2 * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
3 * Copyright (C) 2009, 2010 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 along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 * STMicroelectronics version 1.2.0, Copyright (C) 2010
20 * STMicroelectronics comes with ABSOLUTELY NO WARRANTY.
21 * This is free software, and you are welcome to redistribute it
22 * under certain conditions.
24 * @Author: Christophe RICARD tpmsupport@st.com
26 * @File: tpm_stm_st33_i2c.c
29 * 09/15/2010: First shot driver tpm_tis driver for
33 #include <linux/pci.h>
34 #include <linux/module.h>
35 #include <linux/platform_device.h>
36 #include <linux/i2c.h>
38 #include <linux/miscdevice.h>
39 #include <linux/kernel.h>
40 #include <linux/delay.h>
41 #include <linux/wait.h>
42 #include <linux/string.h>
43 #include <linux/interrupt.h>
44 #include <linux/spinlock.h>
45 #include <linux/sysfs.h>
46 #include <linux/gpio.h>
47 #include <linux/sched.h>
48 #include <linux/uaccess.h>
50 #include <linux/slab.h>
53 #include "tpm_i2c_stm_st33.h"
55 enum stm33zp24_access {
56 TPM_ACCESS_VALID = 0x80,
57 TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
58 TPM_ACCESS_REQUEST_PENDING = 0x04,
59 TPM_ACCESS_REQUEST_USE = 0x02,
62 enum stm33zp24_status {
64 TPM_STS_COMMAND_READY = 0x40,
66 TPM_STS_DATA_AVAIL = 0x10,
67 TPM_STS_DATA_EXPECT = 0x08,
70 enum stm33zp24_int_flags {
71 TPM_GLOBAL_INT_ENABLE = 0x80,
72 TPM_INTF_CMD_READY_INT = 0x080,
73 TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
74 TPM_INTF_WAKE_UP_READY_INT = 0x020,
75 TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
76 TPM_INTF_STS_VALID_INT = 0x002,
77 TPM_INTF_DATA_AVAIL_INT = 0x001,
81 TIS_SHORT_TIMEOUT = 750,
82 TIS_LONG_TIMEOUT = 2000,
87 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
88 * @param: tpm_register, the tpm tis register where the data should be written
89 * @param: tpm_data, the tpm_data to write inside the tpm_register
90 * @param: tpm_size, The length of the data
91 * @return: Returns negative errno, or else the number of bytes written.
93 static int write8_reg(struct i2c_client *client, u8 tpm_register,
94 u8 *tpm_data, u16 tpm_size)
96 struct st33zp24_platform_data *pin_infos;
98 pin_infos = client->dev.platform_data;
100 pin_infos->tpm_i2c_buffer[0][0] = tpm_register;
101 memcpy(&pin_infos->tpm_i2c_buffer[0][1], tpm_data, tpm_size);
102 return i2c_master_send(client, pin_infos->tpm_i2c_buffer[0],
108 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
109 * @param: tpm_register, the tpm tis register where the data should be read
110 * @param: tpm_data, the TPM response
111 * @param: tpm_size, tpm TPM response size to read.
112 * @return: number of byte read successfully: should be one if success.
114 static int read8_reg(struct i2c_client *client, u8 tpm_register,
115 u8 *tpm_data, int tpm_size)
120 data = TPM_DUMMY_BYTE;
121 status = write8_reg(client, tpm_register, &data, 1);
123 status = i2c_master_recv(client, tpm_data, tpm_size);
129 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
130 * @param: client, the chip description
131 * @param: tpm_register, the tpm tis register where the data should be written
132 * @param: tpm_data, the tpm_data to write inside the tpm_register
133 * @param: tpm_size, The length of the data
134 * @return: number of byte written successfully: should be one if success.
136 #define I2C_WRITE_DATA(client, tpm_register, tpm_data, tpm_size) \
137 (write8_reg(client, tpm_register | \
138 TPM_WRITE_DIRECTION, tpm_data, tpm_size))
142 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
143 * @param: tpm, the chip description
144 * @param: tpm_register, the tpm tis register where the data should be read
145 * @param: tpm_data, the TPM response
146 * @param: tpm_size, tpm TPM response size to read.
147 * @return: number of byte read successfully: should be one if success.
149 #define I2C_READ_DATA(client, tpm_register, tpm_data, tpm_size) \
150 (read8_reg(client, tpm_register, tpm_data, tpm_size))
154 * clear the TPM interrupt register.
155 * @param: tpm, the chip description
157 static void clear_interruption(struct i2c_client *client)
160 I2C_READ_DATA(client, TPM_INT_STATUS, &interrupt, 1);
161 I2C_WRITE_DATA(client, TPM_INT_STATUS, &interrupt, 1);
162 I2C_READ_DATA(client, TPM_INT_STATUS, &interrupt, 1);
163 } /* clear_interruption() */
166 * _wait_for_interrupt_serirq_timeout
167 * @param: tpm, the chip description
168 * @param: timeout, the timeout of the interrupt
169 * @return: the status of the interruption.
171 static long _wait_for_interrupt_serirq_timeout(struct tpm_chip *chip,
172 unsigned long timeout)
175 struct i2c_client *client;
176 struct st33zp24_platform_data *pin_infos;
178 client = (struct i2c_client *)TPM_VPRIV(chip);
179 pin_infos = client->dev.platform_data;
181 status = wait_for_completion_interruptible_timeout(
182 &pin_infos->irq_detection,
185 enable_irq(gpio_to_irq(pin_infos->io_serirq));
186 gpio_direction_input(pin_infos->io_serirq);
189 } /* wait_for_interrupt_serirq_timeout() */
191 static int wait_for_serirq_timeout(struct tpm_chip *chip, bool condition,
192 unsigned long timeout)
195 struct i2c_client *client;
197 client = (struct i2c_client *)TPM_VPRIV(chip);
199 status = _wait_for_interrupt_serirq_timeout(chip, timeout);
203 clear_interruption(client);
211 * tpm_stm_i2c_cancel, cancel is not implemented.
212 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
214 static void tpm_stm_i2c_cancel(struct tpm_chip *chip)
216 struct i2c_client *client;
219 client = (struct i2c_client *)TPM_VPRIV(chip);
221 data = TPM_STS_COMMAND_READY;
222 I2C_WRITE_DATA(client, TPM_STS, &data, 1);
223 if (chip->vendor.irq)
224 wait_for_serirq_timeout(chip, 1, chip->vendor.timeout_a);
225 } /* tpm_stm_i2c_cancel() */
228 * tpm_stm_spi_status return the TPM_STS register
229 * @param: chip, the tpm chip description
230 * @return: the TPM_STS register value.
232 static u8 tpm_stm_i2c_status(struct tpm_chip *chip)
234 struct i2c_client *client;
236 client = (struct i2c_client *)TPM_VPRIV(chip);
238 I2C_READ_DATA(client, TPM_STS, &data, 1);
240 } /* tpm_stm_i2c_status() */
244 * check_locality if the locality is active
245 * @param: chip, the tpm chip description
246 * @return: the active locality or -EACCESS.
248 static int check_locality(struct tpm_chip *chip)
250 struct i2c_client *client;
254 client = (struct i2c_client *)TPM_VPRIV(chip);
256 status = I2C_READ_DATA(client, TPM_ACCESS, &data, 1);
257 if (status && (data &
258 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
259 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
260 return chip->vendor.locality;
264 } /* check_locality() */
267 * request_locality request the TPM locality
268 * @param: chip, the chip description
269 * @return: the active locality or EACCESS.
271 static int request_locality(struct tpm_chip *chip)
275 struct i2c_client *client;
278 client = (struct i2c_client *)TPM_VPRIV(chip);
280 if (check_locality(chip) == chip->vendor.locality)
281 return chip->vendor.locality;
283 data = TPM_ACCESS_REQUEST_USE;
284 rc = I2C_WRITE_DATA(client, TPM_ACCESS, &data, 1);
288 if (chip->vendor.irq) {
289 rc = wait_for_serirq_timeout(chip, (check_locality
291 chip->vendor.timeout_a);
293 return chip->vendor.locality;
295 stop = jiffies + chip->vendor.timeout_a;
297 if (check_locality(chip) >= 0)
298 return chip->vendor.locality;
300 } while (time_before(jiffies, stop));
305 } /* request_locality() */
308 * release_locality release the active locality
309 * @param: chip, the tpm chip description.
311 static void release_locality(struct tpm_chip *chip)
313 struct i2c_client *client;
316 client = (struct i2c_client *)TPM_VPRIV(chip);
317 data = TPM_ACCESS_ACTIVE_LOCALITY;
319 I2C_WRITE_DATA(client, TPM_ACCESS, &data, 1);
323 * get_burstcount return the burstcount address 0x19 0x1A
324 * @param: chip, the chip description
325 * return: the burstcount.
327 static int get_burstcount(struct tpm_chip *chip)
330 int burstcnt, status;
333 struct i2c_client *client = (struct i2c_client *)TPM_VPRIV(chip);
335 stop = jiffies + chip->vendor.timeout_d;
337 tpm_reg = TPM_STS + 1;
338 status = I2C_READ_DATA(client, tpm_reg, &temp, 1);
342 tpm_reg = tpm_reg + 1;
344 status = I2C_READ_DATA(client, tpm_reg, &temp, 1);
348 burstcnt |= temp << 8;
352 } while (time_before(jiffies, stop));
356 } /* get_burstcount() */
359 * wait_for_stat wait for a TPM_STS value
360 * @param: chip, the tpm chip description
361 * @param: mask, the value mask to wait
362 * @param: timeout, the timeout
363 * @param: queue, the wait queue.
364 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
366 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
367 wait_queue_head_t *queue)
373 if (chip->vendor.irq) {
374 rc = wait_for_serirq_timeout(chip, ((tpm_stm_i2c_status
380 stop = jiffies + timeout;
383 status = tpm_stm_i2c_status(chip);
384 if ((status & mask) == mask)
386 } while (time_before(jiffies, stop));
389 } /* wait_for_stat() */
392 * recv_data receive data
393 * @param: chip, the tpm chip description
394 * @param: buf, the buffer where the data are received
395 * @param: count, the number of data to receive
396 * @return: the number of bytes read from TPM FIFO.
398 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
400 int size = 0, burstcnt, len;
401 struct i2c_client *client;
403 client = (struct i2c_client *)TPM_VPRIV(chip);
405 while (size < count &&
407 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
408 chip->vendor.timeout_c,
409 &chip->vendor.read_queue)
411 burstcnt = get_burstcount(chip);
414 len = min_t(int, burstcnt, count - size);
415 I2C_READ_DATA(client, TPM_DATA_FIFO, buf + size, len);
422 * tpm_ioserirq_handler the serirq irq handler
423 * @param: irq, the tpm chip description
424 * @param: dev_id, the description of the chip
425 * @return: the status of the handler.
427 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
429 struct tpm_chip *chip = dev_id;
430 struct i2c_client *client;
431 struct st33zp24_platform_data *pin_infos;
433 disable_irq_nosync(irq);
435 client = (struct i2c_client *)TPM_VPRIV(chip);
436 pin_infos = client->dev.platform_data;
438 complete(&pin_infos->irq_detection);
440 } /* tpm_ioserirq_handler() */
444 * tpm_stm_i2c_send send TPM commands through the I2C bus.
446 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
447 * @param: buf, the buffer to send.
448 * @param: count, the number of bytes to send.
449 * @return: In case of success the number of bytes sent.
450 * In other case, a < 0 value describing the issue.
452 static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf,
459 struct i2c_client *client;
463 if (len < TPM_HEADER_SIZE)
466 client = (struct i2c_client *)TPM_VPRIV(chip);
470 ret = request_locality(chip);
474 status = tpm_stm_i2c_status(chip);
475 if ((status & TPM_STS_COMMAND_READY) == 0) {
476 tpm_stm_i2c_cancel(chip);
478 (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
479 &chip->vendor.int_queue) < 0) {
485 for (i = 0; i < len - 1;) {
486 burstcnt = get_burstcount(chip);
489 size = min_t(int, len - i - 1, burstcnt);
490 ret = I2C_WRITE_DATA(client, TPM_DATA_FIFO, buf, size);
497 status = tpm_stm_i2c_status(chip);
498 if ((status & TPM_STS_DATA_EXPECT) == 0) {
503 ret = I2C_WRITE_DATA(client, TPM_DATA_FIFO, buf + len - 1, 1);
507 status = tpm_stm_i2c_status(chip);
508 if ((status & TPM_STS_DATA_EXPECT) != 0) {
514 I2C_WRITE_DATA(client, TPM_STS, &data, 1);
518 tpm_stm_i2c_cancel(chip);
519 release_locality(chip);
524 * tpm_stm_i2c_recv received TPM response through the I2C bus.
525 * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
526 * @param: buf, the buffer to store datas.
527 * @param: count, the number of bytes to send.
528 * @return: In case of success the number of bytes received.
529 * In other case, a < 0 value describing the issue.
531 static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
540 if (count < TPM_HEADER_SIZE) {
545 size = recv_data(chip, buf, TPM_HEADER_SIZE);
546 if (size < TPM_HEADER_SIZE) {
547 dev_err(chip->dev, "Unable to read header\n");
551 expected = be32_to_cpu(*(__be32 *)(buf + 2));
552 if (expected > count) {
557 size += recv_data(chip, &buf[TPM_HEADER_SIZE],
558 expected - TPM_HEADER_SIZE);
559 if (size < expected) {
560 dev_err(chip->dev, "Unable to read remainder of result\n");
566 chip->ops->cancel(chip);
567 release_locality(chip);
571 static bool tpm_st33_i2c_req_canceled(struct tpm_chip *chip, u8 status)
573 return (status == TPM_STS_COMMAND_READY);
576 static const struct tpm_class_ops st_i2c_tpm = {
577 .send = tpm_stm_i2c_send,
578 .recv = tpm_stm_i2c_recv,
579 .cancel = tpm_stm_i2c_cancel,
580 .status = tpm_stm_i2c_status,
581 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
582 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
583 .req_canceled = tpm_st33_i2c_req_canceled,
586 static int interrupts;
587 module_param(interrupts, int, 0444);
588 MODULE_PARM_DESC(interrupts, "Enable interrupts");
590 static int power_mgt = 1;
591 module_param(power_mgt, int, 0444);
592 MODULE_PARM_DESC(power_mgt, "Power Management");
595 * tpm_st33_i2c_probe initialize the TPM device
596 * @param: client, the i2c_client drescription (TPM I2C description).
597 * @param: id, the i2c_device_id struct.
598 * @return: 0 in case of success.
602 tpm_st33_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
606 struct tpm_chip *chip;
607 struct st33zp24_platform_data *platform_data;
609 if (client == NULL) {
610 pr_info("%s: i2c client is NULL. Device not accessible.\n",
616 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
617 dev_info(&client->dev, "client not i2c capable\n");
622 chip = tpm_register_hardware(&client->dev, &st_i2c_tpm);
624 dev_info(&client->dev, "fail chip\n");
629 platform_data = client->dev.platform_data;
631 if (!platform_data) {
632 dev_info(&client->dev, "chip not available\n");
634 goto _tpm_clean_answer;
637 platform_data->tpm_i2c_buffer[0] =
638 kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
639 if (platform_data->tpm_i2c_buffer[0] == NULL) {
641 goto _tpm_clean_answer;
643 platform_data->tpm_i2c_buffer[1] =
644 kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
645 if (platform_data->tpm_i2c_buffer[1] == NULL) {
647 goto _tpm_clean_response1;
650 TPM_VPRIV(chip) = client;
652 chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
653 chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
654 chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
655 chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
657 chip->vendor.locality = LOCALITY0;
660 err = gpio_request(platform_data->io_lpcpd, "TPM IO_LPCPD");
663 gpio_set_value(platform_data->io_lpcpd, 1);
667 init_completion(&platform_data->irq_detection);
668 if (request_locality(chip) != LOCALITY0) {
670 goto _tpm_clean_response2;
672 err = gpio_request(platform_data->io_serirq, "TPM IO_SERIRQ");
676 clear_interruption(client);
677 err = request_irq(gpio_to_irq(platform_data->io_serirq),
678 &tpm_ioserirq_handler,
680 "TPM SERIRQ management", chip);
682 dev_err(chip->dev , "TPM SERIRQ signals %d not available\n",
683 gpio_to_irq(platform_data->io_serirq));
687 err = I2C_READ_DATA(client, TPM_INT_ENABLE, &intmask, 1);
691 intmask |= TPM_INTF_CMD_READY_INT
692 | TPM_INTF_FIFO_AVALAIBLE_INT
693 | TPM_INTF_WAKE_UP_READY_INT
694 | TPM_INTF_LOCALITY_CHANGE_INT
695 | TPM_INTF_STS_VALID_INT
696 | TPM_INTF_DATA_AVAIL_INT;
698 err = I2C_WRITE_DATA(client, TPM_INT_ENABLE, &intmask, 1);
702 intmask = TPM_GLOBAL_INT_ENABLE;
703 err = I2C_WRITE_DATA(client, (TPM_INT_ENABLE + 3), &intmask, 1);
707 err = I2C_READ_DATA(client, TPM_INT_STATUS, &intmask, 1);
711 chip->vendor.irq = interrupts;
713 tpm_gen_interrupt(chip);
716 tpm_get_timeouts(chip);
718 dev_info(chip->dev, "TPM I2C Initialized\n");
721 free_irq(gpio_to_irq(platform_data->io_serirq), (void *)chip);
724 gpio_free(platform_data->io_serirq);
727 gpio_free(platform_data->io_lpcpd);
728 _tpm_clean_response2:
729 kzfree(platform_data->tpm_i2c_buffer[1]);
730 platform_data->tpm_i2c_buffer[1] = NULL;
731 _tpm_clean_response1:
732 kzfree(platform_data->tpm_i2c_buffer[0]);
733 platform_data->tpm_i2c_buffer[0] = NULL;
735 tpm_remove_hardware(chip->dev);
737 pr_info("TPM I2C initialisation fail\n");
742 * tpm_st33_i2c_remove remove the TPM device
743 * @param: client, the i2c_client drescription (TPM I2C description).
744 clear_bit(0, &chip->is_open);
745 * @return: 0 in case of success.
747 static int tpm_st33_i2c_remove(struct i2c_client *client)
749 struct tpm_chip *chip = (struct tpm_chip *)i2c_get_clientdata(client);
750 struct st33zp24_platform_data *pin_infos =
751 ((struct i2c_client *)TPM_VPRIV(chip))->dev.platform_data;
753 if (pin_infos != NULL) {
754 free_irq(pin_infos->io_serirq, chip);
756 gpio_free(pin_infos->io_serirq);
757 gpio_free(pin_infos->io_lpcpd);
759 tpm_remove_hardware(chip->dev);
761 if (pin_infos->tpm_i2c_buffer[1] != NULL) {
762 kzfree(pin_infos->tpm_i2c_buffer[1]);
763 pin_infos->tpm_i2c_buffer[1] = NULL;
765 if (pin_infos->tpm_i2c_buffer[0] != NULL) {
766 kzfree(pin_infos->tpm_i2c_buffer[0]);
767 pin_infos->tpm_i2c_buffer[0] = NULL;
774 #ifdef CONFIG_PM_SLEEP
776 * tpm_st33_i2c_pm_suspend suspend the TPM device
777 * @param: client, the i2c_client drescription (TPM I2C description).
778 * @param: mesg, the power management message.
779 * @return: 0 in case of success.
781 static int tpm_st33_i2c_pm_suspend(struct device *dev)
783 struct st33zp24_platform_data *pin_infos = dev->platform_data;
787 gpio_set_value(pin_infos->io_lpcpd, 0);
789 ret = tpm_pm_suspend(dev);
792 } /* tpm_st33_i2c_suspend() */
795 * tpm_st33_i2c_pm_resume resume the TPM device
796 * @param: client, the i2c_client drescription (TPM I2C description).
797 * @return: 0 in case of success.
799 static int tpm_st33_i2c_pm_resume(struct device *dev)
801 struct tpm_chip *chip = dev_get_drvdata(dev);
802 struct st33zp24_platform_data *pin_infos = dev->platform_data;
807 gpio_set_value(pin_infos->io_lpcpd, 1);
808 ret = wait_for_serirq_timeout(chip,
809 (chip->ops->status(chip) &
810 TPM_STS_VALID) == TPM_STS_VALID,
811 chip->vendor.timeout_b);
813 ret = tpm_pm_resume(dev);
815 tpm_do_selftest(chip);
818 } /* tpm_st33_i2c_pm_resume() */
821 static const struct i2c_device_id tpm_st33_i2c_id[] = {
825 MODULE_DEVICE_TABLE(i2c, tpm_st33_i2c_id);
826 static SIMPLE_DEV_PM_OPS(tpm_st33_i2c_ops, tpm_st33_i2c_pm_suspend,
827 tpm_st33_i2c_pm_resume);
828 static struct i2c_driver tpm_st33_i2c_driver = {
830 .owner = THIS_MODULE,
831 .name = TPM_ST33_I2C,
832 .pm = &tpm_st33_i2c_ops,
834 .probe = tpm_st33_i2c_probe,
835 .remove = tpm_st33_i2c_remove,
836 .id_table = tpm_st33_i2c_id
839 module_i2c_driver(tpm_st33_i2c_driver);
841 MODULE_AUTHOR("Christophe Ricard (tpmsupport@st.com)");
842 MODULE_DESCRIPTION("STM TPM I2C ST33 Driver");
843 MODULE_VERSION("1.2.0");
844 MODULE_LICENSE("GPL");