USB: gadget: f_accessory: New gadget driver for android USB accesories

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

USB: gadget: f_accessory: Misc improvements and cleanup:

- Add URI string

- Replace type string with a description string

- Add a control call to retrieve accessory protocol version (currently 1)

- Driver read() and write() calls now fail after USB disconnect until
  driver file is closed and reopened.

- Misc cleanup work

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

USB: gadget: f_accessory: Clear accessory strings when USB is disconnected

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

USB: gadget: f_accessory: Clear previous strings on ACCESSORY_GET_PROTOCOL

Clearing strings on disconnect does not work since we may receive
a disconnect on some devices when transitioning into accessory mode.
We require an accessory to send ACCESSORY_GET_PROTOCOL before
sending any strings, so any strings from a previous session will be cleared.

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

USB: gadget: f_accessory: Clear disconnected flag when driver file is opened

Fixes a race condition that can occur when entering accessory mode.

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

USB: gadget: f_accessory: Add string for accessory's unique serial number

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

USB: gadget: f_accessory: Set bNumEndpoints to correct value of 2

Change-Id: I24f4e36f196d45436e0573301500c3b93215953d
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/include/linux/usb/f_accessory.h b/include/linux/usb/f_accessory.h
new file mode 100644
index 000000000000..ebcc5f34f554
--- /dev/null
+++ b/include/linux/usb/f_accessory.h
@@ -0,0 +1,81 @@
+/*
+ * Gadget Function Driver for Android USB accessories
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __LINUX_USB_F_ACCESSORY_H
+#define __LINUX_USB_F_ACCESSORY_H
+
+/* Use Google Vendor ID when in accessory mode */
+#define USB_ACCESSORY_VENDOR_ID 0x18D1
+
+
+/* Product ID to use when in accessory mode */
+#define USB_ACCESSORY_PRODUCT_ID 0x2D00
+
+/* Product ID to use when in accessory mode and adb is enabled */
+#define USB_ACCESSORY_ADB_PRODUCT_ID 0x2D01
+
+/* Indexes for strings sent by the host via ACCESSORY_SEND_STRING */
+#define ACCESSORY_STRING_MANUFACTURER   0
+#define ACCESSORY_STRING_MODEL          1
+#define ACCESSORY_STRING_DESCRIPTION    2
+#define ACCESSORY_STRING_VERSION        3
+#define ACCESSORY_STRING_URI            4
+#define ACCESSORY_STRING_SERIAL         5
+
+/* Control request for retrieving device's protocol version (currently 1)
+ *
+ *	requestType:    USB_DIR_IN | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_GET_PROTOCOL
+ *	value:          0
+ *	index:          0
+ *	data            version number (16 bits little endian)
+ */
+#define ACCESSORY_GET_PROTOCOL  51
+
+/* Control request for host to send a string to the device
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_SEND_STRING
+ *	value:          0
+ *	index:          string ID
+ *	data            zero terminated UTF8 string
+ *
+ *  The device can later retrieve these strings via the
+ *  ACCESSORY_GET_STRING_* ioctls
+ */
+#define ACCESSORY_SEND_STRING   52
+
+/* Control request for starting device in accessory mode.
+ * The host sends this after setting all its strings to the device.
+ *
+ *	requestType:    USB_DIR_OUT | USB_TYPE_VENDOR
+ *	request:        ACCESSORY_START
+ *	value:          0
+ *	index:          0
+ *	data            none
+ */
+#define ACCESSORY_START         53
+
+/* ioctls for retrieving strings set by the host */
+#define ACCESSORY_GET_STRING_MANUFACTURER   _IOW('M', 1, char[256])
+#define ACCESSORY_GET_STRING_MODEL          _IOW('M', 2, char[256])
+#define ACCESSORY_GET_STRING_DESCRIPTION    _IOW('M', 3, char[256])
+#define ACCESSORY_GET_STRING_VERSION        _IOW('M', 4, char[256])
+#define ACCESSORY_GET_STRING_URI            _IOW('M', 5, char[256])
+#define ACCESSORY_GET_STRING_SERIAL         _IOW('M', 6, char[256])
+
+#endif /* __LINUX_USB_F_ACCESSORY_H */