A driver covering any I2S class-D speaker amplifier with no I2C/register interface -- just an I2S data line plus an optional GPIO enable (SD) pin -- wired as an output-only AUDIO_CODEC_TYPE device. Has no I2C parent; the device sits standalone in the devicetree and only references the I2S controller by name. Covers the Maxim MAX98357A and NSIway NS4168.

Since these amps have no hardware volume/mute registers, volume and mute are applied in software on the PCM stream via esp_codec_dev's software volume handler.

See https://www.analog.com/media/en/technical-documentation/data-sheets/MAX98357A-MAX98357B.pdf And https://datasheet.lcsc.com/lcsc/2110191830_NSIWAY-NS4168_C965904.pdf

License: Apache v2.0