How to create a node in the dts file that will contain the ADC configuration and how to access it from the application?

Question

Dear All,

I am working on SDK 2.1.0 and I was going through the ADC sample found in ncs/zephyr/samples/drivers/adc directory.

I am working with a custom board, so I want to implement the "overlay" inside the original dts file of the device. The device is effectively a nRF9160 device.

So, what I am trying to do is to create a node that will contain the configuration for the ADC device that I can then later get using

ADC_DT_SPEC_GET

.

What I have tried so far is this:

In my XXX_nrf9160_common.dts file I have added the following node (?):

...

&adc {
	status = "okay";
};

/{
	adc {
		#address-cells = <1>;
		#size-cells = <0>;

		battery: channel@0 {
			reg = <0>;
			zephyr,gain = "ADC_GAIN_1_6";
			zephyr,reference = "ADC_REF_INTERNAL";
			zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
			zephyr,input-positive = <NRF_SAADC_AIN7>;
			zephyr,resolution = <12>;
		};
	};
};

...

I am getting this error:

battery_devices.c: In function 'battery_device_init':
C:/ncs/zephyr/include/zephyr/drivers/adc.h:281:41: error: expected expression before '{' token
  281 | #define ADC_DT_SPEC_STRUCT(ctlr, input) { \
      |                                         ^
C:/ncs/zephyr/include/zephyr/drivers/adc.h:368:2: note: in expansion of macro 'ADC_DT_SPEC_STRUCT'
  368 |  ADC_DT_SPEC_STRUCT(DT_IO_CHANNELS_CTLR_BY_IDX(node_id, idx), \
      |  ^~~~~~~~~~~~~~~~~~
C:/ncs/zephyr/include/zephyr/drivers/adc.h:393:34: note: in expansion of macro 'ADC_DT_SPEC_GET_BY_IDX'
  393 | #define ADC_DT_SPEC_GET(node_id) ADC_DT_SPEC_GET_BY_IDX(node_id, 0)

when doing this:

battery_devices->batt_data = ADC_DT_SPEC_GET(battery);

.

Thank you very much for your assistance