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/smp_lock.h>
  22 #include <linux/poll.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 static DEFINE_MUTEX(iowarrior_open_disc_lock);
  70
  71 /*--------------*/
  72 /*     data     */
  73 /*--------------*/
  74
  75 /* Structure to hold all of our device specific stuff */
  76 struct iowarrior {
  77         struct mutex mutex;                     /* locks this structure */
  78         struct usb_device *udev;                /* save off the usb device pointer */
  79         struct usb_interface *interface;        /* the interface for this device */
  80         unsigned char minor;                    /* the starting minor number for this device */
  81         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
  82         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
  83         struct urb *int_in_urb;         /* the urb for reading data */
  84         unsigned char *int_in_buffer;   /* buffer for data to be read */
  85         unsigned char serial_number;    /* to detect lost packages */
  86         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
  87         wait_queue_head_t read_wait;
  88         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
  89         atomic_t write_busy;            /* number of write-urbs submitted */
  90         atomic_t read_idx;
  91         atomic_t intr_idx;
  92         spinlock_t intr_idx_lock;       /* protects intr_idx */
  93         atomic_t overflow_flag;         /* signals an index 'rollover' */
  94         int present;                    /* this is 1 as long as the device is connected */
  95         int opened;                     /* this is 1 if the device is currently open */
  96         char chip_serial[9];            /* the serial number string of the chip connected */
  97         int report_size;                /* number of bytes in a report */
  98         u16 product_id;
  99 };
 100
 101 /*--------------*/
 102 /*    globals   */
 103 /*--------------*/
 104
 105 /*
 106  *  USB spec identifies 5 second timeouts.
 107  */
 108 #define GET_TIMEOUT 5
 109 #define USB_REQ_GET_REPORT  0x01
 110 //#if 0
 111 static int usb_get_report(struct usb_device *dev,
 112                           struct usb_host_interface *inter, unsigned char type,
 113                           unsigned char id, void *buf, int size)
 114 {
 115         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 116                                USB_REQ_GET_REPORT,
 117                                USB_DIR_IN | USB_TYPE_CLASS |
 118                                USB_RECIP_INTERFACE, (type << 8) + id,
 119                                inter->desc.bInterfaceNumber, buf, size,
 120                                GET_TIMEOUT*HZ);
 121 }
 122 //#endif
 123
 124 #define USB_REQ_SET_REPORT 0x09
 125
 126 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 127                           unsigned char id, void *buf, int size)
 128 {
 129         return usb_control_msg(interface_to_usbdev(intf),
 130                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 131                                USB_REQ_SET_REPORT,
 132                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 133                                (type << 8) + id,
 134                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 135                                size, HZ);
 136 }
 137
 138 /*---------------------*/
 139 /* driver registration */
 140 /*---------------------*/
 141 /* table of devices that work with this driver */
 142 static struct usb_device_id iowarrior_ids[] = {
 143         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 147         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 148         {}                      /* Terminating entry */
 149 };
 150 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 151
 152 /*
 153  * USB callback handler for reading data
 154  */
 155 static void iowarrior_callback(struct urb *urb)
 156 {
 157         struct iowarrior *dev = urb->context;
 158         int intr_idx;
 159         int read_idx;
 160         int aux_idx;
 161         int offset;
 162         int status = urb->status;
 163         int retval;
 164
 165         switch (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         retval = usb_submit_urb(urb, GFP_ATOMIC);
 219         if (retval)
 220                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 221                         __func__, retval);
 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         int status = urb->status;
 232
 233         dev = urb->context;
 234         /* sync/async unlink faults aren't errors */
 235         if (status &&
 236             !(status == -ENOENT ||
 237               status == -ECONNRESET || status == -ESHUTDOWN)) {
 238                 dbg("%s - nonzero write bulk status received: %d",
 239                     __func__, status);
 240         }
 241         /* free up our allocated buffer */
 242         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 243                         urb->transfer_buffer, urb->transfer_dma);
 244         /* tell a waiting writer the interrupt-out-pipe is available again */
 245         atomic_dec(&dev->write_busy);
 246         wake_up_interruptible(&dev->write_wait);
 247 }
 248
 249 /**
 250  *      iowarrior_delete
 251  */
 252 static inline void iowarrior_delete(struct iowarrior *dev)
 253 {
 254         dbg("%s - minor %d", __func__, dev->minor);
 255         kfree(dev->int_in_buffer);
 256         usb_free_urb(dev->int_in_urb);
 257         kfree(dev->read_queue);
 258         kfree(dev);
 259 }
 260
 261 /*---------------------*/
 262 /* fops implementation */
 263 /*---------------------*/
 264
 265 static int read_index(struct iowarrior *dev)
 266 {
 267         int intr_idx, read_idx;
 268
 269         read_idx = atomic_read(&dev->read_idx);
 270         intr_idx = atomic_read(&dev->intr_idx);
 271
 272         return (read_idx == intr_idx ? -1 : read_idx);
 273 }
 274
 275 /**
 276  *  iowarrior_read
 277  */
 278 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 279                               size_t count, loff_t *ppos)
 280 {
 281         struct iowarrior *dev;
 282         int read_idx;
 283         int offset;
 284
 285         dev = (struct iowarrior *)file->private_data;
 286
 287         /* verify that the device wasn't unplugged */
 288         if (dev == NULL || !dev->present)
 289                 return -ENODEV;
 290
 291         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 292
 293         /* read count must be packet size (+ time stamp) */
 294         if ((count != dev->report_size)
 295             && (count != (dev->report_size + 1)))
 296                 return -EINVAL;
 297
 298         /* repeat until no buffer overrun in callback handler occur */
 299         do {
 300                 atomic_set(&dev->overflow_flag, 0);
 301                 if ((read_idx = read_index(dev)) == -1) {
 302                         /* queue emty */
 303                         if (file->f_flags & O_NONBLOCK)
 304                                 return -EAGAIN;
 305                         else {
 306                                 //next line will return when there is either new data, or the device is unplugged
 307                                 int r = wait_event_interruptible(dev->read_wait,
 308                                                                  (!dev->present
 309                                                                   || (read_idx =
 310                                                                       read_index
 311                                                                       (dev)) !=
 312                                                                   -1));
 313                                 if (r) {
 314                                         //we were interrupted by a signal
 315                                         return -ERESTART;
 316                                 }
 317                                 if (!dev->present) {
 318                                         //The device was unplugged
 319                                         return -ENODEV;
 320                                 }
 321                                 if (read_idx == -1) {
 322                                         // Can this happen ???
 323                                         return 0;
 324                                 }
 325                         }
 326                 }
 327
 328                 offset = read_idx * (dev->report_size + 1);
 329                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 330                         return -EFAULT;
 331                 }
 332         } while (atomic_read(&dev->overflow_flag));
 333
 334         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 335         atomic_set(&dev->read_idx, read_idx);
 336         return count;
 337 }
 338
 339 /*
 340  * iowarrior_write
 341  */
 342 static ssize_t iowarrior_write(struct file *file,
 343                                const char __user *user_buffer,
 344                                size_t count, loff_t *ppos)
 345 {
 346         struct iowarrior *dev;
 347         int retval = 0;
 348         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 349         struct urb *int_out_urb = NULL;
 350
 351         dev = (struct iowarrior *)file->private_data;
 352
 353         mutex_lock(&dev->mutex);
 354         /* verify that the device wasn't unplugged */
 355         if (!dev->present) {
 356                 retval = -ENODEV;
 357                 goto exit;
 358         }
 359         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
 360         /* if count is 0 we're already done */
 361         if (count == 0) {
 362                 retval = 0;
 363                 goto exit;
 364         }
 365         /* We only accept full reports */
 366         if (count != dev->report_size) {
 367                 retval = -EINVAL;
 368                 goto exit;
 369         }
 370         switch (dev->product_id) {
 371         case USB_DEVICE_ID_CODEMERCS_IOW24:
 372         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 373         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 374         case USB_DEVICE_ID_CODEMERCS_IOW40:
 375                 /* IOW24 and IOW40 use a synchronous call */
 376                 buf = kmalloc(8, GFP_KERNEL);   /* 8 bytes are enough for both products */
 377                 if (!buf) {
 378                         retval = -ENOMEM;
 379                         goto exit;
 380                 }
 381                 if (copy_from_user(buf, user_buffer, count)) {
 382                         retval = -EFAULT;
 383                         kfree(buf);
 384                         goto exit;
 385                 }
 386                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 387                 kfree(buf);
 388                 goto exit;
 389                 break;
 390         case USB_DEVICE_ID_CODEMERCS_IOW56:
 391                 /* The IOW56 uses asynchronous IO and more urbs */
 392                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 393                         /* Wait until we are below the limit for submitted urbs */
 394                         if (file->f_flags & O_NONBLOCK) {
 395                                 retval = -EAGAIN;
 396                                 goto exit;
 397                         } else {
 398                                 retval = wait_event_interruptible(dev->write_wait,
 399                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 400                                 if (retval) {
 401                                         /* we were interrupted by a signal */
 402                                         retval = -ERESTART;
 403                                         goto exit;
 404                                 }
 405                                 if (!dev->present) {
 406                                         /* The device was unplugged */
 407                                         retval = -ENODEV;
 408                                         goto exit;
 409                                 }
 410                                 if (!dev->opened) {
 411                                         /* We were closed while waiting for an URB */
 412                                         retval = -ENODEV;
 413                                         goto exit;
 414                                 }
 415                         }
 416                 }
 417                 atomic_inc(&dev->write_busy);
 418                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 419                 if (!int_out_urb) {
 420                         retval = -ENOMEM;
 421                         dbg("%s Unable to allocate urb ", __func__);
 422                         goto error_no_urb;
 423                 }
 424                 buf = usb_buffer_alloc(dev->udev, dev->report_size,
 425                                        GFP_KERNEL, &int_out_urb->transfer_dma);
 426                 if (!buf) {
 427                         retval = -ENOMEM;
 428                         dbg("%s Unable to allocate buffer ", __func__);
 429                         goto error_no_buffer;
 430                 }
 431                 usb_fill_int_urb(int_out_urb, dev->udev,
 432                                  usb_sndintpipe(dev->udev,
 433                                                 dev->int_out_endpoint->bEndpointAddress),
 434                                  buf, dev->report_size,
 435                                  iowarrior_write_callback, dev,
 436                                  dev->int_out_endpoint->bInterval);
 437                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 438                 if (copy_from_user(buf, user_buffer, count)) {
 439                         retval = -EFAULT;
 440                         goto error;
 441                 }
 442                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 443                 if (retval) {
 444                         dbg("%s submit error %d for urb nr.%d", __func__,
 445                             retval, atomic_read(&dev->write_busy));
 446                         goto error;
 447                 }
 448                 /* submit was ok */
 449                 retval = count;
 450                 usb_free_urb(int_out_urb);
 451                 goto exit;
 452                 break;
 453         default:
 454                 /* what do we have here ? An unsupported Product-ID ? */
 455                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 456                         __func__, dev->product_id);
 457                 retval = -EFAULT;
 458                 goto exit;
 459                 break;
 460         }
 461 error:
 462         usb_buffer_free(dev->udev, dev->report_size, buf,
 463                         int_out_urb->transfer_dma);
 464 error_no_buffer:
 465         usb_free_urb(int_out_urb);
 466 error_no_urb:
 467         atomic_dec(&dev->write_busy);
 468         wake_up_interruptible(&dev->write_wait);
 469 exit:
 470         mutex_unlock(&dev->mutex);
 471         return retval;
 472 }
 473
 474 /**
 475  *      iowarrior_ioctl
 476  */
 477 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 478                                                         unsigned long arg)
 479 {
 480         struct iowarrior *dev = NULL;
 481         __u8 *buffer;
 482         __u8 __user *user_buffer;
 483         int retval;
 484         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 485
 486         dev = (struct iowarrior *)file->private_data;
 487         if (dev == NULL) {
 488                 return -ENODEV;
 489         }
 490
 491         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 492         if (!buffer)
 493                 return -ENOMEM;
 494
 495         /* lock this object */
 496         lock_kernel();
 497         mutex_lock(&dev->mutex);
 498
 499         /* verify that the device wasn't unplugged */
 500         if (!dev->present) {
 501                 retval = -ENODEV;
 502                 goto error_out;
 503         }
 504
 505         dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
 506             arg);
 507
 508         retval = 0;
 509         io_res = 0;
 510         switch (cmd) {
 511         case IOW_WRITE:
 512                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 513                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 514                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 515                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 516                         user_buffer = (__u8 __user *)arg;
 517                         io_res = copy_from_user(buffer, user_buffer,
 518                                                 dev->report_size);
 519                         if (io_res) {
 520                                 retval = -EFAULT;
 521                         } else {
 522                                 io_res = usb_set_report(dev->interface, 2, 0,
 523                                                         buffer,
 524                                                         dev->report_size);
 525                                 if (io_res < 0)
 526                                         retval = io_res;
 527                         }
 528                 } else {
 529                         retval = -EINVAL;
 530                         dev_err(&dev->interface->dev,
 531                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 532                                 dev->product_id);
 533                 }
 534                 break;
 535         case IOW_READ:
 536                 user_buffer = (__u8 __user *)arg;
 537                 io_res = usb_get_report(dev->udev,
 538                                         dev->interface->cur_altsetting, 1, 0,
 539                                         buffer, dev->report_size);
 540                 if (io_res < 0)
 541                         retval = io_res;
 542                 else {
 543                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 544                         if (io_res < 0)
 545                                 retval = -EFAULT;
 546                 }
 547                 break;
 548         case IOW_GETINFO:
 549                 {
 550                         /* Report available information for the device */
 551                         struct iowarrior_info info;
 552                         /* needed for power consumption */
 553                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 554
 555                         /* directly from the descriptor */
 556                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 557                         info.product = dev->product_id;
 558                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 559
 560                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 561                         info.speed = le16_to_cpu(dev->udev->speed);
 562                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 563                         info.report_size = dev->report_size;
 564
 565                         /* serial number string has been read earlier 8 chars or empty string */
 566                         memcpy(info.serial, dev->chip_serial,
 567                                sizeof(dev->chip_serial));
 568                         if (cfg_descriptor == NULL) {
 569                                 info.power = -1;        /* no information available */
 570                         } else {
 571                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 572                                 info.power = cfg_descriptor->bMaxPower * 2;
 573                         }
 574                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 575                                          sizeof(struct iowarrior_info));
 576                         if (io_res < 0)
 577                                 retval = -EFAULT;
 578                         break;
 579                 }
 580         default:
 581                 /* return that we did not understand this ioctl call */
 582                 retval = -ENOTTY;
 583                 break;
 584         }
 585 error_out:
 586         /* unlock the device */
 587         mutex_unlock(&dev->mutex);
 588         unlock_kernel();
 589         kfree(buffer);
 590         return retval;
 591 }
 592
 593 /**
 594  *      iowarrior_open
 595  */
 596 static int iowarrior_open(struct inode *inode, struct file *file)
 597 {
 598         struct iowarrior *dev = NULL;
 599         struct usb_interface *interface;
 600         int subminor;
 601         int retval = 0;
 602
 603         dbg("%s", __func__);
 604
 605         subminor = iminor(inode);
 606
 607         interface = usb_find_interface(&iowarrior_driver, subminor);
 608         if (!interface) {
 609                 err("%s - error, can't find device for minor %d", __func__,
 610                     subminor);
 611                 return -ENODEV;
 612         }
 613
 614         mutex_lock(&iowarrior_open_disc_lock);
 615         dev = usb_get_intfdata(interface);
 616         if (!dev) {
 617                 mutex_unlock(&iowarrior_open_disc_lock);
 618                 return -ENODEV;
 619         }
 620
 621         mutex_lock(&dev->mutex);
 622         mutex_unlock(&iowarrior_open_disc_lock);
 623
 624         /* Only one process can open each device, no sharing. */
 625         if (dev->opened) {
 626                 retval = -EBUSY;
 627                 goto out;
 628         }
 629
 630         /* setup interrupt handler for receiving values */
 631         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 632                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 633                 retval = -EFAULT;
 634                 goto out;
 635         }
 636         /* increment our usage count for the driver */
 637         ++dev->opened;
 638         /* save our object in the file's private structure */
 639         file->private_data = dev;
 640         retval = 0;
 641
 642 out:
 643         mutex_unlock(&dev->mutex);
 644         return retval;
 645 }
 646
 647 /**
 648  *      iowarrior_release
 649  */
 650 static int iowarrior_release(struct inode *inode, struct file *file)
 651 {
 652         struct iowarrior *dev;
 653         int retval = 0;
 654
 655         dev = (struct iowarrior *)file->private_data;
 656         if (dev == NULL) {
 657                 return -ENODEV;
 658         }
 659
 660         dbg("%s - minor %d", __func__, dev->minor);
 661
 662         /* lock our device */
 663         mutex_lock(&dev->mutex);
 664
 665         if (dev->opened <= 0) {
 666                 retval = -ENODEV;       /* close called more than once */
 667                 mutex_unlock(&dev->mutex);
 668         } else {
 669                 dev->opened = 0;        /* we're closeing now */
 670                 retval = 0;
 671                 if (dev->present) {
 672                         /*
 673                            The device is still connected so we only shutdown
 674                            pending read-/write-ops.
 675                          */
 676                         usb_kill_urb(dev->int_in_urb);
 677                         wake_up_interruptible(&dev->read_wait);
 678                         wake_up_interruptible(&dev->write_wait);
 679                         mutex_unlock(&dev->mutex);
 680                 } else {
 681                         /* The device was unplugged, cleanup resources */
 682                         mutex_unlock(&dev->mutex);
 683                         iowarrior_delete(dev);
 684                 }
 685         }
 686         return retval;
 687 }
 688
 689 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 690 {
 691         struct iowarrior *dev = file->private_data;
 692         unsigned int mask = 0;
 693
 694         if (!dev->present)
 695                 return POLLERR | POLLHUP;
 696
 697         poll_wait(file, &dev->read_wait, wait);
 698         poll_wait(file, &dev->write_wait, wait);
 699
 700         if (!dev->present)
 701                 return POLLERR | POLLHUP;
 702
 703         if (read_index(dev) != -1)
 704                 mask |= POLLIN | POLLRDNORM;
 705
 706         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 707                 mask |= POLLOUT | POLLWRNORM;
 708         return mask;
 709 }
 710
 711 /*
 712  * File operations needed when we register this driver.
 713  * This assumes that this driver NEEDS file operations,
 714  * of course, which means that the driver is expected
 715  * to have a node in the /dev directory. If the USB
 716  * device were for a network interface then the driver
 717  * would use "struct net_driver" instead, and a serial
 718  * device would use "struct tty_driver".
 719  */
 720 static const struct file_operations iowarrior_fops = {
 721         .owner = THIS_MODULE,
 722         .write = iowarrior_write,
 723         .read = iowarrior_read,
 724         .unlocked_ioctl = iowarrior_ioctl,
 725         .open = iowarrior_open,
 726         .release = iowarrior_release,
 727         .poll = iowarrior_poll,
 728 };
 729
 730 static char *iowarrior_nodename(struct device *dev)
 731 {
 732         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 733 }
 734
 735 /*
 736  * usb class driver info in order to get a minor number from the usb core,
 737  * and to have the device registered with devfs and the driver core
 738  */
 739 static struct usb_class_driver iowarrior_class = {
 740         .name = "iowarrior%d",
 741         .nodename = iowarrior_nodename,
 742         .fops = &iowarrior_fops,
 743         .minor_base = IOWARRIOR_MINOR_BASE,
 744 };
 745
 746 /*---------------------------------*/
 747 /*  probe and disconnect functions */
 748 /*---------------------------------*/
 749 /**
 750  *      iowarrior_probe
 751  *
 752  *      Called by the usb core when a new device is connected that it thinks
 753  *      this driver might be interested in.
 754  */
 755 static int iowarrior_probe(struct usb_interface *interface,
 756                            const struct usb_device_id *id)
 757 {
 758         struct usb_device *udev = interface_to_usbdev(interface);
 759         struct iowarrior *dev = NULL;
 760         struct usb_host_interface *iface_desc;
 761         struct usb_endpoint_descriptor *endpoint;
 762         int i;
 763         int retval = -ENOMEM;
 764
 765         /* allocate memory for our device state and intialize it */
 766         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 767         if (dev == NULL) {
 768                 dev_err(&interface->dev, "Out of memory\n");
 769                 return retval;
 770         }
 771
 772         mutex_init(&dev->mutex);
 773
 774         atomic_set(&dev->intr_idx, 0);
 775         atomic_set(&dev->read_idx, 0);
 776         spin_lock_init(&dev->intr_idx_lock);
 777         atomic_set(&dev->overflow_flag, 0);
 778         init_waitqueue_head(&dev->read_wait);
 779         atomic_set(&dev->write_busy, 0);
 780         init_waitqueue_head(&dev->write_wait);
 781
 782         dev->udev = udev;
 783         dev->interface = interface;
 784
 785         iface_desc = interface->cur_altsetting;
 786         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 787
 788         /* set up the endpoint information */
 789         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 790                 endpoint = &iface_desc->endpoint[i].desc;
 791
 792                 if (usb_endpoint_is_int_in(endpoint))
 793                         dev->int_in_endpoint = endpoint;
 794                 if (usb_endpoint_is_int_out(endpoint))
 795                         /* this one will match for the IOWarrior56 only */
 796                         dev->int_out_endpoint = endpoint;
 797         }
 798         /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
 799         dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
 800         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
 801             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
 802                 /* IOWarrior56 has wMaxPacketSize different from report size */
 803                 dev->report_size = 7;
 804
 805         /* create the urb and buffer for reading */
 806         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 807         if (!dev->int_in_urb) {
 808                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 809                 goto error;
 810         }
 811         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 812         if (!dev->int_in_buffer) {
 813                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
 814                 goto error;
 815         }
 816         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 817                          usb_rcvintpipe(dev->udev,
 818                                         dev->int_in_endpoint->bEndpointAddress),
 819                          dev->int_in_buffer, dev->report_size,
 820                          iowarrior_callback, dev,
 821                          dev->int_in_endpoint->bInterval);
 822         /* create an internal buffer for interrupt data from the device */
 823         dev->read_queue =
 824             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 825                     GFP_KERNEL);
 826         if (!dev->read_queue) {
 827                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
 828                 goto error;
 829         }
 830         /* Get the serial-number of the chip */
 831         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 832         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 833                    sizeof(dev->chip_serial));
 834         if (strlen(dev->chip_serial) != 8)
 835                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 836
 837         /* Set the idle timeout to 0, if this is interface 0 */
 838         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 839             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 840                             0x0A,
 841                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 842                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 843         }
 844         /* allow device read and ioctl */
 845         dev->present = 1;
 846
 847         /* we can register the device now, as it is ready */
 848         usb_set_intfdata(interface, dev);
 849
 850         retval = usb_register_dev(interface, &iowarrior_class);
 851         if (retval) {
 852                 /* something prevented us from registering this driver */
 853                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 854                 usb_set_intfdata(interface, NULL);
 855                 goto error;
 856         }
 857
 858         dev->minor = interface->minor;
 859
 860         /* let the user know what node this device is now attached to */
 861         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 862                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 863                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 864         return retval;
 865
 866 error:
 867         iowarrior_delete(dev);
 868         return retval;
 869 }
 870
 871 /**
 872  *      iowarrior_disconnect
 873  *
 874  *      Called by the usb core when the device is removed from the system.
 875  */
 876 static void iowarrior_disconnect(struct usb_interface *interface)
 877 {
 878         struct iowarrior *dev;
 879         int minor;
 880
 881         dev = usb_get_intfdata(interface);
 882         mutex_lock(&iowarrior_open_disc_lock);
 883         usb_set_intfdata(interface, NULL);
 884
 885         minor = dev->minor;
 886
 887         /* give back our minor */
 888         usb_deregister_dev(interface, &iowarrior_class);
 889
 890         mutex_lock(&dev->mutex);
 891
 892         /* prevent device read, write and ioctl */
 893         dev->present = 0;
 894
 895         mutex_unlock(&dev->mutex);
 896         mutex_unlock(&iowarrior_open_disc_lock);
 897
 898         if (dev->opened) {
 899                 /* There is a process that holds a filedescriptor to the device ,
 900                    so we only shutdown read-/write-ops going on.
 901                    Deleting the device is postponed until close() was called.
 902                  */
 903                 usb_kill_urb(dev->int_in_urb);
 904                 wake_up_interruptible(&dev->read_wait);
 905                 wake_up_interruptible(&dev->write_wait);
 906         } else {
 907                 /* no process is using the device, cleanup now */
 908                 iowarrior_delete(dev);
 909         }
 910
 911         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 912                  minor - IOWARRIOR_MINOR_BASE);
 913 }
 914
 915 /* usb specific object needed to register this driver with the usb subsystem */
 916 static struct usb_driver iowarrior_driver = {
 917         .name = "iowarrior",
 918         .probe = iowarrior_probe,
 919         .disconnect = iowarrior_disconnect,
 920         .id_table = iowarrior_ids,
 921 };
 922
 923 static int __init iowarrior_init(void)
 924 {
 925         return usb_register(&iowarrior_driver);
 926 }
 927
 928 static void __exit iowarrior_exit(void)
 929 {
 930         usb_deregister(&iowarrior_driver);
 931 }
 932
 933 module_init(iowarrior_init);
 934 module_exit(iowarrior_exit);