Support request for codec WM8731 porting

Support request for codec WM8731 porting

[Cyril GERMAINE]

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Hello,

I work on a board based from DM365EVM baseboard, but with the WM8731 
codec instead of the TLV320AIC3x.
I tried with several linux kernels (one is the 3.6.6 release). Now the 
playback works but not the capture, and I'm not able to debug this 
issue. I have many "0" frames in the captured data, although data and 
rate on I2S bus is OK. 22 null frames, then 2 non null frames. I tried 
to capture a sinusoidal wave.

Version of kernel : 3.6.6-dirty
Version of alsa lib : 1.0.25

Here are the attached files:
- dmesg.txt : dmesg log after kernel init
- .config
- all the files of the kernel I modified/added for my board
- capture_alsalib_traces.txt : some traces I put in the alsa lib during 
capture
- dmesg_capture.txt : some traces I put in the kernel during capture
- capture_test.wav.hexdump : the result of the capture (arecord -f S16_LE)

I modified the wm8731.c file because I wasn't able to activate the 
required functions of the codec with alsamixer, and I don't undestand 
how dapm works...

Maybe I missed something in the board or platform dependant files? About 
the DMA? I don't undestand why the playback works but not the capture.
I also worked with the kernel provided with the DM365EVM board (from 
Montavista, linux_2.6.18_pro500, DaVinciLSP_02_10_00_08), the results 
are better, I "only" have one null frame for 2 frames, even with a 
stereo input signal (on the left and right input line).

Thanks for your help.


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Re: Support request for codec WM8731 porting

[Daniel Mack]

On 30.11.2012 17:41, Cyril GERMAINE wrote:
> Hello,
> 
> I work on a board based from DM365EVM baseboard, but with the WM8731 
> codec instead of the TLV320AIC3x.
> I tried with several linux kernels (one is the 3.6.6 release). Now the 
> playback works but not the capture, and I'm not able to debug this 
> issue. I have many "0" frames in the captured data, although data and 
> rate on I2S bus is OK.

Do you see the audio gaps in I2S as well? This is the first thing to
investigate on, because if they aren't, your problem is unrelated to the
Codec.

What are the differences between your board and the DM365EVM regarding
the SoC and the clocks ratios? Does the DM365EVM work with 3.6.6? How do
your board support files and ASoC machine driver differ?

Too many open questions here that need to be addressed.


Daniel

Re: Support request for codec WM8731 porting

[Cyril GERMAINE]

Thank you Daniel for your reply.

I found out what was the problem.

I was trying to use the WM8731 in I2S mode (porting from another board), 
but davinci CPU doesn't support true I2S. Switching to DSP mode resolved 
my problems.

Cyril

On 30/11/2012 18:17, Daniel Mack wrote:
> On 30.11.2012 17:41, Cyril GERMAINE wrote:
>> Hello,
>>
>> I work on a board based from DM365EVM baseboard, but with the WM8731
>> codec instead of the TLV320AIC3x.
>> I tried with several linux kernels (one is the 3.6.6 release). Now the
>> playback works but not the capture, and I'm not able to debug this
>> issue. I have many "0" frames in the captured data, although data and
>> rate on I2S bus is OK.
> Do you see the audio gaps in I2S as well? This is the first thing to
> investigate on, because if they aren't, your problem is unrelated to the
> Codec.
>
> What are the differences between your board and the DM365EVM regarding
> the SoC and the clocks ratios? Does the DM365EVM work with 3.6.6? How do
> your board support files and ASoC machine driver differ?
>
> Too many open questions here that need to be addressed.
>
>
> Daniel
>
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>