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 /* temporary variable used between mtp_open() and mtp_gadget_bind() */
 273 static struct mtp_dev *_mtp_dev;
 274
 275 static inline struct mtp_dev *func_to_mtp(struct usb_function *f)
 276 {
 277         return container_of(f, struct mtp_dev, function);
 278 }
 279
 280 static struct usb_request *mtp_request_new(struct usb_ep *ep, int buffer_size)
 281 {
 282         struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
 283         if (!req)
 284                 return NULL;
 285
 286         /* now allocate buffers for the requests */
 287         req->buf = kmalloc(buffer_size, GFP_KERNEL);
 288         if (!req->buf) {
 289                 usb_ep_free_request(ep, req);
 290                 return NULL;
 291         }
 292
 293         return req;
 294 }
 295
 296 static void mtp_request_free(struct usb_request *req, struct usb_ep *ep)
 297 {
 298         if (req) {
 299                 kfree(req->buf);
 300                 usb_ep_free_request(ep, req);
 301         }
 302 }
 303
 304 static inline int mtp_lock(atomic_t *excl)
 305 {
 306         if (atomic_inc_return(excl) == 1) {
 307                 return 0;
 308         } else {
 309                 atomic_dec(excl);
 310                 return -1;
 311         }
 312 }
 313
 314 static inline void mtp_unlock(atomic_t *excl)
 315 {
 316         atomic_dec(excl);
 317 }
 318
 319 /* add a request to the tail of a list */
 320 static void mtp_req_put(struct mtp_dev *dev, struct list_head *head,
 321                 struct usb_request *req)
 322 {
 323         unsigned long flags;
 324
 325         spin_lock_irqsave(&dev->lock, flags);
 326         list_add_tail(&req->list, head);
 327         spin_unlock_irqrestore(&dev->lock, flags);
 328 }
 329
 330 /* remove a request from the head of a list */
 331 static struct usb_request
 332 *mtp_req_get(struct mtp_dev *dev, struct list_head *head)
 333 {
 334         unsigned long flags;
 335         struct usb_request *req;
 336
 337         spin_lock_irqsave(&dev->lock, flags);
 338         if (list_empty(head)) {
 339                 req = 0;
 340         } else {
 341                 req = list_first_entry(head, struct usb_request, list);
 342                 list_del(&req->list);
 343         }
 344         spin_unlock_irqrestore(&dev->lock, flags);
 345         return req;
 346 }
 347
 348 static void mtp_complete_in(struct usb_ep *ep, struct usb_request *req)
 349 {
 350         struct mtp_dev *dev = _mtp_dev;
 351
 352         if (req->status != 0)
 353                 dev->state = STATE_ERROR;
 354
 355         mtp_req_put(dev, &dev->tx_idle, req);
 356
 357         wake_up(&dev->write_wq);
 358 }
 359
 360 static void mtp_complete_out(struct usb_ep *ep, struct usb_request *req)
 361 {
 362         struct mtp_dev *dev = _mtp_dev;
 363
 364         dev->rx_done = 1;
 365         if (req->status != 0)
 366                 dev->state = STATE_ERROR;
 367
 368         wake_up(&dev->read_wq);
 369 }
 370
 371 static void mtp_complete_intr(struct usb_ep *ep, struct usb_request *req)
 372 {
 373         struct mtp_dev *dev = _mtp_dev;
 374
 375         if (req->status != 0)
 376                 dev->state = STATE_ERROR;
 377
 378         mtp_req_put(dev, &dev->intr_idle, req);
 379
 380         wake_up(&dev->intr_wq);
 381 }
 382
 383 static int mtp_create_bulk_endpoints(struct mtp_dev *dev,
 384                                 struct usb_endpoint_descriptor *in_desc,
 385                                 struct usb_endpoint_descriptor *out_desc,
 386                                 struct usb_endpoint_descriptor *intr_desc)
 387 {
 388         struct usb_composite_dev *cdev = dev->cdev;
 389         struct usb_request *req;
 390         struct usb_ep *ep;
 391         int i;
 392
 393         DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
 394
 395         ep = usb_ep_autoconfig(cdev->gadget, in_desc);
 396         if (!ep) {
 397                 DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
 398                 return -ENODEV;
 399         }
 400         DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
 401         ep->driver_data = dev;          /* claim the endpoint */
 402         dev->ep_in = ep;
 403
 404         ep = usb_ep_autoconfig(cdev->gadget, out_desc);
 405         if (!ep) {
 406                 DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
 407                 return -ENODEV;
 408         }
 409         DBG(cdev, "usb_ep_autoconfig for mtp ep_out got %s\n", ep->name);
 410         ep->driver_data = dev;          /* claim the endpoint */
 411         dev->ep_out = ep;
 412
 413         ep = usb_ep_autoconfig(cdev->gadget, out_desc);
 414         if (!ep) {
 415                 DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
 416                 return -ENODEV;
 417         }
 418         DBG(cdev, "usb_ep_autoconfig for mtp ep_out got %s\n", ep->name);
 419         ep->driver_data = dev;          /* claim the endpoint */
 420         dev->ep_out = ep;
 421
 422         ep = usb_ep_autoconfig(cdev->gadget, intr_desc);
 423         if (!ep) {
 424                 DBG(cdev, "usb_ep_autoconfig for ep_intr failed\n");
 425                 return -ENODEV;
 426         }
 427         DBG(cdev, "usb_ep_autoconfig for mtp ep_intr got %s\n", ep->name);
 428         ep->driver_data = dev;          /* claim the endpoint */
 429         dev->ep_intr = ep;
 430
 431         /* now allocate requests for our endpoints */
 432         for (i = 0; i < TX_REQ_MAX; i++) {
 433                 req = mtp_request_new(dev->ep_in, MTP_BULK_BUFFER_SIZE);
 434                 if (!req)
 435                         goto fail;
 436                 req->complete = mtp_complete_in;
 437                 mtp_req_put(dev, &dev->tx_idle, req);
 438         }
 439         for (i = 0; i < RX_REQ_MAX; i++) {
 440                 req = mtp_request_new(dev->ep_out, MTP_BULK_BUFFER_SIZE);
 441                 if (!req)
 442                         goto fail;
 443                 req->complete = mtp_complete_out;
 444                 dev->rx_req[i] = req;
 445         }
 446         for (i = 0; i < INTR_REQ_MAX; i++) {
 447                 req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
 448                 if (!req)
 449                         goto fail;
 450                 req->complete = mtp_complete_intr;
 451                 mtp_req_put(dev, &dev->intr_idle, req);
 452         }
 453
 454         return 0;
 455
 456 fail:
 457         printk(KERN_ERR "mtp_bind() could not allocate requests\n");
 458         return -1;
 459 }
 460
 461 static ssize_t mtp_read(struct file *fp, char __user *buf,
 462         size_t count, loff_t *pos)
 463 {
 464         struct mtp_dev *dev = fp->private_data;
 465         struct usb_composite_dev *cdev = dev->cdev;
 466         struct usb_request *req;
 467         int r = count, xfer;
 468         int ret = 0;
 469
 470         DBG(cdev, "mtp_read(%d)\n", count);
 471
 472         if (count > MTP_BULK_BUFFER_SIZE)
 473                 return -EINVAL;
 474
 475         /* we will block until we're online */
 476         DBG(cdev, "mtp_read: waiting for online state\n");
 477         ret = wait_event_interruptible(dev->read_wq,
 478                 dev->state != STATE_OFFLINE);
 479         if (ret < 0) {
 480                 r = ret;
 481                 goto done;
 482         }
 483         spin_lock_irq(&dev->lock);
 484         if (dev->state == STATE_CANCELED) {
 485                 /* report cancelation to userspace */
 486                 dev->state = STATE_READY;
 487                 spin_unlock_irq(&dev->lock);
 488                 return -ECANCELED;
 489         }
 490         dev->state = STATE_BUSY;
 491         spin_unlock_irq(&dev->lock);
 492
 493 requeue_req:
 494         /* queue a request */
 495         req = dev->rx_req[0];
 496         req->length = count;
 497         dev->rx_done = 0;
 498         ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
 499         if (ret < 0) {
 500                 r = -EIO;
 501                 goto done;
 502         } else {
 503                 DBG(cdev, "rx %p queue\n", req);
 504         }
 505
 506         /* wait for a request to complete */
 507         ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
 508         if (ret < 0) {
 509                 r = ret;
 510                 usb_ep_dequeue(dev->ep_out, req);
 511                 goto done;
 512         }
 513         if (dev->state == STATE_BUSY) {
 514                 /* If we got a 0-len packet, throw it back and try again. */
 515                 if (req->actual == 0)
 516                         goto requeue_req;
 517
 518                 DBG(cdev, "rx %p %d\n", req, req->actual);
 519                 xfer = (req->actual < count) ? req->actual : count;
 520                 r = xfer;
 521                 if (copy_to_user(buf, req->buf, xfer))
 522                         r = -EFAULT;
 523         } else
 524                 r = -EIO;
 525
 526 done:
 527         spin_lock_irq(&dev->lock);
 528         if (dev->state == STATE_CANCELED)
 529                 r = -ECANCELED;
 530         else if (dev->state != STATE_OFFLINE)
 531                 dev->state = STATE_READY;
 532         spin_unlock_irq(&dev->lock);
 533
 534         DBG(cdev, "mtp_read returning %d\n", r);
 535         return r;
 536 }
 537
 538 static ssize_t mtp_write(struct file *fp, const char __user *buf,
 539         size_t count, loff_t *pos)
 540 {
 541         struct mtp_dev *dev = fp->private_data;
 542         struct usb_composite_dev *cdev = dev->cdev;
 543         struct usb_request *req = 0;
 544         int r = count, xfer;
 545         int sendZLP = 0;
 546         int ret;
 547
 548         DBG(cdev, "mtp_write(%d)\n", count);
 549
 550         spin_lock_irq(&dev->lock);
 551         if (dev->state == STATE_CANCELED) {
 552                 /* report cancelation to userspace */
 553                 dev->state = STATE_READY;
 554                 spin_unlock_irq(&dev->lock);
 555                 return -ECANCELED;
 556         }
 557         if (dev->state == STATE_OFFLINE) {
 558                 spin_unlock_irq(&dev->lock);
 559                 return -ENODEV;
 560         }
 561         dev->state = STATE_BUSY;
 562         spin_unlock_irq(&dev->lock);
 563
 564         /* we need to send a zero length packet to signal the end of transfer
 565          * if the transfer size is aligned to a packet boundary.
 566          */
 567         if ((count & (dev->ep_in->maxpacket - 1)) == 0) {
 568                 sendZLP = 1;
 569         }
 570
 571         while (count > 0 || sendZLP) {
 572                 /* so we exit after sending ZLP */
 573                 if (count == 0)
 574                         sendZLP = 0;
 575
 576                 if (dev->state != STATE_BUSY) {
 577                         DBG(cdev, "mtp_write dev->error\n");
 578                         r = -EIO;
 579                         break;
 580                 }
 581
 582                 /* get an idle tx request to use */
 583                 req = 0;
 584                 ret = wait_event_interruptible(dev->write_wq,
 585                         ((req = mtp_req_get(dev, &dev->tx_idle))
 586                                 || dev->state != STATE_BUSY));
 587                 if (!req) {
 588                         r = ret;
 589                         break;
 590                 }
 591
 592                 if (count > MTP_BULK_BUFFER_SIZE)
 593                         xfer = MTP_BULK_BUFFER_SIZE;
 594                 else
 595                         xfer = count;
 596                 if (xfer && copy_from_user(req->buf, buf, xfer)) {
 597                         r = -EFAULT;
 598                         break;
 599                 }
 600
 601                 req->length = xfer;
 602                 ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
 603                 if (ret < 0) {
 604                         DBG(cdev, "mtp_write: xfer error %d\n", ret);
 605                         r = -EIO;
 606                         break;
 607                 }
 608
 609                 buf += xfer;
 610                 count -= xfer;
 611
 612                 /* zero this so we don't try to free it on error exit */
 613                 req = 0;
 614         }
 615
 616         if (req)
 617                 mtp_req_put(dev, &dev->tx_idle, req);
 618
 619         spin_lock_irq(&dev->lock);
 620         if (dev->state == STATE_CANCELED)
 621                 r = -ECANCELED;
 622         else if (dev->state != STATE_OFFLINE)
 623                 dev->state = STATE_READY;
 624         spin_unlock_irq(&dev->lock);
 625
 626         DBG(cdev, "mtp_write returning %d\n", r);
 627         return r;
 628 }
 629
 630 /* read from a local file and write to USB */
 631 static void send_file_work(struct work_struct *data) {
 632         struct mtp_dev  *dev = container_of(data, struct mtp_dev, send_file_work);
 633         struct usb_composite_dev *cdev = dev->cdev;
 634         struct usb_request *req = 0;
 635         struct mtp_data_header *header;
 636         struct file *filp;
 637         loff_t offset;
 638         int64_t count;
 639         int xfer, ret, hdr_size;
 640         int r = 0;
 641         int sendZLP = 0;
 642
 643         /* read our parameters */
 644         smp_rmb();
 645         filp = dev->xfer_file;
 646         offset = dev->xfer_file_offset;
 647         count = dev->xfer_file_length;
 648
 649         DBG(cdev, "send_file_work(%lld %lld)\n", offset, count);
 650
 651         if (dev->xfer_send_header) {
 652                 hdr_size = sizeof(struct mtp_data_header);
 653                 count += hdr_size;
 654         } else {
 655                 hdr_size = 0;
 656         }
 657
 658         /* we need to send a zero length packet to signal the end of transfer
 659          * if the transfer size is aligned to a packet boundary.
 660          */
 661         if ((count & (dev->ep_in->maxpacket - 1)) == 0) {
 662                 sendZLP = 1;
 663         }
 664
 665         while (count > 0 || sendZLP) {
 666                 /* so we exit after sending ZLP */
 667                 if (count == 0)
 668                         sendZLP = 0;
 669
 670                 /* get an idle tx request to use */
 671                 req = 0;
 672                 ret = wait_event_interruptible(dev->write_wq,
 673                         (req = mtp_req_get(dev, &dev->tx_idle))
 674                         || dev->state != STATE_BUSY);
 675                 if (dev->state == STATE_CANCELED) {
 676                         r = -ECANCELED;
 677                         break;
 678                 }
 679                 if (!req) {
 680                         r = ret;
 681                         break;
 682                 }
 683
 684                 if (count > MTP_BULK_BUFFER_SIZE)
 685                         xfer = MTP_BULK_BUFFER_SIZE;
 686                 else
 687                         xfer = count;
 688
 689                 if (hdr_size) {
 690                         /* prepend MTP data header */
 691                         header = (struct mtp_data_header *)req->buf;
 692                         header->length = __cpu_to_le32(count);
 693                         header->type = __cpu_to_le16(2); /* data packet */
 694                         header->command = __cpu_to_le16(dev->xfer_command);
 695                         header->transaction_id = __cpu_to_le32(dev->xfer_transaction_id);
 696                 }
 697
 698                 ret = vfs_read(filp, req->buf + hdr_size, xfer - hdr_size, &offset);
 699                 if (ret < 0) {
 700                         r = ret;
 701                         break;
 702                 }
 703                 xfer = ret + hdr_size;
 704                 hdr_size = 0;
 705
 706                 req->length = xfer;
 707                 ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
 708                 if (ret < 0) {
 709                         DBG(cdev, "send_file_work: xfer error %d\n", ret);
 710                         dev->state = STATE_ERROR;
 711                         r = -EIO;
 712                         break;
 713                 }
 714
 715                 count -= xfer;
 716
 717                 /* zero this so we don't try to free it on error exit */
 718                 req = 0;
 719         }
 720
 721         if (req)
 722                 mtp_req_put(dev, &dev->tx_idle, req);
 723
 724         DBG(cdev, "send_file_work returning %d\n", r);
 725         /* write the result */
 726         dev->xfer_result = r;
 727         smp_wmb();
 728 }
 729
 730 /* read from USB and write to a local file */
 731 static void receive_file_work(struct work_struct *data)
 732 {
 733         struct mtp_dev  *dev = container_of(data, struct mtp_dev, receive_file_work);
 734         struct usb_composite_dev *cdev = dev->cdev;
 735         struct usb_request *read_req = NULL, *write_req = NULL;
 736         struct file *filp;
 737         loff_t offset;
 738         int64_t count;
 739         int ret, cur_buf = 0;
 740         int r = 0;
 741
 742         /* read our parameters */
 743         smp_rmb();
 744         filp = dev->xfer_file;
 745         offset = dev->xfer_file_offset;
 746         count = dev->xfer_file_length;
 747
 748         DBG(cdev, "receive_file_work(%lld)\n", count);
 749
 750         while (count > 0 || write_req) {
 751                 if (count > 0) {
 752                         /* queue a request */
 753                         read_req = dev->rx_req[cur_buf];
 754                         cur_buf = (cur_buf + 1) % RX_REQ_MAX;
 755
 756                         read_req->length = (count > MTP_BULK_BUFFER_SIZE
 757                                         ? MTP_BULK_BUFFER_SIZE : count);
 758                         dev->rx_done = 0;
 759                         ret = usb_ep_queue(dev->ep_out, read_req, GFP_KERNEL);
 760                         if (ret < 0) {
 761                                 r = -EIO;
 762                                 dev->state = STATE_ERROR;
 763                                 break;
 764                         }
 765                 }
 766
 767                 if (write_req) {
 768                         DBG(cdev, "rx %p %d\n", write_req, write_req->actual);
 769                         ret = vfs_write(filp, write_req->buf, write_req->actual,
 770                                 &offset);
 771                         DBG(cdev, "vfs_write %d\n", ret);
 772                         if (ret != write_req->actual) {
 773                                 r = -EIO;
 774                                 dev->state = STATE_ERROR;
 775                                 break;
 776                         }
 777                         write_req = NULL;
 778                 }
 779
 780                 if (read_req) {
 781                         /* wait for our last read to complete */
 782                         ret = wait_event_interruptible(dev->read_wq,
 783                                 dev->rx_done || dev->state != STATE_BUSY);
 784                         if (dev->state == STATE_CANCELED) {
 785                                 r = -ECANCELED;
 786                                 if (!dev->rx_done)
 787                                         usb_ep_dequeue(dev->ep_out, read_req);
 788                                 break;
 789                         }
 790                         /* if xfer_file_length is 0xFFFFFFFF, then we read until
 791                          * we get a zero length packet
 792                          */
 793                         if (count != 0xFFFFFFFF)
 794                                 count -= read_req->actual;
 795                         if (read_req->actual < read_req->length) {
 796                                 /* short packet is used to signal EOF for sizes > 4 gig */
 797                                 DBG(cdev, "got short packet\n");
 798                                 count = 0;
 799                         }
 800
 801                         write_req = read_req;
 802                         read_req = NULL;
 803                 }
 804         }
 805
 806         DBG(cdev, "receive_file_work returning %d\n", r);
 807         /* write the result */
 808         dev->xfer_result = r;
 809         smp_wmb();
 810 }
 811
 812 static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
 813 {
 814         struct usb_request *req= NULL;
 815         int ret;
 816         int length = event->length;
 817
 818         DBG(dev->cdev, "mtp_send_event(%d)\n", event->length);
 819
 820         if (length < 0 || length > INTR_BUFFER_SIZE)
 821                 return -EINVAL;
 822         if (dev->state == STATE_OFFLINE)
 823                 return -ENODEV;
 824
 825         ret = wait_event_interruptible_timeout(dev->intr_wq,
 826                 (req = mtp_req_get(dev, &dev->intr_idle)), msecs_to_jiffies(1000));
 827         if (!req)
 828             return -ETIME;
 829
 830         if (copy_from_user(req->buf, (void __user *)event->data, length)) {
 831                 mtp_req_put(dev, &dev->intr_idle, req);
 832                 return -EFAULT;
 833         }
 834         req->length = length;
 835         ret = usb_ep_queue(dev->ep_intr, req, GFP_KERNEL);
 836         if (ret)
 837                 mtp_req_put(dev, &dev->intr_idle, req);
 838
 839         return ret;
 840 }
 841
 842 static long mtp_ioctl(struct file *fp, unsigned code, unsigned long value)
 843 {
 844         struct mtp_dev *dev = fp->private_data;
 845         struct file *filp = NULL;
 846         int ret = -EINVAL;
 847
 848         if (mtp_lock(&dev->ioctl_excl))
 849                 return -EBUSY;
 850
 851         switch (code) {
 852         case MTP_SEND_FILE:
 853         case MTP_RECEIVE_FILE:
 854         case MTP_SEND_FILE_WITH_HEADER:
 855         {
 856                 struct mtp_file_range   mfr;
 857                 struct work_struct *work;
 858
 859                 spin_lock_irq(&dev->lock);
 860                 if (dev->state == STATE_CANCELED) {
 861                         /* report cancelation to userspace */
 862                         dev->state = STATE_READY;
 863                         spin_unlock_irq(&dev->lock);
 864                         ret = -ECANCELED;
 865                         goto out;
 866                 }
 867                 if (dev->state == STATE_OFFLINE) {
 868                         spin_unlock_irq(&dev->lock);
 869                         ret = -ENODEV;
 870                         goto out;
 871                 }
 872                 dev->state = STATE_BUSY;
 873                 spin_unlock_irq(&dev->lock);
 874
 875                 if (copy_from_user(&mfr, (void __user *)value, sizeof(mfr))) {
 876                         ret = -EFAULT;
 877                         goto fail;
 878                 }
 879                 /* hold a reference to the file while we are working with it */
 880                 filp = fget(mfr.fd);
 881                 if (!filp) {
 882                         ret = -EBADF;
 883                         goto fail;
 884                 }
 885
 886                 /* write the parameters */
 887                 dev->xfer_file = filp;
 888                 dev->xfer_file_offset = mfr.offset;
 889                 dev->xfer_file_length = mfr.length;
 890                 smp_wmb();
 891
 892                 if (code == MTP_SEND_FILE_WITH_HEADER) {
 893                         work = &dev->send_file_work;
 894                         dev->xfer_send_header = 1;
 895                         dev->xfer_command = mfr.command;
 896                         dev->xfer_transaction_id = mfr.transaction_id;
 897                 } else if (code == MTP_SEND_FILE) {
 898                         work = &dev->send_file_work;
 899                         dev->xfer_send_header = 0;
 900                 } else {
 901                         work = &dev->receive_file_work;
 902                 }
 903
 904                 /* We do the file transfer on a work queue so it will run
 905                  * in kernel context, which is necessary for vfs_read and
 906                  * vfs_write to use our buffers in the kernel address space.
 907                  */
 908                 queue_work(dev->wq, work);
 909                 /* wait for operation to complete */
 910                 flush_workqueue(dev->wq);
 911                 fput(filp);
 912
 913                 /* read the result */
 914                 smp_rmb();
 915                 ret = dev->xfer_result;
 916                 break;
 917         }
 918         case MTP_SEND_EVENT:
 919         {
 920                 struct mtp_event        event;
 921                 /* return here so we don't change dev->state below,
 922                  * which would interfere with bulk transfer state.
 923                  */
 924                 if (copy_from_user(&event, (void __user *)value, sizeof(event)))
 925                         ret = -EFAULT;
 926                 else
 927                         ret = mtp_send_event(dev, &event);
 928                 goto out;
 929         }
 930         }
 931
 932 fail:
 933         spin_lock_irq(&dev->lock);
 934         if (dev->state == STATE_CANCELED)
 935                 ret = -ECANCELED;
 936         else if (dev->state != STATE_OFFLINE)
 937                 dev->state = STATE_READY;
 938         spin_unlock_irq(&dev->lock);
 939 out:
 940         mtp_unlock(&dev->ioctl_excl);
 941         DBG(dev->cdev, "ioctl returning %d\n", ret);
 942         return ret;
 943 }
 944
 945 static int mtp_open(struct inode *ip, struct file *fp)
 946 {
 947         printk(KERN_INFO "mtp_open\n");
 948         if (mtp_lock(&_mtp_dev->open_excl))
 949                 return -EBUSY;
 950
 951         /* clear any error condition */
 952         if (_mtp_dev->state != STATE_OFFLINE)
 953                 _mtp_dev->state = STATE_READY;
 954
 955         fp->private_data = _mtp_dev;
 956         return 0;
 957 }
 958
 959 static int mtp_release(struct inode *ip, struct file *fp)
 960 {
 961         printk(KERN_INFO "mtp_release\n");
 962
 963         mtp_unlock(&_mtp_dev->open_excl);
 964         return 0;
 965 }
 966
 967 /* file operations for /dev/mtp_usb */
 968 static const struct file_operations mtp_fops = {
 969         .owner = THIS_MODULE,
 970         .read = mtp_read,
 971         .write = mtp_write,
 972         .unlocked_ioctl = mtp_ioctl,
 973         .open = mtp_open,
 974         .release = mtp_release,
 975 };
 976
 977 static struct miscdevice mtp_device = {
 978         .minor = MISC_DYNAMIC_MINOR,
 979         .name = mtp_shortname,
 980         .fops = &mtp_fops,
 981 };
 982
 983 static int mtp_ctrlrequest(struct usb_composite_dev *cdev,
 984                                 const struct usb_ctrlrequest *ctrl)
 985 {
 986         struct mtp_dev *dev = _mtp_dev;
 987         int     value = -EOPNOTSUPP;
 988         u16     w_index = le16_to_cpu(ctrl->wIndex);
 989         u16     w_value = le16_to_cpu(ctrl->wValue);
 990         u16     w_length = le16_to_cpu(ctrl->wLength);
 991         unsigned long   flags;
 992
 993         VDBG(cdev, "mtp_ctrlrequest "
 994                         "%02x.%02x v%04x i%04x l%u\n",
 995                         ctrl->bRequestType, ctrl->bRequest,
 996                         w_value, w_index, w_length);
 997
 998         /* Handle MTP OS string */
 999         if (ctrl->bRequestType ==
1000                         (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE)
1001                         && ctrl->bRequest == USB_REQ_GET_DESCRIPTOR
1002                         && (w_value >> 8) == USB_DT_STRING
1003                         && (w_value & 0xFF) == MTP_OS_STRING_ID) {
1004                 value = (w_length < sizeof(mtp_os_string)
1005                                 ? w_length : sizeof(mtp_os_string));
1006                 memcpy(cdev->req->buf, mtp_os_string, value);
1007         } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
1008                 /* Handle MTP OS descriptor */
1009                 DBG(cdev, "vendor request: %d index: %d value: %d length: %d\n",
1010                         ctrl->bRequest, w_index, w_value, w_length);
1011
1012                 if (ctrl->bRequest == 1
1013                                 && (ctrl->bRequestType & USB_DIR_IN)
1014                                 && (w_index == 4 || w_index == 5)) {
1015                         value = (w_length < sizeof(mtp_ext_config_desc) ?
1016                                         w_length : sizeof(mtp_ext_config_desc));
1017                         memcpy(cdev->req->buf, &mtp_ext_config_desc, value);
1018                 }
1019         } else if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
1020                 DBG(cdev, "class request: %d index: %d value: %d length: %d\n",
1021                         ctrl->bRequest, w_index, w_value, w_length);
1022
1023                 if (ctrl->bRequest == MTP_REQ_CANCEL && w_index == 0
1024                                 && w_value == 0) {
1025                         DBG(cdev, "MTP_REQ_CANCEL\n");
1026
1027                         spin_lock_irqsave(&dev->lock, flags);
1028                         if (dev->state == STATE_BUSY) {
1029                                 dev->state = STATE_CANCELED;
1030                                 wake_up(&dev->read_wq);
1031                                 wake_up(&dev->write_wq);
1032                         }
1033                         spin_unlock_irqrestore(&dev->lock, flags);
1034
1035                         /* We need to queue a request to read the remaining
1036                          *  bytes, but we don't actually need to look at
1037                          * the contents.
1038                          */
1039                         value = w_length;
1040                 } else if (ctrl->bRequest == MTP_REQ_GET_DEVICE_STATUS
1041                                 && w_index == 0 && w_value == 0) {
1042                         struct mtp_device_status *status = cdev->req->buf;
1043                         status->wLength =
1044                                 __constant_cpu_to_le16(sizeof(*status));
1045
1046                         DBG(cdev, "MTP_REQ_GET_DEVICE_STATUS\n");
1047                         spin_lock_irqsave(&dev->lock, flags);
1048                         /* device status is "busy" until we report
1049                          * the cancelation to userspace
1050                          */
1051                         if (dev->state == STATE_CANCELED)
1052                                 status->wCode =
1053                                         __cpu_to_le16(MTP_RESPONSE_DEVICE_BUSY);
1054                         else
1055                                 status->wCode =
1056                                         __cpu_to_le16(MTP_RESPONSE_OK);
1057                         spin_unlock_irqrestore(&dev->lock, flags);
1058                         value = sizeof(*status);
1059                 }
1060         }
1061
1062         /* respond with data transfer or status phase? */
1063         if (value >= 0) {
1064                 int rc;
1065                 cdev->req->zero = value < w_length;
1066                 cdev->req->length = value;
1067                 rc = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
1068                 if (rc < 0)
1069                         ERROR(cdev, "%s setup response queue error\n", __func__);
1070         }
1071         return value;
1072 }
1073
1074 static int
1075 mtp_function_bind(struct usb_configuration *c, struct usb_function *f)
1076 {
1077         struct usb_composite_dev *cdev = c->cdev;
1078         struct mtp_dev  *dev = func_to_mtp(f);
1079         int                     id;
1080         int                     ret;
1081
1082         dev->cdev = cdev;
1083         DBG(cdev, "mtp_function_bind dev: %p\n", dev);
1084
1085         /* allocate interface ID(s) */
1086         id = usb_interface_id(c, f);
1087         if (id < 0)
1088                 return id;
1089         mtp_interface_desc.bInterfaceNumber = id;
1090
1091         /* allocate endpoints */
1092         ret = mtp_create_bulk_endpoints(dev, &mtp_fullspeed_in_desc,
1093                         &mtp_fullspeed_out_desc, &mtp_intr_desc);
1094         if (ret)
1095                 return ret;
1096
1097         /* support high speed hardware */
1098         if (gadget_is_dualspeed(c->cdev->gadget)) {
1099                 mtp_highspeed_in_desc.bEndpointAddress =
1100                         mtp_fullspeed_in_desc.bEndpointAddress;
1101                 mtp_highspeed_out_desc.bEndpointAddress =
1102                         mtp_fullspeed_out_desc.bEndpointAddress;
1103         }
1104
1105         DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
1106                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1107                         f->name, dev->ep_in->name, dev->ep_out->name);
1108         return 0;
1109 }
1110
1111 static void
1112 mtp_function_unbind(struct usb_configuration *c, struct usb_function *f)
1113 {
1114         struct mtp_dev  *dev = func_to_mtp(f);
1115         struct usb_request *req;
1116         int i;
1117
1118         while ((req = mtp_req_get(dev, &dev->tx_idle)))
1119                 mtp_request_free(req, dev->ep_in);
1120         for (i = 0; i < RX_REQ_MAX; i++)
1121                 mtp_request_free(dev->rx_req[i], dev->ep_out);
1122         while ((req = mtp_req_get(dev, &dev->intr_idle)))
1123                 mtp_request_free(req, dev->ep_intr);
1124         dev->state = STATE_OFFLINE;
1125 }
1126
1127 static int mtp_function_set_alt(struct usb_function *f,
1128                 unsigned intf, unsigned alt)
1129 {
1130         struct mtp_dev  *dev = func_to_mtp(f);
1131         struct usb_composite_dev *cdev = f->config->cdev;
1132         int ret;
1133
1134         DBG(cdev, "mtp_function_set_alt intf: %d alt: %d\n", intf, alt);
1135         ret = usb_ep_enable(dev->ep_in,
1136                         ep_choose(cdev->gadget,
1137                                 &mtp_highspeed_in_desc,
1138                                 &mtp_fullspeed_in_desc));
1139         if (ret)
1140                 return ret;
1141         ret = usb_ep_enable(dev->ep_out,
1142                         ep_choose(cdev->gadget,
1143                                 &mtp_highspeed_out_desc,
1144                                 &mtp_fullspeed_out_desc));
1145         if (ret) {
1146                 usb_ep_disable(dev->ep_in);
1147                 return ret;
1148         }
1149         ret = usb_ep_enable(dev->ep_intr, &mtp_intr_desc);
1150         if (ret) {
1151                 usb_ep_disable(dev->ep_out);
1152                 usb_ep_disable(dev->ep_in);
1153                 return ret;
1154         }
1155         dev->state = STATE_READY;
1156
1157         /* readers may be blocked waiting for us to go online */
1158         wake_up(&dev->read_wq);
1159         return 0;
1160 }
1161
1162 static void mtp_function_disable(struct usb_function *f)
1163 {
1164         struct mtp_dev  *dev = func_to_mtp(f);
1165         struct usb_composite_dev        *cdev = dev->cdev;
1166
1167         DBG(cdev, "mtp_function_disable\n");
1168         dev->state = STATE_OFFLINE;
1169         usb_ep_disable(dev->ep_in);
1170         usb_ep_disable(dev->ep_out);
1171         usb_ep_disable(dev->ep_intr);
1172
1173         /* readers may be blocked waiting for us to go online */
1174         wake_up(&dev->read_wq);
1175
1176         VDBG(cdev, "%s disabled\n", dev->function.name);
1177 }
1178
1179 static int mtp_bind_config(struct usb_configuration *c, bool ptp_config)
1180 {
1181         struct mtp_dev *dev = _mtp_dev;
1182         int ret = 0;
1183
1184         printk(KERN_INFO "mtp_bind_config\n");
1185
1186         /* allocate a string ID for our interface */
1187         if (mtp_string_defs[INTERFACE_STRING_INDEX].id == 0) {
1188                 ret = usb_string_id(c->cdev);
1189                 if (ret < 0)
1190                         return ret;
1191                 mtp_string_defs[INTERFACE_STRING_INDEX].id = ret;
1192                 mtp_interface_desc.iInterface = ret;
1193         }
1194
1195         dev->cdev = c->cdev;
1196         dev->function.name = "mtp";
1197         dev->function.strings = mtp_strings;
1198         if (ptp_config) {
1199                 dev->function.descriptors = fs_ptp_descs;
1200                 dev->function.hs_descriptors = hs_ptp_descs;
1201         } else {
1202                 dev->function.descriptors = fs_mtp_descs;
1203                 dev->function.hs_descriptors = hs_mtp_descs;
1204         }
1205         dev->function.bind = mtp_function_bind;
1206         dev->function.unbind = mtp_function_unbind;
1207         dev->function.set_alt = mtp_function_set_alt;
1208         dev->function.disable = mtp_function_disable;
1209
1210         return usb_add_function(c, &dev->function);
1211 }
1212
1213 static int mtp_setup(void)
1214 {
1215         struct mtp_dev *dev;
1216         int ret;
1217
1218         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1219         if (!dev)
1220                 return -ENOMEM;
1221
1222         spin_lock_init(&dev->lock);
1223         init_waitqueue_head(&dev->read_wq);
1224         init_waitqueue_head(&dev->write_wq);
1225         init_waitqueue_head(&dev->intr_wq);
1226         atomic_set(&dev->open_excl, 0);
1227         atomic_set(&dev->ioctl_excl, 0);
1228         INIT_LIST_HEAD(&dev->tx_idle);
1229         INIT_LIST_HEAD(&dev->intr_idle);
1230
1231         dev->wq = create_singlethread_workqueue("f_mtp");
1232         if (!dev->wq) {
1233                 ret = -ENOMEM;
1234                 goto err1;
1235         }
1236         INIT_WORK(&dev->send_file_work, send_file_work);
1237         INIT_WORK(&dev->receive_file_work, receive_file_work);
1238
1239         _mtp_dev = dev;
1240
1241         ret = misc_register(&mtp_device);
1242         if (ret)
1243                 goto err2;
1244
1245         return 0;
1246
1247 err2:
1248         destroy_workqueue(dev->wq);
1249 err1:
1250         _mtp_dev = NULL;
1251         kfree(dev);
1252         printk(KERN_ERR "mtp gadget driver failed to initialize\n");
1253         return ret;
1254 }
1255
1256 static void mtp_cleanup(void)
1257 {
1258         struct mtp_dev *dev = _mtp_dev;
1259
1260         if (!dev)
1261                 return;
1262
1263         misc_deregister(&mtp_device);
1264         destroy_workqueue(dev->wq);
1265         _mtp_dev = NULL;
1266         kfree(dev);
1267 }