GSM Modem Integration

Outline of a Modem Vendor Plugin

There are two sample implementations under src/plugins/phonevendors/ericsson and src/plugins/phonevendors/wavecom. This section reviews the major components of the wavecom plugin to demonstrate how to write such a plug-in.

The plug-in inherits from the QModemServicePlugin class, which provides modem detection and service creation functions.

    #include <qmodemserviceplugin.h>

    class WavecomPluginImpl : public QModemServicePlugin
    {
        Q_OBJECT
    public:
        WavecomPluginImpl();
        virtual ~WavecomPluginImpl();

        bool supports( const QString& manufacturer );
        QModemService *create( const QString& service,
                               QSerialIODeviceMultiplexer *mux,
                               QObject *parent );
    };

The plug-in declares two functions, supports() and create(), which should be implemented as follows:

    QTOPIA_EXPORT_PLUGIN( WavecomPluginImpl )

    WavecomPluginImpl::WavecomPluginImpl() {}
    WavecomPluginImpl::~WavecomPluginImpl() {}

    bool WavecomPluginImpl::supports( const QString& manufacturer )
    {
        return manufacturer.contains( "WAVECOM" );
    }

    QModemService *WavecomPluginImpl::create
        ( const QString& service, QSerialIODeviceMultiplexer *mux, QObject *parent )
    {
        return new WavecomModemService( service, mux, parent );
    }

The supports() function checks the manufacturer string from the AT+CGMI command against the expected value. The first plug-in that returns true from supports() will used.

The create() function creates a QModemService instance to handle the modem specifics. It is passed the name of the service (usually modem), the multiplexing object that is used to communicate with the modem, and the parent QObject to attach the modem service to.

The modem service implementation inherits from QModemService and should override initialize() to create the vendor-specific functionality handlers:

    #include <qmodemservice.h>
    class WavecomModemService : public QModemService
    {
        Q_OBJECT
    public:
        WavecomModemService
            ( const QString& service, QSerialIODeviceMultiplexer *mux,
              QObject *parent = 0 );
        ~WavecomModemService();

        void initialize();
        ...
    };

    WavecomModemService::WavecomModemService
            ( const QString& service, QSerialIODeviceMultiplexer *mux,
              QObject *parent )
        : QModemService( service, mux, parent )
    {
        ...
    }

    WavecomModemService::~WavecomModemService() {}

    void WavecomModemService::initialize()
    {
        // Create our Wavecom-specific overrides for the service interfaces.
        if ( !supports<QSimInfo>() )
            addInterface( new WavecomSimInfo( this ) );

        if ( !supports<QSimToolkit>() )
            addInterface( new WavecomSimToolkit( this ) );

        if ( !supports<QPhoneBook>() )
            addInterface( new WavecomPhoneBook( this ) );

        if ( !supports<QPhoneRfFunctionality>() )
            addInterface( new WavecomRfFunctionality( this ) );

        if ( !supports<QTelephonyConfiguration>() )
            addInterface( new WavecomConfiguration( this ) );

        if ( !callProvider() )
            setCallProvider( new WavecomCallProvider( this ) );

        // Call QModemService to create other interfaces that we didn't override.
        QModemService::initialize();
    }

Modem services within Qt Extended are split up into several handlers, one for each functionality area (phone calls, network registration, SMS, SIM toolkit, phone books, etc).

The QModemService class creates default implementations based on the 3GPP TS 27.007 and 3GPP TS 27.005 specifications. The modem vendor plug-in overrides those handlers that are different from the standard, and only those that are different. When QModemService::initialize() is called, the missing handlers will be created automatically.

The handlers mentioned above inherit from the following standard classes:

A complete list of classes for accessing AT-based modems can be found on the Modem Classes page.

    [SerialDevices]
    ExternalAccessDevice=/dev/ttyS1:115200