linux/drivers/char/tpm/tpm_i2c_infineon.c
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   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
  60enum i2c_chip_type {
  61        SLB9635,
  62        SLB9645,
  63        UNKNOWN,
  64};
  65
  66/* Structure to store I2C TPM specific stuff */
  67struct 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
  74static 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 */
  95static 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
 157out:
 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
 172static 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 */
 239static 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 * */
 249static 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
 255enum 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
 262enum 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
 270enum 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
 280static 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 */
 299static 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
 312static 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
 333static 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
 350static 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
 357static 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
 381static 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
 404static 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
 436static 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
 474out:
 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
 484static 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;
 553out_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
 563static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status)
 564{
 565        return (status == TPM_STS_COMMAND_READY);
 566}
 567
 568static 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
 578static 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);
 629out_release:
 630        release_locality(chip, chip->vendor.locality, 1);
 631        tpm_dev.client = NULL;
 632out_err:
 633        return rc;
 634}
 635
 636static const struct i2c_device_id tpm_tis_i2c_table[] = {
 637        {"tpm_i2c_infineon", 0},
 638        {"slb9635tt", 0},
 639        {"slb9645tt", 1},
 640        {},
 641};
 642
 643MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
 644
 645#ifdef CONFIG_OF
 646static 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};
 667MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
 668#endif
 669
 670static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
 671
 672static 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
 697static 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
 708static 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                   .owner = THIS_MODULE,
 715                   .pm = &tpm_tis_i2c_ops,
 716                   .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
 717                   },
 718};
 719
 720module_i2c_driver(tpm_tis_i2c_driver);
 721MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
 722MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
 723MODULE_VERSION("2.2.0");
 724MODULE_LICENSE("GPL");
 725