drivers/usb/misc/iowarrior.c

   1 /*
   2  *  Native support for the I/O-Warrior USB devices
   3  *
   4  *  Copyright (c) 2003-2005  Code Mercenaries GmbH
   5  *  written by Christian Lucht <lucht@codemercs.com>
   6  *
   7  *  based on
   8
   9  *  usb-skeleton.c by Greg Kroah-Hartman  <greg@kroah.com>
  10  *  brlvger.c by Stephane Dalton  <sdalton@videotron.ca>
  11  *           and St�hane Doyon   <s.doyon@videotron.ca>
  12  *
  13  *  Released under the GPLv2.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/usb.h>
  18 #include <linux/slab.h>
  19 #include <linux/sched.h>
  20 #include <linux/mutex.h>
  21 #include <linux/poll.h>
  22 #include <linux/usb/iowarrior.h>
  23
  24 /* Version Information */
  25 #define DRIVER_VERSION "v0.4.0"
  26 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
  27 #define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
  28
  29 #define USB_VENDOR_ID_CODEMERCS         1984
  30 /* low speed iowarrior */
  31 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
  32 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
  33 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
  34 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
  35 /* full speed iowarrior */
  36 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
  37
  38 /* Get a minor range for your devices from the usb maintainer */
  39 #ifdef CONFIG_USB_DYNAMIC_MINORS
  40 #define IOWARRIOR_MINOR_BASE    0
  41 #else
  42 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not official yet
  43 #endif
  44
  45 /* interrupt input queue size */
  46 #define MAX_INTERRUPT_BUFFER 16
  47 /*
  48    maximum number of urbs that are submitted for writes at the same time,
  49    this applies to the IOWarrior56 only!
  50    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
  51 */
  52 #define MAX_WRITES_IN_FLIGHT 4
  53
  54 MODULE_AUTHOR(DRIVER_AUTHOR);
  55 MODULE_DESCRIPTION(DRIVER_DESC);
  56 MODULE_LICENSE("GPL");
  57
  58 /* Module parameters */
  59 static DEFINE_MUTEX(iowarrior_mutex);
  60
  61 static struct usb_driver iowarrior_driver;
  62 static DEFINE_MUTEX(iowarrior_open_disc_lock);
  63
  64 /*--------------*/
  65 /*     data     */
  66 /*--------------*/
  67
  68 /* Structure to hold all of our device specific stuff */
  69 struct iowarrior {
  70         struct mutex mutex;                     /* locks this structure */
  71         struct usb_device *udev;                /* save off the usb device pointer */
  72         struct usb_interface *interface;        /* the interface for this device */
  73         unsigned char minor;                    /* the starting minor number for this device */
  74         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
  75         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
  76         struct urb *int_in_urb;         /* the urb for reading data */
  77         unsigned char *int_in_buffer;   /* buffer for data to be read */
  78         unsigned char serial_number;    /* to detect lost packages */
  79         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
  80         wait_queue_head_t read_wait;
  81         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
  82         atomic_t write_busy;            /* number of write-urbs submitted */
  83         atomic_t read_idx;
  84         atomic_t intr_idx;
  85         spinlock_t intr_idx_lock;       /* protects intr_idx */
  86         atomic_t overflow_flag;         /* signals an index 'rollover' */
  87         int present;                    /* this is 1 as long as the device is connected */
  88         int opened;                     /* this is 1 if the device is currently open */
  89         char chip_serial[9];            /* the serial number string of the chip connected */
  90         int report_size;                /* number of bytes in a report */
  91         u16 product_id;
  92 };
  93
  94 /*--------------*/
  95 /*    globals   */
  96 /*--------------*/
  97
  98 /*
  99  *  USB spec identifies 5 second timeouts.
 100  */
 101 #define GET_TIMEOUT 5
 102 #define USB_REQ_GET_REPORT  0x01
 103 //#if 0
 104 static int usb_get_report(struct usb_device *dev,
 105                           struct usb_host_interface *inter, unsigned char type,
 106                           unsigned char id, void *buf, int size)
 107 {
 108         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 109                                USB_REQ_GET_REPORT,
 110                                USB_DIR_IN | USB_TYPE_CLASS |
 111                                USB_RECIP_INTERFACE, (type << 8) + id,
 112                                inter->desc.bInterfaceNumber, buf, size,
 113                                GET_TIMEOUT*HZ);
 114 }
 115 //#endif
 116
 117 #define USB_REQ_SET_REPORT 0x09
 118
 119 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 120                           unsigned char id, void *buf, int size)
 121 {
 122         return usb_control_msg(interface_to_usbdev(intf),
 123                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 124                                USB_REQ_SET_REPORT,
 125                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 126                                (type << 8) + id,
 127                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 128                                size, HZ);
 129 }
 130
 131 /*---------------------*/
 132 /* driver registration */
 133 /*---------------------*/
 134 /* table of devices that work with this driver */
 135 static const struct usb_device_id iowarrior_ids[] = {
 136         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 137         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 138         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 139         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 140         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 141         {}                      /* Terminating entry */
 142 };
 143 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 144
 145 /*
 146  * USB callback handler for reading data
 147  */
 148 static void iowarrior_callback(struct urb *urb)
 149 {
 150         struct iowarrior *dev = urb->context;
 151         int intr_idx;
 152         int read_idx;
 153         int aux_idx;
 154         int offset;
 155         int status = urb->status;
 156         int retval;
 157
 158         switch (status) {
 159         case 0:
 160                 /* success */
 161                 break;
 162         case -ECONNRESET:
 163         case -ENOENT:
 164         case -ESHUTDOWN:
 165                 return;
 166         default:
 167                 goto exit;
 168         }
 169
 170         spin_lock(&dev->intr_idx_lock);
 171         intr_idx = atomic_read(&dev->intr_idx);
 172         /* aux_idx become previous intr_idx */
 173         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 174         read_idx = atomic_read(&dev->read_idx);
 175
 176         /* queue is not empty and it's interface 0 */
 177         if ((intr_idx != read_idx)
 178             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 179                 /* + 1 for serial number */
 180                 offset = aux_idx * (dev->report_size + 1);
 181                 if (!memcmp
 182                     (dev->read_queue + offset, urb->transfer_buffer,
 183                      dev->report_size)) {
 184                         /* equal values on interface 0 will be ignored */
 185                         spin_unlock(&dev->intr_idx_lock);
 186                         goto exit;
 187                 }
 188         }
 189
 190         /* aux_idx become next intr_idx */
 191         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 192         if (read_idx == aux_idx) {
 193                 /* queue full, dropping oldest input */
 194                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 195                 atomic_set(&dev->read_idx, read_idx);
 196                 atomic_set(&dev->overflow_flag, 1);
 197         }
 198
 199         /* +1 for serial number */
 200         offset = intr_idx * (dev->report_size + 1);
 201         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 202                dev->report_size);
 203         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 204
 205         atomic_set(&dev->intr_idx, aux_idx);
 206         spin_unlock(&dev->intr_idx_lock);
 207         /* tell the blocking read about the new data */
 208         wake_up_interruptible(&dev->read_wait);
 209
 210 exit:
 211         retval = usb_submit_urb(urb, GFP_ATOMIC);
 212         if (retval)
 213                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 214                         __func__, retval);
 215
 216 }
 217
 218 /*
 219  * USB Callback handler for write-ops
 220  */
 221 static void iowarrior_write_callback(struct urb *urb)
 222 {
 223         struct iowarrior *dev;
 224         int status = urb->status;
 225
 226         dev = urb->context;
 227         /* sync/async unlink faults aren't errors */
 228         if (status &&
 229             !(status == -ENOENT ||
 230               status == -ECONNRESET || status == -ESHUTDOWN)) {
 231                 dev_dbg(&dev->interface->dev,
 232                         "nonzero write bulk status received: %d\n", status);
 233         }
 234         /* free up our allocated buffer */
 235         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 236                           urb->transfer_buffer, urb->transfer_dma);
 237         /* tell a waiting writer the interrupt-out-pipe is available again */
 238         atomic_dec(&dev->write_busy);
 239         wake_up_interruptible(&dev->write_wait);
 240 }
 241
 242 /**
 243  *      iowarrior_delete
 244  */
 245 static inline void iowarrior_delete(struct iowarrior *dev)
 246 {
 247         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 248         kfree(dev->int_in_buffer);
 249         usb_free_urb(dev->int_in_urb);
 250         kfree(dev->read_queue);
 251         kfree(dev);
 252 }
 253
 254 /*---------------------*/
 255 /* fops implementation */
 256 /*---------------------*/
 257
 258 static int read_index(struct iowarrior *dev)
 259 {
 260         int intr_idx, read_idx;
 261
 262         read_idx = atomic_read(&dev->read_idx);
 263         intr_idx = atomic_read(&dev->intr_idx);
 264
 265         return (read_idx == intr_idx ? -1 : read_idx);
 266 }
 267
 268 /**
 269  *  iowarrior_read
 270  */
 271 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 272                               size_t count, loff_t *ppos)
 273 {
 274         struct iowarrior *dev;
 275         int read_idx;
 276         int offset;
 277
 278         dev = file->private_data;
 279
 280         /* verify that the device wasn't unplugged */
 281         if (!dev || !dev->present)
 282                 return -ENODEV;
 283
 284         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 285                 dev->minor, count);
 286
 287         /* read count must be packet size (+ time stamp) */
 288         if ((count != dev->report_size)
 289             && (count != (dev->report_size + 1)))
 290                 return -EINVAL;
 291
 292         /* repeat until no buffer overrun in callback handler occur */
 293         do {
 294                 atomic_set(&dev->overflow_flag, 0);
 295                 if ((read_idx = read_index(dev)) == -1) {
 296                         /* queue empty */
 297                         if (file->f_flags & O_NONBLOCK)
 298                                 return -EAGAIN;
 299                         else {
 300                                 //next line will return when there is either new data, or the device is unplugged
 301                                 int r = wait_event_interruptible(dev->read_wait,
 302                                                                  (!dev->present
 303                                                                   || (read_idx =
 304                                                                       read_index
 305                                                                       (dev)) !=
 306                                                                   -1));
 307                                 if (r) {
 308                                         //we were interrupted by a signal
 309                                         return -ERESTART;
 310                                 }
 311                                 if (!dev->present) {
 312                                         //The device was unplugged
 313                                         return -ENODEV;
 314                                 }
 315                                 if (read_idx == -1) {
 316                                         // Can this happen ???
 317                                         return 0;
 318                                 }
 319                         }
 320                 }
 321
 322                 offset = read_idx * (dev->report_size + 1);
 323                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 324                         return -EFAULT;
 325                 }
 326         } while (atomic_read(&dev->overflow_flag));
 327
 328         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 329         atomic_set(&dev->read_idx, read_idx);
 330         return count;
 331 }
 332
 333 /*
 334  * iowarrior_write
 335  */
 336 static ssize_t iowarrior_write(struct file *file,
 337                                const char __user *user_buffer,
 338                                size_t count, loff_t *ppos)
 339 {
 340         struct iowarrior *dev;
 341         int retval = 0;
 342         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 343         struct urb *int_out_urb = NULL;
 344
 345         dev = file->private_data;
 346
 347         mutex_lock(&dev->mutex);
 348         /* verify that the device wasn't unplugged */
 349         if (!dev->present) {
 350                 retval = -ENODEV;
 351                 goto exit;
 352         }
 353         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 354                 dev->minor, count);
 355         /* if count is 0 we're already done */
 356         if (count == 0) {
 357                 retval = 0;
 358                 goto exit;
 359         }
 360         /* We only accept full reports */
 361         if (count != dev->report_size) {
 362                 retval = -EINVAL;
 363                 goto exit;
 364         }
 365         switch (dev->product_id) {
 366         case USB_DEVICE_ID_CODEMERCS_IOW24:
 367         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 368         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 369         case USB_DEVICE_ID_CODEMERCS_IOW40:
 370                 /* IOW24 and IOW40 use a synchronous call */
 371                 buf = memdup_user(user_buffer, count);
 372                 if (IS_ERR(buf)) {
 373                         retval = PTR_ERR(buf);
 374                         goto exit;
 375                 }
 376                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 377                 kfree(buf);
 378                 goto exit;
 379                 break;
 380         case USB_DEVICE_ID_CODEMERCS_IOW56:
 381                 /* The IOW56 uses asynchronous IO and more urbs */
 382                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 383                         /* Wait until we are below the limit for submitted urbs */
 384                         if (file->f_flags & O_NONBLOCK) {
 385                                 retval = -EAGAIN;
 386                                 goto exit;
 387                         } else {
 388                                 retval = wait_event_interruptible(dev->write_wait,
 389                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 390                                 if (retval) {
 391                                         /* we were interrupted by a signal */
 392                                         retval = -ERESTART;
 393                                         goto exit;
 394                                 }
 395                                 if (!dev->present) {
 396                                         /* The device was unplugged */
 397                                         retval = -ENODEV;
 398                                         goto exit;
 399                                 }
 400                                 if (!dev->opened) {
 401                                         /* We were closed while waiting for an URB */
 402                                         retval = -ENODEV;
 403                                         goto exit;
 404                                 }
 405                         }
 406                 }
 407                 atomic_inc(&dev->write_busy);
 408                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 409                 if (!int_out_urb) {
 410                         retval = -ENOMEM;
 411                         goto error_no_urb;
 412                 }
 413                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 414                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 415                 if (!buf) {
 416                         retval = -ENOMEM;
 417                         dev_dbg(&dev->interface->dev,
 418                                 "Unable to allocate buffer\n");
 419                         goto error_no_buffer;
 420                 }
 421                 usb_fill_int_urb(int_out_urb, dev->udev,
 422                                  usb_sndintpipe(dev->udev,
 423                                                 dev->int_out_endpoint->bEndpointAddress),
 424                                  buf, dev->report_size,
 425                                  iowarrior_write_callback, dev,
 426                                  dev->int_out_endpoint->bInterval);
 427                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 428                 if (copy_from_user(buf, user_buffer, count)) {
 429                         retval = -EFAULT;
 430                         goto error;
 431                 }
 432                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 433                 if (retval) {
 434                         dev_dbg(&dev->interface->dev,
 435                                 "submit error %d for urb nr.%d\n",
 436                                 retval, atomic_read(&dev->write_busy));
 437                         goto error;
 438                 }
 439                 /* submit was ok */
 440                 retval = count;
 441                 usb_free_urb(int_out_urb);
 442                 goto exit;
 443                 break;
 444         default:
 445                 /* what do we have here ? An unsupported Product-ID ? */
 446                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 447                         __func__, dev->product_id);
 448                 retval = -EFAULT;
 449                 goto exit;
 450                 break;
 451         }
 452 error:
 453         usb_free_coherent(dev->udev, dev->report_size, buf,
 454                           int_out_urb->transfer_dma);
 455 error_no_buffer:
 456         usb_free_urb(int_out_urb);
 457 error_no_urb:
 458         atomic_dec(&dev->write_busy);
 459         wake_up_interruptible(&dev->write_wait);
 460 exit:
 461         mutex_unlock(&dev->mutex);
 462         return retval;
 463 }
 464
 465 /**
 466  *      iowarrior_ioctl
 467  */
 468 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 469                                                         unsigned long arg)
 470 {
 471         struct iowarrior *dev = NULL;
 472         __u8 *buffer;
 473         __u8 __user *user_buffer;
 474         int retval;
 475         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 476
 477         dev = file->private_data;
 478         if (!dev)
 479                 return -ENODEV;
 480
 481         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 482         if (!buffer)
 483                 return -ENOMEM;
 484
 485         /* lock this object */
 486         mutex_lock(&iowarrior_mutex);
 487         mutex_lock(&dev->mutex);
 488
 489         /* verify that the device wasn't unplugged */
 490         if (!dev->present) {
 491                 retval = -ENODEV;
 492                 goto error_out;
 493         }
 494
 495         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 496                 dev->minor, cmd, arg);
 497
 498         retval = 0;
 499         io_res = 0;
 500         switch (cmd) {
 501         case IOW_WRITE:
 502                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 503                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 504                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 505                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 506                         user_buffer = (__u8 __user *)arg;
 507                         io_res = copy_from_user(buffer, user_buffer,
 508                                                 dev->report_size);
 509                         if (io_res) {
 510                                 retval = -EFAULT;
 511                         } else {
 512                                 io_res = usb_set_report(dev->interface, 2, 0,
 513                                                         buffer,
 514                                                         dev->report_size);
 515                                 if (io_res < 0)
 516                                         retval = io_res;
 517                         }
 518                 } else {
 519                         retval = -EINVAL;
 520                         dev_err(&dev->interface->dev,
 521                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 522                                 dev->product_id);
 523                 }
 524                 break;
 525         case IOW_READ:
 526                 user_buffer = (__u8 __user *)arg;
 527                 io_res = usb_get_report(dev->udev,
 528                                         dev->interface->cur_altsetting, 1, 0,
 529                                         buffer, dev->report_size);
 530                 if (io_res < 0)
 531                         retval = io_res;
 532                 else {
 533                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 534                         if (io_res)
 535                                 retval = -EFAULT;
 536                 }
 537                 break;
 538         case IOW_GETINFO:
 539                 {
 540                         /* Report available information for the device */
 541                         struct iowarrior_info info;
 542                         /* needed for power consumption */
 543                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 544
 545                         memset(&info, 0, sizeof(info));
 546                         /* directly from the descriptor */
 547                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 548                         info.product = dev->product_id;
 549                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 550
 551                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 552                         info.speed = dev->udev->speed;
 553                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 554                         info.report_size = dev->report_size;
 555
 556                         /* serial number string has been read earlier 8 chars or empty string */
 557                         memcpy(info.serial, dev->chip_serial,
 558                                sizeof(dev->chip_serial));
 559                         if (cfg_descriptor == NULL) {
 560                                 info.power = -1;        /* no information available */
 561                         } else {
 562                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 563                                 info.power = cfg_descriptor->bMaxPower * 2;
 564                         }
 565                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 566                                          sizeof(struct iowarrior_info));
 567                         if (io_res)
 568                                 retval = -EFAULT;
 569                         break;
 570                 }
 571         default:
 572                 /* return that we did not understand this ioctl call */
 573                 retval = -ENOTTY;
 574                 break;
 575         }
 576 error_out:
 577         /* unlock the device */
 578         mutex_unlock(&dev->mutex);
 579         mutex_unlock(&iowarrior_mutex);
 580         kfree(buffer);
 581         return retval;
 582 }
 583
 584 /**
 585  *      iowarrior_open
 586  */
 587 static int iowarrior_open(struct inode *inode, struct file *file)
 588 {
 589         struct iowarrior *dev = NULL;
 590         struct usb_interface *interface;
 591         int subminor;
 592         int retval = 0;
 593
 594         mutex_lock(&iowarrior_mutex);
 595         subminor = iminor(inode);
 596
 597         interface = usb_find_interface(&iowarrior_driver, subminor);
 598         if (!interface) {
 599                 mutex_unlock(&iowarrior_mutex);
 600                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 601                        __func__, subminor);
 602                 return -ENODEV;
 603         }
 604
 605         mutex_lock(&iowarrior_open_disc_lock);
 606         dev = usb_get_intfdata(interface);
 607         if (!dev) {
 608                 mutex_unlock(&iowarrior_open_disc_lock);
 609                 mutex_unlock(&iowarrior_mutex);
 610                 return -ENODEV;
 611         }
 612
 613         mutex_lock(&dev->mutex);
 614         mutex_unlock(&iowarrior_open_disc_lock);
 615
 616         /* Only one process can open each device, no sharing. */
 617         if (dev->opened) {
 618                 retval = -EBUSY;
 619                 goto out;
 620         }
 621
 622         /* setup interrupt handler for receiving values */
 623         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 624                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 625                 retval = -EFAULT;
 626                 goto out;
 627         }
 628         /* increment our usage count for the driver */
 629         ++dev->opened;
 630         /* save our object in the file's private structure */
 631         file->private_data = dev;
 632         retval = 0;
 633
 634 out:
 635         mutex_unlock(&dev->mutex);
 636         mutex_unlock(&iowarrior_mutex);
 637         return retval;
 638 }
 639
 640 /**
 641  *      iowarrior_release
 642  */
 643 static int iowarrior_release(struct inode *inode, struct file *file)
 644 {
 645         struct iowarrior *dev;
 646         int retval = 0;
 647
 648         dev = file->private_data;
 649         if (!dev)
 650                 return -ENODEV;
 651
 652         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 653
 654         /* lock our device */
 655         mutex_lock(&dev->mutex);
 656
 657         if (dev->opened <= 0) {
 658                 retval = -ENODEV;       /* close called more than once */
 659                 mutex_unlock(&dev->mutex);
 660         } else {
 661                 dev->opened = 0;        /* we're closing now */
 662                 retval = 0;
 663                 if (dev->present) {
 664                         /*
 665                            The device is still connected so we only shutdown
 666                            pending read-/write-ops.
 667                          */
 668                         usb_kill_urb(dev->int_in_urb);
 669                         wake_up_interruptible(&dev->read_wait);
 670                         wake_up_interruptible(&dev->write_wait);
 671                         mutex_unlock(&dev->mutex);
 672                 } else {
 673                         /* The device was unplugged, cleanup resources */
 674                         mutex_unlock(&dev->mutex);
 675                         iowarrior_delete(dev);
 676                 }
 677         }
 678         return retval;
 679 }
 680
 681 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 682 {
 683         struct iowarrior *dev = file->private_data;
 684         unsigned int mask = 0;
 685
 686         if (!dev->present)
 687                 return POLLERR | POLLHUP;
 688
 689         poll_wait(file, &dev->read_wait, wait);
 690         poll_wait(file, &dev->write_wait, wait);
 691
 692         if (!dev->present)
 693                 return POLLERR | POLLHUP;
 694
 695         if (read_index(dev) != -1)
 696                 mask |= POLLIN | POLLRDNORM;
 697
 698         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 699                 mask |= POLLOUT | POLLWRNORM;
 700         return mask;
 701 }
 702
 703 /*
 704  * File operations needed when we register this driver.
 705  * This assumes that this driver NEEDS file operations,
 706  * of course, which means that the driver is expected
 707  * to have a node in the /dev directory. If the USB
 708  * device were for a network interface then the driver
 709  * would use "struct net_driver" instead, and a serial
 710  * device would use "struct tty_driver".
 711  */
 712 static const struct file_operations iowarrior_fops = {
 713         .owner = THIS_MODULE,
 714         .write = iowarrior_write,
 715         .read = iowarrior_read,
 716         .unlocked_ioctl = iowarrior_ioctl,
 717         .open = iowarrior_open,
 718         .release = iowarrior_release,
 719         .poll = iowarrior_poll,
 720         .llseek = noop_llseek,
 721 };
 722
 723 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 724 {
 725         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 726 }
 727
 728 /*
 729  * usb class driver info in order to get a minor number from the usb core,
 730  * and to have the device registered with devfs and the driver core
 731  */
 732 static struct usb_class_driver iowarrior_class = {
 733         .name = "iowarrior%d",
 734         .devnode = iowarrior_devnode,
 735         .fops = &iowarrior_fops,
 736         .minor_base = IOWARRIOR_MINOR_BASE,
 737 };
 738
 739 /*---------------------------------*/
 740 /*  probe and disconnect functions */
 741 /*---------------------------------*/
 742 /**
 743  *      iowarrior_probe
 744  *
 745  *      Called by the usb core when a new device is connected that it thinks
 746  *      this driver might be interested in.
 747  */
 748 static int iowarrior_probe(struct usb_interface *interface,
 749                            const struct usb_device_id *id)
 750 {
 751         struct usb_device *udev = interface_to_usbdev(interface);
 752         struct iowarrior *dev = NULL;
 753         struct usb_host_interface *iface_desc;
 754         int retval = -ENOMEM;
 755         int res;
 756
 757         /* allocate memory for our device state and initialize it */
 758         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 759         if (!dev)
 760                 return retval;
 761
 762         mutex_init(&dev->mutex);
 763
 764         atomic_set(&dev->intr_idx, 0);
 765         atomic_set(&dev->read_idx, 0);
 766         spin_lock_init(&dev->intr_idx_lock);
 767         atomic_set(&dev->overflow_flag, 0);
 768         init_waitqueue_head(&dev->read_wait);
 769         atomic_set(&dev->write_busy, 0);
 770         init_waitqueue_head(&dev->write_wait);
 771
 772         dev->udev = udev;
 773         dev->interface = interface;
 774
 775         iface_desc = interface->cur_altsetting;
 776         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 777
 778         res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
 779         if (res) {
 780                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 781                 retval = res;
 782                 goto error;
 783         }
 784
 785         if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) {
 786                 res = usb_find_last_int_out_endpoint(iface_desc,
 787                                 &dev->int_out_endpoint);
 788                 if (res) {
 789                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 790                         retval = res;
 791                         goto error;
 792                 }
 793         }
 794
 795         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 796         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 797         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 798             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 799                 /* IOWarrior56 has wMaxPacketSize different from report size */
 800                 dev->report_size = 7;
 801
 802         /* create the urb and buffer for reading */
 803         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 804         if (!dev->int_in_urb)
 805                 goto error;
 806         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 807         if (!dev->int_in_buffer)
 808                 goto error;
 809         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 810                          usb_rcvintpipe(dev->udev,
 811                                         dev->int_in_endpoint->bEndpointAddress),
 812                          dev->int_in_buffer, dev->report_size,
 813                          iowarrior_callback, dev,
 814                          dev->int_in_endpoint->bInterval);
 815         /* create an internal buffer for interrupt data from the device */
 816         dev->read_queue =
 817             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 818                     GFP_KERNEL);
 819         if (!dev->read_queue)
 820                 goto error;
 821         /* Get the serial-number of the chip */
 822         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 823         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 824                    sizeof(dev->chip_serial));
 825         if (strlen(dev->chip_serial) != 8)
 826                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 827
 828         /* Set the idle timeout to 0, if this is interface 0 */
 829         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 830             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 831                             0x0A,
 832                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 833                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 834         }
 835         /* allow device read and ioctl */
 836         dev->present = 1;
 837
 838         /* we can register the device now, as it is ready */
 839         usb_set_intfdata(interface, dev);
 840
 841         retval = usb_register_dev(interface, &iowarrior_class);
 842         if (retval) {
 843                 /* something prevented us from registering this driver */
 844                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 845                 usb_set_intfdata(interface, NULL);
 846                 goto error;
 847         }
 848
 849         dev->minor = interface->minor;
 850
 851         /* let the user know what node this device is now attached to */
 852         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 853                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 854                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 855         return retval;
 856
 857 error:
 858         iowarrior_delete(dev);
 859         return retval;
 860 }
 861
 862 /**
 863  *      iowarrior_disconnect
 864  *
 865  *      Called by the usb core when the device is removed from the system.
 866  */
 867 static void iowarrior_disconnect(struct usb_interface *interface)
 868 {
 869         struct iowarrior *dev;
 870         int minor;
 871
 872         dev = usb_get_intfdata(interface);
 873         mutex_lock(&iowarrior_open_disc_lock);
 874         usb_set_intfdata(interface, NULL);
 875
 876         minor = dev->minor;
 877
 878         /* give back our minor */
 879         usb_deregister_dev(interface, &iowarrior_class);
 880
 881         mutex_lock(&dev->mutex);
 882
 883         /* prevent device read, write and ioctl */
 884         dev->present = 0;
 885
 886         mutex_unlock(&dev->mutex);
 887         mutex_unlock(&iowarrior_open_disc_lock);
 888
 889         if (dev->opened) {
 890                 /* There is a process that holds a filedescriptor to the device ,
 891                    so we only shutdown read-/write-ops going on.
 892                    Deleting the device is postponed until close() was called.
 893                  */
 894                 usb_kill_urb(dev->int_in_urb);
 895                 wake_up_interruptible(&dev->read_wait);
 896                 wake_up_interruptible(&dev->write_wait);
 897         } else {
 898                 /* no process is using the device, cleanup now */
 899                 iowarrior_delete(dev);
 900         }
 901
 902         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 903                  minor - IOWARRIOR_MINOR_BASE);
 904 }
 905
 906 /* usb specific object needed to register this driver with the usb subsystem */
 907 static struct usb_driver iowarrior_driver = {
 908         .name = "iowarrior",
 909         .probe = iowarrior_probe,
 910         .disconnect = iowarrior_disconnect,
 911         .id_table = iowarrior_ids,
 912 };
 913
 914 module_usb_driver(iowarrior_driver);