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/init.h>
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/fs.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/kref.h>
  30 #include <linux/slab.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         u8 rigol_quirk;
  92
  93         /* attributes from the USB TMC spec for this device */
  94         u8 TermChar;
  95         bool TermCharEnabled;
  96         bool auto_abort;
  97
  98         bool zombie; /* fd of disconnected device */
  99
 100         struct usbtmc_dev_capabilities  capabilities;
 101         struct kref kref;
 102         struct mutex io_mutex;  /* only one i/o function running at a time */
 103 };
 104 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
 105
 106 struct usbtmc_ID_rigol_quirk {
 107         __u16 idVendor;
 108         __u16 idProduct;
 109 };
 110
 111 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
 112         { 0x1ab1, 0x0588 },
 113         { 0, 0 }
 114 };
 115
 116 /* Forward declarations */
 117 static struct usb_driver usbtmc_driver;
 118
 119 static void usbtmc_delete(struct kref *kref)
 120 {
 121         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 122
 123         usb_put_dev(data->usb_dev);
 124 }
 125
 126 static int usbtmc_open(struct inode *inode, struct file *filp)
 127 {
 128         struct usb_interface *intf;
 129         struct usbtmc_device_data *data;
 130         int retval = 0;
 131
 132         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 133         if (!intf) {
 134                 pr_err("can not find device for minor %d", iminor(inode));
 135                 return -ENODEV;
 136         }
 137
 138         data = usb_get_intfdata(intf);
 139         kref_get(&data->kref);
 140
 141         /* Store pointer in file structure's private data field */
 142         filp->private_data = data;
 143
 144         return retval;
 145 }
 146
 147 static int usbtmc_release(struct inode *inode, struct file *file)
 148 {
 149         struct usbtmc_device_data *data = file->private_data;
 150
 151         kref_put(&data->kref, usbtmc_delete);
 152         return 0;
 153 }
 154
 155 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 156 {
 157         u8 *buffer;
 158         struct device *dev;
 159         int rv;
 160         int n;
 161         int actual;
 162         struct usb_host_interface *current_setting;
 163         int max_size;
 164
 165         dev = &data->intf->dev;
 166         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 167         if (!buffer)
 168                 return -ENOMEM;
 169
 170         rv = usb_control_msg(data->usb_dev,
 171                              usb_rcvctrlpipe(data->usb_dev, 0),
 172                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 173                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 174                              data->bTag_last_read, data->bulk_in,
 175                              buffer, 2, USBTMC_TIMEOUT);
 176
 177         if (rv < 0) {
 178                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 179                 goto exit;
 180         }
 181
 182         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 183
 184         if (buffer[0] == USBTMC_STATUS_FAILED) {
 185                 rv = 0;
 186                 goto exit;
 187         }
 188
 189         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 190                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 191                         buffer[0]);
 192                 rv = -EPERM;
 193                 goto exit;
 194         }
 195
 196         max_size = 0;
 197         current_setting = data->intf->cur_altsetting;
 198         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 199                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 200                         data->bulk_in)
 201                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 202
 203         if (max_size == 0) {
 204                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 205                 rv = -EPERM;
 206                 goto exit;
 207         }
 208
 209         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 210
 211         n = 0;
 212
 213         do {
 214                 dev_dbg(dev, "Reading from bulk in EP\n");
 215
 216                 rv = usb_bulk_msg(data->usb_dev,
 217                                   usb_rcvbulkpipe(data->usb_dev,
 218                                                   data->bulk_in),
 219                                   buffer, USBTMC_SIZE_IOBUFFER,
 220                                   &actual, USBTMC_TIMEOUT);
 221
 222                 n++;
 223
 224                 if (rv < 0) {
 225                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 226                         goto exit;
 227                 }
 228         } while ((actual == max_size) &&
 229                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 230
 231         if (actual == max_size) {
 232                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 233                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 234                 rv = -EPERM;
 235                 goto exit;
 236         }
 237
 238         n = 0;
 239
 240 usbtmc_abort_bulk_in_status:
 241         rv = usb_control_msg(data->usb_dev,
 242                              usb_rcvctrlpipe(data->usb_dev, 0),
 243                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 244                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 245                              0, data->bulk_in, buffer, 0x08,
 246                              USBTMC_TIMEOUT);
 247
 248         if (rv < 0) {
 249                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 250                 goto exit;
 251         }
 252
 253         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 254
 255         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 256                 rv = 0;
 257                 goto exit;
 258         }
 259
 260         if (buffer[0] != USBTMC_STATUS_PENDING) {
 261                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 262                 rv = -EPERM;
 263                 goto exit;
 264         }
 265
 266         if (buffer[1] == 1)
 267                 do {
 268                         dev_dbg(dev, "Reading from bulk in EP\n");
 269
 270                         rv = usb_bulk_msg(data->usb_dev,
 271                                           usb_rcvbulkpipe(data->usb_dev,
 272                                                           data->bulk_in),
 273                                           buffer, USBTMC_SIZE_IOBUFFER,
 274                                           &actual, USBTMC_TIMEOUT);
 275
 276                         n++;
 277
 278                         if (rv < 0) {
 279                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 280                                 goto exit;
 281                         }
 282                 } while ((actual == max_size) &&
 283                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 284
 285         if (actual == max_size) {
 286                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 287                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 288                 rv = -EPERM;
 289                 goto exit;
 290         }
 291
 292         goto usbtmc_abort_bulk_in_status;
 293
 294 exit:
 295         kfree(buffer);
 296         return rv;
 297
 298 }
 299
 300 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 301 {
 302         struct device *dev;
 303         u8 *buffer;
 304         int rv;
 305         int n;
 306
 307         dev = &data->intf->dev;
 308
 309         buffer = kmalloc(8, GFP_KERNEL);
 310         if (!buffer)
 311                 return -ENOMEM;
 312
 313         rv = usb_control_msg(data->usb_dev,
 314                              usb_rcvctrlpipe(data->usb_dev, 0),
 315                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 316                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 317                              data->bTag_last_write, data->bulk_out,
 318                              buffer, 2, USBTMC_TIMEOUT);
 319
 320         if (rv < 0) {
 321                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 322                 goto exit;
 323         }
 324
 325         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 326
 327         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 328                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 329                         buffer[0]);
 330                 rv = -EPERM;
 331                 goto exit;
 332         }
 333
 334         n = 0;
 335
 336 usbtmc_abort_bulk_out_check_status:
 337         rv = usb_control_msg(data->usb_dev,
 338                              usb_rcvctrlpipe(data->usb_dev, 0),
 339                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 340                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 341                              0, data->bulk_out, buffer, 0x08,
 342                              USBTMC_TIMEOUT);
 343         n++;
 344         if (rv < 0) {
 345                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 346                 goto exit;
 347         }
 348
 349         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 350
 351         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 352                 goto usbtmc_abort_bulk_out_clear_halt;
 353
 354         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 355             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 356                 goto usbtmc_abort_bulk_out_check_status;
 357
 358         rv = -EPERM;
 359         goto exit;
 360
 361 usbtmc_abort_bulk_out_clear_halt:
 362         rv = usb_clear_halt(data->usb_dev,
 363                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 364
 365         if (rv < 0) {
 366                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 367                 goto exit;
 368         }
 369         rv = 0;
 370
 371 exit:
 372         kfree(buffer);
 373         return rv;
 374 }
 375
 376 /*
 377  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 378  * @transfer_size: number of bytes to request from the device.
 379  *
 380  * See the USBTMC specification, Table 4.
 381  *
 382  * Also updates bTag_last_write.
 383  */
 384 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 385 {
 386         int retval;
 387         u8 buffer[USBTMC_HEADER_SIZE];
 388         int actual;
 389
 390         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 391          * Refer to class specs for details
 392          */
 393         buffer[0] = 2;
 394         buffer[1] = data->bTag;
 395         buffer[2] = ~data->bTag;
 396         buffer[3] = 0; /* Reserved */
 397         buffer[4] = transfer_size >> 0;
 398         buffer[5] = transfer_size >> 8;
 399         buffer[6] = transfer_size >> 16;
 400         buffer[7] = transfer_size >> 24;
 401         buffer[8] = data->TermCharEnabled * 2;
 402         /* Use term character? */
 403         buffer[9] = data->TermChar;
 404         buffer[10] = 0; /* Reserved */
 405         buffer[11] = 0; /* Reserved */
 406
 407         /* Send bulk URB */
 408         retval = usb_bulk_msg(data->usb_dev,
 409                               usb_sndbulkpipe(data->usb_dev,
 410                                               data->bulk_out),
 411                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 412
 413         /* Store bTag (in case we need to abort) */
 414         data->bTag_last_write = data->bTag;
 415
 416         /* Increment bTag -- and increment again if zero */
 417         data->bTag++;
 418         if (!data->bTag)
 419                 data->bTag++;
 420
 421         if (retval < 0) {
 422                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 423                 return retval;
 424         }
 425
 426         return 0;
 427 }
 428
 429 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 430                            size_t count, loff_t *f_pos)
 431 {
 432         struct usbtmc_device_data *data;
 433         struct device *dev;
 434         u32 n_characters;
 435         u8 *buffer;
 436         int actual;
 437         size_t done;
 438         size_t remaining;
 439         int retval;
 440         size_t this_part;
 441
 442         /* Get pointer to private data structure */
 443         data = filp->private_data;
 444         dev = &data->intf->dev;
 445
 446         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 447         if (!buffer)
 448                 return -ENOMEM;
 449
 450         mutex_lock(&data->io_mutex);
 451         if (data->zombie) {
 452                 retval = -ENODEV;
 453                 goto exit;
 454         }
 455
 456         if (data->rigol_quirk) {
 457                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 458
 459                 retval = send_request_dev_dep_msg_in(data, count);
 460
 461                 if (retval < 0) {
 462                         if (data->auto_abort)
 463                                 usbtmc_ioctl_abort_bulk_out(data);
 464                         goto exit;
 465                 }
 466         }
 467
 468         /* Loop until we have fetched everything we requested */
 469         remaining = count;
 470         this_part = remaining;
 471         done = 0;
 472
 473         while (remaining > 0) {
 474                 if (!data->rigol_quirk) {
 475                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 476
 477                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 478                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 479                         else
 480                                 this_part = remaining;
 481
 482                         retval = send_request_dev_dep_msg_in(data, this_part);
 483                         if (retval < 0) {
 484                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 485                                 if (data->auto_abort)
 486                                         usbtmc_ioctl_abort_bulk_out(data);
 487                                 goto exit;
 488                         }
 489                 }
 490
 491                 /* Send bulk URB */
 492                 retval = usb_bulk_msg(data->usb_dev,
 493                                       usb_rcvbulkpipe(data->usb_dev,
 494                                                       data->bulk_in),
 495                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 496                                       USBTMC_TIMEOUT);
 497
 498                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 499
 500                 /* Store bTag (in case we need to abort) */
 501                 data->bTag_last_read = data->bTag;
 502
 503                 if (retval < 0) {
 504                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 505                         if (data->auto_abort)
 506                                 usbtmc_ioctl_abort_bulk_in(data);
 507                         goto exit;
 508                 }
 509
 510                 /* Parse header in first packet */
 511                 if ((done == 0) || !data->rigol_quirk) {
 512                         /* Sanity checks for the header */
 513                         if (actual < USBTMC_HEADER_SIZE) {
 514                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 515                                 if (data->auto_abort)
 516                                         usbtmc_ioctl_abort_bulk_in(data);
 517                                 goto exit;
 518                         }
 519
 520                         if (buffer[0] != 2) {
 521                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 522                                 if (data->auto_abort)
 523                                         usbtmc_ioctl_abort_bulk_in(data);
 524                                 goto exit;
 525                         }
 526
 527                         if (buffer[1] != data->bTag_last_write) {
 528                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 529                                 if (data->auto_abort)
 530                                         usbtmc_ioctl_abort_bulk_in(data);
 531                                 goto exit;
 532                         }
 533
 534                         /* How many characters did the instrument send? */
 535                         n_characters = buffer[4] +
 536                                        (buffer[5] << 8) +
 537                                        (buffer[6] << 16) +
 538                                        (buffer[7] << 24);
 539
 540                         if (n_characters > this_part) {
 541                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 542                                 if (data->auto_abort)
 543                                         usbtmc_ioctl_abort_bulk_in(data);
 544                                 goto exit;
 545                         }
 546
 547                         /* Remove the USBTMC header */
 548                         actual -= USBTMC_HEADER_SIZE;
 549
 550                         /* Check if the message is smaller than requested */
 551                         if (data->rigol_quirk) {
 552                                 if (remaining > n_characters)
 553                                         remaining = n_characters;
 554                                 /* Remove padding if it exists */
 555                                 if (actual > remaining)
 556                                         actual = remaining;
 557                         }
 558                         else {
 559                                 if (this_part > n_characters)
 560                                         this_part = n_characters;
 561                                 /* Remove padding if it exists */
 562                                 if (actual > this_part)
 563                                         actual = this_part;
 564                         }
 565
 566                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 567
 568                         remaining -= actual;
 569
 570                         /* Terminate if end-of-message bit received from device */
 571                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 572                                 remaining = 0;
 573
 574                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 575
 576
 577                         /* Copy buffer to user space */
 578                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 579                                 /* There must have been an addressing problem */
 580                                 retval = -EFAULT;
 581                                 goto exit;
 582                         }
 583                         done += actual;
 584                 }
 585                 else  {
 586                         if (actual > remaining)
 587                                 actual = remaining;
 588
 589                         remaining -= actual;
 590
 591                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 592
 593                         /* Copy buffer to user space */
 594                         if (copy_to_user(buf + done, buffer, actual)) {
 595                                 /* There must have been an addressing problem */
 596                                 retval = -EFAULT;
 597                                 goto exit;
 598                         }
 599                         done += actual;
 600                 }
 601         }
 602
 603         /* Update file position value */
 604         *f_pos = *f_pos + done;
 605         retval = done;
 606
 607 exit:
 608         mutex_unlock(&data->io_mutex);
 609         kfree(buffer);
 610         return retval;
 611 }
 612
 613 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 614                             size_t count, loff_t *f_pos)
 615 {
 616         struct usbtmc_device_data *data;
 617         u8 *buffer;
 618         int retval;
 619         int actual;
 620         unsigned long int n_bytes;
 621         int remaining;
 622         int done;
 623         int this_part;
 624
 625         data = filp->private_data;
 626
 627         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 628         if (!buffer)
 629                 return -ENOMEM;
 630
 631         mutex_lock(&data->io_mutex);
 632         if (data->zombie) {
 633                 retval = -ENODEV;
 634                 goto exit;
 635         }
 636
 637         remaining = count;
 638         done = 0;
 639
 640         while (remaining > 0) {
 641                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 642                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 643                         buffer[8] = 0;
 644                 } else {
 645                         this_part = remaining;
 646                         buffer[8] = 1;
 647                 }
 648
 649                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 650                 buffer[0] = 1;
 651                 buffer[1] = data->bTag;
 652                 buffer[2] = ~data->bTag;
 653                 buffer[3] = 0; /* Reserved */
 654                 buffer[4] = this_part >> 0;
 655                 buffer[5] = this_part >> 8;
 656                 buffer[6] = this_part >> 16;
 657                 buffer[7] = this_part >> 24;
 658                 /* buffer[8] is set above... */
 659                 buffer[9] = 0; /* Reserved */
 660                 buffer[10] = 0; /* Reserved */
 661                 buffer[11] = 0; /* Reserved */
 662
 663                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 664                         retval = -EFAULT;
 665                         goto exit;
 666                 }
 667
 668                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 669                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 670
 671                 do {
 672                         retval = usb_bulk_msg(data->usb_dev,
 673                                               usb_sndbulkpipe(data->usb_dev,
 674                                                               data->bulk_out),
 675                                               buffer, n_bytes,
 676                                               &actual, USBTMC_TIMEOUT);
 677                         if (retval != 0)
 678                                 break;
 679                         n_bytes -= actual;
 680                 } while (n_bytes);
 681
 682                 data->bTag_last_write = data->bTag;
 683                 data->bTag++;
 684
 685                 if (!data->bTag)
 686                         data->bTag++;
 687
 688                 if (retval < 0) {
 689                         dev_err(&data->intf->dev,
 690                                 "Unable to send data, error %d\n", retval);
 691                         if (data->auto_abort)
 692                                 usbtmc_ioctl_abort_bulk_out(data);
 693                         goto exit;
 694                 }
 695
 696                 remaining -= this_part;
 697                 done += this_part;
 698         }
 699
 700         retval = count;
 701 exit:
 702         mutex_unlock(&data->io_mutex);
 703         kfree(buffer);
 704         return retval;
 705 }
 706
 707 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 708 {
 709         struct usb_host_interface *current_setting;
 710         struct usb_endpoint_descriptor *desc;
 711         struct device *dev;
 712         u8 *buffer;
 713         int rv;
 714         int n;
 715         int actual;
 716         int max_size;
 717
 718         dev = &data->intf->dev;
 719
 720         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 721
 722         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 723         if (!buffer)
 724                 return -ENOMEM;
 725
 726         rv = usb_control_msg(data->usb_dev,
 727                              usb_rcvctrlpipe(data->usb_dev, 0),
 728                              USBTMC_REQUEST_INITIATE_CLEAR,
 729                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 730                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 731         if (rv < 0) {
 732                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 733                 goto exit;
 734         }
 735
 736         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 737
 738         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 739                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 740                 rv = -EPERM;
 741                 goto exit;
 742         }
 743
 744         max_size = 0;
 745         current_setting = data->intf->cur_altsetting;
 746         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 747                 desc = &current_setting->endpoint[n].desc;
 748                 if (desc->bEndpointAddress == data->bulk_in)
 749                         max_size = usb_endpoint_maxp(desc);
 750         }
 751
 752         if (max_size == 0) {
 753                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 754                 rv = -EPERM;
 755                 goto exit;
 756         }
 757
 758         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 759
 760         n = 0;
 761
 762 usbtmc_clear_check_status:
 763
 764         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 765
 766         rv = usb_control_msg(data->usb_dev,
 767                              usb_rcvctrlpipe(data->usb_dev, 0),
 768                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 769                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 770                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 771         if (rv < 0) {
 772                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 773                 goto exit;
 774         }
 775
 776         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 777
 778         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 779                 goto usbtmc_clear_bulk_out_halt;
 780
 781         if (buffer[0] != USBTMC_STATUS_PENDING) {
 782                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 783                 rv = -EPERM;
 784                 goto exit;
 785         }
 786
 787         if (buffer[1] == 1)
 788                 do {
 789                         dev_dbg(dev, "Reading from bulk in EP\n");
 790
 791                         rv = usb_bulk_msg(data->usb_dev,
 792                                           usb_rcvbulkpipe(data->usb_dev,
 793                                                           data->bulk_in),
 794                                           buffer, USBTMC_SIZE_IOBUFFER,
 795                                           &actual, USBTMC_TIMEOUT);
 796                         n++;
 797
 798                         if (rv < 0) {
 799                                 dev_err(dev, "usb_control_msg returned %d\n",
 800                                         rv);
 801                                 goto exit;
 802                         }
 803                 } while ((actual == max_size) &&
 804                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 805
 806         if (actual == max_size) {
 807                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 808                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 809                 rv = -EPERM;
 810                 goto exit;
 811         }
 812
 813         goto usbtmc_clear_check_status;
 814
 815 usbtmc_clear_bulk_out_halt:
 816
 817         rv = usb_clear_halt(data->usb_dev,
 818                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 819         if (rv < 0) {
 820                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 821                 goto exit;
 822         }
 823         rv = 0;
 824
 825 exit:
 826         kfree(buffer);
 827         return rv;
 828 }
 829
 830 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 831 {
 832         int rv;
 833
 834         rv = usb_clear_halt(data->usb_dev,
 835                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 836
 837         if (rv < 0) {
 838                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 839                         rv);
 840                 return rv;
 841         }
 842         return 0;
 843 }
 844
 845 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 846 {
 847         int rv;
 848
 849         rv = usb_clear_halt(data->usb_dev,
 850                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 851
 852         if (rv < 0) {
 853                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 854                         rv);
 855                 return rv;
 856         }
 857         return 0;
 858 }
 859
 860 static int get_capabilities(struct usbtmc_device_data *data)
 861 {
 862         struct device *dev = &data->usb_dev->dev;
 863         char *buffer;
 864         int rv = 0;
 865
 866         buffer = kmalloc(0x18, GFP_KERNEL);
 867         if (!buffer)
 868                 return -ENOMEM;
 869
 870         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 871                              USBTMC_REQUEST_GET_CAPABILITIES,
 872                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 873                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 874         if (rv < 0) {
 875                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 876                 goto err_out;
 877         }
 878
 879         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 880         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 881                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 882                 rv = -EPERM;
 883                 goto err_out;
 884         }
 885         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 886         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 887         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 888         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 889
 890         data->capabilities.interface_capabilities = buffer[4];
 891         data->capabilities.device_capabilities = buffer[5];
 892         data->capabilities.usb488_interface_capabilities = buffer[14];
 893         data->capabilities.usb488_device_capabilities = buffer[15];
 894         rv = 0;
 895
 896 err_out:
 897         kfree(buffer);
 898         return rv;
 899 }
 900
 901 #define capability_attribute(name)                                      \
 902 static ssize_t show_##name(struct device *dev,                          \
 903                            struct device_attribute *attr, char *buf)    \
 904 {                                                                       \
 905         struct usb_interface *intf = to_usb_interface(dev);             \
 906         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 907                                                                         \
 908         return sprintf(buf, "%d\n", data->capabilities.name);           \
 909 }                                                                       \
 910 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 911
 912 capability_attribute(interface_capabilities);
 913 capability_attribute(device_capabilities);
 914 capability_attribute(usb488_interface_capabilities);
 915 capability_attribute(usb488_device_capabilities);
 916
 917 static struct attribute *capability_attrs[] = {
 918         &dev_attr_interface_capabilities.attr,
 919         &dev_attr_device_capabilities.attr,
 920         &dev_attr_usb488_interface_capabilities.attr,
 921         &dev_attr_usb488_device_capabilities.attr,
 922         NULL,
 923 };
 924
 925 static struct attribute_group capability_attr_grp = {
 926         .attrs = capability_attrs,
 927 };
 928
 929 static ssize_t show_TermChar(struct device *dev,
 930                              struct device_attribute *attr, char *buf)
 931 {
 932         struct usb_interface *intf = to_usb_interface(dev);
 933         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 934
 935         return sprintf(buf, "%c\n", data->TermChar);
 936 }
 937
 938 static ssize_t store_TermChar(struct device *dev,
 939                               struct device_attribute *attr,
 940                               const char *buf, size_t count)
 941 {
 942         struct usb_interface *intf = to_usb_interface(dev);
 943         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 944
 945         if (count < 1)
 946                 return -EINVAL;
 947         data->TermChar = buf[0];
 948         return count;
 949 }
 950 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 951
 952 #define data_attribute(name)                                            \
 953 static ssize_t show_##name(struct device *dev,                          \
 954                            struct device_attribute *attr, char *buf)    \
 955 {                                                                       \
 956         struct usb_interface *intf = to_usb_interface(dev);             \
 957         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 958                                                                         \
 959         return sprintf(buf, "%d\n", data->name);                        \
 960 }                                                                       \
 961 static ssize_t store_##name(struct device *dev,                         \
 962                             struct device_attribute *attr,              \
 963                             const char *buf, size_t count)              \
 964 {                                                                       \
 965         struct usb_interface *intf = to_usb_interface(dev);             \
 966         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 967         ssize_t result;                                                 \
 968         unsigned val;                                                   \
 969                                                                         \
 970         result = sscanf(buf, "%u\n", &val);                             \
 971         if (result != 1)                                                \
 972                 result = -EINVAL;                                       \
 973         data->name = val;                                               \
 974         if (result < 0)                                                 \
 975                 return result;                                          \
 976         else                                                            \
 977                 return count;                                           \
 978 }                                                                       \
 979 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 980
 981 data_attribute(TermCharEnabled);
 982 data_attribute(auto_abort);
 983
 984 static struct attribute *data_attrs[] = {
 985         &dev_attr_TermChar.attr,
 986         &dev_attr_TermCharEnabled.attr,
 987         &dev_attr_auto_abort.attr,
 988         NULL,
 989 };
 990
 991 static struct attribute_group data_attr_grp = {
 992         .attrs = data_attrs,
 993 };
 994
 995 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 996 {
 997         struct device *dev;
 998         u8 *buffer;
 999         int rv;
1000
1001         dev = &data->intf->dev;
1002
1003         buffer = kmalloc(2, GFP_KERNEL);
1004         if (!buffer)
1005                 return -ENOMEM;
1006
1007         rv = usb_control_msg(data->usb_dev,
1008                              usb_rcvctrlpipe(data->usb_dev, 0),
1009                              USBTMC_REQUEST_INDICATOR_PULSE,
1010                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1011                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1012
1013         if (rv < 0) {
1014                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1015                 goto exit;
1016         }
1017
1018         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1019
1020         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1021                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1022                 rv = -EPERM;
1023                 goto exit;
1024         }
1025         rv = 0;
1026
1027 exit:
1028         kfree(buffer);
1029         return rv;
1030 }
1031
1032 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1033 {
1034         struct usbtmc_device_data *data;
1035         int retval = -EBADRQC;
1036
1037         data = file->private_data;
1038         mutex_lock(&data->io_mutex);
1039         if (data->zombie) {
1040                 retval = -ENODEV;
1041                 goto skip_io_on_zombie;
1042         }
1043
1044         switch (cmd) {
1045         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1046                 retval = usbtmc_ioctl_clear_out_halt(data);
1047                 break;
1048
1049         case USBTMC_IOCTL_CLEAR_IN_HALT:
1050                 retval = usbtmc_ioctl_clear_in_halt(data);
1051                 break;
1052
1053         case USBTMC_IOCTL_INDICATOR_PULSE:
1054                 retval = usbtmc_ioctl_indicator_pulse(data);
1055                 break;
1056
1057         case USBTMC_IOCTL_CLEAR:
1058                 retval = usbtmc_ioctl_clear(data);
1059                 break;
1060
1061         case USBTMC_IOCTL_ABORT_BULK_OUT:
1062                 retval = usbtmc_ioctl_abort_bulk_out(data);
1063                 break;
1064
1065         case USBTMC_IOCTL_ABORT_BULK_IN:
1066                 retval = usbtmc_ioctl_abort_bulk_in(data);
1067                 break;
1068         }
1069
1070 skip_io_on_zombie:
1071         mutex_unlock(&data->io_mutex);
1072         return retval;
1073 }
1074
1075 static const struct file_operations fops = {
1076         .owner          = THIS_MODULE,
1077         .read           = usbtmc_read,
1078         .write          = usbtmc_write,
1079         .open           = usbtmc_open,
1080         .release        = usbtmc_release,
1081         .unlocked_ioctl = usbtmc_ioctl,
1082         .llseek         = default_llseek,
1083 };
1084
1085 static struct usb_class_driver usbtmc_class = {
1086         .name =         "usbtmc%d",
1087         .fops =         &fops,
1088         .minor_base =   USBTMC_MINOR_BASE,
1089 };
1090
1091
1092 static int usbtmc_probe(struct usb_interface *intf,
1093                         const struct usb_device_id *id)
1094 {
1095         struct usbtmc_device_data *data;
1096         struct usb_host_interface *iface_desc;
1097         struct usb_endpoint_descriptor *endpoint;
1098         int n;
1099         int retcode;
1100
1101         dev_dbg(&intf->dev, "%s called\n", __func__);
1102
1103         data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1104         if (!data) {
1105                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1106                 return -ENOMEM;
1107         }
1108
1109         data->intf = intf;
1110         data->id = id;
1111         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1112         usb_set_intfdata(intf, data);
1113         kref_init(&data->kref);
1114         mutex_init(&data->io_mutex);
1115         data->zombie = 0;
1116
1117         /* Determine if it is a Rigol or not */
1118         data->rigol_quirk = 0;
1119         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1120                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1121                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1122         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1123                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1124                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1125                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1126                         data->rigol_quirk = 1;
1127                         break;
1128                 }
1129         }
1130
1131         /* Initialize USBTMC bTag and other fields */
1132         data->bTag      = 1;
1133         data->TermCharEnabled = 0;
1134         data->TermChar = '\n';
1135
1136         /* USBTMC devices have only one setting, so use that */
1137         iface_desc = data->intf->cur_altsetting;
1138
1139         /* Find bulk in endpoint */
1140         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1141                 endpoint = &iface_desc->endpoint[n].desc;
1142
1143                 if (usb_endpoint_is_bulk_in(endpoint)) {
1144                         data->bulk_in = endpoint->bEndpointAddress;
1145                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1146                                 data->bulk_in);
1147                         break;
1148                 }
1149         }
1150
1151         /* Find bulk out endpoint */
1152         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1153                 endpoint = &iface_desc->endpoint[n].desc;
1154
1155                 if (usb_endpoint_is_bulk_out(endpoint)) {
1156                         data->bulk_out = endpoint->bEndpointAddress;
1157                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1158                                 data->bulk_out);
1159                         break;
1160                 }
1161         }
1162
1163         retcode = get_capabilities(data);
1164         if (retcode)
1165                 dev_err(&intf->dev, "can't read capabilities\n");
1166         else
1167                 retcode = sysfs_create_group(&intf->dev.kobj,
1168                                              &capability_attr_grp);
1169
1170         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1171
1172         retcode = usb_register_dev(intf, &usbtmc_class);
1173         if (retcode) {
1174                 dev_err(&intf->dev, "Not able to get a minor"
1175                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1176                         retcode);
1177                 goto error_register;
1178         }
1179         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1180
1181         return 0;
1182
1183 error_register:
1184         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1185         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1186         kref_put(&data->kref, usbtmc_delete);
1187         return retcode;
1188 }
1189
1190 static void usbtmc_disconnect(struct usb_interface *intf)
1191 {
1192         struct usbtmc_device_data *data;
1193
1194         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1195
1196         data = usb_get_intfdata(intf);
1197         usb_deregister_dev(intf, &usbtmc_class);
1198         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1199         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1200         mutex_lock(&data->io_mutex);
1201         data->zombie = 1;
1202         mutex_unlock(&data->io_mutex);
1203         kref_put(&data->kref, usbtmc_delete);
1204 }
1205
1206 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1207 {
1208         /* this driver does not have pending URBs */
1209         return 0;
1210 }
1211
1212 static int usbtmc_resume(struct usb_interface *intf)
1213 {
1214         return 0;
1215 }
1216
1217 static struct usb_driver usbtmc_driver = {
1218         .name           = "usbtmc",
1219         .id_table       = usbtmc_devices,
1220         .probe          = usbtmc_probe,
1221         .disconnect     = usbtmc_disconnect,
1222         .suspend        = usbtmc_suspend,
1223         .resume         = usbtmc_resume,
1224 };
1225
1226 module_usb_driver(usbtmc_driver);
1227
1228 MODULE_LICENSE("GPL");