drivers/usb/gadget/function/f_printer.c

   1 /*
   2  * f_printer.c - USB printer function driver
   3  *
   4  * Copied from drivers/usb/gadget/legacy/printer.c,
   5  * which was:
   6  *
   7  * printer.c -- Printer gadget driver
   8  *
   9  * Copyright (C) 2003-2005 David Brownell
  10  * Copyright (C) 2006 Craig W. Nadler
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/delay.h>
  21 #include <linux/ioport.h>
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/mutex.h>
  25 #include <linux/errno.h>
  26 #include <linux/init.h>
  27 #include <linux/idr.h>
  28 #include <linux/timer.h>
  29 #include <linux/list.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/device.h>
  32 #include <linux/moduleparam.h>
  33 #include <linux/fs.h>
  34 #include <linux/poll.h>
  35 #include <linux/types.h>
  36 #include <linux/ctype.h>
  37 #include <linux/cdev.h>
  38 #include <linux/kref.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <linux/io.h>
  42 #include <linux/irq.h>
  43 #include <linux/uaccess.h>
  44 #include <asm/unaligned.h>
  45
  46 #include <linux/usb/ch9.h>
  47 #include <linux/usb/composite.h>
  48 #include <linux/usb/gadget.h>
  49 #include <linux/usb/g_printer.h>
  50
  51 #include "u_printer.h"
  52
  53 #define PRINTER_MINORS          4
  54 #define GET_DEVICE_ID           0
  55 #define GET_PORT_STATUS         1
  56 #define SOFT_RESET              2
  57
  58 static int major, minors;
  59 static struct class *usb_gadget_class;
  60 static DEFINE_IDA(printer_ida);
  61 static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
  62
  63 /*-------------------------------------------------------------------------*/
  64
  65 struct printer_dev {
  66         spinlock_t              lock;           /* lock this structure */
  67         /* lock buffer lists during read/write calls */
  68         struct mutex            lock_printer_io;
  69         struct usb_gadget       *gadget;
  70         s8                      interface;
  71         struct usb_ep           *in_ep, *out_ep;
  72         struct kref             kref;
  73         struct list_head        rx_reqs;        /* List of free RX structs */
  74         struct list_head        rx_reqs_active; /* List of Active RX xfers */
  75         struct list_head        rx_buffers;     /* List of completed xfers */
  76         /* wait until there is data to be read. */
  77         wait_queue_head_t       rx_wait;
  78         struct list_head        tx_reqs;        /* List of free TX structs */
  79         struct list_head        tx_reqs_active; /* List of Active TX xfers */
  80         /* Wait until there are write buffers available to use. */
  81         wait_queue_head_t       tx_wait;
  82         /* Wait until all write buffers have been sent. */
  83         wait_queue_head_t       tx_flush_wait;
  84         struct usb_request      *current_rx_req;
  85         size_t                  current_rx_bytes;
  86         u8                      *current_rx_buf;
  87         u8                      printer_status;
  88         u8                      reset_printer;
  89         int                     minor;
  90         struct cdev             printer_cdev;
  91         u8                      printer_cdev_open;
  92         wait_queue_head_t       wait;
  93         unsigned                q_len;
  94         char                    *pnp_string;    /* We don't own memory! */
  95         struct usb_function     function;
  96 };
  97
  98 static inline struct printer_dev *func_to_printer(struct usb_function *f)
  99 {
 100         return container_of(f, struct printer_dev, function);
 101 }
 102
 103 /*-------------------------------------------------------------------------*/
 104
 105 /*
 106  * DESCRIPTORS ... most are static, but strings and (full) configuration
 107  * descriptors are built on demand.
 108  */
 109
 110 /* holds our biggest descriptor */
 111 #define USB_DESC_BUFSIZE                256
 112 #define USB_BUFSIZE                     8192
 113
 114 static struct usb_interface_descriptor intf_desc = {
 115         .bLength =              sizeof(intf_desc),
 116         .bDescriptorType =      USB_DT_INTERFACE,
 117         .bNumEndpoints =        2,
 118         .bInterfaceClass =      USB_CLASS_PRINTER,
 119         .bInterfaceSubClass =   1,      /* Printer Sub-Class */
 120         .bInterfaceProtocol =   2,      /* Bi-Directional */
 121         .iInterface =           0
 122 };
 123
 124 static struct usb_endpoint_descriptor fs_ep_in_desc = {
 125         .bLength =              USB_DT_ENDPOINT_SIZE,
 126         .bDescriptorType =      USB_DT_ENDPOINT,
 127         .bEndpointAddress =     USB_DIR_IN,
 128         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 129 };
 130
 131 static struct usb_endpoint_descriptor fs_ep_out_desc = {
 132         .bLength =              USB_DT_ENDPOINT_SIZE,
 133         .bDescriptorType =      USB_DT_ENDPOINT,
 134         .bEndpointAddress =     USB_DIR_OUT,
 135         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 136 };
 137
 138 static struct usb_descriptor_header *fs_printer_function[] = {
 139         (struct usb_descriptor_header *) &intf_desc,
 140         (struct usb_descriptor_header *) &fs_ep_in_desc,
 141         (struct usb_descriptor_header *) &fs_ep_out_desc,
 142         NULL
 143 };
 144
 145 /*
 146  * usb 2.0 devices need to expose both high speed and full speed
 147  * descriptors, unless they only run at full speed.
 148  */
 149
 150 static struct usb_endpoint_descriptor hs_ep_in_desc = {
 151         .bLength =              USB_DT_ENDPOINT_SIZE,
 152         .bDescriptorType =      USB_DT_ENDPOINT,
 153         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 154         .wMaxPacketSize =       cpu_to_le16(512)
 155 };
 156
 157 static struct usb_endpoint_descriptor hs_ep_out_desc = {
 158         .bLength =              USB_DT_ENDPOINT_SIZE,
 159         .bDescriptorType =      USB_DT_ENDPOINT,
 160         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 161         .wMaxPacketSize =       cpu_to_le16(512)
 162 };
 163
 164 static struct usb_descriptor_header *hs_printer_function[] = {
 165         (struct usb_descriptor_header *) &intf_desc,
 166         (struct usb_descriptor_header *) &hs_ep_in_desc,
 167         (struct usb_descriptor_header *) &hs_ep_out_desc,
 168         NULL
 169 };
 170
 171 /*
 172  * Added endpoint descriptors for 3.0 devices
 173  */
 174
 175 static struct usb_endpoint_descriptor ss_ep_in_desc = {
 176         .bLength =              USB_DT_ENDPOINT_SIZE,
 177         .bDescriptorType =      USB_DT_ENDPOINT,
 178         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 179         .wMaxPacketSize =       cpu_to_le16(1024),
 180 };
 181
 182 static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
 183         .bLength =              sizeof(ss_ep_in_comp_desc),
 184         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 185 };
 186
 187 static struct usb_endpoint_descriptor ss_ep_out_desc = {
 188         .bLength =              USB_DT_ENDPOINT_SIZE,
 189         .bDescriptorType =      USB_DT_ENDPOINT,
 190         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 191         .wMaxPacketSize =       cpu_to_le16(1024),
 192 };
 193
 194 static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
 195         .bLength =              sizeof(ss_ep_out_comp_desc),
 196         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 197 };
 198
 199 static struct usb_descriptor_header *ss_printer_function[] = {
 200         (struct usb_descriptor_header *) &intf_desc,
 201         (struct usb_descriptor_header *) &ss_ep_in_desc,
 202         (struct usb_descriptor_header *) &ss_ep_in_comp_desc,
 203         (struct usb_descriptor_header *) &ss_ep_out_desc,
 204         (struct usb_descriptor_header *) &ss_ep_out_comp_desc,
 205         NULL
 206 };
 207
 208 /* maxpacket and other transfer characteristics vary by speed. */
 209 static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
 210                                         struct usb_endpoint_descriptor *fs,
 211                                         struct usb_endpoint_descriptor *hs,
 212                                         struct usb_endpoint_descriptor *ss)
 213 {
 214         switch (gadget->speed) {
 215         case USB_SPEED_SUPER:
 216                 return ss;
 217         case USB_SPEED_HIGH:
 218                 return hs;
 219         default:
 220                 return fs;
 221         }
 222 }
 223
 224 /*-------------------------------------------------------------------------*/
 225
 226 static void printer_dev_free(struct kref *kref)
 227 {
 228         struct printer_dev *dev = container_of(kref, struct printer_dev, kref);
 229
 230         kfree(dev);
 231 }
 232
 233 static struct usb_request *
 234 printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
 235 {
 236         struct usb_request      *req;
 237
 238         req = usb_ep_alloc_request(ep, gfp_flags);
 239
 240         if (req != NULL) {
 241                 req->length = len;
 242                 req->buf = kmalloc(len, gfp_flags);
 243                 if (req->buf == NULL) {
 244                         usb_ep_free_request(ep, req);
 245                         return NULL;
 246                 }
 247         }
 248
 249         return req;
 250 }
 251
 252 static void
 253 printer_req_free(struct usb_ep *ep, struct usb_request *req)
 254 {
 255         if (ep != NULL && req != NULL) {
 256                 kfree(req->buf);
 257                 usb_ep_free_request(ep, req);
 258         }
 259 }
 260
 261 /*-------------------------------------------------------------------------*/
 262
 263 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 264 {
 265         struct printer_dev      *dev = ep->driver_data;
 266         int                     status = req->status;
 267         unsigned long           flags;
 268
 269         spin_lock_irqsave(&dev->lock, flags);
 270
 271         list_del_init(&req->list);      /* Remode from Active List */
 272
 273         switch (status) {
 274
 275         /* normal completion */
 276         case 0:
 277                 if (req->actual > 0) {
 278                         list_add_tail(&req->list, &dev->rx_buffers);
 279                         DBG(dev, "G_Printer : rx length %d\n", req->actual);
 280                 } else {
 281                         list_add(&req->list, &dev->rx_reqs);
 282                 }
 283                 break;
 284
 285         /* software-driven interface shutdown */
 286         case -ECONNRESET:               /* unlink */
 287         case -ESHUTDOWN:                /* disconnect etc */
 288                 VDBG(dev, "rx shutdown, code %d\n", status);
 289                 list_add(&req->list, &dev->rx_reqs);
 290                 break;
 291
 292         /* for hardware automagic (such as pxa) */
 293         case -ECONNABORTED:             /* endpoint reset */
 294                 DBG(dev, "rx %s reset\n", ep->name);
 295                 list_add(&req->list, &dev->rx_reqs);
 296                 break;
 297
 298         /* data overrun */
 299         case -EOVERFLOW:
 300                 /* FALLTHROUGH */
 301
 302         default:
 303                 DBG(dev, "rx status %d\n", status);
 304                 list_add(&req->list, &dev->rx_reqs);
 305                 break;
 306         }
 307
 308         wake_up_interruptible(&dev->rx_wait);
 309         spin_unlock_irqrestore(&dev->lock, flags);
 310 }
 311
 312 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
 313 {
 314         struct printer_dev      *dev = ep->driver_data;
 315
 316         switch (req->status) {
 317         default:
 318                 VDBG(dev, "tx err %d\n", req->status);
 319                 /* FALLTHROUGH */
 320         case -ECONNRESET:               /* unlink */
 321         case -ESHUTDOWN:                /* disconnect etc */
 322                 break;
 323         case 0:
 324                 break;
 325         }
 326
 327         spin_lock(&dev->lock);
 328         /* Take the request struct off the active list and put it on the
 329          * free list.
 330          */
 331         list_del_init(&req->list);
 332         list_add(&req->list, &dev->tx_reqs);
 333         wake_up_interruptible(&dev->tx_wait);
 334         if (likely(list_empty(&dev->tx_reqs_active)))
 335                 wake_up_interruptible(&dev->tx_flush_wait);
 336
 337         spin_unlock(&dev->lock);
 338 }
 339
 340 /*-------------------------------------------------------------------------*/
 341
 342 static int
 343 printer_open(struct inode *inode, struct file *fd)
 344 {
 345         struct printer_dev      *dev;
 346         unsigned long           flags;
 347         int                     ret = -EBUSY;
 348
 349         dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
 350
 351         spin_lock_irqsave(&dev->lock, flags);
 352
 353         if (!dev->printer_cdev_open) {
 354                 dev->printer_cdev_open = 1;
 355                 fd->private_data = dev;
 356                 ret = 0;
 357                 /* Change the printer status to show that it's on-line. */
 358                 dev->printer_status |= PRINTER_SELECTED;
 359         }
 360
 361         spin_unlock_irqrestore(&dev->lock, flags);
 362
 363         kref_get(&dev->kref);
 364         DBG(dev, "printer_open returned %x\n", ret);
 365         return ret;
 366 }
 367
 368 static int
 369 printer_close(struct inode *inode, struct file *fd)
 370 {
 371         struct printer_dev      *dev = fd->private_data;
 372         unsigned long           flags;
 373
 374         spin_lock_irqsave(&dev->lock, flags);
 375         dev->printer_cdev_open = 0;
 376         fd->private_data = NULL;
 377         /* Change printer status to show that the printer is off-line. */
 378         dev->printer_status &= ~PRINTER_SELECTED;
 379         spin_unlock_irqrestore(&dev->lock, flags);
 380
 381         kref_put(&dev->kref, printer_dev_free);
 382         DBG(dev, "printer_close\n");
 383
 384         return 0;
 385 }
 386
 387 /* This function must be called with interrupts turned off. */
 388 static void
 389 setup_rx_reqs(struct printer_dev *dev)
 390 {
 391         struct usb_request              *req;
 392
 393         while (likely(!list_empty(&dev->rx_reqs))) {
 394                 int error;
 395
 396                 req = container_of(dev->rx_reqs.next,
 397                                 struct usb_request, list);
 398                 list_del_init(&req->list);
 399
 400                 /* The USB Host sends us whatever amount of data it wants to
 401                  * so we always set the length field to the full USB_BUFSIZE.
 402                  * If the amount of data is more than the read() caller asked
 403                  * for it will be stored in the request buffer until it is
 404                  * asked for by read().
 405                  */
 406                 req->length = USB_BUFSIZE;
 407                 req->complete = rx_complete;
 408
 409                 /* here, we unlock, and only unlock, to avoid deadlock. */
 410                 spin_unlock(&dev->lock);
 411                 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
 412                 spin_lock(&dev->lock);
 413                 if (error) {
 414                         DBG(dev, "rx submit --> %d\n", error);
 415                         list_add(&req->list, &dev->rx_reqs);
 416                         break;
 417                 }
 418                 /* if the req is empty, then add it into dev->rx_reqs_active. */
 419                 else if (list_empty(&req->list))
 420                         list_add(&req->list, &dev->rx_reqs_active);
 421         }
 422 }
 423
 424 static ssize_t
 425 printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 426 {
 427         struct printer_dev              *dev = fd->private_data;
 428         unsigned long                   flags;
 429         size_t                          size;
 430         size_t                          bytes_copied;
 431         struct usb_request              *req;
 432         /* This is a pointer to the current USB rx request. */
 433         struct usb_request              *current_rx_req;
 434         /* This is the number of bytes in the current rx buffer. */
 435         size_t                          current_rx_bytes;
 436         /* This is a pointer to the current rx buffer. */
 437         u8                              *current_rx_buf;
 438
 439         if (len == 0)
 440                 return -EINVAL;
 441
 442         DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
 443
 444         mutex_lock(&dev->lock_printer_io);
 445         spin_lock_irqsave(&dev->lock, flags);
 446
 447         /* We will use this flag later to check if a printer reset happened
 448          * after we turn interrupts back on.
 449          */
 450         dev->reset_printer = 0;
 451
 452         setup_rx_reqs(dev);
 453
 454         bytes_copied = 0;
 455         current_rx_req = dev->current_rx_req;
 456         current_rx_bytes = dev->current_rx_bytes;
 457         current_rx_buf = dev->current_rx_buf;
 458         dev->current_rx_req = NULL;
 459         dev->current_rx_bytes = 0;
 460         dev->current_rx_buf = NULL;
 461
 462         /* Check if there is any data in the read buffers. Please note that
 463          * current_rx_bytes is the number of bytes in the current rx buffer.
 464          * If it is zero then check if there are any other rx_buffers that
 465          * are on the completed list. We are only out of data if all rx
 466          * buffers are empty.
 467          */
 468         if ((current_rx_bytes == 0) &&
 469                         (likely(list_empty(&dev->rx_buffers)))) {
 470                 /* Turn interrupts back on before sleeping. */
 471                 spin_unlock_irqrestore(&dev->lock, flags);
 472
 473                 /*
 474                  * If no data is available check if this is a NON-Blocking
 475                  * call or not.
 476                  */
 477                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 478                         mutex_unlock(&dev->lock_printer_io);
 479                         return -EAGAIN;
 480                 }
 481
 482                 /* Sleep until data is available */
 483                 wait_event_interruptible(dev->rx_wait,
 484                                 (likely(!list_empty(&dev->rx_buffers))));
 485                 spin_lock_irqsave(&dev->lock, flags);
 486         }
 487
 488         /* We have data to return then copy it to the caller's buffer.*/
 489         while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
 490                         && len) {
 491                 if (current_rx_bytes == 0) {
 492                         req = container_of(dev->rx_buffers.next,
 493                                         struct usb_request, list);
 494                         list_del_init(&req->list);
 495
 496                         if (req->actual && req->buf) {
 497                                 current_rx_req = req;
 498                                 current_rx_bytes = req->actual;
 499                                 current_rx_buf = req->buf;
 500                         } else {
 501                                 list_add(&req->list, &dev->rx_reqs);
 502                                 continue;
 503                         }
 504                 }
 505
 506                 /* Don't leave irqs off while doing memory copies */
 507                 spin_unlock_irqrestore(&dev->lock, flags);
 508
 509                 if (len > current_rx_bytes)
 510                         size = current_rx_bytes;
 511                 else
 512                         size = len;
 513
 514                 size -= copy_to_user(buf, current_rx_buf, size);
 515                 bytes_copied += size;
 516                 len -= size;
 517                 buf += size;
 518
 519                 spin_lock_irqsave(&dev->lock, flags);
 520
 521                 /* We've disconnected or reset so return. */
 522                 if (dev->reset_printer) {
 523                         list_add(&current_rx_req->list, &dev->rx_reqs);
 524                         spin_unlock_irqrestore(&dev->lock, flags);
 525                         mutex_unlock(&dev->lock_printer_io);
 526                         return -EAGAIN;
 527                 }
 528
 529                 /* If we not returning all the data left in this RX request
 530                  * buffer then adjust the amount of data left in the buffer.
 531                  * Othewise if we are done with this RX request buffer then
 532                  * requeue it to get any incoming data from the USB host.
 533                  */
 534                 if (size < current_rx_bytes) {
 535                         current_rx_bytes -= size;
 536                         current_rx_buf += size;
 537                 } else {
 538                         list_add(&current_rx_req->list, &dev->rx_reqs);
 539                         current_rx_bytes = 0;
 540                         current_rx_buf = NULL;
 541                         current_rx_req = NULL;
 542                 }
 543         }
 544
 545         dev->current_rx_req = current_rx_req;
 546         dev->current_rx_bytes = current_rx_bytes;
 547         dev->current_rx_buf = current_rx_buf;
 548
 549         spin_unlock_irqrestore(&dev->lock, flags);
 550         mutex_unlock(&dev->lock_printer_io);
 551
 552         DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
 553
 554         if (bytes_copied)
 555                 return bytes_copied;
 556         else
 557                 return -EAGAIN;
 558 }
 559
 560 static ssize_t
 561 printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 562 {
 563         struct printer_dev      *dev = fd->private_data;
 564         unsigned long           flags;
 565         size_t                  size;   /* Amount of data in a TX request. */
 566         size_t                  bytes_copied = 0;
 567         struct usb_request      *req;
 568         int                     value;
 569
 570         DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
 571
 572         if (len == 0)
 573                 return -EINVAL;
 574
 575         mutex_lock(&dev->lock_printer_io);
 576         spin_lock_irqsave(&dev->lock, flags);
 577
 578         /* Check if a printer reset happens while we have interrupts on */
 579         dev->reset_printer = 0;
 580
 581         /* Check if there is any available write buffers */
 582         if (likely(list_empty(&dev->tx_reqs))) {
 583                 /* Turn interrupts back on before sleeping. */
 584                 spin_unlock_irqrestore(&dev->lock, flags);
 585
 586                 /*
 587                  * If write buffers are available check if this is
 588                  * a NON-Blocking call or not.
 589                  */
 590                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 591                         mutex_unlock(&dev->lock_printer_io);
 592                         return -EAGAIN;
 593                 }
 594
 595                 /* Sleep until a write buffer is available */
 596                 wait_event_interruptible(dev->tx_wait,
 597                                 (likely(!list_empty(&dev->tx_reqs))));
 598                 spin_lock_irqsave(&dev->lock, flags);
 599         }
 600
 601         while (likely(!list_empty(&dev->tx_reqs)) && len) {
 602
 603                 if (len > USB_BUFSIZE)
 604                         size = USB_BUFSIZE;
 605                 else
 606                         size = len;
 607
 608                 req = container_of(dev->tx_reqs.next, struct usb_request,
 609                                 list);
 610                 list_del_init(&req->list);
 611
 612                 req->complete = tx_complete;
 613                 req->length = size;
 614
 615                 /* Check if we need to send a zero length packet. */
 616                 if (len > size)
 617                         /* They will be more TX requests so no yet. */
 618                         req->zero = 0;
 619                 else
 620                         /* If the data amount is not a multiple of the
 621                          * maxpacket size then send a zero length packet.
 622                          */
 623                         req->zero = ((len % dev->in_ep->maxpacket) == 0);
 624
 625                 /* Don't leave irqs off while doing memory copies */
 626                 spin_unlock_irqrestore(&dev->lock, flags);
 627
 628                 if (copy_from_user(req->buf, buf, size)) {
 629                         list_add(&req->list, &dev->tx_reqs);
 630                         mutex_unlock(&dev->lock_printer_io);
 631                         return bytes_copied;
 632                 }
 633
 634                 bytes_copied += size;
 635                 len -= size;
 636                 buf += size;
 637
 638                 spin_lock_irqsave(&dev->lock, flags);
 639
 640                 /* We've disconnected or reset so free the req and buffer */
 641                 if (dev->reset_printer) {
 642                         list_add(&req->list, &dev->tx_reqs);
 643                         spin_unlock_irqrestore(&dev->lock, flags);
 644                         mutex_unlock(&dev->lock_printer_io);
 645                         return -EAGAIN;
 646                 }
 647
 648                 list_add(&req->list, &dev->tx_reqs_active);
 649
 650                 /* here, we unlock, and only unlock, to avoid deadlock. */
 651                 spin_unlock(&dev->lock);
 652                 value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
 653                 spin_lock(&dev->lock);
 654                 if (value) {
 655                         list_del(&req->list);
 656                         list_add(&req->list, &dev->tx_reqs);
 657                         spin_unlock_irqrestore(&dev->lock, flags);
 658                         mutex_unlock(&dev->lock_printer_io);
 659                         return -EAGAIN;
 660                 }
 661         }
 662
 663         spin_unlock_irqrestore(&dev->lock, flags);
 664         mutex_unlock(&dev->lock_printer_io);
 665
 666         DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
 667
 668         if (bytes_copied)
 669                 return bytes_copied;
 670         else
 671                 return -EAGAIN;
 672 }
 673
 674 static int
 675 printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
 676 {
 677         struct printer_dev      *dev = fd->private_data;
 678         struct inode *inode = file_inode(fd);
 679         unsigned long           flags;
 680         int                     tx_list_empty;
 681
 682         inode_lock(inode);
 683         spin_lock_irqsave(&dev->lock, flags);
 684         tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
 685         spin_unlock_irqrestore(&dev->lock, flags);
 686
 687         if (!tx_list_empty) {
 688                 /* Sleep until all data has been sent */
 689                 wait_event_interruptible(dev->tx_flush_wait,
 690                                 (likely(list_empty(&dev->tx_reqs_active))));
 691         }
 692         inode_unlock(inode);
 693
 694         return 0;
 695 }
 696
 697 static unsigned int
 698 printer_poll(struct file *fd, poll_table *wait)
 699 {
 700         struct printer_dev      *dev = fd->private_data;
 701         unsigned long           flags;
 702         int                     status = 0;
 703
 704         mutex_lock(&dev->lock_printer_io);
 705         spin_lock_irqsave(&dev->lock, flags);
 706         setup_rx_reqs(dev);
 707         spin_unlock_irqrestore(&dev->lock, flags);
 708         mutex_unlock(&dev->lock_printer_io);
 709
 710         poll_wait(fd, &dev->rx_wait, wait);
 711         poll_wait(fd, &dev->tx_wait, wait);
 712
 713         spin_lock_irqsave(&dev->lock, flags);
 714         if (likely(!list_empty(&dev->tx_reqs)))
 715                 status |= POLLOUT | POLLWRNORM;
 716
 717         if (likely(dev->current_rx_bytes) ||
 718                         likely(!list_empty(&dev->rx_buffers)))
 719                 status |= POLLIN | POLLRDNORM;
 720
 721         spin_unlock_irqrestore(&dev->lock, flags);
 722
 723         return status;
 724 }
 725
 726 static long
 727 printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
 728 {
 729         struct printer_dev      *dev = fd->private_data;
 730         unsigned long           flags;
 731         int                     status = 0;
 732
 733         DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
 734
 735         /* handle ioctls */
 736
 737         spin_lock_irqsave(&dev->lock, flags);
 738
 739         switch (code) {
 740         case GADGET_GET_PRINTER_STATUS:
 741                 status = (int)dev->printer_status;
 742                 break;
 743         case GADGET_SET_PRINTER_STATUS:
 744                 dev->printer_status = (u8)arg;
 745                 break;
 746         default:
 747                 /* could not handle ioctl */
 748                 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
 749                                 code);
 750                 status = -ENOTTY;
 751         }
 752
 753         spin_unlock_irqrestore(&dev->lock, flags);
 754
 755         return status;
 756 }
 757
 758 /* used after endpoint configuration */
 759 static const struct file_operations printer_io_operations = {
 760         .owner =        THIS_MODULE,
 761         .open =         printer_open,
 762         .read =         printer_read,
 763         .write =        printer_write,
 764         .fsync =        printer_fsync,
 765         .poll =         printer_poll,
 766         .unlocked_ioctl = printer_ioctl,
 767         .release =      printer_close,
 768         .llseek =       noop_llseek,
 769 };
 770
 771 /*-------------------------------------------------------------------------*/
 772
 773 static int
 774 set_printer_interface(struct printer_dev *dev)
 775 {
 776         int                     result = 0;
 777
 778         dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
 779                                 &ss_ep_in_desc);
 780         dev->in_ep->driver_data = dev;
 781
 782         dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
 783                                     &hs_ep_out_desc, &ss_ep_out_desc);
 784         dev->out_ep->driver_data = dev;
 785
 786         result = usb_ep_enable(dev->in_ep);
 787         if (result != 0) {
 788                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 789                 goto done;
 790         }
 791
 792         result = usb_ep_enable(dev->out_ep);
 793         if (result != 0) {
 794                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 795                 goto done;
 796         }
 797
 798 done:
 799         /* on error, disable any endpoints  */
 800         if (result != 0) {
 801                 (void) usb_ep_disable(dev->in_ep);
 802                 (void) usb_ep_disable(dev->out_ep);
 803                 dev->in_ep->desc = NULL;
 804                 dev->out_ep->desc = NULL;
 805         }
 806
 807         /* caller is responsible for cleanup on error */
 808         return result;
 809 }
 810
 811 static void printer_reset_interface(struct printer_dev *dev)
 812 {
 813         unsigned long   flags;
 814
 815         if (dev->interface < 0)
 816                 return;
 817
 818         DBG(dev, "%s\n", __func__);
 819
 820         if (dev->in_ep->desc)
 821                 usb_ep_disable(dev->in_ep);
 822
 823         if (dev->out_ep->desc)
 824                 usb_ep_disable(dev->out_ep);
 825
 826         spin_lock_irqsave(&dev->lock, flags);
 827         dev->in_ep->desc = NULL;
 828         dev->out_ep->desc = NULL;
 829         dev->interface = -1;
 830         spin_unlock_irqrestore(&dev->lock, flags);
 831 }
 832
 833 /* Change our operational Interface. */
 834 static int set_interface(struct printer_dev *dev, unsigned number)
 835 {
 836         int                     result = 0;
 837
 838         /* Free the current interface */
 839         printer_reset_interface(dev);
 840
 841         result = set_printer_interface(dev);
 842         if (result)
 843                 printer_reset_interface(dev);
 844         else
 845                 dev->interface = number;
 846
 847         if (!result)
 848                 INFO(dev, "Using interface %x\n", number);
 849
 850         return result;
 851 }
 852
 853 static void printer_soft_reset(struct printer_dev *dev)
 854 {
 855         struct usb_request      *req;
 856
 857         INFO(dev, "Received Printer Reset Request\n");
 858
 859         if (usb_ep_disable(dev->in_ep))
 860                 DBG(dev, "Failed to disable USB in_ep\n");
 861         if (usb_ep_disable(dev->out_ep))
 862                 DBG(dev, "Failed to disable USB out_ep\n");
 863
 864         if (dev->current_rx_req != NULL) {
 865                 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
 866                 dev->current_rx_req = NULL;
 867         }
 868         dev->current_rx_bytes = 0;
 869         dev->current_rx_buf = NULL;
 870         dev->reset_printer = 1;
 871
 872         while (likely(!(list_empty(&dev->rx_buffers)))) {
 873                 req = container_of(dev->rx_buffers.next, struct usb_request,
 874                                 list);
 875                 list_del_init(&req->list);
 876                 list_add(&req->list, &dev->rx_reqs);
 877         }
 878
 879         while (likely(!(list_empty(&dev->rx_reqs_active)))) {
 880                 req = container_of(dev->rx_buffers.next, struct usb_request,
 881                                 list);
 882                 list_del_init(&req->list);
 883                 list_add(&req->list, &dev->rx_reqs);
 884         }
 885
 886         while (likely(!(list_empty(&dev->tx_reqs_active)))) {
 887                 req = container_of(dev->tx_reqs_active.next,
 888                                 struct usb_request, list);
 889                 list_del_init(&req->list);
 890                 list_add(&req->list, &dev->tx_reqs);
 891         }
 892
 893         if (usb_ep_enable(dev->in_ep))
 894                 DBG(dev, "Failed to enable USB in_ep\n");
 895         if (usb_ep_enable(dev->out_ep))
 896                 DBG(dev, "Failed to enable USB out_ep\n");
 897
 898         wake_up_interruptible(&dev->rx_wait);
 899         wake_up_interruptible(&dev->tx_wait);
 900         wake_up_interruptible(&dev->tx_flush_wait);
 901 }
 902
 903 /*-------------------------------------------------------------------------*/
 904
 905 static bool gprinter_req_match(struct usb_function *f,
 906                                const struct usb_ctrlrequest *ctrl,
 907                                bool config0)
 908 {
 909         struct printer_dev      *dev = func_to_printer(f);
 910         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 911         u16                     w_value = le16_to_cpu(ctrl->wValue);
 912         u16                     w_length = le16_to_cpu(ctrl->wLength);
 913
 914         if (config0)
 915                 return false;
 916
 917         if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
 918             (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
 919                 return false;
 920
 921         switch (ctrl->bRequest) {
 922         case GET_DEVICE_ID:
 923                 w_index >>= 8;
 924                 if (USB_DIR_IN & ctrl->bRequestType)
 925                         break;
 926                 return false;
 927         case GET_PORT_STATUS:
 928                 if (!w_value && w_length == 1 &&
 929                     (USB_DIR_IN & ctrl->bRequestType))
 930                         break;
 931                 return false;
 932         case SOFT_RESET:
 933                 if (!w_value && !w_length &&
 934                    !(USB_DIR_IN & ctrl->bRequestType))
 935                         break;
 936                 /* fall through */
 937         default:
 938                 return false;
 939         }
 940         return w_index == dev->interface;
 941 }
 942
 943 /*
 944  * The setup() callback implements all the ep0 functionality that's not
 945  * handled lower down.
 946  */
 947 static int printer_func_setup(struct usb_function *f,
 948                 const struct usb_ctrlrequest *ctrl)
 949 {
 950         struct printer_dev *dev = func_to_printer(f);
 951         struct usb_composite_dev *cdev = f->config->cdev;
 952         struct usb_request      *req = cdev->req;
 953         u8                      *buf = req->buf;
 954         int                     value = -EOPNOTSUPP;
 955         u16                     wIndex = le16_to_cpu(ctrl->wIndex);
 956         u16                     wValue = le16_to_cpu(ctrl->wValue);
 957         u16                     wLength = le16_to_cpu(ctrl->wLength);
 958
 959         DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
 960                 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
 961
 962         switch (ctrl->bRequestType&USB_TYPE_MASK) {
 963         case USB_TYPE_CLASS:
 964                 switch (ctrl->bRequest) {
 965                 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
 966                         /* Only one printer interface is supported. */
 967                         if ((wIndex>>8) != dev->interface)
 968                                 break;
 969
 970                         if (!dev->pnp_string) {
 971                                 value = 0;
 972                                 break;
 973                         }
 974                         value = strlen(dev->pnp_string);
 975                         buf[0] = (value >> 8) & 0xFF;
 976                         buf[1] = value & 0xFF;
 977                         memcpy(buf + 2, dev->pnp_string, value);
 978                         DBG(dev, "1284 PNP String: %x %s\n", value,
 979                             dev->pnp_string);
 980                         break;
 981
 982                 case GET_PORT_STATUS: /* Get Port Status */
 983                         /* Only one printer interface is supported. */
 984                         if (wIndex != dev->interface)
 985                                 break;
 986
 987                         buf[0] = dev->printer_status;
 988                         value = min_t(u16, wLength, 1);
 989                         break;
 990
 991                 case SOFT_RESET: /* Soft Reset */
 992                         /* Only one printer interface is supported. */
 993                         if (wIndex != dev->interface)
 994                                 break;
 995
 996                         printer_soft_reset(dev);
 997
 998                         value = 0;
 999                         break;
1000
1001                 default:
1002                         goto unknown;
1003                 }
1004                 break;
1005
1006         default:
1007 unknown:
1008                 VDBG(dev,
1009                         "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
1010                         ctrl->bRequestType, ctrl->bRequest,
1011                         wValue, wIndex, wLength);
1012                 break;
1013         }
1014         /* host either stalls (value < 0) or reports success */
1015         if (value >= 0) {
1016                 req->length = value;
1017                 req->zero = value < wLength;
1018                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1019                 if (value < 0) {
1020                         ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1021                         req->status = 0;
1022                 }
1023         }
1024         return value;
1025 }
1026
1027 static int printer_func_bind(struct usb_configuration *c,
1028                 struct usb_function *f)
1029 {
1030         struct usb_gadget *gadget = c->cdev->gadget;
1031         struct printer_dev *dev = func_to_printer(f);
1032         struct device *pdev;
1033         struct usb_composite_dev *cdev = c->cdev;
1034         struct usb_ep *in_ep;
1035         struct usb_ep *out_ep = NULL;
1036         struct usb_request *req;
1037         dev_t devt;
1038         int id;
1039         int ret;
1040         u32 i;
1041
1042         id = usb_interface_id(c, f);
1043         if (id < 0)
1044                 return id;
1045         intf_desc.bInterfaceNumber = id;
1046
1047         /* finish hookup to lower layer ... */
1048         dev->gadget = gadget;
1049
1050         /* all we really need is bulk IN/OUT */
1051         in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1052         if (!in_ep) {
1053 autoconf_fail:
1054                 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1055                         cdev->gadget->name);
1056                 return -ENODEV;
1057         }
1058
1059         out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1060         if (!out_ep)
1061                 goto autoconf_fail;
1062
1063         /* assumes that all endpoints are dual-speed */
1064         hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1065         hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1066         ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1067         ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1068
1069         ret = usb_assign_descriptors(f, fs_printer_function,
1070                         hs_printer_function, ss_printer_function,
1071                         ss_printer_function);
1072         if (ret)
1073                 return ret;
1074
1075         dev->in_ep = in_ep;
1076         dev->out_ep = out_ep;
1077
1078         ret = -ENOMEM;
1079         for (i = 0; i < dev->q_len; i++) {
1080                 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1081                 if (!req)
1082                         goto fail_tx_reqs;
1083                 list_add(&req->list, &dev->tx_reqs);
1084         }
1085
1086         for (i = 0; i < dev->q_len; i++) {
1087                 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1088                 if (!req)
1089                         goto fail_rx_reqs;
1090                 list_add(&req->list, &dev->rx_reqs);
1091         }
1092
1093         /* Setup the sysfs files for the printer gadget. */
1094         devt = MKDEV(major, dev->minor);
1095         pdev = device_create(usb_gadget_class, NULL, devt,
1096                                   NULL, "g_printer%d", dev->minor);
1097         if (IS_ERR(pdev)) {
1098                 ERROR(dev, "Failed to create device: g_printer\n");
1099                 ret = PTR_ERR(pdev);
1100                 goto fail_rx_reqs;
1101         }
1102
1103         /*
1104          * Register a character device as an interface to a user mode
1105          * program that handles the printer specific functionality.
1106          */
1107         cdev_init(&dev->printer_cdev, &printer_io_operations);
1108         dev->printer_cdev.owner = THIS_MODULE;
1109         ret = cdev_add(&dev->printer_cdev, devt, 1);
1110         if (ret) {
1111                 ERROR(dev, "Failed to open char device\n");
1112                 goto fail_cdev_add;
1113         }
1114
1115         return 0;
1116
1117 fail_cdev_add:
1118         device_destroy(usb_gadget_class, devt);
1119
1120 fail_rx_reqs:
1121         while (!list_empty(&dev->rx_reqs)) {
1122                 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1123                 list_del(&req->list);
1124                 printer_req_free(dev->out_ep, req);
1125         }
1126
1127 fail_tx_reqs:
1128         while (!list_empty(&dev->tx_reqs)) {
1129                 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1130                 list_del(&req->list);
1131                 printer_req_free(dev->in_ep, req);
1132         }
1133
1134         usb_free_all_descriptors(f);
1135         return ret;
1136
1137 }
1138
1139 static int printer_func_set_alt(struct usb_function *f,
1140                 unsigned intf, unsigned alt)
1141 {
1142         struct printer_dev *dev = func_to_printer(f);
1143         int ret = -ENOTSUPP;
1144
1145         if (!alt)
1146                 ret = set_interface(dev, intf);
1147
1148         return ret;
1149 }
1150
1151 static void printer_func_disable(struct usb_function *f)
1152 {
1153         struct printer_dev *dev = func_to_printer(f);
1154
1155         DBG(dev, "%s\n", __func__);
1156
1157         printer_reset_interface(dev);
1158 }
1159
1160 static inline struct f_printer_opts
1161 *to_f_printer_opts(struct config_item *item)
1162 {
1163         return container_of(to_config_group(item), struct f_printer_opts,
1164                             func_inst.group);
1165 }
1166
1167 static void printer_attr_release(struct config_item *item)
1168 {
1169         struct f_printer_opts *opts = to_f_printer_opts(item);
1170
1171         usb_put_function_instance(&opts->func_inst);
1172 }
1173
1174 static struct configfs_item_operations printer_item_ops = {
1175         .release        = printer_attr_release,
1176 };
1177
1178 static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1179                                               char *page)
1180 {
1181         struct f_printer_opts *opts = to_f_printer_opts(item);
1182         int result = 0;
1183
1184         mutex_lock(&opts->lock);
1185         if (!opts->pnp_string)
1186                 goto unlock;
1187
1188         result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
1189         if (result >= PAGE_SIZE) {
1190                 result = PAGE_SIZE;
1191         } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
1192                 page[result++] = '\n';
1193                 page[result] = '\0';
1194         }
1195
1196 unlock:
1197         mutex_unlock(&opts->lock);
1198
1199         return result;
1200 }
1201
1202 static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1203                                                const char *page, size_t len)
1204 {
1205         struct f_printer_opts *opts = to_f_printer_opts(item);
1206         char *new_pnp;
1207         int result;
1208
1209         mutex_lock(&opts->lock);
1210
1211         new_pnp = kstrndup(page, len, GFP_KERNEL);
1212         if (!new_pnp) {
1213                 result = -ENOMEM;
1214                 goto unlock;
1215         }
1216
1217         if (opts->pnp_string_allocated)
1218                 kfree(opts->pnp_string);
1219
1220         opts->pnp_string_allocated = true;
1221         opts->pnp_string = new_pnp;
1222         result = len;
1223 unlock:
1224         mutex_unlock(&opts->lock);
1225
1226         return result;
1227 }
1228
1229 CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1230
1231 static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1232                                          char *page)
1233 {
1234         struct f_printer_opts *opts = to_f_printer_opts(item);
1235         int result;
1236
1237         mutex_lock(&opts->lock);
1238         result = sprintf(page, "%d\n", opts->q_len);
1239         mutex_unlock(&opts->lock);
1240
1241         return result;
1242 }
1243
1244 static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1245                                           const char *page, size_t len)
1246 {
1247         struct f_printer_opts *opts = to_f_printer_opts(item);
1248         int ret;
1249         u16 num;
1250
1251         mutex_lock(&opts->lock);
1252         if (opts->refcnt) {
1253                 ret = -EBUSY;
1254                 goto end;
1255         }
1256
1257         ret = kstrtou16(page, 0, &num);
1258         if (ret)
1259                 goto end;
1260
1261         opts->q_len = (unsigned)num;
1262         ret = len;
1263 end:
1264         mutex_unlock(&opts->lock);
1265         return ret;
1266 }
1267
1268 CONFIGFS_ATTR(f_printer_opts_, q_len);
1269
1270 static struct configfs_attribute *printer_attrs[] = {
1271         &f_printer_opts_attr_pnp_string,
1272         &f_printer_opts_attr_q_len,
1273         NULL,
1274 };
1275
1276 static struct config_item_type printer_func_type = {
1277         .ct_item_ops    = &printer_item_ops,
1278         .ct_attrs       = printer_attrs,
1279         .ct_owner       = THIS_MODULE,
1280 };
1281
1282 static inline int gprinter_get_minor(void)
1283 {
1284         int ret;
1285
1286         ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1287         if (ret >= PRINTER_MINORS) {
1288                 ida_simple_remove(&printer_ida, ret);
1289                 ret = -ENODEV;
1290         }
1291
1292         return ret;
1293 }
1294
1295 static inline void gprinter_put_minor(int minor)
1296 {
1297         ida_simple_remove(&printer_ida, minor);
1298 }
1299
1300 static int gprinter_setup(int);
1301 static void gprinter_cleanup(void);
1302
1303 static void gprinter_free_inst(struct usb_function_instance *f)
1304 {
1305         struct f_printer_opts *opts;
1306
1307         opts = container_of(f, struct f_printer_opts, func_inst);
1308
1309         mutex_lock(&printer_ida_lock);
1310
1311         gprinter_put_minor(opts->minor);
1312         if (ida_is_empty(&printer_ida))
1313                 gprinter_cleanup();
1314
1315         mutex_unlock(&printer_ida_lock);
1316
1317         if (opts->pnp_string_allocated)
1318                 kfree(opts->pnp_string);
1319         kfree(opts);
1320 }
1321
1322 static struct usb_function_instance *gprinter_alloc_inst(void)
1323 {
1324         struct f_printer_opts *opts;
1325         struct usb_function_instance *ret;
1326         int status = 0;
1327
1328         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1329         if (!opts)
1330                 return ERR_PTR(-ENOMEM);
1331
1332         mutex_init(&opts->lock);
1333         opts->func_inst.free_func_inst = gprinter_free_inst;
1334         ret = &opts->func_inst;
1335
1336         mutex_lock(&printer_ida_lock);
1337
1338         if (ida_is_empty(&printer_ida)) {
1339                 status = gprinter_setup(PRINTER_MINORS);
1340                 if (status) {
1341                         ret = ERR_PTR(status);
1342                         kfree(opts);
1343                         goto unlock;
1344                 }
1345         }
1346
1347         opts->minor = gprinter_get_minor();
1348         if (opts->minor < 0) {
1349                 ret = ERR_PTR(opts->minor);
1350                 kfree(opts);
1351                 if (ida_is_empty(&printer_ida))
1352                         gprinter_cleanup();
1353                 goto unlock;
1354         }
1355         config_group_init_type_name(&opts->func_inst.group, "",
1356                                     &printer_func_type);
1357
1358 unlock:
1359         mutex_unlock(&printer_ida_lock);
1360         return ret;
1361 }
1362
1363 static void gprinter_free(struct usb_function *f)
1364 {
1365         struct printer_dev *dev = func_to_printer(f);
1366         struct f_printer_opts *opts;
1367
1368         opts = container_of(f->fi, struct f_printer_opts, func_inst);
1369
1370         kref_put(&dev->kref, printer_dev_free);
1371         mutex_lock(&opts->lock);
1372         --opts->refcnt;
1373         mutex_unlock(&opts->lock);
1374 }
1375
1376 static void printer_func_unbind(struct usb_configuration *c,
1377                 struct usb_function *f)
1378 {
1379         struct printer_dev      *dev;
1380         struct usb_request      *req;
1381
1382         dev = func_to_printer(f);
1383
1384         device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1385
1386         /* Remove Character Device */
1387         cdev_del(&dev->printer_cdev);
1388
1389         /* we must already have been disconnected ... no i/o may be active */
1390         WARN_ON(!list_empty(&dev->tx_reqs_active));
1391         WARN_ON(!list_empty(&dev->rx_reqs_active));
1392
1393         /* Free all memory for this driver. */
1394         while (!list_empty(&dev->tx_reqs)) {
1395                 req = container_of(dev->tx_reqs.next, struct usb_request,
1396                                 list);
1397                 list_del(&req->list);
1398                 printer_req_free(dev->in_ep, req);
1399         }
1400
1401         if (dev->current_rx_req != NULL)
1402                 printer_req_free(dev->out_ep, dev->current_rx_req);
1403
1404         while (!list_empty(&dev->rx_reqs)) {
1405                 req = container_of(dev->rx_reqs.next,
1406                                 struct usb_request, list);
1407                 list_del(&req->list);
1408                 printer_req_free(dev->out_ep, req);
1409         }
1410
1411         while (!list_empty(&dev->rx_buffers)) {
1412                 req = container_of(dev->rx_buffers.next,
1413                                 struct usb_request, list);
1414                 list_del(&req->list);
1415                 printer_req_free(dev->out_ep, req);
1416         }
1417         usb_free_all_descriptors(f);
1418 }
1419
1420 static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1421 {
1422         struct printer_dev      *dev;
1423         struct f_printer_opts   *opts;
1424
1425         opts = container_of(fi, struct f_printer_opts, func_inst);
1426
1427         mutex_lock(&opts->lock);
1428         if (opts->minor >= minors) {
1429                 mutex_unlock(&opts->lock);
1430                 return ERR_PTR(-ENOENT);
1431         }
1432
1433         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1434         if (!dev) {
1435                 mutex_unlock(&opts->lock);
1436                 return ERR_PTR(-ENOMEM);
1437         }
1438
1439         kref_init(&dev->kref);
1440         ++opts->refcnt;
1441         dev->minor = opts->minor;
1442         dev->pnp_string = opts->pnp_string;
1443         dev->q_len = opts->q_len;
1444         mutex_unlock(&opts->lock);
1445
1446         dev->function.name = "printer";
1447         dev->function.bind = printer_func_bind;
1448         dev->function.setup = printer_func_setup;
1449         dev->function.unbind = printer_func_unbind;
1450         dev->function.set_alt = printer_func_set_alt;
1451         dev->function.disable = printer_func_disable;
1452         dev->function.req_match = gprinter_req_match;
1453         dev->function.free_func = gprinter_free;
1454
1455         INIT_LIST_HEAD(&dev->tx_reqs);
1456         INIT_LIST_HEAD(&dev->rx_reqs);
1457         INIT_LIST_HEAD(&dev->rx_buffers);
1458         INIT_LIST_HEAD(&dev->tx_reqs_active);
1459         INIT_LIST_HEAD(&dev->rx_reqs_active);
1460
1461         spin_lock_init(&dev->lock);
1462         mutex_init(&dev->lock_printer_io);
1463         init_waitqueue_head(&dev->rx_wait);
1464         init_waitqueue_head(&dev->tx_wait);
1465         init_waitqueue_head(&dev->tx_flush_wait);
1466
1467         dev->interface = -1;
1468         dev->printer_cdev_open = 0;
1469         dev->printer_status = PRINTER_NOT_ERROR;
1470         dev->current_rx_req = NULL;
1471         dev->current_rx_bytes = 0;
1472         dev->current_rx_buf = NULL;
1473
1474         return &dev->function;
1475 }
1476
1477 DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1478 MODULE_LICENSE("GPL");
1479 MODULE_AUTHOR("Craig Nadler");
1480
1481 static int gprinter_setup(int count)
1482 {
1483         int status;
1484         dev_t devt;
1485
1486         usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1487         if (IS_ERR(usb_gadget_class)) {
1488                 status = PTR_ERR(usb_gadget_class);
1489                 usb_gadget_class = NULL;
1490                 pr_err("unable to create usb_gadget class %d\n", status);
1491                 return status;
1492         }
1493
1494         status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1495         if (status) {
1496                 pr_err("alloc_chrdev_region %d\n", status);
1497                 class_destroy(usb_gadget_class);
1498                 usb_gadget_class = NULL;
1499                 return status;
1500         }
1501
1502         major = MAJOR(devt);
1503         minors = count;
1504
1505         return status;
1506 }
1507
1508 static void gprinter_cleanup(void)
1509 {
1510         if (major) {
1511                 unregister_chrdev_region(MKDEV(major, 0), minors);
1512                 major = minors = 0;
1513         }
1514         class_destroy(usb_gadget_class);
1515         usb_gadget_class = NULL;
1516 }