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

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

On Tuesday 02 Nov 2004 09:52, Patrick Boettcher wrote:
> On Tue, 2 Nov 2004, Andrew de Quincey wrote:
> > > 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?
>
> At the weekend I wrote an email about Twinhan's release of linux drivers
> for their cards:
> http://www.linuxtv.org/mailinglists/linux-dvb/2004/10-2004/msg00914.html
>
> In the archive of the drivers, there is a twinhan_ca.c . I had a short
> look, it looks quite comprehensive even though I don't know much about
> CI/CAM levels.

Sorry - must have missed that mail.

Anyway, I had a look, and compare it with en50221. The actual messages it 
sends (e.g. {0x07,0x40, 0x00,0x00, PCMSG_ENTER_MENU, 0x00,0x00,0xff}) are 
totally custom as well, so there's no point in an interface letting you send 
arbitrary arrays at it either. 

I think you'll have to define a new link type, along with a new IOCTL with an 
associated structure to expose the functionality you need. I think you'll 
have to make it specifically support for the twinhan  
(CI_TYPE_TWINHAN/CI_TYPE_DST?). Although the concept of the calls it exposes 
do exist in the standard, the actual data exchanged is very different 
(greatly simplified).