kernel/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         kfree(data);
 125 }
 126
 127 static int usbtmc_open(struct inode *inode, struct file *filp)
 128 {
 129         struct usb_interface *intf;
 130         struct usbtmc_device_data *data;
 131         int retval = 0;
 132
 133         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 134         if (!intf) {
 135                 pr_err("can not find device for minor %d", iminor(inode));
 136                 return -ENODEV;
 137         }
 138
 139         data = usb_get_intfdata(intf);
 140         kref_get(&data->kref);
 141
 142         /* Store pointer in file structure's private data field */
 143         filp->private_data = data;
 144
 145         return retval;
 146 }
 147
 148 static int usbtmc_release(struct inode *inode, struct file *file)
 149 {
 150         struct usbtmc_device_data *data = file->private_data;
 151
 152         kref_put(&data->kref, usbtmc_delete);
 153         return 0;
 154 }
 155
 156 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 157 {
 158         u8 *buffer;
 159         struct device *dev;
 160         int rv;
 161         int n;
 162         int actual;
 163         struct usb_host_interface *current_setting;
 164         int max_size;
 165
 166         dev = &data->intf->dev;
 167         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 168         if (!buffer)
 169                 return -ENOMEM;
 170
 171         rv = usb_control_msg(data->usb_dev,
 172                              usb_rcvctrlpipe(data->usb_dev, 0),
 173                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 174                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 175                              data->bTag_last_read, data->bulk_in,
 176                              buffer, 2, USBTMC_TIMEOUT);
 177
 178         if (rv < 0) {
 179                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 180                 goto exit;
 181         }
 182
 183         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 184
 185         if (buffer[0] == USBTMC_STATUS_FAILED) {
 186                 rv = 0;
 187                 goto exit;
 188         }
 189
 190         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 191                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 192                         buffer[0]);
 193                 rv = -EPERM;
 194                 goto exit;
 195         }
 196
 197         max_size = 0;
 198         current_setting = data->intf->cur_altsetting;
 199         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 200                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
 201                         data->bulk_in)
 202                         max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 203
 204         if (max_size == 0) {
 205                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 206                 rv = -EPERM;
 207                 goto exit;
 208         }
 209
 210         dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 211
 212         n = 0;
 213
 214         do {
 215                 dev_dbg(dev, "Reading from bulk in EP\n");
 216
 217                 rv = usb_bulk_msg(data->usb_dev,
 218                                   usb_rcvbulkpipe(data->usb_dev,
 219                                                   data->bulk_in),
 220                                   buffer, USBTMC_SIZE_IOBUFFER,
 221                                   &actual, USBTMC_TIMEOUT);
 222
 223                 n++;
 224
 225                 if (rv < 0) {
 226                         dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 227                         goto exit;
 228                 }
 229         } while ((actual == max_size) &&
 230                  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 231
 232         if (actual == max_size) {
 233                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 234                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 235                 rv = -EPERM;
 236                 goto exit;
 237         }
 238
 239         n = 0;
 240
 241 usbtmc_abort_bulk_in_status:
 242         rv = usb_control_msg(data->usb_dev,
 243                              usb_rcvctrlpipe(data->usb_dev, 0),
 244                              USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 245                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 246                              0, data->bulk_in, buffer, 0x08,
 247                              USBTMC_TIMEOUT);
 248
 249         if (rv < 0) {
 250                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 251                 goto exit;
 252         }
 253
 254         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 255
 256         if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 257                 rv = 0;
 258                 goto exit;
 259         }
 260
 261         if (buffer[0] != USBTMC_STATUS_PENDING) {
 262                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 263                 rv = -EPERM;
 264                 goto exit;
 265         }
 266
 267         if (buffer[1] == 1)
 268                 do {
 269                         dev_dbg(dev, "Reading from bulk in EP\n");
 270
 271                         rv = usb_bulk_msg(data->usb_dev,
 272                                           usb_rcvbulkpipe(data->usb_dev,
 273                                                           data->bulk_in),
 274                                           buffer, USBTMC_SIZE_IOBUFFER,
 275                                           &actual, USBTMC_TIMEOUT);
 276
 277                         n++;
 278
 279                         if (rv < 0) {
 280                                 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 281                                 goto exit;
 282                         }
 283                 } while ((actual == max_size) &&
 284                          (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 285
 286         if (actual == max_size) {
 287                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 288                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 289                 rv = -EPERM;
 290                 goto exit;
 291         }
 292
 293         goto usbtmc_abort_bulk_in_status;
 294
 295 exit:
 296         kfree(buffer);
 297         return rv;
 298
 299 }
 300
 301 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 302 {
 303         struct device *dev;
 304         u8 *buffer;
 305         int rv;
 306         int n;
 307
 308         dev = &data->intf->dev;
 309
 310         buffer = kmalloc(8, GFP_KERNEL);
 311         if (!buffer)
 312                 return -ENOMEM;
 313
 314         rv = usb_control_msg(data->usb_dev,
 315                              usb_rcvctrlpipe(data->usb_dev, 0),
 316                              USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 317                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 318                              data->bTag_last_write, data->bulk_out,
 319                              buffer, 2, USBTMC_TIMEOUT);
 320
 321         if (rv < 0) {
 322                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 323                 goto exit;
 324         }
 325
 326         dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 327
 328         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 329                 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 330                         buffer[0]);
 331                 rv = -EPERM;
 332                 goto exit;
 333         }
 334
 335         n = 0;
 336
 337 usbtmc_abort_bulk_out_check_status:
 338         rv = usb_control_msg(data->usb_dev,
 339                              usb_rcvctrlpipe(data->usb_dev, 0),
 340                              USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 341                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 342                              0, data->bulk_out, buffer, 0x08,
 343                              USBTMC_TIMEOUT);
 344         n++;
 345         if (rv < 0) {
 346                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 347                 goto exit;
 348         }
 349
 350         dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 351
 352         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 353                 goto usbtmc_abort_bulk_out_clear_halt;
 354
 355         if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 356             (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 357                 goto usbtmc_abort_bulk_out_check_status;
 358
 359         rv = -EPERM;
 360         goto exit;
 361
 362 usbtmc_abort_bulk_out_clear_halt:
 363         rv = usb_clear_halt(data->usb_dev,
 364                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 365
 366         if (rv < 0) {
 367                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 368                 goto exit;
 369         }
 370         rv = 0;
 371
 372 exit:
 373         kfree(buffer);
 374         return rv;
 375 }
 376
 377 /*
 378  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 379  * @transfer_size: number of bytes to request from the device.
 380  *
 381  * See the USBTMC specification, Table 4.
 382  *
 383  * Also updates bTag_last_write.
 384  */
 385 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
 386 {
 387         int retval;
 388         u8 *buffer;
 389         int actual;
 390
 391         buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
 392         if (!buffer)
 393                 return -ENOMEM;
 394         /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
 395          * Refer to class specs for details
 396          */
 397         buffer[0] = 2;
 398         buffer[1] = data->bTag;
 399         buffer[2] = ~data->bTag;
 400         buffer[3] = 0; /* Reserved */
 401         buffer[4] = transfer_size >> 0;
 402         buffer[5] = transfer_size >> 8;
 403         buffer[6] = transfer_size >> 16;
 404         buffer[7] = transfer_size >> 24;
 405         buffer[8] = data->TermCharEnabled * 2;
 406         /* Use term character? */
 407         buffer[9] = data->TermChar;
 408         buffer[10] = 0; /* Reserved */
 409         buffer[11] = 0; /* Reserved */
 410
 411         /* Send bulk URB */
 412         retval = usb_bulk_msg(data->usb_dev,
 413                               usb_sndbulkpipe(data->usb_dev,
 414                                               data->bulk_out),
 415                               buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
 416
 417         /* Store bTag (in case we need to abort) */
 418         data->bTag_last_write = data->bTag;
 419
 420         /* Increment bTag -- and increment again if zero */
 421         data->bTag++;
 422         if (!data->bTag)
 423                 data->bTag++;
 424
 425         kfree(buffer);
 426         if (retval < 0) {
 427                 dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
 428                 return retval;
 429         }
 430
 431         return 0;
 432 }
 433
 434 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 435                            size_t count, loff_t *f_pos)
 436 {
 437         struct usbtmc_device_data *data;
 438         struct device *dev;
 439         u32 n_characters;
 440         u8 *buffer;
 441         int actual;
 442         size_t done;
 443         size_t remaining;
 444         int retval;
 445         size_t this_part;
 446
 447         /* Get pointer to private data structure */
 448         data = filp->private_data;
 449         dev = &data->intf->dev;
 450
 451         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 452         if (!buffer)
 453                 return -ENOMEM;
 454
 455         mutex_lock(&data->io_mutex);
 456         if (data->zombie) {
 457                 retval = -ENODEV;
 458                 goto exit;
 459         }
 460
 461         if (data->rigol_quirk) {
 462                 dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
 463
 464                 retval = send_request_dev_dep_msg_in(data, count);
 465
 466                 if (retval < 0) {
 467                         if (data->auto_abort)
 468                                 usbtmc_ioctl_abort_bulk_out(data);
 469                         goto exit;
 470                 }
 471         }
 472
 473         /* Loop until we have fetched everything we requested */
 474         remaining = count;
 475         this_part = remaining;
 476         done = 0;
 477
 478         while (remaining > 0) {
 479                 if (!data->rigol_quirk) {
 480                         dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
 481
 482                         if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
 483                                 this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
 484                         else
 485                                 this_part = remaining;
 486
 487                         retval = send_request_dev_dep_msg_in(data, this_part);
 488                         if (retval < 0) {
 489                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 490                                 if (data->auto_abort)
 491                                         usbtmc_ioctl_abort_bulk_out(data);
 492                                 goto exit;
 493                         }
 494                 }
 495
 496                 /* Send bulk URB */
 497                 retval = usb_bulk_msg(data->usb_dev,
 498                                       usb_rcvbulkpipe(data->usb_dev,
 499                                                       data->bulk_in),
 500                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
 501                                       USBTMC_TIMEOUT);
 502
 503                 dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
 504
 505                 /* Store bTag (in case we need to abort) */
 506                 data->bTag_last_read = data->bTag;
 507
 508                 if (retval < 0) {
 509                         dev_dbg(dev, "Unable to read data, error %d\n", retval);
 510                         if (data->auto_abort)
 511                                 usbtmc_ioctl_abort_bulk_in(data);
 512                         goto exit;
 513                 }
 514
 515                 /* Parse header in first packet */
 516                 if ((done == 0) || !data->rigol_quirk) {
 517                         /* Sanity checks for the header */
 518                         if (actual < USBTMC_HEADER_SIZE) {
 519                                 dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
 520                                 if (data->auto_abort)
 521                                         usbtmc_ioctl_abort_bulk_in(data);
 522                                 goto exit;
 523                         }
 524
 525                         if (buffer[0] != 2) {
 526                                 dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
 527                                 if (data->auto_abort)
 528                                         usbtmc_ioctl_abort_bulk_in(data);
 529                                 goto exit;
 530                         }
 531
 532                         if (buffer[1] != data->bTag_last_write) {
 533                                 dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
 534                                 if (data->auto_abort)
 535                                         usbtmc_ioctl_abort_bulk_in(data);
 536                                 goto exit;
 537                         }
 538
 539                         /* How many characters did the instrument send? */
 540                         n_characters = buffer[4] +
 541                                        (buffer[5] << 8) +
 542                                        (buffer[6] << 16) +
 543                                        (buffer[7] << 24);
 544
 545                         if (n_characters > this_part) {
 546                                 dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
 547                                 if (data->auto_abort)
 548                                         usbtmc_ioctl_abort_bulk_in(data);
 549                                 goto exit;
 550                         }
 551
 552                         /* Remove the USBTMC header */
 553                         actual -= USBTMC_HEADER_SIZE;
 554
 555                         /* Check if the message is smaller than requested */
 556                         if (data->rigol_quirk) {
 557                                 if (remaining > n_characters)
 558                                         remaining = n_characters;
 559                                 /* Remove padding if it exists */
 560                                 if (actual > remaining)
 561                                         actual = remaining;
 562                         }
 563                         else {
 564                                 if (this_part > n_characters)
 565                                         this_part = n_characters;
 566                                 /* Remove padding if it exists */
 567                                 if (actual > this_part)
 568                                         actual = this_part;
 569                         }
 570
 571                         dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
 572
 573                         remaining -= actual;
 574
 575                         /* Terminate if end-of-message bit received from device */
 576                         if ((buffer[8] & 0x01) && (actual >= n_characters))
 577                                 remaining = 0;
 578
 579                         dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
 580
 581
 582                         /* Copy buffer to user space */
 583                         if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
 584                                 /* There must have been an addressing problem */
 585                                 retval = -EFAULT;
 586                                 goto exit;
 587                         }
 588                         done += actual;
 589                 }
 590                 else  {
 591                         if (actual > remaining)
 592                                 actual = remaining;
 593
 594                         remaining -= actual;
 595
 596                         dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
 597
 598                         /* Copy buffer to user space */
 599                         if (copy_to_user(buf + done, buffer, actual)) {
 600                                 /* There must have been an addressing problem */
 601                                 retval = -EFAULT;
 602                                 goto exit;
 603                         }
 604                         done += actual;
 605                 }
 606         }
 607
 608         /* Update file position value */
 609         *f_pos = *f_pos + done;
 610         retval = done;
 611
 612 exit:
 613         mutex_unlock(&data->io_mutex);
 614         kfree(buffer);
 615         return retval;
 616 }
 617
 618 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 619                             size_t count, loff_t *f_pos)
 620 {
 621         struct usbtmc_device_data *data;
 622         u8 *buffer;
 623         int retval;
 624         int actual;
 625         unsigned long int n_bytes;
 626         int remaining;
 627         int done;
 628         int this_part;
 629
 630         data = filp->private_data;
 631
 632         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 633         if (!buffer)
 634                 return -ENOMEM;
 635
 636         mutex_lock(&data->io_mutex);
 637         if (data->zombie) {
 638                 retval = -ENODEV;
 639                 goto exit;
 640         }
 641
 642         remaining = count;
 643         done = 0;
 644
 645         while (remaining > 0) {
 646                 if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
 647                         this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
 648                         buffer[8] = 0;
 649                 } else {
 650                         this_part = remaining;
 651                         buffer[8] = 1;
 652                 }
 653
 654                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
 655                 buffer[0] = 1;
 656                 buffer[1] = data->bTag;
 657                 buffer[2] = ~data->bTag;
 658                 buffer[3] = 0; /* Reserved */
 659                 buffer[4] = this_part >> 0;
 660                 buffer[5] = this_part >> 8;
 661                 buffer[6] = this_part >> 16;
 662                 buffer[7] = this_part >> 24;
 663                 /* buffer[8] is set above... */
 664                 buffer[9] = 0; /* Reserved */
 665                 buffer[10] = 0; /* Reserved */
 666                 buffer[11] = 0; /* Reserved */
 667
 668                 if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
 669                         retval = -EFAULT;
 670                         goto exit;
 671                 }
 672
 673                 n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
 674                 memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
 675
 676                 do {
 677                         retval = usb_bulk_msg(data->usb_dev,
 678                                               usb_sndbulkpipe(data->usb_dev,
 679                                                               data->bulk_out),
 680                                               buffer, n_bytes,
 681                                               &actual, USBTMC_TIMEOUT);
 682                         if (retval != 0)
 683                                 break;
 684                         n_bytes -= actual;
 685                 } while (n_bytes);
 686
 687                 data->bTag_last_write = data->bTag;
 688                 data->bTag++;
 689
 690                 if (!data->bTag)
 691                         data->bTag++;
 692
 693                 if (retval < 0) {
 694                         dev_err(&data->intf->dev,
 695                                 "Unable to send data, error %d\n", retval);
 696                         if (data->auto_abort)
 697                                 usbtmc_ioctl_abort_bulk_out(data);
 698                         goto exit;
 699                 }
 700
 701                 remaining -= this_part;
 702                 done += this_part;
 703         }
 704
 705         retval = count;
 706 exit:
 707         mutex_unlock(&data->io_mutex);
 708         kfree(buffer);
 709         return retval;
 710 }
 711
 712 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 713 {
 714         struct usb_host_interface *current_setting;
 715         struct usb_endpoint_descriptor *desc;
 716         struct device *dev;
 717         u8 *buffer;
 718         int rv;
 719         int n;
 720         int actual = 0;
 721         int max_size;
 722
 723         dev = &data->intf->dev;
 724
 725         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 726
 727         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 728         if (!buffer)
 729                 return -ENOMEM;
 730
 731         rv = usb_control_msg(data->usb_dev,
 732                              usb_rcvctrlpipe(data->usb_dev, 0),
 733                              USBTMC_REQUEST_INITIATE_CLEAR,
 734                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 735                              0, 0, buffer, 1, USBTMC_TIMEOUT);
 736         if (rv < 0) {
 737                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 738                 goto exit;
 739         }
 740
 741         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 742
 743         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 744                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 745                 rv = -EPERM;
 746                 goto exit;
 747         }
 748
 749         max_size = 0;
 750         current_setting = data->intf->cur_altsetting;
 751         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 752                 desc = &current_setting->endpoint[n].desc;
 753                 if (desc->bEndpointAddress == data->bulk_in)
 754                         max_size = usb_endpoint_maxp(desc);
 755         }
 756
 757         if (max_size == 0) {
 758                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
 759                 rv = -EPERM;
 760                 goto exit;
 761         }
 762
 763         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 764
 765         n = 0;
 766
 767 usbtmc_clear_check_status:
 768
 769         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 770
 771         rv = usb_control_msg(data->usb_dev,
 772                              usb_rcvctrlpipe(data->usb_dev, 0),
 773                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 774                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 775                              0, 0, buffer, 2, USBTMC_TIMEOUT);
 776         if (rv < 0) {
 777                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 778                 goto exit;
 779         }
 780
 781         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 782
 783         if (buffer[0] == USBTMC_STATUS_SUCCESS)
 784                 goto usbtmc_clear_bulk_out_halt;
 785
 786         if (buffer[0] != USBTMC_STATUS_PENDING) {
 787                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 788                 rv = -EPERM;
 789                 goto exit;
 790         }
 791
 792         if (buffer[1] == 1)
 793                 do {
 794                         dev_dbg(dev, "Reading from bulk in EP\n");
 795
 796                         rv = usb_bulk_msg(data->usb_dev,
 797                                           usb_rcvbulkpipe(data->usb_dev,
 798                                                           data->bulk_in),
 799                                           buffer, USBTMC_SIZE_IOBUFFER,
 800                                           &actual, USBTMC_TIMEOUT);
 801                         n++;
 802
 803                         if (rv < 0) {
 804                                 dev_err(dev, "usb_control_msg returned %d\n",
 805                                         rv);
 806                                 goto exit;
 807                         }
 808                 } while ((actual == max_size) &&
 809                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 810
 811         if (actual == max_size) {
 812                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 813                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 814                 rv = -EPERM;
 815                 goto exit;
 816         }
 817
 818         goto usbtmc_clear_check_status;
 819
 820 usbtmc_clear_bulk_out_halt:
 821
 822         rv = usb_clear_halt(data->usb_dev,
 823                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 824         if (rv < 0) {
 825                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 826                 goto exit;
 827         }
 828         rv = 0;
 829
 830 exit:
 831         kfree(buffer);
 832         return rv;
 833 }
 834
 835 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 836 {
 837         int rv;
 838
 839         rv = usb_clear_halt(data->usb_dev,
 840                             usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 841
 842         if (rv < 0) {
 843                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 844                         rv);
 845                 return rv;
 846         }
 847         return 0;
 848 }
 849
 850 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 851 {
 852         int rv;
 853
 854         rv = usb_clear_halt(data->usb_dev,
 855                             usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 856
 857         if (rv < 0) {
 858                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 859                         rv);
 860                 return rv;
 861         }
 862         return 0;
 863 }
 864
 865 static int get_capabilities(struct usbtmc_device_data *data)
 866 {
 867         struct device *dev = &data->usb_dev->dev;
 868         char *buffer;
 869         int rv = 0;
 870
 871         buffer = kmalloc(0x18, GFP_KERNEL);
 872         if (!buffer)
 873                 return -ENOMEM;
 874
 875         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 876                              USBTMC_REQUEST_GET_CAPABILITIES,
 877                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 878                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 879         if (rv < 0) {
 880                 dev_err(dev, "usb_control_msg returned %d\n", rv);
 881                 goto err_out;
 882         }
 883
 884         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 885         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 886                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 887                 rv = -EPERM;
 888                 goto err_out;
 889         }
 890         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 891         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 892         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 893         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 894
 895         data->capabilities.interface_capabilities = buffer[4];
 896         data->capabilities.device_capabilities = buffer[5];
 897         data->capabilities.usb488_interface_capabilities = buffer[14];
 898         data->capabilities.usb488_device_capabilities = buffer[15];
 899         rv = 0;
 900
 901 err_out:
 902         kfree(buffer);
 903         return rv;
 904 }
 905
 906 #define capability_attribute(name)                                      \
 907 static ssize_t name##_show(struct device *dev,                          \
 908                            struct device_attribute *attr, char *buf)    \
 909 {                                                                       \
 910         struct usb_interface *intf = to_usb_interface(dev);             \
 911         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 912                                                                         \
 913         return sprintf(buf, "%d\n", data->capabilities.name);           \
 914 }                                                                       \
 915 static DEVICE_ATTR_RO(name)
 916
 917 capability_attribute(interface_capabilities);
 918 capability_attribute(device_capabilities);
 919 capability_attribute(usb488_interface_capabilities);
 920 capability_attribute(usb488_device_capabilities);
 921
 922 static struct attribute *capability_attrs[] = {
 923         &dev_attr_interface_capabilities.attr,
 924         &dev_attr_device_capabilities.attr,
 925         &dev_attr_usb488_interface_capabilities.attr,
 926         &dev_attr_usb488_device_capabilities.attr,
 927         NULL,
 928 };
 929
 930 static struct attribute_group capability_attr_grp = {
 931         .attrs = capability_attrs,
 932 };
 933
 934 static ssize_t TermChar_show(struct device *dev,
 935                              struct device_attribute *attr, char *buf)
 936 {
 937         struct usb_interface *intf = to_usb_interface(dev);
 938         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 939
 940         return sprintf(buf, "%c\n", data->TermChar);
 941 }
 942
 943 static ssize_t TermChar_store(struct device *dev,
 944                               struct device_attribute *attr,
 945                               const char *buf, size_t count)
 946 {
 947         struct usb_interface *intf = to_usb_interface(dev);
 948         struct usbtmc_device_data *data = usb_get_intfdata(intf);
 949
 950         if (count < 1)
 951                 return -EINVAL;
 952         data->TermChar = buf[0];
 953         return count;
 954 }
 955 static DEVICE_ATTR_RW(TermChar);
 956
 957 #define data_attribute(name)                                            \
 958 static ssize_t name##_show(struct device *dev,                          \
 959                            struct device_attribute *attr, char *buf)    \
 960 {                                                                       \
 961         struct usb_interface *intf = to_usb_interface(dev);             \
 962         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 963                                                                         \
 964         return sprintf(buf, "%d\n", data->name);                        \
 965 }                                                                       \
 966 static ssize_t name##_store(struct device *dev,                         \
 967                             struct device_attribute *attr,              \
 968                             const char *buf, size_t count)              \
 969 {                                                                       \
 970         struct usb_interface *intf = to_usb_interface(dev);             \
 971         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
 972         ssize_t result;                                                 \
 973         unsigned val;                                                   \
 974                                                                         \
 975         result = sscanf(buf, "%u\n", &val);                             \
 976         if (result != 1)                                                \
 977                 result = -EINVAL;                                       \
 978         data->name = val;                                               \
 979         if (result < 0)                                                 \
 980                 return result;                                          \
 981         else                                                            \
 982                 return count;                                           \
 983 }                                                                       \
 984 static DEVICE_ATTR_RW(name)
 985
 986 data_attribute(TermCharEnabled);
 987 data_attribute(auto_abort);
 988
 989 static struct attribute *data_attrs[] = {
 990         &dev_attr_TermChar.attr,
 991         &dev_attr_TermCharEnabled.attr,
 992         &dev_attr_auto_abort.attr,
 993         NULL,
 994 };
 995
 996 static struct attribute_group data_attr_grp = {
 997         .attrs = data_attrs,
 998 };
 999
1000 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1001 {
1002         struct device *dev;
1003         u8 *buffer;
1004         int rv;
1005
1006         dev = &data->intf->dev;
1007
1008         buffer = kmalloc(2, GFP_KERNEL);
1009         if (!buffer)
1010                 return -ENOMEM;
1011
1012         rv = usb_control_msg(data->usb_dev,
1013                              usb_rcvctrlpipe(data->usb_dev, 0),
1014                              USBTMC_REQUEST_INDICATOR_PULSE,
1015                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1016                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1017
1018         if (rv < 0) {
1019                 dev_err(dev, "usb_control_msg returned %d\n", rv);
1020                 goto exit;
1021         }
1022
1023         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1024
1025         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1026                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1027                 rv = -EPERM;
1028                 goto exit;
1029         }
1030         rv = 0;
1031
1032 exit:
1033         kfree(buffer);
1034         return rv;
1035 }
1036
1037 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1038 {
1039         struct usbtmc_device_data *data;
1040         int retval = -EBADRQC;
1041
1042         data = file->private_data;
1043         mutex_lock(&data->io_mutex);
1044         if (data->zombie) {
1045                 retval = -ENODEV;
1046                 goto skip_io_on_zombie;
1047         }
1048
1049         switch (cmd) {
1050         case USBTMC_IOCTL_CLEAR_OUT_HALT:
1051                 retval = usbtmc_ioctl_clear_out_halt(data);
1052                 break;
1053
1054         case USBTMC_IOCTL_CLEAR_IN_HALT:
1055                 retval = usbtmc_ioctl_clear_in_halt(data);
1056                 break;
1057
1058         case USBTMC_IOCTL_INDICATOR_PULSE:
1059                 retval = usbtmc_ioctl_indicator_pulse(data);
1060                 break;
1061
1062         case USBTMC_IOCTL_CLEAR:
1063                 retval = usbtmc_ioctl_clear(data);
1064                 break;
1065
1066         case USBTMC_IOCTL_ABORT_BULK_OUT:
1067                 retval = usbtmc_ioctl_abort_bulk_out(data);
1068                 break;
1069
1070         case USBTMC_IOCTL_ABORT_BULK_IN:
1071                 retval = usbtmc_ioctl_abort_bulk_in(data);
1072                 break;
1073         }
1074
1075 skip_io_on_zombie:
1076         mutex_unlock(&data->io_mutex);
1077         return retval;
1078 }
1079
1080 static const struct file_operations fops = {
1081         .owner          = THIS_MODULE,
1082         .read           = usbtmc_read,
1083         .write          = usbtmc_write,
1084         .open           = usbtmc_open,
1085         .release        = usbtmc_release,
1086         .unlocked_ioctl = usbtmc_ioctl,
1087         .llseek         = default_llseek,
1088 };
1089
1090 static struct usb_class_driver usbtmc_class = {
1091         .name =         "usbtmc%d",
1092         .fops =         &fops,
1093         .minor_base =   USBTMC_MINOR_BASE,
1094 };
1095
1096
1097 static int usbtmc_probe(struct usb_interface *intf,
1098                         const struct usb_device_id *id)
1099 {
1100         struct usbtmc_device_data *data;
1101         struct usb_host_interface *iface_desc;
1102         struct usb_endpoint_descriptor *endpoint;
1103         int n;
1104         int retcode;
1105
1106         dev_dbg(&intf->dev, "%s called\n", __func__);
1107
1108         data = kmalloc(sizeof(*data), GFP_KERNEL);
1109         if (!data)
1110                 return -ENOMEM;
1111
1112         data->intf = intf;
1113         data->id = id;
1114         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1115         usb_set_intfdata(intf, data);
1116         kref_init(&data->kref);
1117         mutex_init(&data->io_mutex);
1118         data->zombie = 0;
1119
1120         /* Determine if it is a Rigol or not */
1121         data->rigol_quirk = 0;
1122         dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1123                 le16_to_cpu(data->usb_dev->descriptor.idVendor),
1124                 le16_to_cpu(data->usb_dev->descriptor.idProduct));
1125         for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1126                 if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1127                     (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1128                         dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1129                         data->rigol_quirk = 1;
1130                         break;
1131                 }
1132         }
1133
1134         /* Initialize USBTMC bTag and other fields */
1135         data->bTag      = 1;
1136         data->TermCharEnabled = 0;
1137         data->TermChar = '\n';
1138
1139         /* USBTMC devices have only one setting, so use that */
1140         iface_desc = data->intf->cur_altsetting;
1141
1142         /* Find bulk in endpoint */
1143         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1144                 endpoint = &iface_desc->endpoint[n].desc;
1145
1146                 if (usb_endpoint_is_bulk_in(endpoint)) {
1147                         data->bulk_in = endpoint->bEndpointAddress;
1148                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1149                                 data->bulk_in);
1150                         break;
1151                 }
1152         }
1153
1154         /* Find bulk out endpoint */
1155         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1156                 endpoint = &iface_desc->endpoint[n].desc;
1157
1158                 if (usb_endpoint_is_bulk_out(endpoint)) {
1159                         data->bulk_out = endpoint->bEndpointAddress;
1160                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1161                                 data->bulk_out);
1162                         break;
1163                 }
1164         }
1165
1166         retcode = get_capabilities(data);
1167         if (retcode)
1168                 dev_err(&intf->dev, "can't read capabilities\n");
1169         else
1170                 retcode = sysfs_create_group(&intf->dev.kobj,
1171                                              &capability_attr_grp);
1172
1173         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1174
1175         retcode = usb_register_dev(intf, &usbtmc_class);
1176         if (retcode) {
1177                 dev_err(&intf->dev, "Not able to get a minor"
1178                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1179                         retcode);
1180                 goto error_register;
1181         }
1182         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1183
1184         return 0;
1185
1186 error_register:
1187         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1188         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1189         kref_put(&data->kref, usbtmc_delete);
1190         return retcode;
1191 }
1192
1193 static void usbtmc_disconnect(struct usb_interface *intf)
1194 {
1195         struct usbtmc_device_data *data;
1196
1197         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1198
1199         data = usb_get_intfdata(intf);
1200         usb_deregister_dev(intf, &usbtmc_class);
1201         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1202         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1203         mutex_lock(&data->io_mutex);
1204         data->zombie = 1;
1205         mutex_unlock(&data->io_mutex);
1206         kref_put(&data->kref, usbtmc_delete);
1207 }
1208
1209 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1210 {
1211         /* this driver does not have pending URBs */
1212         return 0;
1213 }
1214
1215 static int usbtmc_resume(struct usb_interface *intf)
1216 {
1217         return 0;
1218 }
1219
1220 static struct usb_driver usbtmc_driver = {
1221         .name           = "usbtmc",
1222         .id_table       = usbtmc_devices,
1223         .probe          = usbtmc_probe,
1224         .disconnect     = usbtmc_disconnect,
1225         .suspend        = usbtmc_suspend,
1226         .resume         = usbtmc_resume,
1227 };
1228
1229 module_usb_driver(usbtmc_driver);
1230
1231 MODULE_LICENSE("GPL");