Make port roles more flexible. We have modems that do PPP
on interfaces other than the primary interface, and that
wasn't possible with the old code. So clean up all that
logic and move the port organization code into the core
so we can reduce code in the plugins.
In the new world order, the plugins say whether the port
is a QCDM port, an AT port, or ignored. If it's an AT
port the plugins get to tag it as primary, secondary, or
PPP, or any combination of the 3. This allows for modems
where PPP should really be done on the secondary port
(Huawei E220, Sierra devices) so that the primary port
stays open for command and status.
Modem subclasses no longer get asked to handle port grabbing
themselves. Instead, that's now done by the generic classes
(MMGenericCdma and MMGenericGsm) and the plugins are notified
when a port is grabbed so they can add unsolicited response
handlers for it. After all ports are grabbed by the generic
classes, they get "organized", which assigns various ports
to the roles of PRIMARY, SECONDARY, DATA, and QCDM based
on specific rules and hints that the plugin provided (which
are expressed as MMAtPortFlags). The plugins then have
a chance to perform fixups on the primary port if they choose.
The plugin code is responsible for determining the port
hints (ie MMAtPortFlags) at probe time, instead of having
a combination of the plugin and the modem class do the
job. This simplifies things greatly for the plugins at
the expense of more complicated logic in the core.
Using AT+CFUN=1,0 so that we request to avoid resetting (<rst>=0). Works
properly when powering up after having put the modem in standby mode with
AT+CFUN=4.
Note that the power-up command will only be sent if the check to see if power-up
is needed requests it.
For 3G devices in Class A, AT+WWSM can be used to get or set the allowed mode:
* +WWSM: 0 (2G only)
* +WWSM: 1 (3G only)
* +WWSM: 2,0 (Any)
* +WWSM: 2,1 (2G preferred)
* +WWSM: 2,2 (3G preferred)
For 2G devices, there is no such command, so we will default to Any and allow
2G-only and 2G-preferred setups.
These modems can be configured to use different mobile classes. For each kind of
modem, the best mobile class is the highest one in the following order:
- Class A (3G only mode)
- Class B (PS or CS, GPRS/EDGE or GSM)
- Class CG (PS only, GPRS/EDGE)
- Class CC (CS only, GSM)
