add basic usb hal

usb/Android.bp

+cc_binary {
+    name: "android.hardware.usb@1.0-service.mtk",
+    relative_install_path: "hw",
+    init_rc: ["android.hardware.usb@1.0-service.mtk.rc"],
+    srcs: ["service.cpp", "Usb.cpp"],
+    shared_libs: [
+        "libcutils",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libhwbinder",
+        "libutils",
+        "libhardware",
+        "android.hardware.usb@1.0",
+    ],
+    proprietary: true,
+}

usb/Usb.cpp

+/*
+ * Copyright (C) 2017 The LineageOS 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.
+ */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <utils/Errors.h>
+#include <utils/StrongPointer.h>
+
+#include "Usb.h"
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace V1_0 {
+namespace implementation {
+
+Return<void> Usb::switchRole(const hidl_string &portName,
+                             const PortRole &newRole) {
+    (void)portName;
+    (void)newRole;
+    ALOGE("%s: Not supported", __func__);
+    return Void();
+}
+
+Return<void> Usb::queryPortStatus() {
+    hidl_vec<PortStatus> currentPortStatus;
+    currentPortStatus.resize(1);
+
+    /* this device is not type C and can only be a sink */
+    currentPortStatus[0].portName = "otg_default";
+    currentPortStatus[0].currentDataRole = PortDataRole::DEVICE;
+    currentPortStatus[0].currentPowerRole = PortPowerRole::SINK;
+    currentPortStatus[0].currentMode = PortMode::UFP;
+    currentPortStatus[0].canChangeMode = false;
+    currentPortStatus[0].canChangeDataRole = false;
+    currentPortStatus[0].canChangePowerRole = false;
+    currentPortStatus[0].supportedModes = PortMode::UFP;
+
+    pthread_mutex_lock(&mLock);
+    if (mCallback != NULL) {
+        Return<void> ret =
+                mCallback->notifyPortStatusChange(currentPortStatus, Status::SUCCESS);
+        if (!ret.isOk())
+            ALOGE("queryPortStatus error %s", ret.description().c_str());
+    } else {
+        ALOGI("Notifying userspace skipped. Callback is NULL");
+    }
+    pthread_mutex_unlock(&mLock);
+
+    return Void();
+}
+
+Return<void> Usb::setCallback(const sp<IUsbCallback> &callback) {
+    pthread_mutex_lock(&mLock);
+
+    mCallback = callback;
+    ALOGI("registering callback");
+
+    pthread_mutex_unlock(&mLock);
+    return Void();
+}
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android

usb/Usb.h

+#ifndef ANDROID_HARDWARE_USB_V1_0_USB_H
+#define ANDROID_HARDWARE_USB_V1_0_USB_H
+
+#include <android/hardware/usb/1.0/IUsb.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+#include <utils/Log.h>
+
+#ifdef LOG_TAG
+#undef LOG_TAG
+#endif
+
+#define LOG_TAG "android.hardware.usb@1.0-service.mtk"
+#define UEVENT_MSG_LEN 2048
+
+namespace android {
+namespace hardware {
+namespace usb {
+namespace V1_0 {
+namespace implementation {
+
+using ::android::hardware::usb::V1_0::IUsb;
+using ::android::hardware::usb::V1_0::IUsbCallback;
+using ::android::hardware::usb::V1_0::PortRole;
+using ::android::hidl::base::V1_0::IBase;
+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::sp;
+
+struct Usb : public IUsb {
+    Return<void> switchRole(const hidl_string& portName, const PortRole& role) override;
+    Return<void> setCallback(const sp<IUsbCallback>& callback) override;
+    Return<void> queryPortStatus() override;
+
+    sp<IUsbCallback> mCallback;
+    pthread_mutex_t mLock = PTHREAD_MUTEX_INITIALIZER;
+
+    private:
+        pthread_t mPoll;
+};
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace usb
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_USB_V1_0_USB_H

usb/android.hardware.usb@1.0-service.mtk.rc

+service usb-hal-1-0 /vendor/bin/hw/android.hardware.usb@1.0-service.mtk
+    class hal
+    user system
+    group system

usb/service.cpp

+/*
+ * Copyright (C) 2017 The LineageOS jProject
+ *
+ * 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.
+ */
+
+#include <hidl/HidlTransportSupport.h>
+#include "Usb.h"
+
+using android::sp;
+
+// libhwbinder:
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+
+// Generated HIDL files
+using android::hardware::usb::V1_0::IUsb;
+using android::hardware::usb::V1_0::implementation::Usb;
+
+using android::status_t;
+using android::OK;
+
+int main() {
+    android::sp<IUsb> service = new Usb();
+
+    configureRpcThreadpool(1, true /*callerWillJoin*/);
+    status_t status = service->registerAsService();
+
+    if (status != OK) {
+        ALOGE("Cannot register USB HAL service");
+        return 1;
+    }
+
+    ALOGI("USB HAL Ready.");
+    joinRpcThreadpool();
+    // Under noraml cases, execution will not reach this line.
+    ALOGI("USB HAL failed to join thread pool.");
+    return 1;
+}