There are two reference configurations files, sink and source added for AUDIO-AM62D-EVM for 8-channel support in 3.5 mm jacks.

For other Sitara EVMs, requiring only two channels, no additional configuration is necessary. However, the reference configuration can be adapted to modify sample rate, channel count, period size, and other parameters as needed.

90-pipewire-sink.conf

# PipeWire sink configuration for AM62D.
context.objects = [
    {
        factory = adapter
        args = {
            factory.name = api.alsa.pcm.sink
            node.name = "alsa_audio_sink"
            node.description = "Audio Output"
            media.class = "Audio/Sink"
            api.alsa.period-size = 1024
            api.alsa.headroom = 0
            api.alsa.disable-mmap = false
            api.alsa.disable-batch = false
            api.alsa.path = "hw:AM62D2EVM,0"
            audio.rate = 48000
            audio.channels = 8
            audio.position = [ FL FR FC LFE RL RR SL SR ]
        }
    }
]

91-pipewire-source.conf

# PipeWire source configuration for AM62D.
context.objects = [
    {
        factory = adapter
        args = {
            factory.name = api.alsa.pcm.source
            node.name = "alsa_audio_source"
            node.description = "Audio Input"
            media.class = "Audio/Source"
            api.alsa.period-size = 1024
            api.alsa.headroom = 0
            api.alsa.disable-mmap = false
            api.alsa.disable-batch = false
            api.alsa.path = "hw:AM62D2EVM,0"
            audio.rate = 48000
            audio.channels = 8
            audio.position = [ FL FR FC LFE RL RR SL SR ]
        }
    }
]

context.objects

Main configuration array defining objects created in PipeWire context. Each object in this array becomes a node in the PipeWire graph.

factory = adapter

Specifies that this object be created using the "adapter" factory. Adapters in PipeWire are used to bridge between different APIs (in this case, ALSA to PipeWire). Both configuration files use adapter factory to bridge ALSA hardware to PipeWire nodes.

factory.name

Determines direction: output vs input

node.name

Internal PipeWire node identifier. Creates alsa_audio_sink for playback and alsa_audio_source for capture.

node.description

Human-readable name in audio apps.

media.class

PipeWire media classification "Audio/Sink" for playback and "Audio/Source" for recording.

api.alsa.path

For direct hardware access. Only PipeWire can access the audio hardware and ALSA applications must go through PipeWire.

audio.channels

Configures both input and output for 8-channel audio in case of AUDIO-AM62D-EVM.

These configurations create two fundamental nodes in PipeWire's audio graph:

• Sink Node: Terminal endpoint for 8-channel audio playback
• Source Node: Starting point for 8-channel audio capture

For more information, please refer Alsa Configuration.