com_android_server_UsbDeviceManager.cpp revision 8dcf593f90792272bd21e498da1aeb60fced1989 
1/*
2 * Copyright (C) 2010 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#define LOG_TAG "UsbDeviceManagerJNI"
18#include "utils/Log.h"
19
20#include "jni.h"
21#include "JNIHelp.h"
22#include "android_runtime/AndroidRuntime.h"
23#include "android_runtime/Log.h"
24
25#include <stdio.h>
26#include <asm/byteorder.h>
27#include <sys/types.h>
28#include <sys/stat.h>
29#include <fcntl.h>
30#include <sys/ioctl.h>
31#include <linux/usb/f_accessory.h>
32
33#define DRIVER_NAME "/dev/usb_accessory"
34
35namespace android
36{
37
38static struct parcel_file_descriptor_offsets_t
39{
40    jclass mClass;
41    jmethodID mConstructor;
42} gParcelFileDescriptorOffsets;
43
44static void checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) {
45    if (env->ExceptionCheck()) {
46        ALOGE("An exception was thrown by callback '%s'.", methodName);
47        LOGE_EX(env);
48        env->ExceptionClear();
49    }
50}
51
52static void set_accessory_string(JNIEnv *env, int fd, int cmd, jobjectArray strArray, int index)
53{
54    char buffer[256];
55
56    buffer[0] = 0;
57    int length = ioctl(fd, cmd, buffer);
58    if (buffer[0]) {
59        jstring obj = env->NewStringUTF(buffer);
60        env->SetObjectArrayElement(strArray, index, obj);
61        env->DeleteLocalRef(obj);
62    }
63}
64
65
66static jobjectArray android_server_UsbDeviceManager_getAccessoryStrings(JNIEnv *env,
67                                                                        jobject /* thiz */)
68{
69    int fd = open(DRIVER_NAME, O_RDWR);
70    if (fd < 0) {
71        ALOGE("could not open %s", DRIVER_NAME);
72        return NULL;
73    }
74    jclass stringClass = env->FindClass("java/lang/String");
75    jobjectArray strArray = env->NewObjectArray(6, stringClass, NULL);
76    if (!strArray) goto out;
77    set_accessory_string(env, fd, ACCESSORY_GET_STRING_MANUFACTURER, strArray, 0);
78    set_accessory_string(env, fd, ACCESSORY_GET_STRING_MODEL, strArray, 1);
79    set_accessory_string(env, fd, ACCESSORY_GET_STRING_DESCRIPTION, strArray, 2);
80    set_accessory_string(env, fd, ACCESSORY_GET_STRING_VERSION, strArray, 3);
81    set_accessory_string(env, fd, ACCESSORY_GET_STRING_URI, strArray, 4);
82    set_accessory_string(env, fd, ACCESSORY_GET_STRING_SERIAL, strArray, 5);
83
84out:
85    close(fd);
86    return strArray;
87}
88
89static jobject android_server_UsbDeviceManager_openAccessory(JNIEnv *env, jobject /* thiz */)
90{
91    int fd = open(DRIVER_NAME, O_RDWR);
92    if (fd < 0) {
93        ALOGE("could not open %s", DRIVER_NAME);
94        return NULL;
95    }
96    jobject fileDescriptor = jniCreateFileDescriptor(env, fd);
97    if (fileDescriptor == NULL) {
98        return NULL;
99    }
100    return env->NewObject(gParcelFileDescriptorOffsets.mClass,
101        gParcelFileDescriptorOffsets.mConstructor, fileDescriptor);
102}
103
104static jboolean android_server_UsbDeviceManager_isStartRequested(JNIEnv* /* env */,
105                                                                 jobject /* thiz */)
106{
107    int fd = open(DRIVER_NAME, O_RDWR);
108    if (fd < 0) {
109        ALOGE("could not open %s", DRIVER_NAME);
110        return false;
111    }
112    int result = ioctl(fd, ACCESSORY_IS_START_REQUESTED);
113    close(fd);
114    return (result == 1);
115}
116
117static jint android_server_UsbDeviceManager_getAudioMode(JNIEnv* /* env */, jobject /* thiz */)
118{
119    int fd = open(DRIVER_NAME, O_RDWR);
120    if (fd < 0) {
121        ALOGE("could not open %s", DRIVER_NAME);
122        return false;
123    }
124    int result = ioctl(fd, ACCESSORY_GET_AUDIO_MODE);
125    close(fd);
126    return result;
127}
128
129static JNINativeMethod method_table[] = {
130    { "nativeGetAccessoryStrings",  "()[Ljava/lang/String;",
131                                    (void*)android_server_UsbDeviceManager_getAccessoryStrings },
132    { "nativeOpenAccessory",        "()Landroid/os/ParcelFileDescriptor;",
133                                    (void*)android_server_UsbDeviceManager_openAccessory },
134    { "nativeIsStartRequested",     "()Z",
135                                    (void*)android_server_UsbDeviceManager_isStartRequested },
136    { "nativeGetAudioMode",         "()I",
137                                    (void*)android_server_UsbDeviceManager_getAudioMode },
138};
139
140int register_android_server_UsbDeviceManager(JNIEnv *env)
141{
142    jclass clazz = env->FindClass("com/android/server/usb/UsbDeviceManager");
143    if (clazz == NULL) {
144        ALOGE("Can't find com/android/server/usb/UsbDeviceManager");
145        return -1;
146    }
147
148    clazz = env->FindClass("android/os/ParcelFileDescriptor");
149    LOG_FATAL_IF(clazz == NULL, "Unable to find class android.os.ParcelFileDescriptor");
150    gParcelFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
151    gParcelFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "(Ljava/io/FileDescriptor;)V");
152    LOG_FATAL_IF(gParcelFileDescriptorOffsets.mConstructor == NULL,
153                 "Unable to find constructor for android.os.ParcelFileDescriptor");
154
155    return jniRegisterNativeMethods(env, "com/android/server/usb/UsbDeviceManager",
156            method_table, NELEM(method_table));
157}
158
159};
160