description: Generic PDM MEMS microphone (e.g. SPM1423), I2S PDM RX input

compatible: "generic,spm1423"

properties:
  i2s:
    type: phandle
    required: true
    description: "I2S controller device that carries audio data"
  channels:
    type: int
    default: 1
    description: "Number of PDM mics wired (1 = mono, 2 = stereo)"
  input-gain-percent:
    type: int
    default: 400
    description: "Digital gain multiplier applied by audio_stream, as an integer percentage (100 = 1.0x, 400 = 4.0x). PDM mics have no hardware gain; default 400 matches M5Stack's own SPM1423 reference firmware (magnification=4)."