drivers/usb/gadget/function/f_printer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_printer.c - USB printer function driver
   4  *
   5  * Copied from drivers/usb/gadget/legacy/printer.c,
   6  * which was:
   7  *
   8  * printer.c -- Printer gadget driver
   9  *
  10  * Copyright (C) 2003-2005 David Brownell
  11  * Copyright (C) 2006 Craig W. Nadler
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/delay.h>
  17 #include <linux/ioport.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/mutex.h>
  21 #include <linux/errno.h>
  22 #include <linux/init.h>
  23 #include <linux/idr.h>
  24 #include <linux/timer.h>
  25 #include <linux/list.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/device.h>
  28 #include <linux/moduleparam.h>
  29 #include <linux/fs.h>
  30 #include <linux/poll.h>
  31 #include <linux/types.h>
  32 #include <linux/ctype.h>
  33 #include <linux/cdev.h>
  34 #include <linux/kref.h>
  35
  36 #include <asm/byteorder.h>
  37 #include <linux/io.h>
  38 #include <linux/irq.h>
  39 #include <linux/uaccess.h>
  40 #include <asm/unaligned.h>
  41
  42 #include <linux/usb/ch9.h>
  43 #include <linux/usb/composite.h>
  44 #include <linux/usb/gadget.h>
  45 #include <linux/usb/g_printer.h>
  46
  47 #include "u_printer.h"
  48
  49 #define PRINTER_MINORS          4
  50 #define GET_DEVICE_ID           0
  51 #define GET_PORT_STATUS         1
  52 #define SOFT_RESET              2
  53
  54 static int major, minors;
  55 static struct class *usb_gadget_class;
  56 static DEFINE_IDA(printer_ida);
  57 static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
  58
  59 /*-------------------------------------------------------------------------*/
  60
  61 struct printer_dev {
  62         spinlock_t              lock;           /* lock this structure */
  63         /* lock buffer lists during read/write calls */
  64         struct mutex            lock_printer_io;
  65         struct usb_gadget       *gadget;
  66         s8                      interface;
  67         struct usb_ep           *in_ep, *out_ep;
  68         struct kref             kref;
  69         struct list_head        rx_reqs;        /* List of free RX structs */
  70         struct list_head        rx_reqs_active; /* List of Active RX xfers */
  71         struct list_head        rx_buffers;     /* List of completed xfers */
  72         /* wait until there is data to be read. */
  73         wait_queue_head_t       rx_wait;
  74         struct list_head        tx_reqs;        /* List of free TX structs */
  75         struct list_head        tx_reqs_active; /* List of Active TX xfers */
  76         /* Wait until there are write buffers available to use. */
  77         wait_queue_head_t       tx_wait;
  78         /* Wait until all write buffers have been sent. */
  79         wait_queue_head_t       tx_flush_wait;
  80         struct usb_request      *current_rx_req;
  81         size_t                  current_rx_bytes;
  82         u8                      *current_rx_buf;
  83         u8                      printer_status;
  84         u8                      reset_printer;
  85         int                     minor;
  86         struct cdev             printer_cdev;
  87         u8                      printer_cdev_open;
  88         wait_queue_head_t       wait;
  89         unsigned                q_len;
  90         char                    *pnp_string;    /* We don't own memory! */
  91         struct usb_function     function;
  92 };
  93
  94 static inline struct printer_dev *func_to_printer(struct usb_function *f)
  95 {
  96         return container_of(f, struct printer_dev, function);
  97 }
  98
  99 /*-------------------------------------------------------------------------*/
 100
 101 /*
 102  * DESCRIPTORS ... most are static, but strings and (full) configuration
 103  * descriptors are built on demand.
 104  */
 105
 106 /* holds our biggest descriptor */
 107 #define USB_DESC_BUFSIZE                256
 108 #define USB_BUFSIZE                     8192
 109
 110 static struct usb_interface_descriptor intf_desc = {
 111         .bLength =              sizeof(intf_desc),
 112         .bDescriptorType =      USB_DT_INTERFACE,
 113         .bNumEndpoints =        2,
 114         .bInterfaceClass =      USB_CLASS_PRINTER,
 115         .bInterfaceSubClass =   1,      /* Printer Sub-Class */
 116         .bInterfaceProtocol =   2,      /* Bi-Directional */
 117         .iInterface =           0
 118 };
 119
 120 static struct usb_endpoint_descriptor fs_ep_in_desc = {
 121         .bLength =              USB_DT_ENDPOINT_SIZE,
 122         .bDescriptorType =      USB_DT_ENDPOINT,
 123         .bEndpointAddress =     USB_DIR_IN,
 124         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 125 };
 126
 127 static struct usb_endpoint_descriptor fs_ep_out_desc = {
 128         .bLength =              USB_DT_ENDPOINT_SIZE,
 129         .bDescriptorType =      USB_DT_ENDPOINT,
 130         .bEndpointAddress =     USB_DIR_OUT,
 131         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 132 };
 133
 134 static struct usb_descriptor_header *fs_printer_function[] = {
 135         (struct usb_descriptor_header *) &intf_desc,
 136         (struct usb_descriptor_header *) &fs_ep_in_desc,
 137         (struct usb_descriptor_header *) &fs_ep_out_desc,
 138         NULL
 139 };
 140
 141 /*
 142  * usb 2.0 devices need to expose both high speed and full speed
 143  * descriptors, unless they only run at full speed.
 144  */
 145
 146 static struct usb_endpoint_descriptor hs_ep_in_desc = {
 147         .bLength =              USB_DT_ENDPOINT_SIZE,
 148         .bDescriptorType =      USB_DT_ENDPOINT,
 149         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 150         .wMaxPacketSize =       cpu_to_le16(512)
 151 };
 152
 153 static struct usb_endpoint_descriptor hs_ep_out_desc = {
 154         .bLength =              USB_DT_ENDPOINT_SIZE,
 155         .bDescriptorType =      USB_DT_ENDPOINT,
 156         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 157         .wMaxPacketSize =       cpu_to_le16(512)
 158 };
 159
 160 static struct usb_descriptor_header *hs_printer_function[] = {
 161         (struct usb_descriptor_header *) &intf_desc,
 162         (struct usb_descriptor_header *) &hs_ep_in_desc,
 163         (struct usb_descriptor_header *) &hs_ep_out_desc,
 164         NULL
 165 };
 166
 167 /*
 168  * Added endpoint descriptors for 3.0 devices
 169  */
 170
 171 static struct usb_endpoint_descriptor ss_ep_in_desc = {
 172         .bLength =              USB_DT_ENDPOINT_SIZE,
 173         .bDescriptorType =      USB_DT_ENDPOINT,
 174         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 175         .wMaxPacketSize =       cpu_to_le16(1024),
 176 };
 177
 178 static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
 179         .bLength =              sizeof(ss_ep_in_comp_desc),
 180         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 181 };
 182
 183 static struct usb_endpoint_descriptor ss_ep_out_desc = {
 184         .bLength =              USB_DT_ENDPOINT_SIZE,
 185         .bDescriptorType =      USB_DT_ENDPOINT,
 186         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 187         .wMaxPacketSize =       cpu_to_le16(1024),
 188 };
 189
 190 static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
 191         .bLength =              sizeof(ss_ep_out_comp_desc),
 192         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 193 };
 194
 195 static struct usb_descriptor_header *ss_printer_function[] = {
 196         (struct usb_descriptor_header *) &intf_desc,
 197         (struct usb_descriptor_header *) &ss_ep_in_desc,
 198         (struct usb_descriptor_header *) &ss_ep_in_comp_desc,
 199         (struct usb_descriptor_header *) &ss_ep_out_desc,
 200         (struct usb_descriptor_header *) &ss_ep_out_comp_desc,
 201         NULL
 202 };
 203
 204 /* maxpacket and other transfer characteristics vary by speed. */
 205 static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
 206                                         struct usb_endpoint_descriptor *fs,
 207                                         struct usb_endpoint_descriptor *hs,
 208                                         struct usb_endpoint_descriptor *ss)
 209 {
 210         switch (gadget->speed) {
 211         case USB_SPEED_SUPER:
 212                 return ss;
 213         case USB_SPEED_HIGH:
 214                 return hs;
 215         default:
 216                 return fs;
 217         }
 218 }
 219
 220 /*-------------------------------------------------------------------------*/
 221
 222 static void printer_dev_free(struct kref *kref)
 223 {
 224         struct printer_dev *dev = container_of(kref, struct printer_dev, kref);
 225
 226         kfree(dev);
 227 }
 228
 229 static struct usb_request *
 230 printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
 231 {
 232         struct usb_request      *req;
 233
 234         req = usb_ep_alloc_request(ep, gfp_flags);
 235
 236         if (req != NULL) {
 237                 req->length = len;
 238                 req->buf = kmalloc(len, gfp_flags);
 239                 if (req->buf == NULL) {
 240                         usb_ep_free_request(ep, req);
 241                         return NULL;
 242                 }
 243         }
 244
 245         return req;
 246 }
 247
 248 static void
 249 printer_req_free(struct usb_ep *ep, struct usb_request *req)
 250 {
 251         if (ep != NULL && req != NULL) {
 252                 kfree(req->buf);
 253                 usb_ep_free_request(ep, req);
 254         }
 255 }
 256
 257 /*-------------------------------------------------------------------------*/
 258
 259 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 260 {
 261         struct printer_dev      *dev = ep->driver_data;
 262         int                     status = req->status;
 263         unsigned long           flags;
 264
 265         spin_lock_irqsave(&dev->lock, flags);
 266
 267         list_del_init(&req->list);      /* Remode from Active List */
 268
 269         switch (status) {
 270
 271         /* normal completion */
 272         case 0:
 273                 if (req->actual > 0) {
 274                         list_add_tail(&req->list, &dev->rx_buffers);
 275                         DBG(dev, "G_Printer : rx length %d\n", req->actual);
 276                 } else {
 277                         list_add(&req->list, &dev->rx_reqs);
 278                 }
 279                 break;
 280
 281         /* software-driven interface shutdown */
 282         case -ECONNRESET:               /* unlink */
 283         case -ESHUTDOWN:                /* disconnect etc */
 284                 VDBG(dev, "rx shutdown, code %d\n", status);
 285                 list_add(&req->list, &dev->rx_reqs);
 286                 break;
 287
 288         /* for hardware automagic (such as pxa) */
 289         case -ECONNABORTED:             /* endpoint reset */
 290                 DBG(dev, "rx %s reset\n", ep->name);
 291                 list_add(&req->list, &dev->rx_reqs);
 292                 break;
 293
 294         /* data overrun */
 295         case -EOVERFLOW:
 296                 /* FALLTHROUGH */
 297
 298         default:
 299                 DBG(dev, "rx status %d\n", status);
 300                 list_add(&req->list, &dev->rx_reqs);
 301                 break;
 302         }
 303
 304         wake_up_interruptible(&dev->rx_wait);
 305         spin_unlock_irqrestore(&dev->lock, flags);
 306 }
 307
 308 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
 309 {
 310         struct printer_dev      *dev = ep->driver_data;
 311
 312         switch (req->status) {
 313         default:
 314                 VDBG(dev, "tx err %d\n", req->status);
 315                 /* FALLTHROUGH */
 316         case -ECONNRESET:               /* unlink */
 317         case -ESHUTDOWN:                /* disconnect etc */
 318                 break;
 319         case 0:
 320                 break;
 321         }
 322
 323         spin_lock(&dev->lock);
 324         /* Take the request struct off the active list and put it on the
 325          * free list.
 326          */
 327         list_del_init(&req->list);
 328         list_add(&req->list, &dev->tx_reqs);
 329         wake_up_interruptible(&dev->tx_wait);
 330         if (likely(list_empty(&dev->tx_reqs_active)))
 331                 wake_up_interruptible(&dev->tx_flush_wait);
 332
 333         spin_unlock(&dev->lock);
 334 }
 335
 336 /*-------------------------------------------------------------------------*/
 337
 338 static int
 339 printer_open(struct inode *inode, struct file *fd)
 340 {
 341         struct printer_dev      *dev;
 342         unsigned long           flags;
 343         int                     ret = -EBUSY;
 344
 345         dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
 346
 347         spin_lock_irqsave(&dev->lock, flags);
 348
 349         if (!dev->printer_cdev_open) {
 350                 dev->printer_cdev_open = 1;
 351                 fd->private_data = dev;
 352                 ret = 0;
 353                 /* Change the printer status to show that it's on-line. */
 354                 dev->printer_status |= PRINTER_SELECTED;
 355         }
 356
 357         spin_unlock_irqrestore(&dev->lock, flags);
 358
 359         kref_get(&dev->kref);
 360         DBG(dev, "printer_open returned %x\n", ret);
 361         return ret;
 362 }
 363
 364 static int
 365 printer_close(struct inode *inode, struct file *fd)
 366 {
 367         struct printer_dev      *dev = fd->private_data;
 368         unsigned long           flags;
 369
 370         spin_lock_irqsave(&dev->lock, flags);
 371         dev->printer_cdev_open = 0;
 372         fd->private_data = NULL;
 373         /* Change printer status to show that the printer is off-line. */
 374         dev->printer_status &= ~PRINTER_SELECTED;
 375         spin_unlock_irqrestore(&dev->lock, flags);
 376
 377         kref_put(&dev->kref, printer_dev_free);
 378         DBG(dev, "printer_close\n");
 379
 380         return 0;
 381 }
 382
 383 /* This function must be called with interrupts turned off. */
 384 static void
 385 setup_rx_reqs(struct printer_dev *dev)
 386 {
 387         struct usb_request              *req;
 388
 389         while (likely(!list_empty(&dev->rx_reqs))) {
 390                 int error;
 391
 392                 req = container_of(dev->rx_reqs.next,
 393                                 struct usb_request, list);
 394                 list_del_init(&req->list);
 395
 396                 /* The USB Host sends us whatever amount of data it wants to
 397                  * so we always set the length field to the full USB_BUFSIZE.
 398                  * If the amount of data is more than the read() caller asked
 399                  * for it will be stored in the request buffer until it is
 400                  * asked for by read().
 401                  */
 402                 req->length = USB_BUFSIZE;
 403                 req->complete = rx_complete;
 404
 405                 /* here, we unlock, and only unlock, to avoid deadlock. */
 406                 spin_unlock(&dev->lock);
 407                 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
 408                 spin_lock(&dev->lock);
 409                 if (error) {
 410                         DBG(dev, "rx submit --> %d\n", error);
 411                         list_add(&req->list, &dev->rx_reqs);
 412                         break;
 413                 }
 414                 /* if the req is empty, then add it into dev->rx_reqs_active. */
 415                 else if (list_empty(&req->list))
 416                         list_add(&req->list, &dev->rx_reqs_active);
 417         }
 418 }
 419
 420 static ssize_t
 421 printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 422 {
 423         struct printer_dev              *dev = fd->private_data;
 424         unsigned long                   flags;
 425         size_t                          size;
 426         size_t                          bytes_copied;
 427         struct usb_request              *req;
 428         /* This is a pointer to the current USB rx request. */
 429         struct usb_request              *current_rx_req;
 430         /* This is the number of bytes in the current rx buffer. */
 431         size_t                          current_rx_bytes;
 432         /* This is a pointer to the current rx buffer. */
 433         u8                              *current_rx_buf;
 434
 435         if (len == 0)
 436                 return -EINVAL;
 437
 438         DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
 439
 440         mutex_lock(&dev->lock_printer_io);
 441         spin_lock_irqsave(&dev->lock, flags);
 442
 443         /* We will use this flag later to check if a printer reset happened
 444          * after we turn interrupts back on.
 445          */
 446         dev->reset_printer = 0;
 447
 448         setup_rx_reqs(dev);
 449
 450         bytes_copied = 0;
 451         current_rx_req = dev->current_rx_req;
 452         current_rx_bytes = dev->current_rx_bytes;
 453         current_rx_buf = dev->current_rx_buf;
 454         dev->current_rx_req = NULL;
 455         dev->current_rx_bytes = 0;
 456         dev->current_rx_buf = NULL;
 457
 458         /* Check if there is any data in the read buffers. Please note that
 459          * current_rx_bytes is the number of bytes in the current rx buffer.
 460          * If it is zero then check if there are any other rx_buffers that
 461          * are on the completed list. We are only out of data if all rx
 462          * buffers are empty.
 463          */
 464         if ((current_rx_bytes == 0) &&
 465                         (likely(list_empty(&dev->rx_buffers)))) {
 466                 /* Turn interrupts back on before sleeping. */
 467                 spin_unlock_irqrestore(&dev->lock, flags);
 468
 469                 /*
 470                  * If no data is available check if this is a NON-Blocking
 471                  * call or not.
 472                  */
 473                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 474                         mutex_unlock(&dev->lock_printer_io);
 475                         return -EAGAIN;
 476                 }
 477
 478                 /* Sleep until data is available */
 479                 wait_event_interruptible(dev->rx_wait,
 480                                 (likely(!list_empty(&dev->rx_buffers))));
 481                 spin_lock_irqsave(&dev->lock, flags);
 482         }
 483
 484         /* We have data to return then copy it to the caller's buffer.*/
 485         while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
 486                         && len) {
 487                 if (current_rx_bytes == 0) {
 488                         req = container_of(dev->rx_buffers.next,
 489                                         struct usb_request, list);
 490                         list_del_init(&req->list);
 491
 492                         if (req->actual && req->buf) {
 493                                 current_rx_req = req;
 494                                 current_rx_bytes = req->actual;
 495                                 current_rx_buf = req->buf;
 496                         } else {
 497                                 list_add(&req->list, &dev->rx_reqs);
 498                                 continue;
 499                         }
 500                 }
 501
 502                 /* Don't leave irqs off while doing memory copies */
 503                 spin_unlock_irqrestore(&dev->lock, flags);
 504
 505                 if (len > current_rx_bytes)
 506                         size = current_rx_bytes;
 507                 else
 508                         size = len;
 509
 510                 size -= copy_to_user(buf, current_rx_buf, size);
 511                 bytes_copied += size;
 512                 len -= size;
 513                 buf += size;
 514
 515                 spin_lock_irqsave(&dev->lock, flags);
 516
 517                 /* We've disconnected or reset so return. */
 518                 if (dev->reset_printer) {
 519                         list_add(&current_rx_req->list, &dev->rx_reqs);
 520                         spin_unlock_irqrestore(&dev->lock, flags);
 521                         mutex_unlock(&dev->lock_printer_io);
 522                         return -EAGAIN;
 523                 }
 524
 525                 /* If we not returning all the data left in this RX request
 526                  * buffer then adjust the amount of data left in the buffer.
 527                  * Othewise if we are done with this RX request buffer then
 528                  * requeue it to get any incoming data from the USB host.
 529                  */
 530                 if (size < current_rx_bytes) {
 531                         current_rx_bytes -= size;
 532                         current_rx_buf += size;
 533                 } else {
 534                         list_add(&current_rx_req->list, &dev->rx_reqs);
 535                         current_rx_bytes = 0;
 536                         current_rx_buf = NULL;
 537                         current_rx_req = NULL;
 538                 }
 539         }
 540
 541         dev->current_rx_req = current_rx_req;
 542         dev->current_rx_bytes = current_rx_bytes;
 543         dev->current_rx_buf = current_rx_buf;
 544
 545         spin_unlock_irqrestore(&dev->lock, flags);
 546         mutex_unlock(&dev->lock_printer_io);
 547
 548         DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
 549
 550         if (bytes_copied)
 551                 return bytes_copied;
 552         else
 553                 return -EAGAIN;
 554 }
 555
 556 static ssize_t
 557 printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 558 {
 559         struct printer_dev      *dev = fd->private_data;
 560         unsigned long           flags;
 561         size_t                  size;   /* Amount of data in a TX request. */
 562         size_t                  bytes_copied = 0;
 563         struct usb_request      *req;
 564         int                     value;
 565
 566         DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
 567
 568         if (len == 0)
 569                 return -EINVAL;
 570
 571         mutex_lock(&dev->lock_printer_io);
 572         spin_lock_irqsave(&dev->lock, flags);
 573
 574         /* Check if a printer reset happens while we have interrupts on */
 575         dev->reset_printer = 0;
 576
 577         /* Check if there is any available write buffers */
 578         if (likely(list_empty(&dev->tx_reqs))) {
 579                 /* Turn interrupts back on before sleeping. */
 580                 spin_unlock_irqrestore(&dev->lock, flags);
 581
 582                 /*
 583                  * If write buffers are available check if this is
 584                  * a NON-Blocking call or not.
 585                  */
 586                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 587                         mutex_unlock(&dev->lock_printer_io);
 588                         return -EAGAIN;
 589                 }
 590
 591                 /* Sleep until a write buffer is available */
 592                 wait_event_interruptible(dev->tx_wait,
 593                                 (likely(!list_empty(&dev->tx_reqs))));
 594                 spin_lock_irqsave(&dev->lock, flags);
 595         }
 596
 597         while (likely(!list_empty(&dev->tx_reqs)) && len) {
 598
 599                 if (len > USB_BUFSIZE)
 600                         size = USB_BUFSIZE;
 601                 else
 602                         size = len;
 603
 604                 req = container_of(dev->tx_reqs.next, struct usb_request,
 605                                 list);
 606                 list_del_init(&req->list);
 607
 608                 req->complete = tx_complete;
 609                 req->length = size;
 610
 611                 /* Check if we need to send a zero length packet. */
 612                 if (len > size)
 613                         /* They will be more TX requests so no yet. */
 614                         req->zero = 0;
 615                 else
 616                         /* If the data amount is not a multiple of the
 617                          * maxpacket size then send a zero length packet.
 618                          */
 619                         req->zero = ((len % dev->in_ep->maxpacket) == 0);
 620
 621                 /* Don't leave irqs off while doing memory copies */
 622                 spin_unlock_irqrestore(&dev->lock, flags);
 623
 624                 if (copy_from_user(req->buf, buf, size)) {
 625                         list_add(&req->list, &dev->tx_reqs);
 626                         mutex_unlock(&dev->lock_printer_io);
 627                         return bytes_copied;
 628                 }
 629
 630                 bytes_copied += size;
 631                 len -= size;
 632                 buf += size;
 633
 634                 spin_lock_irqsave(&dev->lock, flags);
 635
 636                 /* We've disconnected or reset so free the req and buffer */
 637                 if (dev->reset_printer) {
 638                         list_add(&req->list, &dev->tx_reqs);
 639                         spin_unlock_irqrestore(&dev->lock, flags);
 640                         mutex_unlock(&dev->lock_printer_io);
 641                         return -EAGAIN;
 642                 }
 643
 644                 list_add(&req->list, &dev->tx_reqs_active);
 645
 646                 /* here, we unlock, and only unlock, to avoid deadlock. */
 647                 spin_unlock(&dev->lock);
 648                 value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
 649                 spin_lock(&dev->lock);
 650                 if (value) {
 651                         list_del(&req->list);
 652                         list_add(&req->list, &dev->tx_reqs);
 653                         spin_unlock_irqrestore(&dev->lock, flags);
 654                         mutex_unlock(&dev->lock_printer_io);
 655                         return -EAGAIN;
 656                 }
 657         }
 658
 659         spin_unlock_irqrestore(&dev->lock, flags);
 660         mutex_unlock(&dev->lock_printer_io);
 661
 662         DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
 663
 664         if (bytes_copied)
 665                 return bytes_copied;
 666         else
 667                 return -EAGAIN;
 668 }
 669
 670 static int
 671 printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
 672 {
 673         struct printer_dev      *dev = fd->private_data;
 674         struct inode *inode = file_inode(fd);
 675         unsigned long           flags;
 676         int                     tx_list_empty;
 677
 678         inode_lock(inode);
 679         spin_lock_irqsave(&dev->lock, flags);
 680         tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
 681         spin_unlock_irqrestore(&dev->lock, flags);
 682
 683         if (!tx_list_empty) {
 684                 /* Sleep until all data has been sent */
 685                 wait_event_interruptible(dev->tx_flush_wait,
 686                                 (likely(list_empty(&dev->tx_reqs_active))));
 687         }
 688         inode_unlock(inode);
 689
 690         return 0;
 691 }
 692
 693 static __poll_t
 694 printer_poll(struct file *fd, poll_table *wait)
 695 {
 696         struct printer_dev      *dev = fd->private_data;
 697         unsigned long           flags;
 698         __poll_t                status = 0;
 699
 700         mutex_lock(&dev->lock_printer_io);
 701         spin_lock_irqsave(&dev->lock, flags);
 702         setup_rx_reqs(dev);
 703         spin_unlock_irqrestore(&dev->lock, flags);
 704         mutex_unlock(&dev->lock_printer_io);
 705
 706         poll_wait(fd, &dev->rx_wait, wait);
 707         poll_wait(fd, &dev->tx_wait, wait);
 708
 709         spin_lock_irqsave(&dev->lock, flags);
 710         if (likely(!list_empty(&dev->tx_reqs)))
 711                 status |= EPOLLOUT | EPOLLWRNORM;
 712
 713         if (likely(dev->current_rx_bytes) ||
 714                         likely(!list_empty(&dev->rx_buffers)))
 715                 status |= EPOLLIN | EPOLLRDNORM;
 716
 717         spin_unlock_irqrestore(&dev->lock, flags);
 718
 719         return status;
 720 }
 721
 722 static long
 723 printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
 724 {
 725         struct printer_dev      *dev = fd->private_data;
 726         unsigned long           flags;
 727         int                     status = 0;
 728
 729         DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
 730
 731         /* handle ioctls */
 732
 733         spin_lock_irqsave(&dev->lock, flags);
 734
 735         switch (code) {
 736         case GADGET_GET_PRINTER_STATUS:
 737                 status = (int)dev->printer_status;
 738                 break;
 739         case GADGET_SET_PRINTER_STATUS:
 740                 dev->printer_status = (u8)arg;
 741                 break;
 742         default:
 743                 /* could not handle ioctl */
 744                 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
 745                                 code);
 746                 status = -ENOTTY;
 747         }
 748
 749         spin_unlock_irqrestore(&dev->lock, flags);
 750
 751         return status;
 752 }
 753
 754 /* used after endpoint configuration */
 755 static const struct file_operations printer_io_operations = {
 756         .owner =        THIS_MODULE,
 757         .open =         printer_open,
 758         .read =         printer_read,
 759         .write =        printer_write,
 760         .fsync =        printer_fsync,
 761         .poll =         printer_poll,
 762         .unlocked_ioctl = printer_ioctl,
 763         .release =      printer_close,
 764         .llseek =       noop_llseek,
 765 };
 766
 767 /*-------------------------------------------------------------------------*/
 768
 769 static int
 770 set_printer_interface(struct printer_dev *dev)
 771 {
 772         int                     result = 0;
 773
 774         dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
 775                                 &ss_ep_in_desc);
 776         dev->in_ep->driver_data = dev;
 777
 778         dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
 779                                     &hs_ep_out_desc, &ss_ep_out_desc);
 780         dev->out_ep->driver_data = dev;
 781
 782         result = usb_ep_enable(dev->in_ep);
 783         if (result != 0) {
 784                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 785                 goto done;
 786         }
 787
 788         result = usb_ep_enable(dev->out_ep);
 789         if (result != 0) {
 790                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 791                 goto done;
 792         }
 793
 794 done:
 795         /* on error, disable any endpoints  */
 796         if (result != 0) {
 797                 (void) usb_ep_disable(dev->in_ep);
 798                 (void) usb_ep_disable(dev->out_ep);
 799                 dev->in_ep->desc = NULL;
 800                 dev->out_ep->desc = NULL;
 801         }
 802
 803         /* caller is responsible for cleanup on error */
 804         return result;
 805 }
 806
 807 static void printer_reset_interface(struct printer_dev *dev)
 808 {
 809         unsigned long   flags;
 810
 811         if (dev->interface < 0)
 812                 return;
 813
 814         DBG(dev, "%s\n", __func__);
 815
 816         if (dev->in_ep->desc)
 817                 usb_ep_disable(dev->in_ep);
 818
 819         if (dev->out_ep->desc)
 820                 usb_ep_disable(dev->out_ep);
 821
 822         spin_lock_irqsave(&dev->lock, flags);
 823         dev->in_ep->desc = NULL;
 824         dev->out_ep->desc = NULL;
 825         dev->interface = -1;
 826         spin_unlock_irqrestore(&dev->lock, flags);
 827 }
 828
 829 /* Change our operational Interface. */
 830 static int set_interface(struct printer_dev *dev, unsigned number)
 831 {
 832         int                     result = 0;
 833
 834         /* Free the current interface */
 835         printer_reset_interface(dev);
 836
 837         result = set_printer_interface(dev);
 838         if (result)
 839                 printer_reset_interface(dev);
 840         else
 841                 dev->interface = number;
 842
 843         if (!result)
 844                 INFO(dev, "Using interface %x\n", number);
 845
 846         return result;
 847 }
 848
 849 static void printer_soft_reset(struct printer_dev *dev)
 850 {
 851         struct usb_request      *req;
 852
 853         INFO(dev, "Received Printer Reset Request\n");
 854
 855         if (usb_ep_disable(dev->in_ep))
 856                 DBG(dev, "Failed to disable USB in_ep\n");
 857         if (usb_ep_disable(dev->out_ep))
 858                 DBG(dev, "Failed to disable USB out_ep\n");
 859
 860         if (dev->current_rx_req != NULL) {
 861                 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
 862                 dev->current_rx_req = NULL;
 863         }
 864         dev->current_rx_bytes = 0;
 865         dev->current_rx_buf = NULL;
 866         dev->reset_printer = 1;
 867
 868         while (likely(!(list_empty(&dev->rx_buffers)))) {
 869                 req = container_of(dev->rx_buffers.next, struct usb_request,
 870                                 list);
 871                 list_del_init(&req->list);
 872                 list_add(&req->list, &dev->rx_reqs);
 873         }
 874
 875         while (likely(!(list_empty(&dev->rx_reqs_active)))) {
 876                 req = container_of(dev->rx_buffers.next, struct usb_request,
 877                                 list);
 878                 list_del_init(&req->list);
 879                 list_add(&req->list, &dev->rx_reqs);
 880         }
 881
 882         while (likely(!(list_empty(&dev->tx_reqs_active)))) {
 883                 req = container_of(dev->tx_reqs_active.next,
 884                                 struct usb_request, list);
 885                 list_del_init(&req->list);
 886                 list_add(&req->list, &dev->tx_reqs);
 887         }
 888
 889         if (usb_ep_enable(dev->in_ep))
 890                 DBG(dev, "Failed to enable USB in_ep\n");
 891         if (usb_ep_enable(dev->out_ep))
 892                 DBG(dev, "Failed to enable USB out_ep\n");
 893
 894         wake_up_interruptible(&dev->rx_wait);
 895         wake_up_interruptible(&dev->tx_wait);
 896         wake_up_interruptible(&dev->tx_flush_wait);
 897 }
 898
 899 /*-------------------------------------------------------------------------*/
 900
 901 static bool gprinter_req_match(struct usb_function *f,
 902                                const struct usb_ctrlrequest *ctrl,
 903                                bool config0)
 904 {
 905         struct printer_dev      *dev = func_to_printer(f);
 906         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 907         u16                     w_value = le16_to_cpu(ctrl->wValue);
 908         u16                     w_length = le16_to_cpu(ctrl->wLength);
 909
 910         if (config0)
 911                 return false;
 912
 913         if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
 914             (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
 915                 return false;
 916
 917         switch (ctrl->bRequest) {
 918         case GET_DEVICE_ID:
 919                 w_index >>= 8;
 920                 if (USB_DIR_IN & ctrl->bRequestType)
 921                         break;
 922                 return false;
 923         case GET_PORT_STATUS:
 924                 if (!w_value && w_length == 1 &&
 925                     (USB_DIR_IN & ctrl->bRequestType))
 926                         break;
 927                 return false;
 928         case SOFT_RESET:
 929                 if (!w_value && !w_length &&
 930                    !(USB_DIR_IN & ctrl->bRequestType))
 931                         break;
 932                 /* fall through */
 933         default:
 934                 return false;
 935         }
 936         return w_index == dev->interface;
 937 }
 938
 939 /*
 940  * The setup() callback implements all the ep0 functionality that's not
 941  * handled lower down.
 942  */
 943 static int printer_func_setup(struct usb_function *f,
 944                 const struct usb_ctrlrequest *ctrl)
 945 {
 946         struct printer_dev *dev = func_to_printer(f);
 947         struct usb_composite_dev *cdev = f->config->cdev;
 948         struct usb_request      *req = cdev->req;
 949         u8                      *buf = req->buf;
 950         int                     value = -EOPNOTSUPP;
 951         u16                     wIndex = le16_to_cpu(ctrl->wIndex);
 952         u16                     wValue = le16_to_cpu(ctrl->wValue);
 953         u16                     wLength = le16_to_cpu(ctrl->wLength);
 954
 955         DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
 956                 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
 957
 958         switch (ctrl->bRequestType&USB_TYPE_MASK) {
 959         case USB_TYPE_CLASS:
 960                 switch (ctrl->bRequest) {
 961                 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
 962                         /* Only one printer interface is supported. */
 963                         if ((wIndex>>8) != dev->interface)
 964                                 break;
 965
 966                         if (!dev->pnp_string) {
 967                                 value = 0;
 968                                 break;
 969                         }
 970                         value = strlen(dev->pnp_string);
 971                         buf[0] = (value >> 8) & 0xFF;
 972                         buf[1] = value & 0xFF;
 973                         memcpy(buf + 2, dev->pnp_string, value);
 974                         DBG(dev, "1284 PNP String: %x %s\n", value,
 975                             dev->pnp_string);
 976                         break;
 977
 978                 case GET_PORT_STATUS: /* Get Port Status */
 979                         /* Only one printer interface is supported. */
 980                         if (wIndex != dev->interface)
 981                                 break;
 982
 983                         buf[0] = dev->printer_status;
 984                         value = min_t(u16, wLength, 1);
 985                         break;
 986
 987                 case SOFT_RESET: /* Soft Reset */
 988                         /* Only one printer interface is supported. */
 989                         if (wIndex != dev->interface)
 990                                 break;
 991
 992                         printer_soft_reset(dev);
 993
 994                         value = 0;
 995                         break;
 996
 997                 default:
 998                         goto unknown;
 999                 }
1000                 break;
1001
1002         default:
1003 unknown:
1004                 VDBG(dev,
1005                         "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
1006                         ctrl->bRequestType, ctrl->bRequest,
1007                         wValue, wIndex, wLength);
1008                 break;
1009         }
1010         /* host either stalls (value < 0) or reports success */
1011         if (value >= 0) {
1012                 req->length = value;
1013                 req->zero = value < wLength;
1014                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1015                 if (value < 0) {
1016                         ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1017                         req->status = 0;
1018                 }
1019         }
1020         return value;
1021 }
1022
1023 static int printer_func_bind(struct usb_configuration *c,
1024                 struct usb_function *f)
1025 {
1026         struct usb_gadget *gadget = c->cdev->gadget;
1027         struct printer_dev *dev = func_to_printer(f);
1028         struct device *pdev;
1029         struct usb_composite_dev *cdev = c->cdev;
1030         struct usb_ep *in_ep;
1031         struct usb_ep *out_ep = NULL;
1032         struct usb_request *req;
1033         dev_t devt;
1034         int id;
1035         int ret;
1036         u32 i;
1037
1038         id = usb_interface_id(c, f);
1039         if (id < 0)
1040                 return id;
1041         intf_desc.bInterfaceNumber = id;
1042
1043         /* finish hookup to lower layer ... */
1044         dev->gadget = gadget;
1045
1046         /* all we really need is bulk IN/OUT */
1047         in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1048         if (!in_ep) {
1049 autoconf_fail:
1050                 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1051                         cdev->gadget->name);
1052                 return -ENODEV;
1053         }
1054
1055         out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1056         if (!out_ep)
1057                 goto autoconf_fail;
1058
1059         /* assumes that all endpoints are dual-speed */
1060         hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1061         hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1062         ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1063         ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1064
1065         ret = usb_assign_descriptors(f, fs_printer_function,
1066                         hs_printer_function, ss_printer_function,
1067                         ss_printer_function);
1068         if (ret)
1069                 return ret;
1070
1071         dev->in_ep = in_ep;
1072         dev->out_ep = out_ep;
1073
1074         ret = -ENOMEM;
1075         for (i = 0; i < dev->q_len; i++) {
1076                 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1077                 if (!req)
1078                         goto fail_tx_reqs;
1079                 list_add(&req->list, &dev->tx_reqs);
1080         }
1081
1082         for (i = 0; i < dev->q_len; i++) {
1083                 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1084                 if (!req)
1085                         goto fail_rx_reqs;
1086                 list_add(&req->list, &dev->rx_reqs);
1087         }
1088
1089         /* Setup the sysfs files for the printer gadget. */
1090         devt = MKDEV(major, dev->minor);
1091         pdev = device_create(usb_gadget_class, NULL, devt,
1092                                   NULL, "g_printer%d", dev->minor);
1093         if (IS_ERR(pdev)) {
1094                 ERROR(dev, "Failed to create device: g_printer\n");
1095                 ret = PTR_ERR(pdev);
1096                 goto fail_rx_reqs;
1097         }
1098
1099         /*
1100          * Register a character device as an interface to a user mode
1101          * program that handles the printer specific functionality.
1102          */
1103         cdev_init(&dev->printer_cdev, &printer_io_operations);
1104         dev->printer_cdev.owner = THIS_MODULE;
1105         ret = cdev_add(&dev->printer_cdev, devt, 1);
1106         if (ret) {
1107                 ERROR(dev, "Failed to open char device\n");
1108                 goto fail_cdev_add;
1109         }
1110
1111         return 0;
1112
1113 fail_cdev_add:
1114         device_destroy(usb_gadget_class, devt);
1115
1116 fail_rx_reqs:
1117         while (!list_empty(&dev->rx_reqs)) {
1118                 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1119                 list_del(&req->list);
1120                 printer_req_free(dev->out_ep, req);
1121         }
1122
1123 fail_tx_reqs:
1124         while (!list_empty(&dev->tx_reqs)) {
1125                 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1126                 list_del(&req->list);
1127                 printer_req_free(dev->in_ep, req);
1128         }
1129
1130         usb_free_all_descriptors(f);
1131         return ret;
1132
1133 }
1134
1135 static int printer_func_set_alt(struct usb_function *f,
1136                 unsigned intf, unsigned alt)
1137 {
1138         struct printer_dev *dev = func_to_printer(f);
1139         int ret = -ENOTSUPP;
1140
1141         if (!alt)
1142                 ret = set_interface(dev, intf);
1143
1144         return ret;
1145 }
1146
1147 static void printer_func_disable(struct usb_function *f)
1148 {
1149         struct printer_dev *dev = func_to_printer(f);
1150
1151         DBG(dev, "%s\n", __func__);
1152
1153         printer_reset_interface(dev);
1154 }
1155
1156 static inline struct f_printer_opts
1157 *to_f_printer_opts(struct config_item *item)
1158 {
1159         return container_of(to_config_group(item), struct f_printer_opts,
1160                             func_inst.group);
1161 }
1162
1163 static void printer_attr_release(struct config_item *item)
1164 {
1165         struct f_printer_opts *opts = to_f_printer_opts(item);
1166
1167         usb_put_function_instance(&opts->func_inst);
1168 }
1169
1170 static struct configfs_item_operations printer_item_ops = {
1171         .release        = printer_attr_release,
1172 };
1173
1174 static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1175                                               char *page)
1176 {
1177         struct f_printer_opts *opts = to_f_printer_opts(item);
1178         int result = 0;
1179
1180         mutex_lock(&opts->lock);
1181         if (!opts->pnp_string)
1182                 goto unlock;
1183
1184         result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
1185         if (result >= PAGE_SIZE) {
1186                 result = PAGE_SIZE;
1187         } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
1188                 page[result++] = '\n';
1189                 page[result] = '\0';
1190         }
1191
1192 unlock:
1193         mutex_unlock(&opts->lock);
1194
1195         return result;
1196 }
1197
1198 static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1199                                                const char *page, size_t len)
1200 {
1201         struct f_printer_opts *opts = to_f_printer_opts(item);
1202         char *new_pnp;
1203         int result;
1204
1205         mutex_lock(&opts->lock);
1206
1207         new_pnp = kstrndup(page, len, GFP_KERNEL);
1208         if (!new_pnp) {
1209                 result = -ENOMEM;
1210                 goto unlock;
1211         }
1212
1213         if (opts->pnp_string_allocated)
1214                 kfree(opts->pnp_string);
1215
1216         opts->pnp_string_allocated = true;
1217         opts->pnp_string = new_pnp;
1218         result = len;
1219 unlock:
1220         mutex_unlock(&opts->lock);
1221
1222         return result;
1223 }
1224
1225 CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1226
1227 static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1228                                          char *page)
1229 {
1230         struct f_printer_opts *opts = to_f_printer_opts(item);
1231         int result;
1232
1233         mutex_lock(&opts->lock);
1234         result = sprintf(page, "%d\n", opts->q_len);
1235         mutex_unlock(&opts->lock);
1236
1237         return result;
1238 }
1239
1240 static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1241                                           const char *page, size_t len)
1242 {
1243         struct f_printer_opts *opts = to_f_printer_opts(item);
1244         int ret;
1245         u16 num;
1246
1247         mutex_lock(&opts->lock);
1248         if (opts->refcnt) {
1249                 ret = -EBUSY;
1250                 goto end;
1251         }
1252
1253         ret = kstrtou16(page, 0, &num);
1254         if (ret)
1255                 goto end;
1256
1257         opts->q_len = (unsigned)num;
1258         ret = len;
1259 end:
1260         mutex_unlock(&opts->lock);
1261         return ret;
1262 }
1263
1264 CONFIGFS_ATTR(f_printer_opts_, q_len);
1265
1266 static struct configfs_attribute *printer_attrs[] = {
1267         &f_printer_opts_attr_pnp_string,
1268         &f_printer_opts_attr_q_len,
1269         NULL,
1270 };
1271
1272 static const struct config_item_type printer_func_type = {
1273         .ct_item_ops    = &printer_item_ops,
1274         .ct_attrs       = printer_attrs,
1275         .ct_owner       = THIS_MODULE,
1276 };
1277
1278 static inline int gprinter_get_minor(void)
1279 {
1280         int ret;
1281
1282         ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1283         if (ret >= PRINTER_MINORS) {
1284                 ida_simple_remove(&printer_ida, ret);
1285                 ret = -ENODEV;
1286         }
1287
1288         return ret;
1289 }
1290
1291 static inline void gprinter_put_minor(int minor)
1292 {
1293         ida_simple_remove(&printer_ida, minor);
1294 }
1295
1296 static int gprinter_setup(int);
1297 static void gprinter_cleanup(void);
1298
1299 static void gprinter_free_inst(struct usb_function_instance *f)
1300 {
1301         struct f_printer_opts *opts;
1302
1303         opts = container_of(f, struct f_printer_opts, func_inst);
1304
1305         mutex_lock(&printer_ida_lock);
1306
1307         gprinter_put_minor(opts->minor);
1308         if (ida_is_empty(&printer_ida))
1309                 gprinter_cleanup();
1310
1311         mutex_unlock(&printer_ida_lock);
1312
1313         if (opts->pnp_string_allocated)
1314                 kfree(opts->pnp_string);
1315         kfree(opts);
1316 }
1317
1318 static struct usb_function_instance *gprinter_alloc_inst(void)
1319 {
1320         struct f_printer_opts *opts;
1321         struct usb_function_instance *ret;
1322         int status = 0;
1323
1324         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1325         if (!opts)
1326                 return ERR_PTR(-ENOMEM);
1327
1328         mutex_init(&opts->lock);
1329         opts->func_inst.free_func_inst = gprinter_free_inst;
1330         ret = &opts->func_inst;
1331
1332         mutex_lock(&printer_ida_lock);
1333
1334         if (ida_is_empty(&printer_ida)) {
1335                 status = gprinter_setup(PRINTER_MINORS);
1336                 if (status) {
1337                         ret = ERR_PTR(status);
1338                         kfree(opts);
1339                         goto unlock;
1340                 }
1341         }
1342
1343         opts->minor = gprinter_get_minor();
1344         if (opts->minor < 0) {
1345                 ret = ERR_PTR(opts->minor);
1346                 kfree(opts);
1347                 if (ida_is_empty(&printer_ida))
1348                         gprinter_cleanup();
1349                 goto unlock;
1350         }
1351         config_group_init_type_name(&opts->func_inst.group, "",
1352                                     &printer_func_type);
1353
1354 unlock:
1355         mutex_unlock(&printer_ida_lock);
1356         return ret;
1357 }
1358
1359 static void gprinter_free(struct usb_function *f)
1360 {
1361         struct printer_dev *dev = func_to_printer(f);
1362         struct f_printer_opts *opts;
1363
1364         opts = container_of(f->fi, struct f_printer_opts, func_inst);
1365
1366         kref_put(&dev->kref, printer_dev_free);
1367         mutex_lock(&opts->lock);
1368         --opts->refcnt;
1369         mutex_unlock(&opts->lock);
1370 }
1371
1372 static void printer_func_unbind(struct usb_configuration *c,
1373                 struct usb_function *f)
1374 {
1375         struct printer_dev      *dev;
1376         struct usb_request      *req;
1377
1378         dev = func_to_printer(f);
1379
1380         device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1381
1382         /* Remove Character Device */
1383         cdev_del(&dev->printer_cdev);
1384
1385         /* we must already have been disconnected ... no i/o may be active */
1386         WARN_ON(!list_empty(&dev->tx_reqs_active));
1387         WARN_ON(!list_empty(&dev->rx_reqs_active));
1388
1389         /* Free all memory for this driver. */
1390         while (!list_empty(&dev->tx_reqs)) {
1391                 req = container_of(dev->tx_reqs.next, struct usb_request,
1392                                 list);
1393                 list_del(&req->list);
1394                 printer_req_free(dev->in_ep, req);
1395         }
1396
1397         if (dev->current_rx_req != NULL)
1398                 printer_req_free(dev->out_ep, dev->current_rx_req);
1399
1400         while (!list_empty(&dev->rx_reqs)) {
1401                 req = container_of(dev->rx_reqs.next,
1402                                 struct usb_request, list);
1403                 list_del(&req->list);
1404                 printer_req_free(dev->out_ep, req);
1405         }
1406
1407         while (!list_empty(&dev->rx_buffers)) {
1408                 req = container_of(dev->rx_buffers.next,
1409                                 struct usb_request, list);
1410                 list_del(&req->list);
1411                 printer_req_free(dev->out_ep, req);
1412         }
1413         usb_free_all_descriptors(f);
1414 }
1415
1416 static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1417 {
1418         struct printer_dev      *dev;
1419         struct f_printer_opts   *opts;
1420
1421         opts = container_of(fi, struct f_printer_opts, func_inst);
1422
1423         mutex_lock(&opts->lock);
1424         if (opts->minor >= minors) {
1425                 mutex_unlock(&opts->lock);
1426                 return ERR_PTR(-ENOENT);
1427         }
1428
1429         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1430         if (!dev) {
1431                 mutex_unlock(&opts->lock);
1432                 return ERR_PTR(-ENOMEM);
1433         }
1434
1435         kref_init(&dev->kref);
1436         ++opts->refcnt;
1437         dev->minor = opts->minor;
1438         dev->pnp_string = opts->pnp_string;
1439         dev->q_len = opts->q_len;
1440         mutex_unlock(&opts->lock);
1441
1442         dev->function.name = "printer";
1443         dev->function.bind = printer_func_bind;
1444         dev->function.setup = printer_func_setup;
1445         dev->function.unbind = printer_func_unbind;
1446         dev->function.set_alt = printer_func_set_alt;
1447         dev->function.disable = printer_func_disable;
1448         dev->function.req_match = gprinter_req_match;
1449         dev->function.free_func = gprinter_free;
1450
1451         INIT_LIST_HEAD(&dev->tx_reqs);
1452         INIT_LIST_HEAD(&dev->rx_reqs);
1453         INIT_LIST_HEAD(&dev->rx_buffers);
1454         INIT_LIST_HEAD(&dev->tx_reqs_active);
1455         INIT_LIST_HEAD(&dev->rx_reqs_active);
1456
1457         spin_lock_init(&dev->lock);
1458         mutex_init(&dev->lock_printer_io);
1459         init_waitqueue_head(&dev->rx_wait);
1460         init_waitqueue_head(&dev->tx_wait);
1461         init_waitqueue_head(&dev->tx_flush_wait);
1462
1463         dev->interface = -1;
1464         dev->printer_cdev_open = 0;
1465         dev->printer_status = PRINTER_NOT_ERROR;
1466         dev->current_rx_req = NULL;
1467         dev->current_rx_bytes = 0;
1468         dev->current_rx_buf = NULL;
1469
1470         return &dev->function;
1471 }
1472
1473 DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1474 MODULE_LICENSE("GPL");
1475 MODULE_AUTHOR("Craig Nadler");
1476
1477 static int gprinter_setup(int count)
1478 {
1479         int status;
1480         dev_t devt;
1481
1482         usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1483         if (IS_ERR(usb_gadget_class)) {
1484                 status = PTR_ERR(usb_gadget_class);
1485                 usb_gadget_class = NULL;
1486                 pr_err("unable to create usb_gadget class %d\n", status);
1487                 return status;
1488         }
1489
1490         status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1491         if (status) {
1492                 pr_err("alloc_chrdev_region %d\n", status);
1493                 class_destroy(usb_gadget_class);
1494                 usb_gadget_class = NULL;
1495                 return status;
1496         }
1497
1498         major = MAJOR(devt);
1499         minors = count;
1500
1501         return status;
1502 }
1503
1504 static void gprinter_cleanup(void)
1505 {
1506         if (major) {
1507                 unregister_chrdev_region(MKDEV(major, 0), minors);
1508                 major = minors = 0;
1509         }
1510         class_destroy(usb_gadget_class);
1511         usb_gadget_class = NULL;
1512 }