git.oblomov.eu Git - linux-2.6/blob - 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/fs.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/kref.h>
  27 #include <linux/mutex.h>
  28 #include <linux/usb.h>
  29 #include <linux/usb/tmc.h>
  30
  31
  32 #define USBTMC_MINOR_BASE       176
  33
  34 /*
  35  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  36  * large as wMaxPacketSize (which is usually 512 bytes).
  37  */
  38 #define USBTMC_SIZE_IOBUFFER    2048
  39
  40 /* Default USB timeout (in milliseconds) */
  41 #define USBTMC_TIMEOUT          10
  42
  43 /*
  44  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  45  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  46  * packet is never read.
  47  */
  48 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  49
  50 static struct usb_device_id usbtmc_devices[] = {
  51         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  52         { 0, } /* terminating entry */
  53 };
  54 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  55
  56 /*
  57  * This structure is the capabilities for the device
  58  * See section 4.2.1.8 of the USBTMC specification for details.
  59  */
  60 struct usbtmc_dev_capabilities {
  61         __u8 interface_capabilities;
  62         __u8 device_capabilities;
  63         __u8 usb488_interface_capabilities;
  64         __u8 usb488_device_capabilities;
  65 };
  66
  67 /* This structure holds private data for each USBTMC device. One copy is
  68  * allocated for each USBTMC device in the driver's probe function.
  69  */
  70 struct usbtmc_device_data {
  71         const struct usb_device_id *id;
  72         struct usb_device *usb_dev;
  73         struct usb_interface *intf;
  74
  75         unsigned int bulk_in;
  76         unsigned int bulk_out;
  77
  78         u8 bTag;
  79         u8 bTag_last_write;     /* needed for abort */
  80         u8 bTag_last_read;      /* needed for abort */
  81
  82         /* attributes from the USB TMC spec for this device */
  83         u8 TermChar;
  84         bool TermCharEnabled;
  85         bool auto_abort;
  86
  87         struct usbtmc_dev_capabilities  capabilities;
  88         struct kref kref;
  89         struct mutex io_mutex;  /* only one i/o function running at a time */
  90 };
  91 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  92
  93 /* Forward declarations */
  94 static struct usb_driver usbtmc_driver;
  95
  96 static void usbtmc_delete(struct kref *kref)
  97 {
  98         struct usbtmc_device_data *data = to_usbtmc_data(kref);
  99
 100         usb_put_dev(data->usb_dev);
 101         kfree(data);
 102 }
 103
 104 static int usbtmc_open(struct inode *inode, struct file *filp)
 105 {
 106         struct usb_interface *intf;
 107         struct usbtmc_device_data *data;
 108         int retval = -ENODEV;
 109
 110         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 111         if (!intf) {
 112                 printk(KERN_ERR KBUILD_MODNAME
 113                        ": can not find device for minor %d", iminor(inode));
 114                 goto exit;
 115         }
 116
 117         data = usb_get_intfdata(intf);
 118         kref_get(&data->kref);
 119
 120         /* Store pointer in file structure's private data field */
 121         filp->private_data = data;
 122
 123 exit:
 124         return retval;
 125 }
 126
 127 static int usbtmc_release(struct inode *inode, struct file *file)
 128 {
 129         struct usbtmc_device_data *data = file->private_data;
 130
 131         kref_put(&data->kref, usbtmc_delete);
 132         return 0;
 133 }
 134
 135 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 136 {
 137         u8 *buffer;
 138         struct device *dev;
 139         int rv;
 140         int n;
 141         int actual;
 142         struct usb_host_interface *current_setting;
 143         int max_size;
 144
 145         dev = &data->intf->dev;
 146         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 147         if (!buffer)
 148                 return -ENOMEM;
 149
 150         rv = usb_control_msg(data->usb_dev,
 151                              usb_rcvctrlpipe(data->usb_dev, 0),
 152                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 153                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 154                              data->bTag_last_read, data->bulk_in,
 155                              buffer, 2, USBTMC_TIMEOUT);
 156
 157         if (rv < 0) {
 158                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 159                 goto exit;
 160         }
 161
 162         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 163
 164         if (buffer[0] == USBTMC_STATUS_FAILED) {
 165                 rv = 0;
 166                 goto exit;
 167         }
 168
 169         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 170                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 171                         buffer[0]);
 172                 rv = -EPERM;
 173                 goto exit;
 174         }
 175
 176         max_size = 0;
 177         current_setting = data->intf->cur_altsetting;
 178         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 179                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 180                         data->bulk_in)
 181                         max_size = le16_to_cpu(current_setting->endpoint[n].
 182                                                 desc.wMaxPacketSize);
 183
 184         if (max_size == 0) {
 185                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 186                 rv = -EPERM;
 187                 goto exit;
 188         }
 189
 190         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 191
 192         n = 0;
 193
 194         do {
 195                 dev_dbg(dev, "Reading from bulk in EP\n");
 196
 197                 rv = usb_bulk_msg(data->usb_dev,
 198                                   usb_rcvbulkpipe(data->usb_dev,
 199                                                   data->bulk_in),
 200                                   buffer, USBTMC_SIZE_IOBUFFER,
 201                                   &actual, USBTMC_TIMEOUT);
 202
 203                 n++;
 204
 205                 if (rv < 0) {
 206                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 207                         goto exit;
 208                 }
 209         } while ((actual == max_size) &&
 210                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 211
 212         if (actual == max_size) {
 213                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 214                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 215                 rv = -EPERM;
 216                 goto exit;
 217         }
 218
 219         n = 0;
 220
 221 usbtmc_abort_bulk_in_status:
 222         rv = usb_control_msg(data->usb_dev,
 223                              usb_rcvctrlpipe(data->usb_dev, 0),
 224                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 225                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 226                              0, data->bulk_in, buffer, 0x08,
 227                              USBTMC_TIMEOUT);
 228
 229         if (rv < 0) {
 230                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 231                 goto exit;
 232         }
 233
 234         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 235
 236         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 237                 rv = 0;
 238                 goto exit;
 239         }
 240
 241         if (buffer[0] != USBTMC_STATUS_PENDING) {
 242                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 243                 rv = -EPERM;
 244                 goto exit;
 245         }
 246
 247         if (buffer[1] == 1)
 248                 do {
 249                         dev_dbg(dev, "Reading from bulk in EP\n");
 250
 251                         rv = usb_bulk_msg(data->usb_dev,
 252                                           usb_rcvbulkpipe(data->usb_dev,
 253                                                           data->bulk_in),
 254                                           buffer, USBTMC_SIZE_IOBUFFER,
 255                                           &actual, USBTMC_TIMEOUT);
 256
 257                         n++;
 258
 259                         if (rv < 0) {
 260                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 261                                 goto exit;
 262                         }
 263                 } while ((actual = max_size) &&
 264                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 265
 266         if (actual == max_size) {
 267                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 268                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 269                 rv = -EPERM;
 270                 goto exit;
 271         }
 272
 273         goto usbtmc_abort_bulk_in_status;
 274
 275 exit:
 276         kfree(buffer);
 277         return rv;
 278
 279 }
 280
 281 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 282 {
 283         struct device *dev;
 284         u8 *buffer;
 285         int rv;
 286         int n;
 287
 288         dev = &data->intf->dev;
 289
 290         buffer = kmalloc(8, GFP_KERNEL);
 291         if (!buffer)
 292                 return -ENOMEM;
 293
 294         rv = usb_control_msg(data->usb_dev,
 295                              usb_rcvctrlpipe(data->usb_dev, 0),
 296                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 297                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 298                              data->bTag_last_write, data->bulk_out,
 299                              buffer, 2, USBTMC_TIMEOUT);
 300
 301         if (rv < 0) {
 302                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 303                 goto exit;
 304         }
 305
 306         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 307
 308         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 309                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 310                         buffer[0]);
 311                 rv = -EPERM;
 312                 goto exit;
 313         }
 314
 315         n = 0;
 316
 317 usbtmc_abort_bulk_out_check_status:
 318         rv = usb_control_msg(data->usb_dev,
 319                              usb_rcvctrlpipe(data->usb_dev, 0),
 320                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 321                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 322                              0, data->bulk_out, buffer, 0x08,
 323                              USBTMC_TIMEOUT);
 324         n++;
 325         if (rv < 0) {
 326                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 327                 goto exit;
 328         }
 329
 330         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 331
 332         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 333                 goto usbtmc_abort_bulk_out_clear_halt;
 334
 335         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 336             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 337                 goto usbtmc_abort_bulk_out_check_status;
 338
 339         rv = -EPERM;
 340         goto exit;
 341
 342 usbtmc_abort_bulk_out_clear_halt:
 343         rv = usb_control_msg(data->usb_dev,
 344                              usb_sndctrlpipe(data->usb_dev, 0),
 345                              USB_REQ_CLEAR_FEATURE,
 346                              USB_DIR_OUT | USB_TYPE_STANDARD |
 347                              USB_RECIP_ENDPOINT,
 348                              USB_ENDPOINT_HALT, data->bulk_out, buffer,
 349                              0, USBTMC_TIMEOUT);
 350
 351         if (rv < 0) {
 352                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 353                 goto exit;
 354         }
 355         rv = 0;
 356
 357 exit:
 358         kfree(buffer);
 359         return rv;
 360 }
 361
 362 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 363                            size_t count, loff_t *f_pos)
 364 {
 365         struct usbtmc_device_data *data;
 366         struct device *dev;
 367         unsigned long int n_characters;
 368         u8 *buffer;
 369         int actual;
 370         int done;
 371         int remaining;
 372         int retval;
 373         int this_part;
 374
 375         /* Get pointer to private data structure */
 376         data = filp->private_data;
 377         dev = &data->intf->dev;
 378
 379         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 380         if (!buffer)
 381                 return -ENOMEM;
 382
 383         mutex_lock(&data->io_mutex);
 384
 385         remaining = count;
 386         done = 0;
 387
 388         while (remaining > 0) {
 389                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 390                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 391                 else
 392                         this_part = remaining;
 393
 394                 /* Setup IO buffer for DEV_DEP_MSG_IN message
 395                  * Refer to class specs for details
 396                  */
 397                 buffer[0] = 2;
 398                 buffer[1] = data->bTag;
 399                 buffer[2] = ~(data->bTag);
 400                 buffer[3] = 0; /* Reserved */
 401                 buffer[4] = (this_part - 12 - 3) & 255;
 402                 buffer[5] = ((this_part - 12 - 3) >> 8) & 255;
 403                 buffer[6] = ((this_part - 12 - 3) >> 16) & 255;
 404                 buffer[7] = ((this_part - 12 - 3) >> 24) & 255;
 405                 buffer[8] = data->TermCharEnabled * 2;
 406                 /* Use term character? */
 407                 buffer[9] = data->TermChar;
 408                 buffer[10] = 0; /* Reserved */
 409                 buffer[11] = 0; /* Reserved */
 410
 411                 /* Send bulk URB */
 412                 retval = usb_bulk_msg(data->usb_dev,
 413                                       usb_sndbulkpipe(data->usb_dev,
 414                                                       data->bulk_out),
 415                                       buffer, 12, &actual, USBTMC_TIMEOUT);
 416
 417                 /* Store bTag (in case we need to abort) */
 418                 data->bTag_last_write = data->bTag;
 419
 420                 /* Increment bTag -- and increment again if zero */
 421                 data->bTag++;
 422                 if (!data->bTag)
 423                         (data->bTag)++;
 424
 425                 if (retval < 0) {
 426                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 427                         if (data->auto_abort)
 428                                 usbtmc_ioctl_abort_bulk_out(data);
 429                         goto exit;
 430                 }
 431
 432                 /* Send bulk URB */
 433                 retval = usb_bulk_msg(data->usb_dev,
 434                                       usb_rcvbulkpipe(data->usb_dev,
 435                                                       data->bulk_in),
 436                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 437                                       USBTMC_TIMEOUT);
 438
 439                 /* Store bTag (in case we need to abort) */
 440                 data->bTag_last_read = data->bTag;
 441
 442                 if (retval < 0) {
 443                         dev_err(dev, "Unable to read data, error %d\n", retval);
 444                         if (data->auto_abort)
 445                                 usbtmc_ioctl_abort_bulk_in(data);
 446                         goto exit;
 447                 }
 448
 449                 /* How many characters did the instrument send? */
 450                 n_characters = buffer[4] +
 451                                (buffer[5] << 8) +
 452                                (buffer[6] << 16) +
 453                                (buffer[7] << 24);
 454
 455                 /* Copy buffer to user space */
 456                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 457                         /* There must have been an addressing problem */
 458                         retval = -EFAULT;
 459                         goto exit;
 460                 }
 461
 462                 done += n_characters;
 463                 if (n_characters < USBTMC_SIZE_IOBUFFER)
 464                         remaining = 0;
 465         }
 466
 467         /* Update file position value */
 468         *f_pos = *f_pos + done;
 469         retval = done;
 470
 471 exit:
 472         mutex_unlock(&data->io_mutex);
 473         kfree(buffer);
 474         return retval;
 475 }
 476
 477 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 478                             size_t count, loff_t *f_pos)
 479 {
 480         struct usbtmc_device_data *data;
 481         u8 *buffer;
 482         int retval;
 483         int actual;
 484         unsigned long int n_bytes;
 485         int n;
 486         int remaining;
 487         int done;
 488         int this_part;
 489
 490         data = filp->private_data;
 491
 492         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 493         if (!buffer)
 494                 return -ENOMEM;
 495
 496         mutex_lock(&data->io_mutex);
 497
 498         remaining = count;
 499         done = 0;
 500
 501         while (remaining > 0) {
 502                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 503                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 504                         buffer[8] = 0;
 505                 } else {
 506                         this_part = remaining;
 507                         buffer[8] = 1;
 508                 }
 509
 510                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 511                 buffer[0] = 1;
 512                 buffer[1] = data->bTag;
 513                 buffer[2] = ~(data->bTag);
 514                 buffer[3] = 0; /* Reserved */
 515                 buffer[4] = this_part & 255;
 516                 buffer[5] = (this_part >> 8) & 255;
 517                 buffer[6] = (this_part >> 16) & 255;
 518                 buffer[7] = (this_part >> 24) & 255;
 519                 /* buffer[8] is set above... */
 520                 buffer[9] = 0; /* Reserved */
 521                 buffer[10] = 0; /* Reserved */
 522                 buffer[11] = 0; /* Reserved */
 523
 524                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 525                         retval = -EFAULT;
 526                         goto exit;
 527                 }
 528
 529                 n_bytes = 12 + this_part;
 530                 if (this_part % 4)
 531                         n_bytes += 4 - this_part % 4;
 532                         for (n = 12 + this_part; n < n_bytes; n++)
 533                                 buffer[n] = 0;
 534
 535                 retval = usb_bulk_msg(data->usb_dev,
 536                                       usb_sndbulkpipe(data->usb_dev,
 537                                                       data->bulk_out),
 538                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 539
 540                 data->bTag_last_write = data->bTag;
 541                 data->bTag++;
 542
 543                 if (!data->bTag)
 544                         data->bTag++;
 545
 546                 if (retval < 0) {
 547                         dev_err(&data->intf->dev,
 548                                 "Unable to send data, error %d\n", retval);
 549                         if (data->auto_abort)
 550                                 usbtmc_ioctl_abort_bulk_out(data);
 551                         goto exit;
 552                 }
 553
 554                 remaining -= this_part;
 555                 done += this_part;
 556         }
 557
 558         retval = count;
 559 exit:
 560         mutex_unlock(&data->io_mutex);
 561         kfree(buffer);
 562         return retval;
 563 }
 564
 565 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 566 {
 567         struct usb_host_interface *current_setting;
 568         struct usb_endpoint_descriptor *desc;
 569         struct device *dev;
 570         u8 *buffer;
 571         int rv;
 572         int n;
 573         int actual;
 574         int max_size;
 575
 576         dev = &data->intf->dev;
 577
 578         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 579
 580         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 581         if (!buffer)
 582                 return -ENOMEM;
 583
 584         rv = usb_control_msg(data->usb_dev,
 585                              usb_rcvctrlpipe(data->usb_dev, 0),
 586                              USBTMC_REQUEST_INITIATE_CLEAR,
 587                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 588                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 589         if (rv < 0) {
 590                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 591                 goto exit;
 592         }
 593
 594         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 595
 596         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 597                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 598                 rv = -EPERM;
 599                 goto exit;
 600         }
 601
 602         max_size = 0;
 603         current_setting = data->intf->cur_altsetting;
 604         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 605                 desc = &current_setting->endpoint[n].desc;
 606                 if (desc->bEndpointAddress == data->bulk_in)
 607                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 608         }
 609
 610         if (max_size == 0) {
 611                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 612                 rv = -EPERM;
 613                 goto exit;
 614         }
 615
 616         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 617
 618         n = 0;
 619
 620 usbtmc_clear_check_status:
 621
 622         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 623
 624         rv = usb_control_msg(data->usb_dev,
 625                              usb_rcvctrlpipe(data->usb_dev, 0),
 626                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 627                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 628                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 629         if (rv < 0) {
 630                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 631                 goto exit;
 632         }
 633
 634         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 635
 636         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 637                 goto usbtmc_clear_bulk_out_halt;
 638
 639         if (buffer[0] != USBTMC_STATUS_PENDING) {
 640                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 641                 rv = -EPERM;
 642                 goto exit;
 643         }
 644
 645         if (buffer[1] == 1)
 646                 do {
 647                         dev_dbg(dev, "Reading from bulk in EP\n");
 648
 649                         rv = usb_bulk_msg(data->usb_dev,
 650                                           usb_rcvbulkpipe(data->usb_dev,
 651                                                           data->bulk_in),
 652                                           buffer, USBTMC_SIZE_IOBUFFER,
 653                                           &actual, USBTMC_TIMEOUT);
 654                         n++;
 655
 656                         if (rv < 0) {
 657                                 dev_err(dev, "usb_control_msg returned %d\n",
 658                                         rv);
 659                                 goto exit;
 660                         }
 661                 } while ((actual == max_size) &&
 662                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 663
 664         if (actual == max_size) {
 665                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 666                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 667                 rv = -EPERM;
 668                 goto exit;
 669         }
 670
 671         goto usbtmc_clear_check_status;
 672
 673 usbtmc_clear_bulk_out_halt:
 674
 675         rv = usb_control_msg(data->usb_dev,
 676                              usb_sndctrlpipe(data->usb_dev, 0),
 677                              USB_REQ_CLEAR_FEATURE,
 678                              USB_DIR_OUT | USB_TYPE_STANDARD |
 679                              USB_RECIP_ENDPOINT,
 680                              USB_ENDPOINT_HALT,
 681                              data->bulk_out, buffer, 0,
 682                              USBTMC_TIMEOUT);
 683         if (rv < 0) {
 684                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 685                 goto exit;
 686         }
 687         rv = 0;
 688
 689 exit:
 690         kfree(buffer);
 691         return rv;
 692 }
 693
 694 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 695 {
 696         u8 *buffer;
 697         int rv;
 698
 699         buffer = kmalloc(2, GFP_KERNEL);
 700         if (!buffer)
 701                 return -ENOMEM;
 702
 703         rv = usb_control_msg(data->usb_dev,
 704                              usb_sndctrlpipe(data->usb_dev, 0),
 705                              USB_REQ_CLEAR_FEATURE,
 706                              USB_DIR_OUT | USB_TYPE_STANDARD |
 707                              USB_RECIP_ENDPOINT,
 708                              USB_ENDPOINT_HALT, data->bulk_out,
 709                              buffer, 0, USBTMC_TIMEOUT);
 710
 711         if (rv < 0) {
 712                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 713                         rv);
 714                 goto exit;
 715         }
 716         rv = 0;
 717
 718 exit:
 719         kfree(buffer);
 720         return rv;
 721 }
 722
 723 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 724 {
 725         u8 *buffer;
 726         int rv;
 727
 728         buffer = kmalloc(2, GFP_KERNEL);
 729         if (!buffer)
 730                 return -ENOMEM;
 731
 732         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 733                              USB_REQ_CLEAR_FEATURE,
 734                              USB_DIR_OUT | USB_TYPE_STANDARD |
 735                              USB_RECIP_ENDPOINT,
 736                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 737                              USBTMC_TIMEOUT);
 738
 739         if (rv < 0) {
 740                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 741                         rv);
 742                 goto exit;
 743         }
 744         rv = 0;
 745
 746 exit:
 747         kfree(buffer);
 748         return rv;
 749 }
 750
 751 static int get_capabilities(struct usbtmc_device_data *data)
 752 {
 753         struct device *dev = &data->usb_dev->dev;
 754         char *buffer;
 755         int rv;
 756
 757         buffer = kmalloc(0x18, GFP_KERNEL);
 758         if (!buffer)
 759                 return -ENOMEM;
 760
 761         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 762                              USBTMC_REQUEST_GET_CAPABILITIES,
 763                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 764                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 765         if (rv < 0) {
 766                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 767                 return rv;
 768         }
 769
 770         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 771         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 772         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 773         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 774         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 775         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 776                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 777                 return -EPERM;
 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         kfree(buffer);
 786         return 0;
 787 }
 788
 789 #define capability_attribute(name)                                      \
 790 static ssize_t show_##name(struct device *dev,                          \
 791                            struct device_attribute *attr, char *buf)    \
 792 {                                                                       \
 793         struct usb_interface *intf = to_usb_interface(dev);             \
 794         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 795                                                                         \
 796         return sprintf(buf, "%d\n", data->capabilities.name);           \
 797 }                                                                       \
 798 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 799
 800 capability_attribute(interface_capabilities);
 801 capability_attribute(device_capabilities);
 802 capability_attribute(usb488_interface_capabilities);
 803 capability_attribute(usb488_device_capabilities);
 804
 805 static struct attribute *capability_attrs[] = {
 806         &dev_attr_interface_capabilities.attr,
 807         &dev_attr_device_capabilities.attr,
 808         &dev_attr_usb488_interface_capabilities.attr,
 809         &dev_attr_usb488_device_capabilities.attr,
 810         NULL,
 811 };
 812
 813 static struct attribute_group capability_attr_grp = {
 814         .attrs = capability_attrs,
 815 };
 816
 817 static ssize_t show_TermChar(struct device *dev,
 818                              struct device_attribute *attr, char *buf)
 819 {
 820         struct usb_interface *intf = to_usb_interface(dev);
 821         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 822
 823         return sprintf(buf, "%c\n", data->TermChar);
 824 }
 825
 826 static ssize_t store_TermChar(struct device *dev,
 827                               struct device_attribute *attr,
 828                               const char *buf, size_t count)
 829 {
 830         struct usb_interface *intf = to_usb_interface(dev);
 831         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 832
 833         if (count < 1)
 834                 return -EINVAL;
 835         data->TermChar = buf[0];
 836         return count;
 837 }
 838 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 839
 840 #define data_attribute(name)                                            \
 841 static ssize_t show_##name(struct device *dev,                          \
 842                            struct device_attribute *attr, char *buf)    \
 843 {                                                                       \
 844         struct usb_interface *intf = to_usb_interface(dev);             \
 845         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 846                                                                         \
 847         return sprintf(buf, "%d\n", data->name);                        \
 848 }                                                                       \
 849 static ssize_t store_##name(struct device *dev,                         \
 850                             struct device_attribute *attr,              \
 851                             const char *buf, size_t count)              \
 852 {                                                                       \
 853         struct usb_interface *intf = to_usb_interface(dev);             \
 854         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 855         ssize_t result;                                                 \
 856         unsigned val;                                                   \
 857                                                                         \
 858         result = sscanf(buf, "%u\n", &val);                             \
 859         if (result != 1)                                                \
 860                 result = -EINVAL;                                       \
 861         data->name = val;                                               \
 862         if (result < 0)                                                 \
 863                 return result;                                          \
 864         else                                                            \
 865                 return count;                                           \
 866 }                                                                       \
 867 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 868
 869 data_attribute(TermCharEnabled);
 870 data_attribute(auto_abort);
 871
 872 static struct attribute *data_attrs[] = {
 873         &dev_attr_TermChar.attr,
 874         &dev_attr_TermCharEnabled.attr,
 875         &dev_attr_auto_abort.attr,
 876         NULL,
 877 };
 878
 879 static struct attribute_group data_attr_grp = {
 880         .attrs = data_attrs,
 881 };
 882
 883 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 884 {
 885         struct device *dev;
 886         u8 *buffer;
 887         int rv;
 888
 889         dev = &data->intf->dev;
 890
 891         buffer = kmalloc(2, GFP_KERNEL);
 892         if (!buffer)
 893                 return -ENOMEM;
 894
 895         rv = usb_control_msg(data->usb_dev,
 896                              usb_rcvctrlpipe(data->usb_dev, 0),
 897                              USBTMC_REQUEST_INDICATOR_PULSE,
 898                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 899                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 900
 901         if (rv < 0) {
 902                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 903                 goto exit;
 904         }
 905
 906         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 907
 908         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 909                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 910                 rv = -EPERM;
 911                 goto exit;
 912         }
 913         rv = 0;
 914
 915 exit:
 916         kfree(buffer);
 917         return rv;
 918 }
 919
 920 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 921 {
 922         struct usbtmc_device_data *data;
 923         int retval = -EBADRQC;
 924
 925         data = file->private_data;
 926         mutex_lock(&data->io_mutex);
 927
 928         switch (cmd) {
 929         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 930                 retval = usbtmc_ioctl_clear_out_halt(data);
 931
 932         case USBTMC_IOCTL_CLEAR_IN_HALT:
 933                 retval = usbtmc_ioctl_clear_in_halt(data);
 934
 935         case USBTMC_IOCTL_INDICATOR_PULSE:
 936                 retval = usbtmc_ioctl_indicator_pulse(data);
 937
 938         case USBTMC_IOCTL_CLEAR:
 939                 retval = usbtmc_ioctl_clear(data);
 940
 941         case USBTMC_IOCTL_ABORT_BULK_OUT:
 942                 retval = usbtmc_ioctl_abort_bulk_out(data);
 943
 944         case USBTMC_IOCTL_ABORT_BULK_IN:
 945                 retval = usbtmc_ioctl_abort_bulk_in(data);
 946         }
 947
 948         mutex_unlock(&data->io_mutex);
 949         return retval;
 950 }
 951
 952 static struct file_operations fops = {
 953         .owner          = THIS_MODULE,
 954         .read           = usbtmc_read,
 955         .write          = usbtmc_write,
 956         .open           = usbtmc_open,
 957         .release        = usbtmc_release,
 958         .unlocked_ioctl = usbtmc_ioctl,
 959 };
 960
 961 static struct usb_class_driver usbtmc_class = {
 962         .name =         "usbtmc%d",
 963         .fops =         &fops,
 964         .minor_base =   USBTMC_MINOR_BASE,
 965 };
 966
 967
 968 static int usbtmc_probe(struct usb_interface *intf,
 969                         const struct usb_device_id *id)
 970 {
 971         struct usbtmc_device_data *data;
 972         struct usb_host_interface *iface_desc;
 973         struct usb_endpoint_descriptor *endpoint;
 974         int n;
 975         int retcode;
 976
 977         dev_dbg(&intf->dev, "%s called\n", __func__);
 978
 979         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
 980         if (!data) {
 981                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
 982                 return -ENOMEM;
 983         }
 984
 985         data->intf = intf;
 986         data->id = id;
 987         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
 988         usb_set_intfdata(intf, data);
 989         kref_init(&data->kref);
 990         mutex_init(&data->io_mutex);
 991
 992         /* Initialize USBTMC bTag and other fields */
 993         data->bTag      = 1;
 994         data->TermCharEnabled = 0;
 995         data->TermChar = '\n';
 996
 997         /* USBTMC devices have only one setting, so use that */
 998         iface_desc = data->intf->cur_altsetting;
 999
1000         /* Find bulk in endpoint */
1001         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1002                 endpoint = &iface_desc->endpoint[n].desc;
1003
1004                 if (usb_endpoint_is_bulk_in(endpoint)) {
1005                         data->bulk_in = endpoint->bEndpointAddress;
1006                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1007                                 data->bulk_in);
1008                         break;
1009                 }
1010         }
1011
1012         /* Find bulk out endpoint */
1013         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1014                 endpoint = &iface_desc->endpoint[n].desc;
1015
1016                 if (usb_endpoint_is_bulk_out(endpoint)) {
1017                         data->bulk_out = endpoint->bEndpointAddress;
1018                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1019                                 data->bulk_out);
1020                         break;
1021                 }
1022         }
1023
1024         retcode = get_capabilities(data);
1025         if (retcode)
1026                 dev_err(&intf->dev, "can't read capabilities\n");
1027         else
1028                 retcode = sysfs_create_group(&intf->dev.kobj,
1029                                              &capability_attr_grp);
1030
1031         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1032
1033         retcode = usb_register_dev(intf, &usbtmc_class);
1034         if (retcode) {
1035                 dev_err(&intf->dev, "Not able to get a minor"
1036                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1037                         retcode);
1038                 goto error_register;
1039         }
1040         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1041
1042         return 0;
1043
1044 error_register:
1045         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1046         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1047         kref_put(&data->kref, usbtmc_delete);
1048         return retcode;
1049 }
1050
1051 static void usbtmc_disconnect(struct usb_interface *intf)
1052 {
1053         struct usbtmc_device_data *data;
1054
1055         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1056
1057         data = usb_get_intfdata(intf);
1058         usb_deregister_dev(intf, &usbtmc_class);
1059         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1060         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1061         kref_put(&data->kref, usbtmc_delete);
1062 }
1063
1064 static struct usb_driver usbtmc_driver = {
1065         .name           = "usbtmc",
1066         .id_table       = usbtmc_devices,
1067         .probe          = usbtmc_probe,
1068         .disconnect     = usbtmc_disconnect
1069 };
1070
1071 static int __init usbtmc_init(void)
1072 {
1073         int retcode;
1074
1075         retcode = usb_register(&usbtmc_driver);
1076         if (retcode)
1077                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1078         return retcode;
1079 }
1080 module_init(usbtmc_init);
1081
1082 static void __exit usbtmc_exit(void)
1083 {
1084         usb_deregister(&usbtmc_driver);
1085 }
1086 module_exit(usbtmc_exit);
1087
1088 MODULE_LICENSE("GPL");