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  */
  28
  29 #include <linux/config.h>
  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
  36 #include <asm/uaccess.h>
  37 #include <linux/input.h>
  38 #include <linux/usb.h>
  39 #include <linux/poll.h>
  40
  41 /* Define these values to match your devices */
  42 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  43 #define USB_DEVICE_ID_CASSY             0x1000  /* USB Product ID for all CASSY-S modules */
  44 #define USB_DEVICE_ID_POCKETCASSY       0x1010  /* USB Product ID for Pocket-CASSY */
  45 #define USB_DEVICE_ID_MOBILECASSY       0x1020  /* USB Product ID for Mobile-CASSY */
  46 #define USB_DEVICE_ID_JWM               0x1080  /* USB Product ID for Joule and Wattmeter */
  47 #define USB_DEVICE_ID_DMMP              0x1081  /* USB Product ID for Digital Multimeter P (reserved) */
  48 #define USB_DEVICE_ID_UMIP              0x1090  /* USB Product ID for UMI P */
  49 #define USB_DEVICE_ID_VIDEOCOM          0x1200  /* USB Product ID for VideoCom */
  50 #define USB_DEVICE_ID_COM3LAB           0x2000  /* USB Product ID for COM3LAB */
  51 #define USB_DEVICE_ID_TELEPORT          0x2010  /* USB Product ID for Terminal Adapter */
  52 #define USB_DEVICE_ID_NETWORKANALYSER   0x2020  /* USB Product ID for Network Analyser */
  53 #define USB_DEVICE_ID_POWERCONTROL      0x2030  /* USB Product ID for Controlling device for Power Electronics */
  54
  55 #define USB_VENDOR_ID_VERNIER           0x08f7
  56 #define USB_DEVICE_ID_VERNIER_LABPRO    0x0001
  57 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
  58 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  59 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  60
  61
  62 #ifdef CONFIG_USB_DYNAMIC_MINORS
  63 #define USB_LD_MINOR_BASE       0
  64 #else
  65 #define USB_LD_MINOR_BASE       176
  66 #endif
  67
  68 /* table of devices that work with this driver */
  69 static struct usb_device_id ld_usb_table [] = {
  70         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_CASSY) },
  71         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_POCKETCASSY) },
  72         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_MOBILECASSY) },
  73         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_JWM) },
  74         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_DMMP) },
  75         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_UMIP) },
  76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_VIDEOCOM) },
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_COM3LAB) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_TELEPORT) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_NETWORKANALYSER) },
  80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_POWERCONTROL) },
  81         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
  82         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  83         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  84         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  85         { }                                     /* Terminating entry */
  86 };
  87 MODULE_DEVICE_TABLE(usb, ld_usb_table);
  88 MODULE_VERSION("V0.12");
  89 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
  90 MODULE_DESCRIPTION("LD USB Driver");
  91 MODULE_LICENSE("GPL");
  92 MODULE_SUPPORTED_DEVICE("LD USB Devices");
  93
  94 #ifdef CONFIG_USB_DEBUG
  95         static int debug = 1;
  96 #else
  97         static int debug = 0;
  98 #endif
  99
 100 /* Use our own dbg macro */
 101 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 102
 103 /* Module parameters */
 104 module_param(debug, int, S_IRUGO | S_IWUSR);
 105 MODULE_PARM_DESC(debug, "Debug enabled or not");
 106
 107 /* All interrupt in transfers are collected in a ring buffer to
 108  * avoid racing conditions and get better performance of the driver.
 109  */
 110 static int ring_buffer_size = 128;
 111 module_param(ring_buffer_size, int, 0);
 112 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 113
 114 /* The write_buffer can contain more than one interrupt out transfer.
 115  */
 116 static int write_buffer_size = 10;
 117 module_param(write_buffer_size, int, 0);
 118 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 119
 120 /* As of kernel version 2.6.4 ehci-hcd uses an
 121  * "only one interrupt transfer per frame" shortcut
 122  * to simplify the scheduling of periodic transfers.
 123  * This conflicts with our standard 1ms intervals for in and out URBs.
 124  * We use default intervals of 2ms for in and 2ms for out transfers,
 125  * which should be fast enough.
 126  * Increase the interval to allow more devices that do interrupt transfers,
 127  * or set to 1 to use the standard interval from the endpoint descriptors.
 128  */
 129 static int min_interrupt_in_interval = 2;
 130 module_param(min_interrupt_in_interval, int, 0);
 131 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 132
 133 static int min_interrupt_out_interval = 2;
 134 module_param(min_interrupt_out_interval, int, 0);
 135 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 136
 137 /* Structure to hold all of our device specific stuff */
 138 struct ld_usb {
 139         struct semaphore        sem;            /* locks this structure */
 140         struct usb_interface*   intf;           /* save off the usb interface pointer */
 141
 142         int                     open_count;     /* number of times this port has been opened */
 143
 144         char*                   ring_buffer;
 145         unsigned int            ring_head;
 146         unsigned int            ring_tail;
 147
 148         wait_queue_head_t       read_wait;
 149         wait_queue_head_t       write_wait;
 150
 151         char*                   interrupt_in_buffer;
 152         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 153         struct urb*             interrupt_in_urb;
 154         int                     interrupt_in_interval;
 155         size_t                  interrupt_in_endpoint_size;
 156         int                     interrupt_in_running;
 157         int                     interrupt_in_done;
 158
 159         char*                   interrupt_out_buffer;
 160         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 161         struct urb*             interrupt_out_urb;
 162         int                     interrupt_out_interval;
 163         size_t                  interrupt_out_endpoint_size;
 164         int                     interrupt_out_busy;
 165 };
 166
 167 /* prevent races between open() and disconnect() */
 168 static DECLARE_MUTEX(disconnect_sem);
 169
 170 static struct usb_driver ld_usb_driver;
 171
 172 /**
 173  *      ld_usb_abort_transfers
 174  *      aborts transfers and frees associated data structures
 175  */
 176 static void ld_usb_abort_transfers(struct ld_usb *dev)
 177 {
 178         /* shutdown transfer */
 179         if (dev->interrupt_in_running) {
 180                 dev->interrupt_in_running = 0;
 181                 if (dev->intf)
 182                         usb_kill_urb(dev->interrupt_in_urb);
 183         }
 184         if (dev->interrupt_out_busy)
 185                 if (dev->intf)
 186                         usb_kill_urb(dev->interrupt_out_urb);
 187 }
 188
 189 /**
 190  *      ld_usb_delete
 191  */
 192 static void ld_usb_delete(struct ld_usb *dev)
 193 {
 194         ld_usb_abort_transfers(dev);
 195
 196         /* free data structures */
 197         usb_free_urb(dev->interrupt_in_urb);
 198         usb_free_urb(dev->interrupt_out_urb);
 199         kfree(dev->ring_buffer);
 200         kfree(dev->interrupt_in_buffer);
 201         kfree(dev->interrupt_out_buffer);
 202         kfree(dev);
 203 }
 204
 205 /**
 206  *      ld_usb_interrupt_in_callback
 207  */
 208 static void ld_usb_interrupt_in_callback(struct urb *urb, struct pt_regs *regs)
 209 {
 210         struct ld_usb *dev = urb->context;
 211         size_t *actual_buffer;
 212         unsigned int next_ring_head;
 213         int retval;
 214
 215         if (urb->status) {
 216                 if (urb->status == -ENOENT ||
 217                     urb->status == -ECONNRESET ||
 218                     urb->status == -ESHUTDOWN) {
 219                         goto exit;
 220                 } else {
 221                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 222                                  __FUNCTION__, urb->status);
 223                         goto resubmit; /* maybe we can recover */
 224                 }
 225         }
 226
 227         if (urb->actual_length > 0) {
 228                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 229                 if (next_ring_head != dev->ring_tail) {
 230                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 231                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 232                         *actual_buffer = urb->actual_length;
 233                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 234                         dev->ring_head = next_ring_head;
 235                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 236                                  __FUNCTION__, urb->actual_length);
 237                 } else
 238                         dev_warn(&dev->intf->dev,
 239                                  "Ring buffer overflow, %d bytes dropped\n",
 240                                  urb->actual_length);
 241         }
 242
 243 resubmit:
 244         /* resubmit if we're still running */
 245         if (dev->interrupt_in_running && dev->intf) {
 246                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 247                 if (retval)
 248                         dev_err(&dev->intf->dev,
 249                                 "usb_submit_urb failed (%d)\n", retval);
 250         }
 251
 252 exit:
 253         dev->interrupt_in_done = 1;
 254         wake_up_interruptible(&dev->read_wait);
 255 }
 256
 257 /**
 258  *      ld_usb_interrupt_out_callback
 259  */
 260 static void ld_usb_interrupt_out_callback(struct urb *urb, struct pt_regs *regs)
 261 {
 262         struct ld_usb *dev = urb->context;
 263
 264         /* sync/async unlink faults aren't errors */
 265         if (urb->status && !(urb->status == -ENOENT ||
 266                              urb->status == -ECONNRESET ||
 267                              urb->status == -ESHUTDOWN))
 268                 dbg_info(&dev->intf->dev,
 269                          "%s - nonzero write interrupt status received: %d\n",
 270                          __FUNCTION__, urb->status);
 271
 272         dev->interrupt_out_busy = 0;
 273         wake_up_interruptible(&dev->write_wait);
 274 }
 275
 276 /**
 277  *      ld_usb_open
 278  */
 279 static int ld_usb_open(struct inode *inode, struct file *file)
 280 {
 281         struct ld_usb *dev;
 282         int subminor;
 283         int retval = 0;
 284         struct usb_interface *interface;
 285
 286         nonseekable_open(inode, file);
 287         subminor = iminor(inode);
 288
 289         down(&disconnect_sem);
 290
 291         interface = usb_find_interface(&ld_usb_driver, subminor);
 292
 293         if (!interface) {
 294                 err("%s - error, can't find device for minor %d\n",
 295                      __FUNCTION__, subminor);
 296                 retval = -ENODEV;
 297                 goto unlock_disconnect_exit;
 298         }
 299
 300         dev = usb_get_intfdata(interface);
 301
 302         if (!dev) {
 303                 retval = -ENODEV;
 304                 goto unlock_disconnect_exit;
 305         }
 306
 307         /* lock this device */
 308         if (down_interruptible(&dev->sem)) {
 309                 retval = -ERESTARTSYS;
 310                 goto unlock_disconnect_exit;
 311         }
 312
 313         /* allow opening only once */
 314         if (dev->open_count) {
 315                 retval = -EBUSY;
 316                 goto unlock_exit;
 317         }
 318         dev->open_count = 1;
 319
 320         /* initialize in direction */
 321         dev->ring_head = 0;
 322         dev->ring_tail = 0;
 323         usb_fill_int_urb(dev->interrupt_in_urb,
 324                          interface_to_usbdev(interface),
 325                          usb_rcvintpipe(interface_to_usbdev(interface),
 326                                         dev->interrupt_in_endpoint->bEndpointAddress),
 327                          dev->interrupt_in_buffer,
 328                          dev->interrupt_in_endpoint_size,
 329                          ld_usb_interrupt_in_callback,
 330                          dev,
 331                          dev->interrupt_in_interval);
 332
 333         dev->interrupt_in_running = 1;
 334         dev->interrupt_in_done = 0;
 335
 336         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 337         if (retval) {
 338                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 339                 dev->interrupt_in_running = 0;
 340                 dev->open_count = 0;
 341                 goto unlock_exit;
 342         }
 343
 344         /* save device in the file's private structure */
 345         file->private_data = dev;
 346
 347 unlock_exit:
 348         up(&dev->sem);
 349
 350 unlock_disconnect_exit:
 351         up(&disconnect_sem);
 352
 353         return retval;
 354 }
 355
 356 /**
 357  *      ld_usb_release
 358  */
 359 static int ld_usb_release(struct inode *inode, struct file *file)
 360 {
 361         struct ld_usb *dev;
 362         int retval = 0;
 363
 364         dev = file->private_data;
 365
 366         if (dev == NULL) {
 367                 retval = -ENODEV;
 368                 goto exit;
 369         }
 370
 371         if (down_interruptible(&dev->sem)) {
 372                 retval = -ERESTARTSYS;
 373                 goto exit;
 374         }
 375
 376         if (dev->open_count != 1) {
 377                 retval = -ENODEV;
 378                 goto unlock_exit;
 379         }
 380         if (dev->intf == NULL) {
 381                 /* the device was unplugged before the file was released */
 382                 up(&dev->sem);
 383                 /* unlock here as ld_usb_delete frees dev */
 384                 ld_usb_delete(dev);
 385                 goto exit;
 386         }
 387
 388         /* wait until write transfer is finished */
 389         if (dev->interrupt_out_busy)
 390                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 391         ld_usb_abort_transfers(dev);
 392         dev->open_count = 0;
 393
 394 unlock_exit:
 395         up(&dev->sem);
 396
 397 exit:
 398         return retval;
 399 }
 400
 401 /**
 402  *      ld_usb_poll
 403  */
 404 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 405 {
 406         struct ld_usb *dev;
 407         unsigned int mask = 0;
 408
 409         dev = file->private_data;
 410
 411         poll_wait(file, &dev->read_wait, wait);
 412         poll_wait(file, &dev->write_wait, wait);
 413
 414         if (dev->ring_head != dev->ring_tail)
 415                 mask |= POLLIN | POLLRDNORM;
 416         if (!dev->interrupt_out_busy)
 417                 mask |= POLLOUT | POLLWRNORM;
 418
 419         return mask;
 420 }
 421
 422 /**
 423  *      ld_usb_read
 424  */
 425 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 426                            loff_t *ppos)
 427 {
 428         struct ld_usb *dev;
 429         size_t *actual_buffer;
 430         size_t bytes_to_read;
 431         int retval = 0;
 432
 433         dev = file->private_data;
 434
 435         /* verify that we actually have some data to read */
 436         if (count == 0)
 437                 goto exit;
 438
 439         /* lock this object */
 440         if (down_interruptible(&dev->sem)) {
 441                 retval = -ERESTARTSYS;
 442                 goto exit;
 443         }
 444
 445         /* verify that the device wasn't unplugged */
 446         if (dev->intf == NULL) {
 447                 retval = -ENODEV;
 448                 err("No device or device unplugged %d\n", retval);
 449                 goto unlock_exit;
 450         }
 451
 452         /* wait for data */
 453         if (dev->ring_head == dev->ring_tail) {
 454                 if (file->f_flags & O_NONBLOCK) {
 455                         retval = -EAGAIN;
 456                         goto unlock_exit;
 457                 }
 458                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 459                 if (retval < 0)
 460                         goto unlock_exit;
 461         }
 462
 463         /* actual_buffer contains actual_length + interrupt_in_buffer */
 464         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 465         bytes_to_read = min(count, *actual_buffer);
 466         if (bytes_to_read < *actual_buffer)
 467                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 468                          *actual_buffer-bytes_to_read);
 469
 470         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 471         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 472                 retval = -EFAULT;
 473                 goto unlock_exit;
 474         }
 475         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 476
 477         retval = bytes_to_read;
 478
 479 unlock_exit:
 480         /* unlock the device */
 481         up(&dev->sem);
 482
 483 exit:
 484         return retval;
 485 }
 486
 487 /**
 488  *      ld_usb_write
 489  */
 490 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 491                             size_t count, loff_t *ppos)
 492 {
 493         struct ld_usb *dev;
 494         size_t bytes_to_write;
 495         int retval = 0;
 496
 497         dev = file->private_data;
 498
 499         /* verify that we actually have some data to write */
 500         if (count == 0)
 501                 goto exit;
 502
 503         /* lock this object */
 504         if (down_interruptible(&dev->sem)) {
 505                 retval = -ERESTARTSYS;
 506                 goto exit;
 507         }
 508
 509         /* verify that the device wasn't unplugged */
 510         if (dev->intf == NULL) {
 511                 retval = -ENODEV;
 512                 err("No device or device unplugged %d\n", retval);
 513                 goto unlock_exit;
 514         }
 515
 516         /* wait until previous transfer is finished */
 517         if (dev->interrupt_out_busy) {
 518                 if (file->f_flags & O_NONBLOCK) {
 519                         retval = -EAGAIN;
 520                         goto unlock_exit;
 521                 }
 522                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 523                 if (retval < 0) {
 524                         goto unlock_exit;
 525                 }
 526         }
 527
 528         /* write the data into interrupt_out_buffer from userspace */
 529         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 530         if (bytes_to_write < count)
 531                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 532         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 533
 534         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 535                 retval = -EFAULT;
 536                 goto unlock_exit;
 537         }
 538
 539         if (dev->interrupt_out_endpoint == NULL) {
 540                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 541                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 542                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 543                                          9,
 544                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 545                                          1 << 8, 0,
 546                                          dev->interrupt_out_buffer,
 547                                          bytes_to_write,
 548                                          USB_CTRL_SET_TIMEOUT * HZ);
 549                 if (retval < 0)
 550                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 551                 goto unlock_exit;
 552         }
 553
 554         /* send off the urb */
 555         usb_fill_int_urb(dev->interrupt_out_urb,
 556                          interface_to_usbdev(dev->intf),
 557                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 558                                         dev->interrupt_out_endpoint->bEndpointAddress),
 559                          dev->interrupt_out_buffer,
 560                          bytes_to_write,
 561                          ld_usb_interrupt_out_callback,
 562                          dev,
 563                          dev->interrupt_out_interval);
 564
 565         dev->interrupt_out_busy = 1;
 566         wmb();
 567
 568         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 569         if (retval) {
 570                 dev->interrupt_out_busy = 0;
 571                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 572                 goto unlock_exit;
 573         }
 574         retval = bytes_to_write;
 575
 576 unlock_exit:
 577         /* unlock the device */
 578         up(&dev->sem);
 579
 580 exit:
 581         return retval;
 582 }
 583
 584 /* file operations needed when we register this driver */
 585 static struct file_operations ld_usb_fops = {
 586         .owner =        THIS_MODULE,
 587         .read  =        ld_usb_read,
 588         .write =        ld_usb_write,
 589         .open =         ld_usb_open,
 590         .release =      ld_usb_release,
 591         .poll =         ld_usb_poll,
 592 };
 593
 594 /*
 595  * usb class driver info in order to get a minor number from the usb core,
 596  * and to have the device registered with devfs and the driver core
 597  */
 598 static struct usb_class_driver ld_usb_class = {
 599         .name =         "ldusb%d",
 600         .fops =         &ld_usb_fops,
 601         .minor_base =   USB_LD_MINOR_BASE,
 602 };
 603
 604 /**
 605  *      ld_usb_probe
 606  *
 607  *      Called by the usb core when a new device is connected that it thinks
 608  *      this driver might be interested in.
 609  */
 610 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 611 {
 612         struct usb_device *udev = interface_to_usbdev(intf);
 613         struct ld_usb *dev = NULL;
 614         struct usb_host_interface *iface_desc;
 615         struct usb_endpoint_descriptor *endpoint;
 616         char *buffer;
 617         int i;
 618         int retval = -ENOMEM;
 619
 620         /* allocate memory for our device state and intialize it */
 621
 622         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
 623         if (dev == NULL) {
 624                 dev_err(&intf->dev, "Out of memory\n");
 625                 goto exit;
 626         }
 627         memset(dev, 0x00, sizeof(*dev));
 628         init_MUTEX(&dev->sem);
 629         dev->intf = intf;
 630         init_waitqueue_head(&dev->read_wait);
 631         init_waitqueue_head(&dev->write_wait);
 632
 633         /* workaround for early firmware versions on fast computers */
 634         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 635             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_CASSY) ||
 636              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_COM3LAB)) &&
 637             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 638                 buffer = kmalloc(256, GFP_KERNEL);
 639                 if (buffer == NULL) {
 640                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 641                         goto error;
 642                 }
 643                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 644                 usb_string(udev, 255, buffer, 256);
 645                 kfree(buffer);
 646         }
 647
 648         iface_desc = intf->cur_altsetting;
 649
 650         /* set up the endpoint information */
 651         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 652                 endpoint = &iface_desc->endpoint[i].desc;
 653
 654                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
 655                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
 656                         dev->interrupt_in_endpoint = endpoint;
 657                 }
 658
 659                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
 660                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
 661                         dev->interrupt_out_endpoint = endpoint;
 662                 }
 663         }
 664         if (dev->interrupt_in_endpoint == NULL) {
 665                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 666                 goto error;
 667         }
 668         if (dev->interrupt_out_endpoint == NULL)
 669                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 670
 671         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 672         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 673         if (!dev->ring_buffer) {
 674                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 675                 goto error;
 676         }
 677         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 678         if (!dev->interrupt_in_buffer) {
 679                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 680                 goto error;
 681         }
 682         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 683         if (!dev->interrupt_in_urb) {
 684                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 685                 goto error;
 686         }
 687         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 688                                                                          udev->descriptor.bMaxPacketSize0;
 689         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 690         if (!dev->interrupt_out_buffer) {
 691                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 692                 goto error;
 693         }
 694         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 695         if (!dev->interrupt_out_urb) {
 696                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 697                 goto error;
 698         }
 699         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 700         if (dev->interrupt_out_endpoint)
 701                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 702
 703         /* we can register the device now, as it is ready */
 704         usb_set_intfdata(intf, dev);
 705
 706         retval = usb_register_dev(intf, &ld_usb_class);
 707         if (retval) {
 708                 /* something prevented us from registering this driver */
 709                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 710                 usb_set_intfdata(intf, NULL);
 711                 goto error;
 712         }
 713
 714         /* let the user know what node this device is now attached to */
 715         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 716                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 717
 718 exit:
 719         return retval;
 720
 721 error:
 722         ld_usb_delete(dev);
 723
 724         return retval;
 725 }
 726
 727 /**
 728  *      ld_usb_disconnect
 729  *
 730  *      Called by the usb core when the device is removed from the system.
 731  */
 732 static void ld_usb_disconnect(struct usb_interface *intf)
 733 {
 734         struct ld_usb *dev;
 735         int minor;
 736
 737         down(&disconnect_sem);
 738
 739         dev = usb_get_intfdata(intf);
 740         usb_set_intfdata(intf, NULL);
 741
 742         down(&dev->sem);
 743
 744         minor = intf->minor;
 745
 746         /* give back our minor */
 747         usb_deregister_dev(intf, &ld_usb_class);
 748
 749         /* if the device is not opened, then we clean up right now */
 750         if (!dev->open_count) {
 751                 up(&dev->sem);
 752                 ld_usb_delete(dev);
 753         } else {
 754                 dev->intf = NULL;
 755                 up(&dev->sem);
 756         }
 757
 758         up(&disconnect_sem);
 759
 760         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 761                  (minor - USB_LD_MINOR_BASE));
 762 }
 763
 764 /* usb specific object needed to register this driver with the usb subsystem */
 765 static struct usb_driver ld_usb_driver = {
 766         .name =         "ldusb",
 767         .probe =        ld_usb_probe,
 768         .disconnect =   ld_usb_disconnect,
 769         .id_table =     ld_usb_table,
 770 };
 771
 772 /**
 773  *      ld_usb_init
 774  */
 775 static int __init ld_usb_init(void)
 776 {
 777         int retval;
 778
 779         /* register this driver with the USB subsystem */
 780         retval = usb_register(&ld_usb_driver);
 781         if (retval)
 782                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
 783
 784         return retval;
 785 }
 786
 787 /**
 788  *      ld_usb_exit
 789  */
 790 static void __exit ld_usb_exit(void)
 791 {
 792         /* deregister this driver with the USB subsystem */
 793         usb_deregister(&ld_usb_driver);
 794 }
 795
 796 module_init(ld_usb_init);
 797 module_exit(ld_usb_exit);
 798