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 #define USB_REQ_GET_REPORT  0x01
 100 //#if 0
 101 static int usb_get_report(struct usb_device *dev,
 102                           struct usb_host_interface *inter, unsigned char type,
 103                           unsigned char id, void *buf, int size)
 104 {
 105         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 106                                USB_REQ_GET_REPORT,
 107                                USB_DIR_IN | USB_TYPE_CLASS |
 108                                USB_RECIP_INTERFACE, (type << 8) + id,
 109                                inter->desc.bInterfaceNumber, buf, size,
 110                                USB_CTRL_GET_TIMEOUT);
 111 }
 112 //#endif
 113
 114 #define USB_REQ_SET_REPORT 0x09
 115
 116 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 117                           unsigned char id, void *buf, int size)
 118 {
 119         return usb_control_msg(interface_to_usbdev(intf),
 120                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 121                                USB_REQ_SET_REPORT,
 122                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 123                                (type << 8) + id,
 124                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 125                                size, 1000);
 126 }
 127
 128 /*---------------------*/
 129 /* driver registration */
 130 /*---------------------*/
 131 /* table of devices that work with this driver */
 132 static const struct usb_device_id iowarrior_ids[] = {
 133         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 134         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 135         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 136         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 137         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 138         {}                      /* Terminating entry */
 139 };
 140 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 141
 142 /*
 143  * USB callback handler for reading data
 144  */
 145 static void iowarrior_callback(struct urb *urb)
 146 {
 147         struct iowarrior *dev = urb->context;
 148         int intr_idx;
 149         int read_idx;
 150         int aux_idx;
 151         int offset;
 152         int status = urb->status;
 153         int retval;
 154
 155         switch (status) {
 156         case 0:
 157                 /* success */
 158                 break;
 159         case -ECONNRESET:
 160         case -ENOENT:
 161         case -ESHUTDOWN:
 162                 return;
 163         default:
 164                 goto exit;
 165         }
 166
 167         spin_lock(&dev->intr_idx_lock);
 168         intr_idx = atomic_read(&dev->intr_idx);
 169         /* aux_idx become previous intr_idx */
 170         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 171         read_idx = atomic_read(&dev->read_idx);
 172
 173         /* queue is not empty and it's interface 0 */
 174         if ((intr_idx != read_idx)
 175             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 176                 /* + 1 for serial number */
 177                 offset = aux_idx * (dev->report_size + 1);
 178                 if (!memcmp
 179                     (dev->read_queue + offset, urb->transfer_buffer,
 180                      dev->report_size)) {
 181                         /* equal values on interface 0 will be ignored */
 182                         spin_unlock(&dev->intr_idx_lock);
 183                         goto exit;
 184                 }
 185         }
 186
 187         /* aux_idx become next intr_idx */
 188         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 189         if (read_idx == aux_idx) {
 190                 /* queue full, dropping oldest input */
 191                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 192                 atomic_set(&dev->read_idx, read_idx);
 193                 atomic_set(&dev->overflow_flag, 1);
 194         }
 195
 196         /* +1 for serial number */
 197         offset = intr_idx * (dev->report_size + 1);
 198         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 199                dev->report_size);
 200         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 201
 202         atomic_set(&dev->intr_idx, aux_idx);
 203         spin_unlock(&dev->intr_idx_lock);
 204         /* tell the blocking read about the new data */
 205         wake_up_interruptible(&dev->read_wait);
 206
 207 exit:
 208         retval = usb_submit_urb(urb, GFP_ATOMIC);
 209         if (retval)
 210                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 211                         __func__, retval);
 212
 213 }
 214
 215 /*
 216  * USB Callback handler for write-ops
 217  */
 218 static void iowarrior_write_callback(struct urb *urb)
 219 {
 220         struct iowarrior *dev;
 221         int status = urb->status;
 222
 223         dev = urb->context;
 224         /* sync/async unlink faults aren't errors */
 225         if (status &&
 226             !(status == -ENOENT ||
 227               status == -ECONNRESET || status == -ESHUTDOWN)) {
 228                 dev_dbg(&dev->interface->dev,
 229                         "nonzero write bulk status received: %d\n", status);
 230         }
 231         /* free up our allocated buffer */
 232         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 233                           urb->transfer_buffer, urb->transfer_dma);
 234         /* tell a waiting writer the interrupt-out-pipe is available again */
 235         atomic_dec(&dev->write_busy);
 236         wake_up_interruptible(&dev->write_wait);
 237 }
 238
 239 /**
 240  *      iowarrior_delete
 241  */
 242 static inline void iowarrior_delete(struct iowarrior *dev)
 243 {
 244         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 245         kfree(dev->int_in_buffer);
 246         usb_free_urb(dev->int_in_urb);
 247         kfree(dev->read_queue);
 248         usb_put_intf(dev->interface);
 249         kfree(dev);
 250 }
 251
 252 /*---------------------*/
 253 /* fops implementation */
 254 /*---------------------*/
 255
 256 static int read_index(struct iowarrior *dev)
 257 {
 258         int intr_idx, read_idx;
 259
 260         read_idx = atomic_read(&dev->read_idx);
 261         intr_idx = atomic_read(&dev->intr_idx);
 262
 263         return (read_idx == intr_idx ? -1 : read_idx);
 264 }
 265
 266 /**
 267  *  iowarrior_read
 268  */
 269 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 270                               size_t count, loff_t *ppos)
 271 {
 272         struct iowarrior *dev;
 273         int read_idx;
 274         int offset;
 275
 276         dev = file->private_data;
 277
 278         /* verify that the device wasn't unplugged */
 279         if (!dev || !dev->present)
 280                 return -ENODEV;
 281
 282         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 283                 dev->minor, count);
 284
 285         /* read count must be packet size (+ time stamp) */
 286         if ((count != dev->report_size)
 287             && (count != (dev->report_size + 1)))
 288                 return -EINVAL;
 289
 290         /* repeat until no buffer overrun in callback handler occur */
 291         do {
 292                 atomic_set(&dev->overflow_flag, 0);
 293                 if ((read_idx = read_index(dev)) == -1) {
 294                         /* queue empty */
 295                         if (file->f_flags & O_NONBLOCK)
 296                                 return -EAGAIN;
 297                         else {
 298                                 //next line will return when there is either new data, or the device is unplugged
 299                                 int r = wait_event_interruptible(dev->read_wait,
 300                                                                  (!dev->present
 301                                                                   || (read_idx =
 302                                                                       read_index
 303                                                                       (dev)) !=
 304                                                                   -1));
 305                                 if (r) {
 306                                         //we were interrupted by a signal
 307                                         return -ERESTART;
 308                                 }
 309                                 if (!dev->present) {
 310                                         //The device was unplugged
 311                                         return -ENODEV;
 312                                 }
 313                                 if (read_idx == -1) {
 314                                         // Can this happen ???
 315                                         return 0;
 316                                 }
 317                         }
 318                 }
 319
 320                 offset = read_idx * (dev->report_size + 1);
 321                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 322                         return -EFAULT;
 323                 }
 324         } while (atomic_read(&dev->overflow_flag));
 325
 326         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 327         atomic_set(&dev->read_idx, read_idx);
 328         return count;
 329 }
 330
 331 /*
 332  * iowarrior_write
 333  */
 334 static ssize_t iowarrior_write(struct file *file,
 335                                const char __user *user_buffer,
 336                                size_t count, loff_t *ppos)
 337 {
 338         struct iowarrior *dev;
 339         int retval = 0;
 340         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 341         struct urb *int_out_urb = NULL;
 342
 343         dev = file->private_data;
 344
 345         mutex_lock(&dev->mutex);
 346         /* verify that the device wasn't unplugged */
 347         if (!dev->present) {
 348                 retval = -ENODEV;
 349                 goto exit;
 350         }
 351         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 352                 dev->minor, count);
 353         /* if count is 0 we're already done */
 354         if (count == 0) {
 355                 retval = 0;
 356                 goto exit;
 357         }
 358         /* We only accept full reports */
 359         if (count != dev->report_size) {
 360                 retval = -EINVAL;
 361                 goto exit;
 362         }
 363         switch (dev->product_id) {
 364         case USB_DEVICE_ID_CODEMERCS_IOW24:
 365         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 366         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 367         case USB_DEVICE_ID_CODEMERCS_IOW40:
 368                 /* IOW24 and IOW40 use a synchronous call */
 369                 buf = kmalloc(count, GFP_KERNEL);
 370                 if (!buf) {
 371                         retval = -ENOMEM;
 372                         goto exit;
 373                 }
 374                 if (copy_from_user(buf, user_buffer, count)) {
 375                         retval = -EFAULT;
 376                         kfree(buf);
 377                         goto exit;
 378                 }
 379                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 380                 kfree(buf);
 381                 goto exit;
 382                 break;
 383         case USB_DEVICE_ID_CODEMERCS_IOW56:
 384                 /* The IOW56 uses asynchronous IO and more urbs */
 385                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 386                         /* Wait until we are below the limit for submitted urbs */
 387                         if (file->f_flags & O_NONBLOCK) {
 388                                 retval = -EAGAIN;
 389                                 goto exit;
 390                         } else {
 391                                 retval = wait_event_interruptible(dev->write_wait,
 392                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 393                                 if (retval) {
 394                                         /* we were interrupted by a signal */
 395                                         retval = -ERESTART;
 396                                         goto exit;
 397                                 }
 398                                 if (!dev->present) {
 399                                         /* The device was unplugged */
 400                                         retval = -ENODEV;
 401                                         goto exit;
 402                                 }
 403                                 if (!dev->opened) {
 404                                         /* We were closed while waiting for an URB */
 405                                         retval = -ENODEV;
 406                                         goto exit;
 407                                 }
 408                         }
 409                 }
 410                 atomic_inc(&dev->write_busy);
 411                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 412                 if (!int_out_urb) {
 413                         retval = -ENOMEM;
 414                         goto error_no_urb;
 415                 }
 416                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 417                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 418                 if (!buf) {
 419                         retval = -ENOMEM;
 420                         dev_dbg(&dev->interface->dev,
 421                                 "Unable to allocate buffer\n");
 422                         goto error_no_buffer;
 423                 }
 424                 usb_fill_int_urb(int_out_urb, dev->udev,
 425                                  usb_sndintpipe(dev->udev,
 426                                                 dev->int_out_endpoint->bEndpointAddress),
 427                                  buf, dev->report_size,
 428                                  iowarrior_write_callback, dev,
 429                                  dev->int_out_endpoint->bInterval);
 430                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 431                 if (copy_from_user(buf, user_buffer, count)) {
 432                         retval = -EFAULT;
 433                         goto error;
 434                 }
 435                 usb_anchor_urb(int_out_urb, &dev->submitted);
 436                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 437                 if (retval) {
 438                         dev_dbg(&dev->interface->dev,
 439                                 "submit error %d for urb nr.%d\n",
 440                                 retval, atomic_read(&dev->write_busy));
 441                         usb_unanchor_urb(int_out_urb);
 442                         goto error;
 443                 }
 444                 /* submit was ok */
 445                 retval = count;
 446                 usb_free_urb(int_out_urb);
 447                 goto exit;
 448                 break;
 449         default:
 450                 /* what do we have here ? An unsupported Product-ID ? */
 451                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 452                         __func__, dev->product_id);
 453                 retval = -EFAULT;
 454                 goto exit;
 455                 break;
 456         }
 457 error:
 458         usb_free_coherent(dev->udev, dev->report_size, buf,
 459                           int_out_urb->transfer_dma);
 460 error_no_buffer:
 461         usb_free_urb(int_out_urb);
 462 error_no_urb:
 463         atomic_dec(&dev->write_busy);
 464         wake_up_interruptible(&dev->write_wait);
 465 exit:
 466         mutex_unlock(&dev->mutex);
 467         return retval;
 468 }
 469
 470 /**
 471  *      iowarrior_ioctl
 472  */
 473 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 474                                                         unsigned long arg)
 475 {
 476         struct iowarrior *dev = NULL;
 477         __u8 *buffer;
 478         __u8 __user *user_buffer;
 479         int retval;
 480         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 481
 482         dev = file->private_data;
 483         if (!dev)
 484                 return -ENODEV;
 485
 486         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 487         if (!buffer)
 488                 return -ENOMEM;
 489
 490         /* lock this object */
 491         mutex_lock(&iowarrior_mutex);
 492         mutex_lock(&dev->mutex);
 493
 494         /* verify that the device wasn't unplugged */
 495         if (!dev->present) {
 496                 retval = -ENODEV;
 497                 goto error_out;
 498         }
 499
 500         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 501                 dev->minor, cmd, arg);
 502
 503         retval = 0;
 504         io_res = 0;
 505         switch (cmd) {
 506         case IOW_WRITE:
 507                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 508                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 509                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 510                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 511                         user_buffer = (__u8 __user *)arg;
 512                         io_res = copy_from_user(buffer, user_buffer,
 513                                                 dev->report_size);
 514                         if (io_res) {
 515                                 retval = -EFAULT;
 516                         } else {
 517                                 io_res = usb_set_report(dev->interface, 2, 0,
 518                                                         buffer,
 519                                                         dev->report_size);
 520                                 if (io_res < 0)
 521                                         retval = io_res;
 522                         }
 523                 } else {
 524                         retval = -EINVAL;
 525                         dev_err(&dev->interface->dev,
 526                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 527                                 dev->product_id);
 528                 }
 529                 break;
 530         case IOW_READ:
 531                 user_buffer = (__u8 __user *)arg;
 532                 io_res = usb_get_report(dev->udev,
 533                                         dev->interface->cur_altsetting, 1, 0,
 534                                         buffer, dev->report_size);
 535                 if (io_res < 0)
 536                         retval = io_res;
 537                 else {
 538                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 539                         if (io_res)
 540                                 retval = -EFAULT;
 541                 }
 542                 break;
 543         case IOW_GETINFO:
 544                 {
 545                         /* Report available information for the device */
 546                         struct iowarrior_info info;
 547                         /* needed for power consumption */
 548                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 549
 550                         memset(&info, 0, sizeof(info));
 551                         /* directly from the descriptor */
 552                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 553                         info.product = dev->product_id;
 554                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 555
 556                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 557                         info.speed = dev->udev->speed;
 558                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 559                         info.report_size = dev->report_size;
 560
 561                         /* serial number string has been read earlier 8 chars or empty string */
 562                         memcpy(info.serial, dev->chip_serial,
 563                                sizeof(dev->chip_serial));
 564                         if (cfg_descriptor == NULL) {
 565                                 info.power = -1;        /* no information available */
 566                         } else {
 567                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 568                                 info.power = cfg_descriptor->bMaxPower * 2;
 569                         }
 570                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 571                                          sizeof(struct iowarrior_info));
 572                         if (io_res)
 573                                 retval = -EFAULT;
 574                         break;
 575                 }
 576         default:
 577                 /* return that we did not understand this ioctl call */
 578                 retval = -ENOTTY;
 579                 break;
 580         }
 581 error_out:
 582         /* unlock the device */
 583         mutex_unlock(&dev->mutex);
 584         mutex_unlock(&iowarrior_mutex);
 585         kfree(buffer);
 586         return retval;
 587 }
 588
 589 /**
 590  *      iowarrior_open
 591  */
 592 static int iowarrior_open(struct inode *inode, struct file *file)
 593 {
 594         struct iowarrior *dev = NULL;
 595         struct usb_interface *interface;
 596         int subminor;
 597         int retval = 0;
 598
 599         mutex_lock(&iowarrior_mutex);
 600         subminor = iminor(inode);
 601
 602         interface = usb_find_interface(&iowarrior_driver, subminor);
 603         if (!interface) {
 604                 mutex_unlock(&iowarrior_mutex);
 605                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 606                        __func__, subminor);
 607                 return -ENODEV;
 608         }
 609
 610         mutex_lock(&iowarrior_open_disc_lock);
 611         dev = usb_get_intfdata(interface);
 612         if (!dev) {
 613                 mutex_unlock(&iowarrior_open_disc_lock);
 614                 mutex_unlock(&iowarrior_mutex);
 615                 return -ENODEV;
 616         }
 617
 618         mutex_lock(&dev->mutex);
 619         mutex_unlock(&iowarrior_open_disc_lock);
 620
 621         /* Only one process can open each device, no sharing. */
 622         if (dev->opened) {
 623                 retval = -EBUSY;
 624                 goto out;
 625         }
 626
 627         /* setup interrupt handler for receiving values */
 628         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 629                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 630                 retval = -EFAULT;
 631                 goto out;
 632         }
 633         /* increment our usage count for the driver */
 634         ++dev->opened;
 635         /* save our object in the file's private structure */
 636         file->private_data = dev;
 637         retval = 0;
 638
 639 out:
 640         mutex_unlock(&dev->mutex);
 641         mutex_unlock(&iowarrior_mutex);
 642         return retval;
 643 }
 644
 645 /**
 646  *      iowarrior_release
 647  */
 648 static int iowarrior_release(struct inode *inode, struct file *file)
 649 {
 650         struct iowarrior *dev;
 651         int retval = 0;
 652
 653         dev = file->private_data;
 654         if (!dev)
 655                 return -ENODEV;
 656
 657         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 658
 659         /* lock our device */
 660         mutex_lock(&dev->mutex);
 661
 662         if (dev->opened <= 0) {
 663                 retval = -ENODEV;       /* close called more than once */
 664                 mutex_unlock(&dev->mutex);
 665         } else {
 666                 dev->opened = 0;        /* we're closing now */
 667                 retval = 0;
 668                 if (dev->present) {
 669                         /*
 670                            The device is still connected so we only shutdown
 671                            pending read-/write-ops.
 672                          */
 673                         usb_kill_urb(dev->int_in_urb);
 674                         wake_up_interruptible(&dev->read_wait);
 675                         wake_up_interruptible(&dev->write_wait);
 676                         mutex_unlock(&dev->mutex);
 677                 } else {
 678                         /* The device was unplugged, cleanup resources */
 679                         mutex_unlock(&dev->mutex);
 680                         iowarrior_delete(dev);
 681                 }
 682         }
 683         return retval;
 684 }
 685
 686 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 687 {
 688         struct iowarrior *dev = file->private_data;
 689         unsigned int mask = 0;
 690
 691         if (!dev->present)
 692                 return POLLERR | POLLHUP;
 693
 694         poll_wait(file, &dev->read_wait, wait);
 695         poll_wait(file, &dev->write_wait, wait);
 696
 697         if (!dev->present)
 698                 return POLLERR | POLLHUP;
 699
 700         if (read_index(dev) != -1)
 701                 mask |= POLLIN | POLLRDNORM;
 702
 703         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 704                 mask |= POLLOUT | POLLWRNORM;
 705         return mask;
 706 }
 707
 708 /*
 709  * File operations needed when we register this driver.
 710  * This assumes that this driver NEEDS file operations,
 711  * of course, which means that the driver is expected
 712  * to have a node in the /dev directory. If the USB
 713  * device were for a network interface then the driver
 714  * would use "struct net_driver" instead, and a serial
 715  * device would use "struct tty_driver".
 716  */
 717 static const struct file_operations iowarrior_fops = {
 718         .owner = THIS_MODULE,
 719         .write = iowarrior_write,
 720         .read = iowarrior_read,
 721         .unlocked_ioctl = iowarrior_ioctl,
 722         .open = iowarrior_open,
 723         .release = iowarrior_release,
 724         .poll = iowarrior_poll,
 725         .llseek = noop_llseek,
 726 };
 727
 728 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 729 {
 730         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 731 }
 732
 733 /*
 734  * usb class driver info in order to get a minor number from the usb core,
 735  * and to have the device registered with devfs and the driver core
 736  */
 737 static struct usb_class_driver iowarrior_class = {
 738         .name = "iowarrior%d",
 739         .devnode = iowarrior_devnode,
 740         .fops = &iowarrior_fops,
 741         .minor_base = IOWARRIOR_MINOR_BASE,
 742 };
 743
 744 /*---------------------------------*/
 745 /*  probe and disconnect functions */
 746 /*---------------------------------*/
 747 /**
 748  *      iowarrior_probe
 749  *
 750  *      Called by the usb core when a new device is connected that it thinks
 751  *      this driver might be interested in.
 752  */
 753 static int iowarrior_probe(struct usb_interface *interface,
 754                            const struct usb_device_id *id)
 755 {
 756         struct usb_device *udev = interface_to_usbdev(interface);
 757         struct iowarrior *dev = NULL;
 758         struct usb_host_interface *iface_desc;
 759         struct usb_endpoint_descriptor *endpoint;
 760         int i;
 761         int retval = -ENOMEM;
 762
 763         /* allocate memory for our device state and initialize it */
 764         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 765         if (!dev)
 766                 return retval;
 767
 768         mutex_init(&dev->mutex);
 769
 770         atomic_set(&dev->intr_idx, 0);
 771         atomic_set(&dev->read_idx, 0);
 772         spin_lock_init(&dev->intr_idx_lock);
 773         atomic_set(&dev->overflow_flag, 0);
 774         init_waitqueue_head(&dev->read_wait);
 775         atomic_set(&dev->write_busy, 0);
 776         init_waitqueue_head(&dev->write_wait);
 777
 778         dev->udev = udev;
 779         dev->interface = usb_get_intf(interface);
 780
 781         iface_desc = interface->cur_altsetting;
 782         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 783
 784         init_usb_anchor(&dev->submitted);
 785
 786         /* set up the endpoint information */
 787         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 788                 endpoint = &iface_desc->endpoint[i].desc;
 789
 790                 if (usb_endpoint_is_int_in(endpoint))
 791                         dev->int_in_endpoint = endpoint;
 792                 if (usb_endpoint_is_int_out(endpoint))
 793                         /* this one will match for the IOWarrior56 only */
 794                         dev->int_out_endpoint = endpoint;
 795         }
 796
 797         if (!dev->int_in_endpoint) {
 798                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 799                 retval = -ENODEV;
 800                 goto error;
 801         }
 802
 803         if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) {
 804                 if (!dev->int_out_endpoint) {
 805                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 806                         retval = -ENODEV;
 807                         goto error;
 808                 }
 809         }
 810
 811         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 812         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 813         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 814             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 815                 /* IOWarrior56 has wMaxPacketSize different from report size */
 816                 dev->report_size = 7;
 817
 818         /* create the urb and buffer for reading */
 819         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 820         if (!dev->int_in_urb)
 821                 goto error;
 822         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 823         if (!dev->int_in_buffer)
 824                 goto error;
 825         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 826                          usb_rcvintpipe(dev->udev,
 827                                         dev->int_in_endpoint->bEndpointAddress),
 828                          dev->int_in_buffer, dev->report_size,
 829                          iowarrior_callback, dev,
 830                          dev->int_in_endpoint->bInterval);
 831         /* create an internal buffer for interrupt data from the device */
 832         dev->read_queue =
 833             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 834                     GFP_KERNEL);
 835         if (!dev->read_queue)
 836                 goto error;
 837         /* Get the serial-number of the chip */
 838         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 839         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 840                    sizeof(dev->chip_serial));
 841         if (strlen(dev->chip_serial) != 8)
 842                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 843
 844         /* Set the idle timeout to 0, if this is interface 0 */
 845         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 846             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 847                             0x0A,
 848                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 849                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 850         }
 851         /* allow device read and ioctl */
 852         dev->present = 1;
 853
 854         /* we can register the device now, as it is ready */
 855         usb_set_intfdata(interface, dev);
 856
 857         retval = usb_register_dev(interface, &iowarrior_class);
 858         if (retval) {
 859                 /* something prevented us from registering this driver */
 860                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 861                 usb_set_intfdata(interface, NULL);
 862                 goto error;
 863         }
 864
 865         dev->minor = interface->minor;
 866
 867         /* let the user know what node this device is now attached to */
 868         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 869                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 870                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 871         return retval;
 872
 873 error:
 874         iowarrior_delete(dev);
 875         return retval;
 876 }
 877
 878 /**
 879  *      iowarrior_disconnect
 880  *
 881  *      Called by the usb core when the device is removed from the system.
 882  */
 883 static void iowarrior_disconnect(struct usb_interface *interface)
 884 {
 885         struct iowarrior *dev;
 886         int minor;
 887
 888         dev = usb_get_intfdata(interface);
 889         mutex_lock(&iowarrior_open_disc_lock);
 890         usb_set_intfdata(interface, NULL);
 891
 892         minor = dev->minor;
 893         mutex_unlock(&iowarrior_open_disc_lock);
 894         /* give back our minor - this will call close() locks need to be dropped at this point*/
 895
 896         usb_deregister_dev(interface, &iowarrior_class);
 897
 898         mutex_lock(&dev->mutex);
 899
 900         /* prevent device read, write and ioctl */
 901         dev->present = 0;
 902
 903         if (dev->opened) {
 904                 /* There is a process that holds a filedescriptor to the device ,
 905                    so we only shutdown read-/write-ops going on.
 906                    Deleting the device is postponed until close() was called.
 907                  */
 908                 usb_kill_urb(dev->int_in_urb);
 909                 usb_kill_anchored_urbs(&dev->submitted);
 910                 wake_up_interruptible(&dev->read_wait);
 911                 wake_up_interruptible(&dev->write_wait);
 912                 mutex_unlock(&dev->mutex);
 913         } else {
 914                 /* no process is using the device, cleanup now */
 915                 mutex_unlock(&dev->mutex);
 916                 iowarrior_delete(dev);
 917         }
 918
 919         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 920                  minor - IOWARRIOR_MINOR_BASE);
 921 }
 922
 923 /* usb specific object needed to register this driver with the usb subsystem */
 924 static struct usb_driver iowarrior_driver = {
 925         .name = "iowarrior",
 926         .probe = iowarrior_probe,
 927         .disconnect = iowarrior_disconnect,
 928         .id_table = iowarrior_ids,
 929 };
 930
 931 module_usb_driver(iowarrior_driver);