drivers/usb/gadget/f_mtp.c

   1 /*
   2  * Gadget Function Driver for MTP
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  * Author: Mike Lockwood <lockwood@android.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 /* #define DEBUG */
  19 /* #define VERBOSE_DEBUG */
  20
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/poll.h>
  24 #include <linux/delay.h>
  25 #include <linux/wait.h>
  26 #include <linux/err.h>
  27 #include <linux/interrupt.h>
  28
  29 #include <linux/types.h>
  30 #include <linux/file.h>
  31 #include <linux/device.h>
  32 #include <linux/miscdevice.h>
  33
  34 #include <linux/usb.h>
  35 #include <linux/usb_usual.h>
  36 #include <linux/usb/ch9.h>
  37 #include <linux/usb/f_mtp.h>
  38
  39 #define MTP_BULK_BUFFER_SIZE       16384
  40 #define INTR_BUFFER_SIZE           28
  41
  42 /* String IDs */
  43 #define INTERFACE_STRING_INDEX  0
  44
  45 /* values for mtp_dev.state */
  46 #define STATE_OFFLINE               0   /* initial state, disconnected */
  47 #define STATE_READY                 1   /* ready for userspace calls */
  48 #define STATE_BUSY                  2   /* processing userspace calls */
  49 #define STATE_CANCELED              3   /* transaction canceled by host */
  50 #define STATE_ERROR                 4   /* error from completion routine */
  51
  52 /* number of tx and rx requests to allocate */
  53 #define TX_REQ_MAX 4
  54 #define RX_REQ_MAX 2
  55 #define INTR_REQ_MAX 5
  56
  57 /* ID for Microsoft MTP OS String */
  58 #define MTP_OS_STRING_ID   0xEE
  59
  60 /* MTP class reqeusts */
  61 #define MTP_REQ_CANCEL              0x64
  62 #define MTP_REQ_GET_EXT_EVENT_DATA  0x65
  63 #define MTP_REQ_RESET               0x66
  64 #define MTP_REQ_GET_DEVICE_STATUS   0x67
  65
  66 /* constants for device status */
  67 #define MTP_RESPONSE_OK             0x2001
  68 #define MTP_RESPONSE_DEVICE_BUSY    0x2019
  69
  70 static const char mtp_shortname[] = "mtp_usb";
  71
  72 struct mtp_dev {
  73         struct usb_function function;
  74         struct usb_composite_dev *cdev;
  75         spinlock_t lock;
  76
  77         struct usb_ep *ep_in;
  78         struct usb_ep *ep_out;
  79         struct usb_ep *ep_intr;
  80
  81         int state;
  82
  83         /* synchronize access to our device file */
  84         atomic_t open_excl;
  85         /* to enforce only one ioctl at a time */
  86         atomic_t ioctl_excl;
  87
  88         struct list_head tx_idle;
  89         struct list_head intr_idle;
  90
  91         wait_queue_head_t read_wq;
  92         wait_queue_head_t write_wq;
  93         wait_queue_head_t intr_wq;
  94         struct usb_request *rx_req[RX_REQ_MAX];
  95         int rx_done;
  96
  97         /* for processing MTP_SEND_FILE, MTP_RECEIVE_FILE and
  98          * MTP_SEND_FILE_WITH_HEADER ioctls on a work queue
  99          */
 100         struct workqueue_struct *wq;
 101         struct work_struct send_file_work;
 102         struct work_struct receive_file_work;
 103         struct file *xfer_file;
 104         loff_t xfer_file_offset;
 105         int64_t xfer_file_length;
 106         unsigned xfer_send_header;
 107         uint16_t xfer_command;
 108         uint32_t xfer_transaction_id;
 109         int xfer_result;
 110 };
 111
 112 static struct usb_interface_descriptor mtp_interface_desc = {
 113         .bLength                = USB_DT_INTERFACE_SIZE,
 114         .bDescriptorType        = USB_DT_INTERFACE,
 115         .bInterfaceNumber       = 0,
 116         .bNumEndpoints          = 3,
 117         .bInterfaceClass        = USB_CLASS_VENDOR_SPEC,
 118         .bInterfaceSubClass     = USB_SUBCLASS_VENDOR_SPEC,
 119         .bInterfaceProtocol     = 0,
 120 };
 121
 122 static struct usb_interface_descriptor ptp_interface_desc = {
 123         .bLength                = USB_DT_INTERFACE_SIZE,
 124         .bDescriptorType        = USB_DT_INTERFACE,
 125         .bInterfaceNumber       = 0,
 126         .bNumEndpoints          = 3,
 127         .bInterfaceClass        = USB_CLASS_STILL_IMAGE,
 128         .bInterfaceSubClass     = 1,
 129         .bInterfaceProtocol     = 1,
 130 };
 131
 132 static struct usb_endpoint_descriptor mtp_highspeed_in_desc = {
 133         .bLength                = USB_DT_ENDPOINT_SIZE,
 134         .bDescriptorType        = USB_DT_ENDPOINT,
 135         .bEndpointAddress       = USB_DIR_IN,
 136         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 137         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 138 };
 139
 140 static struct usb_endpoint_descriptor mtp_highspeed_out_desc = {
 141         .bLength                = USB_DT_ENDPOINT_SIZE,
 142         .bDescriptorType        = USB_DT_ENDPOINT,
 143         .bEndpointAddress       = USB_DIR_OUT,
 144         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 145         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 146 };
 147
 148 static struct usb_endpoint_descriptor mtp_fullspeed_in_desc = {
 149         .bLength                = USB_DT_ENDPOINT_SIZE,
 150         .bDescriptorType        = USB_DT_ENDPOINT,
 151         .bEndpointAddress       = USB_DIR_IN,
 152         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 153 };
 154
 155 static struct usb_endpoint_descriptor mtp_fullspeed_out_desc = {
 156         .bLength                = USB_DT_ENDPOINT_SIZE,
 157         .bDescriptorType        = USB_DT_ENDPOINT,
 158         .bEndpointAddress       = USB_DIR_OUT,
 159         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 160 };
 161
 162 static struct usb_endpoint_descriptor mtp_intr_desc = {
 163         .bLength                = USB_DT_ENDPOINT_SIZE,
 164         .bDescriptorType        = USB_DT_ENDPOINT,
 165         .bEndpointAddress       = USB_DIR_IN,
 166         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 167         .wMaxPacketSize         = __constant_cpu_to_le16(INTR_BUFFER_SIZE),
 168         .bInterval              = 6,
 169 };
 170
 171 static struct usb_descriptor_header *fs_mtp_descs[] = {
 172         (struct usb_descriptor_header *) &mtp_interface_desc,
 173         (struct usb_descriptor_header *) &mtp_fullspeed_in_desc,
 174         (struct usb_descriptor_header *) &mtp_fullspeed_out_desc,
 175         (struct usb_descriptor_header *) &mtp_intr_desc,
 176         NULL,
 177 };
 178
 179 static struct usb_descriptor_header *hs_mtp_descs[] = {
 180         (struct usb_descriptor_header *) &mtp_interface_desc,
 181         (struct usb_descriptor_header *) &mtp_highspeed_in_desc,
 182         (struct usb_descriptor_header *) &mtp_highspeed_out_desc,
 183         (struct usb_descriptor_header *) &mtp_intr_desc,
 184         NULL,
 185 };
 186
 187 static struct usb_descriptor_header *fs_ptp_descs[] = {
 188         (struct usb_descriptor_header *) &ptp_interface_desc,
 189         (struct usb_descriptor_header *) &mtp_fullspeed_in_desc,
 190         (struct usb_descriptor_header *) &mtp_fullspeed_out_desc,
 191         (struct usb_descriptor_header *) &mtp_intr_desc,
 192         NULL,
 193 };
 194
 195 static struct usb_descriptor_header *hs_ptp_descs[] = {
 196         (struct usb_descriptor_header *) &ptp_interface_desc,
 197         (struct usb_descriptor_header *) &mtp_highspeed_in_desc,
 198         (struct usb_descriptor_header *) &mtp_highspeed_out_desc,
 199         (struct usb_descriptor_header *) &mtp_intr_desc,
 200         NULL,
 201 };
 202
 203 static struct usb_string mtp_string_defs[] = {
 204         /* Naming interface "MTP" so libmtp will recognize us */
 205         [INTERFACE_STRING_INDEX].s      = "MTP",
 206         {  },   /* end of list */
 207 };
 208
 209 static struct usb_gadget_strings mtp_string_table = {
 210         .language               = 0x0409,       /* en-US */
 211         .strings                = mtp_string_defs,
 212 };
 213
 214 static struct usb_gadget_strings *mtp_strings[] = {
 215         &mtp_string_table,
 216         NULL,
 217 };
 218
 219 /* Microsoft MTP OS String */
 220 static u8 mtp_os_string[] = {
 221         18, /* sizeof(mtp_os_string) */
 222         USB_DT_STRING,
 223         /* Signature field: "MSFT100" */
 224         'M', 0, 'S', 0, 'F', 0, 'T', 0, '1', 0, '0', 0, '0', 0,
 225         /* vendor code */
 226         1,
 227         /* padding */
 228         0
 229 };
 230
 231 /* Microsoft Extended Configuration Descriptor Header Section */
 232 struct mtp_ext_config_desc_header {
 233         __le32  dwLength;
 234         __u16   bcdVersion;
 235         __le16  wIndex;
 236         __u8    bCount;
 237         __u8    reserved[7];
 238 };
 239
 240 /* Microsoft Extended Configuration Descriptor Function Section */
 241 struct mtp_ext_config_desc_function {
 242         __u8    bFirstInterfaceNumber;
 243         __u8    bInterfaceCount;
 244         __u8    compatibleID[8];
 245         __u8    subCompatibleID[8];
 246         __u8    reserved[6];
 247 };
 248
 249 /* MTP Extended Configuration Descriptor */
 250 struct {
 251         struct mtp_ext_config_desc_header       header;
 252         struct mtp_ext_config_desc_function    function;
 253 } mtp_ext_config_desc = {
 254         .header = {
 255                 .dwLength = __constant_cpu_to_le32(sizeof(mtp_ext_config_desc)),
 256                 .bcdVersion = __constant_cpu_to_le16(0x0100),
 257                 .wIndex = __constant_cpu_to_le16(4),
 258                 .bCount = __constant_cpu_to_le16(1),
 259         },
 260         .function = {
 261                 .bFirstInterfaceNumber = 0,
 262                 .bInterfaceCount = 1,
 263                 .compatibleID = { 'M', 'T', 'P' },
 264         },
 265 };
 266
 267 struct mtp_device_status {
 268         __le16  wLength;
 269         __le16  wCode;
 270 };
 271
 272 struct mtp_data_header {
 273         /* length of packet, including this header */
 274         __le32  length;
 275         /* container type (2 for data packet) */
 276         __le16  type;
 277         /* MTP command code */
 278         __le16  command;
 279         /* MTP transaction ID */
 280         __le32  transaction_id;
 281 };
 282
 283 /* temporary variable used between mtp_open() and mtp_gadget_bind() */
 284 static struct mtp_dev *_mtp_dev;
 285
 286 static inline struct mtp_dev *func_to_mtp(struct usb_function *f)
 287 {
 288         return container_of(f, struct mtp_dev, function);
 289 }
 290
 291 static struct usb_request *mtp_request_new(struct usb_ep *ep, int buffer_size)
 292 {
 293         struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
 294         if (!req)
 295                 return NULL;
 296
 297         /* now allocate buffers for the requests */
 298         req->buf = kmalloc(buffer_size, GFP_KERNEL);
 299         if (!req->buf) {
 300                 usb_ep_free_request(ep, req);
 301                 return NULL;
 302         }
 303
 304         return req;
 305 }
 306
 307 static void mtp_request_free(struct usb_request *req, struct usb_ep *ep)
 308 {
 309         if (req) {
 310                 kfree(req->buf);
 311                 usb_ep_free_request(ep, req);
 312         }
 313 }
 314
 315 static inline int mtp_lock(atomic_t *excl)
 316 {
 317         if (atomic_inc_return(excl) == 1) {
 318                 return 0;
 319         } else {
 320                 atomic_dec(excl);
 321                 return -1;
 322         }
 323 }
 324
 325 static inline void mtp_unlock(atomic_t *excl)
 326 {
 327         atomic_dec(excl);
 328 }
 329
 330 /* add a request to the tail of a list */
 331 static void mtp_req_put(struct mtp_dev *dev, struct list_head *head,
 332                 struct usb_request *req)
 333 {
 334         unsigned long flags;
 335
 336         spin_lock_irqsave(&dev->lock, flags);
 337         list_add_tail(&req->list, head);
 338         spin_unlock_irqrestore(&dev->lock, flags);
 339 }
 340
 341 /* remove a request from the head of a list */
 342 static struct usb_request
 343 *mtp_req_get(struct mtp_dev *dev, struct list_head *head)
 344 {
 345         unsigned long flags;
 346         struct usb_request *req;
 347
 348         spin_lock_irqsave(&dev->lock, flags);
 349         if (list_empty(head)) {
 350                 req = 0;
 351         } else {
 352                 req = list_first_entry(head, struct usb_request, list);
 353                 list_del(&req->list);
 354         }
 355         spin_unlock_irqrestore(&dev->lock, flags);
 356         return req;
 357 }
 358
 359 static void mtp_complete_in(struct usb_ep *ep, struct usb_request *req)
 360 {
 361         struct mtp_dev *dev = _mtp_dev;
 362
 363         if (req->status != 0)
 364                 dev->state = STATE_ERROR;
 365
 366         mtp_req_put(dev, &dev->tx_idle, req);
 367
 368         wake_up(&dev->write_wq);
 369 }
 370
 371 static void mtp_complete_out(struct usb_ep *ep, struct usb_request *req)
 372 {
 373         struct mtp_dev *dev = _mtp_dev;
 374
 375         dev->rx_done = 1;
 376         if (req->status != 0)
 377                 dev->state = STATE_ERROR;
 378
 379         wake_up(&dev->read_wq);
 380 }
 381
 382 static void mtp_complete_intr(struct usb_ep *ep, struct usb_request *req)
 383 {
 384         struct mtp_dev *dev = _mtp_dev;
 385
 386         if (req->status != 0)
 387                 dev->state = STATE_ERROR;
 388
 389         mtp_req_put(dev, &dev->intr_idle, req);
 390
 391         wake_up(&dev->intr_wq);
 392 }
 393
 394 static int mtp_create_bulk_endpoints(struct mtp_dev *dev,
 395                                 struct usb_endpoint_descriptor *in_desc,
 396                                 struct usb_endpoint_descriptor *out_desc,
 397                                 struct usb_endpoint_descriptor *intr_desc)
 398 {
 399         struct usb_composite_dev *cdev = dev->cdev;
 400         struct usb_request *req;
 401         struct usb_ep *ep;
 402         int i;
 403
 404         DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
 405
 406         ep = usb_ep_autoconfig(cdev->gadget, in_desc);
 407         if (!ep) {
 408                 DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
 409                 return -ENODEV;
 410         }
 411         DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
 412         ep->driver_data = dev;          /* claim the endpoint */
 413         dev->ep_in = ep;
 414
 415         ep = usb_ep_autoconfig(cdev->gadget, out_desc);
 416         if (!ep) {
 417                 DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
 418                 return -ENODEV;
 419         }
 420         DBG(cdev, "usb_ep_autoconfig for mtp ep_out got %s\n", ep->name);
 421         ep->driver_data = dev;          /* claim the endpoint */
 422         dev->ep_out = ep;
 423
 424         ep = usb_ep_autoconfig(cdev->gadget, intr_desc);
 425         if (!ep) {
 426                 DBG(cdev, "usb_ep_autoconfig for ep_intr failed\n");
 427                 return -ENODEV;
 428         }
 429         DBG(cdev, "usb_ep_autoconfig for mtp ep_intr got %s\n", ep->name);
 430         ep->driver_data = dev;          /* claim the endpoint */
 431         dev->ep_intr = ep;
 432
 433         /* now allocate requests for our endpoints */
 434         for (i = 0; i < TX_REQ_MAX; i++) {
 435                 req = mtp_request_new(dev->ep_in, MTP_BULK_BUFFER_SIZE);
 436                 if (!req)
 437                         goto fail;
 438                 req->complete = mtp_complete_in;
 439                 mtp_req_put(dev, &dev->tx_idle, req);
 440         }
 441         for (i = 0; i < RX_REQ_MAX; i++) {
 442                 req = mtp_request_new(dev->ep_out, MTP_BULK_BUFFER_SIZE);
 443                 if (!req)
 444                         goto fail;
 445                 req->complete = mtp_complete_out;
 446                 dev->rx_req[i] = req;
 447         }
 448         for (i = 0; i < INTR_REQ_MAX; i++) {
 449                 req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
 450                 if (!req)
 451                         goto fail;
 452                 req->complete = mtp_complete_intr;
 453                 mtp_req_put(dev, &dev->intr_idle, req);
 454         }
 455
 456         return 0;
 457
 458 fail:
 459         printk(KERN_ERR "mtp_bind() could not allocate requests\n");
 460         return -1;
 461 }
 462
 463 static ssize_t mtp_read(struct file *fp, char __user *buf,
 464         size_t count, loff_t *pos)
 465 {
 466         struct mtp_dev *dev = fp->private_data;
 467         struct usb_composite_dev *cdev = dev->cdev;
 468         struct usb_request *req;
 469         int r = count, xfer;
 470         int ret = 0;
 471
 472         DBG(cdev, "mtp_read(%d)\n", count);
 473
 474         if (count > MTP_BULK_BUFFER_SIZE)
 475                 return -EINVAL;
 476
 477         /* we will block until we're online */
 478         DBG(cdev, "mtp_read: waiting for online state\n");
 479         ret = wait_event_interruptible(dev->read_wq,
 480                 dev->state != STATE_OFFLINE);
 481         if (ret < 0) {
 482                 r = ret;
 483                 goto done;
 484         }
 485         spin_lock_irq(&dev->lock);
 486         if (dev->state == STATE_CANCELED) {
 487                 /* report cancelation to userspace */
 488                 dev->state = STATE_READY;
 489                 spin_unlock_irq(&dev->lock);
 490                 return -ECANCELED;
 491         }
 492         dev->state = STATE_BUSY;
 493         spin_unlock_irq(&dev->lock);
 494
 495 requeue_req:
 496         /* queue a request */
 497         req = dev->rx_req[0];
 498         req->length = count;
 499         dev->rx_done = 0;
 500         ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
 501         if (ret < 0) {
 502                 r = -EIO;
 503                 goto done;
 504         } else {
 505                 DBG(cdev, "rx %p queue\n", req);
 506         }
 507
 508         /* wait for a request to complete */
 509         ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
 510         if (ret < 0) {
 511                 r = ret;
 512                 usb_ep_dequeue(dev->ep_out, req);
 513                 goto done;
 514         }
 515         if (dev->state == STATE_BUSY) {
 516                 /* If we got a 0-len packet, throw it back and try again. */
 517                 if (req->actual == 0)
 518                         goto requeue_req;
 519
 520                 DBG(cdev, "rx %p %d\n", req, req->actual);
 521                 xfer = (req->actual < count) ? req->actual : count;
 522                 r = xfer;
 523                 if (copy_to_user(buf, req->buf, xfer))
 524                         r = -EFAULT;
 525         } else
 526                 r = -EIO;
 527
 528 done:
 529         spin_lock_irq(&dev->lock);
 530         if (dev->state == STATE_CANCELED)
 531                 r = -ECANCELED;
 532         else if (dev->state != STATE_OFFLINE)
 533                 dev->state = STATE_READY;
 534         spin_unlock_irq(&dev->lock);
 535
 536         DBG(cdev, "mtp_read returning %d\n", r);
 537         return r;
 538 }
 539
 540 static ssize_t mtp_write(struct file *fp, const char __user *buf,
 541         size_t count, loff_t *pos)
 542 {
 543         struct mtp_dev *dev = fp->private_data;
 544         struct usb_composite_dev *cdev = dev->cdev;
 545         struct usb_request *req = 0;
 546         int r = count, xfer;
 547         int sendZLP = 0;
 548         int ret;
 549
 550         DBG(cdev, "mtp_write(%d)\n", count);
 551
 552         spin_lock_irq(&dev->lock);
 553         if (dev->state == STATE_CANCELED) {
 554                 /* report cancelation to userspace */
 555                 dev->state = STATE_READY;
 556                 spin_unlock_irq(&dev->lock);
 557                 return -ECANCELED;
 558         }
 559         if (dev->state == STATE_OFFLINE) {
 560                 spin_unlock_irq(&dev->lock);
 561                 return -ENODEV;
 562         }
 563         dev->state = STATE_BUSY;
 564         spin_unlock_irq(&dev->lock);
 565
 566         /* we need to send a zero length packet to signal the end of transfer
 567          * if the transfer size is aligned to a packet boundary.
 568          */
 569         if ((count & (dev->ep_in->maxpacket - 1)) == 0)
 570                 sendZLP = 1;
 571
 572         while (count > 0 || sendZLP) {
 573                 /* so we exit after sending ZLP */
 574                 if (count == 0)
 575                         sendZLP = 0;
 576
 577                 if (dev->state != STATE_BUSY) {
 578                         DBG(cdev, "mtp_write dev->error\n");
 579                         r = -EIO;
 580                         break;
 581                 }
 582
 583                 /* get an idle tx request to use */
 584                 req = 0;
 585                 ret = wait_event_interruptible(dev->write_wq,
 586                         ((req = mtp_req_get(dev, &dev->tx_idle))
 587                                 || dev->state != STATE_BUSY));
 588                 if (!req) {
 589                         r = ret;
 590                         break;
 591                 }
 592
 593                 if (count > MTP_BULK_BUFFER_SIZE)
 594                         xfer = MTP_BULK_BUFFER_SIZE;
 595                 else
 596                         xfer = count;
 597                 if (xfer && copy_from_user(req->buf, buf, xfer)) {
 598                         r = -EFAULT;
 599                         break;
 600                 }
 601
 602                 req->length = xfer;
 603                 ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
 604                 if (ret < 0) {
 605                         DBG(cdev, "mtp_write: xfer error %d\n", ret);
 606                         r = -EIO;
 607                         break;
 608                 }
 609
 610                 buf += xfer;
 611                 count -= xfer;
 612
 613                 /* zero this so we don't try to free it on error exit */
 614                 req = 0;
 615         }
 616
 617         if (req)
 618                 mtp_req_put(dev, &dev->tx_idle, req);
 619
 620         spin_lock_irq(&dev->lock);
 621         if (dev->state == STATE_CANCELED)
 622                 r = -ECANCELED;
 623         else if (dev->state != STATE_OFFLINE)
 624                 dev->state = STATE_READY;
 625         spin_unlock_irq(&dev->lock);
 626
 627         DBG(cdev, "mtp_write returning %d\n", r);
 628         return r;
 629 }
 630
 631 /* read from a local file and write to USB */
 632 static void send_file_work(struct work_struct *data)
 633 {
 634         struct mtp_dev *dev = container_of(data, struct mtp_dev,
 635                                                 send_file_work);
 636         struct usb_composite_dev *cdev = dev->cdev;
 637         struct usb_request *req = 0;
 638         struct mtp_data_header *header;
 639         struct file *filp;
 640         loff_t offset;
 641         int64_t count;
 642         int xfer, ret, hdr_size;
 643         int r = 0;
 644         int sendZLP = 0;
 645
 646         /* read our parameters */
 647         smp_rmb();
 648         filp = dev->xfer_file;
 649         offset = dev->xfer_file_offset;
 650         count = dev->xfer_file_length;
 651
 652         DBG(cdev, "send_file_work(%lld %lld)\n", offset, count);
 653
 654         if (dev->xfer_send_header) {
 655                 hdr_size = sizeof(struct mtp_data_header);
 656                 count += hdr_size;
 657         } else {
 658                 hdr_size = 0;
 659         }
 660
 661         /* we need to send a zero length packet to signal the end of transfer
 662          * if the transfer size is aligned to a packet boundary.
 663          */
 664         if ((count & (dev->ep_in->maxpacket - 1)) == 0)
 665                 sendZLP = 1;
 666
 667         while (count > 0 || sendZLP) {
 668                 /* so we exit after sending ZLP */
 669                 if (count == 0)
 670                         sendZLP = 0;
 671
 672                 /* get an idle tx request to use */
 673                 req = 0;
 674                 ret = wait_event_interruptible(dev->write_wq,
 675                         (req = mtp_req_get(dev, &dev->tx_idle))
 676                         || dev->state != STATE_BUSY);
 677                 if (dev->state == STATE_CANCELED) {
 678                         r = -ECANCELED;
 679                         break;
 680                 }
 681                 if (!req) {
 682                         r = ret;
 683                         break;
 684                 }
 685
 686                 if (count > MTP_BULK_BUFFER_SIZE)
 687                         xfer = MTP_BULK_BUFFER_SIZE;
 688                 else
 689                         xfer = count;
 690
 691                 if (hdr_size) {
 692                         /* prepend MTP data header */
 693                         header = (struct mtp_data_header *)req->buf;
 694                         header->length = __cpu_to_le32(count);
 695                         header->type = __cpu_to_le16(2); /* data packet */
 696                         header->command = __cpu_to_le16(dev->xfer_command);
 697                         header->transaction_id =
 698                                         __cpu_to_le32(dev->xfer_transaction_id);
 699                 }
 700
 701                 ret = vfs_read(filp, req->buf + hdr_size, xfer - hdr_size,
 702                                                                 &offset);
 703                 if (ret < 0) {
 704                         r = ret;
 705                         break;
 706                 }
 707                 xfer = ret + hdr_size;
 708                 hdr_size = 0;
 709
 710                 req->length = xfer;
 711                 ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
 712                 if (ret < 0) {
 713                         DBG(cdev, "send_file_work: xfer error %d\n", ret);
 714                         dev->state = STATE_ERROR;
 715                         r = -EIO;
 716                         break;
 717                 }
 718
 719                 count -= xfer;
 720
 721                 /* zero this so we don't try to free it on error exit */
 722                 req = 0;
 723         }
 724
 725         if (req)
 726                 mtp_req_put(dev, &dev->tx_idle, req);
 727
 728         DBG(cdev, "send_file_work returning %d\n", r);
 729         /* write the result */
 730         dev->xfer_result = r;
 731         smp_wmb();
 732 }
 733
 734 /* read from USB and write to a local file */
 735 static void receive_file_work(struct work_struct *data)
 736 {
 737         struct mtp_dev *dev = container_of(data, struct mtp_dev,
 738                                                 receive_file_work);
 739         struct usb_composite_dev *cdev = dev->cdev;
 740         struct usb_request *read_req = NULL, *write_req = NULL;
 741         struct file *filp;
 742         loff_t offset;
 743         int64_t count;
 744         int ret, cur_buf = 0;
 745         int r = 0;
 746
 747         /* read our parameters */
 748         smp_rmb();
 749         filp = dev->xfer_file;
 750         offset = dev->xfer_file_offset;
 751         count = dev->xfer_file_length;
 752
 753         DBG(cdev, "receive_file_work(%lld)\n", count);
 754
 755         while (count > 0 || write_req) {
 756                 if (count > 0) {
 757                         /* queue a request */
 758                         read_req = dev->rx_req[cur_buf];
 759                         cur_buf = (cur_buf + 1) % RX_REQ_MAX;
 760
 761                         read_req->length = (count > MTP_BULK_BUFFER_SIZE
 762                                         ? MTP_BULK_BUFFER_SIZE : count);
 763                         dev->rx_done = 0;
 764                         ret = usb_ep_queue(dev->ep_out, read_req, GFP_KERNEL);
 765                         if (ret < 0) {
 766                                 r = -EIO;
 767                                 dev->state = STATE_ERROR;
 768                                 break;
 769                         }
 770                 }
 771
 772                 if (write_req) {
 773                         DBG(cdev, "rx %p %d\n", write_req, write_req->actual);
 774                         ret = vfs_write(filp, write_req->buf, write_req->actual,
 775                                 &offset);
 776                         DBG(cdev, "vfs_write %d\n", ret);
 777                         if (ret != write_req->actual) {
 778                                 r = -EIO;
 779                                 dev->state = STATE_ERROR;
 780                                 break;
 781                         }
 782                         write_req = NULL;
 783                 }
 784
 785                 if (read_req) {
 786                         /* wait for our last read to complete */
 787                         ret = wait_event_interruptible(dev->read_wq,
 788                                 dev->rx_done || dev->state != STATE_BUSY);
 789                         if (dev->state == STATE_CANCELED) {
 790                                 r = -ECANCELED;
 791                                 if (!dev->rx_done)
 792                                         usb_ep_dequeue(dev->ep_out, read_req);
 793                                 break;
 794                         }
 795                         /* if xfer_file_length is 0xFFFFFFFF, then we read until
 796                          * we get a zero length packet
 797                          */
 798                         if (count != 0xFFFFFFFF)
 799                                 count -= read_req->actual;
 800                         if (read_req->actual < read_req->length) {
 801                                 /*
 802                                  * short packet is used to signal EOF for
 803                                  * sizes > 4 gig
 804                                  */
 805                                 DBG(cdev, "got short packet\n");
 806                                 count = 0;
 807                         }
 808
 809                         write_req = read_req;
 810                         read_req = NULL;
 811                 }
 812         }
 813
 814         DBG(cdev, "receive_file_work returning %d\n", r);
 815         /* write the result */
 816         dev->xfer_result = r;
 817         smp_wmb();
 818 }
 819
 820 static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
 821 {
 822         struct usb_request *req = NULL;
 823         int ret;
 824         int length = event->length;
 825
 826         DBG(dev->cdev, "mtp_send_event(%d)\n", event->length);
 827
 828         if (length < 0 || length > INTR_BUFFER_SIZE)
 829                 return -EINVAL;
 830         if (dev->state == STATE_OFFLINE)
 831                 return -ENODEV;
 832
 833         ret = wait_event_interruptible_timeout(dev->intr_wq,
 834                         (req = mtp_req_get(dev, &dev->intr_idle)),
 835                         msecs_to_jiffies(1000));
 836         if (!req)
 837                 return -ETIME;
 838
 839         if (copy_from_user(req->buf, (void __user *)event->data, length)) {
 840                 mtp_req_put(dev, &dev->intr_idle, req);
 841                 return -EFAULT;
 842         }
 843         req->length = length;
 844         ret = usb_ep_queue(dev->ep_intr, req, GFP_KERNEL);
 845         if (ret)
 846                 mtp_req_put(dev, &dev->intr_idle, req);
 847
 848         return ret;
 849 }
 850
 851 static long mtp_ioctl(struct file *fp, unsigned code, unsigned long value)
 852 {
 853         struct mtp_dev *dev = fp->private_data;
 854         struct file *filp = NULL;
 855         int ret = -EINVAL;
 856
 857         if (mtp_lock(&dev->ioctl_excl))
 858                 return -EBUSY;
 859
 860         switch (code) {
 861         case MTP_SEND_FILE:
 862         case MTP_RECEIVE_FILE:
 863         case MTP_SEND_FILE_WITH_HEADER:
 864         {
 865                 struct mtp_file_range   mfr;
 866                 struct work_struct *work;
 867
 868                 spin_lock_irq(&dev->lock);
 869                 if (dev->state == STATE_CANCELED) {
 870                         /* report cancelation to userspace */
 871                         dev->state = STATE_READY;
 872                         spin_unlock_irq(&dev->lock);
 873                         ret = -ECANCELED;
 874                         goto out;
 875                 }
 876                 if (dev->state == STATE_OFFLINE) {
 877                         spin_unlock_irq(&dev->lock);
 878                         ret = -ENODEV;
 879                         goto out;
 880                 }
 881                 dev->state = STATE_BUSY;
 882                 spin_unlock_irq(&dev->lock);
 883
 884                 if (copy_from_user(&mfr, (void __user *)value, sizeof(mfr))) {
 885                         ret = -EFAULT;
 886                         goto fail;
 887                 }
 888                 /* hold a reference to the file while we are working with it */
 889                 filp = fget(mfr.fd);
 890                 if (!filp) {
 891                         ret = -EBADF;
 892                         goto fail;
 893                 }
 894
 895                 /* write the parameters */
 896                 dev->xfer_file = filp;
 897                 dev->xfer_file_offset = mfr.offset;
 898                 dev->xfer_file_length = mfr.length;
 899                 smp_wmb();
 900
 901                 if (code == MTP_SEND_FILE_WITH_HEADER) {
 902                         work = &dev->send_file_work;
 903                         dev->xfer_send_header = 1;
 904                         dev->xfer_command = mfr.command;
 905                         dev->xfer_transaction_id = mfr.transaction_id;
 906                 } else if (code == MTP_SEND_FILE) {
 907                         work = &dev->send_file_work;
 908                         dev->xfer_send_header = 0;
 909                 } else {
 910                         work = &dev->receive_file_work;
 911                 }
 912
 913                 /* We do the file transfer on a work queue so it will run
 914                  * in kernel context, which is necessary for vfs_read and
 915                  * vfs_write to use our buffers in the kernel address space.
 916                  */
 917                 queue_work(dev->wq, work);
 918                 /* wait for operation to complete */
 919                 flush_workqueue(dev->wq);
 920                 fput(filp);
 921
 922                 /* read the result */
 923                 smp_rmb();
 924                 ret = dev->xfer_result;
 925                 break;
 926         }
 927         case MTP_SEND_EVENT:
 928         {
 929                 struct mtp_event        event;
 930                 /* return here so we don't change dev->state below,
 931                  * which would interfere with bulk transfer state.
 932                  */
 933                 if (copy_from_user(&event, (void __user *)value, sizeof(event)))
 934                         ret = -EFAULT;
 935                 else
 936                         ret = mtp_send_event(dev, &event);
 937                 goto out;
 938         }
 939         }
 940
 941 fail:
 942         spin_lock_irq(&dev->lock);
 943         if (dev->state == STATE_CANCELED)
 944                 ret = -ECANCELED;
 945         else if (dev->state != STATE_OFFLINE)
 946                 dev->state = STATE_READY;
 947         spin_unlock_irq(&dev->lock);
 948 out:
 949         mtp_unlock(&dev->ioctl_excl);
 950         DBG(dev->cdev, "ioctl returning %d\n", ret);
 951         return ret;
 952 }
 953
 954 static int mtp_open(struct inode *ip, struct file *fp)
 955 {
 956         printk(KERN_INFO "mtp_open\n");
 957         if (mtp_lock(&_mtp_dev->open_excl))
 958                 return -EBUSY;
 959
 960         /* clear any error condition */
 961         if (_mtp_dev->state != STATE_OFFLINE)
 962                 _mtp_dev->state = STATE_READY;
 963
 964         fp->private_data = _mtp_dev;
 965         return 0;
 966 }
 967
 968 static int mtp_release(struct inode *ip, struct file *fp)
 969 {
 970         printk(KERN_INFO "mtp_release\n");
 971
 972         mtp_unlock(&_mtp_dev->open_excl);
 973         return 0;
 974 }
 975
 976 /* file operations for /dev/mtp_usb */
 977 static const struct file_operations mtp_fops = {
 978         .owner = THIS_MODULE,
 979         .read = mtp_read,
 980         .write = mtp_write,
 981         .unlocked_ioctl = mtp_ioctl,
 982         .open = mtp_open,
 983         .release = mtp_release,
 984 };
 985
 986 static struct miscdevice mtp_device = {
 987         .minor = MISC_DYNAMIC_MINOR,
 988         .name = mtp_shortname,
 989         .fops = &mtp_fops,
 990 };
 991
 992 static int mtp_ctrlrequest(struct usb_composite_dev *cdev,
 993                                 const struct usb_ctrlrequest *ctrl)
 994 {
 995         struct mtp_dev *dev = _mtp_dev;
 996         int     value = -EOPNOTSUPP;
 997         u16     w_index = le16_to_cpu(ctrl->wIndex);
 998         u16     w_value = le16_to_cpu(ctrl->wValue);
 999         u16     w_length = le16_to_cpu(ctrl->wLength);
1000         unsigned long   flags;
1001
1002         VDBG(cdev, "mtp_ctrlrequest "
1003                         "%02x.%02x v%04x i%04x l%u\n",
1004                         ctrl->bRequestType, ctrl->bRequest,
1005                         w_value, w_index, w_length);
1006
1007         /* Handle MTP OS string */
1008         if (ctrl->bRequestType ==
1009                         (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE)
1010                         && ctrl->bRequest == USB_REQ_GET_DESCRIPTOR
1011                         && (w_value >> 8) == USB_DT_STRING
1012                         && (w_value & 0xFF) == MTP_OS_STRING_ID) {
1013                 value = (w_length < sizeof(mtp_os_string)
1014                                 ? w_length : sizeof(mtp_os_string));
1015                 memcpy(cdev->req->buf, mtp_os_string, value);
1016         } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
1017                 /* Handle MTP OS descriptor */
1018                 DBG(cdev, "vendor request: %d index: %d value: %d length: %d\n",
1019                         ctrl->bRequest, w_index, w_value, w_length);
1020
1021                 if (ctrl->bRequest == 1
1022                                 && (ctrl->bRequestType & USB_DIR_IN)
1023                                 && (w_index == 4 || w_index == 5)) {
1024                         value = (w_length < sizeof(mtp_ext_config_desc) ?
1025                                         w_length : sizeof(mtp_ext_config_desc));
1026                         memcpy(cdev->req->buf, &mtp_ext_config_desc, value);
1027                 }
1028         } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
1029                 DBG(cdev, "class request: %d index: %d value: %d length: %d\n",
1030                         ctrl->bRequest, w_index, w_value, w_length);
1031
1032                 if (ctrl->bRequest == MTP_REQ_CANCEL && w_index == 0
1033                                 && w_value == 0) {
1034                         DBG(cdev, "MTP_REQ_CANCEL\n");
1035
1036                         spin_lock_irqsave(&dev->lock, flags);
1037                         if (dev->state == STATE_BUSY) {
1038                                 dev->state = STATE_CANCELED;
1039                                 wake_up(&dev->read_wq);
1040                                 wake_up(&dev->write_wq);
1041                         }
1042                         spin_unlock_irqrestore(&dev->lock, flags);
1043
1044                         /* We need to queue a request to read the remaining
1045                          *  bytes, but we don't actually need to look at
1046                          * the contents.
1047                          */
1048                         value = w_length;
1049                 } else if (ctrl->bRequest == MTP_REQ_GET_DEVICE_STATUS
1050                                 && w_index == 0 && w_value == 0) {
1051                         struct mtp_device_status *status = cdev->req->buf;
1052                         status->wLength =
1053                                 __constant_cpu_to_le16(sizeof(*status));
1054
1055                         DBG(cdev, "MTP_REQ_GET_DEVICE_STATUS\n");
1056                         spin_lock_irqsave(&dev->lock, flags);
1057                         /* device status is "busy" until we report
1058                          * the cancelation to userspace
1059                          */
1060                         if (dev->state == STATE_CANCELED)
1061                                 status->wCode =
1062                                         __cpu_to_le16(MTP_RESPONSE_DEVICE_BUSY);
1063                         else
1064                                 status->wCode =
1065                                         __cpu_to_le16(MTP_RESPONSE_OK);
1066                         spin_unlock_irqrestore(&dev->lock, flags);
1067                         value = sizeof(*status);
1068                 }
1069         }
1070
1071         /* respond with data transfer or status phase? */
1072         if (value >= 0) {
1073                 int rc;
1074                 cdev->req->zero = value < w_length;
1075                 cdev->req->length = value;
1076                 rc = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
1077                 if (rc < 0)
1078                         ERROR(cdev, "%s: response queue error\n", __func__);
1079         }
1080         return value;
1081 }
1082
1083 static int
1084 mtp_function_bind(struct usb_configuration *c, struct usb_function *f)
1085 {
1086         struct usb_composite_dev *cdev = c->cdev;
1087         struct mtp_dev  *dev = func_to_mtp(f);
1088         int                     id;
1089         int                     ret;
1090
1091         dev->cdev = cdev;
1092         DBG(cdev, "mtp_function_bind dev: %p\n", dev);
1093
1094         /* allocate interface ID(s) */
1095         id = usb_interface_id(c, f);
1096         if (id < 0)
1097                 return id;
1098         mtp_interface_desc.bInterfaceNumber = id;
1099
1100         /* allocate endpoints */
1101         ret = mtp_create_bulk_endpoints(dev, &mtp_fullspeed_in_desc,
1102                         &mtp_fullspeed_out_desc, &mtp_intr_desc);
1103         if (ret)
1104                 return ret;
1105
1106         /* support high speed hardware */
1107         if (gadget_is_dualspeed(c->cdev->gadget)) {
1108                 mtp_highspeed_in_desc.bEndpointAddress =
1109                         mtp_fullspeed_in_desc.bEndpointAddress;
1110                 mtp_highspeed_out_desc.bEndpointAddress =
1111                         mtp_fullspeed_out_desc.bEndpointAddress;
1112         }
1113
1114         DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
1115                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1116                         f->name, dev->ep_in->name, dev->ep_out->name);
1117         return 0;
1118 }
1119
1120 static void
1121 mtp_function_unbind(struct usb_configuration *c, struct usb_function *f)
1122 {
1123         struct mtp_dev  *dev = func_to_mtp(f);
1124         struct usb_request *req;
1125         int i;
1126
1127         while ((req = mtp_req_get(dev, &dev->tx_idle)))
1128                 mtp_request_free(req, dev->ep_in);
1129         for (i = 0; i < RX_REQ_MAX; i++)
1130                 mtp_request_free(dev->rx_req[i], dev->ep_out);
1131         while ((req = mtp_req_get(dev, &dev->intr_idle)))
1132                 mtp_request_free(req, dev->ep_intr);
1133         dev->state = STATE_OFFLINE;
1134 }
1135
1136 static int mtp_function_set_alt(struct usb_function *f,
1137                 unsigned intf, unsigned alt)
1138 {
1139         struct mtp_dev  *dev = func_to_mtp(f);
1140         struct usb_composite_dev *cdev = f->config->cdev;
1141         int ret;
1142
1143         DBG(cdev, "mtp_function_set_alt intf: %d alt: %d\n", intf, alt);
1144
1145         ret = config_ep_by_speed(cdev->gadget, f, dev->ep_in);
1146         if (ret)
1147                 return ret;
1148
1149         ret = usb_ep_enable(dev->ep_in);
1150         if (ret)
1151                 return ret;
1152
1153         ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
1154         if (ret)
1155                 return ret;
1156
1157         ret = usb_ep_enable(dev->ep_out);
1158         if (ret) {
1159                 usb_ep_disable(dev->ep_in);
1160                 return ret;
1161         }
1162
1163         ret = config_ep_by_speed(cdev->gadget, f, dev->ep_intr);
1164         if (ret)
1165                 return ret;
1166
1167         ret = usb_ep_enable(dev->ep_intr);
1168         if (ret) {
1169                 usb_ep_disable(dev->ep_out);
1170                 usb_ep_disable(dev->ep_in);
1171                 return ret;
1172         }
1173         dev->state = STATE_READY;
1174
1175         /* readers may be blocked waiting for us to go online */
1176         wake_up(&dev->read_wq);
1177         return 0;
1178 }
1179
1180 static void mtp_function_disable(struct usb_function *f)
1181 {
1182         struct mtp_dev  *dev = func_to_mtp(f);
1183         struct usb_composite_dev        *cdev = dev->cdev;
1184
1185         DBG(cdev, "mtp_function_disable\n");
1186         dev->state = STATE_OFFLINE;
1187         usb_ep_disable(dev->ep_in);
1188         usb_ep_disable(dev->ep_out);
1189         usb_ep_disable(dev->ep_intr);
1190
1191         /* readers may be blocked waiting for us to go online */
1192         wake_up(&dev->read_wq);
1193
1194         VDBG(cdev, "%s disabled\n", dev->function.name);
1195 }
1196
1197 static int mtp_bind_config(struct usb_configuration *c, bool ptp_config)
1198 {
1199         struct mtp_dev *dev = _mtp_dev;
1200         int ret = 0;
1201
1202         printk(KERN_INFO "mtp_bind_config\n");
1203
1204         /* allocate a string ID for our interface */
1205         if (mtp_string_defs[INTERFACE_STRING_INDEX].id == 0) {
1206                 ret = usb_string_id(c->cdev);
1207                 if (ret < 0)
1208                         return ret;
1209                 mtp_string_defs[INTERFACE_STRING_INDEX].id = ret;
1210                 mtp_interface_desc.iInterface = ret;
1211         }
1212
1213         dev->cdev = c->cdev;
1214         dev->function.name = "mtp";
1215         dev->function.strings = mtp_strings;
1216         if (ptp_config) {
1217                 dev->function.fs_descriptors = fs_ptp_descs;
1218                 dev->function.hs_descriptors = hs_ptp_descs;
1219         } else {
1220                 dev->function.fs_descriptors = fs_mtp_descs;
1221                 dev->function.hs_descriptors = hs_mtp_descs;
1222         }
1223         dev->function.bind = mtp_function_bind;
1224         dev->function.unbind = mtp_function_unbind;
1225         dev->function.set_alt = mtp_function_set_alt;
1226         dev->function.disable = mtp_function_disable;
1227
1228         return usb_add_function(c, &dev->function);
1229 }
1230
1231 static int mtp_setup(void)
1232 {
1233         struct mtp_dev *dev;
1234         int ret;
1235
1236         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1237         if (!dev)
1238                 return -ENOMEM;
1239
1240         spin_lock_init(&dev->lock);
1241         init_waitqueue_head(&dev->read_wq);
1242         init_waitqueue_head(&dev->write_wq);
1243         init_waitqueue_head(&dev->intr_wq);
1244         atomic_set(&dev->open_excl, 0);
1245         atomic_set(&dev->ioctl_excl, 0);
1246         INIT_LIST_HEAD(&dev->tx_idle);
1247         INIT_LIST_HEAD(&dev->intr_idle);
1248
1249         dev->wq = create_singlethread_workqueue("f_mtp");
1250         if (!dev->wq) {
1251                 ret = -ENOMEM;
1252                 goto err1;
1253         }
1254         INIT_WORK(&dev->send_file_work, send_file_work);
1255         INIT_WORK(&dev->receive_file_work, receive_file_work);
1256
1257         _mtp_dev = dev;
1258
1259         ret = misc_register(&mtp_device);
1260         if (ret)
1261                 goto err2;
1262
1263         return 0;
1264
1265 err2:
1266         destroy_workqueue(dev->wq);
1267 err1:
1268         _mtp_dev = NULL;
1269         kfree(dev);
1270         printk(KERN_ERR "mtp gadget driver failed to initialize\n");
1271         return ret;
1272 }
1273
1274 static void mtp_cleanup(void)
1275 {
1276         struct mtp_dev *dev = _mtp_dev;
1277
1278         if (!dev)
1279                 return;
1280
1281         misc_deregister(&mtp_device);
1282         destroy_workqueue(dev->wq);
1283         _mtp_dev = NULL;
1284         kfree(dev);
1285 }