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

[Andreas Kemnade]

On Wed, 2013-10-23 at 18:52 +0200, Andreas Kemnade wrote: 
> 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.

Ok, I found my headphone, I put the gta04 near a window on the side
towards the radio station, replaced the arecord | aplay pipe  in the
script by

arecord -D default:CARD=gta04fm -r 48000 -f S16_LE -c 1 | aplay -r 48000
-f S16_LE -c 1

and I had reception with good sound quality.

Greetings
Andreas Kemnade