2 * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver
4 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
5 * Author(s): Christophe Ricard <christophe-h.ricard@st.com> for STMicroelectronics.
7 * Description: Device driver for ST33ZP24 I2C TPM TCG.
9 * This device driver implements the TPM interface as defined in
10 * the TCG TPM Interface Spec version 1.21, revision 1.0 and the
11 * STMicroelectronics Protocol Stack Specification version 1.2.0.
13 * SPDX-License-Identifier: GPL-2.0+
22 #include <linux/types.h>
23 #include <asm/unaligned.h>
26 #include "tpm_internal.h"
28 #define TPM_ACCESS 0x0
30 #define TPM_DATA_FIFO 0x24
34 #define TPM_DUMMY_BYTE 0xAA
35 #define TPM_ST33ZP24_I2C_SLAVE_ADDR 0x13
37 #define TPM_WRITE_DIRECTION 0x80
40 * st33zp24_i2c_write8_reg
41 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
42 * @param: tpm_register, the tpm tis register where the data should be written
43 * @param: tpm_data, the tpm_data to write inside the tpm_register
44 * @param: tpm_size, The length of the data
45 * @return: Number of byte written successfully else an error code.
47 static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register,
48 const u8 *tpm_data, size_t tpm_size)
50 struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev);
52 chip_priv->buf[0] = tpm_register;
53 memcpy(chip_priv->buf + 1, tpm_data, tpm_size);
55 return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1);
59 * st33zp24_i2c_read8_reg
60 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
61 * @param: tpm_register, the tpm tis register where the data should be read
62 * @param: tpm_data, the TPM response
63 * @param: tpm_size, tpm TPM response size to read.
64 * @return: Number of byte read successfully else an error code.
66 static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register,
67 u8 *tpm_data, size_t tpm_size)
72 data = TPM_DUMMY_BYTE;
73 status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1);
77 return dm_i2c_read(dev, 0, tpm_data, tpm_size);
82 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
83 * @param: phy_id, the phy description
84 * @param: tpm_register, the tpm tis register where the data should be written
85 * @param: tpm_data, the tpm_data to write inside the tpm_register
86 * @param: tpm_size, the length of the data
87 * @return: number of byte written successfully: should be one if success.
89 static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register,
90 const u8 *tpm_data, size_t tpm_size)
92 return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION,
98 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
99 * @param: phy_id, the phy description
100 * @param: tpm_register, the tpm tis register where the data should be read
101 * @param: tpm_data, the TPM response
102 * @param: tpm_size, tpm TPM response size to read.
103 * @return: number of byte read successfully: should be one if success.
105 static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register,
106 u8 *tpm_data, size_t tpm_size)
108 return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size);
112 * st33zp24_i2c_release_locality release the active locality
113 * @param: chip, the tpm chip description.
115 static void st33zp24_i2c_release_locality(struct udevice *dev)
117 u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
119 st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
123 * st33zp24_i2c_check_locality if the locality is active
124 * @param: chip, the tpm chip description
125 * @return: the active locality or -EACCES.
127 static int st33zp24_i2c_check_locality(struct udevice *dev)
129 struct tpm_chip *chip = dev_get_priv(dev);
133 status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1);
134 if (!status && (data &
135 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
136 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
137 return chip->locality;
143 * st33zp24_i2c_request_locality request the TPM locality
144 * @param: chip, the chip description
145 * @return: the active locality or negative value.
147 static int st33zp24_i2c_request_locality(struct udevice *dev)
149 struct tpm_chip *chip = dev_get_priv(dev);
150 unsigned long start, stop;
154 if (st33zp24_i2c_check_locality(dev) == chip->locality)
155 return chip->locality;
157 data = TPM_ACCESS_REQUEST_USE;
158 ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
162 /* wait for locality activated */
163 start = get_timer(0);
164 stop = chip->timeout_a;
166 if (st33zp24_i2c_check_locality(dev) >= 0)
167 return chip->locality;
168 udelay(TPM_TIMEOUT_MS * 1000);
169 } while (get_timer(start) < stop);
175 * st33zp24_i2c_status return the TPM_STS register
176 * @param: chip, the tpm chip description
177 * @return: the TPM_STS register value.
179 static u8 st33zp24_i2c_status(struct udevice *dev)
183 st33zp24_i2c_read(dev, TPM_STS, &data, 1);
189 * st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A
190 * @param: chip, the chip description
191 * return: the burstcount or -TPM_DRIVER_ERR in case of error.
193 static int st33zp24_i2c_get_burstcount(struct udevice *dev)
195 struct tpm_chip *chip = dev_get_priv(dev);
196 unsigned long start, stop;
197 int burstcnt, status;
200 /* wait for burstcount */
201 start = get_timer(0);
202 stop = chip->timeout_d;
204 tpm_reg = TPM_STS + 1;
205 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
209 tpm_reg = TPM_STS + 2;
211 status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
215 burstcnt |= temp << 8;
218 udelay(TIS_SHORT_TIMEOUT_MS * 1000);
219 } while (get_timer(start) < stop);
225 * st33zp24_i2c_cancel, cancel the current command execution or
226 * set STS to COMMAND READY.
227 * @param: chip, tpm_chip description.
229 static void st33zp24_i2c_cancel(struct udevice *dev)
233 data = TPM_STS_COMMAND_READY;
234 st33zp24_i2c_write(dev, TPM_STS, &data, 1);
238 * st33zp24_i2c_wait_for_stat wait for a TPM_STS value
239 * @param: chip, the tpm chip description
240 * @param: mask, the value mask to wait
241 * @param: timeout, the timeout
243 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
245 static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask,
246 unsigned long timeout, int *status)
248 unsigned long start, stop;
250 /* Check current status */
251 *status = st33zp24_i2c_status(dev);
252 if ((*status & mask) == mask)
255 start = get_timer(0);
258 udelay(TPM_TIMEOUT_MS * 1000);
259 *status = st33zp24_i2c_status(dev);
260 if ((*status & mask) == mask)
262 } while (get_timer(start) < stop);
268 * st33zp24_i2c_recv_data receive data
269 * @param: chip, the tpm chip description
270 * @param: buf, the buffer where the data are received
271 * @param: count, the number of data to receive
272 * @return: the number of bytes read from TPM FIFO.
274 static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
276 struct tpm_chip *chip = dev_get_priv(dev);
277 int size = 0, burstcnt, len, ret, status;
279 while (size < count &&
280 st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
281 chip->timeout_c, &status) == 0) {
282 burstcnt = st33zp24_i2c_get_burstcount(dev);
285 len = min_t(int, burstcnt, count - size);
286 ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len);
297 * st33zp24_i2c_recv received TPM response through TPM phy.
298 * @param: chip, tpm_chip description.
299 * @param: buf, the buffer to store data.
300 * @param: count, the number of bytes that can received (sizeof buf).
301 * @return: Returns zero in case of success else -EIO.
303 static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
305 struct tpm_chip *chip = dev_get_priv(dev);
307 unsigned int expected;
312 if (count < TPM_HEADER_SIZE) {
317 size = st33zp24_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
318 if (size < TPM_HEADER_SIZE) {
319 debug("TPM error, unable to read header\n");
323 expected = get_unaligned_be32(buf + 2);
324 if (expected > count || expected < TPM_HEADER_SIZE) {
329 size += st33zp24_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
330 expected - TPM_HEADER_SIZE);
331 if (size < expected) {
332 debug("TPM error, unable to read remaining bytes of result\n");
338 st33zp24_i2c_cancel(dev);
339 st33zp24_i2c_release_locality(dev);
345 * st33zp24_i2c_send send TPM commands through TPM phy.
346 * @param: chip, tpm_chip description.
347 * @param: buf, the buffer to send.
348 * @param: len, the number of bytes to send.
349 * @return: Returns zero in case of success else the negative error code.
351 static int st33zp24_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
353 struct tpm_chip *chip = dev_get_priv(dev);
355 int burstcnt, ret, status;
360 if (len < TPM_HEADER_SIZE)
363 ret = st33zp24_i2c_request_locality(dev);
367 tpm_stat = st33zp24_i2c_status(dev);
368 if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
369 st33zp24_i2c_cancel(dev);
370 if (st33zp24_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
371 chip->timeout_b, &status) < 0) {
377 for (i = 0; i < len - 1;) {
378 burstcnt = st33zp24_i2c_get_burstcount(dev);
382 size = min_t(int, len - i - 1, burstcnt);
383 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size);
390 tpm_stat = st33zp24_i2c_status(dev);
391 if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
396 ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
400 tpm_stat = st33zp24_i2c_status(dev);
401 if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
407 ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1);
414 st33zp24_i2c_cancel(dev);
415 st33zp24_i2c_release_locality(dev);
420 static int st33zp24_i2c_cleanup(struct udevice *dev)
422 st33zp24_i2c_cancel(dev);
424 * The TPM needs some time to clean up here,
425 * so we sleep rather than keeping the bus busy
428 st33zp24_i2c_release_locality(dev);
433 static int st33zp24_i2c_init(struct udevice *dev)
435 struct tpm_chip *chip = dev_get_priv(dev);
439 /* Default timeouts - these could move to the device tree */
440 chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
441 chip->timeout_b = TIS_LONG_TIMEOUT_MS;
442 chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
443 chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
445 chip->locality = LOCALITY0;
448 * A timeout query to TPM can be placed here.
449 * Standard timeout values are used so far
455 static int st33zp24_i2c_open(struct udevice *dev)
457 struct tpm_chip *chip = dev_get_priv(dev);
460 debug("%s: start\n", __func__);
464 rc = st33zp24_i2c_init(dev);
471 static int st33zp24_i2c_close(struct udevice *dev)
473 struct tpm_chip *chip = dev_get_priv(dev);
476 st33zp24_i2c_release_locality(dev);
484 static int st33zp24_i2c_get_desc(struct udevice *dev, char *buf, int size)
486 struct tpm_chip *chip = dev_get_priv(dev);
491 return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
492 chip->is_open ? "open" : "closed",
494 chip->vend_dev >> 16);
497 static const struct tpm_ops st33zp24_i2c_tpm_ops = {
498 .open = st33zp24_i2c_open,
499 .close = st33zp24_i2c_close,
500 .recv = st33zp24_i2c_recv,
501 .send = st33zp24_i2c_send,
502 .cleanup = st33zp24_i2c_cleanup,
503 .get_desc = st33zp24_i2c_get_desc,
506 static int st33zp24_i2c_probe(struct udevice *dev)
508 struct tpm_chip *chip = dev_get_priv(dev);
510 /* Default timeouts */
511 chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
512 chip->timeout_b = TIS_LONG_TIMEOUT_MS;
513 chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
514 chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
516 chip->locality = LOCALITY0;
518 i2c_set_chip_offset_len(dev, 0);
520 debug("ST33ZP24 I2C TPM from STMicroelectronics found\n");
525 static int st33zp24_i2c_remove(struct udevice *dev)
527 st33zp24_i2c_release_locality(dev);
532 static const struct udevice_id st33zp24_i2c_ids[] = {
533 { .compatible = "st,st33zp24-i2c" },
537 U_BOOT_DRIVER(st33zp24_i2c) = {
538 .name = "st33zp24-i2c",
540 .of_match = of_match_ptr(st33zp24_i2c_ids),
541 .probe = st33zp24_i2c_probe,
542 .remove = st33zp24_i2c_remove,
543 .ops = &st33zp24_i2c_tpm_ops,
544 .priv_auto_alloc_size = sizeof(struct tpm_chip),