STHAL 2.4
This version of the soundtrigger HAL adds support for dynamic resource
management by the HAL, allowing it to refuse to start/load and to
preemptively stop/unload models at its discretion.
This give the HAL more freedom to make resource allocation decisions
and avoids the need to precisely model the various constraints and
have them enforced by the framework.
Bug: 178722883
Change-Id: I58807407417fc099b7538e685309d2c846ed66fd
diff --git a/soundtrigger/2.4/ISoundTriggerHwCallback.hal b/soundtrigger/2.4/ISoundTriggerHwCallback.hal
new file mode 100644
index 0000000..594deb0
--- /dev/null
+++ b/soundtrigger/2.4/ISoundTriggerHwCallback.hal
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.soundtrigger@2.4;
+
+import @2.0::SoundModelHandle;
+import @2.1::ISoundTriggerHwCallback;
+
+/**
+ * SoundTrigger HAL per-model Callback interface.
+ */
+interface ISoundTriggerHwCallback extends @2.1::ISoundTriggerHwCallback {
+ /**
+ * Callback method called by the HAL when a model has been unloaded at the HAL implementation's
+ * discretion. Only a stopped model may be unloaded.
+ * This event is NOT sent as part of an unload sequence initiated by the client.
+ *
+ * @param model The model handle.
+ */
+ modelUnloaded(SoundModelHandle model);
+};