drivers/usb/gadget/printer.c

   1 /*
   2  * printer.c -- Printer gadget driver
   3  *
   4  * Copyright (C) 2003-2005 David Brownell
   5  * Copyright (C) 2006 Craig W. Nadler
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/delay.h>
  16 #include <linux/ioport.h>
  17 #include <linux/sched.h>
  18 #include <linux/slab.h>
  19 #include <linux/mutex.h>
  20 #include <linux/errno.h>
  21 #include <linux/init.h>
  22 #include <linux/timer.h>
  23 #include <linux/list.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/device.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/fs.h>
  28 #include <linux/poll.h>
  29 #include <linux/types.h>
  30 #include <linux/ctype.h>
  31 #include <linux/cdev.h>
  32
  33 #include <asm/byteorder.h>
  34 #include <linux/io.h>
  35 #include <linux/irq.h>
  36 #include <linux/uaccess.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <linux/usb/ch9.h>
  40 #include <linux/usb/composite.h>
  41 #include <linux/usb/gadget.h>
  42 #include <linux/usb/g_printer.h>
  43
  44 #include "gadget_chips.h"
  45
  46 USB_GADGET_COMPOSITE_OPTIONS();
  47
  48 #define DRIVER_DESC             "Printer Gadget"
  49 #define DRIVER_VERSION          "2007 OCT 06"
  50
  51 static DEFINE_MUTEX(printer_mutex);
  52 static const char shortname [] = "printer";
  53 static const char driver_desc [] = DRIVER_DESC;
  54
  55 static dev_t g_printer_devno;
  56
  57 static struct class *usb_gadget_class;
  58
  59 /*-------------------------------------------------------------------------*/
  60
  61 struct printer_dev {
  62         spinlock_t              lock;           /* lock this structure */
  63         /* lock buffer lists during read/write calls */
  64         struct mutex            lock_printer_io;
  65         struct usb_gadget       *gadget;
  66         s8                      interface;
  67         struct usb_ep           *in_ep, *out_ep;
  68
  69         struct list_head        rx_reqs;        /* List of free RX structs */
  70         struct list_head        rx_reqs_active; /* List of Active RX xfers */
  71         struct list_head        rx_buffers;     /* List of completed xfers */
  72         /* wait until there is data to be read. */
  73         wait_queue_head_t       rx_wait;
  74         struct list_head        tx_reqs;        /* List of free TX structs */
  75         struct list_head        tx_reqs_active; /* List of Active TX xfers */
  76         /* Wait until there are write buffers available to use. */
  77         wait_queue_head_t       tx_wait;
  78         /* Wait until all write buffers have been sent. */
  79         wait_queue_head_t       tx_flush_wait;
  80         struct usb_request      *current_rx_req;
  81         size_t                  current_rx_bytes;
  82         u8                      *current_rx_buf;
  83         u8                      printer_status;
  84         u8                      reset_printer;
  85         struct cdev             printer_cdev;
  86         struct device           *pdev;
  87         u8                      printer_cdev_open;
  88         wait_queue_head_t       wait;
  89         struct usb_function     function;
  90 };
  91
  92 static struct printer_dev usb_printer_gadget;
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  97  * Instead:  allocate your own, using normal USB-IF procedures.
  98  */
  99
 100 /* Thanks to NetChip Technologies for donating this product ID.
 101  */
 102 #define PRINTER_VENDOR_NUM      0x0525          /* NetChip */
 103 #define PRINTER_PRODUCT_NUM     0xa4a8          /* Linux-USB Printer Gadget */
 104
 105 /* Some systems will want different product identifiers published in the
 106  * device descriptor, either numbers or strings or both.  These string
 107  * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
 108  */
 109
 110 module_param_named(iSerialNum, coverwrite.serial_number, charp, S_IRUGO);
 111 MODULE_PARM_DESC(iSerialNum, "1");
 112
 113 static char *iPNPstring;
 114 module_param(iPNPstring, charp, S_IRUGO);
 115 MODULE_PARM_DESC(iPNPstring, "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;");
 116
 117 /* Number of requests to allocate per endpoint, not used for ep0. */
 118 static unsigned qlen = 10;
 119 module_param(qlen, uint, S_IRUGO|S_IWUSR);
 120
 121 #define QLEN    qlen
 122
 123 /*-------------------------------------------------------------------------*/
 124
 125 /*
 126  * DESCRIPTORS ... most are static, but strings and (full) configuration
 127  * descriptors are built on demand.
 128  */
 129
 130 /* holds our biggest descriptor */
 131 #define USB_DESC_BUFSIZE                256
 132 #define USB_BUFSIZE                     8192
 133
 134 static struct usb_device_descriptor device_desc = {
 135         .bLength =              sizeof device_desc,
 136         .bDescriptorType =      USB_DT_DEVICE,
 137         .bcdUSB =               cpu_to_le16(0x0200),
 138         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 139         .bDeviceSubClass =      0,
 140         .bDeviceProtocol =      0,
 141         .idVendor =             cpu_to_le16(PRINTER_VENDOR_NUM),
 142         .idProduct =            cpu_to_le16(PRINTER_PRODUCT_NUM),
 143         .bNumConfigurations =   1
 144 };
 145
 146 static struct usb_interface_descriptor intf_desc = {
 147         .bLength =              sizeof intf_desc,
 148         .bDescriptorType =      USB_DT_INTERFACE,
 149         .bNumEndpoints =        2,
 150         .bInterfaceClass =      USB_CLASS_PRINTER,
 151         .bInterfaceSubClass =   1,      /* Printer Sub-Class */
 152         .bInterfaceProtocol =   2,      /* Bi-Directional */
 153         .iInterface =           0
 154 };
 155
 156 static struct usb_endpoint_descriptor fs_ep_in_desc = {
 157         .bLength =              USB_DT_ENDPOINT_SIZE,
 158         .bDescriptorType =      USB_DT_ENDPOINT,
 159         .bEndpointAddress =     USB_DIR_IN,
 160         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 161 };
 162
 163 static struct usb_endpoint_descriptor fs_ep_out_desc = {
 164         .bLength =              USB_DT_ENDPOINT_SIZE,
 165         .bDescriptorType =      USB_DT_ENDPOINT,
 166         .bEndpointAddress =     USB_DIR_OUT,
 167         .bmAttributes =         USB_ENDPOINT_XFER_BULK
 168 };
 169
 170 static struct usb_descriptor_header *fs_printer_function[] = {
 171         (struct usb_descriptor_header *) &intf_desc,
 172         (struct usb_descriptor_header *) &fs_ep_in_desc,
 173         (struct usb_descriptor_header *) &fs_ep_out_desc,
 174         NULL
 175 };
 176
 177 /*
 178  * usb 2.0 devices need to expose both high speed and full speed
 179  * descriptors, unless they only run at full speed.
 180  */
 181
 182 static struct usb_endpoint_descriptor hs_ep_in_desc = {
 183         .bLength =              USB_DT_ENDPOINT_SIZE,
 184         .bDescriptorType =      USB_DT_ENDPOINT,
 185         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 186         .wMaxPacketSize =       cpu_to_le16(512)
 187 };
 188
 189 static struct usb_endpoint_descriptor hs_ep_out_desc = {
 190         .bLength =              USB_DT_ENDPOINT_SIZE,
 191         .bDescriptorType =      USB_DT_ENDPOINT,
 192         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 193         .wMaxPacketSize =       cpu_to_le16(512)
 194 };
 195
 196 static struct usb_qualifier_descriptor dev_qualifier = {
 197         .bLength =              sizeof dev_qualifier,
 198         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
 199         .bcdUSB =               cpu_to_le16(0x0200),
 200         .bDeviceClass =         USB_CLASS_PRINTER,
 201         .bNumConfigurations =   1
 202 };
 203
 204 static struct usb_descriptor_header *hs_printer_function[] = {
 205         (struct usb_descriptor_header *) &intf_desc,
 206         (struct usb_descriptor_header *) &hs_ep_in_desc,
 207         (struct usb_descriptor_header *) &hs_ep_out_desc,
 208         NULL
 209 };
 210
 211 static struct usb_otg_descriptor otg_descriptor = {
 212         .bLength =              sizeof otg_descriptor,
 213         .bDescriptorType =      USB_DT_OTG,
 214         .bmAttributes =         USB_OTG_SRP,
 215 };
 216
 217 static const struct usb_descriptor_header *otg_desc[] = {
 218         (struct usb_descriptor_header *) &otg_descriptor,
 219         NULL,
 220 };
 221
 222 /* maxpacket and other transfer characteristics vary by speed. */
 223 #define ep_desc(g, hs, fs) (((g)->speed == USB_SPEED_HIGH)?(hs):(fs))
 224
 225 /*-------------------------------------------------------------------------*/
 226
 227 /* descriptors that are built on-demand */
 228
 229 static char                             product_desc [40] = DRIVER_DESC;
 230 static char                             serial_num [40] = "1";
 231 static char                             pnp_string [1024] =
 232         "XXMFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
 233
 234 /* static strings, in UTF-8 */
 235 static struct usb_string                strings [] = {
 236         [USB_GADGET_MANUFACTURER_IDX].s = "",
 237         [USB_GADGET_PRODUCT_IDX].s = product_desc,
 238         [USB_GADGET_SERIAL_IDX].s =     serial_num,
 239         {  }            /* end of list */
 240 };
 241
 242 static struct usb_gadget_strings        stringtab_dev = {
 243         .language       = 0x0409,       /* en-us */
 244         .strings        = strings,
 245 };
 246
 247 static struct usb_gadget_strings *dev_strings[] = {
 248         &stringtab_dev,
 249         NULL,
 250 };
 251
 252 /*-------------------------------------------------------------------------*/
 253
 254 static struct usb_request *
 255 printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
 256 {
 257         struct usb_request      *req;
 258
 259         req = usb_ep_alloc_request(ep, gfp_flags);
 260
 261         if (req != NULL) {
 262                 req->length = len;
 263                 req->buf = kmalloc(len, gfp_flags);
 264                 if (req->buf == NULL) {
 265                         usb_ep_free_request(ep, req);
 266                         return NULL;
 267                 }
 268         }
 269
 270         return req;
 271 }
 272
 273 static void
 274 printer_req_free(struct usb_ep *ep, struct usb_request *req)
 275 {
 276         if (ep != NULL && req != NULL) {
 277                 kfree(req->buf);
 278                 usb_ep_free_request(ep, req);
 279         }
 280 }
 281
 282 /*-------------------------------------------------------------------------*/
 283
 284 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 285 {
 286         struct printer_dev      *dev = ep->driver_data;
 287         int                     status = req->status;
 288         unsigned long           flags;
 289
 290         spin_lock_irqsave(&dev->lock, flags);
 291
 292         list_del_init(&req->list);      /* Remode from Active List */
 293
 294         switch (status) {
 295
 296         /* normal completion */
 297         case 0:
 298                 if (req->actual > 0) {
 299                         list_add_tail(&req->list, &dev->rx_buffers);
 300                         DBG(dev, "G_Printer : rx length %d\n", req->actual);
 301                 } else {
 302                         list_add(&req->list, &dev->rx_reqs);
 303                 }
 304                 break;
 305
 306         /* software-driven interface shutdown */
 307         case -ECONNRESET:               /* unlink */
 308         case -ESHUTDOWN:                /* disconnect etc */
 309                 VDBG(dev, "rx shutdown, code %d\n", status);
 310                 list_add(&req->list, &dev->rx_reqs);
 311                 break;
 312
 313         /* for hardware automagic (such as pxa) */
 314         case -ECONNABORTED:             /* endpoint reset */
 315                 DBG(dev, "rx %s reset\n", ep->name);
 316                 list_add(&req->list, &dev->rx_reqs);
 317                 break;
 318
 319         /* data overrun */
 320         case -EOVERFLOW:
 321                 /* FALLTHROUGH */
 322
 323         default:
 324                 DBG(dev, "rx status %d\n", status);
 325                 list_add(&req->list, &dev->rx_reqs);
 326                 break;
 327         }
 328
 329         wake_up_interruptible(&dev->rx_wait);
 330         spin_unlock_irqrestore(&dev->lock, flags);
 331 }
 332
 333 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
 334 {
 335         struct printer_dev      *dev = ep->driver_data;
 336
 337         switch (req->status) {
 338         default:
 339                 VDBG(dev, "tx err %d\n", req->status);
 340                 /* FALLTHROUGH */
 341         case -ECONNRESET:               /* unlink */
 342         case -ESHUTDOWN:                /* disconnect etc */
 343                 break;
 344         case 0:
 345                 break;
 346         }
 347
 348         spin_lock(&dev->lock);
 349         /* Take the request struct off the active list and put it on the
 350          * free list.
 351          */
 352         list_del_init(&req->list);
 353         list_add(&req->list, &dev->tx_reqs);
 354         wake_up_interruptible(&dev->tx_wait);
 355         if (likely(list_empty(&dev->tx_reqs_active)))
 356                 wake_up_interruptible(&dev->tx_flush_wait);
 357
 358         spin_unlock(&dev->lock);
 359 }
 360
 361 /*-------------------------------------------------------------------------*/
 362
 363 static int
 364 printer_open(struct inode *inode, struct file *fd)
 365 {
 366         struct printer_dev      *dev;
 367         unsigned long           flags;
 368         int                     ret = -EBUSY;
 369
 370         mutex_lock(&printer_mutex);
 371         dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
 372
 373         spin_lock_irqsave(&dev->lock, flags);
 374
 375         if (!dev->printer_cdev_open) {
 376                 dev->printer_cdev_open = 1;
 377                 fd->private_data = dev;
 378                 ret = 0;
 379                 /* Change the printer status to show that it's on-line. */
 380                 dev->printer_status |= PRINTER_SELECTED;
 381         }
 382
 383         spin_unlock_irqrestore(&dev->lock, flags);
 384
 385         DBG(dev, "printer_open returned %x\n", ret);
 386         mutex_unlock(&printer_mutex);
 387         return ret;
 388 }
 389
 390 static int
 391 printer_close(struct inode *inode, struct file *fd)
 392 {
 393         struct printer_dev      *dev = fd->private_data;
 394         unsigned long           flags;
 395
 396         spin_lock_irqsave(&dev->lock, flags);
 397         dev->printer_cdev_open = 0;
 398         fd->private_data = NULL;
 399         /* Change printer status to show that the printer is off-line. */
 400         dev->printer_status &= ~PRINTER_SELECTED;
 401         spin_unlock_irqrestore(&dev->lock, flags);
 402
 403         DBG(dev, "printer_close\n");
 404
 405         return 0;
 406 }
 407
 408 /* This function must be called with interrupts turned off. */
 409 static void
 410 setup_rx_reqs(struct printer_dev *dev)
 411 {
 412         struct usb_request              *req;
 413
 414         while (likely(!list_empty(&dev->rx_reqs))) {
 415                 int error;
 416
 417                 req = container_of(dev->rx_reqs.next,
 418                                 struct usb_request, list);
 419                 list_del_init(&req->list);
 420
 421                 /* The USB Host sends us whatever amount of data it wants to
 422                  * so we always set the length field to the full USB_BUFSIZE.
 423                  * If the amount of data is more than the read() caller asked
 424                  * for it will be stored in the request buffer until it is
 425                  * asked for by read().
 426                  */
 427                 req->length = USB_BUFSIZE;
 428                 req->complete = rx_complete;
 429
 430                 /* here, we unlock, and only unlock, to avoid deadlock. */
 431                 spin_unlock(&dev->lock);
 432                 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
 433                 spin_lock(&dev->lock);
 434                 if (error) {
 435                         DBG(dev, "rx submit --> %d\n", error);
 436                         list_add(&req->list, &dev->rx_reqs);
 437                         break;
 438                 }
 439                 /* if the req is empty, then add it into dev->rx_reqs_active. */
 440                 else if (list_empty(&req->list)) {
 441                         list_add(&req->list, &dev->rx_reqs_active);
 442                 }
 443         }
 444 }
 445
 446 static ssize_t
 447 printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 448 {
 449         struct printer_dev              *dev = fd->private_data;
 450         unsigned long                   flags;
 451         size_t                          size;
 452         size_t                          bytes_copied;
 453         struct usb_request              *req;
 454         /* This is a pointer to the current USB rx request. */
 455         struct usb_request              *current_rx_req;
 456         /* This is the number of bytes in the current rx buffer. */
 457         size_t                          current_rx_bytes;
 458         /* This is a pointer to the current rx buffer. */
 459         u8                              *current_rx_buf;
 460
 461         if (len == 0)
 462                 return -EINVAL;
 463
 464         DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
 465
 466         mutex_lock(&dev->lock_printer_io);
 467         spin_lock_irqsave(&dev->lock, flags);
 468
 469         /* We will use this flag later to check if a printer reset happened
 470          * after we turn interrupts back on.
 471          */
 472         dev->reset_printer = 0;
 473
 474         setup_rx_reqs(dev);
 475
 476         bytes_copied = 0;
 477         current_rx_req = dev->current_rx_req;
 478         current_rx_bytes = dev->current_rx_bytes;
 479         current_rx_buf = dev->current_rx_buf;
 480         dev->current_rx_req = NULL;
 481         dev->current_rx_bytes = 0;
 482         dev->current_rx_buf = NULL;
 483
 484         /* Check if there is any data in the read buffers. Please note that
 485          * current_rx_bytes is the number of bytes in the current rx buffer.
 486          * If it is zero then check if there are any other rx_buffers that
 487          * are on the completed list. We are only out of data if all rx
 488          * buffers are empty.
 489          */
 490         if ((current_rx_bytes == 0) &&
 491                         (likely(list_empty(&dev->rx_buffers)))) {
 492                 /* Turn interrupts back on before sleeping. */
 493                 spin_unlock_irqrestore(&dev->lock, flags);
 494
 495                 /*
 496                  * If no data is available check if this is a NON-Blocking
 497                  * call or not.
 498                  */
 499                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 500                         mutex_unlock(&dev->lock_printer_io);
 501                         return -EAGAIN;
 502                 }
 503
 504                 /* Sleep until data is available */
 505                 wait_event_interruptible(dev->rx_wait,
 506                                 (likely(!list_empty(&dev->rx_buffers))));
 507                 spin_lock_irqsave(&dev->lock, flags);
 508         }
 509
 510         /* We have data to return then copy it to the caller's buffer.*/
 511         while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
 512                         && len) {
 513                 if (current_rx_bytes == 0) {
 514                         req = container_of(dev->rx_buffers.next,
 515                                         struct usb_request, list);
 516                         list_del_init(&req->list);
 517
 518                         if (req->actual && req->buf) {
 519                                 current_rx_req = req;
 520                                 current_rx_bytes = req->actual;
 521                                 current_rx_buf = req->buf;
 522                         } else {
 523                                 list_add(&req->list, &dev->rx_reqs);
 524                                 continue;
 525                         }
 526                 }
 527
 528                 /* Don't leave irqs off while doing memory copies */
 529                 spin_unlock_irqrestore(&dev->lock, flags);
 530
 531                 if (len > current_rx_bytes)
 532                         size = current_rx_bytes;
 533                 else
 534                         size = len;
 535
 536                 size -= copy_to_user(buf, current_rx_buf, size);
 537                 bytes_copied += size;
 538                 len -= size;
 539                 buf += size;
 540
 541                 spin_lock_irqsave(&dev->lock, flags);
 542
 543                 /* We've disconnected or reset so return. */
 544                 if (dev->reset_printer) {
 545                         list_add(&current_rx_req->list, &dev->rx_reqs);
 546                         spin_unlock_irqrestore(&dev->lock, flags);
 547                         mutex_unlock(&dev->lock_printer_io);
 548                         return -EAGAIN;
 549                 }
 550
 551                 /* If we not returning all the data left in this RX request
 552                  * buffer then adjust the amount of data left in the buffer.
 553                  * Othewise if we are done with this RX request buffer then
 554                  * requeue it to get any incoming data from the USB host.
 555                  */
 556                 if (size < current_rx_bytes) {
 557                         current_rx_bytes -= size;
 558                         current_rx_buf += size;
 559                 } else {
 560                         list_add(&current_rx_req->list, &dev->rx_reqs);
 561                         current_rx_bytes = 0;
 562                         current_rx_buf = NULL;
 563                         current_rx_req = NULL;
 564                 }
 565         }
 566
 567         dev->current_rx_req = current_rx_req;
 568         dev->current_rx_bytes = current_rx_bytes;
 569         dev->current_rx_buf = current_rx_buf;
 570
 571         spin_unlock_irqrestore(&dev->lock, flags);
 572         mutex_unlock(&dev->lock_printer_io);
 573
 574         DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
 575
 576         if (bytes_copied)
 577                 return bytes_copied;
 578         else
 579                 return -EAGAIN;
 580 }
 581
 582 static ssize_t
 583 printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 584 {
 585         struct printer_dev      *dev = fd->private_data;
 586         unsigned long           flags;
 587         size_t                  size;   /* Amount of data in a TX request. */
 588         size_t                  bytes_copied = 0;
 589         struct usb_request      *req;
 590
 591         DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
 592
 593         if (len == 0)
 594                 return -EINVAL;
 595
 596         mutex_lock(&dev->lock_printer_io);
 597         spin_lock_irqsave(&dev->lock, flags);
 598
 599         /* Check if a printer reset happens while we have interrupts on */
 600         dev->reset_printer = 0;
 601
 602         /* Check if there is any available write buffers */
 603         if (likely(list_empty(&dev->tx_reqs))) {
 604                 /* Turn interrupts back on before sleeping. */
 605                 spin_unlock_irqrestore(&dev->lock, flags);
 606
 607                 /*
 608                  * If write buffers are available check if this is
 609                  * a NON-Blocking call or not.
 610                  */
 611                 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
 612                         mutex_unlock(&dev->lock_printer_io);
 613                         return -EAGAIN;
 614                 }
 615
 616                 /* Sleep until a write buffer is available */
 617                 wait_event_interruptible(dev->tx_wait,
 618                                 (likely(!list_empty(&dev->tx_reqs))));
 619                 spin_lock_irqsave(&dev->lock, flags);
 620         }
 621
 622         while (likely(!list_empty(&dev->tx_reqs)) && len) {
 623
 624                 if (len > USB_BUFSIZE)
 625                         size = USB_BUFSIZE;
 626                 else
 627                         size = len;
 628
 629                 req = container_of(dev->tx_reqs.next, struct usb_request,
 630                                 list);
 631                 list_del_init(&req->list);
 632
 633                 req->complete = tx_complete;
 634                 req->length = size;
 635
 636                 /* Check if we need to send a zero length packet. */
 637                 if (len > size)
 638                         /* They will be more TX requests so no yet. */
 639                         req->zero = 0;
 640                 else
 641                         /* If the data amount is not a multple of the
 642                          * maxpacket size then send a zero length packet.
 643                          */
 644                         req->zero = ((len % dev->in_ep->maxpacket) == 0);
 645
 646                 /* Don't leave irqs off while doing memory copies */
 647                 spin_unlock_irqrestore(&dev->lock, flags);
 648
 649                 if (copy_from_user(req->buf, buf, size)) {
 650                         list_add(&req->list, &dev->tx_reqs);
 651                         mutex_unlock(&dev->lock_printer_io);
 652                         return bytes_copied;
 653                 }
 654
 655                 bytes_copied += size;
 656                 len -= size;
 657                 buf += size;
 658
 659                 spin_lock_irqsave(&dev->lock, flags);
 660
 661                 /* We've disconnected or reset so free the req and buffer */
 662                 if (dev->reset_printer) {
 663                         list_add(&req->list, &dev->tx_reqs);
 664                         spin_unlock_irqrestore(&dev->lock, flags);
 665                         mutex_unlock(&dev->lock_printer_io);
 666                         return -EAGAIN;
 667                 }
 668
 669                 if (usb_ep_queue(dev->in_ep, req, GFP_ATOMIC)) {
 670                         list_add(&req->list, &dev->tx_reqs);
 671                         spin_unlock_irqrestore(&dev->lock, flags);
 672                         mutex_unlock(&dev->lock_printer_io);
 673                         return -EAGAIN;
 674                 }
 675
 676                 list_add(&req->list, &dev->tx_reqs_active);
 677
 678         }
 679
 680         spin_unlock_irqrestore(&dev->lock, flags);
 681         mutex_unlock(&dev->lock_printer_io);
 682
 683         DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
 684
 685         if (bytes_copied) {
 686                 return bytes_copied;
 687         } else {
 688                 return -EAGAIN;
 689         }
 690 }
 691
 692 static int
 693 printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
 694 {
 695         struct printer_dev      *dev = fd->private_data;
 696         struct inode *inode = file_inode(fd);
 697         unsigned long           flags;
 698         int                     tx_list_empty;
 699
 700         mutex_lock(&inode->i_mutex);
 701         spin_lock_irqsave(&dev->lock, flags);
 702         tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
 703         spin_unlock_irqrestore(&dev->lock, flags);
 704
 705         if (!tx_list_empty) {
 706                 /* Sleep until all data has been sent */
 707                 wait_event_interruptible(dev->tx_flush_wait,
 708                                 (likely(list_empty(&dev->tx_reqs_active))));
 709         }
 710         mutex_unlock(&inode->i_mutex);
 711
 712         return 0;
 713 }
 714
 715 static unsigned int
 716 printer_poll(struct file *fd, poll_table *wait)
 717 {
 718         struct printer_dev      *dev = fd->private_data;
 719         unsigned long           flags;
 720         int                     status = 0;
 721
 722         mutex_lock(&dev->lock_printer_io);
 723         spin_lock_irqsave(&dev->lock, flags);
 724         setup_rx_reqs(dev);
 725         spin_unlock_irqrestore(&dev->lock, flags);
 726         mutex_unlock(&dev->lock_printer_io);
 727
 728         poll_wait(fd, &dev->rx_wait, wait);
 729         poll_wait(fd, &dev->tx_wait, wait);
 730
 731         spin_lock_irqsave(&dev->lock, flags);
 732         if (likely(!list_empty(&dev->tx_reqs)))
 733                 status |= POLLOUT | POLLWRNORM;
 734
 735         if (likely(dev->current_rx_bytes) ||
 736                         likely(!list_empty(&dev->rx_buffers)))
 737                 status |= POLLIN | POLLRDNORM;
 738
 739         spin_unlock_irqrestore(&dev->lock, flags);
 740
 741         return status;
 742 }
 743
 744 static long
 745 printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
 746 {
 747         struct printer_dev      *dev = fd->private_data;
 748         unsigned long           flags;
 749         int                     status = 0;
 750
 751         DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
 752
 753         /* handle ioctls */
 754
 755         spin_lock_irqsave(&dev->lock, flags);
 756
 757         switch (code) {
 758         case GADGET_GET_PRINTER_STATUS:
 759                 status = (int)dev->printer_status;
 760                 break;
 761         case GADGET_SET_PRINTER_STATUS:
 762                 dev->printer_status = (u8)arg;
 763                 break;
 764         default:
 765                 /* could not handle ioctl */
 766                 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
 767                                 code);
 768                 status = -ENOTTY;
 769         }
 770
 771         spin_unlock_irqrestore(&dev->lock, flags);
 772
 773         return status;
 774 }
 775
 776 /* used after endpoint configuration */
 777 static const struct file_operations printer_io_operations = {
 778         .owner =        THIS_MODULE,
 779         .open =         printer_open,
 780         .read =         printer_read,
 781         .write =        printer_write,
 782         .fsync =        printer_fsync,
 783         .poll =         printer_poll,
 784         .unlocked_ioctl = printer_ioctl,
 785         .release =      printer_close,
 786         .llseek =       noop_llseek,
 787 };
 788
 789 /*-------------------------------------------------------------------------*/
 790
 791 static int
 792 set_printer_interface(struct printer_dev *dev)
 793 {
 794         int                     result = 0;
 795
 796         dev->in_ep->desc = ep_desc(dev->gadget, &hs_ep_in_desc, &fs_ep_in_desc);
 797         dev->in_ep->driver_data = dev;
 798
 799         dev->out_ep->desc = ep_desc(dev->gadget, &hs_ep_out_desc,
 800                                     &fs_ep_out_desc);
 801         dev->out_ep->driver_data = dev;
 802
 803         result = usb_ep_enable(dev->in_ep);
 804         if (result != 0) {
 805                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 806                 goto done;
 807         }
 808
 809         result = usb_ep_enable(dev->out_ep);
 810         if (result != 0) {
 811                 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
 812                 goto done;
 813         }
 814
 815 done:
 816         /* on error, disable any endpoints  */
 817         if (result != 0) {
 818                 (void) usb_ep_disable(dev->in_ep);
 819                 (void) usb_ep_disable(dev->out_ep);
 820                 dev->in_ep->desc = NULL;
 821                 dev->out_ep->desc = NULL;
 822         }
 823
 824         /* caller is responsible for cleanup on error */
 825         return result;
 826 }
 827
 828 static void printer_reset_interface(struct printer_dev *dev)
 829 {
 830         if (dev->interface < 0)
 831                 return;
 832
 833         DBG(dev, "%s\n", __func__);
 834
 835         if (dev->in_ep->desc)
 836                 usb_ep_disable(dev->in_ep);
 837
 838         if (dev->out_ep->desc)
 839                 usb_ep_disable(dev->out_ep);
 840
 841         dev->in_ep->desc = NULL;
 842         dev->out_ep->desc = NULL;
 843         dev->interface = -1;
 844 }
 845
 846 /* Change our operational Interface. */
 847 static int set_interface(struct printer_dev *dev, unsigned number)
 848 {
 849         int                     result = 0;
 850
 851         /* Free the current interface */
 852         printer_reset_interface(dev);
 853
 854         result = set_printer_interface(dev);
 855         if (result)
 856                 printer_reset_interface(dev);
 857         else
 858                 dev->interface = number;
 859
 860         if (!result)
 861                 INFO(dev, "Using interface %x\n", number);
 862
 863         return result;
 864 }
 865
 866 static void printer_soft_reset(struct printer_dev *dev)
 867 {
 868         struct usb_request      *req;
 869
 870         INFO(dev, "Received Printer Reset Request\n");
 871
 872         if (usb_ep_disable(dev->in_ep))
 873                 DBG(dev, "Failed to disable USB in_ep\n");
 874         if (usb_ep_disable(dev->out_ep))
 875                 DBG(dev, "Failed to disable USB out_ep\n");
 876
 877         if (dev->current_rx_req != NULL) {
 878                 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
 879                 dev->current_rx_req = NULL;
 880         }
 881         dev->current_rx_bytes = 0;
 882         dev->current_rx_buf = NULL;
 883         dev->reset_printer = 1;
 884
 885         while (likely(!(list_empty(&dev->rx_buffers)))) {
 886                 req = container_of(dev->rx_buffers.next, struct usb_request,
 887                                 list);
 888                 list_del_init(&req->list);
 889                 list_add(&req->list, &dev->rx_reqs);
 890         }
 891
 892         while (likely(!(list_empty(&dev->rx_reqs_active)))) {
 893                 req = container_of(dev->rx_buffers.next, struct usb_request,
 894                                 list);
 895                 list_del_init(&req->list);
 896                 list_add(&req->list, &dev->rx_reqs);
 897         }
 898
 899         while (likely(!(list_empty(&dev->tx_reqs_active)))) {
 900                 req = container_of(dev->tx_reqs_active.next,
 901                                 struct usb_request, list);
 902                 list_del_init(&req->list);
 903                 list_add(&req->list, &dev->tx_reqs);
 904         }
 905
 906         if (usb_ep_enable(dev->in_ep))
 907                 DBG(dev, "Failed to enable USB in_ep\n");
 908         if (usb_ep_enable(dev->out_ep))
 909                 DBG(dev, "Failed to enable USB out_ep\n");
 910
 911         wake_up_interruptible(&dev->rx_wait);
 912         wake_up_interruptible(&dev->tx_wait);
 913         wake_up_interruptible(&dev->tx_flush_wait);
 914 }
 915
 916 /*-------------------------------------------------------------------------*/
 917
 918 /*
 919  * The setup() callback implements all the ep0 functionality that's not
 920  * handled lower down.
 921  */
 922 static int printer_func_setup(struct usb_function *f,
 923                 const struct usb_ctrlrequest *ctrl)
 924 {
 925         struct printer_dev *dev = container_of(f, struct printer_dev, function);
 926         struct usb_composite_dev *cdev = f->config->cdev;
 927         struct usb_request      *req = cdev->req;
 928         int                     value = -EOPNOTSUPP;
 929         u16                     wIndex = le16_to_cpu(ctrl->wIndex);
 930         u16                     wValue = le16_to_cpu(ctrl->wValue);
 931         u16                     wLength = le16_to_cpu(ctrl->wLength);
 932
 933         DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
 934                 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
 935
 936         switch (ctrl->bRequestType&USB_TYPE_MASK) {
 937         case USB_TYPE_CLASS:
 938                 switch (ctrl->bRequest) {
 939                 case 0: /* Get the IEEE-1284 PNP String */
 940                         /* Only one printer interface is supported. */
 941                         if ((wIndex>>8) != dev->interface)
 942                                 break;
 943
 944                         value = (pnp_string[0]<<8)|pnp_string[1];
 945                         memcpy(req->buf, pnp_string, value);
 946                         DBG(dev, "1284 PNP String: %x %s\n", value,
 947                                         &pnp_string[2]);
 948                         break;
 949
 950                 case 1: /* Get Port Status */
 951                         /* Only one printer interface is supported. */
 952                         if (wIndex != dev->interface)
 953                                 break;
 954
 955                         *(u8 *)req->buf = dev->printer_status;
 956                         value = min(wLength, (u16) 1);
 957                         break;
 958
 959                 case 2: /* Soft Reset */
 960                         /* Only one printer interface is supported. */
 961                         if (wIndex != dev->interface)
 962                                 break;
 963
 964                         printer_soft_reset(dev);
 965
 966                         value = 0;
 967                         break;
 968
 969                 default:
 970                         goto unknown;
 971                 }
 972                 break;
 973
 974         default:
 975 unknown:
 976                 VDBG(dev,
 977                         "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
 978                         ctrl->bRequestType, ctrl->bRequest,
 979                         wValue, wIndex, wLength);
 980                 break;
 981         }
 982         /* host either stalls (value < 0) or reports success */
 983         return value;
 984 }
 985
 986 static int __init printer_func_bind(struct usb_configuration *c,
 987                 struct usb_function *f)
 988 {
 989         struct printer_dev *dev = container_of(f, struct printer_dev, function);
 990         struct usb_composite_dev *cdev = c->cdev;
 991         struct usb_ep *in_ep;
 992         struct usb_ep *out_ep = NULL;
 993         int id;
 994         int ret;
 995
 996         id = usb_interface_id(c, f);
 997         if (id < 0)
 998                 return id;
 999         intf_desc.bInterfaceNumber = id;
1000
1001         /* all we really need is bulk IN/OUT */
1002         in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1003         if (!in_ep) {
1004 autoconf_fail:
1005                 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1006                         cdev->gadget->name);
1007                 return -ENODEV;
1008         }
1009         in_ep->driver_data = in_ep;     /* claim */
1010
1011         out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1012         if (!out_ep)
1013                 goto autoconf_fail;
1014         out_ep->driver_data = out_ep;   /* claim */
1015
1016         /* assumes that all endpoints are dual-speed */
1017         hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1018         hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1019
1020         ret = usb_assign_descriptors(f, fs_printer_function,
1021                         hs_printer_function, NULL);
1022         if (ret)
1023                 return ret;
1024
1025         dev->in_ep = in_ep;
1026         dev->out_ep = out_ep;
1027         return 0;
1028 }
1029
1030 static void printer_func_unbind(struct usb_configuration *c,
1031                 struct usb_function *f)
1032 {
1033         usb_free_all_descriptors(f);
1034 }
1035
1036 static int printer_func_set_alt(struct usb_function *f,
1037                 unsigned intf, unsigned alt)
1038 {
1039         struct printer_dev *dev = container_of(f, struct printer_dev, function);
1040         int ret = -ENOTSUPP;
1041
1042         if (!alt)
1043                 ret = set_interface(dev, intf);
1044
1045         return ret;
1046 }
1047
1048 static void printer_func_disable(struct usb_function *f)
1049 {
1050         struct printer_dev *dev = container_of(f, struct printer_dev, function);
1051         unsigned long           flags;
1052
1053         DBG(dev, "%s\n", __func__);
1054
1055         spin_lock_irqsave(&dev->lock, flags);
1056         printer_reset_interface(dev);
1057         spin_unlock_irqrestore(&dev->lock, flags);
1058 }
1059
1060 static void printer_cfg_unbind(struct usb_configuration *c)
1061 {
1062         struct printer_dev      *dev;
1063         struct usb_request      *req;
1064
1065         dev = &usb_printer_gadget;
1066
1067         DBG(dev, "%s\n", __func__);
1068
1069         /* Remove sysfs files */
1070         device_destroy(usb_gadget_class, g_printer_devno);
1071
1072         /* Remove Character Device */
1073         cdev_del(&dev->printer_cdev);
1074
1075         /* we must already have been disconnected ... no i/o may be active */
1076         WARN_ON(!list_empty(&dev->tx_reqs_active));
1077         WARN_ON(!list_empty(&dev->rx_reqs_active));
1078
1079         /* Free all memory for this driver. */
1080         while (!list_empty(&dev->tx_reqs)) {
1081                 req = container_of(dev->tx_reqs.next, struct usb_request,
1082                                 list);
1083                 list_del(&req->list);
1084                 printer_req_free(dev->in_ep, req);
1085         }
1086
1087         if (dev->current_rx_req != NULL)
1088                 printer_req_free(dev->out_ep, dev->current_rx_req);
1089
1090         while (!list_empty(&dev->rx_reqs)) {
1091                 req = container_of(dev->rx_reqs.next,
1092                                 struct usb_request, list);
1093                 list_del(&req->list);
1094                 printer_req_free(dev->out_ep, req);
1095         }
1096
1097         while (!list_empty(&dev->rx_buffers)) {
1098                 req = container_of(dev->rx_buffers.next,
1099                                 struct usb_request, list);
1100                 list_del(&req->list);
1101                 printer_req_free(dev->out_ep, req);
1102         }
1103 }
1104
1105 static struct usb_configuration printer_cfg_driver = {
1106         .label                  = "printer",
1107         .unbind                 = printer_cfg_unbind,
1108         .bConfigurationValue    = 1,
1109         .bmAttributes           = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
1110 };
1111
1112 static int __init printer_bind_config(struct usb_configuration *c)
1113 {
1114         struct usb_gadget       *gadget = c->cdev->gadget;
1115         struct printer_dev      *dev;
1116         int                     status = -ENOMEM;
1117         size_t                  len;
1118         u32                     i;
1119         struct usb_request      *req;
1120
1121         usb_ep_autoconfig_reset(gadget);
1122
1123         dev = &usb_printer_gadget;
1124
1125         dev->function.name = shortname;
1126         dev->function.bind = printer_func_bind;
1127         dev->function.setup = printer_func_setup;
1128         dev->function.unbind = printer_func_unbind;
1129         dev->function.set_alt = printer_func_set_alt;
1130         dev->function.disable = printer_func_disable;
1131
1132         status = usb_add_function(c, &dev->function);
1133         if (status)
1134                 return status;
1135
1136         /* Setup the sysfs files for the printer gadget. */
1137         dev->pdev = device_create(usb_gadget_class, NULL, g_printer_devno,
1138                                   NULL, "g_printer");
1139         if (IS_ERR(dev->pdev)) {
1140                 ERROR(dev, "Failed to create device: g_printer\n");
1141                 status = PTR_ERR(dev->pdev);
1142                 goto fail;
1143         }
1144
1145         /*
1146          * Register a character device as an interface to a user mode
1147          * program that handles the printer specific functionality.
1148          */
1149         cdev_init(&dev->printer_cdev, &printer_io_operations);
1150         dev->printer_cdev.owner = THIS_MODULE;
1151         status = cdev_add(&dev->printer_cdev, g_printer_devno, 1);
1152         if (status) {
1153                 ERROR(dev, "Failed to open char device\n");
1154                 goto fail;
1155         }
1156
1157         if (iPNPstring)
1158                 strlcpy(&pnp_string[2], iPNPstring, (sizeof pnp_string)-2);
1159
1160         len = strlen(pnp_string);
1161         pnp_string[0] = (len >> 8) & 0xFF;
1162         pnp_string[1] = len & 0xFF;
1163
1164         usb_gadget_set_selfpowered(gadget);
1165
1166         if (gadget_is_otg(gadget)) {
1167                 otg_descriptor.bmAttributes |= USB_OTG_HNP;
1168                 printer_cfg_driver.descriptors = otg_desc;
1169                 printer_cfg_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
1170         }
1171
1172         spin_lock_init(&dev->lock);
1173         mutex_init(&dev->lock_printer_io);
1174         INIT_LIST_HEAD(&dev->tx_reqs);
1175         INIT_LIST_HEAD(&dev->tx_reqs_active);
1176         INIT_LIST_HEAD(&dev->rx_reqs);
1177         INIT_LIST_HEAD(&dev->rx_reqs_active);
1178         INIT_LIST_HEAD(&dev->rx_buffers);
1179         init_waitqueue_head(&dev->rx_wait);
1180         init_waitqueue_head(&dev->tx_wait);
1181         init_waitqueue_head(&dev->tx_flush_wait);
1182
1183         dev->interface = -1;
1184         dev->printer_cdev_open = 0;
1185         dev->printer_status = PRINTER_NOT_ERROR;
1186         dev->current_rx_req = NULL;
1187         dev->current_rx_bytes = 0;
1188         dev->current_rx_buf = NULL;
1189
1190         for (i = 0; i < QLEN; i++) {
1191                 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1192                 if (!req) {
1193                         while (!list_empty(&dev->tx_reqs)) {
1194                                 req = container_of(dev->tx_reqs.next,
1195                                                 struct usb_request, list);
1196                                 list_del(&req->list);
1197                                 printer_req_free(dev->in_ep, req);
1198                         }
1199                         return -ENOMEM;
1200                 }
1201                 list_add(&req->list, &dev->tx_reqs);
1202         }
1203
1204         for (i = 0; i < QLEN; i++) {
1205                 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1206                 if (!req) {
1207                         while (!list_empty(&dev->rx_reqs)) {
1208                                 req = container_of(dev->rx_reqs.next,
1209                                                 struct usb_request, list);
1210                                 list_del(&req->list);
1211                                 printer_req_free(dev->out_ep, req);
1212                         }
1213                         return -ENOMEM;
1214                 }
1215                 list_add(&req->list, &dev->rx_reqs);
1216         }
1217
1218         /* finish hookup to lower layer ... */
1219         dev->gadget = gadget;
1220
1221         INFO(dev, "%s, version: " DRIVER_VERSION "\n", driver_desc);
1222         return 0;
1223
1224 fail:
1225         printer_cfg_unbind(c);
1226         return status;
1227 }
1228
1229 static int printer_unbind(struct usb_composite_dev *cdev)
1230 {
1231         return 0;
1232 }
1233
1234 static int __init printer_bind(struct usb_composite_dev *cdev)
1235 {
1236         int ret;
1237
1238         ret = usb_string_ids_tab(cdev, strings);
1239         if (ret < 0)
1240                 return ret;
1241         device_desc.iManufacturer = strings[USB_GADGET_MANUFACTURER_IDX].id;
1242         device_desc.iProduct = strings[USB_GADGET_PRODUCT_IDX].id;
1243         device_desc.iSerialNumber = strings[USB_GADGET_SERIAL_IDX].id;
1244
1245         ret = usb_add_config(cdev, &printer_cfg_driver, printer_bind_config);
1246         if (ret)
1247                 return ret;
1248         usb_composite_overwrite_options(cdev, &coverwrite);
1249         return ret;
1250 }
1251
1252 static __refdata struct usb_composite_driver printer_driver = {
1253         .name           = shortname,
1254         .dev            = &device_desc,
1255         .strings        = dev_strings,
1256         .max_speed      = USB_SPEED_HIGH,
1257         .bind           = printer_bind,
1258         .unbind         = printer_unbind,
1259 };
1260
1261 static int __init
1262 init(void)
1263 {
1264         int status;
1265
1266         usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1267         if (IS_ERR(usb_gadget_class)) {
1268                 status = PTR_ERR(usb_gadget_class);
1269                 pr_err("unable to create usb_gadget class %d\n", status);
1270                 return status;
1271         }
1272
1273         status = alloc_chrdev_region(&g_printer_devno, 0, 1,
1274                         "USB printer gadget");
1275         if (status) {
1276                 pr_err("alloc_chrdev_region %d\n", status);
1277                 class_destroy(usb_gadget_class);
1278                 return status;
1279         }
1280
1281         status = usb_composite_probe(&printer_driver);
1282         if (status) {
1283                 class_destroy(usb_gadget_class);
1284                 unregister_chrdev_region(g_printer_devno, 1);
1285                 pr_err("usb_gadget_probe_driver %x\n", status);
1286         }
1287
1288         return status;
1289 }
1290 module_init(init);
1291
1292 static void __exit
1293 cleanup(void)
1294 {
1295         mutex_lock(&usb_printer_gadget.lock_printer_io);
1296         usb_composite_unregister(&printer_driver);
1297         unregister_chrdev_region(g_printer_devno, 1);
1298         class_destroy(usb_gadget_class);
1299         mutex_unlock(&usb_printer_gadget.lock_printer_io);
1300 }
1301 module_exit(cleanup);
1302
1303 MODULE_DESCRIPTION(DRIVER_DESC);
1304 MODULE_AUTHOR("Craig Nadler");
1305 MODULE_LICENSE("GPL");