git.sur5r.net Git - u-boot/blob - drivers/tpm/tpm_tis_infineon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2011 Infineon Technologies
   4  *
   5  * Authors:
   6  * Peter Huewe <huewe.external@infineon.com>
   7  *
   8  * Description:
   9  * Device driver for TCG/TCPA TPM (trusted platform module).
  10  * Specifications at www.trustedcomputinggroup.org
  11  *
  12  * This device driver implements the TPM interface as defined in
  13  * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
  14  * Infineon I2C Protocol Stack Specification v0.20.
  15  *
  16  * It is based on the Linux kernel driver tpm.c from Leendert van
  17  * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
  18  *
  19  * Version: 2.1.1
  20  */
  21
  22 #include <common.h>
  23 #include <dm.h>
  24 #include <fdtdec.h>
  25 #include <i2c.h>
  26 #include <tpm-v1.h>
  27 #include <linux/errno.h>
  28 #include <linux/compiler.h>
  29 #include <linux/types.h>
  30 #include <linux/unaligned/be_byteshift.h>
  31
  32 #include "tpm_tis.h"
  33 #include "tpm_internal.h"
  34
  35 enum i2c_chip_type {
  36         SLB9635,
  37         SLB9645,
  38         UNKNOWN,
  39 };
  40
  41 /* expected value for DIDVID register */
  42 #define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
  43 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
  44
  45 static const char * const chip_name[] = {
  46         [SLB9635] = "slb9635tt",
  47         [SLB9645] = "slb9645tt",
  48         [UNKNOWN] = "unknown/fallback to slb9635",
  49 };
  50
  51 #define TPM_ACCESS(l)                   (0x0000 | ((l) << 4))
  52 #define TPM_STS(l)                      (0x0001 | ((l) << 4))
  53 #define TPM_DATA_FIFO(l)                (0x0005 | ((l) << 4))
  54 #define TPM_DID_VID(l)                  (0x0006 | ((l) << 4))
  55
  56 /*
  57  * tpm_tis_i2c_read() - read from TPM register
  58  * @addr: register address to read from
  59  * @buffer: provided by caller
  60  * @len: number of bytes to read
  61  *
  62  * Read len bytes from TPM register and put them into
  63  * buffer (little-endian format, i.e. first byte is put into buffer[0]).
  64  *
  65  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
  66  * values have to be swapped.
  67  *
  68  * Return -EIO on error, 0 on success.
  69  */
  70 static int tpm_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
  71                             size_t len)
  72 {
  73         struct tpm_chip *chip = dev_get_priv(dev);
  74         int rc;
  75         int count;
  76         uint32_t addrbuf = addr;
  77
  78         if ((chip->chip_type == SLB9635) || (chip->chip_type == UNKNOWN)) {
  79                 /* slb9635 protocol should work in both cases */
  80                 for (count = 0; count < MAX_COUNT; count++) {
  81                         rc = dm_i2c_write(dev, 0, (uchar *)&addrbuf, 1);
  82                         if (rc == 0)
  83                                 break;  /* Success, break to skip sleep */
  84                         udelay(SLEEP_DURATION_US);
  85                 }
  86                 if (rc)
  87                         return rc;
  88
  89                 /* After the TPM has successfully received the register address
  90                  * it needs some time, thus we're sleeping here again, before
  91                  * retrieving the data
  92                  */
  93                 for (count = 0; count < MAX_COUNT; count++) {
  94                         udelay(SLEEP_DURATION_US);
  95                         rc = dm_i2c_read(dev, 0, buffer, len);
  96                         if (rc == 0)
  97                                 break;  /* success, break to skip sleep */
  98                 }
  99         } else {
 100                 /*
 101                  * Use a combined read for newer chips.
 102                  * Unfortunately the smbus functions are not suitable due to
 103                  * the 32 byte limit of the smbus.
 104                  * Retries should usually not be needed, but are kept just to
 105                  * be safe on the safe side.
 106                  */
 107                 for (count = 0; count < MAX_COUNT; count++) {
 108                         rc = dm_i2c_read(dev, addr, buffer, len);
 109                         if (rc == 0)
 110                                 break;  /* break here to skip sleep */
 111                         udelay(SLEEP_DURATION_US);
 112                 }
 113         }
 114
 115         /* Take care of 'guard time' */
 116         udelay(SLEEP_DURATION_US);
 117         if (rc)
 118                 return rc;
 119
 120         return 0;
 121 }
 122
 123 static int tpm_tis_i2c_write_generic(struct udevice *dev, u8 addr,
 124                                      const u8 *buffer, size_t len,
 125                                      unsigned int sleep_time_us, u8 max_count)
 126 {
 127         struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
 128         struct tpm_chip *chip = dev_get_priv(dev);
 129         int rc = 0;
 130         int count;
 131
 132         if (chip->chip_type == SLB9635) {
 133                 /* Prepare send buffer to include the address */
 134                 priv->buf[0] = addr;
 135                 memcpy(&(priv->buf[1]), buffer, len);
 136                 buffer = priv->buf;
 137                 len++;
 138                 addr = 0;
 139         }
 140
 141         for (count = 0; count < max_count; count++) {
 142                 rc = dm_i2c_write(dev, addr, buffer, len);
 143                 if (rc == 0)
 144                         break;  /* Success, break to skip sleep */
 145                 udelay(sleep_time_us);
 146         }
 147
 148         /* take care of 'guard time' */
 149         udelay(sleep_time_us);
 150         if (rc)
 151                 return rc;
 152
 153         return 0;
 154 }
 155
 156 /*
 157  * tpm_tis_i2c_write() - write to TPM register
 158  * @addr: register address to write to
 159  * @buffer: containing data to be written
 160  * @len: number of bytes to write
 161  *
 162  * Write len bytes from provided buffer to TPM register (little
 163  * endian format, i.e. buffer[0] is written as first byte).
 164  *
 165  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 166  * values have to be swapped.
 167  *
 168  * NOTE: use this function instead of the tpm_tis_i2c_write_generic function.
 169  *
 170  * Return -EIO on error, 0 on success
 171  */
 172 static int tpm_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
 173                              size_t len)
 174 {
 175         return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
 176                                          SLEEP_DURATION_US, MAX_COUNT);
 177 }
 178
 179 /*
 180  * This function is needed especially for the cleanup situation after
 181  * sending TPM_READY
 182  */
 183 static int tpm_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
 184                                   size_t len)
 185 {
 186         return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
 187                                          SLEEP_DURATION_LONG_US,
 188                                          MAX_COUNT_LONG);
 189 }
 190
 191 static int tpm_tis_i2c_check_locality(struct udevice *dev, int loc)
 192 {
 193         const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
 194         struct tpm_chip *chip = dev_get_priv(dev);
 195         u8 buf;
 196         int rc;
 197
 198         rc = tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1);
 199         if (rc < 0)
 200                 return rc;
 201
 202         if ((buf & mask) == mask) {
 203                 chip->locality = loc;
 204                 return loc;
 205         }
 206
 207         return -ENOENT;
 208 }
 209
 210 static void tpm_tis_i2c_release_locality(struct udevice *dev, int loc,
 211                                          int force)
 212 {
 213         const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
 214         u8 buf;
 215
 216         if (tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1) < 0)
 217                 return;
 218
 219         if (force || (buf & mask) == mask) {
 220                 buf = TPM_ACCESS_ACTIVE_LOCALITY;
 221                 tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
 222         }
 223 }
 224
 225 static int tpm_tis_i2c_request_locality(struct udevice *dev, int loc)
 226 {
 227         struct tpm_chip *chip = dev_get_priv(dev);
 228         unsigned long start, stop;
 229         u8 buf = TPM_ACCESS_REQUEST_USE;
 230         int rc;
 231
 232         rc = tpm_tis_i2c_check_locality(dev, loc);
 233         if (rc >= 0) {
 234                 debug("%s: Already have locality\n", __func__);
 235                 return loc;  /* We already have the locality */
 236         } else if (rc != -ENOENT) {
 237                 debug("%s: Failed to get locality: %d\n", __func__, rc);
 238                 return rc;
 239         }
 240
 241         rc = tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
 242         if (rc) {
 243                 debug("%s: Failed to write to TPM: %d\n", __func__, rc);
 244                 return rc;
 245         }
 246
 247         /* Wait for burstcount */
 248         start = get_timer(0);
 249         stop = chip->timeout_a;
 250         do {
 251                 rc = tpm_tis_i2c_check_locality(dev, loc);
 252                 if (rc >= 0) {
 253                         debug("%s: Have locality\n", __func__);
 254                         return loc;
 255                 } else if (rc != -ENOENT) {
 256                         debug("%s: Failed to get locality: %d\n", __func__, rc);
 257                         return rc;
 258                 }
 259                 mdelay(TPM_TIMEOUT_MS);
 260         } while (get_timer(start) < stop);
 261         debug("%s: Timeout getting locality: %d\n", __func__, rc);
 262
 263         return rc;
 264 }
 265
 266 static u8 tpm_tis_i2c_status(struct udevice *dev)
 267 {
 268         struct tpm_chip *chip = dev_get_priv(dev);
 269         /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
 270         u8 buf;
 271
 272         if (tpm_tis_i2c_read(dev, TPM_STS(chip->locality), &buf, 1) < 0)
 273                 return 0;
 274         else
 275                 return buf;
 276 }
 277
 278 static int tpm_tis_i2c_ready(struct udevice *dev)
 279 {
 280         struct tpm_chip *chip = dev_get_priv(dev);
 281         int rc;
 282
 283         /* This causes the current command to be aborted */
 284         u8 buf = TPM_STS_COMMAND_READY;
 285
 286         debug("%s\n", __func__);
 287         rc = tpm_tis_i2c_write_long(dev, TPM_STS(chip->locality), &buf, 1);
 288         if (rc)
 289                 debug("%s: rc=%d\n", __func__, rc);
 290
 291         return rc;
 292 }
 293
 294 static ssize_t tpm_tis_i2c_get_burstcount(struct udevice *dev)
 295 {
 296         struct tpm_chip *chip = dev_get_priv(dev);
 297         unsigned long start, stop;
 298         ssize_t burstcnt;
 299         u8 addr, buf[3];
 300
 301         /* Wait for burstcount */
 302         /* XXX: Which timeout value? Spec has 2 answers (c & d) */
 303         start = get_timer(0);
 304         stop = chip->timeout_d;
 305         do {
 306                 /* Note: STS is little endian */
 307                 addr = TPM_STS(chip->locality) + 1;
 308                 if (tpm_tis_i2c_read(dev, addr, buf, 3) < 0)
 309                         burstcnt = 0;
 310                 else
 311                         burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
 312
 313                 if (burstcnt)
 314                         return burstcnt;
 315                 mdelay(TPM_TIMEOUT_MS);
 316         } while (get_timer(start) < stop);
 317
 318         return -EBUSY;
 319 }
 320
 321 static int tpm_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
 322                                      unsigned long timeout, int *status)
 323 {
 324         unsigned long start, stop;
 325
 326         /* Check current status */
 327         *status = tpm_tis_i2c_status(dev);
 328         if ((*status & mask) == mask)
 329                 return 0;
 330
 331         start = get_timer(0);
 332         stop = timeout;
 333         do {
 334                 mdelay(TPM_TIMEOUT_MS);
 335                 *status = tpm_tis_i2c_status(dev);
 336                 if ((*status & mask) == mask)
 337                         return 0;
 338         } while (get_timer(start) < stop);
 339
 340         return -ETIMEDOUT;
 341 }
 342
 343 static int tpm_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
 344 {
 345         struct tpm_chip *chip = dev_get_priv(dev);
 346         size_t size = 0;
 347         ssize_t burstcnt;
 348         int rc;
 349
 350         while (size < count) {
 351                 burstcnt = tpm_tis_i2c_get_burstcount(dev);
 352
 353                 /* burstcount < 0 -> tpm is busy */
 354                 if (burstcnt < 0)
 355                         return burstcnt;
 356
 357                 /* Limit received data to max left */
 358                 if (burstcnt > (count - size))
 359                         burstcnt = count - size;
 360
 361                 rc = tpm_tis_i2c_read(dev, TPM_DATA_FIFO(chip->locality),
 362                                       &(buf[size]), burstcnt);
 363                 if (rc == 0)
 364                         size += burstcnt;
 365         }
 366
 367         return size;
 368 }
 369
 370 static int tpm_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
 371 {
 372         struct tpm_chip *chip = dev_get_priv(dev);
 373         int size = 0;
 374         int status;
 375         unsigned int expected;
 376         int rc;
 377
 378         status = tpm_tis_i2c_status(dev);
 379         if (status == TPM_STS_COMMAND_READY)
 380                 return -EINTR;
 381         if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
 382             (TPM_STS_DATA_AVAIL | TPM_STS_VALID))
 383                 return -EAGAIN;
 384
 385         debug("...got it;\n");
 386
 387         /* Read first 10 bytes, including tag, paramsize, and result */
 388         size = tpm_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
 389         if (size < TPM_HEADER_SIZE) {
 390                 debug("Unable to read header\n");
 391                 return size < 0 ? size : -EIO;
 392         }
 393
 394         expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
 395         if ((size_t)expected > count || (size_t)expected < TPM_HEADER_SIZE) {
 396                 debug("Error size=%x, expected=%x, count=%x\n", size, expected,
 397                       count);
 398                 return -ENOSPC;
 399         }
 400
 401         size += tpm_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
 402                                       expected - TPM_HEADER_SIZE);
 403         if (size < expected) {
 404                 debug("Unable to read remainder of result\n");
 405                 return -ETIMEDOUT;
 406         }
 407
 408         rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
 409                                        &status);
 410         if (rc)
 411                 return rc;
 412         if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
 413                 debug("Error left over data\n");
 414                 return -EIO;
 415         }
 416
 417         return size;
 418 }
 419
 420 static int tpm_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
 421 {
 422         struct tpm_chip *chip = dev_get_priv(dev);
 423         int rc, status;
 424         size_t burstcnt;
 425         size_t count = 0;
 426         int retry = 0;
 427         u8 sts = TPM_STS_GO;
 428
 429         debug("%s: len=%d\n", __func__, len);
 430         if (len > TPM_DEV_BUFSIZE)
 431                 return -E2BIG;  /* Command is too long for our tpm, sorry */
 432
 433         if (tpm_tis_i2c_request_locality(dev, 0) < 0)
 434                 return -EBUSY;
 435
 436         status = tpm_tis_i2c_status(dev);
 437         if ((status & TPM_STS_COMMAND_READY) == 0) {
 438                 rc = tpm_tis_i2c_ready(dev);
 439                 if (rc)
 440                         return rc;
 441                 rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
 442                                                chip->timeout_b, &status);
 443                 if (rc)
 444                         return rc;
 445         }
 446
 447         burstcnt = tpm_tis_i2c_get_burstcount(dev);
 448
 449         /* burstcount < 0 -> tpm is busy */
 450         if (burstcnt < 0)
 451                 return burstcnt;
 452
 453         while (count < len) {
 454                 udelay(300);
 455                 if (burstcnt > len - count)
 456                         burstcnt = len - count;
 457
 458 #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
 459                 if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN)
 460                         burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN;
 461 #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
 462
 463                 rc = tpm_tis_i2c_write(dev, TPM_DATA_FIFO(chip->locality),
 464                                        &(buf[count]), burstcnt);
 465                 if (rc == 0)
 466                         count += burstcnt;
 467                 else {
 468                         debug("%s: error\n", __func__);
 469                         if (retry++ > 10)
 470                                 return -EIO;
 471                         rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
 472                                                        chip->timeout_c,
 473                                                        &status);
 474                         if (rc)
 475                                 return rc;
 476
 477                         if ((status & TPM_STS_DATA_EXPECT) == 0)
 478                                 return -EIO;
 479                 }
 480         }
 481
 482         /* Go and do it */
 483         rc = tpm_tis_i2c_write(dev, TPM_STS(chip->locality), &sts, 1);
 484         if (rc < 0)
 485                 return rc;
 486         debug("%s: done, rc=%d\n", __func__, rc);
 487
 488         return len;
 489 }
 490
 491 static int tpm_tis_i2c_cleanup(struct udevice *dev)
 492 {
 493         struct tpm_chip *chip = dev_get_priv(dev);
 494
 495         tpm_tis_i2c_ready(dev);
 496         /*
 497          * The TPM needs some time to clean up here,
 498          * so we sleep rather than keeping the bus busy
 499          */
 500         mdelay(2);
 501         tpm_tis_i2c_release_locality(dev, chip->locality, 0);
 502
 503         return 0;
 504 }
 505
 506 static int tpm_tis_i2c_init(struct udevice *dev)
 507 {
 508         struct tpm_chip *chip = dev_get_priv(dev);
 509         u32 vendor;
 510         u32 expected_did_vid;
 511         int rc;
 512
 513         chip->is_open = 1;
 514
 515         /* Default timeouts - these could move to the device tree */
 516         chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
 517         chip->timeout_b = TIS_LONG_TIMEOUT_MS;
 518         chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
 519         chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
 520
 521         rc = tpm_tis_i2c_request_locality(dev, 0);
 522         if (rc < 0)
 523                 return rc;
 524
 525         /* Read four bytes from DID_VID register */
 526         if (tpm_tis_i2c_read(dev, TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
 527                 tpm_tis_i2c_release_locality(dev, 0, 1);
 528                 return -EIO;
 529         }
 530
 531         if (chip->chip_type == SLB9635) {
 532                 vendor = be32_to_cpu(vendor);
 533                 expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
 534         } else {
 535                 /* device id and byte order has changed for newer i2c tpms */
 536                 expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
 537         }
 538
 539         if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
 540                 pr_err("Vendor id did not match! ID was %08x\n", vendor);
 541                 return -ENODEV;
 542         }
 543
 544         chip->vend_dev = vendor;
 545         debug("1.2 TPM (chip type %s device-id 0x%X)\n",
 546               chip_name[chip->chip_type], vendor >> 16);
 547
 548         /*
 549          * A timeout query to TPM can be placed here.
 550          * Standard timeout values are used so far
 551          */
 552
 553         return 0;
 554 }
 555
 556 static int tpm_tis_i2c_open(struct udevice *dev)
 557 {
 558         struct tpm_chip *chip = dev_get_priv(dev);
 559         int rc;
 560
 561         debug("%s: start\n", __func__);
 562         if (chip->is_open)
 563                 return -EBUSY;
 564         rc = tpm_tis_i2c_init(dev);
 565         if (rc < 0)
 566                 chip->is_open = 0;
 567
 568         return rc;
 569 }
 570
 571 static int tpm_tis_i2c_close(struct udevice *dev)
 572 {
 573         struct tpm_chip *chip = dev_get_priv(dev);
 574
 575         if (chip->is_open) {
 576                 tpm_tis_i2c_release_locality(dev, chip->locality, 1);
 577                 chip->is_open = 0;
 578                 chip->vend_dev = 0;
 579         }
 580
 581         return 0;
 582 }
 583
 584 static int tpm_tis_get_desc(struct udevice *dev, char *buf, int size)
 585 {
 586         struct tpm_chip *chip = dev_get_priv(dev);
 587
 588         if (size < 50)
 589                 return -ENOSPC;
 590
 591         return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
 592                         chip->is_open ? "open" : "closed",
 593                         chip_name[chip->chip_type],
 594                         chip->vend_dev >> 16);
 595 }
 596
 597 static int tpm_tis_i2c_probe(struct udevice *dev)
 598 {
 599         struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
 600         struct tpm_chip *chip = dev_get_priv(dev);
 601
 602         chip->chip_type = dev_get_driver_data(dev);
 603
 604         /* TODO: These need to be checked and tuned */
 605         uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS;
 606         uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS;
 607         uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS;
 608         uc_priv->retry_time_ms = TPM_TIMEOUT_MS;
 609
 610         return 0;
 611 }
 612
 613 static const struct tpm_ops tpm_tis_i2c_ops = {
 614         .open           = tpm_tis_i2c_open,
 615         .close          = tpm_tis_i2c_close,
 616         .get_desc       = tpm_tis_get_desc,
 617         .send           = tpm_tis_i2c_send,
 618         .recv           = tpm_tis_i2c_recv,
 619         .cleanup        = tpm_tis_i2c_cleanup,
 620 };
 621
 622 static const struct udevice_id tpm_tis_i2c_ids[] = {
 623         { .compatible = "infineon,slb9635tt", .data = SLB9635 },
 624         { .compatible = "infineon,slb9645tt", .data = SLB9645 },
 625         { }
 626 };
 627
 628 U_BOOT_DRIVER(tpm_tis_i2c) = {
 629         .name   = "tpm_tis_infineon",
 630         .id     = UCLASS_TPM,
 631         .of_match = tpm_tis_i2c_ids,
 632         .ops    = &tpm_tis_i2c_ops,
 633         .probe  = tpm_tis_i2c_probe,
 634         .priv_auto_alloc_size = sizeof(struct tpm_chip),
 635 };