1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * STMicroelectronics TPM ST33ZP24 SPI UBOOT driver 4 * 5 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved 6 * Author(s): Christophe Ricard <christophe-h.ricard@st.com> for STMicroelectronics. 7 * 8 * Description: Device driver for ST33ZP24 SPI TPM TCG. 9 * 10 * This device driver implements the TPM interface as defined in 11 * the TCG TPM Interface Spec version 1.21, revision 1.0 and the 12 * STMicroelectronics Protocol Stack Specification version 1.2.0. 13 */ 14 15 #include <common.h> 16 #include <dm.h> 17 #include <fdtdec.h> 18 #include <spi.h> 19 #include <tpm.h> 20 #include <errno.h> 21 #include <linux/types.h> 22 #include <asm/unaligned.h> 23 #include <linux/compat.h> 24 25 #include "tpm_tis.h" 26 #include "tpm_internal.h" 27 28 #define TPM_ACCESS 0x0 29 #define TPM_STS 0x18 30 #define TPM_DATA_FIFO 0x24 31 32 #define LOCALITY0 0 33 34 #define TPM_DATA_FIFO 0x24 35 #define TPM_INTF_CAPABILITY 0x14 36 37 #define TPM_DUMMY_BYTE 0x00 38 #define TPM_WRITE_DIRECTION 0x80 39 40 #define MAX_SPI_LATENCY 15 41 #define LOCALITY0 0 42 43 #define ST33ZP24_OK 0x5A 44 #define ST33ZP24_UNDEFINED_ERR 0x80 45 #define ST33ZP24_BADLOCALITY 0x81 46 #define ST33ZP24_TISREGISTER_UKNOWN 0x82 47 #define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83 48 #define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84 49 #define ST33ZP24_BAD_COMMAND_ORDER 0x85 50 #define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86 51 #define ST33ZP24_TPM_FIFO_OVERFLOW 0x89 52 #define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A 53 #define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B 54 #define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90 55 #define ST33ZP24_DUMMY_BYTES 0x00 56 57 /* 58 * TPM command can be up to 2048 byte, A TPM response can be up to 59 * 1024 byte. 60 * Between command and response, there are latency byte (up to 15 61 * usually on st33zp24 2 are enough). 62 * 63 * Overall when sending a command and expecting an answer we need if 64 * worst case: 65 * 2048 (for the TPM command) + 1024 (for the TPM answer). We need 66 * some latency byte before the answer is available (max 15). 67 * We have 2048 + 1024 + 15. 68 */ 69 #define ST33ZP24_SPI_BUFFER_SIZE (TPM_BUFSIZE + (TPM_BUFSIZE / 2) +\ 70 MAX_SPI_LATENCY) 71 72 struct st33zp24_spi_phy { 73 int latency; 74 75 u8 tx_buf[ST33ZP24_SPI_BUFFER_SIZE]; 76 u8 rx_buf[ST33ZP24_SPI_BUFFER_SIZE]; 77 }; 78 79 static int st33zp24_spi_status_to_errno(u8 code) 80 { 81 switch (code) { 82 case ST33ZP24_OK: 83 return 0; 84 case ST33ZP24_UNDEFINED_ERR: 85 case ST33ZP24_BADLOCALITY: 86 case ST33ZP24_TISREGISTER_UKNOWN: 87 case ST33ZP24_LOCALITY_NOT_ACTIVATED: 88 case ST33ZP24_HASH_END_BEFORE_HASH_START: 89 case ST33ZP24_BAD_COMMAND_ORDER: 90 case ST33ZP24_UNEXPECTED_READ_FIFO: 91 case ST33ZP24_UNEXPECTED_WRITE_FIFO: 92 case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END: 93 return -EPROTO; 94 case ST33ZP24_INCORECT_RECEIVED_LENGTH: 95 case ST33ZP24_TPM_FIFO_OVERFLOW: 96 return -EMSGSIZE; 97 case ST33ZP24_DUMMY_BYTES: 98 return -ENOSYS; 99 } 100 return code; 101 } 102 103 /* 104 * st33zp24_spi_send 105 * Send byte to TPM register according to the ST33ZP24 SPI protocol. 106 * @param: tpm, the chip description 107 * @param: tpm_register, the tpm tis register where the data should be written 108 * @param: tpm_data, the tpm_data to write inside the tpm_register 109 * @param: tpm_size, The length of the data 110 * @return: should be zero if success else a negative error code. 111 */ 112 static int st33zp24_spi_write(struct udevice *dev, u8 tpm_register, 113 const u8 *tpm_data, size_t tpm_size) 114 { 115 int total_length = 0, ret; 116 struct spi_slave *slave = dev_get_parent_priv(dev); 117 struct st33zp24_spi_phy *phy = dev_get_platdata(dev); 118 119 u8 *tx_buf = (u8 *)phy->tx_buf; 120 u8 *rx_buf = phy->rx_buf; 121 122 tx_buf[total_length++] = TPM_WRITE_DIRECTION | LOCALITY0; 123 tx_buf[total_length++] = tpm_register; 124 125 if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) { 126 tx_buf[total_length++] = tpm_size >> 8; 127 tx_buf[total_length++] = tpm_size; 128 } 129 memcpy(tx_buf + total_length, tpm_data, tpm_size); 130 total_length += tpm_size; 131 132 memset(tx_buf + total_length, TPM_DUMMY_BYTE, phy->latency); 133 134 total_length += phy->latency; 135 136 ret = spi_claim_bus(slave); 137 if (ret < 0) 138 return ret; 139 140 ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf, 141 SPI_XFER_BEGIN | SPI_XFER_END); 142 if (ret < 0) 143 return ret; 144 145 spi_release_bus(slave); 146 147 if (ret == 0) 148 ret = rx_buf[total_length - 1]; 149 150 return st33zp24_spi_status_to_errno(ret); 151 } 152 153 /* 154 * spi_st33zp24_spi_read8_reg 155 * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. 156 * @param: tpm, the chip description 157 * @param: tpm_loc, the locality to read register from 158 * @param: tpm_register, the tpm tis register where the data should be read 159 * @param: tpm_data, the TPM response 160 * @param: tpm_size, tpm TPM response size to read. 161 * @return: should be zero if success else a negative error code. 162 */ 163 static u8 st33zp24_spi_read8_reg(struct udevice *dev, u8 tpm_register, 164 u8 *tpm_data, size_t tpm_size) 165 { 166 int total_length = 0, ret; 167 struct spi_slave *slave = dev_get_parent_priv(dev); 168 struct st33zp24_spi_phy *phy = dev_get_platdata(dev); 169 170 u8 *tx_buf = (u8 *)phy->tx_buf; 171 u8 *rx_buf = phy->rx_buf; 172 173 /* Pre-Header */ 174 tx_buf[total_length++] = LOCALITY0; 175 tx_buf[total_length++] = tpm_register; 176 177 memset(&tx_buf[total_length], TPM_DUMMY_BYTE, 178 phy->latency + tpm_size); 179 total_length += phy->latency + tpm_size; 180 181 ret = spi_claim_bus(slave); 182 if (ret < 0) 183 return 0; 184 185 ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf, 186 SPI_XFER_BEGIN | SPI_XFER_END); 187 if (ret < 0) 188 return 0; 189 190 spi_release_bus(slave); 191 192 if (tpm_size > 0 && ret == 0) { 193 ret = rx_buf[total_length - tpm_size - 1]; 194 memcpy(tpm_data, rx_buf + total_length - tpm_size, tpm_size); 195 } 196 return ret; 197 } 198 199 /* 200 * st33zp24_spi_recv 201 * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. 202 * @param: phy_id, the phy description 203 * @param: tpm_register, the tpm tis register where the data should be read 204 * @param: tpm_data, the TPM response 205 * @param: tpm_size, tpm TPM response size to read. 206 * @return: number of byte read successfully: should be one if success. 207 */ 208 static int st33zp24_spi_read(struct udevice *dev, u8 tpm_register, 209 u8 *tpm_data, size_t tpm_size) 210 { 211 int ret; 212 213 ret = st33zp24_spi_read8_reg(dev, tpm_register, tpm_data, tpm_size); 214 if (!st33zp24_spi_status_to_errno(ret)) 215 return tpm_size; 216 217 return ret; 218 } 219 220 static int st33zp24_spi_evaluate_latency(struct udevice *dev) 221 { 222 int latency = 1, status = 0; 223 u8 data = 0; 224 struct st33zp24_spi_phy *phy = dev_get_platdata(dev); 225 226 while (!status && latency < MAX_SPI_LATENCY) { 227 phy->latency = latency; 228 status = st33zp24_spi_read8_reg(dev, TPM_INTF_CAPABILITY, 229 &data, 1); 230 latency++; 231 } 232 if (status < 0) 233 return status; 234 if (latency == MAX_SPI_LATENCY) 235 return -ENODEV; 236 237 return latency - 1; 238 } 239 240 /* 241 * st33zp24_spi_release_locality release the active locality 242 * @param: chip, the tpm chip description. 243 */ 244 static void st33zp24_spi_release_locality(struct udevice *dev) 245 { 246 u8 data = TPM_ACCESS_ACTIVE_LOCALITY; 247 248 st33zp24_spi_write(dev, TPM_ACCESS, &data, 1); 249 } 250 251 /* 252 * st33zp24_spi_check_locality if the locality is active 253 * @param: chip, the tpm chip description 254 * @return: the active locality or -EACCES. 255 */ 256 static int st33zp24_spi_check_locality(struct udevice *dev) 257 { 258 u8 data; 259 u8 status; 260 struct tpm_chip *chip = dev_get_priv(dev); 261 262 status = st33zp24_spi_read(dev, TPM_ACCESS, &data, 1); 263 if (status && (data & 264 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == 265 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) 266 return chip->locality; 267 268 return -EACCES; 269 } 270 271 /* 272 * st33zp24_spi_request_locality request the TPM locality 273 * @param: chip, the chip description 274 * @return: the active locality or negative value. 275 */ 276 static int st33zp24_spi_request_locality(struct udevice *dev) 277 { 278 unsigned long start, stop; 279 long ret; 280 u8 data; 281 struct tpm_chip *chip = dev_get_priv(dev); 282 283 if (st33zp24_spi_check_locality(dev) == chip->locality) 284 return chip->locality; 285 286 data = TPM_ACCESS_REQUEST_USE; 287 ret = st33zp24_spi_write(dev, TPM_ACCESS, &data, 1); 288 if (ret < 0) 289 return ret; 290 291 /* wait for locality activated */ 292 start = get_timer(0); 293 stop = chip->timeout_a; 294 do { 295 if (st33zp24_spi_check_locality(dev) >= 0) 296 return chip->locality; 297 udelay(TPM_TIMEOUT_MS * 1000); 298 } while (get_timer(start) < stop); 299 300 return -EACCES; 301 } 302 303 /* 304 * st33zp24_spi_status return the TPM_STS register 305 * @param: chip, the tpm chip description 306 * @return: the TPM_STS register value. 307 */ 308 static u8 st33zp24_spi_status(struct udevice *dev) 309 { 310 u8 data; 311 312 st33zp24_spi_read(dev, TPM_STS, &data, 1); 313 return data; 314 } 315 316 /* 317 * st33zp24_spi_get_burstcount return the burstcount address 0x19 0x1A 318 * @param: chip, the chip description 319 * return: the burstcount or -TPM_DRIVER_ERR in case of error. 320 */ 321 static int st33zp24_spi_get_burstcount(struct udevice *dev) 322 { 323 struct tpm_chip *chip = dev_get_priv(dev); 324 unsigned long start, stop; 325 int burstcnt, status; 326 u8 tpm_reg, temp; 327 328 /* wait for burstcount */ 329 start = get_timer(0); 330 stop = chip->timeout_d; 331 do { 332 tpm_reg = TPM_STS + 1; 333 status = st33zp24_spi_read(dev, tpm_reg, &temp, 1); 334 if (status < 0) 335 return -EBUSY; 336 337 tpm_reg = TPM_STS + 2; 338 burstcnt = temp; 339 status = st33zp24_spi_read(dev, tpm_reg, &temp, 1); 340 if (status < 0) 341 return -EBUSY; 342 343 burstcnt |= temp << 8; 344 if (burstcnt) 345 return burstcnt; 346 udelay(TIS_SHORT_TIMEOUT_MS * 1000); 347 } while (get_timer(start) < stop); 348 349 return -EBUSY; 350 } 351 352 /* 353 * st33zp24_spi_cancel, cancel the current command execution or 354 * set STS to COMMAND READY. 355 * @param: chip, tpm_chip description. 356 */ 357 static void st33zp24_spi_cancel(struct udevice *dev) 358 { 359 u8 data; 360 361 data = TPM_STS_COMMAND_READY; 362 st33zp24_spi_write(dev, TPM_STS, &data, 1); 363 } 364 365 /* 366 * st33zp24_spi_wait_for_stat wait for a TPM_STS value 367 * @param: chip, the tpm chip description 368 * @param: mask, the value mask to wait 369 * @param: timeout, the timeout 370 * @param: status, 371 * @return: the tpm status, 0 if success, -ETIME if timeout is reached. 372 */ 373 static int st33zp24_spi_wait_for_stat(struct udevice *dev, u8 mask, 374 unsigned long timeout, int *status) 375 { 376 unsigned long start, stop; 377 378 /* Check current status */ 379 *status = st33zp24_spi_status(dev); 380 if ((*status & mask) == mask) 381 return 0; 382 383 start = get_timer(0); 384 stop = timeout; 385 do { 386 udelay(TPM_TIMEOUT_MS * 1000); 387 *status = st33zp24_spi_status(dev); 388 if ((*status & mask) == mask) 389 return 0; 390 } while (get_timer(start) < stop); 391 392 return -ETIME; 393 } 394 395 /* 396 * st33zp24_spi_recv_data receive data 397 * @param: chip, the tpm chip description 398 * @param: buf, the buffer where the data are received 399 * @param: count, the number of data to receive 400 * @return: the number of bytes read from TPM FIFO. 401 */ 402 static int st33zp24_spi_recv_data(struct udevice *dev, u8 *buf, size_t count) 403 { 404 struct tpm_chip *chip = dev_get_priv(dev); 405 int size = 0, burstcnt, len, ret, status; 406 407 while (size < count && 408 st33zp24_spi_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 409 chip->timeout_c, &status) == 0) { 410 burstcnt = st33zp24_spi_get_burstcount(dev); 411 if (burstcnt < 0) 412 return burstcnt; 413 len = min_t(int, burstcnt, count - size); 414 ret = st33zp24_spi_read(dev, TPM_DATA_FIFO, buf + size, len); 415 if (ret < 0) 416 return ret; 417 418 size += len; 419 } 420 return size; 421 } 422 423 /* 424 * st33zp24_spi_recv received TPM response through TPM phy. 425 * @param: chip, tpm_chip description. 426 * @param: buf, the buffer to store data. 427 * @param: count, the number of bytes that can received (sizeof buf). 428 * @return: Returns zero in case of success else -EIO. 429 */ 430 static int st33zp24_spi_recv(struct udevice *dev, u8 *buf, size_t count) 431 { 432 struct tpm_chip *chip = dev_get_priv(dev); 433 int size; 434 unsigned int expected; 435 436 if (!chip) 437 return -ENODEV; 438 439 if (count < TPM_HEADER_SIZE) { 440 size = -EIO; 441 goto out; 442 } 443 444 size = st33zp24_spi_recv_data(dev, buf, TPM_HEADER_SIZE); 445 if (size < TPM_HEADER_SIZE) { 446 debug("TPM error, unable to read header\n"); 447 goto out; 448 } 449 450 expected = get_unaligned_be32(buf + 2); 451 if (expected > count || expected < TPM_HEADER_SIZE) { 452 size = -EIO; 453 goto out; 454 } 455 456 size += st33zp24_spi_recv_data(dev, &buf[TPM_HEADER_SIZE], 457 expected - TPM_HEADER_SIZE); 458 if (size < expected) { 459 debug("TPM error, unable to read remaining bytes of result\n"); 460 size = -EIO; 461 goto out; 462 } 463 464 out: 465 st33zp24_spi_cancel(dev); 466 st33zp24_spi_release_locality(dev); 467 468 return size; 469 } 470 471 /* 472 * st33zp24_spi_send send TPM commands through TPM phy. 473 * @param: chip, tpm_chip description. 474 * @param: buf, the buffer to send. 475 * @param: len, the number of bytes to send. 476 * @return: Returns zero in case of success else the negative error code. 477 */ 478 static int st33zp24_spi_send(struct udevice *dev, const u8 *buf, size_t len) 479 { 480 struct tpm_chip *chip = dev_get_priv(dev); 481 u32 i, size; 482 int burstcnt, ret, status; 483 u8 data, tpm_stat; 484 485 if (!chip) 486 return -ENODEV; 487 if (len < TPM_HEADER_SIZE) 488 return -EIO; 489 490 ret = st33zp24_spi_request_locality(dev); 491 if (ret < 0) 492 return ret; 493 494 tpm_stat = st33zp24_spi_status(dev); 495 if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) { 496 st33zp24_spi_cancel(dev); 497 if (st33zp24_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY, 498 chip->timeout_b, &status) < 0) { 499 ret = -ETIME; 500 goto out_err; 501 } 502 } 503 504 for (i = 0; i < len - 1;) { 505 burstcnt = st33zp24_spi_get_burstcount(dev); 506 if (burstcnt < 0) 507 return burstcnt; 508 509 size = min_t(int, len - i - 1, burstcnt); 510 ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + i, size); 511 if (ret < 0) 512 goto out_err; 513 514 i += size; 515 } 516 517 tpm_stat = st33zp24_spi_status(dev); 518 if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) { 519 ret = -EIO; 520 goto out_err; 521 } 522 523 ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + len - 1, 1); 524 if (ret < 0) 525 goto out_err; 526 527 tpm_stat = st33zp24_spi_status(dev); 528 if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) { 529 ret = -EIO; 530 goto out_err; 531 } 532 533 data = TPM_STS_GO; 534 ret = st33zp24_spi_write(dev, TPM_STS, &data, 1); 535 if (ret < 0) 536 goto out_err; 537 538 return len; 539 540 out_err: 541 st33zp24_spi_cancel(dev); 542 st33zp24_spi_release_locality(dev); 543 544 return ret; 545 } 546 547 static int st33zp24_spi_cleanup(struct udevice *dev) 548 { 549 st33zp24_spi_cancel(dev); 550 /* 551 * The TPM needs some time to clean up here, 552 * so we sleep rather than keeping the bus busy 553 */ 554 mdelay(2); 555 st33zp24_spi_release_locality(dev); 556 557 return 0; 558 } 559 560 static int st33zp24_spi_init(struct udevice *dev) 561 { 562 struct tpm_chip *chip = dev_get_priv(dev); 563 struct st33zp24_spi_phy *phy = dev_get_platdata(dev); 564 565 chip->is_open = 1; 566 567 /* Default timeouts - these could move to the device tree */ 568 chip->timeout_a = TIS_SHORT_TIMEOUT_MS; 569 chip->timeout_b = TIS_LONG_TIMEOUT_MS; 570 chip->timeout_c = TIS_SHORT_TIMEOUT_MS; 571 chip->timeout_d = TIS_SHORT_TIMEOUT_MS; 572 573 chip->locality = LOCALITY0; 574 575 phy->latency = st33zp24_spi_evaluate_latency(dev); 576 if (phy->latency <= 0) 577 return -ENODEV; 578 579 /* 580 * A timeout query to TPM can be placed here. 581 * Standard timeout values are used so far 582 */ 583 584 return 0; 585 } 586 587 static int st33zp24_spi_open(struct udevice *dev) 588 { 589 struct tpm_chip *chip = dev_get_priv(dev); 590 int rc; 591 592 debug("%s: start\n", __func__); 593 if (chip->is_open) 594 return -EBUSY; 595 596 rc = st33zp24_spi_init(dev); 597 if (rc < 0) 598 chip->is_open = 0; 599 600 return rc; 601 } 602 603 static int st33zp24_spi_close(struct udevice *dev) 604 { 605 struct tpm_chip *chip = dev_get_priv(dev); 606 607 if (chip->is_open) { 608 st33zp24_spi_release_locality(dev); 609 chip->is_open = 0; 610 chip->vend_dev = 0; 611 } 612 613 return 0; 614 } 615 616 static int st33zp24_spi_get_desc(struct udevice *dev, char *buf, int size) 617 { 618 struct tpm_chip *chip = dev_get_priv(dev); 619 620 if (size < 50) 621 return -ENOSPC; 622 623 return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)", 624 chip->is_open ? "open" : "closed", 625 dev->name, 626 chip->vend_dev >> 16); 627 } 628 629 const struct tpm_ops st33zp24_spi_tpm_ops = { 630 .open = st33zp24_spi_open, 631 .close = st33zp24_spi_close, 632 .recv = st33zp24_spi_recv, 633 .send = st33zp24_spi_send, 634 .cleanup = st33zp24_spi_cleanup, 635 .get_desc = st33zp24_spi_get_desc, 636 }; 637 638 static int st33zp24_spi_probe(struct udevice *dev) 639 { 640 struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev); 641 642 uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS; 643 uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS; 644 uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS; 645 uc_priv->retry_time_ms = TPM_TIMEOUT_MS; 646 647 debug("ST33ZP24 SPI TPM from STMicroelectronics found\n"); 648 649 return 0; 650 } 651 652 static int st33zp24_spi_remove(struct udevice *dev) 653 { 654 st33zp24_spi_release_locality(dev); 655 656 return 0; 657 } 658 659 static const struct udevice_id st33zp24_spi_ids[] = { 660 { .compatible = "st,st33zp24-spi" }, 661 { } 662 }; 663 664 U_BOOT_DRIVER(st33zp24_spi_spi) = { 665 .name = "st33zp24-spi", 666 .id = UCLASS_TPM, 667 .of_match = of_match_ptr(st33zp24_spi_ids), 668 .probe = st33zp24_spi_probe, 669 .remove = st33zp24_spi_remove, 670 .ops = &st33zp24_spi_tpm_ops, 671 .priv_auto_alloc_size = sizeof(struct tpm_chip), 672 .platdata_auto_alloc_size = sizeof(struct st33zp24_spi_phy), 673 }; 674