LXR linux/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 */
  86static 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};
 125MODULE_DEVICE_TABLE(usb, ld_usb_table);
 126MODULE_VERSION("V0.14");
 127MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 128MODULE_DESCRIPTION("LD USB Driver");
 129MODULE_LICENSE("GPL");
 130MODULE_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 */
 142module_param(debug, int, S_IRUGO | S_IWUSR);
 143MODULE_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 */
 148static int ring_buffer_size = 128;
 149module_param(ring_buffer_size, int, 0);
 150MODULE_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 */
 154static int write_buffer_size = 10;
 155module_param(write_buffer_size, int, 0);
 156MODULE_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 */
 167static int min_interrupt_in_interval = 2;
 168module_param(min_interrupt_in_interval, int, 0);
 169MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 170
 171static int min_interrupt_out_interval = 2;
 172module_param(min_interrupt_out_interval, int, 0);
 173MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 174
 175/* Structure to hold all of our device specific stuff */
 176struct 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
 207static struct usb_driver ld_usb_driver;
 208
 209/**
 210 *      ld_usb_abort_transfers
 211 *      aborts transfers and frees associated data structures
 212 */
 213static 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 */
 229static 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 */
 245static 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
 285resubmit:
 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);
 296exit:
 297        dev->interrupt_in_done = 1;
 298        wake_up_interruptible(&dev->read_wait);
 299}
 300
 301/**
 302 *      ld_usb_interrupt_out_callback
 303 */
 304static 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 */
 324static 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                printk(KERN_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
 386unlock_exit:
 387        mutex_unlock(&dev->mutex);
 388
 389        return retval;
 390}
 391
 392/**
 393 *      ld_usb_release
 394 */
 395static 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
 430unlock_exit:
 431        mutex_unlock(&dev->mutex);
 432
 433exit:
 434        return retval;
 435}
 436
 437/**
 438 *      ld_usb_poll
 439 */
 440static 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 */
 464static 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                printk(KERN_ERR "ldusb: 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
 535unlock_exit:
 536        /* unlock the device */
 537        mutex_unlock(&dev->mutex);
 538
 539exit:
 540        return retval;
 541}
 542
 543/**
 544 *      ld_usb_write
 545 */
 546static 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                printk(KERN_ERR "ldusb: 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                        dev_err(&dev->intf->dev,
 607                                "Couldn't submit HID_REQ_SET_REPORT %d\n",
 608                                retval);
 609                goto unlock_exit;
 610        }
 611
 612        /* send off the urb */
 613        usb_fill_int_urb(dev->interrupt_out_urb,
 614                         interface_to_usbdev(dev->intf),
 615                         usb_sndintpipe(interface_to_usbdev(dev->intf),
 616                                        dev->interrupt_out_endpoint->bEndpointAddress),
 617                         dev->interrupt_out_buffer,
 618                         bytes_to_write,
 619                         ld_usb_interrupt_out_callback,
 620                         dev,
 621                         dev->interrupt_out_interval);
 622
 623        dev->interrupt_out_busy = 1;
 624        wmb();
 625
 626        retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 627        if (retval) {
 628                dev->interrupt_out_busy = 0;
 629                dev_err(&dev->intf->dev,
 630                        "Couldn't submit interrupt_out_urb %d\n", retval);
 631                goto unlock_exit;
 632        }
 633        retval = bytes_to_write;
 634
 635unlock_exit:
 636        /* unlock the device */
 637        mutex_unlock(&dev->mutex);
 638
 639exit:
 640        return retval;
 641}
 642
 643/* file operations needed when we register this driver */
 644static const struct file_operations ld_usb_fops = {
 645        .owner =        THIS_MODULE,
 646        .read  =        ld_usb_read,
 647        .write =        ld_usb_write,
 648        .open =         ld_usb_open,
 649        .release =      ld_usb_release,
 650        .poll =         ld_usb_poll,
 651        .llseek =       no_llseek,
 652};
 653
 654/*
 655 * usb class driver info in order to get a minor number from the usb core,
 656 * and to have the device registered with the driver core
 657 */
 658static struct usb_class_driver ld_usb_class = {
 659        .name =         "ldusb%d",
 660        .fops =         &ld_usb_fops,
 661        .minor_base =   USB_LD_MINOR_BASE,
 662};
 663
 664/**
 665 *      ld_usb_probe
 666 *
 667 *      Called by the usb core when a new device is connected that it thinks
 668 *      this driver might be interested in.
 669 */
 670static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 671{
 672        struct usb_device *udev = interface_to_usbdev(intf);
 673        struct ld_usb *dev = NULL;
 674        struct usb_host_interface *iface_desc;
 675        struct usb_endpoint_descriptor *endpoint;
 676        char *buffer;
 677        int i;
 678        int retval = -ENOMEM;
 679
 680        /* allocate memory for our device state and initialize it */
 681
 682        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 683        if (dev == NULL) {
 684                dev_err(&intf->dev, "Out of memory\n");
 685                goto exit;
 686        }
 687        mutex_init(&dev->mutex);
 688        spin_lock_init(&dev->rbsl);
 689        dev->intf = intf;
 690        init_waitqueue_head(&dev->read_wait);
 691        init_waitqueue_head(&dev->write_wait);
 692
 693        /* workaround for early firmware versions on fast computers */
 694        if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 695            ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 696             (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 697            (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 698                buffer = kmalloc(256, GFP_KERNEL);
 699                if (buffer == NULL) {
 700                        dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 701                        goto error;
 702                }
 703                /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 704                usb_string(udev, 255, buffer, 256);
 705                kfree(buffer);
 706        }
 707
 708        iface_desc = intf->cur_altsetting;
 709
 710        /* set up the endpoint information */
 711        for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 712                endpoint = &iface_desc->endpoint[i].desc;
 713
 714                if (usb_endpoint_is_int_in(endpoint))
 715                        dev->interrupt_in_endpoint = endpoint;
 716
 717                if (usb_endpoint_is_int_out(endpoint))
 718                        dev->interrupt_out_endpoint = endpoint;
 719        }
 720        if (dev->interrupt_in_endpoint == NULL) {
 721                dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 722                goto error;
 723        }
 724        if (dev->interrupt_out_endpoint == NULL)
 725                dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 726
 727        dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 728        dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 729        if (!dev->ring_buffer) {
 730                dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 731                goto error;
 732        }
 733        dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 734        if (!dev->interrupt_in_buffer) {
 735                dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 736                goto error;
 737        }
 738        dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 739        if (!dev->interrupt_in_urb) {
 740                dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 741                goto error;
 742        }
 743        dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
 744                                                                         udev->descriptor.bMaxPacketSize0;
 745        dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 746        if (!dev->interrupt_out_buffer) {
 747                dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 748                goto error;
 749        }
 750        dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 751        if (!dev->interrupt_out_urb) {
 752                dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 753                goto error;
 754        }
 755        dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 756        if (dev->interrupt_out_endpoint)
 757                dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 758
 759        /* we can register the device now, as it is ready */
 760        usb_set_intfdata(intf, dev);
 761
 762        retval = usb_register_dev(intf, &ld_usb_class);
 763        if (retval) {
 764                /* something prevented us from registering this driver */
 765                dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 766                usb_set_intfdata(intf, NULL);
 767                goto error;
 768        }
 769
 770        /* let the user know what node this device is now attached to */
 771        dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 772                (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 773
 774exit:
 775        return retval;
 776
 777error:
 778        ld_usb_delete(dev);
 779
 780        return retval;
 781}
 782
 783/**
 784 *      ld_usb_disconnect
 785 *
 786 *      Called by the usb core when the device is removed from the system.
 787 */
 788static void ld_usb_disconnect(struct usb_interface *intf)
 789{
 790        struct ld_usb *dev;
 791        int minor;
 792
 793        dev = usb_get_intfdata(intf);
 794        usb_set_intfdata(intf, NULL);
 795
 796        minor = intf->minor;
 797
 798        /* give back our minor */
 799        usb_deregister_dev(intf, &ld_usb_class);
 800
 801        mutex_lock(&dev->mutex);
 802
 803        /* if the device is not opened, then we clean up right now */
 804        if (!dev->open_count) {
 805                mutex_unlock(&dev->mutex);
 806                ld_usb_delete(dev);
 807        } else {
 808                dev->intf = NULL;
 809                /* wake up pollers */
 810                wake_up_interruptible_all(&dev->read_wait);
 811                wake_up_interruptible_all(&dev->write_wait);
 812                mutex_unlock(&dev->mutex);
 813        }
 814
 815        dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 816                 (minor - USB_LD_MINOR_BASE));
 817}
 818
 819/* usb specific object needed to register this driver with the usb subsystem */
 820static struct usb_driver ld_usb_driver = {
 821        .name =         "ldusb",
 822        .probe =        ld_usb_probe,
 823        .disconnect =   ld_usb_disconnect,
 824        .id_table =     ld_usb_table,
 825};
 826
 827module_usb_driver(ld_usb_driver);
 828
 829