Raspberry Pi (Linux) driver for a BD3490FV
sudo apt install build-essential device-tree-compilermake
make dtsAdd to /boot/config.txt:
dtoverlay=my-amp
Optionally add force_eeprom_read=0 as well to disable any automatic overlay loading if connected to a HAT with EEPROM.
Currently the overlay installed by make dts expects the BD3490FV to be at I2C address 0x40 and a PCM512x to be at I2C address 0x4d (for my custom sound card).