drivers/tpm/tpm_tis_i2c.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  * This device driver implements the TPM interface as defined in
  12  * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
  13  * Infineon I2C Protocol Stack Specification v0.20.
  14  *
  15  * It is based on the Linux kernel driver tpm.c from Leendert van
  16  * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
  17  *
  18  * Version: 2.1.1
  19  *
  20  * SPDX-License-Identifier:     GPL-2.0
  21  */
  22
  23 #include <common.h>
  24 #include <dm.h>
  25 #include <fdtdec.h>
  26 #include <linux/compiler.h>
  27 #include <i2c.h>
  28 #include <tpm.h>
  29 #include <asm-generic/errno.h>
  30 #include <linux/types.h>
  31 #include <linux/unaligned/be_byteshift.h>
  32
  33 #include "tpm_tis_i2c.h"
  34
  35 DECLARE_GLOBAL_DATA_PTR;
  36
  37 /* Max buffer size supported by our tpm */
  38 #define TPM_DEV_BUFSIZE         1260
  39
  40 /* Max number of iterations after i2c NAK */
  41 #define MAX_COUNT               3
  42
  43 /*
  44  * Max number of iterations after i2c NAK for 'long' commands
  45  *
  46  * We need this especially for sending TPM_READY, since the cleanup after the
  47  * transtion to the ready state may take some time, but it is unpredictable
  48  * how long it will take.
  49  */
  50 #define MAX_COUNT_LONG          50
  51
  52 #define SLEEP_DURATION          60      /* in usec */
  53 #define SLEEP_DURATION_LONG     210     /* in usec */
  54
  55 #define TPM_HEADER_SIZE         10
  56
  57 enum tis_access {
  58         TPM_ACCESS_VALID                = 0x80,
  59         TPM_ACCESS_ACTIVE_LOCALITY      = 0x20,
  60         TPM_ACCESS_REQUEST_PENDING      = 0x04,
  61         TPM_ACCESS_REQUEST_USE          = 0x02,
  62 };
  63
  64 enum tis_status {
  65         TPM_STS_VALID                   = 0x80,
  66         TPM_STS_COMMAND_READY           = 0x40,
  67         TPM_STS_GO                      = 0x20,
  68         TPM_STS_DATA_AVAIL              = 0x10,
  69         TPM_STS_DATA_EXPECT             = 0x08,
  70 };
  71
  72 enum tis_defaults {
  73         TIS_SHORT_TIMEOUT               = 750,  /* ms */
  74         TIS_LONG_TIMEOUT                = 2000, /* ms */
  75 };
  76
  77 /* expected value for DIDVID register */
  78 #define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
  79 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
  80
  81 enum i2c_chip_type {
  82         SLB9635,
  83         SLB9645,
  84         UNKNOWN,
  85 };
  86
  87 static const char * const chip_name[] = {
  88         [SLB9635] = "slb9635tt",
  89         [SLB9645] = "slb9645tt",
  90         [UNKNOWN] = "unknown/fallback to slb9635",
  91 };
  92
  93 #define TPM_ACCESS(l)                   (0x0000 | ((l) << 4))
  94 #define TPM_STS(l)                      (0x0001 | ((l) << 4))
  95 #define TPM_DATA_FIFO(l)                (0x0005 | ((l) << 4))
  96 #define TPM_DID_VID(l)                  (0x0006 | ((l) << 4))
  97
  98 enum tpm_duration {
  99         TPM_SHORT = 0,
 100         TPM_MEDIUM = 1,
 101         TPM_LONG = 2,
 102         TPM_UNDEFINED,
 103 };
 104
 105 /* Extended error numbers from linux (see errno.h) */
 106 #define ECANCELED       125     /* Operation Canceled */
 107
 108 /* Timer frequency. Corresponds to msec timer resolution*/
 109 #define HZ              1000
 110
 111 #define TPM_MAX_ORDINAL                 243
 112 #define TPM_MAX_PROTECTED_ORDINAL       12
 113 #define TPM_PROTECTED_ORDINAL_MASK      0xFF
 114
 115 #define TPM_CMD_COUNT_BYTE      2
 116 #define TPM_CMD_ORDINAL_BYTE    6
 117
 118 /*
 119  * Array with one entry per ordinal defining the maximum amount
 120  * of time the chip could take to return the result.  The ordinal
 121  * designation of short, medium or long is defined in a table in
 122  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
 123  * values of the SHORT, MEDIUM, and LONG durations are retrieved
 124  * from the chip during initialization with a call to tpm_get_timeouts.
 125  */
 126 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
 127         TPM_UNDEFINED,          /* 0 */
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_UNDEFINED,
 132         TPM_UNDEFINED,          /* 5 */
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,
 137         TPM_SHORT,              /* 10 */
 138         TPM_SHORT,
 139 };
 140
 141 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
 142         TPM_UNDEFINED,          /* 0 */
 143         TPM_UNDEFINED,
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,          /* 5 */
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_UNDEFINED,
 152         TPM_SHORT,              /* 10 */
 153         TPM_SHORT,
 154         TPM_MEDIUM,
 155         TPM_LONG,
 156         TPM_LONG,
 157         TPM_MEDIUM,             /* 15 */
 158         TPM_SHORT,
 159         TPM_SHORT,
 160         TPM_MEDIUM,
 161         TPM_LONG,
 162         TPM_SHORT,              /* 20 */
 163         TPM_SHORT,
 164         TPM_MEDIUM,
 165         TPM_MEDIUM,
 166         TPM_MEDIUM,
 167         TPM_SHORT,              /* 25 */
 168         TPM_SHORT,
 169         TPM_MEDIUM,
 170         TPM_SHORT,
 171         TPM_SHORT,
 172         TPM_MEDIUM,             /* 30 */
 173         TPM_LONG,
 174         TPM_MEDIUM,
 175         TPM_SHORT,
 176         TPM_SHORT,
 177         TPM_SHORT,              /* 35 */
 178         TPM_MEDIUM,
 179         TPM_MEDIUM,
 180         TPM_UNDEFINED,
 181         TPM_UNDEFINED,
 182         TPM_MEDIUM,             /* 40 */
 183         TPM_LONG,
 184         TPM_MEDIUM,
 185         TPM_SHORT,
 186         TPM_SHORT,
 187         TPM_SHORT,              /* 45 */
 188         TPM_SHORT,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_LONG,
 192         TPM_MEDIUM,             /* 50 */
 193         TPM_MEDIUM,
 194         TPM_UNDEFINED,
 195         TPM_UNDEFINED,
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,          /* 55 */
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_UNDEFINED,
 202         TPM_MEDIUM,             /* 60 */
 203         TPM_MEDIUM,
 204         TPM_MEDIUM,
 205         TPM_SHORT,
 206         TPM_SHORT,
 207         TPM_MEDIUM,             /* 65 */
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_UNDEFINED,
 212         TPM_SHORT,              /* 70 */
 213         TPM_SHORT,
 214         TPM_UNDEFINED,
 215         TPM_UNDEFINED,
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,          /* 75 */
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_UNDEFINED,
 222         TPM_LONG,               /* 80 */
 223         TPM_UNDEFINED,
 224         TPM_MEDIUM,
 225         TPM_LONG,
 226         TPM_SHORT,
 227         TPM_UNDEFINED,          /* 85 */
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_UNDEFINED,
 232         TPM_SHORT,              /* 90 */
 233         TPM_SHORT,
 234         TPM_SHORT,
 235         TPM_SHORT,
 236         TPM_SHORT,
 237         TPM_UNDEFINED,          /* 95 */
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_UNDEFINED,
 242         TPM_MEDIUM,             /* 100 */
 243         TPM_SHORT,
 244         TPM_SHORT,
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,          /* 105 */
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_SHORT,              /* 110 */
 253         TPM_SHORT,
 254         TPM_SHORT,
 255         TPM_SHORT,
 256         TPM_SHORT,
 257         TPM_SHORT,              /* 115 */
 258         TPM_SHORT,
 259         TPM_SHORT,
 260         TPM_UNDEFINED,
 261         TPM_UNDEFINED,
 262         TPM_LONG,               /* 120 */
 263         TPM_LONG,
 264         TPM_MEDIUM,
 265         TPM_UNDEFINED,
 266         TPM_SHORT,
 267         TPM_SHORT,              /* 125 */
 268         TPM_SHORT,
 269         TPM_LONG,
 270         TPM_SHORT,
 271         TPM_SHORT,
 272         TPM_SHORT,              /* 130 */
 273         TPM_MEDIUM,
 274         TPM_UNDEFINED,
 275         TPM_SHORT,
 276         TPM_MEDIUM,
 277         TPM_UNDEFINED,          /* 135 */
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_SHORT,              /* 140 */
 283         TPM_SHORT,
 284         TPM_UNDEFINED,
 285         TPM_UNDEFINED,
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,          /* 145 */
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_UNDEFINED,
 292         TPM_SHORT,              /* 150 */
 293         TPM_MEDIUM,
 294         TPM_MEDIUM,
 295         TPM_SHORT,
 296         TPM_SHORT,
 297         TPM_UNDEFINED,          /* 155 */
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_UNDEFINED,
 302         TPM_SHORT,              /* 160 */
 303         TPM_SHORT,
 304         TPM_SHORT,
 305         TPM_SHORT,
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,          /* 165 */
 308         TPM_UNDEFINED,
 309         TPM_UNDEFINED,
 310         TPM_UNDEFINED,
 311         TPM_UNDEFINED,
 312         TPM_LONG,               /* 170 */
 313         TPM_UNDEFINED,
 314         TPM_UNDEFINED,
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_UNDEFINED,          /* 175 */
 318         TPM_UNDEFINED,
 319         TPM_UNDEFINED,
 320         TPM_UNDEFINED,
 321         TPM_UNDEFINED,
 322         TPM_MEDIUM,             /* 180 */
 323         TPM_SHORT,
 324         TPM_MEDIUM,
 325         TPM_MEDIUM,
 326         TPM_MEDIUM,
 327         TPM_MEDIUM,             /* 185 */
 328         TPM_SHORT,
 329         TPM_UNDEFINED,
 330         TPM_UNDEFINED,
 331         TPM_UNDEFINED,
 332         TPM_UNDEFINED,          /* 190 */
 333         TPM_UNDEFINED,
 334         TPM_UNDEFINED,
 335         TPM_UNDEFINED,
 336         TPM_UNDEFINED,
 337         TPM_UNDEFINED,          /* 195 */
 338         TPM_UNDEFINED,
 339         TPM_UNDEFINED,
 340         TPM_UNDEFINED,
 341         TPM_UNDEFINED,
 342         TPM_SHORT,              /* 200 */
 343         TPM_UNDEFINED,
 344         TPM_UNDEFINED,
 345         TPM_UNDEFINED,
 346         TPM_SHORT,
 347         TPM_SHORT,              /* 205 */
 348         TPM_SHORT,
 349         TPM_SHORT,
 350         TPM_SHORT,
 351         TPM_SHORT,
 352         TPM_MEDIUM,             /* 210 */
 353         TPM_UNDEFINED,
 354         TPM_MEDIUM,
 355         TPM_MEDIUM,
 356         TPM_MEDIUM,
 357         TPM_UNDEFINED,          /* 215 */
 358         TPM_MEDIUM,
 359         TPM_UNDEFINED,
 360         TPM_UNDEFINED,
 361         TPM_SHORT,
 362         TPM_SHORT,              /* 220 */
 363         TPM_SHORT,
 364         TPM_SHORT,
 365         TPM_SHORT,
 366         TPM_SHORT,
 367         TPM_UNDEFINED,          /* 225 */
 368         TPM_UNDEFINED,
 369         TPM_UNDEFINED,
 370         TPM_UNDEFINED,
 371         TPM_UNDEFINED,
 372         TPM_SHORT,              /* 230 */
 373         TPM_LONG,
 374         TPM_MEDIUM,
 375         TPM_UNDEFINED,
 376         TPM_UNDEFINED,
 377         TPM_UNDEFINED,          /* 235 */
 378         TPM_UNDEFINED,
 379         TPM_UNDEFINED,
 380         TPM_UNDEFINED,
 381         TPM_UNDEFINED,
 382         TPM_SHORT,              /* 240 */
 383         TPM_UNDEFINED,
 384         TPM_MEDIUM,
 385 };
 386
 387 /* TPM configuration */
 388 struct tpm {
 389         struct udevice *dev;
 390         char inited;
 391 } tpm;
 392
 393 /* Global structure for tpm chip data */
 394 static struct tpm_chip g_chip;
 395
 396 /* Structure to store I2C TPM specific stuff */
 397 struct tpm_dev {
 398         struct udevice *dev;
 399         u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)];  /* Max buffer size + addr */
 400         enum i2c_chip_type chip_type;
 401 };
 402
 403 static struct tpm_dev tpm_dev;
 404
 405 /*
 406  * iic_tpm_read() - read from TPM register
 407  * @addr: register address to read from
 408  * @buffer: provided by caller
 409  * @len: number of bytes to read
 410  *
 411  * Read len bytes from TPM register and put them into
 412  * buffer (little-endian format, i.e. first byte is put into buffer[0]).
 413  *
 414  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 415  * values have to be swapped.
 416  *
 417  * Return -EIO on error, 0 on success.
 418  */
 419 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
 420 {
 421         int rc;
 422         int count;
 423         uint32_t addrbuf = addr;
 424
 425         if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
 426                 /* slb9635 protocol should work in both cases */
 427                 for (count = 0; count < MAX_COUNT; count++) {
 428                         rc = dm_i2c_write(tpm_dev.dev, 0, (uchar *)&addrbuf, 1);
 429                         if (rc == 0)
 430                                 break;  /* Success, break to skip sleep */
 431                         udelay(SLEEP_DURATION);
 432                 }
 433                 if (rc)
 434                         return -rc;
 435
 436                 /* After the TPM has successfully received the register address
 437                  * it needs some time, thus we're sleeping here again, before
 438                  * retrieving the data
 439                  */
 440                 for (count = 0; count < MAX_COUNT; count++) {
 441                         udelay(SLEEP_DURATION);
 442                         rc = dm_i2c_read(tpm_dev.dev, 0, buffer, len);
 443                         if (rc == 0)
 444                                 break;  /* success, break to skip sleep */
 445                 }
 446         } else {
 447                 /*
 448                  * Use a combined read for newer chips.
 449                  * Unfortunately the smbus functions are not suitable due to
 450                  * the 32 byte limit of the smbus.
 451                  * Retries should usually not be needed, but are kept just to
 452                  * be safe on the safe side.
 453                  */
 454                 for (count = 0; count < MAX_COUNT; count++) {
 455                         rc = dm_i2c_read(tpm_dev.dev, addr, buffer, len);
 456                         if (rc == 0)
 457                                 break;  /* break here to skip sleep */
 458                         udelay(SLEEP_DURATION);
 459                 }
 460         }
 461
 462         /* Take care of 'guard time' */
 463         udelay(SLEEP_DURATION);
 464         if (rc)
 465                 return -rc;
 466
 467         return 0;
 468 }
 469
 470 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
 471                 unsigned int sleep_time, u8 max_count)
 472 {
 473         int rc = 0;
 474         int count;
 475
 476         for (count = 0; count < max_count; count++) {
 477                 rc = dm_i2c_write(tpm_dev.dev, addr, buffer, len);
 478                 if (rc == 0)
 479                         break;  /* Success, break to skip sleep */
 480                 udelay(sleep_time);
 481         }
 482
 483         /* take care of 'guard time' */
 484         udelay(sleep_time);
 485         if (rc)
 486                 return -rc;
 487
 488         return 0;
 489 }
 490
 491 /*
 492  * iic_tpm_write() - write to TPM register
 493  * @addr: register address to write to
 494  * @buffer: containing data to be written
 495  * @len: number of bytes to write
 496  *
 497  * Write len bytes from provided buffer to TPM register (little
 498  * endian format, i.e. buffer[0] is written as first byte).
 499  *
 500  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 501  * values have to be swapped.
 502  *
 503  * NOTE: use this function instead of the iic_tpm_write_generic function.
 504  *
 505  * Return -EIO on error, 0 on success
 506  */
 507 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
 508 {
 509         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
 510                         MAX_COUNT);
 511 }
 512
 513 /*
 514  * This function is needed especially for the cleanup situation after
 515  * sending TPM_READY
 516  */
 517 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
 518 {
 519         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
 520                         MAX_COUNT_LONG);
 521 }
 522
 523 static int check_locality(struct tpm_chip *chip, int loc)
 524 {
 525         const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
 526         u8 buf;
 527         int rc;
 528
 529         rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
 530         if (rc < 0)
 531                 return rc;
 532
 533         if ((buf & mask) == mask) {
 534                 chip->vendor.locality = loc;
 535                 return loc;
 536         }
 537
 538         return -1;
 539 }
 540
 541 static void release_locality(struct tpm_chip *chip, int loc, int force)
 542 {
 543         const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
 544         u8 buf;
 545
 546         if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
 547                 return;
 548
 549         if (force || (buf & mask) == mask) {
 550                 buf = TPM_ACCESS_ACTIVE_LOCALITY;
 551                 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 552         }
 553 }
 554
 555 static int request_locality(struct tpm_chip *chip, int loc)
 556 {
 557         unsigned long start, stop;
 558         u8 buf = TPM_ACCESS_REQUEST_USE;
 559         int rc;
 560
 561         if (check_locality(chip, loc) >= 0)
 562                 return loc;  /* We already have the locality */
 563
 564         rc = iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 565         if (rc)
 566                 return rc;
 567
 568         /* Wait for burstcount */
 569         start = get_timer(0);
 570         stop = chip->vendor.timeout_a;
 571         do {
 572                 if (check_locality(chip, loc) >= 0)
 573                         return loc;
 574                 udelay(TPM_TIMEOUT * 1000);
 575         } while (get_timer(start) < stop);
 576
 577         return -1;
 578 }
 579
 580 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
 581 {
 582         /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
 583         u8 buf;
 584
 585         if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
 586                 return 0;
 587         else
 588                 return buf;
 589 }
 590
 591 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
 592 {
 593         int rc;
 594
 595         /* This causes the current command to be aborted */
 596         u8 buf = TPM_STS_COMMAND_READY;
 597
 598         debug("%s\n", __func__);
 599         rc = iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
 600         if (rc)
 601                 debug("%s: rc=%d\n", __func__, rc);
 602 }
 603
 604 static ssize_t get_burstcount(struct tpm_chip *chip)
 605 {
 606         unsigned long start, stop;
 607         ssize_t burstcnt;
 608         u8 addr, buf[3];
 609
 610         /* Wait for burstcount */
 611         /* XXX: Which timeout value? Spec has 2 answers (c & d) */
 612         start = get_timer(0);
 613         stop = chip->vendor.timeout_d;
 614         do {
 615                 /* Note: STS is little endian */
 616                 addr = TPM_STS(chip->vendor.locality) + 1;
 617                 if (iic_tpm_read(addr, buf, 3) < 0)
 618                         burstcnt = 0;
 619                 else
 620                         burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
 621
 622                 if (burstcnt)
 623                         return burstcnt;
 624                 udelay(TPM_TIMEOUT * 1000);
 625         } while (get_timer(start) < stop);
 626
 627         return -EBUSY;
 628 }
 629
 630 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 631                 int *status)
 632 {
 633         unsigned long start, stop;
 634
 635         /* Check current status */
 636         *status = tpm_tis_i2c_status(chip);
 637         if ((*status & mask) == mask)
 638                 return 0;
 639
 640         start = get_timer(0);
 641         stop = timeout;
 642         do {
 643                 udelay(TPM_TIMEOUT * 1000);
 644                 *status = tpm_tis_i2c_status(chip);
 645                 if ((*status & mask) == mask)
 646                         return 0;
 647         } while (get_timer(start) < stop);
 648
 649         return -ETIME;
 650 }
 651
 652 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 653 {
 654         size_t size = 0;
 655         ssize_t burstcnt;
 656         int rc;
 657
 658         while (size < count) {
 659                 burstcnt = get_burstcount(chip);
 660
 661                 /* burstcount < 0 -> tpm is busy */
 662                 if (burstcnt < 0)
 663                         return burstcnt;
 664
 665                 /* Limit received data to max left */
 666                 if (burstcnt > (count - size))
 667                         burstcnt = count - size;
 668
 669                 rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
 670                                 &(buf[size]), burstcnt);
 671                 if (rc == 0)
 672                         size += burstcnt;
 673         }
 674
 675         return size;
 676 }
 677
 678 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 679 {
 680         int size = 0;
 681         int expected, status;
 682
 683         if (count < TPM_HEADER_SIZE) {
 684                 size = -EIO;
 685                 goto out;
 686         }
 687
 688         /* Read first 10 bytes, including tag, paramsize, and result */
 689         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 690         if (size < TPM_HEADER_SIZE) {
 691                 error("Unable to read header\n");
 692                 goto out;
 693         }
 694
 695         expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
 696         if ((size_t)expected > count) {
 697                 error("Error size=%x, expected=%x, count=%x\n", size, expected,
 698                       count);
 699                 size = -EIO;
 700                 goto out;
 701         }
 702
 703         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 704                         expected - TPM_HEADER_SIZE);
 705         if (size < expected) {
 706                 error("Unable to read remainder of result\n");
 707                 size = -ETIME;
 708                 goto out;
 709         }
 710
 711         wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 712         if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
 713                 error("Error left over data\n");
 714                 size = -EIO;
 715                 goto out;
 716         }
 717
 718 out:
 719         tpm_tis_i2c_ready(chip);
 720         /*
 721          * The TPM needs some time to clean up here,
 722          * so we sleep rather than keeping the bus busy
 723          */
 724         udelay(2000);
 725         release_locality(chip, chip->vendor.locality, 0);
 726
 727         return size;
 728 }
 729
 730 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
 731 {
 732         int rc, status;
 733         size_t burstcnt;
 734         size_t count = 0;
 735         int retry = 0;
 736         u8 sts = TPM_STS_GO;
 737
 738         debug("%s: len=%d\n", __func__, len);
 739         if (len > TPM_DEV_BUFSIZE)
 740                 return -E2BIG;  /* Command is too long for our tpm, sorry */
 741
 742         if (request_locality(chip, 0) < 0)
 743                 return -EBUSY;
 744
 745         status = tpm_tis_i2c_status(chip);
 746         if ((status & TPM_STS_COMMAND_READY) == 0) {
 747                 tpm_tis_i2c_ready(chip);
 748                 if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
 749                                   chip->vendor.timeout_b, &status) < 0) {
 750                         rc = -ETIME;
 751                         goto out_err;
 752                 }
 753         }
 754
 755         burstcnt = get_burstcount(chip);
 756
 757         /* burstcount < 0 -> tpm is busy */
 758         if (burstcnt < 0)
 759                 return burstcnt;
 760
 761         while (count < len) {
 762                 udelay(300);
 763                 if (burstcnt > len - count)
 764                         burstcnt = len - count;
 765
 766 #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
 767                 if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION)
 768                         burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION;
 769 #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
 770
 771                 rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
 772                                 &(buf[count]), burstcnt);
 773                 if (rc == 0)
 774                         count += burstcnt;
 775                 else {
 776                         debug("%s: error\n", __func__);
 777                         if (retry++ > 10) {
 778                                 rc = -EIO;
 779                                 goto out_err;
 780                         }
 781                         rc = wait_for_stat(chip, TPM_STS_VALID,
 782                                            chip->vendor.timeout_c, &status);
 783                         if (rc)
 784                                 goto out_err;
 785
 786                         if ((status & TPM_STS_DATA_EXPECT) == 0) {
 787                                 rc = -EIO;
 788                                 goto out_err;
 789                         }
 790                 }
 791         }
 792
 793         /* Go and do it */
 794         iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
 795         debug("done\n");
 796
 797         return len;
 798
 799 out_err:
 800         debug("%s: out_err\n", __func__);
 801         tpm_tis_i2c_ready(chip);
 802         /*
 803          * The TPM needs some time to clean up here,
 804          * so we sleep rather than keeping the bus busy
 805          */
 806         udelay(2000);
 807         release_locality(chip, chip->vendor.locality, 0);
 808
 809         return rc;
 810 }
 811
 812 static struct tpm_vendor_specific tpm_tis_i2c = {
 813         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 814         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 815         .req_canceled = TPM_STS_COMMAND_READY,
 816 };
 817
 818
 819 static enum i2c_chip_type tpm_vendor_chip_type(void)
 820 {
 821 #if CONFIG_IS_ENABLED(OF_CONTROL)
 822         const void *blob = gd->fdt_blob;
 823
 824         if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
 825                 return SLB9645;
 826
 827         if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
 828                 return SLB9635;
 829 #endif
 830         return UNKNOWN;
 831 }
 832
 833 int tpm_vendor_init(struct udevice *dev)
 834 {
 835         struct tpm_chip *chip;
 836         u32 vendor;
 837         u32 expected_did_vid;
 838
 839         tpm_dev.dev = dev;
 840         tpm_dev.chip_type = tpm_vendor_chip_type();
 841
 842         chip = tpm_register_hardware(&tpm_tis_i2c);
 843         if (chip < 0)
 844                 return -ENODEV;
 845
 846         /* Disable interrupts (not supported) */
 847         chip->vendor.irq = 0;
 848
 849         /* Default timeouts */
 850         chip->vendor.timeout_a = TIS_SHORT_TIMEOUT;
 851         chip->vendor.timeout_b = TIS_LONG_TIMEOUT;
 852         chip->vendor.timeout_c = TIS_SHORT_TIMEOUT;
 853         chip->vendor.timeout_d = TIS_SHORT_TIMEOUT;
 854
 855         if (request_locality(chip, 0) < 0)
 856                 return  -ENODEV;
 857
 858         /* Read four bytes from DID_VID register */
 859         if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
 860                 release_locality(chip, 0, 1);
 861                 return -EIO;
 862         }
 863
 864         if (tpm_dev.chip_type == SLB9635) {
 865                 vendor = be32_to_cpu(vendor);
 866                 expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
 867         } else {
 868                 /* device id and byte order has changed for newer i2c tpms */
 869                 expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
 870         }
 871
 872         if (tpm_dev.chip_type != UNKNOWN && vendor != expected_did_vid) {
 873                 error("Vendor id did not match! ID was %08x\n", vendor);
 874                 return -ENODEV;
 875         }
 876
 877         debug("1.2 TPM (chip type %s device-id 0x%X)\n",
 878               chip_name[tpm_dev.chip_type], vendor >> 16);
 879
 880         /*
 881          * A timeout query to TPM can be placed here.
 882          * Standard timeout values are used so far
 883          */
 884
 885         return 0;
 886 }
 887
 888 void tpm_vendor_cleanup(struct tpm_chip *chip)
 889 {
 890         release_locality(chip, chip->vendor.locality, 1);
 891 }
 892
 893 /* Returns max number of milliseconds to wait */
 894 static unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 895                 u32 ordinal)
 896 {
 897         int duration_idx = TPM_UNDEFINED;
 898         int duration = 0;
 899
 900         if (ordinal < TPM_MAX_ORDINAL) {
 901                 duration_idx = tpm_ordinal_duration[ordinal];
 902         } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 903                         TPM_MAX_PROTECTED_ORDINAL) {
 904                 duration_idx = tpm_protected_ordinal_duration[
 905                                 ordinal & TPM_PROTECTED_ORDINAL_MASK];
 906         }
 907
 908         if (duration_idx != TPM_UNDEFINED)
 909                 duration = chip->vendor.duration[duration_idx];
 910
 911         if (duration <= 0)
 912                 return 2 * 60 * HZ; /* Two minutes timeout */
 913         else
 914                 return duration;
 915 }
 916
 917 static ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
 918 {
 919         int rc;
 920         u32 count, ordinal;
 921         unsigned long start, stop;
 922
 923         struct tpm_chip *chip = &g_chip;
 924
 925         /* switch endianess: big->little */
 926         count = get_unaligned_be32(buf + TPM_CMD_COUNT_BYTE);
 927         ordinal = get_unaligned_be32(buf + TPM_CMD_ORDINAL_BYTE);
 928
 929         if (count == 0) {
 930                 error("no data\n");
 931                 return -ENODATA;
 932         }
 933         if (count > bufsiz) {
 934                 error("invalid count value %x %zx\n", count, bufsiz);
 935                 return -E2BIG;
 936         }
 937
 938         debug("Calling send\n");
 939         rc = tpm_tis_i2c_send(chip, (u8 *)buf, count);
 940         debug("   ... done calling send\n");
 941         if (rc < 0) {
 942                 error("tpm_transmit: tpm_send: error %d\n", rc);
 943                 goto out;
 944         }
 945
 946         if (chip->vendor.irq)
 947                 goto out_recv;
 948
 949         start = get_timer(0);
 950         stop = tpm_calc_ordinal_duration(chip, ordinal);
 951         do {
 952                 debug("waiting for status... %ld %ld\n", start, stop);
 953                 u8 status = tpm_tis_i2c_status(chip);
 954                 if ((status & chip->vendor.req_complete_mask) ==
 955                     chip->vendor.req_complete_val) {
 956                         debug("...got it;\n");
 957                         goto out_recv;
 958                 }
 959
 960                 if (status == chip->vendor.req_canceled) {
 961                         error("Operation Canceled\n");
 962                         rc = -ECANCELED;
 963                         goto out;
 964                 }
 965                 udelay(TPM_TIMEOUT * 1000);
 966         } while (get_timer(start) < stop);
 967
 968         tpm_tis_i2c_ready(chip);
 969         error("Operation Timed out\n");
 970         rc = -ETIME;
 971         goto out;
 972
 973 out_recv:
 974         debug("out_recv: reading response...\n");
 975         rc = tpm_tis_i2c_recv(chip, (u8 *)buf, TPM_BUFSIZE);
 976         if (rc < 0)
 977                 error("tpm_transmit: tpm_recv: error %d\n", rc);
 978
 979 out:
 980         return rc;
 981 }
 982
 983 static int tpm_open_dev(struct udevice *dev)
 984 {
 985         int rc;
 986
 987         debug("%s: start\n", __func__);
 988         if (g_chip.is_open)
 989                 return -EBUSY;
 990         rc = tpm_vendor_init(dev);
 991         if (rc < 0)
 992                 g_chip.is_open = 0;
 993         return rc;
 994 }
 995
 996 static void tpm_close(void)
 997 {
 998         if (g_chip.is_open) {
 999                 tpm_vendor_cleanup(&g_chip);
1000                 g_chip.is_open = 0;
1001         }
1002 }
1003
1004 /**
1005  * Decode TPM configuration.
1006  *
1007  * @param dev   Returns a configuration of TPM device
1008  * @return 0 if ok, -1 on error
1009  */
1010 static int tpm_decode_config(struct tpm *dev)
1011 {
1012         const void *blob = gd->fdt_blob;
1013         struct udevice *bus;
1014         int chip_addr;
1015         int parent;
1016         int node;
1017         int ret;
1018
1019         node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
1020         if (node < 0) {
1021                 node = fdtdec_next_compatible(blob, 0,
1022                                 COMPAT_INFINEON_SLB9645_TPM);
1023         }
1024         if (node < 0) {
1025                 debug("%s: Node not found\n", __func__);
1026                 return -1;
1027         }
1028         parent = fdt_parent_offset(blob, node);
1029         if (parent < 0) {
1030                 debug("%s: Cannot find node parent\n", __func__);
1031                 return -1;
1032         }
1033
1034         /*
1035          * TODO(sjg@chromium.org): Remove this when driver model supports
1036          * TPMs
1037          */
1038         ret = uclass_get_device_by_of_offset(UCLASS_I2C, parent, &bus);
1039         if (ret) {
1040                 debug("Cannot find bus for node '%s: ret=%d'\n",
1041                       fdt_get_name(blob, parent, NULL), ret);
1042                 return ret;
1043         }
1044
1045         chip_addr = fdtdec_get_int(blob, node, "reg", -1);
1046         if (chip_addr == -1) {
1047                 debug("Cannot find reg property for node '%s: ret=%d'\n",
1048                       fdt_get_name(blob, node, NULL), ret);
1049                 return ret;
1050         }
1051         /*
1052          * TODO(sjg@chromium.org): Older TPMs will need to use the older method
1053          * in iic_tpm_read() so the offset length needs to be 0 here.
1054          */
1055         ret = i2c_get_chip(bus, chip_addr, 1, &dev->dev);
1056         if (ret) {
1057                 debug("Cannot find device for node '%s: ret=%d'\n",
1058                       fdt_get_name(blob, node, NULL), ret);
1059                 return ret;
1060         }
1061
1062         return 0;
1063 }
1064
1065 struct tpm_chip *tpm_register_hardware(const struct tpm_vendor_specific *entry)
1066 {
1067         struct tpm_chip *chip;
1068
1069         /* Driver specific per-device data */
1070         chip = &g_chip;
1071         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1072         chip->is_open = 1;
1073
1074         return chip;
1075 }
1076
1077 int tis_init(void)
1078 {
1079         if (tpm.inited)
1080                 return 0;
1081
1082         if (tpm_decode_config(&tpm))
1083                 return -1;
1084
1085         debug("%s: done\n", __func__);
1086
1087         tpm.inited = 1;
1088
1089         return 0;
1090 }
1091
1092 int tis_open(void)
1093 {
1094         int rc;
1095
1096         if (!tpm.inited)
1097                 return -1;
1098
1099         rc = tpm_open_dev(tpm.dev);
1100
1101         return rc;
1102 }
1103
1104 int tis_close(void)
1105 {
1106         if (!tpm.inited)
1107                 return -1;
1108
1109         tpm_close();
1110
1111         return 0;
1112 }
1113
1114 int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
1115                 uint8_t *recvbuf, size_t *rbuf_len)
1116 {
1117         int len;
1118         uint8_t buf[4096];
1119
1120         if (!tpm.inited)
1121                 return -1;
1122
1123         if (sizeof(buf) < sbuf_size)
1124                 return -1;
1125
1126         memcpy(buf, sendbuf, sbuf_size);
1127
1128         len = tpm_transmit(buf, sbuf_size);
1129
1130         if (len < 10) {
1131                 *rbuf_len = 0;
1132                 return -1;
1133         }
1134
1135         memcpy(recvbuf, buf, len);
1136         *rbuf_len = len;
1137
1138         return 0;
1139 }