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 <[email protected]> and
   7  *  Christoph Jung <[email protected]>
   8  *
   9  *  based on
  10
  11  *  usb-skeleton.c by Greg Kroah-Hartman  <[email protected]>
  12  *  brlvger.c by Stephane Dalton  <[email protected]>
  13  *           and Stephane Doyon   <[email protected]>
  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 <[email protected]>"
  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         int retval;
 281
 282         dev = file->private_data;
 283
 284         if (file->f_flags & O_NONBLOCK) {
 285                 retval = mutex_trylock(&dev->mutex);
 286                 if (!retval)
 287                         return -EAGAIN;
 288         } else {
 289                 retval = mutex_lock_interruptible(&dev->mutex);
 290                 if (retval)
 291                         return -ERESTARTSYS;
 292         }
 293
 294         /* verify that the device wasn't unplugged */
 295         if (!dev->present) {
 296                 retval = -ENODEV;
 297                 goto exit;
 298         }
 299
 300         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 301                 dev->minor, count);
 302
 303         /* read count must be packet size (+ time stamp) */
 304         if ((count != dev->report_size)
 305             && (count != (dev->report_size + 1))) {
 306                 retval = -EINVAL;
 307                 goto exit;
 308         }
 309
 310         /* repeat until no buffer overrun in callback handler occur */
 311         do {
 312                 atomic_set(&dev->overflow_flag, 0);
 313                 if ((read_idx = read_index(dev)) == -1) {
 314                         /* queue empty */
 315                         if (file->f_flags & O_NONBLOCK) {
 316                                 retval = -EAGAIN;
 317                                 goto exit;
 318                         }
 319                         else {
 320                                 //next line will return when there is either new data, or the device is unplugged
 321                                 int r = wait_event_interruptible(dev->read_wait,
 322                                                                  (!dev->present
 323                                                                   || (read_idx =
 324                                                                       read_index
 325                                                                       (dev)) !=
 326                                                                   -1));
 327                                 if (r) {
 328                                         //we were interrupted by a signal
 329                                         retval = -ERESTART;
 330                                         goto exit;
 331                                 }
 332                                 if (!dev->present) {
 333                                         //The device was unplugged
 334                                         retval = -ENODEV;
 335                                         goto exit;
 336                                 }
 337                                 if (read_idx == -1) {
 338                                         // Can this happen ???
 339                                         retval = 0;
 340                                         goto exit;
 341                                 }
 342                         }
 343                 }
 344
 345                 offset = read_idx * (dev->report_size + 1);
 346                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
 347                         retval = -EFAULT;
 348                         goto exit;
 349                 }
 350         } while (atomic_read(&dev->overflow_flag));
 351
 352         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
 353         atomic_set(&dev->read_idx, read_idx);
 354         mutex_unlock(&dev->mutex);
 355         return count;
 356
 357 exit:
 358         mutex_unlock(&dev->mutex);
 359         return retval;
 360 }
 361
 362 /*
 363  * iowarrior_write
 364  */
 365 static ssize_t iowarrior_write(struct file *file,
 366                                const char __user *user_buffer,
 367                                size_t count, loff_t *ppos)
 368 {
 369         struct iowarrior *dev;
 370         int retval = 0;
 371         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
 372         struct urb *int_out_urb = NULL;
 373
 374         dev = file->private_data;
 375
 376         mutex_lock(&dev->mutex);
 377         /* verify that the device wasn't unplugged */
 378         if (!dev->present) {
 379                 retval = -ENODEV;
 380                 goto exit;
 381         }
 382         dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
 383                 dev->minor, count);
 384         /* if count is 0 we're already done */
 385         if (count == 0) {
 386                 retval = 0;
 387                 goto exit;
 388         }
 389         /* We only accept full reports */
 390         if (count != dev->report_size) {
 391                 retval = -EINVAL;
 392                 goto exit;
 393         }
 394         switch (dev->product_id) {
 395         case USB_DEVICE_ID_CODEMERCS_IOW24:
 396         case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
 397         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
 398         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
 399         case USB_DEVICE_ID_CODEMERCS_IOW40:
 400                 /* IOW24 and IOW40 use a synchronous call */
 401                 buf = memdup_user(user_buffer, count);
 402                 if (IS_ERR(buf)) {
 403                         retval = PTR_ERR(buf);
 404                         goto exit;
 405                 }
 406                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
 407                 kfree(buf);
 408                 goto exit;
 409         case USB_DEVICE_ID_CODEMERCS_IOW56:
 410         case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 411         case USB_DEVICE_ID_CODEMERCS_IOW28:
 412         case USB_DEVICE_ID_CODEMERCS_IOW28L:
 413         case USB_DEVICE_ID_CODEMERCS_IOW100:
 414                 /* The IOW56 uses asynchronous IO and more urbs */
 415                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
 416                         /* Wait until we are below the limit for submitted urbs */
 417                         if (file->f_flags & O_NONBLOCK) {
 418                                 retval = -EAGAIN;
 419                                 goto exit;
 420                         } else {
 421                                 retval = wait_event_interruptible(dev->write_wait,
 422                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
 423                                 if (retval) {
 424                                         /* we were interrupted by a signal */
 425                                         retval = -ERESTART;
 426                                         goto exit;
 427                                 }
 428                                 if (!dev->present) {
 429                                         /* The device was unplugged */
 430                                         retval = -ENODEV;
 431                                         goto exit;
 432                                 }
 433                                 if (!dev->opened) {
 434                                         /* We were closed while waiting for an URB */
 435                                         retval = -ENODEV;
 436                                         goto exit;
 437                                 }
 438                         }
 439                 }
 440                 atomic_inc(&dev->write_busy);
 441                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 442                 if (!int_out_urb) {
 443                         retval = -ENOMEM;
 444                         goto error_no_urb;
 445                 }
 446                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
 447                                          GFP_KERNEL, &int_out_urb->transfer_dma);
 448                 if (!buf) {
 449                         retval = -ENOMEM;
 450                         dev_dbg(&dev->interface->dev,
 451                                 "Unable to allocate buffer\n");
 452                         goto error_no_buffer;
 453                 }
 454                 usb_fill_int_urb(int_out_urb, dev->udev,
 455                                  usb_sndintpipe(dev->udev,
 456                                                 dev->int_out_endpoint->bEndpointAddress),
 457                                  buf, dev->report_size,
 458                                  iowarrior_write_callback, dev,
 459                                  dev->int_out_endpoint->bInterval);
 460                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 461                 if (copy_from_user(buf, user_buffer, count)) {
 462                         retval = -EFAULT;
 463                         goto error;
 464                 }
 465                 usb_anchor_urb(int_out_urb, &dev->submitted);
 466                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
 467                 if (retval) {
 468                         dev_dbg(&dev->interface->dev,
 469                                 "submit error %d for urb nr.%d\n",
 470                                 retval, atomic_read(&dev->write_busy));
 471                         usb_unanchor_urb(int_out_urb);
 472                         goto error;
 473                 }
 474                 /* submit was ok */
 475                 retval = count;
 476                 usb_free_urb(int_out_urb);
 477                 goto exit;
 478         default:
 479                 /* what do we have here ? An unsupported Product-ID ? */
 480                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
 481                         __func__, dev->product_id);
 482                 retval = -EFAULT;
 483                 goto exit;
 484         }
 485 error:
 486         usb_free_coherent(dev->udev, dev->report_size, buf,
 487                           int_out_urb->transfer_dma);
 488 error_no_buffer:
 489         usb_free_urb(int_out_urb);
 490 error_no_urb:
 491         atomic_dec(&dev->write_busy);
 492         wake_up_interruptible(&dev->write_wait);
 493 exit:
 494         mutex_unlock(&dev->mutex);
 495         return retval;
 496 }
 497
 498 /*
 499  *      iowarrior_ioctl
 500  */
 501 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
 502                                                         unsigned long arg)
 503 {
 504         struct iowarrior *dev = NULL;
 505         __u8 *buffer;
 506         __u8 __user *user_buffer;
 507         int retval;
 508         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
 509
 510         dev = file->private_data;
 511         if (!dev)
 512                 return -ENODEV;
 513
 514         buffer = kzalloc(dev->report_size, GFP_KERNEL);
 515         if (!buffer)
 516                 return -ENOMEM;
 517
 518         mutex_lock(&dev->mutex);
 519
 520         /* verify that the device wasn't unplugged */
 521         if (!dev->present) {
 522                 retval = -ENODEV;
 523                 goto error_out;
 524         }
 525
 526         dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
 527                 dev->minor, cmd, arg);
 528
 529         retval = 0;
 530         switch (cmd) {
 531         case IOW_WRITE:
 532                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
 533                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
 534                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
 535                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
 536                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
 537                         user_buffer = (__u8 __user *)arg;
 538                         io_res = copy_from_user(buffer, user_buffer,
 539                                                 dev->report_size);
 540                         if (io_res) {
 541                                 retval = -EFAULT;
 542                         } else {
 543                                 io_res = usb_set_report(dev->interface, 2, 0,
 544                                                         buffer,
 545                                                         dev->report_size);
 546                                 if (io_res < 0)
 547                                         retval = io_res;
 548                         }
 549                 } else {
 550                         retval = -EINVAL;
 551                         dev_err(&dev->interface->dev,
 552                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
 553                                 dev->product_id);
 554                 }
 555                 break;
 556         case IOW_READ:
 557                 user_buffer = (__u8 __user *)arg;
 558                 io_res = usb_get_report(dev->udev,
 559                                         dev->interface->cur_altsetting, 1, 0,
 560                                         buffer, dev->report_size);
 561                 if (io_res < 0)
 562                         retval = io_res;
 563                 else {
 564                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
 565                         if (io_res)
 566                                 retval = -EFAULT;
 567                 }
 568                 break;
 569         case IOW_GETINFO:
 570                 {
 571                         /* Report available information for the device */
 572                         struct iowarrior_info info;
 573                         /* needed for power consumption */
 574                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
 575
 576                         memset(&info, 0, sizeof(info));
 577                         /* directly from the descriptor */
 578                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 579                         info.product = dev->product_id;
 580                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
 581
 582                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
 583                         info.speed = dev->udev->speed;
 584                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
 585                         info.report_size = dev->report_size;
 586
 587                         /* serial number string has been read earlier 8 chars or empty string */
 588                         memcpy(info.serial, dev->chip_serial,
 589                                sizeof(dev->chip_serial));
 590                         if (cfg_descriptor == NULL) {
 591                                 info.power = -1;        /* no information available */
 592                         } else {
 593                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
 594                                 info.power = cfg_descriptor->bMaxPower * 2;
 595                         }
 596                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
 597                                          sizeof(struct iowarrior_info));
 598                         if (io_res)
 599                                 retval = -EFAULT;
 600                         break;
 601                 }
 602         default:
 603                 /* return that we did not understand this ioctl call */
 604                 retval = -ENOTTY;
 605                 break;
 606         }
 607 error_out:
 608         /* unlock the device */
 609         mutex_unlock(&dev->mutex);
 610         kfree(buffer);
 611         return retval;
 612 }
 613
 614 /*
 615  *      iowarrior_open
 616  */
 617 static int iowarrior_open(struct inode *inode, struct file *file)
 618 {
 619         struct iowarrior *dev = NULL;
 620         struct usb_interface *interface;
 621         int subminor;
 622         int retval = 0;
 623
 624         subminor = iminor(inode);
 625
 626         interface = usb_find_interface(&iowarrior_driver, subminor);
 627         if (!interface) {
 628                 pr_err("%s - error, can't find device for minor %d\n",
 629                        __func__, subminor);
 630                 return -ENODEV;
 631         }
 632
 633         dev = usb_get_intfdata(interface);
 634         if (!dev)
 635                 return -ENODEV;
 636
 637         mutex_lock(&dev->mutex);
 638
 639         /* Only one process can open each device, no sharing. */
 640         if (dev->opened) {
 641                 retval = -EBUSY;
 642                 goto out;
 643         }
 644
 645         /* setup interrupt handler for receiving values */
 646         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
 647                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
 648                 retval = -EFAULT;
 649                 goto out;
 650         }
 651         /* increment our usage count for the driver */
 652         ++dev->opened;
 653         /* save our object in the file's private structure */
 654         file->private_data = dev;
 655         retval = 0;
 656
 657 out:
 658         mutex_unlock(&dev->mutex);
 659         return retval;
 660 }
 661
 662 /*
 663  *      iowarrior_release
 664  */
 665 static int iowarrior_release(struct inode *inode, struct file *file)
 666 {
 667         struct iowarrior *dev;
 668         int retval = 0;
 669
 670         dev = file->private_data;
 671         if (!dev)
 672                 return -ENODEV;
 673
 674         dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
 675
 676         /* lock our device */
 677         mutex_lock(&dev->mutex);
 678
 679         if (dev->opened <= 0) {
 680                 retval = -ENODEV;       /* close called more than once */
 681                 mutex_unlock(&dev->mutex);
 682         } else {
 683                 dev->opened = 0;        /* we're closing now */
 684                 retval = 0;
 685                 if (dev->present) {
 686                         /*
 687                            The device is still connected so we only shutdown
 688                            pending read-/write-ops.
 689                          */
 690                         usb_kill_urb(dev->int_in_urb);
 691                         wake_up_interruptible(&dev->read_wait);
 692                         wake_up_interruptible(&dev->write_wait);
 693                         mutex_unlock(&dev->mutex);
 694                 } else {
 695                         /* The device was unplugged, cleanup resources */
 696                         mutex_unlock(&dev->mutex);
 697                         iowarrior_delete(dev);
 698                 }
 699         }
 700         return retval;
 701 }
 702
 703 static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
 704 {
 705         struct iowarrior *dev = file->private_data;
 706         __poll_t mask = 0;
 707
 708         if (!dev->present)
 709                 return EPOLLERR | EPOLLHUP;
 710
 711         poll_wait(file, &dev->read_wait, wait);
 712         poll_wait(file, &dev->write_wait, wait);
 713
 714         if (!dev->present)
 715                 return EPOLLERR | EPOLLHUP;
 716
 717         if (read_index(dev) != -1)
 718                 mask |= EPOLLIN | EPOLLRDNORM;
 719
 720         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
 721                 mask |= EPOLLOUT | EPOLLWRNORM;
 722         return mask;
 723 }
 724
 725 /*
 726  * File operations needed when we register this driver.
 727  * This assumes that this driver NEEDS file operations,
 728  * of course, which means that the driver is expected
 729  * to have a node in the /dev directory. If the USB
 730  * device were for a network interface then the driver
 731  * would use "struct net_driver" instead, and a serial
 732  * device would use "struct tty_driver".
 733  */
 734 static const struct file_operations iowarrior_fops = {
 735         .owner = THIS_MODULE,
 736         .write = iowarrior_write,
 737         .read = iowarrior_read,
 738         .unlocked_ioctl = iowarrior_ioctl,
 739         .open = iowarrior_open,
 740         .release = iowarrior_release,
 741         .poll = iowarrior_poll,
 742         .llseek = noop_llseek,
 743 };
 744
 745 static char *iowarrior_devnode(const struct device *dev, umode_t *mode)
 746 {
 747         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 748 }
 749
 750 /*
 751  * usb class driver info in order to get a minor number from the usb core,
 752  * and to have the device registered with devfs and the driver core
 753  */
 754 static struct usb_class_driver iowarrior_class = {
 755         .name = "iowarrior%d",
 756         .devnode = iowarrior_devnode,
 757         .fops = &iowarrior_fops,
 758         .minor_base = IOWARRIOR_MINOR_BASE,
 759 };
 760
 761 /*---------------------------------*/
 762 /*  probe and disconnect functions */
 763 /*---------------------------------*/
 764 /*
 765  *      iowarrior_probe
 766  *
 767  *      Called by the usb core when a new device is connected that it thinks
 768  *      this driver might be interested in.
 769  */
 770 static int iowarrior_probe(struct usb_interface *interface,
 771                            const struct usb_device_id *id)
 772 {
 773         struct usb_device *udev = interface_to_usbdev(interface);
 774         struct iowarrior *dev = NULL;
 775         struct usb_host_interface *iface_desc;
 776         int retval = -ENOMEM;
 777         int res;
 778
 779         /* allocate memory for our device state and initialize it */
 780         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
 781         if (!dev)
 782                 return retval;
 783
 784         mutex_init(&dev->mutex);
 785
 786         atomic_set(&dev->intr_idx, 0);
 787         atomic_set(&dev->read_idx, 0);
 788         atomic_set(&dev->overflow_flag, 0);
 789         init_waitqueue_head(&dev->read_wait);
 790         atomic_set(&dev->write_busy, 0);
 791         init_waitqueue_head(&dev->write_wait);
 792
 793         dev->udev = udev;
 794         dev->interface = usb_get_intf(interface);
 795
 796         iface_desc = interface->cur_altsetting;
 797         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
 798
 799         init_usb_anchor(&dev->submitted);
 800
 801         res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
 802         if (res) {
 803                 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
 804                 retval = res;
 805                 goto error;
 806         }
 807
 808         if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
 809             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
 810             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
 811             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
 812             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
 813                 res = usb_find_last_int_out_endpoint(iface_desc,
 814                                 &dev->int_out_endpoint);
 815                 if (res) {
 816                         dev_err(&interface->dev, "no interrupt-out endpoint found\n");
 817                         retval = res;
 818                         goto error;
 819                 }
 820         }
 821
 822         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
 823         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
 824
 825         /*
 826          * Some devices need the report size to be different than the
 827          * endpoint size.
 828          */
 829         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 830                 switch (dev->product_id) {
 831                 case USB_DEVICE_ID_CODEMERCS_IOW56:
 832                 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
 833                         dev->report_size = 7;
 834                         break;
 835
 836                 case USB_DEVICE_ID_CODEMERCS_IOW28:
 837                 case USB_DEVICE_ID_CODEMERCS_IOW28L:
 838                         dev->report_size = 4;
 839                         break;
 840
 841                 case USB_DEVICE_ID_CODEMERCS_IOW100:
 842                         dev->report_size = 12;
 843                         break;
 844                 }
 845         }
 846
 847         /* create the urb and buffer for reading */
 848         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 849         if (!dev->int_in_urb)
 850                 goto error;
 851         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
 852         if (!dev->int_in_buffer)
 853                 goto error;
 854         usb_fill_int_urb(dev->int_in_urb, dev->udev,
 855                          usb_rcvintpipe(dev->udev,
 856                                         dev->int_in_endpoint->bEndpointAddress),
 857                          dev->int_in_buffer, dev->report_size,
 858                          iowarrior_callback, dev,
 859                          dev->int_in_endpoint->bInterval);
 860         /* create an internal buffer for interrupt data from the device */
 861         dev->read_queue =
 862             kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
 863                           GFP_KERNEL);
 864         if (!dev->read_queue)
 865                 goto error;
 866         /* Get the serial-number of the chip */
 867         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 868         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
 869                    sizeof(dev->chip_serial));
 870         if (strlen(dev->chip_serial) != 8)
 871                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
 872
 873         /* Set the idle timeout to 0, if this is interface 0 */
 874         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
 875             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 876                             0x0A,
 877                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
 878                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 879         }
 880         /* allow device read and ioctl */
 881         dev->present = 1;
 882
 883         /* we can register the device now, as it is ready */
 884         usb_set_intfdata(interface, dev);
 885
 886         retval = usb_register_dev(interface, &iowarrior_class);
 887         if (retval) {
 888                 /* something prevented us from registering this driver */
 889                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 890                 goto error;
 891         }
 892
 893         dev->minor = interface->minor;
 894
 895         /* let the user know what node this device is now attached to */
 896         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
 897                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
 898                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
 899         return retval;
 900
 901 error:
 902         iowarrior_delete(dev);
 903         return retval;
 904 }
 905
 906 /*
 907  *      iowarrior_disconnect
 908  *
 909  *      Called by the usb core when the device is removed from the system.
 910  */
 911 static void iowarrior_disconnect(struct usb_interface *interface)
 912 {
 913         struct iowarrior *dev = usb_get_intfdata(interface);
 914
 915         usb_deregister_dev(interface, &iowarrior_class);
 916
 917         mutex_lock(&dev->mutex);
 918
 919         /* prevent device read, write and ioctl */
 920         dev->present = 0;
 921
 922         if (dev->opened) {
 923                 /* There is a process that holds a filedescriptor to the device ,
 924                    so we only shutdown read-/write-ops going on.
 925                    Deleting the device is postponed until close() was called.
 926                  */
 927                 usb_kill_urb(dev->int_in_urb);
 928                 usb_kill_anchored_urbs(&dev->submitted);
 929                 wake_up_interruptible(&dev->read_wait);
 930                 wake_up_interruptible(&dev->write_wait);
 931                 mutex_unlock(&dev->mutex);
 932         } else {
 933                 /* no process is using the device, cleanup now */
 934                 mutex_unlock(&dev->mutex);
 935                 iowarrior_delete(dev);
 936         }
 937 }
 938
 939 /* usb specific object needed to register this driver with the usb subsystem */
 940 static struct usb_driver iowarrior_driver = {
 941         .name = "iowarrior",
 942         .probe = iowarrior_probe,
 943         .disconnect = iowarrior_disconnect,
 944         .id_table = iowarrior_ids,
 945 };
 946
 947 module_usb_driver(iowarrior_driver);