[linux-dvb] Progess on VP-1020

[Ralph Metzler <rjkm@metzlerbros.de>]

Jamie Honan writes:
 > There is a linux binary only module. Some people have accused it of
 > GPL violation, but more of this later.

Yes, I discussed this in more detail a few months ago.


 > The PCI id is all zeroes. On tracking down where the hangs occur, it
 > is in most areas to do with video capture initialisation.
 > 
 > The BT chip is not used for video capture on this card.
 > 
 > In order to prevent lockups, I changed my version of the bttv
 > driver to have the unknown device have zero video inputs, and
 > changed the core driver not to do any capture / video initialisation
 > if video inputs count is zero.
 > 
 > I'm not sure what the right solution is here, because so little
 > of the bttv driver is actually used.

Exactly, it is not really worth using bttv at all for this. The
only code worth using would be I2C and that has to be changed.
But bttv should at least be changed to do less initialization on those
cards (without sub ids) on startup or it will be impossible to
mix Twinhan cards with other Bt8xx cards. 


 > 2. i2c level
 > 
 > The i2c is also slightly different in that gpio pin 0 has to be
 > driven low for i2c signals to go out. After I2c transfer,
 > this pin is left not output enabled. I2c is not done to the tuner
 > but to the asic at addresses aa and ab. Data is sent in small packets,
 > comprising part of the alps tuner dividers and part qpsk codes,
 > and part bits for 13/18 V and 22Khz tone. At this stage
 > I presume the asic sends this data out to relevant parts of the board.

Yup.

 
 > 3. The kernel module.
 > 
 > This module is a fairly transparent elf module. Some people have
 > suggested it is in breach of the GPL because it includes bt848 routines.
 >
 > >From what I can see the bt848 routines are actually derived from
 > the initial linux port of the BSD drivers, which were still (at that
 > stage) under BSD copyright.

What do you mean with "initial linux port of the BSD drivers"?

The initial versions of the routines I found date back to January
1997. The exact versions used in the Twinhan driver seem to be from a late
bttv 0.5.x or early 0.6.x version.


 > It has also been suggested that the card manufacturer should provide
 > more doco / pay for the port etc. This would be good, but unfortunately
 > I have a card and so do other people and I really want it to work.
 > I'm annoyed they advertise it works under Linux, when the support
 > is not whole-hearted. Still ...


Maybe that will change ...



Ralph


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