adb: add libusb implementation for Linux/Darwin.

Add a libusb-based implementation alongside the existing native
implementations, controlled by the ADB_LIBUSB environment variable.

Windows will need more work for the usb driver.

Bug: http://b/31321337
Test: python test_device.py on linux/darwin, with ADB_LIBUSB=0 and 1
Change-Id: Ib68fb2c6c05475eae3ff4cc19f55802a6f489bb7

1 files changed, 57 insertions, 0 deletions

diff --git a/usb.h b/usb.h
new file mode 100644
index 0000000..879bacc
--- /dev/null
+++ b/usb.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#pragma once
+
+// USB host/client interface.
+
+#define ADB_USB_INTERFACE(handle_ref_type)                       \
+    void usb_init();                                             \
+    int usb_write(handle_ref_type h, const void* data, int len); \
+    int usb_read(handle_ref_type h, void* data, int len);        \
+    int usb_close(handle_ref_type h);                            \
+    void usb_kick(handle_ref_type h)
+
+#if defined(_WIN32) || !ADB_HOST
+// Windows and the daemon have a single implementation.
+
+struct usb_handle;
+ADB_USB_INTERFACE(usb_handle*);
+
+#else // linux host || darwin
+// Linux and Darwin clients have native and libusb implementations.
+
+namespace libusb {
+    struct usb_handle;
+    ADB_USB_INTERFACE(libusb::usb_handle*);
+}
+
+namespace native {
+    struct usb_handle;
+    ADB_USB_INTERFACE(native::usb_handle*);
+}
+
+// Empty base that both implementations' opaque handles inherit from.
+struct usb_handle {
+};
+
+ADB_USB_INTERFACE(::usb_handle*);
+
+#endif // linux host || darwin
+
+
+// USB device detection.
+int is_adb_interface(int usb_class, int usb_subclass, int usb_protocol);