usb/gadget/UsbGadget.cpp

/*
 * 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.aidl-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>

#include <android-base/properties.h>

#include <aidl/android/frameworks/stats/IStats.h>

namespace aidl {
namespace android {
namespace hardware {
namespace usb {
namespace gadget {

string enabledPath;
constexpr char kHsi2cPath[] = "/sys/devices/platform/10d50000.hsi2c";
constexpr char kMax77759TcpcDevName[] = "i2c-max77759tcpc";
constexpr unsigned int kMax77759TcpcClientId = 0x25;
constexpr char kAccessoryLimitCurrent[] = "usb_limit_accessory_current";
constexpr char kAccessoryLimitCurrentEnable[] = "usb_limit_accessory_enable";
constexpr char kUpdateSdpEnumTimeout[] = "update_sdp_enum_timeout";

using ::android::base::GetBoolProperty;
using ::android::hardware::google::pixel::usb::kUvcEnabled;

UsbGadget::UsbGadget() : mGadgetIrqPath(""),
      mI2cBusNumber(-1),
      mI2cClientPath("") {
    if (access(OS_DESC_PATH, R_OK) != 0) {
        ALOGE("configfs setup not done yet");
        abort();
    }
}

Status UsbGadget::getUsbGadgetIrqPath() {
    std::string irqs;
    size_t read_pos = 0;
    size_t found_pos = 0;

    if (!ReadFileToString(kProcInterruptsPath, &irqs)) {
        ALOGE("cannot read all interrupts");
        return Status::ERROR;
    }

    while (true) {
        found_pos = irqs.find_first_of("\n", read_pos);
        if (found_pos == std::string::npos) {
            ALOGI("the string of all interrupts is unexpected");
            return Status::ERROR;
        }

        std::string single_irq = irqs.substr(read_pos, found_pos - read_pos);

        if (single_irq.find("dwc3", 0) != std::string::npos) {
            unsigned int dwc3_irq_number;
            size_t dwc3_pos = single_irq.find_first_of(":");
            if (!ParseUint(single_irq.substr(0, dwc3_pos), &dwc3_irq_number)) {
                ALOGI("unknown IRQ strings");
                return Status::ERROR;
            }

            mGadgetIrqPath = kProcIrqPath + single_irq.substr(0, dwc3_pos) + kSmpAffinityList;
            break;
        }

        if (found_pos == irqs.npos) {
            ALOGI("USB gadget doesn't start");
            return Status::ERROR;
        }

        read_pos = found_pos + 1;
    }

    return Status::SUCCESS;
}

void currentFunctionsAppliedCallback(bool functionsApplied, void *payload) {
    UsbGadget *gadget = (UsbGadget *)payload;
    gadget->mCurrentUsbFunctionsApplied = functionsApplied;
    gadget->updateSdpEnumTimeout();
}

ScopedAStatus UsbGadget::getCurrentUsbFunctions(const shared_ptr<IUsbGadgetCallback> &callback,
        int64_t in_transactionId) {
    ScopedAStatus ret = callback->getCurrentUsbFunctionsCb(
        mCurrentUsbFunctions,
        mCurrentUsbFunctionsApplied ? Status::FUNCTIONS_APPLIED : Status::FUNCTIONS_NOT_APPLIED,
        in_transactionId);
    if (!ret.isOk())
        ALOGE("Call to getCurrentUsbFunctionsCb failed %s", ret.getDescription().c_str());

    return ScopedAStatus::ok();
}

ScopedAStatus UsbGadget::getUsbSpeed(const shared_ptr<IUsbGadgetCallback> &callback,
        int64_t in_transactionId) {
    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
            mUsbSpeed = UsbSpeed::UNKNOWN;
    } else {
        ALOGE("Fail to read current speed");
        mUsbSpeed = UsbSpeed::UNKNOWN;
    }

    if (callback) {
        ScopedAStatus ret = callback->getUsbSpeedCb(mUsbSpeed, in_transactionId);

        if (!ret.isOk())
            ALOGE("Call to getUsbSpeedCb failed %s", ret.getDescription().c_str());
    }

    return ScopedAStatus::ok();
}

Status UsbGadget::tearDownGadget() {
    if (Status(resetGadget()) != Status::SUCCESS){
        return Status::ERROR;
    }

    if (monitorFfs.isMonitorRunning()) {
        monitorFfs.reset();
    } else {
        ALOGI("mMonitor not running");
    }
    return Status::SUCCESS;
}

static Status validateAndSetVidPid(int64_t functions) {
    Status ret;
    std::string vendorFunctions = getVendorFunctions();

    switch (functions) {
        case GadgetFunction::MTP:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee1"));
            }
            break;
        case GadgetFunction::ADB |
                GadgetFunction::MTP:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee2"));
            }
            break;
        case GadgetFunction::RNDIS:
        case GadgetFunction::RNDIS |
                GadgetFunction::NCM:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee3"));
            }
            break;
        case GadgetFunction::ADB |
                GadgetFunction::RNDIS:
        case GadgetFunction::ADB |
                GadgetFunction::RNDIS |
                GadgetFunction::NCM:
            if (vendorFunctions == "dm") {
                ret = Status(setVidPid("0x04e8", "0x6862"));
            } else {
                if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                    ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                    ret = Status::CONFIGURATION_NOT_SUPPORTED;
                } else {
                    ret = Status(setVidPid("0x18d1", "0x4ee4"));
                }
            }
            break;
        case GadgetFunction::PTP:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee5"));
            }
            break;
        case GadgetFunction::ADB |
                GadgetFunction::PTP:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee6"));
            }
            break;
        case GadgetFunction::ADB:
            if (vendorFunctions == "dm") {
                ret = Status(setVidPid("0x04e8", "0x6862"));
            } else if (vendorFunctions == "etr_miu") {
                ret = Status(setVidPid("0x18d1", "0x4ee2"));
            } else if (vendorFunctions == "uwb_acm"){
                ret = Status(setVidPid("0x18d1", "0x4ee2"));
            } else {
                if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                    ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                    ret = Status::CONFIGURATION_NOT_SUPPORTED;
                } else {
                    ret = Status(setVidPid("0x18d1", "0x4ee7"));
                }
            }
            break;
        case GadgetFunction::MIDI:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee8"));
            }
            break;
        case GadgetFunction::ADB |
                GadgetFunction::MIDI:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4ee9"));
            }
            break;
        case GadgetFunction::ACCESSORY:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d00"));
            break;
        case GadgetFunction::ADB |
                 GadgetFunction::ACCESSORY:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d01"));
            break;
        case GadgetFunction::AUDIO_SOURCE:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d02"));
            break;
        case GadgetFunction::ADB |
                GadgetFunction::AUDIO_SOURCE:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d03"));
            break;
        case GadgetFunction::ACCESSORY |
                GadgetFunction::AUDIO_SOURCE:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d04"));
            break;
        case GadgetFunction::ADB |
                GadgetFunction::ACCESSORY |
                GadgetFunction::AUDIO_SOURCE:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x2d05"));
            break;
        case GadgetFunction::NCM:
            if (!(vendorFunctions == "user" || vendorFunctions == ""))
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
            ret = Status(setVidPid("0x18d1", "0x4eeb"));
            break;
        case GadgetFunction::ADB |
                GadgetFunction::NCM:
            if (vendorFunctions == "dm") {
                ret = Status(setVidPid("0x04e8", "0x6862"));
            } else {
                if (!(vendorFunctions == "user" || vendorFunctions == ""))
                    ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status(setVidPid("0x18d1", "0x4eec"));
            }
            break;
        case GadgetFunction::UVC:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else if (!GetBoolProperty(kUvcEnabled, false)) {
                ALOGE("UVC function not enabled by config");
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4eed"));
            }
            break;
        case GadgetFunction::ADB | GadgetFunction::UVC:
            if (!(vendorFunctions == "user" || vendorFunctions == "")) {
                ALOGE("Invalid vendorFunctions set: %s", vendorFunctions.c_str());
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else if (!GetBoolProperty(kUvcEnabled, false)) {
                ALOGE("UVC function not enabled by config");
                ret = Status::CONFIGURATION_NOT_SUPPORTED;
            } else {
                ret = Status(setVidPid("0x18d1", "0x4eee"));
            }
            break;
        default:
            ALOGE("Combination not supported");
            ret = Status::CONFIGURATION_NOT_SUPPORTED;
    }
    return ret;
}

ScopedAStatus UsbGadget::reset(const shared_ptr<IUsbGadgetCallback> &callback,
        int64_t in_transactionId) {
    ALOGI("USB Gadget reset");

    if (!WriteStringToFile("none", PULLUP_PATH)) {
        ALOGI("Gadget cannot be pulled down");
        if (callback)
            callback->resetCb(Status::ERROR, in_transactionId);
        return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "Gadget cannot be pulled down");
    }

    usleep(kDisconnectWaitUs);

    if (!WriteStringToFile(kGadgetName, PULLUP_PATH)) {
        ALOGI("Gadget cannot be pulled up");
        if (callback)
            callback->resetCb(Status::ERROR, in_transactionId);
        return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "Gadget cannot be pulled up");
    }
    if (callback)
        callback->resetCb(Status::SUCCESS, in_transactionId);

    return ScopedAStatus::ok();
}

void UsbGadget::updateSdpEnumTimeout() {
    string update_sdp_enum_timeout_path;
    std::string_view i2cPath;

    i2cPath = getI2cClientPath();
    if (i2cPath.empty()) {
        ALOGE("%s: Unable to locate i2c bus node", __func__);
        return;
    }

    update_sdp_enum_timeout_path = std::string{i2cPath} + "/" + kUpdateSdpEnumTimeout;
    if (!WriteStringToFile("1", update_sdp_enum_timeout_path)) {
        ALOGE("%s: Unable to write to %s.", __func__, update_sdp_enum_timeout_path.c_str());
    } else {
        ALOGI("%s: Updated SDP enumeration timeout value.", __func__);
    }
}

Status UsbGadget::setupFunctions(long functions,
        const shared_ptr<IUsbGadgetCallback> &callback, uint64_t timeout,
        int64_t in_transactionId) {
    bool ffsEnabled = false;
    int i = 0;

    if (Status(addGenericAndroidFunctions(&monitorFfs, functions, &ffsEnabled, &i)) !=
        Status::SUCCESS)
        return Status::ERROR;

    std::string vendorFunctions = getVendorFunctions();

    if (vendorFunctions == "dm") {
        ALOGI("enable usbradio debug functions");
        if ((functions & GadgetFunction::RNDIS) != 0) {
            if (linkFunction("acm.gs6", i++))
                return Status::ERROR;
            if (linkFunction("dm.gs7", i++))
                return Status::ERROR;
        } else {
            if (linkFunction("dm.gs7", i++))
                return Status::ERROR;
            if (linkFunction("acm.gs6", i++))
                return Status::ERROR;
        }
    } else if (vendorFunctions == "etr_miu") {
        ALOGI("enable etr_miu functions");
        if (linkFunction("etr_miu.gs11", i++))
            return Status::ERROR;
    } else if (vendorFunctions == "uwb_acm") {
        ALOGI("enable uwb acm function");
        if (linkFunction("acm.uwb0", i++))
            return Status::ERROR;
    }

    if ((functions & GadgetFunction::ADB) != 0) {
        ffsEnabled = true;
        if (Status(addAdb(&monitorFfs, &i)) != Status::SUCCESS)
            return Status::ERROR;
    }

    if ((functions & GadgetFunction::NCM) != 0) {
        ALOGI("setCurrentUsbFunctions ncm");
        if (linkFunction("ncm.gs9", i++))
            return Status::ERROR;
    }

    // Pull up the gadget right away when there are no ffs functions.
    if (!ffsEnabled) {
        if (!WriteStringToFile(kGadgetName, PULLUP_PATH))
            return Status::ERROR;
        mCurrentUsbFunctionsApplied = true;
        if (callback)
            callback->setCurrentUsbFunctionsCb(functions, Status::SUCCESS, in_transactionId);
        updateSdpEnumTimeout();
        return 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);
        ScopedAStatus ret = callback->setCurrentUsbFunctionsCb(
            functions, pullup ? Status::SUCCESS : Status::ERROR, in_transactionId);
        if (!ret.isOk()) {
            ALOGE("setCurrentUsbFunctionsCb error %s", ret.getDescription().c_str());
            return Status::ERROR;
        }
    }
    return Status::SUCCESS;
}

int UsbGadget::getI2cBusNumber() {
    DIR *dp;
    unsigned int busNumber;

    // Since the i2c bus number doesn't change after boot, we only need to get
    // it once.
    if (mI2cBusNumber >= 0) {
        return mI2cBusNumber;
    }

    dp = opendir(kHsi2cPath);
    if (dp != NULL) {
        struct dirent *ep;

        while ((ep = readdir(dp))) {
            if (ep->d_type == DT_DIR) {
                if (sscanf(ep->d_name, "i2c-%u", &busNumber) == 1) {
                    mI2cBusNumber = busNumber;
                    break;
                }
            }
        }
        closedir(dp);
    }

    if (mI2cBusNumber < 0) {
        ALOGE("Failed to open %s", kHsi2cPath);
    }
    return mI2cBusNumber;
}

std::string_view UsbGadget::getI2cClientPath() {
    DIR *dp;
    char i2cClientPathLabeled[PATH_MAX];
    char i2cClientPathUnLabeled[PATH_MAX];

    // Since the I2C client path doesn't change after boot, we only need to get
    // it once.
    if (!mI2cClientPath.empty()) {
        return mI2cClientPath;
    }

    if (getI2cBusNumber() < 0) {
        return std::string_view{""};
    }

    snprintf(i2cClientPathLabeled, sizeof(i2cClientPathLabeled),
             "%s/i2c-%d/%s", kHsi2cPath, mI2cBusNumber,  kMax77759TcpcDevName);
    snprintf(i2cClientPathUnLabeled, sizeof(i2cClientPathUnLabeled),
             "%s/i2c-%d/%d-%04x", kHsi2cPath, mI2cBusNumber, mI2cBusNumber,
             kMax77759TcpcClientId);

    dp = opendir(i2cClientPathLabeled);
    if (dp != NULL) {
        mI2cClientPath.assign(i2cClientPathLabeled);
        closedir(dp);
        return mI2cClientPath;
    }

    dp = opendir(i2cClientPathUnLabeled);
    if (dp != NULL) {
        mI2cClientPath.assign(i2cClientPathUnLabeled);
        closedir(dp);
        return mI2cClientPath;
    }

    ALOGE("Failed to find the i2c client path under %s", kHsi2cPath);
    return std::string_view{""};
}

ScopedAStatus UsbGadget::setCurrentUsbFunctions(long functions,
                                               const shared_ptr<IUsbGadgetCallback> &callback,
                                               int64_t timeout,
                                               int64_t in_transactionId) {
    std::unique_lock<std::mutex> lk(mLockSetCurrentFunction);
    std::string current_usb_power_operation_mode, current_usb_type;
    std::string usb_limit_sink_enable;

    string accessoryCurrentLimitEnablePath, accessoryCurrentLimitPath;
    std::string_view i2cPath;

    mCurrentUsbFunctions = functions;
    mCurrentUsbFunctionsApplied = false;

    i2cPath = getI2cClientPath();
    if (!i2cPath.empty()) {
        accessoryCurrentLimitPath = std::string{i2cPath} + "/" + kAccessoryLimitCurrent;
        accessoryCurrentLimitEnablePath = std::string{i2cPath} + "/" + kAccessoryLimitCurrentEnable;
    } else {
        ALOGE("%s: Unable to locate i2c bus node", __func__);
    }

    // Get the gadget IRQ number before tearDownGadget()
    if (mGadgetIrqPath.empty())
        getUsbGadgetIrqPath();

    // Unlink the gadget and stop the monitor if running.
    Status status = tearDownGadget();
    if (status != 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 == GadgetFunction::NONE) {
        if (callback == NULL)
            return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "callback == NULL");
        ScopedAStatus ret = callback->setCurrentUsbFunctionsCb(functions, Status::SUCCESS, in_transactionId);
        if (!ret.isOk())
            ALOGE("Error while calling setCurrentUsbFunctionsCb %s", ret.getDescription().c_str());
        return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "Error while calling setCurrentUsbFunctionsCb");
    }

    status = validateAndSetVidPid(functions);

    if (status != Status::SUCCESS) {
        goto error;
    }

    status = setupFunctions(functions, callback, timeout, in_transactionId);
    if (status != Status::SUCCESS) {
        goto error;
    }

    if (functions & GadgetFunction::NCM) {
        if (!mGadgetIrqPath.empty()) {
            if (!WriteStringToFile(BIG_CORE, mGadgetIrqPath))
                ALOGI("Cannot move gadget IRQ to big core, path:%s", mGadgetIrqPath.c_str());
        }
    } else {
        if (!mGadgetIrqPath.empty()) {
            if (!WriteStringToFile(MEDIUM_CORE, mGadgetIrqPath))
                ALOGI("Cannot move gadget IRQ to medium core, path:%s", mGadgetIrqPath.c_str());
        }
    }

    if (ReadFileToString(CURRENT_USB_TYPE_PATH, &current_usb_type))
        current_usb_type = Trim(current_usb_type);

    if (ReadFileToString(CURRENT_USB_POWER_OPERATION_MODE_PATH, &current_usb_power_operation_mode))
        current_usb_power_operation_mode = Trim(current_usb_power_operation_mode);

    if (functions & GadgetFunction::ACCESSORY &&
        current_usb_type == "Unknown SDP [CDP] DCP" &&
        (current_usb_power_operation_mode == "default" ||
        current_usb_power_operation_mode == "1.5A")) {
        if (accessoryCurrentLimitPath.empty() || !WriteStringToFile("1300000", accessoryCurrentLimitPath)) {
            ALOGI("Write 1.3A to limit current fail");
        } else {
            if (accessoryCurrentLimitEnablePath.empty() ||
                !WriteStringToFile("1", accessoryCurrentLimitEnablePath)) {
                ALOGI("Enable limit current fail");
            }
        }
    } else {
        if (accessoryCurrentLimitEnablePath.empty() ||
            !WriteStringToFile("0", accessoryCurrentLimitEnablePath))
            ALOGI("unvote accessory limit current failed");
    }

    ALOGI("Usb Gadget setcurrent functions called successfully");
    return ScopedAStatus::ok();

error:
    ALOGI("Usb Gadget setcurrent functions failed");
    if (callback == NULL)
        return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "Usb Gadget setcurrent functions failed");
    ScopedAStatus ret = callback->setCurrentUsbFunctionsCb(functions, status, in_transactionId);
    if (!ret.isOk())
        ALOGE("Error while calling setCurrentUsbFunctionsCb %s", ret.getDescription().c_str());
    return ScopedAStatus::fromServiceSpecificErrorWithMessage(
                -1, "Error while calling setCurrentUsbFunctionsCb");
}
}  // namespace gadget
}  // namespace usb
}  // namespace hardware
}  // namespace android
}  // aidl