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
  65 #define USB_VENDOR_ID_MICROCHIP         0x04d8
  66 #define USB_DEVICE_ID_PICDEM            0x000c
  67
  68 #ifdef CONFIG_USB_DYNAMIC_MINORS
  69 #define USB_LD_MINOR_BASE       0
  70 #else
  71 #define USB_LD_MINOR_BASE       176
  72 #endif
  73
  74 /* table of devices that work with this driver */
  75 static struct usb_device_id ld_usb_table [] = {
  76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
  81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
  82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
  83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
  84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
  85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
  86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
  88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
  89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
  90         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
  91         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  92         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  93         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  94         { USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_PICDEM) },
  95         { }                                     /* Terminating entry */
  96 };
  97 MODULE_DEVICE_TABLE(usb, ld_usb_table);
  98 MODULE_VERSION("V0.13");
  99 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 100 MODULE_DESCRIPTION("LD USB Driver");
 101 MODULE_LICENSE("GPL");
 102 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 103
 104 #ifdef CONFIG_USB_DEBUG
 105         static int debug = 1;
 106 #else
 107         static int debug = 0;
 108 #endif
 109
 110 /* Use our own dbg macro */
 111 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 112
 113 /* Module parameters */
 114 module_param(debug, int, S_IRUGO | S_IWUSR);
 115 MODULE_PARM_DESC(debug, "Debug enabled or not");
 116
 117 /* All interrupt in transfers are collected in a ring buffer to
 118  * avoid racing conditions and get better performance of the driver.
 119  */
 120 static int ring_buffer_size = 128;
 121 module_param(ring_buffer_size, int, 0);
 122 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 123
 124 /* The write_buffer can contain more than one interrupt out transfer.
 125  */
 126 static int write_buffer_size = 10;
 127 module_param(write_buffer_size, int, 0);
 128 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 129
 130 /* As of kernel version 2.6.4 ehci-hcd uses an
 131  * "only one interrupt transfer per frame" shortcut
 132  * to simplify the scheduling of periodic transfers.
 133  * This conflicts with our standard 1ms intervals for in and out URBs.
 134  * We use default intervals of 2ms for in and 2ms for out transfers,
 135  * which should be fast enough.
 136  * Increase the interval to allow more devices that do interrupt transfers,
 137  * or set to 1 to use the standard interval from the endpoint descriptors.
 138  */
 139 static int min_interrupt_in_interval = 2;
 140 module_param(min_interrupt_in_interval, int, 0);
 141 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 142
 143 static int min_interrupt_out_interval = 2;
 144 module_param(min_interrupt_out_interval, int, 0);
 145 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 146
 147 /* Structure to hold all of our device specific stuff */
 148 struct ld_usb {
 149         struct semaphore        sem;            /* locks this structure */
 150         struct usb_interface*   intf;           /* save off the usb interface pointer */
 151
 152         int                     open_count;     /* number of times this port has been opened */
 153
 154         char*                   ring_buffer;
 155         unsigned int            ring_head;
 156         unsigned int            ring_tail;
 157
 158         wait_queue_head_t       read_wait;
 159         wait_queue_head_t       write_wait;
 160
 161         char*                   interrupt_in_buffer;
 162         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 163         struct urb*             interrupt_in_urb;
 164         int                     interrupt_in_interval;
 165         size_t                  interrupt_in_endpoint_size;
 166         int                     interrupt_in_running;
 167         int                     interrupt_in_done;
 168
 169         char*                   interrupt_out_buffer;
 170         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 171         struct urb*             interrupt_out_urb;
 172         int                     interrupt_out_interval;
 173         size_t                  interrupt_out_endpoint_size;
 174         int                     interrupt_out_busy;
 175 };
 176
 177 /* prevent races between open() and disconnect() */
 178 static DEFINE_MUTEX(disconnect_mutex);
 179
 180 static struct usb_driver ld_usb_driver;
 181
 182 /**
 183  *      ld_usb_abort_transfers
 184  *      aborts transfers and frees associated data structures
 185  */
 186 static void ld_usb_abort_transfers(struct ld_usb *dev)
 187 {
 188         /* shutdown transfer */
 189         if (dev->interrupt_in_running) {
 190                 dev->interrupt_in_running = 0;
 191                 if (dev->intf)
 192                         usb_kill_urb(dev->interrupt_in_urb);
 193         }
 194         if (dev->interrupt_out_busy)
 195                 if (dev->intf)
 196                         usb_kill_urb(dev->interrupt_out_urb);
 197 }
 198
 199 /**
 200  *      ld_usb_delete
 201  */
 202 static void ld_usb_delete(struct ld_usb *dev)
 203 {
 204         ld_usb_abort_transfers(dev);
 205
 206         /* free data structures */
 207         usb_free_urb(dev->interrupt_in_urb);
 208         usb_free_urb(dev->interrupt_out_urb);
 209         kfree(dev->ring_buffer);
 210         kfree(dev->interrupt_in_buffer);
 211         kfree(dev->interrupt_out_buffer);
 212         kfree(dev);
 213 }
 214
 215 /**
 216  *      ld_usb_interrupt_in_callback
 217  */
 218 static void ld_usb_interrupt_in_callback(struct urb *urb)
 219 {
 220         struct ld_usb *dev = urb->context;
 221         size_t *actual_buffer;
 222         unsigned int next_ring_head;
 223         int retval;
 224
 225         if (urb->status) {
 226                 if (urb->status == -ENOENT ||
 227                     urb->status == -ECONNRESET ||
 228                     urb->status == -ESHUTDOWN) {
 229                         goto exit;
 230                 } else {
 231                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 232                                  __FUNCTION__, urb->status);
 233                         goto resubmit; /* maybe we can recover */
 234                 }
 235         }
 236
 237         if (urb->actual_length > 0) {
 238                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 239                 if (next_ring_head != dev->ring_tail) {
 240                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 241                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 242                         *actual_buffer = urb->actual_length;
 243                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 244                         dev->ring_head = next_ring_head;
 245                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 246                                  __FUNCTION__, urb->actual_length);
 247                 } else
 248                         dev_warn(&dev->intf->dev,
 249                                  "Ring buffer overflow, %d bytes dropped\n",
 250                                  urb->actual_length);
 251         }
 252
 253 resubmit:
 254         /* resubmit if we're still running */
 255         if (dev->interrupt_in_running && 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         }
 261
 262 exit:
 263         dev->interrupt_in_done = 1;
 264         wake_up_interruptible(&dev->read_wait);
 265 }
 266
 267 /**
 268  *      ld_usb_interrupt_out_callback
 269  */
 270 static void ld_usb_interrupt_out_callback(struct urb *urb)
 271 {
 272         struct ld_usb *dev = urb->context;
 273
 274         /* sync/async unlink faults aren't errors */
 275         if (urb->status && !(urb->status == -ENOENT ||
 276                              urb->status == -ECONNRESET ||
 277                              urb->status == -ESHUTDOWN))
 278                 dbg_info(&dev->intf->dev,
 279                          "%s - nonzero write interrupt status received: %d\n",
 280                          __FUNCTION__, urb->status);
 281
 282         dev->interrupt_out_busy = 0;
 283         wake_up_interruptible(&dev->write_wait);
 284 }
 285
 286 /**
 287  *      ld_usb_open
 288  */
 289 static int ld_usb_open(struct inode *inode, struct file *file)
 290 {
 291         struct ld_usb *dev;
 292         int subminor;
 293         int retval = 0;
 294         struct usb_interface *interface;
 295
 296         nonseekable_open(inode, file);
 297         subminor = iminor(inode);
 298
 299         mutex_lock(&disconnect_mutex);
 300
 301         interface = usb_find_interface(&ld_usb_driver, subminor);
 302
 303         if (!interface) {
 304                 err("%s - error, can't find device for minor %d\n",
 305                      __FUNCTION__, subminor);
 306                 retval = -ENODEV;
 307                 goto unlock_disconnect_exit;
 308         }
 309
 310         dev = usb_get_intfdata(interface);
 311
 312         if (!dev) {
 313                 retval = -ENODEV;
 314                 goto unlock_disconnect_exit;
 315         }
 316
 317         /* lock this device */
 318         if (down_interruptible(&dev->sem)) {
 319                 retval = -ERESTARTSYS;
 320                 goto unlock_disconnect_exit;
 321         }
 322
 323         /* allow opening only once */
 324         if (dev->open_count) {
 325                 retval = -EBUSY;
 326                 goto unlock_exit;
 327         }
 328         dev->open_count = 1;
 329
 330         /* initialize in direction */
 331         dev->ring_head = 0;
 332         dev->ring_tail = 0;
 333         usb_fill_int_urb(dev->interrupt_in_urb,
 334                          interface_to_usbdev(interface),
 335                          usb_rcvintpipe(interface_to_usbdev(interface),
 336                                         dev->interrupt_in_endpoint->bEndpointAddress),
 337                          dev->interrupt_in_buffer,
 338                          dev->interrupt_in_endpoint_size,
 339                          ld_usb_interrupt_in_callback,
 340                          dev,
 341                          dev->interrupt_in_interval);
 342
 343         dev->interrupt_in_running = 1;
 344         dev->interrupt_in_done = 0;
 345
 346         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 347         if (retval) {
 348                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 349                 dev->interrupt_in_running = 0;
 350                 dev->open_count = 0;
 351                 goto unlock_exit;
 352         }
 353
 354         /* save device in the file's private structure */
 355         file->private_data = dev;
 356
 357 unlock_exit:
 358         up(&dev->sem);
 359
 360 unlock_disconnect_exit:
 361         mutex_unlock(&disconnect_mutex);
 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
 443         dev = file->private_data;
 444
 445         /* verify that we actually have some data to read */
 446         if (count == 0)
 447                 goto exit;
 448
 449         /* lock this object */
 450         if (down_interruptible(&dev->sem)) {
 451                 retval = -ERESTARTSYS;
 452                 goto exit;
 453         }
 454
 455         /* verify that the device wasn't unplugged */
 456         if (dev->intf == NULL) {
 457                 retval = -ENODEV;
 458                 err("No device or device unplugged %d\n", retval);
 459                 goto unlock_exit;
 460         }
 461
 462         /* wait for data */
 463         if (dev->ring_head == dev->ring_tail) {
 464                 if (file->f_flags & O_NONBLOCK) {
 465                         retval = -EAGAIN;
 466                         goto unlock_exit;
 467                 }
 468                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 469                 if (retval < 0)
 470                         goto unlock_exit;
 471         }
 472
 473         /* actual_buffer contains actual_length + interrupt_in_buffer */
 474         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 475         bytes_to_read = min(count, *actual_buffer);
 476         if (bytes_to_read < *actual_buffer)
 477                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 478                          *actual_buffer-bytes_to_read);
 479
 480         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 481         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 482                 retval = -EFAULT;
 483                 goto unlock_exit;
 484         }
 485         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 486
 487         retval = bytes_to_read;
 488
 489 unlock_exit:
 490         /* unlock the device */
 491         up(&dev->sem);
 492
 493 exit:
 494         return retval;
 495 }
 496
 497 /**
 498  *      ld_usb_write
 499  */
 500 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 501                             size_t count, loff_t *ppos)
 502 {
 503         struct ld_usb *dev;
 504         size_t bytes_to_write;
 505         int retval = 0;
 506
 507         dev = file->private_data;
 508
 509         /* verify that we actually have some data to write */
 510         if (count == 0)
 511                 goto exit;
 512
 513         /* lock this object */
 514         if (down_interruptible(&dev->sem)) {
 515                 retval = -ERESTARTSYS;
 516                 goto exit;
 517         }
 518
 519         /* verify that the device wasn't unplugged */
 520         if (dev->intf == NULL) {
 521                 retval = -ENODEV;
 522                 err("No device or device unplugged %d\n", retval);
 523                 goto unlock_exit;
 524         }
 525
 526         /* wait until previous transfer is finished */
 527         if (dev->interrupt_out_busy) {
 528                 if (file->f_flags & O_NONBLOCK) {
 529                         retval = -EAGAIN;
 530                         goto unlock_exit;
 531                 }
 532                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 533                 if (retval < 0) {
 534                         goto unlock_exit;
 535                 }
 536         }
 537
 538         /* write the data into interrupt_out_buffer from userspace */
 539         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 540         if (bytes_to_write < count)
 541                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 542         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 543
 544         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 545                 retval = -EFAULT;
 546                 goto unlock_exit;
 547         }
 548
 549         if (dev->interrupt_out_endpoint == NULL) {
 550                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 551                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 552                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 553                                          9,
 554                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 555                                          1 << 8, 0,
 556                                          dev->interrupt_out_buffer,
 557                                          bytes_to_write,
 558                                          USB_CTRL_SET_TIMEOUT * HZ);
 559                 if (retval < 0)
 560                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 561                 goto unlock_exit;
 562         }
 563
 564         /* send off the urb */
 565         usb_fill_int_urb(dev->interrupt_out_urb,
 566                          interface_to_usbdev(dev->intf),
 567                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 568                                         dev->interrupt_out_endpoint->bEndpointAddress),
 569                          dev->interrupt_out_buffer,
 570                          bytes_to_write,
 571                          ld_usb_interrupt_out_callback,
 572                          dev,
 573                          dev->interrupt_out_interval);
 574
 575         dev->interrupt_out_busy = 1;
 576         wmb();
 577
 578         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 579         if (retval) {
 580                 dev->interrupt_out_busy = 0;
 581                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 582                 goto unlock_exit;
 583         }
 584         retval = bytes_to_write;
 585
 586 unlock_exit:
 587         /* unlock the device */
 588         up(&dev->sem);
 589
 590 exit:
 591         return retval;
 592 }
 593
 594 /* file operations needed when we register this driver */
 595 static const struct file_operations ld_usb_fops = {
 596         .owner =        THIS_MODULE,
 597         .read  =        ld_usb_read,
 598         .write =        ld_usb_write,
 599         .open =         ld_usb_open,
 600         .release =      ld_usb_release,
 601         .poll =         ld_usb_poll,
 602 };
 603
 604 /*
 605  * usb class driver info in order to get a minor number from the usb core,
 606  * and to have the device registered with the driver core
 607  */
 608 static struct usb_class_driver ld_usb_class = {
 609         .name =         "ldusb%d",
 610         .fops =         &ld_usb_fops,
 611         .minor_base =   USB_LD_MINOR_BASE,
 612 };
 613
 614 /**
 615  *      ld_usb_probe
 616  *
 617  *      Called by the usb core when a new device is connected that it thinks
 618  *      this driver might be interested in.
 619  */
 620 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 621 {
 622         struct usb_device *udev = interface_to_usbdev(intf);
 623         struct ld_usb *dev = NULL;
 624         struct usb_host_interface *iface_desc;
 625         struct usb_endpoint_descriptor *endpoint;
 626         char *buffer;
 627         int i;
 628         int retval = -ENOMEM;
 629
 630         /* allocate memory for our device state and intialize it */
 631
 632         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 633         if (dev == NULL) {
 634                 dev_err(&intf->dev, "Out of memory\n");
 635                 goto exit;
 636         }
 637         init_MUTEX(&dev->sem);
 638         dev->intf = intf;
 639         init_waitqueue_head(&dev->read_wait);
 640         init_waitqueue_head(&dev->write_wait);
 641
 642         /* workaround for early firmware versions on fast computers */
 643         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 644             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 645              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 646             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 647                 buffer = kmalloc(256, GFP_KERNEL);
 648                 if (buffer == NULL) {
 649                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 650                         goto error;
 651                 }
 652                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 653                 usb_string(udev, 255, buffer, 256);
 654                 kfree(buffer);
 655         }
 656
 657         iface_desc = intf->cur_altsetting;
 658
 659         /* set up the endpoint information */
 660         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 661                 endpoint = &iface_desc->endpoint[i].desc;
 662
 663                 if (usb_endpoint_is_int_in(endpoint))
 664                         dev->interrupt_in_endpoint = endpoint;
 665
 666                 if (usb_endpoint_is_int_out(endpoint))
 667                         dev->interrupt_out_endpoint = endpoint;
 668         }
 669         if (dev->interrupt_in_endpoint == NULL) {
 670                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 671                 goto error;
 672         }
 673         if (dev->interrupt_out_endpoint == NULL)
 674                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 675
 676         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 677         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 678         if (!dev->ring_buffer) {
 679                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 680                 goto error;
 681         }
 682         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 683         if (!dev->interrupt_in_buffer) {
 684                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 685                 goto error;
 686         }
 687         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 688         if (!dev->interrupt_in_urb) {
 689                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 690                 goto error;
 691         }
 692         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 693                                                                          udev->descriptor.bMaxPacketSize0;
 694         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 695         if (!dev->interrupt_out_buffer) {
 696                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 697                 goto error;
 698         }
 699         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 700         if (!dev->interrupt_out_urb) {
 701                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 702                 goto error;
 703         }
 704         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 705         if (dev->interrupt_out_endpoint)
 706                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 707
 708         /* we can register the device now, as it is ready */
 709         usb_set_intfdata(intf, dev);
 710
 711         retval = usb_register_dev(intf, &ld_usb_class);
 712         if (retval) {
 713                 /* something prevented us from registering this driver */
 714                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 715                 usb_set_intfdata(intf, NULL);
 716                 goto error;
 717         }
 718
 719         /* let the user know what node this device is now attached to */
 720         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 721                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 722
 723 exit:
 724         return retval;
 725
 726 error:
 727         ld_usb_delete(dev);
 728
 729         return retval;
 730 }
 731
 732 /**
 733  *      ld_usb_disconnect
 734  *
 735  *      Called by the usb core when the device is removed from the system.
 736  */
 737 static void ld_usb_disconnect(struct usb_interface *intf)
 738 {
 739         struct ld_usb *dev;
 740         int minor;
 741
 742         mutex_lock(&disconnect_mutex);
 743
 744         dev = usb_get_intfdata(intf);
 745         usb_set_intfdata(intf, NULL);
 746
 747         down(&dev->sem);
 748
 749         minor = intf->minor;
 750
 751         /* give back our minor */
 752         usb_deregister_dev(intf, &ld_usb_class);
 753
 754         /* if the device is not opened, then we clean up right now */
 755         if (!dev->open_count) {
 756                 up(&dev->sem);
 757                 ld_usb_delete(dev);
 758         } else {
 759                 dev->intf = NULL;
 760                 up(&dev->sem);
 761         }
 762
 763         mutex_unlock(&disconnect_mutex);
 764
 765         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 766                  (minor - USB_LD_MINOR_BASE));
 767 }
 768
 769 /* usb specific object needed to register this driver with the usb subsystem */
 770 static struct usb_driver ld_usb_driver = {
 771         .name =         "ldusb",
 772         .probe =        ld_usb_probe,
 773         .disconnect =   ld_usb_disconnect,
 774         .id_table =     ld_usb_table,
 775 };
 776
 777 /**
 778  *      ld_usb_init
 779  */
 780 static int __init ld_usb_init(void)
 781 {
 782         int retval;
 783
 784         /* register this driver with the USB subsystem */
 785         retval = usb_register(&ld_usb_driver);
 786         if (retval)
 787                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
 788
 789         return retval;
 790 }
 791
 792 /**
 793  *      ld_usb_exit
 794  */
 795 static void __exit ld_usb_exit(void)
 796 {
 797         /* deregister this driver with the USB subsystem */
 798         usb_deregister(&ld_usb_driver);
 799 }
 800
 801 module_init(ld_usb_init);
 802 module_exit(ld_usb_exit);
 803