This commit enables a new core ModemManager daemon option, so that automatic
detection of available modems is totally disabled: '--no-auto-scan'. Note that
this option also replaces the previously used '--test-no-auto-scan' option,
which was only used during tests.
Along with the new ModemManager option, a new ReportKernelEvent() method in
the API is defined, which allows notifying the daemon of which interfaces it
should be accessing, as well as the main details of each interface. The only
mandatory parameters in the new method are 'action' (add/remove), 'name' (the
name of the interface) and 'subsystem' (the subsystem of the interface).
The mmcli tool has support for using the new api method via several new options:
* The '--report-kernel-event' option allows specifying device ports one by
one, and is a direct mapping of the ReportKernelEvent() method:
$ sudo mmcli --report-kernel-event="action=add,name=wwan0,subsystem=net"
$ sudo mmcli --report-kernel-event="action=add,name=cdc-wdm0,subsystem=usbmisc"
* The '--report-kernel-event-auto-scan' option uses udev monitoring to notify
events automatically to the daemon. This allows to operate in a way
equivalent to the default daemon operation (with implicit auto-scan).
Worth noting that the ReportKernelEvent() method is only usable when
'--no-auto-scan' is explicitly used in the daemon. An error will be reported if
the method is tried while standard udev monitoring is enabled (implicit if
auto scan isn't explicitly disabled in the daemon).
If mmcli is going to be used only to report 'real time' events, an optional
'--initial-kernel-events=[PATH]' may be given in the ModemManager call to
automatically process a set of port kernel events one by one on boot. The file
may e.g. contain:
action=add,name=wwan0,subsystem=net
action=add,name=cdc-wdm0,subsystem=usbmisc
