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 <[email protected]>
   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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/module.h>
  25 #include <linux/kernel.h>
  26 #include <linux/fs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/kref.h>
  29 #include <linux/slab.h>
  30 #include <linux/mutex.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/tmc.h>
  33
  34
  35 #define RIGOL                   1
  36 #define USBTMC_HEADER_SIZE      12
  37 #define USBTMC_MINOR_BASE       176
  38
  39 /*
  40  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  41  * large as wMaxPacketSize (which is usually 512 bytes).
  42  */
  43 #define USBTMC_SIZE_IOBUFFER    2048
  44
  45 /* Default USB timeout (in milliseconds) */
  46 #define USBTMC_TIMEOUT          5000
  47
  48 /*
  49  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  50  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  51  * packet is never read.
  52  */
  53 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
  54
  55 static const struct usb_device_id usbtmc_devices[] = {
  56         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  57         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  58         { 0, } /* terminating entry */
  59 };
  60 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  61
  62 /*
  63  * This structure is the capabilities for the device
  64  * See section 4.2.1.8 of the USBTMC specification,
  65  * and section 4.2.2 of the USBTMC usb488 subclass
  66  * specification for details.
  67  */
  68 struct usbtmc_dev_capabilities {
  69         __u8 interface_capabilities;
  70         __u8 device_capabilities;
  71         __u8 usb488_interface_capabilities;
  72         __u8 usb488_device_capabilities;
  73 };
  74
  75 /* This structure holds private data for each USBTMC device. One copy is
  76  * allocated for each USBTMC device in the driver's probe function.
  77  */
  78 struct usbtmc_device_data {
  79         const struct usb_device_id *id;
  80         struct usb_device *usb_dev;
  81         struct usb_interface *intf;
  82
  83         unsigned int bulk_in;
  84         unsigned int bulk_out;
  85
  86         u8 bTag;
  87         u8 bTag_last_write;     /* needed for abort */
  88         u8 bTag_last_read;      /* needed for abort */
  89
  90         u8 rigol_quirk;
  91
  92         /* attributes from the USB TMC spec for this device */
  93         u8 TermChar;
  94         bool TermCharEnabled;
  95         bool auto_abort;
  96
  97         bool zombie; /* fd of disconnected device */
  98
  99         struct usbtmc_dev_capabilities  capabilities;
 100         struct kref kref;
 101         struct mutex io_mutex;  /* only one i/o function running at a time */
 102 };
 103 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
 104
 105 struct usbtmc_ID_rigol_quirk {
 106         __u16 idVendor;
 107         __u16 idProduct;
 108 };
 109
 110 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
 111         { 0x1ab1, 0x0588 },
 112         { 0, 0 }
 113 };
 114
 115 /* Forward declarations */
 116 static struct usb_driver usbtmc_driver;
 117
 118 static void usbtmc_delete(struct kref *kref)
 119 {
 120         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 121
 122         usb_put_dev(data->usb_dev);
 123 }
 124
 125 static int usbtmc_open(struct inode *inode, struct file *filp)
 126 {
 127         struct usb_interface *intf;
 128         struct usbtmc_device_data *data;
 129         int retval = 0;
 130
 131         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 132         if (!intf) {
 133                 pr_err("can not find device for minor %d", iminor(inode));
 134                 return -ENODEV;
 135         }
 136
 137         data = usb_get_intfdata(intf);
 138         kref_get(&data->kref);
 139
 140         /* Store pointer in file structure's private data field */
 141         filp->private_data = data;
 142
 143         return retval;
 144 }
 145
 146 static int usbtmc_release(struct inode *inode, struct file *file)
 147 {
 148         struct usbtmc_device_data *data = file->private_data;
 149
 150         kref_put(&data->kref, usbtmc_delete);
 151         return 0;
 152 }
 153
 154 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 155 {
 156         u8 *buffer;
 157         struct device *dev;
 158         int rv;
 159         int n;
 160         int actual;
 161         struct usb_host_interface *current_setting;
 162         int max_size;
 163
 164         dev = &data->intf->dev;
 165         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 166         if (!buffer)
 167                 return -ENOMEM;
 168
 169         rv = usb_control_msg(data->usb_dev,
 170                              usb_rcvctrlpipe(data->usb_dev, 0),
 171                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 172                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 173                              data->bTag_last_read, data->bulk_in,
 174                              buffer, 2, USBTMC_TIMEOUT);
 175
 176         if (rv < 0) {
 177                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 178                 goto exit;
 179         }
 180
 181         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 182
 183         if (buffer[0] == USBTMC_STATUS_FAILED) {
 184                 rv = 0;
 185                 goto exit;
 186         }
 187
 188         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 189                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 190                         buffer[0]);
 191                 rv = -EPERM;
 192                 goto exit;
 193         }
 194
 195         max_size = 0;
 196         current_setting = data->intf->cur_altsetting;
 197         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 198                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 199                         data->bulk_in)
 200                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 201
 202         if (max_size == 0) {
 203                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 204                 rv = -EPERM;
 205                 goto exit;
 206         }
 207
 208         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 209
 210         n = 0;
 211
 212         do {
 213                 dev_dbg(dev, "Reading from bulk in EP\n");
 214
 215                 rv = usb_bulk_msg(data->usb_dev,
 216                                   usb_rcvbulkpipe(data->usb_dev,
 217                                                   data->bulk_in),
 218                                   buffer, USBTMC_SIZE_IOBUFFER,
 219                                   &actual, USBTMC_TIMEOUT);
 220
 221                 n++;
 222
 223                 if (rv < 0) {
 224                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 225                         goto exit;
 226                 }
 227         } while ((actual == max_size) &&
 228                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 229
 230         if (actual == max_size) {
 231                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 232                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 233                 rv = -EPERM;
 234                 goto exit;
 235         }
 236
 237         n = 0;
 238
 239 usbtmc_abort_bulk_in_status:
 240         rv = usb_control_msg(data->usb_dev,
 241                              usb_rcvctrlpipe(data->usb_dev, 0),
 242                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 243                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 244                              0, data->bulk_in, buffer, 0x08,
 245                              USBTMC_TIMEOUT);
 246
 247         if (rv < 0) {
 248                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 249                 goto exit;
 250         }
 251
 252         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 253
 254         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 255                 rv = 0;
 256                 goto exit;
 257         }
 258
 259         if (buffer[0] != USBTMC_STATUS_PENDING) {
 260                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 261                 rv = -EPERM;
 262                 goto exit;
 263         }
 264
 265         if (buffer[1] == 1)
 266                 do {
 267                         dev_dbg(dev, "Reading from bulk in EP\n");
 268
 269                         rv = usb_bulk_msg(data->usb_dev,
 270                                           usb_rcvbulkpipe(data->usb_dev,
 271                                                           data->bulk_in),
 272                                           buffer, USBTMC_SIZE_IOBUFFER,
 273                                           &actual, USBTMC_TIMEOUT);
 274
 275                         n++;
 276
 277                         if (rv < 0) {
 278                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 279                                 goto exit;
 280                         }
 281                 } while ((actual == max_size) &&
 282                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 283
 284         if (actual == max_size) {
 285                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 286                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 287                 rv = -EPERM;
 288                 goto exit;
 289         }
 290
 291         goto usbtmc_abort_bulk_in_status;
 292
 293 exit:
 294         kfree(buffer);
 295         return rv;
 296
 297 }
 298
 299 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 300 {
 301         struct device *dev;
 302         u8 *buffer;
 303         int rv;
 304         int n;
 305
 306         dev = &data->intf->dev;
 307
 308         buffer = kmalloc(8, GFP_KERNEL);
 309         if (!buffer)
 310                 return -ENOMEM;
 311
 312         rv = usb_control_msg(data->usb_dev,
 313                              usb_rcvctrlpipe(data->usb_dev, 0),
 314                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 315                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 316                              data->bTag_last_write, data->bulk_out,
 317                              buffer, 2, USBTMC_TIMEOUT);
 318
 319         if (rv < 0) {
 320                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 321                 goto exit;
 322         }
 323
 324         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 325
 326         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 327                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 328                         buffer[0]);
 329                 rv = -EPERM;
 330                 goto exit;
 331         }
 332
 333         n = 0;
 334
 335 usbtmc_abort_bulk_out_check_status:
 336         rv = usb_control_msg(data->usb_dev,
 337                              usb_rcvctrlpipe(data->usb_dev, 0),
 338                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 339                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 340                              0, data->bulk_out, buffer, 0x08,
 341                              USBTMC_TIMEOUT);
 342         n++;
 343         if (rv < 0) {
 344                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 345                 goto exit;
 346         }
 347
 348         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 349
 350         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 351                 goto usbtmc_abort_bulk_out_clear_halt;
 352
 353         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 354             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 355                 goto usbtmc_abort_bulk_out_check_status;
 356
 357         rv = -EPERM;
 358         goto exit;
 359
 360 usbtmc_abort_bulk_out_clear_halt:
 361         rv = usb_clear_halt(data->usb_dev,
 362                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 363
 364         if (rv < 0) {
 365                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 366                 goto exit;
 367         }
 368         rv = 0;
 369
 370 exit:
 371         kfree(buffer);
 372         return rv;
 373 }
 374
 375 /*
 376  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 377  * @transfer_size: number of bytes to request from the device.
 378  *
 379  * See the USBTMC specification, Table 4.
 380  *
 381  * Also updates bTag_last_write.
 382  */
 383 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 384 {
 385         int retval;
 386         u8 *buffer;
 387         int actual;
 388
 389         buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
 390         if (!buffer)
 391                 return -ENOMEM;
 392         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 393          * Refer to class specs for details
 394          */
 395         buffer[0] = 2;
 396         buffer[1] = data->bTag;
 397         buffer[2] = ~data->bTag;
 398         buffer[3] = 0; /* Reserved */
 399         buffer[4] = transfer_size >> 0;
 400         buffer[5] = transfer_size >> 8;
 401         buffer[6] = transfer_size >> 16;
 402         buffer[7] = transfer_size >> 24;
 403         buffer[8] = data->TermCharEnabled * 2;
 404         /* Use term character? */
 405         buffer[9] = data->TermChar;
 406         buffer[10] = 0; /* Reserved */
 407         buffer[11] = 0; /* Reserved */
 408
 409         /* Send bulk URB */
 410         retval = usb_bulk_msg(data->usb_dev,
 411                               usb_sndbulkpipe(data->usb_dev,
 412                                               data->bulk_out),
 413                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 414
 415         /* Store bTag (in case we need to abort) */
 416         data->bTag_last_write = data->bTag;
 417
 418         /* Increment bTag -- and increment again if zero */
 419         data->bTag++;
 420         if (!data->bTag)
 421                 data->bTag++;
 422
 423         kfree(buffer);
 424         if (retval < 0) {
 425                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 426                 return retval;
 427         }
 428
 429         return 0;
 430 }
 431
 432 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 433                            size_t count, loff_t *f_pos)
 434 {
 435         struct usbtmc_device_data *data;
 436         struct device *dev;
 437         u32 n_characters;
 438         u8 *buffer;
 439         int actual;
 440         size_t done;
 441         size_t remaining;
 442         int retval;
 443         size_t this_part;
 444
 445         /* Get pointer to private data structure */
 446         data = filp->private_data;
 447         dev = &data->intf->dev;
 448
 449         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 450         if (!buffer)
 451                 return -ENOMEM;
 452
 453         mutex_lock(&data->io_mutex);
 454         if (data->zombie) {
 455                 retval = -ENODEV;
 456                 goto exit;
 457         }
 458
 459         if (data->rigol_quirk) {
 460                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 461
 462                 retval = send_request_dev_dep_msg_in(data, count);
 463
 464                 if (retval < 0) {
 465                         if (data->auto_abort)
 466                                 usbtmc_ioctl_abort_bulk_out(data);
 467                         goto exit;
 468                 }
 469         }
 470
 471         /* Loop until we have fetched everything we requested */
 472         remaining = count;
 473         this_part = remaining;
 474         done = 0;
 475
 476         while (remaining > 0) {
 477                 if (!data->rigol_quirk) {
 478                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 479
 480                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 481                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 482                         else
 483                                 this_part = remaining;
 484
 485                         retval = send_request_dev_dep_msg_in(data, this_part);
 486                         if (retval < 0) {
 487                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 488                                 if (data->auto_abort)
 489                                         usbtmc_ioctl_abort_bulk_out(data);
 490                                 goto exit;
 491                         }
 492                 }
 493
 494                 /* Send bulk URB */
 495                 retval = usb_bulk_msg(data->usb_dev,
 496                                       usb_rcvbulkpipe(data->usb_dev,
 497                                                       data->bulk_in),
 498                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 499                                       USBTMC_TIMEOUT);
 500
 501                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 502
 503                 /* Store bTag (in case we need to abort) */
 504                 data->bTag_last_read = data->bTag;
 505
 506                 if (retval < 0) {
 507                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 508                         if (data->auto_abort)
 509                                 usbtmc_ioctl_abort_bulk_in(data);
 510                         goto exit;
 511                 }
 512
 513                 /* Parse header in first packet */
 514                 if ((done == 0) || !data->rigol_quirk) {
 515                         /* Sanity checks for the header */
 516                         if (actual < USBTMC_HEADER_SIZE) {
 517                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 518                                 if (data->auto_abort)
 519                                         usbtmc_ioctl_abort_bulk_in(data);
 520                                 goto exit;
 521                         }
 522
 523                         if (buffer[0] != 2) {
 524                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 525                                 if (data->auto_abort)
 526                                         usbtmc_ioctl_abort_bulk_in(data);
 527                                 goto exit;
 528                         }
 529
 530                         if (buffer[1] != data->bTag_last_write) {
 531                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 532                                 if (data->auto_abort)
 533                                         usbtmc_ioctl_abort_bulk_in(data);
 534                                 goto exit;
 535                         }
 536
 537                         /* How many characters did the instrument send? */
 538                         n_characters = buffer[4] +
 539                                        (buffer[5] << 8) +
 540                                        (buffer[6] << 16) +
 541                                        (buffer[7] << 24);
 542
 543                         if (n_characters > this_part) {
 544                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 545                                 if (data->auto_abort)
 546                                         usbtmc_ioctl_abort_bulk_in(data);
 547                                 goto exit;
 548                         }
 549
 550                         /* Remove the USBTMC header */
 551                         actual -= USBTMC_HEADER_SIZE;
 552
 553                         /* Check if the message is smaller than requested */
 554                         if (data->rigol_quirk) {
 555                                 if (remaining > n_characters)
 556                                         remaining = n_characters;
 557                                 /* Remove padding if it exists */
 558                                 if (actual > remaining)
 559                                         actual = remaining;
 560                         }
 561                         else {
 562                                 if (this_part > n_characters)
 563                                         this_part = n_characters;
 564                                 /* Remove padding if it exists */
 565                                 if (actual > this_part)
 566                                         actual = this_part;
 567                         }
 568
 569                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 570
 571                         remaining -= actual;
 572
 573                         /* Terminate if end-of-message bit received from device */
 574                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 575                                 remaining = 0;
 576
 577                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 578
 579
 580                         /* Copy buffer to user space */
 581                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 582                                 /* There must have been an addressing problem */
 583                                 retval = -EFAULT;
 584                                 goto exit;
 585                         }
 586                         done += actual;
 587                 }
 588                 else  {
 589                         if (actual > remaining)
 590                                 actual = remaining;
 591
 592                         remaining -= actual;
 593
 594                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 595
 596                         /* Copy buffer to user space */
 597                         if (copy_to_user(buf + done, buffer, actual)) {
 598                                 /* There must have been an addressing problem */
 599                                 retval = -EFAULT;
 600                                 goto exit;
 601                         }
 602                         done += actual;
 603                 }
 604         }
 605
 606         /* Update file position value */
 607         *f_pos = *f_pos + done;
 608         retval = done;
 609
 610 exit:
 611         mutex_unlock(&data->io_mutex);
 612         kfree(buffer);
 613         return retval;
 614 }
 615
 616 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 617                             size_t count, loff_t *f_pos)
 618 {
 619         struct usbtmc_device_data *data;
 620         u8 *buffer;
 621         int retval;
 622         int actual;
 623         unsigned long int n_bytes;
 624         int remaining;
 625         int done;
 626         int this_part;
 627
 628         data = filp->private_data;
 629
 630         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 631         if (!buffer)
 632                 return -ENOMEM;
 633
 634         mutex_lock(&data->io_mutex);
 635         if (data->zombie) {
 636                 retval = -ENODEV;
 637                 goto exit;
 638         }
 639
 640         remaining = count;
 641         done = 0;
 642
 643         while (remaining > 0) {
 644                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 645                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 646                         buffer[8] = 0;
 647                 } else {
 648                         this_part = remaining;
 649                         buffer[8] = 1;
 650                 }
 651
 652                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 653                 buffer[0] = 1;
 654                 buffer[1] = data->bTag;
 655                 buffer[2] = ~data->bTag;
 656                 buffer[3] = 0; /* Reserved */
 657                 buffer[4] = this_part >> 0;
 658                 buffer[5] = this_part >> 8;
 659                 buffer[6] = this_part >> 16;
 660                 buffer[7] = this_part >> 24;
 661                 /* buffer[8] is set above... */
 662                 buffer[9] = 0; /* Reserved */
 663                 buffer[10] = 0; /* Reserved */
 664                 buffer[11] = 0; /* Reserved */
 665
 666                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 667                         retval = -EFAULT;
 668                         goto exit;
 669                 }
 670
 671                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 672                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 673
 674                 do {
 675                         retval = usb_bulk_msg(data->usb_dev,
 676                                               usb_sndbulkpipe(data->usb_dev,
 677                                                               data->bulk_out),
 678                                               buffer, n_bytes,
 679                                               &actual, USBTMC_TIMEOUT);
 680                         if (retval != 0)
 681                                 break;
 682                         n_bytes -= actual;
 683                 } while (n_bytes);
 684
 685                 data->bTag_last_write = data->bTag;
 686                 data->bTag++;
 687
 688                 if (!data->bTag)
 689                         data->bTag++;
 690
 691                 if (retval < 0) {
 692                         dev_err(&data->intf->dev,
 693                                 "Unable to send data, error %d\n", retval);
 694                         if (data->auto_abort)
 695                                 usbtmc_ioctl_abort_bulk_out(data);
 696                         goto exit;
 697                 }
 698
 699                 remaining -= this_part;
 700                 done += this_part;
 701         }
 702
 703         retval = count;
 704 exit:
 705         mutex_unlock(&data->io_mutex);
 706         kfree(buffer);
 707         return retval;
 708 }
 709
 710 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 711 {
 712         struct usb_host_interface *current_setting;
 713         struct usb_endpoint_descriptor *desc;
 714         struct device *dev;
 715         u8 *buffer;
 716         int rv;
 717         int n;
 718         int actual = 0;
 719         int max_size;
 720
 721         dev = &data->intf->dev;
 722
 723         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 724
 725         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 726         if (!buffer)
 727                 return -ENOMEM;
 728
 729         rv = usb_control_msg(data->usb_dev,
 730                              usb_rcvctrlpipe(data->usb_dev, 0),
 731                              USBTMC_REQUEST_INITIATE_CLEAR,
 732                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 733                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 734         if (rv < 0) {
 735                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 736                 goto exit;
 737         }
 738
 739         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 740
 741         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 742                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 743                 rv = -EPERM;
 744                 goto exit;
 745         }
 746
 747         max_size = 0;
 748         current_setting = data->intf->cur_altsetting;
 749         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 750                 desc = &current_setting->endpoint[n].desc;
 751                 if (desc->bEndpointAddress == data->bulk_in)
 752                         max_size = usb_endpoint_maxp(desc);
 753         }
 754
 755         if (max_size == 0) {
 756                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 757                 rv = -EPERM;
 758                 goto exit;
 759         }
 760
 761         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 762
 763         n = 0;
 764
 765 usbtmc_clear_check_status:
 766
 767         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 768
 769         rv = usb_control_msg(data->usb_dev,
 770                              usb_rcvctrlpipe(data->usb_dev, 0),
 771                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 772                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 773                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 774         if (rv < 0) {
 775                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 776                 goto exit;
 777         }
 778
 779         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 780
 781         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 782                 goto usbtmc_clear_bulk_out_halt;
 783
 784         if (buffer[0] != USBTMC_STATUS_PENDING) {
 785                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 786                 rv = -EPERM;
 787                 goto exit;
 788         }
 789
 790         if (buffer[1] == 1)
 791                 do {
 792                         dev_dbg(dev, "Reading from bulk in EP\n");
 793
 794                         rv = usb_bulk_msg(data->usb_dev,
 795                                           usb_rcvbulkpipe(data->usb_dev,
 796                                                           data->bulk_in),
 797                                           buffer, USBTMC_SIZE_IOBUFFER,
 798                                           &actual, USBTMC_TIMEOUT);
 799                         n++;
 800
 801                         if (rv < 0) {
 802                                 dev_err(dev, "usb_control_msg returned %d\n",
 803                                         rv);
 804                                 goto exit;
 805                         }
 806                 } while ((actual == max_size) &&
 807                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 808
 809         if (actual == max_size) {
 810                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 811                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 812                 rv = -EPERM;
 813                 goto exit;
 814         }
 815
 816         goto usbtmc_clear_check_status;
 817
 818 usbtmc_clear_bulk_out_halt:
 819
 820         rv = usb_clear_halt(data->usb_dev,
 821                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 822         if (rv < 0) {
 823                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 824                 goto exit;
 825         }
 826         rv = 0;
 827
 828 exit:
 829         kfree(buffer);
 830         return rv;
 831 }
 832
 833 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 834 {
 835         int rv;
 836
 837         rv = usb_clear_halt(data->usb_dev,
 838                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 839
 840         if (rv < 0) {
 841                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 842                         rv);
 843                 return rv;
 844         }
 845         return 0;
 846 }
 847
 848 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 849 {
 850         int rv;
 851
 852         rv = usb_clear_halt(data->usb_dev,
 853                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 854
 855         if (rv < 0) {
 856                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 857                         rv);
 858                 return rv;
 859         }
 860         return 0;
 861 }
 862
 863 static int get_capabilities(struct usbtmc_device_data *data)
 864 {
 865         struct device *dev = &data->usb_dev->dev;
 866         char *buffer;
 867         int rv = 0;
 868
 869         buffer = kmalloc(0x18, GFP_KERNEL);
 870         if (!buffer)
 871                 return -ENOMEM;
 872
 873         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 874                              USBTMC_REQUEST_GET_CAPABILITIES,
 875                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 876                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 877         if (rv < 0) {
 878                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 879                 goto err_out;
 880         }
 881
 882         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 883         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 884                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 885                 rv = -EPERM;
 886                 goto err_out;
 887         }
 888         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 889         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 890         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 891         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 892
 893         data->capabilities.interface_capabilities = buffer[4];
 894         data->capabilities.device_capabilities = buffer[5];
 895         data->capabilities.usb488_interface_capabilities = buffer[14];
 896         data->capabilities.usb488_device_capabilities = buffer[15];
 897         rv = 0;
 898
 899 err_out:
 900         kfree(buffer);
 901         return rv;
 902 }
 903
 904 #define capability_attribute(name)                                      \
 905 static ssize_t name##_show(struct device *dev,                          \
 906                            struct device_attribute *attr, char *buf)    \
 907 {                                                                       \
 908         struct usb_interface *intf = to_usb_interface(dev);             \
 909         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 910                                                                         \
 911         return sprintf(buf, "%d\n", data->capabilities.name);           \
 912 }                                                                       \
 913 static DEVICE_ATTR_RO(name)
 914
 915 capability_attribute(interface_capabilities);
 916 capability_attribute(device_capabilities);
 917 capability_attribute(usb488_interface_capabilities);
 918 capability_attribute(usb488_device_capabilities);
 919
 920 static struct attribute *capability_attrs[] = {
 921         &dev_attr_interface_capabilities.attr,
 922         &dev_attr_device_capabilities.attr,
 923         &dev_attr_usb488_interface_capabilities.attr,
 924         &dev_attr_usb488_device_capabilities.attr,
 925         NULL,
 926 };
 927
 928 static struct attribute_group capability_attr_grp = {
 929         .attrs = capability_attrs,
 930 };
 931
 932 static ssize_t TermChar_show(struct device *dev,
 933                              struct device_attribute *attr, char *buf)
 934 {
 935         struct usb_interface *intf = to_usb_interface(dev);
 936         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 937
 938         return sprintf(buf, "%c\n", data->TermChar);
 939 }
 940
 941 static ssize_t TermChar_store(struct device *dev,
 942                               struct device_attribute *attr,
 943                               const char *buf, size_t count)
 944 {
 945         struct usb_interface *intf = to_usb_interface(dev);
 946         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 947
 948         if (count < 1)
 949                 return -EINVAL;
 950         data->TermChar = buf[0];
 951         return count;
 952 }
 953 static DEVICE_ATTR_RW(TermChar);
 954
 955 #define data_attribute(name)                                            \
 956 static ssize_t name##_show(struct device *dev,                          \
 957                            struct device_attribute *attr, char *buf)    \
 958 {                                                                       \
 959         struct usb_interface *intf = to_usb_interface(dev);             \
 960         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 961                                                                         \
 962         return sprintf(buf, "%d\n", data->name);                        \
 963 }                                                                       \
 964 static ssize_t name##_store(struct device *dev,                         \
 965                             struct device_attribute *attr,              \
 966                             const char *buf, size_t count)              \
 967 {                                                                       \
 968         struct usb_interface *intf = to_usb_interface(dev);             \
 969         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 970         ssize_t result;                                                 \
 971         unsigned val;                                                   \
 972                                                                         \
 973         result = sscanf(buf, "%u\n", &val);                             \
 974         if (result != 1)                                                \
 975                 result = -EINVAL;                                       \
 976         data->name = val;                                               \
 977         if (result < 0)                                                 \
 978                 return result;                                          \
 979         else                                                            \
 980                 return count;                                           \
 981 }                                                                       \
 982 static DEVICE_ATTR_RW(name)
 983
 984 data_attribute(TermCharEnabled);
 985 data_attribute(auto_abort);
 986
 987 static struct attribute *data_attrs[] = {
 988         &dev_attr_TermChar.attr,
 989         &dev_attr_TermCharEnabled.attr,
 990         &dev_attr_auto_abort.attr,
 991         NULL,
 992 };
 993
 994 static struct attribute_group data_attr_grp = {
 995         .attrs = data_attrs,
 996 };
 997
 998 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 999 {
1000         struct device *dev;
1001         u8 *buffer;
1002         int rv;
1003
1004         dev = &data->intf->dev;
1005
1006         buffer = kmalloc(2, GFP_KERNEL);
1007         if (!buffer)
1008                 return -ENOMEM;
1009
1010         rv = usb_control_msg(data->usb_dev,
1011                              usb_rcvctrlpipe(data->usb_dev, 0),
1012                              USBTMC_REQUEST_INDICATOR_PULSE,
1013                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1014                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1015
1016         if (rv < 0) {
1017                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1018                 goto exit;
1019         }
1020
1021         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1022
1023         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1024                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1025                 rv = -EPERM;
1026                 goto exit;
1027         }
1028         rv = 0;
1029
1030 exit:
1031         kfree(buffer);
1032         return rv;
1033 }
1034
1035 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1036 {
1037         struct usbtmc_device_data *data;
1038         int retval = -EBADRQC;
1039
1040         data = file->private_data;
1041         mutex_lock(&data->io_mutex);
1042         if (data->zombie) {
1043                 retval = -ENODEV;
1044                 goto skip_io_on_zombie;
1045         }
1046
1047         switch (cmd) {
1048         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1049                 retval = usbtmc_ioctl_clear_out_halt(data);
1050                 break;
1051
1052         case USBTMC_IOCTL_CLEAR_IN_HALT:
1053                 retval = usbtmc_ioctl_clear_in_halt(data);
1054                 break;
1055
1056         case USBTMC_IOCTL_INDICATOR_PULSE:
1057                 retval = usbtmc_ioctl_indicator_pulse(data);
1058                 break;
1059
1060         case USBTMC_IOCTL_CLEAR:
1061                 retval = usbtmc_ioctl_clear(data);
1062                 break;
1063
1064         case USBTMC_IOCTL_ABORT_BULK_OUT:
1065                 retval = usbtmc_ioctl_abort_bulk_out(data);
1066                 break;
1067
1068         case USBTMC_IOCTL_ABORT_BULK_IN:
1069                 retval = usbtmc_ioctl_abort_bulk_in(data);
1070                 break;
1071         }
1072
1073 skip_io_on_zombie:
1074         mutex_unlock(&data->io_mutex);
1075         return retval;
1076 }
1077
1078 static const struct file_operations fops = {
1079         .owner          = THIS_MODULE,
1080         .read           = usbtmc_read,
1081         .write          = usbtmc_write,
1082         .open           = usbtmc_open,
1083         .release        = usbtmc_release,
1084         .unlocked_ioctl = usbtmc_ioctl,
1085         .llseek         = default_llseek,
1086 };
1087
1088 static struct usb_class_driver usbtmc_class = {
1089         .name =         "usbtmc%d",
1090         .fops =         &fops,
1091         .minor_base =   USBTMC_MINOR_BASE,
1092 };
1093
1094
1095 static int usbtmc_probe(struct usb_interface *intf,
1096                         const struct usb_device_id *id)
1097 {
1098         struct usbtmc_device_data *data;
1099         struct usb_host_interface *iface_desc;
1100         struct usb_endpoint_descriptor *endpoint;
1101         int n;
1102         int retcode;
1103
1104         dev_dbg(&intf->dev, "%s called\n", __func__);
1105
1106         data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1107         if (!data)
1108                 return -ENOMEM;
1109
1110         data->intf = intf;
1111         data->id = id;
1112         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1113         usb_set_intfdata(intf, data);
1114         kref_init(&data->kref);
1115         mutex_init(&data->io_mutex);
1116         data->zombie = 0;
1117
1118         /* Determine if it is a Rigol or not */
1119         data->rigol_quirk = 0;
1120         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1121                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1122                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1123         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1124                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1125                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1126                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1127                         data->rigol_quirk = 1;
1128                         break;
1129                 }
1130         }
1131
1132         /* Initialize USBTMC bTag and other fields */
1133         data->bTag      = 1;
1134         data->TermCharEnabled = 0;
1135         data->TermChar = '\n';
1136
1137         /* USBTMC devices have only one setting, so use that */
1138         iface_desc = data->intf->cur_altsetting;
1139
1140         /* Find bulk in endpoint */
1141         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1142                 endpoint = &iface_desc->endpoint[n].desc;
1143
1144                 if (usb_endpoint_is_bulk_in(endpoint)) {
1145                         data->bulk_in = endpoint->bEndpointAddress;
1146                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1147                                 data->bulk_in);
1148                         break;
1149                 }
1150         }
1151
1152         /* Find bulk out endpoint */
1153         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1154                 endpoint = &iface_desc->endpoint[n].desc;
1155
1156                 if (usb_endpoint_is_bulk_out(endpoint)) {
1157                         data->bulk_out = endpoint->bEndpointAddress;
1158                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1159                                 data->bulk_out);
1160                         break;
1161                 }
1162         }
1163
1164         retcode = get_capabilities(data);
1165         if (retcode)
1166                 dev_err(&intf->dev, "can't read capabilities\n");
1167         else
1168                 retcode = sysfs_create_group(&intf->dev.kobj,
1169                                              &capability_attr_grp);
1170
1171         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1172
1173         retcode = usb_register_dev(intf, &usbtmc_class);
1174         if (retcode) {
1175                 dev_err(&intf->dev, "Not able to get a minor"
1176                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1177                         retcode);
1178                 goto error_register;
1179         }
1180         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1181
1182         return 0;
1183
1184 error_register:
1185         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1186         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1187         kref_put(&data->kref, usbtmc_delete);
1188         return retcode;
1189 }
1190
1191 static void usbtmc_disconnect(struct usb_interface *intf)
1192 {
1193         struct usbtmc_device_data *data;
1194
1195         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1196
1197         data = usb_get_intfdata(intf);
1198         usb_deregister_dev(intf, &usbtmc_class);
1199         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1200         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1201         mutex_lock(&data->io_mutex);
1202         data->zombie = 1;
1203         mutex_unlock(&data->io_mutex);
1204         kref_put(&data->kref, usbtmc_delete);
1205 }
1206
1207 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1208 {
1209         /* this driver does not have pending URBs */
1210         return 0;
1211 }
1212
1213 static int usbtmc_resume(struct usb_interface *intf)
1214 {
1215         return 0;
1216 }
1217
1218 static struct usb_driver usbtmc_driver = {
1219         .name           = "usbtmc",
1220         .id_table       = usbtmc_devices,
1221         .probe          = usbtmc_probe,
1222         .disconnect     = usbtmc_disconnect,
1223         .suspend        = usbtmc_suspend,
1224         .resume         = usbtmc_resume,
1225 };
1226
1227 module_usb_driver(usbtmc_driver);
1228
1229 MODULE_LICENSE("GPL");