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/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/sched.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 offical 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 /* Use our own dbg macro */
  55 #undef dbg
  56 #define dbg( format, arg... ) do { if( debug ) printk( KERN_DEBUG __FILE__ ": " format "\n" , ## arg ); } while ( 0 )
  57
  58 MODULE_AUTHOR(DRIVER_AUTHOR);
  59 MODULE_DESCRIPTION(DRIVER_DESC);
  60 MODULE_LICENSE("GPL");
  61
  62 /* Module parameters */
  63 static int debug = 0;
  64 module_param(debug, bool, 0644);
  65 MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
  66
  67 static struct usb_driver iowarrior_driver;
  68 static DEFINE_MUTEX(iowarrior_open_disc_lock);
  69
  70 /*--------------*/
  71 /*     data     */
  72 /*--------------*/
  73
  74 /* Structure to hold all of our device specific stuff */
  75 struct iowarrior {
  76         struct mutex mutex;                     /* locks this structure */
  77         struct usb_device *udev;                /* save off the usb device pointer */
  78         struct usb_interface *interface;        /* the interface for this device */
  79         unsigned char minor;                    /* the starting minor number for this device */
  80         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
  81         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
  82         struct urb *int_in_urb;         /* the urb for reading data */
  83         unsigned char *int_in_buffer;   /* buffer for data to be read */
  84         unsigned char serial_number;    /* to detect lost packages */
  85         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
  86         wait_queue_head_t read_wait;
  87         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
  88         atomic_t write_busy;            /* number of write-urbs submitted */
  89         atomic_t read_idx;
  90         atomic_t intr_idx;
  91         spinlock_t intr_idx_lock;       /* protects intr_idx */
  92         atomic_t overflow_flag;         /* signals an index 'rollover' */
  93         int present;                    /* this is 1 as long as the device is connected */
  94         int opened;                     /* this is 1 if the device is currently open */
  95         char chip_serial[9];            /* the serial number string of the chip connected */
  96         int report_size;                /* number of bytes in a report */
  97         u16 product_id;
  98 };
  99
 100 /*--------------*/
 101 /*    globals   */
 102 /*--------------*/
 103
 104 /*
 105  *  USB spec identifies 5 second timeouts.
 106  */
 107 #define GET_TIMEOUT 5
 108 #define USB_REQ_GET_REPORT  0x01
 109 //#if 0
 110 static int usb_get_report(struct usb_device *dev,
 111                           struct usb_host_interface *inter, unsigned char type,
 112                           unsigned char id, void *buf, int size)
 113 {
 114         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 115                                USB_REQ_GET_REPORT,
 116                                USB_DIR_IN | USB_TYPE_CLASS |
 117                                USB_RECIP_INTERFACE, (type << 8) + id,
 118                                inter->desc.bInterfaceNumber, buf, size,
 119                                GET_TIMEOUT*HZ);
 120 }
 121 //#endif
 122
 123 #define USB_REQ_SET_REPORT 0x09
 124
 125 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 126                           unsigned char id, void *buf, int size)
 127 {
 128         return usb_control_msg(interface_to_usbdev(intf),
 129                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 130                                USB_REQ_SET_REPORT,
 131                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 132                                (type << 8) + id,
 133                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 134                                size, HZ);
 135 }
 136
 137 /*---------------------*/
 138 /* driver registration */
 139 /*---------------------*/
 140 /* table of devices that work with this driver */
 141 static struct usb_device_id iowarrior_ids[] = {
 142         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 143         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 147         {}                      /* Terminating entry */
 148 };
 149 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 150
 151 /*
 152  * USB callback handler for reading data
 153  */
 154 static void iowarrior_callback(struct urb *urb)
 155 {
 156         struct iowarrior *dev = urb->context;
 157         int intr_idx;
 158         int read_idx;
 159         int aux_idx;
 160         int offset;
 161         int status = urb->status;
 162         int retval;
 163
 164         switch (status) {
 165         case 0:
 166                 /* success */
 167                 break;
 168         case -ECONNRESET:
 169         case -ENOENT:
 170         case -ESHUTDOWN:
 171                 return;
 172         default:
 173                 goto exit;
 174         }
 175
 176         spin_lock(&dev->intr_idx_lock);
 177         intr_idx = atomic_read(&dev->intr_idx);
 178         /* aux_idx become previous intr_idx */
 179         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 180         read_idx = atomic_read(&dev->read_idx);
 181
 182         /* queue is not empty and it's interface 0 */
 183         if ((intr_idx != read_idx)
 184             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 185                 /* + 1 for serial number */
 186                 offset = aux_idx * (dev->report_size + 1);
 187                 if (!memcmp
 188                     (dev->read_queue + offset, urb->transfer_buffer,
 189                      dev->report_size)) {
 190                         /* equal values on interface 0 will be ignored */
 191                         spin_unlock(&dev->intr_idx_lock);
 192                         goto exit;
 193                 }
 194         }
 195
 196         /* aux_idx become next intr_idx */
 197         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 198         if (read_idx == aux_idx) {
 199                 /* queue full, dropping oldest input */
 200                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 201                 atomic_set(&dev->read_idx, read_idx);
 202                 atomic_set(&dev->overflow_flag, 1);
 203         }
 204
 205         /* +1 for serial number */
 206         offset = intr_idx * (dev->report_size + 1);
 207         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 208                dev->report_size);
 209         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 210
 211         atomic_set(&dev->intr_idx, aux_idx);
 212         spin_unlock(&dev->intr_idx_lock);
 213         /* tell the blocking read about the new data */
 214         wake_up_interruptible(&dev->read_wait);
 215
 216 exit:
 217         retval = usb_submit_urb(urb, GFP_ATOMIC);
 218         if (retval)
 219                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 220                         __func__, retval);
 221
 222 }
 223
 224 /*
 225  * USB Callback handler for write-ops
 226  */
 227 static void iowarrior_write_callback(struct urb *urb)
 228 {
 229         struct iowarrior *dev;
 230         int status = urb->status;
 231
 232         dev = urb->context;
 233         /* sync/async unlink faults aren't errors */
 234         if (status &&
 235             !(status == -ENOENT ||
 236               status == -ECONNRESET || status == -ESHUTDOWN)) {
 237                 dbg("%s - nonzero write bulk status received: %d",
 238                     __func__, status);
 239         }
 240         /* free up our allocated buffer */
 241         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 242                         urb->transfer_buffer, urb->transfer_dma);
 243         /* tell a waiting writer the interrupt-out-pipe is available again */
 244         atomic_dec(&dev->write_busy);
 245         wake_up_interruptible(&dev->write_wait);
 246 }
 247
 248 /**
 249  *      iowarrior_delete
 250  */
 251 static inline void iowarrior_delete(struct iowarrior *dev)
 252 {
 253         dbg("%s - minor %d", __func__, dev->minor);
 254         kfree(dev->int_in_buffer);
 255         usb_free_urb(dev->int_in_urb);
 256         kfree(dev->read_queue);
 257         kfree(dev);
 258 }
 259
 260 /*---------------------*/
 261 /* fops implementation */
 262 /*---------------------*/
 263
 264 static int read_index(struct iowarrior *dev)
 265 {
 266         int intr_idx, read_idx;
 267
 268         read_idx = atomic_read(&dev->read_idx);
 269         intr_idx = atomic_read(&dev->intr_idx);
 270
 271         return (read_idx == intr_idx ? -1 : read_idx);
 272 }
 273
 274 /**
 275  *  iowarrior_read
 276  */
 277 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 278                               size_t count, loff_t *ppos)
 279 {
 280         struct iowarrior *dev;
 281         int read_idx;
 282         int offset;
 283
 284         dev = (struct iowarrior *)file->private_data;
 285
 286         /* verify that the device wasn't unplugged */
 287         if (dev == NULL || !dev->present)
 288                 return -ENODEV;
 289
 290         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 291
 292         /* read count must be packet size (+ time stamp) */
 293         if ((count != dev->report_size)
 294             && (count != (dev->report_size + 1)))
 295                 return -EINVAL;
 296
 297         /* repeat until no buffer overrun in callback handler occur */
 298         do {
 299                 atomic_set(&dev->overflow_flag, 0);
 300                 if ((read_idx = read_index(dev)) == -1) {
 301                         /* queue emty */
 302                         if (file->f_flags & O_NONBLOCK)
 303                                 return -EAGAIN;
 304                         else {
 305                                 //next line will return when there is either new data, or the device is unplugged
 306                                 int r = wait_event_interruptible(dev->read_wait,
 307                                                                  (!dev->present
 308                                                                   || (read_idx =
 309                                                                       read_index
 310                                                                       (dev)) !=
 311                                                                   -1));
 312                                 if (r) {
 313                                         //we were interrupted by a signal
 314                                         return -ERESTART;
 315                                 }
 316                                 if (!dev->present) {
 317                                         //The device was unplugged
 318                                         return -ENODEV;
 319                                 }
 320                                 if (read_idx == -1) {
 321                                         // Can this happen ???
 322                                         return 0;
 323                                 }
 324                         }
 325                 }
 326
 327                 offset = read_idx * (dev->report_size + 1);
 328                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 329                         return -EFAULT;
 330                 }
 331         } while (atomic_read(&dev->overflow_flag));
 332
 333         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 334         atomic_set(&dev->read_idx, read_idx);
 335         return count;
 336 }
 337
 338 /*
 339  * iowarrior_write
 340  */
 341 static ssize_t iowarrior_write(struct file *file,
 342                                const char __user *user_buffer,
 343                                size_t count, loff_t *ppos)
 344 {
 345         struct iowarrior *dev;
 346         int retval = 0;
 347         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 348         struct urb *int_out_urb = NULL;
 349
 350         dev = (struct iowarrior *)file->private_data;
 351
 352         mutex_lock(&dev->mutex);
 353         /* verify that the device wasn't unplugged */
 354         if (!dev->present) {
 355                 retval = -ENODEV;
 356                 goto exit;
 357         }
 358         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 359         /* if count is 0 we're already done */
 360         if (count == 0) {
 361                 retval = 0;
 362                 goto exit;
 363         }
 364         /* We only accept full reports */
 365         if (count != dev->report_size) {
 366                 retval = -EINVAL;
 367                 goto exit;
 368         }
 369         switch (dev->product_id) {
 370         case USB_DEVICE_ID_CODEMERCS_IOW24:
 371         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 372         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 373         case USB_DEVICE_ID_CODEMERCS_IOW40:
 374                 /* IOW24 and IOW40 use a synchronous call */
 375                 buf = kmalloc(8, GFP_KERNEL);   /* 8 bytes are enough for both products */
 376                 if (!buf) {
 377                         retval = -ENOMEM;
 378                         goto exit;
 379                 }
 380                 if (copy_from_user(buf, user_buffer, count)) {
 381                         retval = -EFAULT;
 382                         kfree(buf);
 383                         goto exit;
 384                 }
 385                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 386                 kfree(buf);
 387                 goto exit;
 388                 break;
 389         case USB_DEVICE_ID_CODEMERCS_IOW56:
 390                 /* The IOW56 uses asynchronous IO and more urbs */
 391                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 392                         /* Wait until we are below the limit for submitted urbs */
 393                         if (file->f_flags & O_NONBLOCK) {
 394                                 retval = -EAGAIN;
 395                                 goto exit;
 396                         } else {
 397                                 retval = wait_event_interruptible(dev->write_wait,
 398                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 399                                 if (retval) {
 400                                         /* we were interrupted by a signal */
 401                                         retval = -ERESTART;
 402                                         goto exit;
 403                                 }
 404                                 if (!dev->present) {
 405                                         /* The device was unplugged */
 406                                         retval = -ENODEV;
 407                                         goto exit;
 408                                 }
 409                                 if (!dev->opened) {
 410                                         /* We were closed while waiting for an URB */
 411                                         retval = -ENODEV;
 412                                         goto exit;
 413                                 }
 414                         }
 415                 }
 416                 atomic_inc(&dev->write_busy);
 417                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 418                 if (!int_out_urb) {
 419                         retval = -ENOMEM;
 420                         dbg("%s Unable to allocate urb ", __func__);
 421                         goto error_no_urb;
 422                 }
 423                 buf = usb_buffer_alloc(dev->udev, dev->report_size,
 424                                        GFP_KERNEL, &int_out_urb->transfer_dma);
 425                 if (!buf) {
 426                         retval = -ENOMEM;
 427                         dbg("%s Unable to allocate buffer ", __func__);
 428                         goto error_no_buffer;
 429                 }
 430                 usb_fill_int_urb(int_out_urb, dev->udev,
 431                                  usb_sndintpipe(dev->udev,
 432                                                 dev->int_out_endpoint->bEndpointAddress),
 433                                  buf, dev->report_size,
 434                                  iowarrior_write_callback, dev,
 435                                  dev->int_out_endpoint->bInterval);
 436                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 437                 if (copy_from_user(buf, user_buffer, count)) {
 438                         retval = -EFAULT;
 439                         goto error;
 440                 }
 441                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 442                 if (retval) {
 443                         dbg("%s submit error %d for urb nr.%d", __func__,
 444                             retval, atomic_read(&dev->write_busy));
 445                         goto error;
 446                 }
 447                 /* submit was ok */
 448                 retval = count;
 449                 usb_free_urb(int_out_urb);
 450                 goto exit;
 451                 break;
 452         default:
 453                 /* what do we have here ? An unsupported Product-ID ? */
 454                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 455                         __func__, dev->product_id);
 456                 retval = -EFAULT;
 457                 goto exit;
 458                 break;
 459         }
 460 error:
 461         usb_buffer_free(dev->udev, dev->report_size, buf,
 462                         int_out_urb->transfer_dma);
 463 error_no_buffer:
 464         usb_free_urb(int_out_urb);
 465 error_no_urb:
 466         atomic_dec(&dev->write_busy);
 467         wake_up_interruptible(&dev->write_wait);
 468 exit:
 469         mutex_unlock(&dev->mutex);
 470         return retval;
 471 }
 472
 473 /**
 474  *      iowarrior_ioctl
 475  */
 476 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 477                                                         unsigned long arg)
 478 {
 479         struct iowarrior *dev = NULL;
 480         __u8 *buffer;
 481         __u8 __user *user_buffer;
 482         int retval;
 483         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 484
 485         dev = (struct iowarrior *)file->private_data;
 486         if (dev == NULL) {
 487                 return -ENODEV;
 488         }
 489
 490         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 491         if (!buffer)
 492                 return -ENOMEM;
 493
 494         /* lock this object */
 495         lock_kernel();
 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         dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
 505             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 < 0)
 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                         /* directly from the descriptor */
 555                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 556                         info.product = dev->product_id;
 557                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 558
 559                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 560                         info.speed = le16_to_cpu(dev->udev->speed);
 561                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 562                         info.report_size = dev->report_size;
 563
 564                         /* serial number string has been read earlier 8 chars or empty string */
 565                         memcpy(info.serial, dev->chip_serial,
 566                                sizeof(dev->chip_serial));
 567                         if (cfg_descriptor == NULL) {
 568                                 info.power = -1;        /* no information available */
 569                         } else {
 570                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 571                                 info.power = cfg_descriptor->bMaxPower * 2;
 572                         }
 573                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 574                                          sizeof(struct iowarrior_info));
 575                         if (io_res < 0)
 576                                 retval = -EFAULT;
 577                         break;
 578                 }
 579         default:
 580                 /* return that we did not understand this ioctl call */
 581                 retval = -ENOTTY;
 582                 break;
 583         }
 584 error_out:
 585         /* unlock the device */
 586         mutex_unlock(&dev->mutex);
 587         unlock_kernel();
 588         kfree(buffer);
 589         return retval;
 590 }
 591
 592 /**
 593  *      iowarrior_open
 594  */
 595 static int iowarrior_open(struct inode *inode, struct file *file)
 596 {
 597         struct iowarrior *dev = NULL;
 598         struct usb_interface *interface;
 599         int subminor;
 600         int retval = 0;
 601
 602         dbg("%s", __func__);
 603
 604         subminor = iminor(inode);
 605
 606         interface = usb_find_interface(&iowarrior_driver, subminor);
 607         if (!interface) {
 608                 err("%s - error, can't find device for minor %d", __func__,
 609                     subminor);
 610                 return -ENODEV;
 611         }
 612
 613         mutex_lock(&iowarrior_open_disc_lock);
 614         dev = usb_get_intfdata(interface);
 615         if (!dev) {
 616                 mutex_unlock(&iowarrior_open_disc_lock);
 617                 return -ENODEV;
 618         }
 619
 620         mutex_lock(&dev->mutex);
 621         mutex_unlock(&iowarrior_open_disc_lock);
 622
 623         /* Only one process can open each device, no sharing. */
 624         if (dev->opened) {
 625                 retval = -EBUSY;
 626                 goto out;
 627         }
 628
 629         /* setup interrupt handler for receiving values */
 630         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 631                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 632                 retval = -EFAULT;
 633                 goto out;
 634         }
 635         /* increment our usage count for the driver */
 636         ++dev->opened;
 637         /* save our object in the file's private structure */
 638         file->private_data = dev;
 639         retval = 0;
 640
 641 out:
 642         mutex_unlock(&dev->mutex);
 643         return retval;
 644 }
 645
 646 /**
 647  *      iowarrior_release
 648  */
 649 static int iowarrior_release(struct inode *inode, struct file *file)
 650 {
 651         struct iowarrior *dev;
 652         int retval = 0;
 653
 654         dev = (struct iowarrior *)file->private_data;
 655         if (dev == NULL) {
 656                 return -ENODEV;
 657         }
 658
 659         dbg("%s - minor %d", __func__, dev->minor);
 660
 661         /* lock our device */
 662         mutex_lock(&dev->mutex);
 663
 664         if (dev->opened <= 0) {
 665                 retval = -ENODEV;       /* close called more than once */
 666                 mutex_unlock(&dev->mutex);
 667         } else {
 668                 dev->opened = 0;        /* we're closeing now */
 669                 retval = 0;
 670                 if (dev->present) {
 671                         /*
 672                            The device is still connected so we only shutdown
 673                            pending read-/write-ops.
 674                          */
 675                         usb_kill_urb(dev->int_in_urb);
 676                         wake_up_interruptible(&dev->read_wait);
 677                         wake_up_interruptible(&dev->write_wait);
 678                         mutex_unlock(&dev->mutex);
 679                 } else {
 680                         /* The device was unplugged, cleanup resources */
 681                         mutex_unlock(&dev->mutex);
 682                         iowarrior_delete(dev);
 683                 }
 684         }
 685         return retval;
 686 }
 687
 688 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 689 {
 690         struct iowarrior *dev = file->private_data;
 691         unsigned int mask = 0;
 692
 693         if (!dev->present)
 694                 return POLLERR | POLLHUP;
 695
 696         poll_wait(file, &dev->read_wait, wait);
 697         poll_wait(file, &dev->write_wait, wait);
 698
 699         if (!dev->present)
 700                 return POLLERR | POLLHUP;
 701
 702         if (read_index(dev) != -1)
 703                 mask |= POLLIN | POLLRDNORM;
 704
 705         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 706                 mask |= POLLOUT | POLLWRNORM;
 707         return mask;
 708 }
 709
 710 /*
 711  * File operations needed when we register this driver.
 712  * This assumes that this driver NEEDS file operations,
 713  * of course, which means that the driver is expected
 714  * to have a node in the /dev directory. If the USB
 715  * device were for a network interface then the driver
 716  * would use "struct net_driver" instead, and a serial
 717  * device would use "struct tty_driver".
 718  */
 719 static const struct file_operations iowarrior_fops = {
 720         .owner = THIS_MODULE,
 721         .write = iowarrior_write,
 722         .read = iowarrior_read,
 723         .unlocked_ioctl = iowarrior_ioctl,
 724         .open = iowarrior_open,
 725         .release = iowarrior_release,
 726         .poll = iowarrior_poll,
 727 };
 728
 729 static char *iowarrior_nodename(struct device *dev)
 730 {
 731         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 732 }
 733
 734 /*
 735  * usb class driver info in order to get a minor number from the usb core,
 736  * and to have the device registered with devfs and the driver core
 737  */
 738 static struct usb_class_driver iowarrior_class = {
 739         .name = "iowarrior%d",
 740         .nodename = iowarrior_nodename,
 741         .fops = &iowarrior_fops,
 742         .minor_base = IOWARRIOR_MINOR_BASE,
 743 };
 744
 745 /*---------------------------------*/
 746 /*  probe and disconnect functions */
 747 /*---------------------------------*/
 748 /**
 749  *      iowarrior_probe
 750  *
 751  *      Called by the usb core when a new device is connected that it thinks
 752  *      this driver might be interested in.
 753  */
 754 static int iowarrior_probe(struct usb_interface *interface,
 755                            const struct usb_device_id *id)
 756 {
 757         struct usb_device *udev = interface_to_usbdev(interface);
 758         struct iowarrior *dev = NULL;
 759         struct usb_host_interface *iface_desc;
 760         struct usb_endpoint_descriptor *endpoint;
 761         int i;
 762         int retval = -ENOMEM;
 763
 764         /* allocate memory for our device state and intialize it */
 765         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 766         if (dev == NULL) {
 767                 dev_err(&interface->dev, "Out of memory\n");
 768                 return retval;
 769         }
 770
 771         mutex_init(&dev->mutex);
 772
 773         atomic_set(&dev->intr_idx, 0);
 774         atomic_set(&dev->read_idx, 0);
 775         spin_lock_init(&dev->intr_idx_lock);
 776         atomic_set(&dev->overflow_flag, 0);
 777         init_waitqueue_head(&dev->read_wait);
 778         atomic_set(&dev->write_busy, 0);
 779         init_waitqueue_head(&dev->write_wait);
 780
 781         dev->udev = udev;
 782         dev->interface = interface;
 783
 784         iface_desc = interface->cur_altsetting;
 785         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 786
 787         /* set up the endpoint information */
 788         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 789                 endpoint = &iface_desc->endpoint[i].desc;
 790
 791                 if (usb_endpoint_is_int_in(endpoint))
 792                         dev->int_in_endpoint = endpoint;
 793                 if (usb_endpoint_is_int_out(endpoint))
 794                         /* this one will match for the IOWarrior56 only */
 795                         dev->int_out_endpoint = endpoint;
 796         }
 797         /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
 798         dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
 799         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 800             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 801                 /* IOWarrior56 has wMaxPacketSize different from report size */
 802                 dev->report_size = 7;
 803
 804         /* create the urb and buffer for reading */
 805         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 806         if (!dev->int_in_urb) {
 807                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 808                 goto error;
 809         }
 810         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 811         if (!dev->int_in_buffer) {
 812                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
 813                 goto error;
 814         }
 815         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 816                          usb_rcvintpipe(dev->udev,
 817                                         dev->int_in_endpoint->bEndpointAddress),
 818                          dev->int_in_buffer, dev->report_size,
 819                          iowarrior_callback, dev,
 820                          dev->int_in_endpoint->bInterval);
 821         /* create an internal buffer for interrupt data from the device */
 822         dev->read_queue =
 823             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 824                     GFP_KERNEL);
 825         if (!dev->read_queue) {
 826                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
 827                 goto error;
 828         }
 829         /* Get the serial-number of the chip */
 830         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 831         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 832                    sizeof(dev->chip_serial));
 833         if (strlen(dev->chip_serial) != 8)
 834                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 835
 836         /* Set the idle timeout to 0, if this is interface 0 */
 837         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 838             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 839                             0x0A,
 840                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 841                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 842         }
 843         /* allow device read and ioctl */
 844         dev->present = 1;
 845
 846         /* we can register the device now, as it is ready */
 847         usb_set_intfdata(interface, dev);
 848
 849         retval = usb_register_dev(interface, &iowarrior_class);
 850         if (retval) {
 851                 /* something prevented us from registering this driver */
 852                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 853                 usb_set_intfdata(interface, NULL);
 854                 goto error;
 855         }
 856
 857         dev->minor = interface->minor;
 858
 859         /* let the user know what node this device is now attached to */
 860         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 861                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 862                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 863         return retval;
 864
 865 error:
 866         iowarrior_delete(dev);
 867         return retval;
 868 }
 869
 870 /**
 871  *      iowarrior_disconnect
 872  *
 873  *      Called by the usb core when the device is removed from the system.
 874  */
 875 static void iowarrior_disconnect(struct usb_interface *interface)
 876 {
 877         struct iowarrior *dev;
 878         int minor;
 879
 880         dev = usb_get_intfdata(interface);
 881         mutex_lock(&iowarrior_open_disc_lock);
 882         usb_set_intfdata(interface, NULL);
 883
 884         minor = dev->minor;
 885
 886         /* give back our minor */
 887         usb_deregister_dev(interface, &iowarrior_class);
 888
 889         mutex_lock(&dev->mutex);
 890
 891         /* prevent device read, write and ioctl */
 892         dev->present = 0;
 893
 894         mutex_unlock(&dev->mutex);
 895         mutex_unlock(&iowarrior_open_disc_lock);
 896
 897         if (dev->opened) {
 898                 /* There is a process that holds a filedescriptor to the device ,
 899                    so we only shutdown read-/write-ops going on.
 900                    Deleting the device is postponed until close() was called.
 901                  */
 902                 usb_kill_urb(dev->int_in_urb);
 903                 wake_up_interruptible(&dev->read_wait);
 904                 wake_up_interruptible(&dev->write_wait);
 905         } else {
 906                 /* no process is using the device, cleanup now */
 907                 iowarrior_delete(dev);
 908         }
 909
 910         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 911                  minor - IOWARRIOR_MINOR_BASE);
 912 }
 913
 914 /* usb specific object needed to register this driver with the usb subsystem */
 915 static struct usb_driver iowarrior_driver = {
 916         .name = "iowarrior",
 917         .probe = iowarrior_probe,
 918         .disconnect = iowarrior_disconnect,
 919         .id_table = iowarrior_ids,
 920 };
 921
 922 static int __init iowarrior_init(void)
 923 {
 924         return usb_register(&iowarrior_driver);
 925 }
 926
 927 static void __exit iowarrior_exit(void)
 928 {
 929         usb_deregister(&iowarrior_driver);
 930 }
 931
 932 module_init(iowarrior_init);
 933 module_exit(iowarrior_exit);