samples/basic/blinky_pwm/boards/nrf52840dk_nrf52840.overlay

&pwm0 {
	status = "disabled";
};

&sw_pwm {
	status = "okay";
	channel-gpios = <&gpio0 13 PWM_POLARITY_INVERTED>;
};

&pwm_led0 {
	pwms = <&sw_pwm 0 PWM_MSEC(20) PWM_POLARITY_INVERTED>;
};