[Gta04-owner] fm-tuner - was Re: hw routing audio patch removed in 3.7?

[Andreas Kemnade]

On Wed, 2013-10-23 at 15:25 +0200, Christoph Mair wrote: 
> On Wed, Oct 23, 2013 at 1:06 PM, Andreas Kemnade <andreas at kemnade.info> wrote:
> > On Mon, 2013-06-24 at 11:38 +0200, Dr. H. Nikolaus Schaller wrote:
> >> Hi,
> >> fm-radio appears to work. At least on one board (the one where I did solder some wires to measure the clocks and PCM signals).
> >> [...]
> >> Now comes the bad news: it works only on one GTA04 board and I don't
> >> know why it fails on the others I have tested. Since they have no wires I
> >> can't check if the clocks are available and the Si47xx is sending PCM
> >> to the CPU or not. Or if there is something unreliable in the McBSP config.
> >>
> >> It could also be some hardware issue. If you look into the schematics, there
> >> are series resistors for the McBSP1 interface. Their values are choosen
> >> based on the recommendations of a reference design we had found.
> >>
> >> But 2k2 appears a little high value, taking into account that we have a 2.5 MHz
> >> clock. I.e. the signals may be damped and too slow so that e.g. the clocks
> >> are not recognized correctly.
> >>
> > I do not understand the connection here. The McBSP sends out its clocks.
> > It should look at the data pin at the right times and interpret whatever
> > is avilable there at sampling time if i understand the I2S stuff
> > correctly. So we should be able to read some suff and arecord should
> > spit out something.
> 
> One thing which comes to my mind: did you mux the clock output pin as
> input? While this seems wrong, the McBSP needs this configuration to
> use its own clock as receive clock. The pin works as output
> nonetheless.
> 
Ehm,.. I should have followed the link about uboot in the mail. As
pinmux settings in uboot are of course right (everything to output I
thought, I have checked that often), I thought hns has accidently run an
ancient uboot instead of an old one...
So I did not update my uboot. Ok, that seems to be the missing part of
information I needed all the time when I was experimenting with that.
At least I now get something out of the McBSP1. Now I am searching my
headphone.

Greetings
Andreas Kemnade