drivers/tpm/tpm.c

   1 /*
   2  * Copyright (C) 2011 Infineon Technologies
   3  *
   4  * Authors:
   5  * Peter Huewe <huewe.external@infineon.com>
   6  *
   7  * Description:
   8  * Device driver for TCG/TCPA TPM (trusted platform module).
   9  * Specifications at www.trustedcomputinggroup.org
  10  *
  11  * It is based on the Linux kernel driver tpm.c from Leendert van
  12  * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
  13  *
  14  * Version: 2.1.1
  15  *
  16  * See file CREDITS for list of people who contributed to this
  17  * project.
  18  *
  19  * This program is free software; you can redistribute it and/or
  20  * modify it under the terms of the GNU General Public License as
  21  * published by the Free Software Foundation, version 2 of the
  22  * License.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  32  * MA 02111-1307 USA
  33  */
  34
  35 #include <config.h>
  36 #include <common.h>
  37 #include <linux/compiler.h>
  38 #include <fdtdec.h>
  39 #include <i2c.h>
  40 #include <tpm.h>
  41 #include <asm-generic/errno.h>
  42 #include <linux/types.h>
  43 #include <linux/unaligned/be_byteshift.h>
  44
  45 #include "tpm_private.h"
  46
  47 DECLARE_GLOBAL_DATA_PTR;
  48
  49 /* TPM configuration */
  50 struct tpm {
  51         int i2c_bus;
  52         int slave_addr;
  53         char inited;
  54         int old_bus;
  55 } tpm;
  56
  57 /* Global structure for tpm chip data */
  58 static struct tpm_chip g_chip;
  59
  60 enum tpm_duration {
  61         TPM_SHORT = 0,
  62         TPM_MEDIUM = 1,
  63         TPM_LONG = 2,
  64         TPM_UNDEFINED,
  65 };
  66
  67 /* Extended error numbers from linux (see errno.h) */
  68 #define ECANCELED       125     /* Operation Canceled */
  69
  70 /* Timer frequency. Corresponds to msec timer resolution*/
  71 #define HZ              1000
  72
  73 #define TPM_MAX_ORDINAL                 243
  74 #define TPM_MAX_PROTECTED_ORDINAL       12
  75 #define TPM_PROTECTED_ORDINAL_MASK      0xFF
  76
  77 #define TPM_CMD_COUNT_BYTE      2
  78 #define TPM_CMD_ORDINAL_BYTE    6
  79
  80 /*
  81  * Array with one entry per ordinal defining the maximum amount
  82  * of time the chip could take to return the result.  The ordinal
  83  * designation of short, medium or long is defined in a table in
  84  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  85  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  86  * from the chip during initialization with a call to tpm_get_timeouts.
  87  */
  88 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  89         TPM_UNDEFINED,          /* 0 */
  90         TPM_UNDEFINED,
  91         TPM_UNDEFINED,
  92         TPM_UNDEFINED,
  93         TPM_UNDEFINED,
  94         TPM_UNDEFINED,          /* 5 */
  95         TPM_UNDEFINED,
  96         TPM_UNDEFINED,
  97         TPM_UNDEFINED,
  98         TPM_UNDEFINED,
  99         TPM_SHORT,              /* 10 */
 100         TPM_SHORT,
 101 };
 102
 103 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
 104         TPM_UNDEFINED,          /* 0 */
 105         TPM_UNDEFINED,
 106         TPM_UNDEFINED,
 107         TPM_UNDEFINED,
 108         TPM_UNDEFINED,
 109         TPM_UNDEFINED,          /* 5 */
 110         TPM_UNDEFINED,
 111         TPM_UNDEFINED,
 112         TPM_UNDEFINED,
 113         TPM_UNDEFINED,
 114         TPM_SHORT,              /* 10 */
 115         TPM_SHORT,
 116         TPM_MEDIUM,
 117         TPM_LONG,
 118         TPM_LONG,
 119         TPM_MEDIUM,             /* 15 */
 120         TPM_SHORT,
 121         TPM_SHORT,
 122         TPM_MEDIUM,
 123         TPM_LONG,
 124         TPM_SHORT,              /* 20 */
 125         TPM_SHORT,
 126         TPM_MEDIUM,
 127         TPM_MEDIUM,
 128         TPM_MEDIUM,
 129         TPM_SHORT,              /* 25 */
 130         TPM_SHORT,
 131         TPM_MEDIUM,
 132         TPM_SHORT,
 133         TPM_SHORT,
 134         TPM_MEDIUM,             /* 30 */
 135         TPM_LONG,
 136         TPM_MEDIUM,
 137         TPM_SHORT,
 138         TPM_SHORT,
 139         TPM_SHORT,              /* 35 */
 140         TPM_MEDIUM,
 141         TPM_MEDIUM,
 142         TPM_UNDEFINED,
 143         TPM_UNDEFINED,
 144         TPM_MEDIUM,             /* 40 */
 145         TPM_LONG,
 146         TPM_MEDIUM,
 147         TPM_SHORT,
 148         TPM_SHORT,
 149         TPM_SHORT,              /* 45 */
 150         TPM_SHORT,
 151         TPM_SHORT,
 152         TPM_SHORT,
 153         TPM_LONG,
 154         TPM_MEDIUM,             /* 50 */
 155         TPM_MEDIUM,
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,          /* 55 */
 160         TPM_UNDEFINED,
 161         TPM_UNDEFINED,
 162         TPM_UNDEFINED,
 163         TPM_UNDEFINED,
 164         TPM_MEDIUM,             /* 60 */
 165         TPM_MEDIUM,
 166         TPM_MEDIUM,
 167         TPM_SHORT,
 168         TPM_SHORT,
 169         TPM_MEDIUM,             /* 65 */
 170         TPM_UNDEFINED,
 171         TPM_UNDEFINED,
 172         TPM_UNDEFINED,
 173         TPM_UNDEFINED,
 174         TPM_SHORT,              /* 70 */
 175         TPM_SHORT,
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_UNDEFINED,
 179         TPM_UNDEFINED,          /* 75 */
 180         TPM_UNDEFINED,
 181         TPM_UNDEFINED,
 182         TPM_UNDEFINED,
 183         TPM_UNDEFINED,
 184         TPM_LONG,               /* 80 */
 185         TPM_UNDEFINED,
 186         TPM_MEDIUM,
 187         TPM_LONG,
 188         TPM_SHORT,
 189         TPM_UNDEFINED,          /* 85 */
 190         TPM_UNDEFINED,
 191         TPM_UNDEFINED,
 192         TPM_UNDEFINED,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,              /* 90 */
 195         TPM_SHORT,
 196         TPM_SHORT,
 197         TPM_SHORT,
 198         TPM_SHORT,
 199         TPM_UNDEFINED,          /* 95 */
 200         TPM_UNDEFINED,
 201         TPM_UNDEFINED,
 202         TPM_UNDEFINED,
 203         TPM_UNDEFINED,
 204         TPM_MEDIUM,             /* 100 */
 205         TPM_SHORT,
 206         TPM_SHORT,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,          /* 105 */
 210         TPM_UNDEFINED,
 211         TPM_UNDEFINED,
 212         TPM_UNDEFINED,
 213         TPM_UNDEFINED,
 214         TPM_SHORT,              /* 110 */
 215         TPM_SHORT,
 216         TPM_SHORT,
 217         TPM_SHORT,
 218         TPM_SHORT,
 219         TPM_SHORT,              /* 115 */
 220         TPM_SHORT,
 221         TPM_SHORT,
 222         TPM_UNDEFINED,
 223         TPM_UNDEFINED,
 224         TPM_LONG,               /* 120 */
 225         TPM_LONG,
 226         TPM_MEDIUM,
 227         TPM_UNDEFINED,
 228         TPM_SHORT,
 229         TPM_SHORT,              /* 125 */
 230         TPM_SHORT,
 231         TPM_LONG,
 232         TPM_SHORT,
 233         TPM_SHORT,
 234         TPM_SHORT,              /* 130 */
 235         TPM_MEDIUM,
 236         TPM_UNDEFINED,
 237         TPM_SHORT,
 238         TPM_MEDIUM,
 239         TPM_UNDEFINED,          /* 135 */
 240         TPM_UNDEFINED,
 241         TPM_UNDEFINED,
 242         TPM_UNDEFINED,
 243         TPM_UNDEFINED,
 244         TPM_SHORT,              /* 140 */
 245         TPM_SHORT,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,          /* 145 */
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_SHORT,              /* 150 */
 255         TPM_MEDIUM,
 256         TPM_MEDIUM,
 257         TPM_SHORT,
 258         TPM_SHORT,
 259         TPM_UNDEFINED,          /* 155 */
 260         TPM_UNDEFINED,
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_SHORT,              /* 160 */
 265         TPM_SHORT,
 266         TPM_SHORT,
 267         TPM_SHORT,
 268         TPM_UNDEFINED,
 269         TPM_UNDEFINED,          /* 165 */
 270         TPM_UNDEFINED,
 271         TPM_UNDEFINED,
 272         TPM_UNDEFINED,
 273         TPM_UNDEFINED,
 274         TPM_LONG,               /* 170 */
 275         TPM_UNDEFINED,
 276         TPM_UNDEFINED,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,          /* 175 */
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_UNDEFINED,
 283         TPM_UNDEFINED,
 284         TPM_MEDIUM,             /* 180 */
 285         TPM_SHORT,
 286         TPM_MEDIUM,
 287         TPM_MEDIUM,
 288         TPM_MEDIUM,
 289         TPM_MEDIUM,             /* 185 */
 290         TPM_SHORT,
 291         TPM_UNDEFINED,
 292         TPM_UNDEFINED,
 293         TPM_UNDEFINED,
 294         TPM_UNDEFINED,          /* 190 */
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,          /* 195 */
 300         TPM_UNDEFINED,
 301         TPM_UNDEFINED,
 302         TPM_UNDEFINED,
 303         TPM_UNDEFINED,
 304         TPM_SHORT,              /* 200 */
 305         TPM_UNDEFINED,
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,
 308         TPM_SHORT,
 309         TPM_SHORT,              /* 205 */
 310         TPM_SHORT,
 311         TPM_SHORT,
 312         TPM_SHORT,
 313         TPM_SHORT,
 314         TPM_MEDIUM,             /* 210 */
 315         TPM_UNDEFINED,
 316         TPM_MEDIUM,
 317         TPM_MEDIUM,
 318         TPM_MEDIUM,
 319         TPM_UNDEFINED,          /* 215 */
 320         TPM_MEDIUM,
 321         TPM_UNDEFINED,
 322         TPM_UNDEFINED,
 323         TPM_SHORT,
 324         TPM_SHORT,              /* 220 */
 325         TPM_SHORT,
 326         TPM_SHORT,
 327         TPM_SHORT,
 328         TPM_SHORT,
 329         TPM_UNDEFINED,          /* 225 */
 330         TPM_UNDEFINED,
 331         TPM_UNDEFINED,
 332         TPM_UNDEFINED,
 333         TPM_UNDEFINED,
 334         TPM_SHORT,              /* 230 */
 335         TPM_LONG,
 336         TPM_MEDIUM,
 337         TPM_UNDEFINED,
 338         TPM_UNDEFINED,
 339         TPM_UNDEFINED,          /* 235 */
 340         TPM_UNDEFINED,
 341         TPM_UNDEFINED,
 342         TPM_UNDEFINED,
 343         TPM_UNDEFINED,
 344         TPM_SHORT,              /* 240 */
 345         TPM_UNDEFINED,
 346         TPM_MEDIUM,
 347 };
 348
 349 /* Returns max number of milliseconds to wait */
 350 static unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 351                 u32 ordinal)
 352 {
 353         int duration_idx = TPM_UNDEFINED;
 354         int duration = 0;
 355
 356         if (ordinal < TPM_MAX_ORDINAL) {
 357                 duration_idx = tpm_ordinal_duration[ordinal];
 358         } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 359                         TPM_MAX_PROTECTED_ORDINAL) {
 360                 duration_idx = tpm_protected_ordinal_duration[
 361                                 ordinal & TPM_PROTECTED_ORDINAL_MASK];
 362         }
 363
 364         if (duration_idx != TPM_UNDEFINED)
 365                 duration = chip->vendor.duration[duration_idx];
 366
 367         if (duration <= 0)
 368                 return 2 * 60 * HZ; /* Two minutes timeout */
 369         else
 370                 return duration;
 371 }
 372
 373 static ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
 374 {
 375         ssize_t rc;
 376         u32 count, ordinal;
 377         unsigned long start, stop;
 378
 379         struct tpm_chip *chip = &g_chip;
 380
 381         /* switch endianess: big->little */
 382         count = get_unaligned_be32(buf + TPM_CMD_COUNT_BYTE);
 383         ordinal = get_unaligned_be32(buf + TPM_CMD_ORDINAL_BYTE);
 384
 385         if (count == 0) {
 386                 error("no data\n");
 387                 return -ENODATA;
 388         }
 389         if (count > bufsiz) {
 390                 error("invalid count value %x %zx\n", count, bufsiz);
 391                 return -E2BIG;
 392         }
 393
 394         rc = chip->vendor.send(chip, (u8 *)buf, count);
 395         if (rc < 0) {
 396                 error("tpm_transmit: tpm_send: error %zd\n", rc);
 397                 goto out;
 398         }
 399
 400         if (chip->vendor.irq)
 401                 goto out_recv;
 402
 403         start = get_timer(0);
 404         stop = tpm_calc_ordinal_duration(chip, ordinal);
 405         do {
 406                 debug("waiting for status...\n");
 407                 u8 status = chip->vendor.status(chip);
 408                 if ((status & chip->vendor.req_complete_mask) ==
 409                     chip->vendor.req_complete_val) {
 410                         debug("...got it;\n");
 411                         goto out_recv;
 412                 }
 413
 414                 if (status == chip->vendor.req_canceled) {
 415                         error("Operation Canceled\n");
 416                         rc = -ECANCELED;
 417                         goto out;
 418                 }
 419                 udelay(TPM_TIMEOUT * 1000);
 420         } while (get_timer(start) < stop);
 421
 422         chip->vendor.cancel(chip);
 423         error("Operation Timed out\n");
 424         rc = -ETIME;
 425         goto out;
 426
 427 out_recv:
 428         debug("out_recv: reading response...\n");
 429         rc = chip->vendor.recv(chip, (u8 *)buf, TPM_BUFSIZE);
 430         if (rc < 0)
 431                 error("tpm_transmit: tpm_recv: error %zd\n", rc);
 432
 433 out:
 434         return rc;
 435 }
 436
 437 static int tpm_open(uint32_t dev_addr)
 438 {
 439         int rc;
 440         if (g_chip.is_open)
 441                 return -EBUSY;
 442         rc = tpm_vendor_init(dev_addr);
 443         if (rc < 0)
 444                 g_chip.is_open = 0;
 445         return rc;
 446 }
 447
 448 static void tpm_close(void)
 449 {
 450         if (g_chip.is_open) {
 451                 tpm_vendor_cleanup(&g_chip);
 452                 g_chip.is_open = 0;
 453         }
 454 }
 455
 456 static int tpm_select(void)
 457 {
 458         int ret;
 459
 460         tpm.old_bus = i2c_get_bus_num();
 461         if (tpm.old_bus != tpm.i2c_bus) {
 462                 ret = i2c_set_bus_num(tpm.i2c_bus);
 463                 if (ret) {
 464                         debug("%s: Fail to set i2c bus %d\n", __func__,
 465                               tpm.i2c_bus);
 466                         return -1;
 467                 }
 468         }
 469         return 0;
 470 }
 471
 472 static int tpm_deselect(void)
 473 {
 474         int ret;
 475
 476         if (tpm.old_bus != i2c_get_bus_num()) {
 477                 ret = i2c_set_bus_num(tpm.old_bus);
 478                 if (ret) {
 479                         debug("%s: Fail to restore i2c bus %d\n",
 480                               __func__, tpm.old_bus);
 481                         return -1;
 482                 }
 483         }
 484         tpm.old_bus = -1;
 485         return 0;
 486 }
 487
 488 /**
 489  * Decode TPM configuration.
 490  *
 491  * @param dev   Returns a configuration of TPM device
 492  * @return 0 if ok, -1 on error
 493  */
 494 static int tpm_decode_config(struct tpm *dev)
 495 {
 496 #ifdef CONFIG_OF_CONTROL
 497         const void *blob = gd->fdt_blob;
 498         int node, parent;
 499         int i2c_bus;
 500
 501         node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
 502         if (node < 0) {
 503                 node = fdtdec_next_compatible(blob, 0,
 504                                 COMPAT_INFINEON_SLB9645_TPM);
 505         }
 506         if (node < 0) {
 507                 debug("%s: Node not found\n", __func__);
 508                 return -1;
 509         }
 510         parent = fdt_parent_offset(blob, node);
 511         if (parent < 0) {
 512                 debug("%s: Cannot find node parent\n", __func__);
 513                 return -1;
 514         }
 515         i2c_bus = i2c_get_bus_num_fdt(parent);
 516         if (i2c_bus < 0)
 517                 return -1;
 518         dev->i2c_bus = i2c_bus;
 519         dev->slave_addr = fdtdec_get_addr(blob, node, "reg");
 520 #else
 521         dev->i2c_bus = CONFIG_TPM_TIS_I2C_BUS_NUMBER;
 522         dev->slave_addr = CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS;
 523 #endif
 524         return 0;
 525 }
 526
 527 struct tpm_chip *tpm_register_hardware(const struct tpm_vendor_specific *entry)
 528 {
 529         struct tpm_chip *chip;
 530
 531         /* Driver specific per-device data */
 532         chip = &g_chip;
 533         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
 534         chip->is_open = 1;
 535
 536         return chip;
 537 }
 538
 539 int tis_init(void)
 540 {
 541         if (tpm.inited)
 542                 return 0;
 543
 544         if (tpm_decode_config(&tpm))
 545                 return -1;
 546
 547         if (tpm_select())
 548                 return -1;
 549
 550         /*
 551          * Probe TPM twice; the first probing might fail because TPM is asleep,
 552          * and the probing can wake up TPM.
 553          */
 554         if (i2c_probe(tpm.slave_addr) && i2c_probe(tpm.slave_addr)) {
 555                 debug("%s: fail to probe i2c addr 0x%x\n", __func__,
 556                       tpm.slave_addr);
 557                 return -1;
 558         }
 559
 560         tpm_deselect();
 561
 562         tpm.inited = 1;
 563
 564         return 0;
 565 }
 566
 567 int tis_open(void)
 568 {
 569         int rc;
 570
 571         if (!tpm.inited)
 572                 return -1;
 573
 574         if (tpm_select())
 575                 return -1;
 576
 577         rc = tpm_open(tpm.slave_addr);
 578
 579         tpm_deselect();
 580
 581         return rc;
 582 }
 583
 584 int tis_close(void)
 585 {
 586         if (!tpm.inited)
 587                 return -1;
 588
 589         if (tpm_select())
 590                 return -1;
 591
 592         tpm_close();
 593
 594         tpm_deselect();
 595
 596         return 0;
 597 }
 598
 599 int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 600                 uint8_t *recvbuf, size_t *rbuf_len)
 601 {
 602         int len;
 603         uint8_t buf[4096];
 604
 605         if (!tpm.inited)
 606                 return -1;
 607
 608         if (sizeof(buf) < sbuf_size)
 609                 return -1;
 610
 611         memcpy(buf, sendbuf, sbuf_size);
 612
 613         if (tpm_select())
 614                 return -1;
 615
 616         len = tpm_transmit(buf, sbuf_size);
 617
 618         tpm_deselect();
 619
 620         if (len < 10) {
 621                 *rbuf_len = 0;
 622                 return -1;
 623         }
 624
 625         memcpy(recvbuf, buf, len);
 626         *rbuf_len = len;
 627
 628         return 0;
 629 }