The microphone arrays for Intel platforms are described in the
ACPI NHLT table. This table is available in sysfs. Parse this
information and use a more common format (json) for output. This
information is usable for the further DSP processing.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Add Intel nhlt acpi table encoder plugin into topology2.0 processing.
Nhlt internal structure is defined in:
https://01.org/sites/default/files/595976_intel_sst_nhlt.pdf
Nhlt acpi table contain vendor specific binary data blobs that are used
in some Intel dsp platforms for configuring the dmic and ssp hardware.
The function of this code is mainly to generate the vendor specific
binary blobs, but as there is existing nhlt parser code and header in
kernel there's no point of re-inventing the container: just use the
existing nhlt acpi table format. Basically this code is creating similar
nhlt acpi table that you would get from: cat
/sys/firmware/acpi/tables/NHLT
This code will have implementation for dmic and ssp endpoints. Thus the
code will translate the topology dai tokens into vendor specific binary
blobs and pack them into nhlt acpi table. Ssp and dmic code is lifted
from Sound Open Firmware (sof) code base, thus it will have BSD-3
license.
This plugin can be enabled from command line with:
alsatplg -DPREPROCESS_PLUGINS="nhlt" -c foo.conf -p -o bar.tplg
You can also dump the nhlt binary into a file with additional define:
-DNHLT_BIN="nhlt.bin"
Link: https://github.com/alsa-project/alsa-utils/pull/129
Signed-off-by: Jaska Uimonen <jaska.uimonen@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
alsaloop allows create a PCM loopback between a PCM capture device
and a PCM playback device.
alsaloop supports multiple soundcards, adaptive clock synchronization,
adaptive rate resampling using the samplerate library (if available in
the system). Also, mixer controls can be redirected from one card to
another (for example Master and PCM).
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
