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i.MX6 & SGTL5000 - Switch from I2S to PCM Format A

Question asked by angelobalke on Oct 12, 2015
Latest reply on Oct 21, 2015 by angelobalke

Hello,

 

i want to change the I2S Format to PCM Format A.

 

I have found in sound/soc/fsl/imx-sgtl5000.c a line, where the i2s format is defined, an so i changed it to dsp_a format (PCM Format A). But only this change is not enough. The LRCLK pin seems to be right and show a typically PCM Format A signal, but no signal appears on the DIN pin. When I play a sound-file in Linux with aplay, no sound is hearing, and aplay seems to be stop working, only CRTL-C stop it.

 

I think the PCM Format A configuration is right, but i have to change something like the routing, so that the audio-signal find the right way.

 

Anybody have a hint for me?

 

 

PS: the reason of change the format, is I have a sometimes a channel switch. I have an application, that streams some sound information on the left channel and another information on the right channel. Sometimes, unknown source of this event, it switch an the channels are swapped. At my measurements, I reproduced it, when I interference the I2S_LRCLK or I2S_SLCK between the SGTL5000 and i.MX6 with my measuring line. So the DIN signal appears, at I2S Format, at the clock edge for the left channel (low-level LRCLK), and sometime for the right channel (high-level LRCLK).

 

The idea behind this, that when the interference, it has no effect to the channel affiliation, only a little scratch or something.

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