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 Stephane 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 static struct usb_driver iowarrior_driver;
  67
  68 /*--------------*/
  69 /*     data     */
  70 /*--------------*/
  71
  72 /* Structure to hold all of our device specific stuff */
  73 struct iowarrior {
  74         struct mutex mutex;                     /* locks this structure */
  75         struct usb_device *udev;                /* save off the usb device pointer */
  76         struct usb_interface *interface;        /* the interface for this device */
  77         unsigned char minor;                    /* the starting minor number for this device */
  78         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
  79         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
  80         struct urb *int_in_urb;         /* the urb for reading data */
  81         unsigned char *int_in_buffer;   /* buffer for data to be read */
  82         unsigned char serial_number;    /* to detect lost packages */
  83         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
  84         wait_queue_head_t read_wait;
  85         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
  86         atomic_t write_busy;            /* number of write-urbs submitted */
  87         atomic_t read_idx;
  88         atomic_t intr_idx;
  89         atomic_t overflow_flag;         /* signals an index 'rollover' */
  90         int present;                    /* this is 1 as long as the device is connected */
  91         int opened;                     /* this is 1 if the device is currently open */
  92         char chip_serial[9];            /* the serial number string of the chip connected */
  93         int report_size;                /* number of bytes in a report */
  94         u16 product_id;
  95         struct usb_anchor submitted;
  96 };
  97
  98 /*--------------*/
  99 /*    globals   */
 100 /*--------------*/
 101
 102 #define USB_REQ_GET_REPORT  0x01
 103 //#if 0
 104 static int usb_get_report(struct usb_device *dev,
 105                           struct usb_host_interface *inter, unsigned char type,
 106                           unsigned char id, void *buf, int size)
 107 {
 108         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 109                                USB_REQ_GET_REPORT,
 110                                USB_DIR_IN | USB_TYPE_CLASS |
 111                                USB_RECIP_INTERFACE, (type << 8) + id,
 112                                inter->desc.bInterfaceNumber, buf, size,
 113                                USB_CTRL_GET_TIMEOUT);
 114 }
 115 //#endif
 116
 117 #define USB_REQ_SET_REPORT 0x09
 118
 119 static int usb_set_report(struct usb_interface *intf, unsigned char type,
 120                           unsigned char id, void *buf, int size)
 121 {
 122         return usb_control_msg(interface_to_usbdev(intf),
 123                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 124                                USB_REQ_SET_REPORT,
 125                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 126                                (type << 8) + id,
 127                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
 128                                size, 1000);
 129 }
 130
 131 /*---------------------*/
 132 /* driver registration */
 133 /*---------------------*/
 134 /* table of devices that work with this driver */
 135 static const struct usb_device_id iowarrior_ids[] = {
 136         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
 137         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
 138         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
 139         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
 140         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
 141         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
 142         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
 143         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
 144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
 145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
 146         {}                      /* Terminating entry */
 147 };
 148 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 149
 150 /*
 151  * USB callback handler for reading data
 152  */
 153 static void iowarrior_callback(struct urb *urb)
 154 {
 155         struct iowarrior *dev = urb->context;
 156         int intr_idx;
 157         int read_idx;
 158         int aux_idx;
 159         int offset;
 160         int status = urb->status;
 161         int retval;
 162
 163         switch (status) {
 164         case 0:
 165                 /* success */
 166                 break;
 167         case -ECONNRESET:
 168         case -ENOENT:
 169         case -ESHUTDOWN:
 170                 return;
 171         default:
 172                 goto exit;
 173         }
 174
 175         intr_idx = atomic_read(&dev->intr_idx);
 176         /* aux_idx become previous intr_idx */
 177         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
 178         read_idx = atomic_read(&dev->read_idx);
 179
 180         /* queue is not empty and it's interface 0 */
 181         if ((intr_idx != read_idx)
 182             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
 183                 /* + 1 for serial number */
 184                 offset = aux_idx * (dev->report_size + 1);
 185                 if (!memcmp
 186                     (dev->read_queue + offset, urb->transfer_buffer,
 187                      dev->report_size)) {
 188                         /* equal values on interface 0 will be ignored */
 189                         goto exit;
 190                 }
 191         }
 192
 193         /* aux_idx become next intr_idx */
 194         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
 195         if (read_idx == aux_idx) {
 196                 /* queue full, dropping oldest input */
 197                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
 198                 atomic_set(&dev->read_idx, read_idx);
 199                 atomic_set(&dev->overflow_flag, 1);
 200         }
 201
 202         /* +1 for serial number */
 203         offset = intr_idx * (dev->report_size + 1);
 204         memcpy(dev->read_queue + offset, urb->transfer_buffer,
 205                dev->report_size);
 206         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
 207
 208         atomic_set(&dev->intr_idx, aux_idx);
 209         /* tell the blocking read about the new data */
 210         wake_up_interruptible(&dev->read_wait);
 211
 212 exit:
 213         retval = usb_submit_urb(urb, GFP_ATOMIC);
 214         if (retval)
 215                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
 216                         __func__, retval);
 217
 218 }
 219
 220 /*
 221  * USB Callback handler for write-ops
 222  */
 223 static void iowarrior_write_callback(struct urb *urb)
 224 {
 225         struct iowarrior *dev;
 226         int status = urb->status;
 227
 228         dev = urb->context;
 229         /* sync/async unlink faults aren't errors */
 230         if (status &&
 231             !(status == -ENOENT ||
 232               status == -ECONNRESET || status == -ESHUTDOWN)) {
 233                 dev_dbg(&dev->interface->dev,
 234                         "nonzero write bulk status received: %d\n", status);
 235         }
 236         /* free up our allocated buffer */
 237         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 238                           urb->transfer_buffer, urb->transfer_dma);
 239         /* tell a waiting writer the interrupt-out-pipe is available again */
 240         atomic_dec(&dev->write_busy);
 241         wake_up_interruptible(&dev->write_wait);
 242 }
 243
 244 /*
 245  *      iowarrior_delete
 246  */
 247 static inline void iowarrior_delete(struct iowarrior *dev)
 248 {
 249         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 250         kfree(dev->int_in_buffer);
 251         usb_free_urb(dev->int_in_urb);
 252         kfree(dev->read_queue);
 253         usb_put_intf(dev->interface);
 254         kfree(dev);
 255 }
 256
 257 /*---------------------*/
 258 /* fops implementation */
 259 /*---------------------*/
 260
 261 static int read_index(struct iowarrior *dev)
 262 {
 263         int intr_idx, read_idx;
 264
 265         read_idx = atomic_read(&dev->read_idx);
 266         intr_idx = atomic_read(&dev->intr_idx);
 267
 268         return (read_idx == intr_idx ? -1 : read_idx);
 269 }
 270
 271 /*
 272  *  iowarrior_read
 273  */
 274 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
 275                               size_t count, loff_t *ppos)
 276 {
 277         struct iowarrior *dev;
 278         int read_idx;
 279         int offset;
 280
 281         dev = file->private_data;
 282
 283         /* verify that the device wasn't unplugged */
 284         if (!dev || !dev->present)
 285                 return -ENODEV;
 286
 287         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 288                 dev->minor, count);
 289
 290         /* read count must be packet size (+ time stamp) */
 291         if ((count != dev->report_size)
 292             && (count != (dev->report_size + 1)))
 293                 return -EINVAL;
 294
 295         /* repeat until no buffer overrun in callback handler occur */
 296         do {
 297                 atomic_set(&dev->overflow_flag, 0);
 298                 if ((read_idx = read_index(dev)) == -1) {
 299                         /* queue empty */
 300                         if (file->f_flags & O_NONBLOCK)
 301                                 return -EAGAIN;
 302                         else {
 303                                 //next line will return when there is either new data, or the device is unplugged
 304                                 int r = wait_event_interruptible(dev->read_wait,
 305                                                                  (!dev->present
 306                                                                   || (read_idx =
 307                                                                       read_index
 308                                                                       (dev)) !=
 309                                                                   -1));
 310                                 if (r) {
 311                                         //we were interrupted by a signal
 312                                         return -ERESTART;
 313                                 }
 314                                 if (!dev->present) {
 315                                         //The device was unplugged
 316                                         return -ENODEV;
 317                                 }
 318                                 if (read_idx == -1) {
 319                                         // Can this happen ???
 320                                         return 0;
 321                                 }
 322                         }
 323                 }
 324
 325                 offset = read_idx * (dev->report_size + 1);
 326                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 327                         return -EFAULT;
 328                 }
 329         } while (atomic_read(&dev->overflow_flag));
 330
 331         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 332         atomic_set(&dev->read_idx, read_idx);
 333         return count;
 334 }
 335
 336 /*
 337  * iowarrior_write
 338  */
 339 static ssize_t iowarrior_write(struct file *file,
 340                                const char __user *user_buffer,
 341                                size_t count, loff_t *ppos)
 342 {
 343         struct iowarrior *dev;
 344         int retval = 0;
 345         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 346         struct urb *int_out_urb = NULL;
 347
 348         dev = file->private_data;
 349
 350         mutex_lock(&dev->mutex);
 351         /* verify that the device wasn't unplugged */
 352         if (!dev->present) {
 353                 retval = -ENODEV;
 354                 goto exit;
 355         }
 356         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 357                 dev->minor, count);
 358         /* if count is 0 we're already done */
 359         if (count == 0) {
 360                 retval = 0;
 361                 goto exit;
 362         }
 363         /* We only accept full reports */
 364         if (count != dev->report_size) {
 365                 retval = -EINVAL;
 366                 goto exit;
 367         }
 368         switch (dev->product_id) {
 369         case USB_DEVICE_ID_CODEMERCS_IOW24:
 370         case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
 371         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 372         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 373         case USB_DEVICE_ID_CODEMERCS_IOW40:
 374                 /* IOW24 and IOW40 use a synchronous call */
 375                 buf = memdup_user(user_buffer, count);
 376                 if (IS_ERR(buf)) {
 377                         retval = PTR_ERR(buf);
 378                         goto exit;
 379                 }
 380                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 381                 kfree(buf);
 382                 goto exit;
 383                 break;
 384         case USB_DEVICE_ID_CODEMERCS_IOW56:
 385         case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 386         case USB_DEVICE_ID_CODEMERCS_IOW28:
 387         case USB_DEVICE_ID_CODEMERCS_IOW28L:
 388         case USB_DEVICE_ID_CODEMERCS_IOW100:
 389                 /* The IOW56 uses asynchronous IO and more urbs */
 390                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 391                         /* Wait until we are below the limit for submitted urbs */
 392                         if (file->f_flags & O_NONBLOCK) {
 393                                 retval = -EAGAIN;
 394                                 goto exit;
 395                         } else {
 396                                 retval = wait_event_interruptible(dev->write_wait,
 397                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 398                                 if (retval) {
 399                                         /* we were interrupted by a signal */
 400                                         retval = -ERESTART;
 401                                         goto exit;
 402                                 }
 403                                 if (!dev->present) {
 404                                         /* The device was unplugged */
 405                                         retval = -ENODEV;
 406                                         goto exit;
 407                                 }
 408                                 if (!dev->opened) {
 409                                         /* We were closed while waiting for an URB */
 410                                         retval = -ENODEV;
 411                                         goto exit;
 412                                 }
 413                         }
 414                 }
 415                 atomic_inc(&dev->write_busy);
 416                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 417                 if (!int_out_urb) {
 418                         retval = -ENOMEM;
 419                         goto error_no_urb;
 420                 }
 421                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 422                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 423                 if (!buf) {
 424                         retval = -ENOMEM;
 425                         dev_dbg(&dev->interface->dev,
 426                                 "Unable to allocate buffer\n");
 427                         goto error_no_buffer;
 428                 }
 429                 usb_fill_int_urb(int_out_urb, dev->udev,
 430                                  usb_sndintpipe(dev->udev,
 431                                                 dev->int_out_endpoint->bEndpointAddress),
 432                                  buf, dev->report_size,
 433                                  iowarrior_write_callback, dev,
 434                                  dev->int_out_endpoint->bInterval);
 435                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 436                 if (copy_from_user(buf, user_buffer, count)) {
 437                         retval = -EFAULT;
 438                         goto error;
 439                 }
 440                 usb_anchor_urb(int_out_urb, &dev->submitted);
 441                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 442                 if (retval) {
 443                         dev_dbg(&dev->interface->dev,
 444                                 "submit error %d for urb nr.%d\n",
 445                                 retval, atomic_read(&dev->write_busy));
 446                         usb_unanchor_urb(int_out_urb);
 447                         goto error;
 448                 }
 449                 /* submit was ok */
 450                 retval = count;
 451                 usb_free_urb(int_out_urb);
 452                 goto exit;
 453                 break;
 454         default:
 455                 /* what do we have here ? An unsupported Product-ID ? */
 456                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 457                         __func__, dev->product_id);
 458                 retval = -EFAULT;
 459                 goto exit;
 460                 break;
 461         }
 462 error:
 463         usb_free_coherent(dev->udev, dev->report_size, buf,
 464                           int_out_urb->transfer_dma);
 465 error_no_buffer:
 466         usb_free_urb(int_out_urb);
 467 error_no_urb:
 468         atomic_dec(&dev->write_busy);
 469         wake_up_interruptible(&dev->write_wait);
 470 exit:
 471         mutex_unlock(&dev->mutex);
 472         return retval;
 473 }
 474
 475 /*
 476  *      iowarrior_ioctl
 477  */
 478 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 479                                                         unsigned long arg)
 480 {
 481         struct iowarrior *dev = NULL;
 482         __u8 *buffer;
 483         __u8 __user *user_buffer;
 484         int retval;
 485         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 486
 487         dev = file->private_data;
 488         if (!dev)
 489                 return -ENODEV;
 490
 491         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 492         if (!buffer)
 493                 return -ENOMEM;
 494
 495         mutex_lock(&dev->mutex);
 496
 497         /* verify that the device wasn't unplugged */
 498         if (!dev->present) {
 499                 retval = -ENODEV;
 500                 goto error_out;
 501         }
 502
 503         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 504                 dev->minor, cmd, arg);
 505
 506         retval = 0;
 507         io_res = 0;
 508         switch (cmd) {
 509         case IOW_WRITE:
 510                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 511                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
 512                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 513                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 514                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 515                         user_buffer = (__u8 __user *)arg;
 516                         io_res = copy_from_user(buffer, user_buffer,
 517                                                 dev->report_size);
 518                         if (io_res) {
 519                                 retval = -EFAULT;
 520                         } else {
 521                                 io_res = usb_set_report(dev->interface, 2, 0,
 522                                                         buffer,
 523                                                         dev->report_size);
 524                                 if (io_res < 0)
 525                                         retval = io_res;
 526                         }
 527                 } else {
 528                         retval = -EINVAL;
 529                         dev_err(&dev->interface->dev,
 530                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 531                                 dev->product_id);
 532                 }
 533                 break;
 534         case IOW_READ:
 535                 user_buffer = (__u8 __user *)arg;
 536                 io_res = usb_get_report(dev->udev,
 537                                         dev->interface->cur_altsetting, 1, 0,
 538                                         buffer, dev->report_size);
 539                 if (io_res < 0)
 540                         retval = io_res;
 541                 else {
 542                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 543                         if (io_res)
 544                                 retval = -EFAULT;
 545                 }
 546                 break;
 547         case IOW_GETINFO:
 548                 {
 549                         /* Report available information for the device */
 550                         struct iowarrior_info info;
 551                         /* needed for power consumption */
 552                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 553
 554                         memset(&info, 0, sizeof(info));
 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 = 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)
 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         kfree(buffer);
 589         return retval;
 590 }
 591
 592 /*
 593  *      iowarrior_open
 594  */
 595 static int iowarrior_open(struct inode *inode, struct file *file)
 596 {
 597         struct iowarrior *dev = NULL;
 598         struct usb_interface *interface;
 599         int subminor;
 600         int retval = 0;
 601
 602         subminor = iminor(inode);
 603
 604         interface = usb_find_interface(&iowarrior_driver, subminor);
 605         if (!interface) {
 606                 pr_err("%s - error, can't find device for minor %d\n",
 607                        __func__, subminor);
 608                 return -ENODEV;
 609         }
 610
 611         dev = usb_get_intfdata(interface);
 612         if (!dev)
 613                 return -ENODEV;
 614
 615         mutex_lock(&dev->mutex);
 616
 617         /* Only one process can open each device, no sharing. */
 618         if (dev->opened) {
 619                 retval = -EBUSY;
 620                 goto out;
 621         }
 622
 623         /* setup interrupt handler for receiving values */
 624         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 625                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 626                 retval = -EFAULT;
 627                 goto out;
 628         }
 629         /* increment our usage count for the driver */
 630         ++dev->opened;
 631         /* save our object in the file's private structure */
 632         file->private_data = dev;
 633         retval = 0;
 634
 635 out:
 636         mutex_unlock(&dev->mutex);
 637         return retval;
 638 }
 639
 640 /*
 641  *      iowarrior_release
 642  */
 643 static int iowarrior_release(struct inode *inode, struct file *file)
 644 {
 645         struct iowarrior *dev;
 646         int retval = 0;
 647
 648         dev = file->private_data;
 649         if (!dev)
 650                 return -ENODEV;
 651
 652         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 653
 654         /* lock our device */
 655         mutex_lock(&dev->mutex);
 656
 657         if (dev->opened <= 0) {
 658                 retval = -ENODEV;       /* close called more than once */
 659                 mutex_unlock(&dev->mutex);
 660         } else {
 661                 dev->opened = 0;        /* we're closing now */
 662                 retval = 0;
 663                 if (dev->present) {
 664                         /*
 665                            The device is still connected so we only shutdown
 666                            pending read-/write-ops.
 667                          */
 668                         usb_kill_urb(dev->int_in_urb);
 669                         wake_up_interruptible(&dev->read_wait);
 670                         wake_up_interruptible(&dev->write_wait);
 671                         mutex_unlock(&dev->mutex);
 672                 } else {
 673                         /* The device was unplugged, cleanup resources */
 674                         mutex_unlock(&dev->mutex);
 675                         iowarrior_delete(dev);
 676                 }
 677         }
 678         return retval;
 679 }
 680
 681 static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
 682 {
 683         struct iowarrior *dev = file->private_data;
 684         __poll_t mask = 0;
 685
 686         if (!dev->present)
 687                 return EPOLLERR | EPOLLHUP;
 688
 689         poll_wait(file, &dev->read_wait, wait);
 690         poll_wait(file, &dev->write_wait, wait);
 691
 692         if (!dev->present)
 693                 return EPOLLERR | EPOLLHUP;
 694
 695         if (read_index(dev) != -1)
 696                 mask |= EPOLLIN | EPOLLRDNORM;
 697
 698         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 699                 mask |= EPOLLOUT | EPOLLWRNORM;
 700         return mask;
 701 }
 702
 703 /*
 704  * File operations needed when we register this driver.
 705  * This assumes that this driver NEEDS file operations,
 706  * of course, which means that the driver is expected
 707  * to have a node in the /dev directory. If the USB
 708  * device were for a network interface then the driver
 709  * would use "struct net_driver" instead, and a serial
 710  * device would use "struct tty_driver".
 711  */
 712 static const struct file_operations iowarrior_fops = {
 713         .owner = THIS_MODULE,
 714         .write = iowarrior_write,
 715         .read = iowarrior_read,
 716         .unlocked_ioctl = iowarrior_ioctl,
 717         .open = iowarrior_open,
 718         .release = iowarrior_release,
 719         .poll = iowarrior_poll,
 720         .llseek = noop_llseek,
 721 };
 722
 723 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 724 {
 725         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 726 }
 727
 728 /*
 729  * usb class driver info in order to get a minor number from the usb core,
 730  * and to have the device registered with devfs and the driver core
 731  */
 732 static struct usb_class_driver iowarrior_class = {
 733         .name = "iowarrior%d",
 734         .devnode = iowarrior_devnode,
 735         .fops = &iowarrior_fops,
 736         .minor_base = IOWARRIOR_MINOR_BASE,
 737 };
 738
 739 /*---------------------------------*/
 740 /*  probe and disconnect functions */
 741 /*---------------------------------*/
 742 /*
 743  *      iowarrior_probe
 744  *
 745  *      Called by the usb core when a new device is connected that it thinks
 746  *      this driver might be interested in.
 747  */
 748 static int iowarrior_probe(struct usb_interface *interface,
 749                            const struct usb_device_id *id)
 750 {
 751         struct usb_device *udev = interface_to_usbdev(interface);
 752         struct iowarrior *dev = NULL;
 753         struct usb_host_interface *iface_desc;
 754         int retval = -ENOMEM;
 755         int res;
 756
 757         /* allocate memory for our device state and initialize it */
 758         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 759         if (!dev)
 760                 return retval;
 761
 762         mutex_init(&dev->mutex);
 763
 764         atomic_set(&dev->intr_idx, 0);
 765         atomic_set(&dev->read_idx, 0);
 766         atomic_set(&dev->overflow_flag, 0);
 767         init_waitqueue_head(&dev->read_wait);
 768         atomic_set(&dev->write_busy, 0);
 769         init_waitqueue_head(&dev->write_wait);
 770
 771         dev->udev = udev;
 772         dev->interface = usb_get_intf(interface);
 773
 774         iface_desc = interface->cur_altsetting;
 775         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 776
 777         init_usb_anchor(&dev->submitted);
 778
 779         res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
 780         if (res) {
 781                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 782                 retval = res;
 783                 goto error;
 784         }
 785
 786         if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
 787             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
 788             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
 789             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
 790             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
 791                 res = usb_find_last_int_out_endpoint(iface_desc,
 792                                 &dev->int_out_endpoint);
 793                 if (res) {
 794                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 795                         retval = res;
 796                         goto error;
 797                 }
 798         }
 799
 800         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 801         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 802
 803         /*
 804          * Some devices need the report size to be different than the
 805          * endpoint size.
 806          */
 807         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 808                 switch (dev->product_id) {
 809                 case USB_DEVICE_ID_CODEMERCS_IOW56:
 810                 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 811                         dev->report_size = 7;
 812                         break;
 813
 814                 case USB_DEVICE_ID_CODEMERCS_IOW28:
 815                 case USB_DEVICE_ID_CODEMERCS_IOW28L:
 816                         dev->report_size = 4;
 817                         break;
 818
 819                 case USB_DEVICE_ID_CODEMERCS_IOW100:
 820                         dev->report_size = 12;
 821                         break;
 822                 }
 823         }
 824
 825         /* create the urb and buffer for reading */
 826         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 827         if (!dev->int_in_urb)
 828                 goto error;
 829         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 830         if (!dev->int_in_buffer)
 831                 goto error;
 832         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 833                          usb_rcvintpipe(dev->udev,
 834                                         dev->int_in_endpoint->bEndpointAddress),
 835                          dev->int_in_buffer, dev->report_size,
 836                          iowarrior_callback, dev,
 837                          dev->int_in_endpoint->bInterval);
 838         /* create an internal buffer for interrupt data from the device */
 839         dev->read_queue =
 840             kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
 841                           GFP_KERNEL);
 842         if (!dev->read_queue)
 843                 goto error;
 844         /* Get the serial-number of the chip */
 845         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 846         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 847                    sizeof(dev->chip_serial));
 848         if (strlen(dev->chip_serial) != 8)
 849                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 850
 851         /* Set the idle timeout to 0, if this is interface 0 */
 852         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 853             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 854                             0x0A,
 855                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 856                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 857         }
 858         /* allow device read and ioctl */
 859         dev->present = 1;
 860
 861         /* we can register the device now, as it is ready */
 862         usb_set_intfdata(interface, dev);
 863
 864         retval = usb_register_dev(interface, &iowarrior_class);
 865         if (retval) {
 866                 /* something prevented us from registering this driver */
 867                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 868                 goto error;
 869         }
 870
 871         dev->minor = interface->minor;
 872
 873         /* let the user know what node this device is now attached to */
 874         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 875                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 876                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 877         return retval;
 878
 879 error:
 880         iowarrior_delete(dev);
 881         return retval;
 882 }
 883
 884 /*
 885  *      iowarrior_disconnect
 886  *
 887  *      Called by the usb core when the device is removed from the system.
 888  */
 889 static void iowarrior_disconnect(struct usb_interface *interface)
 890 {
 891         struct iowarrior *dev = usb_get_intfdata(interface);
 892         int minor = dev->minor;
 893
 894         usb_deregister_dev(interface, &iowarrior_class);
 895
 896         mutex_lock(&dev->mutex);
 897
 898         /* prevent device read, write and ioctl */
 899         dev->present = 0;
 900
 901         if (dev->opened) {
 902                 /* There is a process that holds a filedescriptor to the device ,
 903                    so we only shutdown read-/write-ops going on.
 904                    Deleting the device is postponed until close() was called.
 905                  */
 906                 usb_kill_urb(dev->int_in_urb);
 907                 usb_kill_anchored_urbs(&dev->submitted);
 908                 wake_up_interruptible(&dev->read_wait);
 909                 wake_up_interruptible(&dev->write_wait);
 910                 mutex_unlock(&dev->mutex);
 911         } else {
 912                 /* no process is using the device, cleanup now */
 913                 mutex_unlock(&dev->mutex);
 914                 iowarrior_delete(dev);
 915         }
 916
 917         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
 918                  minor - IOWARRIOR_MINOR_BASE);
 919 }
 920
 921 /* usb specific object needed to register this driver with the usb subsystem */
 922 static struct usb_driver iowarrior_driver = {
 923         .name = "iowarrior",
 924         .probe = iowarrior_probe,
 925         .disconnect = iowarrior_disconnect,
 926         .id_table = iowarrior_ids,
 927 };
 928
 929 module_usb_driver(iowarrior_driver);