Merge changes from topic "USB-GADGET-HAL-v1.2"

* changes:
  Add USB Gadget Hal v1.2 default implementation
  USB Gadget hal v1.2 interface

compatibility_matrices/compatibility_matrix.current.xml

@@ -521,7 +521,7 @@
     </hal>
     <hal format="hidl" optional="true">
         <name>android.hardware.usb.gadget</name>
-        <version>1.0-1</version>
+        <version>1.0-2</version>
         <interface>
             <name>IUsbGadget</name>
             <instance>default</instance>

usb/gadget/1.2/Android.bp

@@ -0,0 +1,17 @@
+// This file is autogenerated by hidl-gen -Landroidbp.
+
+hidl_interface {
+    name: "android.hardware.usb.gadget@1.2",
+    root: "android.hardware",
+    srcs: [
+        "types.hal",
+        "IUsbGadget.hal",
+        "IUsbGadgetCallback.hal",
+    ],
+    interfaces: [
+        "android.hardware.usb.gadget@1.0",
+        "android.hardware.usb.gadget@1.1",
+        "android.hidl.base@1.0",
+    ],
+    gen_java: true,
+}

usb/gadget/1.2/IUsbGadget.hal

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2020 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.usb.gadget@1.2;
+
+import IUsbGadgetCallback;
+import android.hardware.usb.gadget@1.1::IUsbGadget;
+
+interface IUsbGadget extends @1.1::IUsbGadget {
+    /**
+     * The function is used to query current USB speed.
+     *
+     * @param callback IUsbGadgetCallback::getUsbSpeedCb used to propagate
+     *                 current USB speed.
+     */
+    oneway getUsbSpeed(IUsbGadgetCallback callback);
+};

usb/gadget/1.2/IUsbGadgetCallback.hal

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2020 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.usb.gadget@1.2;
+
+import UsbSpeed;
+import android.hardware.usb.gadget@1.0::IUsbGadgetCallback;
+
+interface IUsbGadgetCallback extends @1.0::IUsbGadgetCallback {
+    /**
+     * Used to convey the current USB speed to the caller.
+     * Must be called either when USB state changes due to USB enumeration or
+     * when caller requested for USB speed through getUsbSpeed.
+     *
+     * @param speed USB Speed defined by UsbSpeed showed current USB
+     *              connection speed.
+     */
+    oneway getUsbSpeedCb(UsbSpeed speed);
+};
+

usb/gadget/1.2/default/Android.bp

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+cc_binary {
+    name: "android.hardware.usb.gadget@1.2-service",
+    defaults: ["hidl_defaults"],
+    relative_install_path: "hw",
+    init_rc: ["android.hardware.usb.gadget@1.2-service.rc"],
+    vintf_fragments: ["android.hardware.usb.gadget@1.2-service.xml"],
+    vendor: true,
+    srcs: [
+        "service.cpp",
+        "UsbGadget.cpp",
+    ],
+    shared_libs: [
+        "android.hardware.usb.gadget@1.0",
+        "android.hardware.usb.gadget@1.1",
+        "android.hardware.usb.gadget@1.2",
+        "libbase",
+        "libcutils",
+        "libhardware",
+        "libhidlbase",
+        "liblog",
+        "libutils",
+    ],
+    static_libs: ["libusbconfigfs-2"],
+}

usb/gadget/1.2/default/UsbGadget.cpp

@@ -0,0 +1,286 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "android.hardware.usb.gadget@1.2-service"
+
+#include "UsbGadget.h"
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/inotify.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace gadget {
+namespace V1_2 {
+namespace implementation {
+
+UsbGadget::UsbGadget() {
+    if (access(OS_DESC_PATH, R_OK) != 0) {
+        ALOGE("configfs setup not done yet");
+        abort();
+    }
+}
+
+void currentFunctionsAppliedCallback(bool functionsApplied, void* payload) {
+    UsbGadget* gadget = (UsbGadget*)payload;
+    gadget->mCurrentUsbFunctionsApplied = functionsApplied;
+}
+
+Return<void> UsbGadget::getCurrentUsbFunctions(const sp<V1_0::IUsbGadgetCallback>& callback) {
+    Return<void> ret = callback->getCurrentUsbFunctionsCb(
+            mCurrentUsbFunctions, mCurrentUsbFunctionsApplied ? Status::FUNCTIONS_APPLIED
+                                                              : Status::FUNCTIONS_NOT_APPLIED);
+    if (!ret.isOk()) ALOGE("Call to getCurrentUsbFunctionsCb failed %s", ret.description().c_str());
+
+    return Void();
+}
+
+Return<void> UsbGadget::getUsbSpeed(const sp<V1_2::IUsbGadgetCallback>& callback) {
+    std::string current_speed;
+    if (ReadFileToString(SPEED_PATH, &current_speed)) {
+        current_speed = Trim(current_speed);
+        ALOGI("current USB speed is %s", current_speed.c_str());
+        if (current_speed == "low-speed")
+            mUsbSpeed = UsbSpeed::LOWSPEED;
+        else if (current_speed == "full-speed")
+            mUsbSpeed = UsbSpeed::FULLSPEED;
+        else if (current_speed == "high-speed")
+            mUsbSpeed = UsbSpeed::HIGHSPEED;
+        else if (current_speed == "super-speed")
+            mUsbSpeed = UsbSpeed::SUPERSPEED;
+        else if (current_speed == "super-speed-plus")
+            mUsbSpeed = UsbSpeed::SUPERSPEED_10Gb;
+        else if (current_speed == "UNKNOWN")
+            mUsbSpeed = UsbSpeed::UNKNOWN;
+        else {
+            /**
+             * This part is used for USB4 or reserved speed.
+             *
+             * If reserved speed is detected, it needs to convert to other speeds.
+             * For example:
+             * If the bandwidth of new speed is 7G, adding new if
+             * statement and set mUsbSpeed to SUPERSPEED.
+             * If the bandwidth of new speed is 80G, adding new if
+             * statement and set mUsbSpeed to USB4_GEN3_40Gb.
+             */
+            mUsbSpeed = UsbSpeed::RESERVED_SPEED;
+        }
+    } else {
+        ALOGE("Fail to read current speed");
+        mUsbSpeed = UsbSpeed::UNKNOWN;
+    }
+
+    if (callback) {
+        Return<void> ret = callback->getUsbSpeedCb(mUsbSpeed);
+
+        if (!ret.isOk()) ALOGE("Call to getUsbSpeedCb failed %s", ret.description().c_str());
+    }
+
+    return Void();
+}
+
+V1_0::Status UsbGadget::tearDownGadget() {
+    if (resetGadget() != V1_0::Status::SUCCESS) return V1_0::Status::ERROR;
+
+    if (monitorFfs.isMonitorRunning()) {
+        monitorFfs.reset();
+    } else {
+        ALOGI("mMonitor not running");
+    }
+    return V1_0::Status::SUCCESS;
+}
+
+Return<Status> UsbGadget::reset() {
+    if (!WriteStringToFile("none", PULLUP_PATH)) {
+        ALOGI("Gadget cannot be pulled down");
+        return Status::ERROR;
+    }
+
+    usleep(kDisconnectWaitUs);
+
+    if (!WriteStringToFile(kGadgetName, PULLUP_PATH)) {
+        ALOGI("Gadget cannot be pulled up");
+        return Status::ERROR;
+    }
+
+    return Status::SUCCESS;
+}
+
+static V1_0::Status validateAndSetVidPid(uint64_t functions) {
+    V1_0::Status ret = V1_0::Status::SUCCESS;
+
+    switch (functions) {
+        case static_cast<uint64_t>(V1_2::GadgetFunction::MTP):
+            ret = setVidPid("0x18d1", "0x4ee1");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::MTP:
+            ret = setVidPid("0x18d1", "0x4ee2");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::RNDIS):
+            ret = setVidPid("0x18d1", "0x4ee3");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::RNDIS:
+            ret = setVidPid("0x18d1", "0x4ee4");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::PTP):
+            ret = setVidPid("0x18d1", "0x4ee5");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::PTP:
+            ret = setVidPid("0x18d1", "0x4ee6");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::ADB):
+            ret = setVidPid("0x18d1", "0x4ee7");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::MIDI):
+            ret = setVidPid("0x18d1", "0x4ee8");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::MIDI:
+            ret = setVidPid("0x18d1", "0x4ee9");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::NCM):
+            ret = setVidPid("0x18d1", "0x4eeb");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::NCM:
+            ret = setVidPid("0x18d1", "0x4eec");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::ACCESSORY):
+            ret = setVidPid("0x18d1", "0x2d00");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::ACCESSORY:
+            ret = setVidPid("0x18d1", "0x2d01");
+            break;
+        case static_cast<uint64_t>(V1_2::GadgetFunction::AUDIO_SOURCE):
+            ret = setVidPid("0x18d1", "0x2d02");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::AUDIO_SOURCE:
+            ret = setVidPid("0x18d1", "0x2d03");
+            break;
+        case V1_2::GadgetFunction::ACCESSORY | V1_2::GadgetFunction::AUDIO_SOURCE:
+            ret = setVidPid("0x18d1", "0x2d04");
+            break;
+        case V1_2::GadgetFunction::ADB | V1_2::GadgetFunction::ACCESSORY |
+                V1_2::GadgetFunction::AUDIO_SOURCE:
+            ret = setVidPid("0x18d1", "0x2d05");
+            break;
+        default:
+            ALOGE("Combination not supported");
+            ret = V1_0::Status::CONFIGURATION_NOT_SUPPORTED;
+    }
+    return ret;
+}
+
+V1_0::Status UsbGadget::setupFunctions(uint64_t functions,
+                                       const sp<V1_0::IUsbGadgetCallback>& callback,
+                                       uint64_t timeout) {
+    bool ffsEnabled = false;
+    int i = 0;
+
+    if (addGenericAndroidFunctions(&monitorFfs, functions, &ffsEnabled, &i) !=
+        V1_0::Status::SUCCESS)
+        return V1_0::Status::ERROR;
+
+    if ((functions & V1_2::GadgetFunction::ADB) != 0) {
+        ffsEnabled = true;
+        if (addAdb(&monitorFfs, &i) != V1_0::Status::SUCCESS) return V1_0::Status::ERROR;
+    }
+
+    // Pull up the gadget right away when there are no ffs functions.
+    if (!ffsEnabled) {
+        if (!WriteStringToFile(kGadgetName, PULLUP_PATH)) return V1_0::Status::ERROR;
+        mCurrentUsbFunctionsApplied = true;
+        if (callback) callback->setCurrentUsbFunctionsCb(functions, V1_0::Status::SUCCESS);
+        return V1_0::Status::SUCCESS;
+    }
+
+    monitorFfs.registerFunctionsAppliedCallback(&currentFunctionsAppliedCallback, this);
+    // Monitors the ffs paths to pull up the gadget when descriptors are written.
+    // Also takes of the pulling up the gadget again if the userspace process
+    // dies and restarts.
+    monitorFfs.startMonitor();
+
+    if (kDebug) ALOGI("Mainthread in Cv");
+
+    if (callback) {
+        bool pullup = monitorFfs.waitForPullUp(timeout);
+        Return<void> ret = callback->setCurrentUsbFunctionsCb(
+                functions, pullup ? V1_0::Status::SUCCESS : V1_0::Status::ERROR);
+        if (!ret.isOk()) ALOGE("setCurrentUsbFunctionsCb error %s", ret.description().c_str());
+    }
+
+    return V1_0::Status::SUCCESS;
+}
+
+Return<void> UsbGadget::setCurrentUsbFunctions(uint64_t functions,
+                                               const sp<V1_0::IUsbGadgetCallback>& callback,
+                                               uint64_t timeout) {
+    std::unique_lock<std::mutex> lk(mLockSetCurrentFunction);
+
+    mCurrentUsbFunctions = functions;
+    mCurrentUsbFunctionsApplied = false;
+
+    // Unlink the gadget and stop the monitor if running.
+    V1_0::Status status = tearDownGadget();
+    if (status != V1_0::Status::SUCCESS) {
+        goto error;
+    }
+
+    ALOGI("Returned from tearDown gadget");
+
+    // Leave the gadget pulled down to give time for the host to sense disconnect.
+    usleep(kDisconnectWaitUs);
+
+    if (functions == static_cast<uint64_t>(V1_2::GadgetFunction::NONE)) {
+        if (callback == NULL) return Void();
+        Return<void> ret = callback->setCurrentUsbFunctionsCb(functions, V1_0::Status::SUCCESS);
+        if (!ret.isOk())
+            ALOGE("Error while calling setCurrentUsbFunctionsCb %s", ret.description().c_str());
+        return Void();
+    }
+
+    status = validateAndSetVidPid(functions);
+
+    if (status != V1_0::Status::SUCCESS) {
+        goto error;
+    }
+
+    status = setupFunctions(functions, callback, timeout);
+    if (status != V1_0::Status::SUCCESS) {
+        goto error;
+    }
+
+    ALOGI("Usb Gadget setcurrent functions called successfully");
+    return Void();
+
+error:
+    ALOGI("Usb Gadget setcurrent functions failed");
+    if (callback == NULL) return Void();
+    Return<void> ret = callback->setCurrentUsbFunctionsCb(functions, status);
+    if (!ret.isOk())
+        ALOGE("Error while calling setCurrentUsbFunctionsCb %s", ret.description().c_str());
+    return Void();
+}
+}  // namespace implementation
+}  // namespace V1_2
+}  // namespace gadget
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android

usb/gadget/1.2/default/UsbGadget.h

@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#ifndef ANDROID_HARDWARE_USB_GADGET_V1_2_USBGADGET_H
+#define ANDROID_HARDWARE_USB_GADGET_V1_2_USBGADGET_H
+
+#include <UsbGadgetCommon.h>
+#include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <android/hardware/usb/gadget/1.2/IUsbGadget.h>
+#include <android/hardware/usb/gadget/1.2/types.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <utils/Log.h>
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+#include <string>
+#include <thread>
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace gadget {
+namespace V1_2 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::base::GetProperty;
+using ::android::base::ReadFileToString;
+using ::android::base::SetProperty;
+using ::android::base::Trim;
+using ::android::base::unique_fd;
+using ::android::base::WriteStringToFile;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::usb::gadget::addAdb;
+using ::android::hardware::usb::gadget::addEpollFd;
+using ::android::hardware::usb::gadget::getVendorFunctions;
+using ::android::hardware::usb::gadget::kDebug;
+using ::android::hardware::usb::gadget::kDisconnectWaitUs;
+using ::android::hardware::usb::gadget::linkFunction;
+using ::android::hardware::usb::gadget::MonitorFfs;
+using ::android::hardware::usb::gadget::resetGadget;
+using ::android::hardware::usb::gadget::setVidPid;
+using ::android::hardware::usb::gadget::unlinkFunctions;
+using ::std::string;
+
+constexpr char kGadgetName[] = "11110000.usb";
+static MonitorFfs monitorFfs(kGadgetName);
+
+#define UDC_PATH "/sys/class/udc/11110000.usb/"
+#define SPEED_PATH UDC_PATH "current_speed"
+
+struct UsbGadget : public IUsbGadget {
+    UsbGadget();
+
+    // Makes sure that only one request is processed at a time.
+    std::mutex mLockSetCurrentFunction;
+    uint64_t mCurrentUsbFunctions;
+    bool mCurrentUsbFunctionsApplied;
+    UsbSpeed mUsbSpeed;
+
+    Return<void> setCurrentUsbFunctions(uint64_t functions,
+                                        const sp<V1_0::IUsbGadgetCallback>& callback,
+                                        uint64_t timeout) override;
+
+    Return<void> getCurrentUsbFunctions(const sp<V1_0::IUsbGadgetCallback>& callback) override;
+
+    Return<Status> reset() override;
+
+    Return<void> getUsbSpeed(const sp<V1_2::IUsbGadgetCallback>& callback) override;
+
+  private:
+    V1_0::Status tearDownGadget();
+    V1_0::Status setupFunctions(uint64_t functions, const sp<V1_0::IUsbGadgetCallback>& callback,
+                                uint64_t timeout);
+};
+
+}  // namespace implementation
+}  // namespace V1_2
+}  // namespace gadget
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_USB_V1_2_USBGADGET_H

usb/gadget/1.2/default/android.hardware.usb.gadget@1.2-service.rc

@@ -0,0 +1,7 @@
+service vendor.usb-gadget-hal-1-2 /vendor/bin/hw/android.hardware.usb.gadget@1.2-service
+    interface android.hardware.usb.gadget@1.0::IUsbGadget default
+    interface android.hardware.usb.gadget@1.1::IUsbGadget default
+    interface android.hardware.usb.gadget@1.2::IUsbGadget default
+    class hal
+    user system
+    group system shell mtp

usb/gadget/1.2/default/android.hardware.usb.gadget@1.2-service.xml

@@ -0,0 +1,11 @@
+<manifest version="1.0" type="device">
+    <hal format="hidl">
+        <name>android.hardware.usb.gadget</name>
+        <transport>hwbinder</transport>
+        <version>1.2</version>
+        <interface>
+            <name>IUsbGadget</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+</manifest>

usb/gadget/1.2/default/lib/Android.bp

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+cc_library_static {
+    name: "libusbconfigfs-2",
+    vendor_available: true,
+    export_include_dirs: ["include"],
+
+    srcs: [
+        "UsbGadgetUtils.cpp",
+        "MonitorFfs.cpp",
+    ],
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+
+    shared_libs: [
+        "android.hardware.usb.gadget@1.0",
+        "android.hardware.usb.gadget@1.1",
+        "android.hardware.usb.gadget@1.2",
+        "libbase",
+        "libcutils",
+        "libhidlbase",
+        "libutils",
+    ],
+}

usb/gadget/1.2/default/lib/MonitorFfs.cpp

@@ -0,0 +1,269 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "libusbconfigfs"
+
+#include "include/UsbGadgetCommon.h"
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace gadget {
+
+static volatile bool gadgetPullup;
+
+MonitorFfs::MonitorFfs(const char* const gadget)
+    : mWatchFd(),
+      mEndpointList(),
+      mLock(),
+      mCv(),
+      mLockFd(),
+      mCurrentUsbFunctionsApplied(false),
+      mMonitor(),
+      mCallback(NULL),
+      mPayload(NULL),
+      mGadgetName(gadget),
+      mMonitorRunning(false) {
+    unique_fd eventFd(eventfd(0, 0));
+    if (eventFd == -1) {
+        ALOGE("mEventFd failed to create %d", errno);
+        abort();
+    }
+
+    unique_fd epollFd(epoll_create(2));
+    if (epollFd == -1) {
+        ALOGE("mEpollFd failed to create %d", errno);
+        abort();
+    }
+
+    unique_fd inotifyFd(inotify_init());
+    if (inotifyFd < 0) {
+        ALOGE("inotify init failed");
+        abort();
+    }
+
+    if (addEpollFd(epollFd, inotifyFd) == -1) abort();
+
+    if (addEpollFd(epollFd, eventFd) == -1) abort();
+
+    mEpollFd = move(epollFd);
+    mInotifyFd = move(inotifyFd);
+    mEventFd = move(eventFd);
+    gadgetPullup = false;
+}
+
+static void displayInotifyEvent(struct inotify_event* i) {
+    ALOGE("    wd =%2d; ", i->wd);
+    if (i->cookie > 0) ALOGE("cookie =%4d; ", i->cookie);
+
+    ALOGE("mask = ");
+    if (i->mask & IN_ACCESS) ALOGE("IN_ACCESS ");
+    if (i->mask & IN_ATTRIB) ALOGE("IN_ATTRIB ");
+    if (i->mask & IN_CLOSE_NOWRITE) ALOGE("IN_CLOSE_NOWRITE ");
+    if (i->mask & IN_CLOSE_WRITE) ALOGE("IN_CLOSE_WRITE ");
+    if (i->mask & IN_CREATE) ALOGE("IN_CREATE ");
+    if (i->mask & IN_DELETE) ALOGE("IN_DELETE ");
+    if (i->mask & IN_DELETE_SELF) ALOGE("IN_DELETE_SELF ");
+    if (i->mask & IN_IGNORED) ALOGE("IN_IGNORED ");
+    if (i->mask & IN_ISDIR) ALOGE("IN_ISDIR ");
+    if (i->mask & IN_MODIFY) ALOGE("IN_MODIFY ");
+    if (i->mask & IN_MOVE_SELF) ALOGE("IN_MOVE_SELF ");
+    if (i->mask & IN_MOVED_FROM) ALOGE("IN_MOVED_FROM ");
+    if (i->mask & IN_MOVED_TO) ALOGE("IN_MOVED_TO ");
+    if (i->mask & IN_OPEN) ALOGE("IN_OPEN ");
+    if (i->mask & IN_Q_OVERFLOW) ALOGE("IN_Q_OVERFLOW ");
+    if (i->mask & IN_UNMOUNT) ALOGE("IN_UNMOUNT ");
+    ALOGE("\n");
+
+    if (i->len > 0) ALOGE("        name = %s\n", i->name);
+}
+
+void* MonitorFfs::startMonitorFd(void* param) {
+    MonitorFfs* monitorFfs = (MonitorFfs*)param;
+    char buf[kBufferSize];
+    bool writeUdc = true, stopMonitor = false;
+    struct epoll_event events[kEpollEvents];
+    steady_clock::time_point disconnect;
+
+    bool descriptorWritten = true;
+    for (int i = 0; i < static_cast<int>(monitorFfs->mEndpointList.size()); i++) {
+        if (access(monitorFfs->mEndpointList.at(i).c_str(), R_OK)) {
+            descriptorWritten = false;
+            break;
+        }
+    }
+
+    // notify here if the endpoints are already present.
+    if (descriptorWritten) {
+        usleep(kPullUpDelay);
+        if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
+            lock_guard<mutex> lock(monitorFfs->mLock);
+            monitorFfs->mCurrentUsbFunctionsApplied = true;
+            monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied, monitorFfs->mPayload);
+            gadgetPullup = true;
+            writeUdc = false;
+            ALOGI("GADGET pulled up");
+            monitorFfs->mCv.notify_all();
+        }
+    }
+
+    while (!stopMonitor) {
+        int nrEvents = epoll_wait(monitorFfs->mEpollFd, events, kEpollEvents, -1);
+
+        if (nrEvents <= 0) {
+            ALOGE("epoll wait did not return descriptor number");
+            continue;
+        }
+
+        for (int i = 0; i < nrEvents; i++) {
+            ALOGI("event=%u on fd=%d\n", events[i].events, events[i].data.fd);
+
+            if (events[i].data.fd == monitorFfs->mInotifyFd) {
+                // Process all of the events in buffer returned by read().
+                int numRead = read(monitorFfs->mInotifyFd, buf, kBufferSize);
+                for (char* p = buf; p < buf + numRead;) {
+                    struct inotify_event* event = (struct inotify_event*)p;
+                    if (kDebug) displayInotifyEvent(event);
+
+                    p += sizeof(struct inotify_event) + event->len;
+
+                    bool descriptorPresent = true;
+                    for (int j = 0; j < static_cast<int>(monitorFfs->mEndpointList.size()); j++) {
+                        if (access(monitorFfs->mEndpointList.at(j).c_str(), R_OK)) {
+                            if (kDebug) ALOGI("%s absent", monitorFfs->mEndpointList.at(j).c_str());
+                            descriptorPresent = false;
+                            break;
+                        }
+                    }
+
+                    if (!descriptorPresent && !writeUdc) {
+                        if (kDebug) ALOGI("endpoints not up");
+                        writeUdc = true;
+                        disconnect = std::chrono::steady_clock::now();
+                    } else if (descriptorPresent && writeUdc) {
+                        steady_clock::time_point temp = steady_clock::now();
+
+                        if (std::chrono::duration_cast<microseconds>(temp - disconnect).count() <
+                            kPullUpDelay)
+                            usleep(kPullUpDelay);
+
+                        if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
+                            lock_guard<mutex> lock(monitorFfs->mLock);
+                            monitorFfs->mCurrentUsbFunctionsApplied = true;
+                            monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied,
+                                                  monitorFfs->mPayload);
+                            ALOGI("GADGET pulled up");
+                            writeUdc = false;
+                            gadgetPullup = true;
+                            // notify the main thread to signal userspace.
+                            monitorFfs->mCv.notify_all();
+                        }
+                    }
+                }
+            } else {
+                uint64_t flag;
+                read(monitorFfs->mEventFd, &flag, sizeof(flag));
+                if (flag == 100) {
+                    stopMonitor = true;
+                    break;
+                }
+            }
+        }
+    }
+    return NULL;
+}
+
+void MonitorFfs::reset() {
+    lock_guard<mutex> lock(mLockFd);
+    uint64_t flag = 100;
+    unsigned long ret;
+
+    if (mMonitorRunning) {
+        // Stop the monitor thread by writing into signal fd.
+        ret = TEMP_FAILURE_RETRY(write(mEventFd, &flag, sizeof(flag)));
+        if (ret < 0) ALOGE("Error writing eventfd errno=%d", errno);
+
+        ALOGI("mMonitor signalled to exit");
+        mMonitor->join();
+        ALOGI("mMonitor destroyed");
+        mMonitorRunning = false;
+    }
+
+    for (std::vector<int>::size_type i = 0; i != mWatchFd.size(); i++)
+        inotify_rm_watch(mInotifyFd, mWatchFd[i]);
+
+    mEndpointList.clear();
+    gadgetPullup = false;
+    mCallback = NULL;
+    mPayload = NULL;
+}
+
+bool MonitorFfs::startMonitor() {
+    mMonitor = unique_ptr<thread>(new thread(this->startMonitorFd, this));
+    mMonitorRunning = true;
+    return true;
+}
+
+bool MonitorFfs::isMonitorRunning() {
+    return mMonitorRunning;
+}
+
+bool MonitorFfs::waitForPullUp(int timeout_ms) {
+    std::unique_lock<std::mutex> lk(mLock);
+
+    if (gadgetPullup) return true;
+
+    if (mCv.wait_for(lk, timeout_ms * 1ms, [] { return gadgetPullup; })) {
+        ALOGI("monitorFfs signalled true");
+        return true;
+    } else {
+        ALOGI("monitorFfs signalled error");
+        // continue monitoring as the descriptors might be written at a later
+        // point.
+        return false;
+    }
+}
+
+bool MonitorFfs::addInotifyFd(string fd) {
+    lock_guard<mutex> lock(mLockFd);
+    int wfd;
+
+    wfd = inotify_add_watch(mInotifyFd, fd.c_str(), IN_ALL_EVENTS);
+    if (wfd == -1)
+        return false;
+    else
+        mWatchFd.push_back(wfd);
+
+    return true;
+}
+
+void MonitorFfs::addEndPoint(string ep) {
+    lock_guard<mutex> lock(mLockFd);
+
+    mEndpointList.push_back(ep);
+}
+
+void MonitorFfs::registerFunctionsAppliedCallback(void (*callback)(bool functionsApplied,
+                                                                   void* payload),
+                                                  void* payload) {
+    mCallback = callback;
+    mPayload = payload;
+}
+
+}  // namespace gadget
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android

usb/gadget/1.2/default/lib/UsbGadgetUtils.cpp

@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "libusbconfigfs"
+
+#include "include/UsbGadgetCommon.h"
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace gadget {
+
+int unlinkFunctions(const char* path) {
+    DIR* config = opendir(path);
+    struct dirent* function;
+    char filepath[kMaxFilePathLength];
+    int ret = 0;
+
+    if (config == NULL) return -1;
+
+    // d_type does not seems to be supported in /config
+    // so filtering by name.
+    while (((function = readdir(config)) != NULL)) {
+        if ((strstr(function->d_name, FUNCTION_NAME) == NULL)) continue;
+        // build the path for each file in the folder.
+        sprintf(filepath, "%s/%s", path, function->d_name);
+        ret = remove(filepath);
+        if (ret) {
+            ALOGE("Unable  remove file %s errno:%d", filepath, errno);
+            break;
+        }
+    }
+
+    closedir(config);
+    return ret;
+}
+
+int addEpollFd(const unique_fd& epfd, const unique_fd& fd) {
+    struct epoll_event event;
+    int ret;
+
+    event.data.fd = fd;
+    event.events = EPOLLIN;
+
+    ret = epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &event);
+    if (ret) ALOGE("epoll_ctl error %d", errno);
+
+    return ret;
+}
+
+int linkFunction(const char* function, int index) {
+    char functionPath[kMaxFilePathLength];
+    char link[kMaxFilePathLength];
+
+    sprintf(functionPath, "%s%s", FUNCTIONS_PATH, function);
+    sprintf(link, "%s%d", FUNCTION_PATH, index);
+    if (symlink(functionPath, link)) {
+        ALOGE("Cannot create symlink %s -> %s errno:%d", link, functionPath, errno);
+        return -1;
+    }
+    return 0;
+}
+
+Status setVidPid(const char* vid, const char* pid) {
+    if (!WriteStringToFile(vid, VENDOR_ID_PATH)) return Status::ERROR;
+
+    if (!WriteStringToFile(pid, PRODUCT_ID_PATH)) return Status::ERROR;
+
+    return Status::SUCCESS;
+}
+
+std::string getVendorFunctions() {
+    if (GetProperty(kBuildType, "") == "user") return "user";
+
+    std::string bootMode = GetProperty(PERSISTENT_BOOT_MODE, "");
+    std::string persistVendorFunctions = GetProperty(kPersistentVendorConfig, "");
+    std::string vendorFunctions = GetProperty(kVendorConfig, "");
+    std::string ret = "";
+
+    if (vendorFunctions != "") {
+        ret = vendorFunctions;
+    } else if (bootMode == "usbradio" || bootMode == "factory" || bootMode == "ffbm-00" ||
+               bootMode == "ffbm-01") {
+        if (persistVendorFunctions != "")
+            ret = persistVendorFunctions;
+        else
+            ret = "diag";
+        // vendor.usb.config will reflect the current configured functions
+        SetProperty(kVendorConfig, ret);
+    }
+
+    return ret;
+}
+
+Status resetGadget() {
+    ALOGI("setCurrentUsbFunctions None");
+
+    if (!WriteStringToFile("none", PULLUP_PATH)) ALOGI("Gadget cannot be pulled down");
+
+    if (!WriteStringToFile("0", DEVICE_CLASS_PATH)) return Status::ERROR;
+
+    if (!WriteStringToFile("0", DEVICE_SUB_CLASS_PATH)) return Status::ERROR;
+
+    if (!WriteStringToFile("0", DEVICE_PROTOCOL_PATH)) return Status::ERROR;
+
+    if (!WriteStringToFile("0", DESC_USE_PATH)) return Status::ERROR;
+
+    if (unlinkFunctions(CONFIG_PATH)) return Status::ERROR;
+
+    return Status::SUCCESS;
+}
+
+Status addGenericAndroidFunctions(MonitorFfs* monitorFfs, uint64_t functions, bool* ffsEnabled,
+                                  int* functionCount) {
+    if (((functions & GadgetFunction::MTP) != 0)) {
+        *ffsEnabled = true;
+        ALOGI("setCurrentUsbFunctions mtp");
+        if (!WriteStringToFile("1", DESC_USE_PATH)) return Status::ERROR;
+
+        if (!monitorFfs->addInotifyFd("/dev/usb-ffs/mtp/")) return Status::ERROR;
+
+        if (linkFunction("ffs.mtp", (*functionCount)++)) return Status::ERROR;
+
+        // Add endpoints to be monitored.
+        monitorFfs->addEndPoint("/dev/usb-ffs/mtp/ep1");
+        monitorFfs->addEndPoint("/dev/usb-ffs/mtp/ep2");
+        monitorFfs->addEndPoint("/dev/usb-ffs/mtp/ep3");
+    } else if (((functions & GadgetFunction::PTP) != 0)) {
+        *ffsEnabled = true;
+        ALOGI("setCurrentUsbFunctions ptp");
+        if (!WriteStringToFile("1", DESC_USE_PATH)) return Status::ERROR;
+
+        if (!monitorFfs->addInotifyFd("/dev/usb-ffs/ptp/")) return Status::ERROR;
+
+        if (linkFunction("ffs.ptp", (*functionCount)++)) return Status::ERROR;
+
+        // Add endpoints to be monitored.
+        monitorFfs->addEndPoint("/dev/usb-ffs/ptp/ep1");
+        monitorFfs->addEndPoint("/dev/usb-ffs/ptp/ep2");
+        monitorFfs->addEndPoint("/dev/usb-ffs/ptp/ep3");
+    }
+
+    if ((functions & GadgetFunction::MIDI) != 0) {
+        ALOGI("setCurrentUsbFunctions MIDI");
+        if (linkFunction("midi.gs5", (*functionCount)++)) return Status::ERROR;
+    }
+
+    if ((functions & GadgetFunction::ACCESSORY) != 0) {
+        ALOGI("setCurrentUsbFunctions Accessory");
+        if (linkFunction("accessory.gs2", (*functionCount)++)) return Status::ERROR;
+    }
+
+    if ((functions & GadgetFunction::AUDIO_SOURCE) != 0) {
+        ALOGI("setCurrentUsbFunctions Audio Source");
+        if (linkFunction("audio_source.gs3", (*functionCount)++)) return Status::ERROR;
+    }
+
+    if ((functions & GadgetFunction::RNDIS) != 0) {
+        ALOGI("setCurrentUsbFunctions rndis");
+        if (linkFunction("gsi.rndis", (*functionCount)++)) return Status::ERROR;
+        std::string rndisFunction = GetProperty(kVendorRndisConfig, "");
+        if (rndisFunction != "") {
+            if (linkFunction(rndisFunction.c_str(), (*functionCount)++)) return Status::ERROR;
+        } else {
+            // link gsi.rndis for older pixel projects
+            if (linkFunction("gsi.rndis", (*functionCount)++)) return Status::ERROR;
+        }
+    }
+
+    if ((functions & GadgetFunction::NCM) != 0) {
+        ALOGI("setCurrentUsbFunctions ncm");
+        if (linkFunction("ncm.gs6", (*functionCount)++)) return Status::ERROR;
+    }
+
+    return Status::SUCCESS;
+}
+
+Status addAdb(MonitorFfs* monitorFfs, int* functionCount) {
+    ALOGI("setCurrentUsbFunctions Adb");
+    if (!monitorFfs->addInotifyFd("/dev/usb-ffs/adb/")) return Status::ERROR;
+
+    if (linkFunction("ffs.adb", (*functionCount)++)) return Status::ERROR;
+    monitorFfs->addEndPoint("/dev/usb-ffs/adb/ep1");
+    monitorFfs->addEndPoint("/dev/usb-ffs/adb/ep2");
+    ALOGI("Service started");
+    return Status::SUCCESS;
+}
+
+}  // namespace gadget
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android

usb/gadget/1.2/default/lib/include/UsbGadgetCommon.h

@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#ifndef HARDWARE_USB_USBGADGETCOMMON_H
+#define HARDWARE_USB_USBGADGETCOMMON_H
+
+#include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/unique_fd.h>
+
+#include <android/hardware/usb/gadget/1.2/IUsbGadget.h>
+#include <android/hardware/usb/gadget/1.2/types.h>
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/inotify.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <utils/Log.h>
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+#include <string>
+#include <thread>
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace gadget {
+
+constexpr int kBufferSize = 512;
+constexpr int kMaxFilePathLength = 256;
+constexpr int kEpollEvents = 10;
+constexpr bool kDebug = false;
+constexpr int kDisconnectWaitUs = 100000;
+constexpr int kPullUpDelay = 500000;
+constexpr int kShutdownMonitor = 100;
+
+constexpr char kBuildType[] = "ro.build.type";
+constexpr char kPersistentVendorConfig[] = "persist.vendor.usb.usbradio.config";
+constexpr char kVendorConfig[] = "vendor.usb.config";
+constexpr char kVendorRndisConfig[] = "vendor.usb.rndis.config";
+
+#define GADGET_PATH "/config/usb_gadget/g1/"
+#define PULLUP_PATH GADGET_PATH "UDC"
+#define PERSISTENT_BOOT_MODE "ro.bootmode"
+#define VENDOR_ID_PATH GADGET_PATH "idVendor"
+#define PRODUCT_ID_PATH GADGET_PATH "idProduct"
+#define DEVICE_CLASS_PATH GADGET_PATH "bDeviceClass"
+#define DEVICE_SUB_CLASS_PATH GADGET_PATH "bDeviceSubClass"
+#define DEVICE_PROTOCOL_PATH GADGET_PATH "bDeviceProtocol"
+#define DESC_USE_PATH GADGET_PATH "os_desc/use"
+#define OS_DESC_PATH GADGET_PATH "os_desc/b.1"
+#define CONFIG_PATH GADGET_PATH "configs/b.1/"
+#define FUNCTIONS_PATH GADGET_PATH "functions/"
+#define FUNCTION_NAME "function"
+#define FUNCTION_PATH CONFIG_PATH FUNCTION_NAME
+#define RNDIS_PATH FUNCTIONS_PATH "gsi.rndis"
+
+using ::android::base::GetProperty;
+using ::android::base::SetProperty;
+using ::android::base::unique_fd;
+using ::android::base::WriteStringToFile;
+using ::android::hardware::usb::gadget::V1_0::Status;
+using ::android::hardware::usb::gadget::V1_2::GadgetFunction;
+
+using ::std::lock_guard;
+using ::std::move;
+using ::std::mutex;
+using ::std::string;
+using ::std::thread;
+using ::std::unique_ptr;
+using ::std::vector;
+using ::std::chrono::microseconds;
+using ::std::chrono::steady_clock;
+using ::std::literals::chrono_literals::operator""ms;
+
+// MonitorFfs automously manages gadget pullup by monitoring
+// the ep file status. Restarts the usb gadget when the ep
+// owner restarts.
+class MonitorFfs {
+  private:
+    // Monitors the endpoints Inotify events.
+    unique_fd mInotifyFd;
+    // Control pipe for shutting down the mMonitor thread.
+    // mMonitor exits when SHUTDOWN_MONITOR is written into
+    // mEventFd/
+    unique_fd mEventFd;
+    // Pools on mInotifyFd and mEventFd.
+    unique_fd mEpollFd;
+    vector<int> mWatchFd;
+
+    // Maintains the list of Endpoints.
+    vector<string> mEndpointList;
+    // protects the CV.
+    std::mutex mLock;
+    std::condition_variable mCv;
+    // protects mInotifyFd, mEpollFd.
+    std::mutex mLockFd;
+
+    // Flag to maintain the current status of gadget pullup.
+    bool mCurrentUsbFunctionsApplied;
+
+    // Thread object that executes the ep monitoring logic.
+    unique_ptr<thread> mMonitor;
+    // Callback to be invoked when gadget is pulled up.
+    void (*mCallback)(bool functionsApplied, void* payload);
+    void* mPayload;
+    // Name of the USB gadget. Used for pullup.
+    const char* const mGadgetName;
+    // Monitor State
+    bool mMonitorRunning;
+
+  public:
+    MonitorFfs(const char* const gadget);
+    // Inits all the UniqueFds.
+    void reset();
+    // Starts monitoring endpoints and pullup the gadget when
+    // the descriptors are written.
+    bool startMonitor();
+    // Waits for timeout_ms for gadget pull up to happen.
+    // Returns immediately if the gadget is already pulled up.
+    bool waitForPullUp(int timeout_ms);
+    // Adds the given fd to the watch list.
+    bool addInotifyFd(string fd);
+    // Adds the given endpoint to the watch list.
+    void addEndPoint(string ep);
+    // Registers the async callback from the caller to notify the caller
+    // when the gadget pull up happens.
+    void registerFunctionsAppliedCallback(void (*callback)(bool functionsApplied, void*(payload)),
+                                          void* payload);
+    bool isMonitorRunning();
+    // Ep monitoring and the gadget pull up logic.
+    static void* startMonitorFd(void* param);
+};
+
+//**************** Helper functions ************************//
+
+// Adds the given fd to the epollfd(epfd).
+int addEpollFd(const unique_fd& epfd, const unique_fd& fd);
+// Removes all the usb functions link in the specified path.
+int unlinkFunctions(const char* path);
+// Craetes a configfs link for the function.
+int linkFunction(const char* function, int index);
+// Sets the USB VID and PID.
+Status setVidPid(const char* vid, const char* pid);
+// Extracts vendor functions from the vendor init properties.
+std::string getVendorFunctions();
+// Adds Adb to the usb configuration.
+Status addAdb(MonitorFfs* monitorFfs, int* functionCount);
+// Adds all applicable generic android usb functions other than ADB.
+Status addGenericAndroidFunctions(MonitorFfs* monitorFfs, uint64_t functions, bool* ffsEnabled,
+                                  int* functionCount);
+// Pulls down USB gadget.
+Status resetGadget();
+
+}  // namespace gadget
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android
+#endif

usb/gadget/1.2/default/service.cpp

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "android.hardware.usb.gadget@1.2-service"
+
+#include <hidl/HidlTransportSupport.h>
+#include "UsbGadget.h"
+
+using android::sp;
+
+// libhwbinder:
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+
+// Generated HIDL files
+using android::hardware::usb::gadget::V1_2::IUsbGadget;
+using android::hardware::usb::gadget::V1_2::implementation::UsbGadget;
+
+using android::OK;
+using android::status_t;
+
+int main() {
+    configureRpcThreadpool(1, true /*callerWillJoin*/);
+
+    android::sp<IUsbGadget> service = new UsbGadget();
+
+    status_t status = service->registerAsService();
+
+    if (status != OK) {
+        ALOGE("Cannot register USB Gadget HAL service");
+        return 1;
+    }
+
+    ALOGI("USB Gadget HAL Ready.");
+    joinRpcThreadpool();
+    // Under noraml cases, execution will not reach this line.
+    ALOGI("USB Gadget HAL failed to join thread pool.");
+    return 1;
+}

usb/gadget/1.2/types.hal

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2020 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.usb.gadget@1.2;
+
+import android.hardware.usb.gadget@1.0::GadgetFunction;
+
+enum GadgetFunction : @1.0::GadgetFunction {
+    /**
+     * NCM - NCM function.
+     */
+    NCM = 1 << 10,
+};
+
+enum UsbSpeed : uint32_t {
+    /**
+     * UNKNOWN - Not Connected or Unsupported Speed
+     */
+    UNKNOWN = -1,
+
+    /**
+     * USB Low Speed
+     */
+    LOWSPEED = 0,
+
+    /**
+     * USB Full Speed
+     */
+    FULLSPEED = 1,
+
+    /**
+     * USB High Speed
+     */
+    HIGHSPEED = 2,
+
+    /**
+     * USB Super Speed
+     */
+    SUPERSPEED = 3,
+
+    /**
+     * USB Super Speed 10Gbps
+     */
+    SUPERSPEED_10Gb = 4,
+
+    /**
+     * USB Super Speed 20Gbps
+     */
+    SUPERSPEED_20Gb = 5,
+
+    /**
+     * USB4 Gen2 x 1 (10Gbps)
+     */
+    USB4_GEN2_10Gb = 6,
+
+    /**
+     * USB4 Gen2 x 2 (20Gbps)
+     */
+    USB4_GEN2_20Gb = 7,
+
+    /**
+     * USB4 Gen3 x 1 (20Gbps)
+     */
+    USB4_GEN3_20Gb = 8,
+
+    /**
+     * USB4 Gen3 x 2 (40Gbps)
+     */
+    USB4_GEN3_40Gb = 9,
+
+    /**
+     * This is a suggestion if needed.
+     *
+     * Reserved Speed -- It is a newer speed after USB4 v1.0 announcement.
+     * If this speed is detected, the HAL implementation should convert current
+     * speed to above speeds which is lower and the closest.
+     */
+    RESERVED_SPEED = 64,
+};