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/init.h>
  28 #include <linux/slab.h>
  29 #include <linux/module.h>
  30 #include <linux/mutex.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/poll.h>
  36
  37 /* Define these values to match your devices */
  38 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  39 #define USB_DEVICE_ID_LD_CASSY          0x1000  /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */
  40 #define USB_DEVICE_ID_LD_CASSY2         0x1001  /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */
  41 #define USB_DEVICE_ID_LD_POCKETCASSY    0x1010  /* USB Product ID of Pocket-CASSY */
  42 #define USB_DEVICE_ID_LD_POCKETCASSY2   0x1011  /* USB Product ID of Pocket-CASSY 2 (reserved) */
  43 #define USB_DEVICE_ID_LD_MOBILECASSY    0x1020  /* USB Product ID of Mobile-CASSY */
  44 #define USB_DEVICE_ID_LD_MOBILECASSY2   0x1021  /* USB Product ID of Mobile-CASSY 2 (reserved) */
  45 #define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE      0x1031  /* USB Product ID of Micro-CASSY Voltage */
  46 #define USB_DEVICE_ID_LD_MICROCASSYCURRENT      0x1032  /* USB Product ID of Micro-CASSY Current */
  47 #define USB_DEVICE_ID_LD_MICROCASSYTIME         0x1033  /* USB Product ID of Micro-CASSY Time (reserved) */
  48 #define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE  0x1035  /* USB Product ID of Micro-CASSY Temperature */
  49 #define USB_DEVICE_ID_LD_MICROCASSYPH           0x1038  /* USB Product ID of Micro-CASSY pH */
  50 #define USB_DEVICE_ID_LD_JWM            0x1080  /* USB Product ID of Joule and Wattmeter */
  51 #define USB_DEVICE_ID_LD_DMMP           0x1081  /* USB Product ID of Digital Multimeter P (reserved) */
  52 #define USB_DEVICE_ID_LD_UMIP           0x1090  /* USB Product ID of UMI P */
  53 #define USB_DEVICE_ID_LD_UMIC           0x10A0  /* USB Product ID of UMI C */
  54 #define USB_DEVICE_ID_LD_UMIB           0x10B0  /* USB Product ID of UMI B */
  55 #define USB_DEVICE_ID_LD_XRAY           0x1100  /* USB Product ID of X-Ray Apparatus 55481 */
  56 #define USB_DEVICE_ID_LD_XRAY2          0x1101  /* USB Product ID of X-Ray Apparatus 554800 */
  57 #define USB_DEVICE_ID_LD_XRAYCT         0x1110  /* USB Product ID of X-Ray Apparatus CT 554821*/
  58 #define USB_DEVICE_ID_LD_VIDEOCOM       0x1200  /* USB Product ID of VideoCom */
  59 #define USB_DEVICE_ID_LD_MOTOR          0x1210  /* USB Product ID of Motor (reserved) */
  60 #define USB_DEVICE_ID_LD_COM3LAB        0x2000  /* USB Product ID of COM3LAB */
  61 #define USB_DEVICE_ID_LD_TELEPORT       0x2010  /* USB Product ID of Terminal Adapter */
  62 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
  63 #define USB_DEVICE_ID_LD_POWERCONTROL   0x2030  /* USB Product ID of Converter Control Unit */
  64 #define USB_DEVICE_ID_LD_MACHINETEST    0x2040  /* USB Product ID of Machine Test System */
  65 #define USB_DEVICE_ID_LD_MOSTANALYSER   0x2050  /* USB Product ID of MOST Protocol Analyser */
  66 #define USB_DEVICE_ID_LD_MOSTANALYSER2  0x2051  /* USB Product ID of MOST Protocol Analyser 2 */
  67 #define USB_DEVICE_ID_LD_ABSESP         0x2060  /* USB Product ID of ABS ESP */
  68 #define USB_DEVICE_ID_LD_AUTODATABUS    0x2070  /* USB Product ID of Automotive Data Buses */
  69 #define USB_DEVICE_ID_LD_MCT            0x2080  /* USB Product ID of Microcontroller technique */
  70 #define USB_DEVICE_ID_LD_HYBRID         0x2090  /* USB Product ID of Automotive Hybrid */
  71 #define USB_DEVICE_ID_LD_HEATCONTROL    0x20A0  /* USB Product ID of Heat control */
  72
  73 #define USB_VENDOR_ID_VERNIER           0x08f7
  74 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
  75 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  76 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  77 #define USB_DEVICE_ID_VERNIER_LCSPEC    0x0006
  78
  79 #ifdef CONFIG_USB_DYNAMIC_MINORS
  80 #define USB_LD_MINOR_BASE       0
  81 #else
  82 #define USB_LD_MINOR_BASE       176
  83 #endif
  84
  85 /* table of devices that work with this driver */
  86 static const struct usb_device_id ld_usb_table[] = {
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) },
  89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  90         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) },
  91         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  92         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) },
  93         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) },
  94         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) },
  95         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) },
  96         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) },
  97         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) },
  98         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  99         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
 100         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
 101         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) },
 102         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) },
 103         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) },
 104         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
 105         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
 106         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) },
 107         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
 108         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
 109         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
 110         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
 111         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
 112         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) },
 113         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) },
 114         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) },
 115         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) },
 116         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) },
 117         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) },
 118         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) },
 119         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
 120         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
 121         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
 122         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) },
 123         { }                                     /* Terminating entry */
 124 };
 125 MODULE_DEVICE_TABLE(usb, ld_usb_table);
 126 MODULE_VERSION("V0.14");
 127 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 128 MODULE_DESCRIPTION("LD USB Driver");
 129 MODULE_LICENSE("GPL");
 130 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 131
 132 #ifdef CONFIG_USB_DEBUG
 133         static int debug = 1;
 134 #else
 135         static int debug = 0;
 136 #endif
 137
 138 /* Use our own dbg macro */
 139 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 140
 141 /* Module parameters */
 142 module_param(debug, int, S_IRUGO | S_IWUSR);
 143 MODULE_PARM_DESC(debug, "Debug enabled or not");
 144
 145 /* All interrupt in transfers are collected in a ring buffer to
 146  * avoid racing conditions and get better performance of the driver.
 147  */
 148 static int ring_buffer_size = 128;
 149 module_param(ring_buffer_size, int, 0);
 150 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 151
 152 /* The write_buffer can contain more than one interrupt out transfer.
 153  */
 154 static int write_buffer_size = 10;
 155 module_param(write_buffer_size, int, 0);
 156 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 157
 158 /* As of kernel version 2.6.4 ehci-hcd uses an
 159  * "only one interrupt transfer per frame" shortcut
 160  * to simplify the scheduling of periodic transfers.
 161  * This conflicts with our standard 1ms intervals for in and out URBs.
 162  * We use default intervals of 2ms for in and 2ms for out transfers,
 163  * which should be fast enough.
 164  * Increase the interval to allow more devices that do interrupt transfers,
 165  * or set to 1 to use the standard interval from the endpoint descriptors.
 166  */
 167 static int min_interrupt_in_interval = 2;
 168 module_param(min_interrupt_in_interval, int, 0);
 169 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 170
 171 static int min_interrupt_out_interval = 2;
 172 module_param(min_interrupt_out_interval, int, 0);
 173 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 174
 175 /* Structure to hold all of our device specific stuff */
 176 struct ld_usb {
 177         struct mutex            mutex;          /* locks this structure */
 178         struct usb_interface*   intf;           /* save off the usb interface pointer */
 179
 180         int                     open_count;     /* number of times this port has been opened */
 181
 182         char*                   ring_buffer;
 183         unsigned int            ring_head;
 184         unsigned int            ring_tail;
 185
 186         wait_queue_head_t       read_wait;
 187         wait_queue_head_t       write_wait;
 188
 189         char*                   interrupt_in_buffer;
 190         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 191         struct urb*             interrupt_in_urb;
 192         int                     interrupt_in_interval;
 193         size_t                  interrupt_in_endpoint_size;
 194         int                     interrupt_in_running;
 195         int                     interrupt_in_done;
 196         int                     buffer_overflow;
 197         spinlock_t              rbsl;
 198
 199         char*                   interrupt_out_buffer;
 200         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 201         struct urb*             interrupt_out_urb;
 202         int                     interrupt_out_interval;
 203         size_t                  interrupt_out_endpoint_size;
 204         int                     interrupt_out_busy;
 205 };
 206
 207 static struct usb_driver ld_usb_driver;
 208
 209 /**
 210  *      ld_usb_abort_transfers
 211  *      aborts transfers and frees associated data structures
 212  */
 213 static void ld_usb_abort_transfers(struct ld_usb *dev)
 214 {
 215         /* shutdown transfer */
 216         if (dev->interrupt_in_running) {
 217                 dev->interrupt_in_running = 0;
 218                 if (dev->intf)
 219                         usb_kill_urb(dev->interrupt_in_urb);
 220         }
 221         if (dev->interrupt_out_busy)
 222                 if (dev->intf)
 223                         usb_kill_urb(dev->interrupt_out_urb);
 224 }
 225
 226 /**
 227  *      ld_usb_delete
 228  */
 229 static void ld_usb_delete(struct ld_usb *dev)
 230 {
 231         ld_usb_abort_transfers(dev);
 232
 233         /* free data structures */
 234         usb_free_urb(dev->interrupt_in_urb);
 235         usb_free_urb(dev->interrupt_out_urb);
 236         kfree(dev->ring_buffer);
 237         kfree(dev->interrupt_in_buffer);
 238         kfree(dev->interrupt_out_buffer);
 239         kfree(dev);
 240 }
 241
 242 /**
 243  *      ld_usb_interrupt_in_callback
 244  */
 245 static void ld_usb_interrupt_in_callback(struct urb *urb)
 246 {
 247         struct ld_usb *dev = urb->context;
 248         size_t *actual_buffer;
 249         unsigned int next_ring_head;
 250         int status = urb->status;
 251         int retval;
 252
 253         if (status) {
 254                 if (status == -ENOENT ||
 255                     status == -ECONNRESET ||
 256                     status == -ESHUTDOWN) {
 257                         goto exit;
 258                 } else {
 259                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 260                                  __func__, status);
 261                         spin_lock(&dev->rbsl);
 262                         goto resubmit; /* maybe we can recover */
 263                 }
 264         }
 265
 266         spin_lock(&dev->rbsl);
 267         if (urb->actual_length > 0) {
 268                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 269                 if (next_ring_head != dev->ring_tail) {
 270                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 271                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 272                         *actual_buffer = urb->actual_length;
 273                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 274                         dev->ring_head = next_ring_head;
 275                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
 276                                  __func__, urb->actual_length);
 277                 } else {
 278                         dev_warn(&dev->intf->dev,
 279                                  "Ring buffer overflow, %d bytes dropped\n",
 280                                  urb->actual_length);
 281                         dev->buffer_overflow = 1;
 282                 }
 283         }
 284
 285 resubmit:
 286         /* resubmit if we're still running */
 287         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
 288                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 289                 if (retval) {
 290                         dev_err(&dev->intf->dev,
 291                                 "usb_submit_urb failed (%d)\n", retval);
 292                         dev->buffer_overflow = 1;
 293                 }
 294         }
 295         spin_unlock(&dev->rbsl);
 296 exit:
 297         dev->interrupt_in_done = 1;
 298         wake_up_interruptible(&dev->read_wait);
 299 }
 300
 301 /**
 302  *      ld_usb_interrupt_out_callback
 303  */
 304 static void ld_usb_interrupt_out_callback(struct urb *urb)
 305 {
 306         struct ld_usb *dev = urb->context;
 307         int status = urb->status;
 308
 309         /* sync/async unlink faults aren't errors */
 310         if (status && !(status == -ENOENT ||
 311                         status == -ECONNRESET ||
 312                         status == -ESHUTDOWN))
 313                 dbg_info(&dev->intf->dev,
 314                          "%s - nonzero write interrupt status received: %d\n",
 315                          __func__, status);
 316
 317         dev->interrupt_out_busy = 0;
 318         wake_up_interruptible(&dev->write_wait);
 319 }
 320
 321 /**
 322  *      ld_usb_open
 323  */
 324 static int ld_usb_open(struct inode *inode, struct file *file)
 325 {
 326         struct ld_usb *dev;
 327         int subminor;
 328         int retval;
 329         struct usb_interface *interface;
 330
 331         nonseekable_open(inode, file);
 332         subminor = iminor(inode);
 333
 334         interface = usb_find_interface(&ld_usb_driver, subminor);
 335
 336         if (!interface) {
 337                 err("%s - error, can't find device for minor %d\n",
 338                      __func__, subminor);
 339                 return -ENODEV;
 340         }
 341
 342         dev = usb_get_intfdata(interface);
 343
 344         if (!dev)
 345                 return -ENODEV;
 346
 347         /* lock this device */
 348         if (mutex_lock_interruptible(&dev->mutex))
 349                 return -ERESTARTSYS;
 350
 351         /* allow opening only once */
 352         if (dev->open_count) {
 353                 retval = -EBUSY;
 354                 goto unlock_exit;
 355         }
 356         dev->open_count = 1;
 357
 358         /* initialize in direction */
 359         dev->ring_head = 0;
 360         dev->ring_tail = 0;
 361         dev->buffer_overflow = 0;
 362         usb_fill_int_urb(dev->interrupt_in_urb,
 363                          interface_to_usbdev(interface),
 364                          usb_rcvintpipe(interface_to_usbdev(interface),
 365                                         dev->interrupt_in_endpoint->bEndpointAddress),
 366                          dev->interrupt_in_buffer,
 367                          dev->interrupt_in_endpoint_size,
 368                          ld_usb_interrupt_in_callback,
 369                          dev,
 370                          dev->interrupt_in_interval);
 371
 372         dev->interrupt_in_running = 1;
 373         dev->interrupt_in_done = 0;
 374
 375         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 376         if (retval) {
 377                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 378                 dev->interrupt_in_running = 0;
 379                 dev->open_count = 0;
 380                 goto unlock_exit;
 381         }
 382
 383         /* save device in the file's private structure */
 384         file->private_data = dev;
 385
 386 unlock_exit:
 387         mutex_unlock(&dev->mutex);
 388
 389         return retval;
 390 }
 391
 392 /**
 393  *      ld_usb_release
 394  */
 395 static int ld_usb_release(struct inode *inode, struct file *file)
 396 {
 397         struct ld_usb *dev;
 398         int retval = 0;
 399
 400         dev = file->private_data;
 401
 402         if (dev == NULL) {
 403                 retval = -ENODEV;
 404                 goto exit;
 405         }
 406
 407         if (mutex_lock_interruptible(&dev->mutex)) {
 408                 retval = -ERESTARTSYS;
 409                 goto exit;
 410         }
 411
 412         if (dev->open_count != 1) {
 413                 retval = -ENODEV;
 414                 goto unlock_exit;
 415         }
 416         if (dev->intf == NULL) {
 417                 /* the device was unplugged before the file was released */
 418                 mutex_unlock(&dev->mutex);
 419                 /* unlock here as ld_usb_delete frees dev */
 420                 ld_usb_delete(dev);
 421                 goto exit;
 422         }
 423
 424         /* wait until write transfer is finished */
 425         if (dev->interrupt_out_busy)
 426                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 427         ld_usb_abort_transfers(dev);
 428         dev->open_count = 0;
 429
 430 unlock_exit:
 431         mutex_unlock(&dev->mutex);
 432
 433 exit:
 434         return retval;
 435 }
 436
 437 /**
 438  *      ld_usb_poll
 439  */
 440 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 441 {
 442         struct ld_usb *dev;
 443         unsigned int mask = 0;
 444
 445         dev = file->private_data;
 446
 447         if (!dev->intf)
 448                 return POLLERR | POLLHUP;
 449
 450         poll_wait(file, &dev->read_wait, wait);
 451         poll_wait(file, &dev->write_wait, wait);
 452
 453         if (dev->ring_head != dev->ring_tail)
 454                 mask |= POLLIN | POLLRDNORM;
 455         if (!dev->interrupt_out_busy)
 456                 mask |= POLLOUT | POLLWRNORM;
 457
 458         return mask;
 459 }
 460
 461 /**
 462  *      ld_usb_read
 463  */
 464 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 465                            loff_t *ppos)
 466 {
 467         struct ld_usb *dev;
 468         size_t *actual_buffer;
 469         size_t bytes_to_read;
 470         int retval = 0;
 471         int rv;
 472
 473         dev = file->private_data;
 474
 475         /* verify that we actually have some data to read */
 476         if (count == 0)
 477                 goto exit;
 478
 479         /* lock this object */
 480         if (mutex_lock_interruptible(&dev->mutex)) {
 481                 retval = -ERESTARTSYS;
 482                 goto exit;
 483         }
 484
 485         /* verify that the device wasn't unplugged */
 486         if (dev->intf == NULL) {
 487                 retval = -ENODEV;
 488                 err("No device or device unplugged %d\n", retval);
 489                 goto unlock_exit;
 490         }
 491
 492         /* wait for data */
 493         spin_lock_irq(&dev->rbsl);
 494         if (dev->ring_head == dev->ring_tail) {
 495                 dev->interrupt_in_done = 0;
 496                 spin_unlock_irq(&dev->rbsl);
 497                 if (file->f_flags & O_NONBLOCK) {
 498                         retval = -EAGAIN;
 499                         goto unlock_exit;
 500                 }
 501                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 502                 if (retval < 0)
 503                         goto unlock_exit;
 504         } else {
 505                 spin_unlock_irq(&dev->rbsl);
 506         }
 507
 508         /* actual_buffer contains actual_length + interrupt_in_buffer */
 509         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 510         bytes_to_read = min(count, *actual_buffer);
 511         if (bytes_to_read < *actual_buffer)
 512                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 513                          *actual_buffer-bytes_to_read);
 514
 515         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 516         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 517                 retval = -EFAULT;
 518                 goto unlock_exit;
 519         }
 520         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 521
 522         retval = bytes_to_read;
 523
 524         spin_lock_irq(&dev->rbsl);
 525         if (dev->buffer_overflow) {
 526                 dev->buffer_overflow = 0;
 527                 spin_unlock_irq(&dev->rbsl);
 528                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 529                 if (rv < 0)
 530                         dev->buffer_overflow = 1;
 531         } else {
 532                 spin_unlock_irq(&dev->rbsl);
 533         }
 534
 535 unlock_exit:
 536         /* unlock the device */
 537         mutex_unlock(&dev->mutex);
 538
 539 exit:
 540         return retval;
 541 }
 542
 543 /**
 544  *      ld_usb_write
 545  */
 546 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 547                             size_t count, loff_t *ppos)
 548 {
 549         struct ld_usb *dev;
 550         size_t bytes_to_write;
 551         int retval = 0;
 552
 553         dev = file->private_data;
 554
 555         /* verify that we actually have some data to write */
 556         if (count == 0)
 557                 goto exit;
 558
 559         /* lock this object */
 560         if (mutex_lock_interruptible(&dev->mutex)) {
 561                 retval = -ERESTARTSYS;
 562                 goto exit;
 563         }
 564
 565         /* verify that the device wasn't unplugged */
 566         if (dev->intf == NULL) {
 567                 retval = -ENODEV;
 568                 err("No device or device unplugged %d\n", retval);
 569                 goto unlock_exit;
 570         }
 571
 572         /* wait until previous transfer is finished */
 573         if (dev->interrupt_out_busy) {
 574                 if (file->f_flags & O_NONBLOCK) {
 575                         retval = -EAGAIN;
 576                         goto unlock_exit;
 577                 }
 578                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 579                 if (retval < 0) {
 580                         goto unlock_exit;
 581                 }
 582         }
 583
 584         /* write the data into interrupt_out_buffer from userspace */
 585         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 586         if (bytes_to_write < count)
 587                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 588         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __func__, count, bytes_to_write);
 589
 590         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 591                 retval = -EFAULT;
 592                 goto unlock_exit;
 593         }
 594
 595         if (dev->interrupt_out_endpoint == NULL) {
 596                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 597                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 598                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 599                                          9,
 600                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 601                                          1 << 8, 0,
 602                                          dev->interrupt_out_buffer,
 603                                          bytes_to_write,
 604                                          USB_CTRL_SET_TIMEOUT * HZ);
 605                 if (retval < 0)
 606                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
 607                 goto unlock_exit;
 608         }
 609
 610         /* send off the urb */
 611         usb_fill_int_urb(dev->interrupt_out_urb,
 612                          interface_to_usbdev(dev->intf),
 613                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 614                                         dev->interrupt_out_endpoint->bEndpointAddress),
 615                          dev->interrupt_out_buffer,
 616                          bytes_to_write,
 617                          ld_usb_interrupt_out_callback,
 618                          dev,
 619                          dev->interrupt_out_interval);
 620
 621         dev->interrupt_out_busy = 1;
 622         wmb();
 623
 624         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 625         if (retval) {
 626                 dev->interrupt_out_busy = 0;
 627                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 628                 goto unlock_exit;
 629         }
 630         retval = bytes_to_write;
 631
 632 unlock_exit:
 633         /* unlock the device */
 634         mutex_unlock(&dev->mutex);
 635
 636 exit:
 637         return retval;
 638 }
 639
 640 /* file operations needed when we register this driver */
 641 static const struct file_operations ld_usb_fops = {
 642         .owner =        THIS_MODULE,
 643         .read  =        ld_usb_read,
 644         .write =        ld_usb_write,
 645         .open =         ld_usb_open,
 646         .release =      ld_usb_release,
 647         .poll =         ld_usb_poll,
 648         .llseek =       no_llseek,
 649 };
 650
 651 /*
 652  * usb class driver info in order to get a minor number from the usb core,
 653  * and to have the device registered with the driver core
 654  */
 655 static struct usb_class_driver ld_usb_class = {
 656         .name =         "ldusb%d",
 657         .fops =         &ld_usb_fops,
 658         .minor_base =   USB_LD_MINOR_BASE,
 659 };
 660
 661 /**
 662  *      ld_usb_probe
 663  *
 664  *      Called by the usb core when a new device is connected that it thinks
 665  *      this driver might be interested in.
 666  */
 667 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 668 {
 669         struct usb_device *udev = interface_to_usbdev(intf);
 670         struct ld_usb *dev = NULL;
 671         struct usb_host_interface *iface_desc;
 672         struct usb_endpoint_descriptor *endpoint;
 673         char *buffer;
 674         int i;
 675         int retval = -ENOMEM;
 676
 677         /* allocate memory for our device state and initialize it */
 678
 679         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 680         if (dev == NULL) {
 681                 dev_err(&intf->dev, "Out of memory\n");
 682                 goto exit;
 683         }
 684         mutex_init(&dev->mutex);
 685         spin_lock_init(&dev->rbsl);
 686         dev->intf = intf;
 687         init_waitqueue_head(&dev->read_wait);
 688         init_waitqueue_head(&dev->write_wait);
 689
 690         /* workaround for early firmware versions on fast computers */
 691         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 692             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 693              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 694             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 695                 buffer = kmalloc(256, GFP_KERNEL);
 696                 if (buffer == NULL) {
 697                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 698                         goto error;
 699                 }
 700                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 701                 usb_string(udev, 255, buffer, 256);
 702                 kfree(buffer);
 703         }
 704
 705         iface_desc = intf->cur_altsetting;
 706
 707         /* set up the endpoint information */
 708         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 709                 endpoint = &iface_desc->endpoint[i].desc;
 710
 711                 if (usb_endpoint_is_int_in(endpoint))
 712                         dev->interrupt_in_endpoint = endpoint;
 713
 714                 if (usb_endpoint_is_int_out(endpoint))
 715                         dev->interrupt_out_endpoint = endpoint;
 716         }
 717         if (dev->interrupt_in_endpoint == NULL) {
 718                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 719                 goto error;
 720         }
 721         if (dev->interrupt_out_endpoint == NULL)
 722                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 723
 724         dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 725         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 726         if (!dev->ring_buffer) {
 727                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 728                 goto error;
 729         }
 730         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 731         if (!dev->interrupt_in_buffer) {
 732                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 733                 goto error;
 734         }
 735         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 736         if (!dev->interrupt_in_urb) {
 737                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 738                 goto error;
 739         }
 740         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
 741                                                                          udev->descriptor.bMaxPacketSize0;
 742         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 743         if (!dev->interrupt_out_buffer) {
 744                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 745                 goto error;
 746         }
 747         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 748         if (!dev->interrupt_out_urb) {
 749                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 750                 goto error;
 751         }
 752         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 753         if (dev->interrupt_out_endpoint)
 754                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 755
 756         /* we can register the device now, as it is ready */
 757         usb_set_intfdata(intf, dev);
 758
 759         retval = usb_register_dev(intf, &ld_usb_class);
 760         if (retval) {
 761                 /* something prevented us from registering this driver */
 762                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 763                 usb_set_intfdata(intf, NULL);
 764                 goto error;
 765         }
 766
 767         /* let the user know what node this device is now attached to */
 768         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 769                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 770
 771 exit:
 772         return retval;
 773
 774 error:
 775         ld_usb_delete(dev);
 776
 777         return retval;
 778 }
 779
 780 /**
 781  *      ld_usb_disconnect
 782  *
 783  *      Called by the usb core when the device is removed from the system.
 784  */
 785 static void ld_usb_disconnect(struct usb_interface *intf)
 786 {
 787         struct ld_usb *dev;
 788         int minor;
 789
 790         dev = usb_get_intfdata(intf);
 791         usb_set_intfdata(intf, NULL);
 792
 793         minor = intf->minor;
 794
 795         /* give back our minor */
 796         usb_deregister_dev(intf, &ld_usb_class);
 797
 798         mutex_lock(&dev->mutex);
 799
 800         /* if the device is not opened, then we clean up right now */
 801         if (!dev->open_count) {
 802                 mutex_unlock(&dev->mutex);
 803                 ld_usb_delete(dev);
 804         } else {
 805                 dev->intf = NULL;
 806                 /* wake up pollers */
 807                 wake_up_interruptible_all(&dev->read_wait);
 808                 wake_up_interruptible_all(&dev->write_wait);
 809                 mutex_unlock(&dev->mutex);
 810         }
 811
 812         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 813                  (minor - USB_LD_MINOR_BASE));
 814 }
 815
 816 /* usb specific object needed to register this driver with the usb subsystem */
 817 static struct usb_driver ld_usb_driver = {
 818         .name =         "ldusb",
 819         .probe =        ld_usb_probe,
 820         .disconnect =   ld_usb_disconnect,
 821         .id_table =     ld_usb_table,
 822 };
 823
 824 /**
 825  *      ld_usb_init
 826  */
 827 static int __init ld_usb_init(void)
 828 {
 829         int retval;
 830
 831         /* register this driver with the USB subsystem */
 832         retval = usb_register(&ld_usb_driver);
 833         if (retval)
 834                 err("usb_register failed for the %s driver. Error number %d\n", __FILE__, retval);
 835
 836         return retval;
 837 }
 838
 839 /**
 840  *      ld_usb_exit
 841  */
 842 static void __exit ld_usb_exit(void)
 843 {
 844         /* deregister this driver with the USB subsystem */
 845         usb_deregister(&ld_usb_driver);
 846 }
 847
 848 module_init(ld_usb_init);
 849 module_exit(ld_usb_exit);
 850