drivers/usb/class/usbtmc.c

   1 /**
   2  * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   3  *
   4  * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5  * Copyright (C) 2008 Novell, Inc.
   6  * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * The GNU General Public License is available at
  19  * http://www.gnu.org/copyleft/gpl.html.
  20  */
  21
  22 #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/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/usb.h>
  31 #include <linux/usb/tmc.h>
  32
  33
  34 #define USBTMC_MINOR_BASE       176
  35
  36 /*
  37  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  38  * large as wMaxPacketSize (which is usually 512 bytes).
  39  */
  40 #define USBTMC_SIZE_IOBUFFER    2048
  41
  42 /* Default USB timeout (in milliseconds) */
  43 #define USBTMC_TIMEOUT          5000
  44
  45 /*
  46  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  47  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  48  * packet is never read.
  49  */
  50 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  51
  52 static const struct usb_device_id usbtmc_devices[] = {
  53         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  54         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  55         { 0, } /* terminating entry */
  56 };
  57 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  58
  59 /*
  60  * This structure is the capabilities for the device
  61  * See section 4.2.1.8 of the USBTMC specification,
  62  * and section 4.2.2 of the USBTMC usb488 subclass
  63  * specification for details.
  64  */
  65 struct usbtmc_dev_capabilities {
  66         __u8 interface_capabilities;
  67         __u8 device_capabilities;
  68         __u8 usb488_interface_capabilities;
  69         __u8 usb488_device_capabilities;
  70 };
  71
  72 /* This structure holds private data for each USBTMC device. One copy is
  73  * allocated for each USBTMC device in the driver's probe function.
  74  */
  75 struct usbtmc_device_data {
  76         const struct usb_device_id *id;
  77         struct usb_device *usb_dev;
  78         struct usb_interface *intf;
  79
  80         unsigned int bulk_in;
  81         unsigned int bulk_out;
  82
  83         u8 bTag;
  84         u8 bTag_last_write;     /* needed for abort */
  85         u8 bTag_last_read;      /* needed for abort */
  86
  87         /* attributes from the USB TMC spec for this device */
  88         u8 TermChar;
  89         bool TermCharEnabled;
  90         bool auto_abort;
  91
  92         bool zombie; /* fd of disconnected device */
  93
  94         struct usbtmc_dev_capabilities  capabilities;
  95         struct kref kref;
  96         struct mutex io_mutex;  /* only one i/o function running at a time */
  97 };
  98 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  99
 100 /* Forward declarations */
 101 static struct usb_driver usbtmc_driver;
 102
 103 static void usbtmc_delete(struct kref *kref)
 104 {
 105         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 106
 107         usb_put_dev(data->usb_dev);
 108         kfree(data);
 109 }
 110
 111 static int usbtmc_open(struct inode *inode, struct file *filp)
 112 {
 113         struct usb_interface *intf;
 114         struct usbtmc_device_data *data;
 115         int retval = 0;
 116
 117         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 118         if (!intf) {
 119                 printk(KERN_ERR KBUILD_MODNAME
 120                        ": can not find device for minor %d", iminor(inode));
 121                 retval = -ENODEV;
 122                 goto exit;
 123         }
 124
 125         data = usb_get_intfdata(intf);
 126         kref_get(&data->kref);
 127
 128         /* Store pointer in file structure's private data field */
 129         filp->private_data = data;
 130
 131 exit:
 132         return retval;
 133 }
 134
 135 static int usbtmc_release(struct inode *inode, struct file *file)
 136 {
 137         struct usbtmc_device_data *data = file->private_data;
 138
 139         kref_put(&data->kref, usbtmc_delete);
 140         return 0;
 141 }
 142
 143 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 144 {
 145         u8 *buffer;
 146         struct device *dev;
 147         int rv;
 148         int n;
 149         int actual;
 150         struct usb_host_interface *current_setting;
 151         int max_size;
 152
 153         dev = &data->intf->dev;
 154         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 155         if (!buffer)
 156                 return -ENOMEM;
 157
 158         rv = usb_control_msg(data->usb_dev,
 159                              usb_rcvctrlpipe(data->usb_dev, 0),
 160                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 161                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 162                              data->bTag_last_read, data->bulk_in,
 163                              buffer, 2, USBTMC_TIMEOUT);
 164
 165         if (rv < 0) {
 166                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 167                 goto exit;
 168         }
 169
 170         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 171
 172         if (buffer[0] == USBTMC_STATUS_FAILED) {
 173                 rv = 0;
 174                 goto exit;
 175         }
 176
 177         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 178                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 179                         buffer[0]);
 180                 rv = -EPERM;
 181                 goto exit;
 182         }
 183
 184         max_size = 0;
 185         current_setting = data->intf->cur_altsetting;
 186         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 187                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 188                         data->bulk_in)
 189                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 190
 191         if (max_size == 0) {
 192                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 193                 rv = -EPERM;
 194                 goto exit;
 195         }
 196
 197         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 198
 199         n = 0;
 200
 201         do {
 202                 dev_dbg(dev, "Reading from bulk in EP\n");
 203
 204                 rv = usb_bulk_msg(data->usb_dev,
 205                                   usb_rcvbulkpipe(data->usb_dev,
 206                                                   data->bulk_in),
 207                                   buffer, USBTMC_SIZE_IOBUFFER,
 208                                   &actual, USBTMC_TIMEOUT);
 209
 210                 n++;
 211
 212                 if (rv < 0) {
 213                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 214                         goto exit;
 215                 }
 216         } while ((actual == max_size) &&
 217                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 218
 219         if (actual == max_size) {
 220                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 221                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 222                 rv = -EPERM;
 223                 goto exit;
 224         }
 225
 226         n = 0;
 227
 228 usbtmc_abort_bulk_in_status:
 229         rv = usb_control_msg(data->usb_dev,
 230                              usb_rcvctrlpipe(data->usb_dev, 0),
 231                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 232                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 233                              0, data->bulk_in, buffer, 0x08,
 234                              USBTMC_TIMEOUT);
 235
 236         if (rv < 0) {
 237                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 238                 goto exit;
 239         }
 240
 241         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 242
 243         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 244                 rv = 0;
 245                 goto exit;
 246         }
 247
 248         if (buffer[0] != USBTMC_STATUS_PENDING) {
 249                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 250                 rv = -EPERM;
 251                 goto exit;
 252         }
 253
 254         if (buffer[1] == 1)
 255                 do {
 256                         dev_dbg(dev, "Reading from bulk in EP\n");
 257
 258                         rv = usb_bulk_msg(data->usb_dev,
 259                                           usb_rcvbulkpipe(data->usb_dev,
 260                                                           data->bulk_in),
 261                                           buffer, USBTMC_SIZE_IOBUFFER,
 262                                           &actual, USBTMC_TIMEOUT);
 263
 264                         n++;
 265
 266                         if (rv < 0) {
 267                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 268                                 goto exit;
 269                         }
 270                 } while ((actual == max_size) &&
 271                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 272
 273         if (actual == max_size) {
 274                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 275                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 276                 rv = -EPERM;
 277                 goto exit;
 278         }
 279
 280         goto usbtmc_abort_bulk_in_status;
 281
 282 exit:
 283         kfree(buffer);
 284         return rv;
 285
 286 }
 287
 288 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 289 {
 290         struct device *dev;
 291         u8 *buffer;
 292         int rv;
 293         int n;
 294
 295         dev = &data->intf->dev;
 296
 297         buffer = kmalloc(8, GFP_KERNEL);
 298         if (!buffer)
 299                 return -ENOMEM;
 300
 301         rv = usb_control_msg(data->usb_dev,
 302                              usb_rcvctrlpipe(data->usb_dev, 0),
 303                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 304                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 305                              data->bTag_last_write, data->bulk_out,
 306                              buffer, 2, USBTMC_TIMEOUT);
 307
 308         if (rv < 0) {
 309                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 310                 goto exit;
 311         }
 312
 313         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 314
 315         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 316                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 317                         buffer[0]);
 318                 rv = -EPERM;
 319                 goto exit;
 320         }
 321
 322         n = 0;
 323
 324 usbtmc_abort_bulk_out_check_status:
 325         rv = usb_control_msg(data->usb_dev,
 326                              usb_rcvctrlpipe(data->usb_dev, 0),
 327                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 328                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 329                              0, data->bulk_out, buffer, 0x08,
 330                              USBTMC_TIMEOUT);
 331         n++;
 332         if (rv < 0) {
 333                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 334                 goto exit;
 335         }
 336
 337         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 338
 339         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 340                 goto usbtmc_abort_bulk_out_clear_halt;
 341
 342         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 343             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 344                 goto usbtmc_abort_bulk_out_check_status;
 345
 346         rv = -EPERM;
 347         goto exit;
 348
 349 usbtmc_abort_bulk_out_clear_halt:
 350         rv = usb_clear_halt(data->usb_dev,
 351                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 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         u32 n_characters;
 370         u8 *buffer;
 371         int actual;
 372         size_t done;
 373         size_t remaining;
 374         int retval;
 375         size_t 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         if (data->zombie) {
 387                 retval = -ENODEV;
 388                 goto exit;
 389         }
 390
 391         remaining = count;
 392         done = 0;
 393
 394         while (remaining > 0) {
 395                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 396                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 397                 else
 398                         this_part = remaining;
 399
 400                 /* Setup IO buffer for DEV_DEP_MSG_IN message
 401                  * Refer to class specs for details
 402                  */
 403                 buffer[0] = 2;
 404                 buffer[1] = data->bTag;
 405                 buffer[2] = ~(data->bTag);
 406                 buffer[3] = 0; /* Reserved */
 407                 buffer[4] = (this_part) & 255;
 408                 buffer[5] = ((this_part) >> 8) & 255;
 409                 buffer[6] = ((this_part) >> 16) & 255;
 410                 buffer[7] = ((this_part) >> 24) & 255;
 411                 buffer[8] = data->TermCharEnabled * 2;
 412                 /* Use term character? */
 413                 buffer[9] = data->TermChar;
 414                 buffer[10] = 0; /* Reserved */
 415                 buffer[11] = 0; /* Reserved */
 416
 417                 /* Send bulk URB */
 418                 retval = usb_bulk_msg(data->usb_dev,
 419                                       usb_sndbulkpipe(data->usb_dev,
 420                                                       data->bulk_out),
 421                                       buffer, 12, &actual, USBTMC_TIMEOUT);
 422
 423                 /* Store bTag (in case we need to abort) */
 424                 data->bTag_last_write = data->bTag;
 425
 426                 /* Increment bTag -- and increment again if zero */
 427                 data->bTag++;
 428                 if (!data->bTag)
 429                         (data->bTag)++;
 430
 431                 if (retval < 0) {
 432                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 433                         if (data->auto_abort)
 434                                 usbtmc_ioctl_abort_bulk_out(data);
 435                         goto exit;
 436                 }
 437
 438                 /* Send bulk URB */
 439                 retval = usb_bulk_msg(data->usb_dev,
 440                                       usb_rcvbulkpipe(data->usb_dev,
 441                                                       data->bulk_in),
 442                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 443                                       USBTMC_TIMEOUT);
 444
 445                 /* Store bTag (in case we need to abort) */
 446                 data->bTag_last_read = data->bTag;
 447
 448                 if (retval < 0) {
 449                         dev_err(dev, "Unable to read data, error %d\n", retval);
 450                         if (data->auto_abort)
 451                                 usbtmc_ioctl_abort_bulk_in(data);
 452                         goto exit;
 453                 }
 454
 455                 /* How many characters did the instrument send? */
 456                 n_characters = buffer[4] +
 457                                (buffer[5] << 8) +
 458                                (buffer[6] << 16) +
 459                                (buffer[7] << 24);
 460
 461                 /* Ensure the instrument doesn't lie about it */
 462                 if(n_characters > actual - 12) {
 463                         dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
 464                         n_characters = actual - 12;
 465                 }
 466
 467                 /* Ensure the instrument doesn't send more back than requested */
 468                 if(n_characters > this_part) {
 469                         dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
 470                         n_characters = this_part;
 471                 }
 472
 473                 /* Bound amount of data received by amount of data requested */
 474                 if (n_characters > this_part)
 475                         n_characters = this_part;
 476
 477                 /* Copy buffer to user space */
 478                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 479                         /* There must have been an addressing problem */
 480                         retval = -EFAULT;
 481                         goto exit;
 482                 }
 483
 484                 done += n_characters;
 485                 /* Terminate if end-of-message bit received from device */
 486                 if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 487                         remaining = 0;
 488                 else
 489                         remaining -= n_characters;
 490         }
 491
 492         /* Update file position value */
 493         *f_pos = *f_pos + done;
 494         retval = done;
 495
 496 exit:
 497         mutex_unlock(&data->io_mutex);
 498         kfree(buffer);
 499         return retval;
 500 }
 501
 502 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 503                             size_t count, loff_t *f_pos)
 504 {
 505         struct usbtmc_device_data *data;
 506         u8 *buffer;
 507         int retval;
 508         int actual;
 509         unsigned long int n_bytes;
 510         int remaining;
 511         int done;
 512         int this_part;
 513
 514         data = filp->private_data;
 515
 516         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 517         if (!buffer)
 518                 return -ENOMEM;
 519
 520         mutex_lock(&data->io_mutex);
 521         if (data->zombie) {
 522                 retval = -ENODEV;
 523                 goto exit;
 524         }
 525
 526         remaining = count;
 527         done = 0;
 528
 529         while (remaining > 0) {
 530                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 531                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 532                         buffer[8] = 0;
 533                 } else {
 534                         this_part = remaining;
 535                         buffer[8] = 1;
 536                 }
 537
 538                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 539                 buffer[0] = 1;
 540                 buffer[1] = data->bTag;
 541                 buffer[2] = ~(data->bTag);
 542                 buffer[3] = 0; /* Reserved */
 543                 buffer[4] = this_part & 255;
 544                 buffer[5] = (this_part >> 8) & 255;
 545                 buffer[6] = (this_part >> 16) & 255;
 546                 buffer[7] = (this_part >> 24) & 255;
 547                 /* buffer[8] is set above... */
 548                 buffer[9] = 0; /* Reserved */
 549                 buffer[10] = 0; /* Reserved */
 550                 buffer[11] = 0; /* Reserved */
 551
 552                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 553                         retval = -EFAULT;
 554                         goto exit;
 555                 }
 556
 557                 n_bytes = roundup(12 + this_part, 4);
 558                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 559
 560                 do {
 561                         retval = usb_bulk_msg(data->usb_dev,
 562                                               usb_sndbulkpipe(data->usb_dev,
 563                                                               data->bulk_out),
 564                                               buffer, n_bytes,
 565                                               &actual, USBTMC_TIMEOUT);
 566                         if (retval != 0)
 567                                 break;
 568                         n_bytes -= actual;
 569                 } while (n_bytes);
 570
 571                 data->bTag_last_write = data->bTag;
 572                 data->bTag++;
 573
 574                 if (!data->bTag)
 575                         data->bTag++;
 576
 577                 if (retval < 0) {
 578                         dev_err(&data->intf->dev,
 579                                 "Unable to send data, error %d\n", retval);
 580                         if (data->auto_abort)
 581                                 usbtmc_ioctl_abort_bulk_out(data);
 582                         goto exit;
 583                 }
 584
 585                 remaining -= this_part;
 586                 done += this_part;
 587         }
 588
 589         retval = count;
 590 exit:
 591         mutex_unlock(&data->io_mutex);
 592         kfree(buffer);
 593         return retval;
 594 }
 595
 596 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 597 {
 598         struct usb_host_interface *current_setting;
 599         struct usb_endpoint_descriptor *desc;
 600         struct device *dev;
 601         u8 *buffer;
 602         int rv;
 603         int n;
 604         int actual;
 605         int max_size;
 606
 607         dev = &data->intf->dev;
 608
 609         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 610
 611         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 612         if (!buffer)
 613                 return -ENOMEM;
 614
 615         rv = usb_control_msg(data->usb_dev,
 616                              usb_rcvctrlpipe(data->usb_dev, 0),
 617                              USBTMC_REQUEST_INITIATE_CLEAR,
 618                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 619                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 620         if (rv < 0) {
 621                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 622                 goto exit;
 623         }
 624
 625         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 626
 627         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 628                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 629                 rv = -EPERM;
 630                 goto exit;
 631         }
 632
 633         max_size = 0;
 634         current_setting = data->intf->cur_altsetting;
 635         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 636                 desc = &current_setting->endpoint[n].desc;
 637                 if (desc->bEndpointAddress == data->bulk_in)
 638                         max_size = usb_endpoint_maxp(desc);
 639         }
 640
 641         if (max_size == 0) {
 642                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 643                 rv = -EPERM;
 644                 goto exit;
 645         }
 646
 647         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 648
 649         n = 0;
 650
 651 usbtmc_clear_check_status:
 652
 653         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 654
 655         rv = usb_control_msg(data->usb_dev,
 656                              usb_rcvctrlpipe(data->usb_dev, 0),
 657                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 658                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 659                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 660         if (rv < 0) {
 661                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 662                 goto exit;
 663         }
 664
 665         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 666
 667         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 668                 goto usbtmc_clear_bulk_out_halt;
 669
 670         if (buffer[0] != USBTMC_STATUS_PENDING) {
 671                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 672                 rv = -EPERM;
 673                 goto exit;
 674         }
 675
 676         if (buffer[1] == 1)
 677                 do {
 678                         dev_dbg(dev, "Reading from bulk in EP\n");
 679
 680                         rv = usb_bulk_msg(data->usb_dev,
 681                                           usb_rcvbulkpipe(data->usb_dev,
 682                                                           data->bulk_in),
 683                                           buffer, USBTMC_SIZE_IOBUFFER,
 684                                           &actual, USBTMC_TIMEOUT);
 685                         n++;
 686
 687                         if (rv < 0) {
 688                                 dev_err(dev, "usb_control_msg returned %d\n",
 689                                         rv);
 690                                 goto exit;
 691                         }
 692                 } while ((actual == max_size) &&
 693                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 694
 695         if (actual == max_size) {
 696                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 697                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 698                 rv = -EPERM;
 699                 goto exit;
 700         }
 701
 702         goto usbtmc_clear_check_status;
 703
 704 usbtmc_clear_bulk_out_halt:
 705
 706         rv = usb_clear_halt(data->usb_dev,
 707                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 708         if (rv < 0) {
 709                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 710                 goto exit;
 711         }
 712         rv = 0;
 713
 714 exit:
 715         kfree(buffer);
 716         return rv;
 717 }
 718
 719 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 720 {
 721         u8 *buffer;
 722         int rv;
 723
 724         buffer = kmalloc(2, GFP_KERNEL);
 725         if (!buffer)
 726                 return -ENOMEM;
 727
 728         rv = usb_clear_halt(data->usb_dev,
 729                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 730
 731         if (rv < 0) {
 732                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 733                         rv);
 734                 goto exit;
 735         }
 736         rv = 0;
 737
 738 exit:
 739         kfree(buffer);
 740         return rv;
 741 }
 742
 743 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 744 {
 745         u8 *buffer;
 746         int rv;
 747
 748         buffer = kmalloc(2, GFP_KERNEL);
 749         if (!buffer)
 750                 return -ENOMEM;
 751
 752         rv = usb_clear_halt(data->usb_dev,
 753                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 754
 755         if (rv < 0) {
 756                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 757                         rv);
 758                 goto exit;
 759         }
 760         rv = 0;
 761
 762 exit:
 763         kfree(buffer);
 764         return rv;
 765 }
 766
 767 static int get_capabilities(struct usbtmc_device_data *data)
 768 {
 769         struct device *dev = &data->usb_dev->dev;
 770         char *buffer;
 771         int rv = 0;
 772
 773         buffer = kmalloc(0x18, GFP_KERNEL);
 774         if (!buffer)
 775                 return -ENOMEM;
 776
 777         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 778                              USBTMC_REQUEST_GET_CAPABILITIES,
 779                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 780                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 781         if (rv < 0) {
 782                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 783                 goto err_out;
 784         }
 785
 786         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 787         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 788                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 789                 rv = -EPERM;
 790                 goto err_out;
 791         }
 792         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 793         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 794         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 795         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 796
 797         data->capabilities.interface_capabilities = buffer[4];
 798         data->capabilities.device_capabilities = buffer[5];
 799         data->capabilities.usb488_interface_capabilities = buffer[14];
 800         data->capabilities.usb488_device_capabilities = buffer[15];
 801         rv = 0;
 802
 803 err_out:
 804         kfree(buffer);
 805         return rv;
 806 }
 807
 808 #define capability_attribute(name)                                      \
 809 static ssize_t show_##name(struct device *dev,                          \
 810                            struct device_attribute *attr, char *buf)    \
 811 {                                                                       \
 812         struct usb_interface *intf = to_usb_interface(dev);             \
 813         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 814                                                                         \
 815         return sprintf(buf, "%d\n", data->capabilities.name);           \
 816 }                                                                       \
 817 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 818
 819 capability_attribute(interface_capabilities);
 820 capability_attribute(device_capabilities);
 821 capability_attribute(usb488_interface_capabilities);
 822 capability_attribute(usb488_device_capabilities);
 823
 824 static struct attribute *capability_attrs[] = {
 825         &dev_attr_interface_capabilities.attr,
 826         &dev_attr_device_capabilities.attr,
 827         &dev_attr_usb488_interface_capabilities.attr,
 828         &dev_attr_usb488_device_capabilities.attr,
 829         NULL,
 830 };
 831
 832 static struct attribute_group capability_attr_grp = {
 833         .attrs = capability_attrs,
 834 };
 835
 836 static ssize_t show_TermChar(struct device *dev,
 837                              struct device_attribute *attr, char *buf)
 838 {
 839         struct usb_interface *intf = to_usb_interface(dev);
 840         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 841
 842         return sprintf(buf, "%c\n", data->TermChar);
 843 }
 844
 845 static ssize_t store_TermChar(struct device *dev,
 846                               struct device_attribute *attr,
 847                               const char *buf, size_t count)
 848 {
 849         struct usb_interface *intf = to_usb_interface(dev);
 850         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 851
 852         if (count < 1)
 853                 return -EINVAL;
 854         data->TermChar = buf[0];
 855         return count;
 856 }
 857 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 858
 859 #define data_attribute(name)                                            \
 860 static ssize_t show_##name(struct device *dev,                          \
 861                            struct device_attribute *attr, char *buf)    \
 862 {                                                                       \
 863         struct usb_interface *intf = to_usb_interface(dev);             \
 864         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 865                                                                         \
 866         return sprintf(buf, "%d\n", data->name);                        \
 867 }                                                                       \
 868 static ssize_t store_##name(struct device *dev,                         \
 869                             struct device_attribute *attr,              \
 870                             const char *buf, size_t count)              \
 871 {                                                                       \
 872         struct usb_interface *intf = to_usb_interface(dev);             \
 873         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 874         ssize_t result;                                                 \
 875         unsigned val;                                                   \
 876                                                                         \
 877         result = sscanf(buf, "%u\n", &val);                             \
 878         if (result != 1)                                                \
 879                 result = -EINVAL;                                       \
 880         data->name = val;                                               \
 881         if (result < 0)                                                 \
 882                 return result;                                          \
 883         else                                                            \
 884                 return count;                                           \
 885 }                                                                       \
 886 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 887
 888 data_attribute(TermCharEnabled);
 889 data_attribute(auto_abort);
 890
 891 static struct attribute *data_attrs[] = {
 892         &dev_attr_TermChar.attr,
 893         &dev_attr_TermCharEnabled.attr,
 894         &dev_attr_auto_abort.attr,
 895         NULL,
 896 };
 897
 898 static struct attribute_group data_attr_grp = {
 899         .attrs = data_attrs,
 900 };
 901
 902 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 903 {
 904         struct device *dev;
 905         u8 *buffer;
 906         int rv;
 907
 908         dev = &data->intf->dev;
 909
 910         buffer = kmalloc(2, GFP_KERNEL);
 911         if (!buffer)
 912                 return -ENOMEM;
 913
 914         rv = usb_control_msg(data->usb_dev,
 915                              usb_rcvctrlpipe(data->usb_dev, 0),
 916                              USBTMC_REQUEST_INDICATOR_PULSE,
 917                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 918                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 919
 920         if (rv < 0) {
 921                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 922                 goto exit;
 923         }
 924
 925         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 926
 927         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 928                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 929                 rv = -EPERM;
 930                 goto exit;
 931         }
 932         rv = 0;
 933
 934 exit:
 935         kfree(buffer);
 936         return rv;
 937 }
 938
 939 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 940 {
 941         struct usbtmc_device_data *data;
 942         int retval = -EBADRQC;
 943
 944         data = file->private_data;
 945         mutex_lock(&data->io_mutex);
 946         if (data->zombie) {
 947                 retval = -ENODEV;
 948                 goto skip_io_on_zombie;
 949         }
 950
 951         switch (cmd) {
 952         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 953                 retval = usbtmc_ioctl_clear_out_halt(data);
 954                 break;
 955
 956         case USBTMC_IOCTL_CLEAR_IN_HALT:
 957                 retval = usbtmc_ioctl_clear_in_halt(data);
 958                 break;
 959
 960         case USBTMC_IOCTL_INDICATOR_PULSE:
 961                 retval = usbtmc_ioctl_indicator_pulse(data);
 962                 break;
 963
 964         case USBTMC_IOCTL_CLEAR:
 965                 retval = usbtmc_ioctl_clear(data);
 966                 break;
 967
 968         case USBTMC_IOCTL_ABORT_BULK_OUT:
 969                 retval = usbtmc_ioctl_abort_bulk_out(data);
 970                 break;
 971
 972         case USBTMC_IOCTL_ABORT_BULK_IN:
 973                 retval = usbtmc_ioctl_abort_bulk_in(data);
 974                 break;
 975         }
 976
 977 skip_io_on_zombie:
 978         mutex_unlock(&data->io_mutex);
 979         return retval;
 980 }
 981
 982 static const struct file_operations fops = {
 983         .owner          = THIS_MODULE,
 984         .read           = usbtmc_read,
 985         .write          = usbtmc_write,
 986         .open           = usbtmc_open,
 987         .release        = usbtmc_release,
 988         .unlocked_ioctl = usbtmc_ioctl,
 989         .llseek         = default_llseek,
 990 };
 991
 992 static struct usb_class_driver usbtmc_class = {
 993         .name =         "usbtmc%d",
 994         .fops =         &fops,
 995         .minor_base =   USBTMC_MINOR_BASE,
 996 };
 997
 998
 999 static int usbtmc_probe(struct usb_interface *intf,
1000                         const struct usb_device_id *id)
1001 {
1002         struct usbtmc_device_data *data;
1003         struct usb_host_interface *iface_desc;
1004         struct usb_endpoint_descriptor *endpoint;
1005         int n;
1006         int retcode;
1007
1008         dev_dbg(&intf->dev, "%s called\n", __func__);
1009
1010         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1011         if (!data) {
1012                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1013                 return -ENOMEM;
1014         }
1015
1016         data->intf = intf;
1017         data->id = id;
1018         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1019         usb_set_intfdata(intf, data);
1020         kref_init(&data->kref);
1021         mutex_init(&data->io_mutex);
1022         data->zombie = 0;
1023
1024         /* Initialize USBTMC bTag and other fields */
1025         data->bTag      = 1;
1026         data->TermCharEnabled = 0;
1027         data->TermChar = '\n';
1028
1029         /* USBTMC devices have only one setting, so use that */
1030         iface_desc = data->intf->cur_altsetting;
1031
1032         /* Find bulk in endpoint */
1033         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1034                 endpoint = &iface_desc->endpoint[n].desc;
1035
1036                 if (usb_endpoint_is_bulk_in(endpoint)) {
1037                         data->bulk_in = endpoint->bEndpointAddress;
1038                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1039                                 data->bulk_in);
1040                         break;
1041                 }
1042         }
1043
1044         /* Find bulk out endpoint */
1045         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1046                 endpoint = &iface_desc->endpoint[n].desc;
1047
1048                 if (usb_endpoint_is_bulk_out(endpoint)) {
1049                         data->bulk_out = endpoint->bEndpointAddress;
1050                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1051                                 data->bulk_out);
1052                         break;
1053                 }
1054         }
1055
1056         retcode = get_capabilities(data);
1057         if (retcode)
1058                 dev_err(&intf->dev, "can't read capabilities\n");
1059         else
1060                 retcode = sysfs_create_group(&intf->dev.kobj,
1061                                              &capability_attr_grp);
1062
1063         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1064
1065         retcode = usb_register_dev(intf, &usbtmc_class);
1066         if (retcode) {
1067                 dev_err(&intf->dev, "Not able to get a minor"
1068                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1069                         retcode);
1070                 goto error_register;
1071         }
1072         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1073
1074         return 0;
1075
1076 error_register:
1077         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1078         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1079         kref_put(&data->kref, usbtmc_delete);
1080         return retcode;
1081 }
1082
1083 static void usbtmc_disconnect(struct usb_interface *intf)
1084 {
1085         struct usbtmc_device_data *data;
1086
1087         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1088
1089         data = usb_get_intfdata(intf);
1090         usb_deregister_dev(intf, &usbtmc_class);
1091         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1092         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1093         mutex_lock(&data->io_mutex);
1094         data->zombie = 1;
1095         mutex_unlock(&data->io_mutex);
1096         kref_put(&data->kref, usbtmc_delete);
1097 }
1098
1099 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1100 {
1101         /* this driver does not have pending URBs */
1102         return 0;
1103 }
1104
1105 static int usbtmc_resume(struct usb_interface *intf)
1106 {
1107         return 0;
1108 }
1109
1110 static struct usb_driver usbtmc_driver = {
1111         .name           = "usbtmc",
1112         .id_table       = usbtmc_devices,
1113         .probe          = usbtmc_probe,
1114         .disconnect     = usbtmc_disconnect,
1115         .suspend        = usbtmc_suspend,
1116         .resume         = usbtmc_resume,
1117 };
1118
1119 static int __init usbtmc_init(void)
1120 {
1121         int retcode;
1122
1123         retcode = usb_register(&usbtmc_driver);
1124         if (retcode)
1125                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1126         return retcode;
1127 }
1128 module_init(usbtmc_init);
1129
1130 static void __exit usbtmc_exit(void)
1131 {
1132         usb_deregister(&usbtmc_driver);
1133 }
1134 module_exit(usbtmc_exit);
1135
1136 MODULE_LICENSE("GPL");