SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/version.h>
  23 #include <linux/usb/iowarrior.h>
  24
  25 /* Version Information */
  26 #define DRIVER_VERSION "v0.4.0"
  27 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
  28 #define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
  29
  30 #define USB_VENDOR_ID_CODEMERCS         1984
  31 /* low speed iowarrior */
  32 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
  33 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
  34 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
  35 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
  36 /* full speed iowarrior */
  37 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
  38
  39 /* Get a minor range for your devices from the usb maintainer */
  40 #ifdef CONFIG_USB_DYNAMIC_MINORS
  41 #define IOWARRIOR_MINOR_BASE    0
  42 #else
  43 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not offical yet
  44 #endif
  45
  46 /* interrupt input queue size */
  47 #define MAX_INTERRUPT_BUFFER 16
  48 /*
  49    maximum number of urbs that are submitted for writes at the same time,
  50    this applies to the IOWarrior56 only!
  51    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
  52 */
  53 #define MAX_WRITES_IN_FLIGHT 4
  54
  55 /* Use our own dbg macro */
  56 #undef dbg
  57 #define dbg( format, arg... ) do { if( debug ) printk( KERN_DEBUG __FILE__ ": " format "\n" , ## arg ); } while ( 0 )
  58
  59 MODULE_AUTHOR(DRIVER_AUTHOR);
  60 MODULE_DESCRIPTION(DRIVER_DESC);
  61 MODULE_LICENSE("GPL");
  62
  63 /* Module parameters */
  64 static int debug = 0;
  65 module_param(debug, bool, 0644);
  66 MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
  67
  68 static struct usb_driver iowarrior_driver;
  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 /* prevent races between open() and disconnect() */
 104 static DECLARE_MUTEX(disconnect_sem);
 105
 106 /*
 107  *  USB spec identifies 5 second timeouts.
 108  */
 109 #define GET_TIMEOUT 5
 110 #define USB_REQ_GET_REPORT  0x01
 111 //#if 0
 112 static int usb_get_report(struct usb_device *dev,
 113                           struct usb_host_interface *inter, unsigned char type,
 114                           unsigned char id, void *buf, int size)
 115 {
 116         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 117                                USB_REQ_GET_REPORT,
 118                                USB_DIR_IN | USB_TYPE_CLASS |
 119                                USB_RECIP_INTERFACE, (type << 8) + id,
 120                                inter->desc.bInterfaceNumber, buf, size,
 121                                GET_TIMEOUT*HZ);
 122 }
 123 //#endif
 124
 125 #define USB_REQ_SET_REPORT 0x09
 126
 127 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 128                           unsigned char id, void *buf, int size)
 129 {
 130         return usb_control_msg(interface_to_usbdev(intf),
 131                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 132                                USB_REQ_SET_REPORT,
 133                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 134                                (type << 8) + id,
 135                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 136                                size, HZ);
 137 }
 138
 139 /*---------------------*/
 140 /* driver registration */
 141 /*---------------------*/
 142 /* table of devices that work with this driver */
 143 static struct usb_device_id iowarrior_ids[] = {
 144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 147         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 148         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 149         {}                      /* Terminating entry */
 150 };
 151 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 152
 153 /*
 154  * USB callback handler for reading data
 155  */
 156 static void iowarrior_callback(struct urb *urb)
 157 {
 158         struct iowarrior *dev = (struct iowarrior *)urb->context;
 159         int intr_idx;
 160         int read_idx;
 161         int aux_idx;
 162         int offset;
 163         int status;
 164
 165         switch (urb->status) {
 166         case 0:
 167                 /* success */
 168                 break;
 169         case -ECONNRESET:
 170         case -ENOENT:
 171         case -ESHUTDOWN:
 172                 return;
 173         default:
 174                 goto exit;
 175         }
 176
 177         spin_lock(&dev->intr_idx_lock);
 178         intr_idx = atomic_read(&dev->intr_idx);
 179         /* aux_idx become previous intr_idx */
 180         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 181         read_idx = atomic_read(&dev->read_idx);
 182
 183         /* queue is not empty and it's interface 0 */
 184         if ((intr_idx != read_idx)
 185             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 186                 /* + 1 for serial number */
 187                 offset = aux_idx * (dev->report_size + 1);
 188                 if (!memcmp
 189                     (dev->read_queue + offset, urb->transfer_buffer,
 190                      dev->report_size)) {
 191                         /* equal values on interface 0 will be ignored */
 192                         spin_unlock(&dev->intr_idx_lock);
 193                         goto exit;
 194                 }
 195         }
 196
 197         /* aux_idx become next intr_idx */
 198         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 199         if (read_idx == aux_idx) {
 200                 /* queue full, dropping oldest input */
 201                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 202                 atomic_set(&dev->read_idx, read_idx);
 203                 atomic_set(&dev->overflow_flag, 1);
 204         }
 205
 206         /* +1 for serial number */
 207         offset = intr_idx * (dev->report_size + 1);
 208         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 209                dev->report_size);
 210         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 211
 212         atomic_set(&dev->intr_idx, aux_idx);
 213         spin_unlock(&dev->intr_idx_lock);
 214         /* tell the blocking read about the new data */
 215         wake_up_interruptible(&dev->read_wait);
 216
 217 exit:
 218         status = usb_submit_urb(urb, GFP_ATOMIC);
 219         if (status)
 220                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d",
 221                         __FUNCTION__, status);
 222
 223 }
 224
 225 /*
 226  * USB Callback handler for write-ops
 227  */
 228 static void iowarrior_write_callback(struct urb *urb)
 229 {
 230         struct iowarrior *dev;
 231         dev = (struct iowarrior *)urb->context;
 232         /* sync/async unlink faults aren't errors */
 233         if (urb->status &&
 234             !(urb->status == -ENOENT ||
 235               urb->status == -ECONNRESET || urb->status == -ESHUTDOWN)) {
 236                 dbg("%s - nonzero write bulk status received: %d",
 237                     __func__, urb->status);
 238         }
 239         /* free up our allocated buffer */
 240         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 241                         urb->transfer_buffer, urb->transfer_dma);
 242         /* tell a waiting writer the interrupt-out-pipe is available again */
 243         atomic_dec(&dev->write_busy);
 244         wake_up_interruptible(&dev->write_wait);
 245 }
 246
 247 /**
 248  *      iowarrior_delete
 249  */
 250 static inline void iowarrior_delete(struct iowarrior *dev)
 251 {
 252         dbg("%s - minor %d", __func__, dev->minor);
 253         kfree(dev->int_in_buffer);
 254         usb_free_urb(dev->int_in_urb);
 255         kfree(dev->read_queue);
 256         kfree(dev);
 257 }
 258
 259 /*---------------------*/
 260 /* fops implementation */
 261 /*---------------------*/
 262
 263 static int read_index(struct iowarrior *dev)
 264 {
 265         int intr_idx, read_idx;
 266
 267         read_idx = atomic_read(&dev->read_idx);
 268         intr_idx = atomic_read(&dev->intr_idx);
 269
 270         return (read_idx == intr_idx ? -1 : read_idx);
 271 }
 272
 273 /**
 274  *  iowarrior_read
 275  */
 276 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 277                               size_t count, loff_t *ppos)
 278 {
 279         struct iowarrior *dev;
 280         int read_idx;
 281         int offset;
 282
 283         dev = (struct iowarrior *)file->private_data;
 284
 285         /* verify that the device wasn't unplugged */
 286         if (dev == NULL || !dev->present)
 287                 return -ENODEV;
 288
 289         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 290
 291         /* read count must be packet size (+ time stamp) */
 292         if ((count != dev->report_size)
 293             && (count != (dev->report_size + 1)))
 294                 return -EINVAL;
 295
 296         /* repeat until no buffer overrun in callback handler occur */
 297         do {
 298                 atomic_set(&dev->overflow_flag, 0);
 299                 if ((read_idx = read_index(dev)) == -1) {
 300                         /* queue emty */
 301                         if (file->f_flags & O_NONBLOCK)
 302                                 return -EAGAIN;
 303                         else {
 304                                 //next line will return when there is either new data, or the device is unplugged
 305                                 int r = wait_event_interruptible(dev->read_wait,
 306                                                                  (!dev->present
 307                                                                   || (read_idx =
 308                                                                       read_index
 309                                                                       (dev)) !=
 310                                                                   -1));
 311                                 if (r) {
 312                                         //we were interrupted by a signal
 313                                         return -ERESTART;
 314                                 }
 315                                 if (!dev->present) {
 316                                         //The device was unplugged
 317                                         return -ENODEV;
 318                                 }
 319                                 if (read_idx == -1) {
 320                                         // Can this happen ???
 321                                         return 0;
 322                                 }
 323                         }
 324                 }
 325
 326                 offset = read_idx * (dev->report_size + 1);
 327                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 328                         return -EFAULT;
 329                 }
 330         } while (atomic_read(&dev->overflow_flag));
 331
 332         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 333         atomic_set(&dev->read_idx, read_idx);
 334         return count;
 335 }
 336
 337 /*
 338  * iowarrior_write
 339  */
 340 static ssize_t iowarrior_write(struct file *file,
 341                                const char __user *user_buffer,
 342                                size_t count, loff_t *ppos)
 343 {
 344         struct iowarrior *dev;
 345         int retval = 0;
 346         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 347         struct urb *int_out_urb = NULL;
 348
 349         dev = (struct iowarrior *)file->private_data;
 350
 351         mutex_lock(&dev->mutex);
 352         /* verify that the device wasn't unplugged */
 353         if (dev == NULL || !dev->present) {
 354                 retval = -ENODEV;
 355                 goto exit;
 356         }
 357         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 358         /* if count is 0 we're already done */
 359         if (count == 0) {
 360                 retval = 0;
 361                 goto exit;
 362         }
 363         /* We only accept full reports */
 364         if (count != dev->report_size) {
 365                 retval = -EINVAL;
 366                 goto exit;
 367         }
 368         switch (dev->product_id) {
 369         case USB_DEVICE_ID_CODEMERCS_IOW24:
 370         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 371         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 372         case USB_DEVICE_ID_CODEMERCS_IOW40:
 373                 /* IOW24 and IOW40 use a synchronous call */
 374                 buf = kmalloc(8, GFP_KERNEL);   /* 8 bytes are enough for both products */
 375                 if (!buf) {
 376                         retval = -ENOMEM;
 377                         goto exit;
 378                 }
 379                 if (copy_from_user(buf, user_buffer, count)) {
 380                         retval = -EFAULT;
 381                         kfree(buf);
 382                         goto exit;
 383                 }
 384                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 385                 kfree(buf);
 386                 goto exit;
 387                 break;
 388         case USB_DEVICE_ID_CODEMERCS_IOW56:
 389                 /* The IOW56 uses asynchronous IO and more urbs */
 390                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 391                         /* Wait until we are below the limit for submitted urbs */
 392                         if (file->f_flags & O_NONBLOCK) {
 393                                 retval = -EAGAIN;
 394                                 goto exit;
 395                         } else {
 396                                 retval = wait_event_interruptible(dev->write_wait,
 397                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 398                                 if (retval) {
 399                                         /* we were interrupted by a signal */
 400                                         retval = -ERESTART;
 401                                         goto exit;
 402                                 }
 403                                 if (!dev->present) {
 404                                         /* The device was unplugged */
 405                                         retval = -ENODEV;
 406                                         goto exit;
 407                                 }
 408                                 if (!dev->opened) {
 409                                         /* We were closed while waiting for an URB */
 410                                         retval = -ENODEV;
 411                                         goto exit;
 412                                 }
 413                         }
 414                 }
 415                 atomic_inc(&dev->write_busy);
 416                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 417                 if (!int_out_urb) {
 418                         retval = -ENOMEM;
 419                         dbg("%s Unable to allocate urb ", __func__);
 420                         goto error_no_urb;
 421                 }
 422                 buf = usb_buffer_alloc(dev->udev, dev->report_size,
 423                                        GFP_KERNEL, &int_out_urb->transfer_dma);
 424                 if (!buf) {
 425                         retval = -ENOMEM;
 426                         dbg("%s Unable to allocate buffer ", __func__);
 427                         goto error_no_buffer;
 428                 }
 429                 usb_fill_int_urb(int_out_urb, dev->udev,
 430                                  usb_sndintpipe(dev->udev,
 431                                                 dev->int_out_endpoint->bEndpointAddress),
 432                                  buf, dev->report_size,
 433                                  iowarrior_write_callback, dev,
 434                                  dev->int_out_endpoint->bInterval);
 435                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 436                 if (copy_from_user(buf, user_buffer, count)) {
 437                         retval = -EFAULT;
 438                         goto error;
 439                 }
 440                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 441                 if (retval) {
 442                         dbg("%s submit error %d for urb nr.%d", __func__,
 443                             retval, atomic_read(&dev->write_busy));
 444                         goto error;
 445                 }
 446                 /* submit was ok */
 447                 retval = count;
 448                 usb_free_urb(int_out_urb);
 449                 goto exit;
 450                 break;
 451         default:
 452                 /* what do we have here ? An unsupported Product-ID ? */
 453                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x",
 454                         __FUNCTION__, dev->product_id);
 455                 retval = -EFAULT;
 456                 goto exit;
 457                 break;
 458         }
 459 error:
 460         usb_buffer_free(dev->udev, dev->report_size, buf,
 461                         int_out_urb->transfer_dma);
 462 error_no_buffer:
 463         usb_free_urb(int_out_urb);
 464 error_no_urb:
 465         atomic_dec(&dev->write_busy);
 466         wake_up_interruptible(&dev->write_wait);
 467 exit:
 468         mutex_unlock(&dev->mutex);
 469         return retval;
 470 }
 471
 472 /**
 473  *      iowarrior_ioctl
 474  */
 475 static int iowarrior_ioctl(struct inode *inode, struct file *file,
 476                            unsigned int cmd, unsigned long arg)
 477 {
 478         struct iowarrior *dev = NULL;
 479         __u8 *buffer;
 480         __u8 __user *user_buffer;
 481         int retval;
 482         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 483
 484         dev = (struct iowarrior *)file->private_data;
 485         if (dev == NULL) {
 486                 return -ENODEV;
 487         }
 488
 489         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 490         if (!buffer)
 491                 return -ENOMEM;
 492
 493         /* lock this object */
 494         mutex_lock(&dev->mutex);
 495
 496         /* verify that the device wasn't unplugged */
 497         if (!dev->present) {
 498                 mutex_unlock(&dev->mutex);
 499                 return -ENODEV;
 500         }
 501
 502         dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
 503             arg);
 504
 505         retval = 0;
 506         io_res = 0;
 507         switch (cmd) {
 508         case IOW_WRITE:
 509                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 510                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 511                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 512                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 513                         user_buffer = (__u8 __user *)arg;
 514                         io_res = copy_from_user(buffer, user_buffer,
 515                                                 dev->report_size);
 516                         if (io_res) {
 517                                 retval = -EFAULT;
 518                         } else {
 519                                 io_res = usb_set_report(dev->interface, 2, 0,
 520                                                         buffer,
 521                                                         dev->report_size);
 522                                 if (io_res < 0)
 523                                         retval = io_res;
 524                         }
 525                 } else {
 526                         retval = -EINVAL;
 527                         dev_err(&dev->interface->dev,
 528                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.",
 529                                 dev->product_id);
 530                 }
 531                 break;
 532         case IOW_READ:
 533                 user_buffer = (__u8 __user *)arg;
 534                 io_res = usb_get_report(dev->udev,
 535                                         dev->interface->cur_altsetting, 1, 0,
 536                                         buffer, dev->report_size);
 537                 if (io_res < 0)
 538                         retval = io_res;
 539                 else {
 540                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 541                         if (io_res < 0)
 542                                 retval = -EFAULT;
 543                 }
 544                 break;
 545         case IOW_GETINFO:
 546                 {
 547                         /* Report available information for the device */
 548                         struct iowarrior_info info;
 549                         /* needed for power consumption */
 550                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 551
 552                         /* directly from the descriptor */
 553                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 554                         info.product = dev->product_id;
 555                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 556
 557                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 558                         info.speed = le16_to_cpu(dev->udev->speed);
 559                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 560                         info.report_size = dev->report_size;
 561
 562                         /* serial number string has been read earlier 8 chars or empty string */
 563                         memcpy(info.serial, dev->chip_serial,
 564                                sizeof(dev->chip_serial));
 565                         if (cfg_descriptor == NULL) {
 566                                 info.power = -1;        /* no information available */
 567                         } else {
 568                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 569                                 info.power = cfg_descriptor->bMaxPower * 2;
 570                         }
 571                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 572                                          sizeof(struct iowarrior_info));
 573                         if (io_res < 0)
 574                                 retval = -EFAULT;
 575                         break;
 576                 }
 577         default:
 578                 /* return that we did not understand this ioctl call */
 579                 retval = -ENOTTY;
 580                 break;
 581         }
 582
 583         /* unlock the device */
 584         mutex_unlock(&dev->mutex);
 585         return retval;
 586 }
 587
 588 /**
 589  *      iowarrior_open
 590  */
 591 static int iowarrior_open(struct inode *inode, struct file *file)
 592 {
 593         struct iowarrior *dev = NULL;
 594         struct usb_interface *interface;
 595         int subminor;
 596         int retval = 0;
 597
 598         dbg("%s", __func__);
 599
 600         subminor = iminor(inode);
 601
 602         /* prevent disconnects */
 603         down(&disconnect_sem);
 604
 605         interface = usb_find_interface(&iowarrior_driver, subminor);
 606         if (!interface) {
 607                 err("%s - error, can't find device for minor %d", __FUNCTION__,
 608                     subminor);
 609                 retval = -ENODEV;
 610                 goto out;
 611         }
 612
 613         dev = usb_get_intfdata(interface);
 614         if (!dev) {
 615                 retval = -ENODEV;
 616                 goto out;
 617         }
 618
 619         /* Only one process can open each device, no sharing. */
 620         if (dev->opened) {
 621                 retval = -EBUSY;
 622                 goto out;
 623         }
 624
 625         /* setup interrupt handler for receiving values */
 626         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 627                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 628                 retval = -EFAULT;
 629                 goto out;
 630         }
 631         /* increment our usage count for the driver */
 632         ++dev->opened;
 633         /* save our object in the file's private structure */
 634         file->private_data = dev;
 635         retval = 0;
 636
 637 out:
 638         up(&disconnect_sem);
 639         return retval;
 640 }
 641
 642 /**
 643  *      iowarrior_release
 644  */
 645 static int iowarrior_release(struct inode *inode, struct file *file)
 646 {
 647         struct iowarrior *dev;
 648         int retval = 0;
 649
 650         dev = (struct iowarrior *)file->private_data;
 651         if (dev == NULL) {
 652                 return -ENODEV;
 653         }
 654
 655         dbg("%s - minor %d", __func__, dev->minor);
 656
 657         /* lock our device */
 658         mutex_lock(&dev->mutex);
 659
 660         if (dev->opened <= 0) {
 661                 retval = -ENODEV;       /* close called more than once */
 662                 mutex_unlock(&dev->mutex);
 663         } else {
 664                 dev->opened = 0;        /* we're closeing now */
 665                 retval = 0;
 666                 if (dev->present) {
 667                         /*
 668                            The device is still connected so we only shutdown
 669                            pending read-/write-ops.
 670                          */
 671                         usb_kill_urb(dev->int_in_urb);
 672                         wake_up_interruptible(&dev->read_wait);
 673                         wake_up_interruptible(&dev->write_wait);
 674                         mutex_unlock(&dev->mutex);
 675                 } else {
 676                         /* The device was unplugged, cleanup resources */
 677                         mutex_unlock(&dev->mutex);
 678                         iowarrior_delete(dev);
 679                 }
 680         }
 681         return retval;
 682 }
 683
 684 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 685 {
 686         struct iowarrior *dev = file->private_data;
 687         unsigned int mask = 0;
 688
 689         if (!dev->present)
 690                 return POLLERR | POLLHUP;
 691
 692         poll_wait(file, &dev->read_wait, wait);
 693         poll_wait(file, &dev->write_wait, wait);
 694
 695         if (!dev->present)
 696                 return POLLERR | POLLHUP;
 697
 698         if (read_index(dev) != -1)
 699                 mask |= POLLIN | POLLRDNORM;
 700
 701         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 702                 mask |= POLLOUT | POLLWRNORM;
 703         return mask;
 704 }
 705
 706 /*
 707  * File operations needed when we register this driver.
 708  * This assumes that this driver NEEDS file operations,
 709  * of course, which means that the driver is expected
 710  * to have a node in the /dev directory. If the USB
 711  * device were for a network interface then the driver
 712  * would use "struct net_driver" instead, and a serial
 713  * device would use "struct tty_driver".
 714  */
 715 static struct file_operations iowarrior_fops = {
 716         .owner = THIS_MODULE,
 717         .write = iowarrior_write,
 718         .read = iowarrior_read,
 719         .ioctl = iowarrior_ioctl,
 720         .open = iowarrior_open,
 721         .release = iowarrior_release,
 722         .poll = iowarrior_poll,
 723 };
 724
 725 /*
 726  * usb class driver info in order to get a minor number from the usb core,
 727  * and to have the device registered with devfs and the driver core
 728  */
 729 static struct usb_class_driver iowarrior_class = {
 730         .name = "iowarrior%d",
 731         .fops = &iowarrior_fops,
 732         .minor_base = IOWARRIOR_MINOR_BASE,
 733 };
 734
 735 /*---------------------------------*/
 736 /*  probe and disconnect functions */
 737 /*---------------------------------*/
 738 /**
 739  *      iowarrior_probe
 740  *
 741  *      Called by the usb core when a new device is connected that it thinks
 742  *      this driver might be interested in.
 743  */
 744 static int iowarrior_probe(struct usb_interface *interface,
 745                            const struct usb_device_id *id)
 746 {
 747         struct usb_device *udev = interface_to_usbdev(interface);
 748         struct iowarrior *dev = NULL;
 749         struct usb_host_interface *iface_desc;
 750         struct usb_endpoint_descriptor *endpoint;
 751         int i;
 752         int retval = -ENOMEM;
 753
 754         /* allocate memory for our device state and intialize it */
 755         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 756         if (dev == NULL) {
 757                 dev_err(&interface->dev, "Out of memory");
 758                 return retval;
 759         }
 760
 761         mutex_init(&dev->mutex);
 762
 763         atomic_set(&dev->intr_idx, 0);
 764         atomic_set(&dev->read_idx, 0);
 765         spin_lock_init(&dev->intr_idx_lock);
 766         atomic_set(&dev->overflow_flag, 0);
 767         init_waitqueue_head(&dev->read_wait);
 768         atomic_set(&dev->write_busy, 0);
 769         init_waitqueue_head(&dev->write_wait);
 770
 771         dev->udev = udev;
 772         dev->interface = interface;
 773
 774         iface_desc = interface->cur_altsetting;
 775         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 776
 777         /* set up the endpoint information */
 778         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 779                 endpoint = &iface_desc->endpoint[i].desc;
 780
 781                 if (usb_endpoint_is_int_in(endpoint))
 782                         dev->int_in_endpoint = endpoint;
 783                 if (usb_endpoint_is_int_out(endpoint))
 784                         /* this one will match for the IOWarrior56 only */
 785                         dev->int_out_endpoint = endpoint;
 786         }
 787         /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
 788         dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
 789         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 790             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 791                 /* IOWarrior56 has wMaxPacketSize different from report size */
 792                 dev->report_size = 7;
 793
 794         /* create the urb and buffer for reading */
 795         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 796         if (!dev->int_in_urb) {
 797                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 798                 goto error;
 799         }
 800         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 801         if (!dev->int_in_buffer) {
 802                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
 803                 goto error;
 804         }
 805         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 806                          usb_rcvintpipe(dev->udev,
 807                                         dev->int_in_endpoint->bEndpointAddress),
 808                          dev->int_in_buffer, dev->report_size,
 809                          iowarrior_callback, dev,
 810                          dev->int_in_endpoint->bInterval);
 811         /* create an internal buffer for interrupt data from the device */
 812         dev->read_queue =
 813             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 814                     GFP_KERNEL);
 815         if (!dev->read_queue) {
 816                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
 817                 goto error;
 818         }
 819         /* Get the serial-number of the chip */
 820         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 821         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 822                    sizeof(dev->chip_serial));
 823         if (strlen(dev->chip_serial) != 8)
 824                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 825
 826         /* Set the idle timeout to 0, if this is interface 0 */
 827         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 828             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 829                             0x0A,
 830                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 831                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 832         }
 833         /* allow device read and ioctl */
 834         dev->present = 1;
 835
 836         /* we can register the device now, as it is ready */
 837         usb_set_intfdata(interface, dev);
 838
 839         retval = usb_register_dev(interface, &iowarrior_class);
 840         if (retval) {
 841                 /* something prevented us from registering this driver */
 842                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 843                 usb_set_intfdata(interface, NULL);
 844                 goto error;
 845         }
 846
 847         dev->minor = interface->minor;
 848
 849         /* let the user know what node this device is now attached to */
 850         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 851                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 852                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 853         return retval;
 854
 855 error:
 856         iowarrior_delete(dev);
 857         return retval;
 858 }
 859
 860 /**
 861  *      iowarrior_disconnect
 862  *
 863  *      Called by the usb core when the device is removed from the system.
 864  */
 865 static void iowarrior_disconnect(struct usb_interface *interface)
 866 {
 867         struct iowarrior *dev;
 868         int minor;
 869
 870         /* prevent races with open() */
 871         down(&disconnect_sem);
 872
 873         dev = usb_get_intfdata(interface);
 874         usb_set_intfdata(interface, NULL);
 875
 876         mutex_lock(&dev->mutex);
 877
 878         minor = dev->minor;
 879
 880         /* give back our minor */
 881         usb_deregister_dev(interface, &iowarrior_class);
 882
 883         /* prevent device read, write and ioctl */
 884         dev->present = 0;
 885
 886         mutex_unlock(&dev->mutex);
 887
 888         if (dev->opened) {
 889                 /* There is a process that holds a filedescriptor to the device ,
 890                    so we only shutdown read-/write-ops going on.
 891                    Deleting the device is postponed until close() was called.
 892                  */
 893                 usb_kill_urb(dev->int_in_urb);
 894                 wake_up_interruptible(&dev->read_wait);
 895                 wake_up_interruptible(&dev->write_wait);
 896         } else {
 897                 /* no process is using the device, cleanup now */
 898                 iowarrior_delete(dev);
 899         }
 900         up(&disconnect_sem);
 901
 902         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 903                  minor - IOWARRIOR_MINOR_BASE);
 904 }
 905
 906 /* usb specific object needed to register this driver with the usb subsystem */
 907 static struct usb_driver iowarrior_driver = {
 908         .name = "iowarrior",
 909         .probe = iowarrior_probe,
 910         .disconnect = iowarrior_disconnect,
 911         .id_table = iowarrior_ids,
 912 };
 913
 914 static int __init iowarrior_init(void)
 915 {
 916         return usb_register(&iowarrior_driver);
 917 }
 918
 919 static void __exit iowarrior_exit(void)
 920 {
 921         usb_deregister(&iowarrior_driver);
 922 }
 923
 924 module_init(iowarrior_init);
 925 module_exit(iowarrior_exit);