Pileus Git - ~andy/linux/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         unsigned long int n_characters;
 373         u8 *buffer;
 374         int actual;
 375         int done;
 376         int remaining;
 377         int retval;
 378         int 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 - 12 - 3) & 255;
 411                 buffer[5] = ((this_part - 12 - 3) >> 8) & 255;
 412                 buffer[6] = ((this_part - 12 - 3) >> 16) & 255;
 413                 buffer[7] = ((this_part - 12 - 3) >> 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                 /* Copy buffer to user space */
 465                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 466                         /* There must have been an addressing problem */
 467                         retval = -EFAULT;
 468                         goto exit;
 469                 }
 470
 471                 done += n_characters;
 472                 if (n_characters < USBTMC_SIZE_IOBUFFER)
 473                         remaining = 0;
 474         }
 475
 476         /* Update file position value */
 477         *f_pos = *f_pos + done;
 478         retval = done;
 479
 480 exit:
 481         mutex_unlock(&data->io_mutex);
 482         kfree(buffer);
 483         return retval;
 484 }
 485
 486 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 487                             size_t count, loff_t *f_pos)
 488 {
 489         struct usbtmc_device_data *data;
 490         u8 *buffer;
 491         int retval;
 492         int actual;
 493         unsigned long int n_bytes;
 494         int remaining;
 495         int done;
 496         int this_part;
 497
 498         data = filp->private_data;
 499
 500         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 501         if (!buffer)
 502                 return -ENOMEM;
 503
 504         mutex_lock(&data->io_mutex);
 505         if (data->zombie) {
 506                 retval = -ENODEV;
 507                 goto exit;
 508         }
 509
 510         remaining = count;
 511         done = 0;
 512
 513         while (remaining > 0) {
 514                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 515                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 516                         buffer[8] = 0;
 517                 } else {
 518                         this_part = remaining;
 519                         buffer[8] = 1;
 520                 }
 521
 522                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 523                 buffer[0] = 1;
 524                 buffer[1] = data->bTag;
 525                 buffer[2] = ~(data->bTag);
 526                 buffer[3] = 0; /* Reserved */
 527                 buffer[4] = this_part & 255;
 528                 buffer[5] = (this_part >> 8) & 255;
 529                 buffer[6] = (this_part >> 16) & 255;
 530                 buffer[7] = (this_part >> 24) & 255;
 531                 /* buffer[8] is set above... */
 532                 buffer[9] = 0; /* Reserved */
 533                 buffer[10] = 0; /* Reserved */
 534                 buffer[11] = 0; /* Reserved */
 535
 536                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 537                         retval = -EFAULT;
 538                         goto exit;
 539                 }
 540
 541                 n_bytes = roundup(12 + this_part, 4);
 542                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 543
 544                 retval = usb_bulk_msg(data->usb_dev,
 545                                       usb_sndbulkpipe(data->usb_dev,
 546                                                       data->bulk_out),
 547                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 548
 549                 data->bTag_last_write = data->bTag;
 550                 data->bTag++;
 551
 552                 if (!data->bTag)
 553                         data->bTag++;
 554
 555                 if (retval < 0) {
 556                         dev_err(&data->intf->dev,
 557                                 "Unable to send data, error %d\n", retval);
 558                         if (data->auto_abort)
 559                                 usbtmc_ioctl_abort_bulk_out(data);
 560                         goto exit;
 561                 }
 562
 563                 remaining -= this_part;
 564                 done += this_part;
 565         }
 566
 567         retval = count;
 568 exit:
 569         mutex_unlock(&data->io_mutex);
 570         kfree(buffer);
 571         return retval;
 572 }
 573
 574 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 575 {
 576         struct usb_host_interface *current_setting;
 577         struct usb_endpoint_descriptor *desc;
 578         struct device *dev;
 579         u8 *buffer;
 580         int rv;
 581         int n;
 582         int actual;
 583         int max_size;
 584
 585         dev = &data->intf->dev;
 586
 587         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 588
 589         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 590         if (!buffer)
 591                 return -ENOMEM;
 592
 593         rv = usb_control_msg(data->usb_dev,
 594                              usb_rcvctrlpipe(data->usb_dev, 0),
 595                              USBTMC_REQUEST_INITIATE_CLEAR,
 596                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 597                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 598         if (rv < 0) {
 599                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 600                 goto exit;
 601         }
 602
 603         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 604
 605         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 606                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 607                 rv = -EPERM;
 608                 goto exit;
 609         }
 610
 611         max_size = 0;
 612         current_setting = data->intf->cur_altsetting;
 613         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 614                 desc = &current_setting->endpoint[n].desc;
 615                 if (desc->bEndpointAddress == data->bulk_in)
 616                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 617         }
 618
 619         if (max_size == 0) {
 620                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 621                 rv = -EPERM;
 622                 goto exit;
 623         }
 624
 625         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 626
 627         n = 0;
 628
 629 usbtmc_clear_check_status:
 630
 631         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 632
 633         rv = usb_control_msg(data->usb_dev,
 634                              usb_rcvctrlpipe(data->usb_dev, 0),
 635                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 636                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 637                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 638         if (rv < 0) {
 639                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 640                 goto exit;
 641         }
 642
 643         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 644
 645         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 646                 goto usbtmc_clear_bulk_out_halt;
 647
 648         if (buffer[0] != USBTMC_STATUS_PENDING) {
 649                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 650                 rv = -EPERM;
 651                 goto exit;
 652         }
 653
 654         if (buffer[1] == 1)
 655                 do {
 656                         dev_dbg(dev, "Reading from bulk in EP\n");
 657
 658                         rv = usb_bulk_msg(data->usb_dev,
 659                                           usb_rcvbulkpipe(data->usb_dev,
 660                                                           data->bulk_in),
 661                                           buffer, USBTMC_SIZE_IOBUFFER,
 662                                           &actual, USBTMC_TIMEOUT);
 663                         n++;
 664
 665                         if (rv < 0) {
 666                                 dev_err(dev, "usb_control_msg returned %d\n",
 667                                         rv);
 668                                 goto exit;
 669                         }
 670                 } while ((actual == max_size) &&
 671                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 672
 673         if (actual == max_size) {
 674                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 675                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 676                 rv = -EPERM;
 677                 goto exit;
 678         }
 679
 680         goto usbtmc_clear_check_status;
 681
 682 usbtmc_clear_bulk_out_halt:
 683
 684         rv = usb_control_msg(data->usb_dev,
 685                              usb_sndctrlpipe(data->usb_dev, 0),
 686                              USB_REQ_CLEAR_FEATURE,
 687                              USB_DIR_OUT | USB_TYPE_STANDARD |
 688                              USB_RECIP_ENDPOINT,
 689                              USB_ENDPOINT_HALT,
 690                              data->bulk_out, buffer, 0,
 691                              USBTMC_TIMEOUT);
 692         if (rv < 0) {
 693                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 694                 goto exit;
 695         }
 696         rv = 0;
 697
 698 exit:
 699         kfree(buffer);
 700         return rv;
 701 }
 702
 703 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 704 {
 705         u8 *buffer;
 706         int rv;
 707
 708         buffer = kmalloc(2, GFP_KERNEL);
 709         if (!buffer)
 710                 return -ENOMEM;
 711
 712         rv = usb_control_msg(data->usb_dev,
 713                              usb_sndctrlpipe(data->usb_dev, 0),
 714                              USB_REQ_CLEAR_FEATURE,
 715                              USB_DIR_OUT | USB_TYPE_STANDARD |
 716                              USB_RECIP_ENDPOINT,
 717                              USB_ENDPOINT_HALT, data->bulk_out,
 718                              buffer, 0, USBTMC_TIMEOUT);
 719
 720         if (rv < 0) {
 721                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 722                         rv);
 723                 goto exit;
 724         }
 725         rv = 0;
 726
 727 exit:
 728         kfree(buffer);
 729         return rv;
 730 }
 731
 732 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 733 {
 734         u8 *buffer;
 735         int rv;
 736
 737         buffer = kmalloc(2, GFP_KERNEL);
 738         if (!buffer)
 739                 return -ENOMEM;
 740
 741         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 742                              USB_REQ_CLEAR_FEATURE,
 743                              USB_DIR_OUT | USB_TYPE_STANDARD |
 744                              USB_RECIP_ENDPOINT,
 745                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 746                              USBTMC_TIMEOUT);
 747
 748         if (rv < 0) {
 749                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 750                         rv);
 751                 goto exit;
 752         }
 753         rv = 0;
 754
 755 exit:
 756         kfree(buffer);
 757         return rv;
 758 }
 759
 760 static int get_capabilities(struct usbtmc_device_data *data)
 761 {
 762         struct device *dev = &data->usb_dev->dev;
 763         char *buffer;
 764         int rv = 0;
 765
 766         buffer = kmalloc(0x18, GFP_KERNEL);
 767         if (!buffer)
 768                 return -ENOMEM;
 769
 770         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 771                              USBTMC_REQUEST_GET_CAPABILITIES,
 772                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 773                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 774         if (rv < 0) {
 775                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 776                 goto err_out;
 777         }
 778
 779         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 780         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 781         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 782         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 783         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 784         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 785                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 786                 rv = -EPERM;
 787                 goto err_out;
 788         }
 789
 790         data->capabilities.interface_capabilities = buffer[4];
 791         data->capabilities.device_capabilities = buffer[5];
 792         data->capabilities.usb488_interface_capabilities = buffer[14];
 793         data->capabilities.usb488_device_capabilities = buffer[15];
 794
 795 err_out:
 796         kfree(buffer);
 797         return rv;
 798 }
 799
 800 #define capability_attribute(name)                                      \
 801 static ssize_t show_##name(struct device *dev,                          \
 802                            struct device_attribute *attr, char *buf)    \
 803 {                                                                       \
 804         struct usb_interface *intf = to_usb_interface(dev);             \
 805         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 806                                                                         \
 807         return sprintf(buf, "%d\n", data->capabilities.name);           \
 808 }                                                                       \
 809 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 810
 811 capability_attribute(interface_capabilities);
 812 capability_attribute(device_capabilities);
 813 capability_attribute(usb488_interface_capabilities);
 814 capability_attribute(usb488_device_capabilities);
 815
 816 static struct attribute *capability_attrs[] = {
 817         &dev_attr_interface_capabilities.attr,
 818         &dev_attr_device_capabilities.attr,
 819         &dev_attr_usb488_interface_capabilities.attr,
 820         &dev_attr_usb488_device_capabilities.attr,
 821         NULL,
 822 };
 823
 824 static struct attribute_group capability_attr_grp = {
 825         .attrs = capability_attrs,
 826 };
 827
 828 static ssize_t show_TermChar(struct device *dev,
 829                              struct device_attribute *attr, char *buf)
 830 {
 831         struct usb_interface *intf = to_usb_interface(dev);
 832         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 833
 834         return sprintf(buf, "%c\n", data->TermChar);
 835 }
 836
 837 static ssize_t store_TermChar(struct device *dev,
 838                               struct device_attribute *attr,
 839                               const char *buf, size_t count)
 840 {
 841         struct usb_interface *intf = to_usb_interface(dev);
 842         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 843
 844         if (count < 1)
 845                 return -EINVAL;
 846         data->TermChar = buf[0];
 847         return count;
 848 }
 849 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 850
 851 #define data_attribute(name)                                            \
 852 static ssize_t show_##name(struct device *dev,                          \
 853                            struct device_attribute *attr, char *buf)    \
 854 {                                                                       \
 855         struct usb_interface *intf = to_usb_interface(dev);             \
 856         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 857                                                                         \
 858         return sprintf(buf, "%d\n", data->name);                        \
 859 }                                                                       \
 860 static ssize_t store_##name(struct device *dev,                         \
 861                             struct device_attribute *attr,              \
 862                             const char *buf, size_t count)              \
 863 {                                                                       \
 864         struct usb_interface *intf = to_usb_interface(dev);             \
 865         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 866         ssize_t result;                                                 \
 867         unsigned val;                                                   \
 868                                                                         \
 869         result = sscanf(buf, "%u\n", &val);                             \
 870         if (result != 1)                                                \
 871                 result = -EINVAL;                                       \
 872         data->name = val;                                               \
 873         if (result < 0)                                                 \
 874                 return result;                                          \
 875         else                                                            \
 876                 return count;                                           \
 877 }                                                                       \
 878 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 879
 880 data_attribute(TermCharEnabled);
 881 data_attribute(auto_abort);
 882
 883 static struct attribute *data_attrs[] = {
 884         &dev_attr_TermChar.attr,
 885         &dev_attr_TermCharEnabled.attr,
 886         &dev_attr_auto_abort.attr,
 887         NULL,
 888 };
 889
 890 static struct attribute_group data_attr_grp = {
 891         .attrs = data_attrs,
 892 };
 893
 894 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 895 {
 896         struct device *dev;
 897         u8 *buffer;
 898         int rv;
 899
 900         dev = &data->intf->dev;
 901
 902         buffer = kmalloc(2, GFP_KERNEL);
 903         if (!buffer)
 904                 return -ENOMEM;
 905
 906         rv = usb_control_msg(data->usb_dev,
 907                              usb_rcvctrlpipe(data->usb_dev, 0),
 908                              USBTMC_REQUEST_INDICATOR_PULSE,
 909                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 910                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 911
 912         if (rv < 0) {
 913                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 914                 goto exit;
 915         }
 916
 917         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 918
 919         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 920                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 921                 rv = -EPERM;
 922                 goto exit;
 923         }
 924         rv = 0;
 925
 926 exit:
 927         kfree(buffer);
 928         return rv;
 929 }
 930
 931 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 932 {
 933         struct usbtmc_device_data *data;
 934         int retval = -EBADRQC;
 935
 936         data = file->private_data;
 937         mutex_lock(&data->io_mutex);
 938         if (data->zombie) {
 939                 retval = -ENODEV;
 940                 goto skip_io_on_zombie;
 941         }
 942
 943         switch (cmd) {
 944         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 945                 retval = usbtmc_ioctl_clear_out_halt(data);
 946                 break;
 947
 948         case USBTMC_IOCTL_CLEAR_IN_HALT:
 949                 retval = usbtmc_ioctl_clear_in_halt(data);
 950                 break;
 951
 952         case USBTMC_IOCTL_INDICATOR_PULSE:
 953                 retval = usbtmc_ioctl_indicator_pulse(data);
 954                 break;
 955
 956         case USBTMC_IOCTL_CLEAR:
 957                 retval = usbtmc_ioctl_clear(data);
 958                 break;
 959
 960         case USBTMC_IOCTL_ABORT_BULK_OUT:
 961                 retval = usbtmc_ioctl_abort_bulk_out(data);
 962                 break;
 963
 964         case USBTMC_IOCTL_ABORT_BULK_IN:
 965                 retval = usbtmc_ioctl_abort_bulk_in(data);
 966                 break;
 967         }
 968
 969 skip_io_on_zombie:
 970         mutex_unlock(&data->io_mutex);
 971         return retval;
 972 }
 973
 974 static struct file_operations fops = {
 975         .owner          = THIS_MODULE,
 976         .read           = usbtmc_read,
 977         .write          = usbtmc_write,
 978         .open           = usbtmc_open,
 979         .release        = usbtmc_release,
 980         .unlocked_ioctl = usbtmc_ioctl,
 981 };
 982
 983 static struct usb_class_driver usbtmc_class = {
 984         .name =         "usbtmc%d",
 985         .fops =         &fops,
 986         .minor_base =   USBTMC_MINOR_BASE,
 987 };
 988
 989
 990 static int usbtmc_probe(struct usb_interface *intf,
 991                         const struct usb_device_id *id)
 992 {
 993         struct usbtmc_device_data *data;
 994         struct usb_host_interface *iface_desc;
 995         struct usb_endpoint_descriptor *endpoint;
 996         int n;
 997         int retcode;
 998
 999         dev_dbg(&intf->dev, "%s called\n", __func__);
1000
1001         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1002         if (!data) {
1003                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1004                 return -ENOMEM;
1005         }
1006
1007         data->intf = intf;
1008         data->id = id;
1009         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1010         usb_set_intfdata(intf, data);
1011         kref_init(&data->kref);
1012         mutex_init(&data->io_mutex);
1013         data->zombie = 0;
1014
1015         /* Initialize USBTMC bTag and other fields */
1016         data->bTag      = 1;
1017         data->TermCharEnabled = 0;
1018         data->TermChar = '\n';
1019
1020         /* USBTMC devices have only one setting, so use that */
1021         iface_desc = data->intf->cur_altsetting;
1022
1023         /* Find bulk in endpoint */
1024         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1025                 endpoint = &iface_desc->endpoint[n].desc;
1026
1027                 if (usb_endpoint_is_bulk_in(endpoint)) {
1028                         data->bulk_in = endpoint->bEndpointAddress;
1029                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1030                                 data->bulk_in);
1031                         break;
1032                 }
1033         }
1034
1035         /* Find bulk out endpoint */
1036         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1037                 endpoint = &iface_desc->endpoint[n].desc;
1038
1039                 if (usb_endpoint_is_bulk_out(endpoint)) {
1040                         data->bulk_out = endpoint->bEndpointAddress;
1041                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1042                                 data->bulk_out);
1043                         break;
1044                 }
1045         }
1046
1047         retcode = get_capabilities(data);
1048         if (retcode)
1049                 dev_err(&intf->dev, "can't read capabilities\n");
1050         else
1051                 retcode = sysfs_create_group(&intf->dev.kobj,
1052                                              &capability_attr_grp);
1053
1054         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1055
1056         retcode = usb_register_dev(intf, &usbtmc_class);
1057         if (retcode) {
1058                 dev_err(&intf->dev, "Not able to get a minor"
1059                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1060                         retcode);
1061                 goto error_register;
1062         }
1063         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1064
1065         return 0;
1066
1067 error_register:
1068         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1069         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1070         kref_put(&data->kref, usbtmc_delete);
1071         return retcode;
1072 }
1073
1074 static void usbtmc_disconnect(struct usb_interface *intf)
1075 {
1076         struct usbtmc_device_data *data;
1077
1078         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1079
1080         data = usb_get_intfdata(intf);
1081         usb_deregister_dev(intf, &usbtmc_class);
1082         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1083         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1084         mutex_lock(&data->io_mutex);
1085         data->zombie = 1;
1086         mutex_unlock(&data->io_mutex);
1087         kref_put(&data->kref, usbtmc_delete);
1088 }
1089
1090 static struct usb_driver usbtmc_driver = {
1091         .name           = "usbtmc",
1092         .id_table       = usbtmc_devices,
1093         .probe          = usbtmc_probe,
1094         .disconnect     = usbtmc_disconnect
1095 };
1096
1097 static int __init usbtmc_init(void)
1098 {
1099         int retcode;
1100
1101         retcode = usb_register(&usbtmc_driver);
1102         if (retcode)
1103                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1104         return retcode;
1105 }
1106 module_init(usbtmc_init);
1107
1108 static void __exit usbtmc_exit(void)
1109 {
1110         usb_deregister(&usbtmc_driver);
1111 }
1112 module_exit(usbtmc_exit);
1113
1114 MODULE_LICENSE("GPL");