Re: receiving data from mcbsp1 in master mode

[Andreas Kemnade <andreas@kemnade.info>]

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Hi,

On Tue, 21 Aug 2012 16:42:19 +0300
Peter Ujfalusi <peter.ujfalusi@ti.com> wrote:

> On 08/21/2012 08:42 AM, Andreas Kemnade wrote:
> > Hi,
> > 
> > I tried a couple of times with different kernels to use mcbsp1 of dm3730
> > in master mode (so that it sends out clocks).
> > The result always is that I can send data out. but arecord gets no input. It
> > waits for input but does not get anything, although clocks are generated,
> > checked that with a scope. 
> > 
> > I even took a driver which works in master mode on another mcbsp and just changed
> > the mcbsp number.
> > What needs to be done to receive data from mcbsp1?
> 
> You should check the PIN mux configuration of McBSP1 FSR/CLKR pins. McBSP1 on
> dm3730 have 6 pin configuration. I think the capture should work fine if you
> select the FSX as FSR source, and CLKX as CLKR source.
>
if I understand the TRM correctly, according to Figure 21-26 in chapter 21.4.2.3.
if GSYNC is set, the receiver uses the signal from the sample rate generator,
so CLKX does not need to be the CLKR source.
But I tried also with the DEVCONF0 MCBSP1_CLKR bit as you proposed.
I tried
 snd_soc_dai_set_sysclk(cpu_dai, OMAP_MCBSP_CLKR_SRC_CLKX, 0,
                                     SND_SOC_CLOCK_OUT);
 snd_soc_dai_set_sysclk(cpu_dai, OMAP_MCBSP_FSR_SRC_FSX, 0,
                                     SND_SOC_CLOCK_OUT);

 That is why I send you my patch about that mux settings. But I had no success.
The CLKX as CLKR source and FSX as FSR source setting I have only seen when
mcbsp1 is used in slave mode. If you know any working code which uses mcbsp1 in
master mode then let me know.

Greetings
Andreas Kemnade

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