IMX SSI TDM 32-channel SabreLite

[ertan_esgun]

Hello there,

I am using Boundary Devices's SabreLite Board (https://boundarydevices.com/product/sabre-lite-imx6-sbc/​) with Yocto Project.

I am trying to use 32-channel TDM over SSI (Slave mode, 8Khz, 32-channel, 8bit per channel).

SabreLite board has SGTL5000. I removed it and i am gonna use the SSI pins connected to SGTL5000.

And here is my questions:

1) First of all, can i do that?

2) Does ALSA support TDM((Slave mode, 8Khz, 32-channel, 8bit per channel).)?

3) And if answers of question 1 and euestion 2 is yes, tell me how please

Thank you for your interest.

Good Luck.

[rosciio]

Hi everyone,

i'm working on that argument. I would like configure the ssi into Network mode. I have done this, so, I modified the register to do it, but now I can't understand how linux show on user space "/proc/asound/card0/pcmX" X times my slot.

any one can explain me this?

thank you very much

Marco From Italy

[jerryyan]

Hi Marco,

   I am now also struggling on this issue. Can you share your solution with us? 

   I use SSI to connect to a CS42888 codec, As state in document of CS42888, the SCLK should be 256xFs, but in fsl_ssi.c, if  4 channels used, the BCLK will be set to 4*32*Fs=128Fs, not 256Fs.  Is there any misunderstanding ?

[nguyenanhduc]

Dear Ertan,

I am implementing a system almost the as the same as yours and also struggling with the low-level software stuff.

I am wondering if you are making any progress and could you please share your experience,

Thank you in advance,

[igorpadykov]

also it may be useful to look at

Documentation/bindings/sound/tdm-slot.txt

http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/Documentation/devicetree/bindings/s...

and sources of ssi dai driver in linux/sound/soc/fsl/fsl_ssi.c

Best regards

igor

[fabio_estevam]

The kernel NXP provides does not support 32 channels in the SSI interface.

There is a new series from Arnaud Mouiche that allows such usecase in the mainline kernel.This series appears in the 4.7-rc series and you can find it at:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/log/sound/soc/fsl/fsl_ssi.c?id=refs/...