usb: gadget: mtp: Add MTP/PTP function

USB gadget function driver used by the Android framework to
implement the MTP and PTP protocols. It creates a character device
that provides an interface for fast transfer of files and
supports transferring files greater than 4GB.

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

drivers/usb/gadget/android.c

@@ -45,6 +45,7 @@
 #include "f_mass_storage.c"
 #include "u_serial.c"
 #include "f_acm.c"
+#include "f_mtp.c"
 #define USB_ETH_RNDIS y
 #include "f_rndis.c"
 #include "rndis.c"
@@ -264,6 +265,69 @@ static struct android_usb_function acm_function = {
 };
 
 
+static int
+mtp_function_init(struct android_usb_function *f,
+		struct usb_composite_dev *cdev)
+{
+	return mtp_setup();
+}
+
+static void mtp_function_cleanup(struct android_usb_function *f)
+{
+	mtp_cleanup();
+}
+
+static int
+mtp_function_bind_config(struct android_usb_function *f,
+		struct usb_configuration *c)
+{
+	return mtp_bind_config(c, false);
+}
+
+static int
+ptp_function_init(struct android_usb_function *f,
+		struct usb_composite_dev *cdev)
+{
+	/* nothing to do - initialization is handled by mtp_function_init */
+	return 0;
+}
+
+static void ptp_function_cleanup(struct android_usb_function *f)
+{
+	/* nothing to do - cleanup is handled by mtp_function_cleanup */
+}
+
+static int
+ptp_function_bind_config(struct android_usb_function *f,
+		struct usb_configuration *c)
+{
+	return mtp_bind_config(c, true);
+}
+
+static int mtp_function_ctrlrequest(struct android_usb_function *f,
+					struct usb_composite_dev *cdev,
+					const struct usb_ctrlrequest *c)
+{
+	return mtp_ctrlrequest(cdev, c);
+}
+
+static struct android_usb_function mtp_function = {
+	.name		= "mtp",
+	.init		= mtp_function_init,
+	.cleanup	= mtp_function_cleanup,
+	.bind_config	= mtp_function_bind_config,
+	.ctrlrequest	= mtp_function_ctrlrequest,
+};
+
+/* PTP function is same as MTP with slightly different interface descriptor */
+static struct android_usb_function ptp_function = {
+	.name		= "ptp",
+	.init		= ptp_function_init,
+	.cleanup	= ptp_function_cleanup,
+	.bind_config	= ptp_function_bind_config,
+};
+
+
 struct rndis_function_config {
 	u8      ethaddr[ETH_ALEN];
 	u32     vendorID;
@@ -543,6 +607,8 @@ static struct android_usb_function mass_storage_function = {
 
 static struct android_usb_function *supported_functions[] = {
 	&acm_function,
+	&mtp_function,
+	&ptp_function,
 	&rndis_function,
 	&mass_storage_function,
 	NULL

include/linux/usb/f_mtp.h

@@ -0,0 +1,75 @@
+/*
+ * Gadget Function Driver for MTP
+ *
+ * Copyright (C) 2010 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_MTP_H
+#define __LINUX_USB_F_MTP_H
+
+#include <linux/ioctl.h>
+
+#ifdef __KERNEL__
+
+struct mtp_data_header {
+	/* length of packet, including this header */
+	uint32_t	length;
+	/* container type (2 for data packet) */
+	uint16_t	type;
+	/* MTP command code */
+	uint16_t    command;
+	/* MTP transaction ID */
+	uint32_t	transaction_id;
+};
+
+#endif /* __KERNEL__ */
+
+struct mtp_file_range {
+	/* file descriptor for file to transfer */
+	int			fd;
+	/* offset in file for start of transfer */
+	loff_t		offset;
+	/* number of bytes to transfer */
+	int64_t		length;
+	/* MTP command ID for data header,
+	 * used only for MTP_SEND_FILE_WITH_HEADER
+	 */
+	uint16_t	command;
+	/* MTP transaction ID for data header,
+	 * used only for MTP_SEND_FILE_WITH_HEADER
+	 */
+	uint32_t	transaction_id;
+};
+
+struct mtp_event {
+	/* size of the event */
+	size_t		length;
+	/* event data to send */
+	void		*data;
+};
+
+/* Sends the specified file range to the host */
+#define MTP_SEND_FILE              _IOW('M', 0, struct mtp_file_range)
+/* Receives data from the host and writes it to a file.
+ * The file is created if it does not exist.
+ */
+#define MTP_RECEIVE_FILE           _IOW('M', 1, struct mtp_file_range)
+/* Sends an event to the host via the interrupt endpoint */
+#define MTP_SEND_EVENT             _IOW('M', 3, struct mtp_event)
+/* Sends the specified file range to the host,
+ * with a 12 byte MTP data packet header at the beginning.
+ */
+#define MTP_SEND_FILE_WITH_HEADER  _IOW('M', 4, struct mtp_file_range)
+
+#endif /* __LINUX_USB_F_MTP_H */