How can I enable DMIC (digital microphone)?


#1

Hi:

I would like to use the DMIC as the recording device.

The DMIC is connect to GPIO0 and GPIO1. I have configurared the pinmux as 4. What should I do the allow the Android app to capture sound from it?

A couple questions:

  1. Is the existing driver support this DMIC?
  2. What Mixer command shall I use to make the correct routing?

Thanks
Kevin


#2

Forgot to mention:

I am using DragonBoard™ 410c.


#3

Hi Kevin,

I haven’t use DMIC, But is still believe you can route audio to DMIC by below app:

You can also achieve the same by changing UCM file device/qcom/msm8916_32/mixer_paths.xml

FYR:
https://source.android.com/devices/audio/implement.html

Shweta


#4

Hi Shweta:

Thanks for your reply.

Looking at this file: msm8916-pinctrl.dtsi, I found this:

cdc-dmic-lines {
			qcom,pins = <&gp 0>, <&gp 1>;
			qcom,num-grp-pins = <2>;
			qcom,pin-func = <4>;
			label = "cdc-dmic-lines";
			cdc_dmic_lines_act: dmic_lines_on {
				drive-strength = <8>;
			};
			cdc_dmic_lines_sus: dmic_lines_off {
				drive-strength = <2>;
				bias-disable;
			};
		};

It defines the proper pin-mux for GPIO0 and GPIO1. But no driver uses cdc_dmic_lines_act or cdc_dmic_lines_sus.
Can I draw a conclusion that DMIC is NOT implemented in the my current BSP? If so, I don’t bother to try changing the audio routing etc…

Thanks
Kevin


#5

Hi,

can anyone help me enabling DMIC in audio mezzanine board for android version.?

Im using dargon board 410c

Regards,
Chaithra