1 // SPDX-License-Identifier: GPL-2.0
10  * - Use an interrupt for transaction status instead of hardcoded delays.
11  * - Must use write+wait+read read protocol.
12  * - All 4 bytes of status register must be read/written at once.
13  * - Burst count max is 63 bytes, and burst count behaves slightly differently
15  * - When reading from FIFO the full burstcnt must be read instead of just
37 #define TPM_CR50_I2C_MAX_RETRIES	3		/* Max retries due to I2C errors */
48  * struct tpm_i2c_cr50_priv_data - Driver private data.
49  * @irq:	Irq number used for this chip.
51  * @tpm_ready:	Struct used by irq handler to signal R/W readiness.
52  * @buf:	Buffer used for i2c writes, with i2c address prepended to content.
63  * tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
65  * @tpm_info:	TPM chip information.
69  * processing but is instead used to avoid fixed delays.
76 	struct tpm_chip *chip = tpm_info;  in tpm_cr50_i2c_int_handler()  local
77 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_int_handler()
79 	complete(&priv->tpm_ready);  in tpm_cr50_i2c_int_handler()
85  * tpm_cr50_i2c_wait_tpm_ready() - Wait for tpm to signal ready.
86  * @chip: A TPM chip.
89  * delay for the TPM to be ready.
92  * - 0:		Success.
93  * - -errno:	A POSIX error code.
95 static int tpm_cr50_i2c_wait_tpm_ready(struct tpm_chip *chip)  in tpm_cr50_i2c_wait_tpm_ready()  argument
97 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_wait_tpm_ready()
100 	if (priv->irq <= 0) {  in tpm_cr50_i2c_wait_tpm_ready()
105 	/* Wait for interrupt to indicate TPM is ready to respond */  in tpm_cr50_i2c_wait_tpm_ready()
106 	if (!wait_for_completion_timeout(&priv->tpm_ready, chip->timeout_a)) {  in tpm_cr50_i2c_wait_tpm_ready()
107 		dev_warn(&chip->dev, "Timeout waiting for TPM ready\n");  in tpm_cr50_i2c_wait_tpm_ready()
108 		return -ETIMEDOUT;  in tpm_cr50_i2c_wait_tpm_ready()
115  * tpm_cr50_i2c_enable_tpm_irq() - Enable TPM irq.
116  * @chip: A TPM chip.
118 static void tpm_cr50_i2c_enable_tpm_irq(struct tpm_chip *chip)  in tpm_cr50_i2c_enable_tpm_irq()  argument
120 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_enable_tpm_irq()
122 	if (priv->irq > 0) {  in tpm_cr50_i2c_enable_tpm_irq()
123 		reinit_completion(&priv->tpm_ready);  in tpm_cr50_i2c_enable_tpm_irq()
124 		enable_irq(priv->irq);  in tpm_cr50_i2c_enable_tpm_irq()
129  * tpm_cr50_i2c_disable_tpm_irq() - Disable TPM irq.
130  * @chip: A TPM chip.
132 static void tpm_cr50_i2c_disable_tpm_irq(struct tpm_chip *chip)  in tpm_cr50_i2c_disable_tpm_irq()  argument
134 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_disable_tpm_irq()
136 	if (priv->irq > 0)  in tpm_cr50_i2c_disable_tpm_irq()
137 		disable_irq(priv->irq);  in tpm_cr50_i2c_disable_tpm_irq()
141  * tpm_cr50_i2c_transfer_message() - Transfer a message over i2c.
144  * @msg:	Message to transfer.
150  * - 0:		Success.
151  * - -errno:	A POSIX error code.
171 	return -EIO;  in tpm_cr50_i2c_transfer_message()
175  * tpm_cr50_i2c_read() - Read from TPM register.
176  * @chip:	A TPM chip.
177  * @addr:	Register address to read from.
179  * @len:	Number of bytes to read.
181  * Sends the register address byte to the TPM, then waits until TPM
186  * - 0:		Success.
187  * - -errno:	A POSIX error code.
189 static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t len)  in tpm_cr50_i2c_read()  argument
191 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  in tpm_cr50_i2c_read()
193 		.addr = client->addr,  in tpm_cr50_i2c_read()
198 		.addr = client->addr,  in tpm_cr50_i2c_read()
206 	tpm_cr50_i2c_enable_tpm_irq(chip);  in tpm_cr50_i2c_read()
208 	/* Send the register address byte to the TPM */  in tpm_cr50_i2c_read()
209 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);  in tpm_cr50_i2c_read()
213 	/* Wait for TPM to be ready with response data */  in tpm_cr50_i2c_read()
214 	rc = tpm_cr50_i2c_wait_tpm_ready(chip);  in tpm_cr50_i2c_read()
219 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);  in tpm_cr50_i2c_read()
222 	tpm_cr50_i2c_disable_tpm_irq(chip);  in tpm_cr50_i2c_read()
231  * tpm_cr50_i2c_write()- Write to TPM register.
232  * @chip:	A TPM chip.
233  * @addr:	Register address to write to.
234  * @buffer:	Data to write.
235  * @len:	Number of bytes to write.
237  * The provided address is prepended to the data in 'buffer', the
238  * combined address+data is sent to the TPM, then wait for TPM to
242  * - 0:		Success.
243  * - -errno:	A POSIX error code.
245 static int tpm_cr50_i2c_write(struct tpm_chip *chip, u8 addr, u8 *buffer,  in tpm_cr50_i2c_write()  argument
248 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_write()
249 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  in tpm_cr50_i2c_write()
251 		.addr = client->addr,  in tpm_cr50_i2c_write()
253 		.buf = priv->buf  in tpm_cr50_i2c_write()
257 	if (len > TPM_CR50_MAX_BUFSIZE - 1)  in tpm_cr50_i2c_write()
258 		return -EINVAL;  in tpm_cr50_i2c_write()
260 	/* Prepend the 'register address' to the buffer */  in tpm_cr50_i2c_write()
261 	priv->buf[0] = addr;  in tpm_cr50_i2c_write()
262 	memcpy(priv->buf + 1, buffer, len);  in tpm_cr50_i2c_write()
265 	tpm_cr50_i2c_enable_tpm_irq(chip);  in tpm_cr50_i2c_write()
268 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);  in tpm_cr50_i2c_write()
272 	/* Wait for TPM to be ready, ignore timeout */  in tpm_cr50_i2c_write()
273 	tpm_cr50_i2c_wait_tpm_ready(chip);  in tpm_cr50_i2c_write()
276 	tpm_cr50_i2c_disable_tpm_irq(chip);  in tpm_cr50_i2c_write()
285  * tpm_cr50_check_locality() - Verify if required TPM locality is active.
286  * @chip: A TPM chip.
287  * @loc: Locality to be verified
290  * - loc:	Success.
291  * - -errno:	A POSIX error code.
293 static int tpm_cr50_check_locality(struct tpm_chip *chip, int loc)  in tpm_cr50_check_locality()  argument
299 	rc = tpm_cr50_i2c_read(chip, TPM_I2C_ACCESS(loc), &buf, sizeof(buf));  in tpm_cr50_check_locality()
306 	return -EIO;  in tpm_cr50_check_locality()
310  * tpm_cr50_release_locality() - Release TPM locality.
311  * @chip:	A TPM chip.
312  * @loc:	Locality to be released
315  * - 0:		Success.
316  * - -errno:	A POSIX error code.
318 static int tpm_cr50_release_locality(struct tpm_chip *chip, int loc)  in tpm_cr50_release_locality()  argument
320 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  in tpm_cr50_release_locality()
326 	rc = tpm_cr50_i2c_read(chip, addr, &buf, sizeof(buf));  in tpm_cr50_release_locality()
332 		rc = tpm_cr50_i2c_write(chip, addr, &buf, sizeof(buf));  in tpm_cr50_release_locality()
336 	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_release_locality()
341  * tpm_cr50_request_locality() - Request TPM locality.
342  * @chip: A TPM chip.
343  * @loc: Locality to be requested.
346  * - loc:	Success.
347  * - -errno:	A POSIX error code.
349 static int tpm_cr50_request_locality(struct tpm_chip *chip, int loc)  in tpm_cr50_request_locality()  argument
351 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  in tpm_cr50_request_locality()
356 	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_request_locality()
358 	if (tpm_cr50_check_locality(chip, loc) == loc)  in tpm_cr50_request_locality()
361 	rc = tpm_cr50_i2c_write(chip, TPM_I2C_ACCESS(loc), &buf, sizeof(buf));  in tpm_cr50_request_locality()
365 	stop = jiffies + chip->timeout_a;  in tpm_cr50_request_locality()
367 		if (tpm_cr50_check_locality(chip, loc) == loc)  in tpm_cr50_request_locality()
373 	rc = -ETIMEDOUT;  in tpm_cr50_request_locality()
376 	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_request_locality()
381  * tpm_cr50_i2c_tis_status() - Read cr50 tis status.
382  * @chip: A TPM chip.
384  * cr50 requires all 4 bytes of status register to be read.
389 static u8 tpm_cr50_i2c_tis_status(struct tpm_chip *chip)  in tpm_cr50_i2c_tis_status()  argument
393 	if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(chip->locality), buf, sizeof(buf)) < 0)  in tpm_cr50_i2c_tis_status()
400  * tpm_cr50_i2c_tis_set_ready() - Set status register to ready.
401  * @chip: A TPM chip.
403  * cr50 requires all 4 bytes of status register to be written.
405 static void tpm_cr50_i2c_tis_set_ready(struct tpm_chip *chip)  in tpm_cr50_i2c_tis_set_ready()  argument
409 	tpm_cr50_i2c_write(chip, TPM_I2C_STS(chip->locality), buf, sizeof(buf));  in tpm_cr50_i2c_tis_set_ready()
414  * tpm_cr50_i2c_get_burst_and_status() - Get burst count and status.
415  * @chip:	A TPM chip.
424  * - 0:		Success.
425  * - -errno:	A POSIX error code.
427 static int tpm_cr50_i2c_get_burst_and_status(struct tpm_chip *chip, u8 mask,  in tpm_cr50_i2c_get_burst_and_status()  argument
436 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_get_burst_and_status()
439 		if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(chip->locality), buf, sizeof(buf)) < 0) {  in tpm_cr50_i2c_get_burst_and_status()
448 		    *burst > 0 && *burst <= TPM_CR50_MAX_BUFSIZE - 1)  in tpm_cr50_i2c_get_burst_and_status()
454 	dev_err(&chip->dev, "Timeout reading burst and status\n");  in tpm_cr50_i2c_get_burst_and_status()
455 	return -ETIMEDOUT;  in tpm_cr50_i2c_get_burst_and_status()
459  * tpm_cr50_i2c_tis_recv() - TPM reception callback.
460  * @chip:	A TPM chip.
462  * @buf_len:	Buffer length to read.
465  * - >= 0:	Number of read bytes.
466  * - -errno:	A POSIX error code.
468 static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)  in tpm_cr50_i2c_tis_recv()  argument
473 	u8 addr = TPM_I2C_DATA_FIFO(chip->locality);  in tpm_cr50_i2c_tis_recv()
478 		return -EINVAL;  in tpm_cr50_i2c_tis_recv()
480 	rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
485 		dev_err(&chip->dev,  in tpm_cr50_i2c_tis_recv()
488 		rc = -EIO;  in tpm_cr50_i2c_tis_recv()
493 	rc = tpm_cr50_i2c_read(chip, addr, buf, burstcnt);  in tpm_cr50_i2c_tis_recv()
495 		dev_err(&chip->dev, "Read of first chunk failed\n");  in tpm_cr50_i2c_tis_recv()
502 		dev_err(&chip->dev, "Buffer too small to receive i2c data\n");  in tpm_cr50_i2c_tis_recv()
503 		rc = -E2BIG;  in tpm_cr50_i2c_tis_recv()
511 		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
515 		len = min_t(size_t, burstcnt, expected - cur);  in tpm_cr50_i2c_tis_recv()
516 		rc = tpm_cr50_i2c_read(chip, addr, buf + cur, len);  in tpm_cr50_i2c_tis_recv()
518 			dev_err(&chip->dev, "Read failed\n");  in tpm_cr50_i2c_tis_recv()
526 	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
530 		dev_err(&chip->dev, "Data still available\n");  in tpm_cr50_i2c_tis_recv()
531 		rc = -EIO;  in tpm_cr50_i2c_tis_recv()
539 	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)  in tpm_cr50_i2c_tis_recv()
540 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_recv()
546  * tpm_cr50_i2c_tis_send() - TPM transmission callback.
547  * @chip:	A TPM chip.
548  * @buf:	Buffer to send.
552  * - 0:		Success.
553  * - -errno:	A POSIX error code.
555 static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)  in tpm_cr50_i2c_tis_send()  argument
564 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_tis_send()
565 	while (!(tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)) {  in tpm_cr50_i2c_tis_send()
567 			rc = -ETIMEDOUT;  in tpm_cr50_i2c_tis_send()
571 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_send()
582 		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_send()
587 		 * Use burstcnt - 1 to account for the address byte  in tpm_cr50_i2c_tis_send()
590 		limit = min_t(size_t, burstcnt - 1, len);  in tpm_cr50_i2c_tis_send()
591 		rc = tpm_cr50_i2c_write(chip, TPM_I2C_DATA_FIFO(chip->locality),  in tpm_cr50_i2c_tis_send()
594 			dev_err(&chip->dev, "Write failed\n");  in tpm_cr50_i2c_tis_send()
599 		len -= limit;  in tpm_cr50_i2c_tis_send()
603 	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);  in tpm_cr50_i2c_tis_send()
607 		dev_err(&chip->dev, "Data still expected\n");  in tpm_cr50_i2c_tis_send()
608 		rc = -EIO;  in tpm_cr50_i2c_tis_send()
613 	rc = tpm_cr50_i2c_write(chip, TPM_I2C_STS(chip->locality), tpm_go,  in tpm_cr50_i2c_tis_send()
616 		dev_err(&chip->dev, "Start command failed\n");  in tpm_cr50_i2c_tis_send()
623 	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)  in tpm_cr50_i2c_tis_send()
624 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_send()
630  * tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
631  * @chip:	A TPM chip.
637 static bool tpm_cr50_i2c_req_canceled(struct tpm_chip *chip, u8 status)  in tpm_cr50_i2c_req_canceled()  argument
648 	ret = device_property_read_u8(dev, "firmware-power-managed", &val);  in tpm_cr50_i2c_is_firmware_power_managed()
685  * tpm_cr50_vid_to_name() - Maps VID to name.
686  * @vendor:	Vendor identifier to map to name
706  * tpm_cr50_i2c_probe() - Driver probe function.
710  * - 0:		Success.
711  * - -errno:	A POSIX error code.
716 	struct device *dev = &client->dev;  in tpm_cr50_i2c_probe()
717 	struct tpm_chip *chip;  in tpm_cr50_i2c_probe()  local
723 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in tpm_cr50_i2c_probe()
724 		return -ENODEV;  in tpm_cr50_i2c_probe()
726 	chip = tpmm_chip_alloc(dev, &cr50_i2c);  in tpm_cr50_i2c_probe()
727 	if (IS_ERR(chip))  in tpm_cr50_i2c_probe()
728 		return PTR_ERR(chip);  in tpm_cr50_i2c_probe()
732 		return -ENOMEM;  in tpm_cr50_i2c_probe()
734 	/* cr50 is a TPM 2.0 chip */  in tpm_cr50_i2c_probe()
735 	chip->flags |= TPM_CHIP_FLAG_TPM2;  in tpm_cr50_i2c_probe()
737 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED;  in tpm_cr50_i2c_probe()
740 	chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
741 	chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);  in tpm_cr50_i2c_probe()
742 	chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
743 	chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
745 	dev_set_drvdata(&chip->dev, priv);  in tpm_cr50_i2c_probe()
746 	init_completion(&priv->tpm_ready);  in tpm_cr50_i2c_probe()
748 	if (client->irq > 0) {  in tpm_cr50_i2c_probe()
749 		rc = devm_request_irq(dev, client->irq, tpm_cr50_i2c_int_handler,  in tpm_cr50_i2c_probe()
752 				      dev->driver->name, chip);  in tpm_cr50_i2c_probe()
754 			dev_err(dev, "Failed to probe IRQ %d\n", client->irq);  in tpm_cr50_i2c_probe()
758 		priv->irq = client->irq;  in tpm_cr50_i2c_probe()
764 	loc = tpm_cr50_request_locality(chip, TPM_CR50_I2C_DEFAULT_LOC);  in tpm_cr50_i2c_probe()
771 	rc = tpm_cr50_i2c_read(chip, TPM_I2C_DID_VID(loc), buf, sizeof(buf));  in tpm_cr50_i2c_probe()
774 		if (tpm_cr50_release_locality(chip, loc))  in tpm_cr50_i2c_probe()
779 	rc = tpm_cr50_release_locality(chip, loc);  in tpm_cr50_i2c_probe()
790 		return -ENODEV;  in tpm_cr50_i2c_probe()
795 		 client->addr, client->irq, vendor >> 16);  in tpm_cr50_i2c_probe()
796 	return tpm_chip_register(chip);  in tpm_cr50_i2c_probe()
800  * tpm_cr50_i2c_remove() - Driver remove function.
804  * - 0:		Success.
805  * - -errno:	A POSIX error code.
809 	struct tpm_chip *chip = i2c_get_clientdata(client);  in tpm_cr50_i2c_remove()  local
810 	struct device *dev = &client->dev;  in tpm_cr50_i2c_remove()
812 	if (!chip) {  in tpm_cr50_i2c_remove()
817 	tpm_chip_unregister(chip);  in tpm_cr50_i2c_remove()