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
  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
  66 #ifdef CONFIG_USB_DYNAMIC_MINORS
  67 #define USB_LD_MINOR_BASE       0
  68 #else
  69 #define USB_LD_MINOR_BASE       176
  70 #endif
  71
  72 /* table of devices that work with this driver */
  73 static struct usb_device_id ld_usb_table [] = {
  74         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  75         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
  80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
  81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
  82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
  83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
  84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
  85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
  86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
  88         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
  89         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  90         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  91         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  92         { }                                     /* Terminating entry */
  93 };
  94 MODULE_DEVICE_TABLE(usb, ld_usb_table);
  95 MODULE_VERSION("V0.13");
  96 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
  97 MODULE_DESCRIPTION("LD USB Driver");
  98 MODULE_LICENSE("GPL");
  99 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 100
 101 #ifdef CONFIG_USB_DEBUG
 102         static int debug = 1;
 103 #else
 104         static int debug = 0;
 105 #endif
 106
 107 /* Use our own dbg macro */
 108 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 109
 110 /* Module parameters */
 111 module_param(debug, int, S_IRUGO | S_IWUSR);
 112 MODULE_PARM_DESC(debug, "Debug enabled or not");
 113
 114 /* All interrupt in transfers are collected in a ring buffer to
 115  * avoid racing conditions and get better performance of the driver.
 116  */
 117 static int ring_buffer_size = 128;
 118 module_param(ring_buffer_size, int, 0);
 119 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 120
 121 /* The write_buffer can contain more than one interrupt out transfer.
 122  */
 123 static int write_buffer_size = 10;
 124 module_param(write_buffer_size, int, 0);
 125 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 126
 127 /* As of kernel version 2.6.4 ehci-hcd uses an
 128  * "only one interrupt transfer per frame" shortcut
 129  * to simplify the scheduling of periodic transfers.
 130  * This conflicts with our standard 1ms intervals for in and out URBs.
 131  * We use default intervals of 2ms for in and 2ms for out transfers,
 132  * which should be fast enough.
 133  * Increase the interval to allow more devices that do interrupt transfers,
 134  * or set to 1 to use the standard interval from the endpoint descriptors.
 135  */
 136 static int min_interrupt_in_interval = 2;
 137 module_param(min_interrupt_in_interval, int, 0);
 138 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 139
 140 static int min_interrupt_out_interval = 2;
 141 module_param(min_interrupt_out_interval, int, 0);
 142 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 143
 144 /* Structure to hold all of our device specific stuff */
 145 struct ld_usb {
 146         struct semaphore        sem;            /* locks this structure */
 147         struct usb_interface*   intf;           /* save off the usb interface pointer */
 148
 149         int                     open_count;     /* number of times this port has been opened */
 150
 151         char*                   ring_buffer;
 152         unsigned int            ring_head;
 153         unsigned int            ring_tail;
 154
 155         wait_queue_head_t       read_wait;
 156         wait_queue_head_t       write_wait;
 157
 158         char*                   interrupt_in_buffer;
 159         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 160         struct urb*             interrupt_in_urb;
 161         int                     interrupt_in_interval;
 162         size_t                  interrupt_in_endpoint_size;
 163         int                     interrupt_in_running;
 164         int                     interrupt_in_done;
 165
 166         char*                   interrupt_out_buffer;
 167         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 168         struct urb*             interrupt_out_urb;
 169         int                     interrupt_out_interval;
 170         size_t                  interrupt_out_endpoint_size;
 171         int                     interrupt_out_busy;
 172 };
 173
 174 /* prevent races between open() and disconnect() */
 175 static DECLARE_MUTEX(disconnect_sem);
 176
 177 static struct usb_driver ld_usb_driver;
 178
 179 /**
 180  *      ld_usb_abort_transfers
 181  *      aborts transfers and frees associated data structures
 182  */
 183 static void ld_usb_abort_transfers(struct ld_usb *dev)
 184 {
 185         /* shutdown transfer */
 186         if (dev->interrupt_in_running) {
 187                 dev->interrupt_in_running = 0;
 188                 if (dev->intf)
 189                         usb_kill_urb(dev->interrupt_in_urb);
 190         }
 191         if (dev->interrupt_out_busy)
 192                 if (dev->intf)
 193                         usb_kill_urb(dev->interrupt_out_urb);
 194 }
 195
 196 /**
 197  *      ld_usb_delete
 198  */
 199 static void ld_usb_delete(struct ld_usb *dev)
 200 {
 201         ld_usb_abort_transfers(dev);
 202
 203         /* free data structures */
 204         usb_free_urb(dev->interrupt_in_urb);
 205         usb_free_urb(dev->interrupt_out_urb);
 206         kfree(dev->ring_buffer);
 207         kfree(dev->interrupt_in_buffer);
 208         kfree(dev->interrupt_out_buffer);
 209         kfree(dev);
 210 }
 211
 212 /**
 213  *      ld_usb_interrupt_in_callback
 214  */
 215 static void ld_usb_interrupt_in_callback(struct urb *urb, struct pt_regs *regs)
 216 {
 217         struct ld_usb *dev = urb->context;
 218         size_t *actual_buffer;
 219         unsigned int next_ring_head;
 220         int retval;
 221
 222         if (urb->status) {
 223                 if (urb->status == -ENOENT ||
 224                     urb->status == -ECONNRESET ||
 225                     urb->status == -ESHUTDOWN) {
 226                         goto exit;
 227                 } else {
 228                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 229                                  __FUNCTION__, urb->status);
 230                         goto resubmit; /* maybe we can recover */
 231                 }
 232         }
 233
 234         if (urb->actual_length > 0) {
 235                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 236                 if (next_ring_head != dev->ring_tail) {
 237                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 238                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 239                         *actual_buffer = urb->actual_length;
 240                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 241                         dev->ring_head = next_ring_head;
 242                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 243                                  __FUNCTION__, urb->actual_length);
 244                 } else
 245                         dev_warn(&dev->intf->dev,
 246                                  "Ring buffer overflow, %d bytes dropped\n",
 247                                  urb->actual_length);
 248         }
 249
 250 resubmit:
 251         /* resubmit if we're still running */
 252         if (dev->interrupt_in_running && dev->intf) {
 253                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 254                 if (retval)
 255                         dev_err(&dev->intf->dev,
 256                                 "usb_submit_urb failed (%d)\n", retval);
 257         }
 258
 259 exit:
 260         dev->interrupt_in_done = 1;
 261         wake_up_interruptible(&dev->read_wait);
 262 }
 263
 264 /**
 265  *      ld_usb_interrupt_out_callback
 266  */
 267 static void ld_usb_interrupt_out_callback(struct urb *urb, struct pt_regs *regs)
 268 {
 269         struct ld_usb *dev = urb->context;
 270
 271         /* sync/async unlink faults aren't errors */
 272         if (urb->status && !(urb->status == -ENOENT ||
 273                              urb->status == -ECONNRESET ||
 274                              urb->status == -ESHUTDOWN))
 275                 dbg_info(&dev->intf->dev,
 276                          "%s - nonzero write interrupt status received: %d\n",
 277                          __FUNCTION__, urb->status);
 278
 279         dev->interrupt_out_busy = 0;
 280         wake_up_interruptible(&dev->write_wait);
 281 }
 282
 283 /**
 284  *      ld_usb_open
 285  */
 286 static int ld_usb_open(struct inode *inode, struct file *file)
 287 {
 288         struct ld_usb *dev;
 289         int subminor;
 290         int retval = 0;
 291         struct usb_interface *interface;
 292
 293         nonseekable_open(inode, file);
 294         subminor = iminor(inode);
 295
 296         down(&disconnect_sem);
 297
 298         interface = usb_find_interface(&ld_usb_driver, subminor);
 299
 300         if (!interface) {
 301                 err("%s - error, can't find device for minor %d\n",
 302                      __FUNCTION__, subminor);
 303                 retval = -ENODEV;
 304                 goto unlock_disconnect_exit;
 305         }
 306
 307         dev = usb_get_intfdata(interface);
 308
 309         if (!dev) {
 310                 retval = -ENODEV;
 311                 goto unlock_disconnect_exit;
 312         }
 313
 314         /* lock this device */
 315         if (down_interruptible(&dev->sem)) {
 316                 retval = -ERESTARTSYS;
 317                 goto unlock_disconnect_exit;
 318         }
 319
 320         /* allow opening only once */
 321         if (dev->open_count) {
 322                 retval = -EBUSY;
 323                 goto unlock_exit;
 324         }
 325         dev->open_count = 1;
 326
 327         /* initialize in direction */
 328         dev->ring_head = 0;
 329         dev->ring_tail = 0;
 330         usb_fill_int_urb(dev->interrupt_in_urb,
 331                          interface_to_usbdev(interface),
 332                          usb_rcvintpipe(interface_to_usbdev(interface),
 333                                         dev->interrupt_in_endpoint->bEndpointAddress),
 334                          dev->interrupt_in_buffer,
 335                          dev->interrupt_in_endpoint_size,
 336                          ld_usb_interrupt_in_callback,
 337                          dev,
 338                          dev->interrupt_in_interval);
 339
 340         dev->interrupt_in_running = 1;
 341         dev->interrupt_in_done = 0;
 342
 343         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 344         if (retval) {
 345                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 346                 dev->interrupt_in_running = 0;
 347                 dev->open_count = 0;
 348                 goto unlock_exit;
 349         }
 350
 351         /* save device in the file's private structure */
 352         file->private_data = dev;
 353
 354 unlock_exit:
 355         up(&dev->sem);
 356
 357 unlock_disconnect_exit:
 358         up(&disconnect_sem);
 359
 360         return retval;
 361 }
 362
 363 /**
 364  *      ld_usb_release
 365  */
 366 static int ld_usb_release(struct inode *inode, struct file *file)
 367 {
 368         struct ld_usb *dev;
 369         int retval = 0;
 370
 371         dev = file->private_data;
 372
 373         if (dev == NULL) {
 374                 retval = -ENODEV;
 375                 goto exit;
 376         }
 377
 378         if (down_interruptible(&dev->sem)) {
 379                 retval = -ERESTARTSYS;
 380                 goto exit;
 381         }
 382
 383         if (dev->open_count != 1) {
 384                 retval = -ENODEV;
 385                 goto unlock_exit;
 386         }
 387         if (dev->intf == NULL) {
 388                 /* the device was unplugged before the file was released */
 389                 up(&dev->sem);
 390                 /* unlock here as ld_usb_delete frees dev */
 391                 ld_usb_delete(dev);
 392                 goto exit;
 393         }
 394
 395         /* wait until write transfer is finished */
 396         if (dev->interrupt_out_busy)
 397                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 398         ld_usb_abort_transfers(dev);
 399         dev->open_count = 0;
 400
 401 unlock_exit:
 402         up(&dev->sem);
 403
 404 exit:
 405         return retval;
 406 }
 407
 408 /**
 409  *      ld_usb_poll
 410  */
 411 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 412 {
 413         struct ld_usb *dev;
 414         unsigned int mask = 0;
 415
 416         dev = file->private_data;
 417
 418         poll_wait(file, &dev->read_wait, wait);
 419         poll_wait(file, &dev->write_wait, wait);
 420
 421         if (dev->ring_head != dev->ring_tail)
 422                 mask |= POLLIN | POLLRDNORM;
 423         if (!dev->interrupt_out_busy)
 424                 mask |= POLLOUT | POLLWRNORM;
 425
 426         return mask;
 427 }
 428
 429 /**
 430  *      ld_usb_read
 431  */
 432 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 433                            loff_t *ppos)
 434 {
 435         struct ld_usb *dev;
 436         size_t *actual_buffer;
 437         size_t bytes_to_read;
 438         int retval = 0;
 439
 440         dev = file->private_data;
 441
 442         /* verify that we actually have some data to read */
 443         if (count == 0)
 444                 goto exit;
 445
 446         /* lock this object */
 447         if (down_interruptible(&dev->sem)) {
 448                 retval = -ERESTARTSYS;
 449                 goto exit;
 450         }
 451
 452         /* verify that the device wasn't unplugged */
 453         if (dev->intf == NULL) {
 454                 retval = -ENODEV;
 455                 err("No device or device unplugged %d\n", retval);
 456                 goto unlock_exit;
 457         }
 458
 459         /* wait for data */
 460         if (dev->ring_head == dev->ring_tail) {
 461                 if (file->f_flags & O_NONBLOCK) {
 462                         retval = -EAGAIN;
 463                         goto unlock_exit;
 464                 }
 465                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 466                 if (retval < 0)
 467                         goto unlock_exit;
 468         }
 469
 470         /* actual_buffer contains actual_length + interrupt_in_buffer */
 471         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 472         bytes_to_read = min(count, *actual_buffer);
 473         if (bytes_to_read < *actual_buffer)
 474                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 475                          *actual_buffer-bytes_to_read);
 476
 477         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 478         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 479                 retval = -EFAULT;
 480                 goto unlock_exit;
 481         }
 482         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 483
 484         retval = bytes_to_read;
 485
 486 unlock_exit:
 487         /* unlock the device */
 488         up(&dev->sem);
 489
 490 exit:
 491         return retval;
 492 }
 493
 494 /**
 495  *      ld_usb_write
 496  */
 497 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 498                             size_t count, loff_t *ppos)
 499 {
 500         struct ld_usb *dev;
 501         size_t bytes_to_write;
 502         int retval = 0;
 503
 504         dev = file->private_data;
 505
 506         /* verify that we actually have some data to write */
 507         if (count == 0)
 508                 goto exit;
 509
 510         /* lock this object */
 511         if (down_interruptible(&dev->sem)) {
 512                 retval = -ERESTARTSYS;
 513                 goto exit;
 514         }
 515
 516         /* verify that the device wasn't unplugged */
 517         if (dev->intf == NULL) {
 518                 retval = -ENODEV;
 519                 err("No device or device unplugged %d\n", retval);
 520                 goto unlock_exit;
 521         }
 522
 523         /* wait until previous transfer is finished */
 524         if (dev->interrupt_out_busy) {
 525                 if (file->f_flags & O_NONBLOCK) {
 526                         retval = -EAGAIN;
 527                         goto unlock_exit;
 528                 }
 529                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 530                 if (retval < 0) {
 531                         goto unlock_exit;
 532                 }
 533         }
 534
 535         /* write the data into interrupt_out_buffer from userspace */
 536         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 537         if (bytes_to_write < count)
 538                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 539         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 540
 541         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 542                 retval = -EFAULT;
 543                 goto unlock_exit;
 544         }
 545
 546         if (dev->interrupt_out_endpoint == NULL) {
 547                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 548                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 549                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 550                                          9,
 551                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 552                                          1 << 8, 0,
 553                                          dev->interrupt_out_buffer,
 554                                          bytes_to_write,
 555                                          USB_CTRL_SET_TIMEOUT * HZ);
 556                 if (retval < 0)
 557                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 558                 goto unlock_exit;
 559         }
 560
 561         /* send off the urb */
 562         usb_fill_int_urb(dev->interrupt_out_urb,
 563                          interface_to_usbdev(dev->intf),
 564                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 565                                         dev->interrupt_out_endpoint->bEndpointAddress),
 566                          dev->interrupt_out_buffer,
 567                          bytes_to_write,
 568                          ld_usb_interrupt_out_callback,
 569                          dev,
 570                          dev->interrupt_out_interval);
 571
 572         dev->interrupt_out_busy = 1;
 573         wmb();
 574
 575         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 576         if (retval) {
 577                 dev->interrupt_out_busy = 0;
 578                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 579                 goto unlock_exit;
 580         }
 581         retval = bytes_to_write;
 582
 583 unlock_exit:
 584         /* unlock the device */
 585         up(&dev->sem);
 586
 587 exit:
 588         return retval;
 589 }
 590
 591 /* file operations needed when we register this driver */
 592 static struct file_operations ld_usb_fops = {
 593         .owner =        THIS_MODULE,
 594         .read  =        ld_usb_read,
 595         .write =        ld_usb_write,
 596         .open =         ld_usb_open,
 597         .release =      ld_usb_release,
 598         .poll =         ld_usb_poll,
 599 };
 600
 601 /*
 602  * usb class driver info in order to get a minor number from the usb core,
 603  * and to have the device registered with the driver core
 604  */
 605 static struct usb_class_driver ld_usb_class = {
 606         .name =         "ldusb%d",
 607         .fops =         &ld_usb_fops,
 608         .minor_base =   USB_LD_MINOR_BASE,
 609 };
 610
 611 /**
 612  *      ld_usb_probe
 613  *
 614  *      Called by the usb core when a new device is connected that it thinks
 615  *      this driver might be interested in.
 616  */
 617 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 618 {
 619         struct usb_device *udev = interface_to_usbdev(intf);
 620         struct ld_usb *dev = NULL;
 621         struct usb_host_interface *iface_desc;
 622         struct usb_endpoint_descriptor *endpoint;
 623         char *buffer;
 624         int i;
 625         int retval = -ENOMEM;
 626
 627         /* allocate memory for our device state and intialize it */
 628
 629         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
 630         if (dev == NULL) {
 631                 dev_err(&intf->dev, "Out of memory\n");
 632                 goto exit;
 633         }
 634         memset(dev, 0x00, sizeof(*dev));
 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         down(&disconnect_sem);
 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         up(&disconnect_sem);
 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