2 * STMicroelectronics TPM Linux driver for TPM ST33ZP24
3 * Copyright (C) 2009 - 2016 STMicroelectronics
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/delay.h>
23 #include <linux/wait.h>
24 #include <linux/freezer.h>
25 #include <linux/string.h>
26 #include <linux/interrupt.h>
27 #include <linux/gpio.h>
28 #include <linux/sched.h>
29 #include <linux/uaccess.h>
31 #include <linux/slab.h>
36 #define TPM_ACCESS 0x0
38 #define TPM_DATA_FIFO 0x24
39 #define TPM_INTF_CAPABILITY 0x14
40 #define TPM_INT_STATUS 0x10
41 #define TPM_INT_ENABLE 0x08
45 enum st33zp24_access {
46 TPM_ACCESS_VALID = 0x80,
47 TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
48 TPM_ACCESS_REQUEST_PENDING = 0x04,
49 TPM_ACCESS_REQUEST_USE = 0x02,
52 enum st33zp24_status {
54 TPM_STS_COMMAND_READY = 0x40,
56 TPM_STS_DATA_AVAIL = 0x10,
57 TPM_STS_DATA_EXPECT = 0x08,
60 enum st33zp24_int_flags {
61 TPM_GLOBAL_INT_ENABLE = 0x80,
62 TPM_INTF_CMD_READY_INT = 0x080,
63 TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
64 TPM_INTF_WAKE_UP_READY_INT = 0x020,
65 TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
66 TPM_INTF_STS_VALID_INT = 0x002,
67 TPM_INTF_DATA_AVAIL_INT = 0x001,
71 TIS_SHORT_TIMEOUT = 750,
72 TIS_LONG_TIMEOUT = 2000,
76 * clear_interruption clear the pending interrupt.
77 * @param: tpm_dev, the tpm device device.
78 * @return: the interrupt status value.
80 static u8 clear_interruption(struct st33zp24_dev *tpm_dev)
84 tpm_dev->ops->recv(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
85 tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
87 } /* clear_interruption() */
90 * st33zp24_cancel, cancel the current command execution or
91 * set STS to COMMAND READY.
92 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
94 static void st33zp24_cancel(struct tpm_chip *chip)
96 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
99 data = TPM_STS_COMMAND_READY;
100 tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
101 } /* st33zp24_cancel() */
104 * st33zp24_status return the TPM_STS register
105 * @param: chip, the tpm chip description
106 * @return: the TPM_STS register value.
108 static u8 st33zp24_status(struct tpm_chip *chip)
110 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
113 tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS, &data, 1);
115 } /* st33zp24_status() */
118 * check_locality if the locality is active
119 * @param: chip, the tpm chip description
120 * @return: true if LOCALITY0 is active, otherwise false
122 static bool check_locality(struct tpm_chip *chip)
124 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
128 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
129 if (status && (data &
130 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
131 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
135 } /* check_locality() */
138 * request_locality request the TPM locality
139 * @param: chip, the chip description
140 * @return: the active locality or negative value.
142 static int request_locality(struct tpm_chip *chip)
144 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
149 if (check_locality(chip))
150 return tpm_dev->locality;
152 data = TPM_ACCESS_REQUEST_USE;
153 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
157 stop = jiffies + chip->timeout_a;
159 /* Request locality is usually effective after the request */
161 if (check_locality(chip))
162 return tpm_dev->locality;
164 } while (time_before(jiffies, stop));
166 /* could not get locality */
168 } /* request_locality() */
171 * release_locality release the active locality
172 * @param: chip, the tpm chip description.
174 static void release_locality(struct tpm_chip *chip)
176 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
179 data = TPM_ACCESS_ACTIVE_LOCALITY;
181 tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
185 * get_burstcount return the burstcount value
186 * @param: chip, the chip description
187 * return: the burstcount or negative value.
189 static int get_burstcount(struct tpm_chip *chip)
191 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
193 int burstcnt, status;
196 stop = jiffies + chip->timeout_d;
198 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 1,
204 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 2,
209 burstcnt |= temp << 8;
213 } while (time_before(jiffies, stop));
215 } /* get_burstcount() */
219 * wait_for_tpm_stat_cond
220 * @param: chip, chip description
221 * @param: mask, expected mask value
222 * @param: check_cancel, does the command expected to be canceled ?
223 * @param: canceled, did we received a cancel request ?
224 * @return: true if status == mask or if the command is canceled.
225 * false in other cases.
227 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
228 bool check_cancel, bool *canceled)
230 u8 status = chip->ops->status(chip);
233 if ((status & mask) == mask)
235 if (check_cancel && chip->ops->req_canceled(chip, status)) {
243 * wait_for_stat wait for a TPM_STS value
244 * @param: chip, the tpm chip description
245 * @param: mask, the value mask to wait
246 * @param: timeout, the timeout
247 * @param: queue, the wait queue.
248 * @param: check_cancel, does the command can be cancelled ?
249 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
251 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
252 wait_queue_head_t *queue, bool check_cancel)
254 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
257 bool canceled = false;
262 /* check current status */
263 status = st33zp24_status(chip);
264 if ((status & mask) == mask)
267 stop = jiffies + timeout;
269 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
270 cur_intrs = tpm_dev->intrs;
271 clear_interruption(tpm_dev);
272 enable_irq(tpm_dev->irq);
275 if (ret == -ERESTARTSYS && freezing(current))
276 clear_thread_flag(TIF_SIGPENDING);
278 timeout = stop - jiffies;
279 if ((long) timeout <= 0)
282 ret = wait_event_interruptible_timeout(*queue,
283 cur_intrs != tpm_dev->intrs,
285 clear_interruption(tpm_dev);
286 condition = wait_for_tpm_stat_cond(chip, mask,
287 check_cancel, &canceled);
288 if (ret >= 0 && condition) {
293 } while (ret == -ERESTARTSYS && freezing(current));
295 disable_irq_nosync(tpm_dev->irq);
300 status = chip->ops->status(chip);
301 if ((status & mask) == mask)
303 } while (time_before(jiffies, stop));
307 } /* wait_for_stat() */
310 * recv_data receive data
311 * @param: chip, the tpm chip description
312 * @param: buf, the buffer where the data are received
313 * @param: count, the number of data to receive
314 * @return: the number of bytes read from TPM FIFO.
316 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
318 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
319 int size = 0, burstcnt, len, ret;
321 while (size < count &&
323 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
325 &tpm_dev->read_queue, true) == 0) {
326 burstcnt = get_burstcount(chip);
329 len = min_t(int, burstcnt, count - size);
330 ret = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_DATA_FIFO,
341 * tpm_ioserirq_handler the serirq irq handler
342 * @param: irq, the tpm chip description
343 * @param: dev_id, the description of the chip
344 * @return: the status of the handler.
346 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
348 struct tpm_chip *chip = dev_id;
349 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
352 wake_up_interruptible(&tpm_dev->read_queue);
353 disable_irq_nosync(tpm_dev->irq);
356 } /* tpm_ioserirq_handler() */
359 * st33zp24_send send TPM commands through the I2C bus.
361 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
362 * @param: buf, the buffer to send.
363 * @param: count, the number of bytes to send.
364 * @return: In case of success the number of bytes sent.
365 * In other case, a < 0 value describing the issue.
367 static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
370 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
371 u32 status, i, size, ordinal;
378 if (len < TPM_HEADER_SIZE)
381 ret = request_locality(chip);
385 status = st33zp24_status(chip);
386 if ((status & TPM_STS_COMMAND_READY) == 0) {
387 st33zp24_cancel(chip);
389 (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
390 &tpm_dev->read_queue, false) < 0) {
396 for (i = 0; i < len - 1;) {
397 burstcnt = get_burstcount(chip);
400 size = min_t(int, len - i - 1, burstcnt);
401 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
409 status = st33zp24_status(chip);
410 if ((status & TPM_STS_DATA_EXPECT) == 0) {
415 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
420 status = st33zp24_status(chip);
421 if ((status & TPM_STS_DATA_EXPECT) != 0) {
427 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
431 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
432 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
434 ret = wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
435 tpm_calc_ordinal_duration(chip, ordinal),
436 &tpm_dev->read_queue, false);
443 st33zp24_cancel(chip);
444 release_locality(chip);
449 * st33zp24_recv received TPM response through TPM phy.
450 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
451 * @param: buf, the buffer to store datas.
452 * @param: count, the number of bytes to send.
453 * @return: In case of success the number of bytes received.
454 * In other case, a < 0 value describing the issue.
456 static int st33zp24_recv(struct tpm_chip *chip, unsigned char *buf,
465 if (count < TPM_HEADER_SIZE) {
470 size = recv_data(chip, buf, TPM_HEADER_SIZE);
471 if (size < TPM_HEADER_SIZE) {
472 dev_err(&chip->dev, "Unable to read header\n");
476 expected = be32_to_cpu(*(__be32 *)(buf + 2));
477 if (expected > count) {
482 size += recv_data(chip, &buf[TPM_HEADER_SIZE],
483 expected - TPM_HEADER_SIZE);
484 if (size < expected) {
485 dev_err(&chip->dev, "Unable to read remainder of result\n");
490 st33zp24_cancel(chip);
491 release_locality(chip);
496 * st33zp24_req_canceled
497 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
498 * @param: status, the TPM status.
499 * @return: Does TPM ready to compute a new command ? true.
501 static bool st33zp24_req_canceled(struct tpm_chip *chip, u8 status)
503 return (status == TPM_STS_COMMAND_READY);
506 static const struct tpm_class_ops st33zp24_tpm = {
507 .flags = TPM_OPS_AUTO_STARTUP,
508 .send = st33zp24_send,
509 .recv = st33zp24_recv,
510 .cancel = st33zp24_cancel,
511 .status = st33zp24_status,
512 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
513 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
514 .req_canceled = st33zp24_req_canceled,
518 * st33zp24_probe initialize the TPM device
519 * @param: client, the i2c_client drescription (TPM I2C description).
520 * @param: id, the i2c_device_id struct.
521 * @return: 0 in case of success.
524 int st33zp24_probe(void *phy_id, const struct st33zp24_phy_ops *ops,
525 struct device *dev, int irq, int io_lpcpd)
529 struct tpm_chip *chip;
530 struct st33zp24_dev *tpm_dev;
532 chip = tpmm_chip_alloc(dev, &st33zp24_tpm);
534 return PTR_ERR(chip);
536 tpm_dev = devm_kzalloc(dev, sizeof(struct st33zp24_dev),
541 tpm_dev->phy_id = phy_id;
543 dev_set_drvdata(&chip->dev, tpm_dev);
545 chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
546 chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
547 chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
548 chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
550 tpm_dev->locality = LOCALITY0;
553 /* INTERRUPT Setup */
554 init_waitqueue_head(&tpm_dev->read_queue);
557 if (request_locality(chip) != LOCALITY0) {
559 goto _tpm_clean_answer;
562 clear_interruption(tpm_dev);
563 ret = devm_request_irq(dev, irq, tpm_ioserirq_handler,
564 IRQF_TRIGGER_HIGH, "TPM SERIRQ management",
567 dev_err(&chip->dev, "TPM SERIRQ signals %d not available\n",
569 goto _tpm_clean_answer;
572 intmask |= TPM_INTF_CMD_READY_INT
573 | TPM_INTF_STS_VALID_INT
574 | TPM_INTF_DATA_AVAIL_INT;
576 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_ENABLE,
579 goto _tpm_clean_answer;
581 intmask = TPM_GLOBAL_INT_ENABLE;
582 ret = tpm_dev->ops->send(tpm_dev->phy_id, (TPM_INT_ENABLE + 3),
585 goto _tpm_clean_answer;
588 chip->flags |= TPM_CHIP_FLAG_IRQ;
590 disable_irq_nosync(tpm_dev->irq);
593 return tpm_chip_register(chip);
595 dev_info(&chip->dev, "TPM initialization fail\n");
598 EXPORT_SYMBOL(st33zp24_probe);
601 * st33zp24_remove remove the TPM device
602 * @param: tpm_data, the tpm phy.
603 * @return: 0 in case of success.
605 int st33zp24_remove(struct tpm_chip *chip)
607 tpm_chip_unregister(chip);
610 EXPORT_SYMBOL(st33zp24_remove);
612 #ifdef CONFIG_PM_SLEEP
614 * st33zp24_pm_suspend suspend the TPM device
615 * @param: tpm_data, the tpm phy.
616 * @param: mesg, the power management message.
617 * @return: 0 in case of success.
619 int st33zp24_pm_suspend(struct device *dev)
621 struct tpm_chip *chip = dev_get_drvdata(dev);
622 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
626 if (gpio_is_valid(tpm_dev->io_lpcpd))
627 gpio_set_value(tpm_dev->io_lpcpd, 0);
629 ret = tpm_pm_suspend(dev);
632 } /* st33zp24_pm_suspend() */
633 EXPORT_SYMBOL(st33zp24_pm_suspend);
636 * st33zp24_pm_resume resume the TPM device
637 * @param: tpm_data, the tpm phy.
638 * @return: 0 in case of success.
640 int st33zp24_pm_resume(struct device *dev)
642 struct tpm_chip *chip = dev_get_drvdata(dev);
643 struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
646 if (gpio_is_valid(tpm_dev->io_lpcpd)) {
647 gpio_set_value(tpm_dev->io_lpcpd, 1);
648 ret = wait_for_stat(chip,
649 TPM_STS_VALID, chip->timeout_b,
650 &tpm_dev->read_queue, false);
652 ret = tpm_pm_resume(dev);
654 tpm_do_selftest(chip);
657 } /* st33zp24_pm_resume() */
658 EXPORT_SYMBOL(st33zp24_pm_resume);
661 MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)");
662 MODULE_DESCRIPTION("ST33ZP24 TPM 1.2 driver");
663 MODULE_VERSION("1.3.0");
664 MODULE_LICENSE("GPL");