1 /******************************************************************************
2 * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501,
3 * based on the TCG TPM Interface Spec version 1.2.
4 * Specifications at www.trustedcomputinggroup.org
6 * Copyright (C) 2011, Nuvoton Technology Corporation.
7 * Dan Morav <dan.morav@nuvoton.com>
8 * Copyright (C) 2013, Obsidian Research Corp.
9 * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see http://www.gnu.org/licenses/>.
24 * Nuvoton contact information: APC.Support@nuvoton.com
25 *****************************************************************************/
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/slab.h>
31 #include <linux/interrupt.h>
32 #include <linux/wait.h>
33 #include <linux/i2c.h>
36 /* I2C interface offsets */
38 #define TPM_BURST_COUNT 0x01
39 #define TPM_DATA_FIFO_W 0x20
40 #define TPM_DATA_FIFO_R 0x40
41 #define TPM_VID_DID_RID 0x60
42 /* TPM command header size */
43 #define TPM_HEADER_SIZE 10
46 * I2C bus device maximum buffer size w/o counting I2C address or command
47 * i.e. max size required for I2C write is 34 = addr, command, 32 bytes data
49 #define TPM_I2C_MAX_BUF_SIZE 32
50 #define TPM_I2C_RETRY_COUNT 32
51 #define TPM_I2C_BUS_DELAY 1 /* msec */
52 #define TPM_I2C_RETRY_DELAY_SHORT 2 /* msec */
53 #define TPM_I2C_RETRY_DELAY_LONG 10 /* msec */
55 #define I2C_DRIVER_NAME "tpm_i2c_nuvoton"
61 static s32 i2c_nuvoton_read_buf(struct i2c_client *client, u8 offset, u8 size,
66 status = i2c_smbus_read_i2c_block_data(client, offset, size, data);
68 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
69 offset, size, (int)size, data, status);
73 static s32 i2c_nuvoton_write_buf(struct i2c_client *client, u8 offset, u8 size,
78 status = i2c_smbus_write_i2c_block_data(client, offset, size, data);
80 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
81 offset, size, (int)size, data, status);
85 #define TPM_STS_VALID 0x80
86 #define TPM_STS_COMMAND_READY 0x40
87 #define TPM_STS_GO 0x20
88 #define TPM_STS_DATA_AVAIL 0x10
89 #define TPM_STS_EXPECT 0x08
90 #define TPM_STS_RESPONSE_RETRY 0x02
91 #define TPM_STS_ERR_VAL 0x07 /* bit2...bit0 reads always 0 */
93 #define TPM_I2C_SHORT_TIMEOUT 750 /* ms */
94 #define TPM_I2C_LONG_TIMEOUT 2000 /* 2 sec */
96 /* read TPM_STS register */
97 static u8 i2c_nuvoton_read_status(struct tpm_chip *chip)
99 struct i2c_client *client = to_i2c_client(chip->dev);
103 status = i2c_nuvoton_read_buf(client, TPM_STS, 1, &data);
105 dev_err(chip->dev, "%s() error return %d\n", __func__,
107 data = TPM_STS_ERR_VAL;
113 /* write byte to TPM_STS register */
114 static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
119 /* this causes the current command to be aborted */
120 for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
121 status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
122 msleep(TPM_I2C_BUS_DELAY);
127 /* write commandReady to TPM_STS register */
128 static void i2c_nuvoton_ready(struct tpm_chip *chip)
130 struct i2c_client *client = to_i2c_client(chip->dev);
133 /* this causes the current command to be aborted */
134 status = i2c_nuvoton_write_status(client, TPM_STS_COMMAND_READY);
137 "%s() fail to write TPM_STS.commandReady\n", __func__);
140 /* read burstCount field from TPM_STS register
141 * return -1 on fail to read */
142 static int i2c_nuvoton_get_burstcount(struct i2c_client *client,
143 struct tpm_chip *chip)
145 unsigned long stop = jiffies + chip->vendor.timeout_d;
147 int burst_count = -1;
150 /* wait for burstcount to be non-zero */
152 /* in I2C burstCount is 1 byte */
153 status = i2c_nuvoton_read_buf(client, TPM_BURST_COUNT, 1,
155 if (status > 0 && data > 0) {
156 burst_count = min_t(u8, TPM_I2C_MAX_BUF_SIZE, data);
159 msleep(TPM_I2C_BUS_DELAY);
160 } while (time_before(jiffies, stop));
166 * WPCT301/NPCT501 SINT# supports only dataAvail
167 * any call to this function which is not waiting for dataAvail will
168 * set queue to NULL to avoid waiting for interrupt
170 static bool i2c_nuvoton_check_status(struct tpm_chip *chip, u8 mask, u8 value)
172 u8 status = i2c_nuvoton_read_status(chip);
173 return (status != TPM_STS_ERR_VAL) && ((status & mask) == value);
176 static int i2c_nuvoton_wait_for_stat(struct tpm_chip *chip, u8 mask, u8 value,
177 u32 timeout, wait_queue_head_t *queue)
179 if (chip->vendor.irq && queue) {
182 struct priv_data *priv = chip->vendor.priv;
183 unsigned int cur_intrs = priv->intrs;
185 enable_irq(chip->vendor.irq);
186 rc = wait_event_interruptible_timeout(*queue,
187 cur_intrs != priv->intrs,
191 /* At this point we know that the SINT pin is asserted, so we
192 * do not need to do i2c_nuvoton_check_status */
194 unsigned long ten_msec, stop;
197 /* check current status */
198 status_valid = i2c_nuvoton_check_status(chip, mask, value);
202 /* use polling to wait for the event */
203 ten_msec = jiffies + msecs_to_jiffies(TPM_I2C_RETRY_DELAY_LONG);
204 stop = jiffies + timeout;
206 if (time_before(jiffies, ten_msec))
207 msleep(TPM_I2C_RETRY_DELAY_SHORT);
209 msleep(TPM_I2C_RETRY_DELAY_LONG);
210 status_valid = i2c_nuvoton_check_status(chip, mask,
214 } while (time_before(jiffies, stop));
216 dev_err(chip->dev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
221 /* wait for dataAvail field to be set in the TPM_STS register */
222 static int i2c_nuvoton_wait_for_data_avail(struct tpm_chip *chip, u32 timeout,
223 wait_queue_head_t *queue)
225 return i2c_nuvoton_wait_for_stat(chip,
226 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
227 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
231 /* Read @count bytes into @buf from TPM_RD_FIFO register */
232 static int i2c_nuvoton_recv_data(struct i2c_client *client,
233 struct tpm_chip *chip, u8 *buf, size_t count)
236 int burst_count, bytes2read, size = 0;
238 while (size < count &&
239 i2c_nuvoton_wait_for_data_avail(chip,
240 chip->vendor.timeout_c,
241 &chip->vendor.read_queue) == 0) {
242 burst_count = i2c_nuvoton_get_burstcount(client, chip);
243 if (burst_count < 0) {
245 "%s() fail to read burstCount=%d\n", __func__,
249 bytes2read = min_t(size_t, burst_count, count - size);
250 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_R,
251 bytes2read, &buf[size]);
254 "%s() fail on i2c_nuvoton_read_buf()=%d\n",
258 dev_dbg(chip->dev, "%s(%d):", __func__, bytes2read);
265 /* Read TPM command results */
266 static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
268 struct device *dev = chip->dev;
269 struct i2c_client *client = to_i2c_client(dev);
271 int expected, status, burst_count, retries, size = 0;
273 if (count < TPM_HEADER_SIZE) {
274 i2c_nuvoton_ready(chip); /* return to idle */
275 dev_err(dev, "%s() count < header size\n", __func__);
278 for (retries = 0; retries < TPM_RETRY; retries++) {
280 /* if this is not the first trial, set responseRetry */
281 i2c_nuvoton_write_status(client,
282 TPM_STS_RESPONSE_RETRY);
285 * read first available (> 10 bytes), including:
286 * tag, paramsize, and result
288 status = i2c_nuvoton_wait_for_data_avail(
289 chip, chip->vendor.timeout_c, &chip->vendor.read_queue);
291 dev_err(dev, "%s() timeout on dataAvail\n", __func__);
295 burst_count = i2c_nuvoton_get_burstcount(client, chip);
296 if (burst_count < 0) {
297 dev_err(dev, "%s() fail to get burstCount\n", __func__);
301 size = i2c_nuvoton_recv_data(client, chip, buf,
303 if (size < TPM_HEADER_SIZE) {
304 dev_err(dev, "%s() fail to read header\n", __func__);
309 * convert number of expected bytes field from big endian 32 bit
312 expected = be32_to_cpu(*(__be32 *) (buf + 2));
313 if (expected > count) {
314 dev_err(dev, "%s() expected > count\n", __func__);
318 rc = i2c_nuvoton_recv_data(client, chip, &buf[size],
321 if (rc < 0 || size < expected) {
322 dev_err(dev, "%s() fail to read remainder of result\n",
327 if (i2c_nuvoton_wait_for_stat(
328 chip, TPM_STS_VALID | TPM_STS_DATA_AVAIL,
329 TPM_STS_VALID, chip->vendor.timeout_c,
331 dev_err(dev, "%s() error left over data\n", __func__);
337 i2c_nuvoton_ready(chip);
338 dev_dbg(chip->dev, "%s() -> %d\n", __func__, size);
345 * If interrupts are used (signaled by an irq set in the vendor structure)
346 * tpm.c can skip polling for the data to be available as the interrupt is
349 static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
351 struct device *dev = chip->dev;
352 struct i2c_client *client = to_i2c_client(dev);
355 int burst_count, bytes2write, retries, rc = -EIO;
357 for (retries = 0; retries < TPM_RETRY; retries++) {
358 i2c_nuvoton_ready(chip);
359 if (i2c_nuvoton_wait_for_stat(chip, TPM_STS_COMMAND_READY,
360 TPM_STS_COMMAND_READY,
361 chip->vendor.timeout_b, NULL)) {
362 dev_err(dev, "%s() timeout on commandReady\n",
368 while (count < len - 1) {
369 burst_count = i2c_nuvoton_get_burstcount(client,
371 if (burst_count < 0) {
372 dev_err(dev, "%s() fail get burstCount\n",
377 bytes2write = min_t(size_t, burst_count,
379 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W,
380 bytes2write, &buf[count]);
382 dev_err(dev, "%s() fail i2cWriteBuf\n",
386 dev_dbg(dev, "%s(%d):", __func__, bytes2write);
387 count += bytes2write;
388 rc = i2c_nuvoton_wait_for_stat(chip,
393 chip->vendor.timeout_c,
396 dev_err(dev, "%s() timeout on Expect\n",
405 /* write last byte */
406 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W, 1,
409 dev_err(dev, "%s() fail to write last byte\n",
414 dev_dbg(dev, "%s(last): %02x", __func__, buf[count]);
415 rc = i2c_nuvoton_wait_for_stat(chip,
416 TPM_STS_VALID | TPM_STS_EXPECT,
418 chip->vendor.timeout_c, NULL);
420 dev_err(dev, "%s() timeout on Expect to clear\n",
428 /* retries == TPM_RETRY */
429 i2c_nuvoton_ready(chip);
432 /* execute the TPM command */
433 rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
435 dev_err(dev, "%s() fail to write Go\n", __func__);
436 i2c_nuvoton_ready(chip);
439 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
440 rc = i2c_nuvoton_wait_for_data_avail(chip,
441 tpm_calc_ordinal_duration(chip,
443 &chip->vendor.read_queue);
445 dev_err(dev, "%s() timeout command duration\n", __func__);
446 i2c_nuvoton_ready(chip);
450 dev_dbg(dev, "%s() -> %zd\n", __func__, len);
454 static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
456 return (status == TPM_STS_COMMAND_READY);
459 static const struct file_operations i2c_nuvoton_ops = {
460 .owner = THIS_MODULE,
465 .release = tpm_release,
468 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
469 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
470 static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL);
471 static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL);
472 static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL);
473 static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated, NULL);
474 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
475 static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
476 static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
477 static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
479 static struct attribute *i2c_nuvoton_attrs[] = {
480 &dev_attr_pubek.attr,
482 &dev_attr_enabled.attr,
483 &dev_attr_active.attr,
484 &dev_attr_owned.attr,
485 &dev_attr_temp_deactivated.attr,
487 &dev_attr_cancel.attr,
488 &dev_attr_durations.attr,
489 &dev_attr_timeouts.attr,
493 static struct attribute_group i2c_nuvoton_attr_grp = {
494 .attrs = i2c_nuvoton_attrs
497 static const struct tpm_vendor_specific tpm_i2c = {
498 .status = i2c_nuvoton_read_status,
499 .recv = i2c_nuvoton_recv,
500 .send = i2c_nuvoton_send,
501 .cancel = i2c_nuvoton_ready,
502 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
503 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
504 .req_canceled = i2c_nuvoton_req_canceled,
505 .attr_group = &i2c_nuvoton_attr_grp,
506 .miscdev.fops = &i2c_nuvoton_ops,
509 /* The only purpose for the handler is to signal to any waiting threads that
510 * the interrupt is currently being asserted. The driver does not do any
511 * processing triggered by interrupts, and the chip provides no way to mask at
512 * the source (plus that would be slow over I2C). Run the IRQ as a one-shot,
513 * this means it cannot be shared. */
514 static irqreturn_t i2c_nuvoton_int_handler(int dummy, void *dev_id)
516 struct tpm_chip *chip = dev_id;
517 struct priv_data *priv = chip->vendor.priv;
520 wake_up(&chip->vendor.read_queue);
521 disable_irq_nosync(chip->vendor.irq);
525 static int get_vid(struct i2c_client *client, u32 *res)
527 static const u8 vid_did_rid_value[] = { 0x50, 0x10, 0xfe };
531 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
533 rc = i2c_nuvoton_read_buf(client, TPM_VID_DID_RID, 4, (u8 *)&temp);
537 /* check WPCT301 values - ignore RID */
538 if (memcmp(&temp, vid_did_rid_value, sizeof(vid_did_rid_value))) {
540 * f/w rev 2.81 has an issue where the VID_DID_RID is not
541 * reporting the right value. so give it another chance at
542 * offset 0x20 (FIFO_W).
544 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_W, 4,
549 /* check WPCT301 values - ignore RID */
550 if (memcmp(&temp, vid_did_rid_value,
551 sizeof(vid_did_rid_value)))
559 static int i2c_nuvoton_probe(struct i2c_client *client,
560 const struct i2c_device_id *id)
563 struct tpm_chip *chip;
564 struct device *dev = &client->dev;
567 rc = get_vid(client, &vid);
571 dev_info(dev, "VID: %04X DID: %02X RID: %02X\n", (u16) vid,
572 (u8) (vid >> 16), (u8) (vid >> 24));
574 chip = tpm_register_hardware(dev, &tpm_i2c);
576 dev_err(dev, "%s() error in tpm_register_hardware\n", __func__);
580 chip->vendor.priv = devm_kzalloc(dev, sizeof(struct priv_data),
582 init_waitqueue_head(&chip->vendor.read_queue);
583 init_waitqueue_head(&chip->vendor.int_queue);
585 /* Default timeouts */
586 chip->vendor.timeout_a = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
587 chip->vendor.timeout_b = msecs_to_jiffies(TPM_I2C_LONG_TIMEOUT);
588 chip->vendor.timeout_c = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
589 chip->vendor.timeout_d = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
592 * I2C intfcaps (interrupt capabilitieis) in the chip are hard coded to:
593 * TPM_INTF_INT_LEVEL_LOW | TPM_INTF_DATA_AVAIL_INT
594 * The IRQ should be set in the i2c_board_info (which is done
595 * automatically in of_i2c_register_devices, for device tree users */
596 chip->vendor.irq = client->irq;
598 if (chip->vendor.irq) {
599 dev_dbg(dev, "%s() chip-vendor.irq\n", __func__);
600 rc = devm_request_irq(dev, chip->vendor.irq,
601 i2c_nuvoton_int_handler,
603 chip->vendor.miscdev.name,
606 dev_err(dev, "%s() Unable to request irq: %d for use\n",
607 __func__, chip->vendor.irq);
608 chip->vendor.irq = 0;
610 /* Clear any pending interrupt */
611 i2c_nuvoton_ready(chip);
612 /* - wait for TPM_STS==0xA0 (stsValid, commandReady) */
613 rc = i2c_nuvoton_wait_for_stat(chip,
614 TPM_STS_COMMAND_READY,
615 TPM_STS_COMMAND_READY,
616 chip->vendor.timeout_b,
620 * TIS is in ready state
621 * write dummy byte to enter reception state
622 * TPM_DATA_FIFO_W <- rc (0)
624 rc = i2c_nuvoton_write_buf(client,
629 /* TPM_STS <- 0x40 (commandReady) */
630 i2c_nuvoton_ready(chip);
633 * timeout_b reached - command was
634 * aborted. TIS should now be in idle state -
635 * only TPM_STS_VALID should be set
637 if (i2c_nuvoton_read_status(chip) !=
646 if (tpm_get_timeouts(chip)) {
651 if (tpm_do_selftest(chip)) {
659 tpm_dev_vendor_release(chip);
660 tpm_remove_hardware(chip->dev);
664 static int i2c_nuvoton_remove(struct i2c_client *client)
666 struct device *dev = &(client->dev);
667 struct tpm_chip *chip = dev_get_drvdata(dev);
670 tpm_dev_vendor_release(chip);
671 tpm_remove_hardware(dev);
677 static const struct i2c_device_id i2c_nuvoton_id[] = {
678 {I2C_DRIVER_NAME, 0},
681 MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
684 static const struct of_device_id i2c_nuvoton_of_match[] = {
685 {.compatible = "nuvoton,npct501"},
686 {.compatible = "winbond,wpct301"},
689 MODULE_DEVICE_TABLE(of, i2c_nuvoton_of_match);
692 static SIMPLE_DEV_PM_OPS(i2c_nuvoton_pm_ops, tpm_pm_suspend, tpm_pm_resume);
694 static struct i2c_driver i2c_nuvoton_driver = {
695 .id_table = i2c_nuvoton_id,
696 .probe = i2c_nuvoton_probe,
697 .remove = i2c_nuvoton_remove,
699 .name = I2C_DRIVER_NAME,
700 .owner = THIS_MODULE,
701 .pm = &i2c_nuvoton_pm_ops,
702 .of_match_table = of_match_ptr(i2c_nuvoton_of_match),
706 module_i2c_driver(i2c_nuvoton_driver);
708 MODULE_AUTHOR("Dan Morav (dan.morav@nuvoton.com)");
709 MODULE_DESCRIPTION("Nuvoton TPM I2C Driver");
710 MODULE_LICENSE("GPL");