drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Copyright (C) 2014 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <[email protected]>
   7  * Dave Safford <[email protected]>
   8  * Reiner Sailer <[email protected]>
   9  * Kylene Hall <[email protected]>
  10  *
  11  * Maintained by: <[email protected]>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation, version 2 of the
  19  * License.
  20  *
  21  * Note, the TPM chip is not interrupt driven (only polling)
  22  * and can have very long timeouts (minutes!). Hence the unusual
  23  * calls to msleep.
  24  *
  25  */
  26
  27 #include <linux/poll.h>
  28 #include <linux/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/freezer.h>
  32 #include <linux/pm_runtime.h>
  33
  34 #include "tpm.h"
  35 #include "tpm_eventlog.h"
  36
  37 #define TPM_MAX_ORDINAL 243
  38 #define TSC_MAX_ORDINAL 12
  39 #define TPM_PROTECTED_COMMAND 0x00
  40 #define TPM_CONNECTION_COMMAND 0x40
  41
  42 /*
  43  * Bug workaround - some TPM's don't flush the most
  44  * recently changed pcr on suspend, so force the flush
  45  * with an extend to the selected _unused_ non-volatile pcr.
  46  */
  47 static int tpm_suspend_pcr;
  48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  49 MODULE_PARM_DESC(suspend_pcr,
  50                  "PCR to use for dummy writes to facilitate flush on suspend.");
  51
  52 /*
  53  * Array with one entry per ordinal defining the maximum amount
  54  * of time the chip could take to return the result.  The ordinal
  55  * designation of short, medium or long is defined in a table in
  56  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  57  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  58  * from the chip during initialization with a call to tpm_get_timeouts.
  59  */
  60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  61         TPM_UNDEFINED,          /* 0 */
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,          /* 5 */
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_SHORT,              /* 10 */
  72         TPM_SHORT,
  73         TPM_MEDIUM,
  74         TPM_LONG,
  75         TPM_LONG,
  76         TPM_MEDIUM,             /* 15 */
  77         TPM_SHORT,
  78         TPM_SHORT,
  79         TPM_MEDIUM,
  80         TPM_LONG,
  81         TPM_SHORT,              /* 20 */
  82         TPM_SHORT,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_MEDIUM,
  86         TPM_SHORT,              /* 25 */
  87         TPM_SHORT,
  88         TPM_MEDIUM,
  89         TPM_SHORT,
  90         TPM_SHORT,
  91         TPM_MEDIUM,             /* 30 */
  92         TPM_LONG,
  93         TPM_MEDIUM,
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_SHORT,              /* 35 */
  97         TPM_MEDIUM,
  98         TPM_MEDIUM,
  99         TPM_UNDEFINED,
 100         TPM_UNDEFINED,
 101         TPM_MEDIUM,             /* 40 */
 102         TPM_LONG,
 103         TPM_MEDIUM,
 104         TPM_SHORT,
 105         TPM_SHORT,
 106         TPM_SHORT,              /* 45 */
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_SHORT,
 110         TPM_LONG,
 111         TPM_MEDIUM,             /* 50 */
 112         TPM_MEDIUM,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,          /* 55 */
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_UNDEFINED,
 121         TPM_MEDIUM,             /* 60 */
 122         TPM_MEDIUM,
 123         TPM_MEDIUM,
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_MEDIUM,             /* 65 */
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_SHORT,              /* 70 */
 132         TPM_SHORT,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,          /* 75 */
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_UNDEFINED,
 141         TPM_LONG,               /* 80 */
 142         TPM_UNDEFINED,
 143         TPM_MEDIUM,
 144         TPM_LONG,
 145         TPM_SHORT,
 146         TPM_UNDEFINED,          /* 85 */
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_SHORT,              /* 90 */
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_SHORT,
 156         TPM_UNDEFINED,          /* 95 */
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_UNDEFINED,
 161         TPM_MEDIUM,             /* 100 */
 162         TPM_SHORT,
 163         TPM_SHORT,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,          /* 105 */
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_UNDEFINED,
 171         TPM_SHORT,              /* 110 */
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,
 176         TPM_SHORT,              /* 115 */
 177         TPM_SHORT,
 178         TPM_SHORT,
 179         TPM_UNDEFINED,
 180         TPM_UNDEFINED,
 181         TPM_LONG,               /* 120 */
 182         TPM_LONG,
 183         TPM_MEDIUM,
 184         TPM_UNDEFINED,
 185         TPM_SHORT,
 186         TPM_SHORT,              /* 125 */
 187         TPM_SHORT,
 188         TPM_LONG,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,              /* 130 */
 192         TPM_MEDIUM,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,
 195         TPM_MEDIUM,
 196         TPM_UNDEFINED,          /* 135 */
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_SHORT,              /* 140 */
 202         TPM_SHORT,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,
 206         TPM_UNDEFINED,          /* 145 */
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,              /* 150 */
 212         TPM_MEDIUM,
 213         TPM_MEDIUM,
 214         TPM_SHORT,
 215         TPM_SHORT,
 216         TPM_UNDEFINED,          /* 155 */
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_SHORT,              /* 160 */
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_SHORT,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,          /* 165 */
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_LONG,               /* 170 */
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,          /* 175 */
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_MEDIUM,             /* 180 */
 242         TPM_SHORT,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,
 246         TPM_MEDIUM,             /* 185 */
 247         TPM_SHORT,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,          /* 190 */
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,          /* 195 */
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_SHORT,              /* 200 */
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,
 265         TPM_SHORT,
 266         TPM_SHORT,              /* 205 */
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_SHORT,
 271         TPM_MEDIUM,             /* 210 */
 272         TPM_UNDEFINED,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_MEDIUM,
 276         TPM_UNDEFINED,          /* 215 */
 277         TPM_MEDIUM,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_SHORT,
 281         TPM_SHORT,              /* 220 */
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_UNDEFINED,          /* 225 */
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_SHORT,              /* 230 */
 292         TPM_LONG,
 293         TPM_MEDIUM,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,          /* 235 */
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_SHORT,              /* 240 */
 302         TPM_UNDEFINED,
 303         TPM_MEDIUM,
 304 };
 305
 306 /*
 307  * Returns max number of jiffies to wait
 308  */
 309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 310                                            u32 ordinal)
 311 {
 312         int duration_idx = TPM_UNDEFINED;
 313         int duration = 0;
 314
 315         /*
 316          * We only have a duration table for protected commands, where the upper
 317          * 16 bits are 0. For the few other ordinals the fallback will be used.
 318          */
 319         if (ordinal < TPM_MAX_ORDINAL)
 320                 duration_idx = tpm_ordinal_duration[ordinal];
 321
 322         if (duration_idx != TPM_UNDEFINED)
 323                 duration = chip->duration[duration_idx];
 324         if (duration <= 0)
 325                 return 2 * 60 * HZ;
 326         else
 327                 return duration;
 328 }
 329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 330
 331 /**
 332  * tmp_transmit - Internal kernel interface to transmit TPM commands.
 333  *
 334  * @chip: TPM chip to use
 335  * @buf: TPM command buffer
 336  * @bufsiz: length of the TPM command buffer
 337  * @flags: tpm transmit flags - bitmap
 338  *
 339  * Return:
 340  *     0 when the operation is successful.
 341  *     A negative number for system errors (errno).
 342  */
 343 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 344                      unsigned int flags)
 345 {
 346         ssize_t rc;
 347         u32 count, ordinal;
 348         unsigned long stop;
 349
 350         if (bufsiz < TPM_HEADER_SIZE)
 351                 return -EINVAL;
 352
 353         if (bufsiz > TPM_BUFSIZE)
 354                 bufsiz = TPM_BUFSIZE;
 355
 356         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 357         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 358         if (count == 0)
 359                 return -ENODATA;
 360         if (count > bufsiz) {
 361                 dev_err(&chip->dev,
 362                         "invalid count value %x %zx\n", count, bufsiz);
 363                 return -E2BIG;
 364         }
 365
 366         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 367                 mutex_lock(&chip->tpm_mutex);
 368
 369         if (chip->dev.parent)
 370                 pm_runtime_get_sync(chip->dev.parent);
 371
 372         rc = chip->ops->send(chip, (u8 *) buf, count);
 373         if (rc < 0) {
 374                 dev_err(&chip->dev,
 375                         "tpm_transmit: tpm_send: error %zd\n", rc);
 376                 goto out;
 377         }
 378
 379         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 380                 goto out_recv;
 381
 382         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 383                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 384         else
 385                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 386         do {
 387                 u8 status = chip->ops->status(chip);
 388                 if ((status & chip->ops->req_complete_mask) ==
 389                     chip->ops->req_complete_val)
 390                         goto out_recv;
 391
 392                 if (chip->ops->req_canceled(chip, status)) {
 393                         dev_err(&chip->dev, "Operation Canceled\n");
 394                         rc = -ECANCELED;
 395                         goto out;
 396                 }
 397
 398                 msleep(TPM_TIMEOUT);    /* CHECK */
 399                 rmb();
 400         } while (time_before(jiffies, stop));
 401
 402         chip->ops->cancel(chip);
 403         dev_err(&chip->dev, "Operation Timed out\n");
 404         rc = -ETIME;
 405         goto out;
 406
 407 out_recv:
 408         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 409         if (rc < 0)
 410                 dev_err(&chip->dev,
 411                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 412 out:
 413         if (chip->dev.parent)
 414                 pm_runtime_put_sync(chip->dev.parent);
 415
 416         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 417                 mutex_unlock(&chip->tpm_mutex);
 418         return rc;
 419 }
 420
 421 /**
 422  * tmp_transmit_cmd - send a tpm command to the device
 423  *    The function extracts tpm out header return code
 424  *
 425  * @chip: TPM chip to use
 426  * @buf: TPM command buffer
 427  * @bufsiz: length of the buffer
 428  * @min_rsp_body_length: minimum expected length of response body
 429  * @flags: tpm transmit flags - bitmap
 430  * @desc: command description used in the error message
 431  *
 432  * Return:
 433  *     0 when the operation is successful.
 434  *     A negative number for system errors (errno).
 435  *     A positive number for a TPM error.
 436  */
 437 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf,
 438                          size_t bufsiz, size_t min_rsp_body_length,
 439                          unsigned int flags, const char *desc)
 440 {
 441         const struct tpm_output_header *header;
 442         int err;
 443         ssize_t len;
 444
 445         len = tpm_transmit(chip, (const u8 *)buf, bufsiz, flags);
 446         if (len <  0)
 447                 return len;
 448         else if (len < TPM_HEADER_SIZE)
 449                 return -EFAULT;
 450
 451         header = buf;
 452         if (len != be32_to_cpu(header->length))
 453                 return -EFAULT;
 454
 455         err = be32_to_cpu(header->return_code);
 456         if (err != 0 && desc)
 457                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 458                         desc);
 459         if (err)
 460                 return err;
 461
 462         if (len < min_rsp_body_length + TPM_HEADER_SIZE)
 463                 return -EFAULT;
 464
 465         return 0;
 466 }
 467
 468 #define TPM_DIGEST_SIZE 20
 469 #define TPM_RET_CODE_IDX 6
 470 #define TPM_INTERNAL_RESULT_SIZE 200
 471 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 472 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 473
 474 static const struct tpm_input_header tpm_getcap_header = {
 475         .tag = TPM_TAG_RQU_COMMAND,
 476         .length = cpu_to_be32(22),
 477         .ordinal = TPM_ORD_GET_CAP
 478 };
 479
 480 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 481                    const char *desc, size_t min_cap_length)
 482 {
 483         struct tpm_cmd_t tpm_cmd;
 484         int rc;
 485
 486         tpm_cmd.header.in = tpm_getcap_header;
 487         if (subcap_id == TPM_CAP_VERSION_1_1 ||
 488             subcap_id == TPM_CAP_VERSION_1_2) {
 489                 tpm_cmd.params.getcap_in.cap = cpu_to_be32(subcap_id);
 490                 /*subcap field not necessary */
 491                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 492                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 493         } else {
 494                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 495                     subcap_id == TPM_CAP_FLAG_VOL)
 496                         tpm_cmd.params.getcap_in.cap =
 497                                 cpu_to_be32(TPM_CAP_FLAG);
 498                 else
 499                         tpm_cmd.params.getcap_in.cap =
 500                                 cpu_to_be32(TPM_CAP_PROP);
 501                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 502                 tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
 503         }
 504         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 505                               min_cap_length, 0, desc);
 506         if (!rc)
 507                 *cap = tpm_cmd.params.getcap_out.cap;
 508         return rc;
 509 }
 510 EXPORT_SYMBOL_GPL(tpm_getcap);
 511
 512 #define TPM_ORD_STARTUP cpu_to_be32(153)
 513 #define TPM_ST_CLEAR cpu_to_be16(1)
 514 #define TPM_ST_STATE cpu_to_be16(2)
 515 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 516 static const struct tpm_input_header tpm_startup_header = {
 517         .tag = TPM_TAG_RQU_COMMAND,
 518         .length = cpu_to_be32(12),
 519         .ordinal = TPM_ORD_STARTUP
 520 };
 521
 522 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 523 {
 524         struct tpm_cmd_t start_cmd;
 525         start_cmd.header.in = tpm_startup_header;
 526
 527         start_cmd.params.startup_in.startup_type = startup_type;
 528         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 529                                 0, "attempting to start the TPM");
 530 }
 531
 532 int tpm_get_timeouts(struct tpm_chip *chip)
 533 {
 534         cap_t cap;
 535         unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
 536         ssize_t rc;
 537
 538         if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
 539                 return 0;
 540
 541         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 542                 /* Fixed timeouts for TPM2 */
 543                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 544                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 545                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 546                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 547                 chip->duration[TPM_SHORT] =
 548                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 549                 chip->duration[TPM_MEDIUM] =
 550                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 551                 chip->duration[TPM_LONG] =
 552                     msecs_to_jiffies(TPM2_DURATION_LONG);
 553
 554                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 555                 return 0;
 556         }
 557
 558         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
 559                         sizeof(cap.timeout));
 560         if (rc == TPM_ERR_INVALID_POSTINIT) {
 561                 /* The TPM is not started, we are the first to talk to it.
 562                    Execute a startup command. */
 563                 dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
 564                 if (tpm_startup(chip, TPM_ST_CLEAR))
 565                         return rc;
 566
 567                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 568                                 "attempting to determine the timeouts",
 569                                 sizeof(cap.timeout));
 570         }
 571
 572         if (rc) {
 573                 dev_err(&chip->dev,
 574                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 575                         rc);
 576                 return rc;
 577         }
 578
 579         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 580         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 581         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 582         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 583         timeout_chip[0] = be32_to_cpu(cap.timeout.a);
 584         timeout_chip[1] = be32_to_cpu(cap.timeout.b);
 585         timeout_chip[2] = be32_to_cpu(cap.timeout.c);
 586         timeout_chip[3] = be32_to_cpu(cap.timeout.d);
 587         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 588
 589         /*
 590          * Provide ability for vendor overrides of timeout values in case
 591          * of misreporting.
 592          */
 593         if (chip->ops->update_timeouts != NULL)
 594                 chip->timeout_adjusted =
 595                         chip->ops->update_timeouts(chip, timeout_eff);
 596
 597         if (!chip->timeout_adjusted) {
 598                 /* Restore default if chip reported 0 */
 599                 int i;
 600
 601                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 602                         if (timeout_eff[i])
 603                                 continue;
 604
 605                         timeout_eff[i] = timeout_old[i];
 606                         chip->timeout_adjusted = true;
 607                 }
 608
 609                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 610                         /* timeouts in msec rather usec */
 611                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 612                                 timeout_eff[i] *= 1000;
 613                         chip->timeout_adjusted = true;
 614                 }
 615         }
 616
 617         /* Report adjusted timeouts */
 618         if (chip->timeout_adjusted) {
 619                 dev_info(&chip->dev,
 620                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 621                          timeout_chip[0], timeout_eff[0],
 622                          timeout_chip[1], timeout_eff[1],
 623                          timeout_chip[2], timeout_eff[2],
 624                          timeout_chip[3], timeout_eff[3]);
 625         }
 626
 627         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 628         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 629         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 630         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 631
 632         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 633                         "attempting to determine the durations",
 634                         sizeof(cap.duration));
 635         if (rc)
 636                 return rc;
 637
 638         chip->duration[TPM_SHORT] =
 639                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 640         chip->duration[TPM_MEDIUM] =
 641                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 642         chip->duration[TPM_LONG] =
 643                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 644
 645         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 646          * value wrong and apparently reports msecs rather than usecs. So we
 647          * fix up the resulting too-small TPM_SHORT value to make things work.
 648          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 649          */
 650         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 651                 chip->duration[TPM_SHORT] = HZ;
 652                 chip->duration[TPM_MEDIUM] *= 1000;
 653                 chip->duration[TPM_LONG] *= 1000;
 654                 chip->duration_adjusted = true;
 655                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 656         }
 657
 658         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 659         return 0;
 660 }
 661 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 662
 663 #define TPM_ORD_CONTINUE_SELFTEST 83
 664 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 665
 666 static const struct tpm_input_header continue_selftest_header = {
 667         .tag = TPM_TAG_RQU_COMMAND,
 668         .length = cpu_to_be32(10),
 669         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 670 };
 671
 672 /**
 673  * tpm_continue_selftest -- run TPM's selftest
 674  * @chip: TPM chip to use
 675  *
 676  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 677  * a TPM error code.
 678  */
 679 static int tpm_continue_selftest(struct tpm_chip *chip)
 680 {
 681         int rc;
 682         struct tpm_cmd_t cmd;
 683
 684         cmd.header.in = continue_selftest_header;
 685         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0, 0,
 686                               "continue selftest");
 687         return rc;
 688 }
 689
 690 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 691 #define READ_PCR_RESULT_SIZE 30
 692 #define READ_PCR_RESULT_BODY_SIZE 20
 693 static const struct tpm_input_header pcrread_header = {
 694         .tag = TPM_TAG_RQU_COMMAND,
 695         .length = cpu_to_be32(14),
 696         .ordinal = TPM_ORDINAL_PCRREAD
 697 };
 698
 699 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 700 {
 701         int rc;
 702         struct tpm_cmd_t cmd;
 703
 704         cmd.header.in = pcrread_header;
 705         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 706         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 707                               READ_PCR_RESULT_BODY_SIZE, 0,
 708                               "attempting to read a pcr value");
 709
 710         if (rc == 0)
 711                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 712                        TPM_DIGEST_SIZE);
 713         return rc;
 714 }
 715
 716 /**
 717  * tpm_is_tpm2 - is the chip a TPM2 chip?
 718  * @chip_num:   tpm idx # or ANY
 719  *
 720  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 721  * is a TPM2 chip.
 722  */
 723 int tpm_is_tpm2(u32 chip_num)
 724 {
 725         struct tpm_chip *chip;
 726         int rc;
 727
 728         chip = tpm_chip_find_get(chip_num);
 729         if (chip == NULL)
 730                 return -ENODEV;
 731
 732         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 733
 734         tpm_put_ops(chip);
 735
 736         return rc;
 737 }
 738 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 739
 740 /**
 741  * tpm_pcr_read - read a pcr value
 742  * @chip_num:   tpm idx # or ANY
 743  * @pcr_idx:    pcr idx to retrieve
 744  * @res_buf:    TPM_PCR value
 745  *              size of res_buf is 20 bytes (or NULL if you don't care)
 746  *
 747  * The TPM driver should be built-in, but for whatever reason it
 748  * isn't, protect against the chip disappearing, by incrementing
 749  * the module usage count.
 750  */
 751 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 752 {
 753         struct tpm_chip *chip;
 754         int rc;
 755
 756         chip = tpm_chip_find_get(chip_num);
 757         if (chip == NULL)
 758                 return -ENODEV;
 759         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 760                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 761         else
 762                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 763         tpm_put_ops(chip);
 764         return rc;
 765 }
 766 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 767
 768 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 769 #define EXTEND_PCR_RESULT_SIZE 34
 770 #define EXTEND_PCR_RESULT_BODY_SIZE 20
 771 static const struct tpm_input_header pcrextend_header = {
 772         .tag = TPM_TAG_RQU_COMMAND,
 773         .length = cpu_to_be32(34),
 774         .ordinal = TPM_ORD_PCR_EXTEND
 775 };
 776
 777 /**
 778  * tpm_pcr_extend - extend pcr value with hash
 779  * @chip_num:   tpm idx # or AN&
 780  * @pcr_idx:    pcr idx to extend
 781  * @hash:       hash value used to extend pcr value
 782  *
 783  * The TPM driver should be built-in, but for whatever reason it
 784  * isn't, protect against the chip disappearing, by incrementing
 785  * the module usage count.
 786  */
 787 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 788 {
 789         struct tpm_cmd_t cmd;
 790         int rc;
 791         struct tpm_chip *chip;
 792         struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
 793         u32 count = 0;
 794         int i;
 795
 796         chip = tpm_chip_find_get(chip_num);
 797         if (chip == NULL)
 798                 return -ENODEV;
 799
 800         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 801                 memset(digest_list, 0, sizeof(digest_list));
 802
 803                 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
 804                             chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
 805                         digest_list[i].alg_id = chip->active_banks[i];
 806                         memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
 807                         count++;
 808                 }
 809
 810                 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
 811                 tpm_put_ops(chip);
 812                 return rc;
 813         }
 814
 815         cmd.header.in = pcrextend_header;
 816         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 817         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 818         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 819                               EXTEND_PCR_RESULT_BODY_SIZE, 0,
 820                               "attempting extend a PCR value");
 821
 822         tpm_put_ops(chip);
 823         return rc;
 824 }
 825 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 826
 827 /**
 828  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 829  *                   can receive further commands
 830  * @chip: TPM chip to use
 831  *
 832  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 833  * a TPM error code.
 834  */
 835 int tpm_do_selftest(struct tpm_chip *chip)
 836 {
 837         int rc;
 838         unsigned int loops;
 839         unsigned int delay_msec = 100;
 840         unsigned long duration;
 841         u8 dummy[TPM_DIGEST_SIZE];
 842
 843         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 844
 845         loops = jiffies_to_msecs(duration) / delay_msec;
 846
 847         rc = tpm_continue_selftest(chip);
 848         /* This may fail if there was no TPM driver during a suspend/resume
 849          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 850          */
 851         if (rc)
 852                 return rc;
 853
 854         do {
 855                 /* Attempt to read a PCR value */
 856                 rc = tpm_pcr_read_dev(chip, 0, dummy);
 857
 858                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 859                  * around 300ms while the self test is ongoing, keep trying
 860                  * until the self test duration expires. */
 861                 if (rc == -ETIME) {
 862                         dev_info(
 863                             &chip->dev, HW_ERR
 864                             "TPM command timed out during continue self test");
 865                         msleep(delay_msec);
 866                         continue;
 867                 }
 868
 869                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 870                         dev_info(&chip->dev,
 871                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 872                         /* TPM is disabled and/or deactivated; driver can
 873                          * proceed and TPM does handle commands for
 874                          * suspend/resume correctly
 875                          */
 876                         return 0;
 877                 }
 878                 if (rc != TPM_WARN_DOING_SELFTEST)
 879                         return rc;
 880                 msleep(delay_msec);
 881         } while (--loops > 0);
 882
 883         return rc;
 884 }
 885 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 886
 887 /**
 888  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 889  *                     sequence
 890  * @chip: TPM chip to use
 891  *
 892  * Returns 0 on success, < 0 in case of fatal error.
 893  */
 894 int tpm1_auto_startup(struct tpm_chip *chip)
 895 {
 896         int rc;
 897
 898         rc = tpm_get_timeouts(chip);
 899         if (rc)
 900                 goto out;
 901         rc = tpm_do_selftest(chip);
 902         if (rc) {
 903                 dev_err(&chip->dev, "TPM self test failed\n");
 904                 goto out;
 905         }
 906
 907         return rc;
 908 out:
 909         if (rc > 0)
 910                 rc = -ENODEV;
 911         return rc;
 912 }
 913
 914 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 915 {
 916         struct tpm_chip *chip;
 917         int rc;
 918
 919         chip = tpm_chip_find_get(chip_num);
 920         if (chip == NULL)
 921                 return -ENODEV;
 922
 923         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, 0, "attempting tpm_cmd");
 924
 925         tpm_put_ops(chip);
 926         return rc;
 927 }
 928 EXPORT_SYMBOL_GPL(tpm_send);
 929
 930 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 931                                         bool check_cancel, bool *canceled)
 932 {
 933         u8 status = chip->ops->status(chip);
 934
 935         *canceled = false;
 936         if ((status & mask) == mask)
 937                 return true;
 938         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 939                 *canceled = true;
 940                 return true;
 941         }
 942         return false;
 943 }
 944
 945 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 946                       wait_queue_head_t *queue, bool check_cancel)
 947 {
 948         unsigned long stop;
 949         long rc;
 950         u8 status;
 951         bool canceled = false;
 952
 953         /* check current status */
 954         status = chip->ops->status(chip);
 955         if ((status & mask) == mask)
 956                 return 0;
 957
 958         stop = jiffies + timeout;
 959
 960         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 961 again:
 962                 timeout = stop - jiffies;
 963                 if ((long)timeout <= 0)
 964                         return -ETIME;
 965                 rc = wait_event_interruptible_timeout(*queue,
 966                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 967                                                &canceled),
 968                         timeout);
 969                 if (rc > 0) {
 970                         if (canceled)
 971                                 return -ECANCELED;
 972                         return 0;
 973                 }
 974                 if (rc == -ERESTARTSYS && freezing(current)) {
 975                         clear_thread_flag(TIF_SIGPENDING);
 976                         goto again;
 977                 }
 978         } else {
 979                 do {
 980                         msleep(TPM_TIMEOUT);
 981                         status = chip->ops->status(chip);
 982                         if ((status & mask) == mask)
 983                                 return 0;
 984                 } while (time_before(jiffies, stop));
 985         }
 986         return -ETIME;
 987 }
 988 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 989
 990 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 991 #define SAVESTATE_RESULT_SIZE 10
 992
 993 static const struct tpm_input_header savestate_header = {
 994         .tag = TPM_TAG_RQU_COMMAND,
 995         .length = cpu_to_be32(10),
 996         .ordinal = TPM_ORD_SAVESTATE
 997 };
 998
 999 /*
1000  * We are about to suspend. Save the TPM state
1001  * so that it can be restored.
1002  */
1003 int tpm_pm_suspend(struct device *dev)
1004 {
1005         struct tpm_chip *chip = dev_get_drvdata(dev);
1006         struct tpm_cmd_t cmd;
1007         int rc, try;
1008
1009         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1010
1011         if (chip == NULL)
1012                 return -ENODEV;
1013
1014         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1015                 tpm2_shutdown(chip, TPM2_SU_STATE);
1016                 return 0;
1017         }
1018
1019         /* for buggy tpm, flush pcrs with extend to selected dummy */
1020         if (tpm_suspend_pcr) {
1021                 cmd.header.in = pcrextend_header;
1022                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1023                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1024                        TPM_DIGEST_SIZE);
1025                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1026                                      EXTEND_PCR_RESULT_BODY_SIZE, 0,
1027                                       "extending dummy pcr before suspend");
1028         }
1029
1030         /* now do the actual savestate */
1031         for (try = 0; try < TPM_RETRY; try++) {
1032                 cmd.header.in = savestate_header;
1033                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
1034                                       0, NULL);
1035
1036                 /*
1037                  * If the TPM indicates that it is too busy to respond to
1038                  * this command then retry before giving up.  It can take
1039                  * several seconds for this TPM to be ready.
1040                  *
1041                  * This can happen if the TPM has already been sent the
1042                  * SaveState command before the driver has loaded.  TCG 1.2
1043                  * specification states that any communication after SaveState
1044                  * may cause the TPM to invalidate previously saved state.
1045                  */
1046                 if (rc != TPM_WARN_RETRY)
1047                         break;
1048                 msleep(TPM_TIMEOUT_RETRY);
1049         }
1050
1051         if (rc)
1052                 dev_err(&chip->dev,
1053                         "Error (%d) sending savestate before suspend\n", rc);
1054         else if (try > 0)
1055                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1056                          try * TPM_TIMEOUT_RETRY);
1057
1058         return rc;
1059 }
1060 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1061
1062 /*
1063  * Resume from a power safe. The BIOS already restored
1064  * the TPM state.
1065  */
1066 int tpm_pm_resume(struct device *dev)
1067 {
1068         struct tpm_chip *chip = dev_get_drvdata(dev);
1069
1070         if (chip == NULL)
1071                 return -ENODEV;
1072
1073         return 0;
1074 }
1075 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1076
1077 #define TPM_GETRANDOM_RESULT_SIZE       18
1078 static const struct tpm_input_header tpm_getrandom_header = {
1079         .tag = TPM_TAG_RQU_COMMAND,
1080         .length = cpu_to_be32(14),
1081         .ordinal = TPM_ORD_GET_RANDOM
1082 };
1083
1084 /**
1085  * tpm_get_random() - Get random bytes from the tpm's RNG
1086  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1087  * @out: destination buffer for the random bytes
1088  * @max: the max number of bytes to write to @out
1089  *
1090  * Returns < 0 on error and the number of bytes read on success
1091  */
1092 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1093 {
1094         struct tpm_chip *chip;
1095         struct tpm_cmd_t tpm_cmd;
1096         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1097         int err, total = 0, retries = 5;
1098         u8 *dest = out;
1099
1100         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1101                 return -EINVAL;
1102
1103         chip = tpm_chip_find_get(chip_num);
1104         if (chip == NULL)
1105                 return -ENODEV;
1106
1107         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1108                 err = tpm2_get_random(chip, out, max);
1109                 tpm_put_ops(chip);
1110                 return err;
1111         }
1112
1113         do {
1114                 tpm_cmd.header.in = tpm_getrandom_header;
1115                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1116
1117                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1118                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1119                                        offsetof(struct tpm_getrandom_out,
1120                                                 rng_data),
1121                                        0, "attempting get random");
1122                 if (err)
1123                         break;
1124
1125                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1126
1127                 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1128                 if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1129                               recd) {
1130                         total = -EFAULT;
1131                         break;
1132                 }
1133                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1134
1135                 dest += recd;
1136                 total += recd;
1137                 num_bytes -= recd;
1138         } while (retries-- && total < max);
1139
1140         tpm_put_ops(chip);
1141         return total ? total : -EIO;
1142 }
1143 EXPORT_SYMBOL_GPL(tpm_get_random);
1144
1145 /**
1146  * tpm_seal_trusted() - seal a trusted key
1147  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1148  * @options: authentication values and other options
1149  * @payload: the key data in clear and encrypted form
1150  *
1151  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1152  * are supported.
1153  */
1154 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1155                      struct trusted_key_options *options)
1156 {
1157         struct tpm_chip *chip;
1158         int rc;
1159
1160         chip = tpm_chip_find_get(chip_num);
1161         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1162                 return -ENODEV;
1163
1164         rc = tpm2_seal_trusted(chip, payload, options);
1165
1166         tpm_put_ops(chip);
1167         return rc;
1168 }
1169 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1170
1171 /**
1172  * tpm_unseal_trusted() - unseal a trusted key
1173  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1174  * @options: authentication values and other options
1175  * @payload: the key data in clear and encrypted form
1176  *
1177  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1178  * are supported.
1179  */
1180 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1181                        struct trusted_key_options *options)
1182 {
1183         struct tpm_chip *chip;
1184         int rc;
1185
1186         chip = tpm_chip_find_get(chip_num);
1187         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1188                 return -ENODEV;
1189
1190         rc = tpm2_unseal_trusted(chip, payload, options);
1191
1192         tpm_put_ops(chip);
1193
1194         return rc;
1195 }
1196 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1197
1198 static int __init tpm_init(void)
1199 {
1200         int rc;
1201
1202         tpm_class = class_create(THIS_MODULE, "tpm");
1203         if (IS_ERR(tpm_class)) {
1204                 pr_err("couldn't create tpm class\n");
1205                 return PTR_ERR(tpm_class);
1206         }
1207
1208         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1209         if (rc < 0) {
1210                 pr_err("tpm: failed to allocate char dev region\n");
1211                 class_destroy(tpm_class);
1212                 return rc;
1213         }
1214
1215         return 0;
1216 }
1217
1218 static void __exit tpm_exit(void)
1219 {
1220         idr_destroy(&dev_nums_idr);
1221         class_destroy(tpm_class);
1222         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1223 }
1224
1225 subsys_initcall(tpm_init);
1226 module_exit(tpm_exit);
1227
1228 MODULE_AUTHOR("Leendert van Doorn ([email protected])");
1229 MODULE_DESCRIPTION("TPM Driver");
1230 MODULE_VERSION("2.0");
1231 MODULE_LICENSE("GPL");