Aleksander Morgado
31215aba32
For loading current capabilities we use a mix of "Technology Preference" (TP), "System Selection Preference" (SSP) and DMS-reported capabilities. But, as we also use TP and SSP for allowed modes, it may be the case that we end up leaving 4G out of the allowed modes, which afterwards will make the modem not report LTE as current capabilitiy, as TP/SSP don't include LTE. So, just assume LTE is a current capability if DMS-reported capabilities include it. We can really do this because LTE is the only 4G technology, the same logic wouldn't apply correctly for 2G or 3G (due to having different techs for 3GPP and 3GPP2).
ModemManager. The problem ModemManager tries to solve is to provide a unified high level API for communicating with (mobile broadband) modems. While the basic commands are standardized, the more advanced operations (like signal quality monitoring while connected) varies a lot. Using. ModemManager is a system daemon and is not meant to be used directly from the command line. However, since it provides DBus API, it is possible to use 'dbus-send' command to control it from the terminal. There's an example program (tests/mm-test.py) that demonstrates the basic API usage. Implementation. ModemManager is a DBus system bus activated service (meaning it's started automatically when a request arrives). It is written in C. The devices are queried from udev and automatically updated based on hardware events. There's a GInterface (MMModem) that defines the modem interface and any device specific implementation must implement it. There are two generic MMModem implementations to support the basic operations (one for GSM, one for CDMA,) which are common for all cards. 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 MMModem 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's a fully working plugin in the plugins/ directory for Huawei cards that can be used as an example for writing new plugins. Writing new plugins is highly encouraged! API. The 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!