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[USBTMC_HEADER_SIZE];
 387         int actual;
 388
 389         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 390          * Refer to class specs for details
 391          */
 392         buffer[0] = 2;
 393         buffer[1] = data->bTag;
 394         buffer[2] = ~data->bTag;
 395         buffer[3] = 0; /* Reserved */
 396         buffer[4] = transfer_size >> 0;
 397         buffer[5] = transfer_size >> 8;
 398         buffer[6] = transfer_size >> 16;
 399         buffer[7] = transfer_size >> 24;
 400         buffer[8] = data->TermCharEnabled * 2;
 401         /* Use term character? */
 402         buffer[9] = data->TermChar;
 403         buffer[10] = 0; /* Reserved */
 404         buffer[11] = 0; /* Reserved */
 405
 406         /* Send bulk URB */
 407         retval = usb_bulk_msg(data->usb_dev,
 408                               usb_sndbulkpipe(data->usb_dev,
 409                                               data->bulk_out),
 410                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 411
 412         /* Store bTag (in case we need to abort) */
 413         data->bTag_last_write = data->bTag;
 414
 415         /* Increment bTag -- and increment again if zero */
 416         data->bTag++;
 417         if (!data->bTag)
 418                 data->bTag++;
 419
 420         if (retval < 0) {
 421                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 422                 return retval;
 423         }
 424
 425         return 0;
 426 }
 427
 428 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 429                            size_t count, loff_t *f_pos)
 430 {
 431         struct usbtmc_device_data *data;
 432         struct device *dev;
 433         u32 n_characters;
 434         u8 *buffer;
 435         int actual;
 436         size_t done;
 437         size_t remaining;
 438         int retval;
 439         size_t this_part;
 440
 441         /* Get pointer to private data structure */
 442         data = filp->private_data;
 443         dev = &data->intf->dev;
 444
 445         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 446         if (!buffer)
 447                 return -ENOMEM;
 448
 449         mutex_lock(&data->io_mutex);
 450         if (data->zombie) {
 451                 retval = -ENODEV;
 452                 goto exit;
 453         }
 454
 455         if (data->rigol_quirk) {
 456                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 457
 458                 retval = send_request_dev_dep_msg_in(data, count);
 459
 460                 if (retval < 0) {
 461                         if (data->auto_abort)
 462                                 usbtmc_ioctl_abort_bulk_out(data);
 463                         goto exit;
 464                 }
 465         }
 466
 467         /* Loop until we have fetched everything we requested */
 468         remaining = count;
 469         this_part = remaining;
 470         done = 0;
 471
 472         while (remaining > 0) {
 473                 if (!data->rigol_quirk) {
 474                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 475
 476                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 477                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 478                         else
 479                                 this_part = remaining;
 480
 481                         retval = send_request_dev_dep_msg_in(data, this_part);
 482                         if (retval < 0) {
 483                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 484                                 if (data->auto_abort)
 485                                         usbtmc_ioctl_abort_bulk_out(data);
 486                                 goto exit;
 487                         }
 488                 }
 489
 490                 /* Send bulk URB */
 491                 retval = usb_bulk_msg(data->usb_dev,
 492                                       usb_rcvbulkpipe(data->usb_dev,
 493                                                       data->bulk_in),
 494                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 495                                       USBTMC_TIMEOUT);
 496
 497                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 498
 499                 /* Store bTag (in case we need to abort) */
 500                 data->bTag_last_read = data->bTag;
 501
 502                 if (retval < 0) {
 503                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 504                         if (data->auto_abort)
 505                                 usbtmc_ioctl_abort_bulk_in(data);
 506                         goto exit;
 507                 }
 508
 509                 /* Parse header in first packet */
 510                 if ((done == 0) || !data->rigol_quirk) {
 511                         /* Sanity checks for the header */
 512                         if (actual < USBTMC_HEADER_SIZE) {
 513                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 514                                 if (data->auto_abort)
 515                                         usbtmc_ioctl_abort_bulk_in(data);
 516                                 goto exit;
 517                         }
 518
 519                         if (buffer[0] != 2) {
 520                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 521                                 if (data->auto_abort)
 522                                         usbtmc_ioctl_abort_bulk_in(data);
 523                                 goto exit;
 524                         }
 525
 526                         if (buffer[1] != data->bTag_last_write) {
 527                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 528                                 if (data->auto_abort)
 529                                         usbtmc_ioctl_abort_bulk_in(data);
 530                                 goto exit;
 531                         }
 532
 533                         /* How many characters did the instrument send? */
 534                         n_characters = buffer[4] +
 535                                        (buffer[5] << 8) +
 536                                        (buffer[6] << 16) +
 537                                        (buffer[7] << 24);
 538
 539                         if (n_characters > this_part) {
 540                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 541                                 if (data->auto_abort)
 542                                         usbtmc_ioctl_abort_bulk_in(data);
 543                                 goto exit;
 544                         }
 545
 546                         /* Remove the USBTMC header */
 547                         actual -= USBTMC_HEADER_SIZE;
 548
 549                         /* Check if the message is smaller than requested */
 550                         if (data->rigol_quirk) {
 551                                 if (remaining > n_characters)
 552                                         remaining = n_characters;
 553                                 /* Remove padding if it exists */
 554                                 if (actual > remaining)
 555                                         actual = remaining;
 556                         }
 557                         else {
 558                                 if (this_part > n_characters)
 559                                         this_part = n_characters;
 560                                 /* Remove padding if it exists */
 561                                 if (actual > this_part)
 562                                         actual = this_part;
 563                         }
 564
 565                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 566
 567                         remaining -= actual;
 568
 569                         /* Terminate if end-of-message bit received from device */
 570                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 571                                 remaining = 0;
 572
 573                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 574
 575
 576                         /* Copy buffer to user space */
 577                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 578                                 /* There must have been an addressing problem */
 579                                 retval = -EFAULT;
 580                                 goto exit;
 581                         }
 582                         done += actual;
 583                 }
 584                 else  {
 585                         if (actual > remaining)
 586                                 actual = remaining;
 587
 588                         remaining -= actual;
 589
 590                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 591
 592                         /* Copy buffer to user space */
 593                         if (copy_to_user(buf + done, buffer, actual)) {
 594                                 /* There must have been an addressing problem */
 595                                 retval = -EFAULT;
 596                                 goto exit;
 597                         }
 598                         done += actual;
 599                 }
 600         }
 601
 602         /* Update file position value */
 603         *f_pos = *f_pos + done;
 604         retval = done;
 605
 606 exit:
 607         mutex_unlock(&data->io_mutex);
 608         kfree(buffer);
 609         return retval;
 610 }
 611
 612 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 613                             size_t count, loff_t *f_pos)
 614 {
 615         struct usbtmc_device_data *data;
 616         u8 *buffer;
 617         int retval;
 618         int actual;
 619         unsigned long int n_bytes;
 620         int remaining;
 621         int done;
 622         int this_part;
 623
 624         data = filp->private_data;
 625
 626         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 627         if (!buffer)
 628                 return -ENOMEM;
 629
 630         mutex_lock(&data->io_mutex);
 631         if (data->zombie) {
 632                 retval = -ENODEV;
 633                 goto exit;
 634         }
 635
 636         remaining = count;
 637         done = 0;
 638
 639         while (remaining > 0) {
 640                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 641                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 642                         buffer[8] = 0;
 643                 } else {
 644                         this_part = remaining;
 645                         buffer[8] = 1;
 646                 }
 647
 648                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 649                 buffer[0] = 1;
 650                 buffer[1] = data->bTag;
 651                 buffer[2] = ~data->bTag;
 652                 buffer[3] = 0; /* Reserved */
 653                 buffer[4] = this_part >> 0;
 654                 buffer[5] = this_part >> 8;
 655                 buffer[6] = this_part >> 16;
 656                 buffer[7] = this_part >> 24;
 657                 /* buffer[8] is set above... */
 658                 buffer[9] = 0; /* Reserved */
 659                 buffer[10] = 0; /* Reserved */
 660                 buffer[11] = 0; /* Reserved */
 661
 662                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 663                         retval = -EFAULT;
 664                         goto exit;
 665                 }
 666
 667                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 668                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 669
 670                 do {
 671                         retval = usb_bulk_msg(data->usb_dev,
 672                                               usb_sndbulkpipe(data->usb_dev,
 673                                                               data->bulk_out),
 674                                               buffer, n_bytes,
 675                                               &actual, USBTMC_TIMEOUT);
 676                         if (retval != 0)
 677                                 break;
 678                         n_bytes -= actual;
 679                 } while (n_bytes);
 680
 681                 data->bTag_last_write = data->bTag;
 682                 data->bTag++;
 683
 684                 if (!data->bTag)
 685                         data->bTag++;
 686
 687                 if (retval < 0) {
 688                         dev_err(&data->intf->dev,
 689                                 "Unable to send data, error %d\n", retval);
 690                         if (data->auto_abort)
 691                                 usbtmc_ioctl_abort_bulk_out(data);
 692                         goto exit;
 693                 }
 694
 695                 remaining -= this_part;
 696                 done += this_part;
 697         }
 698
 699         retval = count;
 700 exit:
 701         mutex_unlock(&data->io_mutex);
 702         kfree(buffer);
 703         return retval;
 704 }
 705
 706 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 707 {
 708         struct usb_host_interface *current_setting;
 709         struct usb_endpoint_descriptor *desc;
 710         struct device *dev;
 711         u8 *buffer;
 712         int rv;
 713         int n;
 714         int actual;
 715         int max_size;
 716
 717         dev = &data->intf->dev;
 718
 719         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 720
 721         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 722         if (!buffer)
 723                 return -ENOMEM;
 724
 725         rv = usb_control_msg(data->usb_dev,
 726                              usb_rcvctrlpipe(data->usb_dev, 0),
 727                              USBTMC_REQUEST_INITIATE_CLEAR,
 728                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 729                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 730         if (rv < 0) {
 731                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 732                 goto exit;
 733         }
 734
 735         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 736
 737         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 738                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 739                 rv = -EPERM;
 740                 goto exit;
 741         }
 742
 743         max_size = 0;
 744         current_setting = data->intf->cur_altsetting;
 745         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 746                 desc = &current_setting->endpoint[n].desc;
 747                 if (desc->bEndpointAddress == data->bulk_in)
 748                         max_size = usb_endpoint_maxp(desc);
 749         }
 750
 751         if (max_size == 0) {
 752                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 753                 rv = -EPERM;
 754                 goto exit;
 755         }
 756
 757         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 758
 759         n = 0;
 760
 761 usbtmc_clear_check_status:
 762
 763         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 764
 765         rv = usb_control_msg(data->usb_dev,
 766                              usb_rcvctrlpipe(data->usb_dev, 0),
 767                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 768                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 769                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 770         if (rv < 0) {
 771                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 772                 goto exit;
 773         }
 774
 775         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 776
 777         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 778                 goto usbtmc_clear_bulk_out_halt;
 779
 780         if (buffer[0] != USBTMC_STATUS_PENDING) {
 781                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 782                 rv = -EPERM;
 783                 goto exit;
 784         }
 785
 786         if (buffer[1] == 1)
 787                 do {
 788                         dev_dbg(dev, "Reading from bulk in EP\n");
 789
 790                         rv = usb_bulk_msg(data->usb_dev,
 791                                           usb_rcvbulkpipe(data->usb_dev,
 792                                                           data->bulk_in),
 793                                           buffer, USBTMC_SIZE_IOBUFFER,
 794                                           &actual, USBTMC_TIMEOUT);
 795                         n++;
 796
 797                         if (rv < 0) {
 798                                 dev_err(dev, "usb_control_msg returned %d\n",
 799                                         rv);
 800                                 goto exit;
 801                         }
 802                 } while ((actual == max_size) &&
 803                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 804
 805         if (actual == max_size) {
 806                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 807                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 808                 rv = -EPERM;
 809                 goto exit;
 810         }
 811
 812         goto usbtmc_clear_check_status;
 813
 814 usbtmc_clear_bulk_out_halt:
 815
 816         rv = usb_clear_halt(data->usb_dev,
 817                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 818         if (rv < 0) {
 819                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 820                 goto exit;
 821         }
 822         rv = 0;
 823
 824 exit:
 825         kfree(buffer);
 826         return rv;
 827 }
 828
 829 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 830 {
 831         int rv;
 832
 833         rv = usb_clear_halt(data->usb_dev,
 834                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 835
 836         if (rv < 0) {
 837                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 838                         rv);
 839                 return rv;
 840         }
 841         return 0;
 842 }
 843
 844 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 845 {
 846         int rv;
 847
 848         rv = usb_clear_halt(data->usb_dev,
 849                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 850
 851         if (rv < 0) {
 852                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 853                         rv);
 854                 return rv;
 855         }
 856         return 0;
 857 }
 858
 859 static int get_capabilities(struct usbtmc_device_data *data)
 860 {
 861         struct device *dev = &data->usb_dev->dev;
 862         char *buffer;
 863         int rv = 0;
 864
 865         buffer = kmalloc(0x18, GFP_KERNEL);
 866         if (!buffer)
 867                 return -ENOMEM;
 868
 869         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 870                              USBTMC_REQUEST_GET_CAPABILITIES,
 871                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 872                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 873         if (rv < 0) {
 874                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 875                 goto err_out;
 876         }
 877
 878         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 879         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 880                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 881                 rv = -EPERM;
 882                 goto err_out;
 883         }
 884         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 885         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 886         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 887         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 888
 889         data->capabilities.interface_capabilities = buffer[4];
 890         data->capabilities.device_capabilities = buffer[5];
 891         data->capabilities.usb488_interface_capabilities = buffer[14];
 892         data->capabilities.usb488_device_capabilities = buffer[15];
 893         rv = 0;
 894
 895 err_out:
 896         kfree(buffer);
 897         return rv;
 898 }
 899
 900 #define capability_attribute(name)                                      \
 901 static ssize_t name##_show(struct device *dev,                          \
 902                            struct device_attribute *attr, char *buf)    \
 903 {                                                                       \
 904         struct usb_interface *intf = to_usb_interface(dev);             \
 905         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 906                                                                         \
 907         return sprintf(buf, "%d\n", data->capabilities.name);           \
 908 }                                                                       \
 909 static DEVICE_ATTR_RO(name)
 910
 911 capability_attribute(interface_capabilities);
 912 capability_attribute(device_capabilities);
 913 capability_attribute(usb488_interface_capabilities);
 914 capability_attribute(usb488_device_capabilities);
 915
 916 static struct attribute *capability_attrs[] = {
 917         &dev_attr_interface_capabilities.attr,
 918         &dev_attr_device_capabilities.attr,
 919         &dev_attr_usb488_interface_capabilities.attr,
 920         &dev_attr_usb488_device_capabilities.attr,
 921         NULL,
 922 };
 923
 924 static struct attribute_group capability_attr_grp = {
 925         .attrs = capability_attrs,
 926 };
 927
 928 static ssize_t TermChar_show(struct device *dev,
 929                              struct device_attribute *attr, char *buf)
 930 {
 931         struct usb_interface *intf = to_usb_interface(dev);
 932         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 933
 934         return sprintf(buf, "%c\n", data->TermChar);
 935 }
 936
 937 static ssize_t TermChar_store(struct device *dev,
 938                               struct device_attribute *attr,
 939                               const char *buf, size_t count)
 940 {
 941         struct usb_interface *intf = to_usb_interface(dev);
 942         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 943
 944         if (count < 1)
 945                 return -EINVAL;
 946         data->TermChar = buf[0];
 947         return count;
 948 }
 949 static DEVICE_ATTR_RW(TermChar);
 950
 951 #define data_attribute(name)                                            \
 952 static ssize_t name##_show(struct device *dev,                          \
 953                            struct device_attribute *attr, char *buf)    \
 954 {                                                                       \
 955         struct usb_interface *intf = to_usb_interface(dev);             \
 956         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 957                                                                         \
 958         return sprintf(buf, "%d\n", data->name);                        \
 959 }                                                                       \
 960 static ssize_t name##_store(struct device *dev,                         \
 961                             struct device_attribute *attr,              \
 962                             const char *buf, size_t count)              \
 963 {                                                                       \
 964         struct usb_interface *intf = to_usb_interface(dev);             \
 965         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 966         ssize_t result;                                                 \
 967         unsigned val;                                                   \
 968                                                                         \
 969         result = sscanf(buf, "%u\n", &val);                             \
 970         if (result != 1)                                                \
 971                 result = -EINVAL;                                       \
 972         data->name = val;                                               \
 973         if (result < 0)                                                 \
 974                 return result;                                          \
 975         else                                                            \
 976                 return count;                                           \
 977 }                                                                       \
 978 static DEVICE_ATTR_RW(name)
 979
 980 data_attribute(TermCharEnabled);
 981 data_attribute(auto_abort);
 982
 983 static struct attribute *data_attrs[] = {
 984         &dev_attr_TermChar.attr,
 985         &dev_attr_TermCharEnabled.attr,
 986         &dev_attr_auto_abort.attr,
 987         NULL,
 988 };
 989
 990 static struct attribute_group data_attr_grp = {
 991         .attrs = data_attrs,
 992 };
 993
 994 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 995 {
 996         struct device *dev;
 997         u8 *buffer;
 998         int rv;
 999
1000         dev = &data->intf->dev;
1001
1002         buffer = kmalloc(2, GFP_KERNEL);
1003         if (!buffer)
1004                 return -ENOMEM;
1005
1006         rv = usb_control_msg(data->usb_dev,
1007                              usb_rcvctrlpipe(data->usb_dev, 0),
1008                              USBTMC_REQUEST_INDICATOR_PULSE,
1009                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1010                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1011
1012         if (rv < 0) {
1013                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1014                 goto exit;
1015         }
1016
1017         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1018
1019         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1020                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1021                 rv = -EPERM;
1022                 goto exit;
1023         }
1024         rv = 0;
1025
1026 exit:
1027         kfree(buffer);
1028         return rv;
1029 }
1030
1031 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1032 {
1033         struct usbtmc_device_data *data;
1034         int retval = -EBADRQC;
1035
1036         data = file->private_data;
1037         mutex_lock(&data->io_mutex);
1038         if (data->zombie) {
1039                 retval = -ENODEV;
1040                 goto skip_io_on_zombie;
1041         }
1042
1043         switch (cmd) {
1044         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1045                 retval = usbtmc_ioctl_clear_out_halt(data);
1046                 break;
1047
1048         case USBTMC_IOCTL_CLEAR_IN_HALT:
1049                 retval = usbtmc_ioctl_clear_in_halt(data);
1050                 break;
1051
1052         case USBTMC_IOCTL_INDICATOR_PULSE:
1053                 retval = usbtmc_ioctl_indicator_pulse(data);
1054                 break;
1055
1056         case USBTMC_IOCTL_CLEAR:
1057                 retval = usbtmc_ioctl_clear(data);
1058                 break;
1059
1060         case USBTMC_IOCTL_ABORT_BULK_OUT:
1061                 retval = usbtmc_ioctl_abort_bulk_out(data);
1062                 break;
1063
1064         case USBTMC_IOCTL_ABORT_BULK_IN:
1065                 retval = usbtmc_ioctl_abort_bulk_in(data);
1066                 break;
1067         }
1068
1069 skip_io_on_zombie:
1070         mutex_unlock(&data->io_mutex);
1071         return retval;
1072 }
1073
1074 static const struct file_operations fops = {
1075         .owner          = THIS_MODULE,
1076         .read           = usbtmc_read,
1077         .write          = usbtmc_write,
1078         .open           = usbtmc_open,
1079         .release        = usbtmc_release,
1080         .unlocked_ioctl = usbtmc_ioctl,
1081         .llseek         = default_llseek,
1082 };
1083
1084 static struct usb_class_driver usbtmc_class = {
1085         .name =         "usbtmc%d",
1086         .fops =         &fops,
1087         .minor_base =   USBTMC_MINOR_BASE,
1088 };
1089
1090
1091 static int usbtmc_probe(struct usb_interface *intf,
1092                         const struct usb_device_id *id)
1093 {
1094         struct usbtmc_device_data *data;
1095         struct usb_host_interface *iface_desc;
1096         struct usb_endpoint_descriptor *endpoint;
1097         int n;
1098         int retcode;
1099
1100         dev_dbg(&intf->dev, "%s called\n", __func__);
1101
1102         data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1103         if (!data) {
1104                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1105                 return -ENOMEM;
1106         }
1107
1108         data->intf = intf;
1109         data->id = id;
1110         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1111         usb_set_intfdata(intf, data);
1112         kref_init(&data->kref);
1113         mutex_init(&data->io_mutex);
1114         data->zombie = 0;
1115
1116         /* Determine if it is a Rigol or not */
1117         data->rigol_quirk = 0;
1118         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1119                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1120                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1121         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1122                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1123                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1124                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1125                         data->rigol_quirk = 1;
1126                         break;
1127                 }
1128         }
1129
1130         /* Initialize USBTMC bTag and other fields */
1131         data->bTag      = 1;
1132         data->TermCharEnabled = 0;
1133         data->TermChar = '\n';
1134
1135         /* USBTMC devices have only one setting, so use that */
1136         iface_desc = data->intf->cur_altsetting;
1137
1138         /* Find bulk in endpoint */
1139         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1140                 endpoint = &iface_desc->endpoint[n].desc;
1141
1142                 if (usb_endpoint_is_bulk_in(endpoint)) {
1143                         data->bulk_in = endpoint->bEndpointAddress;
1144                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1145                                 data->bulk_in);
1146                         break;
1147                 }
1148         }
1149
1150         /* Find bulk out endpoint */
1151         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1152                 endpoint = &iface_desc->endpoint[n].desc;
1153
1154                 if (usb_endpoint_is_bulk_out(endpoint)) {
1155                         data->bulk_out = endpoint->bEndpointAddress;
1156                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1157                                 data->bulk_out);
1158                         break;
1159                 }
1160         }
1161
1162         retcode = get_capabilities(data);
1163         if (retcode)
1164                 dev_err(&intf->dev, "can't read capabilities\n");
1165         else
1166                 retcode = sysfs_create_group(&intf->dev.kobj,
1167                                              &capability_attr_grp);
1168
1169         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1170
1171         retcode = usb_register_dev(intf, &usbtmc_class);
1172         if (retcode) {
1173                 dev_err(&intf->dev, "Not able to get a minor"
1174                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1175                         retcode);
1176                 goto error_register;
1177         }
1178         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1179
1180         return 0;
1181
1182 error_register:
1183         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1184         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1185         kref_put(&data->kref, usbtmc_delete);
1186         return retcode;
1187 }
1188
1189 static void usbtmc_disconnect(struct usb_interface *intf)
1190 {
1191         struct usbtmc_device_data *data;
1192
1193         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1194
1195         data = usb_get_intfdata(intf);
1196         usb_deregister_dev(intf, &usbtmc_class);
1197         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1198         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1199         mutex_lock(&data->io_mutex);
1200         data->zombie = 1;
1201         mutex_unlock(&data->io_mutex);
1202         kref_put(&data->kref, usbtmc_delete);
1203 }
1204
1205 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1206 {
1207         /* this driver does not have pending URBs */
1208         return 0;
1209 }
1210
1211 static int usbtmc_resume(struct usb_interface *intf)
1212 {
1213         return 0;
1214 }
1215
1216 static struct usb_driver usbtmc_driver = {
1217         .name           = "usbtmc",
1218         .id_table       = usbtmc_devices,
1219         .probe          = usbtmc_probe,
1220         .disconnect     = usbtmc_disconnect,
1221         .suspend        = usbtmc_suspend,
1222         .resume         = usbtmc_resume,
1223 };
1224
1225 module_usb_driver(usbtmc_driver);
1226
1227 MODULE_LICENSE("GPL");