[linux-dvb] Re: KNC1 and clones Common Interface

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

On Thursday 24 Jun 2004 00:06, Kenneth Aafløy wrote:
> Hi,
>
> I've done some more probing on my Typhoon CI today, and I have found that:
>
> Remark: gpio 0 is hardwired to the saa7113 interface.
>
> CAM detection can be performed by:
> 	- lovering gpio 1-3
> 	- setting gpio 3 to input
> 	- small delay
> 	- checking if gpio 3 is high
> 	   (actually both gpio 2 and 3 go hi)
>
> Reading the attribute memory of the CAM is done by:
> 	- setting gpio 2-3 low
> 	- setting gpio 1 high
> 	- read data
>
> This has the strange effect of repeating the CI attribute memory every
> 0x200 bytes, any other gpio setting gives zero, so it makes me think that
> they might have used the audio_a interface for addressing, as the audio_b
> interface is connected to the frontend, but the audio_a interface is shared
> between the saa7113 (not present here) and the ci interface. I have yet to
> test this theory, but I will soon, what stumps me however is why the heck
> would the attribute space be presented when the audio_a interface is not
> yet even programmed?
>
> Hope you get a clear picture of where I stand as of right now, and that you
> trow any ideas however crazy they might be, I'll test!!

Nice to see you're having some success!

I think there may be something wrong still though; I _think_ I've seen some 
CAMs which have > 0x200 bytes of attribute memory - it seems to be the 
fashion to put the PCMCIA Config Option register round about 0x200.

Any chance of you getting a digital multimeter and beeping out the GPIO 
connections on the card? I found that invaluable for the TT one.