drivers/usb/class/usbtmc.c

   1 /**
   2  * drivers/usb/class/usbtmc.c - USB Test & Measurment 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 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/fs.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/kref.h>
  28 #include <linux/mutex.h>
  29 #include <linux/usb.h>
  30 #include <linux/usb/tmc.h>
  31
  32
  33 #define USBTMC_MINOR_BASE       176
  34
  35 /*
  36  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  37  * large as wMaxPacketSize (which is usually 512 bytes).
  38  */
  39 #define USBTMC_SIZE_IOBUFFER    2048
  40
  41 /* Default USB timeout (in milliseconds) */
  42 #define USBTMC_TIMEOUT          10
  43
  44 /*
  45  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  46  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  47  * packet is never read.
  48  */
  49 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  50
  51 static struct usb_device_id usbtmc_devices[] = {
  52         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  53         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  54         { 0, } /* terminating entry */
  55 };
  56 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  57
  58 /*
  59  * This structure is the capabilities for the device
  60  * See section 4.2.1.8 of the USBTMC specification for details.
  61  */
  62 struct usbtmc_dev_capabilities {
  63         __u8 interface_capabilities;
  64         __u8 device_capabilities;
  65         __u8 usb488_interface_capabilities;
  66         __u8 usb488_device_capabilities;
  67 };
  68
  69 /* This structure holds private data for each USBTMC device. One copy is
  70  * allocated for each USBTMC device in the driver's probe function.
  71  */
  72 struct usbtmc_device_data {
  73         const struct usb_device_id *id;
  74         struct usb_device *usb_dev;
  75         struct usb_interface *intf;
  76
  77         unsigned int bulk_in;
  78         unsigned int bulk_out;
  79
  80         u8 bTag;
  81         u8 bTag_last_write;     /* needed for abort */
  82         u8 bTag_last_read;      /* needed for abort */
  83
  84         /* attributes from the USB TMC spec for this device */
  85         u8 TermChar;
  86         bool TermCharEnabled;
  87         bool auto_abort;
  88
  89         struct usbtmc_dev_capabilities  capabilities;
  90         struct kref kref;
  91         struct mutex io_mutex;  /* only one i/o function running at a time */
  92 };
  93 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  94
  95 /* Forward declarations */
  96 static struct usb_driver usbtmc_driver;
  97
  98 static void usbtmc_delete(struct kref *kref)
  99 {
 100         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 101
 102         usb_put_dev(data->usb_dev);
 103         kfree(data);
 104 }
 105
 106 static int usbtmc_open(struct inode *inode, struct file *filp)
 107 {
 108         struct usb_interface *intf;
 109         struct usbtmc_device_data *data;
 110         int retval = 0;
 111
 112         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 113         if (!intf) {
 114                 printk(KERN_ERR KBUILD_MODNAME
 115                        ": can not find device for minor %d", iminor(inode));
 116                 retval = -ENODEV;
 117                 goto exit;
 118         }
 119
 120         data = usb_get_intfdata(intf);
 121         kref_get(&data->kref);
 122
 123         /* Store pointer in file structure's private data field */
 124         filp->private_data = data;
 125
 126 exit:
 127         return retval;
 128 }
 129
 130 static int usbtmc_release(struct inode *inode, struct file *file)
 131 {
 132         struct usbtmc_device_data *data = file->private_data;
 133
 134         kref_put(&data->kref, usbtmc_delete);
 135         return 0;
 136 }
 137
 138 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 139 {
 140         u8 *buffer;
 141         struct device *dev;
 142         int rv;
 143         int n;
 144         int actual;
 145         struct usb_host_interface *current_setting;
 146         int max_size;
 147
 148         dev = &data->intf->dev;
 149         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 150         if (!buffer)
 151                 return -ENOMEM;
 152
 153         rv = usb_control_msg(data->usb_dev,
 154                              usb_rcvctrlpipe(data->usb_dev, 0),
 155                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 156                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 157                              data->bTag_last_read, data->bulk_in,
 158                              buffer, 2, USBTMC_TIMEOUT);
 159
 160         if (rv < 0) {
 161                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 162                 goto exit;
 163         }
 164
 165         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 166
 167         if (buffer[0] == USBTMC_STATUS_FAILED) {
 168                 rv = 0;
 169                 goto exit;
 170         }
 171
 172         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 173                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 174                         buffer[0]);
 175                 rv = -EPERM;
 176                 goto exit;
 177         }
 178
 179         max_size = 0;
 180         current_setting = data->intf->cur_altsetting;
 181         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 182                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 183                         data->bulk_in)
 184                         max_size = le16_to_cpu(current_setting->endpoint[n].
 185                                                 desc.wMaxPacketSize);
 186
 187         if (max_size == 0) {
 188                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 189                 rv = -EPERM;
 190                 goto exit;
 191         }
 192
 193         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 194
 195         n = 0;
 196
 197         do {
 198                 dev_dbg(dev, "Reading from bulk in EP\n");
 199
 200                 rv = usb_bulk_msg(data->usb_dev,
 201                                   usb_rcvbulkpipe(data->usb_dev,
 202                                                   data->bulk_in),
 203                                   buffer, USBTMC_SIZE_IOBUFFER,
 204                                   &actual, USBTMC_TIMEOUT);
 205
 206                 n++;
 207
 208                 if (rv < 0) {
 209                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 210                         goto exit;
 211                 }
 212         } while ((actual == max_size) &&
 213                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 214
 215         if (actual == max_size) {
 216                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 217                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 218                 rv = -EPERM;
 219                 goto exit;
 220         }
 221
 222         n = 0;
 223
 224 usbtmc_abort_bulk_in_status:
 225         rv = usb_control_msg(data->usb_dev,
 226                              usb_rcvctrlpipe(data->usb_dev, 0),
 227                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 228                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 229                              0, data->bulk_in, buffer, 0x08,
 230                              USBTMC_TIMEOUT);
 231
 232         if (rv < 0) {
 233                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 234                 goto exit;
 235         }
 236
 237         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 238
 239         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 240                 rv = 0;
 241                 goto exit;
 242         }
 243
 244         if (buffer[0] != USBTMC_STATUS_PENDING) {
 245                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 246                 rv = -EPERM;
 247                 goto exit;
 248         }
 249
 250         if (buffer[1] == 1)
 251                 do {
 252                         dev_dbg(dev, "Reading from bulk in EP\n");
 253
 254                         rv = usb_bulk_msg(data->usb_dev,
 255                                           usb_rcvbulkpipe(data->usb_dev,
 256                                                           data->bulk_in),
 257                                           buffer, USBTMC_SIZE_IOBUFFER,
 258                                           &actual, USBTMC_TIMEOUT);
 259
 260                         n++;
 261
 262                         if (rv < 0) {
 263                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 264                                 goto exit;
 265                         }
 266                 } while ((actual = max_size) &&
 267                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 268
 269         if (actual == max_size) {
 270                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 271                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 272                 rv = -EPERM;
 273                 goto exit;
 274         }
 275
 276         goto usbtmc_abort_bulk_in_status;
 277
 278 exit:
 279         kfree(buffer);
 280         return rv;
 281
 282 }
 283
 284 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 285 {
 286         struct device *dev;
 287         u8 *buffer;
 288         int rv;
 289         int n;
 290
 291         dev = &data->intf->dev;
 292
 293         buffer = kmalloc(8, GFP_KERNEL);
 294         if (!buffer)
 295                 return -ENOMEM;
 296
 297         rv = usb_control_msg(data->usb_dev,
 298                              usb_rcvctrlpipe(data->usb_dev, 0),
 299                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 300                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 301                              data->bTag_last_write, data->bulk_out,
 302                              buffer, 2, USBTMC_TIMEOUT);
 303
 304         if (rv < 0) {
 305                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 306                 goto exit;
 307         }
 308
 309         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 310
 311         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 312                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 313                         buffer[0]);
 314                 rv = -EPERM;
 315                 goto exit;
 316         }
 317
 318         n = 0;
 319
 320 usbtmc_abort_bulk_out_check_status:
 321         rv = usb_control_msg(data->usb_dev,
 322                              usb_rcvctrlpipe(data->usb_dev, 0),
 323                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 324                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 325                              0, data->bulk_out, buffer, 0x08,
 326                              USBTMC_TIMEOUT);
 327         n++;
 328         if (rv < 0) {
 329                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 330                 goto exit;
 331         }
 332
 333         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 334
 335         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 336                 goto usbtmc_abort_bulk_out_clear_halt;
 337
 338         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 339             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 340                 goto usbtmc_abort_bulk_out_check_status;
 341
 342         rv = -EPERM;
 343         goto exit;
 344
 345 usbtmc_abort_bulk_out_clear_halt:
 346         rv = usb_control_msg(data->usb_dev,
 347                              usb_sndctrlpipe(data->usb_dev, 0),
 348                              USB_REQ_CLEAR_FEATURE,
 349                              USB_DIR_OUT | USB_TYPE_STANDARD |
 350                              USB_RECIP_ENDPOINT,
 351                              USB_ENDPOINT_HALT, data->bulk_out, buffer,
 352                              0, USBTMC_TIMEOUT);
 353
 354         if (rv < 0) {
 355                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 356                 goto exit;
 357         }
 358         rv = 0;
 359
 360 exit:
 361         kfree(buffer);
 362         return rv;
 363 }
 364
 365 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 366                            size_t count, loff_t *f_pos)
 367 {
 368         struct usbtmc_device_data *data;
 369         struct device *dev;
 370         unsigned long int n_characters;
 371         u8 *buffer;
 372         int actual;
 373         int done;
 374         int remaining;
 375         int retval;
 376         int this_part;
 377
 378         /* Get pointer to private data structure */
 379         data = filp->private_data;
 380         dev = &data->intf->dev;
 381
 382         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 383         if (!buffer)
 384                 return -ENOMEM;
 385
 386         mutex_lock(&data->io_mutex);
 387
 388         remaining = count;
 389         done = 0;
 390
 391         while (remaining > 0) {
 392                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 393                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 394                 else
 395                         this_part = remaining;
 396
 397                 /* Setup IO buffer for DEV_DEP_MSG_IN message
 398                  * Refer to class specs for details
 399                  */
 400                 buffer[0] = 2;
 401                 buffer[1] = data->bTag;
 402                 buffer[2] = ~(data->bTag);
 403                 buffer[3] = 0; /* Reserved */
 404                 buffer[4] = (this_part - 12 - 3) & 255;
 405                 buffer[5] = ((this_part - 12 - 3) >> 8) & 255;
 406                 buffer[6] = ((this_part - 12 - 3) >> 16) & 255;
 407                 buffer[7] = ((this_part - 12 - 3) >> 24) & 255;
 408                 buffer[8] = data->TermCharEnabled * 2;
 409                 /* Use term character? */
 410                 buffer[9] = data->TermChar;
 411                 buffer[10] = 0; /* Reserved */
 412                 buffer[11] = 0; /* Reserved */
 413
 414                 /* Send bulk URB */
 415                 retval = usb_bulk_msg(data->usb_dev,
 416                                       usb_sndbulkpipe(data->usb_dev,
 417                                                       data->bulk_out),
 418                                       buffer, 12, &actual, USBTMC_TIMEOUT);
 419
 420                 /* Store bTag (in case we need to abort) */
 421                 data->bTag_last_write = data->bTag;
 422
 423                 /* Increment bTag -- and increment again if zero */
 424                 data->bTag++;
 425                 if (!data->bTag)
 426                         (data->bTag)++;
 427
 428                 if (retval < 0) {
 429                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 430                         if (data->auto_abort)
 431                                 usbtmc_ioctl_abort_bulk_out(data);
 432                         goto exit;
 433                 }
 434
 435                 /* Send bulk URB */
 436                 retval = usb_bulk_msg(data->usb_dev,
 437                                       usb_rcvbulkpipe(data->usb_dev,
 438                                                       data->bulk_in),
 439                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 440                                       USBTMC_TIMEOUT);
 441
 442                 /* Store bTag (in case we need to abort) */
 443                 data->bTag_last_read = data->bTag;
 444
 445                 if (retval < 0) {
 446                         dev_err(dev, "Unable to read data, error %d\n", retval);
 447                         if (data->auto_abort)
 448                                 usbtmc_ioctl_abort_bulk_in(data);
 449                         goto exit;
 450                 }
 451
 452                 /* How many characters did the instrument send? */
 453                 n_characters = buffer[4] +
 454                                (buffer[5] << 8) +
 455                                (buffer[6] << 16) +
 456                                (buffer[7] << 24);
 457
 458                 /* Copy buffer to user space */
 459                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 460                         /* There must have been an addressing problem */
 461                         retval = -EFAULT;
 462                         goto exit;
 463                 }
 464
 465                 done += n_characters;
 466                 if (n_characters < USBTMC_SIZE_IOBUFFER)
 467                         remaining = 0;
 468         }
 469
 470         /* Update file position value */
 471         *f_pos = *f_pos + done;
 472         retval = done;
 473
 474 exit:
 475         mutex_unlock(&data->io_mutex);
 476         kfree(buffer);
 477         return retval;
 478 }
 479
 480 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 481                             size_t count, loff_t *f_pos)
 482 {
 483         struct usbtmc_device_data *data;
 484         u8 *buffer;
 485         int retval;
 486         int actual;
 487         unsigned long int n_bytes;
 488         int remaining;
 489         int done;
 490         int this_part;
 491
 492         data = filp->private_data;
 493
 494         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 495         if (!buffer)
 496                 return -ENOMEM;
 497
 498         mutex_lock(&data->io_mutex);
 499
 500         remaining = count;
 501         done = 0;
 502
 503         while (remaining > 0) {
 504                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 505                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 506                         buffer[8] = 0;
 507                 } else {
 508                         this_part = remaining;
 509                         buffer[8] = 1;
 510                 }
 511
 512                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 513                 buffer[0] = 1;
 514                 buffer[1] = data->bTag;
 515                 buffer[2] = ~(data->bTag);
 516                 buffer[3] = 0; /* Reserved */
 517                 buffer[4] = this_part & 255;
 518                 buffer[5] = (this_part >> 8) & 255;
 519                 buffer[6] = (this_part >> 16) & 255;
 520                 buffer[7] = (this_part >> 24) & 255;
 521                 /* buffer[8] is set above... */
 522                 buffer[9] = 0; /* Reserved */
 523                 buffer[10] = 0; /* Reserved */
 524                 buffer[11] = 0; /* Reserved */
 525
 526                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 527                         retval = -EFAULT;
 528                         goto exit;
 529                 }
 530
 531                 n_bytes = roundup(12 + this_part, 4);
 532                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 533
 534                 retval = usb_bulk_msg(data->usb_dev,
 535                                       usb_sndbulkpipe(data->usb_dev,
 536                                                       data->bulk_out),
 537                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 538
 539                 data->bTag_last_write = data->bTag;
 540                 data->bTag++;
 541
 542                 if (!data->bTag)
 543                         data->bTag++;
 544
 545                 if (retval < 0) {
 546                         dev_err(&data->intf->dev,
 547                                 "Unable to send data, error %d\n", retval);
 548                         if (data->auto_abort)
 549                                 usbtmc_ioctl_abort_bulk_out(data);
 550                         goto exit;
 551                 }
 552
 553                 remaining -= this_part;
 554                 done += this_part;
 555         }
 556
 557         retval = count;
 558 exit:
 559         mutex_unlock(&data->io_mutex);
 560         kfree(buffer);
 561         return retval;
 562 }
 563
 564 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 565 {
 566         struct usb_host_interface *current_setting;
 567         struct usb_endpoint_descriptor *desc;
 568         struct device *dev;
 569         u8 *buffer;
 570         int rv;
 571         int n;
 572         int actual;
 573         int max_size;
 574
 575         dev = &data->intf->dev;
 576
 577         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 578
 579         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 580         if (!buffer)
 581                 return -ENOMEM;
 582
 583         rv = usb_control_msg(data->usb_dev,
 584                              usb_rcvctrlpipe(data->usb_dev, 0),
 585                              USBTMC_REQUEST_INITIATE_CLEAR,
 586                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 587                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 588         if (rv < 0) {
 589                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 590                 goto exit;
 591         }
 592
 593         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 594
 595         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 596                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 597                 rv = -EPERM;
 598                 goto exit;
 599         }
 600
 601         max_size = 0;
 602         current_setting = data->intf->cur_altsetting;
 603         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 604                 desc = &current_setting->endpoint[n].desc;
 605                 if (desc->bEndpointAddress == data->bulk_in)
 606                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 607         }
 608
 609         if (max_size == 0) {
 610                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 611                 rv = -EPERM;
 612                 goto exit;
 613         }
 614
 615         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 616
 617         n = 0;
 618
 619 usbtmc_clear_check_status:
 620
 621         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 622
 623         rv = usb_control_msg(data->usb_dev,
 624                              usb_rcvctrlpipe(data->usb_dev, 0),
 625                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 626                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 627                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 628         if (rv < 0) {
 629                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 630                 goto exit;
 631         }
 632
 633         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 634
 635         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 636                 goto usbtmc_clear_bulk_out_halt;
 637
 638         if (buffer[0] != USBTMC_STATUS_PENDING) {
 639                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 640                 rv = -EPERM;
 641                 goto exit;
 642         }
 643
 644         if (buffer[1] == 1)
 645                 do {
 646                         dev_dbg(dev, "Reading from bulk in EP\n");
 647
 648                         rv = usb_bulk_msg(data->usb_dev,
 649                                           usb_rcvbulkpipe(data->usb_dev,
 650                                                           data->bulk_in),
 651                                           buffer, USBTMC_SIZE_IOBUFFER,
 652                                           &actual, USBTMC_TIMEOUT);
 653                         n++;
 654
 655                         if (rv < 0) {
 656                                 dev_err(dev, "usb_control_msg returned %d\n",
 657                                         rv);
 658                                 goto exit;
 659                         }
 660                 } while ((actual == max_size) &&
 661                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 662
 663         if (actual == max_size) {
 664                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 665                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 666                 rv = -EPERM;
 667                 goto exit;
 668         }
 669
 670         goto usbtmc_clear_check_status;
 671
 672 usbtmc_clear_bulk_out_halt:
 673
 674         rv = usb_control_msg(data->usb_dev,
 675                              usb_sndctrlpipe(data->usb_dev, 0),
 676                              USB_REQ_CLEAR_FEATURE,
 677                              USB_DIR_OUT | USB_TYPE_STANDARD |
 678                              USB_RECIP_ENDPOINT,
 679                              USB_ENDPOINT_HALT,
 680                              data->bulk_out, buffer, 0,
 681                              USBTMC_TIMEOUT);
 682         if (rv < 0) {
 683                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 684                 goto exit;
 685         }
 686         rv = 0;
 687
 688 exit:
 689         kfree(buffer);
 690         return rv;
 691 }
 692
 693 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 694 {
 695         u8 *buffer;
 696         int rv;
 697
 698         buffer = kmalloc(2, GFP_KERNEL);
 699         if (!buffer)
 700                 return -ENOMEM;
 701
 702         rv = usb_control_msg(data->usb_dev,
 703                              usb_sndctrlpipe(data->usb_dev, 0),
 704                              USB_REQ_CLEAR_FEATURE,
 705                              USB_DIR_OUT | USB_TYPE_STANDARD |
 706                              USB_RECIP_ENDPOINT,
 707                              USB_ENDPOINT_HALT, data->bulk_out,
 708                              buffer, 0, USBTMC_TIMEOUT);
 709
 710         if (rv < 0) {
 711                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 712                         rv);
 713                 goto exit;
 714         }
 715         rv = 0;
 716
 717 exit:
 718         kfree(buffer);
 719         return rv;
 720 }
 721
 722 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 723 {
 724         u8 *buffer;
 725         int rv;
 726
 727         buffer = kmalloc(2, GFP_KERNEL);
 728         if (!buffer)
 729                 return -ENOMEM;
 730
 731         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 732                              USB_REQ_CLEAR_FEATURE,
 733                              USB_DIR_OUT | USB_TYPE_STANDARD |
 734                              USB_RECIP_ENDPOINT,
 735                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 736                              USBTMC_TIMEOUT);
 737
 738         if (rv < 0) {
 739                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 740                         rv);
 741                 goto exit;
 742         }
 743         rv = 0;
 744
 745 exit:
 746         kfree(buffer);
 747         return rv;
 748 }
 749
 750 static int get_capabilities(struct usbtmc_device_data *data)
 751 {
 752         struct device *dev = &data->usb_dev->dev;
 753         char *buffer;
 754         int rv = 0;
 755
 756         buffer = kmalloc(0x18, GFP_KERNEL);
 757         if (!buffer)
 758                 return -ENOMEM;
 759
 760         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 761                              USBTMC_REQUEST_GET_CAPABILITIES,
 762                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 763                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 764         if (rv < 0) {
 765                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 766                 goto err_out;
 767         }
 768
 769         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 770         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 771         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 772         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 773         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 774         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 775                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 776                 rv = -EPERM;
 777                 goto err_out;
 778         }
 779
 780         data->capabilities.interface_capabilities = buffer[4];
 781         data->capabilities.device_capabilities = buffer[5];
 782         data->capabilities.usb488_interface_capabilities = buffer[14];
 783         data->capabilities.usb488_device_capabilities = buffer[15];
 784
 785 err_out:
 786         kfree(buffer);
 787         return rv;
 788 }
 789
 790 #define capability_attribute(name)                                      \
 791 static ssize_t show_##name(struct device *dev,                          \
 792                            struct device_attribute *attr, char *buf)    \
 793 {                                                                       \
 794         struct usb_interface *intf = to_usb_interface(dev);             \
 795         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 796                                                                         \
 797         return sprintf(buf, "%d\n", data->capabilities.name);           \
 798 }                                                                       \
 799 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 800
 801 capability_attribute(interface_capabilities);
 802 capability_attribute(device_capabilities);
 803 capability_attribute(usb488_interface_capabilities);
 804 capability_attribute(usb488_device_capabilities);
 805
 806 static struct attribute *capability_attrs[] = {
 807         &dev_attr_interface_capabilities.attr,
 808         &dev_attr_device_capabilities.attr,
 809         &dev_attr_usb488_interface_capabilities.attr,
 810         &dev_attr_usb488_device_capabilities.attr,
 811         NULL,
 812 };
 813
 814 static struct attribute_group capability_attr_grp = {
 815         .attrs = capability_attrs,
 816 };
 817
 818 static ssize_t show_TermChar(struct device *dev,
 819                              struct device_attribute *attr, char *buf)
 820 {
 821         struct usb_interface *intf = to_usb_interface(dev);
 822         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 823
 824         return sprintf(buf, "%c\n", data->TermChar);
 825 }
 826
 827 static ssize_t store_TermChar(struct device *dev,
 828                               struct device_attribute *attr,
 829                               const char *buf, size_t count)
 830 {
 831         struct usb_interface *intf = to_usb_interface(dev);
 832         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 833
 834         if (count < 1)
 835                 return -EINVAL;
 836         data->TermChar = buf[0];
 837         return count;
 838 }
 839 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 840
 841 #define data_attribute(name)                                            \
 842 static ssize_t show_##name(struct device *dev,                          \
 843                            struct device_attribute *attr, char *buf)    \
 844 {                                                                       \
 845         struct usb_interface *intf = to_usb_interface(dev);             \
 846         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 847                                                                         \
 848         return sprintf(buf, "%d\n", data->name);                        \
 849 }                                                                       \
 850 static ssize_t store_##name(struct device *dev,                         \
 851                             struct device_attribute *attr,              \
 852                             const char *buf, size_t count)              \
 853 {                                                                       \
 854         struct usb_interface *intf = to_usb_interface(dev);             \
 855         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 856         ssize_t result;                                                 \
 857         unsigned val;                                                   \
 858                                                                         \
 859         result = sscanf(buf, "%u\n", &val);                             \
 860         if (result != 1)                                                \
 861                 result = -EINVAL;                                       \
 862         data->name = val;                                               \
 863         if (result < 0)                                                 \
 864                 return result;                                          \
 865         else                                                            \
 866                 return count;                                           \
 867 }                                                                       \
 868 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 869
 870 data_attribute(TermCharEnabled);
 871 data_attribute(auto_abort);
 872
 873 static struct attribute *data_attrs[] = {
 874         &dev_attr_TermChar.attr,
 875         &dev_attr_TermCharEnabled.attr,
 876         &dev_attr_auto_abort.attr,
 877         NULL,
 878 };
 879
 880 static struct attribute_group data_attr_grp = {
 881         .attrs = data_attrs,
 882 };
 883
 884 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 885 {
 886         struct device *dev;
 887         u8 *buffer;
 888         int rv;
 889
 890         dev = &data->intf->dev;
 891
 892         buffer = kmalloc(2, GFP_KERNEL);
 893         if (!buffer)
 894                 return -ENOMEM;
 895
 896         rv = usb_control_msg(data->usb_dev,
 897                              usb_rcvctrlpipe(data->usb_dev, 0),
 898                              USBTMC_REQUEST_INDICATOR_PULSE,
 899                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 900                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 901
 902         if (rv < 0) {
 903                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 904                 goto exit;
 905         }
 906
 907         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 908
 909         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 910                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 911                 rv = -EPERM;
 912                 goto exit;
 913         }
 914         rv = 0;
 915
 916 exit:
 917         kfree(buffer);
 918         return rv;
 919 }
 920
 921 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 922 {
 923         struct usbtmc_device_data *data;
 924         int retval = -EBADRQC;
 925
 926         data = file->private_data;
 927         mutex_lock(&data->io_mutex);
 928
 929         switch (cmd) {
 930         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 931                 retval = usbtmc_ioctl_clear_out_halt(data);
 932                 break;
 933
 934         case USBTMC_IOCTL_CLEAR_IN_HALT:
 935                 retval = usbtmc_ioctl_clear_in_halt(data);
 936                 break;
 937
 938         case USBTMC_IOCTL_INDICATOR_PULSE:
 939                 retval = usbtmc_ioctl_indicator_pulse(data);
 940                 break;
 941
 942         case USBTMC_IOCTL_CLEAR:
 943                 retval = usbtmc_ioctl_clear(data);
 944                 break;
 945
 946         case USBTMC_IOCTL_ABORT_BULK_OUT:
 947                 retval = usbtmc_ioctl_abort_bulk_out(data);
 948                 break;
 949
 950         case USBTMC_IOCTL_ABORT_BULK_IN:
 951                 retval = usbtmc_ioctl_abort_bulk_in(data);
 952                 break;
 953         }
 954
 955         mutex_unlock(&data->io_mutex);
 956         return retval;
 957 }
 958
 959 static struct file_operations fops = {
 960         .owner          = THIS_MODULE,
 961         .read           = usbtmc_read,
 962         .write          = usbtmc_write,
 963         .open           = usbtmc_open,
 964         .release        = usbtmc_release,
 965         .unlocked_ioctl = usbtmc_ioctl,
 966 };
 967
 968 static struct usb_class_driver usbtmc_class = {
 969         .name =         "usbtmc%d",
 970         .fops =         &fops,
 971         .minor_base =   USBTMC_MINOR_BASE,
 972 };
 973
 974
 975 static int usbtmc_probe(struct usb_interface *intf,
 976                         const struct usb_device_id *id)
 977 {
 978         struct usbtmc_device_data *data;
 979         struct usb_host_interface *iface_desc;
 980         struct usb_endpoint_descriptor *endpoint;
 981         int n;
 982         int retcode;
 983
 984         dev_dbg(&intf->dev, "%s called\n", __func__);
 985
 986         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
 987         if (!data) {
 988                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
 989                 return -ENOMEM;
 990         }
 991
 992         data->intf = intf;
 993         data->id = id;
 994         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
 995         usb_set_intfdata(intf, data);
 996         kref_init(&data->kref);
 997         mutex_init(&data->io_mutex);
 998
 999         /* Initialize USBTMC bTag and other fields */
1000         data->bTag      = 1;
1001         data->TermCharEnabled = 0;
1002         data->TermChar = '\n';
1003
1004         /* USBTMC devices have only one setting, so use that */
1005         iface_desc = data->intf->cur_altsetting;
1006
1007         /* Find bulk in endpoint */
1008         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1009                 endpoint = &iface_desc->endpoint[n].desc;
1010
1011                 if (usb_endpoint_is_bulk_in(endpoint)) {
1012                         data->bulk_in = endpoint->bEndpointAddress;
1013                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1014                                 data->bulk_in);
1015                         break;
1016                 }
1017         }
1018
1019         /* Find bulk out endpoint */
1020         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1021                 endpoint = &iface_desc->endpoint[n].desc;
1022
1023                 if (usb_endpoint_is_bulk_out(endpoint)) {
1024                         data->bulk_out = endpoint->bEndpointAddress;
1025                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1026                                 data->bulk_out);
1027                         break;
1028                 }
1029         }
1030
1031         retcode = get_capabilities(data);
1032         if (retcode)
1033                 dev_err(&intf->dev, "can't read capabilities\n");
1034         else
1035                 retcode = sysfs_create_group(&intf->dev.kobj,
1036                                              &capability_attr_grp);
1037
1038         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1039
1040         retcode = usb_register_dev(intf, &usbtmc_class);
1041         if (retcode) {
1042                 dev_err(&intf->dev, "Not able to get a minor"
1043                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1044                         retcode);
1045                 goto error_register;
1046         }
1047         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1048
1049         return 0;
1050
1051 error_register:
1052         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1053         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1054         kref_put(&data->kref, usbtmc_delete);
1055         return retcode;
1056 }
1057
1058 static void usbtmc_disconnect(struct usb_interface *intf)
1059 {
1060         struct usbtmc_device_data *data;
1061
1062         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1063
1064         data = usb_get_intfdata(intf);
1065         usb_deregister_dev(intf, &usbtmc_class);
1066         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1067         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1068         kref_put(&data->kref, usbtmc_delete);
1069 }
1070
1071 static struct usb_driver usbtmc_driver = {
1072         .name           = "usbtmc",
1073         .id_table       = usbtmc_devices,
1074         .probe          = usbtmc_probe,
1075         .disconnect     = usbtmc_disconnect
1076 };
1077
1078 static int __init usbtmc_init(void)
1079 {
1080         int retcode;
1081
1082         retcode = usb_register(&usbtmc_driver);
1083         if (retcode)
1084                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1085         return retcode;
1086 }
1087 module_init(usbtmc_init);
1088
1089 static void __exit usbtmc_exit(void)
1090 {
1091         usb_deregister(&usbtmc_driver);
1092 }
1093 module_exit(usbtmc_exit);
1094
1095 MODULE_LICENSE("GPL");