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