adb/daemon/usb.h

#pragma once

/*
 * Copyright (C) 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.
 */

#include <atomic>
#include <condition_variable>
#include <mutex>

// Writes larger than 16k fail on some devices (seed with 3.10.49-g209ea2f in particular).
#define USB_FFS_MAX_WRITE 16384

// The kernel allocates a contiguous buffer for reads, which can fail for large ones due to
// fragmentation. 16k chosen arbitrarily to match the write limit.
#define USB_FFS_MAX_READ 16384

struct usb_handle {
    usb_handle() : kicked(false) {
    }

    std::condition_variable notify;
    std::mutex lock;
    std::atomic<bool> kicked;
    bool open_new_connection = true;

    int (*write)(usb_handle* h, const void* data, int len);
    int (*read)(usb_handle* h, void* data, int len);
    void (*kick)(usb_handle* h);
    void (*close)(usb_handle* h);

    // FunctionFS
    int control = -1;
    int bulk_out = -1; /* "out" from the host's perspective => source for adbd */
    int bulk_in = -1;  /* "in" from the host's perspective => sink for adbd */
};

bool init_functionfs(struct usb_handle* h);