1 // SPDX-License-Identifier: GPL-2.0+
3 * STMicroelectronics TPM ST33ZP24 SPI UBOOT driver
5 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
6 * Author(s): Christophe Ricard <christophe-h.ricard@st.com> for STMicroelectronics.
8 * Description: Device driver for ST33ZP24 SPI TPM TCG.
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.
21 #include <linux/types.h>
22 #include <asm/unaligned.h>
23 #include <linux/compat.h>
26 #include "tpm_internal.h"
28 #define TPM_ACCESS 0x0
30 #define TPM_DATA_FIFO 0x24
34 #define TPM_DATA_FIFO 0x24
35 #define TPM_INTF_CAPABILITY 0x14
37 #define TPM_DUMMY_BYTE 0x00
38 #define TPM_WRITE_DIRECTION 0x80
40 #define MAX_SPI_LATENCY 15
43 #define ST33ZP24_OK 0x5A
44 #define ST33ZP24_UNDEFINED_ERR 0x80
45 #define ST33ZP24_BADLOCALITY 0x81
46 #define ST33ZP24_TISREGISTER_UKNOWN 0x82
47 #define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83
48 #define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84
49 #define ST33ZP24_BAD_COMMAND_ORDER 0x85
50 #define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86
51 #define ST33ZP24_TPM_FIFO_OVERFLOW 0x89
52 #define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A
53 #define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B
54 #define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90
55 #define ST33ZP24_DUMMY_BYTES 0x00
58 * TPM command can be up to 2048 byte, A TPM response can be up to
60 * Between command and response, there are latency byte (up to 15
61 * usually on st33zp24 2 are enough).
63 * Overall when sending a command and expecting an answer we need if
65 * 2048 (for the TPM command) + 1024 (for the TPM answer). We need
66 * some latency byte before the answer is available (max 15).
67 * We have 2048 + 1024 + 15.
69 #define ST33ZP24_SPI_BUFFER_SIZE (TPM_BUFSIZE + (TPM_BUFSIZE / 2) +\
72 struct st33zp24_spi_phy {
75 u8 tx_buf[ST33ZP24_SPI_BUFFER_SIZE];
76 u8 rx_buf[ST33ZP24_SPI_BUFFER_SIZE];
79 static int st33zp24_spi_status_to_errno(u8 code)
84 case ST33ZP24_UNDEFINED_ERR:
85 case ST33ZP24_BADLOCALITY:
86 case ST33ZP24_TISREGISTER_UKNOWN:
87 case ST33ZP24_LOCALITY_NOT_ACTIVATED:
88 case ST33ZP24_HASH_END_BEFORE_HASH_START:
89 case ST33ZP24_BAD_COMMAND_ORDER:
90 case ST33ZP24_UNEXPECTED_READ_FIFO:
91 case ST33ZP24_UNEXPECTED_WRITE_FIFO:
92 case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END:
94 case ST33ZP24_INCORECT_RECEIVED_LENGTH:
95 case ST33ZP24_TPM_FIFO_OVERFLOW:
97 case ST33ZP24_DUMMY_BYTES:
105 * Send byte to TPM register according to the ST33ZP24 SPI protocol.
106 * @param: tpm, the chip description
107 * @param: tpm_register, the tpm tis register where the data should be written
108 * @param: tpm_data, the tpm_data to write inside the tpm_register
109 * @param: tpm_size, The length of the data
110 * @return: should be zero if success else a negative error code.
112 static int st33zp24_spi_write(struct udevice *dev, u8 tpm_register,
113 const u8 *tpm_data, size_t tpm_size)
115 int total_length = 0, ret;
116 struct spi_slave *slave = dev_get_parent_priv(dev);
117 struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
119 u8 *tx_buf = (u8 *)phy->tx_buf;
120 u8 *rx_buf = phy->rx_buf;
122 tx_buf[total_length++] = TPM_WRITE_DIRECTION | LOCALITY0;
123 tx_buf[total_length++] = tpm_register;
125 if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) {
126 tx_buf[total_length++] = tpm_size >> 8;
127 tx_buf[total_length++] = tpm_size;
129 memcpy(tx_buf + total_length, tpm_data, tpm_size);
130 total_length += tpm_size;
132 memset(tx_buf + total_length, TPM_DUMMY_BYTE, phy->latency);
134 total_length += phy->latency;
136 ret = spi_claim_bus(slave);
140 ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf,
141 SPI_XFER_BEGIN | SPI_XFER_END);
145 spi_release_bus(slave);
148 ret = rx_buf[total_length - 1];
150 return st33zp24_spi_status_to_errno(ret);
154 * spi_st33zp24_spi_read8_reg
155 * Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
156 * @param: tpm, the chip description
157 * @param: tpm_loc, the locality to read register from
158 * @param: tpm_register, the tpm tis register where the data should be read
159 * @param: tpm_data, the TPM response
160 * @param: tpm_size, tpm TPM response size to read.
161 * @return: should be zero if success else a negative error code.
163 static u8 st33zp24_spi_read8_reg(struct udevice *dev, u8 tpm_register,
164 u8 *tpm_data, size_t tpm_size)
166 int total_length = 0, ret;
167 struct spi_slave *slave = dev_get_parent_priv(dev);
168 struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
170 u8 *tx_buf = (u8 *)phy->tx_buf;
171 u8 *rx_buf = phy->rx_buf;
174 tx_buf[total_length++] = LOCALITY0;
175 tx_buf[total_length++] = tpm_register;
177 memset(&tx_buf[total_length], TPM_DUMMY_BYTE,
178 phy->latency + tpm_size);
179 total_length += phy->latency + tpm_size;
181 ret = spi_claim_bus(slave);
185 ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf,
186 SPI_XFER_BEGIN | SPI_XFER_END);
190 spi_release_bus(slave);
192 if (tpm_size > 0 && ret == 0) {
193 ret = rx_buf[total_length - tpm_size - 1];
194 memcpy(tpm_data, rx_buf + total_length - tpm_size, tpm_size);
201 * Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
202 * @param: phy_id, the phy description
203 * @param: tpm_register, the tpm tis register where the data should be read
204 * @param: tpm_data, the TPM response
205 * @param: tpm_size, tpm TPM response size to read.
206 * @return: number of byte read successfully: should be one if success.
208 static int st33zp24_spi_read(struct udevice *dev, u8 tpm_register,
209 u8 *tpm_data, size_t tpm_size)
213 ret = st33zp24_spi_read8_reg(dev, tpm_register, tpm_data, tpm_size);
214 if (!st33zp24_spi_status_to_errno(ret))
220 static int st33zp24_spi_evaluate_latency(struct udevice *dev)
222 int latency = 1, status = 0;
224 struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
226 while (!status && latency < MAX_SPI_LATENCY) {
227 phy->latency = latency;
228 status = st33zp24_spi_read8_reg(dev, TPM_INTF_CAPABILITY,
234 if (latency == MAX_SPI_LATENCY)
241 * st33zp24_spi_release_locality release the active locality
242 * @param: chip, the tpm chip description.
244 static void st33zp24_spi_release_locality(struct udevice *dev)
246 u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
248 st33zp24_spi_write(dev, TPM_ACCESS, &data, 1);
252 * st33zp24_spi_check_locality if the locality is active
253 * @param: chip, the tpm chip description
254 * @return: the active locality or -EACCES.
256 static int st33zp24_spi_check_locality(struct udevice *dev)
260 struct tpm_chip *chip = dev_get_priv(dev);
262 status = st33zp24_spi_read(dev, TPM_ACCESS, &data, 1);
263 if (status && (data &
264 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
265 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
266 return chip->locality;
272 * st33zp24_spi_request_locality request the TPM locality
273 * @param: chip, the chip description
274 * @return: the active locality or negative value.
276 static int st33zp24_spi_request_locality(struct udevice *dev)
278 unsigned long start, stop;
281 struct tpm_chip *chip = dev_get_priv(dev);
283 if (st33zp24_spi_check_locality(dev) == chip->locality)
284 return chip->locality;
286 data = TPM_ACCESS_REQUEST_USE;
287 ret = st33zp24_spi_write(dev, TPM_ACCESS, &data, 1);
291 /* wait for locality activated */
292 start = get_timer(0);
293 stop = chip->timeout_a;
295 if (st33zp24_spi_check_locality(dev) >= 0)
296 return chip->locality;
297 udelay(TPM_TIMEOUT_MS * 1000);
298 } while (get_timer(start) < stop);
304 * st33zp24_spi_status return the TPM_STS register
305 * @param: chip, the tpm chip description
306 * @return: the TPM_STS register value.
308 static u8 st33zp24_spi_status(struct udevice *dev)
312 st33zp24_spi_read(dev, TPM_STS, &data, 1);
317 * st33zp24_spi_get_burstcount return the burstcount address 0x19 0x1A
318 * @param: chip, the chip description
319 * return: the burstcount or -TPM_DRIVER_ERR in case of error.
321 static int st33zp24_spi_get_burstcount(struct udevice *dev)
323 struct tpm_chip *chip = dev_get_priv(dev);
324 unsigned long start, stop;
325 int burstcnt, status;
328 /* wait for burstcount */
329 start = get_timer(0);
330 stop = chip->timeout_d;
332 tpm_reg = TPM_STS + 1;
333 status = st33zp24_spi_read(dev, tpm_reg, &temp, 1);
337 tpm_reg = TPM_STS + 2;
339 status = st33zp24_spi_read(dev, tpm_reg, &temp, 1);
343 burstcnt |= temp << 8;
346 udelay(TIS_SHORT_TIMEOUT_MS * 1000);
347 } while (get_timer(start) < stop);
353 * st33zp24_spi_cancel, cancel the current command execution or
354 * set STS to COMMAND READY.
355 * @param: chip, tpm_chip description.
357 static void st33zp24_spi_cancel(struct udevice *dev)
361 data = TPM_STS_COMMAND_READY;
362 st33zp24_spi_write(dev, TPM_STS, &data, 1);
366 * st33zp24_spi_wait_for_stat wait for a TPM_STS value
367 * @param: chip, the tpm chip description
368 * @param: mask, the value mask to wait
369 * @param: timeout, the timeout
371 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
373 static int st33zp24_spi_wait_for_stat(struct udevice *dev, u8 mask,
374 unsigned long timeout, int *status)
376 unsigned long start, stop;
378 /* Check current status */
379 *status = st33zp24_spi_status(dev);
380 if ((*status & mask) == mask)
383 start = get_timer(0);
386 udelay(TPM_TIMEOUT_MS * 1000);
387 *status = st33zp24_spi_status(dev);
388 if ((*status & mask) == mask)
390 } while (get_timer(start) < stop);
396 * st33zp24_spi_recv_data receive data
397 * @param: chip, the tpm chip description
398 * @param: buf, the buffer where the data are received
399 * @param: count, the number of data to receive
400 * @return: the number of bytes read from TPM FIFO.
402 static int st33zp24_spi_recv_data(struct udevice *dev, u8 *buf, size_t count)
404 struct tpm_chip *chip = dev_get_priv(dev);
405 int size = 0, burstcnt, len, ret, status;
407 while (size < count &&
408 st33zp24_spi_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
409 chip->timeout_c, &status) == 0) {
410 burstcnt = st33zp24_spi_get_burstcount(dev);
413 len = min_t(int, burstcnt, count - size);
414 ret = st33zp24_spi_read(dev, TPM_DATA_FIFO, buf + size, len);
424 * st33zp24_spi_recv received TPM response through TPM phy.
425 * @param: chip, tpm_chip description.
426 * @param: buf, the buffer to store data.
427 * @param: count, the number of bytes that can received (sizeof buf).
428 * @return: Returns zero in case of success else -EIO.
430 static int st33zp24_spi_recv(struct udevice *dev, u8 *buf, size_t count)
432 struct tpm_chip *chip = dev_get_priv(dev);
434 unsigned int expected;
439 if (count < TPM_HEADER_SIZE) {
444 size = st33zp24_spi_recv_data(dev, buf, TPM_HEADER_SIZE);
445 if (size < TPM_HEADER_SIZE) {
446 debug("TPM error, unable to read header\n");
450 expected = get_unaligned_be32(buf + 2);
451 if (expected > count || expected < TPM_HEADER_SIZE) {
456 size += st33zp24_spi_recv_data(dev, &buf[TPM_HEADER_SIZE],
457 expected - TPM_HEADER_SIZE);
458 if (size < expected) {
459 debug("TPM error, unable to read remaining bytes of result\n");
465 st33zp24_spi_cancel(dev);
466 st33zp24_spi_release_locality(dev);
472 * st33zp24_spi_send send TPM commands through TPM phy.
473 * @param: chip, tpm_chip description.
474 * @param: buf, the buffer to send.
475 * @param: len, the number of bytes to send.
476 * @return: Returns zero in case of success else the negative error code.
478 static int st33zp24_spi_send(struct udevice *dev, const u8 *buf, size_t len)
480 struct tpm_chip *chip = dev_get_priv(dev);
482 int burstcnt, ret, status;
487 if (len < TPM_HEADER_SIZE)
490 ret = st33zp24_spi_request_locality(dev);
494 tpm_stat = st33zp24_spi_status(dev);
495 if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
496 st33zp24_spi_cancel(dev);
497 if (st33zp24_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY,
498 chip->timeout_b, &status) < 0) {
504 for (i = 0; i < len - 1;) {
505 burstcnt = st33zp24_spi_get_burstcount(dev);
509 size = min_t(int, len - i - 1, burstcnt);
510 ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + i, size);
517 tpm_stat = st33zp24_spi_status(dev);
518 if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
523 ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
527 tpm_stat = st33zp24_spi_status(dev);
528 if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
534 ret = st33zp24_spi_write(dev, TPM_STS, &data, 1);
541 st33zp24_spi_cancel(dev);
542 st33zp24_spi_release_locality(dev);
547 static int st33zp24_spi_cleanup(struct udevice *dev)
549 st33zp24_spi_cancel(dev);
551 * The TPM needs some time to clean up here,
552 * so we sleep rather than keeping the bus busy
555 st33zp24_spi_release_locality(dev);
560 static int st33zp24_spi_init(struct udevice *dev)
562 struct tpm_chip *chip = dev_get_priv(dev);
563 struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
567 /* Default timeouts - these could move to the device tree */
568 chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
569 chip->timeout_b = TIS_LONG_TIMEOUT_MS;
570 chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
571 chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
573 chip->locality = LOCALITY0;
575 phy->latency = st33zp24_spi_evaluate_latency(dev);
576 if (phy->latency <= 0)
580 * A timeout query to TPM can be placed here.
581 * Standard timeout values are used so far
587 static int st33zp24_spi_open(struct udevice *dev)
589 struct tpm_chip *chip = dev_get_priv(dev);
592 debug("%s: start\n", __func__);
596 rc = st33zp24_spi_init(dev);
603 static int st33zp24_spi_close(struct udevice *dev)
605 struct tpm_chip *chip = dev_get_priv(dev);
608 st33zp24_spi_release_locality(dev);
616 static int st33zp24_spi_get_desc(struct udevice *dev, char *buf, int size)
618 struct tpm_chip *chip = dev_get_priv(dev);
623 return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
624 chip->is_open ? "open" : "closed",
626 chip->vend_dev >> 16);
629 const struct tpm_ops st33zp24_spi_tpm_ops = {
630 .open = st33zp24_spi_open,
631 .close = st33zp24_spi_close,
632 .recv = st33zp24_spi_recv,
633 .send = st33zp24_spi_send,
634 .cleanup = st33zp24_spi_cleanup,
635 .get_desc = st33zp24_spi_get_desc,
638 static int st33zp24_spi_probe(struct udevice *dev)
640 struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
642 uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS;
643 uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS;
644 uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS;
645 uc_priv->retry_time_ms = TPM_TIMEOUT_MS;
647 debug("ST33ZP24 SPI TPM from STMicroelectronics found\n");
652 static int st33zp24_spi_remove(struct udevice *dev)
654 st33zp24_spi_release_locality(dev);
659 static const struct udevice_id st33zp24_spi_ids[] = {
660 { .compatible = "st,st33zp24-spi" },
664 U_BOOT_DRIVER(st33zp24_spi_spi) = {
665 .name = "st33zp24-spi",
667 .of_match = of_match_ptr(st33zp24_spi_ids),
668 .probe = st33zp24_spi_probe,
669 .remove = st33zp24_spi_remove,
670 .ops = &st33zp24_spi_tpm_ops,
671 .priv_auto_alloc_size = sizeof(struct tpm_chip),
672 .platdata_auto_alloc_size = sizeof(struct st33zp24_spi_phy),