Control external amplifier via GPIO

HI all,

I am using an STM32MP15-EV1 eval board and will connect an external amplifier to the HEADSET output. I would like this amplifier to be automatically switched on / off when sound is being played. If I am correct this is supported in the audio-graph-card machine driver via the pa-gpios property. However I cannot make this work. I am adding the following in the DT:

sound {

pa-gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;

};

What else needs to be done?

Thanks,

Guillermo