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 * See file CREDITS for list of people who contributed to this
23 * This program is free software; you can redistribute it and/or
24 * modify it under the terms of the GNU General Public License as
25 * published by the Free Software Foundation, version 2 of the
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
33 * You should have received a copy of the GNU General Public License
34 * along with this program; if not, write to the Free Software
35 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
42 #include <linux/compiler.h>
45 #include <asm-generic/errno.h>
46 #include <linux/types.h>
47 #include <linux/unaligned/be_byteshift.h>
49 #include "tpm_private.h"
51 DECLARE_GLOBAL_DATA_PTR;
53 /* Address of the TPM on the I2C bus */
54 #define TPM_I2C_ADDR 0x20
56 /* Max buffer size supported by our tpm */
57 #define TPM_DEV_BUFSIZE 1260
59 /* Max number of iterations after i2c NAK */
63 * Max number of iterations after i2c NAK for 'long' commands
65 * We need this especially for sending TPM_READY, since the cleanup after the
66 * transtion to the ready state may take some time, but it is unpredictable
67 * how long it will take.
69 #define MAX_COUNT_LONG 50
71 #define SLEEP_DURATION 60 /* in usec */
72 #define SLEEP_DURATION_LONG 210 /* in usec */
74 #define TPM_HEADER_SIZE 10
77 * Expected value for DIDVID register
79 * The only device the system knows about at this moment is Infineon slb9635.
81 #define TPM_TIS_I2C_DID_VID 0x000b15d1L
84 TPM_ACCESS_VALID = 0x80,
85 TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
86 TPM_ACCESS_REQUEST_PENDING = 0x04,
87 TPM_ACCESS_REQUEST_USE = 0x02,
92 TPM_STS_COMMAND_READY = 0x40,
94 TPM_STS_DATA_AVAIL = 0x10,
95 TPM_STS_DATA_EXPECT = 0x08,
99 TIS_SHORT_TIMEOUT = 750, /* ms */
100 TIS_LONG_TIMEOUT = 2000, /* ms */
103 /* expected value for DIDVID register */
104 #define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
105 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
113 static const char * const chip_name[] = {
114 [SLB9635] = "slb9635tt",
115 [SLB9645] = "slb9645tt",
116 [UNKNOWN] = "unknown/fallback to slb9635",
119 #define TPM_ACCESS(l) (0x0000 | ((l) << 4))
120 #define TPM_STS(l) (0x0001 | ((l) << 4))
121 #define TPM_DATA_FIFO(l) (0x0005 | ((l) << 4))
122 #define TPM_DID_VID(l) (0x0006 | ((l) << 4))
124 /* Structure to store I2C TPM specific stuff */
131 u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */
132 enum i2c_chip_type chip_type;
135 static struct tpm_dev tpm_dev = {
136 #ifndef CONFIG_DM_I2C
141 static struct tpm_dev tpm_dev;
144 * iic_tpm_read() - read from TPM register
145 * @addr: register address to read from
146 * @buffer: provided by caller
147 * @len: number of bytes to read
149 * Read len bytes from TPM register and put them into
150 * buffer (little-endian format, i.e. first byte is put into buffer[0]).
152 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
153 * values have to be swapped.
155 * Return -EIO on error, 0 on success.
157 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
161 uint32_t addrbuf = addr;
163 if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
164 /* slb9635 protocol should work in both cases */
165 for (count = 0; count < MAX_COUNT; count++) {
167 rc = dm_i2c_write(tpm_dev.dev, 0, (uchar *)&addrbuf, 1);
169 rc = i2c_write(tpm_dev.addr, 0, 0,
170 (uchar *)&addrbuf, 1);
173 break; /* Success, break to skip sleep */
174 udelay(SLEEP_DURATION);
179 /* After the TPM has successfully received the register address
180 * it needs some time, thus we're sleeping here again, before
181 * retrieving the data
183 for (count = 0; count < MAX_COUNT; count++) {
184 udelay(SLEEP_DURATION);
186 rc = dm_i2c_read(tpm_dev.dev, 0, buffer, len);
188 rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
191 break; /* success, break to skip sleep */
195 * Use a combined read for newer chips.
196 * Unfortunately the smbus functions are not suitable due to
197 * the 32 byte limit of the smbus.
198 * Retries should usually not be needed, but are kept just to
199 * be safe on the safe side.
201 for (count = 0; count < MAX_COUNT; count++) {
203 rc = dm_i2c_read(tpm_dev.dev, addr, buffer, len);
205 rc = i2c_read(tpm_dev.addr, addr, 1, buffer, len);
208 break; /* break here to skip sleep */
209 udelay(SLEEP_DURATION);
213 /* Take care of 'guard time' */
214 udelay(SLEEP_DURATION);
221 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
222 unsigned int sleep_time, u8 max_count)
227 /* Prepare send buffer */
228 #ifndef CONFIG_DM_I2C
229 tpm_dev.buf[0] = addr;
230 memcpy(&(tpm_dev.buf[1]), buffer, len);
231 buffer = tpm_dev.buf;
235 for (count = 0; count < max_count; count++) {
237 rc = dm_i2c_write(tpm_dev.dev, addr, buffer, len);
239 rc = i2c_write(tpm_dev.addr, 0, 0, buffer, len);
242 break; /* Success, break to skip sleep */
246 /* take care of 'guard time' */
255 * iic_tpm_write() - write to TPM register
256 * @addr: register address to write to
257 * @buffer: containing data to be written
258 * @len: number of bytes to write
260 * Write len bytes from provided buffer to TPM register (little
261 * endian format, i.e. buffer[0] is written as first byte).
263 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
264 * values have to be swapped.
266 * NOTE: use this function instead of the iic_tpm_write_generic function.
268 * Return -EIO on error, 0 on success
270 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
272 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
277 * This function is needed especially for the cleanup situation after
280 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
282 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
286 static int check_locality(struct tpm_chip *chip, int loc)
288 const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
292 rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
296 if ((buf & mask) == mask) {
297 chip->vendor.locality = loc;
304 static void release_locality(struct tpm_chip *chip, int loc, int force)
306 const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
309 if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
312 if (force || (buf & mask) == mask) {
313 buf = TPM_ACCESS_ACTIVE_LOCALITY;
314 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
318 static int request_locality(struct tpm_chip *chip, int loc)
320 unsigned long start, stop;
321 u8 buf = TPM_ACCESS_REQUEST_USE;
324 if (check_locality(chip, loc) >= 0)
325 return loc; /* We already have the locality */
327 rc = iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
331 /* Wait for burstcount */
332 start = get_timer(0);
333 stop = chip->vendor.timeout_a;
335 if (check_locality(chip, loc) >= 0)
337 udelay(TPM_TIMEOUT * 1000);
338 } while (get_timer(start) < stop);
343 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
345 /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
348 if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
354 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
358 /* This causes the current command to be aborted */
359 u8 buf = TPM_STS_COMMAND_READY;
361 debug("%s\n", __func__);
362 rc = iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
364 debug("%s: rc=%d\n", __func__, rc);
367 static ssize_t get_burstcount(struct tpm_chip *chip)
369 unsigned long start, stop;
373 /* Wait for burstcount */
374 /* XXX: Which timeout value? Spec has 2 answers (c & d) */
375 start = get_timer(0);
376 stop = chip->vendor.timeout_d;
378 /* Note: STS is little endian */
379 addr = TPM_STS(chip->vendor.locality) + 1;
380 if (iic_tpm_read(addr, buf, 3) < 0)
383 burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
387 udelay(TPM_TIMEOUT * 1000);
388 } while (get_timer(start) < stop);
393 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
396 unsigned long start, stop;
398 /* Check current status */
399 *status = tpm_tis_i2c_status(chip);
400 if ((*status & mask) == mask)
403 start = get_timer(0);
406 udelay(TPM_TIMEOUT * 1000);
407 *status = tpm_tis_i2c_status(chip);
408 if ((*status & mask) == mask)
410 } while (get_timer(start) < stop);
415 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
421 while (size < count) {
422 burstcnt = get_burstcount(chip);
424 /* burstcount < 0 -> tpm is busy */
428 /* Limit received data to max left */
429 if (burstcnt > (count - size))
430 burstcnt = count - size;
432 rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
433 &(buf[size]), burstcnt);
441 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
444 int expected, status;
446 if (count < TPM_HEADER_SIZE) {
451 /* Read first 10 bytes, including tag, paramsize, and result */
452 size = recv_data(chip, buf, TPM_HEADER_SIZE);
453 if (size < TPM_HEADER_SIZE) {
454 error("Unable to read header\n");
458 expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
459 if ((size_t)expected > count) {
460 error("Error size=%x, expected=%x, count=%x\n", size, expected,
466 size += recv_data(chip, &buf[TPM_HEADER_SIZE],
467 expected - TPM_HEADER_SIZE);
468 if (size < expected) {
469 error("Unable to read remainder of result\n");
474 wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
475 if (status & TPM_STS_DATA_AVAIL) { /* Retry? */
476 error("Error left over data\n");
482 tpm_tis_i2c_ready(chip);
484 * The TPM needs some time to clean up here,
485 * so we sleep rather than keeping the bus busy
488 release_locality(chip, chip->vendor.locality, 0);
493 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
501 debug("%s: len=%d\n", __func__, len);
502 if (len > TPM_DEV_BUFSIZE)
503 return -E2BIG; /* Command is too long for our tpm, sorry */
505 if (request_locality(chip, 0) < 0)
508 status = tpm_tis_i2c_status(chip);
509 if ((status & TPM_STS_COMMAND_READY) == 0) {
510 tpm_tis_i2c_ready(chip);
511 if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
512 chip->vendor.timeout_b, &status) < 0) {
518 burstcnt = get_burstcount(chip);
520 /* burstcount < 0 -> tpm is busy */
524 while (count < len) {
526 if (burstcnt > len - count)
527 burstcnt = len - count;
529 #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
530 if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION)
531 burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION;
532 #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
534 rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
535 &(buf[count]), burstcnt);
539 debug("%s: error\n", __func__);
544 rc = wait_for_stat(chip, TPM_STS_VALID,
545 chip->vendor.timeout_c, &status);
549 if ((status & TPM_STS_DATA_EXPECT) == 0) {
557 iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
563 debug("%s: out_err\n", __func__);
564 tpm_tis_i2c_ready(chip);
566 * The TPM needs some time to clean up here,
567 * so we sleep rather than keeping the bus busy
570 release_locality(chip, chip->vendor.locality, 0);
575 static struct tpm_vendor_specific tpm_tis_i2c = {
576 .status = tpm_tis_i2c_status,
577 .recv = tpm_tis_i2c_recv,
578 .send = tpm_tis_i2c_send,
579 .cancel = tpm_tis_i2c_ready,
580 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
581 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
582 .req_canceled = TPM_STS_COMMAND_READY,
586 static enum i2c_chip_type tpm_vendor_chip_type(void)
588 #if CONFIG_IS_ENABLED(OF_CONTROL)
589 const void *blob = gd->fdt_blob;
591 if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
594 if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
600 static int tpm_vendor_init_common(void)
602 struct tpm_chip *chip;
604 u32 expected_did_vid;
606 tpm_dev.chip_type = tpm_vendor_chip_type();
608 chip = tpm_register_hardware(&tpm_tis_i2c);
612 /* Disable interrupts (not supported) */
613 chip->vendor.irq = 0;
615 /* Default timeouts */
616 chip->vendor.timeout_a = TIS_SHORT_TIMEOUT;
617 chip->vendor.timeout_b = TIS_LONG_TIMEOUT;
618 chip->vendor.timeout_c = TIS_SHORT_TIMEOUT;
619 chip->vendor.timeout_d = TIS_SHORT_TIMEOUT;
621 if (request_locality(chip, 0) < 0)
624 /* Read four bytes from DID_VID register */
625 if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
626 release_locality(chip, 0, 1);
630 if (tpm_dev.chip_type == SLB9635) {
631 vendor = be32_to_cpu(vendor);
632 expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
634 /* device id and byte order has changed for newer i2c tpms */
635 expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
638 if (tpm_dev.chip_type != UNKNOWN && vendor != expected_did_vid) {
639 error("Vendor id did not match! ID was %08x\n", vendor);
643 debug("1.2 TPM (chip type %s device-id 0x%X)\n",
644 chip_name[tpm_dev.chip_type], vendor >> 16);
647 * A timeout query to TPM can be placed here.
648 * Standard timeout values are used so far
655 /* Initialisation of i2c tpm */
656 int tpm_vendor_init_dev(struct udevice *dev)
659 return tpm_vendor_init_common();
662 /* Initialisation of i2c tpm */
663 int tpm_vendor_init(uint32_t dev_addr)
668 old_addr = tpm_dev.addr;
670 tpm_dev.addr = dev_addr;
672 rc = tpm_vendor_init_common();
674 tpm_dev.addr = old_addr;
680 void tpm_vendor_cleanup(struct tpm_chip *chip)
682 release_locality(chip, chip->vendor.locality, 1);