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_GOTEMP    0x0002
  61 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  62 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  63 #define USB_DEVICE_ID_VERNIER_LCSPEC    0x0006
  64
  65 #ifdef CONFIG_USB_DYNAMIC_MINORS
  66 #define USB_LD_MINOR_BASE       0
  67 #else
  68 #define USB_LD_MINOR_BASE       176
  69 #endif
  70
  71 /* table of devices that work with this driver */
  72 static const struct usb_device_id ld_usb_table[] = {
  73         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  74         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  75         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
  80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
  81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
  82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
  83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
  84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
  85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
  86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
  87         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  88         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  89         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  90         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) },
  91         { }                                     /* Terminating entry */
  92 };
  93 MODULE_DEVICE_TABLE(usb, ld_usb_table);
  94 MODULE_VERSION("V0.13");
  95 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
  96 MODULE_DESCRIPTION("LD USB Driver");
  97 MODULE_LICENSE("GPL");
  98 MODULE_SUPPORTED_DEVICE("LD USB Devices");
  99
 100 #ifdef CONFIG_USB_DEBUG
 101         static int debug = 1;
 102 #else
 103         static int debug = 0;
 104 #endif
 105
 106 /* Use our own dbg macro */
 107 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 108
 109 /* Module parameters */
 110 module_param(debug, int, S_IRUGO | S_IWUSR);
 111 MODULE_PARM_DESC(debug, "Debug enabled or not");
 112
 113 /* All interrupt in transfers are collected in a ring buffer to
 114  * avoid racing conditions and get better performance of the driver.
 115  */
 116 static int ring_buffer_size = 128;
 117 module_param(ring_buffer_size, int, 0);
 118 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 119
 120 /* The write_buffer can contain more than one interrupt out transfer.
 121  */
 122 static int write_buffer_size = 10;
 123 module_param(write_buffer_size, int, 0);
 124 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 125
 126 /* As of kernel version 2.6.4 ehci-hcd uses an
 127  * "only one interrupt transfer per frame" shortcut
 128  * to simplify the scheduling of periodic transfers.
 129  * This conflicts with our standard 1ms intervals for in and out URBs.
 130  * We use default intervals of 2ms for in and 2ms for out transfers,
 131  * which should be fast enough.
 132  * Increase the interval to allow more devices that do interrupt transfers,
 133  * or set to 1 to use the standard interval from the endpoint descriptors.
 134  */
 135 static int min_interrupt_in_interval = 2;
 136 module_param(min_interrupt_in_interval, int, 0);
 137 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 138
 139 static int min_interrupt_out_interval = 2;
 140 module_param(min_interrupt_out_interval, int, 0);
 141 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 142
 143 /* Structure to hold all of our device specific stuff */
 144 struct ld_usb {
 145         struct mutex            mutex;          /* locks this structure */
 146         struct usb_interface*   intf;           /* save off the usb interface pointer */
 147
 148         int                     open_count;     /* number of times this port has been opened */
 149
 150         char*                   ring_buffer;
 151         unsigned int            ring_head;
 152         unsigned int            ring_tail;
 153
 154         wait_queue_head_t       read_wait;
 155         wait_queue_head_t       write_wait;
 156
 157         char*                   interrupt_in_buffer;
 158         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 159         struct urb*             interrupt_in_urb;
 160         int                     interrupt_in_interval;
 161         size_t                  interrupt_in_endpoint_size;
 162         int                     interrupt_in_running;
 163         int                     interrupt_in_done;
 164         int                     buffer_overflow;
 165         spinlock_t              rbsl;
 166
 167         char*                   interrupt_out_buffer;
 168         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 169         struct urb*             interrupt_out_urb;
 170         int                     interrupt_out_interval;
 171         size_t                  interrupt_out_endpoint_size;
 172         int                     interrupt_out_busy;
 173 };
 174
 175 static struct usb_driver ld_usb_driver;
 176
 177 /**
 178  *      ld_usb_abort_transfers
 179  *      aborts transfers and frees associated data structures
 180  */
 181 static void ld_usb_abort_transfers(struct ld_usb *dev)
 182 {
 183         /* shutdown transfer */
 184         if (dev->interrupt_in_running) {
 185                 dev->interrupt_in_running = 0;
 186                 if (dev->intf)
 187                         usb_kill_urb(dev->interrupt_in_urb);
 188         }
 189         if (dev->interrupt_out_busy)
 190                 if (dev->intf)
 191                         usb_kill_urb(dev->interrupt_out_urb);
 192 }
 193
 194 /**
 195  *      ld_usb_delete
 196  */
 197 static void ld_usb_delete(struct ld_usb *dev)
 198 {
 199         ld_usb_abort_transfers(dev);
 200
 201         /* free data structures */
 202         usb_free_urb(dev->interrupt_in_urb);
 203         usb_free_urb(dev->interrupt_out_urb);
 204         kfree(dev->ring_buffer);
 205         kfree(dev->interrupt_in_buffer);
 206         kfree(dev->interrupt_out_buffer);
 207         kfree(dev);
 208 }
 209
 210 /**
 211  *      ld_usb_interrupt_in_callback
 212  */
 213 static void ld_usb_interrupt_in_callback(struct urb *urb)
 214 {
 215         struct ld_usb *dev = urb->context;
 216         size_t *actual_buffer;
 217         unsigned int next_ring_head;
 218         int status = urb->status;
 219         int retval;
 220
 221         if (status) {
 222                 if (status == -ENOENT ||
 223                     status == -ECONNRESET ||
 224                     status == -ESHUTDOWN) {
 225                         goto exit;
 226                 } else {
 227                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 228                                  __func__, status);
 229                         spin_lock(&dev->rbsl);
 230                         goto resubmit; /* maybe we can recover */
 231                 }
 232         }
 233
 234         spin_lock(&dev->rbsl);
 235         if (urb->actual_length > 0) {
 236                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 237                 if (next_ring_head != dev->ring_tail) {
 238                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 239                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 240                         *actual_buffer = urb->actual_length;
 241                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 242                         dev->ring_head = next_ring_head;
 243                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 244                                  __func__, urb->actual_length);
 245                 } else {
 246                         dev_warn(&dev->intf->dev,
 247                                  "Ring buffer overflow, %d bytes dropped\n",
 248                                  urb->actual_length);
 249                         dev->buffer_overflow = 1;
 250                 }
 251         }
 252
 253 resubmit:
 254         /* resubmit if we're still running */
 255         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
 256                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 257                 if (retval) {
 258                         dev_err(&dev->intf->dev,
 259                                 "usb_submit_urb failed (%d)\n", retval);
 260                         dev->buffer_overflow = 1;
 261                 }
 262         }
 263         spin_unlock(&dev->rbsl);
 264 exit:
 265         dev->interrupt_in_done = 1;
 266         wake_up_interruptible(&dev->read_wait);
 267 }
 268
 269 /**
 270  *      ld_usb_interrupt_out_callback
 271  */
 272 static void ld_usb_interrupt_out_callback(struct urb *urb)
 273 {
 274         struct ld_usb *dev = urb->context;
 275         int status = urb->status;
 276
 277         /* sync/async unlink faults aren't errors */
 278         if (status && !(status == -ENOENT ||
 279                         status == -ECONNRESET ||
 280                         status == -ESHUTDOWN))
 281                 dbg_info(&dev->intf->dev,
 282                          "%s - nonzero write interrupt status received: %d\n",
 283                          __func__, status);
 284
 285         dev->interrupt_out_busy = 0;
 286         wake_up_interruptible(&dev->write_wait);
 287 }
 288
 289 /**
 290  *      ld_usb_open
 291  */
 292 static int ld_usb_open(struct inode *inode, struct file *file)
 293 {
 294         struct ld_usb *dev;
 295         int subminor;
 296         int retval;
 297         struct usb_interface *interface;
 298
 299         nonseekable_open(inode, file);
 300         subminor = iminor(inode);
 301
 302         interface = usb_find_interface(&ld_usb_driver, subminor);
 303
 304         if (!interface) {
 305                 err("%s - error, can't find device for minor %d\n",
 306                      __func__, subminor);
 307                 return -ENODEV;
 308         }
 309
 310         dev = usb_get_intfdata(interface);
 311
 312         if (!dev)
 313                 return -ENODEV;
 314
 315         /* lock this device */
 316         if (mutex_lock_interruptible(&dev->mutex))
 317                 return -ERESTARTSYS;
 318
 319         /* allow opening only once */
 320         if (dev->open_count) {
 321                 retval = -EBUSY;
 322                 goto unlock_exit;
 323         }
 324         dev->open_count = 1;
 325
 326         /* initialize in direction */
 327         dev->ring_head = 0;
 328         dev->ring_tail = 0;
 329         dev->buffer_overflow = 0;
 330         usb_fill_int_urb(dev->interrupt_in_urb,
 331                          interface_to_usbdev(interface),
 332                          usb_rcvintpipe(interface_to_usbdev(interface),
 333                                         dev->interrupt_in_endpoint->bEndpointAddress),
 334                          dev->interrupt_in_buffer,
 335                          dev->interrupt_in_endpoint_size,
 336                          ld_usb_interrupt_in_callback,
 337                          dev,
 338                          dev->interrupt_in_interval);
 339
 340         dev->interrupt_in_running = 1;
 341         dev->interrupt_in_done = 0;
 342
 343         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 344         if (retval) {
 345                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 346                 dev->interrupt_in_running = 0;
 347                 dev->open_count = 0;
 348                 goto unlock_exit;
 349         }
 350
 351         /* save device in the file's private structure */
 352         file->private_data = dev;
 353
 354 unlock_exit:
 355         mutex_unlock(&dev->mutex);
 356
 357         return retval;
 358 }
 359
 360 /**
 361  *      ld_usb_release
 362  */
 363 static int ld_usb_release(struct inode *inode, struct file *file)
 364 {
 365         struct ld_usb *dev;
 366         int retval = 0;
 367
 368         dev = file->private_data;
 369
 370         if (dev == NULL) {
 371                 retval = -ENODEV;
 372                 goto exit;
 373         }
 374
 375         if (mutex_lock_interruptible(&dev->mutex)) {
 376                 retval = -ERESTARTSYS;
 377                 goto exit;
 378         }
 379
 380         if (dev->open_count != 1) {
 381                 retval = -ENODEV;
 382                 goto unlock_exit;
 383         }
 384         if (dev->intf == NULL) {
 385                 /* the device was unplugged before the file was released */
 386                 mutex_unlock(&dev->mutex);
 387                 /* unlock here as ld_usb_delete frees dev */
 388                 ld_usb_delete(dev);
 389                 goto exit;
 390         }
 391
 392         /* wait until write transfer is finished */
 393         if (dev->interrupt_out_busy)
 394                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 395         ld_usb_abort_transfers(dev);
 396         dev->open_count = 0;
 397
 398 unlock_exit:
 399         mutex_unlock(&dev->mutex);
 400
 401 exit:
 402         return retval;
 403 }
 404
 405 /**
 406  *      ld_usb_poll
 407  */
 408 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 409 {
 410         struct ld_usb *dev;
 411         unsigned int mask = 0;
 412
 413         dev = file->private_data;
 414
 415         if (!dev->intf)
 416                 return POLLERR | POLLHUP;
 417
 418         poll_wait(file, &dev->read_wait, wait);
 419         poll_wait(file, &dev->write_wait, wait);
 420
 421         if (dev->ring_head != dev->ring_tail)
 422                 mask |= POLLIN | POLLRDNORM;
 423         if (!dev->interrupt_out_busy)
 424                 mask |= POLLOUT | POLLWRNORM;
 425
 426         return mask;
 427 }
 428
 429 /**
 430  *      ld_usb_read
 431  */
 432 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 433                            loff_t *ppos)
 434 {
 435         struct ld_usb *dev;
 436         size_t *actual_buffer;
 437         size_t bytes_to_read;
 438         int retval = 0;
 439         int rv;
 440
 441         dev = file->private_data;
 442
 443         /* verify that we actually have some data to read */
 444         if (count == 0)
 445                 goto exit;
 446
 447         /* lock this object */
 448         if (mutex_lock_interruptible(&dev->mutex)) {
 449                 retval = -ERESTARTSYS;
 450                 goto exit;
 451         }
 452
 453         /* verify that the device wasn't unplugged */
 454         if (dev->intf == NULL) {
 455                 retval = -ENODEV;
 456                 err("No device or device unplugged %d\n", retval);
 457                 goto unlock_exit;
 458         }
 459
 460         /* wait for data */
 461         spin_lock_irq(&dev->rbsl);
 462         if (dev->ring_head == dev->ring_tail) {
 463                 dev->interrupt_in_done = 0;
 464                 spin_unlock_irq(&dev->rbsl);
 465                 if (file->f_flags & O_NONBLOCK) {
 466                         retval = -EAGAIN;
 467                         goto unlock_exit;
 468                 }
 469                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 470                 if (retval < 0)
 471                         goto unlock_exit;
 472         } else {
 473                 spin_unlock_irq(&dev->rbsl);
 474         }
 475
 476         /* actual_buffer contains actual_length + interrupt_in_buffer */
 477         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 478         bytes_to_read = min(count, *actual_buffer);
 479         if (bytes_to_read < *actual_buffer)
 480                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 481                          *actual_buffer-bytes_to_read);
 482
 483         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 484         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 485                 retval = -EFAULT;
 486                 goto unlock_exit;
 487         }
 488         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 489
 490         retval = bytes_to_read;
 491
 492         spin_lock_irq(&dev->rbsl);
 493         if (dev->buffer_overflow) {
 494                 dev->buffer_overflow = 0;
 495                 spin_unlock_irq(&dev->rbsl);
 496                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 497                 if (rv < 0)
 498                         dev->buffer_overflow = 1;
 499         } else {
 500                 spin_unlock_irq(&dev->rbsl);
 501         }
 502
 503 unlock_exit:
 504         /* unlock the device */
 505         mutex_unlock(&dev->mutex);
 506
 507 exit:
 508         return retval;
 509 }
 510
 511 /**
 512  *      ld_usb_write
 513  */
 514 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 515                             size_t count, loff_t *ppos)
 516 {
 517         struct ld_usb *dev;
 518         size_t bytes_to_write;
 519         int retval = 0;
 520
 521         dev = file->private_data;
 522
 523         /* verify that we actually have some data to write */
 524         if (count == 0)
 525                 goto exit;
 526
 527         /* lock this object */
 528         if (mutex_lock_interruptible(&dev->mutex)) {
 529                 retval = -ERESTARTSYS;
 530                 goto exit;
 531         }
 532
 533         /* verify that the device wasn't unplugged */
 534         if (dev->intf == NULL) {
 535                 retval = -ENODEV;
 536                 err("No device or device unplugged %d\n", retval);
 537                 goto unlock_exit;
 538         }
 539
 540         /* wait until previous transfer is finished */
 541         if (dev->interrupt_out_busy) {
 542                 if (file->f_flags & O_NONBLOCK) {
 543                         retval = -EAGAIN;
 544                         goto unlock_exit;
 545                 }
 546                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 547                 if (retval < 0) {
 548                         goto unlock_exit;
 549                 }
 550         }
 551
 552         /* write the data into interrupt_out_buffer from userspace */
 553         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 554         if (bytes_to_write < count)
 555                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 556         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __func__, count, bytes_to_write);
 557
 558         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 559                 retval = -EFAULT;
 560                 goto unlock_exit;
 561         }
 562
 563         if (dev->interrupt_out_endpoint == NULL) {
 564                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 565                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 566                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 567                                          9,
 568                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 569                                          1 << 8, 0,
 570                                          dev->interrupt_out_buffer,
 571                                          bytes_to_write,
 572                                          USB_CTRL_SET_TIMEOUT * HZ);
 573                 if (retval < 0)
 574                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 575                 goto unlock_exit;
 576         }
 577
 578         /* send off the urb */
 579         usb_fill_int_urb(dev->interrupt_out_urb,
 580                          interface_to_usbdev(dev->intf),
 581                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 582                                         dev->interrupt_out_endpoint->bEndpointAddress),
 583                          dev->interrupt_out_buffer,
 584                          bytes_to_write,
 585                          ld_usb_interrupt_out_callback,
 586                          dev,
 587                          dev->interrupt_out_interval);
 588
 589         dev->interrupt_out_busy = 1;
 590         wmb();
 591
 592         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 593         if (retval) {
 594                 dev->interrupt_out_busy = 0;
 595                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 596                 goto unlock_exit;
 597         }
 598         retval = bytes_to_write;
 599
 600 unlock_exit:
 601         /* unlock the device */
 602         mutex_unlock(&dev->mutex);
 603
 604 exit:
 605         return retval;
 606 }
 607
 608 /* file operations needed when we register this driver */
 609 static const struct file_operations ld_usb_fops = {
 610         .owner =        THIS_MODULE,
 611         .read  =        ld_usb_read,
 612         .write =        ld_usb_write,
 613         .open =         ld_usb_open,
 614         .release =      ld_usb_release,
 615         .poll =         ld_usb_poll,
 616         .llseek =       no_llseek,
 617 };
 618
 619 /*
 620  * usb class driver info in order to get a minor number from the usb core,
 621  * and to have the device registered with the driver core
 622  */
 623 static struct usb_class_driver ld_usb_class = {
 624         .name =         "ldusb%d",
 625         .fops =         &ld_usb_fops,
 626         .minor_base =   USB_LD_MINOR_BASE,
 627 };
 628
 629 /**
 630  *      ld_usb_probe
 631  *
 632  *      Called by the usb core when a new device is connected that it thinks
 633  *      this driver might be interested in.
 634  */
 635 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 636 {
 637         struct usb_device *udev = interface_to_usbdev(intf);
 638         struct ld_usb *dev = NULL;
 639         struct usb_host_interface *iface_desc;
 640         struct usb_endpoint_descriptor *endpoint;
 641         char *buffer;
 642         int i;
 643         int retval = -ENOMEM;
 644
 645         /* allocate memory for our device state and initialize it */
 646
 647         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 648         if (dev == NULL) {
 649                 dev_err(&intf->dev, "Out of memory\n");
 650                 goto exit;
 651         }
 652         mutex_init(&dev->mutex);
 653         spin_lock_init(&dev->rbsl);
 654         dev->intf = intf;
 655         init_waitqueue_head(&dev->read_wait);
 656         init_waitqueue_head(&dev->write_wait);
 657
 658         /* workaround for early firmware versions on fast computers */
 659         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 660             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 661              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 662             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 663                 buffer = kmalloc(256, GFP_KERNEL);
 664                 if (buffer == NULL) {
 665                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 666                         goto error;
 667                 }
 668                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 669                 usb_string(udev, 255, buffer, 256);
 670                 kfree(buffer);
 671         }
 672
 673         iface_desc = intf->cur_altsetting;
 674
 675         /* set up the endpoint information */
 676         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 677                 endpoint = &iface_desc->endpoint[i].desc;
 678
 679                 if (usb_endpoint_is_int_in(endpoint))
 680                         dev->interrupt_in_endpoint = endpoint;
 681
 682                 if (usb_endpoint_is_int_out(endpoint))
 683                         dev->interrupt_out_endpoint = endpoint;
 684         }
 685         if (dev->interrupt_in_endpoint == NULL) {
 686                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 687                 goto error;
 688         }
 689         if (dev->interrupt_out_endpoint == NULL)
 690                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 691
 692         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 693         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 694         if (!dev->ring_buffer) {
 695                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 696                 goto error;
 697         }
 698         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 699         if (!dev->interrupt_in_buffer) {
 700                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 701                 goto error;
 702         }
 703         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 704         if (!dev->interrupt_in_urb) {
 705                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 706                 goto error;
 707         }
 708         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 709                                                                          udev->descriptor.bMaxPacketSize0;
 710         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 711         if (!dev->interrupt_out_buffer) {
 712                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 713                 goto error;
 714         }
 715         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 716         if (!dev->interrupt_out_urb) {
 717                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 718                 goto error;
 719         }
 720         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 721         if (dev->interrupt_out_endpoint)
 722                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 723
 724         /* we can register the device now, as it is ready */
 725         usb_set_intfdata(intf, dev);
 726
 727         retval = usb_register_dev(intf, &ld_usb_class);
 728         if (retval) {
 729                 /* something prevented us from registering this driver */
 730                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 731                 usb_set_intfdata(intf, NULL);
 732                 goto error;
 733         }
 734
 735         /* let the user know what node this device is now attached to */
 736         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 737                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 738
 739 exit:
 740         return retval;
 741
 742 error:
 743         ld_usb_delete(dev);
 744
 745         return retval;
 746 }
 747
 748 /**
 749  *      ld_usb_disconnect
 750  *
 751  *      Called by the usb core when the device is removed from the system.
 752  */
 753 static void ld_usb_disconnect(struct usb_interface *intf)
 754 {
 755         struct ld_usb *dev;
 756         int minor;
 757
 758         dev = usb_get_intfdata(intf);
 759         usb_set_intfdata(intf, NULL);
 760
 761         minor = intf->minor;
 762
 763         /* give back our minor */
 764         usb_deregister_dev(intf, &ld_usb_class);
 765
 766         mutex_lock(&dev->mutex);
 767
 768         /* if the device is not opened, then we clean up right now */
 769         if (!dev->open_count) {
 770                 mutex_unlock(&dev->mutex);
 771                 ld_usb_delete(dev);
 772         } else {
 773                 dev->intf = NULL;
 774                 /* wake up pollers */
 775                 wake_up_interruptible_all(&dev->read_wait);
 776                 wake_up_interruptible_all(&dev->write_wait);
 777                 mutex_unlock(&dev->mutex);
 778         }
 779
 780         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 781                  (minor - USB_LD_MINOR_BASE));
 782 }
 783
 784 /* usb specific object needed to register this driver with the usb subsystem */
 785 static struct usb_driver ld_usb_driver = {
 786         .name =         "ldusb",
 787         .probe =        ld_usb_probe,
 788         .disconnect =   ld_usb_disconnect,
 789         .id_table =     ld_usb_table,
 790 };
 791
 792 /**
 793  *      ld_usb_init
 794  */
 795 static int __init ld_usb_init(void)
 796 {
 797         int retval;
 798
 799         /* register this driver with the USB subsystem */
 800         retval = usb_register(&ld_usb_driver);
 801         if (retval)
 802                 err("usb_register failed for the %s driver. Error number %d\n", __FILE__, retval);
 803
 804         return retval;
 805 }
 806
 807 /**
 808  *      ld_usb_exit
 809  */
 810 static void __exit ld_usb_exit(void)
 811 {
 812         /* deregister this driver with the USB subsystem */
 813         usb_deregister(&ld_usb_driver);
 814 }
 815
 816 module_init(ld_usb_init);
 817 module_exit(ld_usb_exit);
 818