1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * STMicroelectronics TPM Linux driver for TPM ST33ZP24 4 * Copyright (C) 2009 - 2016 STMicroelectronics 5 */ 6 7 #include <linux/module.h> 8 #include <linux/fs.h> 9 #include <linux/kernel.h> 10 #include <linux/delay.h> 11 #include <linux/wait.h> 12 #include <linux/freezer.h> 13 #include <linux/string.h> 14 #include <linux/interrupt.h> 15 #include <linux/gpio.h> 16 #include <linux/sched.h> 17 #include <linux/uaccess.h> 18 #include <linux/io.h> 19 #include <linux/slab.h> 20 21 #include "../tpm.h" 22 #include "st33zp24.h" 23 24 #define TPM_ACCESS 0x0 25 #define TPM_STS 0x18 26 #define TPM_DATA_FIFO 0x24 27 #define TPM_INTF_CAPABILITY 0x14 28 #define TPM_INT_STATUS 0x10 29 #define TPM_INT_ENABLE 0x08 30 31 #define LOCALITY0 0 32 33 enum st33zp24_access { 34 TPM_ACCESS_VALID = 0x80, 35 TPM_ACCESS_ACTIVE_LOCALITY = 0x20, 36 TPM_ACCESS_REQUEST_PENDING = 0x04, 37 TPM_ACCESS_REQUEST_USE = 0x02, 38 }; 39 40 enum st33zp24_status { 41 TPM_STS_VALID = 0x80, 42 TPM_STS_COMMAND_READY = 0x40, 43 TPM_STS_GO = 0x20, 44 TPM_STS_DATA_AVAIL = 0x10, 45 TPM_STS_DATA_EXPECT = 0x08, 46 }; 47 48 enum st33zp24_int_flags { 49 TPM_GLOBAL_INT_ENABLE = 0x80, 50 TPM_INTF_CMD_READY_INT = 0x080, 51 TPM_INTF_FIFO_AVALAIBLE_INT = 0x040, 52 TPM_INTF_WAKE_UP_READY_INT = 0x020, 53 TPM_INTF_LOCALITY_CHANGE_INT = 0x004, 54 TPM_INTF_STS_VALID_INT = 0x002, 55 TPM_INTF_DATA_AVAIL_INT = 0x001, 56 }; 57 58 enum tis_defaults { 59 TIS_SHORT_TIMEOUT = 750, 60 TIS_LONG_TIMEOUT = 2000, 61 }; 62 63 /* 64 * clear_interruption clear the pending interrupt. 65 * @param: tpm_dev, the tpm device device. 66 * @return: the interrupt status value. 67 */ 68 static u8 clear_interruption(struct st33zp24_dev *tpm_dev) 69 { 70 u8 interrupt; 71 72 tpm_dev->ops->recv(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1); 73 tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1); 74 return interrupt; 75 } /* clear_interruption() */ 76 77 /* 78 * st33zp24_cancel, cancel the current command execution or 79 * set STS to COMMAND READY. 80 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h 81 */ 82 static void st33zp24_cancel(struct tpm_chip *chip) 83 { 84 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 85 u8 data; 86 87 data = TPM_STS_COMMAND_READY; 88 tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1); 89 } /* st33zp24_cancel() */ 90 91 /* 92 * st33zp24_status return the TPM_STS register 93 * @param: chip, the tpm chip description 94 * @return: the TPM_STS register value. 95 */ 96 static u8 st33zp24_status(struct tpm_chip *chip) 97 { 98 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 99 u8 data; 100 101 tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS, &data, 1); 102 return data; 103 } /* st33zp24_status() */ 104 105 /* 106 * check_locality if the locality is active 107 * @param: chip, the tpm chip description 108 * @return: true if LOCALITY0 is active, otherwise false 109 */ 110 static bool check_locality(struct tpm_chip *chip) 111 { 112 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 113 u8 data; 114 u8 status; 115 116 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1); 117 if (status && (data & 118 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == 119 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) 120 return true; 121 122 return false; 123 } /* check_locality() */ 124 125 /* 126 * request_locality request the TPM locality 127 * @param: chip, the chip description 128 * @return: the active locality or negative value. 129 */ 130 static int request_locality(struct tpm_chip *chip) 131 { 132 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 133 unsigned long stop; 134 long ret; 135 u8 data; 136 137 if (check_locality(chip)) 138 return tpm_dev->locality; 139 140 data = TPM_ACCESS_REQUEST_USE; 141 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1); 142 if (ret < 0) 143 return ret; 144 145 stop = jiffies + chip->timeout_a; 146 147 /* Request locality is usually effective after the request */ 148 do { 149 if (check_locality(chip)) 150 return tpm_dev->locality; 151 msleep(TPM_TIMEOUT); 152 } while (time_before(jiffies, stop)); 153 154 /* could not get locality */ 155 return -EACCES; 156 } /* request_locality() */ 157 158 /* 159 * release_locality release the active locality 160 * @param: chip, the tpm chip description. 161 */ 162 static void release_locality(struct tpm_chip *chip) 163 { 164 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 165 u8 data; 166 167 data = TPM_ACCESS_ACTIVE_LOCALITY; 168 169 tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1); 170 } 171 172 /* 173 * get_burstcount return the burstcount value 174 * @param: chip, the chip description 175 * return: the burstcount or negative value. 176 */ 177 static int get_burstcount(struct tpm_chip *chip) 178 { 179 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 180 unsigned long stop; 181 int burstcnt, status; 182 u8 temp; 183 184 stop = jiffies + chip->timeout_d; 185 do { 186 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 1, 187 &temp, 1); 188 if (status < 0) 189 return -EBUSY; 190 191 burstcnt = temp; 192 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 2, 193 &temp, 1); 194 if (status < 0) 195 return -EBUSY; 196 197 burstcnt |= temp << 8; 198 if (burstcnt) 199 return burstcnt; 200 msleep(TPM_TIMEOUT); 201 } while (time_before(jiffies, stop)); 202 return -EBUSY; 203 } /* get_burstcount() */ 204 205 206 /* 207 * wait_for_tpm_stat_cond 208 * @param: chip, chip description 209 * @param: mask, expected mask value 210 * @param: check_cancel, does the command expected to be canceled ? 211 * @param: canceled, did we received a cancel request ? 212 * @return: true if status == mask or if the command is canceled. 213 * false in other cases. 214 */ 215 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, 216 bool check_cancel, bool *canceled) 217 { 218 u8 status = chip->ops->status(chip); 219 220 *canceled = false; 221 if ((status & mask) == mask) 222 return true; 223 if (check_cancel && chip->ops->req_canceled(chip, status)) { 224 *canceled = true; 225 return true; 226 } 227 return false; 228 } 229 230 /* 231 * wait_for_stat wait for a TPM_STS value 232 * @param: chip, the tpm chip description 233 * @param: mask, the value mask to wait 234 * @param: timeout, the timeout 235 * @param: queue, the wait queue. 236 * @param: check_cancel, does the command can be cancelled ? 237 * @return: the tpm status, 0 if success, -ETIME if timeout is reached. 238 */ 239 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, 240 wait_queue_head_t *queue, bool check_cancel) 241 { 242 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 243 unsigned long stop; 244 int ret = 0; 245 bool canceled = false; 246 bool condition; 247 u32 cur_intrs; 248 u8 status; 249 250 /* check current status */ 251 status = st33zp24_status(chip); 252 if ((status & mask) == mask) 253 return 0; 254 255 stop = jiffies + timeout; 256 257 if (chip->flags & TPM_CHIP_FLAG_IRQ) { 258 cur_intrs = tpm_dev->intrs; 259 clear_interruption(tpm_dev); 260 enable_irq(tpm_dev->irq); 261 262 do { 263 if (ret == -ERESTARTSYS && freezing(current)) 264 clear_thread_flag(TIF_SIGPENDING); 265 266 timeout = stop - jiffies; 267 if ((long) timeout <= 0) 268 return -1; 269 270 ret = wait_event_interruptible_timeout(*queue, 271 cur_intrs != tpm_dev->intrs, 272 timeout); 273 clear_interruption(tpm_dev); 274 condition = wait_for_tpm_stat_cond(chip, mask, 275 check_cancel, &canceled); 276 if (ret >= 0 && condition) { 277 if (canceled) 278 return -ECANCELED; 279 return 0; 280 } 281 } while (ret == -ERESTARTSYS && freezing(current)); 282 283 disable_irq_nosync(tpm_dev->irq); 284 285 } else { 286 do { 287 msleep(TPM_TIMEOUT); 288 status = chip->ops->status(chip); 289 if ((status & mask) == mask) 290 return 0; 291 } while (time_before(jiffies, stop)); 292 } 293 294 return -ETIME; 295 } /* wait_for_stat() */ 296 297 /* 298 * recv_data receive data 299 * @param: chip, the tpm chip description 300 * @param: buf, the buffer where the data are received 301 * @param: count, the number of data to receive 302 * @return: the number of bytes read from TPM FIFO. 303 */ 304 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) 305 { 306 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 307 int size = 0, burstcnt, len, ret; 308 309 while (size < count && 310 wait_for_stat(chip, 311 TPM_STS_DATA_AVAIL | TPM_STS_VALID, 312 chip->timeout_c, 313 &tpm_dev->read_queue, true) == 0) { 314 burstcnt = get_burstcount(chip); 315 if (burstcnt < 0) 316 return burstcnt; 317 len = min_t(int, burstcnt, count - size); 318 ret = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_DATA_FIFO, 319 buf + size, len); 320 if (ret < 0) 321 return ret; 322 323 size += len; 324 } 325 return size; 326 } 327 328 /* 329 * tpm_ioserirq_handler the serirq irq handler 330 * @param: irq, the tpm chip description 331 * @param: dev_id, the description of the chip 332 * @return: the status of the handler. 333 */ 334 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) 335 { 336 struct tpm_chip *chip = dev_id; 337 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 338 339 tpm_dev->intrs++; 340 wake_up_interruptible(&tpm_dev->read_queue); 341 disable_irq_nosync(tpm_dev->irq); 342 343 return IRQ_HANDLED; 344 } /* tpm_ioserirq_handler() */ 345 346 /* 347 * st33zp24_send send TPM commands through the I2C bus. 348 * 349 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h 350 * @param: buf, the buffer to send. 351 * @param: count, the number of bytes to send. 352 * @return: In case of success the number of bytes sent. 353 * In other case, a < 0 value describing the issue. 354 */ 355 static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf, 356 size_t len) 357 { 358 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 359 u32 status, i, size, ordinal; 360 int burstcnt = 0; 361 int ret; 362 u8 data; 363 364 if (len < TPM_HEADER_SIZE) 365 return -EBUSY; 366 367 ret = request_locality(chip); 368 if (ret < 0) 369 return ret; 370 371 status = st33zp24_status(chip); 372 if ((status & TPM_STS_COMMAND_READY) == 0) { 373 st33zp24_cancel(chip); 374 if (wait_for_stat 375 (chip, TPM_STS_COMMAND_READY, chip->timeout_b, 376 &tpm_dev->read_queue, false) < 0) { 377 ret = -ETIME; 378 goto out_err; 379 } 380 } 381 382 for (i = 0; i < len - 1;) { 383 burstcnt = get_burstcount(chip); 384 if (burstcnt < 0) 385 return burstcnt; 386 size = min_t(int, len - i - 1, burstcnt); 387 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO, 388 buf + i, size); 389 if (ret < 0) 390 goto out_err; 391 392 i += size; 393 } 394 395 status = st33zp24_status(chip); 396 if ((status & TPM_STS_DATA_EXPECT) == 0) { 397 ret = -EIO; 398 goto out_err; 399 } 400 401 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO, 402 buf + len - 1, 1); 403 if (ret < 0) 404 goto out_err; 405 406 status = st33zp24_status(chip); 407 if ((status & TPM_STS_DATA_EXPECT) != 0) { 408 ret = -EIO; 409 goto out_err; 410 } 411 412 data = TPM_STS_GO; 413 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1); 414 if (ret < 0) 415 goto out_err; 416 417 if (chip->flags & TPM_CHIP_FLAG_IRQ) { 418 ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); 419 420 ret = wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 421 tpm_calc_ordinal_duration(chip, ordinal), 422 &tpm_dev->read_queue, false); 423 if (ret < 0) 424 goto out_err; 425 } 426 427 return 0; 428 out_err: 429 st33zp24_cancel(chip); 430 release_locality(chip); 431 return ret; 432 } 433 434 /* 435 * st33zp24_recv received TPM response through TPM phy. 436 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h. 437 * @param: buf, the buffer to store datas. 438 * @param: count, the number of bytes to send. 439 * @return: In case of success the number of bytes received. 440 * In other case, a < 0 value describing the issue. 441 */ 442 static int st33zp24_recv(struct tpm_chip *chip, unsigned char *buf, 443 size_t count) 444 { 445 int size = 0; 446 u32 expected; 447 448 if (!chip) 449 return -EBUSY; 450 451 if (count < TPM_HEADER_SIZE) { 452 size = -EIO; 453 goto out; 454 } 455 456 size = recv_data(chip, buf, TPM_HEADER_SIZE); 457 if (size < TPM_HEADER_SIZE) { 458 dev_err(&chip->dev, "Unable to read header\n"); 459 goto out; 460 } 461 462 expected = be32_to_cpu(*(__be32 *)(buf + 2)); 463 if (expected > count || expected < TPM_HEADER_SIZE) { 464 size = -EIO; 465 goto out; 466 } 467 468 size += recv_data(chip, &buf[TPM_HEADER_SIZE], 469 expected - TPM_HEADER_SIZE); 470 if (size < expected) { 471 dev_err(&chip->dev, "Unable to read remainder of result\n"); 472 size = -ETIME; 473 } 474 475 out: 476 st33zp24_cancel(chip); 477 release_locality(chip); 478 return size; 479 } 480 481 /* 482 * st33zp24_req_canceled 483 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h. 484 * @param: status, the TPM status. 485 * @return: Does TPM ready to compute a new command ? true. 486 */ 487 static bool st33zp24_req_canceled(struct tpm_chip *chip, u8 status) 488 { 489 return (status == TPM_STS_COMMAND_READY); 490 } 491 492 static const struct tpm_class_ops st33zp24_tpm = { 493 .flags = TPM_OPS_AUTO_STARTUP, 494 .send = st33zp24_send, 495 .recv = st33zp24_recv, 496 .cancel = st33zp24_cancel, 497 .status = st33zp24_status, 498 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID, 499 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID, 500 .req_canceled = st33zp24_req_canceled, 501 }; 502 503 /* 504 * st33zp24_probe initialize the TPM device 505 * @param: client, the i2c_client drescription (TPM I2C description). 506 * @param: id, the i2c_device_id struct. 507 * @return: 0 in case of success. 508 * -1 in other case. 509 */ 510 int st33zp24_probe(void *phy_id, const struct st33zp24_phy_ops *ops, 511 struct device *dev, int irq, int io_lpcpd) 512 { 513 int ret; 514 u8 intmask = 0; 515 struct tpm_chip *chip; 516 struct st33zp24_dev *tpm_dev; 517 518 chip = tpmm_chip_alloc(dev, &st33zp24_tpm); 519 if (IS_ERR(chip)) 520 return PTR_ERR(chip); 521 522 tpm_dev = devm_kzalloc(dev, sizeof(struct st33zp24_dev), 523 GFP_KERNEL); 524 if (!tpm_dev) 525 return -ENOMEM; 526 527 tpm_dev->phy_id = phy_id; 528 tpm_dev->ops = ops; 529 dev_set_drvdata(&chip->dev, tpm_dev); 530 531 chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT); 532 chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT); 533 chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT); 534 chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT); 535 536 tpm_dev->locality = LOCALITY0; 537 538 if (irq) { 539 /* INTERRUPT Setup */ 540 init_waitqueue_head(&tpm_dev->read_queue); 541 tpm_dev->intrs = 0; 542 543 if (request_locality(chip) != LOCALITY0) { 544 ret = -ENODEV; 545 goto _tpm_clean_answer; 546 } 547 548 clear_interruption(tpm_dev); 549 ret = devm_request_irq(dev, irq, tpm_ioserirq_handler, 550 IRQF_TRIGGER_HIGH, "TPM SERIRQ management", 551 chip); 552 if (ret < 0) { 553 dev_err(&chip->dev, "TPM SERIRQ signals %d not available\n", 554 irq); 555 goto _tpm_clean_answer; 556 } 557 558 intmask |= TPM_INTF_CMD_READY_INT 559 | TPM_INTF_STS_VALID_INT 560 | TPM_INTF_DATA_AVAIL_INT; 561 562 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_ENABLE, 563 &intmask, 1); 564 if (ret < 0) 565 goto _tpm_clean_answer; 566 567 intmask = TPM_GLOBAL_INT_ENABLE; 568 ret = tpm_dev->ops->send(tpm_dev->phy_id, (TPM_INT_ENABLE + 3), 569 &intmask, 1); 570 if (ret < 0) 571 goto _tpm_clean_answer; 572 573 tpm_dev->irq = irq; 574 chip->flags |= TPM_CHIP_FLAG_IRQ; 575 576 disable_irq_nosync(tpm_dev->irq); 577 } 578 579 return tpm_chip_register(chip); 580 _tpm_clean_answer: 581 dev_info(&chip->dev, "TPM initialization fail\n"); 582 return ret; 583 } 584 EXPORT_SYMBOL(st33zp24_probe); 585 586 /* 587 * st33zp24_remove remove the TPM device 588 * @param: tpm_data, the tpm phy. 589 * @return: 0 in case of success. 590 */ 591 int st33zp24_remove(struct tpm_chip *chip) 592 { 593 tpm_chip_unregister(chip); 594 return 0; 595 } 596 EXPORT_SYMBOL(st33zp24_remove); 597 598 #ifdef CONFIG_PM_SLEEP 599 /* 600 * st33zp24_pm_suspend suspend the TPM device 601 * @param: tpm_data, the tpm phy. 602 * @param: mesg, the power management message. 603 * @return: 0 in case of success. 604 */ 605 int st33zp24_pm_suspend(struct device *dev) 606 { 607 struct tpm_chip *chip = dev_get_drvdata(dev); 608 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 609 610 int ret = 0; 611 612 if (gpio_is_valid(tpm_dev->io_lpcpd)) 613 gpio_set_value(tpm_dev->io_lpcpd, 0); 614 else 615 ret = tpm_pm_suspend(dev); 616 617 return ret; 618 } /* st33zp24_pm_suspend() */ 619 EXPORT_SYMBOL(st33zp24_pm_suspend); 620 621 /* 622 * st33zp24_pm_resume resume the TPM device 623 * @param: tpm_data, the tpm phy. 624 * @return: 0 in case of success. 625 */ 626 int st33zp24_pm_resume(struct device *dev) 627 { 628 struct tpm_chip *chip = dev_get_drvdata(dev); 629 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); 630 int ret = 0; 631 632 if (gpio_is_valid(tpm_dev->io_lpcpd)) { 633 gpio_set_value(tpm_dev->io_lpcpd, 1); 634 ret = wait_for_stat(chip, 635 TPM_STS_VALID, chip->timeout_b, 636 &tpm_dev->read_queue, false); 637 } else { 638 ret = tpm_pm_resume(dev); 639 if (!ret) 640 tpm1_do_selftest(chip); 641 } 642 return ret; 643 } /* st33zp24_pm_resume() */ 644 EXPORT_SYMBOL(st33zp24_pm_resume); 645 #endif 646 647 MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)"); 648 MODULE_DESCRIPTION("ST33ZP24 TPM 1.2 driver"); 649 MODULE_VERSION("1.3.0"); 650 MODULE_LICENSE("GPL"); 651