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 & 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/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          5000
  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,
  61  * and section 4.2.2 of the USBTMC usb488 subclass
  62  * specification for details.
  63  */
  64 struct usbtmc_dev_capabilities {
  65         __u8 interface_capabilities;
  66         __u8 device_capabilities;
  67         __u8 usb488_interface_capabilities;
  68         __u8 usb488_device_capabilities;
  69 };
  70
  71 /* This structure holds private data for each USBTMC device. One copy is
  72  * allocated for each USBTMC device in the driver's probe function.
  73  */
  74 struct usbtmc_device_data {
  75         const struct usb_device_id *id;
  76         struct usb_device *usb_dev;
  77         struct usb_interface *intf;
  78
  79         unsigned int bulk_in;
  80         unsigned int bulk_out;
  81
  82         u8 bTag;
  83         u8 bTag_last_write;     /* needed for abort */
  84         u8 bTag_last_read;      /* needed for abort */
  85
  86         /* attributes from the USB TMC spec for this device */
  87         u8 TermChar;
  88         bool TermCharEnabled;
  89         bool auto_abort;
  90
  91         bool zombie; /* fd of disconnected device */
  92
  93         struct usbtmc_dev_capabilities  capabilities;
  94         struct kref kref;
  95         struct mutex io_mutex;  /* only one i/o function running at a time */
  96 };
  97 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  98
  99 /* Forward declarations */
 100 static struct usb_driver usbtmc_driver;
 101
 102 static void usbtmc_delete(struct kref *kref)
 103 {
 104         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 105
 106         usb_put_dev(data->usb_dev);
 107         kfree(data);
 108 }
 109
 110 static int usbtmc_open(struct inode *inode, struct file *filp)
 111 {
 112         struct usb_interface *intf;
 113         struct usbtmc_device_data *data;
 114         int retval = 0;
 115
 116         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 117         if (!intf) {
 118                 printk(KERN_ERR KBUILD_MODNAME
 119                        ": can not find device for minor %d", iminor(inode));
 120                 retval = -ENODEV;
 121                 goto exit;
 122         }
 123
 124         data = usb_get_intfdata(intf);
 125         kref_get(&data->kref);
 126
 127         /* Store pointer in file structure's private data field */
 128         filp->private_data = data;
 129
 130 exit:
 131         return retval;
 132 }
 133
 134 static int usbtmc_release(struct inode *inode, struct file *file)
 135 {
 136         struct usbtmc_device_data *data = file->private_data;
 137
 138         kref_put(&data->kref, usbtmc_delete);
 139         return 0;
 140 }
 141
 142 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 143 {
 144         u8 *buffer;
 145         struct device *dev;
 146         int rv;
 147         int n;
 148         int actual;
 149         struct usb_host_interface *current_setting;
 150         int max_size;
 151
 152         dev = &data->intf->dev;
 153         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 154         if (!buffer)
 155                 return -ENOMEM;
 156
 157         rv = usb_control_msg(data->usb_dev,
 158                              usb_rcvctrlpipe(data->usb_dev, 0),
 159                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 160                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 161                              data->bTag_last_read, data->bulk_in,
 162                              buffer, 2, USBTMC_TIMEOUT);
 163
 164         if (rv < 0) {
 165                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 166                 goto exit;
 167         }
 168
 169         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 170
 171         if (buffer[0] == USBTMC_STATUS_FAILED) {
 172                 rv = 0;
 173                 goto exit;
 174         }
 175
 176         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 177                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 178                         buffer[0]);
 179                 rv = -EPERM;
 180                 goto exit;
 181         }
 182
 183         max_size = 0;
 184         current_setting = data->intf->cur_altsetting;
 185         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 186                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 187                         data->bulk_in)
 188                         max_size = le16_to_cpu(current_setting->endpoint[n].
 189                                                 desc.wMaxPacketSize);
 190
 191         if (max_size == 0) {
 192                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 193                 rv = -EPERM;
 194                 goto exit;
 195         }
 196
 197         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 198
 199         n = 0;
 200
 201         do {
 202                 dev_dbg(dev, "Reading from bulk in EP\n");
 203
 204                 rv = usb_bulk_msg(data->usb_dev,
 205                                   usb_rcvbulkpipe(data->usb_dev,
 206                                                   data->bulk_in),
 207                                   buffer, USBTMC_SIZE_IOBUFFER,
 208                                   &actual, USBTMC_TIMEOUT);
 209
 210                 n++;
 211
 212                 if (rv < 0) {
 213                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 214                         goto exit;
 215                 }
 216         } while ((actual == max_size) &&
 217                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 218
 219         if (actual == max_size) {
 220                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 221                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 222                 rv = -EPERM;
 223                 goto exit;
 224         }
 225
 226         n = 0;
 227
 228 usbtmc_abort_bulk_in_status:
 229         rv = usb_control_msg(data->usb_dev,
 230                              usb_rcvctrlpipe(data->usb_dev, 0),
 231                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 232                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 233                              0, data->bulk_in, buffer, 0x08,
 234                              USBTMC_TIMEOUT);
 235
 236         if (rv < 0) {
 237                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 238                 goto exit;
 239         }
 240
 241         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 242
 243         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 244                 rv = 0;
 245                 goto exit;
 246         }
 247
 248         if (buffer[0] != USBTMC_STATUS_PENDING) {
 249                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 250                 rv = -EPERM;
 251                 goto exit;
 252         }
 253
 254         if (buffer[1] == 1)
 255                 do {
 256                         dev_dbg(dev, "Reading from bulk in EP\n");
 257
 258                         rv = usb_bulk_msg(data->usb_dev,
 259                                           usb_rcvbulkpipe(data->usb_dev,
 260                                                           data->bulk_in),
 261                                           buffer, USBTMC_SIZE_IOBUFFER,
 262                                           &actual, USBTMC_TIMEOUT);
 263
 264                         n++;
 265
 266                         if (rv < 0) {
 267                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 268                                 goto exit;
 269                         }
 270                 } while ((actual = max_size) &&
 271                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 272
 273         if (actual == max_size) {
 274                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 275                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 276                 rv = -EPERM;
 277                 goto exit;
 278         }
 279
 280         goto usbtmc_abort_bulk_in_status;
 281
 282 exit:
 283         kfree(buffer);
 284         return rv;
 285
 286 }
 287
 288 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 289 {
 290         struct device *dev;
 291         u8 *buffer;
 292         int rv;
 293         int n;
 294
 295         dev = &data->intf->dev;
 296
 297         buffer = kmalloc(8, GFP_KERNEL);
 298         if (!buffer)
 299                 return -ENOMEM;
 300
 301         rv = usb_control_msg(data->usb_dev,
 302                              usb_rcvctrlpipe(data->usb_dev, 0),
 303                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 304                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 305                              data->bTag_last_write, data->bulk_out,
 306                              buffer, 2, USBTMC_TIMEOUT);
 307
 308         if (rv < 0) {
 309                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 310                 goto exit;
 311         }
 312
 313         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 314
 315         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 316                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 317                         buffer[0]);
 318                 rv = -EPERM;
 319                 goto exit;
 320         }
 321
 322         n = 0;
 323
 324 usbtmc_abort_bulk_out_check_status:
 325         rv = usb_control_msg(data->usb_dev,
 326                              usb_rcvctrlpipe(data->usb_dev, 0),
 327                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 328                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 329                              0, data->bulk_out, buffer, 0x08,
 330                              USBTMC_TIMEOUT);
 331         n++;
 332         if (rv < 0) {
 333                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 334                 goto exit;
 335         }
 336
 337         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 338
 339         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 340                 goto usbtmc_abort_bulk_out_clear_halt;
 341
 342         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 343             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 344                 goto usbtmc_abort_bulk_out_check_status;
 345
 346         rv = -EPERM;
 347         goto exit;
 348
 349 usbtmc_abort_bulk_out_clear_halt:
 350         rv = usb_control_msg(data->usb_dev,
 351                              usb_sndctrlpipe(data->usb_dev, 0),
 352                              USB_REQ_CLEAR_FEATURE,
 353                              USB_DIR_OUT | USB_TYPE_STANDARD |
 354                              USB_RECIP_ENDPOINT,
 355                              USB_ENDPOINT_HALT, data->bulk_out, buffer,
 356                              0, USBTMC_TIMEOUT);
 357
 358         if (rv < 0) {
 359                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 360                 goto exit;
 361         }
 362         rv = 0;
 363
 364 exit:
 365         kfree(buffer);
 366         return rv;
 367 }
 368
 369 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 370                            size_t count, loff_t *f_pos)
 371 {
 372         struct usbtmc_device_data *data;
 373         struct device *dev;
 374         u32 n_characters;
 375         u8 *buffer;
 376         int actual;
 377         size_t done;
 378         size_t remaining;
 379         int retval;
 380         size_t this_part;
 381
 382         /* Get pointer to private data structure */
 383         data = filp->private_data;
 384         dev = &data->intf->dev;
 385
 386         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 387         if (!buffer)
 388                 return -ENOMEM;
 389
 390         mutex_lock(&data->io_mutex);
 391         if (data->zombie) {
 392                 retval = -ENODEV;
 393                 goto exit;
 394         }
 395
 396         remaining = count;
 397         done = 0;
 398
 399         while (remaining > 0) {
 400                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 401                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 402                 else
 403                         this_part = remaining;
 404
 405                 /* Setup IO buffer for DEV_DEP_MSG_IN message
 406                  * Refer to class specs for details
 407                  */
 408                 buffer[0] = 2;
 409                 buffer[1] = data->bTag;
 410                 buffer[2] = ~(data->bTag);
 411                 buffer[3] = 0; /* Reserved */
 412                 buffer[4] = (this_part) & 255;
 413                 buffer[5] = ((this_part) >> 8) & 255;
 414                 buffer[6] = ((this_part) >> 16) & 255;
 415                 buffer[7] = ((this_part) >> 24) & 255;
 416                 buffer[8] = data->TermCharEnabled * 2;
 417                 /* Use term character? */
 418                 buffer[9] = data->TermChar;
 419                 buffer[10] = 0; /* Reserved */
 420                 buffer[11] = 0; /* Reserved */
 421
 422                 /* Send bulk URB */
 423                 retval = usb_bulk_msg(data->usb_dev,
 424                                       usb_sndbulkpipe(data->usb_dev,
 425                                                       data->bulk_out),
 426                                       buffer, 12, &actual, USBTMC_TIMEOUT);
 427
 428                 /* Store bTag (in case we need to abort) */
 429                 data->bTag_last_write = data->bTag;
 430
 431                 /* Increment bTag -- and increment again if zero */
 432                 data->bTag++;
 433                 if (!data->bTag)
 434                         (data->bTag)++;
 435
 436                 if (retval < 0) {
 437                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 438                         if (data->auto_abort)
 439                                 usbtmc_ioctl_abort_bulk_out(data);
 440                         goto exit;
 441                 }
 442
 443                 /* Send bulk URB */
 444                 retval = usb_bulk_msg(data->usb_dev,
 445                                       usb_rcvbulkpipe(data->usb_dev,
 446                                                       data->bulk_in),
 447                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 448                                       USBTMC_TIMEOUT);
 449
 450                 /* Store bTag (in case we need to abort) */
 451                 data->bTag_last_read = data->bTag;
 452
 453                 if (retval < 0) {
 454                         dev_err(dev, "Unable to read data, error %d\n", retval);
 455                         if (data->auto_abort)
 456                                 usbtmc_ioctl_abort_bulk_in(data);
 457                         goto exit;
 458                 }
 459
 460                 /* How many characters did the instrument send? */
 461                 n_characters = buffer[4] +
 462                                (buffer[5] << 8) +
 463                                (buffer[6] << 16) +
 464                                (buffer[7] << 24);
 465
 466                 /* Ensure the instrument doesn't lie about it */
 467                 if(n_characters > actual - 12) {
 468                         dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
 469                         n_characters = actual - 12;
 470                 }
 471
 472                 /* Ensure the instrument doesn't send more back than requested */
 473                 if(n_characters > this_part) {
 474                         dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
 475                         n_characters = this_part;
 476                 }
 477
 478                 /* Bound amount of data received by amount of data requested */
 479                 if (n_characters > this_part)
 480                         n_characters = this_part;
 481
 482                 /* Copy buffer to user space */
 483                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 484                         /* There must have been an addressing problem */
 485                         retval = -EFAULT;
 486                         goto exit;
 487                 }
 488
 489                 done += n_characters;
 490                 /* Terminate if end-of-message bit recieved from device */
 491                 if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 492                         remaining = 0;
 493                 else
 494                         remaining -= n_characters;
 495         }
 496
 497         /* Update file position value */
 498         *f_pos = *f_pos + done;
 499         retval = done;
 500
 501 exit:
 502         mutex_unlock(&data->io_mutex);
 503         kfree(buffer);
 504         return retval;
 505 }
 506
 507 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 508                             size_t count, loff_t *f_pos)
 509 {
 510         struct usbtmc_device_data *data;
 511         u8 *buffer;
 512         int retval;
 513         int actual;
 514         unsigned long int n_bytes;
 515         int remaining;
 516         int done;
 517         int this_part;
 518
 519         data = filp->private_data;
 520
 521         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 522         if (!buffer)
 523                 return -ENOMEM;
 524
 525         mutex_lock(&data->io_mutex);
 526         if (data->zombie) {
 527                 retval = -ENODEV;
 528                 goto exit;
 529         }
 530
 531         remaining = count;
 532         done = 0;
 533
 534         while (remaining > 0) {
 535                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 536                         this_part = USBTMC_SIZE_IOBUFFER - 12;
 537                         buffer[8] = 0;
 538                 } else {
 539                         this_part = remaining;
 540                         buffer[8] = 1;
 541                 }
 542
 543                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 544                 buffer[0] = 1;
 545                 buffer[1] = data->bTag;
 546                 buffer[2] = ~(data->bTag);
 547                 buffer[3] = 0; /* Reserved */
 548                 buffer[4] = this_part & 255;
 549                 buffer[5] = (this_part >> 8) & 255;
 550                 buffer[6] = (this_part >> 16) & 255;
 551                 buffer[7] = (this_part >> 24) & 255;
 552                 /* buffer[8] is set above... */
 553                 buffer[9] = 0; /* Reserved */
 554                 buffer[10] = 0; /* Reserved */
 555                 buffer[11] = 0; /* Reserved */
 556
 557                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
 558                         retval = -EFAULT;
 559                         goto exit;
 560                 }
 561
 562                 n_bytes = roundup(12 + this_part, 4);
 563                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 564
 565                 retval = usb_bulk_msg(data->usb_dev,
 566                                       usb_sndbulkpipe(data->usb_dev,
 567                                                       data->bulk_out),
 568                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
 569
 570                 data->bTag_last_write = data->bTag;
 571                 data->bTag++;
 572
 573                 if (!data->bTag)
 574                         data->bTag++;
 575
 576                 if (retval < 0) {
 577                         dev_err(&data->intf->dev,
 578                                 "Unable to send data, error %d\n", retval);
 579                         if (data->auto_abort)
 580                                 usbtmc_ioctl_abort_bulk_out(data);
 581                         goto exit;
 582                 }
 583
 584                 remaining -= this_part;
 585                 done += this_part;
 586         }
 587
 588         retval = count;
 589 exit:
 590         mutex_unlock(&data->io_mutex);
 591         kfree(buffer);
 592         return retval;
 593 }
 594
 595 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 596 {
 597         struct usb_host_interface *current_setting;
 598         struct usb_endpoint_descriptor *desc;
 599         struct device *dev;
 600         u8 *buffer;
 601         int rv;
 602         int n;
 603         int actual;
 604         int max_size;
 605
 606         dev = &data->intf->dev;
 607
 608         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 609
 610         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 611         if (!buffer)
 612                 return -ENOMEM;
 613
 614         rv = usb_control_msg(data->usb_dev,
 615                              usb_rcvctrlpipe(data->usb_dev, 0),
 616                              USBTMC_REQUEST_INITIATE_CLEAR,
 617                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 618                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 619         if (rv < 0) {
 620                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 621                 goto exit;
 622         }
 623
 624         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 625
 626         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 627                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 628                 rv = -EPERM;
 629                 goto exit;
 630         }
 631
 632         max_size = 0;
 633         current_setting = data->intf->cur_altsetting;
 634         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 635                 desc = &current_setting->endpoint[n].desc;
 636                 if (desc->bEndpointAddress == data->bulk_in)
 637                         max_size = le16_to_cpu(desc->wMaxPacketSize);
 638         }
 639
 640         if (max_size == 0) {
 641                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 642                 rv = -EPERM;
 643                 goto exit;
 644         }
 645
 646         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 647
 648         n = 0;
 649
 650 usbtmc_clear_check_status:
 651
 652         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 653
 654         rv = usb_control_msg(data->usb_dev,
 655                              usb_rcvctrlpipe(data->usb_dev, 0),
 656                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 657                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 658                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 659         if (rv < 0) {
 660                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 661                 goto exit;
 662         }
 663
 664         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 665
 666         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 667                 goto usbtmc_clear_bulk_out_halt;
 668
 669         if (buffer[0] != USBTMC_STATUS_PENDING) {
 670                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 671                 rv = -EPERM;
 672                 goto exit;
 673         }
 674
 675         if (buffer[1] == 1)
 676                 do {
 677                         dev_dbg(dev, "Reading from bulk in EP\n");
 678
 679                         rv = usb_bulk_msg(data->usb_dev,
 680                                           usb_rcvbulkpipe(data->usb_dev,
 681                                                           data->bulk_in),
 682                                           buffer, USBTMC_SIZE_IOBUFFER,
 683                                           &actual, USBTMC_TIMEOUT);
 684                         n++;
 685
 686                         if (rv < 0) {
 687                                 dev_err(dev, "usb_control_msg returned %d\n",
 688                                         rv);
 689                                 goto exit;
 690                         }
 691                 } while ((actual == max_size) &&
 692                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 693
 694         if (actual == max_size) {
 695                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 696                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 697                 rv = -EPERM;
 698                 goto exit;
 699         }
 700
 701         goto usbtmc_clear_check_status;
 702
 703 usbtmc_clear_bulk_out_halt:
 704
 705         rv = usb_control_msg(data->usb_dev,
 706                              usb_sndctrlpipe(data->usb_dev, 0),
 707                              USB_REQ_CLEAR_FEATURE,
 708                              USB_DIR_OUT | USB_TYPE_STANDARD |
 709                              USB_RECIP_ENDPOINT,
 710                              USB_ENDPOINT_HALT,
 711                              data->bulk_out, buffer, 0,
 712                              USBTMC_TIMEOUT);
 713         if (rv < 0) {
 714                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 715                 goto exit;
 716         }
 717         rv = 0;
 718
 719 exit:
 720         kfree(buffer);
 721         return rv;
 722 }
 723
 724 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 725 {
 726         u8 *buffer;
 727         int rv;
 728
 729         buffer = kmalloc(2, GFP_KERNEL);
 730         if (!buffer)
 731                 return -ENOMEM;
 732
 733         rv = usb_control_msg(data->usb_dev,
 734                              usb_sndctrlpipe(data->usb_dev, 0),
 735                              USB_REQ_CLEAR_FEATURE,
 736                              USB_DIR_OUT | USB_TYPE_STANDARD |
 737                              USB_RECIP_ENDPOINT,
 738                              USB_ENDPOINT_HALT, data->bulk_out,
 739                              buffer, 0, USBTMC_TIMEOUT);
 740
 741         if (rv < 0) {
 742                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 743                         rv);
 744                 goto exit;
 745         }
 746         rv = 0;
 747
 748 exit:
 749         kfree(buffer);
 750         return rv;
 751 }
 752
 753 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 754 {
 755         u8 *buffer;
 756         int rv;
 757
 758         buffer = kmalloc(2, GFP_KERNEL);
 759         if (!buffer)
 760                 return -ENOMEM;
 761
 762         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
 763                              USB_REQ_CLEAR_FEATURE,
 764                              USB_DIR_OUT | USB_TYPE_STANDARD |
 765                              USB_RECIP_ENDPOINT,
 766                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
 767                              USBTMC_TIMEOUT);
 768
 769         if (rv < 0) {
 770                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 771                         rv);
 772                 goto exit;
 773         }
 774         rv = 0;
 775
 776 exit:
 777         kfree(buffer);
 778         return rv;
 779 }
 780
 781 static int get_capabilities(struct usbtmc_device_data *data)
 782 {
 783         struct device *dev = &data->usb_dev->dev;
 784         char *buffer;
 785         int rv = 0;
 786
 787         buffer = kmalloc(0x18, GFP_KERNEL);
 788         if (!buffer)
 789                 return -ENOMEM;
 790
 791         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 792                              USBTMC_REQUEST_GET_CAPABILITIES,
 793                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 794                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 795         if (rv < 0) {
 796                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 797                 goto err_out;
 798         }
 799
 800         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 801         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 802                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 803                 rv = -EPERM;
 804                 goto err_out;
 805         }
 806         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 807         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 808         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 809         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 810
 811         data->capabilities.interface_capabilities = buffer[4];
 812         data->capabilities.device_capabilities = buffer[5];
 813         data->capabilities.usb488_interface_capabilities = buffer[14];
 814         data->capabilities.usb488_device_capabilities = buffer[15];
 815         rv = 0;
 816
 817 err_out:
 818         kfree(buffer);
 819         return rv;
 820 }
 821
 822 #define capability_attribute(name)                                      \
 823 static ssize_t show_##name(struct device *dev,                          \
 824                            struct device_attribute *attr, char *buf)    \
 825 {                                                                       \
 826         struct usb_interface *intf = to_usb_interface(dev);             \
 827         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 828                                                                         \
 829         return sprintf(buf, "%d\n", data->capabilities.name);           \
 830 }                                                                       \
 831 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 832
 833 capability_attribute(interface_capabilities);
 834 capability_attribute(device_capabilities);
 835 capability_attribute(usb488_interface_capabilities);
 836 capability_attribute(usb488_device_capabilities);
 837
 838 static struct attribute *capability_attrs[] = {
 839         &dev_attr_interface_capabilities.attr,
 840         &dev_attr_device_capabilities.attr,
 841         &dev_attr_usb488_interface_capabilities.attr,
 842         &dev_attr_usb488_device_capabilities.attr,
 843         NULL,
 844 };
 845
 846 static struct attribute_group capability_attr_grp = {
 847         .attrs = capability_attrs,
 848 };
 849
 850 static ssize_t show_TermChar(struct device *dev,
 851                              struct device_attribute *attr, char *buf)
 852 {
 853         struct usb_interface *intf = to_usb_interface(dev);
 854         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 855
 856         return sprintf(buf, "%c\n", data->TermChar);
 857 }
 858
 859 static ssize_t store_TermChar(struct device *dev,
 860                               struct device_attribute *attr,
 861                               const char *buf, size_t count)
 862 {
 863         struct usb_interface *intf = to_usb_interface(dev);
 864         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 865
 866         if (count < 1)
 867                 return -EINVAL;
 868         data->TermChar = buf[0];
 869         return count;
 870 }
 871 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 872
 873 #define data_attribute(name)                                            \
 874 static ssize_t show_##name(struct device *dev,                          \
 875                            struct device_attribute *attr, char *buf)    \
 876 {                                                                       \
 877         struct usb_interface *intf = to_usb_interface(dev);             \
 878         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 879                                                                         \
 880         return sprintf(buf, "%d\n", data->name);                        \
 881 }                                                                       \
 882 static ssize_t store_##name(struct device *dev,                         \
 883                             struct device_attribute *attr,              \
 884                             const char *buf, size_t count)              \
 885 {                                                                       \
 886         struct usb_interface *intf = to_usb_interface(dev);             \
 887         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 888         ssize_t result;                                                 \
 889         unsigned val;                                                   \
 890                                                                         \
 891         result = sscanf(buf, "%u\n", &val);                             \
 892         if (result != 1)                                                \
 893                 result = -EINVAL;                                       \
 894         data->name = val;                                               \
 895         if (result < 0)                                                 \
 896                 return result;                                          \
 897         else                                                            \
 898                 return count;                                           \
 899 }                                                                       \
 900 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 901
 902 data_attribute(TermCharEnabled);
 903 data_attribute(auto_abort);
 904
 905 static struct attribute *data_attrs[] = {
 906         &dev_attr_TermChar.attr,
 907         &dev_attr_TermCharEnabled.attr,
 908         &dev_attr_auto_abort.attr,
 909         NULL,
 910 };
 911
 912 static struct attribute_group data_attr_grp = {
 913         .attrs = data_attrs,
 914 };
 915
 916 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 917 {
 918         struct device *dev;
 919         u8 *buffer;
 920         int rv;
 921
 922         dev = &data->intf->dev;
 923
 924         buffer = kmalloc(2, GFP_KERNEL);
 925         if (!buffer)
 926                 return -ENOMEM;
 927
 928         rv = usb_control_msg(data->usb_dev,
 929                              usb_rcvctrlpipe(data->usb_dev, 0),
 930                              USBTMC_REQUEST_INDICATOR_PULSE,
 931                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 932                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 933
 934         if (rv < 0) {
 935                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 936                 goto exit;
 937         }
 938
 939         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 940
 941         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 942                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 943                 rv = -EPERM;
 944                 goto exit;
 945         }
 946         rv = 0;
 947
 948 exit:
 949         kfree(buffer);
 950         return rv;
 951 }
 952
 953 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 954 {
 955         struct usbtmc_device_data *data;
 956         int retval = -EBADRQC;
 957
 958         data = file->private_data;
 959         mutex_lock(&data->io_mutex);
 960         if (data->zombie) {
 961                 retval = -ENODEV;
 962                 goto skip_io_on_zombie;
 963         }
 964
 965         switch (cmd) {
 966         case USBTMC_IOCTL_CLEAR_OUT_HALT:
 967                 retval = usbtmc_ioctl_clear_out_halt(data);
 968                 break;
 969
 970         case USBTMC_IOCTL_CLEAR_IN_HALT:
 971                 retval = usbtmc_ioctl_clear_in_halt(data);
 972                 break;
 973
 974         case USBTMC_IOCTL_INDICATOR_PULSE:
 975                 retval = usbtmc_ioctl_indicator_pulse(data);
 976                 break;
 977
 978         case USBTMC_IOCTL_CLEAR:
 979                 retval = usbtmc_ioctl_clear(data);
 980                 break;
 981
 982         case USBTMC_IOCTL_ABORT_BULK_OUT:
 983                 retval = usbtmc_ioctl_abort_bulk_out(data);
 984                 break;
 985
 986         case USBTMC_IOCTL_ABORT_BULK_IN:
 987                 retval = usbtmc_ioctl_abort_bulk_in(data);
 988                 break;
 989         }
 990
 991 skip_io_on_zombie:
 992         mutex_unlock(&data->io_mutex);
 993         return retval;
 994 }
 995
 996 static const struct file_operations fops = {
 997         .owner          = THIS_MODULE,
 998         .read           = usbtmc_read,
 999         .write          = usbtmc_write,
1000         .open           = usbtmc_open,
1001         .release        = usbtmc_release,
1002         .unlocked_ioctl = usbtmc_ioctl,
1003 };
1004
1005 static struct usb_class_driver usbtmc_class = {
1006         .name =         "usbtmc%d",
1007         .fops =         &fops,
1008         .minor_base =   USBTMC_MINOR_BASE,
1009 };
1010
1011
1012 static int usbtmc_probe(struct usb_interface *intf,
1013                         const struct usb_device_id *id)
1014 {
1015         struct usbtmc_device_data *data;
1016         struct usb_host_interface *iface_desc;
1017         struct usb_endpoint_descriptor *endpoint;
1018         int n;
1019         int retcode;
1020
1021         dev_dbg(&intf->dev, "%s called\n", __func__);
1022
1023         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1024         if (!data) {
1025                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1026                 return -ENOMEM;
1027         }
1028
1029         data->intf = intf;
1030         data->id = id;
1031         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1032         usb_set_intfdata(intf, data);
1033         kref_init(&data->kref);
1034         mutex_init(&data->io_mutex);
1035         data->zombie = 0;
1036
1037         /* Initialize USBTMC bTag and other fields */
1038         data->bTag      = 1;
1039         data->TermCharEnabled = 0;
1040         data->TermChar = '\n';
1041
1042         /* USBTMC devices have only one setting, so use that */
1043         iface_desc = data->intf->cur_altsetting;
1044
1045         /* Find bulk in endpoint */
1046         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1047                 endpoint = &iface_desc->endpoint[n].desc;
1048
1049                 if (usb_endpoint_is_bulk_in(endpoint)) {
1050                         data->bulk_in = endpoint->bEndpointAddress;
1051                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1052                                 data->bulk_in);
1053                         break;
1054                 }
1055         }
1056
1057         /* Find bulk out endpoint */
1058         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1059                 endpoint = &iface_desc->endpoint[n].desc;
1060
1061                 if (usb_endpoint_is_bulk_out(endpoint)) {
1062                         data->bulk_out = endpoint->bEndpointAddress;
1063                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1064                                 data->bulk_out);
1065                         break;
1066                 }
1067         }
1068
1069         retcode = get_capabilities(data);
1070         if (retcode)
1071                 dev_err(&intf->dev, "can't read capabilities\n");
1072         else
1073                 retcode = sysfs_create_group(&intf->dev.kobj,
1074                                              &capability_attr_grp);
1075
1076         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1077
1078         retcode = usb_register_dev(intf, &usbtmc_class);
1079         if (retcode) {
1080                 dev_err(&intf->dev, "Not able to get a minor"
1081                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1082                         retcode);
1083                 goto error_register;
1084         }
1085         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1086
1087         return 0;
1088
1089 error_register:
1090         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1091         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1092         kref_put(&data->kref, usbtmc_delete);
1093         return retcode;
1094 }
1095
1096 static void usbtmc_disconnect(struct usb_interface *intf)
1097 {
1098         struct usbtmc_device_data *data;
1099
1100         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1101
1102         data = usb_get_intfdata(intf);
1103         usb_deregister_dev(intf, &usbtmc_class);
1104         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1105         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1106         mutex_lock(&data->io_mutex);
1107         data->zombie = 1;
1108         mutex_unlock(&data->io_mutex);
1109         kref_put(&data->kref, usbtmc_delete);
1110 }
1111
1112 static int usbtmc_suspend (struct usb_interface *intf, pm_message_t message)
1113 {
1114         /* this driver does not have pending URBs */
1115         return 0;
1116 }
1117
1118 static int usbtmc_resume (struct usb_interface *intf)
1119 {
1120         return 0;
1121 }
1122
1123 static struct usb_driver usbtmc_driver = {
1124         .name           = "usbtmc",
1125         .id_table       = usbtmc_devices,
1126         .probe          = usbtmc_probe,
1127         .disconnect     = usbtmc_disconnect,
1128         .suspend        = usbtmc_suspend,
1129         .resume         = usbtmc_resume,
1130 };
1131
1132 static int __init usbtmc_init(void)
1133 {
1134         int retcode;
1135
1136         retcode = usb_register(&usbtmc_driver);
1137         if (retcode)
1138                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1139         return retcode;
1140 }
1141 module_init(usbtmc_init);
1142
1143 static void __exit usbtmc_exit(void)
1144 {
1145         usb_deregister(&usbtmc_driver);
1146 }
1147 module_exit(usbtmc_exit);
1148
1149 MODULE_LICENSE("GPL");