DO NOT MERGE: USB accessory support library

This provides a mechanism for developing applications to work with
USB accessories in versions of android prior to the introduction
of the android.hardware.UsbManager APIs.

Applications should link against the com.android.future.usb.accessory
library to use this support.

Change-Id: I0b61e20b63eec42c506f0895a0c9a439bdfdf7f5
Signed-off-by: Mike Lockwood <lockwood@android.com>

10 files changed, 1286 insertions, 0 deletions

diff --git a/libs/usb/tests/AccessoryChat/Android.mk b/libs/usb/tests/AccessoryChat/Android.mk
new file mode 100644
index 0000000..d555961
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/Android.mk
@@ -0,0 +1,31 @@
+#
+# Copyright (C) 2011 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.
+#
+
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE_TAGS := tests
+
+LOCAL_SRC_FILES := $(call all-subdir-java-files)
+
+LOCAL_PACKAGE_NAME := AccessoryChatGB
+
+LOCAL_JAVA_LIBRARIES := com.android.future.usb.accessory
+
+# Force an old SDK version to make sure we aren't using newer UsbManager APIs
+LOCAL_SDK_VERSION := 8
+
+include $(BUILD_PACKAGE)
diff --git a/libs/usb/tests/AccessoryChat/AndroidManifest.xml b/libs/usb/tests/AccessoryChat/AndroidManifest.xml
new file mode 100644
index 0000000..d6093ae
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/AndroidManifest.xml
@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2011 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.
+-->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+        package="com.android.accessorychat">
+
+    <application>
+        <uses-library android:name="com.android.future.usb.accessory" />
+
+        <activity android:name="AccessoryChat" android:label="Accessory Chat GB">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" />
+            </intent-filter>
+
+            <meta-data android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED"
+                android:resource="@xml/accessory_filter" />
+        </activity>
+    </application>
+    <uses-sdk android:minSdkVersion="10" />
+</manifest>
diff --git a/libs/usb/tests/AccessoryChat/README.txt b/libs/usb/tests/AccessoryChat/README.txt
new file mode 100644
index 0000000..d2ce11e
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/README.txt
@@ -0,0 +1,10 @@
+This is a test app for the USB accessory APIs.  It consists of two parts:
+
+AccessoryChat - A Java app with a chat-like UI that sends and receives strings
+                via the UsbAccessory class.
+
+accessorychat - A C command-line program that communicates with AccessoryChat.
+                This program behaves as if it were a USB accessory.
+                It builds both for the host (Linux PC) and as an android
+                command line program, which will work if run as root on an
+                android device with USB host support
diff --git a/libs/usb/tests/AccessoryChat/accessorychat/Android.mk b/libs/usb/tests/AccessoryChat/accessorychat/Android.mk
new file mode 100644
index 0000000..5a7b30e
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/accessorychat/Android.mk
@@ -0,0 +1,21 @@
+LOCAL_PATH:= $(call my-dir)
+
+# Build for Linux (desktop) host
+ifeq ($(HOST_OS),linux)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := accessorychat.c usbhost.c
+
+LOCAL_MODULE := accessorychat
+
+LOCAL_C_INCLUDES += bionic/libc/kernel/common
+LOCAL_STATIC_LIBRARIES := libcutils
+LOCAL_LDLIBS += -lpthread
+LOCAL_CFLAGS := -g -O0
+
+include $(BUILD_HOST_EXECUTABLE)
+
+endif
diff --git a/libs/usb/tests/AccessoryChat/accessorychat/accessorychat.c b/libs/usb/tests/AccessoryChat/accessorychat/accessorychat.c
new file mode 100644
index 0000000..94cc0ce
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/accessorychat/accessorychat.c
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include <usbhost/usbhost.h>
+#include <linux/usb/f_accessory.h>
+
+struct usb_device *sDevice = NULL;
+
+static void* read_thread(void* arg) {
+    int endpoint = (int)arg;
+    int ret = 0;
+
+    while (sDevice && ret >= 0) {
+        char    buffer[16384];
+
+        ret = usb_device_bulk_transfer(sDevice, endpoint, buffer, sizeof(buffer), 1000);
+        if (ret < 0 && errno == ETIMEDOUT)
+            ret = 0;
+        if (ret > 0) {
+            fwrite(buffer, 1, ret, stdout);
+            printf("\n");
+            fflush(stdout);
+        }
+    }
+
+    return NULL;
+}
+
+static void* write_thread(void* arg) {
+    int endpoint = (int)arg;
+    int ret = 0;
+
+    while (ret >= 0) {
+        char    buffer[16384];
+        char *line = fgets(buffer, sizeof(buffer), stdin);
+        if (!line || !sDevice)
+            break;
+        ret = usb_device_bulk_transfer(sDevice, endpoint, line, strlen(line), 1000);
+    }
+
+    return NULL;
+}
+
+static void send_string(struct usb_device *device, int index, const char* string) {
+    int ret = usb_device_control_transfer(device, USB_DIR_OUT | USB_TYPE_VENDOR,
+            ACCESSORY_SEND_STRING, 0, index, (void *)string, strlen(string) + 1, 0);
+}
+
+static int usb_device_added(const char *devname, void* client_data) {
+    struct usb_descriptor_header* desc;
+    struct usb_descriptor_iter iter;
+    uint16_t vendorId, productId;
+    int ret;
+    pthread_t th;
+
+    struct usb_device *device = usb_device_open(devname);
+    if (!device) {
+        fprintf(stderr, "usb_device_open failed\n");
+        return 0;
+    }
+
+    vendorId = usb_device_get_vendor_id(device);
+    productId = usb_device_get_product_id(device);
+
+    if (vendorId == 0x18D1 || vendorId == 0x22B8) {
+        if (!sDevice && (productId == 0x2D00 || productId == 0x2D01)) {
+            struct usb_descriptor_header* desc;
+            struct usb_descriptor_iter iter;
+            struct usb_interface_descriptor *intf = NULL;
+            struct usb_endpoint_descriptor *ep1 = NULL;
+            struct usb_endpoint_descriptor *ep2 = NULL;
+
+            printf("Found android device in accessory mode\n");
+            sDevice = device;
+
+            usb_descriptor_iter_init(device, &iter);
+            while ((desc = usb_descriptor_iter_next(&iter)) != NULL && (!intf || !ep1 || !ep2)) {
+                if (desc->bDescriptorType == USB_DT_INTERFACE) {
+                    intf = (struct usb_interface_descriptor *)desc;
+                } else if (desc->bDescriptorType == USB_DT_ENDPOINT) {
+                    if (ep1)
+                        ep2 = (struct usb_endpoint_descriptor *)desc;
+                    else
+                        ep1 = (struct usb_endpoint_descriptor *)desc;
+                }
+            }
+
+            if (!intf) {
+                fprintf(stderr, "interface not found\n");
+                exit(1);
+            }
+            if (!ep1 || !ep2) {
+                fprintf(stderr, "endpoints not found\n");
+                exit(1);
+            }
+
+            if (usb_device_claim_interface(device, intf->bInterfaceNumber)) {
+                fprintf(stderr, "usb_device_claim_interface failed errno: %d\n", errno);
+                exit(1);
+            }
+
+            if ((ep1->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) {
+                pthread_create(&th, NULL, read_thread, (void *)ep1->bEndpointAddress);
+                pthread_create(&th, NULL, write_thread, (void *)ep2->bEndpointAddress);
+            } else {
+                pthread_create(&th, NULL, read_thread, (void *)ep2->bEndpointAddress);
+                pthread_create(&th, NULL, write_thread, (void *)ep1->bEndpointAddress);
+            }
+        } else {
+            printf("Found possible android device - attempting to switch to accessory mode\n");
+
+            send_string(device, ACCESSORY_STRING_MANUFACTURER, "Google, Inc.");
+            send_string(device, ACCESSORY_STRING_MODEL, "AccessoryChat");
+            send_string(device, ACCESSORY_STRING_TYPE, "Sample Program");
+            send_string(device, ACCESSORY_STRING_VERSION, "1.0");
+
+            ret = usb_device_control_transfer(device, USB_DIR_OUT | USB_TYPE_VENDOR,
+                    ACCESSORY_START, 0, 0, 0, 0, 0);
+            return 0;
+        }
+    }
+
+    if (device != sDevice)
+        usb_device_close(device);
+
+    return 0;
+}
+
+static int usb_device_removed(const char *devname, void* client_data) {
+    if (sDevice && !strcmp(usb_device_get_name(sDevice), devname)) {
+        usb_device_close(sDevice);
+        sDevice = NULL;
+        // exit when we are disconnected
+        return 1;
+    }
+    return 0;
+}
+
+
+int main(int argc, char* argv[]) {
+    struct usb_host_context* context = usb_host_init();
+    if (!context) {
+        fprintf(stderr, "usb_host_init failed");
+        return 1;
+    }
+
+    // this will never return so it is safe to pass thiz directly
+    usb_host_run(context, usb_device_added, usb_device_removed, NULL, NULL);
+    return 0;
+}
diff --git a/libs/usb/tests/AccessoryChat/accessorychat/usbhost.c b/libs/usb/tests/AccessoryChat/accessorychat/usbhost.c
new file mode 100644
index 0000000..f5a7c3f
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/accessorychat/usbhost.c
@@ -0,0 +1,574 @@
+/*
+ * Copyright (C) 2010 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 DEBUG 1
+#if DEBUG
+
+#ifdef USE_LIBLOG
+#define LOG_TAG "usbhost"
+#include "utils/Log.h"
+#define D LOGD
+#else
+#define D printf
+#endif
+
+#else
+#define D(...)
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/inotify.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+#include <pthread.h>
+
+#include <linux/usbdevice_fs.h>
+#include <asm/byteorder.h>
+
+#include "usbhost/usbhost.h"
+
+#define USB_FS_DIR "/dev/bus/usb"
+#define USB_FS_ID_SCANNER   "/dev/bus/usb/%d/%d"
+#define USB_FS_ID_FORMAT    "/dev/bus/usb/%03d/%03d"
+
+
+struct usb_host_context {
+    int fd;
+};
+
+struct usb_device {
+    char dev_name[64];
+    unsigned char desc[4096];
+    int desc_length;
+    int fd;
+    int writeable;
+};
+
+static inline int badname(const char *name)
+{
+    while(*name) {
+        if(!isdigit(*name++)) return 1;
+    }
+    return 0;
+}
+
+/* returns true if one of the callbacks indicates we are done */
+static int find_existing_devices(usb_device_added_cb added_cb,
+                                  usb_device_removed_cb removed_cb,
+                                  void *client_data)
+{
+    char busname[32], devname[32];
+    DIR *busdir , *devdir ;
+    struct dirent *de;
+    int done = 0;
+
+    busdir = opendir(USB_FS_DIR);
+    if(busdir == 0) return 1;
+
+    while ((de = readdir(busdir)) != 0 && !done) {
+        if(badname(de->d_name)) continue;
+
+        snprintf(busname, sizeof busname, "%s/%s", USB_FS_DIR, de->d_name);
+        devdir = opendir(busname);
+        if(devdir == 0) continue;
+
+        while ((de = readdir(devdir)) && !done) {
+            if(badname(de->d_name)) continue;
+
+            snprintf(devname, sizeof devname, "%s/%s", busname, de->d_name);
+            done = added_cb(devname, client_data);
+        } // end of devdir while
+        closedir(devdir);
+    } //end of busdir while
+    closedir(busdir);
+
+    return done;
+}
+
+struct usb_host_context *usb_host_init()
+{
+    struct usb_host_context *context = calloc(1, sizeof(struct usb_host_context));
+    if (!context) {
+        fprintf(stderr, "out of memory in usb_host_context\n");
+        return NULL;
+    }
+    context->fd = inotify_init();
+    if (context->fd < 0) {
+        fprintf(stderr, "inotify_init failed\n");
+        free(context);
+        return NULL;
+    }
+    return context;
+}
+
+void usb_host_cleanup(struct usb_host_context *context)
+{
+    close(context->fd);
+    free(context);
+}
+
+void usb_host_run(struct usb_host_context *context,
+                  usb_device_added_cb added_cb,
+                  usb_device_removed_cb removed_cb,
+                  usb_discovery_done_cb discovery_done_cb,
+                  void *client_data)
+{
+    struct inotify_event* event;
+    char event_buf[512];
+    char path[100];
+    int i, ret, done = 0;
+    int wd, wds[10];
+    int wd_count = sizeof(wds) / sizeof(wds[0]);
+
+    D("Created device discovery thread\n");
+
+    /* watch for files added and deleted within USB_FS_DIR */
+    memset(wds, 0, sizeof(wds));
+    /* watch the root for new subdirectories */
+    wds[0] = inotify_add_watch(context->fd, USB_FS_DIR, IN_CREATE | IN_DELETE);
+    if (wds[0] < 0) {
+        fprintf(stderr, "inotify_add_watch failed\n");
+        if (discovery_done_cb)
+            discovery_done_cb(client_data);
+        return;
+    }
+
+    /* watch existing subdirectories of USB_FS_DIR */
+    for (i = 1; i < wd_count; i++) {
+        snprintf(path, sizeof(path), "%s/%03d", USB_FS_DIR, i);
+        ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
+        if (ret > 0)
+            wds[i] = ret;
+    }
+
+    /* check for existing devices first, after we have inotify set up */
+    done = find_existing_devices(added_cb, removed_cb, client_data);
+    if (discovery_done_cb)
+        done |= discovery_done_cb(client_data);
+
+    while (!done) {
+        ret = read(context->fd, event_buf, sizeof(event_buf));
+        if (ret >= (int)sizeof(struct inotify_event)) {
+            event = (struct inotify_event *)event_buf;
+            wd = event->wd;
+            if (wd == wds[0]) {
+                i = atoi(event->name);
+                snprintf(path, sizeof(path), "%s/%s", USB_FS_DIR, event->name);
+                D("new subdirectory %s: index: %d\n", path, i);
+                if (i > 0 && i < wd_count) {
+                ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
+                if (ret > 0)
+                    wds[i] = ret;
+                }
+            } else {
+                for (i = 1; i < wd_count && !done; i++) {
+                    if (wd == wds[i]) {
+                        snprintf(path, sizeof(path), "%s/%03d/%s", USB_FS_DIR, i, event->name);
+                        if (event->mask == IN_CREATE) {
+                            D("new device %s\n", path);
+                            done = added_cb(path, client_data);
+                        } else if (event->mask == IN_DELETE) {
+                            D("gone device %s\n", path);
+                            done = removed_cb(path, client_data);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+struct usb_device *usb_device_open(const char *dev_name)
+{
+    int fd, did_retry = 0, writeable = 1;
+
+    D("usb_device_open %s\n", dev_name);
+
+retry:
+    fd = open(dev_name, O_RDWR);
+    if (fd < 0) {
+        /* if we fail, see if have read-only access */
+        fd = open(dev_name, O_RDONLY);
+        D("usb_device_open open returned %d errno %d\n", fd, errno);
+        if (fd < 0 && (errno == EACCES || errno == ENOENT) && !did_retry) {
+            /* work around race condition between inotify and permissions management */
+            sleep(1);
+            did_retry = 1;
+            goto retry;
+        }
+
+        if (fd < 0)
+            return NULL;
+        writeable = 0;
+        D("[ usb open read-only %s fd = %d]\n", dev_name, fd);
+    }
+
+    struct usb_device* result = usb_device_new(dev_name, fd);
+    if (result)
+        result->writeable = writeable;
+    return result;
+}
+
+void usb_device_close(struct usb_device *device)
+{
+    close(device->fd);
+    free(device);
+}
+
+struct usb_device *usb_device_new(const char *dev_name, int fd)
+{
+    struct usb_device *device = calloc(1, sizeof(struct usb_device));
+    int length;
+
+    D("usb_device_new %s fd: %d\n", dev_name, fd);
+
+    if (lseek(fd, 0, SEEK_SET) != 0)
+        goto failed;
+    length = read(fd, device->desc, sizeof(device->desc));
+    D("usb_device_new read returned %d errno %d\n", length, errno);
+    if (length < 0)
+        goto failed;
+
+    strncpy(device->dev_name, dev_name, sizeof(device->dev_name) - 1);
+    device->fd = fd;
+    device->desc_length = length;
+    // assume we are writeable, since usb_device_get_fd will only return writeable fds
+    device->writeable = 1;
+    return device;
+
+failed:
+    close(fd);
+    free(device);
+    return NULL;
+}
+
+static int usb_device_reopen_writeable(struct usb_device *device)
+{
+    if (device->writeable)
+        return 1;
+
+    int fd = open(device->dev_name, O_RDWR);
+    if (fd >= 0) {
+        close(device->fd);
+        device->fd = fd;
+        device->writeable = 1;
+        return 1;
+    }
+    D("usb_device_reopen_writeable failed errno %d\n", errno);
+    return 0;
+}
+
+int usb_device_get_fd(struct usb_device *device)
+{
+    if (!usb_device_reopen_writeable(device))
+        return -1;
+    return device->fd;
+}
+
+const char* usb_device_get_name(struct usb_device *device)
+{
+    return device->dev_name;
+}
+
+int usb_device_get_unique_id(struct usb_device *device)
+{
+    int bus = 0, dev = 0;
+    sscanf(device->dev_name, USB_FS_ID_SCANNER, &bus, &dev);
+    return bus * 1000 + dev;
+}
+
+int usb_device_get_unique_id_from_name(const char* name)
+{
+    int bus = 0, dev = 0;
+    sscanf(name, USB_FS_ID_SCANNER, &bus, &dev);
+    return bus * 1000 + dev;
+}
+
+char* usb_device_get_name_from_unique_id(int id)
+{
+    int bus = id / 1000;
+    int dev = id % 1000;
+    char* result = (char *)calloc(1, strlen(USB_FS_ID_FORMAT));
+    snprintf(result, strlen(USB_FS_ID_FORMAT) - 1, USB_FS_ID_FORMAT, bus, dev);
+    return result;
+}
+
+uint16_t usb_device_get_vendor_id(struct usb_device *device)
+{
+    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
+    return __le16_to_cpu(desc->idVendor);
+}
+
+uint16_t usb_device_get_product_id(struct usb_device *device)
+{
+    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
+    return __le16_to_cpu(desc->idProduct);
+}
+
+const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device)
+{
+    return (struct usb_device_descriptor*)device->desc;
+}
+
+char* usb_device_get_string(struct usb_device *device, int id)
+{
+    char string[256];
+    __u16 buffer[128];
+    __u16 languages[128];
+    int i, result;
+    int languageCount = 0;
+
+    string[0] = 0;
+    memset(languages, 0, sizeof(languages));
+
+    // read list of supported languages
+    result = usb_device_control_transfer(device,
+            USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
+            (USB_DT_STRING << 8) | 0, 0, languages, sizeof(languages), 0);
+    if (result > 0)
+        languageCount = (result - 2) / 2;
+
+    for (i = 1; i <= languageCount; i++) {
+        memset(buffer, 0, sizeof(buffer));
+
+        result = usb_device_control_transfer(device,
+                USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
+                (USB_DT_STRING << 8) | id, languages[i], buffer, sizeof(buffer), 0);
+        if (result > 0) {
+            int i;
+            // skip first word, and copy the rest to the string, changing shorts to bytes.
+            result /= 2;
+            for (i = 1; i < result; i++)
+                string[i - 1] = buffer[i];
+            string[i - 1] = 0;
+            return strdup(string);
+        }
+    }
+
+    return NULL;
+}
+
+char* usb_device_get_manufacturer_name(struct usb_device *device)
+{
+    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
+
+    if (desc->iManufacturer)
+        return usb_device_get_string(device, desc->iManufacturer);
+    else
+        return NULL;
+}
+
+char* usb_device_get_product_name(struct usb_device *device)
+{
+    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
+
+    if (desc->iProduct)
+        return usb_device_get_string(device, desc->iProduct);
+    else
+        return NULL;
+}
+
+char* usb_device_get_serial(struct usb_device *device)
+{
+    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
+
+    if (desc->iSerialNumber)
+        return usb_device_get_string(device, desc->iSerialNumber);
+    else
+        return NULL;
+}
+
+int usb_device_is_writeable(struct usb_device *device)
+{
+    return device->writeable;
+}
+
+void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter)
+{
+    iter->config = device->desc;
+    iter->config_end = device->desc + device->desc_length;
+    iter->curr_desc = device->desc;
+}
+
+struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter)
+{
+    struct usb_descriptor_header* next;
+    if (iter->curr_desc >= iter->config_end)
+        return NULL;
+    next = (struct usb_descriptor_header*)iter->curr_desc;
+    iter->curr_desc += next->bLength;
+    return next;
+}
+
+int usb_device_claim_interface(struct usb_device *device, unsigned int interface)
+{
+    return ioctl(device->fd, USBDEVFS_CLAIMINTERFACE, &interface);
+}
+
+int usb_device_release_interface(struct usb_device *device, unsigned int interface)
+{
+    return ioctl(device->fd, USBDEVFS_RELEASEINTERFACE, &interface);
+}
+
+int usb_device_connect_kernel_driver(struct usb_device *device,
+        unsigned int interface, int connect)
+{
+    struct usbdevfs_ioctl ctl;
+
+    ctl.ifno = interface;
+    ctl.ioctl_code = (connect ? USBDEVFS_CONNECT : USBDEVFS_DISCONNECT);
+    ctl.data = NULL;
+    return ioctl(device->fd, USBDEVFS_IOCTL, &ctl);
+}
+
+int usb_device_control_transfer(struct usb_device *device,
+                            int requestType,
+                            int request,
+                            int value,
+                            int index,
+                            void* buffer,
+                            int length,
+                            unsigned int timeout)
+{
+    struct usbdevfs_ctrltransfer  ctrl;
+
+    // this usually requires read/write permission
+    if (!usb_device_reopen_writeable(device))
+        return -1;
+
+    memset(&ctrl, 0, sizeof(ctrl));
+    ctrl.bRequestType = requestType;
+    ctrl.bRequest = request;
+    ctrl.wValue = value;
+    ctrl.wIndex = index;
+    ctrl.wLength = length;
+    ctrl.data = buffer;
+    ctrl.timeout = timeout;
+    return ioctl(device->fd, USBDEVFS_CONTROL, &ctrl);
+}
+
+int usb_device_bulk_transfer(struct usb_device *device,
+                            int endpoint,
+                            void* buffer,
+                            int length,
+                            unsigned int timeout)
+{
+    struct usbdevfs_bulktransfer  ctrl;
+
+    memset(&ctrl, 0, sizeof(ctrl));
+    ctrl.ep = endpoint;
+    ctrl.len = length;
+    ctrl.data = buffer;
+    ctrl.timeout = timeout;
+    return ioctl(device->fd, USBDEVFS_BULK, &ctrl);
+}
+
+struct usb_request *usb_request_new(struct usb_device *dev,
+        const struct usb_endpoint_descriptor *ep_desc)
+{
+    struct usbdevfs_urb *urb = calloc(1, sizeof(struct usbdevfs_urb));
+    if (!urb)
+        return NULL;
+
+    if ((ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
+        urb->type = USBDEVFS_URB_TYPE_BULK;
+    else if ((ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
+        urb->type = USBDEVFS_URB_TYPE_INTERRUPT;
+    else {
+        D("Unsupported endpoint type %d", ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
+        free(urb);
+        return NULL;
+    }
+    urb->endpoint = ep_desc->bEndpointAddress;
+
+    struct usb_request *req = calloc(1, sizeof(struct usb_request));
+    if (!req) {
+        free(urb);
+        return NULL;
+    }
+
+    req->dev = dev;
+    req->max_packet_size = __le16_to_cpu(ep_desc->wMaxPacketSize);
+    req->private_data = urb;
+    req->endpoint = urb->endpoint;
+    urb->usercontext = req;
+
+    return req;
+}
+
+void usb_request_free(struct usb_request *req)
+{
+    free(req->private_data);
+    free(req);
+}
+
+int usb_request_queue(struct usb_request *req)
+{
+    struct usbdevfs_urb *urb = (struct usbdevfs_urb*)req->private_data;
+    int res;
+
+    urb->status = -1;
+    urb->buffer = req->buffer;
+    urb->buffer_length = req->buffer_length;
+
+    do {
+        res = ioctl(req->dev->fd, USBDEVFS_SUBMITURB, urb);
+    } while((res < 0) && (errno == EINTR));
+
+    return res;
+}
+
+struct usb_request *usb_request_wait(struct usb_device *dev)
+{
+    struct usbdevfs_urb *urb = NULL;
+    struct usb_request *req = NULL;
+    int res;
+
+    while (1) {
+        int res = ioctl(dev->fd, USBDEVFS_REAPURB, &urb);
+        D("USBDEVFS_REAPURB returned %d\n", res);
+        if (res < 0) {
+            if(errno == EINTR) {
+                continue;
+            }
+            D("[ reap urb - error ]\n");
+            return NULL;
+        } else {
+            D("[ urb @%p status = %d, actual = %d ]\n",
+                urb, urb->status, urb->actual_length);
+            req = (struct usb_request*)urb->usercontext;
+            req->actual_length = urb->actual_length;
+        }
+        break;
+    }
+    return req;
+}
+
+int usb_request_cancel(struct usb_request *req)
+{
+    struct usbdevfs_urb *urb = ((struct usbdevfs_urb*)req->private_data);
+    return ioctl(req->dev->fd, USBDEVFS_DISCARDURB, &urb);
+}
+
diff --git a/libs/usb/tests/AccessoryChat/accessorychat/usbhost/usbhost.h b/libs/usb/tests/AccessoryChat/accessorychat/usbhost/usbhost.h
new file mode 100644
index 0000000..9a6b59c
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/accessorychat/usbhost/usbhost.h
@@ -0,0 +1,219 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef __USB_HOST_H
+#define __USB_HOST_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 20)
+#include <linux/usb/ch9.h>
+#else
+#include <linux/usb_ch9.h>
+#endif
+
+struct usb_host_context;
+struct usb_endpoint_descriptor;
+
+struct usb_descriptor_iter {
+    unsigned char*  config;
+    unsigned char*  config_end;
+    unsigned char*  curr_desc;
+};
+
+struct usb_request
+{
+    struct usb_device *dev;
+    void* buffer;
+    int buffer_length;
+    int actual_length;
+    int max_packet_size;
+    void *private_data; /* struct usbdevfs_urb* */
+    int endpoint;
+    void *client_data;  /* free for use by client */
+};
+
+/* Callback for notification when new USB devices are attached.
+ * Return true to exit from usb_host_run.
+ */
+typedef int (* usb_device_added_cb)(const char *dev_name, void *client_data);
+
+/* Callback for notification when USB devices are removed.
+ * Return true to exit from usb_host_run.
+ */
+typedef int (* usb_device_removed_cb)(const char *dev_name, void *client_data);
+
+/* Callback indicating that initial device discovery is done.
+ * Return true to exit from usb_host_run.
+ */
+typedef int (* usb_discovery_done_cb)(void *client_data);
+
+/* Call this to initialize the USB host library. */
+struct usb_host_context *usb_host_init(void);
+
+/* Call this to cleanup the USB host library. */
+void usb_host_cleanup(struct usb_host_context *context);
+
+/* Call this to monitor the USB bus for new and removed devices.
+ * This is intended to be called from a dedicated thread,
+ * as it will not return until one of the callbacks returns true.
+ * added_cb will be called immediately for each existing USB device,
+ * and subsequently each time a new device is added.
+ * removed_cb is called when USB devices are removed from the bus.
+ * discovery_done_cb is called after the initial discovery of already
+ * connected devices is complete.
+ */
+void usb_host_run(struct usb_host_context *context,
+                  usb_device_added_cb added_cb,
+                  usb_device_removed_cb removed_cb,
+                  usb_discovery_done_cb discovery_done_cb,
+                  void *client_data);
+
+/* Creates a usb_device object for a USB device */
+struct usb_device *usb_device_open(const char *dev_name);
+
+/* Releases all resources associated with the USB device */
+void usb_device_close(struct usb_device *device);
+
+/* Creates a usb_device object for already open USB device */
+struct usb_device *usb_device_new(const char *dev_name, int fd);
+
+/* Returns the file descriptor for the usb_device */
+int usb_device_get_fd(struct usb_device *device);
+
+/* Returns the name for the USB device, which is the same as
+ * the dev_name passed to usb_device_open()
+ */
+const char* usb_device_get_name(struct usb_device *device);
+
+/* Returns a unique ID for the device.
+ *Currently this is generated from the dev_name path.
+ */
+int usb_device_get_unique_id(struct usb_device *device);
+
+/* Returns a unique ID for the device name.
+ * Currently this is generated from the device path.
+ */
+int usb_device_get_unique_id_from_name(const char* name);
+
+/* Returns the device name for the unique ID.
+ * Call free() to deallocate the returned string */
+char* usb_device_get_name_from_unique_id(int id);
+
+/* Returns the USB vendor ID from the device descriptor for the USB device */
+uint16_t usb_device_get_vendor_id(struct usb_device *device);
+
+/* Returns the USB product ID from the device descriptor for the USB device */
+uint16_t usb_device_get_product_id(struct usb_device *device);
+
+const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device);
+
+/* Returns a USB descriptor string for the given string ID.
+ * Used to implement usb_device_get_manufacturer_name,
+ * usb_device_get_product_name and usb_device_get_serial.
+ * Call free() to free the result when you are done with it.
+ */
+char* usb_device_get_string(struct usb_device *device, int id);
+
+/* Returns the manufacturer name for the USB device.
+ * Call free() to free the result when you are done with it.
+ */
+char* usb_device_get_manufacturer_name(struct usb_device *device);
+
+/* Returns the product name for the USB device.
+ * Call free() to free the result when you are done with it.
+ */
+char* usb_device_get_product_name(struct usb_device *device);
+
+/* Returns the USB serial number for the USB device.
+ * Call free() to free the result when you are done with it.
+ */
+char* usb_device_get_serial(struct usb_device *device);
+
+/* Returns true if we have write access to the USB device,
+ * and false if we only have access to the USB device configuration.
+ */
+int usb_device_is_writeable(struct usb_device *device);
+
+/* Initializes a usb_descriptor_iter, which can be used to iterate through all
+ * the USB descriptors for a USB device.
+ */
+void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter);
+
+/* Returns the next USB descriptor for a device, or NULL if we have reached the
+ * end of the list.
+ */
+struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter);
+
+/* Claims the specified interface of a USB device */
+int usb_device_claim_interface(struct usb_device *device, unsigned int interface);
+
+/* Releases the specified interface of a USB device */
+int usb_device_release_interface(struct usb_device *device, unsigned int interface);
+
+/* Requests the kernel to connect or disconnect its driver for the specified interface.
+ * This can be used to ask the kernel to disconnect its driver for a device
+ * so usb_device_claim_interface can claim it instead.
+ */
+int usb_device_connect_kernel_driver(struct usb_device *device,
+        unsigned int interface, int connect);
+
+/* Sends a control message to the specified device on endpoint zero */
+int usb_device_control_transfer(struct usb_device *device,
+                            int requestType,
+                            int request,
+                            int value,
+                            int index,
+                            void* buffer,
+                            int length,
+                            unsigned int timeout);
+
+/* Reads or writes on a bulk endpoint.
+ * Returns number of bytes transferred, or negative value for error.
+ */
+int usb_device_bulk_transfer(struct usb_device *device,
+                            int endpoint,
+                            void* buffer,
+                            int length,
+                            unsigned int timeout);
+
+/* Creates a new usb_request. */
+struct usb_request *usb_request_new(struct usb_device *dev,
+        const struct usb_endpoint_descriptor *ep_desc);
+
+/* Releases all resources associated with the request */
+void usb_request_free(struct usb_request *req);
+
+/* Submits a read or write request on the specified device */
+int usb_request_queue(struct usb_request *req);
+
+ /* Waits for the results of a previous usb_request_queue operation.
+  * Returns a usb_request, or NULL for error.
+  */
+struct usb_request *usb_request_wait(struct usb_device *dev);
+
+/* Cancels a pending usb_request_queue() operation. */
+int usb_request_cancel(struct usb_request *req);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* __USB_HOST_H */
diff --git a/libs/usb/tests/AccessoryChat/res/layout/accessory_chat.xml b/libs/usb/tests/AccessoryChat/res/layout/accessory_chat.xml
new file mode 100644
index 0000000..596ecbf
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/res/layout/accessory_chat.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2011 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.
+-->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    >
+
+    <ScrollView android:id="@+id/scroll"
+        android:layout_width="match_parent"
+        android:layout_height="0px"
+        android:layout_weight="1"
+        >
+        <TextView android:id="@+id/log"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="25dp"
+            android:textSize="12sp"
+            android:textColor="#ffffffff"
+            />
+    </ScrollView>
+
+    <EditText android:id="@+id/message"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:capitalize="sentences"
+        android:autoText="true"
+        android:singleLine="true"
+        />
+
+</LinearLayout>
+
+
diff --git a/libs/usb/tests/AccessoryChat/res/xml/accessory_filter.xml b/libs/usb/tests/AccessoryChat/res/xml/accessory_filter.xml
new file mode 100644
index 0000000..588946f
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/res/xml/accessory_filter.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2011 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.
+-->
+<resources>
+    <usb-accessory manufacturer="Google, Inc." model="AccessoryChat" type="Sample Program" version="1.0" />
+</resources>
diff --git a/libs/usb/tests/AccessoryChat/src/com/android/accessorychat/AccessoryChat.java b/libs/usb/tests/AccessoryChat/src/com/android/accessorychat/AccessoryChat.java
new file mode 100644
index 0000000..5cf02c7
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/src/com/android/accessorychat/AccessoryChat.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+package com.android.accessorychat;
+
+import android.app.Activity;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Message;
+import android.os.ParcelFileDescriptor;
+import android.view.KeyEvent;
+import android.view.View;
+import android.view.inputmethod.EditorInfo;
+import android.util.Log;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import com.android.future.usb.UsbAccessory;
+import com.android.future.usb.UsbManager;
+
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class AccessoryChat extends Activity implements Runnable, TextView.OnEditorActionListener {
+
+    private static final String TAG = "AccessoryChat";
+    TextView mLog;
+    EditText mEditText;
+    ParcelFileDescriptor mFileDescriptor;
+    FileInputStream mInputStream;
+    FileOutputStream mOutputStream;
+
+    private static final int MESSAGE_LOG = 1;
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.accessory_chat);
+        mLog = (TextView)findViewById(R.id.log);
+        mEditText = (EditText)findViewById(R.id.message);
+        mEditText.setOnEditorActionListener(this);
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+
+        Intent intent = getIntent();
+        Log.d(TAG, "intent: " + intent);
+        UsbManager manager = UsbManager.getInstance();
+        UsbAccessory[] accessories = manager.getAccessoryList();
+        UsbAccessory accessory = (accessories == null ? null : accessories[0]);
+        if (accessory != null) {
+            mFileDescriptor = manager.openAccessory(accessory);
+            if (mFileDescriptor != null) {
+                FileDescriptor fd = mFileDescriptor.getFileDescriptor();
+                mInputStream = new FileInputStream(fd);
+                mOutputStream = new FileOutputStream(fd);
+                Thread thread = new Thread(null, this, "AccessoryChat");
+                thread.start();
+            } else {
+                Log.d(TAG, "openAccessory fail");
+            }
+        } else {
+            Log.d(TAG, "mAccessory is null");
+        }
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        if (mFileDescriptor != null) {
+            try {
+                mFileDescriptor.close();
+            } catch (IOException e) {
+            } finally {
+                mFileDescriptor = null;
+            }
+        }
+    }
+
+    @Override
+    public void onDestroy() {
+       super.onDestroy();
+    }
+
+    public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
+        if (actionId == EditorInfo.IME_ACTION_DONE && mOutputStream != null) {
+            try {
+                mOutputStream.write(v.getText().toString().getBytes());
+            } catch (IOException e) {
+                Log.e(TAG, "write failed", e);
+            }
+            v.setText("");
+            return true;
+        }
+        Log.d(TAG, "onEditorAction " + actionId + " event: " + event);
+        return false;
+    }
+
+    public void run() {
+        int ret = 0;
+        byte[] buffer = new byte[16384];
+        while (ret >= 0) {
+            try {
+                ret = mInputStream.read(buffer);
+            } catch (IOException e) {
+                break;
+            }
+
+            if (ret > 0) {
+                Message m = Message.obtain(mHandler, MESSAGE_LOG);
+                String text = new String(buffer, 0, ret);
+                Log.d(TAG, "chat: " + text);
+                m.obj = text;
+                mHandler.sendMessage(m);
+            }
+        }
+        Log.d(TAG, "thread out");
+    }
+
+   Handler mHandler = new Handler() {
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+                case MESSAGE_LOG:
+                    mLog.setText(mLog.getText() + "\n" + (String)msg.obj);
+                    break;
+             }
+        }
+    };
+}
+
+