Issues with analog and digital microphones on the G520

AOSP
1

Hi MTK team,

Platform: Genio 520 (MT8391), Android 15

Current status:

2 analog microphones (AMIC) are working correctly via PMIC

Audio recording path is verified

Questions:

What is the correct way to fully disable the AMIC in the audio stack?

What is the correct configuration to enable 4-channel DMIC on MT8391 (audio_device.xml, and DTS, ProjectConfig.mk,…)?

Thanks.

2

Dear Hoa_ND,

To disable the Analog Microphone (AMIC) in the audio stack for the Genio 520 (MT8391) on Android 15, need to perform the following modifications.

1. Audio HAL Layer (audio_device.xml)

  • Remove the AUDIO_DEVICE_IN_BUILTIN_MIC-related mappings that are associated with the analog microphone.
  • Ensure no remaining paths are routing to AMIC.

In audio_device.xml, remove or comment out any mapping that links AUDIO_DEVICE_IN_BUILTIN_MIC to an AMIC path.

2. Build System (ProjectConfig.mk)

Update the project-level configuration to update the audio drivers that digital microphones are the primary input.

# Change the microphone type support
MTK_DIGITAL_MIC_SUPPORT = yes

This setting ensures the system treats digital microphones (DMIC) as the primary audio input path instead of AMIC.

4-Channel DMIC Configuration Reference

For configuration details to enable 4-channel DMIC on MT8391, please refer to the following forum link:

How to use tinymix commands to configure 4-channel DMIC on Genio series platforms

Thanks.

5

Dear MediaTek Team,

Platform: Genio 520 (MT8391) + Android 15

I would like to confirm the exact full paths of the following files for our project:

  • ProjectConfig.mk – where we set MTK_DIGITAL_MIC_SUPPORT = yes
  • audio_device.xml – where we disable AMIC paths and add 4-channel DMIC paths

  1. Could you please provide the correct paths ?

  2. When we want to completely disable AMIC and enable 4-channel DMIC, do we need to modify any Device Tree file?

  3. Are there any instructional documents?

6

Dear Hao_ND,

Have you signed NDA with Mediatek?
If so, could you please share the release notes for the code base you are currently using?

Thank you.

7

Dear MediaTek Team,
I deleted the AUDIO_DEVICE_IN_BUILTIN_MIC mappings related to analog microphones, but the digital microphone still doesn’t work:
aiot8391p2_64_bsp:/ # tinycap /data/hoa_test.wav -D 0 -d 21 -c 4 -r 48000 -b 32 -T 15

Capturing sample: 4 ch, 48000 hz, 32 bit

start errorCaptured 0 frames

aiot8391p2_64_bsp:/ # tinymix | grep DMIC

Failed to mixer_ctl_get_array

37 ENUM 1 MTKAIF_DMIC Off

40 ENUM 1 AP DMIC Used Off

127 BOOL 1 UL6_CH1 AP_DMIC_UL_CH1 Off

132 BOOL 1 UL6_CH2 AP_DMIC_UL_CH2 Off

138 BOOL 1 UL7_CH1 AP_DMIC_UL_CH3 Off

144 BOOL 1 UL7_CH2 AP_DMIC_UL_CH4 Off

155 BOOL 1 UL_CM0_CH1 AP_DMIC_UL_CH1 Off

161 BOOL 1 UL_CM0_CH2 AP_DMIC_UL_CH2 Off

167 BOOL 1 UL_CM0_CH3 AP_DMIC_UL_CH3 Off

172 BOOL 1 UL_CM0_CH4 AP_DMIC_UL_CH4 Off

518 ENUM 1 UL_SRC_MUX DMIC

519 ENUM 1 UL2_SRC_MUX DMIC

521 ENUM 1 DMIC0_MUX DMIC_DATA0

522 ENUM 1 DMIC1_MUX DMIC_DATA1_L_1

523 ENUM 1 DMIC2_MUX DMIC_DATA1_L

What do I need to do?
Thanks.

8

Dear Hoa_ND,

For better understanding and support, please confirm the NDA status with MediaTek.

Thank you.

9

How do I confirm the status of my non-disclosure agreement (NDA) with MediaTek?

10

Hi Hoa_ND,

You can check the NDA status using the link below:

How to Apply for NDA

Please follow the steps in the provided instructions to apply for the NDA.

Thank you,
Santosh

11

What do I need to do next?

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12

Hi,

I’ve sent you an email regarding your NDA application status. Please check your inbox.