I have connected I2S-0 to an external audio codec (Freescale SGTL5000). This also includes the audio master clock and I2C_GP0. The codec has an internal reset therefore I did not connect GPIO19_AUD_RST.
The codec does not show up as a device once the system is booted. I’ve tried the following commands to find the codec but it is not present:
cat /proc/asound/car*/co* | grep Codec
cat /proc/asound/car*/co*/* | head
I’ve also tried alsamixer with no luck.
When I monitor the I2S and master clock lines using an oscilloscope I notice there is no activity on these lines at all (not during boot, reset, or once the system has booted into Ubuntu).
How does the Jetson TX1 module discover audio codecs over I2S? Should this be automatic or do I need to make software changes?