In stereo case the pdm stream continuosly alternates 1-bit from
the left channel with 1-bit from the right channel. In this case
we need first to demultiplex channels bits on byte basis.
Then the Open_PDM_Filter library has to be called twice, one for
each channel.
Signed-off-by: Armando Visconti <armando.visconti@st.com>
This driver supports ST Microelectronics digital pdm microphones
(MPxxDTyy) connected through different peripherals. Currently only
I2S is supported.
The driver makes use internally of the OpenPDM2PCM library
to convert the PDM audio stream to PCM. Currently the
oversampling factor is fixed to 64.
Signed-off-by: Armando Visconti <armando.visconti@st.com>