1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver 4 * 5 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved 6 * Author(s): Christophe Ricard <christophe-h.ricard (at) st.com> for STMicroelectronics. 7 * 8 * Description: Device driver for ST33ZP24 I2C TPM TCG. 9 * 10 * This device driver implements the TPM interface as defined in 11 * the TCG TPM Interface Spec version 1.21, revision 1.0 and the 12 * STMicroelectronics Protocol Stack Specification version 1.2.0. 13 */ 14 15 #include <common.h> 16 #include <dm.h> 17 #include <fdtdec.h> 18 #include <i2c.h> 19 #include <tpm-v1.h> 20 #include <errno.h> 21 #include <linux/types.h> 22 #include <asm/unaligned.h> 23 24 #include "tpm_tis.h" 25 #include "tpm_internal.h" 26 27 #define TPM_ACCESS 0x0 28 #define TPM_STS 0x18 29 #define TPM_DATA_FIFO 0x24 30 31 #define LOCALITY0 0 32 33 #define TPM_DUMMY_BYTE 0xAA 34 #define TPM_ST33ZP24_I2C_SLAVE_ADDR 0x13 35 36 #define TPM_WRITE_DIRECTION 0x80 37 38 /* 39 * st33zp24_i2c_write8_reg 40 * Send byte to the TIS register according to the ST33ZP24 I2C protocol. 41 * @param: tpm_register, the tpm tis register where the data should be written 42 * @param: tpm_data, the tpm_data to write inside the tpm_register 43 * @param: tpm_size, The length of the data 44 * @return: Number of byte written successfully else an error code. 45 */ 46 static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register, 47 const u8 *tpm_data, size_t tpm_size) 48 { 49 struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev); 50 51 chip_priv->buf[0] = tpm_register; 52 memcpy(chip_priv->buf + 1, tpm_data, tpm_size); 53 54 return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1); 55 } 56 57 /* 58 * st33zp24_i2c_read8_reg 59 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. 60 * @param: tpm_register, the tpm tis register where the data should be read 61 * @param: tpm_data, the TPM response 62 * @param: tpm_size, tpm TPM response size to read. 63 * @return: Number of byte read successfully else an error code. 64 */ 65 static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register, 66 u8 *tpm_data, size_t tpm_size) 67 { 68 int status; 69 u8 data; 70 71 data = TPM_DUMMY_BYTE; 72 status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1); 73 if (status < 0) 74 return status; 75 76 return dm_i2c_read(dev, 0, tpm_data, tpm_size); 77 } 78 79 /* 80 * st33zp24_i2c_write 81 * Send byte to the TIS register according to the ST33ZP24 I2C protocol. 82 * @param: phy_id, the phy description 83 * @param: tpm_register, the tpm tis register where the data should be written 84 * @param: tpm_data, the tpm_data to write inside the tpm_register 85 * @param: tpm_size, the length of the data 86 * @return: number of byte written successfully: should be one if success. 87 */ 88 static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register, 89 const u8 *tpm_data, size_t tpm_size) 90 { 91 return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION, 92 tpm_data, tpm_size); 93 } 94 95 /* 96 * st33zp24_i2c_read 97 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. 98 * @param: phy_id, the phy description 99 * @param: tpm_register, the tpm tis register where the data should be read 100 * @param: tpm_data, the TPM response 101 * @param: tpm_size, tpm TPM response size to read. 102 * @return: number of byte read successfully: should be one if success. 103 */ 104 static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register, 105 u8 *tpm_data, size_t tpm_size) 106 { 107 return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size); 108 } 109 110 /* 111 * st33zp24_i2c_release_locality release the active locality 112 * @param: chip, the tpm chip description. 113 */ 114 static void st33zp24_i2c_release_locality(struct udevice *dev) 115 { 116 u8 data = TPM_ACCESS_ACTIVE_LOCALITY; 117 118 st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1); 119 } 120 121 /* 122 * st33zp24_i2c_check_locality if the locality is active 123 * @param: chip, the tpm chip description 124 * @return: the active locality or -EACCES. 125 */ 126 static int st33zp24_i2c_check_locality(struct udevice *dev) 127 { 128 struct tpm_chip *chip = dev_get_priv(dev); 129 u8 data; 130 u8 status; 131 132 status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1); 133 if (!status && (data & 134 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == 135 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) 136 return chip->locality; 137 138 return -EACCES; 139 } 140 141 /* 142 * st33zp24_i2c_request_locality request the TPM locality 143 * @param: chip, the chip description 144 * @return: the active locality or negative value. 145 */ 146 static int st33zp24_i2c_request_locality(struct udevice *dev) 147 { 148 struct tpm_chip *chip = dev_get_priv(dev); 149 unsigned long start, stop; 150 long ret; 151 u8 data; 152 153 if (st33zp24_i2c_check_locality(dev) == chip->locality) 154 return chip->locality; 155 156 data = TPM_ACCESS_REQUEST_USE; 157 ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1); 158 if (ret < 0) 159 return ret; 160 161 /* wait for locality activated */ 162 start = get_timer(0); 163 stop = chip->timeout_a; 164 do { 165 if (st33zp24_i2c_check_locality(dev) >= 0) 166 return chip->locality; 167 udelay(TPM_TIMEOUT_MS * 1000); 168 } while (get_timer(start) < stop); 169 170 return -EACCES; 171 } 172 173 /* 174 * st33zp24_i2c_status return the TPM_STS register 175 * @param: chip, the tpm chip description 176 * @return: the TPM_STS register value. 177 */ 178 static u8 st33zp24_i2c_status(struct udevice *dev) 179 { 180 u8 data; 181 182 st33zp24_i2c_read(dev, TPM_STS, &data, 1); 183 184 return data; 185 } 186 187 /* 188 * st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A 189 * @param: chip, the chip description 190 * return: the burstcount or -TPM_DRIVER_ERR in case of error. 191 */ 192 static int st33zp24_i2c_get_burstcount(struct udevice *dev) 193 { 194 struct tpm_chip *chip = dev_get_priv(dev); 195 unsigned long start, stop; 196 int burstcnt, status; 197 u8 tpm_reg, temp; 198 199 /* wait for burstcount */ 200 start = get_timer(0); 201 stop = chip->timeout_d; 202 do { 203 tpm_reg = TPM_STS + 1; 204 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1); 205 if (status < 0) 206 return -EBUSY; 207 208 tpm_reg = TPM_STS + 2; 209 burstcnt = temp; 210 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1); 211 if (status < 0) 212 return -EBUSY; 213 214 burstcnt |= temp << 8; 215 if (burstcnt) 216 return burstcnt; 217 udelay(TIS_SHORT_TIMEOUT_MS * 1000); 218 } while (get_timer(start) < stop); 219 220 return -EBUSY; 221 } 222 223 /* 224 * st33zp24_i2c_cancel, cancel the current command execution or 225 * set STS to COMMAND READY. 226 * @param: chip, tpm_chip description. 227 */ 228 static void st33zp24_i2c_cancel(struct udevice *dev) 229 { 230 u8 data; 231 232 data = TPM_STS_COMMAND_READY; 233 st33zp24_i2c_write(dev, TPM_STS, &data, 1); 234 } 235 236 /* 237 * st33zp24_i2c_wait_for_stat wait for a TPM_STS value 238 * @param: chip, the tpm chip description 239 * @param: mask, the value mask to wait 240 * @param: timeout, the timeout 241 * @param: status, 242 * @return: the tpm status, 0 if success, -ETIME if timeout is reached. 243 */ 244 static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask, 245 unsigned long timeout, int *status) 246 { 247 unsigned long start, stop; 248 249 /* Check current status */ 250 *status = st33zp24_i2c_status(dev); 251 if ((*status & mask) == mask) 252 return 0; 253 254 start = get_timer(0); 255 stop = timeout; 256 do { 257 udelay(TPM_TIMEOUT_MS * 1000); 258 *status = st33zp24_i2c_status(dev); 259 if ((*status & mask) == mask) 260 return 0; 261 } while (get_timer(start) < stop); 262 263 return -ETIME; 264 } 265 266 /* 267 * st33zp24_i2c_recv_data receive data 268 * @param: chip, the tpm chip description 269 * @param: buf, the buffer where the data are received 270 * @param: count, the number of data to receive 271 * @return: the number of bytes read from TPM FIFO. 272 */ 273 static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count) 274 { 275 struct tpm_chip *chip = dev_get_priv(dev); 276 int size = 0, burstcnt, len, ret, status; 277 278 while (size < count && 279 st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 280 chip->timeout_c, &status) == 0) { 281 burstcnt = st33zp24_i2c_get_burstcount(dev); 282 if (burstcnt < 0) 283 return burstcnt; 284 len = min_t(int, burstcnt, count - size); 285 ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len); 286 if (ret < 0) 287 return ret; 288 289 size += len; 290 } 291 292 return size; 293 } 294 295 /* 296 * st33zp24_i2c_recv received TPM response through TPM phy. 297 * @param: chip, tpm_chip description. 298 * @param: buf, the buffer to store data. 299 * @param: count, the number of bytes that can received (sizeof buf). 300 * @return: Returns zero in case of success else -EIO. 301 */ 302 static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count) 303 { 304 struct tpm_chip *chip = dev_get_priv(dev); 305 int size; 306 unsigned int 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 || expected < TPM_HEADER_SIZE) { 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
