1 /******************************************************************************
2 * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501/NPCT6XX,
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>
34 #include <linux/of_device.h>
37 /* I2C interface offsets */
39 #define TPM_BURST_COUNT 0x01
40 #define TPM_DATA_FIFO_W 0x20
41 #define TPM_DATA_FIFO_R 0x40
42 #define TPM_VID_DID_RID 0x60
43 /* TPM command header size */
44 #define TPM_HEADER_SIZE 10
47 * I2C bus device maximum buffer size w/o counting I2C address or command
48 * i.e. max size required for I2C write is 34 = addr, command, 32 bytes data
50 #define TPM_I2C_MAX_BUF_SIZE 32
51 #define TPM_I2C_RETRY_COUNT 32
52 #define TPM_I2C_BUS_DELAY 1 /* msec */
53 #define TPM_I2C_RETRY_DELAY_SHORT 2 /* msec */
54 #define TPM_I2C_RETRY_DELAY_LONG 10 /* msec */
56 #define OF_IS_TPM2 ((void *)1)
62 wait_queue_head_t read_queue;
65 static s32 i2c_nuvoton_read_buf(struct i2c_client *client, u8 offset, u8 size,
70 status = i2c_smbus_read_i2c_block_data(client, offset, size, data);
72 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
73 offset, size, (int)size, data, status);
77 static s32 i2c_nuvoton_write_buf(struct i2c_client *client, u8 offset, u8 size,
82 status = i2c_smbus_write_i2c_block_data(client, offset, size, data);
84 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
85 offset, size, (int)size, data, status);
89 #define TPM_STS_VALID 0x80
90 #define TPM_STS_COMMAND_READY 0x40
91 #define TPM_STS_GO 0x20
92 #define TPM_STS_DATA_AVAIL 0x10
93 #define TPM_STS_EXPECT 0x08
94 #define TPM_STS_RESPONSE_RETRY 0x02
95 #define TPM_STS_ERR_VAL 0x07 /* bit2...bit0 reads always 0 */
97 #define TPM_I2C_SHORT_TIMEOUT 750 /* ms */
98 #define TPM_I2C_LONG_TIMEOUT 2000 /* 2 sec */
100 /* read TPM_STS register */
101 static u8 i2c_nuvoton_read_status(struct tpm_chip *chip)
103 struct i2c_client *client = to_i2c_client(chip->dev.parent);
107 status = i2c_nuvoton_read_buf(client, TPM_STS, 1, &data);
109 dev_err(&chip->dev, "%s() error return %d\n", __func__,
111 data = TPM_STS_ERR_VAL;
117 /* write byte to TPM_STS register */
118 static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
123 /* this causes the current command to be aborted */
124 for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
125 status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
126 msleep(TPM_I2C_BUS_DELAY);
131 /* write commandReady to TPM_STS register */
132 static void i2c_nuvoton_ready(struct tpm_chip *chip)
134 struct i2c_client *client = to_i2c_client(chip->dev.parent);
137 /* this causes the current command to be aborted */
138 status = i2c_nuvoton_write_status(client, TPM_STS_COMMAND_READY);
141 "%s() fail to write TPM_STS.commandReady\n", __func__);
144 /* read burstCount field from TPM_STS register
145 * return -1 on fail to read */
146 static int i2c_nuvoton_get_burstcount(struct i2c_client *client,
147 struct tpm_chip *chip)
149 unsigned long stop = jiffies + chip->timeout_d;
151 int burst_count = -1;
154 /* wait for burstcount to be non-zero */
156 /* in I2C burstCount is 1 byte */
157 status = i2c_nuvoton_read_buf(client, TPM_BURST_COUNT, 1,
159 if (status > 0 && data > 0) {
160 burst_count = min_t(u8, TPM_I2C_MAX_BUF_SIZE, data);
163 msleep(TPM_I2C_BUS_DELAY);
164 } while (time_before(jiffies, stop));
170 * WPCT301/NPCT501/NPCT6XX SINT# supports only dataAvail
171 * any call to this function which is not waiting for dataAvail will
172 * set queue to NULL to avoid waiting for interrupt
174 static bool i2c_nuvoton_check_status(struct tpm_chip *chip, u8 mask, u8 value)
176 u8 status = i2c_nuvoton_read_status(chip);
177 return (status != TPM_STS_ERR_VAL) && ((status & mask) == value);
180 static int i2c_nuvoton_wait_for_stat(struct tpm_chip *chip, u8 mask, u8 value,
181 u32 timeout, wait_queue_head_t *queue)
183 if ((chip->flags & TPM_CHIP_FLAG_IRQ) && queue) {
185 struct priv_data *priv = dev_get_drvdata(&chip->dev);
186 unsigned int cur_intrs = priv->intrs;
188 enable_irq(priv->irq);
189 rc = wait_event_interruptible_timeout(*queue,
190 cur_intrs != priv->intrs,
194 /* At this point we know that the SINT pin is asserted, so we
195 * do not need to do i2c_nuvoton_check_status */
197 unsigned long ten_msec, stop;
200 /* check current status */
201 status_valid = i2c_nuvoton_check_status(chip, mask, value);
205 /* use polling to wait for the event */
206 ten_msec = jiffies + msecs_to_jiffies(TPM_I2C_RETRY_DELAY_LONG);
207 stop = jiffies + timeout;
209 if (time_before(jiffies, ten_msec))
210 msleep(TPM_I2C_RETRY_DELAY_SHORT);
212 msleep(TPM_I2C_RETRY_DELAY_LONG);
213 status_valid = i2c_nuvoton_check_status(chip, mask,
217 } while (time_before(jiffies, stop));
219 dev_err(&chip->dev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
224 /* wait for dataAvail field to be set in the TPM_STS register */
225 static int i2c_nuvoton_wait_for_data_avail(struct tpm_chip *chip, u32 timeout,
226 wait_queue_head_t *queue)
228 return i2c_nuvoton_wait_for_stat(chip,
229 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
230 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
234 /* Read @count bytes into @buf from TPM_RD_FIFO register */
235 static int i2c_nuvoton_recv_data(struct i2c_client *client,
236 struct tpm_chip *chip, u8 *buf, size_t count)
238 struct priv_data *priv = dev_get_drvdata(&chip->dev);
240 int burst_count, bytes2read, size = 0;
242 while (size < count &&
243 i2c_nuvoton_wait_for_data_avail(chip,
245 &priv->read_queue) == 0) {
246 burst_count = i2c_nuvoton_get_burstcount(client, chip);
247 if (burst_count < 0) {
249 "%s() fail to read burstCount=%d\n", __func__,
253 bytes2read = min_t(size_t, burst_count, count - size);
254 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_R,
255 bytes2read, &buf[size]);
258 "%s() fail on i2c_nuvoton_read_buf()=%d\n",
262 dev_dbg(&chip->dev, "%s(%d):", __func__, bytes2read);
269 /* Read TPM command results */
270 static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
272 struct priv_data *priv = dev_get_drvdata(&chip->dev);
273 struct device *dev = chip->dev.parent;
274 struct i2c_client *client = to_i2c_client(dev);
276 int expected, status, burst_count, retries, size = 0;
278 if (count < TPM_HEADER_SIZE) {
279 i2c_nuvoton_ready(chip); /* return to idle */
280 dev_err(dev, "%s() count < header size\n", __func__);
283 for (retries = 0; retries < TPM_RETRY; retries++) {
285 /* if this is not the first trial, set responseRetry */
286 i2c_nuvoton_write_status(client,
287 TPM_STS_RESPONSE_RETRY);
290 * read first available (> 10 bytes), including:
291 * tag, paramsize, and result
293 status = i2c_nuvoton_wait_for_data_avail(
294 chip, chip->timeout_c, &priv->read_queue);
296 dev_err(dev, "%s() timeout on dataAvail\n", __func__);
300 burst_count = i2c_nuvoton_get_burstcount(client, chip);
301 if (burst_count < 0) {
302 dev_err(dev, "%s() fail to get burstCount\n", __func__);
306 size = i2c_nuvoton_recv_data(client, chip, buf,
308 if (size < TPM_HEADER_SIZE) {
309 dev_err(dev, "%s() fail to read header\n", __func__);
314 * convert number of expected bytes field from big endian 32 bit
317 expected = be32_to_cpu(*(__be32 *) (buf + 2));
318 if (expected > count) {
319 dev_err(dev, "%s() expected > count\n", __func__);
323 rc = i2c_nuvoton_recv_data(client, chip, &buf[size],
326 if (rc < 0 || size < expected) {
327 dev_err(dev, "%s() fail to read remainder of result\n",
332 if (i2c_nuvoton_wait_for_stat(
333 chip, TPM_STS_VALID | TPM_STS_DATA_AVAIL,
334 TPM_STS_VALID, chip->timeout_c,
336 dev_err(dev, "%s() error left over data\n", __func__);
342 i2c_nuvoton_ready(chip);
343 dev_dbg(&chip->dev, "%s() -> %d\n", __func__, size);
350 * If interrupts are used (signaled by an irq set in the vendor structure)
351 * tpm.c can skip polling for the data to be available as the interrupt is
354 static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
356 struct priv_data *priv = dev_get_drvdata(&chip->dev);
357 struct device *dev = chip->dev.parent;
358 struct i2c_client *client = to_i2c_client(dev);
361 int burst_count, bytes2write, retries, rc = -EIO;
363 for (retries = 0; retries < TPM_RETRY; retries++) {
364 i2c_nuvoton_ready(chip);
365 if (i2c_nuvoton_wait_for_stat(chip, TPM_STS_COMMAND_READY,
366 TPM_STS_COMMAND_READY,
367 chip->timeout_b, NULL)) {
368 dev_err(dev, "%s() timeout on commandReady\n",
374 while (count < len - 1) {
375 burst_count = i2c_nuvoton_get_burstcount(client,
377 if (burst_count < 0) {
378 dev_err(dev, "%s() fail get burstCount\n",
383 bytes2write = min_t(size_t, burst_count,
385 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W,
386 bytes2write, &buf[count]);
388 dev_err(dev, "%s() fail i2cWriteBuf\n",
392 dev_dbg(dev, "%s(%d):", __func__, bytes2write);
393 count += bytes2write;
394 rc = i2c_nuvoton_wait_for_stat(chip,
402 dev_err(dev, "%s() timeout on Expect\n",
411 /* write last byte */
412 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W, 1,
415 dev_err(dev, "%s() fail to write last byte\n",
420 dev_dbg(dev, "%s(last): %02x", __func__, buf[count]);
421 rc = i2c_nuvoton_wait_for_stat(chip,
422 TPM_STS_VALID | TPM_STS_EXPECT,
424 chip->timeout_c, NULL);
426 dev_err(dev, "%s() timeout on Expect to clear\n",
434 /* retries == TPM_RETRY */
435 i2c_nuvoton_ready(chip);
438 /* execute the TPM command */
439 rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
441 dev_err(dev, "%s() fail to write Go\n", __func__);
442 i2c_nuvoton_ready(chip);
445 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
446 rc = i2c_nuvoton_wait_for_data_avail(chip,
447 tpm_calc_ordinal_duration(chip,
451 dev_err(dev, "%s() timeout command duration\n", __func__);
452 i2c_nuvoton_ready(chip);
456 dev_dbg(dev, "%s() -> %zd\n", __func__, len);
460 static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
462 return (status == TPM_STS_COMMAND_READY);
465 static const struct tpm_class_ops tpm_i2c = {
466 .flags = TPM_OPS_AUTO_STARTUP,
467 .status = i2c_nuvoton_read_status,
468 .recv = i2c_nuvoton_recv,
469 .send = i2c_nuvoton_send,
470 .cancel = i2c_nuvoton_ready,
471 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
472 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
473 .req_canceled = i2c_nuvoton_req_canceled,
476 /* The only purpose for the handler is to signal to any waiting threads that
477 * the interrupt is currently being asserted. The driver does not do any
478 * processing triggered by interrupts, and the chip provides no way to mask at
479 * the source (plus that would be slow over I2C). Run the IRQ as a one-shot,
480 * this means it cannot be shared. */
481 static irqreturn_t i2c_nuvoton_int_handler(int dummy, void *dev_id)
483 struct tpm_chip *chip = dev_id;
484 struct priv_data *priv = dev_get_drvdata(&chip->dev);
487 wake_up(&priv->read_queue);
488 disable_irq_nosync(priv->irq);
492 static int get_vid(struct i2c_client *client, u32 *res)
494 static const u8 vid_did_rid_value[] = { 0x50, 0x10, 0xfe };
498 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
500 rc = i2c_nuvoton_read_buf(client, TPM_VID_DID_RID, 4, (u8 *)&temp);
504 /* check WPCT301 values - ignore RID */
505 if (memcmp(&temp, vid_did_rid_value, sizeof(vid_did_rid_value))) {
507 * f/w rev 2.81 has an issue where the VID_DID_RID is not
508 * reporting the right value. so give it another chance at
509 * offset 0x20 (FIFO_W).
511 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_W, 4,
516 /* check WPCT301 values - ignore RID */
517 if (memcmp(&temp, vid_did_rid_value,
518 sizeof(vid_did_rid_value)))
526 static int i2c_nuvoton_probe(struct i2c_client *client,
527 const struct i2c_device_id *id)
530 struct tpm_chip *chip;
531 struct device *dev = &client->dev;
532 struct priv_data *priv;
535 rc = get_vid(client, &vid);
539 dev_info(dev, "VID: %04X DID: %02X RID: %02X\n", (u16) vid,
540 (u8) (vid >> 16), (u8) (vid >> 24));
542 chip = tpmm_chip_alloc(dev, &tpm_i2c);
544 return PTR_ERR(chip);
546 priv = devm_kzalloc(dev, sizeof(struct priv_data), GFP_KERNEL);
551 const struct of_device_id *of_id;
553 of_id = of_match_device(dev->driver->of_match_table, dev);
554 if (of_id && of_id->data == OF_IS_TPM2)
555 chip->flags |= TPM_CHIP_FLAG_TPM2;
557 if (id->driver_data == I2C_IS_TPM2)
558 chip->flags |= TPM_CHIP_FLAG_TPM2;
560 init_waitqueue_head(&priv->read_queue);
562 /* Default timeouts */
563 chip->timeout_a = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
564 chip->timeout_b = msecs_to_jiffies(TPM_I2C_LONG_TIMEOUT);
565 chip->timeout_c = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
566 chip->timeout_d = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
568 dev_set_drvdata(&chip->dev, priv);
571 * I2C intfcaps (interrupt capabilitieis) in the chip are hard coded to:
572 * TPM_INTF_INT_LEVEL_LOW | TPM_INTF_DATA_AVAIL_INT
573 * The IRQ should be set in the i2c_board_info (which is done
574 * automatically in of_i2c_register_devices, for device tree users */
575 priv->irq = client->irq;
577 dev_dbg(dev, "%s() priv->irq\n", __func__);
578 rc = devm_request_irq(dev, client->irq,
579 i2c_nuvoton_int_handler,
581 dev_name(&chip->dev),
584 dev_err(dev, "%s() Unable to request irq: %d for use\n",
585 __func__, priv->irq);
588 chip->flags |= TPM_CHIP_FLAG_IRQ;
589 /* Clear any pending interrupt */
590 i2c_nuvoton_ready(chip);
591 /* - wait for TPM_STS==0xA0 (stsValid, commandReady) */
592 rc = i2c_nuvoton_wait_for_stat(chip,
593 TPM_STS_COMMAND_READY,
594 TPM_STS_COMMAND_READY,
599 * TIS is in ready state
600 * write dummy byte to enter reception state
601 * TPM_DATA_FIFO_W <- rc (0)
603 rc = i2c_nuvoton_write_buf(client,
608 /* TPM_STS <- 0x40 (commandReady) */
609 i2c_nuvoton_ready(chip);
612 * timeout_b reached - command was
613 * aborted. TIS should now be in idle state -
614 * only TPM_STS_VALID should be set
616 if (i2c_nuvoton_read_status(chip) !=
623 return tpm_chip_register(chip);
626 static int i2c_nuvoton_remove(struct i2c_client *client)
628 struct tpm_chip *chip = i2c_get_clientdata(client);
630 tpm_chip_unregister(chip);
634 static const struct i2c_device_id i2c_nuvoton_id[] = {
636 {"tpm2_i2c_nuvoton", .driver_data = I2C_IS_TPM2},
639 MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
642 static const struct of_device_id i2c_nuvoton_of_match[] = {
643 {.compatible = "nuvoton,npct501"},
644 {.compatible = "winbond,wpct301"},
645 {.compatible = "nuvoton,npct601", .data = OF_IS_TPM2},
648 MODULE_DEVICE_TABLE(of, i2c_nuvoton_of_match);
651 static SIMPLE_DEV_PM_OPS(i2c_nuvoton_pm_ops, tpm_pm_suspend, tpm_pm_resume);
653 static struct i2c_driver i2c_nuvoton_driver = {
654 .id_table = i2c_nuvoton_id,
655 .probe = i2c_nuvoton_probe,
656 .remove = i2c_nuvoton_remove,
658 .name = "tpm_i2c_nuvoton",
659 .pm = &i2c_nuvoton_pm_ops,
660 .of_match_table = of_match_ptr(i2c_nuvoton_of_match),
664 module_i2c_driver(i2c_nuvoton_driver);
666 MODULE_AUTHOR("Dan Morav (dan.morav@nuvoton.com)");
667 MODULE_DESCRIPTION("Nuvoton TPM I2C Driver");
668 MODULE_LICENSE("GPL");