78-mm-test.rules
ACTION!="add|change|move|bind", GOTO="mm_test_rules_end"
SUBSYSTEMS=="usb", ATTRS{bInterfaceNumber}=="?*", ENV{.MM_USBIFNUM}="$attr{bInterfaceNumber}"
ATTRS{idVendor}=="2cb7", ATTRS{idProduct}=="0007", ENV{.MM_USBIFNUM}=="00", ENV{ID_MM_REQUIRED}="1"
LABEL="mm_test_rules_end"
$ sudo udevadm control --reload
$ sudo udevadm trigger
$ sudo udevadm info -p /sys/class/usbmisc/cdc-wdm0
...
E: ID_MM_REQUIRED=1
E: ID_MM_CANDIDATE=1
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 provide 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+. Code of Conduct. Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms, which you can find in the following link: https://www.freedesktop.org/wiki/CodeOfConduct CoC issues may be raised to the project maintainers at the following address: modemmanager-devel-owner@lists.freedesktop.org