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_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 } /* check_locality() */
 242
 243 /*
 244  * request_locality request the TPM locality
 245  * @param: chip, the chip description
 246  * @return: the active locality or EACCESS.
 247  */
 248 static int request_locality(struct tpm_chip *chip)
 249 {
 250         unsigned long stop;
 251         long ret;
 252         struct tpm_stm_dev *tpm_dev;
 253         u8 data;
 254
 255         if (check_locality(chip) == chip->vendor.locality)
 256                 return chip->vendor.locality;
 257
 258         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 259
 260         data = TPM_ACCESS_REQUEST_USE;
 261         ret = I2C_WRITE_DATA(tpm_dev, TPM_ACCESS, &data, 1);
 262         if (ret < 0)
 263                 goto end;
 264
 265         stop = jiffies + chip->vendor.timeout_a;
 266
 267         /* Request locality is usually effective after the request */
 268         do {
 269                 if (check_locality(chip) >= 0)
 270                         return chip->vendor.locality;
 271                 msleep(TPM_TIMEOUT);
 272         } while (time_before(jiffies, stop));
 273         ret = -EACCES;
 274 end:
 275         return ret;
 276 } /* request_locality() */
 277
 278 /*
 279  * release_locality release the active locality
 280  * @param: chip, the tpm chip description.
 281  */
 282 static void release_locality(struct tpm_chip *chip)
 283 {
 284         struct tpm_stm_dev *tpm_dev;
 285         u8 data;
 286
 287         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 288         data = TPM_ACCESS_ACTIVE_LOCALITY;
 289
 290         I2C_WRITE_DATA(tpm_dev, TPM_ACCESS, &data, 1);
 291 }
 292
 293 /*
 294  * get_burstcount return the burstcount address 0x19 0x1A
 295  * @param: chip, the chip description
 296  * return: the burstcount.
 297  */
 298 static int get_burstcount(struct tpm_chip *chip)
 299 {
 300         unsigned long stop;
 301         int burstcnt, status;
 302         u8 tpm_reg, temp;
 303         struct tpm_stm_dev *tpm_dev;
 304
 305         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 306
 307         stop = jiffies + chip->vendor.timeout_d;
 308         do {
 309                 tpm_reg = TPM_STS + 1;
 310                 status = I2C_READ_DATA(tpm_dev, tpm_reg, &temp, 1);
 311                 if (status < 0)
 312                         goto end;
 313
 314                 tpm_reg = tpm_reg + 1;
 315                 burstcnt = temp;
 316                 status = I2C_READ_DATA(tpm_dev, tpm_reg, &temp, 1);
 317                 if (status < 0)
 318                         goto end;
 319
 320                 burstcnt |= temp << 8;
 321                 if (burstcnt)
 322                         return burstcnt;
 323                 msleep(TPM_TIMEOUT);
 324         } while (time_before(jiffies, stop));
 325
 326 end:
 327         return -EBUSY;
 328 } /* get_burstcount() */
 329
 330 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 331                                 bool check_cancel, bool *canceled)
 332 {
 333         u8 status = chip->ops->status(chip);
 334
 335         *canceled = false;
 336         if ((status & mask) == mask)
 337                 return true;
 338         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 339                 *canceled = true;
 340                 return true;
 341         }
 342         return false;
 343 }
 344
 345 /*
 346  * interrupt_to_status
 347  * @param: irq_mask, the irq mask value to wait
 348  * @return: the corresponding tpm_sts value
 349  */
 350 static u8 interrupt_to_status(u8 irq_mask)
 351 {
 352         u8 status = 0;
 353
 354         if ((irq_mask & TPM_INTF_STS_VALID_INT) == TPM_INTF_STS_VALID_INT)
 355                 status |= TPM_STS_VALID;
 356         if ((irq_mask & TPM_INTF_DATA_AVAIL_INT) == TPM_INTF_DATA_AVAIL_INT)
 357                 status |= TPM_STS_DATA_AVAIL;
 358         if ((irq_mask & TPM_INTF_CMD_READY_INT) == TPM_INTF_CMD_READY_INT)
 359                 status |= TPM_STS_COMMAND_READY;
 360
 361         return status;
 362 } /* status_to_interrupt() */
 363
 364 /*
 365  * wait_for_stat wait for a TPM_STS value
 366  * @param: chip, the tpm chip description
 367  * @param: mask, the value mask to wait
 368  * @param: timeout, the timeout
 369  * @param: queue, the wait queue.
 370  * @param: check_cancel, does the command can be cancelled ?
 371  * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
 372  */
 373 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 374                         wait_queue_head_t *queue, bool check_cancel)
 375 {
 376         unsigned long stop;
 377         int ret;
 378         bool canceled = false;
 379         bool condition;
 380         u32 cur_intrs;
 381         u8 interrupt, status;
 382         struct tpm_stm_dev *tpm_dev;
 383
 384         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 385
 386         /* check current status */
 387         status = tpm_stm_i2c_status(chip);
 388         if ((status & mask) == mask)
 389                 return 0;
 390
 391         stop = jiffies + timeout;
 392
 393         if (chip->vendor.irq) {
 394                 cur_intrs = tpm_dev->intrs;
 395                 interrupt = clear_interruption(tpm_dev);
 396                 enable_irq(chip->vendor.irq);
 397
 398 again:
 399                 timeout = stop - jiffies;
 400                 if ((long) timeout <= 0)
 401                         return -1;
 402
 403                 ret = wait_event_interruptible_timeout(*queue,
 404                                         cur_intrs != tpm_dev->intrs, timeout);
 405
 406                 interrupt |= clear_interruption(tpm_dev);
 407                 status = interrupt_to_status(interrupt);
 408                 condition = wait_for_tpm_stat_cond(chip, mask,
 409                                                    check_cancel, &canceled);
 410
 411                 if (ret >= 0 && condition) {
 412                         if (canceled)
 413                                 return -ECANCELED;
 414                         return 0;
 415                 }
 416                 if (ret == -ERESTARTSYS && freezing(current)) {
 417                         clear_thread_flag(TIF_SIGPENDING);
 418                         goto again;
 419                 }
 420                 disable_irq_nosync(chip->vendor.irq);
 421
 422         } else {
 423                 do {
 424                         msleep(TPM_TIMEOUT);
 425                         status = chip->ops->status(chip);
 426                         if ((status & mask) == mask)
 427                                 return 0;
 428                 } while (time_before(jiffies, stop));
 429         }
 430
 431         return -ETIME;
 432 } /* wait_for_stat() */
 433
 434 /*
 435  * recv_data receive data
 436  * @param: chip, the tpm chip description
 437  * @param: buf, the buffer where the data are received
 438  * @param: count, the number of data to receive
 439  * @return: the number of bytes read from TPM FIFO.
 440  */
 441 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 442 {
 443         int size = 0, burstcnt, len, ret;
 444         struct tpm_stm_dev *tpm_dev;
 445
 446         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 447
 448         while (size < count &&
 449                wait_for_stat(chip,
 450                              TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 451                              chip->vendor.timeout_c,
 452                              &chip->vendor.read_queue, true) == 0) {
 453                 burstcnt = get_burstcount(chip);
 454                 if (burstcnt < 0)
 455                         return burstcnt;
 456                 len = min_t(int, burstcnt, count - size);
 457                 ret = I2C_READ_DATA(tpm_dev, TPM_DATA_FIFO, buf + size, len);
 458                 if (ret < 0)
 459                         return ret;
 460
 461                 size += len;
 462         }
 463         return size;
 464 }
 465
 466 /*
 467  * tpm_ioserirq_handler the serirq irq handler
 468  * @param: irq, the tpm chip description
 469  * @param: dev_id, the description of the chip
 470  * @return: the status of the handler.
 471  */
 472 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
 473 {
 474         struct tpm_chip *chip = dev_id;
 475         struct tpm_stm_dev *tpm_dev;
 476
 477         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 478
 479         tpm_dev->intrs++;
 480         wake_up_interruptible(&chip->vendor.read_queue);
 481         disable_irq_nosync(chip->vendor.irq);
 482
 483         return IRQ_HANDLED;
 484 } /* tpm_ioserirq_handler() */
 485
 486
 487 /*
 488  * tpm_stm_i2c_send send TPM commands through the I2C bus.
 489  *
 490  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
 491  * @param: buf, the buffer to send.
 492  * @param: count, the number of bytes to send.
 493  * @return: In case of success the number of bytes sent.
 494  *                      In other case, a < 0 value describing the issue.
 495  */
 496 static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf,
 497                             size_t len)
 498 {
 499         u32 status, i, size;
 500         int burstcnt = 0;
 501         int ret;
 502         u8 data;
 503         struct i2c_client *client;
 504         struct tpm_stm_dev *tpm_dev;
 505
 506         if (!chip)
 507                 return -EBUSY;
 508         if (len < TPM_HEADER_SIZE)
 509                 return -EBUSY;
 510
 511         tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 512         client = tpm_dev->client;
 513
 514         client->flags = 0;
 515
 516         ret = request_locality(chip);
 517         if (ret < 0)
 518                 return ret;
 519
 520         status = tpm_stm_i2c_status(chip);
 521         if ((status & TPM_STS_COMMAND_READY) == 0) {
 522                 tpm_stm_i2c_cancel(chip);
 523                 if (wait_for_stat
 524                     (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
 525                      &chip->vendor.read_queue, false) < 0) {
 526                         ret = -ETIME;
 527                         goto out_err;
 528                 }
 529         }
 530
 531         for (i = 0; i < len - 1;) {
 532                 burstcnt = get_burstcount(chip);
 533                 if (burstcnt < 0)
 534                         return burstcnt;
 535                 size = min_t(int, len - i - 1, burstcnt);
 536                 ret = I2C_WRITE_DATA(tpm_dev, TPM_DATA_FIFO, buf + i, size);
 537                 if (ret < 0)
 538                         goto out_err;
 539
 540                 i += size;
 541         }
 542
 543         status = tpm_stm_i2c_status(chip);
 544         if ((status & TPM_STS_DATA_EXPECT) == 0) {
 545                 ret = -EIO;
 546                 goto out_err;
 547         }
 548
 549         ret = I2C_WRITE_DATA(tpm_dev, TPM_DATA_FIFO, buf + len - 1, 1);
 550         if (ret < 0)
 551                 goto out_err;
 552
 553         status = tpm_stm_i2c_status(chip);
 554         if ((status & TPM_STS_DATA_EXPECT) != 0) {
 555                 ret = -EIO;
 556                 goto out_err;
 557         }
 558
 559         data = TPM_STS_GO;
 560         I2C_WRITE_DATA(tpm_dev, TPM_STS, &data, 1);
 561
 562         return len;
 563 out_err:
 564         tpm_stm_i2c_cancel(chip);
 565         release_locality(chip);
 566         return ret;
 567 }
 568
 569 /*
 570  * tpm_stm_i2c_recv received TPM response through the I2C bus.
 571  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
 572  * @param: buf, the buffer to store datas.
 573  * @param: count, the number of bytes to send.
 574  * @return: In case of success the number of bytes received.
 575  *          In other case, a < 0 value describing the issue.
 576  */
 577 static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
 578                             size_t count)
 579 {
 580         int size = 0;
 581         int expected;
 582
 583         if (!chip)
 584                 return -EBUSY;
 585
 586         if (count < TPM_HEADER_SIZE) {
 587                 size = -EIO;
 588                 goto out;
 589         }
 590
 591         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 592         if (size < TPM_HEADER_SIZE) {
 593                 dev_err(chip->pdev, "Unable to read header\n");
 594                 goto out;
 595         }
 596
 597         expected = be32_to_cpu(*(__be32 *)(buf + 2));
 598         if (expected > count) {
 599                 size = -EIO;
 600                 goto out;
 601         }
 602
 603         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 604                         expected - TPM_HEADER_SIZE);
 605         if (size < expected) {
 606                 dev_err(chip->pdev, "Unable to read remainder of result\n");
 607                 size = -ETIME;
 608                 goto out;
 609         }
 610
 611 out:
 612         chip->ops->cancel(chip);
 613         release_locality(chip);
 614         return size;
 615 }
 616
 617 static bool tpm_stm_i2c_req_canceled(struct tpm_chip *chip, u8 status)
 618 {
 619         return (status == TPM_STS_COMMAND_READY);
 620 }
 621
 622 static const struct tpm_class_ops st_i2c_tpm = {
 623         .send = tpm_stm_i2c_send,
 624         .recv = tpm_stm_i2c_recv,
 625         .cancel = tpm_stm_i2c_cancel,
 626         .status = tpm_stm_i2c_status,
 627         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 628         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 629         .req_canceled = tpm_stm_i2c_req_canceled,
 630 };
 631
 632 #ifdef CONFIG_OF
 633 static int tpm_stm_i2c_of_request_resources(struct tpm_chip *chip)
 634 {
 635         struct device_node *pp;
 636         struct tpm_stm_dev *tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 637         struct i2c_client *client = tpm_dev->client;
 638         int gpio;
 639         int ret;
 640
 641         pp = client->dev.of_node;
 642         if (!pp) {
 643                 dev_err(chip->pdev, "No platform data\n");
 644                 return -ENODEV;
 645         }
 646
 647         /* Get GPIO from device tree */
 648         gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0);
 649         if (gpio < 0) {
 650                 dev_err(chip->pdev, "Failed to retrieve lpcpd-gpios from dts.\n");
 651                 tpm_dev->io_lpcpd = -1;
 652                 /*
 653                  * lpcpd pin is not specified. This is not an issue as
 654                  * power management can be also managed by TPM specific
 655                  * commands. So leave with a success status code.
 656                  */
 657                 return 0;
 658         }
 659         /* GPIO request and configuration */
 660         ret = devm_gpio_request_one(&client->dev, gpio,
 661                         GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD");
 662         if (ret) {
 663                 dev_err(chip->pdev, "Failed to request lpcpd pin\n");
 664                 return -ENODEV;
 665         }
 666         tpm_dev->io_lpcpd = gpio;
 667
 668         return 0;
 669 }
 670 #else
 671 static int tpm_stm_i2c_of_request_resources(struct tpm_chip *chip)
 672 {
 673         return -ENODEV;
 674 }
 675 #endif
 676
 677 static int tpm_stm_i2c_request_resources(struct i2c_client *client,
 678                                          struct tpm_chip *chip)
 679 {
 680         struct st33zp24_platform_data *pdata;
 681         struct tpm_stm_dev *tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
 682         int ret;
 683
 684         pdata = client->dev.platform_data;
 685         if (!pdata) {
 686                 dev_err(chip->pdev, "No platform data\n");
 687                 return -ENODEV;
 688         }
 689
 690         /* store for late use */
 691         tpm_dev->io_lpcpd = pdata->io_lpcpd;
 692
 693         if (gpio_is_valid(pdata->io_lpcpd)) {
 694                 ret = devm_gpio_request_one(&client->dev,
 695                                 pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH,
 696                                 "TPM IO_LPCPD");
 697                 if (ret) {
 698                         dev_err(chip->pdev, "%s : reset gpio_request failed\n",
 699                                 __FILE__);
 700                         return ret;
 701                 }
 702         }
 703
 704         return 0;
 705 }
 706
 707 /*
 708  * tpm_stm_i2c_probe initialize the TPM device
 709  * @param: client, the i2c_client drescription (TPM I2C description).
 710  * @param: id, the i2c_device_id struct.
 711  * @return: 0 in case of success.
 712  *       -1 in other case.
 713  */
 714 static int
 715 tpm_stm_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
 716 {
 717         int ret;
 718         u8 intmask = 0;
 719         struct tpm_chip *chip;
 720         struct st33zp24_platform_data *platform_data;
 721         struct tpm_stm_dev *tpm_dev;
 722
 723         if (!client) {
 724                 pr_info("%s: i2c client is NULL. Device not accessible.\n",
 725                         __func__);
 726                 return -ENODEV;
 727         }
 728
 729         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 730                 dev_info(&client->dev, "client not i2c capable\n");
 731                 return -ENODEV;
 732         }
 733
 734         tpm_dev = devm_kzalloc(&client->dev, sizeof(struct tpm_stm_dev),
 735                                GFP_KERNEL);
 736         if (!tpm_dev)
 737                 return -ENOMEM;
 738
 739         chip = tpmm_chip_alloc(&client->dev, &st_i2c_tpm);
 740         if (IS_ERR(chip))
 741                 return PTR_ERR(chip);
 742
 743         TPM_VPRIV(chip) = tpm_dev;
 744         tpm_dev->client = client;
 745
 746         platform_data = client->dev.platform_data;
 747         if (!platform_data && client->dev.of_node) {
 748                 ret = tpm_stm_i2c_of_request_resources(chip);
 749                 if (ret)
 750                         goto _tpm_clean_answer;
 751         } else if (platform_data) {
 752                 ret = tpm_stm_i2c_request_resources(client, chip);
 753                 if (ret)
 754                         goto _tpm_clean_answer;
 755         }
 756
 757         chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 758         chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
 759         chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 760         chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 761
 762         chip->vendor.locality = LOCALITY0;
 763
 764         if (client->irq) {
 765                 /* INTERRUPT Setup */
 766                 init_waitqueue_head(&chip->vendor.read_queue);
 767                 tpm_dev->intrs = 0;
 768
 769                 if (request_locality(chip) != LOCALITY0) {
 770                         ret = -ENODEV;
 771                         goto _tpm_clean_answer;
 772                 }
 773
 774                 clear_interruption(tpm_dev);
 775                 ret = devm_request_irq(&client->dev, client->irq,
 776                                 tpm_ioserirq_handler,
 777                                 IRQF_TRIGGER_HIGH,
 778                                 "TPM SERIRQ management", chip);
 779                 if (ret < 0) {
 780                         dev_err(chip->pdev , "TPM SERIRQ signals %d not available\n",
 781                                 client->irq);
 782                         goto _tpm_clean_answer;
 783                 }
 784
 785                 intmask |= TPM_INTF_CMD_READY_INT
 786                         |  TPM_INTF_STS_VALID_INT
 787                         |  TPM_INTF_DATA_AVAIL_INT;
 788
 789                 ret = I2C_WRITE_DATA(tpm_dev, TPM_INT_ENABLE, &intmask, 1);
 790                 if (ret < 0)
 791                         goto _tpm_clean_answer;
 792
 793                 intmask = TPM_GLOBAL_INT_ENABLE;
 794                 ret = I2C_WRITE_DATA(tpm_dev, (TPM_INT_ENABLE + 3),
 795                                      &intmask, 1);
 796                 if (ret < 0)
 797                         goto _tpm_clean_answer;
 798
 799                 chip->vendor.irq = client->irq;
 800
 801                 disable_irq_nosync(chip->vendor.irq);
 802
 803                 tpm_gen_interrupt(chip);
 804         }
 805
 806         tpm_get_timeouts(chip);
 807         tpm_do_selftest(chip);
 808
 809         return tpm_chip_register(chip);
 810 _tpm_clean_answer:
 811         dev_info(chip->pdev, "TPM I2C initialisation fail\n");
 812         return ret;
 813 }
 814
 815 /*
 816  * tpm_stm_i2c_remove remove the TPM device
 817  * @param: client, the i2c_client description (TPM I2C description).
 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
 894 static struct i2c_driver tpm_stm_i2c_driver = {
 895         .driver = {
 896                 .owner = THIS_MODULE,
 897                 .name = TPM_ST33_I2C,
 898                 .pm = &tpm_stm_i2c_ops,
 899                 .of_match_table = of_match_ptr(of_st33zp24_i2c_match),
 900         },
 901         .probe = tpm_stm_i2c_probe,
 902         .remove = tpm_stm_i2c_remove,
 903         .id_table = tpm_stm_i2c_id
 904 };
 905
 906 module_i2c_driver(tpm_stm_i2c_driver);
 907
 908 MODULE_AUTHOR("Christophe Ricard (tpmsupport@st.com)");
 909 MODULE_DESCRIPTION("STM TPM I2C ST33 Driver");
 910 MODULE_VERSION("1.2.1");
 911 MODULE_LICENSE("GPL");