drivers/usb/misc/iowarrior.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Native support for the I/O-Warrior USB devices
   4  *
   5  *  Copyright (c) 2003-2005, 2020  Code Mercenaries GmbH
   6  *  written by Christian Lucht <lucht@codemercs.com> and
   7  *  Christoph Jung <jung@codemercs.com>
   8  *
   9  *  based on
  10
  11  *  usb-skeleton.c by Greg Kroah-Hartman  <greg@kroah.com>
  12  *  brlvger.c by Stephane Dalton  <sdalton@videotron.ca>
  13  *           and St�hane Doyon   <s.doyon@videotron.ca>
  14  *
  15  *  Released under the GPLv2.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/usb.h>
  20 #include <linux/slab.h>
  21 #include <linux/sched.h>
  22 #include <linux/mutex.h>
  23 #include <linux/poll.h>
  24 #include <linux/usb/iowarrior.h>
  25
  26 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
  27 #define DRIVER_DESC "USB IO-Warrior driver"
  28
  29 #define USB_VENDOR_ID_CODEMERCS         1984
  30 /* low speed iowarrior */
  31 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
  32 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
  33 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
  34 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
  35 /* full speed iowarrior */
  36 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
  37 /* fuller speed iowarrior */
  38 #define USB_DEVICE_ID_CODEMERCS_IOW28   0x1504
  39 #define USB_DEVICE_ID_CODEMERCS_IOW28L  0x1505
  40 #define USB_DEVICE_ID_CODEMERCS_IOW100  0x1506
  41
  42 /* OEMed devices */
  43 #define USB_DEVICE_ID_CODEMERCS_IOW24SAG        0x158a
  44 #define USB_DEVICE_ID_CODEMERCS_IOW56AM         0x158b
  45
  46 /* Get a minor range for your devices from the usb maintainer */
  47 #ifdef CONFIG_USB_DYNAMIC_MINORS
  48 #define IOWARRIOR_MINOR_BASE    0
  49 #else
  50 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not official yet
  51 #endif
  52
  53 /* interrupt input queue size */
  54 #define MAX_INTERRUPT_BUFFER 16
  55 /*
  56    maximum number of urbs that are submitted for writes at the same time,
  57    this applies to the IOWarrior56 only!
  58    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
  59 */
  60 #define MAX_WRITES_IN_FLIGHT 4
  61
  62 MODULE_AUTHOR(DRIVER_AUTHOR);
  63 MODULE_DESCRIPTION(DRIVER_DESC);
  64 MODULE_LICENSE("GPL");
  65
  66 /* Module parameters */
  67 static DEFINE_MUTEX(iowarrior_mutex);
  68
  69 static struct usb_driver iowarrior_driver;
  70 static DEFINE_MUTEX(iowarrior_open_disc_lock);
  71
  72 /*--------------*/
  73 /*     data     */
  74 /*--------------*/
  75
  76 /* Structure to hold all of our device specific stuff */
  77 struct iowarrior {
  78         struct mutex mutex;                     /* locks this structure */
  79         struct usb_device *udev;                /* save off the usb device pointer */
  80         struct usb_interface *interface;        /* the interface for this device */
  81         unsigned char minor;                    /* the starting minor number for this device */
  82         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
  83         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
  84         struct urb *int_in_urb;         /* the urb for reading data */
  85         unsigned char *int_in_buffer;   /* buffer for data to be read */
  86         unsigned char serial_number;    /* to detect lost packages */
  87         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
  88         wait_queue_head_t read_wait;
  89         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
  90         atomic_t write_busy;            /* number of write-urbs submitted */
  91         atomic_t read_idx;
  92         atomic_t 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         intr_idx = atomic_read(&dev->intr_idx);
 180         /* aux_idx become previous intr_idx */
 181         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 182         read_idx = atomic_read(&dev->read_idx);
 183
 184         /* queue is not empty and it's interface 0 */
 185         if ((intr_idx != read_idx)
 186             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 187                 /* + 1 for serial number */
 188                 offset = aux_idx * (dev->report_size + 1);
 189                 if (!memcmp
 190                     (dev->read_queue + offset, urb->transfer_buffer,
 191                      dev->report_size)) {
 192                         /* equal values on interface 0 will be ignored */
 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         /* tell the blocking read about the new data */
 214         wake_up_interruptible(&dev->read_wait);
 215
 216 exit:
 217         retval = usb_submit_urb(urb, GFP_ATOMIC);
 218         if (retval)
 219                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 220                         __func__, retval);
 221
 222 }
 223
 224 /*
 225  * USB Callback handler for write-ops
 226  */
 227 static void iowarrior_write_callback(struct urb *urb)
 228 {
 229         struct iowarrior *dev;
 230         int status = urb->status;
 231
 232         dev = urb->context;
 233         /* sync/async unlink faults aren't errors */
 234         if (status &&
 235             !(status == -ENOENT ||
 236               status == -ECONNRESET || status == -ESHUTDOWN)) {
 237                 dev_dbg(&dev->interface->dev,
 238                         "nonzero write bulk status received: %d\n", status);
 239         }
 240         /* free up our allocated buffer */
 241         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 242                           urb->transfer_buffer, urb->transfer_dma);
 243         /* tell a waiting writer the interrupt-out-pipe is available again */
 244         atomic_dec(&dev->write_busy);
 245         wake_up_interruptible(&dev->write_wait);
 246 }
 247
 248 /**
 249  *      iowarrior_delete
 250  */
 251 static inline void iowarrior_delete(struct iowarrior *dev)
 252 {
 253         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 254         kfree(dev->int_in_buffer);
 255         usb_free_urb(dev->int_in_urb);
 256         kfree(dev->read_queue);
 257         usb_put_intf(dev->interface);
 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 = file->private_data;
 286
 287         /* verify that the device wasn't unplugged */
 288         if (!dev || !dev->present)
 289                 return -ENODEV;
 290
 291         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 292                 dev->minor, count);
 293
 294         /* read count must be packet size (+ time stamp) */
 295         if ((count != dev->report_size)
 296             && (count != (dev->report_size + 1)))
 297                 return -EINVAL;
 298
 299         /* repeat until no buffer overrun in callback handler occur */
 300         do {
 301                 atomic_set(&dev->overflow_flag, 0);
 302                 if ((read_idx = read_index(dev)) == -1) {
 303                         /* queue empty */
 304                         if (file->f_flags & O_NONBLOCK)
 305                                 return -EAGAIN;
 306                         else {
 307                                 //next line will return when there is either new data, or the device is unplugged
 308                                 int r = wait_event_interruptible(dev->read_wait,
 309                                                                  (!dev->present
 310                                                                   || (read_idx =
 311                                                                       read_index
 312                                                                       (dev)) !=
 313                                                                   -1));
 314                                 if (r) {
 315                                         //we were interrupted by a signal
 316                                         return -ERESTART;
 317                                 }
 318                                 if (!dev->present) {
 319                                         //The device was unplugged
 320                                         return -ENODEV;
 321                                 }
 322                                 if (read_idx == -1) {
 323                                         // Can this happen ???
 324                                         return 0;
 325                                 }
 326                         }
 327                 }
 328
 329                 offset = read_idx * (dev->report_size + 1);
 330                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 331                         return -EFAULT;
 332                 }
 333         } while (atomic_read(&dev->overflow_flag));
 334
 335         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 336         atomic_set(&dev->read_idx, read_idx);
 337         return count;
 338 }
 339
 340 /*
 341  * iowarrior_write
 342  */
 343 static ssize_t iowarrior_write(struct file *file,
 344                                const char __user *user_buffer,
 345                                size_t count, loff_t *ppos)
 346 {
 347         struct iowarrior *dev;
 348         int retval = 0;
 349         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 350         struct urb *int_out_urb = NULL;
 351
 352         dev = file->private_data;
 353
 354         mutex_lock(&dev->mutex);
 355         /* verify that the device wasn't unplugged */
 356         if (!dev->present) {
 357                 retval = -ENODEV;
 358                 goto exit;
 359         }
 360         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 361                 dev->minor, count);
 362         /* if count is 0 we're already done */
 363         if (count == 0) {
 364                 retval = 0;
 365                 goto exit;
 366         }
 367         /* We only accept full reports */
 368         if (count != dev->report_size) {
 369                 retval = -EINVAL;
 370                 goto exit;
 371         }
 372         switch (dev->product_id) {
 373         case USB_DEVICE_ID_CODEMERCS_IOW24:
 374         case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
 375         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 376         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 377         case USB_DEVICE_ID_CODEMERCS_IOW40:
 378                 /* IOW24 and IOW40 use a synchronous call */
 379                 buf = memdup_user(user_buffer, count);
 380                 if (IS_ERR(buf)) {
 381                         retval = PTR_ERR(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         case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 390         case USB_DEVICE_ID_CODEMERCS_IOW28:
 391         case USB_DEVICE_ID_CODEMERCS_IOW28L:
 392         case USB_DEVICE_ID_CODEMERCS_IOW100:
 393                 /* The IOW56 uses asynchronous IO and more urbs */
 394                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 395                         /* Wait until we are below the limit for submitted urbs */
 396                         if (file->f_flags & O_NONBLOCK) {
 397                                 retval = -EAGAIN;
 398                                 goto exit;
 399                         } else {
 400                                 retval = wait_event_interruptible(dev->write_wait,
 401                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 402                                 if (retval) {
 403                                         /* we were interrupted by a signal */
 404                                         retval = -ERESTART;
 405                                         goto exit;
 406                                 }
 407                                 if (!dev->present) {
 408                                         /* The device was unplugged */
 409                                         retval = -ENODEV;
 410                                         goto exit;
 411                                 }
 412                                 if (!dev->opened) {
 413                                         /* We were closed while waiting for an URB */
 414                                         retval = -ENODEV;
 415                                         goto exit;
 416                                 }
 417                         }
 418                 }
 419                 atomic_inc(&dev->write_busy);
 420                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 421                 if (!int_out_urb) {
 422                         retval = -ENOMEM;
 423                         goto error_no_urb;
 424                 }
 425                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 426                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 427                 if (!buf) {
 428                         retval = -ENOMEM;
 429                         dev_dbg(&dev->interface->dev,
 430                                 "Unable to allocate buffer\n");
 431                         goto error_no_buffer;
 432                 }
 433                 usb_fill_int_urb(int_out_urb, dev->udev,
 434                                  usb_sndintpipe(dev->udev,
 435                                                 dev->int_out_endpoint->bEndpointAddress),
 436                                  buf, dev->report_size,
 437                                  iowarrior_write_callback, dev,
 438                                  dev->int_out_endpoint->bInterval);
 439                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 440                 if (copy_from_user(buf, user_buffer, count)) {
 441                         retval = -EFAULT;
 442                         goto error;
 443                 }
 444                 usb_anchor_urb(int_out_urb, &dev->submitted);
 445                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 446                 if (retval) {
 447                         dev_dbg(&dev->interface->dev,
 448                                 "submit error %d for urb nr.%d\n",
 449                                 retval, atomic_read(&dev->write_busy));
 450                         usb_unanchor_urb(int_out_urb);
 451                         goto error;
 452                 }
 453                 /* submit was ok */
 454                 retval = count;
 455                 usb_free_urb(int_out_urb);
 456                 goto exit;
 457                 break;
 458         default:
 459                 /* what do we have here ? An unsupported Product-ID ? */
 460                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 461                         __func__, dev->product_id);
 462                 retval = -EFAULT;
 463                 goto exit;
 464                 break;
 465         }
 466 error:
 467         usb_free_coherent(dev->udev, dev->report_size, buf,
 468                           int_out_urb->transfer_dma);
 469 error_no_buffer:
 470         usb_free_urb(int_out_urb);
 471 error_no_urb:
 472         atomic_dec(&dev->write_busy);
 473         wake_up_interruptible(&dev->write_wait);
 474 exit:
 475         mutex_unlock(&dev->mutex);
 476         return retval;
 477 }
 478
 479 /**
 480  *      iowarrior_ioctl
 481  */
 482 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 483                                                         unsigned long arg)
 484 {
 485         struct iowarrior *dev = NULL;
 486         __u8 *buffer;
 487         __u8 __user *user_buffer;
 488         int retval;
 489         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 490
 491         dev = file->private_data;
 492         if (!dev)
 493                 return -ENODEV;
 494
 495         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 496         if (!buffer)
 497                 return -ENOMEM;
 498
 499         /* lock this object */
 500         mutex_lock(&iowarrior_mutex);
 501         mutex_lock(&dev->mutex);
 502
 503         /* verify that the device wasn't unplugged */
 504         if (!dev->present) {
 505                 retval = -ENODEV;
 506                 goto error_out;
 507         }
 508
 509         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 510                 dev->minor, cmd, arg);
 511
 512         retval = 0;
 513         io_res = 0;
 514         switch (cmd) {
 515         case IOW_WRITE:
 516                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 517                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
 518                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 519                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 520                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 521                         user_buffer = (__u8 __user *)arg;
 522                         io_res = copy_from_user(buffer, user_buffer,
 523                                                 dev->report_size);
 524                         if (io_res) {
 525                                 retval = -EFAULT;
 526                         } else {
 527                                 io_res = usb_set_report(dev->interface, 2, 0,
 528                                                         buffer,
 529                                                         dev->report_size);
 530                                 if (io_res < 0)
 531                                         retval = io_res;
 532                         }
 533                 } else {
 534                         retval = -EINVAL;
 535                         dev_err(&dev->interface->dev,
 536                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 537                                 dev->product_id);
 538                 }
 539                 break;
 540         case IOW_READ:
 541                 user_buffer = (__u8 __user *)arg;
 542                 io_res = usb_get_report(dev->udev,
 543                                         dev->interface->cur_altsetting, 1, 0,
 544                                         buffer, dev->report_size);
 545                 if (io_res < 0)
 546                         retval = io_res;
 547                 else {
 548                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 549                         if (io_res)
 550                                 retval = -EFAULT;
 551                 }
 552                 break;
 553         case IOW_GETINFO:
 554                 {
 555                         /* Report available information for the device */
 556                         struct iowarrior_info info;
 557                         /* needed for power consumption */
 558                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 559
 560                         memset(&info, 0, sizeof(info));
 561                         /* directly from the descriptor */
 562                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 563                         info.product = dev->product_id;
 564                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 565
 566                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 567                         info.speed = dev->udev->speed;
 568                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 569                         info.report_size = dev->report_size;
 570
 571                         /* serial number string has been read earlier 8 chars or empty string */
 572                         memcpy(info.serial, dev->chip_serial,
 573                                sizeof(dev->chip_serial));
 574                         if (cfg_descriptor == NULL) {
 575                                 info.power = -1;        /* no information available */
 576                         } else {
 577                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 578                                 info.power = cfg_descriptor->bMaxPower * 2;
 579                         }
 580                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 581                                          sizeof(struct iowarrior_info));
 582                         if (io_res)
 583                                 retval = -EFAULT;
 584                         break;
 585                 }
 586         default:
 587                 /* return that we did not understand this ioctl call */
 588                 retval = -ENOTTY;
 589                 break;
 590         }
 591 error_out:
 592         /* unlock the device */
 593         mutex_unlock(&dev->mutex);
 594         mutex_unlock(&iowarrior_mutex);
 595         kfree(buffer);
 596         return retval;
 597 }
 598
 599 /**
 600  *      iowarrior_open
 601  */
 602 static int iowarrior_open(struct inode *inode, struct file *file)
 603 {
 604         struct iowarrior *dev = NULL;
 605         struct usb_interface *interface;
 606         int subminor;
 607         int retval = 0;
 608
 609         mutex_lock(&iowarrior_mutex);
 610         subminor = iminor(inode);
 611
 612         interface = usb_find_interface(&iowarrior_driver, subminor);
 613         if (!interface) {
 614                 mutex_unlock(&iowarrior_mutex);
 615                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 616                        __func__, subminor);
 617                 return -ENODEV;
 618         }
 619
 620         mutex_lock(&iowarrior_open_disc_lock);
 621         dev = usb_get_intfdata(interface);
 622         if (!dev) {
 623                 mutex_unlock(&iowarrior_open_disc_lock);
 624                 mutex_unlock(&iowarrior_mutex);
 625                 return -ENODEV;
 626         }
 627
 628         mutex_lock(&dev->mutex);
 629         mutex_unlock(&iowarrior_open_disc_lock);
 630
 631         /* Only one process can open each device, no sharing. */
 632         if (dev->opened) {
 633                 retval = -EBUSY;
 634                 goto out;
 635         }
 636
 637         /* setup interrupt handler for receiving values */
 638         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 639                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 640                 retval = -EFAULT;
 641                 goto out;
 642         }
 643         /* increment our usage count for the driver */
 644         ++dev->opened;
 645         /* save our object in the file's private structure */
 646         file->private_data = dev;
 647         retval = 0;
 648
 649 out:
 650         mutex_unlock(&dev->mutex);
 651         mutex_unlock(&iowarrior_mutex);
 652         return retval;
 653 }
 654
 655 /**
 656  *      iowarrior_release
 657  */
 658 static int iowarrior_release(struct inode *inode, struct file *file)
 659 {
 660         struct iowarrior *dev;
 661         int retval = 0;
 662
 663         dev = file->private_data;
 664         if (!dev)
 665                 return -ENODEV;
 666
 667         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 668
 669         /* lock our device */
 670         mutex_lock(&dev->mutex);
 671
 672         if (dev->opened <= 0) {
 673                 retval = -ENODEV;       /* close called more than once */
 674                 mutex_unlock(&dev->mutex);
 675         } else {
 676                 dev->opened = 0;        /* we're closing now */
 677                 retval = 0;
 678                 if (dev->present) {
 679                         /*
 680                            The device is still connected so we only shutdown
 681                            pending read-/write-ops.
 682                          */
 683                         usb_kill_urb(dev->int_in_urb);
 684                         wake_up_interruptible(&dev->read_wait);
 685                         wake_up_interruptible(&dev->write_wait);
 686                         mutex_unlock(&dev->mutex);
 687                 } else {
 688                         /* The device was unplugged, cleanup resources */
 689                         mutex_unlock(&dev->mutex);
 690                         iowarrior_delete(dev);
 691                 }
 692         }
 693         return retval;
 694 }
 695
 696 static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
 697 {
 698         struct iowarrior *dev = file->private_data;
 699         __poll_t mask = 0;
 700
 701         if (!dev->present)
 702                 return EPOLLERR | EPOLLHUP;
 703
 704         poll_wait(file, &dev->read_wait, wait);
 705         poll_wait(file, &dev->write_wait, wait);
 706
 707         if (!dev->present)
 708                 return EPOLLERR | EPOLLHUP;
 709
 710         if (read_index(dev) != -1)
 711                 mask |= EPOLLIN | EPOLLRDNORM;
 712
 713         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 714                 mask |= EPOLLOUT | EPOLLWRNORM;
 715         return mask;
 716 }
 717
 718 /*
 719  * File operations needed when we register this driver.
 720  * This assumes that this driver NEEDS file operations,
 721  * of course, which means that the driver is expected
 722  * to have a node in the /dev directory. If the USB
 723  * device were for a network interface then the driver
 724  * would use "struct net_driver" instead, and a serial
 725  * device would use "struct tty_driver".
 726  */
 727 static const struct file_operations iowarrior_fops = {
 728         .owner = THIS_MODULE,
 729         .write = iowarrior_write,
 730         .read = iowarrior_read,
 731         .unlocked_ioctl = iowarrior_ioctl,
 732         .open = iowarrior_open,
 733         .release = iowarrior_release,
 734         .poll = iowarrior_poll,
 735         .llseek = noop_llseek,
 736 };
 737
 738 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 739 {
 740         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 741 }
 742
 743 /*
 744  * usb class driver info in order to get a minor number from the usb core,
 745  * and to have the device registered with devfs and the driver core
 746  */
 747 static struct usb_class_driver iowarrior_class = {
 748         .name = "iowarrior%d",
 749         .devnode = iowarrior_devnode,
 750         .fops = &iowarrior_fops,
 751         .minor_base = IOWARRIOR_MINOR_BASE,
 752 };
 753
 754 /*---------------------------------*/
 755 /*  probe and disconnect functions */
 756 /*---------------------------------*/
 757 /**
 758  *      iowarrior_probe
 759  *
 760  *      Called by the usb core when a new device is connected that it thinks
 761  *      this driver might be interested in.
 762  */
 763 static int iowarrior_probe(struct usb_interface *interface,
 764                            const struct usb_device_id *id)
 765 {
 766         struct usb_device *udev = interface_to_usbdev(interface);
 767         struct iowarrior *dev = NULL;
 768         struct usb_host_interface *iface_desc;
 769         int retval = -ENOMEM;
 770         int res;
 771
 772         /* allocate memory for our device state and initialize it */
 773         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 774         if (!dev)
 775                 return retval;
 776
 777         mutex_init(&dev->mutex);
 778
 779         atomic_set(&dev->intr_idx, 0);
 780         atomic_set(&dev->read_idx, 0);
 781         atomic_set(&dev->overflow_flag, 0);
 782         init_waitqueue_head(&dev->read_wait);
 783         atomic_set(&dev->write_busy, 0);
 784         init_waitqueue_head(&dev->write_wait);
 785
 786         dev->udev = udev;
 787         dev->interface = usb_get_intf(interface);
 788
 789         iface_desc = interface->cur_altsetting;
 790         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 791
 792         init_usb_anchor(&dev->submitted);
 793
 794         res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
 795         if (res) {
 796                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 797                 retval = res;
 798                 goto error;
 799         }
 800
 801         if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
 802             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
 803             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
 804             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
 805             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
 806                 res = usb_find_last_int_out_endpoint(iface_desc,
 807                                 &dev->int_out_endpoint);
 808                 if (res) {
 809                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 810                         retval = res;
 811                         goto error;
 812                 }
 813         }
 814
 815         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 816         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 817
 818         /*
 819          * Some devices need the report size to be different than the
 820          * endpoint size.
 821          */
 822         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 823                 switch (dev->product_id) {
 824                 case USB_DEVICE_ID_CODEMERCS_IOW56:
 825                 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 826                         dev->report_size = 7;
 827                         break;
 828
 829                 case USB_DEVICE_ID_CODEMERCS_IOW28:
 830                 case USB_DEVICE_ID_CODEMERCS_IOW28L:
 831                         dev->report_size = 4;
 832                         break;
 833
 834                 case USB_DEVICE_ID_CODEMERCS_IOW100:
 835                         dev->report_size = 12;
 836                         break;
 837                 }
 838         }
 839
 840         /* create the urb and buffer for reading */
 841         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 842         if (!dev->int_in_urb)
 843                 goto error;
 844         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 845         if (!dev->int_in_buffer)
 846                 goto error;
 847         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 848                          usb_rcvintpipe(dev->udev,
 849                                         dev->int_in_endpoint->bEndpointAddress),
 850                          dev->int_in_buffer, dev->report_size,
 851                          iowarrior_callback, dev,
 852                          dev->int_in_endpoint->bInterval);
 853         /* create an internal buffer for interrupt data from the device */
 854         dev->read_queue =
 855             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
 856                     GFP_KERNEL);
 857         if (!dev->read_queue)
 858                 goto error;
 859         /* Get the serial-number of the chip */
 860         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 861         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 862                    sizeof(dev->chip_serial));
 863         if (strlen(dev->chip_serial) != 8)
 864                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 865
 866         /* Set the idle timeout to 0, if this is interface 0 */
 867         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 868             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 869                             0x0A,
 870                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 871                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 872         }
 873         /* allow device read and ioctl */
 874         dev->present = 1;
 875
 876         /* we can register the device now, as it is ready */
 877         usb_set_intfdata(interface, dev);
 878
 879         retval = usb_register_dev(interface, &iowarrior_class);
 880         if (retval) {
 881                 /* something prevented us from registering this driver */
 882                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 883                 usb_set_intfdata(interface, NULL);
 884                 goto error;
 885         }
 886
 887         dev->minor = interface->minor;
 888
 889         /* let the user know what node this device is now attached to */
 890         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 891                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 892                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 893         return retval;
 894
 895 error:
 896         iowarrior_delete(dev);
 897         return retval;
 898 }
 899
 900 /**
 901  *      iowarrior_disconnect
 902  *
 903  *      Called by the usb core when the device is removed from the system.
 904  */
 905 static void iowarrior_disconnect(struct usb_interface *interface)
 906 {
 907         struct iowarrior *dev;
 908         int minor;
 909
 910         dev = usb_get_intfdata(interface);
 911         mutex_lock(&iowarrior_open_disc_lock);
 912         usb_set_intfdata(interface, NULL);
 913
 914         minor = dev->minor;
 915         mutex_unlock(&iowarrior_open_disc_lock);
 916         /* give back our minor - this will call close() locks need to be dropped at this point*/
 917
 918         usb_deregister_dev(interface, &iowarrior_class);
 919
 920         mutex_lock(&dev->mutex);
 921
 922         /* prevent device read, write and ioctl */
 923         dev->present = 0;
 924
 925         if (dev->opened) {
 926                 /* There is a process that holds a filedescriptor to the device ,
 927                    so we only shutdown read-/write-ops going on.
 928                    Deleting the device is postponed until close() was called.
 929                  */
 930                 usb_kill_urb(dev->int_in_urb);
 931                 usb_kill_anchored_urbs(&dev->submitted);
 932                 wake_up_interruptible(&dev->read_wait);
 933                 wake_up_interruptible(&dev->write_wait);
 934                 mutex_unlock(&dev->mutex);
 935         } else {
 936                 /* no process is using the device, cleanup now */
 937                 mutex_unlock(&dev->mutex);
 938                 iowarrior_delete(dev);
 939         }
 940
 941         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 942                  minor - IOWARRIOR_MINOR_BASE);
 943 }
 944
 945 /* usb specific object needed to register this driver with the usb subsystem */
 946 static struct usb_driver iowarrior_driver = {
 947         .name = "iowarrior",
 948         .probe = iowarrior_probe,
 949         .disconnect = iowarrior_disconnect,
 950         .id_table = iowarrior_ids,
 951 };
 952
 953 module_usb_driver(iowarrior_driver);