diff --git a/media/Android.bp b/media/Android.bp
index ad4f96c..22bbdb6 100644
--- a/media/Android.bp
+++ b/media/Android.bp
@@ -65,6 +65,9 @@
         "aidl/android/media/audio/common/AudioEncapsulationType.aidl",
         "aidl/android/media/audio/common/AudioFormatDescription.aidl",
         "aidl/android/media/audio/common/AudioFormatType.aidl",
+        "aidl/android/media/audio/common/AudioGain.aidl",
+        "aidl/android/media/audio/common/AudioGainConfig.aidl",
+        "aidl/android/media/audio/common/AudioGainMode.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicy.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicyInfo.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicyType.aidl",
diff --git a/media/aidl/android/media/audio/common/AudioGain.aidl b/media/aidl/android/media/audio/common/AudioGain.aidl
new file mode 100644
index 0000000..90fdeb6
--- /dev/null
+++ b/media/aidl/android/media/audio/common/AudioGain.aidl
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 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.media.audio.common;
+
+import android.media.audio.common.AudioChannelLayout;
+
+/**
+ * This structure represents a gain stage. A gain stage is always attached
+ * to an AudioPort.
+ *
+ * {@hide}
+ */
+@JavaDerive(equals=true, toString=true)
+@VintfStability
+parcelable AudioGain {
+    /** Bitmask, indexed by AudioGainMode. */
+    int mode;
+    /** For AudioGainMode.CHANNELS, specifies controlled channels. */
+    AudioChannelLayout channelMask;
+    /** Minimum gain value in millibels. */
+    int minValue;
+    /** Maximum gain value in millibels. */
+    int maxValue;
+    /** Default gain value in millibels. */
+    int defaultValue;
+    /** Gain step in millibels. */
+    int stepValue;
+    /** Minimum ramp duration in milliseconds. */
+    int minRampMs;
+    /** Maximum ramp duration in milliseconds. */
+    int maxRampMs;
+}
diff --git a/media/aidl/android/media/audio/common/AudioGainConfig.aidl b/media/aidl/android/media/audio/common/AudioGainConfig.aidl
new file mode 100644
index 0000000..a247111
--- /dev/null
+++ b/media/aidl/android/media/audio/common/AudioGainConfig.aidl
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 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.media.audio.common;
+
+import android.media.audio.common.AudioChannelLayout;
+
+/**
+ * The gain configuration structure is used to get or set the gain values of a
+ * given AudioPort.
+ *
+ * {@hide}
+ */
+@JavaDerive(equals=true, toString=true)
+@VintfStability
+parcelable AudioGainConfig {
+    /** Index of the corresponding AudioGain in AudioPort.gains. */
+    int index;
+    /** Bitmask, indexed by AudioGainMode. */
+    int mode;
+    /** For AudioGainMode.CHANNELS, specifies controlled channels. */
+    AudioChannelLayout channelMask;
+    /**
+     * Gain values in millibels. For each channel ordered from LSb to MSb in
+     * channel mask. The number of values is 1 in joint mode, otherwise equals
+     * the number of bits implied by channelMask.
+     */
+    int[] values;
+    /** Ramp duration in milliseconds. */
+    int rampDurationMs;
+}
diff --git a/media/aidl/android/media/audio/common/AudioGainMode.aidl b/media/aidl/android/media/audio/common/AudioGainMode.aidl
new file mode 100644
index 0000000..e46752e
--- /dev/null
+++ b/media/aidl/android/media/audio/common/AudioGainMode.aidl
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 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.media.audio.common;
+
+/**
+ * Type of gain control exposed by an audio port. The values are
+ * indexes of bits in a bitmask.
+ *
+ * {@hide}
+ */
+@VintfStability
+@Backing(type="byte")
+enum AudioGainMode {
+    /** Gain is the same for all channels. */
+    JOINT = 0,
+    /** The gain is set individually for each channel. */
+    CHANNELS = 1,
+    /** Ramping is applied. */
+    RAMP = 2,
+}
diff --git a/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGain.aidl b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGain.aidl
new file mode 100644
index 0000000..71891eb
--- /dev/null
+++ b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGain.aidl
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package android.media.audio.common;
+/* @hide */
+@JavaDerive(equals=true, toString=true) @VintfStability
+parcelable AudioGain {
+  int mode;
+  android.media.audio.common.AudioChannelLayout channelMask;
+  int minValue;
+  int maxValue;
+  int defaultValue;
+  int stepValue;
+  int minRampMs;
+  int maxRampMs;
+}
diff --git a/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainConfig.aidl b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainConfig.aidl
new file mode 100644
index 0000000..01877c7
--- /dev/null
+++ b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainConfig.aidl
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package android.media.audio.common;
+/* @hide */
+@JavaDerive(equals=true, toString=true) @VintfStability
+parcelable AudioGainConfig {
+  int index;
+  int mode;
+  android.media.audio.common.AudioChannelLayout channelMask;
+  int[] values;
+  int rampDurationMs;
+}
diff --git a/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainMode.aidl b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainMode.aidl
new file mode 100644
index 0000000..fddc20c
--- /dev/null
+++ b/media/aidl_api/android.media.audio.common.types/current/android/media/audio/common/AudioGainMode.aidl
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package android.media.audio.common;
+/* @hide */
+@Backing(type="byte") @VintfStability
+enum AudioGainMode {
+  JOINT = 0,
+  CHANNELS = 1,
+  RAMP = 2,
+}