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.google.android.usb library
to use this support.

Change-Id: I48ff80467fd9a6667aa84a758eca754132f546b9
Signed-off-by: Mike Lockwood <lockwood@android.com>

2 files changed, 208 insertions, 0 deletions

diff --git a/libs/usb/tests/AccessoryChat/accessorychat/Android.mk b/libs/usb/tests/AccessoryChat/accessorychat/Android.mk
new file mode 100644
index 0000000..300224a
--- /dev/null
+++ b/libs/usb/tests/AccessoryChat/accessorychat/Android.mk
@@ -0,0 +1,34 @@
+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
+
+LOCAL_MODULE := accessorychat
+
+LOCAL_C_INCLUDES += bionic/libc/kernel/common
+LOCAL_STATIC_LIBRARIES := libusbhost libcutils
+LOCAL_LDLIBS += -lpthread
+LOCAL_CFLAGS := -g -O0
+
+include $(BUILD_HOST_EXECUTABLE)
+
+endif
+
+# Build for device
+include $(CLEAR_VARS)
+
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := accessorychat.c
+
+LOCAL_MODULE := accessorychat
+
+LOCAL_SHARED_LIBRARIES := libusbhost libcutils
+
+include $(BUILD_EXECUTABLE)
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;
+}