On Mon, Feb 21, 2022 at 04:05:12PM +0100, Sascha Hauer wrote:

I have several i.MX8 boards here which have codecs connected to them which are really just plane D/A converters without any control interface like a pcm1754 or a pcm4104 in hardware mode. Currently we use the simple-audio-card OF driver with custom codec code in sound/soc/codecs/. The codec does nothing except specifying desired rates, channels and formats. Is this the way to go or is there some device tree solution to get rid of the codec?

That's the right way to go - the CODEC will have some constraints on what it supports that need to be advertised, sometimes there's GPIOs for a control interface and someone might want to hook up a clock or some regulators. There's several existing drivers like this.