usb_linux_client.c revision 4f6e8d7a00cbeda1e70cc15be9c4af1018bdad53 
1/*
2 * Copyright (C) 2007 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 <stdio.h>
18#include <stdlib.h>
19#include <unistd.h>
20#include <string.h>
21
22#include <sys/ioctl.h>
23#include <sys/types.h>
24#include <dirent.h>
25#include <errno.h>
26
27#include "sysdeps.h"
28
29#define   TRACE_TAG  TRACE_USB
30#include "adb.h"
31
32
33struct usb_handle
34{
35    int fd;
36    adb_cond_t notify;
37    adb_mutex_t lock;
38};
39
40void usb_cleanup()
41{
42    // nothing to do here
43}
44
45static void *usb_open_thread(void *x)
46{
47    struct usb_handle *usb = (struct usb_handle *)x;
48    int fd;
49
50    while (1) {
51        // wait until the USB device needs opening
52        adb_mutex_lock(&usb->lock);
53        while (usb->fd != -1)
54            adb_cond_wait(&usb->notify, &usb->lock);
55        adb_mutex_unlock(&usb->lock);
56
57        D("[ usb_thread - opening device ]\n");
58        do {
59            /* XXX use inotify? */
60            fd = unix_open("/dev/android_adb", O_RDWR);
61            if (fd < 0) {
62                // to support older kernels
63                fd = unix_open("/dev/android", O_RDWR);
64            }
65            if (fd < 0) {
66                adb_sleep_ms(1000);
67            }
68        } while (fd < 0);
69        D("[ opening device succeeded ]\n");
70
71        close_on_exec(fd);
72        usb->fd = fd;
73
74        D("[ usb_thread - registering device ]\n");
75        register_usb_transport(usb, 0);
76    }
77
78    // never gets here
79    return 0;
80}
81
82int usb_write(usb_handle *h, const void *data, int len)
83{
84    int n;
85
86    D("[ write %d ]\n", len);
87    n = adb_write(h->fd, data, len);
88    if(n != len) {
89        D("ERROR: n = %d, errno = %d (%s)\n",
90            n, errno, strerror(errno));
91        return -1;
92    }
93    D("[ done ]\n");
94    return 0;
95}
96
97int usb_read(usb_handle *h, void *data, int len)
98{
99    int n;
100
101    D("[ read %d ]\n", len);
102    n = adb_read(h->fd, data, len);
103    if(n != len) {
104        D("ERROR: n = %d, errno = %d (%s)\n",
105            n, errno, strerror(errno));
106        return -1;
107    }
108    return 0;
109}
110
111void usb_init()
112{
113    usb_handle *h;
114    adb_thread_t tid;
115    int fd;
116
117    h = calloc(1, sizeof(usb_handle));
118    h->fd = -1;
119    adb_cond_init(&h->notify, 0);
120    adb_mutex_init(&h->lock, 0);
121
122    // Open the file /dev/android_adb_enable to trigger
123    // the enabling of the adb USB function in the kernel.
124    // We never touch this file again - just leave it open
125    // indefinitely so the kernel will know when we are running
126    // and when we are not.
127    fd = unix_open("/dev/android_adb_enable", O_RDWR);
128    if (fd < 0) {
129       D("failed to open /dev/android_adb_enable\n");
130    } else {
131        close_on_exec(fd);
132    }
133
134    D("[ usb_init - starting thread ]\n");
135    if(adb_thread_create(&tid, usb_open_thread, h)){
136        fatal_errno("cannot create usb thread");
137    }
138}
139
140void usb_kick(usb_handle *h)
141{
142    D("usb_kick\n");
143    adb_mutex_lock(&h->lock);
144    adb_close(h->fd);
145    h->fd = -1;
146
147    // notify usb_open_thread that we are disconnected
148    adb_cond_signal(&h->notify);
149    adb_mutex_unlock(&h->lock);
150}
151
152int usb_close(usb_handle *h)
153{
154    // nothing to do here
155    return 0;
156}
157