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  */
  27
  28 #include <linux/config.h>
  29 #include <linux/kernel.h>
  30 #include <linux/errno.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/module.h>
  34
  35 #include <asm/uaccess.h>
  36 #include <linux/input.h>
  37 #include <linux/usb.h>
  38 #include <linux/poll.h>
  39
  40 /* Define these values to match your devices */
  41 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  42 #define USB_DEVICE_ID_CASSY             0x1000  /* USB Product ID for all CASSY-S modules */
  43 #define USB_DEVICE_ID_POCKETCASSY       0x1010  /* USB Product ID for Pocket-CASSY */
  44 #define USB_DEVICE_ID_MOBILECASSY       0x1020  /* USB Product ID for Mobile-CASSY */
  45 #define USB_DEVICE_ID_JWM               0x1080  /* USB Product ID for Joule and Wattmeter */
  46 #define USB_DEVICE_ID_DMMP              0x1081  /* USB Product ID for Digital Multimeter P (reserved) */
  47 #define USB_DEVICE_ID_UMIP              0x1090  /* USB Product ID for UMI P */
  48 #define USB_DEVICE_ID_VIDEOCOM          0x1200  /* USB Product ID for VideoCom */
  49 #define USB_DEVICE_ID_COM3LAB           0x2000  /* USB Product ID for COM3LAB */
  50 #define USB_DEVICE_ID_TELEPORT          0x2010  /* USB Product ID for Terminal Adapter */
  51 #define USB_DEVICE_ID_NETWORKANALYSER   0x2020  /* USB Product ID for Network Analyser */
  52 #define USB_DEVICE_ID_POWERCONTROL      0x2030  /* USB Product ID for Controlling device for Power Electronics */
  53
  54 #define USB_VENDOR_ID_VERNIER           0x08f7
  55 #define USB_DEVICE_ID_VERNIER_LABPRO    0x0001
  56 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
  57 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  58 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  59
  60
  61 #ifdef CONFIG_USB_DYNAMIC_MINORS
  62 #define USB_LD_MINOR_BASE       0
  63 #else
  64 #define USB_LD_MINOR_BASE       176
  65 #endif
  66
  67 /* table of devices that work with this driver */
  68 static struct usb_device_id ld_usb_table [] = {
  69         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_CASSY) },
  70         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_POCKETCASSY) },
  71         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_MOBILECASSY) },
  72         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_JWM) },
  73         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_DMMP) },
  74         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_UMIP) },
  75         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_VIDEOCOM) },
  76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_COM3LAB) },
  77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_TELEPORT) },
  78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_NETWORKANALYSER) },
  79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_POWERCONTROL) },
  80         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
  81         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
  82         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
  83         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
  84         { }                                     /* Terminating entry */
  85 };
  86 MODULE_DEVICE_TABLE(usb, ld_usb_table);
  87 MODULE_VERSION("V0.11");
  88 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
  89 MODULE_DESCRIPTION("LD USB Driver");
  90 MODULE_LICENSE("GPL");
  91 MODULE_SUPPORTED_DEVICE("LD USB Devices");
  92
  93 #ifdef CONFIG_USB_DEBUG
  94         static int debug = 1;
  95 #else
  96         static int debug = 0;
  97 #endif
  98
  99 /* Use our own dbg macro */
 100 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 101
 102 /* Module parameters */
 103 module_param(debug, int, S_IRUGO | S_IWUSR);
 104 MODULE_PARM_DESC(debug, "Debug enabled or not");
 105
 106 /* All interrupt in transfers are collected in a ring buffer to
 107  * avoid racing conditions and get better performance of the driver.
 108  */
 109 static int ring_buffer_size = 128;
 110 module_param(ring_buffer_size, int, 0);
 111 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 112
 113 /* The write_buffer can contain more than one interrupt out transfer.
 114  */
 115 static int write_buffer_size = 10;
 116 module_param(write_buffer_size, int, 0);
 117 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 118
 119 /* As of kernel version 2.6.4 ehci-hcd uses an
 120  * "only one interrupt transfer per frame" shortcut
 121  * to simplify the scheduling of periodic transfers.
 122  * This conflicts with our standard 1ms intervals for in and out URBs.
 123  * We use default intervals of 2ms for in and 2ms for out transfers,
 124  * which should be fast enough.
 125  * Increase the interval to allow more devices that do interrupt transfers,
 126  * or set to 1 to use the standard interval from the endpoint descriptors.
 127  */
 128 static int min_interrupt_in_interval = 2;
 129 module_param(min_interrupt_in_interval, int, 0);
 130 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 131
 132 static int min_interrupt_out_interval = 2;
 133 module_param(min_interrupt_out_interval, int, 0);
 134 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 135
 136 /* Structure to hold all of our device specific stuff */
 137 struct ld_usb {
 138         struct semaphore        sem;            /* locks this structure */
 139         struct usb_interface*   intf;           /* save off the usb interface pointer */
 140
 141         int                     open_count;     /* number of times this port has been opened */
 142
 143         char*                   ring_buffer;
 144         unsigned int            ring_head;
 145         unsigned int            ring_tail;
 146
 147         wait_queue_head_t       read_wait;
 148         wait_queue_head_t       write_wait;
 149
 150         char*                   interrupt_in_buffer;
 151         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 152         struct urb*             interrupt_in_urb;
 153         int                     interrupt_in_interval;
 154         size_t                  interrupt_in_endpoint_size;
 155         int                     interrupt_in_running;
 156         int                     interrupt_in_done;
 157
 158         char*                   interrupt_out_buffer;
 159         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 160         struct urb*             interrupt_out_urb;
 161         int                     interrupt_out_interval;
 162         size_t                  interrupt_out_endpoint_size;
 163         int                     interrupt_out_busy;
 164 };
 165
 166 /* prevent races between open() and disconnect() */
 167 static DECLARE_MUTEX(disconnect_sem);
 168
 169 static struct usb_driver ld_usb_driver;
 170
 171 /**
 172  *      ld_usb_abort_transfers
 173  *      aborts transfers and frees associated data structures
 174  */
 175 static void ld_usb_abort_transfers(struct ld_usb *dev)
 176 {
 177         /* shutdown transfer */
 178         if (dev->interrupt_in_running) {
 179                 dev->interrupt_in_running = 0;
 180                 if (dev->intf)
 181                         usb_kill_urb(dev->interrupt_in_urb);
 182         }
 183         if (dev->interrupt_out_busy)
 184                 if (dev->intf)
 185                         usb_kill_urb(dev->interrupt_out_urb);
 186 }
 187
 188 /**
 189  *      ld_usb_delete
 190  */
 191 static void ld_usb_delete(struct ld_usb *dev)
 192 {
 193         ld_usb_abort_transfers(dev);
 194
 195         /* free data structures */
 196         usb_free_urb(dev->interrupt_in_urb);
 197         usb_free_urb(dev->interrupt_out_urb);
 198         kfree(dev->ring_buffer);
 199         kfree(dev->interrupt_in_buffer);
 200         kfree(dev->interrupt_out_buffer);
 201         kfree(dev);
 202 }
 203
 204 /**
 205  *      ld_usb_interrupt_in_callback
 206  */
 207 static void ld_usb_interrupt_in_callback(struct urb *urb, struct pt_regs *regs)
 208 {
 209         struct ld_usb *dev = urb->context;
 210         size_t *actual_buffer;
 211         unsigned int next_ring_head;
 212         int retval;
 213
 214         if (urb->status) {
 215                 if (urb->status == -ENOENT ||
 216                     urb->status == -ECONNRESET ||
 217                     urb->status == -ESHUTDOWN) {
 218                         goto exit;
 219                 } else {
 220                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 221                                  __FUNCTION__, urb->status);
 222                         goto resubmit; /* maybe we can recover */
 223                 }
 224         }
 225
 226         if (urb->actual_length > 0) {
 227                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 228                 if (next_ring_head != dev->ring_tail) {
 229                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 230                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 231                         *actual_buffer = urb->actual_length;
 232                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 233                         dev->ring_head = next_ring_head;
 234                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 235                                  __FUNCTION__, urb->actual_length);
 236                 } else
 237                         dev_warn(&dev->intf->dev,
 238                                  "Ring buffer overflow, %d bytes dropped\n",
 239                                  urb->actual_length);
 240         }
 241
 242 resubmit:
 243         /* resubmit if we're still running */
 244         if (dev->interrupt_in_running && dev->intf) {
 245                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 246                 if (retval)
 247                         dev_err(&dev->intf->dev,
 248                                 "usb_submit_urb failed (%d)\n", retval);
 249         }
 250
 251 exit:
 252         dev->interrupt_in_done = 1;
 253         wake_up_interruptible(&dev->read_wait);
 254 }
 255
 256 /**
 257  *      ld_usb_interrupt_out_callback
 258  */
 259 static void ld_usb_interrupt_out_callback(struct urb *urb, struct pt_regs *regs)
 260 {
 261         struct ld_usb *dev = urb->context;
 262
 263         /* sync/async unlink faults aren't errors */
 264         if (urb->status && !(urb->status == -ENOENT ||
 265                              urb->status == -ECONNRESET ||
 266                              urb->status == -ESHUTDOWN))
 267                 dbg_info(&dev->intf->dev,
 268                          "%s - nonzero write interrupt status received: %d\n",
 269                          __FUNCTION__, urb->status);
 270
 271         dev->interrupt_out_busy = 0;
 272         wake_up_interruptible(&dev->write_wait);
 273 }
 274
 275 /**
 276  *      ld_usb_open
 277  */
 278 static int ld_usb_open(struct inode *inode, struct file *file)
 279 {
 280         struct ld_usb *dev;
 281         int subminor;
 282         int retval = 0;
 283         struct usb_interface *interface;
 284
 285         nonseekable_open(inode, file);
 286         subminor = iminor(inode);
 287
 288         down(&disconnect_sem);
 289
 290         interface = usb_find_interface(&ld_usb_driver, subminor);
 291
 292         if (!interface) {
 293                 err("%s - error, can't find device for minor %d\n",
 294                      __FUNCTION__, subminor);
 295                 retval = -ENODEV;
 296                 goto unlock_disconnect_exit;
 297         }
 298
 299         dev = usb_get_intfdata(interface);
 300
 301         if (!dev) {
 302                 retval = -ENODEV;
 303                 goto unlock_disconnect_exit;
 304         }
 305
 306         /* lock this device */
 307         if (down_interruptible(&dev->sem)) {
 308                 retval = -ERESTARTSYS;
 309                 goto unlock_disconnect_exit;
 310         }
 311
 312         /* allow opening only once */
 313         if (dev->open_count) {
 314                 retval = -EBUSY;
 315                 goto unlock_exit;
 316         }
 317         dev->open_count = 1;
 318
 319         /* initialize in direction */
 320         dev->ring_head = 0;
 321         dev->ring_tail = 0;
 322         usb_fill_int_urb(dev->interrupt_in_urb,
 323                          interface_to_usbdev(interface),
 324                          usb_rcvintpipe(interface_to_usbdev(interface),
 325                                         dev->interrupt_in_endpoint->bEndpointAddress),
 326                          dev->interrupt_in_buffer,
 327                          dev->interrupt_in_endpoint_size,
 328                          ld_usb_interrupt_in_callback,
 329                          dev,
 330                          dev->interrupt_in_interval);
 331
 332         dev->interrupt_in_running = 1;
 333         dev->interrupt_in_done = 0;
 334
 335         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 336         if (retval) {
 337                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 338                 dev->interrupt_in_running = 0;
 339                 dev->open_count = 0;
 340                 goto unlock_exit;
 341         }
 342
 343         /* save device in the file's private structure */
 344         file->private_data = dev;
 345
 346 unlock_exit:
 347         up(&dev->sem);
 348
 349 unlock_disconnect_exit:
 350         up(&disconnect_sem);
 351
 352         return retval;
 353 }
 354
 355 /**
 356  *      ld_usb_release
 357  */
 358 static int ld_usb_release(struct inode *inode, struct file *file)
 359 {
 360         struct ld_usb *dev;
 361         int retval = 0;
 362
 363         dev = file->private_data;
 364
 365         if (dev == NULL) {
 366                 retval = -ENODEV;
 367                 goto exit;
 368         }
 369
 370         if (down_interruptible(&dev->sem)) {
 371                 retval = -ERESTARTSYS;
 372                 goto exit;
 373         }
 374
 375         if (dev->open_count != 1) {
 376                 retval = -ENODEV;
 377                 goto unlock_exit;
 378         }
 379         if (dev->intf == NULL) {
 380                 /* the device was unplugged before the file was released */
 381                 up(&dev->sem);
 382                 /* unlock here as ld_usb_delete frees dev */
 383                 ld_usb_delete(dev);
 384                 goto exit;
 385         }
 386
 387         /* wait until write transfer is finished */
 388         if (dev->interrupt_out_busy)
 389                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 390         ld_usb_abort_transfers(dev);
 391         dev->open_count = 0;
 392
 393 unlock_exit:
 394         up(&dev->sem);
 395
 396 exit:
 397         return retval;
 398 }
 399
 400 /**
 401  *      ld_usb_poll
 402  */
 403 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 404 {
 405         struct ld_usb *dev;
 406         unsigned int mask = 0;
 407
 408         dev = file->private_data;
 409
 410         poll_wait(file, &dev->read_wait, wait);
 411         poll_wait(file, &dev->write_wait, wait);
 412
 413         if (dev->ring_head != dev->ring_tail)
 414                 mask |= POLLIN | POLLRDNORM;
 415         if (!dev->interrupt_out_busy)
 416                 mask |= POLLOUT | POLLWRNORM;
 417
 418         return mask;
 419 }
 420
 421 /**
 422  *      ld_usb_read
 423  */
 424 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 425                            loff_t *ppos)
 426 {
 427         struct ld_usb *dev;
 428         size_t *actual_buffer;
 429         size_t bytes_to_read;
 430         int retval = 0;
 431
 432         dev = file->private_data;
 433
 434         /* verify that we actually have some data to read */
 435         if (count == 0)
 436                 goto exit;
 437
 438         /* lock this object */
 439         if (down_interruptible(&dev->sem)) {
 440                 retval = -ERESTARTSYS;
 441                 goto exit;
 442         }
 443
 444         /* verify that the device wasn't unplugged */
 445         if (dev->intf == NULL) {
 446                 retval = -ENODEV;
 447                 err("No device or device unplugged %d\n", retval);
 448                 goto unlock_exit;
 449         }
 450
 451         /* wait for data */
 452         if (dev->ring_head == dev->ring_tail) {
 453                 if (file->f_flags & O_NONBLOCK) {
 454                         retval = -EAGAIN;
 455                         goto unlock_exit;
 456                 }
 457                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 458                 if (retval < 0)
 459                         goto unlock_exit;
 460         }
 461
 462         /* actual_buffer contains actual_length + interrupt_in_buffer */
 463         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 464         bytes_to_read = min(count, *actual_buffer);
 465         if (bytes_to_read < *actual_buffer)
 466                 dev_warn(&dev->intf->dev, "Read buffer overflow, %d bytes dropped\n",
 467                          *actual_buffer-bytes_to_read);
 468
 469         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 470         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 471                 retval = -EFAULT;
 472                 goto unlock_exit;
 473         }
 474         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 475
 476         retval = bytes_to_read;
 477
 478 unlock_exit:
 479         /* unlock the device */
 480         up(&dev->sem);
 481
 482 exit:
 483         return retval;
 484 }
 485
 486 /**
 487  *      ld_usb_write
 488  */
 489 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 490                             size_t count, loff_t *ppos)
 491 {
 492         struct ld_usb *dev;
 493         size_t bytes_to_write;
 494         int retval = 0;
 495
 496         dev = file->private_data;
 497
 498         /* verify that we actually have some data to write */
 499         if (count == 0)
 500                 goto exit;
 501
 502         /* lock this object */
 503         if (down_interruptible(&dev->sem)) {
 504                 retval = -ERESTARTSYS;
 505                 goto exit;
 506         }
 507
 508         /* verify that the device wasn't unplugged */
 509         if (dev->intf == NULL) {
 510                 retval = -ENODEV;
 511                 err("No device or device unplugged %d\n", retval);
 512                 goto unlock_exit;
 513         }
 514
 515         /* wait until previous transfer is finished */
 516         if (dev->interrupt_out_busy) {
 517                 if (file->f_flags & O_NONBLOCK) {
 518                         retval = -EAGAIN;
 519                         goto unlock_exit;
 520                 }
 521                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 522                 if (retval < 0) {
 523                         goto unlock_exit;
 524                 }
 525         }
 526
 527         /* write the data into interrupt_out_buffer from userspace */
 528         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 529         if (bytes_to_write < count)
 530                 dev_warn(&dev->intf->dev, "Write buffer overflow, %d bytes dropped\n",count-bytes_to_write);
 531         dbg_info(&dev->intf->dev, "%s: count = %d, bytes_to_write = %d\n", __FUNCTION__, count, bytes_to_write);
 532
 533         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 534                 retval = -EFAULT;
 535                 goto unlock_exit;
 536         }
 537
 538         if (dev->interrupt_out_endpoint == NULL) {
 539                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 540                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 541                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 542                                          9,
 543                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 544                                          1 << 8, 0,
 545                                          dev->interrupt_out_buffer,
 546                                          bytes_to_write,
 547                                          USB_CTRL_SET_TIMEOUT * HZ);
 548                 if (retval < 0)
 549                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 550                 goto unlock_exit;
 551         }
 552
 553         /* send off the urb */
 554         usb_fill_int_urb(dev->interrupt_out_urb,
 555                          interface_to_usbdev(dev->intf),
 556                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 557                                         dev->interrupt_out_endpoint->bEndpointAddress),
 558                          dev->interrupt_out_buffer,
 559                          bytes_to_write,
 560                          ld_usb_interrupt_out_callback,
 561                          dev,
 562                          dev->interrupt_out_interval);
 563
 564         dev->interrupt_out_busy = 1;
 565         wmb();
 566
 567         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 568         if (retval) {
 569                 dev->interrupt_out_busy = 0;
 570                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 571                 goto unlock_exit;
 572         }
 573         retval = bytes_to_write;
 574
 575 unlock_exit:
 576         /* unlock the device */
 577         up(&dev->sem);
 578
 579 exit:
 580         return retval;
 581 }
 582
 583 /* file operations needed when we register this driver */
 584 static struct file_operations ld_usb_fops = {
 585         .owner =        THIS_MODULE,
 586         .read  =        ld_usb_read,
 587         .write =        ld_usb_write,
 588         .open =         ld_usb_open,
 589         .release =      ld_usb_release,
 590         .poll =         ld_usb_poll,
 591 };
 592
 593 /*
 594  * usb class driver info in order to get a minor number from the usb core,
 595  * and to have the device registered with devfs and the driver core
 596  */
 597 static struct usb_class_driver ld_usb_class = {
 598         .name =         "ldusb%d",
 599         .fops =         &ld_usb_fops,
 600         .minor_base =   USB_LD_MINOR_BASE,
 601 };
 602
 603 /**
 604  *      ld_usb_probe
 605  *
 606  *      Called by the usb core when a new device is connected that it thinks
 607  *      this driver might be interested in.
 608  */
 609 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 610 {
 611         struct usb_device *udev = interface_to_usbdev(intf);
 612         struct ld_usb *dev = NULL;
 613         struct usb_host_interface *iface_desc;
 614         struct usb_endpoint_descriptor *endpoint;
 615         char *buffer;
 616         int i;
 617         int retval = -ENOMEM;
 618
 619         /* allocate memory for our device state and intialize it */
 620
 621         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
 622         if (dev == NULL) {
 623                 dev_err(&intf->dev, "Out of memory\n");
 624                 goto exit;
 625         }
 626         memset(dev, 0x00, sizeof(*dev));
 627         init_MUTEX(&dev->sem);
 628         dev->intf = intf;
 629         init_waitqueue_head(&dev->read_wait);
 630         init_waitqueue_head(&dev->write_wait);
 631
 632         /* workaround for early firmware versions on fast computers */
 633         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 634             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_CASSY) ||
 635              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_COM3LAB)) &&
 636             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 637                 buffer = kmalloc(256, GFP_KERNEL);
 638                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 639                 usb_string(udev, 255, buffer, 256);
 640                 kfree(buffer);
 641         }
 642
 643         iface_desc = intf->cur_altsetting;
 644
 645         /* set up the endpoint information */
 646         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 647                 endpoint = &iface_desc->endpoint[i].desc;
 648
 649                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
 650                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
 651                         dev->interrupt_in_endpoint = endpoint;
 652                 }
 653
 654                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
 655                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
 656                         dev->interrupt_out_endpoint = endpoint;
 657                 }
 658         }
 659         if (dev->interrupt_in_endpoint == NULL) {
 660                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 661                 goto error;
 662         }
 663         if (dev->interrupt_out_endpoint == NULL)
 664                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 665
 666         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 667         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 668         if (!dev->ring_buffer) {
 669                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 670                 goto error;
 671         }
 672         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 673         if (!dev->interrupt_in_buffer) {
 674                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 675                 goto error;
 676         }
 677         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 678         if (!dev->interrupt_in_urb) {
 679                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 680                 goto error;
 681         }
 682         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 683                                                                          udev->descriptor.bMaxPacketSize0;
 684         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 685         if (!dev->interrupt_out_buffer) {
 686                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 687                 goto error;
 688         }
 689         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 690         if (!dev->interrupt_out_urb) {
 691                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 692                 goto error;
 693         }
 694         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 695         if (dev->interrupt_out_endpoint)
 696                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 697
 698         /* we can register the device now, as it is ready */
 699         usb_set_intfdata(intf, dev);
 700
 701         retval = usb_register_dev(intf, &ld_usb_class);
 702         if (retval) {
 703                 /* something prevented us from registering this driver */
 704                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 705                 usb_set_intfdata(intf, NULL);
 706                 goto error;
 707         }
 708
 709         /* let the user know what node this device is now attached to */
 710         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 711                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 712
 713 exit:
 714         return retval;
 715
 716 error:
 717         ld_usb_delete(dev);
 718
 719         return retval;
 720 }
 721
 722 /**
 723  *      ld_usb_disconnect
 724  *
 725  *      Called by the usb core when the device is removed from the system.
 726  */
 727 static void ld_usb_disconnect(struct usb_interface *intf)
 728 {
 729         struct ld_usb *dev;
 730         int minor;
 731
 732         down(&disconnect_sem);
 733
 734         dev = usb_get_intfdata(intf);
 735         usb_set_intfdata(intf, NULL);
 736
 737         down(&dev->sem);
 738
 739         minor = intf->minor;
 740
 741         /* give back our minor */
 742         usb_deregister_dev(intf, &ld_usb_class);
 743
 744         /* if the device is not opened, then we clean up right now */
 745         if (!dev->open_count) {
 746                 up(&dev->sem);
 747                 ld_usb_delete(dev);
 748         } else {
 749                 dev->intf = NULL;
 750                 up(&dev->sem);
 751         }
 752
 753         up(&disconnect_sem);
 754
 755         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 756                  (minor - USB_LD_MINOR_BASE));
 757 }
 758
 759 /* usb specific object needed to register this driver with the usb subsystem */
 760 static struct usb_driver ld_usb_driver = {
 761         .owner =        THIS_MODULE,
 762         .name =         "ldusb",
 763         .probe =        ld_usb_probe,
 764         .disconnect =   ld_usb_disconnect,
 765         .id_table =     ld_usb_table,
 766 };
 767
 768 /**
 769  *      ld_usb_init
 770  */
 771 static int __init ld_usb_init(void)
 772 {
 773         int retval;
 774
 775         /* register this driver with the USB subsystem */
 776         retval = usb_register(&ld_usb_driver);
 777         if (retval)
 778                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
 779
 780         return retval;
 781 }
 782
 783 /**
 784  *      ld_usb_exit
 785  */
 786 static void __exit ld_usb_exit(void)
 787 {
 788         /* deregister this driver with the USB subsystem */
 789         usb_deregister(&ld_usb_driver);
 790 }
 791
 792 module_init(ld_usb_init);
 793 module_exit(ld_usb_exit);
 794