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
  25 #include <linux/kernel.h>
  26 #include <linux/errno.h>
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/mutex.h>
  30
  31 #include <asm/uaccess.h>
  32 #include <linux/input.h>
  33 #include <linux/usb.h>
  34 #include <linux/poll.h>
  35
  36 /* Define these values to match your devices */
  37 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  38 #define USB_DEVICE_ID_LD_CASSY          0x1000  /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */
  39 #define USB_DEVICE_ID_LD_CASSY2         0x1001  /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */
  40 #define USB_DEVICE_ID_LD_POCKETCASSY    0x1010  /* USB Product ID of Pocket-CASSY */
  41 #define USB_DEVICE_ID_LD_POCKETCASSY2   0x1011  /* USB Product ID of Pocket-CASSY 2 (reserved) */
  42 #define USB_DEVICE_ID_LD_MOBILECASSY    0x1020  /* USB Product ID of Mobile-CASSY */
  43 #define USB_DEVICE_ID_LD_MOBILECASSY2   0x1021  /* USB Product ID of Mobile-CASSY 2 (reserved) */
  44 #define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE      0x1031  /* USB Product ID of Micro-CASSY Voltage */
  45 #define USB_DEVICE_ID_LD_MICROCASSYCURRENT      0x1032  /* USB Product ID of Micro-CASSY Current */
  46 #define USB_DEVICE_ID_LD_MICROCASSYTIME         0x1033  /* USB Product ID of Micro-CASSY Time (reserved) */
  47 #define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE  0x1035  /* USB Product ID of Micro-CASSY Temperature */
  48 #define USB_DEVICE_ID_LD_MICROCASSYPH           0x1038  /* USB Product ID of Micro-CASSY pH */
  49 #define USB_DEVICE_ID_LD_POWERANALYSERCASSY     0x1040  /* USB Product ID of Power Analyser CASSY */
  50 #define USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY       0x1042  /* USB Product ID of Converter Controller CASSY */
  51 #define USB_DEVICE_ID_LD_MACHINETESTCASSY       0x1043  /* USB Product ID of Machine Test CASSY */
  52 #define USB_DEVICE_ID_LD_JWM            0x1080  /* USB Product ID of Joule and Wattmeter */
  53 #define USB_DEVICE_ID_LD_DMMP           0x1081  /* USB Product ID of Digital Multimeter P (reserved) */
  54 #define USB_DEVICE_ID_LD_UMIP           0x1090  /* USB Product ID of UMI P */
  55 #define USB_DEVICE_ID_LD_UMIC           0x10A0  /* USB Product ID of UMI C */
  56 #define USB_DEVICE_ID_LD_UMIB           0x10B0  /* USB Product ID of UMI B */
  57 #define USB_DEVICE_ID_LD_XRAY           0x1100  /* USB Product ID of X-Ray Apparatus 55481 */
  58 #define USB_DEVICE_ID_LD_XRAY2          0x1101  /* USB Product ID of X-Ray Apparatus 554800 */
  59 #define USB_DEVICE_ID_LD_XRAYCT         0x1110  /* USB Product ID of X-Ray Apparatus CT 554821*/
  60 #define USB_DEVICE_ID_LD_VIDEOCOM       0x1200  /* USB Product ID of VideoCom */
  61 #define USB_DEVICE_ID_LD_MOTOR          0x1210  /* USB Product ID of Motor (reserved) */
  62 #define USB_DEVICE_ID_LD_COM3LAB        0x2000  /* USB Product ID of COM3LAB */
  63 #define USB_DEVICE_ID_LD_TELEPORT       0x2010  /* USB Product ID of Terminal Adapter */
  64 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
  65 #define USB_DEVICE_ID_LD_POWERCONTROL   0x2030  /* USB Product ID of Converter Control Unit */
  66 #define USB_DEVICE_ID_LD_MACHINETEST    0x2040  /* USB Product ID of Machine Test System */
  67 #define USB_DEVICE_ID_LD_MOSTANALYSER   0x2050  /* USB Product ID of MOST Protocol Analyser */
  68 #define USB_DEVICE_ID_LD_MOSTANALYSER2  0x2051  /* USB Product ID of MOST Protocol Analyser 2 */
  69 #define USB_DEVICE_ID_LD_ABSESP         0x2060  /* USB Product ID of ABS ESP */
  70 #define USB_DEVICE_ID_LD_AUTODATABUS    0x2070  /* USB Product ID of Automotive Data Buses */
  71 #define USB_DEVICE_ID_LD_MCT            0x2080  /* USB Product ID of Microcontroller technique */
  72 #define USB_DEVICE_ID_LD_HYBRID         0x2090  /* USB Product ID of Automotive Hybrid */
  73 #define USB_DEVICE_ID_LD_HEATCONTROL    0x20A0  /* USB Product ID of Heat control */
  74
  75 #ifdef CONFIG_USB_DYNAMIC_MINORS
  76 #define USB_LD_MINOR_BASE       0
  77 #else
  78 #define USB_LD_MINOR_BASE       176
  79 #endif
  80
  81 /* table of devices that work with this driver */
  82 static const struct usb_device_id ld_usb_table[] = {
  83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) },
  85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) },
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) },
  89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) },
  90         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) },
  91         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) },
  92         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) },
  93         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) },
  94         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERANALYSERCASSY) },
  95         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY) },
  96         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETESTCASSY) },
  97         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  98         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
  99         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
 100         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) },
 101         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) },
 102         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) },
 103         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
 104         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
 105         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) },
 106         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
 107         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
 108         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
 109         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
 110         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
 111         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) },
 112         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) },
 113         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) },
 114         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) },
 115         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) },
 116         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) },
 117         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) },
 118         { }                                     /* Terminating entry */
 119 };
 120 MODULE_DEVICE_TABLE(usb, ld_usb_table);
 121 MODULE_VERSION("V0.14");
 122 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 123 MODULE_DESCRIPTION("LD USB Driver");
 124 MODULE_LICENSE("GPL");
 125 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 126
 127 /* All interrupt in transfers are collected in a ring buffer to
 128  * avoid racing conditions and get better performance of the driver.
 129  */
 130 static int ring_buffer_size = 128;
 131 module_param(ring_buffer_size, int, 0);
 132 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 133
 134 /* The write_buffer can contain more than one interrupt out transfer.
 135  */
 136 static int write_buffer_size = 10;
 137 module_param(write_buffer_size, int, 0);
 138 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 139
 140 /* As of kernel version 2.6.4 ehci-hcd uses an
 141  * "only one interrupt transfer per frame" shortcut
 142  * to simplify the scheduling of periodic transfers.
 143  * This conflicts with our standard 1ms intervals for in and out URBs.
 144  * We use default intervals of 2ms for in and 2ms for out transfers,
 145  * which should be fast enough.
 146  * Increase the interval to allow more devices that do interrupt transfers,
 147  * or set to 1 to use the standard interval from the endpoint descriptors.
 148  */
 149 static int min_interrupt_in_interval = 2;
 150 module_param(min_interrupt_in_interval, int, 0);
 151 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 152
 153 static int min_interrupt_out_interval = 2;
 154 module_param(min_interrupt_out_interval, int, 0);
 155 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 156
 157 /* Structure to hold all of our device specific stuff */
 158 struct ld_usb {
 159         struct mutex            mutex;          /* locks this structure */
 160         struct usb_interface*   intf;           /* save off the usb interface pointer */
 161         unsigned long           disconnected:1;
 162
 163         int                     open_count;     /* number of times this port has been opened */
 164
 165         char*                   ring_buffer;
 166         unsigned int            ring_head;
 167         unsigned int            ring_tail;
 168
 169         wait_queue_head_t       read_wait;
 170         wait_queue_head_t       write_wait;
 171
 172         char*                   interrupt_in_buffer;
 173         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 174         struct urb*             interrupt_in_urb;
 175         int                     interrupt_in_interval;
 176         size_t                  interrupt_in_endpoint_size;
 177         int                     interrupt_in_running;
 178         int                     interrupt_in_done;
 179         int                     buffer_overflow;
 180         spinlock_t              rbsl;
 181
 182         char*                   interrupt_out_buffer;
 183         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 184         struct urb*             interrupt_out_urb;
 185         int                     interrupt_out_interval;
 186         size_t                  interrupt_out_endpoint_size;
 187         int                     interrupt_out_busy;
 188 };
 189
 190 static struct usb_driver ld_usb_driver;
 191
 192 /**
 193  *      ld_usb_abort_transfers
 194  *      aborts transfers and frees associated data structures
 195  */
 196 static void ld_usb_abort_transfers(struct ld_usb *dev)
 197 {
 198         /* shutdown transfer */
 199         if (dev->interrupt_in_running) {
 200                 dev->interrupt_in_running = 0;
 201                 usb_kill_urb(dev->interrupt_in_urb);
 202         }
 203         if (dev->interrupt_out_busy)
 204                 usb_kill_urb(dev->interrupt_out_urb);
 205 }
 206
 207 /**
 208  *      ld_usb_delete
 209  */
 210 static void ld_usb_delete(struct ld_usb *dev)
 211 {
 212         /* free data structures */
 213         usb_free_urb(dev->interrupt_in_urb);
 214         usb_free_urb(dev->interrupt_out_urb);
 215         kfree(dev->ring_buffer);
 216         kfree(dev->interrupt_in_buffer);
 217         kfree(dev->interrupt_out_buffer);
 218         kfree(dev);
 219 }
 220
 221 /**
 222  *      ld_usb_interrupt_in_callback
 223  */
 224 static void ld_usb_interrupt_in_callback(struct urb *urb)
 225 {
 226         struct ld_usb *dev = urb->context;
 227         size_t *actual_buffer;
 228         unsigned int next_ring_head;
 229         int status = urb->status;
 230         int retval;
 231
 232         if (status) {
 233                 if (status == -ENOENT ||
 234                     status == -ECONNRESET ||
 235                     status == -ESHUTDOWN) {
 236                         goto exit;
 237                 } else {
 238                         dev_dbg(&dev->intf->dev,
 239                                 "%s: nonzero status received: %d\n", __func__,
 240                                 status);
 241                         spin_lock(&dev->rbsl);
 242                         goto resubmit; /* maybe we can recover */
 243                 }
 244         }
 245
 246         spin_lock(&dev->rbsl);
 247         if (urb->actual_length > 0) {
 248                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 249                 if (next_ring_head != dev->ring_tail) {
 250                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 251                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 252                         *actual_buffer = urb->actual_length;
 253                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 254                         dev->ring_head = next_ring_head;
 255                         dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
 256                                 __func__, urb->actual_length);
 257                 } else {
 258                         dev_warn(&dev->intf->dev,
 259                                  "Ring buffer overflow, %d bytes dropped\n",
 260                                  urb->actual_length);
 261                         dev->buffer_overflow = 1;
 262                 }
 263         }
 264
 265 resubmit:
 266         /* resubmit if we're still running */
 267         if (dev->interrupt_in_running && !dev->buffer_overflow) {
 268                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 269                 if (retval) {
 270                         dev_err(&dev->intf->dev,
 271                                 "usb_submit_urb failed (%d)\n", retval);
 272                         dev->buffer_overflow = 1;
 273                 }
 274         }
 275         spin_unlock(&dev->rbsl);
 276 exit:
 277         dev->interrupt_in_done = 1;
 278         wake_up_interruptible(&dev->read_wait);
 279 }
 280
 281 /**
 282  *      ld_usb_interrupt_out_callback
 283  */
 284 static void ld_usb_interrupt_out_callback(struct urb *urb)
 285 {
 286         struct ld_usb *dev = urb->context;
 287         int status = urb->status;
 288
 289         /* sync/async unlink faults aren't errors */
 290         if (status && !(status == -ENOENT ||
 291                         status == -ECONNRESET ||
 292                         status == -ESHUTDOWN))
 293                 dev_dbg(&dev->intf->dev,
 294                         "%s - nonzero write interrupt status received: %d\n",
 295                         __func__, status);
 296
 297         dev->interrupt_out_busy = 0;
 298         wake_up_interruptible(&dev->write_wait);
 299 }
 300
 301 /**
 302  *      ld_usb_open
 303  */
 304 static int ld_usb_open(struct inode *inode, struct file *file)
 305 {
 306         struct ld_usb *dev;
 307         int subminor;
 308         int retval;
 309         struct usb_interface *interface;
 310
 311         nonseekable_open(inode, file);
 312         subminor = iminor(inode);
 313
 314         interface = usb_find_interface(&ld_usb_driver, subminor);
 315
 316         if (!interface) {
 317                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 318                        __func__, subminor);
 319                 return -ENODEV;
 320         }
 321
 322         dev = usb_get_intfdata(interface);
 323
 324         if (!dev)
 325                 return -ENODEV;
 326
 327         /* lock this device */
 328         if (mutex_lock_interruptible(&dev->mutex))
 329                 return -ERESTARTSYS;
 330
 331         /* allow opening only once */
 332         if (dev->open_count) {
 333                 retval = -EBUSY;
 334                 goto unlock_exit;
 335         }
 336         dev->open_count = 1;
 337
 338         /* initialize in direction */
 339         dev->ring_head = 0;
 340         dev->ring_tail = 0;
 341         dev->buffer_overflow = 0;
 342         usb_fill_int_urb(dev->interrupt_in_urb,
 343                          interface_to_usbdev(interface),
 344                          usb_rcvintpipe(interface_to_usbdev(interface),
 345                                         dev->interrupt_in_endpoint->bEndpointAddress),
 346                          dev->interrupt_in_buffer,
 347                          dev->interrupt_in_endpoint_size,
 348                          ld_usb_interrupt_in_callback,
 349                          dev,
 350                          dev->interrupt_in_interval);
 351
 352         dev->interrupt_in_running = 1;
 353         dev->interrupt_in_done = 0;
 354
 355         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 356         if (retval) {
 357                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 358                 dev->interrupt_in_running = 0;
 359                 dev->open_count = 0;
 360                 goto unlock_exit;
 361         }
 362
 363         /* save device in the file's private structure */
 364         file->private_data = dev;
 365
 366 unlock_exit:
 367         mutex_unlock(&dev->mutex);
 368
 369         return retval;
 370 }
 371
 372 /**
 373  *      ld_usb_release
 374  */
 375 static int ld_usb_release(struct inode *inode, struct file *file)
 376 {
 377         struct ld_usb *dev;
 378         int retval = 0;
 379
 380         dev = file->private_data;
 381
 382         if (dev == NULL) {
 383                 retval = -ENODEV;
 384                 goto exit;
 385         }
 386
 387         mutex_lock(&dev->mutex);
 388
 389         if (dev->open_count != 1) {
 390                 retval = -ENODEV;
 391                 goto unlock_exit;
 392         }
 393         if (dev->disconnected) {
 394                 /* the device was unplugged before the file was released */
 395                 mutex_unlock(&dev->mutex);
 396                 /* unlock here as ld_usb_delete frees dev */
 397                 ld_usb_delete(dev);
 398                 goto exit;
 399         }
 400
 401         /* wait until write transfer is finished */
 402         if (dev->interrupt_out_busy)
 403                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 404         ld_usb_abort_transfers(dev);
 405         dev->open_count = 0;
 406
 407 unlock_exit:
 408         mutex_unlock(&dev->mutex);
 409
 410 exit:
 411         return retval;
 412 }
 413
 414 /**
 415  *      ld_usb_poll
 416  */
 417 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 418 {
 419         struct ld_usb *dev;
 420         unsigned int mask = 0;
 421
 422         dev = file->private_data;
 423
 424         if (dev->disconnected)
 425                 return POLLERR | POLLHUP;
 426
 427         poll_wait(file, &dev->read_wait, wait);
 428         poll_wait(file, &dev->write_wait, wait);
 429
 430         if (dev->ring_head != dev->ring_tail)
 431                 mask |= POLLIN | POLLRDNORM;
 432         if (!dev->interrupt_out_busy)
 433                 mask |= POLLOUT | POLLWRNORM;
 434
 435         return mask;
 436 }
 437
 438 /**
 439  *      ld_usb_read
 440  */
 441 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 442                            loff_t *ppos)
 443 {
 444         struct ld_usb *dev;
 445         size_t *actual_buffer;
 446         size_t bytes_to_read;
 447         int retval = 0;
 448         int rv;
 449
 450         dev = file->private_data;
 451
 452         /* verify that we actually have some data to read */
 453         if (count == 0)
 454                 goto exit;
 455
 456         /* lock this object */
 457         if (mutex_lock_interruptible(&dev->mutex)) {
 458                 retval = -ERESTARTSYS;
 459                 goto exit;
 460         }
 461
 462         /* verify that the device wasn't unplugged */
 463         if (dev->disconnected) {
 464                 retval = -ENODEV;
 465                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 466                 goto unlock_exit;
 467         }
 468
 469         /* wait for data */
 470         spin_lock_irq(&dev->rbsl);
 471         while (dev->ring_head == dev->ring_tail) {
 472                 dev->interrupt_in_done = 0;
 473                 spin_unlock_irq(&dev->rbsl);
 474                 if (file->f_flags & O_NONBLOCK) {
 475                         retval = -EAGAIN;
 476                         goto unlock_exit;
 477                 }
 478                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 479                 if (retval < 0)
 480                         goto unlock_exit;
 481
 482                 spin_lock_irq(&dev->rbsl);
 483         }
 484         spin_unlock_irq(&dev->rbsl);
 485
 486         /* actual_buffer contains actual_length + interrupt_in_buffer */
 487         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 488         if (*actual_buffer > dev->interrupt_in_endpoint_size) {
 489                 retval = -EIO;
 490                 goto unlock_exit;
 491         }
 492         bytes_to_read = min(count, *actual_buffer);
 493         if (bytes_to_read < *actual_buffer)
 494                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 495                          *actual_buffer-bytes_to_read);
 496
 497         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 498         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 499                 retval = -EFAULT;
 500                 goto unlock_exit;
 501         }
 502         retval = bytes_to_read;
 503
 504         spin_lock_irq(&dev->rbsl);
 505         dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
 506
 507         if (dev->buffer_overflow) {
 508                 dev->buffer_overflow = 0;
 509                 spin_unlock_irq(&dev->rbsl);
 510                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 511                 if (rv < 0)
 512                         dev->buffer_overflow = 1;
 513         } else {
 514                 spin_unlock_irq(&dev->rbsl);
 515         }
 516
 517 unlock_exit:
 518         /* unlock the device */
 519         mutex_unlock(&dev->mutex);
 520
 521 exit:
 522         return retval;
 523 }
 524
 525 /**
 526  *      ld_usb_write
 527  */
 528 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 529                             size_t count, loff_t *ppos)
 530 {
 531         struct ld_usb *dev;
 532         size_t bytes_to_write;
 533         int retval = 0;
 534
 535         dev = file->private_data;
 536
 537         /* verify that we actually have some data to write */
 538         if (count == 0)
 539                 goto exit;
 540
 541         /* lock this object */
 542         if (mutex_lock_interruptible(&dev->mutex)) {
 543                 retval = -ERESTARTSYS;
 544                 goto exit;
 545         }
 546
 547         /* verify that the device wasn't unplugged */
 548         if (dev->disconnected) {
 549                 retval = -ENODEV;
 550                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 551                 goto unlock_exit;
 552         }
 553
 554         /* wait until previous transfer is finished */
 555         if (dev->interrupt_out_busy) {
 556                 if (file->f_flags & O_NONBLOCK) {
 557                         retval = -EAGAIN;
 558                         goto unlock_exit;
 559                 }
 560                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 561                 if (retval < 0) {
 562                         goto unlock_exit;
 563                 }
 564         }
 565
 566         /* write the data into interrupt_out_buffer from userspace */
 567         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 568         if (bytes_to_write < count)
 569                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 570         dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
 571                 __func__, count, bytes_to_write);
 572
 573         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 574                 retval = -EFAULT;
 575                 goto unlock_exit;
 576         }
 577
 578         if (dev->interrupt_out_endpoint == NULL) {
 579                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 580                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 581                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 582                                          9,
 583                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 584                                          1 << 8, 0,
 585                                          dev->interrupt_out_buffer,
 586                                          bytes_to_write,
 587                                          USB_CTRL_SET_TIMEOUT);
 588                 if (retval < 0)
 589                         dev_err(&dev->intf->dev,
 590                                 "Couldn't submit HID_REQ_SET_REPORT %d\n",
 591                                 retval);
 592                 goto unlock_exit;
 593         }
 594
 595         /* send off the urb */
 596         usb_fill_int_urb(dev->interrupt_out_urb,
 597                          interface_to_usbdev(dev->intf),
 598                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 599                                         dev->interrupt_out_endpoint->bEndpointAddress),
 600                          dev->interrupt_out_buffer,
 601                          bytes_to_write,
 602                          ld_usb_interrupt_out_callback,
 603                          dev,
 604                          dev->interrupt_out_interval);
 605
 606         dev->interrupt_out_busy = 1;
 607         wmb();
 608
 609         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 610         if (retval) {
 611                 dev->interrupt_out_busy = 0;
 612                 dev_err(&dev->intf->dev,
 613                         "Couldn't submit interrupt_out_urb %d\n", retval);
 614                 goto unlock_exit;
 615         }
 616         retval = bytes_to_write;
 617
 618 unlock_exit:
 619         /* unlock the device */
 620         mutex_unlock(&dev->mutex);
 621
 622 exit:
 623         return retval;
 624 }
 625
 626 /* file operations needed when we register this driver */
 627 static const struct file_operations ld_usb_fops = {
 628         .owner =        THIS_MODULE,
 629         .read  =        ld_usb_read,
 630         .write =        ld_usb_write,
 631         .open =         ld_usb_open,
 632         .release =      ld_usb_release,
 633         .poll =         ld_usb_poll,
 634         .llseek =       no_llseek,
 635 };
 636
 637 /*
 638  * usb class driver info in order to get a minor number from the usb core,
 639  * and to have the device registered with the driver core
 640  */
 641 static struct usb_class_driver ld_usb_class = {
 642         .name =         "ldusb%d",
 643         .fops =         &ld_usb_fops,
 644         .minor_base =   USB_LD_MINOR_BASE,
 645 };
 646
 647 /**
 648  *      ld_usb_probe
 649  *
 650  *      Called by the usb core when a new device is connected that it thinks
 651  *      this driver might be interested in.
 652  */
 653 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 654 {
 655         struct usb_device *udev = interface_to_usbdev(intf);
 656         struct ld_usb *dev = NULL;
 657         struct usb_host_interface *iface_desc;
 658         struct usb_endpoint_descriptor *endpoint;
 659         char *buffer;
 660         int i;
 661         int retval = -ENOMEM;
 662
 663         /* allocate memory for our device state and initialize it */
 664
 665         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 666         if (dev == NULL) {
 667                 dev_err(&intf->dev, "Out of memory\n");
 668                 goto exit;
 669         }
 670         mutex_init(&dev->mutex);
 671         spin_lock_init(&dev->rbsl);
 672         dev->intf = intf;
 673         init_waitqueue_head(&dev->read_wait);
 674         init_waitqueue_head(&dev->write_wait);
 675
 676         /* workaround for early firmware versions on fast computers */
 677         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 678             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 679              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 680             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 681                 buffer = kmalloc(256, GFP_KERNEL);
 682                 if (buffer == NULL) {
 683                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 684                         goto error;
 685                 }
 686                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 687                 usb_string(udev, 255, buffer, 256);
 688                 kfree(buffer);
 689         }
 690
 691         iface_desc = intf->cur_altsetting;
 692
 693         /* set up the endpoint information */
 694         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 695                 endpoint = &iface_desc->endpoint[i].desc;
 696
 697                 if (usb_endpoint_is_int_in(endpoint))
 698                         dev->interrupt_in_endpoint = endpoint;
 699
 700                 if (usb_endpoint_is_int_out(endpoint))
 701                         dev->interrupt_out_endpoint = endpoint;
 702         }
 703         if (dev->interrupt_in_endpoint == NULL) {
 704                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 705                 goto error;
 706         }
 707         if (dev->interrupt_out_endpoint == NULL)
 708                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 709
 710         dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 711         dev->ring_buffer = kcalloc(ring_buffer_size,
 712                         sizeof(size_t) + dev->interrupt_in_endpoint_size,
 713                         GFP_KERNEL);
 714         if (!dev->ring_buffer) {
 715                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 716                 goto error;
 717         }
 718         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 719         if (!dev->interrupt_in_buffer) {
 720                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 721                 goto error;
 722         }
 723         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 724         if (!dev->interrupt_in_urb) {
 725                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 726                 goto error;
 727         }
 728         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
 729                                                                          udev->descriptor.bMaxPacketSize0;
 730         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 731         if (!dev->interrupt_out_buffer) {
 732                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 733                 goto error;
 734         }
 735         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 736         if (!dev->interrupt_out_urb) {
 737                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 738                 goto error;
 739         }
 740         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 741         if (dev->interrupt_out_endpoint)
 742                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 743
 744         /* we can register the device now, as it is ready */
 745         usb_set_intfdata(intf, dev);
 746
 747         retval = usb_register_dev(intf, &ld_usb_class);
 748         if (retval) {
 749                 /* something prevented us from registering this driver */
 750                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 751                 usb_set_intfdata(intf, NULL);
 752                 goto error;
 753         }
 754
 755         /* let the user know what node this device is now attached to */
 756         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 757                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 758
 759 exit:
 760         return retval;
 761
 762 error:
 763         ld_usb_delete(dev);
 764
 765         return retval;
 766 }
 767
 768 /**
 769  *      ld_usb_disconnect
 770  *
 771  *      Called by the usb core when the device is removed from the system.
 772  */
 773 static void ld_usb_disconnect(struct usb_interface *intf)
 774 {
 775         struct ld_usb *dev;
 776         int minor;
 777
 778         dev = usb_get_intfdata(intf);
 779         usb_set_intfdata(intf, NULL);
 780
 781         minor = intf->minor;
 782
 783         /* give back our minor */
 784         usb_deregister_dev(intf, &ld_usb_class);
 785
 786         usb_poison_urb(dev->interrupt_in_urb);
 787         usb_poison_urb(dev->interrupt_out_urb);
 788
 789         mutex_lock(&dev->mutex);
 790
 791         /* if the device is not opened, then we clean up right now */
 792         if (!dev->open_count) {
 793                 mutex_unlock(&dev->mutex);
 794                 ld_usb_delete(dev);
 795         } else {
 796                 dev->disconnected = 1;
 797                 /* wake up pollers */
 798                 wake_up_interruptible_all(&dev->read_wait);
 799                 wake_up_interruptible_all(&dev->write_wait);
 800                 mutex_unlock(&dev->mutex);
 801         }
 802
 803         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 804                  (minor - USB_LD_MINOR_BASE));
 805 }
 806
 807 /* usb specific object needed to register this driver with the usb subsystem */
 808 static struct usb_driver ld_usb_driver = {
 809         .name =         "ldusb",
 810         .probe =        ld_usb_probe,
 811         .disconnect =   ld_usb_disconnect,
 812         .id_table =     ld_usb_table,
 813 };
 814
 815 module_usb_driver(ld_usb_driver);
 816