How to customize device tree to output I2S over uart3 and uart4

I am trying to wrap my head around customizing my device tree to output I2S signal over uart3 and uart4 pins, using those pins over the dedicated toradex I2S pins so as to exceed the samplerate of toradex’s built in I2S codec, which aspects of device tree should I change?


I would rather recommend using the dedicated Apalis DAP1 aka digital audio pins on the MXM3 pins 194, 196, 198, 200, 202 and 204 for your purpose. This way your design is future prove and any Apalis module should be able to drive your audio codec.

As for the device tree changes this involves 2 distinct areas:

  1. The pin muxing aka pinctrl (e.g. similar to this)
  2. The particular codec configuration (e.g. similar to this)

Please have a look at the following article concerning device tree customisation in general.

Plus you may need to enable your particular codecs driver to be included in the kernel.