[linux-dvb] Re: [PATCHES] Frontend kernel i2c conversion.

[Johannes Stezenbach <js@convergence.de>]

Hi Gerd,

I hope you don't mind if I address you directly in this
thread, I don't know if you're still reading linux-dvb.

On Mon, Jul 19, 2004 at 05:35:37PM +0200, Ralph Metzler wrote:
> Kenneth Aafløy writes:
>  > > On Sun, Jul 18, 2004 at 01:04:02AM +0200, Kenneth Aafløy wrote:
>  > > > On Sunday 18 July 2004 00:09, Ralph Metzler wrote:
>  > > > > No, I also considered this before implementing the FE_(UN)REGISTER
>  > > > > stuff but adapters with more than one I2C bus/frontend will not work
>  > > > > like this. It also makes the frontend driver and dvbdev depend on I2C
>  > > > > driver structs even if you are not using I2C.
...
>  > > Sorry, but to get all this done properly in the way you want to do it
>  > > (i.e. without the kernel i2c registration callback) you will basically
>  > > have to reimplement the whole dvb_i2c layer again ...
>  > 
>  > And that is unacceptable, is it not? Because the goal here is to remove that 
>  > layer completly, or have I missed something.
> 
> No, absolutely right, that is exactly my point.
> 
> The dvb_i2c layer was useful to either directly program I2C hardware
> or to put it on top of existing I2C drivers which were in separate
> drivers which knew nothing about DVB (like in the bt878 case).
> But the whole point of changing to kernel I2C was to get rid of this
> extra layer. In the bt878 case this probably is not possible without
> changing the bttv driver. Either it has to be changed to be more like
> the saa7146, where it only supplies basic functions and the upper
> layers (analog TV or DVB) initialize and use only what they need. 
> Or one has to build the DVB parts directly into the bttv driver 
> like, AFAIK, it is done with the saa7134 and cx88 drivers.
> 
> In the meantime it would probably also be enough just not to 
> initialize I2C for DVB cards int bttv and export the I2C functions for 
> external use?
> Or maybe one could even use the kernel I2C layer on top of itself ...

What's your opinion on this matter? Would you accept a patch
for bttv-i2c to expose the hooks required by DVB? Or do can
you propose a different solution?


Regards,
Johannes