1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "sync_clock.h"
18
19#include <errno.h>
20#include <fcntl.h>
21#include <linux/usbdevice_fs.h>
22#include <stdio.h>
23#include <string.h>
24#include <sys/ioctl.h>
25#include <sys/types.h>
26#include <unistd.h>
27
28
29int main(int argc, char ** argv) {
30    if(argc < 2) {
31        printf("Usage %s <device_path>\n"
32               "Try `lsusb | grep eensy` and use /dev/bus/usb/<Bus>/<Device>\n",
33               argv[0]);
34        return 1;
35    }
36
37    printf("Opening %s\n", argv[1]);
38    int fd = open(argv[1], O_RDWR);
39    printf("open() fd=%d, errno=%d, %s\n", fd, errno, strerror(errno));
40
41    // The interface and endpoint numbers are defined by the TeensyUSB. They may
42    // be different depending on the mode (Serial vs HID) the Teensy code is
43    // compiled in. A real app would employ some discovery logic here. To list
44    // the interfaces and endpoints use `lsusb --verbose` or an app like USB
45    // Host Viewer on Android. Look for a "CDC Data" interface (class 0x0a).
46    int interface = 1;
47    int ep_out = 0x03;
48    int ep_in = 0x84;
49
50    int ret = ioctl(fd, USBDEVFS_CLAIMINTERFACE, &interface);
51    printf("Interface claimed retval=%d, errno=%d, %s\n", ret, errno, strerror(errno));
52    if (errno == EBUSY) {
53        printf("You may need to run 'sudo rmmod cdc_acm' to release the "
54               "interface claimed by the kernel serial driver.");
55        return 1;
56    }
57
58    struct clock_connection clk;
59    clk.fd = fd;
60    clk.endpoint_in = ep_in;
61    clk.endpoint_out = ep_out;
62
63    sync_clocks(&clk);
64
65    printf("===========================\n"
66           "sync_clocks base_t=%lld, minE=%d, maxE=%d\n",
67           (long long int)clk.t_base, clk.minE, clk.maxE);
68
69    // Check for clock drift. Try sleeping here to let it actually drift away.
70    update_bounds(&clk);
71
72    printf("*** UPDATE ****************\n"
73           "Update_bounds base_t=%lld, minE=%d, maxE=%d\n",
74           (long long int)(clk.t_base), clk.minE, clk.maxE
75    );
76
77
78    close(fd);
79    return 0;
80}