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         if (mutex_lock_interruptible(&dev->mutex)) {
 388                 retval = -ERESTARTSYS;
 389                 goto exit;
 390         }
 391
 392         if (dev->open_count != 1) {
 393                 retval = -ENODEV;
 394                 goto unlock_exit;
 395         }
 396         if (dev->disconnected) {
 397                 /* the device was unplugged before the file was released */
 398                 mutex_unlock(&dev->mutex);
 399                 /* unlock here as ld_usb_delete frees dev */
 400                 ld_usb_delete(dev);
 401                 goto exit;
 402         }
 403
 404         /* wait until write transfer is finished */
 405         if (dev->interrupt_out_busy)
 406                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 407         ld_usb_abort_transfers(dev);
 408         dev->open_count = 0;
 409
 410 unlock_exit:
 411         mutex_unlock(&dev->mutex);
 412
 413 exit:
 414         return retval;
 415 }
 416
 417 /**
 418  *      ld_usb_poll
 419  */
 420 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 421 {
 422         struct ld_usb *dev;
 423         unsigned int mask = 0;
 424
 425         dev = file->private_data;
 426
 427         if (dev->disconnected)
 428                 return POLLERR | POLLHUP;
 429
 430         poll_wait(file, &dev->read_wait, wait);
 431         poll_wait(file, &dev->write_wait, wait);
 432
 433         if (dev->ring_head != dev->ring_tail)
 434                 mask |= POLLIN | POLLRDNORM;
 435         if (!dev->interrupt_out_busy)
 436                 mask |= POLLOUT | POLLWRNORM;
 437
 438         return mask;
 439 }
 440
 441 /**
 442  *      ld_usb_read
 443  */
 444 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 445                            loff_t *ppos)
 446 {
 447         struct ld_usb *dev;
 448         size_t *actual_buffer;
 449         size_t bytes_to_read;
 450         int retval = 0;
 451         int rv;
 452
 453         dev = file->private_data;
 454
 455         /* verify that we actually have some data to read */
 456         if (count == 0)
 457                 goto exit;
 458
 459         /* lock this object */
 460         if (mutex_lock_interruptible(&dev->mutex)) {
 461                 retval = -ERESTARTSYS;
 462                 goto exit;
 463         }
 464
 465         /* verify that the device wasn't unplugged */
 466         if (dev->disconnected) {
 467                 retval = -ENODEV;
 468                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 469                 goto unlock_exit;
 470         }
 471
 472         /* wait for data */
 473         spin_lock_irq(&dev->rbsl);
 474         if (dev->ring_head == dev->ring_tail) {
 475                 dev->interrupt_in_done = 0;
 476                 spin_unlock_irq(&dev->rbsl);
 477                 if (file->f_flags & O_NONBLOCK) {
 478                         retval = -EAGAIN;
 479                         goto unlock_exit;
 480                 }
 481                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 482                 if (retval < 0)
 483                         goto unlock_exit;
 484         } else {
 485                 spin_unlock_irq(&dev->rbsl);
 486         }
 487
 488         /* actual_buffer contains actual_length + interrupt_in_buffer */
 489         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 490         bytes_to_read = min(count, *actual_buffer);
 491         if (bytes_to_read < *actual_buffer)
 492                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 493                          *actual_buffer-bytes_to_read);
 494
 495         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 496         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 497                 retval = -EFAULT;
 498                 goto unlock_exit;
 499         }
 500         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 501
 502         retval = bytes_to_read;
 503
 504         spin_lock_irq(&dev->rbsl);
 505         if (dev->buffer_overflow) {
 506                 dev->buffer_overflow = 0;
 507                 spin_unlock_irq(&dev->rbsl);
 508                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 509                 if (rv < 0)
 510                         dev->buffer_overflow = 1;
 511         } else {
 512                 spin_unlock_irq(&dev->rbsl);
 513         }
 514
 515 unlock_exit:
 516         /* unlock the device */
 517         mutex_unlock(&dev->mutex);
 518
 519 exit:
 520         return retval;
 521 }
 522
 523 /**
 524  *      ld_usb_write
 525  */
 526 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 527                             size_t count, loff_t *ppos)
 528 {
 529         struct ld_usb *dev;
 530         size_t bytes_to_write;
 531         int retval = 0;
 532
 533         dev = file->private_data;
 534
 535         /* verify that we actually have some data to write */
 536         if (count == 0)
 537                 goto exit;
 538
 539         /* lock this object */
 540         if (mutex_lock_interruptible(&dev->mutex)) {
 541                 retval = -ERESTARTSYS;
 542                 goto exit;
 543         }
 544
 545         /* verify that the device wasn't unplugged */
 546         if (dev->disconnected) {
 547                 retval = -ENODEV;
 548                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 549                 goto unlock_exit;
 550         }
 551
 552         /* wait until previous transfer is finished */
 553         if (dev->interrupt_out_busy) {
 554                 if (file->f_flags & O_NONBLOCK) {
 555                         retval = -EAGAIN;
 556                         goto unlock_exit;
 557                 }
 558                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 559                 if (retval < 0) {
 560                         goto unlock_exit;
 561                 }
 562         }
 563
 564         /* write the data into interrupt_out_buffer from userspace */
 565         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 566         if (bytes_to_write < count)
 567                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 568         dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
 569                 __func__, count, bytes_to_write);
 570
 571         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 572                 retval = -EFAULT;
 573                 goto unlock_exit;
 574         }
 575
 576         if (dev->interrupt_out_endpoint == NULL) {
 577                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 578                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 579                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 580                                          9,
 581                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 582                                          1 << 8, 0,
 583                                          dev->interrupt_out_buffer,
 584                                          bytes_to_write,
 585                                          USB_CTRL_SET_TIMEOUT * HZ);
 586                 if (retval < 0)
 587                         dev_err(&dev->intf->dev,
 588                                 "Couldn't submit HID_REQ_SET_REPORT %d\n",
 589                                 retval);
 590                 goto unlock_exit;
 591         }
 592
 593         /* send off the urb */
 594         usb_fill_int_urb(dev->interrupt_out_urb,
 595                          interface_to_usbdev(dev->intf),
 596                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 597                                         dev->interrupt_out_endpoint->bEndpointAddress),
 598                          dev->interrupt_out_buffer,
 599                          bytes_to_write,
 600                          ld_usb_interrupt_out_callback,
 601                          dev,
 602                          dev->interrupt_out_interval);
 603
 604         dev->interrupt_out_busy = 1;
 605         wmb();
 606
 607         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 608         if (retval) {
 609                 dev->interrupt_out_busy = 0;
 610                 dev_err(&dev->intf->dev,
 611                         "Couldn't submit interrupt_out_urb %d\n", retval);
 612                 goto unlock_exit;
 613         }
 614         retval = bytes_to_write;
 615
 616 unlock_exit:
 617         /* unlock the device */
 618         mutex_unlock(&dev->mutex);
 619
 620 exit:
 621         return retval;
 622 }
 623
 624 /* file operations needed when we register this driver */
 625 static const struct file_operations ld_usb_fops = {
 626         .owner =        THIS_MODULE,
 627         .read  =        ld_usb_read,
 628         .write =        ld_usb_write,
 629         .open =         ld_usb_open,
 630         .release =      ld_usb_release,
 631         .poll =         ld_usb_poll,
 632         .llseek =       no_llseek,
 633 };
 634
 635 /*
 636  * usb class driver info in order to get a minor number from the usb core,
 637  * and to have the device registered with the driver core
 638  */
 639 static struct usb_class_driver ld_usb_class = {
 640         .name =         "ldusb%d",
 641         .fops =         &ld_usb_fops,
 642         .minor_base =   USB_LD_MINOR_BASE,
 643 };
 644
 645 /**
 646  *      ld_usb_probe
 647  *
 648  *      Called by the usb core when a new device is connected that it thinks
 649  *      this driver might be interested in.
 650  */
 651 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 652 {
 653         struct usb_device *udev = interface_to_usbdev(intf);
 654         struct ld_usb *dev = NULL;
 655         struct usb_host_interface *iface_desc;
 656         struct usb_endpoint_descriptor *endpoint;
 657         char *buffer;
 658         int i;
 659         int retval = -ENOMEM;
 660
 661         /* allocate memory for our device state and initialize it */
 662
 663         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 664         if (dev == NULL) {
 665                 dev_err(&intf->dev, "Out of memory\n");
 666                 goto exit;
 667         }
 668         mutex_init(&dev->mutex);
 669         spin_lock_init(&dev->rbsl);
 670         dev->intf = intf;
 671         init_waitqueue_head(&dev->read_wait);
 672         init_waitqueue_head(&dev->write_wait);
 673
 674         /* workaround for early firmware versions on fast computers */
 675         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 676             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 677              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 678             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 679                 buffer = kmalloc(256, GFP_KERNEL);
 680                 if (buffer == NULL) {
 681                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 682                         goto error;
 683                 }
 684                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 685                 usb_string(udev, 255, buffer, 256);
 686                 kfree(buffer);
 687         }
 688
 689         iface_desc = intf->cur_altsetting;
 690
 691         /* set up the endpoint information */
 692         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 693                 endpoint = &iface_desc->endpoint[i].desc;
 694
 695                 if (usb_endpoint_is_int_in(endpoint))
 696                         dev->interrupt_in_endpoint = endpoint;
 697
 698                 if (usb_endpoint_is_int_out(endpoint))
 699                         dev->interrupt_out_endpoint = endpoint;
 700         }
 701         if (dev->interrupt_in_endpoint == NULL) {
 702                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 703                 goto error;
 704         }
 705         if (dev->interrupt_out_endpoint == NULL)
 706                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 707
 708         dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 709         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 710         if (!dev->ring_buffer) {
 711                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 712                 goto error;
 713         }
 714         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 715         if (!dev->interrupt_in_buffer) {
 716                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 717                 goto error;
 718         }
 719         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 720         if (!dev->interrupt_in_urb) {
 721                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 722                 goto error;
 723         }
 724         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
 725                                                                          udev->descriptor.bMaxPacketSize0;
 726         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 727         if (!dev->interrupt_out_buffer) {
 728                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 729                 goto error;
 730         }
 731         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 732         if (!dev->interrupt_out_urb) {
 733                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 734                 goto error;
 735         }
 736         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 737         if (dev->interrupt_out_endpoint)
 738                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 739
 740         /* we can register the device now, as it is ready */
 741         usb_set_intfdata(intf, dev);
 742
 743         retval = usb_register_dev(intf, &ld_usb_class);
 744         if (retval) {
 745                 /* something prevented us from registering this driver */
 746                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 747                 usb_set_intfdata(intf, NULL);
 748                 goto error;
 749         }
 750
 751         /* let the user know what node this device is now attached to */
 752         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 753                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 754
 755 exit:
 756         return retval;
 757
 758 error:
 759         ld_usb_delete(dev);
 760
 761         return retval;
 762 }
 763
 764 /**
 765  *      ld_usb_disconnect
 766  *
 767  *      Called by the usb core when the device is removed from the system.
 768  */
 769 static void ld_usb_disconnect(struct usb_interface *intf)
 770 {
 771         struct ld_usb *dev;
 772         int minor;
 773
 774         dev = usb_get_intfdata(intf);
 775         usb_set_intfdata(intf, NULL);
 776
 777         minor = intf->minor;
 778
 779         /* give back our minor */
 780         usb_deregister_dev(intf, &ld_usb_class);
 781
 782         usb_poison_urb(dev->interrupt_in_urb);
 783         usb_poison_urb(dev->interrupt_out_urb);
 784
 785         mutex_lock(&dev->mutex);
 786
 787         /* if the device is not opened, then we clean up right now */
 788         if (!dev->open_count) {
 789                 mutex_unlock(&dev->mutex);
 790                 ld_usb_delete(dev);
 791         } else {
 792                 dev->disconnected = 1;
 793                 /* wake up pollers */
 794                 wake_up_interruptible_all(&dev->read_wait);
 795                 wake_up_interruptible_all(&dev->write_wait);
 796                 mutex_unlock(&dev->mutex);
 797         }
 798
 799         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 800                  (minor - USB_LD_MINOR_BASE));
 801 }
 802
 803 /* usb specific object needed to register this driver with the usb subsystem */
 804 static struct usb_driver ld_usb_driver = {
 805         .name =         "ldusb",
 806         .probe =        ld_usb_probe,
 807         .disconnect =   ld_usb_disconnect,
 808         .id_table =     ld_usb_table,
 809 };
 810
 811 module_usb_driver(ld_usb_driver);
 812