[linux-dvb] Re: High level CA implementation..

[Andrew de Quincey <adq_dvb@lidskialf.net>]

On Tuesday 02 Nov 2004 06:24, Manu Abraham wrote:
> On Mon November 1 2004 10:44 pm, Holger Waechtler wrote:
> > Manu Abraham wrote:
> > >Hi,
> > > Can somebody explain me a little bit how a high level CA driver/system
> > > be implemented as per the V3 API ?
> > >
> > >The current implementation is based on the Transport Level driver,
> > > whereas i'm looking at a higher level CA system, where most of the
> > > transport level functions are held in the ASIC, as in the case of the
> > > Twinhan card.
> > >
> > >If somebody could give me an idea, that would be really helpful.
> >
> > By setting slot->type to CA_CI_LINK you can implement your driver on the
> > link layer interface if you want to do so. Take a look on Andrew's
> > dvb_ca_en50221.c implementation used by the budget_ci driver, is your
> > interface really on a higher level than the link layer?
>
> Yes, it is almost as good as the interface is exposed directly to
> userspace. Almost everything is done in the ASIC.
>
> Even dvb libraries are implemented in the driver itself by the
> manufacturer, which can at least taken out into userspace.
>
> What i am wondering is that, then an implementation of such a DVB driver
> would not be adhering to the linux-DVB API ?
>
>
> Andrew's driver works in the transport layer and there is no use for such
> an implementation in this case. All the layers happen to be embedded into
> the ASIC. The only thing one can do is send a message to the
> CA_SEND_MESSAGE, or get a message CA_GET_MESSAGE or get the application
> info CA_GET_APP_INFO. Nothing more

IMO, those three should be exposed. What kind of messages can you send/receive 
to it? Can you give an example?

I think you're going to have to add an extension to the API - theres no 
support for anything like that right now. It'd be good to add a standardised 
extension though.