audiomixer: add steering wheel event processing support

Subscribe to volume events from the agl-service-signal-composer
service, and enable up/down/mute event processing applied to the
Master mixer control.

Bug-AGL: SPEC-3024
Change-Id: I76bb66c7274875371a581568092c600dfd543e0f
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

audiomixer: README.md: add API documentation

Bug-AGL: SPEC-2473

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
Change-Id: Ic9fbbf6cc1f91f8699a3ba897b3984d8e4ddf244

binding: use afb_api_queue_job to queue events to run async

Apparently the binder does not like manual interventions to the
event loop and it has its own mechanism for queueing events
to run asynchronously.

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
Change-Id: Iefef031b4ad8932bbf36a5213a119908de48b41f

audiomixer: use pipewire's debug system in the audiomixer thread

Because the binder doesn't like printing messages with its own
mechanism from other threads.

Change-Id: I6fac81fc6de58f7cbbf2f93b9795c0833e44d85c
Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>

audiomixer: fix a couple of stupid mistakes

This makes the code actually work now

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
Change-Id: I8dad07fc463ca00d4f16be63f0ad73946f6da0bc

Initial binding version

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
Change-Id: I89e493d88c7fa1309f1b2991d346fc496caa6898

Initial empty repository