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         struct usb_anchor submitted;
  93 };
  94
  95 /*--------------*/
  96 /*    globals   */
  97 /*--------------*/
  98
  99 /*
 100  *  USB spec identifies 5 second timeouts.
 101  */
 102 #define GET_TIMEOUT 5
 103 #define USB_REQ_GET_REPORT  0x01
 104 //#if 0
 105 static int usb_get_report(struct usb_device *dev,
 106                           struct usb_host_interface *inter, unsigned char type,
 107                           unsigned char id, void *buf, int size)
 108 {
 109         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 110                                USB_REQ_GET_REPORT,
 111                                USB_DIR_IN | USB_TYPE_CLASS |
 112                                USB_RECIP_INTERFACE, (type << 8) + id,
 113                                inter->desc.bInterfaceNumber, buf, size,
 114                                GET_TIMEOUT*HZ);
 115 }
 116 //#endif
 117
 118 #define USB_REQ_SET_REPORT 0x09
 119
 120 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 121                           unsigned char id, void *buf, int size)
 122 {
 123         return usb_control_msg(interface_to_usbdev(intf),
 124                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 125                                USB_REQ_SET_REPORT,
 126                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 127                                (type << 8) + id,
 128                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 129                                size, HZ);
 130 }
 131
 132 /*---------------------*/
 133 /* driver registration */
 134 /*---------------------*/
 135 /* table of devices that work with this driver */
 136 static const struct usb_device_id iowarrior_ids[] = {
 137         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 138         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 139         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 140         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 141         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 142         {}                      /* Terminating entry */
 143 };
 144 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 145
 146 /*
 147  * USB callback handler for reading data
 148  */
 149 static void iowarrior_callback(struct urb *urb)
 150 {
 151         struct iowarrior *dev = urb->context;
 152         int intr_idx;
 153         int read_idx;
 154         int aux_idx;
 155         int offset;
 156         int status = urb->status;
 157         int retval;
 158
 159         switch (status) {
 160         case 0:
 161                 /* success */
 162                 break;
 163         case -ECONNRESET:
 164         case -ENOENT:
 165         case -ESHUTDOWN:
 166                 return;
 167         default:
 168                 goto exit;
 169         }
 170
 171         spin_lock(&dev->intr_idx_lock);
 172         intr_idx = atomic_read(&dev->intr_idx);
 173         /* aux_idx become previous intr_idx */
 174         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 175         read_idx = atomic_read(&dev->read_idx);
 176
 177         /* queue is not empty and it's interface 0 */
 178         if ((intr_idx != read_idx)
 179             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 180                 /* + 1 for serial number */
 181                 offset = aux_idx * (dev->report_size + 1);
 182                 if (!memcmp
 183                     (dev->read_queue + offset, urb->transfer_buffer,
 184                      dev->report_size)) {
 185                         /* equal values on interface 0 will be ignored */
 186                         spin_unlock(&dev->intr_idx_lock);
 187                         goto exit;
 188                 }
 189         }
 190
 191         /* aux_idx become next intr_idx */
 192         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 193         if (read_idx == aux_idx) {
 194                 /* queue full, dropping oldest input */
 195                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 196                 atomic_set(&dev->read_idx, read_idx);
 197                 atomic_set(&dev->overflow_flag, 1);
 198         }
 199
 200         /* +1 for serial number */
 201         offset = intr_idx * (dev->report_size + 1);
 202         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 203                dev->report_size);
 204         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 205
 206         atomic_set(&dev->intr_idx, aux_idx);
 207         spin_unlock(&dev->intr_idx_lock);
 208         /* tell the blocking read about the new data */
 209         wake_up_interruptible(&dev->read_wait);
 210
 211 exit:
 212         retval = usb_submit_urb(urb, GFP_ATOMIC);
 213         if (retval)
 214                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 215                         __func__, retval);
 216
 217 }
 218
 219 /*
 220  * USB Callback handler for write-ops
 221  */
 222 static void iowarrior_write_callback(struct urb *urb)
 223 {
 224         struct iowarrior *dev;
 225         int status = urb->status;
 226
 227         dev = urb->context;
 228         /* sync/async unlink faults aren't errors */
 229         if (status &&
 230             !(status == -ENOENT ||
 231               status == -ECONNRESET || status == -ESHUTDOWN)) {
 232                 dev_dbg(&dev->interface->dev,
 233                         "nonzero write bulk status received: %d\n", status);
 234         }
 235         /* free up our allocated buffer */
 236         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 237                           urb->transfer_buffer, urb->transfer_dma);
 238         /* tell a waiting writer the interrupt-out-pipe is available again */
 239         atomic_dec(&dev->write_busy);
 240         wake_up_interruptible(&dev->write_wait);
 241 }
 242
 243 /**
 244  *      iowarrior_delete
 245  */
 246 static inline void iowarrior_delete(struct iowarrior *dev)
 247 {
 248         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 249         kfree(dev->int_in_buffer);
 250         usb_free_urb(dev->int_in_urb);
 251         kfree(dev->read_queue);
 252         usb_put_intf(dev->interface);
 253         kfree(dev);
 254 }
 255
 256 /*---------------------*/
 257 /* fops implementation */
 258 /*---------------------*/
 259
 260 static int read_index(struct iowarrior *dev)
 261 {
 262         int intr_idx, read_idx;
 263
 264         read_idx = atomic_read(&dev->read_idx);
 265         intr_idx = atomic_read(&dev->intr_idx);
 266
 267         return (read_idx == intr_idx ? -1 : read_idx);
 268 }
 269
 270 /**
 271  *  iowarrior_read
 272  */
 273 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 274                               size_t count, loff_t *ppos)
 275 {
 276         struct iowarrior *dev;
 277         int read_idx;
 278         int offset;
 279
 280         dev = file->private_data;
 281
 282         /* verify that the device wasn't unplugged */
 283         if (!dev || !dev->present)
 284                 return -ENODEV;
 285
 286         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 287                 dev->minor, count);
 288
 289         /* read count must be packet size (+ time stamp) */
 290         if ((count != dev->report_size)
 291             && (count != (dev->report_size + 1)))
 292                 return -EINVAL;
 293
 294         /* repeat until no buffer overrun in callback handler occur */
 295         do {
 296                 atomic_set(&dev->overflow_flag, 0);
 297                 if ((read_idx = read_index(dev)) == -1) {
 298                         /* queue empty */
 299                         if (file->f_flags & O_NONBLOCK)
 300                                 return -EAGAIN;
 301                         else {
 302                                 //next line will return when there is either new data, or the device is unplugged
 303                                 int r = wait_event_interruptible(dev->read_wait,
 304                                                                  (!dev->present
 305                                                                   || (read_idx =
 306                                                                       read_index
 307                                                                       (dev)) !=
 308                                                                   -1));
 309                                 if (r) {
 310                                         //we were interrupted by a signal
 311                                         return -ERESTART;
 312                                 }
 313                                 if (!dev->present) {
 314                                         //The device was unplugged
 315                                         return -ENODEV;
 316                                 }
 317                                 if (read_idx == -1) {
 318                                         // Can this happen ???
 319                                         return 0;
 320                                 }
 321                         }
 322                 }
 323
 324                 offset = read_idx * (dev->report_size + 1);
 325                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 326                         return -EFAULT;
 327                 }
 328         } while (atomic_read(&dev->overflow_flag));
 329
 330         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 331         atomic_set(&dev->read_idx, read_idx);
 332         return count;
 333 }
 334
 335 /*
 336  * iowarrior_write
 337  */
 338 static ssize_t iowarrior_write(struct file *file,
 339                                const char __user *user_buffer,
 340                                size_t count, loff_t *ppos)
 341 {
 342         struct iowarrior *dev;
 343         int retval = 0;
 344         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 345         struct urb *int_out_urb = NULL;
 346
 347         dev = file->private_data;
 348
 349         mutex_lock(&dev->mutex);
 350         /* verify that the device wasn't unplugged */
 351         if (!dev->present) {
 352                 retval = -ENODEV;
 353                 goto exit;
 354         }
 355         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 356                 dev->minor, count);
 357         /* if count is 0 we're already done */
 358         if (count == 0) {
 359                 retval = 0;
 360                 goto exit;
 361         }
 362         /* We only accept full reports */
 363         if (count != dev->report_size) {
 364                 retval = -EINVAL;
 365                 goto exit;
 366         }
 367         switch (dev->product_id) {
 368         case USB_DEVICE_ID_CODEMERCS_IOW24:
 369         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 370         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 371         case USB_DEVICE_ID_CODEMERCS_IOW40:
 372                 /* IOW24 and IOW40 use a synchronous call */
 373                 buf = kmalloc(count, GFP_KERNEL);
 374                 if (!buf) {
 375                         retval = -ENOMEM;
 376                         goto exit;
 377                 }
 378                 if (copy_from_user(buf, user_buffer, count)) {
 379                         retval = -EFAULT;
 380                         kfree(buf);
 381                         goto exit;
 382                 }
 383                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 384                 kfree(buf);
 385                 goto exit;
 386                 break;
 387         case USB_DEVICE_ID_CODEMERCS_IOW56:
 388                 /* The IOW56 uses asynchronous IO and more urbs */
 389                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 390                         /* Wait until we are below the limit for submitted urbs */
 391                         if (file->f_flags & O_NONBLOCK) {
 392                                 retval = -EAGAIN;
 393                                 goto exit;
 394                         } else {
 395                                 retval = wait_event_interruptible(dev->write_wait,
 396                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 397                                 if (retval) {
 398                                         /* we were interrupted by a signal */
 399                                         retval = -ERESTART;
 400                                         goto exit;
 401                                 }
 402                                 if (!dev->present) {
 403                                         /* The device was unplugged */
 404                                         retval = -ENODEV;
 405                                         goto exit;
 406                                 }
 407                                 if (!dev->opened) {
 408                                         /* We were closed while waiting for an URB */
 409                                         retval = -ENODEV;
 410                                         goto exit;
 411                                 }
 412                         }
 413                 }
 414                 atomic_inc(&dev->write_busy);
 415                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 416                 if (!int_out_urb) {
 417                         retval = -ENOMEM;
 418                         goto error_no_urb;
 419                 }
 420                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 421                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 422                 if (!buf) {
 423                         retval = -ENOMEM;
 424                         dev_dbg(&dev->interface->dev,
 425                                 "Unable to allocate buffer\n");
 426                         goto error_no_buffer;
 427                 }
 428                 usb_fill_int_urb(int_out_urb, dev->udev,
 429                                  usb_sndintpipe(dev->udev,
 430                                                 dev->int_out_endpoint->bEndpointAddress),
 431                                  buf, dev->report_size,
 432                                  iowarrior_write_callback, dev,
 433                                  dev->int_out_endpoint->bInterval);
 434                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 435                 if (copy_from_user(buf, user_buffer, count)) {
 436                         retval = -EFAULT;
 437                         goto error;
 438                 }
 439                 usb_anchor_urb(int_out_urb, &dev->submitted);
 440                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 441                 if (retval) {
 442                         dev_dbg(&dev->interface->dev,
 443                                 "submit error %d for urb nr.%d\n",
 444                                 retval, atomic_read(&dev->write_busy));
 445                         usb_unanchor_urb(int_out_urb);
 446                         goto error;
 447                 }
 448                 /* submit was ok */
 449                 retval = count;
 450                 usb_free_urb(int_out_urb);
 451                 goto exit;
 452                 break;
 453         default:
 454                 /* what do we have here ? An unsupported Product-ID ? */
 455                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 456                         __func__, dev->product_id);
 457                 retval = -EFAULT;
 458                 goto exit;
 459                 break;
 460         }
 461 error:
 462         usb_free_coherent(dev->udev, dev->report_size, buf,
 463                           int_out_urb->transfer_dma);
 464 error_no_buffer:
 465         usb_free_urb(int_out_urb);
 466 error_no_urb:
 467         atomic_dec(&dev->write_busy);
 468         wake_up_interruptible(&dev->write_wait);
 469 exit:
 470         mutex_unlock(&dev->mutex);
 471         return retval;
 472 }
 473
 474 /**
 475  *      iowarrior_ioctl
 476  */
 477 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 478                                                         unsigned long arg)
 479 {
 480         struct iowarrior *dev = NULL;
 481         __u8 *buffer;
 482         __u8 __user *user_buffer;
 483         int retval;
 484         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 485
 486         dev = file->private_data;
 487         if (!dev)
 488                 return -ENODEV;
 489
 490         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 491         if (!buffer)
 492                 return -ENOMEM;
 493
 494         /* lock this object */
 495         mutex_lock(&iowarrior_mutex);
 496         mutex_lock(&dev->mutex);
 497
 498         /* verify that the device wasn't unplugged */
 499         if (!dev->present) {
 500                 retval = -ENODEV;
 501                 goto error_out;
 502         }
 503
 504         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 505                 dev->minor, cmd, arg);
 506
 507         retval = 0;
 508         io_res = 0;
 509         switch (cmd) {
 510         case IOW_WRITE:
 511                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 512                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 513                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 514                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 515                         user_buffer = (__u8 __user *)arg;
 516                         io_res = copy_from_user(buffer, user_buffer,
 517                                                 dev->report_size);
 518                         if (io_res) {
 519                                 retval = -EFAULT;
 520                         } else {
 521                                 io_res = usb_set_report(dev->interface, 2, 0,
 522                                                         buffer,
 523                                                         dev->report_size);
 524                                 if (io_res < 0)
 525                                         retval = io_res;
 526                         }
 527                 } else {
 528                         retval = -EINVAL;
 529                         dev_err(&dev->interface->dev,
 530                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 531                                 dev->product_id);
 532                 }
 533                 break;
 534         case IOW_READ:
 535                 user_buffer = (__u8 __user *)arg;
 536                 io_res = usb_get_report(dev->udev,
 537                                         dev->interface->cur_altsetting, 1, 0,
 538                                         buffer, dev->report_size);
 539                 if (io_res < 0)
 540                         retval = io_res;
 541                 else {
 542                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 543                         if (io_res)
 544                                 retval = -EFAULT;
 545                 }
 546                 break;
 547         case IOW_GETINFO:
 548                 {
 549                         /* Report available information for the device */
 550                         struct iowarrior_info info;
 551                         /* needed for power consumption */
 552                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 553
 554                         memset(&info, 0, sizeof(info));
 555                         /* directly from the descriptor */
 556                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 557                         info.product = dev->product_id;
 558                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 559
 560                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 561                         info.speed = dev->udev->speed;
 562                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 563                         info.report_size = dev->report_size;
 564
 565                         /* serial number string has been read earlier 8 chars or empty string */
 566                         memcpy(info.serial, dev->chip_serial,
 567                                sizeof(dev->chip_serial));
 568                         if (cfg_descriptor == NULL) {
 569                                 info.power = -1;        /* no information available */
 570                         } else {
 571                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 572                                 info.power = cfg_descriptor->bMaxPower * 2;
 573                         }
 574                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 575                                          sizeof(struct iowarrior_info));
 576                         if (io_res)
 577                                 retval = -EFAULT;
 578                         break;
 579                 }
 580         default:
 581                 /* return that we did not understand this ioctl call */
 582                 retval = -ENOTTY;
 583                 break;
 584         }
 585 error_out:
 586         /* unlock the device */
 587         mutex_unlock(&dev->mutex);
 588         mutex_unlock(&iowarrior_mutex);
 589         kfree(buffer);
 590         return retval;
 591 }
 592
 593 /**
 594  *      iowarrior_open
 595  */
 596 static int iowarrior_open(struct inode *inode, struct file *file)
 597 {
 598         struct iowarrior *dev = NULL;
 599         struct usb_interface *interface;
 600         int subminor;
 601         int retval = 0;
 602
 603         mutex_lock(&iowarrior_mutex);
 604         subminor = iminor(inode);
 605
 606         interface = usb_find_interface(&iowarrior_driver, subminor);
 607         if (!interface) {
 608                 mutex_unlock(&iowarrior_mutex);
 609                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 610                        __func__, subminor);
 611                 return -ENODEV;
 612         }
 613
 614         mutex_lock(&iowarrior_open_disc_lock);
 615         dev = usb_get_intfdata(interface);
 616         if (!dev) {
 617                 mutex_unlock(&iowarrior_open_disc_lock);
 618                 mutex_unlock(&iowarrior_mutex);
 619                 return -ENODEV;
 620         }
 621
 622         mutex_lock(&dev->mutex);
 623         mutex_unlock(&iowarrior_open_disc_lock);
 624
 625         /* Only one process can open each device, no sharing. */
 626         if (dev->opened) {
 627                 retval = -EBUSY;
 628                 goto out;
 629         }
 630
 631         /* setup interrupt handler for receiving values */
 632         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 633                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 634                 retval = -EFAULT;
 635                 goto out;
 636         }
 637         /* increment our usage count for the driver */
 638         ++dev->opened;
 639         /* save our object in the file's private structure */
 640         file->private_data = dev;
 641         retval = 0;
 642
 643 out:
 644         mutex_unlock(&dev->mutex);
 645         mutex_unlock(&iowarrior_mutex);
 646         return retval;
 647 }
 648
 649 /**
 650  *      iowarrior_release
 651  */
 652 static int iowarrior_release(struct inode *inode, struct file *file)
 653 {
 654         struct iowarrior *dev;
 655         int retval = 0;
 656
 657         dev = file->private_data;
 658         if (!dev)
 659                 return -ENODEV;
 660
 661         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 662
 663         /* lock our device */
 664         mutex_lock(&dev->mutex);
 665
 666         if (dev->opened <= 0) {
 667                 retval = -ENODEV;       /* close called more than once */
 668                 mutex_unlock(&dev->mutex);
 669         } else {
 670                 dev->opened = 0;        /* we're closing now */
 671                 retval = 0;
 672                 if (dev->present) {
 673                         /*
 674                            The device is still connected so we only shutdown
 675                            pending read-/write-ops.
 676                          */
 677                         usb_kill_urb(dev->int_in_urb);
 678                         wake_up_interruptible(&dev->read_wait);
 679                         wake_up_interruptible(&dev->write_wait);
 680                         mutex_unlock(&dev->mutex);
 681                 } else {
 682                         /* The device was unplugged, cleanup resources */
 683                         mutex_unlock(&dev->mutex);
 684                         iowarrior_delete(dev);
 685                 }
 686         }
 687         return retval;
 688 }
 689
 690 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 691 {
 692         struct iowarrior *dev = file->private_data;
 693         unsigned int mask = 0;
 694
 695         if (!dev->present)
 696                 return POLLERR | POLLHUP;
 697
 698         poll_wait(file, &dev->read_wait, wait);
 699         poll_wait(file, &dev->write_wait, wait);
 700
 701         if (!dev->present)
 702                 return POLLERR | POLLHUP;
 703
 704         if (read_index(dev) != -1)
 705                 mask |= POLLIN | POLLRDNORM;
 706
 707         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 708                 mask |= POLLOUT | POLLWRNORM;
 709         return mask;
 710 }
 711
 712 /*
 713  * File operations needed when we register this driver.
 714  * This assumes that this driver NEEDS file operations,
 715  * of course, which means that the driver is expected
 716  * to have a node in the /dev directory. If the USB
 717  * device were for a network interface then the driver
 718  * would use "struct net_driver" instead, and a serial
 719  * device would use "struct tty_driver".
 720  */
 721 static const struct file_operations iowarrior_fops = {
 722         .owner = THIS_MODULE,
 723         .write = iowarrior_write,
 724         .read = iowarrior_read,
 725         .unlocked_ioctl = iowarrior_ioctl,
 726         .open = iowarrior_open,
 727         .release = iowarrior_release,
 728         .poll = iowarrior_poll,
 729         .llseek = noop_llseek,
 730 };
 731
 732 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 733 {
 734         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 735 }
 736
 737 /*
 738  * usb class driver info in order to get a minor number from the usb core,
 739  * and to have the device registered with devfs and the driver core
 740  */
 741 static struct usb_class_driver iowarrior_class = {
 742         .name = "iowarrior%d",
 743         .devnode = iowarrior_devnode,
 744         .fops = &iowarrior_fops,
 745         .minor_base = IOWARRIOR_MINOR_BASE,
 746 };
 747
 748 /*---------------------------------*/
 749 /*  probe and disconnect functions */
 750 /*---------------------------------*/
 751 /**
 752  *      iowarrior_probe
 753  *
 754  *      Called by the usb core when a new device is connected that it thinks
 755  *      this driver might be interested in.
 756  */
 757 static int iowarrior_probe(struct usb_interface *interface,
 758                            const struct usb_device_id *id)
 759 {
 760         struct usb_device *udev = interface_to_usbdev(interface);
 761         struct iowarrior *dev = NULL;
 762         struct usb_host_interface *iface_desc;
 763         struct usb_endpoint_descriptor *endpoint;
 764         int i;
 765         int retval = -ENOMEM;
 766
 767         /* allocate memory for our device state and initialize it */
 768         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 769         if (!dev)
 770                 return retval;
 771
 772         mutex_init(&dev->mutex);
 773
 774         atomic_set(&dev->intr_idx, 0);
 775         atomic_set(&dev->read_idx, 0);
 776         spin_lock_init(&dev->intr_idx_lock);
 777         atomic_set(&dev->overflow_flag, 0);
 778         init_waitqueue_head(&dev->read_wait);
 779         atomic_set(&dev->write_busy, 0);
 780         init_waitqueue_head(&dev->write_wait);
 781
 782         dev->udev = udev;
 783         dev->interface = usb_get_intf(interface);
 784
 785         iface_desc = interface->cur_altsetting;
 786         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 787
 788         init_usb_anchor(&dev->submitted);
 789
 790         /* set up the endpoint information */
 791         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 792                 endpoint = &iface_desc->endpoint[i].desc;
 793
 794                 if (usb_endpoint_is_int_in(endpoint))
 795                         dev->int_in_endpoint = endpoint;
 796                 if (usb_endpoint_is_int_out(endpoint))
 797                         /* this one will match for the IOWarrior56 only */
 798                         dev->int_out_endpoint = endpoint;
 799         }
 800
 801         if (!dev->int_in_endpoint) {
 802                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 803                 retval = -ENODEV;
 804                 goto error;
 805         }
 806
 807         if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) {
 808                 if (!dev->int_out_endpoint) {
 809                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 810                         retval = -ENODEV;
 811                         goto error;
 812                 }
 813         }
 814
 815         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 816         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 817         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 818             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 819                 /* IOWarrior56 has wMaxPacketSize different from report size */
 820                 dev->report_size = 7;
 821
 822         /* create the urb and buffer for reading */
 823         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 824         if (!dev->int_in_urb)
 825                 goto error;
 826         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 827         if (!dev->int_in_buffer)
 828                 goto error;
 829         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 830                          usb_rcvintpipe(dev->udev,
 831                                         dev->int_in_endpoint->bEndpointAddress),
 832                          dev->int_in_buffer, dev->report_size,
 833                          iowarrior_callback, dev,
 834                          dev->int_in_endpoint->bInterval);
 835         /* create an internal buffer for interrupt data from the device */
 836         dev->read_queue =
 837             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 838                     GFP_KERNEL);
 839         if (!dev->read_queue)
 840                 goto error;
 841         /* Get the serial-number of the chip */
 842         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 843         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 844                    sizeof(dev->chip_serial));
 845         if (strlen(dev->chip_serial) != 8)
 846                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 847
 848         /* Set the idle timeout to 0, if this is interface 0 */
 849         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 850             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 851                             0x0A,
 852                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 853                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 854         }
 855         /* allow device read and ioctl */
 856         dev->present = 1;
 857
 858         /* we can register the device now, as it is ready */
 859         usb_set_intfdata(interface, dev);
 860
 861         retval = usb_register_dev(interface, &iowarrior_class);
 862         if (retval) {
 863                 /* something prevented us from registering this driver */
 864                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 865                 usb_set_intfdata(interface, NULL);
 866                 goto error;
 867         }
 868
 869         dev->minor = interface->minor;
 870
 871         /* let the user know what node this device is now attached to */
 872         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 873                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 874                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 875         return retval;
 876
 877 error:
 878         iowarrior_delete(dev);
 879         return retval;
 880 }
 881
 882 /**
 883  *      iowarrior_disconnect
 884  *
 885  *      Called by the usb core when the device is removed from the system.
 886  */
 887 static void iowarrior_disconnect(struct usb_interface *interface)
 888 {
 889         struct iowarrior *dev;
 890         int minor;
 891
 892         dev = usb_get_intfdata(interface);
 893         mutex_lock(&iowarrior_open_disc_lock);
 894         usb_set_intfdata(interface, NULL);
 895
 896         minor = dev->minor;
 897         mutex_unlock(&iowarrior_open_disc_lock);
 898         /* give back our minor - this will call close() locks need to be dropped at this point*/
 899
 900         usb_deregister_dev(interface, &iowarrior_class);
 901
 902         mutex_lock(&dev->mutex);
 903
 904         /* prevent device read, write and ioctl */
 905         dev->present = 0;
 906
 907         if (dev->opened) {
 908                 /* There is a process that holds a filedescriptor to the device ,
 909                    so we only shutdown read-/write-ops going on.
 910                    Deleting the device is postponed until close() was called.
 911                  */
 912                 usb_kill_urb(dev->int_in_urb);
 913                 usb_kill_anchored_urbs(&dev->submitted);
 914                 wake_up_interruptible(&dev->read_wait);
 915                 wake_up_interruptible(&dev->write_wait);
 916                 mutex_unlock(&dev->mutex);
 917         } else {
 918                 /* no process is using the device, cleanup now */
 919                 mutex_unlock(&dev->mutex);
 920                 iowarrior_delete(dev);
 921         }
 922
 923         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 924                  minor - IOWARRIOR_MINOR_BASE);
 925 }
 926
 927 /* usb specific object needed to register this driver with the usb subsystem */
 928 static struct usb_driver iowarrior_driver = {
 929         .name = "iowarrior",
 930         .probe = iowarrior_probe,
 931         .disconnect = iowarrior_disconnect,
 932         .id_table = iowarrior_ids,
 933 };
 934
 935 module_usb_driver(iowarrior_driver);