How to add a new devicetree in nrf5340 audio dk?

[LandyWang]

Hello,

I am using nrf5340 audio dk to make some modifications and tests.

When I add a devicetree to the overlay file and use DEVICE_DT_GET to get the device object, it always occur build fail: undefined reference to '__device_dts_ord_N'.

For example the following modification:

nrf5340_audio_dk_nrf5340_cpuapp.overlay:

&pdm0{
	status = "okay";
	clk-pin = <41>;
	din-pin = <38>;
};

and using DEVICE_DT_GET in code:

	const struct device *mic_dev = DEVICE_DT_GET(DT_NODELABEL(pdm0));
    
	if (!device_is_ready(mic_dev)) {
		return;
	}

I don't know if there are other steps needed to add devicetree.

[haakonsh]

Meybe we need to define the pins with pinctrl:

&pinctrl{
    pdm0_default: pdm0_default {
		group1 {
			psels = <NRF_PSEL(PDM_CLK, 1, 9)>,
			        <NRF_PSEL(PDM_DIN, 1, 6)>;
		};
	};

	pdm0_sleep: pdm0_sleep {
		group1 {
			psels = <NRF_PSEL(PDM_CLK, 1, 9)>,
			        <NRF_PSEL(PDM_DIN, 1, 6)>;
			low-power-enable;
		};
	};
};

&pdm0{
	status = "okay";
};

And that CONFIG_NRFX_PDM is set.

[LandyWang]

Hi,

Thank you for your reply.

I add pinctrl define to the overlay file and set CONFIG_NRFX_PDM, but an undefined reference error still occurs.

Then I modify the overlay file as below, it still build fail with the same error.

&pinctrl{
    pdm0_default: pdm0_default {
		group1 {
			psels = <NRF_PSEL(PDM_CLK, 1, 9)>,
			        <NRF_PSEL(PDM_DIN, 1, 6)>;
		};
	};

	pdm0_sleep: pdm0_sleep {
		group1 {
			psels = <NRF_PSEL(PDM_CLK, 1, 9)>,
			        <NRF_PSEL(PDM_DIN, 1, 6)>;
			low-power-enable;
		};
	};
};
&pdm0{
	compatible = "nordic,nrf-pdm";
	status = "okay";
	pinctrl-0 = <&pdm0_default>;
	pinctrl-1 = <&pdm0_sleep>;
	pinctrl-names = "default", "sleep";
};

Here is the config I added to my prj.conf.

CONFIG_AUDIO_DMIC=y
CONFIG_DMA=y
CONFIG_HEAP_MEM_POOL_SIZE=1024
CONFIG_NRFX_PDM=y

[haakonsh]

Try this: 

CONFIG_AUDIO=y
CONFIG_AUDIO_DMIC=y
CONFIG_DMA=y
CONFIG_HEAP_MEM_POOL_SIZE=1024

If CONFIG_AUDIO is not set then the dmic_nrfx_pdm.c driver will never 

[LandyWang]

Thank you for your assistance.It's working for me .