bcm2835-analog-audio: Is my driver PWM, ALSA or neither

[Gottfried Haider]

In the way I would want to use it:

"echo 0 > /sys/class/pwm/pwmchip0/export" should simply disable all
audio co-use of the channel, until the user - or the program -
releases it again by writing to unexport.

Plus some way (device tree overlay?) to permanently disable the audio
functionality, which might be necessary if you have some device
permanently hooked up, which shouldn't be receiving startup chimes or
the like

Best,
Gottfried