drivers/usb/class/usbtmc.c

   1 /**
   2  * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   3  *
   4  * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5  * Copyright (C) 2008 Novell, Inc.
   6  * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * The GNU General Public License is available at
  19  * http://www.gnu.org/copyleft/gpl.html.
  20  */
  21
  22 #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         { 0x1ab1, 0x04b0 },
 113         { 0, 0 }
 114 };
 115
 116 /* Forward declarations */
 117 static struct usb_driver usbtmc_driver;
 118
 119 static void usbtmc_delete(struct kref *kref)
 120 {
 121         struct usbtmc_device_data *data = to_usbtmc_data(kref);
 122
 123         usb_put_dev(data->usb_dev);
 124 }
 125
 126 static int usbtmc_open(struct inode *inode, struct file *filp)
 127 {
 128         struct usb_interface *intf;
 129         struct usbtmc_device_data *data;
 130         int retval = 0;
 131
 132         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 133         if (!intf) {
 134                 pr_err("can not find device for minor %d", iminor(inode));
 135                 return -ENODEV;
 136         }
 137
 138         data = usb_get_intfdata(intf);
 139         kref_get(&data->kref);
 140
 141         /* Store pointer in file structure's private data field */
 142         filp->private_data = data;
 143
 144         return retval;
 145 }
 146
 147 static int usbtmc_release(struct inode *inode, struct file *file)
 148 {
 149         struct usbtmc_device_data *data = file->private_data;
 150
 151         kref_put(&data->kref, usbtmc_delete);
 152         return 0;
 153 }
 154
 155 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 156 {
 157         u8 *buffer;
 158         struct device *dev;
 159         int rv;
 160         int n;
 161         int actual;
 162         struct usb_host_interface *current_setting;
 163         int max_size;
 164
 165         dev = &data->intf->dev;
 166         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 167         if (!buffer)
 168                 return -ENOMEM;
 169
 170         rv = usb_control_msg(data->usb_dev,
 171                              usb_rcvctrlpipe(data->usb_dev, 0),
 172                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 173                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 174                              data->bTag_last_read, data->bulk_in,
 175                              buffer, 2, USBTMC_TIMEOUT);
 176
 177         if (rv < 0) {
 178                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 179                 goto exit;
 180         }
 181
 182         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 183
 184         if (buffer[0] == USBTMC_STATUS_FAILED) {
 185                 rv = 0;
 186                 goto exit;
 187         }
 188
 189         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 190                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 191                         buffer[0]);
 192                 rv = -EPERM;
 193                 goto exit;
 194         }
 195
 196         max_size = 0;
 197         current_setting = data->intf->cur_altsetting;
 198         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 199                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 200                         data->bulk_in)
 201                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 202
 203         if (max_size == 0) {
 204                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 205                 rv = -EPERM;
 206                 goto exit;
 207         }
 208
 209         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 210
 211         n = 0;
 212
 213         do {
 214                 dev_dbg(dev, "Reading from bulk in EP\n");
 215
 216                 rv = usb_bulk_msg(data->usb_dev,
 217                                   usb_rcvbulkpipe(data->usb_dev,
 218                                                   data->bulk_in),
 219                                   buffer, USBTMC_SIZE_IOBUFFER,
 220                                   &actual, USBTMC_TIMEOUT);
 221
 222                 n++;
 223
 224                 if (rv < 0) {
 225                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 226                         goto exit;
 227                 }
 228         } while ((actual == max_size) &&
 229                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 230
 231         if (actual == max_size) {
 232                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 233                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 234                 rv = -EPERM;
 235                 goto exit;
 236         }
 237
 238         n = 0;
 239
 240 usbtmc_abort_bulk_in_status:
 241         rv = usb_control_msg(data->usb_dev,
 242                              usb_rcvctrlpipe(data->usb_dev, 0),
 243                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 244                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 245                              0, data->bulk_in, buffer, 0x08,
 246                              USBTMC_TIMEOUT);
 247
 248         if (rv < 0) {
 249                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 250                 goto exit;
 251         }
 252
 253         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 254
 255         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 256                 rv = 0;
 257                 goto exit;
 258         }
 259
 260         if (buffer[0] != USBTMC_STATUS_PENDING) {
 261                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 262                 rv = -EPERM;
 263                 goto exit;
 264         }
 265
 266         if (buffer[1] == 1)
 267                 do {
 268                         dev_dbg(dev, "Reading from bulk in EP\n");
 269
 270                         rv = usb_bulk_msg(data->usb_dev,
 271                                           usb_rcvbulkpipe(data->usb_dev,
 272                                                           data->bulk_in),
 273                                           buffer, USBTMC_SIZE_IOBUFFER,
 274                                           &actual, USBTMC_TIMEOUT);
 275
 276                         n++;
 277
 278                         if (rv < 0) {
 279                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 280                                 goto exit;
 281                         }
 282                 } while ((actual == max_size) &&
 283                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 284
 285         if (actual == max_size) {
 286                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 287                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 288                 rv = -EPERM;
 289                 goto exit;
 290         }
 291
 292         goto usbtmc_abort_bulk_in_status;
 293
 294 exit:
 295         kfree(buffer);
 296         return rv;
 297
 298 }
 299
 300 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 301 {
 302         struct device *dev;
 303         u8 *buffer;
 304         int rv;
 305         int n;
 306
 307         dev = &data->intf->dev;
 308
 309         buffer = kmalloc(8, GFP_KERNEL);
 310         if (!buffer)
 311                 return -ENOMEM;
 312
 313         rv = usb_control_msg(data->usb_dev,
 314                              usb_rcvctrlpipe(data->usb_dev, 0),
 315                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 316                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 317                              data->bTag_last_write, data->bulk_out,
 318                              buffer, 2, USBTMC_TIMEOUT);
 319
 320         if (rv < 0) {
 321                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 322                 goto exit;
 323         }
 324
 325         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 326
 327         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 328                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 329                         buffer[0]);
 330                 rv = -EPERM;
 331                 goto exit;
 332         }
 333
 334         n = 0;
 335
 336 usbtmc_abort_bulk_out_check_status:
 337         rv = usb_control_msg(data->usb_dev,
 338                              usb_rcvctrlpipe(data->usb_dev, 0),
 339                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 340                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 341                              0, data->bulk_out, buffer, 0x08,
 342                              USBTMC_TIMEOUT);
 343         n++;
 344         if (rv < 0) {
 345                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 346                 goto exit;
 347         }
 348
 349         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 350
 351         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 352                 goto usbtmc_abort_bulk_out_clear_halt;
 353
 354         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 355             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 356                 goto usbtmc_abort_bulk_out_check_status;
 357
 358         rv = -EPERM;
 359         goto exit;
 360
 361 usbtmc_abort_bulk_out_clear_halt:
 362         rv = usb_clear_halt(data->usb_dev,
 363                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 364
 365         if (rv < 0) {
 366                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 367                 goto exit;
 368         }
 369         rv = 0;
 370
 371 exit:
 372         kfree(buffer);
 373         return rv;
 374 }
 375
 376 /*
 377  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 378  * @transfer_size: number of bytes to request from the device.
 379  *
 380  * See the USBTMC specification, Table 4.
 381  *
 382  * Also updates bTag_last_write.
 383  */
 384 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 385 {
 386         int retval;
 387         u8 *buffer;
 388         int actual;
 389
 390         buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
 391         if (!buffer)
 392                 return -ENOMEM;
 393         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 394          * Refer to class specs for details
 395          */
 396         buffer[0] = 2;
 397         buffer[1] = data->bTag;
 398         buffer[2] = ~data->bTag;
 399         buffer[3] = 0; /* Reserved */
 400         buffer[4] = transfer_size >> 0;
 401         buffer[5] = transfer_size >> 8;
 402         buffer[6] = transfer_size >> 16;
 403         buffer[7] = transfer_size >> 24;
 404         buffer[8] = data->TermCharEnabled * 2;
 405         /* Use term character? */
 406         buffer[9] = data->TermChar;
 407         buffer[10] = 0; /* Reserved */
 408         buffer[11] = 0; /* Reserved */
 409
 410         /* Send bulk URB */
 411         retval = usb_bulk_msg(data->usb_dev,
 412                               usb_sndbulkpipe(data->usb_dev,
 413                                               data->bulk_out),
 414                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 415
 416         /* Store bTag (in case we need to abort) */
 417         data->bTag_last_write = data->bTag;
 418
 419         /* Increment bTag -- and increment again if zero */
 420         data->bTag++;
 421         if (!data->bTag)
 422                 data->bTag++;
 423
 424         kfree(buffer);
 425         if (retval < 0) {
 426                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 427                 return retval;
 428         }
 429
 430         return 0;
 431 }
 432
 433 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 434                            size_t count, loff_t *f_pos)
 435 {
 436         struct usbtmc_device_data *data;
 437         struct device *dev;
 438         u32 n_characters;
 439         u8 *buffer;
 440         int actual;
 441         size_t done;
 442         size_t remaining;
 443         int retval;
 444         size_t this_part;
 445
 446         /* Get pointer to private data structure */
 447         data = filp->private_data;
 448         dev = &data->intf->dev;
 449
 450         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 451         if (!buffer)
 452                 return -ENOMEM;
 453
 454         mutex_lock(&data->io_mutex);
 455         if (data->zombie) {
 456                 retval = -ENODEV;
 457                 goto exit;
 458         }
 459
 460         if (data->rigol_quirk) {
 461                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 462
 463                 retval = send_request_dev_dep_msg_in(data, count);
 464
 465                 if (retval < 0) {
 466                         if (data->auto_abort)
 467                                 usbtmc_ioctl_abort_bulk_out(data);
 468                         goto exit;
 469                 }
 470         }
 471
 472         /* Loop until we have fetched everything we requested */
 473         remaining = count;
 474         this_part = remaining;
 475         done = 0;
 476
 477         while (remaining > 0) {
 478                 if (!data->rigol_quirk) {
 479                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 480
 481                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 482                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 483                         else
 484                                 this_part = remaining;
 485
 486                         retval = send_request_dev_dep_msg_in(data, this_part);
 487                         if (retval < 0) {
 488                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 489                                 if (data->auto_abort)
 490                                         usbtmc_ioctl_abort_bulk_out(data);
 491                                 goto exit;
 492                         }
 493                 }
 494
 495                 /* Send bulk URB */
 496                 retval = usb_bulk_msg(data->usb_dev,
 497                                       usb_rcvbulkpipe(data->usb_dev,
 498                                                       data->bulk_in),
 499                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 500                                       USBTMC_TIMEOUT);
 501
 502                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 503
 504                 /* Store bTag (in case we need to abort) */
 505                 data->bTag_last_read = data->bTag;
 506
 507                 if (retval < 0) {
 508                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 509                         if (data->auto_abort)
 510                                 usbtmc_ioctl_abort_bulk_in(data);
 511                         goto exit;
 512                 }
 513
 514                 /* Parse header in first packet */
 515                 if ((done == 0) || !data->rigol_quirk) {
 516                         /* Sanity checks for the header */
 517                         if (actual < USBTMC_HEADER_SIZE) {
 518                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 519                                 if (data->auto_abort)
 520                                         usbtmc_ioctl_abort_bulk_in(data);
 521                                 goto exit;
 522                         }
 523
 524                         if (buffer[0] != 2) {
 525                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 526                                 if (data->auto_abort)
 527                                         usbtmc_ioctl_abort_bulk_in(data);
 528                                 goto exit;
 529                         }
 530
 531                         if (buffer[1] != data->bTag_last_write) {
 532                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 533                                 if (data->auto_abort)
 534                                         usbtmc_ioctl_abort_bulk_in(data);
 535                                 goto exit;
 536                         }
 537
 538                         /* How many characters did the instrument send? */
 539                         n_characters = buffer[4] +
 540                                        (buffer[5] << 8) +
 541                                        (buffer[6] << 16) +
 542                                        (buffer[7] << 24);
 543
 544                         if (n_characters > this_part) {
 545                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 546                                 if (data->auto_abort)
 547                                         usbtmc_ioctl_abort_bulk_in(data);
 548                                 goto exit;
 549                         }
 550
 551                         /* Remove the USBTMC header */
 552                         actual -= USBTMC_HEADER_SIZE;
 553
 554                         /* Check if the message is smaller than requested */
 555                         if (data->rigol_quirk) {
 556                                 if (remaining > n_characters)
 557                                         remaining = n_characters;
 558                                 /* Remove padding if it exists */
 559                                 if (actual > remaining)
 560                                         actual = remaining;
 561                         }
 562                         else {
 563                                 if (this_part > n_characters)
 564                                         this_part = n_characters;
 565                                 /* Remove padding if it exists */
 566                                 if (actual > this_part)
 567                                         actual = this_part;
 568                         }
 569
 570                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 571
 572                         remaining -= actual;
 573
 574                         /* Terminate if end-of-message bit received from device */
 575                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 576                                 remaining = 0;
 577
 578                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 579
 580
 581                         /* Copy buffer to user space */
 582                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 583                                 /* There must have been an addressing problem */
 584                                 retval = -EFAULT;
 585                                 goto exit;
 586                         }
 587                         done += actual;
 588                 }
 589                 else  {
 590                         if (actual > remaining)
 591                                 actual = remaining;
 592
 593                         remaining -= actual;
 594
 595                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 596
 597                         /* Copy buffer to user space */
 598                         if (copy_to_user(buf + done, buffer, actual)) {
 599                                 /* There must have been an addressing problem */
 600                                 retval = -EFAULT;
 601                                 goto exit;
 602                         }
 603                         done += actual;
 604                 }
 605         }
 606
 607         /* Update file position value */
 608         *f_pos = *f_pos + done;
 609         retval = done;
 610
 611 exit:
 612         mutex_unlock(&data->io_mutex);
 613         kfree(buffer);
 614         return retval;
 615 }
 616
 617 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 618                             size_t count, loff_t *f_pos)
 619 {
 620         struct usbtmc_device_data *data;
 621         u8 *buffer;
 622         int retval;
 623         int actual;
 624         unsigned long int n_bytes;
 625         int remaining;
 626         int done;
 627         int this_part;
 628
 629         data = filp->private_data;
 630
 631         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 632         if (!buffer)
 633                 return -ENOMEM;
 634
 635         mutex_lock(&data->io_mutex);
 636         if (data->zombie) {
 637                 retval = -ENODEV;
 638                 goto exit;
 639         }
 640
 641         remaining = count;
 642         done = 0;
 643
 644         while (remaining > 0) {
 645                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 646                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 647                         buffer[8] = 0;
 648                 } else {
 649                         this_part = remaining;
 650                         buffer[8] = 1;
 651                 }
 652
 653                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 654                 buffer[0] = 1;
 655                 buffer[1] = data->bTag;
 656                 buffer[2] = ~data->bTag;
 657                 buffer[3] = 0; /* Reserved */
 658                 buffer[4] = this_part >> 0;
 659                 buffer[5] = this_part >> 8;
 660                 buffer[6] = this_part >> 16;
 661                 buffer[7] = this_part >> 24;
 662                 /* buffer[8] is set above... */
 663                 buffer[9] = 0; /* Reserved */
 664                 buffer[10] = 0; /* Reserved */
 665                 buffer[11] = 0; /* Reserved */
 666
 667                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 668                         retval = -EFAULT;
 669                         goto exit;
 670                 }
 671
 672                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 673                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 674
 675                 do {
 676                         retval = usb_bulk_msg(data->usb_dev,
 677                                               usb_sndbulkpipe(data->usb_dev,
 678                                                               data->bulk_out),
 679                                               buffer, n_bytes,
 680                                               &actual, USBTMC_TIMEOUT);
 681                         if (retval != 0)
 682                                 break;
 683                         n_bytes -= actual;
 684                 } while (n_bytes);
 685
 686                 data->bTag_last_write = data->bTag;
 687                 data->bTag++;
 688
 689                 if (!data->bTag)
 690                         data->bTag++;
 691
 692                 if (retval < 0) {
 693                         dev_err(&data->intf->dev,
 694                                 "Unable to send data, error %d\n", retval);
 695                         if (data->auto_abort)
 696                                 usbtmc_ioctl_abort_bulk_out(data);
 697                         goto exit;
 698                 }
 699
 700                 remaining -= this_part;
 701                 done += this_part;
 702         }
 703
 704         retval = count;
 705 exit:
 706         mutex_unlock(&data->io_mutex);
 707         kfree(buffer);
 708         return retval;
 709 }
 710
 711 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 712 {
 713         struct usb_host_interface *current_setting;
 714         struct usb_endpoint_descriptor *desc;
 715         struct device *dev;
 716         u8 *buffer;
 717         int rv;
 718         int n;
 719         int actual = 0;
 720         int max_size;
 721
 722         dev = &data->intf->dev;
 723
 724         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 725
 726         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 727         if (!buffer)
 728                 return -ENOMEM;
 729
 730         rv = usb_control_msg(data->usb_dev,
 731                              usb_rcvctrlpipe(data->usb_dev, 0),
 732                              USBTMC_REQUEST_INITIATE_CLEAR,
 733                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 734                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 735         if (rv < 0) {
 736                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 737                 goto exit;
 738         }
 739
 740         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 741
 742         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 743                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 744                 rv = -EPERM;
 745                 goto exit;
 746         }
 747
 748         max_size = 0;
 749         current_setting = data->intf->cur_altsetting;
 750         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 751                 desc = &current_setting->endpoint[n].desc;
 752                 if (desc->bEndpointAddress == data->bulk_in)
 753                         max_size = usb_endpoint_maxp(desc);
 754         }
 755
 756         if (max_size == 0) {
 757                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 758                 rv = -EPERM;
 759                 goto exit;
 760         }
 761
 762         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 763
 764         n = 0;
 765
 766 usbtmc_clear_check_status:
 767
 768         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 769
 770         rv = usb_control_msg(data->usb_dev,
 771                              usb_rcvctrlpipe(data->usb_dev, 0),
 772                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 773                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 774                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 775         if (rv < 0) {
 776                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 777                 goto exit;
 778         }
 779
 780         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 781
 782         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 783                 goto usbtmc_clear_bulk_out_halt;
 784
 785         if (buffer[0] != USBTMC_STATUS_PENDING) {
 786                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 787                 rv = -EPERM;
 788                 goto exit;
 789         }
 790
 791         if (buffer[1] == 1)
 792                 do {
 793                         dev_dbg(dev, "Reading from bulk in EP\n");
 794
 795                         rv = usb_bulk_msg(data->usb_dev,
 796                                           usb_rcvbulkpipe(data->usb_dev,
 797                                                           data->bulk_in),
 798                                           buffer, USBTMC_SIZE_IOBUFFER,
 799                                           &actual, USBTMC_TIMEOUT);
 800                         n++;
 801
 802                         if (rv < 0) {
 803                                 dev_err(dev, "usb_control_msg returned %d\n",
 804                                         rv);
 805                                 goto exit;
 806                         }
 807                 } while ((actual == max_size) &&
 808                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 809
 810         if (actual == max_size) {
 811                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 812                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 813                 rv = -EPERM;
 814                 goto exit;
 815         }
 816
 817         goto usbtmc_clear_check_status;
 818
 819 usbtmc_clear_bulk_out_halt:
 820
 821         rv = usb_clear_halt(data->usb_dev,
 822                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 823         if (rv < 0) {
 824                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 825                 goto exit;
 826         }
 827         rv = 0;
 828
 829 exit:
 830         kfree(buffer);
 831         return rv;
 832 }
 833
 834 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 835 {
 836         int rv;
 837
 838         rv = usb_clear_halt(data->usb_dev,
 839                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 840
 841         if (rv < 0) {
 842                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 843                         rv);
 844                 return rv;
 845         }
 846         return 0;
 847 }
 848
 849 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 850 {
 851         int rv;
 852
 853         rv = usb_clear_halt(data->usb_dev,
 854                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 855
 856         if (rv < 0) {
 857                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 858                         rv);
 859                 return rv;
 860         }
 861         return 0;
 862 }
 863
 864 static int get_capabilities(struct usbtmc_device_data *data)
 865 {
 866         struct device *dev = &data->usb_dev->dev;
 867         char *buffer;
 868         int rv = 0;
 869
 870         buffer = kmalloc(0x18, GFP_KERNEL);
 871         if (!buffer)
 872                 return -ENOMEM;
 873
 874         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 875                              USBTMC_REQUEST_GET_CAPABILITIES,
 876                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 877                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 878         if (rv < 0) {
 879                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 880                 goto err_out;
 881         }
 882
 883         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 884         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 885                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 886                 rv = -EPERM;
 887                 goto err_out;
 888         }
 889         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 890         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 891         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 892         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 893
 894         data->capabilities.interface_capabilities = buffer[4];
 895         data->capabilities.device_capabilities = buffer[5];
 896         data->capabilities.usb488_interface_capabilities = buffer[14];
 897         data->capabilities.usb488_device_capabilities = buffer[15];
 898         rv = 0;
 899
 900 err_out:
 901         kfree(buffer);
 902         return rv;
 903 }
 904
 905 #define capability_attribute(name)                                      \
 906 static ssize_t name##_show(struct device *dev,                          \
 907                            struct device_attribute *attr, char *buf)    \
 908 {                                                                       \
 909         struct usb_interface *intf = to_usb_interface(dev);             \
 910         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 911                                                                         \
 912         return sprintf(buf, "%d\n", data->capabilities.name);           \
 913 }                                                                       \
 914 static DEVICE_ATTR_RO(name)
 915
 916 capability_attribute(interface_capabilities);
 917 capability_attribute(device_capabilities);
 918 capability_attribute(usb488_interface_capabilities);
 919 capability_attribute(usb488_device_capabilities);
 920
 921 static struct attribute *capability_attrs[] = {
 922         &dev_attr_interface_capabilities.attr,
 923         &dev_attr_device_capabilities.attr,
 924         &dev_attr_usb488_interface_capabilities.attr,
 925         &dev_attr_usb488_device_capabilities.attr,
 926         NULL,
 927 };
 928
 929 static struct attribute_group capability_attr_grp = {
 930         .attrs = capability_attrs,
 931 };
 932
 933 static ssize_t TermChar_show(struct device *dev,
 934                              struct device_attribute *attr, char *buf)
 935 {
 936         struct usb_interface *intf = to_usb_interface(dev);
 937         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 938
 939         return sprintf(buf, "%c\n", data->TermChar);
 940 }
 941
 942 static ssize_t TermChar_store(struct device *dev,
 943                               struct device_attribute *attr,
 944                               const char *buf, size_t count)
 945 {
 946         struct usb_interface *intf = to_usb_interface(dev);
 947         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 948
 949         if (count < 1)
 950                 return -EINVAL;
 951         data->TermChar = buf[0];
 952         return count;
 953 }
 954 static DEVICE_ATTR_RW(TermChar);
 955
 956 #define data_attribute(name)                                            \
 957 static ssize_t name##_show(struct device *dev,                          \
 958                            struct device_attribute *attr, char *buf)    \
 959 {                                                                       \
 960         struct usb_interface *intf = to_usb_interface(dev);             \
 961         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 962                                                                         \
 963         return sprintf(buf, "%d\n", data->name);                        \
 964 }                                                                       \
 965 static ssize_t name##_store(struct device *dev,                         \
 966                             struct device_attribute *attr,              \
 967                             const char *buf, size_t count)              \
 968 {                                                                       \
 969         struct usb_interface *intf = to_usb_interface(dev);             \
 970         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 971         ssize_t result;                                                 \
 972         unsigned val;                                                   \
 973                                                                         \
 974         result = sscanf(buf, "%u\n", &val);                             \
 975         if (result != 1)                                                \
 976                 result = -EINVAL;                                       \
 977         data->name = val;                                               \
 978         if (result < 0)                                                 \
 979                 return result;                                          \
 980         else                                                            \
 981                 return count;                                           \
 982 }                                                                       \
 983 static DEVICE_ATTR_RW(name)
 984
 985 data_attribute(TermCharEnabled);
 986 data_attribute(auto_abort);
 987
 988 static struct attribute *data_attrs[] = {
 989         &dev_attr_TermChar.attr,
 990         &dev_attr_TermCharEnabled.attr,
 991         &dev_attr_auto_abort.attr,
 992         NULL,
 993 };
 994
 995 static struct attribute_group data_attr_grp = {
 996         .attrs = data_attrs,
 997 };
 998
 999 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1000 {
1001         struct device *dev;
1002         u8 *buffer;
1003         int rv;
1004
1005         dev = &data->intf->dev;
1006
1007         buffer = kmalloc(2, GFP_KERNEL);
1008         if (!buffer)
1009                 return -ENOMEM;
1010
1011         rv = usb_control_msg(data->usb_dev,
1012                              usb_rcvctrlpipe(data->usb_dev, 0),
1013                              USBTMC_REQUEST_INDICATOR_PULSE,
1014                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1015                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1016
1017         if (rv < 0) {
1018                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1019                 goto exit;
1020         }
1021
1022         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1023
1024         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1025                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1026                 rv = -EPERM;
1027                 goto exit;
1028         }
1029         rv = 0;
1030
1031 exit:
1032         kfree(buffer);
1033         return rv;
1034 }
1035
1036 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1037 {
1038         struct usbtmc_device_data *data;
1039         int retval = -EBADRQC;
1040
1041         data = file->private_data;
1042         mutex_lock(&data->io_mutex);
1043         if (data->zombie) {
1044                 retval = -ENODEV;
1045                 goto skip_io_on_zombie;
1046         }
1047
1048         switch (cmd) {
1049         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1050                 retval = usbtmc_ioctl_clear_out_halt(data);
1051                 break;
1052
1053         case USBTMC_IOCTL_CLEAR_IN_HALT:
1054                 retval = usbtmc_ioctl_clear_in_halt(data);
1055                 break;
1056
1057         case USBTMC_IOCTL_INDICATOR_PULSE:
1058                 retval = usbtmc_ioctl_indicator_pulse(data);
1059                 break;
1060
1061         case USBTMC_IOCTL_CLEAR:
1062                 retval = usbtmc_ioctl_clear(data);
1063                 break;
1064
1065         case USBTMC_IOCTL_ABORT_BULK_OUT:
1066                 retval = usbtmc_ioctl_abort_bulk_out(data);
1067                 break;
1068
1069         case USBTMC_IOCTL_ABORT_BULK_IN:
1070                 retval = usbtmc_ioctl_abort_bulk_in(data);
1071                 break;
1072         }
1073
1074 skip_io_on_zombie:
1075         mutex_unlock(&data->io_mutex);
1076         return retval;
1077 }
1078
1079 static const struct file_operations fops = {
1080         .owner          = THIS_MODULE,
1081         .read           = usbtmc_read,
1082         .write          = usbtmc_write,
1083         .open           = usbtmc_open,
1084         .release        = usbtmc_release,
1085         .unlocked_ioctl = usbtmc_ioctl,
1086         .llseek         = default_llseek,
1087 };
1088
1089 static struct usb_class_driver usbtmc_class = {
1090         .name =         "usbtmc%d",
1091         .fops =         &fops,
1092         .minor_base =   USBTMC_MINOR_BASE,
1093 };
1094
1095
1096 static int usbtmc_probe(struct usb_interface *intf,
1097                         const struct usb_device_id *id)
1098 {
1099         struct usbtmc_device_data *data;
1100         struct usb_host_interface *iface_desc;
1101         struct usb_endpoint_descriptor *endpoint;
1102         int n;
1103         int retcode;
1104
1105         dev_dbg(&intf->dev, "%s called\n", __func__);
1106
1107         data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1108         if (!data)
1109                 return -ENOMEM;
1110
1111         data->intf = intf;
1112         data->id = id;
1113         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1114         usb_set_intfdata(intf, data);
1115         kref_init(&data->kref);
1116         mutex_init(&data->io_mutex);
1117         data->zombie = 0;
1118
1119         /* Determine if it is a Rigol or not */
1120         data->rigol_quirk = 0;
1121         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1122                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1123                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1124         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1125                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1126                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1127                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1128                         data->rigol_quirk = 1;
1129                         break;
1130                 }
1131         }
1132
1133         /* Initialize USBTMC bTag and other fields */
1134         data->bTag      = 1;
1135         data->TermCharEnabled = 0;
1136         data->TermChar = '\n';
1137
1138         /* USBTMC devices have only one setting, so use that */
1139         iface_desc = data->intf->cur_altsetting;
1140
1141         /* Find bulk in endpoint */
1142         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1143                 endpoint = &iface_desc->endpoint[n].desc;
1144
1145                 if (usb_endpoint_is_bulk_in(endpoint)) {
1146                         data->bulk_in = endpoint->bEndpointAddress;
1147                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1148                                 data->bulk_in);
1149                         break;
1150                 }
1151         }
1152
1153         /* Find bulk out endpoint */
1154         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1155                 endpoint = &iface_desc->endpoint[n].desc;
1156
1157                 if (usb_endpoint_is_bulk_out(endpoint)) {
1158                         data->bulk_out = endpoint->bEndpointAddress;
1159                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1160                                 data->bulk_out);
1161                         break;
1162                 }
1163         }
1164
1165         retcode = get_capabilities(data);
1166         if (retcode)
1167                 dev_err(&intf->dev, "can't read capabilities\n");
1168         else
1169                 retcode = sysfs_create_group(&intf->dev.kobj,
1170                                              &capability_attr_grp);
1171
1172         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1173
1174         retcode = usb_register_dev(intf, &usbtmc_class);
1175         if (retcode) {
1176                 dev_err(&intf->dev, "Not able to get a minor"
1177                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1178                         retcode);
1179                 goto error_register;
1180         }
1181         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1182
1183         return 0;
1184
1185 error_register:
1186         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1187         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1188         kref_put(&data->kref, usbtmc_delete);
1189         return retcode;
1190 }
1191
1192 static void usbtmc_disconnect(struct usb_interface *intf)
1193 {
1194         struct usbtmc_device_data *data;
1195
1196         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1197
1198         data = usb_get_intfdata(intf);
1199         usb_deregister_dev(intf, &usbtmc_class);
1200         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1201         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1202         mutex_lock(&data->io_mutex);
1203         data->zombie = 1;
1204         mutex_unlock(&data->io_mutex);
1205         kref_put(&data->kref, usbtmc_delete);
1206 }
1207
1208 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1209 {
1210         /* this driver does not have pending URBs */
1211         return 0;
1212 }
1213
1214 static int usbtmc_resume(struct usb_interface *intf)
1215 {
1216         return 0;
1217 }
1218
1219 static struct usb_driver usbtmc_driver = {
1220         .name           = "usbtmc",
1221         .id_table       = usbtmc_devices,
1222         .probe          = usbtmc_probe,
1223         .disconnect     = usbtmc_disconnect,
1224         .suspend        = usbtmc_suspend,
1225         .resume         = usbtmc_resume,
1226 };
1227
1228 module_usb_driver(usbtmc_driver);
1229
1230 MODULE_LICENSE("GPL");