diff --git a/wifi/1.2/Android.bp b/wifi/1.2/Android.bp
index 100b36b..f41324e 100644
--- a/wifi/1.2/Android.bp
+++ b/wifi/1.2/Android.bp
@@ -10,6 +10,7 @@
         "types.hal",
         "IWifi.hal",
         "IWifiChip.hal",
+        "IWifiChipEventCallback.hal",
         "IWifiNanIface.hal",
         "IWifiNanIfaceEventCallback.hal",
     ],
diff --git a/wifi/1.2/IWifiChip.hal b/wifi/1.2/IWifiChip.hal
index 72cbf81..d336a33 100644
--- a/wifi/1.2/IWifiChip.hal
+++ b/wifi/1.2/IWifiChip.hal
@@ -16,7 +16,9 @@
 
 package android.hardware.wifi@1.2;
 
+import @1.0::WifiStatus;
 import @1.1::IWifiChip;
+import IWifiChipEventCallback;
 
 /**
  * Interface that represents a chip that must be configured as a single unit.
@@ -24,4 +26,18 @@
  * to perform operations like NAN, RTT, etc.
  */
 interface IWifiChip extends @1.1::IWifiChip {
+    /**
+     * Requests notifications of significant events on this chip. Multiple calls
+     * to this must register multiple callbacks each of which must receive all
+     * events.
+     *
+     * @param callback An instance of the |IWifiChipEventCallback| HIDL interface
+     *        object.
+     * @return status WifiStatus of the operation.
+     *         Possible status codes:
+     *         |WifiStatusCode.SUCCESS|,
+     *         |WifiStatusCode.ERROR_WIFI_CHIP_INVALID|
+     */
+    registerEventCallback_1_2(IWifiChipEventCallback callback)
+        generates (WifiStatus status);
 };
diff --git a/wifi/1.2/IWifiChipEventCallback.hal b/wifi/1.2/IWifiChipEventCallback.hal
new file mode 100644
index 0000000..5d2e7e9
--- /dev/null
+++ b/wifi/1.2/IWifiChipEventCallback.hal
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2017 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.wifi@1.2;
+
+import @1.0::IWifiChipEventCallback;
+import @1.0::WifiBand;
+
+/**
+ * Wifi chip event callbacks.
+ */
+interface IWifiChipEventCallback extends @1.0::IWifiChipEventCallback {
+    /**
+     * Struct describing the state of each iface operating on the radio chain
+     * (hardware MAC) on the device.
+     */
+    struct IfaceInfo {
+        /** Name of the interface (For ex: "wlan0"). */
+        string name;
+        /** Wifi channel on which this interface is operating. */
+        uint32_t channel;
+    };
+
+    /**
+     * Struct describing the state of each hardware radio chain (hardware MAC)
+     * on the device.
+     */
+    struct RadioModeInfo {
+        /**
+         * Identifier for this radio chain. This is vendor dependent & used
+         * only for debugging purposes.
+         */
+        uint32_t radioId;
+        /**
+         * List of bands on which this radio chain is operating.
+         * Can be one of:
+         * a) WifiBand.BAND_24GHZ => 2.4Ghz.
+         * b) WifiBand.BAND_5GHZ => 5Ghz.
+         * c) WifiBand.BAND_24GHZ_5GHZ = 2.4Ghz + 5Ghz (Radio is time sharing
+         * across the 2 bands).
+         */
+        WifiBand bandInfo;
+        /** List of interfaces on this radio chain (hardware MAC). */
+        vec<IfaceInfo> ifaceInfos;
+    };
+
+    /**
+     * Asynchronous callback indicating a radio mode change.
+     * Radio mode change could be a result of:
+     * a) Bringing up concurrent interfaces (For ex: STA + AP).
+     * b) Change in operating band of one of the concurrent interfaces (For ex:
+     * STA connection moved from 2.4G to 5G)
+     *
+     * @param radioModeInfos List of RadioModeInfo structures for each
+     * radio chain (hardware MAC) on the device.
+     */
+    oneway onRadioModeChange(vec<RadioModeInfo> radioModeInfos);
+};
diff --git a/wifi/1.2/default/wifi_chip.cpp b/wifi/1.2/default/wifi_chip.cpp
index bc3404a..a4b52b9 100644
--- a/wifi/1.2/default/wifi_chip.cpp
+++ b/wifi/1.2/default/wifi_chip.cpp
@@ -306,7 +306,7 @@
 }
 
 Return<void> WifiChip::registerEventCallback(
-    const sp<IWifiChipEventCallback>& event_callback,
+    const sp<V1_0::IWifiChipEventCallback>& event_callback,
     registerEventCallback_cb hidl_status_cb) {
     return validateAndCall(this, WifiStatusCode::ERROR_WIFI_CHIP_INVALID,
                            &WifiChip::registerEventCallbackInternal,
@@ -520,6 +520,14 @@
                            hidl_status_cb);
 }
 
+Return<void> WifiChip::registerEventCallback_1_2(
+    const sp<IWifiChipEventCallback>& event_callback,
+    registerEventCallback_cb hidl_status_cb) {
+    return validateAndCall(this, WifiStatusCode::ERROR_WIFI_CHIP_INVALID,
+                           &WifiChip::registerEventCallbackInternal_1_2,
+                           hidl_status_cb, event_callback);
+}
+
 Return<void> WifiChip::debug(const hidl_handle& handle,
                              const hidl_vec<hidl_string>&) {
     if (handle != nullptr && handle->numFds >= 1) {
@@ -556,11 +564,9 @@
 }
 
 WifiStatus WifiChip::registerEventCallbackInternal(
-    const sp<IWifiChipEventCallback>& event_callback) {
-    if (!event_cb_handler_.addCallback(event_callback)) {
-        return createWifiStatus(WifiStatusCode::ERROR_UNKNOWN);
-    }
-    return createWifiStatus(WifiStatusCode::SUCCESS);
+    const sp<V1_0::IWifiChipEventCallback>& /* event_callback */) {
+    // Deprecated support for this callback.
+    return createWifiStatus(WifiStatusCode::ERROR_NOT_SUPPORTED);
 }
 
 std::pair<WifiStatus, uint32_t> WifiChip::getCapabilitiesInternal() {
@@ -997,6 +1003,14 @@
     return createWifiStatusFromLegacyError(legacy_status);
 }
 
+WifiStatus WifiChip::registerEventCallbackInternal_1_2(
+    const sp<IWifiChipEventCallback>& event_callback) {
+    if (!event_cb_handler_.addCallback(event_callback)) {
+        return createWifiStatus(WifiStatusCode::ERROR_UNKNOWN);
+    }
+    return createWifiStatus(WifiStatusCode::SUCCESS);
+}
+
 WifiStatus WifiChip::handleChipConfiguration(
     /* NONNULL */ std::unique_lock<std::recursive_mutex>* lock,
     ChipModeId mode_id) {
diff --git a/wifi/1.2/default/wifi_chip.h b/wifi/1.2/default/wifi_chip.h
index 4ffa8da..c51f6b1 100644
--- a/wifi/1.2/default/wifi_chip.h
+++ b/wifi/1.2/default/wifi_chip.h
@@ -74,7 +74,7 @@
     // HIDL methods exposed.
     Return<void> getId(getId_cb hidl_status_cb) override;
     Return<void> registerEventCallback(
-        const sp<IWifiChipEventCallback>& event_callback,
+        const sp<V1_0::IWifiChipEventCallback>& event_callback,
         registerEventCallback_cb hidl_status_cb) override;
     Return<void> getCapabilities(getCapabilities_cb hidl_status_cb) override;
     Return<void> getAvailableModes(
@@ -138,6 +138,9 @@
         resetTxPowerScenario_cb hidl_status_cb) override;
     Return<void> debug(const hidl_handle& handle,
                        const hidl_vec<hidl_string>& options) override;
+    Return<void> registerEventCallback_1_2(
+        const sp<IWifiChipEventCallback>& event_callback,
+        registerEventCallback_1_2_cb hidl_status_cb) override;
 
    private:
     void invalidateAndRemoveAllIfaces();
@@ -145,7 +148,7 @@
     // Corresponding worker functions for the HIDL methods.
     std::pair<WifiStatus, ChipId> getIdInternal();
     WifiStatus registerEventCallbackInternal(
-        const sp<IWifiChipEventCallback>& event_callback);
+        const sp<V1_0::IWifiChipEventCallback>& event_callback);
     std::pair<WifiStatus, uint32_t> getCapabilitiesInternal();
     std::pair<WifiStatus, std::vector<ChipMode>> getAvailableModesInternal();
     WifiStatus configureChipInternal(
@@ -192,6 +195,8 @@
     WifiStatus enableDebugErrorAlertsInternal(bool enable);
     WifiStatus selectTxPowerScenarioInternal(TxPowerScenario scenario);
     WifiStatus resetTxPowerScenarioInternal();
+    WifiStatus registerEventCallbackInternal_1_2(
+        const sp<IWifiChipEventCallback>& event_callback);
 
     WifiStatus handleChipConfiguration(
         std::unique_lock<std::recursive_mutex>* lock, ChipModeId mode_id);