New APIs for USB host support:

UsbManager:
- is now a service retrievable via Context.getSystemService(Context.USB_SERVICE).
- provides support for returning a list all connected USB devices
- broadcasts ACTION_USB_DEVICE_ATTACHED and USB_DEVICE_DETACHED when devices
  are added and removed from the USB host bus

UsbDevice:
- represents an attached USB device.

UsbInterface:
- represents an interface on a USB device
- devices may have multiple interfaces if they provide multiple
   sets of functionality (for example, android phones typically have interfaces
   for both USB mass storage and adb)

UsbEndpoint:
- represents an endpoint on a USB interface
- endpoints are used for sending or receiving data
  (only in one or the other direction)

UsbRequest:
- encapsulates a send or receive request to be sent over an endpoint

Change-Id: Ieef3e434c62760770ea839070cf5eba1a705967a
Signed-off-by: Mike Lockwood <lockwood@android.com>

3 files changed, 213 insertions, 0 deletions

diff --git a/services/jni/Android.mk b/services/jni/Android.mk
index f5a5b4d..be37d5d 100644
--- a/services/jni/Android.mk
+++ b/services/jni/Android.mk
@@ -12,6 +12,7 @@ LOCAL_SRC_FILES:= \
     com_android_server_LightsService.cpp \
     com_android_server_PowerManagerService.cpp \
     com_android_server_SystemServer.cpp \
+    com_android_server_UsbService.cpp \
     com_android_server_VibratorService.cpp \
     com_android_server_location_GpsLocationProvider.cpp \
     onload.cpp
diff --git a/services/jni/com_android_server_UsbService.cpp b/services/jni/com_android_server_UsbService.cpp
new file mode 100644
index 0000000..ef22111
--- /dev/null
+++ b/services/jni/com_android_server_UsbService.cpp
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2009 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.
+ */
+
+#define LOG_TAG "UsbService"
+#include "utils/Log.h"
+
+#include "jni.h"
+#include "JNIHelp.h"
+#include "android_runtime/AndroidRuntime.h"
+#include "utils/Vector.h"
+
+#include <usbhost/usbhost.h>
+
+#include <stdio.h>
+#include <asm/byteorder.h>
+
+namespace android
+{
+
+static struct file_descriptor_offsets_t
+{
+    jclass mClass;
+    jmethodID mConstructor;
+    jfieldID mDescriptor;
+} gFileDescriptorOffsets;
+
+static struct parcel_file_descriptor_offsets_t
+{
+    jclass mClass;
+    jmethodID mConstructor;
+} gParcelFileDescriptorOffsets;
+
+static jmethodID method_usbDeviceAdded;
+static jmethodID method_usbDeviceRemoved;
+
+static void checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) {
+    if (env->ExceptionCheck()) {
+        LOGE("An exception was thrown by callback '%s'.", methodName);
+        LOGE_EX(env);
+        env->ExceptionClear();
+    }
+}
+
+static int usb_device_added(const char *devname, void* client_data) {
+    struct usb_descriptor_header* desc;
+    struct usb_descriptor_iter iter;
+
+    struct usb_device *device = usb_device_open(devname);
+    if (!device) {
+        LOGE("usb_device_open failed\n");
+        return 0;
+    }
+
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    jobject thiz = (jobject)client_data;
+    Vector<int> interfaceValues;
+    Vector<int> endpointValues;
+    const usb_device_descriptor* deviceDesc = usb_device_get_device_descriptor(device);
+
+    uint16_t vendorId = usb_device_get_vendor_id(device);
+    uint16_t productId = usb_device_get_product_id(device);
+    uint8_t deviceClass = deviceDesc->bDeviceClass;
+    uint8_t deviceSubClass = deviceDesc->bDeviceSubClass;
+    uint8_t protocol = deviceDesc->bDeviceProtocol;
+
+    usb_descriptor_iter_init(device, &iter);
+
+    while ((desc = usb_descriptor_iter_next(&iter)) != NULL) {
+        if (desc->bDescriptorType == USB_DT_INTERFACE) {
+            struct usb_interface_descriptor *interface = (struct usb_interface_descriptor *)desc;
+
+            // push class, subclass, protocol and number of endpoints into interfaceValues vector
+            interfaceValues.add(interface->bInterfaceNumber);
+            interfaceValues.add(interface->bInterfaceClass);
+            interfaceValues.add(interface->bInterfaceSubClass);
+            interfaceValues.add(interface->bInterfaceProtocol);
+            interfaceValues.add(interface->bNumEndpoints);
+        } else if (desc->bDescriptorType == USB_DT_ENDPOINT) {
+            struct usb_endpoint_descriptor *endpoint = (struct usb_endpoint_descriptor *)desc;
+
+            // push address, attributes, max packet size and interval into endpointValues vector
+            endpointValues.add(endpoint->bEndpointAddress);
+            endpointValues.add(endpoint->bmAttributes);
+            endpointValues.add(__le16_to_cpu(endpoint->wMaxPacketSize));
+            endpointValues.add(endpoint->bInterval);
+        }
+    }
+
+    usb_device_close(device);
+
+    // handle generic device notification
+    int length = interfaceValues.size();
+    jintArray interfaceArray = env->NewIntArray(length);
+    env->SetIntArrayRegion(interfaceArray, 0, length, interfaceValues.array());
+
+    length = endpointValues.size();
+    jintArray endpointArray = env->NewIntArray(length);
+    env->SetIntArrayRegion(endpointArray, 0, length, endpointValues.array());
+
+    env->CallVoidMethod(thiz, method_usbDeviceAdded,
+            env->NewStringUTF(devname), vendorId, productId, deviceClass,
+            deviceSubClass, protocol, interfaceArray, endpointArray);
+    checkAndClearExceptionFromCallback(env, __FUNCTION__);
+
+    return 0;
+}
+
+static int usb_device_removed(const char *devname, void* client_data) {
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    jobject thiz = (jobject)client_data;
+
+    env->CallVoidMethod(thiz, method_usbDeviceRemoved, env->NewStringUTF(devname));
+    checkAndClearExceptionFromCallback(env, __FUNCTION__);
+    return 0;
+}
+
+static void android_server_UsbService_monitorUsbHostBus(JNIEnv *env, jobject thiz)
+{
+    struct usb_host_context* context = usb_host_init();
+    if (!context) {
+        LOGE("usb_host_init failed");
+        return;
+    }
+    // this will never return so it is safe to pass thiz directly
+    usb_host_run(context, usb_device_added, usb_device_removed, NULL, (void *)thiz);
+}
+
+static jobject android_server_UsbService_openDevice(JNIEnv *env, jobject thiz, jstring deviceName)
+{
+    const char *deviceNameStr = env->GetStringUTFChars(deviceName, NULL);
+    struct usb_device* device = usb_device_open(deviceNameStr);
+    env->ReleaseStringUTFChars(deviceName, deviceNameStr);
+
+    if (!device)
+        return NULL;
+
+    int fd = usb_device_get_fd(device);
+    if (fd < 0)
+        return NULL;
+    int newFD = dup(fd);
+    usb_device_close(device);
+
+    jobject fileDescriptor = env->NewObject(gFileDescriptorOffsets.mClass,
+        gFileDescriptorOffsets.mConstructor);
+    if (fileDescriptor != NULL) {
+        env->SetIntField(fileDescriptor, gFileDescriptorOffsets.mDescriptor, newFD);
+    } else {
+        return NULL;
+    }
+    return env->NewObject(gParcelFileDescriptorOffsets.mClass,
+        gParcelFileDescriptorOffsets.mConstructor, fileDescriptor);
+}
+
+static JNINativeMethod method_table[] = {
+    { "monitorUsbHostBus", "()V", (void*)android_server_UsbService_monitorUsbHostBus },
+    { "nativeOpenDevice",  "(Ljava/lang/String;)Landroid/os/ParcelFileDescriptor;",
+                                  (void*)android_server_UsbService_openDevice },
+};
+
+int register_android_server_UsbService(JNIEnv *env)
+{
+    jclass clazz = env->FindClass("com/android/server/UsbService");
+    if (clazz == NULL) {
+        LOGE("Can't find com/android/server/UsbService");
+        return -1;
+    }
+    method_usbDeviceAdded = env->GetMethodID(clazz, "usbDeviceAdded", "(Ljava/lang/String;IIIII[I[I)V");
+    if (method_usbDeviceAdded == NULL) {
+        LOGE("Can't find usbDeviceAdded");
+        return -1;
+    }
+    method_usbDeviceRemoved = env->GetMethodID(clazz, "usbDeviceRemoved", "(Ljava/lang/String;)V");
+    if (method_usbDeviceRemoved == NULL) {
+        LOGE("Can't find usbDeviceRemoved");
+        return -1;
+    }
+
+   clazz = env->FindClass("java/io/FileDescriptor");
+    LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
+    gFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
+    gFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "()V");
+    gFileDescriptorOffsets.mDescriptor = env->GetFieldID(clazz, "descriptor", "I");
+    LOG_FATAL_IF(gFileDescriptorOffsets.mDescriptor == NULL,
+                 "Unable to find descriptor field in java.io.FileDescriptor");
+
+   clazz = env->FindClass("android/os/ParcelFileDescriptor");
+    LOG_FATAL_IF(clazz == NULL, "Unable to find class android.os.ParcelFileDescriptor");
+    gParcelFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
+    gParcelFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "(Ljava/io/FileDescriptor;)V");
+    LOG_FATAL_IF(gParcelFileDescriptorOffsets.mConstructor == NULL,
+                 "Unable to find constructor for android.os.ParcelFileDescriptor");
+
+    return jniRegisterNativeMethods(env, "com/android/server/UsbService",
+            method_table, NELEM(method_table));
+}
+
+};
diff --git a/services/jni/onload.cpp b/services/jni/onload.cpp
index bdd6d80..37b520b 100644
--- a/services/jni/onload.cpp
+++ b/services/jni/onload.cpp
@@ -13,6 +13,7 @@ int register_android_server_InputWindowHandle(JNIEnv* env);
 int register_android_server_InputManager(JNIEnv* env);
 int register_android_server_LightsService(JNIEnv* env);
 int register_android_server_PowerManagerService(JNIEnv* env);
+int register_android_server_UsbService(JNIEnv* env);
 int register_android_server_VibratorService(JNIEnv* env);
 int register_android_server_SystemServer(JNIEnv* env);
 int register_android_server_location_GpsLocationProvider(JNIEnv* env);
@@ -40,6 +41,7 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved)
     register_android_server_LightsService(env);
     register_android_server_AlarmManagerService(env);
     register_android_server_BatteryService(env);
+    register_android_server_UsbService(env);
     register_android_server_VibratorService(env);
     register_android_server_SystemServer(env);
     register_android_server_location_GpsLocationProvider(env);