SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/usb/class/usbtmc.c

   1 /**
   2  * drivers/usb/class/usbtmc.c - USB Test & Measurment class driver
   3  *
   4  * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5  * Copyright (C) 2008 Novell, Inc.
   6  * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * The GNU General Public License is available at
  19  * http://www.gnu.org/copyleft/gpl.html.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/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                 /* Copy buffer to user space */
 477                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 478                         /* There must have been an addressing problem */
 479                         retval = -EFAULT;
 480                         goto exit;
 481                 }
 482
 483                 done += n_characters;
 484                 if (n_characters < USBTMC_SIZE_IOBUFFER)
 485                         remaining = 0;
 486                 else
 487                         remaining -= n_characters;
 488         }
 489
 490         /* Update file position value */
 491         *f_pos = *f_pos + done;
 492         retval = done;
 493
 494 exit:
 495         mutex_unlock(&data->io_mutex);
 496         kfree(buffer);
 497         return retval;
 498 }
 499
 500 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 501                             size_t count, loff_t *f_pos)
 502 {
 503         struct usbtmc_device_data *data;
 504         u8 *buffer;
 505         int retval;
 506         int actual;
 507         unsigned long int n_bytes;
 508         int remaining;
 509         int done;
 510         int this_part;
 511
 512         data = filp->private_data;
 513
 514         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 515         if (!buffer)
 516                 return -ENOMEM;
 517
 518         mutex_lock(&data->io_mutex);
 519         if (data->zombie) {
 520                 retval = -ENODEV;
 521                 goto exit;
 522         }
 523
 524         remaining = count;
 525         done = 0;
 526
 527         while (remaining > 0) {
 528                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 529                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 530                         buffer[8] = 0;
 531                 } else {
 532                         this_part = remaining;
 533                         buffer[8] = 1;
 534                 }
 535
 536                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 537                 buffer[0] = 1;
 538                 buffer[1] = data->bTag;
 539                 buffer[2] = ~(data->bTag);
 540                 buffer[3] = 0; /* Reserved */
 541                 buffer[4] = this_part & 255;
 542                 buffer[5] = (this_part >> 8) & 255;
 543                 buffer[6] = (this_part >> 16) & 255;
 544                 buffer[7] = (this_part >> 24) & 255;
 545                 /* buffer[8] is set above... */
 546                 buffer[9] = 0; /* Reserved */
 547                 buffer[10] = 0; /* Reserved */
 548                 buffer[11] = 0; /* Reserved */
 549
 550                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 551                         retval = -EFAULT;
 552                         goto exit;
 553                 }
 554
 555                 n_bytes = roundup(12 + this_part, 4);
 556                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 557
 558                 retval = usb_bulk_msg(data->usb_dev,
 559                                       usb_sndbulkpipe(data->usb_dev,
 560                                                       data->bulk_out),
 561                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 562
 563                 data->bTag_last_write = data->bTag;
 564                 data->bTag++;
 565
 566                 if (!data->bTag)
 567                         data->bTag++;
 568
 569                 if (retval < 0) {
 570                         dev_err(&data->intf->dev,
 571                                 "Unable to send data, error %d\n", retval);
 572                         if (data->auto_abort)
 573                                 usbtmc_ioctl_abort_bulk_out(data);
 574                         goto exit;
 575                 }
 576
 577                 remaining -= this_part;
 578                 done += this_part;
 579         }
 580
 581         retval = count;
 582 exit:
 583         mutex_unlock(&data->io_mutex);
 584         kfree(buffer);
 585         return retval;
 586 }
 587
 588 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 589 {
 590         struct usb_host_interface *current_setting;
 591         struct usb_endpoint_descriptor *desc;
 592         struct device *dev;
 593         u8 *buffer;
 594         int rv;
 595         int n;
 596         int actual;
 597         int max_size;
 598
 599         dev = &data->intf->dev;
 600
 601         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 602
 603         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 604         if (!buffer)
 605                 return -ENOMEM;
 606
 607         rv = usb_control_msg(data->usb_dev,
 608                              usb_rcvctrlpipe(data->usb_dev, 0),
 609                              USBTMC_REQUEST_INITIATE_CLEAR,
 610                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 611                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 612         if (rv < 0) {
 613                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 614                 goto exit;
 615         }
 616
 617         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 618
 619         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 620                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 621                 rv = -EPERM;
 622                 goto exit;
 623         }
 624
 625         max_size = 0;
 626         current_setting = data->intf->cur_altsetting;
 627         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 628                 desc = &current_setting->endpoint[n].desc;
 629                 if (desc->bEndpointAddress == data->bulk_in)
 630                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 631         }
 632
 633         if (max_size == 0) {
 634                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 635                 rv = -EPERM;
 636                 goto exit;
 637         }
 638
 639         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 640
 641         n = 0;
 642
 643 usbtmc_clear_check_status:
 644
 645         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 646
 647         rv = usb_control_msg(data->usb_dev,
 648                              usb_rcvctrlpipe(data->usb_dev, 0),
 649                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 650                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 651                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 652         if (rv < 0) {
 653                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 654                 goto exit;
 655         }
 656
 657         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 658
 659         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 660                 goto usbtmc_clear_bulk_out_halt;
 661
 662         if (buffer[0] != USBTMC_STATUS_PENDING) {
 663                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 664                 rv = -EPERM;
 665                 goto exit;
 666         }
 667
 668         if (buffer[1] == 1)
 669                 do {
 670                         dev_dbg(dev, "Reading from bulk in EP\n");
 671
 672                         rv = usb_bulk_msg(data->usb_dev,
 673                                           usb_rcvbulkpipe(data->usb_dev,
 674                                                           data->bulk_in),
 675                                           buffer, USBTMC_SIZE_IOBUFFER,
 676                                           &actual, USBTMC_TIMEOUT);
 677                         n++;
 678
 679                         if (rv < 0) {
 680                                 dev_err(dev, "usb_control_msg returned %d\n",
 681                                         rv);
 682                                 goto exit;
 683                         }
 684                 } while ((actual == max_size) &&
 685                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 686
 687         if (actual == max_size) {
 688                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 689                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 690                 rv = -EPERM;
 691                 goto exit;
 692         }
 693
 694         goto usbtmc_clear_check_status;
 695
 696 usbtmc_clear_bulk_out_halt:
 697
 698         rv = usb_control_msg(data->usb_dev,
 699                              usb_sndctrlpipe(data->usb_dev, 0),
 700                              USB_REQ_CLEAR_FEATURE,
 701                              USB_DIR_OUT | USB_TYPE_STANDARD |
 702                              USB_RECIP_ENDPOINT,
 703                              USB_ENDPOINT_HALT,
 704                              data->bulk_out, buffer, 0,
 705                              USBTMC_TIMEOUT);
 706         if (rv < 0) {
 707                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 708                 goto exit;
 709         }
 710         rv = 0;
 711
 712 exit:
 713         kfree(buffer);
 714         return rv;
 715 }
 716
 717 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 718 {
 719         u8 *buffer;
 720         int rv;
 721
 722         buffer = kmalloc(2, GFP_KERNEL);
 723         if (!buffer)
 724                 return -ENOMEM;
 725
 726         rv = usb_control_msg(data->usb_dev,
 727                              usb_sndctrlpipe(data->usb_dev, 0),
 728                              USB_REQ_CLEAR_FEATURE,
 729                              USB_DIR_OUT | USB_TYPE_STANDARD |
 730                              USB_RECIP_ENDPOINT,
 731                              USB_ENDPOINT_HALT, data->bulk_out,
 732                              buffer, 0, USBTMC_TIMEOUT);
 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_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 756                              USB_REQ_CLEAR_FEATURE,
 757                              USB_DIR_OUT | USB_TYPE_STANDARD |
 758                              USB_RECIP_ENDPOINT,
 759                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 760                              USBTMC_TIMEOUT);
 761
 762         if (rv < 0) {
 763                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 764                         rv);
 765                 goto exit;
 766         }
 767         rv = 0;
 768
 769 exit:
 770         kfree(buffer);
 771         return rv;
 772 }
 773
 774 static int get_capabilities(struct usbtmc_device_data *data)
 775 {
 776         struct device *dev = &data->usb_dev->dev;
 777         char *buffer;
 778         int rv = 0;
 779
 780         buffer = kmalloc(0x18, GFP_KERNEL);
 781         if (!buffer)
 782                 return -ENOMEM;
 783
 784         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 785                              USBTMC_REQUEST_GET_CAPABILITIES,
 786                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 787                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 788         if (rv < 0) {
 789                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 790                 goto err_out;
 791         }
 792
 793         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 794         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 795         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 796         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 797         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 798         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 799                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 800                 rv = -EPERM;
 801                 goto err_out;
 802         }
 803
 804         data->capabilities.interface_capabilities = buffer[4];
 805         data->capabilities.device_capabilities = buffer[5];
 806         data->capabilities.usb488_interface_capabilities = buffer[14];
 807         data->capabilities.usb488_device_capabilities = buffer[15];
 808
 809 err_out:
 810         kfree(buffer);
 811         return rv;
 812 }
 813
 814 #define capability_attribute(name)                                      \
 815 static ssize_t show_##name(struct device *dev,                          \
 816                            struct device_attribute *attr, char *buf)    \
 817 {                                                                       \
 818         struct usb_interface *intf = to_usb_interface(dev);             \
 819         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 820                                                                         \
 821         return sprintf(buf, "%d\n", data->capabilities.name);           \
 822 }                                                                       \
 823 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 824
 825 capability_attribute(interface_capabilities);
 826 capability_attribute(device_capabilities);
 827 capability_attribute(usb488_interface_capabilities);
 828 capability_attribute(usb488_device_capabilities);
 829
 830 static struct attribute *capability_attrs[] = {
 831         &dev_attr_interface_capabilities.attr,
 832         &dev_attr_device_capabilities.attr,
 833         &dev_attr_usb488_interface_capabilities.attr,
 834         &dev_attr_usb488_device_capabilities.attr,
 835         NULL,
 836 };
 837
 838 static struct attribute_group capability_attr_grp = {
 839         .attrs = capability_attrs,
 840 };
 841
 842 static ssize_t show_TermChar(struct device *dev,
 843                              struct device_attribute *attr, char *buf)
 844 {
 845         struct usb_interface *intf = to_usb_interface(dev);
 846         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 847
 848         return sprintf(buf, "%c\n", data->TermChar);
 849 }
 850
 851 static ssize_t store_TermChar(struct device *dev,
 852                               struct device_attribute *attr,
 853                               const char *buf, size_t count)
 854 {
 855         struct usb_interface *intf = to_usb_interface(dev);
 856         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 857
 858         if (count < 1)
 859                 return -EINVAL;
 860         data->TermChar = buf[0];
 861         return count;
 862 }
 863 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 864
 865 #define data_attribute(name)                                            \
 866 static ssize_t show_##name(struct device *dev,                          \
 867                            struct device_attribute *attr, char *buf)    \
 868 {                                                                       \
 869         struct usb_interface *intf = to_usb_interface(dev);             \
 870         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 871                                                                         \
 872         return sprintf(buf, "%d\n", data->name);                        \
 873 }                                                                       \
 874 static ssize_t store_##name(struct device *dev,                         \
 875                             struct device_attribute *attr,              \
 876                             const char *buf, size_t count)              \
 877 {                                                                       \
 878         struct usb_interface *intf = to_usb_interface(dev);             \
 879         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 880         ssize_t result;                                                 \
 881         unsigned val;                                                   \
 882                                                                         \
 883         result = sscanf(buf, "%u\n", &val);                             \
 884         if (result != 1)                                                \
 885                 result = -EINVAL;                                       \
 886         data->name = val;                                               \
 887         if (result < 0)                                                 \
 888                 return result;                                          \
 889         else                                                            \
 890                 return count;                                           \
 891 }                                                                       \
 892 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 893
 894 data_attribute(TermCharEnabled);
 895 data_attribute(auto_abort);
 896
 897 static struct attribute *data_attrs[] = {
 898         &dev_attr_TermChar.attr,
 899         &dev_attr_TermCharEnabled.attr,
 900         &dev_attr_auto_abort.attr,
 901         NULL,
 902 };
 903
 904 static struct attribute_group data_attr_grp = {
 905         .attrs = data_attrs,
 906 };
 907
 908 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 909 {
 910         struct device *dev;
 911         u8 *buffer;
 912         int rv;
 913
 914         dev = &data->intf->dev;
 915
 916         buffer = kmalloc(2, GFP_KERNEL);
 917         if (!buffer)
 918                 return -ENOMEM;
 919
 920         rv = usb_control_msg(data->usb_dev,
 921                              usb_rcvctrlpipe(data->usb_dev, 0),
 922                              USBTMC_REQUEST_INDICATOR_PULSE,
 923                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 924                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 925
 926         if (rv < 0) {
 927                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 928                 goto exit;
 929         }
 930
 931         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 932
 933         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 934                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 935                 rv = -EPERM;
 936                 goto exit;
 937         }
 938         rv = 0;
 939
 940 exit:
 941         kfree(buffer);
 942         return rv;
 943 }
 944
 945 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 946 {
 947         struct usbtmc_device_data *data;
 948         int retval = -EBADRQC;
 949
 950         data = file->private_data;
 951         mutex_lock(&data->io_mutex);
 952         if (data->zombie) {
 953                 retval = -ENODEV;
 954                 goto skip_io_on_zombie;
 955         }
 956
 957         switch (cmd) {
 958         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 959                 retval = usbtmc_ioctl_clear_out_halt(data);
 960                 break;
 961
 962         case USBTMC_IOCTL_CLEAR_IN_HALT:
 963                 retval = usbtmc_ioctl_clear_in_halt(data);
 964                 break;
 965
 966         case USBTMC_IOCTL_INDICATOR_PULSE:
 967                 retval = usbtmc_ioctl_indicator_pulse(data);
 968                 break;
 969
 970         case USBTMC_IOCTL_CLEAR:
 971                 retval = usbtmc_ioctl_clear(data);
 972                 break;
 973
 974         case USBTMC_IOCTL_ABORT_BULK_OUT:
 975                 retval = usbtmc_ioctl_abort_bulk_out(data);
 976                 break;
 977
 978         case USBTMC_IOCTL_ABORT_BULK_IN:
 979                 retval = usbtmc_ioctl_abort_bulk_in(data);
 980                 break;
 981         }
 982
 983 skip_io_on_zombie:
 984         mutex_unlock(&data->io_mutex);
 985         return retval;
 986 }
 987
 988 static struct file_operations fops = {
 989         .owner          = THIS_MODULE,
 990         .read           = usbtmc_read,
 991         .write          = usbtmc_write,
 992         .open           = usbtmc_open,
 993         .release        = usbtmc_release,
 994         .unlocked_ioctl = usbtmc_ioctl,
 995 };
 996
 997 static struct usb_class_driver usbtmc_class = {
 998         .name =         "usbtmc%d",
 999         .fops =         &fops,
1000         .minor_base =   USBTMC_MINOR_BASE,
1001 };
1002
1003
1004 static int usbtmc_probe(struct usb_interface *intf,
1005                         const struct usb_device_id *id)
1006 {
1007         struct usbtmc_device_data *data;
1008         struct usb_host_interface *iface_desc;
1009         struct usb_endpoint_descriptor *endpoint;
1010         int n;
1011         int retcode;
1012
1013         dev_dbg(&intf->dev, "%s called\n", __func__);
1014
1015         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1016         if (!data) {
1017                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1018                 return -ENOMEM;
1019         }
1020
1021         data->intf = intf;
1022         data->id = id;
1023         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1024         usb_set_intfdata(intf, data);
1025         kref_init(&data->kref);
1026         mutex_init(&data->io_mutex);
1027         data->zombie = 0;
1028
1029         /* Initialize USBTMC bTag and other fields */
1030         data->bTag      = 1;
1031         data->TermCharEnabled = 0;
1032         data->TermChar = '\n';
1033
1034         /* USBTMC devices have only one setting, so use that */
1035         iface_desc = data->intf->cur_altsetting;
1036
1037         /* Find bulk in endpoint */
1038         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1039                 endpoint = &iface_desc->endpoint[n].desc;
1040
1041                 if (usb_endpoint_is_bulk_in(endpoint)) {
1042                         data->bulk_in = endpoint->bEndpointAddress;
1043                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1044                                 data->bulk_in);
1045                         break;
1046                 }
1047         }
1048
1049         /* Find bulk out endpoint */
1050         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1051                 endpoint = &iface_desc->endpoint[n].desc;
1052
1053                 if (usb_endpoint_is_bulk_out(endpoint)) {
1054                         data->bulk_out = endpoint->bEndpointAddress;
1055                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1056                                 data->bulk_out);
1057                         break;
1058                 }
1059         }
1060
1061         retcode = get_capabilities(data);
1062         if (retcode)
1063                 dev_err(&intf->dev, "can't read capabilities\n");
1064         else
1065                 retcode = sysfs_create_group(&intf->dev.kobj,
1066                                              &capability_attr_grp);
1067
1068         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1069
1070         retcode = usb_register_dev(intf, &usbtmc_class);
1071         if (retcode) {
1072                 dev_err(&intf->dev, "Not able to get a minor"
1073                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1074                         retcode);
1075                 goto error_register;
1076         }
1077         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1078
1079         return 0;
1080
1081 error_register:
1082         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1083         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1084         kref_put(&data->kref, usbtmc_delete);
1085         return retcode;
1086 }
1087
1088 static void usbtmc_disconnect(struct usb_interface *intf)
1089 {
1090         struct usbtmc_device_data *data;
1091
1092         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1093
1094         data = usb_get_intfdata(intf);
1095         usb_deregister_dev(intf, &usbtmc_class);
1096         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1097         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1098         mutex_lock(&data->io_mutex);
1099         data->zombie = 1;
1100         mutex_unlock(&data->io_mutex);
1101         kref_put(&data->kref, usbtmc_delete);
1102 }
1103
1104 static int usbtmc_suspend (struct usb_interface *intf, pm_message_t message)
1105 {
1106         /* this driver does not have pending URBs */
1107         return 0;
1108 }
1109
1110 static int usbtmc_resume (struct usb_interface *intf)
1111 {
1112         return 0;
1113 }
1114
1115 static struct usb_driver usbtmc_driver = {
1116         .name           = "usbtmc",
1117         .id_table       = usbtmc_devices,
1118         .probe          = usbtmc_probe,
1119         .disconnect     = usbtmc_disconnect,
1120         .suspend        = usbtmc_suspend,
1121         .resume         = usbtmc_resume,
1122 };
1123
1124 static int __init usbtmc_init(void)
1125 {
1126         int retcode;
1127
1128         retcode = usb_register(&usbtmc_driver);
1129         if (retcode)
1130                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1131         return retcode;
1132 }
1133 module_init(usbtmc_init);
1134
1135 static void __exit usbtmc_exit(void)
1136 {
1137         usb_deregister(&usbtmc_driver);
1138 }
1139 module_exit(usbtmc_exit);
1140
1141 MODULE_LICENSE("GPL");