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path: root/drivers/usb/gadget/f_mtp.c
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Diffstat (limited to 'drivers/usb/gadget/f_mtp.c')
-rw-r--r--drivers/usb/gadget/f_mtp.c1473
1 files changed, 1473 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_mtp.c b/drivers/usb/gadget/f_mtp.c
new file mode 100644
index 000000000000..79053fda2864
--- /dev/null
+++ b/drivers/usb/gadget/f_mtp.c
@@ -0,0 +1,1473 @@
+/*
+ * 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.
+ *
+ */
+
+/* #define DEBUG */
+/* #define VERBOSE_DEBUG */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+
+#include <linux/types.h>
+#include <linux/file.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+
+#include <linux/usb.h>
+#include <linux/usb_usual.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/f_mtp.h>
+#include <linux/configfs.h>
+#include <linux/usb/composite.h>
+
+#include "configfs.h"
+
+#define MTP_BULK_BUFFER_SIZE 16384
+#define INTR_BUFFER_SIZE 28
+#define MAX_INST_NAME_LEN 40
+
+/* String IDs */
+#define INTERFACE_STRING_INDEX 0
+
+/* values for mtp_dev.state */
+#define STATE_OFFLINE 0 /* initial state, disconnected */
+#define STATE_READY 1 /* ready for userspace calls */
+#define STATE_BUSY 2 /* processing userspace calls */
+#define STATE_CANCELED 3 /* transaction canceled by host */
+#define STATE_ERROR 4 /* error from completion routine */
+
+/* number of tx and rx requests to allocate */
+#define TX_REQ_MAX 4
+#define RX_REQ_MAX 2
+#define INTR_REQ_MAX 5
+
+/* ID for Microsoft MTP OS String */
+#define MTP_OS_STRING_ID 0xEE
+
+/* MTP class reqeusts */
+#define MTP_REQ_CANCEL 0x64
+#define MTP_REQ_GET_EXT_EVENT_DATA 0x65
+#define MTP_REQ_RESET 0x66
+#define MTP_REQ_GET_DEVICE_STATUS 0x67
+
+/* constants for device status */
+#define MTP_RESPONSE_OK 0x2001
+#define MTP_RESPONSE_DEVICE_BUSY 0x2019
+#define DRIVER_NAME "mtp"
+
+static const char mtp_shortname[] = DRIVER_NAME "_usb";
+
+struct mtp_dev {
+ struct usb_function function;
+ struct usb_composite_dev *cdev;
+ spinlock_t lock;
+
+ struct usb_ep *ep_in;
+ struct usb_ep *ep_out;
+ struct usb_ep *ep_intr;
+
+ int state;
+
+ /* synchronize access to our device file */
+ atomic_t open_excl;
+ /* to enforce only one ioctl at a time */
+ atomic_t ioctl_excl;
+
+ struct list_head tx_idle;
+ struct list_head intr_idle;
+
+ wait_queue_head_t read_wq;
+ wait_queue_head_t write_wq;
+ wait_queue_head_t intr_wq;
+ struct usb_request *rx_req[RX_REQ_MAX];
+ int rx_done;
+
+ /* for processing MTP_SEND_FILE, MTP_RECEIVE_FILE and
+ * MTP_SEND_FILE_WITH_HEADER ioctls on a work queue
+ */
+ struct workqueue_struct *wq;
+ struct work_struct send_file_work;
+ struct work_struct receive_file_work;
+ struct file *xfer_file;
+ loff_t xfer_file_offset;
+ int64_t xfer_file_length;
+ unsigned xfer_send_header;
+ uint16_t xfer_command;
+ uint32_t xfer_transaction_id;
+ int xfer_result;
+};
+
+static struct usb_interface_descriptor mtp_interface_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 0,
+ .bNumEndpoints = 3,
+ .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+ .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC,
+ .bInterfaceProtocol = 0,
+};
+
+static struct usb_interface_descriptor ptp_interface_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 0,
+ .bNumEndpoints = 3,
+ .bInterfaceClass = USB_CLASS_STILL_IMAGE,
+ .bInterfaceSubClass = 1,
+ .bInterfaceProtocol = 1,
+};
+
+static struct usb_endpoint_descriptor mtp_highspeed_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor mtp_highspeed_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor mtp_fullspeed_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor mtp_fullspeed_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor mtp_intr_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = __constant_cpu_to_le16(INTR_BUFFER_SIZE),
+ .bInterval = 6,
+};
+
+static struct usb_descriptor_header *fs_mtp_descs[] = {
+ (struct usb_descriptor_header *) &mtp_interface_desc,
+ (struct usb_descriptor_header *) &mtp_fullspeed_in_desc,
+ (struct usb_descriptor_header *) &mtp_fullspeed_out_desc,
+ (struct usb_descriptor_header *) &mtp_intr_desc,
+ NULL,
+};
+
+static struct usb_descriptor_header *hs_mtp_descs[] = {
+ (struct usb_descriptor_header *) &mtp_interface_desc,
+ (struct usb_descriptor_header *) &mtp_highspeed_in_desc,
+ (struct usb_descriptor_header *) &mtp_highspeed_out_desc,
+ (struct usb_descriptor_header *) &mtp_intr_desc,
+ NULL,
+};
+
+static struct usb_descriptor_header *fs_ptp_descs[] = {
+ (struct usb_descriptor_header *) &ptp_interface_desc,
+ (struct usb_descriptor_header *) &mtp_fullspeed_in_desc,
+ (struct usb_descriptor_header *) &mtp_fullspeed_out_desc,
+ (struct usb_descriptor_header *) &mtp_intr_desc,
+ NULL,
+};
+
+static struct usb_descriptor_header *hs_ptp_descs[] = {
+ (struct usb_descriptor_header *) &ptp_interface_desc,
+ (struct usb_descriptor_header *) &mtp_highspeed_in_desc,
+ (struct usb_descriptor_header *) &mtp_highspeed_out_desc,
+ (struct usb_descriptor_header *) &mtp_intr_desc,
+ NULL,
+};
+
+static struct usb_string mtp_string_defs[] = {
+ /* Naming interface "MTP" so libmtp will recognize us */
+ [INTERFACE_STRING_INDEX].s = "MTP",
+ { }, /* end of list */
+};
+
+static struct usb_gadget_strings mtp_string_table = {
+ .language = 0x0409, /* en-US */
+ .strings = mtp_string_defs,
+};
+
+static struct usb_gadget_strings *mtp_strings[] = {
+ &mtp_string_table,
+ NULL,
+};
+
+/* Microsoft MTP OS String */
+static u8 mtp_os_string[] = {
+ 18, /* sizeof(mtp_os_string) */
+ USB_DT_STRING,
+ /* Signature field: "MSFT100" */
+ 'M', 0, 'S', 0, 'F', 0, 'T', 0, '1', 0, '0', 0, '0', 0,
+ /* vendor code */
+ 1,
+ /* padding */
+ 0
+};
+
+/* Microsoft Extended Configuration Descriptor Header Section */
+struct mtp_ext_config_desc_header {
+ __le32 dwLength;
+ __u16 bcdVersion;
+ __le16 wIndex;
+ __u8 bCount;
+ __u8 reserved[7];
+};
+
+/* Microsoft Extended Configuration Descriptor Function Section */
+struct mtp_ext_config_desc_function {
+ __u8 bFirstInterfaceNumber;
+ __u8 bInterfaceCount;
+ __u8 compatibleID[8];
+ __u8 subCompatibleID[8];
+ __u8 reserved[6];
+};
+
+/* MTP Extended Configuration Descriptor */
+struct {
+ struct mtp_ext_config_desc_header header;
+ struct mtp_ext_config_desc_function function;
+} mtp_ext_config_desc = {
+ .header = {
+ .dwLength = __constant_cpu_to_le32(sizeof(mtp_ext_config_desc)),
+ .bcdVersion = __constant_cpu_to_le16(0x0100),
+ .wIndex = __constant_cpu_to_le16(4),
+ .bCount = __constant_cpu_to_le16(1),
+ },
+ .function = {
+ .bFirstInterfaceNumber = 0,
+ .bInterfaceCount = 1,
+ .compatibleID = { 'M', 'T', 'P' },
+ },
+};
+
+struct mtp_device_status {
+ __le16 wLength;
+ __le16 wCode;
+};
+
+struct mtp_data_header {
+ /* length of packet, including this header */
+ __le32 length;
+ /* container type (2 for data packet) */
+ __le16 type;
+ /* MTP command code */
+ __le16 command;
+ /* MTP transaction ID */
+ __le32 transaction_id;
+};
+
+struct mtp_instance {
+ struct usb_function_instance func_inst;
+ const char *name;
+ struct mtp_dev *dev;
+};
+
+/* temporary variable used between mtp_open() and mtp_gadget_bind() */
+static struct mtp_dev *_mtp_dev;
+
+static inline struct mtp_dev *func_to_mtp(struct usb_function *f)
+{
+ return container_of(f, struct mtp_dev, function);
+}
+
+static struct usb_request *mtp_request_new(struct usb_ep *ep, int buffer_size)
+{
+ struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (!req)
+ return NULL;
+
+ /* now allocate buffers for the requests */
+ req->buf = kmalloc(buffer_size, GFP_KERNEL);
+ if (!req->buf) {
+ usb_ep_free_request(ep, req);
+ return NULL;
+ }
+
+ return req;
+}
+
+static void mtp_request_free(struct usb_request *req, struct usb_ep *ep)
+{
+ if (req) {
+ kfree(req->buf);
+ usb_ep_free_request(ep, req);
+ }
+}
+
+static inline int mtp_lock(atomic_t *excl)
+{
+ if (atomic_inc_return(excl) == 1) {
+ return 0;
+ } else {
+ atomic_dec(excl);
+ return -1;
+ }
+}
+
+static inline void mtp_unlock(atomic_t *excl)
+{
+ atomic_dec(excl);
+}
+
+/* add a request to the tail of a list */
+static void mtp_req_put(struct mtp_dev *dev, struct list_head *head,
+ struct usb_request *req)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ list_add_tail(&req->list, head);
+ spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/* remove a request from the head of a list */
+static struct usb_request
+*mtp_req_get(struct mtp_dev *dev, struct list_head *head)
+{
+ unsigned long flags;
+ struct usb_request *req;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (list_empty(head)) {
+ req = 0;
+ } else {
+ req = list_first_entry(head, struct usb_request, list);
+ list_del(&req->list);
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return req;
+}
+
+static void mtp_complete_in(struct usb_ep *ep, struct usb_request *req)
+{
+ struct mtp_dev *dev = _mtp_dev;
+
+ if (req->status != 0)
+ dev->state = STATE_ERROR;
+
+ mtp_req_put(dev, &dev->tx_idle, req);
+
+ wake_up(&dev->write_wq);
+}
+
+static void mtp_complete_out(struct usb_ep *ep, struct usb_request *req)
+{
+ struct mtp_dev *dev = _mtp_dev;
+
+ dev->rx_done = 1;
+ if (req->status != 0)
+ dev->state = STATE_ERROR;
+
+ wake_up(&dev->read_wq);
+}
+
+static void mtp_complete_intr(struct usb_ep *ep, struct usb_request *req)
+{
+ struct mtp_dev *dev = _mtp_dev;
+
+ if (req->status != 0)
+ dev->state = STATE_ERROR;
+
+ mtp_req_put(dev, &dev->intr_idle, req);
+
+ wake_up(&dev->intr_wq);
+}
+
+static int mtp_create_bulk_endpoints(struct mtp_dev *dev,
+ struct usb_endpoint_descriptor *in_desc,
+ struct usb_endpoint_descriptor *out_desc,
+ struct usb_endpoint_descriptor *intr_desc)
+{
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *req;
+ struct usb_ep *ep;
+ int i;
+
+ DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
+
+ ep = usb_ep_autoconfig(cdev->gadget, in_desc);
+ if (!ep) {
+ DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
+ return -ENODEV;
+ }
+ DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
+ ep->driver_data = dev; /* claim the endpoint */
+ dev->ep_in = ep;
+
+ ep = usb_ep_autoconfig(cdev->gadget, out_desc);
+ if (!ep) {
+ DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
+ return -ENODEV;
+ }
+ DBG(cdev, "usb_ep_autoconfig for mtp ep_out got %s\n", ep->name);
+ ep->driver_data = dev; /* claim the endpoint */
+ dev->ep_out = ep;
+
+ ep = usb_ep_autoconfig(cdev->gadget, intr_desc);
+ if (!ep) {
+ DBG(cdev, "usb_ep_autoconfig for ep_intr failed\n");
+ return -ENODEV;
+ }
+ DBG(cdev, "usb_ep_autoconfig for mtp ep_intr got %s\n", ep->name);
+ ep->driver_data = dev; /* claim the endpoint */
+ dev->ep_intr = ep;
+
+ /* now allocate requests for our endpoints */
+ for (i = 0; i < TX_REQ_MAX; i++) {
+ req = mtp_request_new(dev->ep_in, MTP_BULK_BUFFER_SIZE);
+ if (!req)
+ goto fail;
+ req->complete = mtp_complete_in;
+ mtp_req_put(dev, &dev->tx_idle, req);
+ }
+ for (i = 0; i < RX_REQ_MAX; i++) {
+ req = mtp_request_new(dev->ep_out, MTP_BULK_BUFFER_SIZE);
+ if (!req)
+ goto fail;
+ req->complete = mtp_complete_out;
+ dev->rx_req[i] = req;
+ }
+ for (i = 0; i < INTR_REQ_MAX; i++) {
+ req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
+ if (!req)
+ goto fail;
+ req->complete = mtp_complete_intr;
+ mtp_req_put(dev, &dev->intr_idle, req);
+ }
+
+ return 0;
+
+fail:
+ pr_err("mtp_bind() could not allocate requests\n");
+ return -1;
+}
+
+static ssize_t mtp_read(struct file *fp, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct mtp_dev *dev = fp->private_data;
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *req;
+ ssize_t r = count;
+ unsigned xfer;
+ int ret = 0;
+
+ DBG(cdev, "mtp_read(%zu)\n", count);
+
+ if (count > MTP_BULK_BUFFER_SIZE)
+ return -EINVAL;
+
+ /* we will block until we're online */
+ DBG(cdev, "mtp_read: waiting for online state\n");
+ ret = wait_event_interruptible(dev->read_wq,
+ dev->state != STATE_OFFLINE);
+ if (ret < 0) {
+ r = ret;
+ goto done;
+ }
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED) {
+ /* report cancelation to userspace */
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+ return -ECANCELED;
+ }
+ dev->state = STATE_BUSY;
+ spin_unlock_irq(&dev->lock);
+
+requeue_req:
+ /* queue a request */
+ req = dev->rx_req[0];
+ req->length = count;
+ dev->rx_done = 0;
+ ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
+ if (ret < 0) {
+ r = -EIO;
+ goto done;
+ } else {
+ DBG(cdev, "rx %p queue\n", req);
+ }
+
+ /* wait for a request to complete */
+ ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
+ if (ret < 0) {
+ r = ret;
+ usb_ep_dequeue(dev->ep_out, req);
+ goto done;
+ }
+ if (dev->state == STATE_BUSY) {
+ /* If we got a 0-len packet, throw it back and try again. */
+ if (req->actual == 0)
+ goto requeue_req;
+
+ DBG(cdev, "rx %p %d\n", req, req->actual);
+ xfer = (req->actual < count) ? req->actual : count;
+ r = xfer;
+ if (copy_to_user(buf, req->buf, xfer))
+ r = -EFAULT;
+ } else
+ r = -EIO;
+
+done:
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED)
+ r = -ECANCELED;
+ else if (dev->state != STATE_OFFLINE)
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+
+ DBG(cdev, "mtp_read returning %zd\n", r);
+ return r;
+}
+
+static ssize_t mtp_write(struct file *fp, const char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct mtp_dev *dev = fp->private_data;
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *req = 0;
+ ssize_t r = count;
+ unsigned xfer;
+ int sendZLP = 0;
+ int ret;
+
+ DBG(cdev, "mtp_write(%zu)\n", count);
+
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED) {
+ /* report cancelation to userspace */
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+ return -ECANCELED;
+ }
+ if (dev->state == STATE_OFFLINE) {
+ spin_unlock_irq(&dev->lock);
+ return -ENODEV;
+ }
+ dev->state = STATE_BUSY;
+ spin_unlock_irq(&dev->lock);
+
+ /* we need to send a zero length packet to signal the end of transfer
+ * if the transfer size is aligned to a packet boundary.
+ */
+ if ((count & (dev->ep_in->maxpacket - 1)) == 0)
+ sendZLP = 1;
+
+ while (count > 0 || sendZLP) {
+ /* so we exit after sending ZLP */
+ if (count == 0)
+ sendZLP = 0;
+
+ if (dev->state != STATE_BUSY) {
+ DBG(cdev, "mtp_write dev->error\n");
+ r = -EIO;
+ break;
+ }
+
+ /* get an idle tx request to use */
+ req = 0;
+ ret = wait_event_interruptible(dev->write_wq,
+ ((req = mtp_req_get(dev, &dev->tx_idle))
+ || dev->state != STATE_BUSY));
+ if (!req) {
+ r = ret;
+ break;
+ }
+
+ if (count > MTP_BULK_BUFFER_SIZE)
+ xfer = MTP_BULK_BUFFER_SIZE;
+ else
+ xfer = count;
+ if (xfer && copy_from_user(req->buf, buf, xfer)) {
+ r = -EFAULT;
+ break;
+ }
+
+ req->length = xfer;
+ ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
+ if (ret < 0) {
+ DBG(cdev, "mtp_write: xfer error %d\n", ret);
+ r = -EIO;
+ break;
+ }
+
+ buf += xfer;
+ count -= xfer;
+
+ /* zero this so we don't try to free it on error exit */
+ req = 0;
+ }
+
+ if (req)
+ mtp_req_put(dev, &dev->tx_idle, req);
+
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED)
+ r = -ECANCELED;
+ else if (dev->state != STATE_OFFLINE)
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+
+ DBG(cdev, "mtp_write returning %zd\n", r);
+ return r;
+}
+
+/* read from a local file and write to USB */
+static void send_file_work(struct work_struct *data)
+{
+ struct mtp_dev *dev = container_of(data, struct mtp_dev,
+ send_file_work);
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *req = 0;
+ struct mtp_data_header *header;
+ struct file *filp;
+ loff_t offset;
+ int64_t count;
+ int xfer, ret, hdr_size;
+ int r = 0;
+ int sendZLP = 0;
+
+ /* read our parameters */
+ smp_rmb();
+ filp = dev->xfer_file;
+ offset = dev->xfer_file_offset;
+ count = dev->xfer_file_length;
+
+ DBG(cdev, "send_file_work(%lld %lld)\n", offset, count);
+
+ if (dev->xfer_send_header) {
+ hdr_size = sizeof(struct mtp_data_header);
+ count += hdr_size;
+ } else {
+ hdr_size = 0;
+ }
+
+ /* we need to send a zero length packet to signal the end of transfer
+ * if the transfer size is aligned to a packet boundary.
+ */
+ if ((count & (dev->ep_in->maxpacket - 1)) == 0)
+ sendZLP = 1;
+
+ while (count > 0 || sendZLP) {
+ /* so we exit after sending ZLP */
+ if (count == 0)
+ sendZLP = 0;
+
+ /* get an idle tx request to use */
+ req = 0;
+ ret = wait_event_interruptible(dev->write_wq,
+ (req = mtp_req_get(dev, &dev->tx_idle))
+ || dev->state != STATE_BUSY);
+ if (dev->state == STATE_CANCELED) {
+ r = -ECANCELED;
+ break;
+ }
+ if (!req) {
+ r = ret;
+ break;
+ }
+
+ if (count > MTP_BULK_BUFFER_SIZE)
+ xfer = MTP_BULK_BUFFER_SIZE;
+ else
+ xfer = count;
+
+ if (hdr_size) {
+ /* prepend MTP data header */
+ header = (struct mtp_data_header *)req->buf;
+ header->length = __cpu_to_le32(count);
+ header->type = __cpu_to_le16(2); /* data packet */
+ header->command = __cpu_to_le16(dev->xfer_command);
+ header->transaction_id =
+ __cpu_to_le32(dev->xfer_transaction_id);
+ }
+
+ ret = vfs_read(filp, req->buf + hdr_size, xfer - hdr_size,
+ &offset);
+ if (ret < 0) {
+ r = ret;
+ break;
+ }
+ xfer = ret + hdr_size;
+ hdr_size = 0;
+
+ req->length = xfer;
+ ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
+ if (ret < 0) {
+ DBG(cdev, "send_file_work: xfer error %d\n", ret);
+ dev->state = STATE_ERROR;
+ r = -EIO;
+ break;
+ }
+
+ count -= xfer;
+
+ /* zero this so we don't try to free it on error exit */
+ req = 0;
+ }
+
+ if (req)
+ mtp_req_put(dev, &dev->tx_idle, req);
+
+ DBG(cdev, "send_file_work returning %d\n", r);
+ /* write the result */
+ dev->xfer_result = r;
+ smp_wmb();
+}
+
+/* read from USB and write to a local file */
+static void receive_file_work(struct work_struct *data)
+{
+ struct mtp_dev *dev = container_of(data, struct mtp_dev,
+ receive_file_work);
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *read_req = NULL, *write_req = NULL;
+ struct file *filp;
+ loff_t offset;
+ int64_t count;
+ int ret, cur_buf = 0;
+ int r = 0;
+
+ /* read our parameters */
+ smp_rmb();
+ filp = dev->xfer_file;
+ offset = dev->xfer_file_offset;
+ count = dev->xfer_file_length;
+
+ DBG(cdev, "receive_file_work(%lld)\n", count);
+
+ while (count > 0 || write_req) {
+ if (count > 0) {
+ /* queue a request */
+ read_req = dev->rx_req[cur_buf];
+ cur_buf = (cur_buf + 1) % RX_REQ_MAX;
+
+ read_req->length = (count > MTP_BULK_BUFFER_SIZE
+ ? MTP_BULK_BUFFER_SIZE : count);
+ dev->rx_done = 0;
+ ret = usb_ep_queue(dev->ep_out, read_req, GFP_KERNEL);
+ if (ret < 0) {
+ r = -EIO;
+ dev->state = STATE_ERROR;
+ break;
+ }
+ }
+
+ if (write_req) {
+ DBG(cdev, "rx %p %d\n", write_req, write_req->actual);
+ ret = vfs_write(filp, write_req->buf, write_req->actual,
+ &offset);
+ DBG(cdev, "vfs_write %d\n", ret);
+ if (ret != write_req->actual) {
+ r = -EIO;
+ dev->state = STATE_ERROR;
+ break;
+ }
+ write_req = NULL;
+ }
+
+ if (read_req) {
+ /* wait for our last read to complete */
+ ret = wait_event_interruptible(dev->read_wq,
+ dev->rx_done || dev->state != STATE_BUSY);
+ if (dev->state == STATE_CANCELED) {
+ r = -ECANCELED;
+ if (!dev->rx_done)
+ usb_ep_dequeue(dev->ep_out, read_req);
+ break;
+ }
+ /* if xfer_file_length is 0xFFFFFFFF, then we read until
+ * we get a zero length packet
+ */
+ if (count != 0xFFFFFFFF)
+ count -= read_req->actual;
+ if (read_req->actual < read_req->length) {
+ /*
+ * short packet is used to signal EOF for
+ * sizes > 4 gig
+ */
+ DBG(cdev, "got short packet\n");
+ count = 0;
+ }
+
+ write_req = read_req;
+ read_req = NULL;
+ }
+ }
+
+ DBG(cdev, "receive_file_work returning %d\n", r);
+ /* write the result */
+ dev->xfer_result = r;
+ smp_wmb();
+}
+
+static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
+{
+ struct usb_request *req = NULL;
+ int ret;
+ int length = event->length;
+
+ DBG(dev->cdev, "mtp_send_event(%zu)\n", event->length);
+
+ if (length < 0 || length > INTR_BUFFER_SIZE)
+ return -EINVAL;
+ if (dev->state == STATE_OFFLINE)
+ return -ENODEV;
+
+ ret = wait_event_interruptible_timeout(dev->intr_wq,
+ (req = mtp_req_get(dev, &dev->intr_idle)),
+ msecs_to_jiffies(1000));
+ if (!req)
+ return -ETIME;
+
+ if (copy_from_user(req->buf, (void __user *)event->data, length)) {
+ mtp_req_put(dev, &dev->intr_idle, req);
+ return -EFAULT;
+ }
+ req->length = length;
+ ret = usb_ep_queue(dev->ep_intr, req, GFP_KERNEL);
+ if (ret)
+ mtp_req_put(dev, &dev->intr_idle, req);
+
+ return ret;
+}
+
+static long mtp_ioctl(struct file *fp, unsigned code, unsigned long value)
+{
+ struct mtp_dev *dev = fp->private_data;
+ struct file *filp = NULL;
+ int ret = -EINVAL;
+
+ if (mtp_lock(&dev->ioctl_excl))
+ return -EBUSY;
+
+ switch (code) {
+ case MTP_SEND_FILE:
+ case MTP_RECEIVE_FILE:
+ case MTP_SEND_FILE_WITH_HEADER:
+ {
+ struct mtp_file_range mfr;
+ struct work_struct *work;
+
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED) {
+ /* report cancelation to userspace */
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+ ret = -ECANCELED;
+ goto out;
+ }
+ if (dev->state == STATE_OFFLINE) {
+ spin_unlock_irq(&dev->lock);
+ ret = -ENODEV;
+ goto out;
+ }
+ dev->state = STATE_BUSY;
+ spin_unlock_irq(&dev->lock);
+
+ if (copy_from_user(&mfr, (void __user *)value, sizeof(mfr))) {
+ ret = -EFAULT;
+ goto fail;
+ }
+ /* hold a reference to the file while we are working with it */
+ filp = fget(mfr.fd);
+ if (!filp) {
+ ret = -EBADF;
+ goto fail;
+ }
+
+ /* write the parameters */
+ dev->xfer_file = filp;
+ dev->xfer_file_offset = mfr.offset;
+ dev->xfer_file_length = mfr.length;
+ smp_wmb();
+
+ if (code == MTP_SEND_FILE_WITH_HEADER) {
+ work = &dev->send_file_work;
+ dev->xfer_send_header = 1;
+ dev->xfer_command = mfr.command;
+ dev->xfer_transaction_id = mfr.transaction_id;
+ } else if (code == MTP_SEND_FILE) {
+ work = &dev->send_file_work;
+ dev->xfer_send_header = 0;
+ } else {
+ work = &dev->receive_file_work;
+ }
+
+ /* We do the file transfer on a work queue so it will run
+ * in kernel context, which is necessary for vfs_read and
+ * vfs_write to use our buffers in the kernel address space.
+ */
+ queue_work(dev->wq, work);
+ /* wait for operation to complete */
+ flush_workqueue(dev->wq);
+ fput(filp);
+
+ /* read the result */
+ smp_rmb();
+ ret = dev->xfer_result;
+ break;
+ }
+ case MTP_SEND_EVENT:
+ {
+ struct mtp_event event;
+ /* return here so we don't change dev->state below,
+ * which would interfere with bulk transfer state.
+ */
+ if (copy_from_user(&event, (void __user *)value, sizeof(event)))
+ ret = -EFAULT;
+ else
+ ret = mtp_send_event(dev, &event);
+ goto out;
+ }
+ }
+
+fail:
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_CANCELED)
+ ret = -ECANCELED;
+ else if (dev->state != STATE_OFFLINE)
+ dev->state = STATE_READY;
+ spin_unlock_irq(&dev->lock);
+out:
+ mtp_unlock(&dev->ioctl_excl);
+ DBG(dev->cdev, "ioctl returning %d\n", ret);
+ return ret;
+}
+
+static int mtp_open(struct inode *ip, struct file *fp)
+{
+ printk(KERN_INFO "mtp_open\n");
+ if (mtp_lock(&_mtp_dev->open_excl))
+ return -EBUSY;
+
+ /* clear any error condition */
+ if (_mtp_dev->state != STATE_OFFLINE)
+ _mtp_dev->state = STATE_READY;
+
+ fp->private_data = _mtp_dev;
+ return 0;
+}
+
+static int mtp_release(struct inode *ip, struct file *fp)
+{
+ printk(KERN_INFO "mtp_release\n");
+
+ mtp_unlock(&_mtp_dev->open_excl);
+ return 0;
+}
+
+/* file operations for /dev/mtp_usb */
+static const struct file_operations mtp_fops = {
+ .owner = THIS_MODULE,
+ .read = mtp_read,
+ .write = mtp_write,
+ .unlocked_ioctl = mtp_ioctl,
+ .open = mtp_open,
+ .release = mtp_release,
+};
+
+static struct miscdevice mtp_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = mtp_shortname,
+ .fops = &mtp_fops,
+};
+
+static int mtp_ctrlrequest(struct usb_composite_dev *cdev,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct mtp_dev *dev = _mtp_dev;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+ unsigned long flags;
+
+ VDBG(cdev, "mtp_ctrlrequest "
+ "%02x.%02x v%04x i%04x l%u\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+
+ /* Handle MTP OS string */
+ if (ctrl->bRequestType ==
+ (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE)
+ && ctrl->bRequest == USB_REQ_GET_DESCRIPTOR
+ && (w_value >> 8) == USB_DT_STRING
+ && (w_value & 0xFF) == MTP_OS_STRING_ID) {
+ value = (w_length < sizeof(mtp_os_string)
+ ? w_length : sizeof(mtp_os_string));
+ memcpy(cdev->req->buf, mtp_os_string, value);
+ } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
+ /* Handle MTP OS descriptor */
+ DBG(cdev, "vendor request: %d index: %d value: %d length: %d\n",
+ ctrl->bRequest, w_index, w_value, w_length);
+
+ if (ctrl->bRequest == 1
+ && (ctrl->bRequestType & USB_DIR_IN)
+ && (w_index == 4 || w_index == 5)) {
+ value = (w_length < sizeof(mtp_ext_config_desc) ?
+ w_length : sizeof(mtp_ext_config_desc));
+ memcpy(cdev->req->buf, &mtp_ext_config_desc, value);
+ }
+ } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
+ DBG(cdev, "class request: %d index: %d value: %d length: %d\n",
+ ctrl->bRequest, w_index, w_value, w_length);
+
+ if (ctrl->bRequest == MTP_REQ_CANCEL && w_index == 0
+ && w_value == 0) {
+ DBG(cdev, "MTP_REQ_CANCEL\n");
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state == STATE_BUSY) {
+ dev->state = STATE_CANCELED;
+ wake_up(&dev->read_wq);
+ wake_up(&dev->write_wq);
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ /* We need to queue a request to read the remaining
+ * bytes, but we don't actually need to look at
+ * the contents.
+ */
+ value = w_length;
+ } else if (ctrl->bRequest == MTP_REQ_GET_DEVICE_STATUS
+ && w_index == 0 && w_value == 0) {
+ struct mtp_device_status *status = cdev->req->buf;
+ status->wLength =
+ __constant_cpu_to_le16(sizeof(*status));
+
+ DBG(cdev, "MTP_REQ_GET_DEVICE_STATUS\n");
+ spin_lock_irqsave(&dev->lock, flags);
+ /* device status is "busy" until we report
+ * the cancelation to userspace
+ */
+ if (dev->state == STATE_CANCELED)
+ status->wCode =
+ __cpu_to_le16(MTP_RESPONSE_DEVICE_BUSY);
+ else
+ status->wCode =
+ __cpu_to_le16(MTP_RESPONSE_OK);
+ spin_unlock_irqrestore(&dev->lock, flags);
+ value = sizeof(*status);
+ }
+ }
+
+ /* respond with data transfer or status phase? */
+ if (value >= 0) {
+ int rc;
+ cdev->req->zero = value < w_length;
+ cdev->req->length = value;
+ rc = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
+ if (rc < 0)
+ ERROR(cdev, "%s: response queue error\n", __func__);
+ }
+ return value;
+}
+
+static int
+mtp_function_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct mtp_dev *dev = func_to_mtp(f);
+ int id;
+ int ret;
+
+ dev->cdev = cdev;
+ DBG(cdev, "mtp_function_bind dev: %p\n", dev);
+
+ /* allocate interface ID(s) */
+ id = usb_interface_id(c, f);
+ if (id < 0)
+ return id;
+ mtp_interface_desc.bInterfaceNumber = id;
+
+ if (mtp_string_defs[INTERFACE_STRING_INDEX].id == 0) {
+ ret = usb_string_id(c->cdev);
+ if (ret < 0)
+ return ret;
+ mtp_string_defs[INTERFACE_STRING_INDEX].id = ret;
+ mtp_interface_desc.iInterface = ret;
+ }
+ /* allocate endpoints */
+ ret = mtp_create_bulk_endpoints(dev, &mtp_fullspeed_in_desc,
+ &mtp_fullspeed_out_desc, &mtp_intr_desc);
+ if (ret)
+ return ret;
+
+ /* support high speed hardware */
+ if (gadget_is_dualspeed(c->cdev->gadget)) {
+ mtp_highspeed_in_desc.bEndpointAddress =
+ mtp_fullspeed_in_desc.bEndpointAddress;
+ mtp_highspeed_out_desc.bEndpointAddress =
+ mtp_fullspeed_out_desc.bEndpointAddress;
+ }
+
+ DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ f->name, dev->ep_in->name, dev->ep_out->name);
+ return 0;
+}
+
+static void
+mtp_function_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct mtp_dev *dev = func_to_mtp(f);
+ struct usb_request *req;
+ int i;
+
+ mtp_string_defs[INTERFACE_STRING_INDEX].id = 0;
+ while ((req = mtp_req_get(dev, &dev->tx_idle)))
+ mtp_request_free(req, dev->ep_in);
+ for (i = 0; i < RX_REQ_MAX; i++)
+ mtp_request_free(dev->rx_req[i], dev->ep_out);
+ while ((req = mtp_req_get(dev, &dev->intr_idle)))
+ mtp_request_free(req, dev->ep_intr);
+ dev->state = STATE_OFFLINE;
+}
+
+static int mtp_function_set_alt(struct usb_function *f,
+ unsigned intf, unsigned alt)
+{
+ struct mtp_dev *dev = func_to_mtp(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+ int ret;
+
+ DBG(cdev, "mtp_function_set_alt intf: %d alt: %d\n", intf, alt);
+
+ ret = config_ep_by_speed(cdev->gadget, f, dev->ep_in);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(dev->ep_in);
+ if (ret)
+ return ret;
+
+ ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(dev->ep_out);
+ if (ret) {
+ usb_ep_disable(dev->ep_in);
+ return ret;
+ }
+
+ ret = config_ep_by_speed(cdev->gadget, f, dev->ep_intr);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(dev->ep_intr);
+ if (ret) {
+ usb_ep_disable(dev->ep_out);
+ usb_ep_disable(dev->ep_in);
+ return ret;
+ }
+ dev->state = STATE_READY;
+
+ /* readers may be blocked waiting for us to go online */
+ wake_up(&dev->read_wq);
+ return 0;
+}
+
+static void mtp_function_disable(struct usb_function *f)
+{
+ struct mtp_dev *dev = func_to_mtp(f);
+ struct usb_composite_dev *cdev = dev->cdev;
+
+ DBG(cdev, "mtp_function_disable\n");
+ dev->state = STATE_OFFLINE;
+ usb_ep_disable(dev->ep_in);
+ usb_ep_disable(dev->ep_out);
+ usb_ep_disable(dev->ep_intr);
+
+ /* readers may be blocked waiting for us to go online */
+ wake_up(&dev->read_wq);
+
+ VDBG(cdev, "%s disabled\n", dev->function.name);
+}
+
+static int __maybe_unused mtp_bind_config(struct usb_configuration *c, bool ptp_config)
+{
+ struct mtp_dev *dev = _mtp_dev;
+ int ret = 0;
+
+ printk(KERN_INFO "mtp_bind_config\n");
+
+ /* allocate a string ID for our interface */
+ if (mtp_string_defs[INTERFACE_STRING_INDEX].id == 0) {
+ ret = usb_string_id(c->cdev);
+ if (ret < 0)
+ return ret;
+ mtp_string_defs[INTERFACE_STRING_INDEX].id = ret;
+ mtp_interface_desc.iInterface = ret;
+ }
+
+ dev->cdev = c->cdev;
+ dev->function.name = DRIVER_NAME;
+ dev->function.strings = mtp_strings;
+ if (ptp_config) {
+ dev->function.fs_descriptors = fs_ptp_descs;
+ dev->function.hs_descriptors = hs_ptp_descs;
+ } else {
+ dev->function.fs_descriptors = fs_mtp_descs;
+ dev->function.hs_descriptors = hs_mtp_descs;
+ }
+ dev->function.bind = mtp_function_bind;
+ dev->function.unbind = mtp_function_unbind;
+ dev->function.set_alt = mtp_function_set_alt;
+ dev->function.disable = mtp_function_disable;
+
+ return usb_add_function(c, &dev->function);
+}
+
+static int __mtp_setup(struct mtp_instance *fi_mtp)
+{
+ struct mtp_dev *dev;
+ int ret;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+
+ if (fi_mtp != NULL)
+ fi_mtp->dev = dev;
+
+ if (!dev)
+ return -ENOMEM;
+
+ spin_lock_init(&dev->lock);
+ init_waitqueue_head(&dev->read_wq);
+ init_waitqueue_head(&dev->write_wq);
+ init_waitqueue_head(&dev->intr_wq);
+ atomic_set(&dev->open_excl, 0);
+ atomic_set(&dev->ioctl_excl, 0);
+ INIT_LIST_HEAD(&dev->tx_idle);
+ INIT_LIST_HEAD(&dev->intr_idle);
+
+ dev->wq = create_singlethread_workqueue("f_mtp");
+ if (!dev->wq) {
+ ret = -ENOMEM;
+ goto err1;
+ }
+ INIT_WORK(&dev->send_file_work, send_file_work);
+ INIT_WORK(&dev->receive_file_work, receive_file_work);
+
+ _mtp_dev = dev;
+
+ ret = misc_register(&mtp_device);
+ if (ret)
+ goto err2;
+
+ return 0;
+
+err2:
+ destroy_workqueue(dev->wq);
+err1:
+ _mtp_dev = NULL;
+ kfree(dev);
+ printk(KERN_ERR "mtp gadget driver failed to initialize\n");
+ return ret;
+}
+
+static int __maybe_unused mtp_setup(void)
+{
+ return __mtp_setup(NULL);
+}
+
+static int mtp_setup_configfs(struct mtp_instance *fi_mtp)
+{
+ return __mtp_setup(fi_mtp);
+}
+
+
+static void mtp_cleanup(void)
+{
+ struct mtp_dev *dev = _mtp_dev;
+
+ if (!dev)
+ return;
+
+ misc_deregister(&mtp_device);
+ destroy_workqueue(dev->wq);
+ _mtp_dev = NULL;
+ kfree(dev);
+}
+
+static struct mtp_instance *to_mtp_instance(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct mtp_instance,
+ func_inst.group);
+}
+
+static void mtp_attr_release(struct config_item *item)
+{
+ struct mtp_instance *fi_mtp = to_mtp_instance(item);
+ usb_put_function_instance(&fi_mtp->func_inst);
+}
+
+static struct configfs_item_operations mtp_item_ops = {
+ .release = mtp_attr_release,
+};
+
+static struct config_item_type mtp_func_type = {
+ .ct_item_ops = &mtp_item_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+
+static struct mtp_instance *to_fi_mtp(struct usb_function_instance *fi)
+{
+ return container_of(fi, struct mtp_instance, func_inst);
+}
+
+static int mtp_set_inst_name(struct usb_function_instance *fi, const char *name)
+{
+ struct mtp_instance *fi_mtp;
+ char *ptr;
+ int name_len;
+
+ name_len = strlen(name) + 1;
+ if (name_len > MAX_INST_NAME_LEN)
+ return -ENAMETOOLONG;
+
+ ptr = kstrndup(name, name_len, GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ fi_mtp = to_fi_mtp(fi);
+ fi_mtp->name = ptr;
+
+ return 0;
+}
+
+static void mtp_free_inst(struct usb_function_instance *fi)
+{
+ struct mtp_instance *fi_mtp;
+
+ fi_mtp = to_fi_mtp(fi);
+ kfree(fi_mtp->name);
+ mtp_cleanup();
+ kfree(fi_mtp);
+}
+
+struct usb_function_instance *alloc_inst_mtp_ptp(bool mtp_config)
+{
+ struct mtp_instance *fi_mtp;
+ int ret = 0;
+
+ fi_mtp = kzalloc(sizeof(*fi_mtp), GFP_KERNEL);
+ if (!fi_mtp)
+ return ERR_PTR(-ENOMEM);
+ fi_mtp->func_inst.set_inst_name = mtp_set_inst_name;
+ fi_mtp->func_inst.free_func_inst = mtp_free_inst;
+
+ if (mtp_config) {
+ ret = mtp_setup_configfs(fi_mtp);
+ if (ret) {
+ kfree(fi_mtp);
+ pr_err("Error setting MTP\n");
+ return ERR_PTR(ret);
+ }
+ } else
+ fi_mtp->dev = _mtp_dev;
+
+ config_group_init_type_name(&fi_mtp->func_inst.group,
+ "", &mtp_func_type);
+
+ return &fi_mtp->func_inst;
+}
+EXPORT_SYMBOL_GPL(alloc_inst_mtp_ptp);
+
+static struct usb_function_instance *mtp_alloc_inst(void)
+{
+ return alloc_inst_mtp_ptp(true);
+}
+
+static int mtp_ctrlreq_configfs(struct usb_function *f,
+ const struct usb_ctrlrequest *ctrl)
+{
+ return mtp_ctrlrequest(f->config->cdev, ctrl);
+}
+
+static void mtp_free(struct usb_function *f)
+{
+ /*NO-OP: no function specific resource allocation in mtp_alloc*/
+}
+
+struct usb_function *function_alloc_mtp_ptp(struct usb_function_instance *fi,
+ bool mtp_config)
+{
+ struct mtp_instance *fi_mtp = to_fi_mtp(fi);
+ struct mtp_dev *dev;
+
+ /*
+ * PTP piggybacks on MTP function so make sure we have
+ * created MTP function before we associate this PTP
+ * function with a gadget configuration.
+ */
+ if (fi_mtp->dev == NULL) {
+ pr_err("Error: Create MTP function before linking"
+ " PTP function with a gadget configuration\n");
+ pr_err("\t1: Delete existing PTP function if any\n");
+ pr_err("\t2: Create MTP function\n");
+ pr_err("\t3: Create and symlink PTP function"
+ " with a gadget configuration\n");
+ return NULL;
+ }
+
+ dev = fi_mtp->dev;
+ dev->function.name = DRIVER_NAME;
+ dev->function.strings = mtp_strings;
+ if (mtp_config) {
+ dev->function.fs_descriptors = fs_mtp_descs;
+ dev->function.hs_descriptors = hs_mtp_descs;
+ } else {
+ dev->function.fs_descriptors = fs_ptp_descs;
+ dev->function.hs_descriptors = hs_ptp_descs;
+ }
+ dev->function.bind = mtp_function_bind;
+ dev->function.unbind = mtp_function_unbind;
+ dev->function.set_alt = mtp_function_set_alt;
+ dev->function.disable = mtp_function_disable;
+ dev->function.setup = mtp_ctrlreq_configfs;
+ dev->function.free_func = mtp_free;
+
+ return &dev->function;
+}
+EXPORT_SYMBOL_GPL(function_alloc_mtp_ptp);
+
+static struct usb_function *mtp_alloc(struct usb_function_instance *fi)
+{
+ return function_alloc_mtp_ptp(fi, true);
+}
+
+DECLARE_USB_FUNCTION_INIT(mtp, mtp_alloc_inst, mtp_alloc);
+MODULE_LICENSE("GPL");