I designed my own dual DAC RPI hat a few years ago. I used a hardware configurable DAC (WM8741) that required no register programming. I simply selected the generic I2S DAC in Volumio, and it works perfectly.
I am now planning to design another RPI hat that uses the AKM 4191 digital modulator and AK4499EXEQ DAC.
Both of these parts require the internal registers to be programmed.
I am potentially planning to submit this as a formal Volumio RPI DAC that can be selected within the Volumio OS.
I have read through the I2S DAC section in I2S DACs | Volumio Developers Documentation and I understand how to design the HW serial interface.
But the documentation at the link above does not provide me enough information on how to program the modulator and DAC registers. Specifically, what do I need to do to configure the internal registers and program them to the exact settings I need, specifically for the AKM4191 and AK4499EXEQ ? Do I need to write a driver for them? If so, can you provide some guidance on how to do this?
Any help would be greatly appreciated.