[linux-dvb] Re: Twinhan CA

[olivier <bitmap@pan.homelinux.com>]

Manu Abraham <manu@kromtek.com> disait récemment :

> Hi,

Hi,

> Well timing issues mostly solved, Conditional Access ah, most of the SI 
> parsing is done by Twinhan in the driver. To make it simple the Twinhan 
> driver does  get the SI from the DMA buffer, which is similar to the ring 
> buffer as per the Linux DVB API.

Yes, this is horrible :/

> Since originally the demarcation between the frontend and CA device was null, 
> i initially used the frontend device itself as the conditional access device, 
> but later on moved to register /dev/dvb/adapterX/ca0 for the device.

How this device is used by  the userspace program ?  Do you have ioctl
and CA_GET/SET_MSG or read/write ioctl ?

> 1)A complete solution would be libdvb or libdvb2 itself.
> 
> There is a place-holder for libdvb2 at linuxtv, eventhough no developments has 
> undergone so far.

You can use cam_set and cam_test from LIBDVB 0.5.5
(http://www.metzlerbros.org/dvb/).

The file cam_set/libdvbsi/ci.cc implements full EN50221 protocol, just
cut what is not needed for twinhan. This is what I've done. 

> 2)Another solution would be to hack scan to a certain extent to harvest 
> information from SI, and set these parameters through *zap.

3) Hard-code some  ca_descriptor in the driver, this  should be enough
   for testing. 

Anyway, I'm very interested by  getting your working driver now. Maybe
I'll be able to help you.

Olivier