[alsa-devel] Driver for Maxim MAX9744 Stereo Amplifier

[Tom Rinehart]

I am trying to develop a driver the the Maxim MAX9744 20W Class D Stereo Amplifier.  (see https://www.maximintegrated.com/en/products/analog/audio/MAX9744.html <https://www.maximintegrated.com/en/products/analog/audio/MAX9744.html>).  It is very similar to the MAX9768 10W Class D Mono amplifier which has a linux driver. (see https://www.maximintegrated.com/en/products/analog/audio/MAX9768.html <https://www.maximintegrated.com/en/products/analog/audio/MAX9768.html>)  From a control perspective, both look to be the same from their data sheets.  Volume is controlled through i2c, and it has mute and shutdown controlled through gpio.  The MAX9744 has a volume control that changes both channels together.  When I try to use the MAX9768 driver it shows up as a mono amplifier in alsamixer.  What do I need to change in the driver to have it recognize stereo input and output but with the volume control tied together (not independent for each channel)?  It seems like I should be able to modify the MAX9768 driver to work with the MAX9744.

I have an Adafruit board with the MAX9744 amplifier on it so it is easy to test: https://www.adafruit.com/product/1752 <https://www.adafruit.com/product/1752>.