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/init.h>
  25 #include <linux/i2c.h>
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/wait.h>
  29 #include "tpm.h"
  30
  31 /* max. buffer size supported by our TPM */
  32 #define TPM_BUFSIZE 1260
  33
  34 /* max. number of iterations after I2C NAK */
  35 #define MAX_COUNT 3
  36
  37 #define SLEEP_DURATION_LOW 55
  38 #define SLEEP_DURATION_HI 65
  39
  40 /* max. number of iterations after I2C NAK for 'long' commands
  41  * we need this especially for sending TPM_READY, since the cleanup after the
  42  * transtion to the ready state may take some time, but it is unpredictable
  43  * how long it will take.
  44  */
  45 #define MAX_COUNT_LONG 50
  46
  47 #define SLEEP_DURATION_LONG_LOW 200
  48 #define SLEEP_DURATION_LONG_HI 220
  49
  50 /* After sending TPM_READY to 'reset' the TPM we have to sleep even longer */
  51 #define SLEEP_DURATION_RESET_LOW 2400
  52 #define SLEEP_DURATION_RESET_HI 2600
  53
  54 /* we want to use usleep_range instead of msleep for the 5ms TPM_TIMEOUT */
  55 #define TPM_TIMEOUT_US_LOW (TPM_TIMEOUT * 1000)
  56 #define TPM_TIMEOUT_US_HI  (TPM_TIMEOUT_US_LOW + 2000)
  57
  58 /* expected value for DIDVID register */
  59 #define TPM_TIS_I2C_DID_VID_9635 0xd1150b00L
  60 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
  61
  62 enum i2c_chip_type {
  63         SLB9635,
  64         SLB9645,
  65         UNKNOWN,
  66 };
  67
  68 /* Structure to store I2C TPM specific stuff */
  69 struct tpm_inf_dev {
  70         struct i2c_client *client;
  71         u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */
  72         struct tpm_chip *chip;
  73         enum i2c_chip_type chip_type;
  74 };
  75
  76 static struct tpm_inf_dev tpm_dev;
  77 static struct i2c_driver tpm_tis_i2c_driver;
  78
  79 /*
  80  * iic_tpm_read() - read from TPM register
  81  * @addr: register address to read from
  82  * @buffer: provided by caller
  83  * @len: number of bytes to read
  84  *
  85  * Read len bytes from TPM register and put them into
  86  * buffer (little-endian format, i.e. first byte is put into buffer[0]).
  87  *
  88  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
  89  * values have to be swapped.
  90  *
  91  * NOTE: We can't unfortunately use the combined read/write functions
  92  * provided by the i2c core as the TPM currently does not support the
  93  * repeated start condition and due to it's special requirements.
  94  * The i2c_smbus* functions do not work for this chip.
  95  *
  96  * Return -EIO on error, 0 on success.
  97  */
  98 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
  99 {
 100
 101         struct i2c_msg msg1 = {
 102                 .addr = tpm_dev.client->addr,
 103                 .len = 1,
 104                 .buf = &addr
 105         };
 106         struct i2c_msg msg2 = {
 107                 .addr = tpm_dev.client->addr,
 108                 .flags = I2C_M_RD,
 109                 .len = len,
 110                 .buf = buffer
 111         };
 112         struct i2c_msg msgs[] = {msg1, msg2};
 113
 114         int rc = 0;
 115         int count;
 116
 117         /* Lock the adapter for the duration of the whole sequence. */
 118         if (!tpm_dev.client->adapter->algo->master_xfer)
 119                 return -EOPNOTSUPP;
 120         i2c_lock_adapter(tpm_dev.client->adapter);
 121
 122         if (tpm_dev.chip_type == SLB9645) {
 123                 /* use a combined read for newer chips
 124                  * unfortunately the smbus functions are not suitable due to
 125                  * the 32 byte limit of the smbus.
 126                  * retries should usually not be needed, but are kept just to
 127                  * be on the safe side.
 128                  */
 129                 for (count = 0; count < MAX_COUNT; count++) {
 130                         rc = __i2c_transfer(tpm_dev.client->adapter, msgs, 2);
 131                         if (rc > 0)
 132                                 break;  /* break here to skip sleep */
 133                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 134                 }
 135         } else {
 136                 /* slb9635 protocol should work in all cases */
 137                 for (count = 0; count < MAX_COUNT; count++) {
 138                         rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
 139                         if (rc > 0)
 140                                 break;  /* break here to skip sleep */
 141
 142                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 143                 }
 144
 145                 if (rc <= 0)
 146                         goto out;
 147
 148                 /* After the TPM has successfully received the register address
 149                  * it needs some time, thus we're sleeping here again, before
 150                  * retrieving the data
 151                  */
 152                 for (count = 0; count < MAX_COUNT; count++) {
 153                         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 154                         rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
 155                         if (rc > 0)
 156                                 break;
 157                 }
 158         }
 159
 160 out:
 161         i2c_unlock_adapter(tpm_dev.client->adapter);
 162         /* take care of 'guard time' */
 163         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 164
 165         /* __i2c_transfer returns the number of successfully transferred
 166          * messages.
 167          * So rc should be greater than 0 here otherwise we have an error.
 168          */
 169         if (rc <= 0)
 170                 return -EIO;
 171
 172         return 0;
 173 }
 174
 175 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
 176                                  unsigned int sleep_low,
 177                                  unsigned int sleep_hi, u8 max_count)
 178 {
 179         int rc = -EIO;
 180         int count;
 181
 182         struct i2c_msg msg1 = {
 183                 .addr = tpm_dev.client->addr,
 184                 .len = len + 1,
 185                 .buf = tpm_dev.buf
 186         };
 187
 188         if (len > TPM_BUFSIZE)
 189                 return -EINVAL;
 190
 191         if (!tpm_dev.client->adapter->algo->master_xfer)
 192                 return -EOPNOTSUPP;
 193         i2c_lock_adapter(tpm_dev.client->adapter);
 194
 195         /* prepend the 'register address' to the buffer */
 196         tpm_dev.buf[0] = addr;
 197         memcpy(&(tpm_dev.buf[1]), buffer, len);
 198
 199         /*
 200          * NOTE: We have to use these special mechanisms here and unfortunately
 201          * cannot rely on the standard behavior of i2c_transfer.
 202          * Even for newer chips the smbus functions are not
 203          * suitable due to the 32 byte limit of the smbus.
 204          */
 205         for (count = 0; count < max_count; count++) {
 206                 rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
 207                 if (rc > 0)
 208                         break;
 209                 usleep_range(sleep_low, sleep_hi);
 210         }
 211
 212         i2c_unlock_adapter(tpm_dev.client->adapter);
 213         /* take care of 'guard time' */
 214         usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
 215
 216         /* __i2c_transfer returns the number of successfully transferred
 217          * messages.
 218          * So rc should be greater than 0 here otherwise we have an error.
 219          */
 220         if (rc <= 0)
 221                 return -EIO;
 222
 223         return 0;
 224 }
 225
 226 /*
 227  * iic_tpm_write() - write to TPM register
 228  * @addr: register address to write to
 229  * @buffer: containing data to be written
 230  * @len: number of bytes to write
 231  *
 232  * Write len bytes from provided buffer to TPM register (little
 233  * endian format, i.e. buffer[0] is written as first byte).
 234  *
 235  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 236  * values have to be swapped.
 237  *
 238  * NOTE: use this function instead of the iic_tpm_write_generic function.
 239  *
 240  * Return -EIO on error, 0 on success
 241  */
 242 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
 243 {
 244         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LOW,
 245                                      SLEEP_DURATION_HI, MAX_COUNT);
 246 }
 247
 248 /*
 249  * This function is needed especially for the cleanup situation after
 250  * sending TPM_READY
 251  * */
 252 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
 253 {
 254         return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG_LOW,
 255                                      SLEEP_DURATION_LONG_HI, MAX_COUNT_LONG);
 256 }
 257
 258 enum tis_access {
 259         TPM_ACCESS_VALID = 0x80,
 260         TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
 261         TPM_ACCESS_REQUEST_PENDING = 0x04,
 262         TPM_ACCESS_REQUEST_USE = 0x02,
 263 };
 264
 265 enum tis_status {
 266         TPM_STS_VALID = 0x80,
 267         TPM_STS_COMMAND_READY = 0x40,
 268         TPM_STS_GO = 0x20,
 269         TPM_STS_DATA_AVAIL = 0x10,
 270         TPM_STS_DATA_EXPECT = 0x08,
 271 };
 272
 273 enum tis_defaults {
 274         TIS_SHORT_TIMEOUT = 750,        /* ms */
 275         TIS_LONG_TIMEOUT = 2000,        /* 2 sec */
 276 };
 277
 278 #define TPM_ACCESS(l)                   (0x0000 | ((l) << 4))
 279 #define TPM_STS(l)                      (0x0001 | ((l) << 4))
 280 #define TPM_DATA_FIFO(l)                (0x0005 | ((l) << 4))
 281 #define TPM_DID_VID(l)                  (0x0006 | ((l) << 4))
 282
 283 static int check_locality(struct tpm_chip *chip, int loc)
 284 {
 285         u8 buf;
 286         int rc;
 287
 288         rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
 289         if (rc < 0)
 290                 return rc;
 291
 292         if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
 293             (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
 294                 chip->vendor.locality = loc;
 295                 return loc;
 296         }
 297
 298         return -EIO;
 299 }
 300
 301 /* implementation similar to tpm_tis */
 302 static void release_locality(struct tpm_chip *chip, int loc, int force)
 303 {
 304         u8 buf;
 305         if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
 306                 return;
 307
 308         if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
 309             (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) {
 310                 buf = TPM_ACCESS_ACTIVE_LOCALITY;
 311                 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 312         }
 313 }
 314
 315 static int request_locality(struct tpm_chip *chip, int loc)
 316 {
 317         unsigned long stop;
 318         u8 buf = TPM_ACCESS_REQUEST_USE;
 319
 320         if (check_locality(chip, loc) >= 0)
 321                 return loc;
 322
 323         iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
 324
 325         /* wait for burstcount */
 326         stop = jiffies + chip->vendor.timeout_a;
 327         do {
 328                 if (check_locality(chip, loc) >= 0)
 329                         return loc;
 330                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 331         } while (time_before(jiffies, stop));
 332
 333         return -ETIME;
 334 }
 335
 336 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
 337 {
 338         /* NOTE: since I2C read may fail, return 0 in this case --> time-out */
 339         u8 buf = 0xFF;
 340         u8 i = 0;
 341
 342         do {
 343                 if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
 344                         return 0;
 345
 346                 i++;
 347         /* if locallity is set STS should not be 0xFF */
 348         } while ((buf == 0xFF) && i < 10);
 349
 350         return buf;
 351 }
 352
 353 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
 354 {
 355         /* this causes the current command to be aborted */
 356         u8 buf = TPM_STS_COMMAND_READY;
 357         iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
 358 }
 359
 360 static ssize_t get_burstcount(struct tpm_chip *chip)
 361 {
 362         unsigned long stop;
 363         ssize_t burstcnt;
 364         u8 buf[3];
 365
 366         /* wait for burstcount */
 367         /* which timeout value, spec has 2 answers (c & d) */
 368         stop = jiffies + chip->vendor.timeout_d;
 369         do {
 370                 /* Note: STS is little endian */
 371                 if (iic_tpm_read(TPM_STS(chip->vendor.locality)+1, buf, 3) < 0)
 372                         burstcnt = 0;
 373                 else
 374                         burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
 375
 376                 if (burstcnt)
 377                         return burstcnt;
 378
 379                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 380         } while (time_before(jiffies, stop));
 381         return -EBUSY;
 382 }
 383
 384 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 385                          int *status)
 386 {
 387         unsigned long stop;
 388
 389         /* check current status */
 390         *status = tpm_tis_i2c_status(chip);
 391         if ((*status != 0xFF) && (*status & mask) == mask)
 392                 return 0;
 393
 394         stop = jiffies + timeout;
 395         do {
 396                 /* since we just checked the status, give the TPM some time */
 397                 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
 398                 *status = tpm_tis_i2c_status(chip);
 399                 if ((*status & mask) == mask)
 400                         return 0;
 401
 402         } while (time_before(jiffies, stop));
 403
 404         return -ETIME;
 405 }
 406
 407 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 408 {
 409         size_t size = 0;
 410         ssize_t burstcnt;
 411         u8 retries = 0;
 412         int rc;
 413
 414         while (size < count) {
 415                 burstcnt = get_burstcount(chip);
 416
 417                 /* burstcnt < 0 = TPM is busy */
 418                 if (burstcnt < 0)
 419                         return burstcnt;
 420
 421                 /* limit received data to max. left */
 422                 if (burstcnt > (count - size))
 423                         burstcnt = count - size;
 424
 425                 rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
 426                                   &(buf[size]), burstcnt);
 427                 if (rc == 0)
 428                         size += burstcnt;
 429                 else if (rc < 0)
 430                         retries++;
 431
 432                 /* avoid endless loop in case of broken HW */
 433                 if (retries > MAX_COUNT_LONG)
 434                         return -EIO;
 435         }
 436         return size;
 437 }
 438
 439 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 440 {
 441         int size = 0;
 442         int expected, status;
 443
 444         if (count < TPM_HEADER_SIZE) {
 445                 size = -EIO;
 446                 goto out;
 447         }
 448
 449         /* read first 10 bytes, including tag, paramsize, and result */
 450         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 451         if (size < TPM_HEADER_SIZE) {
 452                 dev_err(chip->dev, "Unable to read header\n");
 453                 goto out;
 454         }
 455
 456         expected = be32_to_cpu(*(__be32 *)(buf + 2));
 457         if ((size_t) expected > count) {
 458                 size = -EIO;
 459                 goto out;
 460         }
 461
 462         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 463                           expected - TPM_HEADER_SIZE);
 464         if (size < expected) {
 465                 dev_err(chip->dev, "Unable to read remainder of result\n");
 466                 size = -ETIME;
 467                 goto out;
 468         }
 469
 470         wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 471         if (status & TPM_STS_DATA_AVAIL) {      /* retry? */
 472                 dev_err(chip->dev, "Error left over data\n");
 473                 size = -EIO;
 474                 goto out;
 475         }
 476
 477 out:
 478         tpm_tis_i2c_ready(chip);
 479         /* The TPM needs some time to clean up here,
 480          * so we sleep rather than keeping the bus busy
 481          */
 482         usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
 483         release_locality(chip, chip->vendor.locality, 0);
 484         return size;
 485 }
 486
 487 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
 488 {
 489         int rc, status;
 490         ssize_t burstcnt;
 491         size_t count = 0;
 492         u8 retries = 0;
 493         u8 sts = TPM_STS_GO;
 494
 495         if (len > TPM_BUFSIZE)
 496                 return -E2BIG;  /* command is too long for our tpm, sorry */
 497
 498         if (request_locality(chip, 0) < 0)
 499                 return -EBUSY;
 500
 501         status = tpm_tis_i2c_status(chip);
 502         if ((status & TPM_STS_COMMAND_READY) == 0) {
 503                 tpm_tis_i2c_ready(chip);
 504                 if (wait_for_stat
 505                     (chip, TPM_STS_COMMAND_READY,
 506                      chip->vendor.timeout_b, &status) < 0) {
 507                         rc = -ETIME;
 508                         goto out_err;
 509                 }
 510         }
 511
 512         while (count < len - 1) {
 513                 burstcnt = get_burstcount(chip);
 514
 515                 /* burstcnt < 0 = TPM is busy */
 516                 if (burstcnt < 0)
 517                         return burstcnt;
 518
 519                 if (burstcnt > (len - 1 - count))
 520                         burstcnt = len - 1 - count;
 521
 522                 rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
 523                                    &(buf[count]), burstcnt);
 524                 if (rc == 0)
 525                         count += burstcnt;
 526                 else if (rc < 0)
 527                         retries++;
 528
 529                 /* avoid endless loop in case of broken HW */
 530                 if (retries > MAX_COUNT_LONG) {
 531                         rc = -EIO;
 532                         goto out_err;
 533                 }
 534
 535                 wait_for_stat(chip, TPM_STS_VALID,
 536                               chip->vendor.timeout_c, &status);
 537
 538                 if ((status & TPM_STS_DATA_EXPECT) == 0) {
 539                         rc = -EIO;
 540                         goto out_err;
 541                 }
 542         }
 543
 544         /* write last byte */
 545         iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
 546         wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 547         if ((status & TPM_STS_DATA_EXPECT) != 0) {
 548                 rc = -EIO;
 549                 goto out_err;
 550         }
 551
 552         /* go and do it */
 553         iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
 554
 555         return len;
 556 out_err:
 557         tpm_tis_i2c_ready(chip);
 558         /* The TPM needs some time to clean up here,
 559          * so we sleep rather than keeping the bus busy
 560          */
 561         usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
 562         release_locality(chip, chip->vendor.locality, 0);
 563         return rc;
 564 }
 565
 566 static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status)
 567 {
 568         return (status == TPM_STS_COMMAND_READY);
 569 }
 570
 571 static const struct file_operations tis_ops = {
 572         .owner = THIS_MODULE,
 573         .llseek = no_llseek,
 574         .open = tpm_open,
 575         .read = tpm_read,
 576         .write = tpm_write,
 577         .release = tpm_release,
 578 };
 579
 580 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
 581 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
 582 static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL);
 583 static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL);
 584 static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL);
 585 static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated, NULL);
 586 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps_1_2, NULL);
 587 static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
 588 static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
 589 static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
 590
 591 static struct attribute *tis_attrs[] = {
 592         &dev_attr_pubek.attr,
 593         &dev_attr_pcrs.attr,
 594         &dev_attr_enabled.attr,
 595         &dev_attr_active.attr,
 596         &dev_attr_owned.attr,
 597         &dev_attr_temp_deactivated.attr,
 598         &dev_attr_caps.attr,
 599         &dev_attr_cancel.attr,
 600         &dev_attr_durations.attr,
 601         &dev_attr_timeouts.attr,
 602         NULL,
 603 };
 604
 605 static struct attribute_group tis_attr_grp = {
 606         .attrs = tis_attrs
 607 };
 608
 609 static struct tpm_vendor_specific tpm_tis_i2c = {
 610         .status = tpm_tis_i2c_status,
 611         .recv = tpm_tis_i2c_recv,
 612         .send = tpm_tis_i2c_send,
 613         .cancel = tpm_tis_i2c_ready,
 614         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 615         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 616         .req_canceled = tpm_tis_i2c_req_canceled,
 617         .attr_group = &tis_attr_grp,
 618         .miscdev.fops = &tis_ops,
 619 };
 620
 621 static int tpm_tis_i2c_init(struct device *dev)
 622 {
 623         u32 vendor;
 624         int rc = 0;
 625         struct tpm_chip *chip;
 626
 627         chip = tpm_register_hardware(dev, &tpm_tis_i2c);
 628         if (!chip) {
 629                 dev_err(dev, "could not register hardware\n");
 630                 rc = -ENODEV;
 631                 goto out_err;
 632         }
 633
 634         /* Disable interrupts */
 635         chip->vendor.irq = 0;
 636
 637         /* Default timeouts */
 638         chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 639         chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
 640         chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 641         chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 642
 643         if (request_locality(chip, 0) != 0) {
 644                 dev_err(dev, "could not request locality\n");
 645                 rc = -ENODEV;
 646                 goto out_vendor;
 647         }
 648
 649         /* read four bytes from DID_VID register */
 650         if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
 651                 dev_err(dev, "could not read vendor id\n");
 652                 rc = -EIO;
 653                 goto out_release;
 654         }
 655
 656         if (vendor == TPM_TIS_I2C_DID_VID_9645) {
 657                 tpm_dev.chip_type = SLB9645;
 658         } else if (vendor == TPM_TIS_I2C_DID_VID_9635) {
 659                 tpm_dev.chip_type = SLB9635;
 660         } else {
 661                 dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
 662                 rc = -ENODEV;
 663                 goto out_release;
 664         }
 665
 666         dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
 667
 668         INIT_LIST_HEAD(&chip->vendor.list);
 669         tpm_dev.chip = chip;
 670
 671         tpm_get_timeouts(chip);
 672         tpm_do_selftest(chip);
 673
 674         return 0;
 675
 676 out_release:
 677         release_locality(chip, chip->vendor.locality, 1);
 678
 679 out_vendor:
 680         /* close file handles */
 681         tpm_dev_vendor_release(chip);
 682
 683         /* remove hardware */
 684         tpm_remove_hardware(chip->dev);
 685
 686         /* reset these pointers, otherwise we oops */
 687         chip->dev->release = NULL;
 688         chip->release = NULL;
 689         tpm_dev.client = NULL;
 690         dev_set_drvdata(chip->dev, chip);
 691 out_err:
 692         return rc;
 693 }
 694
 695 static const struct i2c_device_id tpm_tis_i2c_table[] = {
 696         {"tpm_i2c_infineon", 0},
 697         {"slb9635tt", 0},
 698         {"slb9645tt", 1},
 699         {},
 700 };
 701
 702 MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
 703
 704 #ifdef CONFIG_OF
 705 static const struct of_device_id tpm_tis_i2c_of_match[] = {
 706         {
 707                 .name = "tpm_i2c_infineon",
 708                 .type = "tpm",
 709                 .compatible = "infineon,tpm_i2c_infineon",
 710                 .data = (void *)0
 711         },
 712         {
 713                 .name = "slb9635tt",
 714                 .type = "tpm",
 715                 .compatible = "infineon,slb9635tt",
 716                 .data = (void *)0
 717         },
 718         {
 719                 .name = "slb9645tt",
 720                 .type = "tpm",
 721                 .compatible = "infineon,slb9645tt",
 722                 .data = (void *)1
 723         },
 724         {},
 725 };
 726 MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
 727 #endif
 728
 729 static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
 730
 731 static int tpm_tis_i2c_probe(struct i2c_client *client,
 732                              const struct i2c_device_id *id)
 733 {
 734         int rc;
 735         struct device *dev = &(client->dev);
 736
 737         if (tpm_dev.client != NULL) {
 738                 dev_err(dev, "This driver only supports one client at a time\n");
 739                 return -EBUSY;  /* We only support one client */
 740         }
 741
 742         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 743                 dev_err(dev, "no algorithms associated to the i2c bus\n");
 744                 return -ENODEV;
 745         }
 746
 747         client->driver = &tpm_tis_i2c_driver;
 748         tpm_dev.client = client;
 749         rc = tpm_tis_i2c_init(&client->dev);
 750         if (rc != 0) {
 751                 client->driver = NULL;
 752                 tpm_dev.client = NULL;
 753                 rc = -ENODEV;
 754         }
 755         return rc;
 756 }
 757
 758 static int tpm_tis_i2c_remove(struct i2c_client *client)
 759 {
 760         struct tpm_chip *chip = tpm_dev.chip;
 761         release_locality(chip, chip->vendor.locality, 1);
 762
 763         /* close file handles */
 764         tpm_dev_vendor_release(chip);
 765
 766         /* remove hardware */
 767         tpm_remove_hardware(chip->dev);
 768
 769         /* reset these pointers, otherwise we oops */
 770         chip->dev->release = NULL;
 771         chip->release = NULL;
 772         tpm_dev.client = NULL;
 773         dev_set_drvdata(chip->dev, chip);
 774
 775         return 0;
 776 }
 777
 778 static struct i2c_driver tpm_tis_i2c_driver = {
 779         .id_table = tpm_tis_i2c_table,
 780         .probe = tpm_tis_i2c_probe,
 781         .remove = tpm_tis_i2c_remove,
 782         .driver = {
 783                    .name = "tpm_i2c_infineon",
 784                    .owner = THIS_MODULE,
 785                    .pm = &tpm_tis_i2c_ops,
 786                    .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
 787                    },
 788 };
 789
 790 module_i2c_driver(tpm_tis_i2c_driver);
 791 MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
 792 MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
 793 MODULE_VERSION("2.2.0");
 794 MODULE_LICENSE("GPL");