1 /* 2 * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver 3 * 4 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved 5 * Author(s): Christophe Ricard <christophe-h.ricard@st.com> for STMicroelectronics. 6 * 7 * Description: Device driver for ST33ZP24 I2C TPM TCG. 8 * 9 * This device driver implements the TPM interface as defined in 10 * the TCG TPM Interface Spec version 1.21, revision 1.0 and the 11 * STMicroelectronics Protocol Stack Specification version 1.2.0. 12 * 13 * SPDX-License-Identifier: GPL-2.0+ 14 */ 15 16 #include <common.h> 17 #include <dm.h> 18 #include <fdtdec.h> 19 #include <i2c.h> 20 #include <tpm.h> 21 #include <errno.h> 22 #include <linux/types.h> 23 #include <asm/unaligned.h> 24 25 #include "tpm_tis.h" 26 #include "tpm_internal.h" 27 28 #define TPM_ACCESS 0x0 29 #define TPM_STS 0x18 30 #define TPM_DATA_FIFO 0x24 31 32 #define LOCALITY0 0 33 34 #define TPM_DUMMY_BYTE 0xAA 35 #define TPM_ST33ZP24_I2C_SLAVE_ADDR 0x13 36 37 #define TPM_WRITE_DIRECTION 0x80 38 39 /* 40 * st33zp24_i2c_write8_reg 41 * Send byte to the TIS register according to the ST33ZP24 I2C protocol. 42 * @param: tpm_register, the tpm tis register where the data should be written 43 * @param: tpm_data, the tpm_data to write inside the tpm_register 44 * @param: tpm_size, The length of the data 45 * @return: Number of byte written successfully else an error code. 46 */ 47 static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register, 48 const u8 *tpm_data, size_t tpm_size) 49 { 50 struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev); 51 52 chip_priv->buf[0] = tpm_register; 53 memcpy(chip_priv->buf + 1, tpm_data, tpm_size); 54 55 return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1); 56 } 57 58 /* 59 * st33zp24_i2c_read8_reg 60 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. 61 * @param: tpm_register, the tpm tis register where the data should be read 62 * @param: tpm_data, the TPM response 63 * @param: tpm_size, tpm TPM response size to read. 64 * @return: Number of byte read successfully else an error code. 65 */ 66 static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register, 67 u8 *tpm_data, size_t tpm_size) 68 { 69 int status; 70 u8 data; 71 72 data = TPM_DUMMY_BYTE; 73 status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1); 74 if (status < 0) 75 return status; 76 77 return dm_i2c_read(dev, 0, tpm_data, tpm_size); 78 } 79 80 /* 81 * st33zp24_i2c_write 82 * Send byte to the TIS register according to the ST33ZP24 I2C protocol. 83 * @param: phy_id, the phy description 84 * @param: tpm_register, the tpm tis register where the data should be written 85 * @param: tpm_data, the tpm_data to write inside the tpm_register 86 * @param: tpm_size, the length of the data 87 * @return: number of byte written successfully: should be one if success. 88 */ 89 static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register, 90 const u8 *tpm_data, size_t tpm_size) 91 { 92 return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION, 93 tpm_data, tpm_size); 94 } 95 96 /* 97 * st33zp24_i2c_read 98 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. 99 * @param: phy_id, the phy description 100 * @param: tpm_register, the tpm tis register where the data should be read 101 * @param: tpm_data, the TPM response 102 * @param: tpm_size, tpm TPM response size to read. 103 * @return: number of byte read successfully: should be one if success. 104 */ 105 static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register, 106 u8 *tpm_data, size_t tpm_size) 107 { 108 return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size); 109 } 110 111 /* 112 * st33zp24_i2c_release_locality release the active locality 113 * @param: chip, the tpm chip description. 114 */ 115 static void st33zp24_i2c_release_locality(struct udevice *dev) 116 { 117 u8 data = TPM_ACCESS_ACTIVE_LOCALITY; 118 119 st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1); 120 } 121 122 /* 123 * st33zp24_i2c_check_locality if the locality is active 124 * @param: chip, the tpm chip description 125 * @return: the active locality or -EACCES. 126 */ 127 static int st33zp24_i2c_check_locality(struct udevice *dev) 128 { 129 struct tpm_chip *chip = dev_get_priv(dev); 130 u8 data; 131 u8 status; 132 133 status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1); 134 if (!status && (data & 135 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == 136 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) 137 return chip->locality; 138 139 return -EACCES; 140 } 141 142 /* 143 * st33zp24_i2c_request_locality request the TPM locality 144 * @param: chip, the chip description 145 * @return: the active locality or negative value. 146 */ 147 static int st33zp24_i2c_request_locality(struct udevice *dev) 148 { 149 struct tpm_chip *chip = dev_get_priv(dev); 150 unsigned long start, stop; 151 long ret; 152 u8 data; 153 154 if (st33zp24_i2c_check_locality(dev) == chip->locality) 155 return chip->locality; 156 157 data = TPM_ACCESS_REQUEST_USE; 158 ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1); 159 if (ret < 0) 160 return ret; 161 162 /* wait for locality activated */ 163 start = get_timer(0); 164 stop = chip->timeout_a; 165 do { 166 if (st33zp24_i2c_check_locality(dev) >= 0) 167 return chip->locality; 168 udelay(TPM_TIMEOUT_MS * 1000); 169 } while (get_timer(start) < stop); 170 171 return -EACCES; 172 } 173 174 /* 175 * st33zp24_i2c_status return the TPM_STS register 176 * @param: chip, the tpm chip description 177 * @return: the TPM_STS register value. 178 */ 179 static u8 st33zp24_i2c_status(struct udevice *dev) 180 { 181 u8 data; 182 183 st33zp24_i2c_read(dev, TPM_STS, &data, 1); 184 185 return data; 186 } 187 188 /* 189 * st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A 190 * @param: chip, the chip description 191 * return: the burstcount or -TPM_DRIVER_ERR in case of error. 192 */ 193 static int st33zp24_i2c_get_burstcount(struct udevice *dev) 194 { 195 struct tpm_chip *chip = dev_get_priv(dev); 196 unsigned long start, stop; 197 int burstcnt, status; 198 u8 tpm_reg, temp; 199 200 /* wait for burstcount */ 201 start = get_timer(0); 202 stop = chip->timeout_d; 203 do { 204 tpm_reg = TPM_STS + 1; 205 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1); 206 if (status < 0) 207 return -EBUSY; 208 209 tpm_reg = TPM_STS + 2; 210 burstcnt = temp; 211 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1); 212 if (status < 0) 213 return -EBUSY; 214 215 burstcnt |= temp << 8; 216 if (burstcnt) 217 return burstcnt; 218 udelay(TIS_SHORT_TIMEOUT_MS * 1000); 219 } while (get_timer(start) < stop); 220 221 return -EBUSY; 222 } 223 224 /* 225 * st33zp24_i2c_cancel, cancel the current command execution or 226 * set STS to COMMAND READY. 227 * @param: chip, tpm_chip description. 228 */ 229 static void st33zp24_i2c_cancel(struct udevice *dev) 230 { 231 u8 data; 232 233 data = TPM_STS_COMMAND_READY; 234 st33zp24_i2c_write(dev, TPM_STS, &data, 1); 235 } 236 237 /* 238 * st33zp24_i2c_wait_for_stat wait for a TPM_STS value 239 * @param: chip, the tpm chip description 240 * @param: mask, the value mask to wait 241 * @param: timeout, the timeout 242 * @param: status, 243 * @return: the tpm status, 0 if success, -ETIME if timeout is reached. 244 */ 245 static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask, 246 unsigned long timeout, int *status) 247 { 248 unsigned long start, stop; 249 250 /* Check current status */ 251 *status = st33zp24_i2c_status(dev); 252 if ((*status & mask) == mask) 253 return 0; 254 255 start = get_timer(0); 256 stop = timeout; 257 do { 258 udelay(TPM_TIMEOUT_MS * 1000); 259 *status = st33zp24_i2c_status(dev); 260 if ((*status & mask) == mask) 261 return 0; 262 } while (get_timer(start) < stop); 263 264 return -ETIME; 265 } 266 267 /* 268 * st33zp24_i2c_recv_data receive data 269 * @param: chip, the tpm chip description 270 * @param: buf, the buffer where the data are received 271 * @param: count, the number of data to receive 272 * @return: the number of bytes read from TPM FIFO. 273 */ 274 static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count) 275 { 276 struct tpm_chip *chip = dev_get_priv(dev); 277 int size = 0, burstcnt, len, ret, status; 278 279 while (size < count && 280 st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 281 chip->timeout_c, &status) == 0) { 282 burstcnt = st33zp24_i2c_get_burstcount(dev); 283 if (burstcnt < 0) 284 return burstcnt; 285 len = min_t(int, burstcnt, count - size); 286 ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len); 287 if (ret < 0) 288 return ret; 289 290 size += len; 291 } 292 293 return size; 294 } 295 296 /* 297 * st33zp24_i2c_recv received TPM response through TPM phy. 298 * @param: chip, tpm_chip description. 299 * @param: buf, the buffer to store data. 300 * @param: count, the number of bytes that can received (sizeof buf). 301 * @return: Returns zero in case of success else -EIO. 302 */ 303 static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count) 304 { 305 struct tpm_chip *chip = dev_get_priv(dev); 306 int size, expected; 307 308 if (!chip) 309 return -ENODEV; 310 311 if (count < TPM_HEADER_SIZE) { 312 size = -EIO; 313 goto out; 314 } 315 316 size = st33zp24_i2c_recv_data(dev, buf, TPM_HEADER_SIZE); 317 if (size < TPM_HEADER_SIZE) { 318 debug("TPM error, unable to read header\n"); 319 goto out; 320 } 321 322 expected = get_unaligned_be32(buf + 2); 323 if (expected > count) { 324 size = -EIO; 325 goto out; 326 } 327 328 size += st33zp24_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE], 329 expected - TPM_HEADER_SIZE); 330 if (size < expected) { 331 debug("TPM error, unable to read remaining bytes of result\n"); 332 size = -EIO; 333 goto out; 334 } 335 336 out: 337 st33zp24_i2c_cancel(dev); 338 st33zp24_i2c_release_locality(dev); 339 340 return size; 341 } 342 343 /* 344 * st33zp24_i2c_send send TPM commands through TPM phy. 345 * @param: chip, tpm_chip description. 346 * @param: buf, the buffer to send. 347 * @param: len, the number of bytes to send. 348 * @return: Returns zero in case of success else the negative error code. 349 */ 350 static int st33zp24_i2c_send(struct udevice *dev, const u8 *buf, size_t len) 351 { 352 struct tpm_chip *chip = dev_get_priv(dev); 353 u32 i, size; 354 int burstcnt, ret, status; 355 u8 data, tpm_stat; 356 357 if (!chip) 358 return -ENODEV; 359 if (len < TPM_HEADER_SIZE) 360 return -EIO; 361 362 ret = st33zp24_i2c_request_locality(dev); 363 if (ret < 0) 364 return ret; 365 366 tpm_stat = st33zp24_i2c_status(dev); 367 if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) { 368 st33zp24_i2c_cancel(dev); 369 if (st33zp24_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY, 370 chip->timeout_b, &status) < 0) { 371 ret = -ETIME; 372 goto out_err; 373 } 374 } 375 376 for (i = 0; i < len - 1;) { 377 burstcnt = st33zp24_i2c_get_burstcount(dev); 378 if (burstcnt < 0) 379 return burstcnt; 380 381 size = min_t(int, len - i - 1, burstcnt); 382 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size); 383 if (ret < 0) 384 goto out_err; 385 386 i += size; 387 } 388 389 tpm_stat = st33zp24_i2c_status(dev); 390 if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) { 391 ret = -EIO; 392 goto out_err; 393 } 394 395 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1); 396 if (ret < 0) 397 goto out_err; 398 399 tpm_stat = st33zp24_i2c_status(dev); 400 if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) { 401 ret = -EIO; 402 goto out_err; 403 } 404 405 data = TPM_STS_GO; 406 ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1); 407 if (ret < 0) 408 goto out_err; 409 410 return len; 411 412 out_err: 413 st33zp24_i2c_cancel(dev); 414 st33zp24_i2c_release_locality(dev); 415 416 return ret; 417 } 418 419 static int st33zp24_i2c_cleanup(struct udevice *dev) 420 { 421 st33zp24_i2c_cancel(dev); 422 /* 423 * The TPM needs some time to clean up here, 424 * so we sleep rather than keeping the bus busy 425 */ 426 mdelay(2); 427 st33zp24_i2c_release_locality(dev); 428 429 return 0; 430 } 431 432 static int st33zp24_i2c_init(struct udevice *dev) 433 { 434 struct tpm_chip *chip = dev_get_priv(dev); 435 436 chip->is_open = 1; 437 438 /* Default timeouts - these could move to the device tree */ 439 chip->timeout_a = TIS_SHORT_TIMEOUT_MS; 440 chip->timeout_b = TIS_LONG_TIMEOUT_MS; 441 chip->timeout_c = TIS_SHORT_TIMEOUT_MS; 442 chip->timeout_d = TIS_SHORT_TIMEOUT_MS; 443 444 chip->locality = LOCALITY0; 445 446 /* 447 * A timeout query to TPM can be placed here. 448 * Standard timeout values are used so far 449 */ 450 451 return 0; 452 } 453 454 static int st33zp24_i2c_open(struct udevice *dev) 455 { 456 struct tpm_chip *chip = dev_get_priv(dev); 457 int rc; 458 459 debug("%s: start\n", __func__); 460 if (chip->is_open) 461 return -EBUSY; 462 463 rc = st33zp24_i2c_init(dev); 464 if (rc < 0) 465 chip->is_open = 0; 466 467 return rc; 468 } 469 470 static int st33zp24_i2c_close(struct udevice *dev) 471 { 472 struct tpm_chip *chip = dev_get_priv(dev); 473 474 if (chip->is_open) { 475 st33zp24_i2c_release_locality(dev); 476 chip->is_open = 0; 477 chip->vend_dev = 0; 478 } 479 480 return 0; 481 } 482 483 static int st33zp24_i2c_get_desc(struct udevice *dev, char *buf, int size) 484 { 485 struct tpm_chip *chip = dev_get_priv(dev); 486 487 if (size < 50) 488 return -ENOSPC; 489 490 return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)", 491 chip->is_open ? "open" : "closed", 492 dev->name, 493 chip->vend_dev >> 16); 494 } 495 496 static const struct tpm_ops st33zp24_i2c_tpm_ops = { 497 .open = st33zp24_i2c_open, 498 .close = st33zp24_i2c_close, 499 .recv = st33zp24_i2c_recv, 500 .send = st33zp24_i2c_send, 501 .cleanup = st33zp24_i2c_cleanup, 502 .get_desc = st33zp24_i2c_get_desc, 503 }; 504 505 static int st33zp24_i2c_probe(struct udevice *dev) 506 { 507 struct tpm_chip *chip = dev_get_priv(dev); 508 509 /* Default timeouts */ 510 chip->timeout_a = TIS_SHORT_TIMEOUT_MS; 511 chip->timeout_b = TIS_LONG_TIMEOUT_MS; 512 chip->timeout_c = TIS_SHORT_TIMEOUT_MS; 513 chip->timeout_d = TIS_SHORT_TIMEOUT_MS; 514 515 chip->locality = LOCALITY0; 516 517 i2c_set_chip_offset_len(dev, 0); 518 519 debug("ST33ZP24 I2C TPM from STMicroelectronics found\n"); 520 521 return 0; 522 } 523 524 static int st33zp24_i2c_remove(struct udevice *dev) 525 { 526 st33zp24_i2c_release_locality(dev); 527 528 return 0; 529 } 530 531 static const struct udevice_id st33zp24_i2c_ids[] = { 532 { .compatible = "st,st33zp24-i2c" }, 533 { } 534 }; 535 536 U_BOOT_DRIVER(st33zp24_i2c) = { 537 .name = "st33zp24-i2c", 538 .id = UCLASS_TPM, 539 .of_match = of_match_ptr(st33zp24_i2c_ids), 540 .probe = st33zp24_i2c_probe, 541 .remove = st33zp24_i2c_remove, 542 .ops = &st33zp24_i2c_tpm_ops, 543 .priv_auto_alloc_size = sizeof(struct tpm_chip), 544 }; 545