Aleksander Morgado
1f813c4e96
All ports of the same modem reported by the kernel will all be associated with
a common 'uid' (unique id), which uniquely identifies the physical device. This
logic was already in place, what we do now is avoid calling it the 'sysfs
path' of the physical device, because we may not want to use that to identify
a device.
This logic now also enables the possibility of "naming" the modems in a unique
way by setting the "ID_MM_PHYSDEV_UID" property in the "usb_device" that owns
all the ports.
E.g. a custom device has 4 modems in 4 different USB ports. The device path of
each USB device will always be the same, so the naming rules could go like this:
$ vim /usr/lib/udev/rules.d/78-mm-naming.rules
ACTION!="add|change|move", GOTO="mm_naming_rules_end"
DEVPATH=="/devices/pci0000:00/0000:00:1d.0/usb4/4-1/4-1.5/4-1.5.1", ENV{ID_MM_PHYSDEV_UID}="USB-MODEM-1"
DEVPATH=="/devices/pci0000:00/0000:00:1d.0/usb4/4-1/4-1.5/4-1.5.2", ENV{ID_MM_PHYSDEV_UID}="USB-MODEM-2"
DEVPATH=="/devices/pci0000:00/0000:00:1d.0/usb4/4-1/4-1.5/4-1.5.3", ENV{ID_MM_PHYSDEV_UID}="USB-MODEM-3"
DEVPATH=="/devices/pci0000:00/0000:00:1d.0/usb4/4-1/4-1.5/4-1.5.4", ENV{ID_MM_PHYSDEV_UID}="USB-MODEM-4"
LABEL="mm_naming_rules_end"
Each of the modems found will have a unique UID retrieved from the previous list
of rules. Then, "mmcli" has also been updated to allow using the UID instead of
the modem DBus path or index, e.g.:
$ sudo mmcli -m USB-MODEM-1
/org/freedesktop/ModemManager1/Modem/0 (device id '988d83252c0598f670c2d69d5f41e077204a92fd')
-------------------------
Hardware | manufacturer: 'ZTE CORPORATION'
| model: 'MF637'
| revision: 'BD_W7P673A3F3V1.0.0B04'
| supported: 'gsm-umts'
| current: 'gsm-umts'
| equipment id: '356516027657837'
-------------------------
System | device: 'USB-MODEM-1'
| drivers: 'option'
| plugin: 'ZTE'
| primary port: 'ttyUSB5'
| ports: 'ttyUSB5 (at)'
...
$ sudo mmcli -m USB-MODEM-1 --enable
...
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+.