drivers/char/tpm/tpm_i2c_infineon.c

   1 /*
   2  * Copyright (C) 2012,2013 Infineon Technologies
   3  *
   4  * Authors:
   5  * Peter Huewe <peter.huewe@infineon.com>
   6  *
   7  * Device driver for TCG/TCPA TPM (trusted platform module).
   8  * Specifications at www.trustedcomputinggroup.org
   9  *
  10  * This device driver implements the TPM interface as defined in
  11  * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
  12  * Infineon I2C Protocol Stack Specification v0.20.
  13  *
  14  * It is based on the original tpm_tis device driver from Leendert van
  15  * Dorn and Kyleen Hall.
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License as
  19  * published by the Free Software Foundation, version 2 of the
  20  * License.
  21  *
  22  *
  23  */
  24 #include <linux/i2c.h>
  25 #include <linux/module.h>
  26 #include <linux/wait.h>
  27 #include "tpm.h"
  28
  29 /* max. buffer size supported by our TPM */
  30 #define TPM_BUFSIZE 1260
  31
  32 /* max. number of iterations after I2C NAK */
  33 #define MAX_COUNT 3
  34
  35 #define SLEEP_DURATION_LOW 55
  36 #define SLEEP_DURATION_HI 65
  37
  38 /* max. number of iterations after I2C NAK for 'long' commands
  39  * we need this especially for sending TPM_READY, since the cleanup after the
  40  * transtion to the ready state may take some time, but it is unpredictable
  41  * how long it will take.
  42  */
  43 #define MAX_COUNT_LONG 50
  44
  45 #define SLEEP_DURATION_LONG_LOW 200
  46 #define SLEEP_DURATION_LONG_HI 220
  47
  48 /* After sending TPM_READY to 'reset' the TPM we have to sleep even longer */
  49 #define SLEEP_DURATION_RESET_LOW 2400
  50 #define SLEEP_DURATION_RESET_HI 2600
  51
  52 /* we want to use usleep_range instead of msleep for the 5ms TPM_TIMEOUT */
  53 #define TPM_TIMEOUT_US_LOW (TPM_TIMEOUT * 1000)
  54 #define TPM_TIMEOUT_US_HI  (TPM_TIMEOUT_US_LOW + 2000)
  55
  56 /* expected value for DIDVID register */
  57 #define TPM_TIS_I2C_DID_VID_9635 0xd1150b00L
  58 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
  59
  60 enum i2c_chip_type {
  61         SLB9635,
  62         SLB9645,
  63         UNKNOWN,
  64 };
  65
  66 /* Structure to store I2C TPM specific stuff */
  67 struct tpm_inf_dev {
  68         struct i2c_client *client;
  69         u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */
  70         struct tpm_chip *chip;
  71         enum i2c_chip_type chip_type;
  72 };
  73
  74 static struct tpm_inf_dev tpm_dev;
  75
  76 /*
  77  * iic_tpm_read() - read from TPM register
  78  * @addr: register address to read from
  79  * @buffer: provided by caller
  80  * @len: number of bytes to read
  81  *
  82  * Read len bytes from TPM register and put them into
  83  * buffer (little-endian format, i.e. first byte is put into buffer[0]).
  84  *
  85  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
  86  * values have to be swapped.
  87  *
  88  * NOTE: We can't unfortunately use the combined read/write functions
  89  * provided by the i2c core as the TPM currently does not support the
  90  * repeated start condition and due to it's special requirements.
  91  * The i2c_smbus* functions do not work for this chip.
  92  *
  93  * Return -EIO on error, 0 on success.
  94  */
  95 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
  96 {
  97
  98         struct i2c_msg msg1 = {
  99                 .addr = tpm_dev.client->addr,
 100                 .len = 1,
 101                 .buf = &addr
 102         };
 103         struct i2c_msg msg2 = {
 104                 .addr = tpm_dev.client->addr,
 105                 .flags = I2C_M_RD,
 106                 .len = len,
 107                 .buf = buffer
 108         };
 109         struct i2c_msg msgs[] = {msg1, msg2};
 110
 111         int rc = 0;
 112         int count;
 113
 114         /* Lock the adapter for the duration of the whole sequence. */
 115         if (!tpm_dev.client->adapter->algo->master_xfer)
 116                 return -EOPNOTSUPP;
 117         i2c_lock_adapter(tpm_dev.client->adapter);
 118
 119         if (tpm_dev.chip_type == SLB9645) {
 120                 /* use a combined read for newer chips
 121                  * unfortunately the smbus functions are not suitable due to
 122                  * the 32 byte limit of the smbus.
 123                  * retries should usually not be needed, but are kept just to
 124                  * be on the safe side.
 125                  */
 126                 for (count = 0; count < MAX_COUNT; count++) {
 127                         rc = __i2c_transfer(tpm_dev.client->adapter, msgs, 2);
 128                         if (rc > 0)
 129                                 break;  /* break here to skip sleep */
 130                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 131                 }
 132         } else {
 133                 /* slb9635 protocol should work in all cases */
 134                 for (count = 0; count < MAX_COUNT; count++) {
 135                         rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
 136                         if (rc > 0)
 137                                 break;  /* break here to skip sleep */
 138
 139                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 140                 }
 141
 142                 if (rc <= 0)
 143                         goto out;
 144
 145                 /* After the TPM has successfully received the register address
 146                  * it needs some time, thus we're sleeping here again, before
 147                  * retrieving the data
 148                  */
 149                 for (count = 0; count < MAX_COUNT; count++) {
 150                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 151                         rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
 152                         if (rc > 0)
 153                                 break;
 154                 }
 155         }
 156
 157 out:
 158         i2c_unlock_adapter(tpm_dev.client->adapter);
 159         /* take care of 'guard time' */
 160         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 161
 162         /* __i2c_transfer returns the number of successfully transferred
 163          * messages.
 164          * So rc should be greater than 0 here otherwise we have an error.
 165          */
 166         if (rc <= 0)
 167                 return -EIO;
 168
 169         return 0;
 170 }
 171
 172 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
 173                                  unsigned int sleep_low,
 174                                  unsigned int sleep_hi, u8 max_count)
 175 {
 176         int rc = -EIO;
 177         int count;
 178
 179         struct i2c_msg msg1 = {
 180                 .addr = tpm_dev.client->addr,
 181                 .len = len + 1,
 182                 .buf = tpm_dev.buf
 183         };
 184
 185         if (len > TPM_BUFSIZE)
 186                 return -EINVAL;
 187
 188         if (!tpm_dev.client->adapter->algo->master_xfer)
 189                 return -EOPNOTSUPP;
 190         i2c_lock_adapter(tpm_dev.client->adapter);
 191
 192         /* prepend the 'register address' to the buffer */
 193         tpm_dev.buf[0] = addr;
 194         memcpy(&(tpm_dev.buf[1]), buffer, len);
 195
 196         /*
 197          * NOTE: We have to use these special mechanisms here and unfortunately
 198          * cannot rely on the standard behavior of i2c_transfer.
 199          * Even for newer chips the smbus functions are not
 200          * suitable due to the 32 byte limit of the smbus.
 201          */
 202         for (count = 0; count < max_count; count++) {
 203                 rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
 204                 if (rc > 0)
 205                         break;
 206                 usleep_range(sleep_low, sleep_hi);
 207         }
 208
 209         i2c_unlock_adapter(tpm_dev.client->adapter);
 210         /* take care of 'guard time' */
 211         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 212
 213         /* __i2c_transfer returns the number of successfully transferred
 214          * messages.
 215          * So rc should be greater than 0 here otherwise we have an error.
 216          */
 217         if (rc <= 0)
 218                 return -EIO;
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * iic_tpm_write() - write to TPM register
 225  * @addr: register address to write to
 226  * @buffer: containing data to be written
 227  * @len: number of bytes to write
 228  *
 229  * Write len bytes from provided buffer to TPM register (little
 230  * endian format, i.e. buffer[0] is written as first byte).
 231  *
 232  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 233  * values have to be swapped.
 234  *
 235  * NOTE: use this function instead of the iic_tpm_write_generic function.
 236  *
 237  * Return -EIO on error, 0 on success
 238  */
 239 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
 240 {
 241         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LOW,
 242                                      SLEEP_DURATION_HI, MAX_COUNT);
 243 }
 244
 245 /*
 246  * This function is needed especially for the cleanup situation after
 247  * sending TPM_READY
 248  * */
 249 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
 250 {
 251         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG_LOW,
 252                                      SLEEP_DURATION_LONG_HI, MAX_COUNT_LONG);
 253 }
 254
 255 enum tis_access {
 256         TPM_ACCESS_VALID = 0x80,
 257         TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
 258         TPM_ACCESS_REQUEST_PENDING = 0x04,
 259         TPM_ACCESS_REQUEST_USE = 0x02,
 260 };
 261
 262 enum tis_status {
 263         TPM_STS_VALID = 0x80,
 264         TPM_STS_COMMAND_READY = 0x40,
 265         TPM_STS_GO = 0x20,
 266         TPM_STS_DATA_AVAIL = 0x10,
 267         TPM_STS_DATA_EXPECT = 0x08,
 268 };
 269
 270 enum tis_defaults {
 271         TIS_SHORT_TIMEOUT = 750,        /* ms */
 272         TIS_LONG_TIMEOUT = 2000,        /* 2 sec */
 273 };
 274
 275 #define TPM_ACCESS(l)                   (0x0000 | ((l) << 4))
 276 #define TPM_STS(l)                      (0x0001 | ((l) << 4))
 277 #define TPM_DATA_FIFO(l)                (0x0005 | ((l) << 4))
 278 #define TPM_DID_VID(l)                  (0x0006 | ((l) << 4))
 279
 280 static int check_locality(struct tpm_chip *chip, int loc)
 281 {
 282         u8 buf;
 283         int rc;
 284
 285         rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
 286         if (rc < 0)
 287                 return rc;
 288
 289         if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
 290             (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
 291                 chip->vendor.locality = loc;
 292                 return loc;
 293         }
 294
 295         return -EIO;
 296 }
 297
 298 /* implementation similar to tpm_tis */
 299 static void release_locality(struct tpm_chip *chip, int loc, int force)
 300 {
 301         u8 buf;
 302         if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
 303                 return;
 304
 305         if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
 306             (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) {
 307                 buf = TPM_ACCESS_ACTIVE_LOCALITY;
 308                 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 309         }
 310 }
 311
 312 static int request_locality(struct tpm_chip *chip, int loc)
 313 {
 314         unsigned long stop;
 315         u8 buf = TPM_ACCESS_REQUEST_USE;
 316
 317         if (check_locality(chip, loc) >= 0)
 318                 return loc;
 319
 320         iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 321
 322         /* wait for burstcount */
 323         stop = jiffies + chip->vendor.timeout_a;
 324         do {
 325                 if (check_locality(chip, loc) >= 0)
 326                         return loc;
 327                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 328         } while (time_before(jiffies, stop));
 329
 330         return -ETIME;
 331 }
 332
 333 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
 334 {
 335         /* NOTE: since I2C read may fail, return 0 in this case --> time-out */
 336         u8 buf = 0xFF;
 337         u8 i = 0;
 338
 339         do {
 340                 if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
 341                         return 0;
 342
 343                 i++;
 344         /* if locallity is set STS should not be 0xFF */
 345         } while ((buf == 0xFF) && i < 10);
 346
 347         return buf;
 348 }
 349
 350 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
 351 {
 352         /* this causes the current command to be aborted */
 353         u8 buf = TPM_STS_COMMAND_READY;
 354         iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
 355 }
 356
 357 static ssize_t get_burstcount(struct tpm_chip *chip)
 358 {
 359         unsigned long stop;
 360         ssize_t burstcnt;
 361         u8 buf[3];
 362
 363         /* wait for burstcount */
 364         /* which timeout value, spec has 2 answers (c & d) */
 365         stop = jiffies + chip->vendor.timeout_d;
 366         do {
 367                 /* Note: STS is little endian */
 368                 if (iic_tpm_read(TPM_STS(chip->vendor.locality)+1, buf, 3) < 0)
 369                         burstcnt = 0;
 370                 else
 371                         burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
 372
 373                 if (burstcnt)
 374                         return burstcnt;
 375
 376                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 377         } while (time_before(jiffies, stop));
 378         return -EBUSY;
 379 }
 380
 381 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 382                          int *status)
 383 {
 384         unsigned long stop;
 385
 386         /* check current status */
 387         *status = tpm_tis_i2c_status(chip);
 388         if ((*status != 0xFF) && (*status & mask) == mask)
 389                 return 0;
 390
 391         stop = jiffies + timeout;
 392         do {
 393                 /* since we just checked the status, give the TPM some time */
 394                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 395                 *status = tpm_tis_i2c_status(chip);
 396                 if ((*status & mask) == mask)
 397                         return 0;
 398
 399         } while (time_before(jiffies, stop));
 400
 401         return -ETIME;
 402 }
 403
 404 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 405 {
 406         size_t size = 0;
 407         ssize_t burstcnt;
 408         u8 retries = 0;
 409         int rc;
 410
 411         while (size < count) {
 412                 burstcnt = get_burstcount(chip);
 413
 414                 /* burstcnt < 0 = TPM is busy */
 415                 if (burstcnt < 0)
 416                         return burstcnt;
 417
 418                 /* limit received data to max. left */
 419                 if (burstcnt > (count - size))
 420                         burstcnt = count - size;
 421
 422                 rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
 423                                   &(buf[size]), burstcnt);
 424                 if (rc == 0)
 425                         size += burstcnt;
 426                 else if (rc < 0)
 427                         retries++;
 428
 429                 /* avoid endless loop in case of broken HW */
 430                 if (retries > MAX_COUNT_LONG)
 431                         return -EIO;
 432         }
 433         return size;
 434 }
 435
 436 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 437 {
 438         int size = 0;
 439         int expected, status;
 440
 441         if (count < TPM_HEADER_SIZE) {
 442                 size = -EIO;
 443                 goto out;
 444         }
 445
 446         /* read first 10 bytes, including tag, paramsize, and result */
 447         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 448         if (size < TPM_HEADER_SIZE) {
 449                 dev_err(chip->pdev, "Unable to read header\n");
 450                 goto out;
 451         }
 452
 453         expected = be32_to_cpu(*(__be32 *)(buf + 2));
 454         if ((size_t) expected > count) {
 455                 size = -EIO;
 456                 goto out;
 457         }
 458
 459         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 460                           expected - TPM_HEADER_SIZE);
 461         if (size < expected) {
 462                 dev_err(chip->pdev, "Unable to read remainder of result\n");
 463                 size = -ETIME;
 464                 goto out;
 465         }
 466
 467         wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 468         if (status & TPM_STS_DATA_AVAIL) {      /* retry? */
 469                 dev_err(chip->pdev, "Error left over data\n");
 470                 size = -EIO;
 471                 goto out;
 472         }
 473
 474 out:
 475         tpm_tis_i2c_ready(chip);
 476         /* The TPM needs some time to clean up here,
 477          * so we sleep rather than keeping the bus busy
 478          */
 479         usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
 480         release_locality(chip, chip->vendor.locality, 0);
 481         return size;
 482 }
 483
 484 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
 485 {
 486         int rc, status;
 487         ssize_t burstcnt;
 488         size_t count = 0;
 489         u8 retries = 0;
 490         u8 sts = TPM_STS_GO;
 491
 492         if (len > TPM_BUFSIZE)
 493                 return -E2BIG;  /* command is too long for our tpm, sorry */
 494
 495         if (request_locality(chip, 0) < 0)
 496                 return -EBUSY;
 497
 498         status = tpm_tis_i2c_status(chip);
 499         if ((status & TPM_STS_COMMAND_READY) == 0) {
 500                 tpm_tis_i2c_ready(chip);
 501                 if (wait_for_stat
 502                     (chip, TPM_STS_COMMAND_READY,
 503                      chip->vendor.timeout_b, &status) < 0) {
 504                         rc = -ETIME;
 505                         goto out_err;
 506                 }
 507         }
 508
 509         while (count < len - 1) {
 510                 burstcnt = get_burstcount(chip);
 511
 512                 /* burstcnt < 0 = TPM is busy */
 513                 if (burstcnt < 0)
 514                         return burstcnt;
 515
 516                 if (burstcnt > (len - 1 - count))
 517                         burstcnt = len - 1 - count;
 518
 519                 rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
 520                                    &(buf[count]), burstcnt);
 521                 if (rc == 0)
 522                         count += burstcnt;
 523                 else if (rc < 0)
 524                         retries++;
 525
 526                 /* avoid endless loop in case of broken HW */
 527                 if (retries > MAX_COUNT_LONG) {
 528                         rc = -EIO;
 529                         goto out_err;
 530                 }
 531
 532                 wait_for_stat(chip, TPM_STS_VALID,
 533                               chip->vendor.timeout_c, &status);
 534
 535                 if ((status & TPM_STS_DATA_EXPECT) == 0) {
 536                         rc = -EIO;
 537                         goto out_err;
 538                 }
 539         }
 540
 541         /* write last byte */
 542         iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
 543         wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 544         if ((status & TPM_STS_DATA_EXPECT) != 0) {
 545                 rc = -EIO;
 546                 goto out_err;
 547         }
 548
 549         /* go and do it */
 550         iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
 551
 552         return len;
 553 out_err:
 554         tpm_tis_i2c_ready(chip);
 555         /* The TPM needs some time to clean up here,
 556          * so we sleep rather than keeping the bus busy
 557          */
 558         usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
 559         release_locality(chip, chip->vendor.locality, 0);
 560         return rc;
 561 }
 562
 563 static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status)
 564 {
 565         return (status == TPM_STS_COMMAND_READY);
 566 }
 567
 568 static const struct tpm_class_ops tpm_tis_i2c = {
 569         .status = tpm_tis_i2c_status,
 570         .recv = tpm_tis_i2c_recv,
 571         .send = tpm_tis_i2c_send,
 572         .cancel = tpm_tis_i2c_ready,
 573         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 574         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 575         .req_canceled = tpm_tis_i2c_req_canceled,
 576 };
 577
 578 static int tpm_tis_i2c_init(struct device *dev)
 579 {
 580         u32 vendor;
 581         int rc = 0;
 582         struct tpm_chip *chip;
 583
 584         chip = tpmm_chip_alloc(dev, &tpm_tis_i2c);
 585         if (IS_ERR(chip))
 586                 return PTR_ERR(chip);
 587
 588         /* Disable interrupts */
 589         chip->vendor.irq = 0;
 590
 591         /* Default timeouts */
 592         chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 593         chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
 594         chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 595         chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 596
 597         if (request_locality(chip, 0) != 0) {
 598                 dev_err(dev, "could not request locality\n");
 599                 rc = -ENODEV;
 600                 goto out_err;
 601         }
 602
 603         /* read four bytes from DID_VID register */
 604         if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
 605                 dev_err(dev, "could not read vendor id\n");
 606                 rc = -EIO;
 607                 goto out_release;
 608         }
 609
 610         if (vendor == TPM_TIS_I2C_DID_VID_9645) {
 611                 tpm_dev.chip_type = SLB9645;
 612         } else if (vendor == TPM_TIS_I2C_DID_VID_9635) {
 613                 tpm_dev.chip_type = SLB9635;
 614         } else {
 615                 dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
 616                 rc = -ENODEV;
 617                 goto out_release;
 618         }
 619
 620         dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
 621
 622         INIT_LIST_HEAD(&chip->vendor.list);
 623         tpm_dev.chip = chip;
 624
 625         tpm_get_timeouts(chip);
 626         tpm_do_selftest(chip);
 627
 628         return tpm_chip_register(chip);
 629 out_release:
 630         release_locality(chip, chip->vendor.locality, 1);
 631         tpm_dev.client = NULL;
 632 out_err:
 633         return rc;
 634 }
 635
 636 static const struct i2c_device_id tpm_tis_i2c_table[] = {
 637         {"tpm_i2c_infineon", 0},
 638         {"slb9635tt", 0},
 639         {"slb9645tt", 1},
 640         {},
 641 };
 642
 643 MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
 644
 645 #ifdef CONFIG_OF
 646 static const struct of_device_id tpm_tis_i2c_of_match[] = {
 647         {
 648                 .name = "tpm_i2c_infineon",
 649                 .type = "tpm",
 650                 .compatible = "infineon,tpm_i2c_infineon",
 651                 .data = (void *)0
 652         },
 653         {
 654                 .name = "slb9635tt",
 655                 .type = "tpm",
 656                 .compatible = "infineon,slb9635tt",
 657                 .data = (void *)0
 658         },
 659         {
 660                 .name = "slb9645tt",
 661                 .type = "tpm",
 662                 .compatible = "infineon,slb9645tt",
 663                 .data = (void *)1
 664         },
 665         {},
 666 };
 667 MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
 668 #endif
 669
 670 static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
 671
 672 static int tpm_tis_i2c_probe(struct i2c_client *client,
 673                              const struct i2c_device_id *id)
 674 {
 675         int rc;
 676         struct device *dev = &(client->dev);
 677
 678         if (tpm_dev.client != NULL) {
 679                 dev_err(dev, "This driver only supports one client at a time\n");
 680                 return -EBUSY;  /* We only support one client */
 681         }
 682
 683         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 684                 dev_err(dev, "no algorithms associated to the i2c bus\n");
 685                 return -ENODEV;
 686         }
 687
 688         tpm_dev.client = client;
 689         rc = tpm_tis_i2c_init(&client->dev);
 690         if (rc != 0) {
 691                 tpm_dev.client = NULL;
 692                 rc = -ENODEV;
 693         }
 694         return rc;
 695 }
 696
 697 static int tpm_tis_i2c_remove(struct i2c_client *client)
 698 {
 699         struct tpm_chip *chip = tpm_dev.chip;
 700
 701         tpm_chip_unregister(chip);
 702         release_locality(chip, chip->vendor.locality, 1);
 703         tpm_dev.client = NULL;
 704
 705         return 0;
 706 }
 707
 708 static struct i2c_driver tpm_tis_i2c_driver = {
 709         .id_table = tpm_tis_i2c_table,
 710         .probe = tpm_tis_i2c_probe,
 711         .remove = tpm_tis_i2c_remove,
 712         .driver = {
 713                    .name = "tpm_i2c_infineon",
 714                    .pm = &tpm_tis_i2c_ops,
 715                    .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
 716                    },
 717 };
 718
 719 module_i2c_driver(tpm_tis_i2c_driver);
 720 MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
 721 MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
 722 MODULE_VERSION("2.2.0");
 723 MODULE_LICENSE("GPL");