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         bool zombie; /* fd of disconnected device */
  90
  91         struct usbtmc_dev_capabilities  capabilities;
  92         struct kref kref;
  93         struct mutex io_mutex;  /* only one i/o function running at a time */
  94 };
  95 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  96
  97 /* Forward declarations */
  98 static struct usb_driver usbtmc_driver;
  99
 100 static void usbtmc_delete(struct kref *kref)
 101 {
 102         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 103
 104         usb_put_dev(data->usb_dev);
 105         kfree(data);
 106 }
 107
 108 static int usbtmc_open(struct inode *inode, struct file *filp)
 109 {
 110         struct usb_interface *intf;
 111         struct usbtmc_device_data *data;
 112         int retval = 0;
 113
 114         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 115         if (!intf) {
 116                 printk(KERN_ERR KBUILD_MODNAME
 117                        ": can not find device for minor %d", iminor(inode));
 118                 retval = -ENODEV;
 119                 goto exit;
 120         }
 121
 122         data = usb_get_intfdata(intf);
 123         kref_get(&data->kref);
 124
 125         /* Store pointer in file structure's private data field */
 126         filp->private_data = data;
 127
 128 exit:
 129         return retval;
 130 }
 131
 132 static int usbtmc_release(struct inode *inode, struct file *file)
 133 {
 134         struct usbtmc_device_data *data = file->private_data;
 135
 136         kref_put(&data->kref, usbtmc_delete);
 137         return 0;
 138 }
 139
 140 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 141 {
 142         u8 *buffer;
 143         struct device *dev;
 144         int rv;
 145         int n;
 146         int actual;
 147         struct usb_host_interface *current_setting;
 148         int max_size;
 149
 150         dev = &data->intf->dev;
 151         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 152         if (!buffer)
 153                 return -ENOMEM;
 154
 155         rv = usb_control_msg(data->usb_dev,
 156                              usb_rcvctrlpipe(data->usb_dev, 0),
 157                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 158                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 159                              data->bTag_last_read, data->bulk_in,
 160                              buffer, 2, USBTMC_TIMEOUT);
 161
 162         if (rv < 0) {
 163                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 164                 goto exit;
 165         }
 166
 167         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 168
 169         if (buffer[0] == USBTMC_STATUS_FAILED) {
 170                 rv = 0;
 171                 goto exit;
 172         }
 173
 174         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 175                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 176                         buffer[0]);
 177                 rv = -EPERM;
 178                 goto exit;
 179         }
 180
 181         max_size = 0;
 182         current_setting = data->intf->cur_altsetting;
 183         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 184                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 185                         data->bulk_in)
 186                         max_size = le16_to_cpu(current_setting->endpoint[n].
 187                                                 desc.wMaxPacketSize);
 188
 189         if (max_size == 0) {
 190                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 191                 rv = -EPERM;
 192                 goto exit;
 193         }
 194
 195         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 196
 197         n = 0;
 198
 199         do {
 200                 dev_dbg(dev, "Reading from bulk in EP\n");
 201
 202                 rv = usb_bulk_msg(data->usb_dev,
 203                                   usb_rcvbulkpipe(data->usb_dev,
 204                                                   data->bulk_in),
 205                                   buffer, USBTMC_SIZE_IOBUFFER,
 206                                   &actual, USBTMC_TIMEOUT);
 207
 208                 n++;
 209
 210                 if (rv < 0) {
 211                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 212                         goto exit;
 213                 }
 214         } while ((actual == max_size) &&
 215                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 216
 217         if (actual == max_size) {
 218                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 219                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 220                 rv = -EPERM;
 221                 goto exit;
 222         }
 223
 224         n = 0;
 225
 226 usbtmc_abort_bulk_in_status:
 227         rv = usb_control_msg(data->usb_dev,
 228                              usb_rcvctrlpipe(data->usb_dev, 0),
 229                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 230                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 231                              0, data->bulk_in, buffer, 0x08,
 232                              USBTMC_TIMEOUT);
 233
 234         if (rv < 0) {
 235                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 236                 goto exit;
 237         }
 238
 239         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 240
 241         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 242                 rv = 0;
 243                 goto exit;
 244         }
 245
 246         if (buffer[0] != USBTMC_STATUS_PENDING) {
 247                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 248                 rv = -EPERM;
 249                 goto exit;
 250         }
 251
 252         if (buffer[1] == 1)
 253                 do {
 254                         dev_dbg(dev, "Reading from bulk in EP\n");
 255
 256                         rv = usb_bulk_msg(data->usb_dev,
 257                                           usb_rcvbulkpipe(data->usb_dev,
 258                                                           data->bulk_in),
 259                                           buffer, USBTMC_SIZE_IOBUFFER,
 260                                           &actual, USBTMC_TIMEOUT);
 261
 262                         n++;
 263
 264                         if (rv < 0) {
 265                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 266                                 goto exit;
 267                         }
 268                 } while ((actual = max_size) &&
 269                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 270
 271         if (actual == max_size) {
 272                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 273                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 274                 rv = -EPERM;
 275                 goto exit;
 276         }
 277
 278         goto usbtmc_abort_bulk_in_status;
 279
 280 exit:
 281         kfree(buffer);
 282         return rv;
 283
 284 }
 285
 286 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 287 {
 288         struct device *dev;
 289         u8 *buffer;
 290         int rv;
 291         int n;
 292
 293         dev = &data->intf->dev;
 294
 295         buffer = kmalloc(8, GFP_KERNEL);
 296         if (!buffer)
 297                 return -ENOMEM;
 298
 299         rv = usb_control_msg(data->usb_dev,
 300                              usb_rcvctrlpipe(data->usb_dev, 0),
 301                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 302                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 303                              data->bTag_last_write, data->bulk_out,
 304                              buffer, 2, USBTMC_TIMEOUT);
 305
 306         if (rv < 0) {
 307                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 308                 goto exit;
 309         }
 310
 311         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 312
 313         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 314                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 315                         buffer[0]);
 316                 rv = -EPERM;
 317                 goto exit;
 318         }
 319
 320         n = 0;
 321
 322 usbtmc_abort_bulk_out_check_status:
 323         rv = usb_control_msg(data->usb_dev,
 324                              usb_rcvctrlpipe(data->usb_dev, 0),
 325                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 326                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 327                              0, data->bulk_out, buffer, 0x08,
 328                              USBTMC_TIMEOUT);
 329         n++;
 330         if (rv < 0) {
 331                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 332                 goto exit;
 333         }
 334
 335         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 336
 337         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 338                 goto usbtmc_abort_bulk_out_clear_halt;
 339
 340         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 341             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 342                 goto usbtmc_abort_bulk_out_check_status;
 343
 344         rv = -EPERM;
 345         goto exit;
 346
 347 usbtmc_abort_bulk_out_clear_halt:
 348         rv = usb_control_msg(data->usb_dev,
 349                              usb_sndctrlpipe(data->usb_dev, 0),
 350                              USB_REQ_CLEAR_FEATURE,
 351                              USB_DIR_OUT | USB_TYPE_STANDARD |
 352                              USB_RECIP_ENDPOINT,
 353                              USB_ENDPOINT_HALT, data->bulk_out, buffer,
 354                              0, USBTMC_TIMEOUT);
 355
 356         if (rv < 0) {
 357                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 358                 goto exit;
 359         }
 360         rv = 0;
 361
 362 exit:
 363         kfree(buffer);
 364         return rv;
 365 }
 366
 367 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 368                            size_t count, loff_t *f_pos)
 369 {
 370         struct usbtmc_device_data *data;
 371         struct device *dev;
 372         u32 n_characters;
 373         u8 *buffer;
 374         int actual;
 375         size_t done;
 376         size_t remaining;
 377         int retval;
 378         size_t this_part;
 379
 380         /* Get pointer to private data structure */
 381         data = filp->private_data;
 382         dev = &data->intf->dev;
 383
 384         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 385         if (!buffer)
 386                 return -ENOMEM;
 387
 388         mutex_lock(&data->io_mutex);
 389         if (data->zombie) {
 390                 retval = -ENODEV;
 391                 goto exit;
 392         }
 393
 394         remaining = count;
 395         done = 0;
 396
 397         while (remaining > 0) {
 398                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 399                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 400                 else
 401                         this_part = remaining;
 402
 403                 /* Setup IO buffer for DEV_DEP_MSG_IN message
 404                  * Refer to class specs for details
 405                  */
 406                 buffer[0] = 2;
 407                 buffer[1] = data->bTag;
 408                 buffer[2] = ~(data->bTag);
 409                 buffer[3] = 0; /* Reserved */
 410                 buffer[4] = (this_part) & 255;
 411                 buffer[5] = ((this_part) >> 8) & 255;
 412                 buffer[6] = ((this_part) >> 16) & 255;
 413                 buffer[7] = ((this_part) >> 24) & 255;
 414                 buffer[8] = data->TermCharEnabled * 2;
 415                 /* Use term character? */
 416                 buffer[9] = data->TermChar;
 417                 buffer[10] = 0; /* Reserved */
 418                 buffer[11] = 0; /* Reserved */
 419
 420                 /* Send bulk URB */
 421                 retval = usb_bulk_msg(data->usb_dev,
 422                                       usb_sndbulkpipe(data->usb_dev,
 423                                                       data->bulk_out),
 424                                       buffer, 12, &actual, USBTMC_TIMEOUT);
 425
 426                 /* Store bTag (in case we need to abort) */
 427                 data->bTag_last_write = data->bTag;
 428
 429                 /* Increment bTag -- and increment again if zero */
 430                 data->bTag++;
 431                 if (!data->bTag)
 432                         (data->bTag)++;
 433
 434                 if (retval < 0) {
 435                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 436                         if (data->auto_abort)
 437                                 usbtmc_ioctl_abort_bulk_out(data);
 438                         goto exit;
 439                 }
 440
 441                 /* Send bulk URB */
 442                 retval = usb_bulk_msg(data->usb_dev,
 443                                       usb_rcvbulkpipe(data->usb_dev,
 444                                                       data->bulk_in),
 445                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 446                                       USBTMC_TIMEOUT);
 447
 448                 /* Store bTag (in case we need to abort) */
 449                 data->bTag_last_read = data->bTag;
 450
 451                 if (retval < 0) {
 452                         dev_err(dev, "Unable to read data, error %d\n", retval);
 453                         if (data->auto_abort)
 454                                 usbtmc_ioctl_abort_bulk_in(data);
 455                         goto exit;
 456                 }
 457
 458                 /* How many characters did the instrument send? */
 459                 n_characters = buffer[4] +
 460                                (buffer[5] << 8) +
 461                                (buffer[6] << 16) +
 462                                (buffer[7] << 24);
 463
 464                 /* Ensure the instrument doesn't lie about it */
 465                 if(n_characters > actual - 12) {
 466                         dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
 467                         n_characters = actual - 12;
 468                 }
 469
 470                 /* Ensure the instrument doesn't send more back than requested */
 471                 if(n_characters > this_part) {
 472                         dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
 473                         n_characters = this_part;
 474                 }
 475
 476                 /* Bound amount of data received by amount of data requested */
 477                 if (n_characters > this_part)
 478                         n_characters = this_part;
 479
 480                 /* Copy buffer to user space */
 481                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 482                         /* There must have been an addressing problem */
 483                         retval = -EFAULT;
 484                         goto exit;
 485                 }
 486
 487                 done += n_characters;
 488                 /* Terminate if end-of-message bit recieved from device */
 489                 if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 490                         remaining = 0;
 491                 else
 492                         remaining -= n_characters;
 493         }
 494
 495         /* Update file position value */
 496         *f_pos = *f_pos + done;
 497         retval = done;
 498
 499 exit:
 500         mutex_unlock(&data->io_mutex);
 501         kfree(buffer);
 502         return retval;
 503 }
 504
 505 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 506                             size_t count, loff_t *f_pos)
 507 {
 508         struct usbtmc_device_data *data;
 509         u8 *buffer;
 510         int retval;
 511         int actual;
 512         unsigned long int n_bytes;
 513         int remaining;
 514         int done;
 515         int this_part;
 516
 517         data = filp->private_data;
 518
 519         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 520         if (!buffer)
 521                 return -ENOMEM;
 522
 523         mutex_lock(&data->io_mutex);
 524         if (data->zombie) {
 525                 retval = -ENODEV;
 526                 goto exit;
 527         }
 528
 529         remaining = count;
 530         done = 0;
 531
 532         while (remaining > 0) {
 533                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 534                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 535                         buffer[8] = 0;
 536                 } else {
 537                         this_part = remaining;
 538                         buffer[8] = 1;
 539                 }
 540
 541                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 542                 buffer[0] = 1;
 543                 buffer[1] = data->bTag;
 544                 buffer[2] = ~(data->bTag);
 545                 buffer[3] = 0; /* Reserved */
 546                 buffer[4] = this_part & 255;
 547                 buffer[5] = (this_part >> 8) & 255;
 548                 buffer[6] = (this_part >> 16) & 255;
 549                 buffer[7] = (this_part >> 24) & 255;
 550                 /* buffer[8] is set above... */
 551                 buffer[9] = 0; /* Reserved */
 552                 buffer[10] = 0; /* Reserved */
 553                 buffer[11] = 0; /* Reserved */
 554
 555                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 556                         retval = -EFAULT;
 557                         goto exit;
 558                 }
 559
 560                 n_bytes = roundup(12 + this_part, 4);
 561                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 562
 563                 retval = usb_bulk_msg(data->usb_dev,
 564                                       usb_sndbulkpipe(data->usb_dev,
 565                                                       data->bulk_out),
 566                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 567
 568                 data->bTag_last_write = data->bTag;
 569                 data->bTag++;
 570
 571                 if (!data->bTag)
 572                         data->bTag++;
 573
 574                 if (retval < 0) {
 575                         dev_err(&data->intf->dev,
 576                                 "Unable to send data, error %d\n", retval);
 577                         if (data->auto_abort)
 578                                 usbtmc_ioctl_abort_bulk_out(data);
 579                         goto exit;
 580                 }
 581
 582                 remaining -= this_part;
 583                 done += this_part;
 584         }
 585
 586         retval = count;
 587 exit:
 588         mutex_unlock(&data->io_mutex);
 589         kfree(buffer);
 590         return retval;
 591 }
 592
 593 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 594 {
 595         struct usb_host_interface *current_setting;
 596         struct usb_endpoint_descriptor *desc;
 597         struct device *dev;
 598         u8 *buffer;
 599         int rv;
 600         int n;
 601         int actual;
 602         int max_size;
 603
 604         dev = &data->intf->dev;
 605
 606         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 607
 608         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 609         if (!buffer)
 610                 return -ENOMEM;
 611
 612         rv = usb_control_msg(data->usb_dev,
 613                              usb_rcvctrlpipe(data->usb_dev, 0),
 614                              USBTMC_REQUEST_INITIATE_CLEAR,
 615                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 616                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 617         if (rv < 0) {
 618                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 619                 goto exit;
 620         }
 621
 622         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 623
 624         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 625                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 626                 rv = -EPERM;
 627                 goto exit;
 628         }
 629
 630         max_size = 0;
 631         current_setting = data->intf->cur_altsetting;
 632         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 633                 desc = &current_setting->endpoint[n].desc;
 634                 if (desc->bEndpointAddress == data->bulk_in)
 635                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 636         }
 637
 638         if (max_size == 0) {
 639                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 640                 rv = -EPERM;
 641                 goto exit;
 642         }
 643
 644         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 645
 646         n = 0;
 647
 648 usbtmc_clear_check_status:
 649
 650         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 651
 652         rv = usb_control_msg(data->usb_dev,
 653                              usb_rcvctrlpipe(data->usb_dev, 0),
 654                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 655                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 656                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 657         if (rv < 0) {
 658                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 659                 goto exit;
 660         }
 661
 662         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 663
 664         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 665                 goto usbtmc_clear_bulk_out_halt;
 666
 667         if (buffer[0] != USBTMC_STATUS_PENDING) {
 668                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 669                 rv = -EPERM;
 670                 goto exit;
 671         }
 672
 673         if (buffer[1] == 1)
 674                 do {
 675                         dev_dbg(dev, "Reading from bulk in EP\n");
 676
 677                         rv = usb_bulk_msg(data->usb_dev,
 678                                           usb_rcvbulkpipe(data->usb_dev,
 679                                                           data->bulk_in),
 680                                           buffer, USBTMC_SIZE_IOBUFFER,
 681                                           &actual, USBTMC_TIMEOUT);
 682                         n++;
 683
 684                         if (rv < 0) {
 685                                 dev_err(dev, "usb_control_msg returned %d\n",
 686                                         rv);
 687                                 goto exit;
 688                         }
 689                 } while ((actual == max_size) &&
 690                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 691
 692         if (actual == max_size) {
 693                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 694                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 695                 rv = -EPERM;
 696                 goto exit;
 697         }
 698
 699         goto usbtmc_clear_check_status;
 700
 701 usbtmc_clear_bulk_out_halt:
 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,
 709                              data->bulk_out, buffer, 0,
 710                              USBTMC_TIMEOUT);
 711         if (rv < 0) {
 712                 dev_err(dev, "usb_control_msg returned %d\n", 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_out_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,
 732                              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_out,
 737                              buffer, 0, 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 usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 752 {
 753         u8 *buffer;
 754         int rv;
 755
 756         buffer = kmalloc(2, GFP_KERNEL);
 757         if (!buffer)
 758                 return -ENOMEM;
 759
 760         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 761                              USB_REQ_CLEAR_FEATURE,
 762                              USB_DIR_OUT | USB_TYPE_STANDARD |
 763                              USB_RECIP_ENDPOINT,
 764                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 765                              USBTMC_TIMEOUT);
 766
 767         if (rv < 0) {
 768                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 769                         rv);
 770                 goto exit;
 771         }
 772         rv = 0;
 773
 774 exit:
 775         kfree(buffer);
 776         return rv;
 777 }
 778
 779 static int get_capabilities(struct usbtmc_device_data *data)
 780 {
 781         struct device *dev = &data->usb_dev->dev;
 782         char *buffer;
 783         int rv = 0;
 784
 785         buffer = kmalloc(0x18, GFP_KERNEL);
 786         if (!buffer)
 787                 return -ENOMEM;
 788
 789         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 790                              USBTMC_REQUEST_GET_CAPABILITIES,
 791                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 792                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 793         if (rv < 0) {
 794                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 795                 goto err_out;
 796         }
 797
 798         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 799         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 800         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 801         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 802         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 803         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 804                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 805                 rv = -EPERM;
 806                 goto err_out;
 807         }
 808
 809         data->capabilities.interface_capabilities = buffer[4];
 810         data->capabilities.device_capabilities = buffer[5];
 811         data->capabilities.usb488_interface_capabilities = buffer[14];
 812         data->capabilities.usb488_device_capabilities = buffer[15];
 813
 814 err_out:
 815         kfree(buffer);
 816         return rv;
 817 }
 818
 819 #define capability_attribute(name)                                      \
 820 static ssize_t show_##name(struct device *dev,                          \
 821                            struct device_attribute *attr, char *buf)    \
 822 {                                                                       \
 823         struct usb_interface *intf = to_usb_interface(dev);             \
 824         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 825                                                                         \
 826         return sprintf(buf, "%d\n", data->capabilities.name);           \
 827 }                                                                       \
 828 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 829
 830 capability_attribute(interface_capabilities);
 831 capability_attribute(device_capabilities);
 832 capability_attribute(usb488_interface_capabilities);
 833 capability_attribute(usb488_device_capabilities);
 834
 835 static struct attribute *capability_attrs[] = {
 836         &dev_attr_interface_capabilities.attr,
 837         &dev_attr_device_capabilities.attr,
 838         &dev_attr_usb488_interface_capabilities.attr,
 839         &dev_attr_usb488_device_capabilities.attr,
 840         NULL,
 841 };
 842
 843 static struct attribute_group capability_attr_grp = {
 844         .attrs = capability_attrs,
 845 };
 846
 847 static ssize_t show_TermChar(struct device *dev,
 848                              struct device_attribute *attr, char *buf)
 849 {
 850         struct usb_interface *intf = to_usb_interface(dev);
 851         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 852
 853         return sprintf(buf, "%c\n", data->TermChar);
 854 }
 855
 856 static ssize_t store_TermChar(struct device *dev,
 857                               struct device_attribute *attr,
 858                               const char *buf, size_t count)
 859 {
 860         struct usb_interface *intf = to_usb_interface(dev);
 861         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 862
 863         if (count < 1)
 864                 return -EINVAL;
 865         data->TermChar = buf[0];
 866         return count;
 867 }
 868 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 869
 870 #define data_attribute(name)                                            \
 871 static ssize_t show_##name(struct device *dev,                          \
 872                            struct device_attribute *attr, char *buf)    \
 873 {                                                                       \
 874         struct usb_interface *intf = to_usb_interface(dev);             \
 875         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 876                                                                         \
 877         return sprintf(buf, "%d\n", data->name);                        \
 878 }                                                                       \
 879 static ssize_t store_##name(struct device *dev,                         \
 880                             struct device_attribute *attr,              \
 881                             const char *buf, size_t count)              \
 882 {                                                                       \
 883         struct usb_interface *intf = to_usb_interface(dev);             \
 884         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 885         ssize_t result;                                                 \
 886         unsigned val;                                                   \
 887                                                                         \
 888         result = sscanf(buf, "%u\n", &val);                             \
 889         if (result != 1)                                                \
 890                 result = -EINVAL;                                       \
 891         data->name = val;                                               \
 892         if (result < 0)                                                 \
 893                 return result;                                          \
 894         else                                                            \
 895                 return count;                                           \
 896 }                                                                       \
 897 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 898
 899 data_attribute(TermCharEnabled);
 900 data_attribute(auto_abort);
 901
 902 static struct attribute *data_attrs[] = {
 903         &dev_attr_TermChar.attr,
 904         &dev_attr_TermCharEnabled.attr,
 905         &dev_attr_auto_abort.attr,
 906         NULL,
 907 };
 908
 909 static struct attribute_group data_attr_grp = {
 910         .attrs = data_attrs,
 911 };
 912
 913 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 914 {
 915         struct device *dev;
 916         u8 *buffer;
 917         int rv;
 918
 919         dev = &data->intf->dev;
 920
 921         buffer = kmalloc(2, GFP_KERNEL);
 922         if (!buffer)
 923                 return -ENOMEM;
 924
 925         rv = usb_control_msg(data->usb_dev,
 926                              usb_rcvctrlpipe(data->usb_dev, 0),
 927                              USBTMC_REQUEST_INDICATOR_PULSE,
 928                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 929                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 930
 931         if (rv < 0) {
 932                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 933                 goto exit;
 934         }
 935
 936         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 937
 938         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 939                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 940                 rv = -EPERM;
 941                 goto exit;
 942         }
 943         rv = 0;
 944
 945 exit:
 946         kfree(buffer);
 947         return rv;
 948 }
 949
 950 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 951 {
 952         struct usbtmc_device_data *data;
 953         int retval = -EBADRQC;
 954
 955         data = file->private_data;
 956         mutex_lock(&data->io_mutex);
 957         if (data->zombie) {
 958                 retval = -ENODEV;
 959                 goto skip_io_on_zombie;
 960         }
 961
 962         switch (cmd) {
 963         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 964                 retval = usbtmc_ioctl_clear_out_halt(data);
 965                 break;
 966
 967         case USBTMC_IOCTL_CLEAR_IN_HALT:
 968                 retval = usbtmc_ioctl_clear_in_halt(data);
 969                 break;
 970
 971         case USBTMC_IOCTL_INDICATOR_PULSE:
 972                 retval = usbtmc_ioctl_indicator_pulse(data);
 973                 break;
 974
 975         case USBTMC_IOCTL_CLEAR:
 976                 retval = usbtmc_ioctl_clear(data);
 977                 break;
 978
 979         case USBTMC_IOCTL_ABORT_BULK_OUT:
 980                 retval = usbtmc_ioctl_abort_bulk_out(data);
 981                 break;
 982
 983         case USBTMC_IOCTL_ABORT_BULK_IN:
 984                 retval = usbtmc_ioctl_abort_bulk_in(data);
 985                 break;
 986         }
 987
 988 skip_io_on_zombie:
 989         mutex_unlock(&data->io_mutex);
 990         return retval;
 991 }
 992
 993 static struct file_operations fops = {
 994         .owner          = THIS_MODULE,
 995         .read           = usbtmc_read,
 996         .write          = usbtmc_write,
 997         .open           = usbtmc_open,
 998         .release        = usbtmc_release,
 999         .unlocked_ioctl = usbtmc_ioctl,
1000 };
1001
1002 static struct usb_class_driver usbtmc_class = {
1003         .name =         "usbtmc%d",
1004         .fops =         &fops,
1005         .minor_base =   USBTMC_MINOR_BASE,
1006 };
1007
1008
1009 static int usbtmc_probe(struct usb_interface *intf,
1010                         const struct usb_device_id *id)
1011 {
1012         struct usbtmc_device_data *data;
1013         struct usb_host_interface *iface_desc;
1014         struct usb_endpoint_descriptor *endpoint;
1015         int n;
1016         int retcode;
1017
1018         dev_dbg(&intf->dev, "%s called\n", __func__);
1019
1020         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1021         if (!data) {
1022                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1023                 return -ENOMEM;
1024         }
1025
1026         data->intf = intf;
1027         data->id = id;
1028         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1029         usb_set_intfdata(intf, data);
1030         kref_init(&data->kref);
1031         mutex_init(&data->io_mutex);
1032         data->zombie = 0;
1033
1034         /* Initialize USBTMC bTag and other fields */
1035         data->bTag      = 1;
1036         data->TermCharEnabled = 0;
1037         data->TermChar = '\n';
1038
1039         /* USBTMC devices have only one setting, so use that */
1040         iface_desc = data->intf->cur_altsetting;
1041
1042         /* Find bulk in endpoint */
1043         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1044                 endpoint = &iface_desc->endpoint[n].desc;
1045
1046                 if (usb_endpoint_is_bulk_in(endpoint)) {
1047                         data->bulk_in = endpoint->bEndpointAddress;
1048                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1049                                 data->bulk_in);
1050                         break;
1051                 }
1052         }
1053
1054         /* Find bulk out endpoint */
1055         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1056                 endpoint = &iface_desc->endpoint[n].desc;
1057
1058                 if (usb_endpoint_is_bulk_out(endpoint)) {
1059                         data->bulk_out = endpoint->bEndpointAddress;
1060                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1061                                 data->bulk_out);
1062                         break;
1063                 }
1064         }
1065
1066         retcode = get_capabilities(data);
1067         if (retcode)
1068                 dev_err(&intf->dev, "can't read capabilities\n");
1069         else
1070                 retcode = sysfs_create_group(&intf->dev.kobj,
1071                                              &capability_attr_grp);
1072
1073         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1074
1075         retcode = usb_register_dev(intf, &usbtmc_class);
1076         if (retcode) {
1077                 dev_err(&intf->dev, "Not able to get a minor"
1078                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1079                         retcode);
1080                 goto error_register;
1081         }
1082         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1083
1084         return 0;
1085
1086 error_register:
1087         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1088         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1089         kref_put(&data->kref, usbtmc_delete);
1090         return retcode;
1091 }
1092
1093 static void usbtmc_disconnect(struct usb_interface *intf)
1094 {
1095         struct usbtmc_device_data *data;
1096
1097         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1098
1099         data = usb_get_intfdata(intf);
1100         usb_deregister_dev(intf, &usbtmc_class);
1101         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1102         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1103         mutex_lock(&data->io_mutex);
1104         data->zombie = 1;
1105         mutex_unlock(&data->io_mutex);
1106         kref_put(&data->kref, usbtmc_delete);
1107 }
1108
1109 static int usbtmc_suspend (struct usb_interface *intf, pm_message_t message)
1110 {
1111         /* this driver does not have pending URBs */
1112         return 0;
1113 }
1114
1115 static int usbtmc_resume (struct usb_interface *intf)
1116 {
1117         return 0;
1118 }
1119
1120 static struct usb_driver usbtmc_driver = {
1121         .name           = "usbtmc",
1122         .id_table       = usbtmc_devices,
1123         .probe          = usbtmc_probe,
1124         .disconnect     = usbtmc_disconnect,
1125         .suspend        = usbtmc_suspend,
1126         .resume         = usbtmc_resume,
1127 };
1128
1129 static int __init usbtmc_init(void)
1130 {
1131         int retcode;
1132
1133         retcode = usb_register(&usbtmc_driver);
1134         if (retcode)
1135                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1136         return retcode;
1137 }
1138 module_init(usbtmc_init);
1139
1140 static void __exit usbtmc_exit(void)
1141 {
1142         usb_deregister(&usbtmc_driver);
1143 }
1144 module_exit(usbtmc_exit);
1145
1146 MODULE_LICENSE("GPL");