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