system/uapp/xdc-test/xdc-device.cpp

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <fuchsia/usb/debug/c/fidl.h>
#include <lib/fzl/fdio.h>

#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>

#include <utility>

#include "xdc-init.h"

static const char* const DEV_XDC_DIR = "/dev/class/usb-dbc";

zx_status_t configure_xdc(uint32_t stream_id, fbl::unique_fd* out_fd) {
    DIR* d = opendir(DEV_XDC_DIR);
    if (d == nullptr) {
        fprintf(stderr, "Could not open dir: \"%s\"\n", DEV_XDC_DIR);
        return ZX_ERR_BAD_STATE;
    }

    struct dirent* de;
    while ((de = readdir(d)) != nullptr) {
        int fd = openat(dirfd(d), de->d_name, O_RDWR);
        if (fd < 0) {
            continue;
        }
        fzl::FdioCaller caller{fbl::unique_fd(fd)};
        zx_status_t status;
        zx_status_t res = fuchsia_usb_debug_DeviceSetStream(caller.borrow_channel(),
                                                            stream_id, &status);
        if (res == ZX_OK) {
            res = status;
        }
        if (res != ZX_OK) {
            fprintf(stderr, "Failed to set stream id %u for device \"%s/%s\", err: %d\n",
                    stream_id, DEV_XDC_DIR, de->d_name, res);
            continue;
        }
        printf("Configured debug device \"%s/%s\", stream id %u\n",
               DEV_XDC_DIR, de->d_name, stream_id);
        *out_fd = caller.release();
        closedir(d);
        return ZX_OK;
    }
    closedir(d);

    fprintf(stderr, "No debug device found\n");
    return ZX_ERR_NOT_FOUND;
}