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