drivers/usb/class/usbtmc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /**
   3  * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   4  *
   5  * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   6  * Copyright (C) 2008 Novell, Inc.
   7  * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/fs.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/kref.h>
  17 #include <linux/slab.h>
  18 #include <linux/poll.h>
  19 #include <linux/mutex.h>
  20 #include <linux/usb.h>
  21 #include <linux/usb/tmc.h>
  22
  23
  24 #define RIGOL                   1
  25 #define USBTMC_HEADER_SIZE      12
  26 #define USBTMC_MINOR_BASE       176
  27
  28 /*
  29  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  30  * large as wMaxPacketSize (which is usually 512 bytes).
  31  */
  32 #define USBTMC_SIZE_IOBUFFER    2048
  33
  34 /* Default USB timeout (in milliseconds) */
  35 #define USBTMC_TIMEOUT          5000
  36
  37 /*
  38  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  39  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  40  * packet is never read.
  41  */
  42 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  43
  44 static const struct usb_device_id usbtmc_devices[] = {
  45         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  46         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  47         { 0, } /* terminating entry */
  48 };
  49 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  50
  51 /*
  52  * This structure is the capabilities for the device
  53  * See section 4.2.1.8 of the USBTMC specification,
  54  * and section 4.2.2 of the USBTMC usb488 subclass
  55  * specification for details.
  56  */
  57 struct usbtmc_dev_capabilities {
  58         __u8 interface_capabilities;
  59         __u8 device_capabilities;
  60         __u8 usb488_interface_capabilities;
  61         __u8 usb488_device_capabilities;
  62 };
  63
  64 /* This structure holds private data for each USBTMC device. One copy is
  65  * allocated for each USBTMC device in the driver's probe function.
  66  */
  67 struct usbtmc_device_data {
  68         const struct usb_device_id *id;
  69         struct usb_device *usb_dev;
  70         struct usb_interface *intf;
  71
  72         unsigned int bulk_in;
  73         unsigned int bulk_out;
  74
  75         u8 bTag;
  76         u8 bTag_last_write;     /* needed for abort */
  77         u8 bTag_last_read;      /* needed for abort */
  78
  79         /* data for interrupt in endpoint handling */
  80         u8             bNotify1;
  81         u8             bNotify2;
  82         u16            ifnum;
  83         u8             iin_bTag;
  84         u8            *iin_buffer;
  85         atomic_t       iin_data_valid;
  86         unsigned int   iin_ep;
  87         int            iin_ep_present;
  88         int            iin_interval;
  89         struct urb    *iin_urb;
  90         u16            iin_wMaxPacketSize;
  91         atomic_t       srq_asserted;
  92
  93         /* coalesced usb488_caps from usbtmc_dev_capabilities */
  94         __u8 usb488_caps;
  95
  96         u8 rigol_quirk;
  97
  98         /* attributes from the USB TMC spec for this device */
  99         u8 TermChar;
 100         bool TermCharEnabled;
 101         bool auto_abort;
 102
 103         bool zombie; /* fd of disconnected device */
 104
 105         struct usbtmc_dev_capabilities  capabilities;
 106         struct kref kref;
 107         struct mutex io_mutex;  /* only one i/o function running at a time */
 108         wait_queue_head_t waitq;
 109         struct fasync_struct *fasync;
 110 };
 111 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
 112
 113 struct usbtmc_ID_rigol_quirk {
 114         __u16 idVendor;
 115         __u16 idProduct;
 116 };
 117
 118 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
 119         { 0x1ab1, 0x0588 },
 120         { 0x1ab1, 0x04b0 },
 121         { 0, 0 }
 122 };
 123
 124 /* Forward declarations */
 125 static struct usb_driver usbtmc_driver;
 126
 127 static void usbtmc_delete(struct kref *kref)
 128 {
 129         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 130
 131         usb_put_dev(data->usb_dev);
 132         kfree(data);
 133 }
 134
 135 static int usbtmc_open(struct inode *inode, struct file *filp)
 136 {
 137         struct usb_interface *intf;
 138         struct usbtmc_device_data *data;
 139         int retval = 0;
 140
 141         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 142         if (!intf) {
 143                 pr_err("can not find device for minor %d", iminor(inode));
 144                 return -ENODEV;
 145         }
 146
 147         data = usb_get_intfdata(intf);
 148         /* Protect reference to data from file structure until release */
 149         kref_get(&data->kref);
 150
 151         /* Store pointer in file structure's private data field */
 152         filp->private_data = data;
 153
 154         return retval;
 155 }
 156
 157 static int usbtmc_release(struct inode *inode, struct file *file)
 158 {
 159         struct usbtmc_device_data *data = file->private_data;
 160
 161         kref_put(&data->kref, usbtmc_delete);
 162         return 0;
 163 }
 164
 165 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 166 {
 167         u8 *buffer;
 168         struct device *dev;
 169         int rv;
 170         int n;
 171         int actual;
 172         struct usb_host_interface *current_setting;
 173         int max_size;
 174
 175         dev = &data->intf->dev;
 176         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 177         if (!buffer)
 178                 return -ENOMEM;
 179
 180         rv = usb_control_msg(data->usb_dev,
 181                              usb_rcvctrlpipe(data->usb_dev, 0),
 182                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 183                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 184                              data->bTag_last_read, data->bulk_in,
 185                              buffer, 2, USBTMC_TIMEOUT);
 186
 187         if (rv < 0) {
 188                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 189                 goto exit;
 190         }
 191
 192         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 193
 194         if (buffer[0] == USBTMC_STATUS_FAILED) {
 195                 rv = 0;
 196                 goto exit;
 197         }
 198
 199         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 200                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 201                         buffer[0]);
 202                 rv = -EPERM;
 203                 goto exit;
 204         }
 205
 206         max_size = 0;
 207         current_setting = data->intf->cur_altsetting;
 208         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 209                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 210                         data->bulk_in)
 211                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 212
 213         if (max_size == 0) {
 214                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 215                 rv = -EPERM;
 216                 goto exit;
 217         }
 218
 219         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 220
 221         n = 0;
 222
 223         do {
 224                 dev_dbg(dev, "Reading from bulk in EP\n");
 225
 226                 rv = usb_bulk_msg(data->usb_dev,
 227                                   usb_rcvbulkpipe(data->usb_dev,
 228                                                   data->bulk_in),
 229                                   buffer, USBTMC_SIZE_IOBUFFER,
 230                                   &actual, USBTMC_TIMEOUT);
 231
 232                 n++;
 233
 234                 if (rv < 0) {
 235                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 236                         goto exit;
 237                 }
 238         } while ((actual == max_size) &&
 239                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 240
 241         if (actual == max_size) {
 242                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 243                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 244                 rv = -EPERM;
 245                 goto exit;
 246         }
 247
 248         n = 0;
 249
 250 usbtmc_abort_bulk_in_status:
 251         rv = usb_control_msg(data->usb_dev,
 252                              usb_rcvctrlpipe(data->usb_dev, 0),
 253                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 254                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 255                              0, data->bulk_in, buffer, 0x08,
 256                              USBTMC_TIMEOUT);
 257
 258         if (rv < 0) {
 259                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 260                 goto exit;
 261         }
 262
 263         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 264
 265         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 266                 rv = 0;
 267                 goto exit;
 268         }
 269
 270         if (buffer[0] != USBTMC_STATUS_PENDING) {
 271                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 272                 rv = -EPERM;
 273                 goto exit;
 274         }
 275
 276         if (buffer[1] == 1)
 277                 do {
 278                         dev_dbg(dev, "Reading from bulk in EP\n");
 279
 280                         rv = usb_bulk_msg(data->usb_dev,
 281                                           usb_rcvbulkpipe(data->usb_dev,
 282                                                           data->bulk_in),
 283                                           buffer, USBTMC_SIZE_IOBUFFER,
 284                                           &actual, USBTMC_TIMEOUT);
 285
 286                         n++;
 287
 288                         if (rv < 0) {
 289                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 290                                 goto exit;
 291                         }
 292                 } while ((actual == max_size) &&
 293                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 294
 295         if (actual == max_size) {
 296                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 297                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 298                 rv = -EPERM;
 299                 goto exit;
 300         }
 301
 302         goto usbtmc_abort_bulk_in_status;
 303
 304 exit:
 305         kfree(buffer);
 306         return rv;
 307
 308 }
 309
 310 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 311 {
 312         struct device *dev;
 313         u8 *buffer;
 314         int rv;
 315         int n;
 316
 317         dev = &data->intf->dev;
 318
 319         buffer = kmalloc(8, GFP_KERNEL);
 320         if (!buffer)
 321                 return -ENOMEM;
 322
 323         rv = usb_control_msg(data->usb_dev,
 324                              usb_rcvctrlpipe(data->usb_dev, 0),
 325                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 326                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 327                              data->bTag_last_write, data->bulk_out,
 328                              buffer, 2, USBTMC_TIMEOUT);
 329
 330         if (rv < 0) {
 331                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 332                 goto exit;
 333         }
 334
 335         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 336
 337         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 338                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 339                         buffer[0]);
 340                 rv = -EPERM;
 341                 goto exit;
 342         }
 343
 344         n = 0;
 345
 346 usbtmc_abort_bulk_out_check_status:
 347         rv = usb_control_msg(data->usb_dev,
 348                              usb_rcvctrlpipe(data->usb_dev, 0),
 349                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 350                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 351                              0, data->bulk_out, buffer, 0x08,
 352                              USBTMC_TIMEOUT);
 353         n++;
 354         if (rv < 0) {
 355                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 356                 goto exit;
 357         }
 358
 359         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 360
 361         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 362                 goto usbtmc_abort_bulk_out_clear_halt;
 363
 364         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 365             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 366                 goto usbtmc_abort_bulk_out_check_status;
 367
 368         rv = -EPERM;
 369         goto exit;
 370
 371 usbtmc_abort_bulk_out_clear_halt:
 372         rv = usb_clear_halt(data->usb_dev,
 373                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 374
 375         if (rv < 0) {
 376                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 377                 goto exit;
 378         }
 379         rv = 0;
 380
 381 exit:
 382         kfree(buffer);
 383         return rv;
 384 }
 385
 386 static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
 387                                 void __user *arg)
 388 {
 389         struct device *dev = &data->intf->dev;
 390         u8 *buffer;
 391         u8 tag;
 392         __u8 stb;
 393         int rv;
 394
 395         dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n",
 396                 data->iin_ep_present);
 397
 398         buffer = kmalloc(8, GFP_KERNEL);
 399         if (!buffer)
 400                 return -ENOMEM;
 401
 402         atomic_set(&data->iin_data_valid, 0);
 403
 404         /* must issue read_stb before using poll or select */
 405         atomic_set(&data->srq_asserted, 0);
 406
 407         rv = usb_control_msg(data->usb_dev,
 408                         usb_rcvctrlpipe(data->usb_dev, 0),
 409                         USBTMC488_REQUEST_READ_STATUS_BYTE,
 410                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 411                         data->iin_bTag,
 412                         data->ifnum,
 413                         buffer, 0x03, USBTMC_TIMEOUT);
 414         if (rv < 0) {
 415                 dev_err(dev, "stb usb_control_msg returned %d\n", rv);
 416                 goto exit;
 417         }
 418
 419         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 420                 dev_err(dev, "control status returned %x\n", buffer[0]);
 421                 rv = -EIO;
 422                 goto exit;
 423         }
 424
 425         if (data->iin_ep_present) {
 426                 rv = wait_event_interruptible_timeout(
 427                         data->waitq,
 428                         atomic_read(&data->iin_data_valid) != 0,
 429                         USBTMC_TIMEOUT);
 430                 if (rv < 0) {
 431                         dev_dbg(dev, "wait interrupted %d\n", rv);
 432                         goto exit;
 433                 }
 434
 435                 if (rv == 0) {
 436                         dev_dbg(dev, "wait timed out\n");
 437                         rv = -ETIME;
 438                         goto exit;
 439                 }
 440
 441                 tag = data->bNotify1 & 0x7f;
 442                 if (tag != data->iin_bTag) {
 443                         dev_err(dev, "expected bTag %x got %x\n",
 444                                 data->iin_bTag, tag);
 445                 }
 446
 447                 stb = data->bNotify2;
 448         } else {
 449                 stb = buffer[2];
 450         }
 451
 452         rv = copy_to_user(arg, &stb, sizeof(stb));
 453         if (rv)
 454                 rv = -EFAULT;
 455
 456  exit:
 457         /* bump interrupt bTag */
 458         data->iin_bTag += 1;
 459         if (data->iin_bTag > 127)
 460                 /* 1 is for SRQ see USBTMC-USB488 subclass spec section 4.3.1 */
 461                 data->iin_bTag = 2;
 462
 463         kfree(buffer);
 464         return rv;
 465 }
 466
 467 static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
 468                                 void __user *arg, unsigned int cmd)
 469 {
 470         struct device *dev = &data->intf->dev;
 471         __u8 val;
 472         u8 *buffer;
 473         u16 wValue;
 474         int rv;
 475
 476         if (!(data->usb488_caps & USBTMC488_CAPABILITY_SIMPLE))
 477                 return -EINVAL;
 478
 479         buffer = kmalloc(8, GFP_KERNEL);
 480         if (!buffer)
 481                 return -ENOMEM;
 482
 483         if (cmd == USBTMC488_REQUEST_REN_CONTROL) {
 484                 rv = copy_from_user(&val, arg, sizeof(val));
 485                 if (rv) {
 486                         rv = -EFAULT;
 487                         goto exit;
 488                 }
 489                 wValue = val ? 1 : 0;
 490         } else {
 491                 wValue = 0;
 492         }
 493
 494         rv = usb_control_msg(data->usb_dev,
 495                         usb_rcvctrlpipe(data->usb_dev, 0),
 496                         cmd,
 497                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 498                         wValue,
 499                         data->ifnum,
 500                         buffer, 0x01, USBTMC_TIMEOUT);
 501         if (rv < 0) {
 502                 dev_err(dev, "simple usb_control_msg failed %d\n", rv);
 503                 goto exit;
 504         } else if (rv != 1) {
 505                 dev_warn(dev, "simple usb_control_msg returned %d\n", rv);
 506                 rv = -EIO;
 507                 goto exit;
 508         }
 509
 510         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 511                 dev_err(dev, "simple control status returned %x\n", buffer[0]);
 512                 rv = -EIO;
 513                 goto exit;
 514         }
 515         rv = 0;
 516
 517  exit:
 518         kfree(buffer);
 519         return rv;
 520 }
 521
 522 /*
 523  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-OUT endpoint.
 524  * @transfer_size: number of bytes to request from the device.
 525  *
 526  * See the USBTMC specification, Table 4.
 527  *
 528  * Also updates bTag_last_write.
 529  */
 530 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 531 {
 532         int retval;
 533         u8 *buffer;
 534         int actual;
 535
 536         buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
 537         if (!buffer)
 538                 return -ENOMEM;
 539         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 540          * Refer to class specs for details
 541          */
 542         buffer[0] = 2;
 543         buffer[1] = data->bTag;
 544         buffer[2] = ~data->bTag;
 545         buffer[3] = 0; /* Reserved */
 546         buffer[4] = transfer_size >> 0;
 547         buffer[5] = transfer_size >> 8;
 548         buffer[6] = transfer_size >> 16;
 549         buffer[7] = transfer_size >> 24;
 550         buffer[8] = data->TermCharEnabled * 2;
 551         /* Use term character? */
 552         buffer[9] = data->TermChar;
 553         buffer[10] = 0; /* Reserved */
 554         buffer[11] = 0; /* Reserved */
 555
 556         /* Send bulk URB */
 557         retval = usb_bulk_msg(data->usb_dev,
 558                               usb_sndbulkpipe(data->usb_dev,
 559                                               data->bulk_out),
 560                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 561
 562         /* Store bTag (in case we need to abort) */
 563         data->bTag_last_write = data->bTag;
 564
 565         /* Increment bTag -- and increment again if zero */
 566         data->bTag++;
 567         if (!data->bTag)
 568                 data->bTag++;
 569
 570         kfree(buffer);
 571         if (retval < 0) {
 572                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 573                 return retval;
 574         }
 575
 576         return 0;
 577 }
 578
 579 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 580                            size_t count, loff_t *f_pos)
 581 {
 582         struct usbtmc_device_data *data;
 583         struct device *dev;
 584         u32 n_characters;
 585         u8 *buffer;
 586         int actual;
 587         size_t done;
 588         size_t remaining;
 589         int retval;
 590         size_t this_part;
 591
 592         /* Get pointer to private data structure */
 593         data = filp->private_data;
 594         dev = &data->intf->dev;
 595
 596         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 597         if (!buffer)
 598                 return -ENOMEM;
 599
 600         mutex_lock(&data->io_mutex);
 601         if (data->zombie) {
 602                 retval = -ENODEV;
 603                 goto exit;
 604         }
 605
 606         if (data->rigol_quirk) {
 607                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 608
 609                 retval = send_request_dev_dep_msg_in(data, count);
 610
 611                 if (retval < 0) {
 612                         if (data->auto_abort)
 613                                 usbtmc_ioctl_abort_bulk_out(data);
 614                         goto exit;
 615                 }
 616         }
 617
 618         /* Loop until we have fetched everything we requested */
 619         remaining = count;
 620         this_part = remaining;
 621         done = 0;
 622
 623         while (remaining > 0) {
 624                 if (!data->rigol_quirk) {
 625                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 626
 627                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 628                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 629                         else
 630                                 this_part = remaining;
 631
 632                         retval = send_request_dev_dep_msg_in(data, this_part);
 633                         if (retval < 0) {
 634                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 635                                 if (data->auto_abort)
 636                                         usbtmc_ioctl_abort_bulk_out(data);
 637                                 goto exit;
 638                         }
 639                 }
 640
 641                 /* Send bulk URB */
 642                 retval = usb_bulk_msg(data->usb_dev,
 643                                       usb_rcvbulkpipe(data->usb_dev,
 644                                                       data->bulk_in),
 645                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 646                                       USBTMC_TIMEOUT);
 647
 648                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 649
 650                 /* Store bTag (in case we need to abort) */
 651                 data->bTag_last_read = data->bTag;
 652
 653                 if (retval < 0) {
 654                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 655                         if (data->auto_abort)
 656                                 usbtmc_ioctl_abort_bulk_in(data);
 657                         goto exit;
 658                 }
 659
 660                 /* Parse header in first packet */
 661                 if ((done == 0) || !data->rigol_quirk) {
 662                         /* Sanity checks for the header */
 663                         if (actual < USBTMC_HEADER_SIZE) {
 664                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 665                                 if (data->auto_abort)
 666                                         usbtmc_ioctl_abort_bulk_in(data);
 667                                 goto exit;
 668                         }
 669
 670                         if (buffer[0] != 2) {
 671                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 672                                 if (data->auto_abort)
 673                                         usbtmc_ioctl_abort_bulk_in(data);
 674                                 goto exit;
 675                         }
 676
 677                         if (buffer[1] != data->bTag_last_write) {
 678                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 679                                 if (data->auto_abort)
 680                                         usbtmc_ioctl_abort_bulk_in(data);
 681                                 goto exit;
 682                         }
 683
 684                         /* How many characters did the instrument send? */
 685                         n_characters = buffer[4] +
 686                                        (buffer[5] << 8) +
 687                                        (buffer[6] << 16) +
 688                                        (buffer[7] << 24);
 689
 690                         if (n_characters > this_part) {
 691                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 692                                 if (data->auto_abort)
 693                                         usbtmc_ioctl_abort_bulk_in(data);
 694                                 goto exit;
 695                         }
 696
 697                         /* Remove the USBTMC header */
 698                         actual -= USBTMC_HEADER_SIZE;
 699
 700                         /* Check if the message is smaller than requested */
 701                         if (data->rigol_quirk) {
 702                                 if (remaining > n_characters)
 703                                         remaining = n_characters;
 704                                 /* Remove padding if it exists */
 705                                 if (actual > remaining)
 706                                         actual = remaining;
 707                         }
 708                         else {
 709                                 if (this_part > n_characters)
 710                                         this_part = n_characters;
 711                                 /* Remove padding if it exists */
 712                                 if (actual > this_part)
 713                                         actual = this_part;
 714                         }
 715
 716                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 717
 718                         remaining -= actual;
 719
 720                         /* Terminate if end-of-message bit received from device */
 721                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 722                                 remaining = 0;
 723
 724                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 725
 726
 727                         /* Copy buffer to user space */
 728                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 729                                 /* There must have been an addressing problem */
 730                                 retval = -EFAULT;
 731                                 goto exit;
 732                         }
 733                         done += actual;
 734                 }
 735                 else  {
 736                         if (actual > remaining)
 737                                 actual = remaining;
 738
 739                         remaining -= actual;
 740
 741                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 742
 743                         /* Copy buffer to user space */
 744                         if (copy_to_user(buf + done, buffer, actual)) {
 745                                 /* There must have been an addressing problem */
 746                                 retval = -EFAULT;
 747                                 goto exit;
 748                         }
 749                         done += actual;
 750                 }
 751         }
 752
 753         /* Update file position value */
 754         *f_pos = *f_pos + done;
 755         retval = done;
 756
 757 exit:
 758         mutex_unlock(&data->io_mutex);
 759         kfree(buffer);
 760         return retval;
 761 }
 762
 763 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 764                             size_t count, loff_t *f_pos)
 765 {
 766         struct usbtmc_device_data *data;
 767         u8 *buffer;
 768         int retval;
 769         int actual;
 770         unsigned long int n_bytes;
 771         int remaining;
 772         int done;
 773         int this_part;
 774
 775         data = filp->private_data;
 776
 777         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 778         if (!buffer)
 779                 return -ENOMEM;
 780
 781         mutex_lock(&data->io_mutex);
 782         if (data->zombie) {
 783                 retval = -ENODEV;
 784                 goto exit;
 785         }
 786
 787         remaining = count;
 788         done = 0;
 789
 790         while (remaining > 0) {
 791                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 792                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 793                         buffer[8] = 0;
 794                 } else {
 795                         this_part = remaining;
 796                         buffer[8] = 1;
 797                 }
 798
 799                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 800                 buffer[0] = 1;
 801                 buffer[1] = data->bTag;
 802                 buffer[2] = ~data->bTag;
 803                 buffer[3] = 0; /* Reserved */
 804                 buffer[4] = this_part >> 0;
 805                 buffer[5] = this_part >> 8;
 806                 buffer[6] = this_part >> 16;
 807                 buffer[7] = this_part >> 24;
 808                 /* buffer[8] is set above... */
 809                 buffer[9] = 0; /* Reserved */
 810                 buffer[10] = 0; /* Reserved */
 811                 buffer[11] = 0; /* Reserved */
 812
 813                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 814                         retval = -EFAULT;
 815                         goto exit;
 816                 }
 817
 818                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 819                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 820
 821                 do {
 822                         retval = usb_bulk_msg(data->usb_dev,
 823                                               usb_sndbulkpipe(data->usb_dev,
 824                                                               data->bulk_out),
 825                                               buffer, n_bytes,
 826                                               &actual, USBTMC_TIMEOUT);
 827                         if (retval != 0)
 828                                 break;
 829                         n_bytes -= actual;
 830                 } while (n_bytes);
 831
 832                 data->bTag_last_write = data->bTag;
 833                 data->bTag++;
 834
 835                 if (!data->bTag)
 836                         data->bTag++;
 837
 838                 if (retval < 0) {
 839                         dev_err(&data->intf->dev,
 840                                 "Unable to send data, error %d\n", retval);
 841                         if (data->auto_abort)
 842                                 usbtmc_ioctl_abort_bulk_out(data);
 843                         goto exit;
 844                 }
 845
 846                 remaining -= this_part;
 847                 done += this_part;
 848         }
 849
 850         retval = count;
 851 exit:
 852         mutex_unlock(&data->io_mutex);
 853         kfree(buffer);
 854         return retval;
 855 }
 856
 857 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 858 {
 859         struct usb_host_interface *current_setting;
 860         struct usb_endpoint_descriptor *desc;
 861         struct device *dev;
 862         u8 *buffer;
 863         int rv;
 864         int n;
 865         int actual = 0;
 866         int max_size;
 867
 868         dev = &data->intf->dev;
 869
 870         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 871
 872         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 873         if (!buffer)
 874                 return -ENOMEM;
 875
 876         rv = usb_control_msg(data->usb_dev,
 877                              usb_rcvctrlpipe(data->usb_dev, 0),
 878                              USBTMC_REQUEST_INITIATE_CLEAR,
 879                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 880                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 881         if (rv < 0) {
 882                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 883                 goto exit;
 884         }
 885
 886         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 887
 888         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 889                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 890                 rv = -EPERM;
 891                 goto exit;
 892         }
 893
 894         max_size = 0;
 895         current_setting = data->intf->cur_altsetting;
 896         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 897                 desc = &current_setting->endpoint[n].desc;
 898                 if (desc->bEndpointAddress == data->bulk_in)
 899                         max_size = usb_endpoint_maxp(desc);
 900         }
 901
 902         if (max_size == 0) {
 903                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 904                 rv = -EPERM;
 905                 goto exit;
 906         }
 907
 908         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 909
 910         n = 0;
 911
 912 usbtmc_clear_check_status:
 913
 914         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 915
 916         rv = usb_control_msg(data->usb_dev,
 917                              usb_rcvctrlpipe(data->usb_dev, 0),
 918                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 919                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 920                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 921         if (rv < 0) {
 922                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 923                 goto exit;
 924         }
 925
 926         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 927
 928         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 929                 goto usbtmc_clear_bulk_out_halt;
 930
 931         if (buffer[0] != USBTMC_STATUS_PENDING) {
 932                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 933                 rv = -EPERM;
 934                 goto exit;
 935         }
 936
 937         if (buffer[1] == 1)
 938                 do {
 939                         dev_dbg(dev, "Reading from bulk in EP\n");
 940
 941                         rv = usb_bulk_msg(data->usb_dev,
 942                                           usb_rcvbulkpipe(data->usb_dev,
 943                                                           data->bulk_in),
 944                                           buffer, USBTMC_SIZE_IOBUFFER,
 945                                           &actual, USBTMC_TIMEOUT);
 946                         n++;
 947
 948                         if (rv < 0) {
 949                                 dev_err(dev, "usb_control_msg returned %d\n",
 950                                         rv);
 951                                 goto exit;
 952                         }
 953                 } while ((actual == max_size) &&
 954                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 955
 956         if (actual == max_size) {
 957                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 958                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 959                 rv = -EPERM;
 960                 goto exit;
 961         }
 962
 963         goto usbtmc_clear_check_status;
 964
 965 usbtmc_clear_bulk_out_halt:
 966
 967         rv = usb_clear_halt(data->usb_dev,
 968                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 969         if (rv < 0) {
 970                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 971                 goto exit;
 972         }
 973         rv = 0;
 974
 975 exit:
 976         kfree(buffer);
 977         return rv;
 978 }
 979
 980 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 981 {
 982         int rv;
 983
 984         rv = usb_clear_halt(data->usb_dev,
 985                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 986
 987         if (rv < 0) {
 988                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 989                         rv);
 990                 return rv;
 991         }
 992         return 0;
 993 }
 994
 995 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 996 {
 997         int rv;
 998
 999         rv = usb_clear_halt(data->usb_dev,
1000                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
1001
1002         if (rv < 0) {
1003                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
1004                         rv);
1005                 return rv;
1006         }
1007         return 0;
1008 }
1009
1010 static int get_capabilities(struct usbtmc_device_data *data)
1011 {
1012         struct device *dev = &data->usb_dev->dev;
1013         char *buffer;
1014         int rv = 0;
1015
1016         buffer = kmalloc(0x18, GFP_KERNEL);
1017         if (!buffer)
1018                 return -ENOMEM;
1019
1020         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
1021                              USBTMC_REQUEST_GET_CAPABILITIES,
1022                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1023                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
1024         if (rv < 0) {
1025                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1026                 goto err_out;
1027         }
1028
1029         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1030         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1031                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1032                 rv = -EPERM;
1033                 goto err_out;
1034         }
1035         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
1036         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
1037         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
1038         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
1039
1040         data->capabilities.interface_capabilities = buffer[4];
1041         data->capabilities.device_capabilities = buffer[5];
1042         data->capabilities.usb488_interface_capabilities = buffer[14];
1043         data->capabilities.usb488_device_capabilities = buffer[15];
1044         data->usb488_caps = (buffer[14] & 0x07) | ((buffer[15] & 0x0f) << 4);
1045         rv = 0;
1046
1047 err_out:
1048         kfree(buffer);
1049         return rv;
1050 }
1051
1052 #define capability_attribute(name)                                      \
1053 static ssize_t name##_show(struct device *dev,                          \
1054                            struct device_attribute *attr, char *buf)    \
1055 {                                                                       \
1056         struct usb_interface *intf = to_usb_interface(dev);             \
1057         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1058                                                                         \
1059         return sprintf(buf, "%d\n", data->capabilities.name);           \
1060 }                                                                       \
1061 static DEVICE_ATTR_RO(name)
1062
1063 capability_attribute(interface_capabilities);
1064 capability_attribute(device_capabilities);
1065 capability_attribute(usb488_interface_capabilities);
1066 capability_attribute(usb488_device_capabilities);
1067
1068 static struct attribute *capability_attrs[] = {
1069         &dev_attr_interface_capabilities.attr,
1070         &dev_attr_device_capabilities.attr,
1071         &dev_attr_usb488_interface_capabilities.attr,
1072         &dev_attr_usb488_device_capabilities.attr,
1073         NULL,
1074 };
1075
1076 static const struct attribute_group capability_attr_grp = {
1077         .attrs = capability_attrs,
1078 };
1079
1080 static ssize_t TermChar_show(struct device *dev,
1081                              struct device_attribute *attr, char *buf)
1082 {
1083         struct usb_interface *intf = to_usb_interface(dev);
1084         struct usbtmc_device_data *data = usb_get_intfdata(intf);
1085
1086         return sprintf(buf, "%c\n", data->TermChar);
1087 }
1088
1089 static ssize_t TermChar_store(struct device *dev,
1090                               struct device_attribute *attr,
1091                               const char *buf, size_t count)
1092 {
1093         struct usb_interface *intf = to_usb_interface(dev);
1094         struct usbtmc_device_data *data = usb_get_intfdata(intf);
1095
1096         if (count < 1)
1097                 return -EINVAL;
1098         data->TermChar = buf[0];
1099         return count;
1100 }
1101 static DEVICE_ATTR_RW(TermChar);
1102
1103 #define data_attribute(name)                                            \
1104 static ssize_t name##_show(struct device *dev,                          \
1105                            struct device_attribute *attr, char *buf)    \
1106 {                                                                       \
1107         struct usb_interface *intf = to_usb_interface(dev);             \
1108         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1109                                                                         \
1110         return sprintf(buf, "%d\n", data->name);                        \
1111 }                                                                       \
1112 static ssize_t name##_store(struct device *dev,                         \
1113                             struct device_attribute *attr,              \
1114                             const char *buf, size_t count)              \
1115 {                                                                       \
1116         struct usb_interface *intf = to_usb_interface(dev);             \
1117         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
1118         ssize_t result;                                                 \
1119         unsigned val;                                                   \
1120                                                                         \
1121         result = sscanf(buf, "%u\n", &val);                             \
1122         if (result != 1)                                                \
1123                 result = -EINVAL;                                       \
1124         data->name = val;                                               \
1125         if (result < 0)                                                 \
1126                 return result;                                          \
1127         else                                                            \
1128                 return count;                                           \
1129 }                                                                       \
1130 static DEVICE_ATTR_RW(name)
1131
1132 data_attribute(TermCharEnabled);
1133 data_attribute(auto_abort);
1134
1135 static struct attribute *data_attrs[] = {
1136         &dev_attr_TermChar.attr,
1137         &dev_attr_TermCharEnabled.attr,
1138         &dev_attr_auto_abort.attr,
1139         NULL,
1140 };
1141
1142 static const struct attribute_group data_attr_grp = {
1143         .attrs = data_attrs,
1144 };
1145
1146 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1147 {
1148         struct device *dev;
1149         u8 *buffer;
1150         int rv;
1151
1152         dev = &data->intf->dev;
1153
1154         buffer = kmalloc(2, GFP_KERNEL);
1155         if (!buffer)
1156                 return -ENOMEM;
1157
1158         rv = usb_control_msg(data->usb_dev,
1159                              usb_rcvctrlpipe(data->usb_dev, 0),
1160                              USBTMC_REQUEST_INDICATOR_PULSE,
1161                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1162                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1163
1164         if (rv < 0) {
1165                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1166                 goto exit;
1167         }
1168
1169         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1170
1171         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1172                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1173                 rv = -EPERM;
1174                 goto exit;
1175         }
1176         rv = 0;
1177
1178 exit:
1179         kfree(buffer);
1180         return rv;
1181 }
1182
1183 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1184 {
1185         struct usbtmc_device_data *data;
1186         int retval = -EBADRQC;
1187
1188         data = file->private_data;
1189         mutex_lock(&data->io_mutex);
1190         if (data->zombie) {
1191                 retval = -ENODEV;
1192                 goto skip_io_on_zombie;
1193         }
1194
1195         switch (cmd) {
1196         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1197                 retval = usbtmc_ioctl_clear_out_halt(data);
1198                 break;
1199
1200         case USBTMC_IOCTL_CLEAR_IN_HALT:
1201                 retval = usbtmc_ioctl_clear_in_halt(data);
1202                 break;
1203
1204         case USBTMC_IOCTL_INDICATOR_PULSE:
1205                 retval = usbtmc_ioctl_indicator_pulse(data);
1206                 break;
1207
1208         case USBTMC_IOCTL_CLEAR:
1209                 retval = usbtmc_ioctl_clear(data);
1210                 break;
1211
1212         case USBTMC_IOCTL_ABORT_BULK_OUT:
1213                 retval = usbtmc_ioctl_abort_bulk_out(data);
1214                 break;
1215
1216         case USBTMC_IOCTL_ABORT_BULK_IN:
1217                 retval = usbtmc_ioctl_abort_bulk_in(data);
1218                 break;
1219
1220         case USBTMC488_IOCTL_GET_CAPS:
1221                 retval = copy_to_user((void __user *)arg,
1222                                 &data->usb488_caps,
1223                                 sizeof(data->usb488_caps));
1224                 if (retval)
1225                         retval = -EFAULT;
1226                 break;
1227
1228         case USBTMC488_IOCTL_READ_STB:
1229                 retval = usbtmc488_ioctl_read_stb(data, (void __user *)arg);
1230                 break;
1231
1232         case USBTMC488_IOCTL_REN_CONTROL:
1233                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1234                                                 USBTMC488_REQUEST_REN_CONTROL);
1235                 break;
1236
1237         case USBTMC488_IOCTL_GOTO_LOCAL:
1238                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1239                                                 USBTMC488_REQUEST_GOTO_LOCAL);
1240                 break;
1241
1242         case USBTMC488_IOCTL_LOCAL_LOCKOUT:
1243                 retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1244                                                 USBTMC488_REQUEST_LOCAL_LOCKOUT);
1245                 break;
1246         }
1247
1248 skip_io_on_zombie:
1249         mutex_unlock(&data->io_mutex);
1250         return retval;
1251 }
1252
1253 static int usbtmc_fasync(int fd, struct file *file, int on)
1254 {
1255         struct usbtmc_device_data *data = file->private_data;
1256
1257         return fasync_helper(fd, file, on, &data->fasync);
1258 }
1259
1260 static __poll_t usbtmc_poll(struct file *file, poll_table *wait)
1261 {
1262         struct usbtmc_device_data *data = file->private_data;
1263         __poll_t mask;
1264
1265         mutex_lock(&data->io_mutex);
1266
1267         if (data->zombie) {
1268                 mask = POLLHUP | POLLERR;
1269                 goto no_poll;
1270         }
1271
1272         poll_wait(file, &data->waitq, wait);
1273
1274         mask = (atomic_read(&data->srq_asserted)) ? POLLIN | POLLRDNORM : 0;
1275
1276 no_poll:
1277         mutex_unlock(&data->io_mutex);
1278         return mask;
1279 }
1280
1281 static const struct file_operations fops = {
1282         .owner          = THIS_MODULE,
1283         .read           = usbtmc_read,
1284         .write          = usbtmc_write,
1285         .open           = usbtmc_open,
1286         .release        = usbtmc_release,
1287         .unlocked_ioctl = usbtmc_ioctl,
1288         .fasync         = usbtmc_fasync,
1289         .poll           = usbtmc_poll,
1290         .llseek         = default_llseek,
1291 };
1292
1293 static struct usb_class_driver usbtmc_class = {
1294         .name =         "usbtmc%d",
1295         .fops =         &fops,
1296         .minor_base =   USBTMC_MINOR_BASE,
1297 };
1298
1299 static void usbtmc_interrupt(struct urb *urb)
1300 {
1301         struct usbtmc_device_data *data = urb->context;
1302         struct device *dev = &data->intf->dev;
1303         int status = urb->status;
1304         int rv;
1305
1306         dev_dbg(&data->intf->dev, "int status: %d len %d\n",
1307                 status, urb->actual_length);
1308
1309         switch (status) {
1310         case 0: /* SUCCESS */
1311                 /* check for valid STB notification */
1312                 if (data->iin_buffer[0] > 0x81) {
1313                         data->bNotify1 = data->iin_buffer[0];
1314                         data->bNotify2 = data->iin_buffer[1];
1315                         atomic_set(&data->iin_data_valid, 1);
1316                         wake_up_interruptible(&data->waitq);
1317                         goto exit;
1318                 }
1319                 /* check for SRQ notification */
1320                 if (data->iin_buffer[0] == 0x81) {
1321                         if (data->fasync)
1322                                 kill_fasync(&data->fasync,
1323                                         SIGIO, POLL_IN);
1324
1325                         atomic_set(&data->srq_asserted, 1);
1326                         wake_up_interruptible(&data->waitq);
1327                         goto exit;
1328                 }
1329                 dev_warn(dev, "invalid notification: %x\n", data->iin_buffer[0]);
1330                 break;
1331         case -EOVERFLOW:
1332                 dev_err(dev, "overflow with length %d, actual length is %d\n",
1333                         data->iin_wMaxPacketSize, urb->actual_length);
1334                 /* fall through */
1335         case -ECONNRESET:
1336         case -ENOENT:
1337         case -ESHUTDOWN:
1338         case -EILSEQ:
1339         case -ETIME:
1340                 /* urb terminated, clean up */
1341                 dev_dbg(dev, "urb terminated, status: %d\n", status);
1342                 return;
1343         default:
1344                 dev_err(dev, "unknown status received: %d\n", status);
1345         }
1346 exit:
1347         rv = usb_submit_urb(urb, GFP_ATOMIC);
1348         if (rv)
1349                 dev_err(dev, "usb_submit_urb failed: %d\n", rv);
1350 }
1351
1352 static void usbtmc_free_int(struct usbtmc_device_data *data)
1353 {
1354         if (!data->iin_ep_present || !data->iin_urb)
1355                 return;
1356         usb_kill_urb(data->iin_urb);
1357         kfree(data->iin_buffer);
1358         usb_free_urb(data->iin_urb);
1359         kref_put(&data->kref, usbtmc_delete);
1360 }
1361
1362 static int usbtmc_probe(struct usb_interface *intf,
1363                         const struct usb_device_id *id)
1364 {
1365         struct usbtmc_device_data *data;
1366         struct usb_host_interface *iface_desc;
1367         struct usb_endpoint_descriptor *bulk_in, *bulk_out, *int_in;
1368         int n;
1369         int retcode;
1370
1371         dev_dbg(&intf->dev, "%s called\n", __func__);
1372
1373         data = kzalloc(sizeof(*data), GFP_KERNEL);
1374         if (!data)
1375                 return -ENOMEM;
1376
1377         data->intf = intf;
1378         data->id = id;
1379         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1380         usb_set_intfdata(intf, data);
1381         kref_init(&data->kref);
1382         mutex_init(&data->io_mutex);
1383         init_waitqueue_head(&data->waitq);
1384         atomic_set(&data->iin_data_valid, 0);
1385         atomic_set(&data->srq_asserted, 0);
1386         data->zombie = 0;
1387
1388         /* Determine if it is a Rigol or not */
1389         data->rigol_quirk = 0;
1390         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1391                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1392                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1393         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1394                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1395                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1396                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1397                         data->rigol_quirk = 1;
1398                         break;
1399                 }
1400         }
1401
1402         /* Initialize USBTMC bTag and other fields */
1403         data->bTag      = 1;
1404         data->TermCharEnabled = 0;
1405         data->TermChar = '\n';
1406         /*  2 <= bTag <= 127   USBTMC-USB488 subclass specification 4.3.1 */
1407         data->iin_bTag = 2;
1408
1409         /* USBTMC devices have only one setting, so use that */
1410         iface_desc = data->intf->cur_altsetting;
1411         data->ifnum = iface_desc->desc.bInterfaceNumber;
1412
1413         /* Find bulk endpoints */
1414         retcode = usb_find_common_endpoints(iface_desc,
1415                         &bulk_in, &bulk_out, NULL, NULL);
1416         if (retcode) {
1417                 dev_err(&intf->dev, "bulk endpoints not found\n");
1418                 goto err_put;
1419         }
1420
1421         data->bulk_in = bulk_in->bEndpointAddress;
1422         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n", data->bulk_in);
1423
1424         data->bulk_out = bulk_out->bEndpointAddress;
1425         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n", data->bulk_out);
1426
1427         /* Find int endpoint */
1428         retcode = usb_find_int_in_endpoint(iface_desc, &int_in);
1429         if (!retcode) {
1430                 data->iin_ep_present = 1;
1431                 data->iin_ep = int_in->bEndpointAddress;
1432                 data->iin_wMaxPacketSize = usb_endpoint_maxp(int_in);
1433                 data->iin_interval = int_in->bInterval;
1434                 dev_dbg(&intf->dev, "Found Int in endpoint at %u\n",
1435                                 data->iin_ep);
1436         }
1437
1438         retcode = get_capabilities(data);
1439         if (retcode)
1440                 dev_err(&intf->dev, "can't read capabilities\n");
1441         else
1442                 retcode = sysfs_create_group(&intf->dev.kobj,
1443                                              &capability_attr_grp);
1444
1445         if (data->iin_ep_present) {
1446                 /* allocate int urb */
1447                 data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
1448                 if (!data->iin_urb) {
1449                         retcode = -ENOMEM;
1450                         goto error_register;
1451                 }
1452
1453                 /* Protect interrupt in endpoint data until iin_urb is freed */
1454                 kref_get(&data->kref);
1455
1456                 /* allocate buffer for interrupt in */
1457                 data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
1458                                         GFP_KERNEL);
1459                 if (!data->iin_buffer) {
1460                         retcode = -ENOMEM;
1461                         goto error_register;
1462                 }
1463
1464                 /* fill interrupt urb */
1465                 usb_fill_int_urb(data->iin_urb, data->usb_dev,
1466                                 usb_rcvintpipe(data->usb_dev, data->iin_ep),
1467                                 data->iin_buffer, data->iin_wMaxPacketSize,
1468                                 usbtmc_interrupt,
1469                                 data, data->iin_interval);
1470
1471                 retcode = usb_submit_urb(data->iin_urb, GFP_KERNEL);
1472                 if (retcode) {
1473                         dev_err(&intf->dev, "Failed to submit iin_urb\n");
1474                         goto error_register;
1475                 }
1476         }
1477
1478         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1479
1480         retcode = usb_register_dev(intf, &usbtmc_class);
1481         if (retcode) {
1482                 dev_err(&intf->dev, "Not able to get a minor"
1483                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1484                         retcode);
1485                 goto error_register;
1486         }
1487         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1488
1489         return 0;
1490
1491 error_register:
1492         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1493         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1494         usbtmc_free_int(data);
1495 err_put:
1496         kref_put(&data->kref, usbtmc_delete);
1497         return retcode;
1498 }
1499
1500 static void usbtmc_disconnect(struct usb_interface *intf)
1501 {
1502         struct usbtmc_device_data *data;
1503
1504         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1505
1506         data = usb_get_intfdata(intf);
1507         usb_deregister_dev(intf, &usbtmc_class);
1508         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1509         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1510         mutex_lock(&data->io_mutex);
1511         data->zombie = 1;
1512         wake_up_all(&data->waitq);
1513         mutex_unlock(&data->io_mutex);
1514         usbtmc_free_int(data);
1515         kref_put(&data->kref, usbtmc_delete);
1516 }
1517
1518 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1519 {
1520         /* this driver does not have pending URBs */
1521         return 0;
1522 }
1523
1524 static int usbtmc_resume(struct usb_interface *intf)
1525 {
1526         return 0;
1527 }
1528
1529 static struct usb_driver usbtmc_driver = {
1530         .name           = "usbtmc",
1531         .id_table       = usbtmc_devices,
1532         .probe          = usbtmc_probe,
1533         .disconnect     = usbtmc_disconnect,
1534         .suspend        = usbtmc_suspend,
1535         .resume         = usbtmc_resume,
1536 };
1537
1538 module_usb_driver(usbtmc_driver);
1539
1540 MODULE_LICENSE("GPL");