drivers/char/tpm/tpm_i2c_stm_st33.c

   1 /*
   2  * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
   3  * Copyright (C) 2009, 2010, 2014  STMicroelectronics
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * STMicroelectronics version 1.2.1, Copyright (C) 2014
  19  * STMicroelectronics comes with ABSOLUTELY NO WARRANTY.
  20  * This is free software, and you are welcome to redistribute it
  21  * under certain conditions.
  22  *
  23  * @Author: Christophe RICARD tpmsupport@st.com
  24  *
  25  * @File: tpm_stm_st33_i2c.c
  26  *
  27  * @Synopsis:
  28  *      09/15/2010:     First shot driver tpm_tis driver for
  29  *                       lpc is used as model.
  30  */
  31
  32 #include <linux/pci.h>
  33 #include <linux/module.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/i2c.h>
  36 #include <linux/fs.h>
  37 #include <linux/miscdevice.h>
  38 #include <linux/kernel.h>
  39 #include <linux/delay.h>
  40 #include <linux/wait.h>
  41 #include <linux/freezer.h>
  42 #include <linux/string.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/sysfs.h>
  45 #include <linux/gpio.h>
  46 #include <linux/sched.h>
  47 #include <linux/uaccess.h>
  48 #include <linux/io.h>
  49 #include <linux/slab.h>
  50 #include <linux/of_irq.h>
  51 #include <linux/of_gpio.h>
  52
  53 #include <linux/platform_data/tpm_i2c_stm_st33.h>
  54 #include "tpm.h"
  55
  56 #define TPM_ACCESS                      0x0
  57 #define TPM_STS                         0x18
  58 #define TPM_HASH_END                    0x20
  59 #define TPM_DATA_FIFO                   0x24
  60 #define TPM_HASH_DATA                   0x24
  61 #define TPM_HASH_START                  0x28
  62 #define TPM_INTF_CAPABILITY             0x14
  63 #define TPM_INT_STATUS                  0x10
  64 #define TPM_INT_ENABLE                  0x08
  65
  66 #define TPM_DUMMY_BYTE                  0xAA
  67 #define TPM_WRITE_DIRECTION             0x80
  68 #define TPM_HEADER_SIZE                 10
  69 #define TPM_BUFSIZE                     2048
  70
  71 #define LOCALITY0               0
  72
  73
  74 enum stm33zp24_access {
  75         TPM_ACCESS_VALID = 0x80,
  76         TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
  77         TPM_ACCESS_REQUEST_PENDING = 0x04,
  78         TPM_ACCESS_REQUEST_USE = 0x02,
  79 };
  80
  81 enum stm33zp24_status {
  82         TPM_STS_VALID = 0x80,
  83         TPM_STS_COMMAND_READY = 0x40,
  84         TPM_STS_GO = 0x20,
  85         TPM_STS_DATA_AVAIL = 0x10,
  86         TPM_STS_DATA_EXPECT = 0x08,
  87 };
  88
  89 enum stm33zp24_int_flags {
  90         TPM_GLOBAL_INT_ENABLE = 0x80,
  91         TPM_INTF_CMD_READY_INT = 0x080,
  92         TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
  93         TPM_INTF_WAKE_UP_READY_INT = 0x020,
  94         TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
  95         TPM_INTF_STS_VALID_INT = 0x002,
  96         TPM_INTF_DATA_AVAIL_INT = 0x001,
  97 };
  98
  99 enum tis_defaults {
 100         TIS_SHORT_TIMEOUT = 750,
 101         TIS_LONG_TIMEOUT = 2000,
 102 };
 103
 104 struct tpm_stm_dev {
 105         struct i2c_client *client;
 106         struct tpm_chip *chip;
 107         u8 buf[TPM_BUFSIZE + 1];
 108         u32 intrs;
 109         int io_lpcpd;
 110 };
 111
 112 /*
 113  * write8_reg
 114  * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
 115  * @param: tpm_register, the tpm tis register where the data should be written
 116  * @param: tpm_data, the tpm_data to write inside the tpm_register
 117  * @param: tpm_size, The length of the data
 118  * @return: Returns negative errno, or else the number of bytes written.
 119  */
 120 static int write8_reg(struct tpm_stm_dev *tpm_dev, u8 tpm_register,
 121                       u8 *tpm_data, u16 tpm_size)
 122 {
 123         tpm_dev->buf[0] = tpm_register;
 124         memcpy(tpm_dev->buf + 1, tpm_data, tpm_size);
 125         return i2c_master_send(tpm_dev->client, tpm_dev->buf, tpm_size + 1);
 126 } /* write8_reg() */
 127
 128 /*
 129  * read8_reg
 130  * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
 131  * @param: tpm_register, the tpm tis register where the data should be read
 132  * @param: tpm_data, the TPM response
 133  * @param: tpm_size, tpm TPM response size to read.
 134  * @return: number of byte read successfully: should be one if success.
 135  */
 136 static int read8_reg(struct tpm_stm_dev *tpm_dev, u8 tpm_register,
 137                     u8 *tpm_data, int tpm_size)
 138 {
 139         u8 status = 0;
 140         u8 data;
 141
 142         data = TPM_DUMMY_BYTE;
 143         status = write8_reg(tpm_dev, tpm_register, &data, 1);
 144         if (status == 2)
 145                 status = i2c_master_recv(tpm_dev->client, tpm_data, tpm_size);
 146         return status;
 147 } /* read8_reg() */
 148
 149 /*
 150  * I2C_WRITE_DATA
 151  * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
 152  * @param: tpm_dev, the chip description
 153  * @param: tpm_register, the tpm tis register where the data should be written
 154  * @param: tpm_data, the tpm_data to write inside the tpm_register
 155  * @param: tpm_size, The length of the data
 156  * @return: number of byte written successfully: should be one if success.
 157  */
 158 #define I2C_WRITE_DATA(tpm_dev, tpm_register, tpm_data, tpm_size) \
 159         (write8_reg(tpm_dev, tpm_register | \
 160         TPM_WRITE_DIRECTION, tpm_data, tpm_size))
 161
 162 /*
 163  * I2C_READ_DATA
 164  * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
 165  * @param: tpm_dev, the chip description
 166  * @param: tpm_register, the tpm tis register where the data should be read
 167  * @param: tpm_data, the TPM response
 168  * @param: tpm_size, tpm TPM response size to read.
 169  * @return: number of byte read successfully: should be one if success.
 170  */
 171 #define I2C_READ_DATA(tpm_dev, tpm_register, tpm_data, tpm_size) \
 172         (read8_reg(tpm_dev, tpm_register, tpm_data, tpm_size))
 173
 174 /*
 175  * clear_interruption
 176  * clear the TPM interrupt register.
 177  * @param: tpm, the chip description
 178  * @return: the TPM_INT_STATUS value
 179  */
 180 static u8 clear_interruption(struct tpm_stm_dev *tpm_dev)
 181 {
 182         u8 interrupt;
 183
 184         I2C_READ_DATA(tpm_dev, TPM_INT_STATUS, &interrupt, 1);
 185         I2C_WRITE_DATA(tpm_dev, TPM_INT_STATUS, &interrupt, 1);
 186         return interrupt;
 187 } /* clear_interruption() */
 188
 189 /*
 190  * tpm_stm_i2c_cancel, cancel is not implemented.
 191  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
 192  */
 193 static void tpm_stm_i2c_cancel(struct tpm_chip *chip)
 194 {
 195         struct tpm_stm_dev *tpm_dev;
 196         u8 data;
 197
 198         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 199
 200         data = TPM_STS_COMMAND_READY;
 201         I2C_WRITE_DATA(tpm_dev, TPM_STS, &data, 1);
 202 } /* tpm_stm_i2c_cancel() */
 203
 204 /*
 205  * tpm_stm_spi_status return the TPM_STS register
 206  * @param: chip, the tpm chip description
 207  * @return: the TPM_STS register value.
 208  */
 209 static u8 tpm_stm_i2c_status(struct tpm_chip *chip)
 210 {
 211         struct tpm_stm_dev *tpm_dev;
 212         u8 data;
 213
 214         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 215
 216         I2C_READ_DATA(tpm_dev, TPM_STS, &data, 1);
 217         return data;
 218 } /* tpm_stm_i2c_status() */
 219
 220
 221 /*
 222  * check_locality if the locality is active
 223  * @param: chip, the tpm chip description
 224  * @return: the active locality or -EACCESS.
 225  */
 226 static int check_locality(struct tpm_chip *chip)
 227 {
 228         struct tpm_stm_dev *tpm_dev;
 229         u8 data;
 230         u8 status;
 231
 232         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 233
 234         status = I2C_READ_DATA(tpm_dev, TPM_ACCESS, &data, 1);
 235         if (status && (data &
 236                 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
 237                 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
 238                 return chip->vendor.locality;
 239
 240         return -EACCES;
 241
 242 } /* check_locality() */
 243
 244 /*
 245  * request_locality request the TPM locality
 246  * @param: chip, the chip description
 247  * @return: the active locality or EACCESS.
 248  */
 249 static int request_locality(struct tpm_chip *chip)
 250 {
 251         unsigned long stop;
 252         long ret;
 253         struct tpm_stm_dev *tpm_dev;
 254         u8 data;
 255
 256         if (check_locality(chip) == chip->vendor.locality)
 257                 return chip->vendor.locality;
 258
 259         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 260
 261         data = TPM_ACCESS_REQUEST_USE;
 262         ret = I2C_WRITE_DATA(tpm_dev, TPM_ACCESS, &data, 1);
 263         if (ret < 0)
 264                 goto end;
 265
 266         stop = jiffies + chip->vendor.timeout_a;
 267
 268         /* Request locality is usually effective after the request */
 269         do {
 270                 if (check_locality(chip) >= 0)
 271                         return chip->vendor.locality;
 272                 msleep(TPM_TIMEOUT);
 273         } while (time_before(jiffies, stop));
 274         ret = -EACCES;
 275 end:
 276         return ret;
 277 } /* request_locality() */
 278
 279 /*
 280  * release_locality release the active locality
 281  * @param: chip, the tpm chip description.
 282  */
 283 static void release_locality(struct tpm_chip *chip)
 284 {
 285         struct tpm_stm_dev *tpm_dev;
 286         u8 data;
 287
 288         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 289         data = TPM_ACCESS_ACTIVE_LOCALITY;
 290
 291         I2C_WRITE_DATA(tpm_dev, TPM_ACCESS, &data, 1);
 292 }
 293
 294 /*
 295  * get_burstcount return the burstcount address 0x19 0x1A
 296  * @param: chip, the chip description
 297  * return: the burstcount.
 298  */
 299 static int get_burstcount(struct tpm_chip *chip)
 300 {
 301         unsigned long stop;
 302         int burstcnt, status;
 303         u8 tpm_reg, temp;
 304         struct tpm_stm_dev *tpm_dev;
 305
 306         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 307
 308         stop = jiffies + chip->vendor.timeout_d;
 309         do {
 310                 tpm_reg = TPM_STS + 1;
 311                 status = I2C_READ_DATA(tpm_dev, tpm_reg, &temp, 1);
 312                 if (status < 0)
 313                         goto end;
 314
 315                 tpm_reg = tpm_reg + 1;
 316                 burstcnt = temp;
 317                 status = I2C_READ_DATA(tpm_dev, tpm_reg, &temp, 1);
 318                 if (status < 0)
 319                         goto end;
 320
 321                 burstcnt |= temp << 8;
 322                 if (burstcnt)
 323                         return burstcnt;
 324                 msleep(TPM_TIMEOUT);
 325         } while (time_before(jiffies, stop));
 326
 327 end:
 328         return -EBUSY;
 329 } /* get_burstcount() */
 330
 331 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 332                                 bool check_cancel, bool *canceled)
 333 {
 334         u8 status = chip->ops->status(chip);
 335
 336         *canceled = false;
 337         if ((status & mask) == mask)
 338                 return true;
 339         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 340                 *canceled = true;
 341                 return true;
 342         }
 343         return false;
 344 }
 345
 346 /*
 347  * interrupt_to_status
 348  * @param: irq_mask, the irq mask value to wait
 349  * @return: the corresponding tpm_sts value
 350  */
 351 static u8 interrupt_to_status(u8 irq_mask)
 352 {
 353         u8 status = 0;
 354
 355         if ((irq_mask & TPM_INTF_STS_VALID_INT) ==  TPM_INTF_STS_VALID_INT)
 356                 status |= TPM_STS_VALID;
 357         if ((irq_mask & TPM_INTF_DATA_AVAIL_INT) == TPM_INTF_DATA_AVAIL_INT)
 358                 status |= TPM_STS_DATA_AVAIL;
 359         if ((irq_mask & TPM_INTF_CMD_READY_INT) == TPM_INTF_CMD_READY_INT)
 360                 status |= TPM_STS_COMMAND_READY;
 361
 362         return status;
 363 } /* status_to_interrupt() */
 364
 365 /*
 366  * 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: queue, the wait queue.
 371  * @param: check_cancel, does the command can be cancelled ?
 372  * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
 373  */
 374 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 375                         wait_queue_head_t *queue, bool check_cancel)
 376 {
 377         unsigned long stop;
 378         int r;
 379         bool canceled = false;
 380         bool condition;
 381         u32 cur_intrs;
 382         u8 interrupt, status;
 383         struct tpm_stm_dev *tpm_dev;
 384
 385         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 386
 387         /* check current status */
 388         status = tpm_stm_i2c_status(chip);
 389         if ((status & mask) == mask)
 390                 return 0;
 391
 392         stop = jiffies + timeout;
 393
 394         if (chip->vendor.irq) {
 395                 cur_intrs = tpm_dev->intrs;
 396                 interrupt = clear_interruption(tpm_dev);
 397                 enable_irq(chip->vendor.irq);
 398
 399 again:
 400                 timeout = stop - jiffies;
 401                 if ((long) timeout <= 0)
 402                         return -1;
 403
 404                 r = wait_event_interruptible_timeout(*queue,
 405                                         cur_intrs != tpm_dev->intrs, timeout);
 406
 407                 interrupt |= clear_interruption(tpm_dev);
 408                 status = interrupt_to_status(interrupt);
 409                 condition = wait_for_tpm_stat_cond(chip, mask,
 410                                                    check_cancel, &canceled);
 411
 412                 if (r >= 0 && condition) {
 413                         if (canceled)
 414                                 return -ECANCELED;
 415                         return 0;
 416                 }
 417                 if (r == -ERESTARTSYS && freezing(current)) {
 418                         clear_thread_flag(TIF_SIGPENDING);
 419                         goto again;
 420                 }
 421                 disable_irq_nosync(chip->vendor.irq);
 422
 423         } else {
 424                 do {
 425                         msleep(TPM_TIMEOUT);
 426                         status = chip->ops->status(chip);
 427                         if ((status & mask) == mask)
 428                                 return 0;
 429                 } while (time_before(jiffies, stop));
 430         }
 431
 432         return -ETIME;
 433 } /* wait_for_stat() */
 434
 435 /*
 436  * recv_data receive data
 437  * @param: chip, the tpm chip description
 438  * @param: buf, the buffer where the data are received
 439  * @param: count, the number of data to receive
 440  * @return: the number of bytes read from TPM FIFO.
 441  */
 442 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 443 {
 444         int size = 0, burstcnt, len;
 445         struct tpm_stm_dev *tpm_dev;
 446
 447         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 448
 449         while (size < count &&
 450                wait_for_stat(chip,
 451                              TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 452                              chip->vendor.timeout_c,
 453                              &chip->vendor.read_queue, true) == 0) {
 454                 burstcnt = get_burstcount(chip);
 455                 if (burstcnt < 0)
 456                         return burstcnt;
 457                 len = min_t(int, burstcnt, count - size);
 458                 I2C_READ_DATA(tpm_dev, TPM_DATA_FIFO, buf + size, len);
 459                 size += len;
 460         }
 461         return size;
 462 }
 463
 464 /*
 465  * tpm_ioserirq_handler the serirq irq handler
 466  * @param: irq, the tpm chip description
 467  * @param: dev_id, the description of the chip
 468  * @return: the status of the handler.
 469  */
 470 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
 471 {
 472         struct tpm_chip *chip = dev_id;
 473         struct tpm_stm_dev *tpm_dev;
 474
 475         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 476
 477         tpm_dev->intrs++;
 478         wake_up_interruptible(&chip->vendor.read_queue);
 479         disable_irq_nosync(chip->vendor.irq);
 480
 481         return IRQ_HANDLED;
 482 } /* tpm_ioserirq_handler() */
 483
 484
 485 /*
 486  * tpm_stm_i2c_send send TPM commands through the I2C bus.
 487  *
 488  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
 489  * @param: buf, the buffer to send.
 490  * @param: count, the number of bytes to send.
 491  * @return: In case of success the number of bytes sent.
 492  *                      In other case, a < 0 value describing the issue.
 493  */
 494 static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf,
 495                             size_t len)
 496 {
 497         u32 status, i, size;
 498         int burstcnt = 0;
 499         int ret;
 500         u8 data;
 501         struct i2c_client *client;
 502         struct tpm_stm_dev *tpm_dev;
 503
 504         if (!chip)
 505                 return -EBUSY;
 506         if (len < TPM_HEADER_SIZE)
 507                 return -EBUSY;
 508
 509         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 510         client = tpm_dev->client;
 511
 512         client->flags = 0;
 513
 514         ret = request_locality(chip);
 515         if (ret < 0)
 516                 return ret;
 517
 518         status = tpm_stm_i2c_status(chip);
 519         if ((status & TPM_STS_COMMAND_READY) == 0) {
 520                 tpm_stm_i2c_cancel(chip);
 521                 if (wait_for_stat
 522                     (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
 523                      &chip->vendor.read_queue, false) < 0) {
 524                         ret = -ETIME;
 525                         goto out_err;
 526                 }
 527         }
 528
 529         for (i = 0; i < len - 1;) {
 530                 burstcnt = get_burstcount(chip);
 531                 if (burstcnt < 0)
 532                         return burstcnt;
 533                 size = min_t(int, len - i - 1, burstcnt);
 534                 ret = I2C_WRITE_DATA(tpm_dev, TPM_DATA_FIFO, buf + i, size);
 535                 if (ret < 0)
 536                         goto out_err;
 537
 538                 i += size;
 539         }
 540
 541         status = tpm_stm_i2c_status(chip);
 542         if ((status & TPM_STS_DATA_EXPECT) == 0) {
 543                 ret = -EIO;
 544                 goto out_err;
 545         }
 546
 547         ret = I2C_WRITE_DATA(tpm_dev, TPM_DATA_FIFO, buf + len - 1, 1);
 548         if (ret < 0)
 549                 goto out_err;
 550
 551         status = tpm_stm_i2c_status(chip);
 552         if ((status & TPM_STS_DATA_EXPECT) != 0) {
 553                 ret = -EIO;
 554                 goto out_err;
 555         }
 556
 557         data = TPM_STS_GO;
 558         I2C_WRITE_DATA(tpm_dev, TPM_STS, &data, 1);
 559
 560         return len;
 561 out_err:
 562         tpm_stm_i2c_cancel(chip);
 563         release_locality(chip);
 564         return ret;
 565 }
 566
 567 /*
 568  * tpm_stm_i2c_recv received TPM response through the I2C bus.
 569  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
 570  * @param: buf, the buffer to store datas.
 571  * @param: count, the number of bytes to send.
 572  * @return: In case of success the number of bytes received.
 573  *              In other case, a < 0 value describing the issue.
 574  */
 575 static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
 576                             size_t count)
 577 {
 578         int size = 0;
 579         int expected;
 580
 581         if (!chip)
 582                 return -EBUSY;
 583
 584         if (count < TPM_HEADER_SIZE) {
 585                 size = -EIO;
 586                 goto out;
 587         }
 588
 589         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 590         if (size < TPM_HEADER_SIZE) {
 591                 dev_err(chip->dev, "Unable to read header\n");
 592                 goto out;
 593         }
 594
 595         expected = be32_to_cpu(*(__be32 *)(buf + 2));
 596         if (expected > count) {
 597                 size = -EIO;
 598                 goto out;
 599         }
 600
 601         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 602                         expected - TPM_HEADER_SIZE);
 603         if (size < expected) {
 604                 dev_err(chip->dev, "Unable to read remainder of result\n");
 605                 size = -ETIME;
 606                 goto out;
 607         }
 608
 609 out:
 610         chip->ops->cancel(chip);
 611         release_locality(chip);
 612         return size;
 613 }
 614
 615 static bool tpm_stm_i2c_req_canceled(struct tpm_chip *chip, u8 status)
 616 {
 617         return (status == TPM_STS_COMMAND_READY);
 618 }
 619
 620 static const struct tpm_class_ops st_i2c_tpm = {
 621         .send = tpm_stm_i2c_send,
 622         .recv = tpm_stm_i2c_recv,
 623         .cancel = tpm_stm_i2c_cancel,
 624         .status = tpm_stm_i2c_status,
 625         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 626         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 627         .req_canceled = tpm_stm_i2c_req_canceled,
 628 };
 629
 630 #ifdef CONFIG_OF
 631 static int tpm_stm_i2c_of_request_resources(struct tpm_chip *chip)
 632 {
 633         struct device_node *pp;
 634         struct tpm_stm_dev *tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 635         struct i2c_client *client = tpm_dev->client;
 636
 637         int gpio;
 638         int ret;
 639
 640         pp = client->dev.of_node;
 641         if (!pp) {
 642                 dev_err(chip->dev, "No platform data\n");
 643                 return -ENODEV;
 644         }
 645
 646         /* Get GPIO from device tree */
 647         gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0);
 648         if (gpio < 0) {
 649                 dev_err(chip->dev, "Failed to retrieve lpcpd-gpios from dts.\n");
 650                 tpm_dev->io_lpcpd = -1;
 651                 /*
 652                  * lpcpd pin is not specified. This is not an issue as
 653                  * power management can be also managed by TPM specific
 654                  * commands. So leave with a success status code.
 655                  */
 656                 return 0;
 657         }
 658         /* GPIO request and configuration */
 659         ret = devm_gpio_request_one(&client->dev, gpio,
 660                         GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD");
 661         if (ret) {
 662                 dev_err(chip->dev, "Failed to request lpcpd pin\n");
 663                 return -ENODEV;
 664         }
 665         tpm_dev->io_lpcpd = gpio;
 666
 667         return 0;
 668 }
 669 #else
 670 static int tpm_stm_i2c_of_request_resources(struct tpm_chip *chip)
 671 {
 672         return -ENODEV;
 673 }
 674 #endif
 675
 676 static int tpm_stm_i2c_request_resources(struct i2c_client *client,
 677                                          struct tpm_chip *chip)
 678 {
 679         struct st33zp24_platform_data *pdata;
 680         struct tpm_stm_dev *tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 681         int ret;
 682
 683         pdata = client->dev.platform_data;
 684         if (!pdata) {
 685                 dev_err(chip->dev, "No platform data\n");
 686                 return -ENODEV;
 687         }
 688
 689         /* store for late use */
 690         tpm_dev->io_lpcpd = pdata->io_lpcpd;
 691
 692         if (gpio_is_valid(pdata->io_lpcpd)) {
 693                 ret = devm_gpio_request_one(&client->dev,
 694                                 pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH,
 695                                 "TPM IO_LPCPD");
 696                 if (ret) {
 697                         dev_err(chip->dev, "%s : reset gpio_request failed\n",
 698                                 __FILE__);
 699                         return ret;
 700                 }
 701         }
 702
 703         return 0;
 704 }
 705
 706 /*
 707  * tpm_stm_i2c_probe initialize the TPM device
 708  * @param: client, the i2c_client drescription (TPM I2C description).
 709  * @param: id, the i2c_device_id struct.
 710  * @return: 0 in case of success.
 711  *       -1 in other case.
 712  */
 713 static int
 714 tpm_stm_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
 715 {
 716         int ret;
 717         u8 intmask = 0;
 718         struct tpm_chip *chip;
 719         struct st33zp24_platform_data *platform_data;
 720         struct tpm_stm_dev *tpm_dev;
 721
 722         if (!client) {
 723                 pr_info("%s: i2c client is NULL. Device not accessible.\n",
 724                         __func__);
 725                 return -ENODEV;
 726         }
 727
 728         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 729                 dev_info(&client->dev, "client not i2c capable\n");
 730                 return -ENODEV;
 731         }
 732
 733         tpm_dev = devm_kzalloc(&client->dev, sizeof(struct tpm_stm_dev),
 734                                GFP_KERNEL);
 735         if (!tpm_dev)
 736                 return -ENOMEM;
 737
 738         chip = tpmm_chip_alloc(&client->dev, &st_i2c_tpm);
 739         if (IS_ERR(chip))
 740                 return PTR_ERR(chip);
 741
 742         TPM_VPRIV(chip) = tpm_dev;
 743         tpm_dev->client = client;
 744
 745         platform_data = client->dev.platform_data;
 746         if (!platform_data && client->dev.of_node) {
 747                 ret = tpm_stm_i2c_of_request_resources(chip);
 748                 if (ret)
 749                         goto _tpm_clean_answer;
 750         } else if (platform_data) {
 751                 ret = tpm_stm_i2c_request_resources(client, chip);
 752                 if (ret)
 753                         goto _tpm_clean_answer;
 754         }
 755
 756         chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 757         chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
 758         chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 759         chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 760
 761         chip->vendor.locality = LOCALITY0;
 762
 763         if (client->irq) {
 764                 /* INTERRUPT Setup */
 765                 init_waitqueue_head(&chip->vendor.read_queue);
 766                 tpm_dev->intrs = 0;
 767
 768                 if (request_locality(chip) != LOCALITY0) {
 769                         ret = -ENODEV;
 770                         goto _tpm_clean_answer;
 771                 }
 772
 773                 clear_interruption(tpm_dev);
 774                 ret = devm_request_irq(&client->dev, client->irq,
 775                                 tpm_ioserirq_handler,
 776                                 IRQF_TRIGGER_HIGH,
 777                                 "TPM SERIRQ management", chip);
 778                 if (ret < 0) {
 779                         dev_err(chip->dev , "TPM SERIRQ signals %d not available\n",
 780                                 client->irq);
 781                         goto _tpm_clean_answer;
 782                 }
 783
 784                 intmask |= TPM_INTF_CMD_READY_INT
 785                         |  TPM_INTF_STS_VALID_INT
 786                         |  TPM_INTF_DATA_AVAIL_INT;
 787
 788                 ret = I2C_WRITE_DATA(tpm_dev, TPM_INT_ENABLE, &intmask, 1);
 789                 if (ret < 0)
 790                         goto _tpm_clean_answer;
 791
 792                 intmask = TPM_GLOBAL_INT_ENABLE;
 793                 ret = I2C_WRITE_DATA(tpm_dev, (TPM_INT_ENABLE + 3),
 794                                      &intmask, 1);
 795                 if (ret < 0)
 796                         goto _tpm_clean_answer;
 797
 798                 chip->vendor.irq = client->irq;
 799
 800                 disable_irq_nosync(chip->vendor.irq);
 801
 802                 tpm_gen_interrupt(chip);
 803         }
 804
 805         tpm_get_timeouts(chip);
 806         tpm_do_selftest(chip);
 807
 808         return tpm_chip_register(chip);
 809 _tpm_clean_answer:
 810         dev_info(chip->dev, "TPM I2C initialisation fail\n");
 811         return ret;
 812 }
 813
 814 /*
 815  * tpm_stm_i2c_remove remove the TPM device
 816  * @param: client, the i2c_client drescription (TPM I2C description).
 817  *              clear_bit(0, &chip->is_open);
 818  * @return: 0 in case of success.
 819  */
 820 static int tpm_stm_i2c_remove(struct i2c_client *client)
 821 {
 822         struct tpm_chip *chip =
 823                 (struct tpm_chip *) i2c_get_clientdata(client);
 824
 825         if (chip)
 826                 tpm_chip_unregister(chip);
 827
 828         return 0;
 829 }
 830
 831 #ifdef CONFIG_PM_SLEEP
 832 /*
 833  * tpm_stm_i2c_pm_suspend suspend the TPM device
 834  * @param: client, the i2c_client drescription (TPM I2C description).
 835  * @param: mesg, the power management message.
 836  * @return: 0 in case of success.
 837  */
 838 static int tpm_stm_i2c_pm_suspend(struct device *dev)
 839 {
 840         struct st33zp24_platform_data *pin_infos = dev->platform_data;
 841         int ret = 0;
 842
 843         if (gpio_is_valid(pin_infos->io_lpcpd))
 844                 gpio_set_value(pin_infos->io_lpcpd, 0);
 845         else
 846                 ret = tpm_pm_suspend(dev);
 847
 848         return ret;
 849 }                               /* tpm_stm_i2c_suspend() */
 850
 851 /*
 852  * tpm_stm_i2c_pm_resume resume the TPM device
 853  * @param: client, the i2c_client drescription (TPM I2C description).
 854  * @return: 0 in case of success.
 855  */
 856 static int tpm_stm_i2c_pm_resume(struct device *dev)
 857 {
 858         struct tpm_chip *chip = dev_get_drvdata(dev);
 859         struct st33zp24_platform_data *pin_infos = dev->platform_data;
 860
 861         int ret = 0;
 862
 863         if (gpio_is_valid(pin_infos->io_lpcpd)) {
 864                 gpio_set_value(pin_infos->io_lpcpd, 1);
 865                 ret = wait_for_stat(chip,
 866                                 TPM_STS_VALID, chip->vendor.timeout_b,
 867                                 &chip->vendor.read_queue, false);
 868         } else {
 869                 ret = tpm_pm_resume(dev);
 870                 if (!ret)
 871                         tpm_do_selftest(chip);
 872         }
 873         return ret;
 874 } /* tpm_stm_i2c_pm_resume() */
 875 #endif
 876
 877 static const struct i2c_device_id tpm_stm_i2c_id[] = {
 878         {TPM_ST33_I2C, 0},
 879         {}
 880 };
 881 MODULE_DEVICE_TABLE(i2c, tpm_stm_i2c_id);
 882
 883 #ifdef CONFIG_OF
 884 static const struct of_device_id of_st33zp24_i2c_match[] = {
 885         { .compatible = "st,st33zp24-i2c", },
 886         {}
 887 };
 888 MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match);
 889 #endif
 890
 891 static SIMPLE_DEV_PM_OPS(tpm_stm_i2c_ops, tpm_stm_i2c_pm_suspend,
 892         tpm_stm_i2c_pm_resume);
 893 static struct i2c_driver tpm_stm_i2c_driver = {
 894         .driver = {
 895                 .owner = THIS_MODULE,
 896                 .name = TPM_ST33_I2C,
 897                 .pm = &tpm_stm_i2c_ops,
 898                 .of_match_table = of_match_ptr(of_st33zp24_i2c_match),
 899         },
 900         .probe = tpm_stm_i2c_probe,
 901         .remove = tpm_stm_i2c_remove,
 902         .id_table = tpm_stm_i2c_id
 903 };
 904
 905 module_i2c_driver(tpm_stm_i2c_driver);
 906
 907 MODULE_AUTHOR("Christophe Ricard (tpmsupport@st.com)");
 908 MODULE_DESCRIPTION("STM TPM I2C ST33 Driver");
 909 MODULE_VERSION("1.2.1");
 910 MODULE_LICENSE("GPL");