drivers/usb/class/usbtmc.c

   1 /**
   2  * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   3  *
   4  * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5  * Copyright (C) 2008 Novell, Inc.
   6  * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * The GNU General Public License is available at
  19  * http://www.gnu.org/copyleft/gpl.html.
  20  */
  21
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/fs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/kref.h>
  29 #include <linux/slab.h>
  30 #include <linux/poll.h>
  31 #include <linux/mutex.h>
  32 #include <linux/usb.h>
  33 #include <linux/usb/tmc.h>
  34
  35
  36 #define RIGOL                   1
  37 #define USBTMC_HEADER_SIZE      12
  38 #define USBTMC_MINOR_BASE       176
  39
  40 /*
  41  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  42  * large as wMaxPacketSize (which is usually 512 bytes).
  43  */
  44 #define USBTMC_SIZE_IOBUFFER    2048
  45
  46 /* Default USB timeout (in milliseconds) */
  47 #define USBTMC_TIMEOUT          5000
  48
  49 /*
  50  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  51  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  52  * packet is never read.
  53  */
  54 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  55
  56 static const struct usb_device_id usbtmc_devices[] = {
  57         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  58         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  59         { 0, } /* terminating entry */
  60 };
  61 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  62
  63 /*
  64  * This structure is the capabilities for the device
  65  * See section 4.2.1.8 of the USBTMC specification,
  66  * and section 4.2.2 of the USBTMC usb488 subclass
  67  * specification for details.
  68  */
  69 struct usbtmc_dev_capabilities {
  70         __u8 interface_capabilities;
  71         __u8 device_capabilities;
  72         __u8 usb488_interface_capabilities;
  73         __u8 usb488_device_capabilities;
  74 };
  75
  76 /* This structure holds private data for each USBTMC device. One copy is
  77  * allocated for each USBTMC device in the driver's probe function.
  78  */
  79 struct usbtmc_device_data {
  80         const struct usb_device_id *id;
  81         struct usb_device *usb_dev;
  82         struct usb_interface *intf;
  83
  84         unsigned int bulk_in;
  85         unsigned int bulk_out;
  86
  87         u8 bTag;
  88         u8 bTag_last_write;     /* needed for abort */
  89         u8 bTag_last_read;      /* needed for abort */
  90
  91         /* data for interrupt in endpoint handling */
  92         u8             bNotify1;
  93         u8             bNotify2;
  94         u16            ifnum;
  95         u8             iin_bTag;
  96         u8            *iin_buffer;
  97         atomic_t       iin_data_valid;
  98         unsigned int   iin_ep;
  99         int            iin_ep_present;
 100         int            iin_interval;
 101         struct urb    *iin_urb;
 102         u16            iin_wMaxPacketSize;
 103         atomic_t       srq_asserted;
 104
 105         /* coalesced usb488_caps from usbtmc_dev_capabilities */
 106         __u8 usb488_caps;
 107
 108         u8 rigol_quirk;
 109
 110         /* attributes from the USB TMC spec for this device */
 111         u8 TermChar;
 112         bool TermCharEnabled;
 113         bool auto_abort;
 114
 115         bool zombie; /* fd of disconnected device */
 116
 117         struct usbtmc_dev_capabilities  capabilities;
 118         struct kref kref;
 119         struct mutex io_mutex;  /* only one i/o function running at a time */
 120         wait_queue_head_t waitq;
 121         struct fasync_struct *fasync;
 122 };
 123 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
 124
 125 struct usbtmc_ID_rigol_quirk {
 126         __u16 idVendor;
 127         __u16 idProduct;
 128 };
 129
 130 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
 131         { 0x1ab1, 0x0588 },
 132         { 0x1ab1, 0x04b0 },
 133         { 0, 0 }
 134 };
 135
 136 /* Forward declarations */
 137 static struct usb_driver usbtmc_driver;
 138
 139 static void usbtmc_delete(struct kref *kref)
 140 {
 141         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 142
 143         usb_put_dev(data->usb_dev);
 144 }
 145
 146 static int usbtmc_open(struct inode *inode, struct file *filp)
 147 {
 148         struct usb_interface *intf;
 149         struct usbtmc_device_data *data;
 150         int retval = 0;
 151
 152         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 153         if (!intf) {
 154                 pr_err("can not find device for minor %d", iminor(inode));
 155                 return -ENODEV;
 156         }
 157
 158         data = usb_get_intfdata(intf);
 159         kref_get(&data->kref);
 160
 161         /* Store pointer in file structure's private data field */
 162         filp->private_data = data;
 163
 164         return retval;
 165 }
 166
 167 static int usbtmc_release(struct inode *inode, struct file *file)
 168 {
 169         struct usbtmc_device_data *data = file->private_data;
 170
 171         kref_put(&data->kref, usbtmc_delete);
 172         return 0;
 173 }
 174
 175 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 176 {
 177         u8 *buffer;
 178         struct device *dev;
 179         int rv;
 180         int n;
 181         int actual;
 182         struct usb_host_interface *current_setting;
 183         int max_size;
 184
 185         dev = &data->intf->dev;
 186         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 187         if (!buffer)
 188                 return -ENOMEM;
 189
 190         rv = usb_control_msg(data->usb_dev,
 191                              usb_rcvctrlpipe(data->usb_dev, 0),
 192                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 193                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 194                              data->bTag_last_read, data->bulk_in,
 195                              buffer, 2, USBTMC_TIMEOUT);
 196
 197         if (rv < 0) {
 198                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 199                 goto exit;
 200         }
 201
 202         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 203
 204         if (buffer[0] == USBTMC_STATUS_FAILED) {
 205                 rv = 0;
 206                 goto exit;
 207         }
 208
 209         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 210                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 211                         buffer[0]);
 212                 rv = -EPERM;
 213                 goto exit;
 214         }
 215
 216         max_size = 0;
 217         current_setting = data->intf->cur_altsetting;
 218         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 219                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 220                         data->bulk_in)
 221                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 222
 223         if (max_size == 0) {
 224                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 225                 rv = -EPERM;
 226                 goto exit;
 227         }
 228
 229         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 230
 231         n = 0;
 232
 233         do {
 234                 dev_dbg(dev, "Reading from bulk in EP\n");
 235
 236                 rv = usb_bulk_msg(data->usb_dev,
 237                                   usb_rcvbulkpipe(data->usb_dev,
 238                                                   data->bulk_in),
 239                                   buffer, USBTMC_SIZE_IOBUFFER,
 240                                   &actual, USBTMC_TIMEOUT);
 241
 242                 n++;
 243
 244                 if (rv < 0) {
 245                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 246                         goto exit;
 247                 }
 248         } while ((actual == max_size) &&
 249                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 250
 251         if (actual == max_size) {
 252                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 253                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 254                 rv = -EPERM;
 255                 goto exit;
 256         }
 257
 258         n = 0;
 259
 260 usbtmc_abort_bulk_in_status:
 261         rv = usb_control_msg(data->usb_dev,
 262                              usb_rcvctrlpipe(data->usb_dev, 0),
 263                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 264                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 265                              0, data->bulk_in, buffer, 0x08,
 266                              USBTMC_TIMEOUT);
 267
 268         if (rv < 0) {
 269                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 270                 goto exit;
 271         }
 272
 273         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 274
 275         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 276                 rv = 0;
 277                 goto exit;
 278         }
 279
 280         if (buffer[0] != USBTMC_STATUS_PENDING) {
 281                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 282                 rv = -EPERM;
 283                 goto exit;
 284         }
 285
 286         if (buffer[1] == 1)
 287                 do {
 288                         dev_dbg(dev, "Reading from bulk in EP\n");
 289
 290                         rv = usb_bulk_msg(data->usb_dev,
 291                                           usb_rcvbulkpipe(data->usb_dev,
 292                                                           data->bulk_in),
 293                                           buffer, USBTMC_SIZE_IOBUFFER,
 294                                           &actual, USBTMC_TIMEOUT);
 295
 296                         n++;
 297
 298                         if (rv < 0) {
 299                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 300                                 goto exit;
 301                         }
 302                 } while ((actual == max_size) &&
 303                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 304
 305         if (actual == max_size) {
 306                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 307                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 308                 rv = -EPERM;
 309                 goto exit;
 310         }
 311
 312         goto usbtmc_abort_bulk_in_status;
 313
 314 exit:
 315         kfree(buffer);
 316         return rv;
 317
 318 }
 319
 320 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 321 {
 322         struct device *dev;
 323         u8 *buffer;
 324         int rv;
 325         int n;
 326
 327         dev = &data->intf->dev;
 328
 329         buffer = kmalloc(8, GFP_KERNEL);
 330         if (!buffer)
 331                 return -ENOMEM;
 332
 333         rv = usb_control_msg(data->usb_dev,
 334                              usb_rcvctrlpipe(data->usb_dev, 0),
 335                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 336                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 337                              data->bTag_last_write, data->bulk_out,
 338                              buffer, 2, USBTMC_TIMEOUT);
 339
 340         if (rv < 0) {
 341                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 342                 goto exit;
 343         }
 344
 345         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 346
 347         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 348                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 349                         buffer[0]);
 350                 rv = -EPERM;
 351                 goto exit;
 352         }
 353
 354         n = 0;
 355
 356 usbtmc_abort_bulk_out_check_status:
 357         rv = usb_control_msg(data->usb_dev,
 358                              usb_rcvctrlpipe(data->usb_dev, 0),
 359                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 360                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 361                              0, data->bulk_out, buffer, 0x08,
 362                              USBTMC_TIMEOUT);
 363         n++;
 364         if (rv < 0) {
 365                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 366                 goto exit;
 367         }
 368
 369         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 370
 371         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 372                 goto usbtmc_abort_bulk_out_clear_halt;
 373
 374         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 375             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 376                 goto usbtmc_abort_bulk_out_check_status;
 377
 378         rv = -EPERM;
 379         goto exit;
 380
 381 usbtmc_abort_bulk_out_clear_halt:
 382         rv = usb_clear_halt(data->usb_dev,
 383                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 384
 385         if (rv < 0) {
 386                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 387                 goto exit;
 388         }
 389         rv = 0;
 390
 391 exit:
 392         kfree(buffer);
 393         return rv;
 394 }
 395
 396 static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
 397                                 void __user *arg)
 398 {
 399         struct device *dev = &data->intf->dev;
 400         u8 *buffer;
 401         u8 tag;
 402         __u8 stb;
 403         int rv;
 404
 405         dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n",
 406                 data->iin_ep_present);
 407
 408         buffer = kmalloc(8, GFP_KERNEL);
 409         if (!buffer)
 410                 return -ENOMEM;
 411
 412         atomic_set(&data->iin_data_valid, 0);
 413
 414         /* must issue read_stb before using poll or select */
 415         atomic_set(&data->srq_asserted, 0);
 416
 417         rv = usb_control_msg(data->usb_dev,
 418                         usb_rcvctrlpipe(data->usb_dev, 0),
 419                         USBTMC488_REQUEST_READ_STATUS_BYTE,
 420                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 421                         data->iin_bTag,
 422                         data->ifnum,
 423                         buffer, 0x03, USBTMC_TIMEOUT);
 424         if (rv < 0) {
 425                 dev_err(dev, "stb usb_control_msg returned %d\n", rv);
 426                 goto exit;
 427         }
 428
 429         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 430                 dev_err(dev, "control status returned %x\n", buffer[0]);
 431                 rv = -EIO;
 432                 goto exit;
 433         }
 434
 435         if (data->iin_ep_present) {
 436                 rv = wait_event_interruptible_timeout(
 437                         data->waitq,
 438                         atomic_read(&data->iin_data_valid) != 0,
 439                         USBTMC_TIMEOUT);
 440                 if (rv < 0) {
 441                         dev_dbg(dev, "wait interrupted %d\n", rv);
 442                         goto exit;
 443                 }
 444
 445                 if (rv == 0) {
 446                         dev_dbg(dev, "wait timed out\n");
 447                         rv = -ETIME;
 448                         goto exit;
 449                 }
 450
 451                 tag = data->bNotify1 & 0x7f;
 452                 if (tag != data->iin_bTag) {
 453                         dev_err(dev, "expected bTag %x got %x\n",
 454                                 data->iin_bTag, tag);
 455                 }
 456
 457                 stb = data->bNotify2;
 458         } else {
 459                 stb = buffer[2];
 460         }
 461
 462         rv = copy_to_user(arg, &stb, sizeof(stb));
 463         if (rv)
 464                 rv = -EFAULT;
 465
 466  exit:
 467         /* bump interrupt bTag */
 468         data->iin_bTag += 1;
 469         if (data->iin_bTag > 127)
 470                 /* 1 is for SRQ see USBTMC-USB488 subclass spec section 4.3.1 */
 471                 data->iin_bTag = 2;
 472
 473         kfree(buffer);
 474         return rv;
 475 }
 476
 477 static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
 478                                 void __user *arg, unsigned int cmd)
 479 {
 480         struct device *dev = &data->intf->dev;
 481         __u8 val;
 482         u8 *buffer;
 483         u16 wValue;
 484         int rv;
 485
 486         if (!(data->usb488_caps & USBTMC488_CAPABILITY_SIMPLE))
 487                 return -EINVAL;
 488
 489         buffer = kmalloc(8, GFP_KERNEL);
 490         if (!buffer)
 491                 return -ENOMEM;
 492
 493         if (cmd == USBTMC488_REQUEST_REN_CONTROL) {
 494                 rv = copy_from_user(&val, arg, sizeof(val));
 495                 if (rv) {
 496                         rv = -EFAULT;
 497                         goto exit;
 498                 }
 499                 wValue = val ? 1 : 0;
 500         } else {
 501                 wValue = 0;
 502         }
 503
 504         rv = usb_control_msg(data->usb_dev,
 505                         usb_rcvctrlpipe(data->usb_dev, 0),
 506                         cmd,
 507                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 508                         wValue,
 509                         data->ifnum,
 510                         buffer, 0x01, USBTMC_TIMEOUT);
 511         if (rv < 0) {
 512                 dev_err(dev, "simple usb_control_msg failed %d\n", rv);
 513                 goto exit;
 514         } else if (rv != 1) {
 515                 dev_warn(dev, "simple usb_control_msg returned %d\n", rv);
 516                 rv = -EIO;
 517                 goto exit;
 518         }
 519
 520         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 521                 dev_err(dev, "simple control status returned %x\n", buffer[0]);
 522                 rv = -EIO;
 523                 goto exit;
 524         }
 525         rv = 0;
 526
 527  exit:
 528         kfree(buffer);
 529         return rv;
 530 }
 531
 532 /*
 533  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 534  * @transfer_size: number of bytes to request from the device.
 535  *
 536  * See the USBTMC specification, Table 4.
 537  *
 538  * Also updates bTag_last_write.
 539  */
 540 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 541 {
 542         int retval;
 543         u8 *buffer;
 544         int actual;
 545
 546         buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
 547         if (!buffer)
 548                 return -ENOMEM;
 549         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 550          * Refer to class specs for details
 551          */
 552         buffer[0] = 2;
 553         buffer[1] = data->bTag;
 554         buffer[2] = ~data->bTag;
 555         buffer[3] = 0; /* Reserved */
 556         buffer[4] = transfer_size >> 0;
 557         buffer[5] = transfer_size >> 8;
 558         buffer[6] = transfer_size >> 16;
 559         buffer[7] = transfer_size >> 24;
 560         buffer[8] = data->TermCharEnabled * 2;
 561         /* Use term character? */
 562         buffer[9] = data->TermChar;
 563         buffer[10] = 0; /* Reserved */
 564         buffer[11] = 0; /* Reserved */
 565
 566         /* Send bulk URB */
 567         retval = usb_bulk_msg(data->usb_dev,
 568                               usb_sndbulkpipe(data->usb_dev,
 569                                               data->bulk_out),
 570                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 571
 572         /* Store bTag (in case we need to abort) */
 573         data->bTag_last_write = data->bTag;
 574
 575         /* Increment bTag -- and increment again if zero */
 576         data->bTag++;
 577         if (!data->bTag)
 578                 data->bTag++;
 579
 580         kfree(buffer);
 581         if (retval < 0) {
 582                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 583                 return retval;
 584         }
 585
 586         return 0;
 587 }
 588
 589 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 590                            size_t count, loff_t *f_pos)
 591 {
 592         struct usbtmc_device_data *data;
 593         struct device *dev;
 594         u32 n_characters;
 595         u8 *buffer;
 596         int actual;
 597         size_t done;
 598         size_t remaining;
 599         int retval;
 600         size_t this_part;
 601
 602         /* Get pointer to private data structure */
 603         data = filp->private_data;
 604         dev = &data->intf->dev;
 605
 606         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 607         if (!buffer)
 608                 return -ENOMEM;
 609
 610         mutex_lock(&data->io_mutex);
 611         if (data->zombie) {
 612                 retval = -ENODEV;
 613                 goto exit;
 614         }
 615
 616         if (data->rigol_quirk) {
 617                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 618
 619                 retval = send_request_dev_dep_msg_in(data, count);
 620
 621                 if (retval < 0) {
 622                         if (data->auto_abort)
 623                                 usbtmc_ioctl_abort_bulk_out(data);
 624                         goto exit;
 625                 }
 626         }
 627
 628         /* Loop until we have fetched everything we requested */
 629         remaining = count;
 630         this_part = remaining;
 631         done = 0;
 632
 633         while (remaining > 0) {
 634                 if (!data->rigol_quirk) {
 635                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 636
 637                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 638                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 639                         else
 640                                 this_part = remaining;
 641
 642                         retval = send_request_dev_dep_msg_in(data, this_part);
 643                         if (retval < 0) {
 644                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 645                                 if (data->auto_abort)
 646                                         usbtmc_ioctl_abort_bulk_out(data);
 647                                 goto exit;
 648                         }
 649                 }
 650
 651                 /* Send bulk URB */
 652                 retval = usb_bulk_msg(data->usb_dev,
 653                                       usb_rcvbulkpipe(data->usb_dev,
 654                                                       data->bulk_in),
 655                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 656                                       USBTMC_TIMEOUT);
 657
 658                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 659
 660                 /* Store bTag (in case we need to abort) */
 661                 data->bTag_last_read = data->bTag;
 662
 663                 if (retval < 0) {
 664                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 665                         if (data->auto_abort)
 666                                 usbtmc_ioctl_abort_bulk_in(data);
 667                         goto exit;
 668                 }
 669
 670                 /* Parse header in first packet */
 671                 if ((done == 0) || !data->rigol_quirk) {
 672                         /* Sanity checks for the header */
 673                         if (actual < USBTMC_HEADER_SIZE) {
 674                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 675                                 if (data->auto_abort)
 676                                         usbtmc_ioctl_abort_bulk_in(data);
 677                                 goto exit;
 678                         }
 679
 680                         if (buffer[0] != 2) {
 681                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 682                                 if (data->auto_abort)
 683                                         usbtmc_ioctl_abort_bulk_in(data);
 684                                 goto exit;
 685                         }
 686
 687                         if (buffer[1] != data->bTag_last_write) {
 688                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 689                                 if (data->auto_abort)
 690                                         usbtmc_ioctl_abort_bulk_in(data);
 691                                 goto exit;
 692                         }
 693
 694                         /* How many characters did the instrument send? */
 695                         n_characters = buffer[4] +
 696                                        (buffer[5] << 8) +
 697                                        (buffer[6] << 16) +
 698                                        (buffer[7] << 24);
 699
 700                         if (n_characters > this_part) {
 701                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 702                                 if (data->auto_abort)
 703                                         usbtmc_ioctl_abort_bulk_in(data);
 704                                 goto exit;
 705                         }
 706
 707                         /* Remove the USBTMC header */
 708                         actual -= USBTMC_HEADER_SIZE;
 709
 710                         /* Check if the message is smaller than requested */
 711                         if (data->rigol_quirk) {
 712                                 if (remaining > n_characters)
 713                                         remaining = n_characters;
 714                                 /* Remove padding if it exists */
 715                                 if (actual > remaining)
 716                                         actual = remaining;
 717                         }
 718                         else {
 719                                 if (this_part > n_characters)
 720                                         this_part = n_characters;
 721                                 /* Remove padding if it exists */
 722                                 if (actual > this_part)
 723                                         actual = this_part;
 724                         }
 725
 726                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 727
 728                         remaining -= actual;
 729
 730                         /* Terminate if end-of-message bit received from device */
 731                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 732                                 remaining = 0;
 733
 734                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 735
 736
 737                         /* Copy buffer to user space */
 738                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 739                                 /* There must have been an addressing problem */
 740                                 retval = -EFAULT;
 741                                 goto exit;
 742                         }
 743                         done += actual;
 744                 }
 745                 else  {
 746                         if (actual > remaining)
 747                                 actual = remaining;
 748
 749                         remaining -= actual;
 750
 751                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 752
 753                         /* Copy buffer to user space */
 754                         if (copy_to_user(buf + done, buffer, actual)) {
 755                                 /* There must have been an addressing problem */
 756                                 retval = -EFAULT;
 757                                 goto exit;
 758                         }
 759                         done += actual;
 760                 }
 761         }
 762
 763         /* Update file position value */
 764         *f_pos = *f_pos + done;
 765         retval = done;
 766
 767 exit:
 768         mutex_unlock(&data->io_mutex);
 769         kfree(buffer);
 770         return retval;
 771 }
 772
 773 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 774                             size_t count, loff_t *f_pos)
 775 {
 776         struct usbtmc_device_data *data;
 777         u8 *buffer;
 778         int retval;
 779         int actual;
 780         unsigned long int n_bytes;
 781         int remaining;
 782         int done;
 783         int this_part;
 784
 785         data = filp->private_data;
 786
 787         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 788         if (!buffer)
 789                 return -ENOMEM;
 790
 791         mutex_lock(&data->io_mutex);
 792         if (data->zombie) {
 793                 retval = -ENODEV;
 794                 goto exit;
 795         }
 796
 797         remaining = count;
 798         done = 0;
 799
 800         while (remaining > 0) {
 801                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 802                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 803                         buffer[8] = 0;
 804                 } else {
 805                         this_part = remaining;
 806                         buffer[8] = 1;
 807                 }
 808
 809                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 810                 buffer[0] = 1;
 811                 buffer[1] = data->bTag;
 812                 buffer[2] = ~data->bTag;
 813                 buffer[3] = 0; /* Reserved */
 814                 buffer[4] = this_part >> 0;
 815                 buffer[5] = this_part >> 8;
 816                 buffer[6] = this_part >> 16;
 817                 buffer[7] = this_part >> 24;
 818                 /* buffer[8] is set above... */
 819                 buffer[9] = 0; /* Reserved */
 820                 buffer[10] = 0; /* Reserved */
 821                 buffer[11] = 0; /* Reserved */
 822
 823                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 824                         retval = -EFAULT;
 825                         goto exit;
 826                 }
 827
 828                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 829                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 830
 831                 do {
 832                         retval = usb_bulk_msg(data->usb_dev,
 833                                               usb_sndbulkpipe(data->usb_dev,
 834                                                               data->bulk_out),
 835                                               buffer, n_bytes,
 836                                               &actual, USBTMC_TIMEOUT);
 837                         if (retval != 0)
 838                                 break;
 839                         n_bytes -= actual;
 840                 } while (n_bytes);
 841
 842                 data->bTag_last_write = data->bTag;
 843                 data->bTag++;
 844
 845                 if (!data->bTag)
 846                         data->bTag++;
 847
 848                 if (retval < 0) {
 849                         dev_err(&data->intf->dev,
 850                                 "Unable to send data, error %d\n", retval);
 851                         if (data->auto_abort)
 852                                 usbtmc_ioctl_abort_bulk_out(data);
 853                         goto exit;
 854                 }
 855
 856                 remaining -= this_part;
 857                 done += this_part;
 858         }
 859
 860         retval = count;
 861 exit:
 862         mutex_unlock(&data->io_mutex);
 863         kfree(buffer);
 864         return retval;
 865 }
 866
 867 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 868 {
 869         struct usb_host_interface *current_setting;
 870         struct usb_endpoint_descriptor *desc;
 871         struct device *dev;
 872         u8 *buffer;
 873         int rv;
 874         int n;
 875         int actual = 0;
 876         int max_size;
 877
 878         dev = &data->intf->dev;
 879
 880         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 881
 882         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 883         if (!buffer)
 884                 return -ENOMEM;
 885
 886         rv = usb_control_msg(data->usb_dev,
 887                              usb_rcvctrlpipe(data->usb_dev, 0),
 888                              USBTMC_REQUEST_INITIATE_CLEAR,
 889                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 890                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 891         if (rv < 0) {
 892                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 893                 goto exit;
 894         }
 895
 896         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 897
 898         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 899                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 900                 rv = -EPERM;
 901                 goto exit;
 902         }
 903
 904         max_size = 0;
 905         current_setting = data->intf->cur_altsetting;
 906         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 907                 desc = &current_setting->endpoint[n].desc;
 908                 if (desc->bEndpointAddress == data->bulk_in)
 909                         max_size = usb_endpoint_maxp(desc);
 910         }
 911
 912         if (max_size == 0) {
 913                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 914                 rv = -EPERM;
 915                 goto exit;
 916         }
 917
 918         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 919
 920         n = 0;
 921
 922 usbtmc_clear_check_status:
 923
 924         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 925
 926         rv = usb_control_msg(data->usb_dev,
 927                              usb_rcvctrlpipe(data->usb_dev, 0),
 928                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 929                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 930                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 931         if (rv < 0) {
 932                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 933                 goto exit;
 934         }
 935
 936         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 937
 938         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 939                 goto usbtmc_clear_bulk_out_halt;
 940
 941         if (buffer[0] != USBTMC_STATUS_PENDING) {
 942                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 943                 rv = -EPERM;
 944                 goto exit;
 945         }
 946
 947         if (buffer[1] == 1)
 948                 do {
 949                         dev_dbg(dev, "Reading from bulk in EP\n");
 950
 951                         rv = usb_bulk_msg(data->usb_dev,
 952                                           usb_rcvbulkpipe(data->usb_dev,
 953                                                           data->bulk_in),
 954                                           buffer, USBTMC_SIZE_IOBUFFER,
 955                                           &actual, USBTMC_TIMEOUT);
 956                         n++;
 957
 958                         if (rv < 0) {
 959                                 dev_err(dev, "usb_control_msg returned %d\n",
 960                                         rv);
 961                                 goto exit;
 962                         }
 963                 } while ((actual == max_size) &&
 964                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 965
 966         if (actual == max_size) {
 967                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 968                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 969                 rv = -EPERM;
 970                 goto exit;
 971         }
 972
 973         goto usbtmc_clear_check_status;
 974
 975 usbtmc_clear_bulk_out_halt:
 976
 977         rv = usb_clear_halt(data->usb_dev,
 978                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 979         if (rv < 0) {
 980                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 981                 goto exit;
 982         }
 983         rv = 0;
 984
 985 exit:
 986         kfree(buffer);
 987         return rv;
 988 }
 989
 990 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 991 {
 992         int rv;
 993
 994         rv = usb_clear_halt(data->usb_dev,
 995                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 996
 997         if (rv < 0) {
 998                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 999                         rv);
1000                 return rv;
1001         }
1002         return 0;
1003 }
1004
1005 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
1006 {
1007         int rv;
1008
1009         rv = usb_clear_halt(data->usb_dev,
1010                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
1011
1012         if (rv < 0) {
1013                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
1014                         rv);
1015                 return rv;
1016         }
1017         return 0;
1018 }
1019
1020 static int get_capabilities(struct usbtmc_device_data *data)
1021 {
1022         struct device *dev = &data->usb_dev->dev;
1023         char *buffer;
1024         int rv = 0;
1025
1026         buffer = kmalloc(0x18, GFP_KERNEL);
1027         if (!buffer)
1028                 return -ENOMEM;
1029
1030         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
1031                              USBTMC_REQUEST_GET_CAPABILITIES,
1032                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1033                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
1034         if (rv < 0) {
1035                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1036                 goto err_out;
1037         }
1038
1039         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1040         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1041                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1042                 rv = -EPERM;
1043                 goto err_out;
1044         }
1045         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
1046         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
1047         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
1048         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
1049
1050         data->capabilities.interface_capabilities = buffer[4];
1051         data->capabilities.device_capabilities = buffer[5];
1052         data->capabilities.usb488_interface_capabilities = buffer[14];
1053         data->capabilities.usb488_device_capabilities = buffer[15];
1054         data->usb488_caps = (buffer[14] & 0x07) | ((buffer[15] & 0x0f) << 4);
1055         rv = 0;
1056
1057 err_out:
1058         kfree(buffer);
1059         return rv;
1060 }
1061
1062 #define capability_attribute(name)                                      \
1063 static ssize_t name##_show(struct device *dev,                          \
1064                            struct device_attribute *attr, char *buf)    \
1065 {                                                                       \
1066         struct usb_interface *intf = to_usb_interface(dev);             \
1067         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1068                                                                         \
1069         return sprintf(buf, "%d\n", data->capabilities.name);           \
1070 }                                                                       \
1071 static DEVICE_ATTR_RO(name)
1072
1073 capability_attribute(interface_capabilities);
1074 capability_attribute(device_capabilities);
1075 capability_attribute(usb488_interface_capabilities);
1076 capability_attribute(usb488_device_capabilities);
1077
1078 static struct attribute *capability_attrs[] = {
1079         &dev_attr_interface_capabilities.attr,
1080         &dev_attr_device_capabilities.attr,
1081         &dev_attr_usb488_interface_capabilities.attr,
1082         &dev_attr_usb488_device_capabilities.attr,
1083         NULL,
1084 };
1085
1086 static struct attribute_group capability_attr_grp = {
1087         .attrs = capability_attrs,
1088 };
1089
1090 static ssize_t TermChar_show(struct device *dev,
1091                              struct device_attribute *attr, char *buf)
1092 {
1093         struct usb_interface *intf = to_usb_interface(dev);
1094         struct usbtmc_device_data *data = usb_get_intfdata(intf);
1095
1096         return sprintf(buf, "%c\n", data->TermChar);
1097 }
1098
1099 static ssize_t TermChar_store(struct device *dev,
1100                               struct device_attribute *attr,
1101                               const char *buf, size_t count)
1102 {
1103         struct usb_interface *intf = to_usb_interface(dev);
1104         struct usbtmc_device_data *data = usb_get_intfdata(intf);
1105
1106         if (count < 1)
1107                 return -EINVAL;
1108         data->TermChar = buf[0];
1109         return count;
1110 }
1111 static DEVICE_ATTR_RW(TermChar);
1112
1113 #define data_attribute(name)                                            \
1114 static ssize_t name##_show(struct device *dev,                          \
1115                            struct device_attribute *attr, char *buf)    \
1116 {                                                                       \
1117         struct usb_interface *intf = to_usb_interface(dev);             \
1118         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1119                                                                         \
1120         return sprintf(buf, "%d\n", data->name);                        \
1121 }                                                                       \
1122 static ssize_t name##_store(struct device *dev,                         \
1123                             struct device_attribute *attr,              \
1124                             const char *buf, size_t count)              \
1125 {                                                                       \
1126         struct usb_interface *intf = to_usb_interface(dev);             \
1127         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1128         ssize_t result;                                                 \
1129         unsigned val;                                                   \
1130                                                                         \
1131         result = sscanf(buf, "%u\n", &val);                             \
1132         if (result != 1)                                                \
1133                 result = -EINVAL;                                       \
1134         data->name = val;                                               \
1135         if (result < 0)                                                 \
1136                 return result;                                          \
1137         else                                                            \
1138                 return count;                                           \
1139 }                                                                       \
1140 static DEVICE_ATTR_RW(name)
1141
1142 data_attribute(TermCharEnabled);
1143 data_attribute(auto_abort);
1144
1145 static struct attribute *data_attrs[] = {
1146         &dev_attr_TermChar.attr,
1147         &dev_attr_TermCharEnabled.attr,
1148         &dev_attr_auto_abort.attr,
1149         NULL,
1150 };
1151
1152 static struct attribute_group data_attr_grp = {
1153         .attrs = data_attrs,
1154 };
1155
1156 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1157 {
1158         struct device *dev;
1159         u8 *buffer;
1160         int rv;
1161
1162         dev = &data->intf->dev;
1163
1164         buffer = kmalloc(2, GFP_KERNEL);
1165         if (!buffer)
1166                 return -ENOMEM;
1167
1168         rv = usb_control_msg(data->usb_dev,
1169                              usb_rcvctrlpipe(data->usb_dev, 0),
1170                              USBTMC_REQUEST_INDICATOR_PULSE,
1171                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1172                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1173
1174         if (rv < 0) {
1175                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1176                 goto exit;
1177         }
1178
1179         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1180
1181         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1182                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1183                 rv = -EPERM;
1184                 goto exit;
1185         }
1186         rv = 0;
1187
1188 exit:
1189         kfree(buffer);
1190         return rv;
1191 }
1192
1193 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1194 {
1195         struct usbtmc_device_data *data;
1196         int retval = -EBADRQC;
1197
1198         data = file->private_data;
1199         mutex_lock(&data->io_mutex);
1200         if (data->zombie) {
1201                 retval = -ENODEV;
1202                 goto skip_io_on_zombie;
1203         }
1204
1205         switch (cmd) {
1206         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1207                 retval = usbtmc_ioctl_clear_out_halt(data);
1208                 break;
1209
1210         case USBTMC_IOCTL_CLEAR_IN_HALT:
1211                 retval = usbtmc_ioctl_clear_in_halt(data);
1212                 break;
1213
1214         case USBTMC_IOCTL_INDICATOR_PULSE:
1215                 retval = usbtmc_ioctl_indicator_pulse(data);
1216                 break;
1217
1218         case USBTMC_IOCTL_CLEAR:
1219                 retval = usbtmc_ioctl_clear(data);
1220                 break;
1221
1222         case USBTMC_IOCTL_ABORT_BULK_OUT:
1223                 retval = usbtmc_ioctl_abort_bulk_out(data);
1224                 break;
1225
1226         case USBTMC_IOCTL_ABORT_BULK_IN:
1227                 retval = usbtmc_ioctl_abort_bulk_in(data);
1228                 break;
1229
1230         case USBTMC488_IOCTL_GET_CAPS:
1231                 retval = copy_to_user((void __user *)arg,
1232                                 &data->usb488_caps,
1233                                 sizeof(data->usb488_caps));
1234                 if (retval)
1235                         retval = -EFAULT;
1236                 break;
1237
1238         case USBTMC488_IOCTL_READ_STB:
1239                 retval = usbtmc488_ioctl_read_stb(data, (void __user *)arg);
1240                 break;
1241
1242         case USBTMC488_IOCTL_REN_CONTROL:
1243                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1244                                                 USBTMC488_REQUEST_REN_CONTROL);
1245                 break;
1246
1247         case USBTMC488_IOCTL_GOTO_LOCAL:
1248                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1249                                                 USBTMC488_REQUEST_GOTO_LOCAL);
1250                 break;
1251
1252         case USBTMC488_IOCTL_LOCAL_LOCKOUT:
1253                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1254                                                 USBTMC488_REQUEST_LOCAL_LOCKOUT);
1255                 break;
1256         }
1257
1258 skip_io_on_zombie:
1259         mutex_unlock(&data->io_mutex);
1260         return retval;
1261 }
1262
1263 static int usbtmc_fasync(int fd, struct file *file, int on)
1264 {
1265         struct usbtmc_device_data *data = file->private_data;
1266
1267         return fasync_helper(fd, file, on, &data->fasync);
1268 }
1269
1270 static unsigned int usbtmc_poll(struct file *file, poll_table *wait)
1271 {
1272         struct usbtmc_device_data *data = file->private_data;
1273         unsigned int mask;
1274
1275         mutex_lock(&data->io_mutex);
1276
1277         if (data->zombie) {
1278                 mask = POLLHUP | POLLERR;
1279                 goto no_poll;
1280         }
1281
1282         poll_wait(file, &data->waitq, wait);
1283
1284         mask = (atomic_read(&data->srq_asserted)) ? POLLIN | POLLRDNORM : 0;
1285
1286 no_poll:
1287         mutex_unlock(&data->io_mutex);
1288         return mask;
1289 }
1290
1291 static const struct file_operations fops = {
1292         .owner          = THIS_MODULE,
1293         .read           = usbtmc_read,
1294         .write          = usbtmc_write,
1295         .open           = usbtmc_open,
1296         .release        = usbtmc_release,
1297         .unlocked_ioctl = usbtmc_ioctl,
1298         .fasync         = usbtmc_fasync,
1299         .poll           = usbtmc_poll,
1300         .llseek         = default_llseek,
1301 };
1302
1303 static struct usb_class_driver usbtmc_class = {
1304         .name =         "usbtmc%d",
1305         .fops =         &fops,
1306         .minor_base =   USBTMC_MINOR_BASE,
1307 };
1308
1309 static void usbtmc_interrupt(struct urb *urb)
1310 {
1311         struct usbtmc_device_data *data = urb->context;
1312         struct device *dev = &data->intf->dev;
1313         int status = urb->status;
1314         int rv;
1315
1316         dev_dbg(&data->intf->dev, "int status: %d len %d\n",
1317                 status, urb->actual_length);
1318
1319         switch (status) {
1320         case 0: /* SUCCESS */
1321                 /* check for valid STB notification */
1322                 if (data->iin_buffer[0] > 0x81) {
1323                         data->bNotify1 = data->iin_buffer[0];
1324                         data->bNotify2 = data->iin_buffer[1];
1325                         atomic_set(&data->iin_data_valid, 1);
1326                         wake_up_interruptible(&data->waitq);
1327                         goto exit;
1328                 }
1329                 /* check for SRQ notification */
1330                 if (data->iin_buffer[0] == 0x81) {
1331                         if (data->fasync)
1332                                 kill_fasync(&data->fasync,
1333                                         SIGIO, POLL_IN);
1334
1335                         atomic_set(&data->srq_asserted, 1);
1336                         wake_up_interruptible(&data->waitq);
1337                         goto exit;
1338                 }
1339                 dev_warn(dev, "invalid notification: %x\n", data->iin_buffer[0]);
1340                 break;
1341         case -EOVERFLOW:
1342                 dev_err(dev, "overflow with length %d, actual length is %d\n",
1343                         data->iin_wMaxPacketSize, urb->actual_length);
1344         case -ECONNRESET:
1345         case -ENOENT:
1346         case -ESHUTDOWN:
1347         case -EILSEQ:
1348         case -ETIME:
1349                 /* urb terminated, clean up */
1350                 dev_dbg(dev, "urb terminated, status: %d\n", status);
1351                 return;
1352         default:
1353                 dev_err(dev, "unknown status received: %d\n", status);
1354         }
1355 exit:
1356         rv = usb_submit_urb(urb, GFP_ATOMIC);
1357         if (rv)
1358                 dev_err(dev, "usb_submit_urb failed: %d\n", rv);
1359 }
1360
1361 static void usbtmc_free_int(struct usbtmc_device_data *data)
1362 {
1363         if (!data->iin_ep_present || !data->iin_urb)
1364                 return;
1365         usb_kill_urb(data->iin_urb);
1366         kfree(data->iin_buffer);
1367         usb_free_urb(data->iin_urb);
1368         kref_put(&data->kref, usbtmc_delete);
1369 }
1370
1371 static int usbtmc_probe(struct usb_interface *intf,
1372                         const struct usb_device_id *id)
1373 {
1374         struct usbtmc_device_data *data;
1375         struct usb_host_interface *iface_desc;
1376         struct usb_endpoint_descriptor *endpoint;
1377         int n;
1378         int retcode;
1379
1380         dev_dbg(&intf->dev, "%s called\n", __func__);
1381
1382         data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1383         if (!data)
1384                 return -ENOMEM;
1385
1386         data->intf = intf;
1387         data->id = id;
1388         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1389         usb_set_intfdata(intf, data);
1390         kref_init(&data->kref);
1391         mutex_init(&data->io_mutex);
1392         init_waitqueue_head(&data->waitq);
1393         atomic_set(&data->iin_data_valid, 0);
1394         atomic_set(&data->srq_asserted, 0);
1395         data->zombie = 0;
1396
1397         /* Determine if it is a Rigol or not */
1398         data->rigol_quirk = 0;
1399         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1400                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1401                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1402         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1403                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1404                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1405                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1406                         data->rigol_quirk = 1;
1407                         break;
1408                 }
1409         }
1410
1411         /* Initialize USBTMC bTag and other fields */
1412         data->bTag      = 1;
1413         data->TermCharEnabled = 0;
1414         data->TermChar = '\n';
1415         /*  2 <= bTag <= 127   USBTMC-USB488 subclass specification 4.3.1 */
1416         data->iin_bTag = 2;
1417
1418         /* USBTMC devices have only one setting, so use that */
1419         iface_desc = data->intf->cur_altsetting;
1420         data->ifnum = iface_desc->desc.bInterfaceNumber;
1421
1422         /* Find bulk in endpoint */
1423         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1424                 endpoint = &iface_desc->endpoint[n].desc;
1425
1426                 if (usb_endpoint_is_bulk_in(endpoint)) {
1427                         data->bulk_in = endpoint->bEndpointAddress;
1428                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1429                                 data->bulk_in);
1430                         break;
1431                 }
1432         }
1433
1434         /* Find bulk out endpoint */
1435         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1436                 endpoint = &iface_desc->endpoint[n].desc;
1437
1438                 if (usb_endpoint_is_bulk_out(endpoint)) {
1439                         data->bulk_out = endpoint->bEndpointAddress;
1440                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1441                                 data->bulk_out);
1442                         break;
1443                 }
1444         }
1445         /* Find int endpoint */
1446         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1447                 endpoint = &iface_desc->endpoint[n].desc;
1448
1449                 if (usb_endpoint_is_int_in(endpoint)) {
1450                         data->iin_ep_present = 1;
1451                         data->iin_ep = endpoint->bEndpointAddress;
1452                         data->iin_wMaxPacketSize = usb_endpoint_maxp(endpoint);
1453                         data->iin_interval = endpoint->bInterval;
1454                         dev_dbg(&intf->dev, "Found Int in endpoint at %u\n",
1455                                 data->iin_ep);
1456                         break;
1457                 }
1458         }
1459
1460         retcode = get_capabilities(data);
1461         if (retcode)
1462                 dev_err(&intf->dev, "can't read capabilities\n");
1463         else
1464                 retcode = sysfs_create_group(&intf->dev.kobj,
1465                                              &capability_attr_grp);
1466
1467         if (data->iin_ep_present) {
1468                 /* allocate int urb */
1469                 data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
1470                 if (!data->iin_urb)
1471                         goto error_register;
1472
1473                 /* will reference data in int urb */
1474                 kref_get(&data->kref);
1475
1476                 /* allocate buffer for interrupt in */
1477                 data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
1478                                         GFP_KERNEL);
1479                 if (!data->iin_buffer) {
1480                         dev_err(&intf->dev, "Failed to allocate int buf\n");
1481                         goto error_register;
1482                 }
1483
1484                 /* fill interrupt urb */
1485                 usb_fill_int_urb(data->iin_urb, data->usb_dev,
1486                                 usb_rcvintpipe(data->usb_dev, data->iin_ep),
1487                                 data->iin_buffer, data->iin_wMaxPacketSize,
1488                                 usbtmc_interrupt,
1489                                 data, data->iin_interval);
1490
1491                 retcode = usb_submit_urb(data->iin_urb, GFP_KERNEL);
1492                 if (retcode) {
1493                         dev_err(&intf->dev, "Failed to submit iin_urb\n");
1494                         goto error_register;
1495                 }
1496         }
1497
1498         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1499
1500         retcode = usb_register_dev(intf, &usbtmc_class);
1501         if (retcode) {
1502                 dev_err(&intf->dev, "Not able to get a minor"
1503                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1504                         retcode);
1505                 goto error_register;
1506         }
1507         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1508
1509         return 0;
1510
1511 error_register:
1512         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1513         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1514         usbtmc_free_int(data);
1515         kref_put(&data->kref, usbtmc_delete);
1516         return retcode;
1517 }
1518
1519 static void usbtmc_disconnect(struct usb_interface *intf)
1520 {
1521         struct usbtmc_device_data *data;
1522
1523         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1524
1525         data = usb_get_intfdata(intf);
1526         usb_deregister_dev(intf, &usbtmc_class);
1527         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1528         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1529         mutex_lock(&data->io_mutex);
1530         data->zombie = 1;
1531         wake_up_all(&data->waitq);
1532         mutex_unlock(&data->io_mutex);
1533         usbtmc_free_int(data);
1534         kref_put(&data->kref, usbtmc_delete);
1535 }
1536
1537 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1538 {
1539         /* this driver does not have pending URBs */
1540         return 0;
1541 }
1542
1543 static int usbtmc_resume(struct usb_interface *intf)
1544 {
1545         return 0;
1546 }
1547
1548 static struct usb_driver usbtmc_driver = {
1549         .name           = "usbtmc",
1550         .id_table       = usbtmc_devices,
1551         .probe          = usbtmc_probe,
1552         .disconnect     = usbtmc_disconnect,
1553         .suspend        = usbtmc_suspend,
1554         .resume         = usbtmc_resume,
1555 };
1556
1557 module_usb_driver(usbtmc_driver);
1558
1559 MODULE_LICENSE("GPL");