[linux-dvb] fmd1216 integration

Trent Piepho xyzzy at speakeasy.org
Thu Mar 15 06:39:25 CET 2007


On Wed, 14 Mar 2007, Hartmut Hackmann wrote:
> >>> How does that happen?  I figured P4 just changed the SAW filters, but it
> >>> enables/disables the tda9887 too?
> >>>
> >> I have no idea why and how this is done, i just observed that...
> >
> > I wonder if this is a problem for the v4l tuner module.  If one doesn't
> > start and then stop the dvb frontend before using analog, how does the
> > tda9887 get turned on?
> >
> It is a BIG problem. The tuner initialization code turns the tda9886 on,
> but now things depend on the module initialization order whether the tda
> is found or not. I haven't used my board in analog mode after the tda9887
> merge but things look like it doesn't work any more :-(
> Unfortunately i know about at least one board that needs the opposite
> load order.

In the datasheet for the Philips TUV1236D tuner, it describes how the
TDA9885 is turned on and off by one of the GPIO pins of the NXT2004
demodulator.  The same pin also powers off and on the "digital IF section",
whatever that is exactly (obviously the NXT2004 isn't powering itself down
with its own GPIO pin).

I imagine this is a big problem for v4l, needing to talk to the ATSC
demodulator to turn the analog demodulator on.

Anyway, the FMD1216ME datasheet doesn't say anything about turning the
TDA9887 on or off.  Still, it stands to reason that Philips would have
added the ability to do this for the same reason they added it to the
TUV1236D.

Do you have a datasheet or design guide that explains about needing to turn
the tda9887 on?  Is it one of the TUA6034 ports that controls it?

If analog doesn't work the fmd1216, then I don't think a dvb-pll
integration patch should be obligated to fix it.  But, I don't want to
break anything that does work now.

I wonder how the other users of the fmd1216, in the cx88 and cxusb driver,
work in analog mode?  Maybe they don't?

> > My plan was to come up with a patch that converted all the users of fmd1216
> > at once.
> >
> Ok, less work for me.

If you want, I can make a simple patch that fixes the bug in
fmd1216me_sleep quickly to apply first.



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