Initial commit for usb daemon

usbd checks whether adb is enabled by default, if yes,
would start adbd and would call into usb hal to configure
usb gadget stack.

Bug: 63669128
Test: Verify that adb gets configured when enabled
Change-Id: If6d06cdadd6d93f181d56619142cbbb04d39a5cd

usbd/Android.bp

@@ -0,0 +1,16 @@
+cc_binary {
+    name: "usbd",
+    init_rc: ["usbd.rc"],
+    srcs: ["usbd.cpp"],
+    shared_libs: [
+        "libbase",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libutils",
+        "libhardware",
+        "android.hardware.usb.gadget@1.0",
+        "libcutils",
+    ],
+}
+

usbd/usbd.cpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2018 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 "usbd"
+
+#include <string>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android/hardware/usb/gadget/1.0/IUsbGadget.h>
+
+#define PERSISTENT_USB_CONFIG "persist.sys.usb.config"
+
+using android::base::GetProperty;
+using android::base::SetProperty;
+using android::hardware::usb::gadget::V1_0::GadgetFunction;
+using android::hardware::usb::gadget::V1_0::IUsbGadget;
+using android::hardware::Return;
+
+int main(int /*argc*/, char** /*argv*/) {
+    android::sp<IUsbGadget> gadget = IUsbGadget::getService();
+    Return<void> ret;
+
+    if (gadget != nullptr) {
+        LOG(INFO) << "Usb HAL found.";
+        std::string function = GetProperty(PERSISTENT_USB_CONFIG, "");
+        if (function == "adb") {
+            LOG(INFO) << "peristent prop is adb";
+            SetProperty("ctl.start", "adbd");
+            ret = gadget->setCurrentUsbFunctions(static_cast<uint64_t>(GadgetFunction::ADB),
+                                                 nullptr, 0);
+        } else {
+            LOG(INFO) << "Signal MTP to enable default functions";
+            ret = gadget->setCurrentUsbFunctions(static_cast<uint64_t>(GadgetFunction::MTP),
+                                                 nullptr, 0);
+        }
+
+        if (!ret.isOk()) LOG(ERROR) << "Error while invoking usb hal";
+    } else {
+        LOG(INFO) << "Usb HAL not found";
+    }
+    exit(0);
+}

usbd/usbd.rc

@@ -0,0 +1,5 @@
+service usbd /system/bin/usbd
+    class late_start
+    oneshot
+    user root
+    group root usb