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