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/mutex.h>
  29 #include <linux/smp_lock.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         lock_kernel();
 118         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 119         if (!intf) {
 120                 printk(KERN_ERR KBUILD_MODNAME
 121                        ": can not find device for minor %d", iminor(inode));
 122                 retval = -ENODEV;
 123                 goto exit;
 124         }
 125
 126         data = usb_get_intfdata(intf);
 127         kref_get(&data->kref);
 128
 129         /* Store pointer in file structure's private data field */
 130         filp->private_data = data;
 131
 132 exit:
 133         unlock_kernel();
 134         return retval;
 135 }
 136
 137 static int usbtmc_release(struct inode *inode, struct file *file)
 138 {
 139         struct usbtmc_device_data *data = file->private_data;
 140
 141         kref_put(&data->kref, usbtmc_delete);
 142         return 0;
 143 }
 144
 145 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 146 {
 147         u8 *buffer;
 148         struct device *dev;
 149         int rv;
 150         int n;
 151         int actual;
 152         struct usb_host_interface *current_setting;
 153         int max_size;
 154
 155         dev = &data->intf->dev;
 156         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 157         if (!buffer)
 158                 return -ENOMEM;
 159
 160         rv = usb_control_msg(data->usb_dev,
 161                              usb_rcvctrlpipe(data->usb_dev, 0),
 162                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 163                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 164                              data->bTag_last_read, data->bulk_in,
 165                              buffer, 2, USBTMC_TIMEOUT);
 166
 167         if (rv < 0) {
 168                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 169                 goto exit;
 170         }
 171
 172         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 173
 174         if (buffer[0] == USBTMC_STATUS_FAILED) {
 175                 rv = 0;
 176                 goto exit;
 177         }
 178
 179         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 180                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 181                         buffer[0]);
 182                 rv = -EPERM;
 183                 goto exit;
 184         }
 185
 186         max_size = 0;
 187         current_setting = data->intf->cur_altsetting;
 188         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 189                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 190                         data->bulk_in)
 191                         max_size = le16_to_cpu(current_setting->endpoint[n].
 192                                                 desc.wMaxPacketSize);
 193
 194         if (max_size == 0) {
 195                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 196                 rv = -EPERM;
 197                 goto exit;
 198         }
 199
 200         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 201
 202         n = 0;
 203
 204         do {
 205                 dev_dbg(dev, "Reading from bulk in EP\n");
 206
 207                 rv = usb_bulk_msg(data->usb_dev,
 208                                   usb_rcvbulkpipe(data->usb_dev,
 209                                                   data->bulk_in),
 210                                   buffer, USBTMC_SIZE_IOBUFFER,
 211                                   &actual, USBTMC_TIMEOUT);
 212
 213                 n++;
 214
 215                 if (rv < 0) {
 216                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 217                         goto exit;
 218                 }
 219         } while ((actual == max_size) &&
 220                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 221
 222         if (actual == max_size) {
 223                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 224                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 225                 rv = -EPERM;
 226                 goto exit;
 227         }
 228
 229         n = 0;
 230
 231 usbtmc_abort_bulk_in_status:
 232         rv = usb_control_msg(data->usb_dev,
 233                              usb_rcvctrlpipe(data->usb_dev, 0),
 234                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 235                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 236                              0, data->bulk_in, buffer, 0x08,
 237                              USBTMC_TIMEOUT);
 238
 239         if (rv < 0) {
 240                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 241                 goto exit;
 242         }
 243
 244         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 245
 246         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 247                 rv = 0;
 248                 goto exit;
 249         }
 250
 251         if (buffer[0] != USBTMC_STATUS_PENDING) {
 252                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 253                 rv = -EPERM;
 254                 goto exit;
 255         }
 256
 257         if (buffer[1] == 1)
 258                 do {
 259                         dev_dbg(dev, "Reading from bulk in EP\n");
 260
 261                         rv = usb_bulk_msg(data->usb_dev,
 262                                           usb_rcvbulkpipe(data->usb_dev,
 263                                                           data->bulk_in),
 264                                           buffer, USBTMC_SIZE_IOBUFFER,
 265                                           &actual, USBTMC_TIMEOUT);
 266
 267                         n++;
 268
 269                         if (rv < 0) {
 270                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 271                                 goto exit;
 272                         }
 273                 } while ((actual = max_size) &&
 274                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 275
 276         if (actual == max_size) {
 277                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 278                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 279                 rv = -EPERM;
 280                 goto exit;
 281         }
 282
 283         goto usbtmc_abort_bulk_in_status;
 284
 285 exit:
 286         kfree(buffer);
 287         return rv;
 288
 289 }
 290
 291 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 292 {
 293         struct device *dev;
 294         u8 *buffer;
 295         int rv;
 296         int n;
 297
 298         dev = &data->intf->dev;
 299
 300         buffer = kmalloc(8, GFP_KERNEL);
 301         if (!buffer)
 302                 return -ENOMEM;
 303
 304         rv = usb_control_msg(data->usb_dev,
 305                              usb_rcvctrlpipe(data->usb_dev, 0),
 306                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 307                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 308                              data->bTag_last_write, data->bulk_out,
 309                              buffer, 2, USBTMC_TIMEOUT);
 310
 311         if (rv < 0) {
 312                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 313                 goto exit;
 314         }
 315
 316         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 317
 318         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 319                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 320                         buffer[0]);
 321                 rv = -EPERM;
 322                 goto exit;
 323         }
 324
 325         n = 0;
 326
 327 usbtmc_abort_bulk_out_check_status:
 328         rv = usb_control_msg(data->usb_dev,
 329                              usb_rcvctrlpipe(data->usb_dev, 0),
 330                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 331                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 332                              0, data->bulk_out, buffer, 0x08,
 333                              USBTMC_TIMEOUT);
 334         n++;
 335         if (rv < 0) {
 336                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 337                 goto exit;
 338         }
 339
 340         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 341
 342         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 343                 goto usbtmc_abort_bulk_out_clear_halt;
 344
 345         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 346             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 347                 goto usbtmc_abort_bulk_out_check_status;
 348
 349         rv = -EPERM;
 350         goto exit;
 351
 352 usbtmc_abort_bulk_out_clear_halt:
 353         rv = usb_clear_halt(data->usb_dev,
 354                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 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                 do {
 564                         retval = usb_bulk_msg(data->usb_dev,
 565                                               usb_sndbulkpipe(data->usb_dev,
 566                                                               data->bulk_out),
 567                                               buffer, n_bytes,
 568                                               &actual, USBTMC_TIMEOUT);
 569                         if (retval != 0)
 570                                 break;
 571                         n_bytes -= actual;
 572                 } while (n_bytes);
 573
 574                 data->bTag_last_write = data->bTag;
 575                 data->bTag++;
 576
 577                 if (!data->bTag)
 578                         data->bTag++;
 579
 580                 if (retval < 0) {
 581                         dev_err(&data->intf->dev,
 582                                 "Unable to send data, error %d\n", retval);
 583                         if (data->auto_abort)
 584                                 usbtmc_ioctl_abort_bulk_out(data);
 585                         goto exit;
 586                 }
 587
 588                 remaining -= this_part;
 589                 done += this_part;
 590         }
 591
 592         retval = count;
 593 exit:
 594         mutex_unlock(&data->io_mutex);
 595         kfree(buffer);
 596         return retval;
 597 }
 598
 599 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 600 {
 601         struct usb_host_interface *current_setting;
 602         struct usb_endpoint_descriptor *desc;
 603         struct device *dev;
 604         u8 *buffer;
 605         int rv;
 606         int n;
 607         int actual;
 608         int max_size;
 609
 610         dev = &data->intf->dev;
 611
 612         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 613
 614         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 615         if (!buffer)
 616                 return -ENOMEM;
 617
 618         rv = usb_control_msg(data->usb_dev,
 619                              usb_rcvctrlpipe(data->usb_dev, 0),
 620                              USBTMC_REQUEST_INITIATE_CLEAR,
 621                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 622                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 623         if (rv < 0) {
 624                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 625                 goto exit;
 626         }
 627
 628         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 629
 630         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 631                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 632                 rv = -EPERM;
 633                 goto exit;
 634         }
 635
 636         max_size = 0;
 637         current_setting = data->intf->cur_altsetting;
 638         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 639                 desc = &current_setting->endpoint[n].desc;
 640                 if (desc->bEndpointAddress == data->bulk_in)
 641                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 642         }
 643
 644         if (max_size == 0) {
 645                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 646                 rv = -EPERM;
 647                 goto exit;
 648         }
 649
 650         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 651
 652         n = 0;
 653
 654 usbtmc_clear_check_status:
 655
 656         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 657
 658         rv = usb_control_msg(data->usb_dev,
 659                              usb_rcvctrlpipe(data->usb_dev, 0),
 660                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 661                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 662                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 663         if (rv < 0) {
 664                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 665                 goto exit;
 666         }
 667
 668         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 669
 670         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 671                 goto usbtmc_clear_bulk_out_halt;
 672
 673         if (buffer[0] != USBTMC_STATUS_PENDING) {
 674                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 675                 rv = -EPERM;
 676                 goto exit;
 677         }
 678
 679         if (buffer[1] == 1)
 680                 do {
 681                         dev_dbg(dev, "Reading from bulk in EP\n");
 682
 683                         rv = usb_bulk_msg(data->usb_dev,
 684                                           usb_rcvbulkpipe(data->usb_dev,
 685                                                           data->bulk_in),
 686                                           buffer, USBTMC_SIZE_IOBUFFER,
 687                                           &actual, USBTMC_TIMEOUT);
 688                         n++;
 689
 690                         if (rv < 0) {
 691                                 dev_err(dev, "usb_control_msg returned %d\n",
 692                                         rv);
 693                                 goto exit;
 694                         }
 695                 } while ((actual == max_size) &&
 696                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 697
 698         if (actual == max_size) {
 699                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 700                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 701                 rv = -EPERM;
 702                 goto exit;
 703         }
 704
 705         goto usbtmc_clear_check_status;
 706
 707 usbtmc_clear_bulk_out_halt:
 708
 709         rv = usb_clear_halt(data->usb_dev,
 710                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 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_clear_halt(data->usb_dev,
 732                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 733
 734         if (rv < 0) {
 735                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 736                         rv);
 737                 goto exit;
 738         }
 739         rv = 0;
 740
 741 exit:
 742         kfree(buffer);
 743         return rv;
 744 }
 745
 746 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 747 {
 748         u8 *buffer;
 749         int rv;
 750
 751         buffer = kmalloc(2, GFP_KERNEL);
 752         if (!buffer)
 753                 return -ENOMEM;
 754
 755         rv = usb_clear_halt(data->usb_dev,
 756                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 757
 758         if (rv < 0) {
 759                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 760                         rv);
 761                 goto exit;
 762         }
 763         rv = 0;
 764
 765 exit:
 766         kfree(buffer);
 767         return rv;
 768 }
 769
 770 static int get_capabilities(struct usbtmc_device_data *data)
 771 {
 772         struct device *dev = &data->usb_dev->dev;
 773         char *buffer;
 774         int rv = 0;
 775
 776         buffer = kmalloc(0x18, GFP_KERNEL);
 777         if (!buffer)
 778                 return -ENOMEM;
 779
 780         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 781                              USBTMC_REQUEST_GET_CAPABILITIES,
 782                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 783                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 784         if (rv < 0) {
 785                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 786                 goto err_out;
 787         }
 788
 789         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 790         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 791                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 792                 rv = -EPERM;
 793                 goto err_out;
 794         }
 795         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 796         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 797         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 798         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 799
 800         data->capabilities.interface_capabilities = buffer[4];
 801         data->capabilities.device_capabilities = buffer[5];
 802         data->capabilities.usb488_interface_capabilities = buffer[14];
 803         data->capabilities.usb488_device_capabilities = buffer[15];
 804         rv = 0;
 805
 806 err_out:
 807         kfree(buffer);
 808         return rv;
 809 }
 810
 811 #define capability_attribute(name)                                      \
 812 static ssize_t show_##name(struct device *dev,                          \
 813                            struct device_attribute *attr, char *buf)    \
 814 {                                                                       \
 815         struct usb_interface *intf = to_usb_interface(dev);             \
 816         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 817                                                                         \
 818         return sprintf(buf, "%d\n", data->capabilities.name);           \
 819 }                                                                       \
 820 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 821
 822 capability_attribute(interface_capabilities);
 823 capability_attribute(device_capabilities);
 824 capability_attribute(usb488_interface_capabilities);
 825 capability_attribute(usb488_device_capabilities);
 826
 827 static struct attribute *capability_attrs[] = {
 828         &dev_attr_interface_capabilities.attr,
 829         &dev_attr_device_capabilities.attr,
 830         &dev_attr_usb488_interface_capabilities.attr,
 831         &dev_attr_usb488_device_capabilities.attr,
 832         NULL,
 833 };
 834
 835 static struct attribute_group capability_attr_grp = {
 836         .attrs = capability_attrs,
 837 };
 838
 839 static ssize_t show_TermChar(struct device *dev,
 840                              struct device_attribute *attr, char *buf)
 841 {
 842         struct usb_interface *intf = to_usb_interface(dev);
 843         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 844
 845         return sprintf(buf, "%c\n", data->TermChar);
 846 }
 847
 848 static ssize_t store_TermChar(struct device *dev,
 849                               struct device_attribute *attr,
 850                               const char *buf, size_t count)
 851 {
 852         struct usb_interface *intf = to_usb_interface(dev);
 853         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 854
 855         if (count < 1)
 856                 return -EINVAL;
 857         data->TermChar = buf[0];
 858         return count;
 859 }
 860 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 861
 862 #define data_attribute(name)                                            \
 863 static ssize_t show_##name(struct device *dev,                          \
 864                            struct device_attribute *attr, char *buf)    \
 865 {                                                                       \
 866         struct usb_interface *intf = to_usb_interface(dev);             \
 867         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 868                                                                         \
 869         return sprintf(buf, "%d\n", data->name);                        \
 870 }                                                                       \
 871 static ssize_t store_##name(struct device *dev,                         \
 872                             struct device_attribute *attr,              \
 873                             const char *buf, size_t count)              \
 874 {                                                                       \
 875         struct usb_interface *intf = to_usb_interface(dev);             \
 876         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 877         ssize_t result;                                                 \
 878         unsigned val;                                                   \
 879                                                                         \
 880         result = sscanf(buf, "%u\n", &val);                             \
 881         if (result != 1)                                                \
 882                 result = -EINVAL;                                       \
 883         data->name = val;                                               \
 884         if (result < 0)                                                 \
 885                 return result;                                          \
 886         else                                                            \
 887                 return count;                                           \
 888 }                                                                       \
 889 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 890
 891 data_attribute(TermCharEnabled);
 892 data_attribute(auto_abort);
 893
 894 static struct attribute *data_attrs[] = {
 895         &dev_attr_TermChar.attr,
 896         &dev_attr_TermCharEnabled.attr,
 897         &dev_attr_auto_abort.attr,
 898         NULL,
 899 };
 900
 901 static struct attribute_group data_attr_grp = {
 902         .attrs = data_attrs,
 903 };
 904
 905 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 906 {
 907         struct device *dev;
 908         u8 *buffer;
 909         int rv;
 910
 911         dev = &data->intf->dev;
 912
 913         buffer = kmalloc(2, GFP_KERNEL);
 914         if (!buffer)
 915                 return -ENOMEM;
 916
 917         rv = usb_control_msg(data->usb_dev,
 918                              usb_rcvctrlpipe(data->usb_dev, 0),
 919                              USBTMC_REQUEST_INDICATOR_PULSE,
 920                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 921                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 922
 923         if (rv < 0) {
 924                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 925                 goto exit;
 926         }
 927
 928         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 929
 930         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 931                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 932                 rv = -EPERM;
 933                 goto exit;
 934         }
 935         rv = 0;
 936
 937 exit:
 938         kfree(buffer);
 939         return rv;
 940 }
 941
 942 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 943 {
 944         struct usbtmc_device_data *data;
 945         int retval = -EBADRQC;
 946
 947         data = file->private_data;
 948         mutex_lock(&data->io_mutex);
 949         if (data->zombie) {
 950                 retval = -ENODEV;
 951                 goto skip_io_on_zombie;
 952         }
 953
 954         switch (cmd) {
 955         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 956                 retval = usbtmc_ioctl_clear_out_halt(data);
 957                 break;
 958
 959         case USBTMC_IOCTL_CLEAR_IN_HALT:
 960                 retval = usbtmc_ioctl_clear_in_halt(data);
 961                 break;
 962
 963         case USBTMC_IOCTL_INDICATOR_PULSE:
 964                 retval = usbtmc_ioctl_indicator_pulse(data);
 965                 break;
 966
 967         case USBTMC_IOCTL_CLEAR:
 968                 retval = usbtmc_ioctl_clear(data);
 969                 break;
 970
 971         case USBTMC_IOCTL_ABORT_BULK_OUT:
 972                 retval = usbtmc_ioctl_abort_bulk_out(data);
 973                 break;
 974
 975         case USBTMC_IOCTL_ABORT_BULK_IN:
 976                 retval = usbtmc_ioctl_abort_bulk_in(data);
 977                 break;
 978         }
 979
 980 skip_io_on_zombie:
 981         mutex_unlock(&data->io_mutex);
 982         return retval;
 983 }
 984
 985 static const struct file_operations fops = {
 986         .owner          = THIS_MODULE,
 987         .read           = usbtmc_read,
 988         .write          = usbtmc_write,
 989         .open           = usbtmc_open,
 990         .release        = usbtmc_release,
 991         .unlocked_ioctl = usbtmc_ioctl,
 992 };
 993
 994 static struct usb_class_driver usbtmc_class = {
 995         .name =         "usbtmc%d",
 996         .fops =         &fops,
 997         .minor_base =   USBTMC_MINOR_BASE,
 998 };
 999
1000
1001 static int usbtmc_probe(struct usb_interface *intf,
1002                         const struct usb_device_id *id)
1003 {
1004         struct usbtmc_device_data *data;
1005         struct usb_host_interface *iface_desc;
1006         struct usb_endpoint_descriptor *endpoint;
1007         int n;
1008         int retcode;
1009
1010         dev_dbg(&intf->dev, "%s called\n", __func__);
1011
1012         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1013         if (!data) {
1014                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1015                 return -ENOMEM;
1016         }
1017
1018         data->intf = intf;
1019         data->id = id;
1020         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1021         usb_set_intfdata(intf, data);
1022         kref_init(&data->kref);
1023         mutex_init(&data->io_mutex);
1024         data->zombie = 0;
1025
1026         /* Initialize USBTMC bTag and other fields */
1027         data->bTag      = 1;
1028         data->TermCharEnabled = 0;
1029         data->TermChar = '\n';
1030
1031         /* USBTMC devices have only one setting, so use that */
1032         iface_desc = data->intf->cur_altsetting;
1033
1034         /* Find bulk in endpoint */
1035         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1036                 endpoint = &iface_desc->endpoint[n].desc;
1037
1038                 if (usb_endpoint_is_bulk_in(endpoint)) {
1039                         data->bulk_in = endpoint->bEndpointAddress;
1040                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1041                                 data->bulk_in);
1042                         break;
1043                 }
1044         }
1045
1046         /* Find bulk out endpoint */
1047         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1048                 endpoint = &iface_desc->endpoint[n].desc;
1049
1050                 if (usb_endpoint_is_bulk_out(endpoint)) {
1051                         data->bulk_out = endpoint->bEndpointAddress;
1052                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1053                                 data->bulk_out);
1054                         break;
1055                 }
1056         }
1057
1058         retcode = get_capabilities(data);
1059         if (retcode)
1060                 dev_err(&intf->dev, "can't read capabilities\n");
1061         else
1062                 retcode = sysfs_create_group(&intf->dev.kobj,
1063                                              &capability_attr_grp);
1064
1065         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1066
1067         retcode = usb_register_dev(intf, &usbtmc_class);
1068         if (retcode) {
1069                 dev_err(&intf->dev, "Not able to get a minor"
1070                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1071                         retcode);
1072                 goto error_register;
1073         }
1074         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1075
1076         return 0;
1077
1078 error_register:
1079         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1080         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1081         kref_put(&data->kref, usbtmc_delete);
1082         return retcode;
1083 }
1084
1085 static void usbtmc_disconnect(struct usb_interface *intf)
1086 {
1087         struct usbtmc_device_data *data;
1088
1089         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1090
1091         data = usb_get_intfdata(intf);
1092         usb_deregister_dev(intf, &usbtmc_class);
1093         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1094         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1095         mutex_lock(&data->io_mutex);
1096         data->zombie = 1;
1097         mutex_unlock(&data->io_mutex);
1098         kref_put(&data->kref, usbtmc_delete);
1099 }
1100
1101 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1102 {
1103         /* this driver does not have pending URBs */
1104         return 0;
1105 }
1106
1107 static int usbtmc_resume(struct usb_interface *intf)
1108 {
1109         return 0;
1110 }
1111
1112 static struct usb_driver usbtmc_driver = {
1113         .name           = "usbtmc",
1114         .id_table       = usbtmc_devices,
1115         .probe          = usbtmc_probe,
1116         .disconnect     = usbtmc_disconnect,
1117         .suspend        = usbtmc_suspend,
1118         .resume         = usbtmc_resume,
1119 };
1120
1121 static int __init usbtmc_init(void)
1122 {
1123         int retcode;
1124
1125         retcode = usb_register(&usbtmc_driver);
1126         if (retcode)
1127                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1128         return retcode;
1129 }
1130 module_init(usbtmc_init);
1131
1132 static void __exit usbtmc_exit(void)
1133 {
1134         usb_deregister(&usbtmc_driver);
1135 }
1136 module_exit(usbtmc_exit);
1137
1138 MODULE_LICENSE("GPL");