[review] Provide TAC in addition to LAC in Location interface

[Aleksander Morgado]

Hey all,

This MR updates the Location interface to provide a separate Tracking
Area Code value (TAC) in addition to the Location Area Code (LAC).

https://gitlab.freedesktop.org/mobile-broadband/ModemManager/merge_requests/22

The generic AT-based modem implementation is updated so that the CEREG
is considered to be reporting TAC, as well as GREG when AcT is LTE (as
per 3GPP TS 27.007).

The QMI based modem implementation is also updated, so that TAC values
are read and considered in the location info in addition to the LAC
values (NAS APIs give both LAC and TAC fields in LTE, not totally sure
why).

I'm working on an MBIM implementation using AT&T extensions that also
provide TAC and LAC separately.

My only concern right now would be that clients using the API used to
expect TAC given in the LAC field (we were doing that implicitly when
parsing CREG/CEREG), and that would no longer be true. Zeeshan, would
this be a big issue for geoclue?

Comments?

-- 
Aleksander
https://aleksander.es