drivers/tpm/tpm_tis_st33zp24_spi.c

   1 /*
   2  * STMicroelectronics TPM ST33ZP24 SPI UBOOT driver
   3  *
   4  * Copyright (C) 2016 STMicroelectronics
   5  *
   6  * Description: Device driver for ST33ZP24 SPI TPM TCG.
   7  *
   8  * This device driver implements the TPM interface as defined in
   9  * the TCG TPM Interface Spec version 1.21, revision 1.0 and the
  10  * STMicroelectronics Protocol Stack Specification version 1.2.0.
  11  *
  12  * SPDX-License-Identifier:     GPL-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, expected;
 434
 435         if (!chip)
 436                 return -ENODEV;
 437
 438         if (count < TPM_HEADER_SIZE) {
 439                 size = -EIO;
 440                 goto out;
 441         }
 442
 443         size = st33zp24_spi_recv_data(dev, buf, TPM_HEADER_SIZE);
 444         if (size < TPM_HEADER_SIZE) {
 445                 debug("TPM error, unable to read header\n");
 446                 goto out;
 447         }
 448
 449         expected = get_unaligned_be32(buf + 2);
 450         if (expected > count) {
 451                 size = -EIO;
 452                 goto out;
 453         }
 454
 455         size += st33zp24_spi_recv_data(dev, &buf[TPM_HEADER_SIZE],
 456                                    expected - TPM_HEADER_SIZE);
 457         if (size < expected) {
 458                 debug("TPM error, unable to read remaining bytes of result\n");
 459                 size = -EIO;
 460                 goto out;
 461         }
 462
 463 out:
 464         st33zp24_spi_cancel(dev);
 465         st33zp24_spi_release_locality(dev);
 466
 467         return size;
 468 }
 469
 470 /*
 471  * st33zp24_spi_send send TPM commands through TPM phy.
 472  * @param: chip, tpm_chip description.
 473  * @param: buf, the buffer to send.
 474  * @param: len, the number of bytes to send.
 475  * @return: Returns zero in case of success else the negative error code.
 476  */
 477 static int st33zp24_spi_send(struct udevice *dev, const u8 *buf, size_t len)
 478 {
 479         struct tpm_chip *chip = dev_get_priv(dev);
 480         u32 i, size;
 481         int burstcnt, ret, status;
 482         u8 data, tpm_stat;
 483
 484         if (!chip)
 485                 return -ENODEV;
 486         if (len < TPM_HEADER_SIZE)
 487                 return -EIO;
 488
 489         ret = st33zp24_spi_request_locality(dev);
 490         if (ret < 0)
 491                 return ret;
 492
 493         tpm_stat = st33zp24_spi_status(dev);
 494         if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
 495                 st33zp24_spi_cancel(dev);
 496                 if (st33zp24_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY,
 497                                                chip->timeout_b, &status) < 0) {
 498                         ret = -ETIME;
 499                         goto out_err;
 500                 }
 501         }
 502
 503         for (i = 0; i < len - 1;) {
 504                 burstcnt = st33zp24_spi_get_burstcount(dev);
 505                 if (burstcnt < 0)
 506                         return burstcnt;
 507
 508                 size = min_t(int, len - i - 1, burstcnt);
 509                 ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + i, size);
 510                 if (ret < 0)
 511                         goto out_err;
 512
 513                 i += size;
 514         }
 515
 516         tpm_stat = st33zp24_spi_status(dev);
 517         if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
 518                 ret = -EIO;
 519                 goto out_err;
 520         }
 521
 522         ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
 523         if (ret < 0)
 524                 goto out_err;
 525
 526         tpm_stat = st33zp24_spi_status(dev);
 527         if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
 528                 ret = -EIO;
 529                 goto out_err;
 530         }
 531
 532         data = TPM_STS_GO;
 533         ret = st33zp24_spi_write(dev, TPM_STS, &data, 1);
 534         if (ret < 0)
 535                 goto out_err;
 536
 537         return len;
 538
 539 out_err:
 540         st33zp24_spi_cancel(dev);
 541         st33zp24_spi_release_locality(dev);
 542
 543         return ret;
 544 }
 545
 546 static int st33zp24_spi_cleanup(struct udevice *dev)
 547 {
 548         st33zp24_spi_cancel(dev);
 549         /*
 550          * The TPM needs some time to clean up here,
 551          * so we sleep rather than keeping the bus busy
 552          */
 553         mdelay(2);
 554         st33zp24_spi_release_locality(dev);
 555
 556         return 0;
 557 }
 558
 559 static int st33zp24_spi_init(struct udevice *dev)
 560 {
 561         struct tpm_chip *chip = dev_get_priv(dev);
 562         struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
 563
 564         chip->is_open = 1;
 565
 566         /* Default timeouts - these could move to the device tree */
 567         chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
 568         chip->timeout_b = TIS_LONG_TIMEOUT_MS;
 569         chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
 570         chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
 571
 572         chip->locality = LOCALITY0;
 573
 574         phy->latency = st33zp24_spi_evaluate_latency(dev);
 575         if (phy->latency <= 0)
 576                 return -ENODEV;
 577
 578         /*
 579          * A timeout query to TPM can be placed here.
 580          * Standard timeout values are used so far
 581          */
 582
 583         return 0;
 584 }
 585
 586 static int st33zp24_spi_open(struct udevice *dev)
 587 {
 588         struct tpm_chip *chip = dev_get_priv(dev);
 589         int rc;
 590
 591         debug("%s: start\n", __func__);
 592         if (chip->is_open)
 593                 return -EBUSY;
 594
 595         rc = st33zp24_spi_init(dev);
 596         if (rc < 0)
 597                 chip->is_open = 0;
 598
 599         return rc;
 600 }
 601
 602 static int st33zp24_spi_close(struct udevice *dev)
 603 {
 604         struct tpm_chip *chip = dev_get_priv(dev);
 605
 606         if (chip->is_open) {
 607                 st33zp24_spi_release_locality(dev);
 608                 chip->is_open = 0;
 609                 chip->vend_dev = 0;
 610         }
 611
 612         return 0;
 613 }
 614
 615 static int st33zp24_spi_get_desc(struct udevice *dev, char *buf, int size)
 616 {
 617         struct tpm_chip *chip = dev_get_priv(dev);
 618
 619         if (size < 50)
 620                 return -ENOSPC;
 621
 622         return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
 623                         chip->is_open ? "open" : "closed",
 624                         dev->name,
 625                         chip->vend_dev >> 16);
 626 }
 627
 628 const struct tpm_ops st33zp24_spi_tpm_ops = {
 629         .open = st33zp24_spi_open,
 630         .close = st33zp24_spi_close,
 631         .recv = st33zp24_spi_recv,
 632         .send = st33zp24_spi_send,
 633         .cleanup = st33zp24_spi_cleanup,
 634         .get_desc = st33zp24_spi_get_desc,
 635 };
 636
 637 static int st33zp24_spi_probe(struct udevice *dev)
 638 {
 639         struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
 640
 641         uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS;
 642         uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS;
 643         uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS;
 644         uc_priv->retry_time_ms = TPM_TIMEOUT_MS;
 645
 646         debug("ST33ZP24 SPI TPM from STMicroelectronics found\n");
 647
 648         return 0;
 649 }
 650
 651 static int st33zp24_spi_remove(struct udevice *dev)
 652 {
 653         st33zp24_spi_release_locality(dev);
 654
 655         return 0;
 656 }
 657
 658 static const struct udevice_id st33zp24_spi_ids[] = {
 659         { .compatible = "st,st33zp24-spi" },
 660         { }
 661 };
 662
 663 U_BOOT_DRIVER(st33zp24_spi_spi) = {
 664         .name   = "st33zp24-spi",
 665         .id     = UCLASS_TPM,
 666         .of_match = of_match_ptr(st33zp24_spi_ids),
 667         .probe  = st33zp24_spi_probe,
 668         .remove = st33zp24_spi_remove,
 669         .ops = &st33zp24_spi_tpm_ops,
 670         .priv_auto_alloc_size = sizeof(struct tpm_chip),
 671         .platdata_auto_alloc_size = sizeof(struct st33zp24_spi_phy),
 672 };