drivers/usb/misc/iowarrior.c

   1 /*
   2  *  Native support for the I/O-Warrior USB devices
   3  *
   4  *  Copyright (c) 2003-2005, 2020  Code Mercenaries GmbH
   5  *  written by Christian Lucht <lucht@codemercs.com> and
   6  *  Christoph Jung <jung@codemercs.com>
   7  *
   8  *  based on
   9
  10  *  usb-skeleton.c by Greg Kroah-Hartman  <greg@kroah.com>
  11  *  brlvger.c by Stephane Dalton  <sdalton@videotron.ca>
  12  *           and St�hane Doyon   <s.doyon@videotron.ca>
  13  *
  14  *  Released under the GPLv2.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/usb.h>
  19 #include <linux/slab.h>
  20 #include <linux/sched.h>
  21 #include <linux/mutex.h>
  22 #include <linux/poll.h>
  23 #include <linux/usb/iowarrior.h>
  24
  25 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
  26 #define DRIVER_DESC "USB IO-Warrior driver"
  27
  28 #define USB_VENDOR_ID_CODEMERCS         1984
  29 /* low speed iowarrior */
  30 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
  31 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
  32 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
  33 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
  34 /* full speed iowarrior */
  35 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
  36 /* fuller speed iowarrior */
  37 #define USB_DEVICE_ID_CODEMERCS_IOW28   0x1504
  38 #define USB_DEVICE_ID_CODEMERCS_IOW28L  0x1505
  39 #define USB_DEVICE_ID_CODEMERCS_IOW100  0x1506
  40
  41 /* OEMed devices */
  42 #define USB_DEVICE_ID_CODEMERCS_IOW24SAG        0x158a
  43 #define USB_DEVICE_ID_CODEMERCS_IOW56AM         0x158b
  44
  45 /* Get a minor range for your devices from the usb maintainer */
  46 #ifdef CONFIG_USB_DYNAMIC_MINORS
  47 #define IOWARRIOR_MINOR_BASE    0
  48 #else
  49 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not official yet
  50 #endif
  51
  52 /* interrupt input queue size */
  53 #define MAX_INTERRUPT_BUFFER 16
  54 /*
  55    maximum number of urbs that are submitted for writes at the same time,
  56    this applies to the IOWarrior56 only!
  57    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
  58 */
  59 #define MAX_WRITES_IN_FLIGHT 4
  60
  61 MODULE_AUTHOR(DRIVER_AUTHOR);
  62 MODULE_DESCRIPTION(DRIVER_DESC);
  63 MODULE_LICENSE("GPL");
  64
  65 /* Module parameters */
  66 static DEFINE_MUTEX(iowarrior_mutex);
  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         struct usb_anchor submitted;
 100 };
 101
 102 /*--------------*/
 103 /*    globals   */
 104 /*--------------*/
 105
 106 #define USB_REQ_GET_REPORT  0x01
 107 //#if 0
 108 static int usb_get_report(struct usb_device *dev,
 109                           struct usb_host_interface *inter, unsigned char type,
 110                           unsigned char id, void *buf, int size)
 111 {
 112         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 113                                USB_REQ_GET_REPORT,
 114                                USB_DIR_IN | USB_TYPE_CLASS |
 115                                USB_RECIP_INTERFACE, (type << 8) + id,
 116                                inter->desc.bInterfaceNumber, buf, size,
 117                                USB_CTRL_GET_TIMEOUT);
 118 }
 119 //#endif
 120
 121 #define USB_REQ_SET_REPORT 0x09
 122
 123 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 124                           unsigned char id, void *buf, int size)
 125 {
 126         return usb_control_msg(interface_to_usbdev(intf),
 127                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 128                                USB_REQ_SET_REPORT,
 129                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 130                                (type << 8) + id,
 131                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 132                                size, 1000);
 133 }
 134
 135 /*---------------------*/
 136 /* driver registration */
 137 /*---------------------*/
 138 /* table of devices that work with this driver */
 139 static const struct usb_device_id iowarrior_ids[] = {
 140         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 141         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 142         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 143         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
 146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
 147         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
 148         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
 149         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
 150         {}                      /* Terminating entry */
 151 };
 152 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 153
 154 /*
 155  * USB callback handler for reading data
 156  */
 157 static void iowarrior_callback(struct urb *urb)
 158 {
 159         struct iowarrior *dev = urb->context;
 160         int intr_idx;
 161         int read_idx;
 162         int aux_idx;
 163         int offset;
 164         int status = urb->status;
 165         int retval;
 166
 167         switch (status) {
 168         case 0:
 169                 /* success */
 170                 break;
 171         case -ECONNRESET:
 172         case -ENOENT:
 173         case -ESHUTDOWN:
 174                 return;
 175         default:
 176                 goto exit;
 177         }
 178
 179         spin_lock(&dev->intr_idx_lock);
 180         intr_idx = atomic_read(&dev->intr_idx);
 181         /* aux_idx become previous intr_idx */
 182         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 183         read_idx = atomic_read(&dev->read_idx);
 184
 185         /* queue is not empty and it's interface 0 */
 186         if ((intr_idx != read_idx)
 187             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 188                 /* + 1 for serial number */
 189                 offset = aux_idx * (dev->report_size + 1);
 190                 if (!memcmp
 191                     (dev->read_queue + offset, urb->transfer_buffer,
 192                      dev->report_size)) {
 193                         /* equal values on interface 0 will be ignored */
 194                         spin_unlock(&dev->intr_idx_lock);
 195                         goto exit;
 196                 }
 197         }
 198
 199         /* aux_idx become next intr_idx */
 200         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 201         if (read_idx == aux_idx) {
 202                 /* queue full, dropping oldest input */
 203                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 204                 atomic_set(&dev->read_idx, read_idx);
 205                 atomic_set(&dev->overflow_flag, 1);
 206         }
 207
 208         /* +1 for serial number */
 209         offset = intr_idx * (dev->report_size + 1);
 210         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 211                dev->report_size);
 212         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 213
 214         atomic_set(&dev->intr_idx, aux_idx);
 215         spin_unlock(&dev->intr_idx_lock);
 216         /* tell the blocking read about the new data */
 217         wake_up_interruptible(&dev->read_wait);
 218
 219 exit:
 220         retval = usb_submit_urb(urb, GFP_ATOMIC);
 221         if (retval)
 222                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 223                         __func__, retval);
 224
 225 }
 226
 227 /*
 228  * USB Callback handler for write-ops
 229  */
 230 static void iowarrior_write_callback(struct urb *urb)
 231 {
 232         struct iowarrior *dev;
 233         int status = urb->status;
 234
 235         dev = urb->context;
 236         /* sync/async unlink faults aren't errors */
 237         if (status &&
 238             !(status == -ENOENT ||
 239               status == -ECONNRESET || status == -ESHUTDOWN)) {
 240                 dev_dbg(&dev->interface->dev,
 241                         "nonzero write bulk status received: %d\n", status);
 242         }
 243         /* free up our allocated buffer */
 244         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 245                           urb->transfer_buffer, urb->transfer_dma);
 246         /* tell a waiting writer the interrupt-out-pipe is available again */
 247         atomic_dec(&dev->write_busy);
 248         wake_up_interruptible(&dev->write_wait);
 249 }
 250
 251 /**
 252  *      iowarrior_delete
 253  */
 254 static inline void iowarrior_delete(struct iowarrior *dev)
 255 {
 256         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 257         kfree(dev->int_in_buffer);
 258         usb_free_urb(dev->int_in_urb);
 259         kfree(dev->read_queue);
 260         usb_put_intf(dev->interface);
 261         kfree(dev);
 262 }
 263
 264 /*---------------------*/
 265 /* fops implementation */
 266 /*---------------------*/
 267
 268 static int read_index(struct iowarrior *dev)
 269 {
 270         int intr_idx, read_idx;
 271
 272         read_idx = atomic_read(&dev->read_idx);
 273         intr_idx = atomic_read(&dev->intr_idx);
 274
 275         return (read_idx == intr_idx ? -1 : read_idx);
 276 }
 277
 278 /**
 279  *  iowarrior_read
 280  */
 281 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 282                               size_t count, loff_t *ppos)
 283 {
 284         struct iowarrior *dev;
 285         int read_idx;
 286         int offset;
 287
 288         dev = file->private_data;
 289
 290         /* verify that the device wasn't unplugged */
 291         if (!dev || !dev->present)
 292                 return -ENODEV;
 293
 294         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 295                 dev->minor, count);
 296
 297         /* read count must be packet size (+ time stamp) */
 298         if ((count != dev->report_size)
 299             && (count != (dev->report_size + 1)))
 300                 return -EINVAL;
 301
 302         /* repeat until no buffer overrun in callback handler occur */
 303         do {
 304                 atomic_set(&dev->overflow_flag, 0);
 305                 if ((read_idx = read_index(dev)) == -1) {
 306                         /* queue empty */
 307                         if (file->f_flags & O_NONBLOCK)
 308                                 return -EAGAIN;
 309                         else {
 310                                 //next line will return when there is either new data, or the device is unplugged
 311                                 int r = wait_event_interruptible(dev->read_wait,
 312                                                                  (!dev->present
 313                                                                   || (read_idx =
 314                                                                       read_index
 315                                                                       (dev)) !=
 316                                                                   -1));
 317                                 if (r) {
 318                                         //we were interrupted by a signal
 319                                         return -ERESTART;
 320                                 }
 321                                 if (!dev->present) {
 322                                         //The device was unplugged
 323                                         return -ENODEV;
 324                                 }
 325                                 if (read_idx == -1) {
 326                                         // Can this happen ???
 327                                         return 0;
 328                                 }
 329                         }
 330                 }
 331
 332                 offset = read_idx * (dev->report_size + 1);
 333                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 334                         return -EFAULT;
 335                 }
 336         } while (atomic_read(&dev->overflow_flag));
 337
 338         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 339         atomic_set(&dev->read_idx, read_idx);
 340         return count;
 341 }
 342
 343 /*
 344  * iowarrior_write
 345  */
 346 static ssize_t iowarrior_write(struct file *file,
 347                                const char __user *user_buffer,
 348                                size_t count, loff_t *ppos)
 349 {
 350         struct iowarrior *dev;
 351         int retval = 0;
 352         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 353         struct urb *int_out_urb = NULL;
 354
 355         dev = file->private_data;
 356
 357         mutex_lock(&dev->mutex);
 358         /* verify that the device wasn't unplugged */
 359         if (!dev->present) {
 360                 retval = -ENODEV;
 361                 goto exit;
 362         }
 363         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 364                 dev->minor, count);
 365         /* if count is 0 we're already done */
 366         if (count == 0) {
 367                 retval = 0;
 368                 goto exit;
 369         }
 370         /* We only accept full reports */
 371         if (count != dev->report_size) {
 372                 retval = -EINVAL;
 373                 goto exit;
 374         }
 375         switch (dev->product_id) {
 376         case USB_DEVICE_ID_CODEMERCS_IOW24:
 377         case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
 378         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 379         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 380         case USB_DEVICE_ID_CODEMERCS_IOW40:
 381                 /* IOW24 and IOW40 use a synchronous call */
 382                 buf = memdup_user(user_buffer, count);
 383                 if (IS_ERR(buf)) {
 384                         retval = PTR_ERR(buf);
 385                         goto exit;
 386                 }
 387                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 388                 kfree(buf);
 389                 goto exit;
 390                 break;
 391         case USB_DEVICE_ID_CODEMERCS_IOW56:
 392         case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 393         case USB_DEVICE_ID_CODEMERCS_IOW28:
 394         case USB_DEVICE_ID_CODEMERCS_IOW28L:
 395         case USB_DEVICE_ID_CODEMERCS_IOW100:
 396                 /* The IOW56 uses asynchronous IO and more urbs */
 397                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 398                         /* Wait until we are below the limit for submitted urbs */
 399                         if (file->f_flags & O_NONBLOCK) {
 400                                 retval = -EAGAIN;
 401                                 goto exit;
 402                         } else {
 403                                 retval = wait_event_interruptible(dev->write_wait,
 404                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 405                                 if (retval) {
 406                                         /* we were interrupted by a signal */
 407                                         retval = -ERESTART;
 408                                         goto exit;
 409                                 }
 410                                 if (!dev->present) {
 411                                         /* The device was unplugged */
 412                                         retval = -ENODEV;
 413                                         goto exit;
 414                                 }
 415                                 if (!dev->opened) {
 416                                         /* We were closed while waiting for an URB */
 417                                         retval = -ENODEV;
 418                                         goto exit;
 419                                 }
 420                         }
 421                 }
 422                 atomic_inc(&dev->write_busy);
 423                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 424                 if (!int_out_urb) {
 425                         retval = -ENOMEM;
 426                         goto error_no_urb;
 427                 }
 428                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 429                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 430                 if (!buf) {
 431                         retval = -ENOMEM;
 432                         dev_dbg(&dev->interface->dev,
 433                                 "Unable to allocate buffer\n");
 434                         goto error_no_buffer;
 435                 }
 436                 usb_fill_int_urb(int_out_urb, dev->udev,
 437                                  usb_sndintpipe(dev->udev,
 438                                                 dev->int_out_endpoint->bEndpointAddress),
 439                                  buf, dev->report_size,
 440                                  iowarrior_write_callback, dev,
 441                                  dev->int_out_endpoint->bInterval);
 442                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 443                 if (copy_from_user(buf, user_buffer, count)) {
 444                         retval = -EFAULT;
 445                         goto error;
 446                 }
 447                 usb_anchor_urb(int_out_urb, &dev->submitted);
 448                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 449                 if (retval) {
 450                         dev_dbg(&dev->interface->dev,
 451                                 "submit error %d for urb nr.%d\n",
 452                                 retval, atomic_read(&dev->write_busy));
 453                         usb_unanchor_urb(int_out_urb);
 454                         goto error;
 455                 }
 456                 /* submit was ok */
 457                 retval = count;
 458                 usb_free_urb(int_out_urb);
 459                 goto exit;
 460                 break;
 461         default:
 462                 /* what do we have here ? An unsupported Product-ID ? */
 463                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 464                         __func__, dev->product_id);
 465                 retval = -EFAULT;
 466                 goto exit;
 467                 break;
 468         }
 469 error:
 470         usb_free_coherent(dev->udev, dev->report_size, buf,
 471                           int_out_urb->transfer_dma);
 472 error_no_buffer:
 473         usb_free_urb(int_out_urb);
 474 error_no_urb:
 475         atomic_dec(&dev->write_busy);
 476         wake_up_interruptible(&dev->write_wait);
 477 exit:
 478         mutex_unlock(&dev->mutex);
 479         return retval;
 480 }
 481
 482 /**
 483  *      iowarrior_ioctl
 484  */
 485 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 486                                                         unsigned long arg)
 487 {
 488         struct iowarrior *dev = NULL;
 489         __u8 *buffer;
 490         __u8 __user *user_buffer;
 491         int retval;
 492         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 493
 494         dev = file->private_data;
 495         if (!dev)
 496                 return -ENODEV;
 497
 498         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 499         if (!buffer)
 500                 return -ENOMEM;
 501
 502         /* lock this object */
 503         mutex_lock(&iowarrior_mutex);
 504         mutex_lock(&dev->mutex);
 505
 506         /* verify that the device wasn't unplugged */
 507         if (!dev->present) {
 508                 retval = -ENODEV;
 509                 goto error_out;
 510         }
 511
 512         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 513                 dev->minor, cmd, arg);
 514
 515         retval = 0;
 516         io_res = 0;
 517         switch (cmd) {
 518         case IOW_WRITE:
 519                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 520                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
 521                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 522                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 523                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 524                         user_buffer = (__u8 __user *)arg;
 525                         io_res = copy_from_user(buffer, user_buffer,
 526                                                 dev->report_size);
 527                         if (io_res) {
 528                                 retval = -EFAULT;
 529                         } else {
 530                                 io_res = usb_set_report(dev->interface, 2, 0,
 531                                                         buffer,
 532                                                         dev->report_size);
 533                                 if (io_res < 0)
 534                                         retval = io_res;
 535                         }
 536                 } else {
 537                         retval = -EINVAL;
 538                         dev_err(&dev->interface->dev,
 539                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 540                                 dev->product_id);
 541                 }
 542                 break;
 543         case IOW_READ:
 544                 user_buffer = (__u8 __user *)arg;
 545                 io_res = usb_get_report(dev->udev,
 546                                         dev->interface->cur_altsetting, 1, 0,
 547                                         buffer, dev->report_size);
 548                 if (io_res < 0)
 549                         retval = io_res;
 550                 else {
 551                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 552                         if (io_res)
 553                                 retval = -EFAULT;
 554                 }
 555                 break;
 556         case IOW_GETINFO:
 557                 {
 558                         /* Report available information for the device */
 559                         struct iowarrior_info info;
 560                         /* needed for power consumption */
 561                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 562
 563                         memset(&info, 0, sizeof(info));
 564                         /* directly from the descriptor */
 565                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 566                         info.product = dev->product_id;
 567                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 568
 569                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 570                         info.speed = dev->udev->speed;
 571                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 572                         info.report_size = dev->report_size;
 573
 574                         /* serial number string has been read earlier 8 chars or empty string */
 575                         memcpy(info.serial, dev->chip_serial,
 576                                sizeof(dev->chip_serial));
 577                         if (cfg_descriptor == NULL) {
 578                                 info.power = -1;        /* no information available */
 579                         } else {
 580                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 581                                 info.power = cfg_descriptor->bMaxPower * 2;
 582                         }
 583                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 584                                          sizeof(struct iowarrior_info));
 585                         if (io_res)
 586                                 retval = -EFAULT;
 587                         break;
 588                 }
 589         default:
 590                 /* return that we did not understand this ioctl call */
 591                 retval = -ENOTTY;
 592                 break;
 593         }
 594 error_out:
 595         /* unlock the device */
 596         mutex_unlock(&dev->mutex);
 597         mutex_unlock(&iowarrior_mutex);
 598         kfree(buffer);
 599         return retval;
 600 }
 601
 602 /**
 603  *      iowarrior_open
 604  */
 605 static int iowarrior_open(struct inode *inode, struct file *file)
 606 {
 607         struct iowarrior *dev = NULL;
 608         struct usb_interface *interface;
 609         int subminor;
 610         int retval = 0;
 611
 612         mutex_lock(&iowarrior_mutex);
 613         subminor = iminor(inode);
 614
 615         interface = usb_find_interface(&iowarrior_driver, subminor);
 616         if (!interface) {
 617                 mutex_unlock(&iowarrior_mutex);
 618                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 619                        __func__, subminor);
 620                 return -ENODEV;
 621         }
 622
 623         mutex_lock(&iowarrior_open_disc_lock);
 624         dev = usb_get_intfdata(interface);
 625         if (!dev) {
 626                 mutex_unlock(&iowarrior_open_disc_lock);
 627                 mutex_unlock(&iowarrior_mutex);
 628                 return -ENODEV;
 629         }
 630
 631         mutex_lock(&dev->mutex);
 632         mutex_unlock(&iowarrior_open_disc_lock);
 633
 634         /* Only one process can open each device, no sharing. */
 635         if (dev->opened) {
 636                 retval = -EBUSY;
 637                 goto out;
 638         }
 639
 640         /* setup interrupt handler for receiving values */
 641         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 642                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 643                 retval = -EFAULT;
 644                 goto out;
 645         }
 646         /* increment our usage count for the driver */
 647         ++dev->opened;
 648         /* save our object in the file's private structure */
 649         file->private_data = dev;
 650         retval = 0;
 651
 652 out:
 653         mutex_unlock(&dev->mutex);
 654         mutex_unlock(&iowarrior_mutex);
 655         return retval;
 656 }
 657
 658 /**
 659  *      iowarrior_release
 660  */
 661 static int iowarrior_release(struct inode *inode, struct file *file)
 662 {
 663         struct iowarrior *dev;
 664         int retval = 0;
 665
 666         dev = file->private_data;
 667         if (!dev)
 668                 return -ENODEV;
 669
 670         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 671
 672         /* lock our device */
 673         mutex_lock(&dev->mutex);
 674
 675         if (dev->opened <= 0) {
 676                 retval = -ENODEV;       /* close called more than once */
 677                 mutex_unlock(&dev->mutex);
 678         } else {
 679                 dev->opened = 0;        /* we're closing now */
 680                 retval = 0;
 681                 if (dev->present) {
 682                         /*
 683                            The device is still connected so we only shutdown
 684                            pending read-/write-ops.
 685                          */
 686                         usb_kill_urb(dev->int_in_urb);
 687                         wake_up_interruptible(&dev->read_wait);
 688                         wake_up_interruptible(&dev->write_wait);
 689                         mutex_unlock(&dev->mutex);
 690                 } else {
 691                         /* The device was unplugged, cleanup resources */
 692                         mutex_unlock(&dev->mutex);
 693                         iowarrior_delete(dev);
 694                 }
 695         }
 696         return retval;
 697 }
 698
 699 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
 700 {
 701         struct iowarrior *dev = file->private_data;
 702         unsigned int mask = 0;
 703
 704         if (!dev->present)
 705                 return POLLERR | POLLHUP;
 706
 707         poll_wait(file, &dev->read_wait, wait);
 708         poll_wait(file, &dev->write_wait, wait);
 709
 710         if (!dev->present)
 711                 return POLLERR | POLLHUP;
 712
 713         if (read_index(dev) != -1)
 714                 mask |= POLLIN | POLLRDNORM;
 715
 716         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 717                 mask |= POLLOUT | POLLWRNORM;
 718         return mask;
 719 }
 720
 721 /*
 722  * File operations needed when we register this driver.
 723  * This assumes that this driver NEEDS file operations,
 724  * of course, which means that the driver is expected
 725  * to have a node in the /dev directory. If the USB
 726  * device were for a network interface then the driver
 727  * would use "struct net_driver" instead, and a serial
 728  * device would use "struct tty_driver".
 729  */
 730 static const struct file_operations iowarrior_fops = {
 731         .owner = THIS_MODULE,
 732         .write = iowarrior_write,
 733         .read = iowarrior_read,
 734         .unlocked_ioctl = iowarrior_ioctl,
 735         .open = iowarrior_open,
 736         .release = iowarrior_release,
 737         .poll = iowarrior_poll,
 738         .llseek = noop_llseek,
 739 };
 740
 741 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 742 {
 743         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 744 }
 745
 746 /*
 747  * usb class driver info in order to get a minor number from the usb core,
 748  * and to have the device registered with devfs and the driver core
 749  */
 750 static struct usb_class_driver iowarrior_class = {
 751         .name = "iowarrior%d",
 752         .devnode = iowarrior_devnode,
 753         .fops = &iowarrior_fops,
 754         .minor_base = IOWARRIOR_MINOR_BASE,
 755 };
 756
 757 /*---------------------------------*/
 758 /*  probe and disconnect functions */
 759 /*---------------------------------*/
 760 /**
 761  *      iowarrior_probe
 762  *
 763  *      Called by the usb core when a new device is connected that it thinks
 764  *      this driver might be interested in.
 765  */
 766 static int iowarrior_probe(struct usb_interface *interface,
 767                            const struct usb_device_id *id)
 768 {
 769         struct usb_device *udev = interface_to_usbdev(interface);
 770         struct iowarrior *dev = NULL;
 771         struct usb_host_interface *iface_desc;
 772         int retval = -ENOMEM;
 773         int res;
 774
 775         /* allocate memory for our device state and initialize it */
 776         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 777         if (!dev)
 778                 return retval;
 779
 780         mutex_init(&dev->mutex);
 781
 782         atomic_set(&dev->intr_idx, 0);
 783         atomic_set(&dev->read_idx, 0);
 784         spin_lock_init(&dev->intr_idx_lock);
 785         atomic_set(&dev->overflow_flag, 0);
 786         init_waitqueue_head(&dev->read_wait);
 787         atomic_set(&dev->write_busy, 0);
 788         init_waitqueue_head(&dev->write_wait);
 789
 790         dev->udev = udev;
 791         dev->interface = usb_get_intf(interface);
 792
 793         iface_desc = interface->cur_altsetting;
 794         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 795
 796         init_usb_anchor(&dev->submitted);
 797
 798         res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
 799         if (res) {
 800                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 801                 retval = res;
 802                 goto error;
 803         }
 804
 805         if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
 806             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
 807             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
 808             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
 809             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
 810                 res = usb_find_last_int_out_endpoint(iface_desc,
 811                                 &dev->int_out_endpoint);
 812                 if (res) {
 813                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 814                         retval = res;
 815                         goto error;
 816                 }
 817         }
 818
 819         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 820         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 821
 822         /*
 823          * Some devices need the report size to be different than the
 824          * endpoint size.
 825          */
 826         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 827                 switch (dev->product_id) {
 828                 case USB_DEVICE_ID_CODEMERCS_IOW56:
 829                 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 830                         dev->report_size = 7;
 831                         break;
 832
 833                 case USB_DEVICE_ID_CODEMERCS_IOW28:
 834                 case USB_DEVICE_ID_CODEMERCS_IOW28L:
 835                         dev->report_size = 4;
 836                         break;
 837
 838                 case USB_DEVICE_ID_CODEMERCS_IOW100:
 839                         dev->report_size = 13;
 840                         break;
 841                 }
 842         }
 843
 844         /* create the urb and buffer for reading */
 845         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 846         if (!dev->int_in_urb)
 847                 goto error;
 848         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 849         if (!dev->int_in_buffer)
 850                 goto error;
 851         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 852                          usb_rcvintpipe(dev->udev,
 853                                         dev->int_in_endpoint->bEndpointAddress),
 854                          dev->int_in_buffer, dev->report_size,
 855                          iowarrior_callback, dev,
 856                          dev->int_in_endpoint->bInterval);
 857         /* create an internal buffer for interrupt data from the device */
 858         dev->read_queue =
 859             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 860                     GFP_KERNEL);
 861         if (!dev->read_queue)
 862                 goto error;
 863         /* Get the serial-number of the chip */
 864         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 865         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 866                    sizeof(dev->chip_serial));
 867         if (strlen(dev->chip_serial) != 8)
 868                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 869
 870         /* Set the idle timeout to 0, if this is interface 0 */
 871         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 872             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 873                             0x0A,
 874                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 875                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 876         }
 877         /* allow device read and ioctl */
 878         dev->present = 1;
 879
 880         /* we can register the device now, as it is ready */
 881         usb_set_intfdata(interface, dev);
 882
 883         retval = usb_register_dev(interface, &iowarrior_class);
 884         if (retval) {
 885                 /* something prevented us from registering this driver */
 886                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 887                 usb_set_intfdata(interface, NULL);
 888                 goto error;
 889         }
 890
 891         dev->minor = interface->minor;
 892
 893         /* let the user know what node this device is now attached to */
 894         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 895                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 896                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 897         return retval;
 898
 899 error:
 900         iowarrior_delete(dev);
 901         return retval;
 902 }
 903
 904 /**
 905  *      iowarrior_disconnect
 906  *
 907  *      Called by the usb core when the device is removed from the system.
 908  */
 909 static void iowarrior_disconnect(struct usb_interface *interface)
 910 {
 911         struct iowarrior *dev;
 912         int minor;
 913
 914         dev = usb_get_intfdata(interface);
 915         mutex_lock(&iowarrior_open_disc_lock);
 916         usb_set_intfdata(interface, NULL);
 917
 918         minor = dev->minor;
 919         mutex_unlock(&iowarrior_open_disc_lock);
 920         /* give back our minor - this will call close() locks need to be dropped at this point*/
 921
 922         usb_deregister_dev(interface, &iowarrior_class);
 923
 924         mutex_lock(&dev->mutex);
 925
 926         /* prevent device read, write and ioctl */
 927         dev->present = 0;
 928
 929         if (dev->opened) {
 930                 /* There is a process that holds a filedescriptor to the device ,
 931                    so we only shutdown read-/write-ops going on.
 932                    Deleting the device is postponed until close() was called.
 933                  */
 934                 usb_kill_urb(dev->int_in_urb);
 935                 usb_kill_anchored_urbs(&dev->submitted);
 936                 wake_up_interruptible(&dev->read_wait);
 937                 wake_up_interruptible(&dev->write_wait);
 938                 mutex_unlock(&dev->mutex);
 939         } else {
 940                 /* no process is using the device, cleanup now */
 941                 mutex_unlock(&dev->mutex);
 942                 iowarrior_delete(dev);
 943         }
 944
 945         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 946                  minor - IOWARRIOR_MINOR_BASE);
 947 }
 948
 949 /* usb specific object needed to register this driver with the usb subsystem */
 950 static struct usb_driver iowarrior_driver = {
 951         .name = "iowarrior",
 952         .probe = iowarrior_probe,
 953         .disconnect = iowarrior_disconnect,
 954         .id_table = iowarrior_ids,
 955 };
 956
 957 module_usb_driver(iowarrior_driver);