As we've introduced virtual inheritance to support EMACInterface, we can
no longer use C-style casts or static_cast to downcast from
NetworkInterface to more specific types. RTTI is disabled in the
toolchains, so dynamic_cast is unavailables.
Add virtual downcast methods to permit conversions to the 6 derived
classes. Probably only needed for EMACInterface, WiFiInterface and
EthInterface, but handles the set.
For keep supporting external APIs with the same name (supposedly there are a larger
number of users of those APIs), BufferedSerial and ATParser are being renamed.
BufferedSerial becomes UARTSerial, will complement a future USBSerial etc.
ATParser becomes ATCmdParser.
* UARTSerial moves to /drivers
* APN_db.h is moved from platform to cellular/util/.
* Original CellularInterface is restored for backward compatability (again, supposedly there
are users of that).
* A new file, CellularBase is added which will now servce as the base class for all
upcoming drivers.
* Special restructuring for the driver has been undertaken. This makes a clear cut distinction
between an on-board or an off-board implementation.
- PPPCellularInterface is a generic network interface that works with a generic FileHandle
and PPP. A derived class is needed to pass that FileHandle.
- PPPCellularInterface provides some base functionality like network registration, AT setup,
PPP connection etc. Lower level job is delegated to the derived classes and various modem
specific APIs are provided which are supposed to be overridden.
- UARTCellularInterface is derived from PPPCellularInterface. It constructs a FileHandle and
passes it back to PPPCellularInterface as well as provides modem hangupf functionality.
In future we could proive a USBInterface that would derive from PPPCellularInterface and could
pass the FileHandle back.
- OnboardCellularInterface is derived from UARTCellularInterfae and provides hooks to
the target provided implementation of onbard_modem_api.h. An off-board modem, i.e, a modem on
a shield has to override the modem_init(), modem_power_up() etc as it cannot use
onboard_modem_api.h.
Martin Kojtal
Kevin Bracey
Hasnain Virk