drivers/usb/misc/ldusb.c

   1 /**
   2  * Generic USB driver for report based interrupt in/out devices
   3  * like LD Didactic's USB devices. LD Didactic's USB devices are
   4  * HID devices which do not use HID report definitons (they use
   5  * raw interrupt in and our reports only for communication).
   6  *
   7  * This driver uses a ring buffer for time critical reading of
   8  * interrupt in reports and provides read and write methods for
   9  * raw interrupt reports (similar to the Windows HID driver).
  10  * Devices based on the book USB COMPLETE by Jan Axelson may need
  11  * such a compatibility to the Windows HID driver.
  12  *
  13  * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
  14  *
  15  *      This program is free software; you can redistribute it and/or
  16  *      modify it under the terms of the GNU General Public License as
  17  *      published by the Free Software Foundation; either version 2 of
  18  *      the License, or (at your option) any later version.
  19  *
  20  * Derived from Lego USB Tower driver
  21  * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
  22  *               2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
  23  *
  24  * V0.1  (mh) Initial version
  25  * V0.11 (mh) Added raw support for HID 1.0 devices (no interrupt out endpoint)
  26  * V0.12 (mh) Added kmalloc check for string buffer
  27  * V0.13 (mh) Added support for LD X-Ray and Machine Test System
  28  */
  29
  30 #include <linux/kernel.h>
  31 #include <linux/errno.h>
  32 #include <linux/init.h>
  33 #include <linux/slab.h>
  34 #include <linux/module.h>
  35 #include <linux/mutex.h>
  36
  37 #include <asm/uaccess.h>
  38 #include <linux/input.h>
  39 #include <linux/usb.h>
  40 #include <linux/poll.h>
  41
  42 /* Define these values to match your devices */
  43 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  44 #define USB_DEVICE_ID_LD_CASSY          0x1000  /* USB Product ID of CASSY-S */
  45 #define USB_DEVICE_ID_LD_POCKETCASSY    0x1010  /* USB Product ID of Pocket-CASSY */
  46 #define USB_DEVICE_ID_LD_MOBILECASSY    0x1020  /* USB Product ID of Mobile-CASSY */
  47 #define USB_DEVICE_ID_LD_JWM            0x1080  /* USB Product ID of Joule and Wattmeter */
  48 #define USB_DEVICE_ID_LD_DMMP           0x1081  /* USB Product ID of Digital Multimeter P (reserved) */
  49 #define USB_DEVICE_ID_LD_UMIP           0x1090  /* USB Product ID of UMI P */
  50 #define USB_DEVICE_ID_LD_XRAY1          0x1100  /* USB Product ID of X-Ray Apparatus */
  51 #define USB_DEVICE_ID_LD_XRAY2          0x1101  /* USB Product ID of X-Ray Apparatus */
  52 #define USB_DEVICE_ID_LD_VIDEOCOM       0x1200  /* USB Product ID of VideoCom */
  53 #define USB_DEVICE_ID_LD_COM3LAB        0x2000  /* USB Product ID of COM3LAB */
  54 #define USB_DEVICE_ID_LD_TELEPORT       0x2010  /* USB Product ID of Terminal Adapter */
  55 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
  56 #define USB_DEVICE_ID_LD_POWERCONTROL   0x2030  /* USB Product ID of Converter Control Unit */
  57 #define USB_DEVICE_ID_LD_MACHINETEST    0x2040  /* USB Product ID of Machine Test System */
  58
  59 #define USB_VENDOR_ID_VERNIER           0x08f7
  60 #define USB_DEVICE_ID_VERNIER_LABPRO    0x0001
  61 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
  62 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  63 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  64 #define USB_DEVICE_ID_VERNIER_LCSPEC    0x0006
  65
  66 #define USB_VENDOR_ID_MICROCHIP         0x04d8
  67 #define USB_DEVICE_ID_PICDEM            0x000c
  68
  69 #ifdef CONFIG_USB_DYNAMIC_MINORS
  70 #define USB_LD_MINOR_BASE       0
  71 #else
  72 #define USB_LD_MINOR_BASE       176
  73 #endif
  74
  75 /* table of devices that work with this driver */
  76 static struct usb_device_id ld_usb_table [] = {
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
  82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
  83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
  84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
  85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
  86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
  88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
  89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
  90         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
  91         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
  92         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  93         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  94         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  95         { USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_PICDEM) },
  96         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) },
  97         { }                                     /* Terminating entry */
  98 };
  99 MODULE_DEVICE_TABLE(usb, ld_usb_table);
 100 MODULE_VERSION("V0.13");
 101 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 102 MODULE_DESCRIPTION("LD USB Driver");
 103 MODULE_LICENSE("GPL");
 104 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 105
 106 #ifdef CONFIG_USB_DEBUG
 107         static int debug = 1;
 108 #else
 109         static int debug = 0;
 110 #endif
 111
 112 /* Use our own dbg macro */
 113 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 114
 115 /* Module parameters */
 116 module_param(debug, int, S_IRUGO | S_IWUSR);
 117 MODULE_PARM_DESC(debug, "Debug enabled or not");
 118
 119 /* All interrupt in transfers are collected in a ring buffer to
 120  * avoid racing conditions and get better performance of the driver.
 121  */
 122 static int ring_buffer_size = 128;
 123 module_param(ring_buffer_size, int, 0);
 124 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 125
 126 /* The write_buffer can contain more than one interrupt out transfer.
 127  */
 128 static int write_buffer_size = 10;
 129 module_param(write_buffer_size, int, 0);
 130 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 131
 132 /* As of kernel version 2.6.4 ehci-hcd uses an
 133  * "only one interrupt transfer per frame" shortcut
 134  * to simplify the scheduling of periodic transfers.
 135  * This conflicts with our standard 1ms intervals for in and out URBs.
 136  * We use default intervals of 2ms for in and 2ms for out transfers,
 137  * which should be fast enough.
 138  * Increase the interval to allow more devices that do interrupt transfers,
 139  * or set to 1 to use the standard interval from the endpoint descriptors.
 140  */
 141 static int min_interrupt_in_interval = 2;
 142 module_param(min_interrupt_in_interval, int, 0);
 143 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 144
 145 static int min_interrupt_out_interval = 2;
 146 module_param(min_interrupt_out_interval, int, 0);
 147 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 148
 149 /* Structure to hold all of our device specific stuff */
 150 struct ld_usb {
 151         struct semaphore        sem;            /* locks this structure */
 152         struct usb_interface*   intf;           /* save off the usb interface pointer */
 153
 154         int                     open_count;     /* number of times this port has been opened */
 155
 156         char*                   ring_buffer;
 157         unsigned int            ring_head;
 158         unsigned int            ring_tail;
 159
 160         wait_queue_head_t       read_wait;
 161         wait_queue_head_t       write_wait;
 162
 163         char*                   interrupt_in_buffer;
 164         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 165         struct urb*             interrupt_in_urb;
 166         int                     interrupt_in_interval;
 167         size_t                  interrupt_in_endpoint_size;
 168         int                     interrupt_in_running;
 169         int                     interrupt_in_done;
 170         int                     buffer_overflow;
 171         spinlock_t              rbsl;
 172
 173         char*                   interrupt_out_buffer;
 174         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 175         struct urb*             interrupt_out_urb;
 176         int                     interrupt_out_interval;
 177         size_t                  interrupt_out_endpoint_size;
 178         int                     interrupt_out_busy;
 179 };
 180
 181 static struct usb_driver ld_usb_driver;
 182
 183 /**
 184  *      ld_usb_abort_transfers
 185  *      aborts transfers and frees associated data structures
 186  */
 187 static void ld_usb_abort_transfers(struct ld_usb *dev)
 188 {
 189         /* shutdown transfer */
 190         if (dev->interrupt_in_running) {
 191                 dev->interrupt_in_running = 0;
 192                 if (dev->intf)
 193                         usb_kill_urb(dev->interrupt_in_urb);
 194         }
 195         if (dev->interrupt_out_busy)
 196                 if (dev->intf)
 197                         usb_kill_urb(dev->interrupt_out_urb);
 198 }
 199
 200 /**
 201  *      ld_usb_delete
 202  */
 203 static void ld_usb_delete(struct ld_usb *dev)
 204 {
 205         ld_usb_abort_transfers(dev);
 206
 207         /* free data structures */
 208         usb_free_urb(dev->interrupt_in_urb);
 209         usb_free_urb(dev->interrupt_out_urb);
 210         kfree(dev->ring_buffer);
 211         kfree(dev->interrupt_in_buffer);
 212         kfree(dev->interrupt_out_buffer);
 213         kfree(dev);
 214 }
 215
 216 /**
 217  *      ld_usb_interrupt_in_callback
 218  */
 219 static void ld_usb_interrupt_in_callback(struct urb *urb)
 220 {
 221         struct ld_usb *dev = urb->context;
 222         size_t *actual_buffer;
 223         unsigned int next_ring_head;
 224         int status = urb->status;
 225         int retval;
 226
 227         if (status) {
 228                 if (status == -ENOENT ||
 229                     status == -ECONNRESET ||
 230                     status == -ESHUTDOWN) {
 231                         goto exit;
 232                 } else {
 233                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 234                                  __FUNCTION__, status);
 235                         spin_lock(&dev->rbsl);
 236                         goto resubmit; /* maybe we can recover */
 237                 }
 238         }
 239
 240         spin_lock(&dev->rbsl);
 241         if (urb->actual_length > 0) {
 242                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 243                 if (next_ring_head != dev->ring_tail) {
 244                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 245                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 246                         *actual_buffer = urb->actual_length;
 247                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 248                         dev->ring_head = next_ring_head;
 249                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 250                                  __FUNCTION__, urb->actual_length);
 251                 } else {
 252                         dev_warn(&dev->intf->dev,
 253                                  "Ring buffer overflow, %d bytes dropped\n",
 254                                  urb->actual_length);
 255                         dev->buffer_overflow = 1;
 256                 }
 257         }
 258
 259 resubmit:
 260         /* resubmit if we're still running */
 261         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
 262                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 263                 if (retval) {
 264                         dev_err(&dev->intf->dev,
 265                                 "usb_submit_urb failed (%d)\n", retval);
 266                         dev->buffer_overflow = 1;
 267                 }
 268         }
 269         spin_unlock(&dev->rbsl);
 270 exit:
 271         dev->interrupt_in_done = 1;
 272         wake_up_interruptible(&dev->read_wait);
 273 }
 274
 275 /**
 276  *      ld_usb_interrupt_out_callback
 277  */
 278 static void ld_usb_interrupt_out_callback(struct urb *urb)
 279 {
 280         struct ld_usb *dev = urb->context;
 281         int status = urb->status;
 282
 283         /* sync/async unlink faults aren't errors */
 284         if (status && !(status == -ENOENT ||
 285                         status == -ECONNRESET ||
 286                         status == -ESHUTDOWN))
 287                 dbg_info(&dev->intf->dev,
 288                          "%s - nonzero write interrupt status received: %d\n",
 289                          __FUNCTION__, status);
 290
 291         dev->interrupt_out_busy = 0;
 292         wake_up_interruptible(&dev->write_wait);
 293 }
 294
 295 /**
 296  *      ld_usb_open
 297  */
 298 static int ld_usb_open(struct inode *inode, struct file *file)
 299 {
 300         struct ld_usb *dev;
 301         int subminor;
 302         int retval;
 303         struct usb_interface *interface;
 304
 305         nonseekable_open(inode, file);
 306         subminor = iminor(inode);
 307
 308         interface = usb_find_interface(&ld_usb_driver, subminor);
 309
 310         if (!interface) {
 311                 err("%s - error, can't find device for minor %d\n",
 312                      __FUNCTION__, subminor);
 313                 return -ENODEV;
 314         }
 315
 316         dev = usb_get_intfdata(interface);
 317
 318         if (!dev)
 319                 return -ENODEV;
 320
 321         /* lock this device */
 322         if (down_interruptible(&dev->sem))
 323                 return -ERESTARTSYS;
 324
 325         /* allow opening only once */
 326         if (dev->open_count) {
 327                 retval = -EBUSY;
 328                 goto unlock_exit;
 329         }
 330         dev->open_count = 1;
 331
 332         /* initialize in direction */
 333         dev->ring_head = 0;
 334         dev->ring_tail = 0;
 335         dev->buffer_overflow = 0;
 336         usb_fill_int_urb(dev->interrupt_in_urb,
 337                          interface_to_usbdev(interface),
 338                          usb_rcvintpipe(interface_to_usbdev(interface),
 339                                         dev->interrupt_in_endpoint->bEndpointAddress),
 340                          dev->interrupt_in_buffer,
 341                          dev->interrupt_in_endpoint_size,
 342                          ld_usb_interrupt_in_callback,
 343                          dev,
 344                          dev->interrupt_in_interval);
 345
 346         dev->interrupt_in_running = 1;
 347         dev->interrupt_in_done = 0;
 348
 349         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 350         if (retval) {
 351                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 352                 dev->interrupt_in_running = 0;
 353                 dev->open_count = 0;
 354                 goto unlock_exit;
 355         }
 356
 357         /* save device in the file's private structure */
 358         file->private_data = dev;
 359
 360 unlock_exit:
 361         up(&dev->sem);
 362
 363         return retval;
 364 }
 365
 366 /**
 367  *      ld_usb_release
 368  */
 369 static int ld_usb_release(struct inode *inode, struct file *file)
 370 {
 371         struct ld_usb *dev;
 372         int retval = 0;
 373
 374         dev = file->private_data;
 375
 376         if (dev == NULL) {
 377                 retval = -ENODEV;
 378                 goto exit;
 379         }
 380
 381         if (down_interruptible(&dev->sem)) {
 382                 retval = -ERESTARTSYS;
 383                 goto exit;
 384         }
 385
 386         if (dev->open_count != 1) {
 387                 retval = -ENODEV;
 388                 goto unlock_exit;
 389         }
 390         if (dev->intf == NULL) {
 391                 /* the device was unplugged before the file was released */
 392                 up(&dev->sem);
 393                 /* unlock here as ld_usb_delete frees dev */
 394                 ld_usb_delete(dev);
 395                 goto exit;
 396         }
 397
 398         /* wait until write transfer is finished */
 399         if (dev->interrupt_out_busy)
 400                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 401         ld_usb_abort_transfers(dev);
 402         dev->open_count = 0;
 403
 404 unlock_exit:
 405         up(&dev->sem);
 406
 407 exit:
 408         return retval;
 409 }
 410
 411 /**
 412  *      ld_usb_poll
 413  */
 414 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 415 {
 416         struct ld_usb *dev;
 417         unsigned int mask = 0;
 418
 419         dev = file->private_data;
 420
 421         poll_wait(file, &dev->read_wait, wait);
 422         poll_wait(file, &dev->write_wait, wait);
 423
 424         if (dev->ring_head != dev->ring_tail)
 425                 mask |= POLLIN | POLLRDNORM;
 426         if (!dev->interrupt_out_busy)
 427                 mask |= POLLOUT | POLLWRNORM;
 428
 429         return mask;
 430 }
 431
 432 /**
 433  *      ld_usb_read
 434  */
 435 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 436                            loff_t *ppos)
 437 {
 438         struct ld_usb *dev;
 439         size_t *actual_buffer;
 440         size_t bytes_to_read;
 441         int retval = 0;
 442         int rv;
 443
 444         dev = file->private_data;
 445
 446         /* verify that we actually have some data to read */
 447         if (count == 0)
 448                 goto exit;
 449
 450         /* lock this object */
 451         if (down_interruptible(&dev->sem)) {
 452                 retval = -ERESTARTSYS;
 453                 goto exit;
 454         }
 455
 456         /* verify that the device wasn't unplugged */
 457         if (dev->intf == NULL) {
 458                 retval = -ENODEV;
 459                 err("No device or device unplugged %d\n", retval);
 460                 goto unlock_exit;
 461         }
 462
 463         /* wait for data */
 464         spin_lock_irq(&dev->rbsl);
 465         if (dev->ring_head == dev->ring_tail) {
 466                 dev->interrupt_in_done = 0;
 467                 spin_unlock_irq(&dev->rbsl);
 468                 if (file->f_flags & O_NONBLOCK) {
 469                         retval = -EAGAIN;
 470                         goto unlock_exit;
 471                 }
 472                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 473                 if (retval < 0)
 474                         goto unlock_exit;
 475         } else {
 476                 spin_unlock_irq(&dev->rbsl);
 477         }
 478
 479         /* actual_buffer contains actual_length + interrupt_in_buffer */
 480         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 481         bytes_to_read = min(count, *actual_buffer);
 482         if (bytes_to_read < *actual_buffer)
 483                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 484                          *actual_buffer-bytes_to_read);
 485
 486         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 487         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 488                 retval = -EFAULT;
 489                 goto unlock_exit;
 490         }
 491         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 492
 493         retval = bytes_to_read;
 494
 495         spin_lock_irq(&dev->rbsl);
 496         if (dev->buffer_overflow) {
 497                 dev->buffer_overflow = 0;
 498                 spin_unlock_irq(&dev->rbsl);
 499                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 500                 if (rv < 0)
 501                         dev->buffer_overflow = 1;
 502         } else {
 503                 spin_unlock_irq(&dev->rbsl);
 504         }
 505
 506 unlock_exit:
 507         /* unlock the device */
 508         up(&dev->sem);
 509
 510 exit:
 511         return retval;
 512 }
 513
 514 /**
 515  *      ld_usb_write
 516  */
 517 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 518                             size_t count, loff_t *ppos)
 519 {
 520         struct ld_usb *dev;
 521         size_t bytes_to_write;
 522         int retval = 0;
 523
 524         dev = file->private_data;
 525
 526         /* verify that we actually have some data to write */
 527         if (count == 0)
 528                 goto exit;
 529
 530         /* lock this object */
 531         if (down_interruptible(&dev->sem)) {
 532                 retval = -ERESTARTSYS;
 533                 goto exit;
 534         }
 535
 536         /* verify that the device wasn't unplugged */
 537         if (dev->intf == NULL) {
 538                 retval = -ENODEV;
 539                 err("No device or device unplugged %d\n", retval);
 540                 goto unlock_exit;
 541         }
 542
 543         /* wait until previous transfer is finished */
 544         if (dev->interrupt_out_busy) {
 545                 if (file->f_flags & O_NONBLOCK) {
 546                         retval = -EAGAIN;
 547                         goto unlock_exit;
 548                 }
 549                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 550                 if (retval < 0) {
 551                         goto unlock_exit;
 552                 }
 553         }
 554
 555         /* write the data into interrupt_out_buffer from userspace */
 556         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 557         if (bytes_to_write < count)
 558                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 559         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 560
 561         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 562                 retval = -EFAULT;
 563                 goto unlock_exit;
 564         }
 565
 566         if (dev->interrupt_out_endpoint == NULL) {
 567                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 568                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 569                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 570                                          9,
 571                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 572                                          1 << 8, 0,
 573                                          dev->interrupt_out_buffer,
 574                                          bytes_to_write,
 575                                          USB_CTRL_SET_TIMEOUT * HZ);
 576                 if (retval < 0)
 577                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 578                 goto unlock_exit;
 579         }
 580
 581         /* send off the urb */
 582         usb_fill_int_urb(dev->interrupt_out_urb,
 583                          interface_to_usbdev(dev->intf),
 584                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 585                                         dev->interrupt_out_endpoint->bEndpointAddress),
 586                          dev->interrupt_out_buffer,
 587                          bytes_to_write,
 588                          ld_usb_interrupt_out_callback,
 589                          dev,
 590                          dev->interrupt_out_interval);
 591
 592         dev->interrupt_out_busy = 1;
 593         wmb();
 594
 595         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 596         if (retval) {
 597                 dev->interrupt_out_busy = 0;
 598                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 599                 goto unlock_exit;
 600         }
 601         retval = bytes_to_write;
 602
 603 unlock_exit:
 604         /* unlock the device */
 605         up(&dev->sem);
 606
 607 exit:
 608         return retval;
 609 }
 610
 611 /* file operations needed when we register this driver */
 612 static const struct file_operations ld_usb_fops = {
 613         .owner =        THIS_MODULE,
 614         .read  =        ld_usb_read,
 615         .write =        ld_usb_write,
 616         .open =         ld_usb_open,
 617         .release =      ld_usb_release,
 618         .poll =         ld_usb_poll,
 619 };
 620
 621 /*
 622  * usb class driver info in order to get a minor number from the usb core,
 623  * and to have the device registered with the driver core
 624  */
 625 static struct usb_class_driver ld_usb_class = {
 626         .name =         "ldusb%d",
 627         .fops =         &ld_usb_fops,
 628         .minor_base =   USB_LD_MINOR_BASE,
 629 };
 630
 631 /**
 632  *      ld_usb_probe
 633  *
 634  *      Called by the usb core when a new device is connected that it thinks
 635  *      this driver might be interested in.
 636  */
 637 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 638 {
 639         struct usb_device *udev = interface_to_usbdev(intf);
 640         struct ld_usb *dev = NULL;
 641         struct usb_host_interface *iface_desc;
 642         struct usb_endpoint_descriptor *endpoint;
 643         char *buffer;
 644         int i;
 645         int retval = -ENOMEM;
 646
 647         /* allocate memory for our device state and intialize it */
 648
 649         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 650         if (dev == NULL) {
 651                 dev_err(&intf->dev, "Out of memory\n");
 652                 goto exit;
 653         }
 654         init_MUTEX(&dev->sem);
 655         spin_lock_init(&dev->rbsl);
 656         dev->intf = intf;
 657         init_waitqueue_head(&dev->read_wait);
 658         init_waitqueue_head(&dev->write_wait);
 659
 660         /* workaround for early firmware versions on fast computers */
 661         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 662             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 663              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 664             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 665                 buffer = kmalloc(256, GFP_KERNEL);
 666                 if (buffer == NULL) {
 667                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 668                         goto error;
 669                 }
 670                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 671                 usb_string(udev, 255, buffer, 256);
 672                 kfree(buffer);
 673         }
 674
 675         iface_desc = intf->cur_altsetting;
 676
 677         /* set up the endpoint information */
 678         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 679                 endpoint = &iface_desc->endpoint[i].desc;
 680
 681                 if (usb_endpoint_is_int_in(endpoint))
 682                         dev->interrupt_in_endpoint = endpoint;
 683
 684                 if (usb_endpoint_is_int_out(endpoint))
 685                         dev->interrupt_out_endpoint = endpoint;
 686         }
 687         if (dev->interrupt_in_endpoint == NULL) {
 688                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 689                 goto error;
 690         }
 691         if (dev->interrupt_out_endpoint == NULL)
 692                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 693
 694         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 695         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 696         if (!dev->ring_buffer) {
 697                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 698                 goto error;
 699         }
 700         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 701         if (!dev->interrupt_in_buffer) {
 702                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 703                 goto error;
 704         }
 705         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 706         if (!dev->interrupt_in_urb) {
 707                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 708                 goto error;
 709         }
 710         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 711                                                                          udev->descriptor.bMaxPacketSize0;
 712         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 713         if (!dev->interrupt_out_buffer) {
 714                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 715                 goto error;
 716         }
 717         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 718         if (!dev->interrupt_out_urb) {
 719                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 720                 goto error;
 721         }
 722         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 723         if (dev->interrupt_out_endpoint)
 724                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 725
 726         /* we can register the device now, as it is ready */
 727         usb_set_intfdata(intf, dev);
 728
 729         retval = usb_register_dev(intf, &ld_usb_class);
 730         if (retval) {
 731                 /* something prevented us from registering this driver */
 732                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 733                 usb_set_intfdata(intf, NULL);
 734                 goto error;
 735         }
 736
 737         /* let the user know what node this device is now attached to */
 738         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 739                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 740
 741 exit:
 742         return retval;
 743
 744 error:
 745         ld_usb_delete(dev);
 746
 747         return retval;
 748 }
 749
 750 /**
 751  *      ld_usb_disconnect
 752  *
 753  *      Called by the usb core when the device is removed from the system.
 754  */
 755 static void ld_usb_disconnect(struct usb_interface *intf)
 756 {
 757         struct ld_usb *dev;
 758         int minor;
 759
 760         dev = usb_get_intfdata(intf);
 761         usb_set_intfdata(intf, NULL);
 762
 763         minor = intf->minor;
 764
 765         /* give back our minor */
 766         usb_deregister_dev(intf, &ld_usb_class);
 767
 768         down(&dev->sem);
 769
 770         /* if the device is not opened, then we clean up right now */
 771         if (!dev->open_count) {
 772                 up(&dev->sem);
 773                 ld_usb_delete(dev);
 774         } else {
 775                 dev->intf = NULL;
 776                 up(&dev->sem);
 777         }
 778
 779         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 780                  (minor - USB_LD_MINOR_BASE));
 781 }
 782
 783 /* usb specific object needed to register this driver with the usb subsystem */
 784 static struct usb_driver ld_usb_driver = {
 785         .name =         "ldusb",
 786         .probe =        ld_usb_probe,
 787         .disconnect =   ld_usb_disconnect,
 788         .id_table =     ld_usb_table,
 789 };
 790
 791 /**
 792  *      ld_usb_init
 793  */
 794 static int __init ld_usb_init(void)
 795 {
 796         int retval;
 797
 798         /* register this driver with the USB subsystem */
 799         retval = usb_register(&ld_usb_driver);
 800         if (retval)
 801                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
 802
 803         return retval;
 804 }
 805
 806 /**
 807  *      ld_usb_exit
 808  */
 809 static void __exit ld_usb_exit(void)
 810 {
 811         /* deregister this driver with the USB subsystem */
 812         usb_deregister(&ld_usb_driver);
 813 }
 814
 815 module_init(ld_usb_init);
 816 module_exit(ld_usb_exit);
 817