1 // SPDX-License-Identifier: GPL-2.0+
3 * STMicroelectronics TPM ST33ZP24 I2C 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 I2C 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>
25 #include "tpm_internal.h"
27 #define TPM_ACCESS 0x0
29 #define TPM_DATA_FIFO 0x24
33 #define TPM_DUMMY_BYTE 0xAA
34 #define TPM_ST33ZP24_I2C_SLAVE_ADDR 0x13
36 #define TPM_WRITE_DIRECTION 0x80
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.
46 static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register,
47 const u8 *tpm_data, size_t tpm_size)
49 struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev);
51 chip_priv->buf[0] = tpm_register;
52 memcpy(chip_priv->buf + 1, tpm_data, tpm_size);
54 return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1);
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.
65 static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register,
66 u8 *tpm_data, size_t tpm_size)
71 data = TPM_DUMMY_BYTE;
72 status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1);
76 return dm_i2c_read(dev, 0, tpm_data, tpm_size);
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.
88 static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register,
89 const u8 *tpm_data, size_t tpm_size)
91 return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION,
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.
104 static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register,
105 u8 *tpm_data, size_t tpm_size)
107 return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size);
111 * st33zp24_i2c_release_locality release the active locality
112 * @param: chip, the tpm chip description.
114 static void st33zp24_i2c_release_locality(struct udevice *dev)
116 u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
118 st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
122 * st33zp24_i2c_check_locality if the locality is active
123 * @param: chip, the tpm chip description
124 * @return: the active locality or -EACCES.
126 static int st33zp24_i2c_check_locality(struct udevice *dev)
128 struct tpm_chip *chip = dev_get_priv(dev);
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;
142 * st33zp24_i2c_request_locality request the TPM locality
143 * @param: chip, the chip description
144 * @return: the active locality or negative value.
146 static int st33zp24_i2c_request_locality(struct udevice *dev)
148 struct tpm_chip *chip = dev_get_priv(dev);
149 unsigned long start, stop;
153 if (st33zp24_i2c_check_locality(dev) == chip->locality)
154 return chip->locality;
156 data = TPM_ACCESS_REQUEST_USE;
157 ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
161 /* wait for locality activated */
162 start = get_timer(0);
163 stop = chip->timeout_a;
165 if (st33zp24_i2c_check_locality(dev) >= 0)
166 return chip->locality;
167 udelay(TPM_TIMEOUT_MS * 1000);
168 } while (get_timer(start) < stop);
174 * st33zp24_i2c_status return the TPM_STS register
175 * @param: chip, the tpm chip description
176 * @return: the TPM_STS register value.
178 static u8 st33zp24_i2c_status(struct udevice *dev)
182 st33zp24_i2c_read(dev, TPM_STS, &data, 1);
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.
192 static int st33zp24_i2c_get_burstcount(struct udevice *dev)
194 struct tpm_chip *chip = dev_get_priv(dev);
195 unsigned long start, stop;
196 int burstcnt, status;
199 /* wait for burstcount */
200 start = get_timer(0);
201 stop = chip->timeout_d;
203 tpm_reg = TPM_STS + 1;
204 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
208 tpm_reg = TPM_STS + 2;
210 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
214 burstcnt |= temp << 8;
217 udelay(TIS_SHORT_TIMEOUT_MS * 1000);
218 } while (get_timer(start) < stop);
224 * st33zp24_i2c_cancel, cancel the current command execution or
225 * set STS to COMMAND READY.
226 * @param: chip, tpm_chip description.
228 static void st33zp24_i2c_cancel(struct udevice *dev)
232 data = TPM_STS_COMMAND_READY;
233 st33zp24_i2c_write(dev, TPM_STS, &data, 1);
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
242 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
244 static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask,
245 unsigned long timeout, int *status)
247 unsigned long start, stop;
249 /* Check current status */
250 *status = st33zp24_i2c_status(dev);
251 if ((*status & mask) == mask)
254 start = get_timer(0);
257 udelay(TPM_TIMEOUT_MS * 1000);
258 *status = st33zp24_i2c_status(dev);
259 if ((*status & mask) == mask)
261 } while (get_timer(start) < stop);
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.
273 static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
275 struct tpm_chip *chip = dev_get_priv(dev);
276 int size = 0, burstcnt, len, ret, status;
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);
284 len = min_t(int, burstcnt, count - size);
285 ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len);
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.
302 static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
304 struct tpm_chip *chip = dev_get_priv(dev);
306 unsigned int expected;
311 if (count < TPM_HEADER_SIZE) {
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");
322 expected = get_unaligned_be32(buf + 2);
323 if (expected > count || expected < TPM_HEADER_SIZE) {
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");
337 st33zp24_i2c_cancel(dev);
338 st33zp24_i2c_release_locality(dev);
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.
350 static int st33zp24_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
352 struct tpm_chip *chip = dev_get_priv(dev);
354 int burstcnt, ret, status;
359 if (len < TPM_HEADER_SIZE)
362 ret = st33zp24_i2c_request_locality(dev);
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) {
376 for (i = 0; i < len - 1;) {
377 burstcnt = st33zp24_i2c_get_burstcount(dev);
381 size = min_t(int, len - i - 1, burstcnt);
382 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size);
389 tpm_stat = st33zp24_i2c_status(dev);
390 if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
395 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
399 tpm_stat = st33zp24_i2c_status(dev);
400 if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
406 ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1);
413 st33zp24_i2c_cancel(dev);
414 st33zp24_i2c_release_locality(dev);
419 static int st33zp24_i2c_cleanup(struct udevice *dev)
421 st33zp24_i2c_cancel(dev);
423 * The TPM needs some time to clean up here,
424 * so we sleep rather than keeping the bus busy
427 st33zp24_i2c_release_locality(dev);
432 static int st33zp24_i2c_init(struct udevice *dev)
434 struct tpm_chip *chip = dev_get_priv(dev);
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;
444 chip->locality = LOCALITY0;
447 * A timeout query to TPM can be placed here.
448 * Standard timeout values are used so far
454 static int st33zp24_i2c_open(struct udevice *dev)
456 struct tpm_chip *chip = dev_get_priv(dev);
459 debug("%s: start\n", __func__);
463 rc = st33zp24_i2c_init(dev);
470 static int st33zp24_i2c_close(struct udevice *dev)
472 struct tpm_chip *chip = dev_get_priv(dev);
475 st33zp24_i2c_release_locality(dev);
483 static int st33zp24_i2c_get_desc(struct udevice *dev, char *buf, int size)
485 struct tpm_chip *chip = dev_get_priv(dev);
490 return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
491 chip->is_open ? "open" : "closed",
493 chip->vend_dev >> 16);
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,
505 static int st33zp24_i2c_probe(struct udevice *dev)
507 struct tpm_chip *chip = dev_get_priv(dev);
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;
515 chip->locality = LOCALITY0;
517 i2c_set_chip_offset_len(dev, 0);
519 debug("ST33ZP24 I2C TPM from STMicroelectronics found\n");
524 static int st33zp24_i2c_remove(struct udevice *dev)
526 st33zp24_i2c_release_locality(dev);
531 static const struct udevice_id st33zp24_i2c_ids[] = {
532 { .compatible = "st,st33zp24-i2c" },
536 U_BOOT_DRIVER(st33zp24_i2c) = {
537 .name = "st33zp24-i2c",
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),