I am currently stuck in implementing a new device tree overlay to initialize two sound controller: PCM5142 and WM8804. The used board is the DACBerry ONE (https://www.osaelectronics.com/product/dacberry-one-for-raspberry-pi-1ab-2b-3b/).
I can see both chips in the I2C at the adresses 0x4c (PCM5142) and 0x3b (WM8804). They are in software mode and can be configured via an I2C accessible register.
I am also able to initialize them as ALSA cards with a few device tree overlays, for example:
- iqaudio-dacplus for the PCM5142 (https://github.com/raspberrypi/linux/blob/rpi-4.14.y/arch/arm/boot/dts/overlays/iqaudio-dacplus-overlay.dts)
- justboom-digi for the WM8804 (https://github.com/raspberrypi/linux/blob/rpi-4.14.y/arch/arm/boot/dts/overlays/justboom-digi-overlay.dts)
With those overlays I can either use the PCM5142 or the WM8804, not both chips simultaneously as ALSA sound interfaces. It should be possible (also confirmed from the manufacturer of the board), but it is not implemented yet.
My idea was to create a new overlay which uses both initialization routines from the both overlays mentioned above which gives me both chips as ALSA cards, but I am unsure how to do that.