2 * Copyright (C) 2011 Infineon Technologies
5 * Peter Huewe <huewe.external@infineon.com>
8 * Device driver for TCG/TCPA TPM (trusted platform module).
9 * Specifications at www.trustedcomputinggroup.org
11 * This device driver implements the TPM interface as defined in
12 * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
13 * Infineon I2C Protocol Stack Specification v0.20.
15 * It is based on the Linux kernel driver tpm.c from Leendert van
16 * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
20 * SPDX-License-Identifier: GPL-2.0
26 #include <linux/compiler.h>
29 #include <asm-generic/errno.h>
30 #include <linux/types.h>
31 #include <linux/unaligned/be_byteshift.h>
33 #include "tpm_tis_i2c.h"
35 DECLARE_GLOBAL_DATA_PTR;
37 static const char * const chip_name[] = {
38 [SLB9635] = "slb9635tt",
39 [SLB9645] = "slb9645tt",
40 [UNKNOWN] = "unknown/fallback to slb9635",
43 static struct tpm_chip g_chip;
46 * iic_tpm_read() - read from TPM register
47 * @addr: register address to read from
48 * @buffer: provided by caller
49 * @len: number of bytes to read
51 * Read len bytes from TPM register and put them into
52 * buffer (little-endian format, i.e. first byte is put into buffer[0]).
54 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
55 * values have to be swapped.
57 * Return -EIO on error, 0 on success.
59 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
63 uint32_t addrbuf = addr;
65 if ((g_chip.chip_type == SLB9635) || (g_chip.chip_type == UNKNOWN)) {
66 /* slb9635 protocol should work in both cases */
67 for (count = 0; count < MAX_COUNT; count++) {
68 rc = dm_i2c_write(g_chip.dev, 0, (uchar *)&addrbuf, 1);
70 break; /* Success, break to skip sleep */
71 udelay(SLEEP_DURATION);
76 /* After the TPM has successfully received the register address
77 * it needs some time, thus we're sleeping here again, before
80 for (count = 0; count < MAX_COUNT; count++) {
81 udelay(SLEEP_DURATION);
82 rc = dm_i2c_read(g_chip.dev, 0, buffer, len);
84 break; /* success, break to skip sleep */
88 * Use a combined read for newer chips.
89 * Unfortunately the smbus functions are not suitable due to
90 * the 32 byte limit of the smbus.
91 * Retries should usually not be needed, but are kept just to
92 * be safe on the safe side.
94 for (count = 0; count < MAX_COUNT; count++) {
95 rc = dm_i2c_read(g_chip.dev, addr, buffer, len);
97 break; /* break here to skip sleep */
98 udelay(SLEEP_DURATION);
102 /* Take care of 'guard time' */
103 udelay(SLEEP_DURATION);
110 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
111 unsigned int sleep_time, u8 max_count)
116 for (count = 0; count < max_count; count++) {
117 rc = dm_i2c_write(g_chip.dev, addr, buffer, len);
119 break; /* Success, break to skip sleep */
123 /* take care of 'guard time' */
132 * iic_tpm_write() - write to TPM register
133 * @addr: register address to write to
134 * @buffer: containing data to be written
135 * @len: number of bytes to write
137 * Write len bytes from provided buffer to TPM register (little
138 * endian format, i.e. buffer[0] is written as first byte).
140 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
141 * values have to be swapped.
143 * NOTE: use this function instead of the iic_tpm_write_generic function.
145 * Return -EIO on error, 0 on success
147 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
149 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
154 * This function is needed especially for the cleanup situation after
157 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
159 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
163 static int check_locality(struct tpm_chip *chip, int loc)
165 const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
169 rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
173 if ((buf & mask) == mask) {
174 chip->locality = loc;
181 static void release_locality(struct tpm_chip *chip, int loc, int force)
183 const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
186 if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
189 if (force || (buf & mask) == mask) {
190 buf = TPM_ACCESS_ACTIVE_LOCALITY;
191 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
195 static int request_locality(struct tpm_chip *chip, int loc)
197 unsigned long start, stop;
198 u8 buf = TPM_ACCESS_REQUEST_USE;
201 if (check_locality(chip, loc) >= 0)
202 return loc; /* We already have the locality */
204 rc = iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
208 /* Wait for burstcount */
209 start = get_timer(0);
210 stop = chip->timeout_a;
212 if (check_locality(chip, loc) >= 0)
214 udelay(TPM_TIMEOUT * 1000);
215 } while (get_timer(start) < stop);
220 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
222 /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
225 if (iic_tpm_read(TPM_STS(chip->locality), &buf, 1) < 0)
231 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
235 /* This causes the current command to be aborted */
236 u8 buf = TPM_STS_COMMAND_READY;
238 debug("%s\n", __func__);
239 rc = iic_tpm_write_long(TPM_STS(chip->locality), &buf, 1);
241 debug("%s: rc=%d\n", __func__, rc);
244 static ssize_t get_burstcount(struct tpm_chip *chip)
246 unsigned long start, stop;
250 /* Wait for burstcount */
251 /* XXX: Which timeout value? Spec has 2 answers (c & d) */
252 start = get_timer(0);
253 stop = chip->timeout_d;
255 /* Note: STS is little endian */
256 addr = TPM_STS(chip->locality) + 1;
257 if (iic_tpm_read(addr, buf, 3) < 0)
260 burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
264 udelay(TPM_TIMEOUT * 1000);
265 } while (get_timer(start) < stop);
270 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
273 unsigned long start, stop;
275 /* Check current status */
276 *status = tpm_tis_i2c_status(chip);
277 if ((*status & mask) == mask)
280 start = get_timer(0);
283 udelay(TPM_TIMEOUT * 1000);
284 *status = tpm_tis_i2c_status(chip);
285 if ((*status & mask) == mask)
287 } while (get_timer(start) < stop);
292 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
298 while (size < count) {
299 burstcnt = get_burstcount(chip);
301 /* burstcount < 0 -> tpm is busy */
305 /* Limit received data to max left */
306 if (burstcnt > (count - size))
307 burstcnt = count - size;
309 rc = iic_tpm_read(TPM_DATA_FIFO(chip->locality),
310 &(buf[size]), burstcnt);
318 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
321 int expected, status;
323 if (count < TPM_HEADER_SIZE) {
328 /* Read first 10 bytes, including tag, paramsize, and result */
329 size = recv_data(chip, buf, TPM_HEADER_SIZE);
330 if (size < TPM_HEADER_SIZE) {
331 error("Unable to read header\n");
335 expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
336 if ((size_t)expected > count) {
337 error("Error size=%x, expected=%x, count=%x\n", size, expected,
343 size += recv_data(chip, &buf[TPM_HEADER_SIZE],
344 expected - TPM_HEADER_SIZE);
345 if (size < expected) {
346 error("Unable to read remainder of result\n");
351 wait_for_stat(chip, TPM_STS_VALID, chip->timeout_c, &status);
352 if (status & TPM_STS_DATA_AVAIL) { /* Retry? */
353 error("Error left over data\n");
359 tpm_tis_i2c_ready(chip);
361 * The TPM needs some time to clean up here,
362 * so we sleep rather than keeping the bus busy
365 release_locality(chip, chip->locality, 0);
370 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
378 debug("%s: len=%d\n", __func__, len);
379 if (len > TPM_DEV_BUFSIZE)
380 return -E2BIG; /* Command is too long for our tpm, sorry */
382 if (request_locality(chip, 0) < 0)
385 status = tpm_tis_i2c_status(chip);
386 if ((status & TPM_STS_COMMAND_READY) == 0) {
387 tpm_tis_i2c_ready(chip);
388 if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
389 chip->timeout_b, &status) < 0) {
395 burstcnt = get_burstcount(chip);
397 /* burstcount < 0 -> tpm is busy */
401 while (count < len) {
403 if (burstcnt > len - count)
404 burstcnt = len - count;
406 #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
407 if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION)
408 burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION;
409 #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
411 rc = iic_tpm_write(TPM_DATA_FIFO(chip->locality),
412 &(buf[count]), burstcnt);
416 debug("%s: error\n", __func__);
421 rc = wait_for_stat(chip, TPM_STS_VALID,
422 chip->timeout_c, &status);
426 if ((status & TPM_STS_DATA_EXPECT) == 0) {
434 iic_tpm_write(TPM_STS(chip->locality), &sts, 1);
440 debug("%s: out_err\n", __func__);
441 tpm_tis_i2c_ready(chip);
443 * The TPM needs some time to clean up here,
444 * so we sleep rather than keeping the bus busy
447 release_locality(chip, chip->locality, 0);
452 static enum i2c_chip_type tpm_tis_i2c_chip_type(void)
454 #if CONFIG_IS_ENABLED(OF_CONTROL)
455 const void *blob = gd->fdt_blob;
457 if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
460 if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
466 static int tpm_tis_i2c_init(struct udevice *dev)
468 struct tpm_chip *chip = &g_chip;
470 u32 expected_did_vid;
473 g_chip.chip_type = tpm_tis_i2c_chip_type();
476 /* Disable interrupts (not supported) */
479 /* Default timeouts */
480 chip->timeout_a = TIS_SHORT_TIMEOUT;
481 chip->timeout_b = TIS_LONG_TIMEOUT;
482 chip->timeout_c = TIS_SHORT_TIMEOUT;
483 chip->timeout_d = TIS_SHORT_TIMEOUT;
484 chip->req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
485 chip->req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
486 chip->req_canceled = TPM_STS_COMMAND_READY;
488 if (request_locality(chip, 0) < 0)
491 /* Read four bytes from DID_VID register */
492 if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
493 release_locality(chip, 0, 1);
497 if (g_chip.chip_type == SLB9635) {
498 vendor = be32_to_cpu(vendor);
499 expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
501 /* device id and byte order has changed for newer i2c tpms */
502 expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
505 if (g_chip.chip_type != UNKNOWN && vendor != expected_did_vid) {
506 error("Vendor id did not match! ID was %08x\n", vendor);
510 debug("1.2 TPM (chip type %s device-id 0x%X)\n",
511 chip_name[g_chip.chip_type], vendor >> 16);
514 * A timeout query to TPM can be placed here.
515 * Standard timeout values are used so far
521 /* Returns max number of milliseconds to wait */
522 static unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
525 int duration_idx = TPM_UNDEFINED;
528 if (ordinal < TPM_MAX_ORDINAL) {
529 duration_idx = tpm_ordinal_duration[ordinal];
530 } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
531 TPM_MAX_PROTECTED_ORDINAL) {
532 duration_idx = tpm_protected_ordinal_duration[
533 ordinal & TPM_PROTECTED_ORDINAL_MASK];
536 if (duration_idx != TPM_UNDEFINED)
537 duration = chip->duration[duration_idx];
540 return 2 * 60 * HZ; /* Two minutes timeout */
545 static ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
549 unsigned long start, stop;
551 struct tpm_chip *chip = &g_chip;
553 /* switch endianess: big->little */
554 count = get_unaligned_be32(buf + TPM_CMD_COUNT_BYTE);
555 ordinal = get_unaligned_be32(buf + TPM_CMD_ORDINAL_BYTE);
561 if (count > bufsiz) {
562 error("invalid count value %x %zx\n", count, bufsiz);
566 debug("Calling send\n");
567 rc = tpm_tis_i2c_send(chip, (u8 *)buf, count);
568 debug(" ... done calling send\n");
570 error("tpm_transmit: tpm_send: error %d\n", rc);
577 start = get_timer(0);
578 stop = tpm_calc_ordinal_duration(chip, ordinal);
580 debug("waiting for status... %ld %ld\n", start, stop);
581 u8 status = tpm_tis_i2c_status(chip);
582 if ((status & chip->req_complete_mask) ==
583 chip->req_complete_val) {
584 debug("...got it;\n");
588 if (status == chip->req_canceled) {
589 error("Operation Canceled\n");
593 udelay(TPM_TIMEOUT * 1000);
594 } while (get_timer(start) < stop);
596 tpm_tis_i2c_ready(chip);
597 error("Operation Timed out\n");
602 debug("out_recv: reading response...\n");
603 rc = tpm_tis_i2c_recv(chip, (u8 *)buf, TPM_BUFSIZE);
605 error("tpm_transmit: tpm_recv: error %d\n", rc);
611 static int tpm_open_dev(struct udevice *dev)
615 debug("%s: start\n", __func__);
618 rc = tpm_tis_i2c_init(dev);
624 static void tpm_close(void)
626 if (g_chip.is_open) {
627 release_locality(&g_chip, g_chip.locality, 1);
633 * Decode TPM configuration.
635 * @param dev Returns a configuration of TPM device
636 * @return 0 if ok, -1 on error
638 static int tpm_decode_config(struct tpm_chip *chip)
640 const void *blob = gd->fdt_blob;
647 node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
649 node = fdtdec_next_compatible(blob, 0,
650 COMPAT_INFINEON_SLB9645_TPM);
653 debug("%s: Node not found\n", __func__);
656 parent = fdt_parent_offset(blob, node);
658 debug("%s: Cannot find node parent\n", __func__);
663 * TODO(sjg@chromium.org): Remove this when driver model supports
666 ret = uclass_get_device_by_of_offset(UCLASS_I2C, parent, &bus);
668 debug("Cannot find bus for node '%s: ret=%d'\n",
669 fdt_get_name(blob, parent, NULL), ret);
673 chip_addr = fdtdec_get_int(blob, node, "reg", -1);
674 if (chip_addr == -1) {
675 debug("Cannot find reg property for node '%s: ret=%d'\n",
676 fdt_get_name(blob, node, NULL), ret);
680 * TODO(sjg@chromium.org): Older TPMs will need to use the older method
681 * in iic_tpm_read() so the offset length needs to be 0 here.
683 ret = i2c_get_chip(bus, chip_addr, 1, &chip->dev);
685 debug("Cannot find device for node '%s: ret=%d'\n",
686 fdt_get_name(blob, node, NULL), ret);
698 if (tpm_decode_config(&g_chip))
701 debug("%s: done\n", __func__);
715 rc = tpm_open_dev(g_chip.dev);
730 int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
731 uint8_t *recvbuf, size_t *rbuf_len)
739 if (sizeof(buf) < sbuf_size)
742 memcpy(buf, sendbuf, sbuf_size);
744 len = tpm_transmit(buf, sbuf_size);
751 memcpy(recvbuf, buf, len);