SAI with PDM microphone on STM32MP157CAA

[johnnyc]

Is it possible to use SAI for PDM microphones and ALSA with the current Linux kernel on a STM32MP157CAA SoC?

[PatrickF]

Hi @johnnyc​ 

As far as I know, SAI Linux driver only supports I2S.

It is recommended and also more efficient (thanks to HW filters) to connect PDM microphones to DFSDM,

See

• https://wiki.st.com/stm32mpu/wiki/DFSDM_internal_peripheral
• https://wiki.st.com/stm32mpu/wiki/DFSDM_device_tree_configuration
• https://wiki.st.com/stm32mpu/wiki/DFSDM_Linux_driver
• https://wiki.st.com/stm32mpu/wiki/Soundcard_configuration

Regards.