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
35 #define TPM_CR50_I2C_MAX_RETRIES	3		/* Max retries due to I2C errors */
45  * struct tpm_i2c_cr50_priv_data - Driver private data.
46  * @irq:	Irq number used for this chip.
48  * @tpm_ready:	Struct used by irq handler to signal R/W readiness.
49  * @buf:	Buffer used for i2c writes, with i2c address prepended to content.
60  * tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
62  * @tpm_info:	TPM chip information.
66  * processing but is instead used to avoid fixed delays.
73 	struct tpm_chip *chip = tpm_info;  in tpm_cr50_i2c_int_handler()  local
74 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_int_handler()
76 	complete(&priv->tpm_ready);  in tpm_cr50_i2c_int_handler()
82  * tpm_cr50_i2c_wait_tpm_ready() - Wait for tpm to signal ready.
83  * @chip: A TPM chip.
86  * delay for the TPM to be ready.
89  * - 0:		Success.
90  * - -errno:	A POSIX error code.
92 static int tpm_cr50_i2c_wait_tpm_ready(struct tpm_chip *chip)  in tpm_cr50_i2c_wait_tpm_ready()  argument
94 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_wait_tpm_ready()
97 	if (priv->irq <= 0) {  in tpm_cr50_i2c_wait_tpm_ready()
102 	/* Wait for interrupt to indicate TPM is ready to respond */  in tpm_cr50_i2c_wait_tpm_ready()
103 	if (!wait_for_completion_timeout(&priv->tpm_ready, chip->timeout_a)) {  in tpm_cr50_i2c_wait_tpm_ready()
104 		dev_warn(&chip->dev, "Timeout waiting for TPM ready\n");  in tpm_cr50_i2c_wait_tpm_ready()
105 		return -ETIMEDOUT;  in tpm_cr50_i2c_wait_tpm_ready()
112  * tpm_cr50_i2c_enable_tpm_irq() - Enable TPM irq.
113  * @chip: A TPM chip.
115 static void tpm_cr50_i2c_enable_tpm_irq(struct tpm_chip *chip)  in tpm_cr50_i2c_enable_tpm_irq()  argument
117 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_enable_tpm_irq()
119 	if (priv->irq > 0) {  in tpm_cr50_i2c_enable_tpm_irq()
120 		reinit_completion(&priv->tpm_ready);  in tpm_cr50_i2c_enable_tpm_irq()
121 		enable_irq(priv->irq);  in tpm_cr50_i2c_enable_tpm_irq()
126  * tpm_cr50_i2c_disable_tpm_irq() - Disable TPM irq.
127  * @chip: A TPM chip.
129 static void tpm_cr50_i2c_disable_tpm_irq(struct tpm_chip *chip)  in tpm_cr50_i2c_disable_tpm_irq()  argument
131 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_disable_tpm_irq()
133 	if (priv->irq > 0)  in tpm_cr50_i2c_disable_tpm_irq()
134 		disable_irq(priv->irq);  in tpm_cr50_i2c_disable_tpm_irq()
138  * tpm_cr50_i2c_transfer_message() - Transfer a message over i2c.
141  * @msg:	Message to transfer.
147  * - 0:		Success.
148  * - -errno:	A POSIX error code.
168 	return -EIO;  in tpm_cr50_i2c_transfer_message()
172  * tpm_cr50_i2c_read() - Read from TPM register.
173  * @chip:	A TPM chip.
174  * @addr:	Register address to read from.
176  * @len:	Number of bytes to read.
178  * Sends the register address byte to the TPM, then waits until TPM
183  * - 0:		Success.
184  * - -errno:	A POSIX error code.
186 static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t len)  in tpm_cr50_i2c_read()  argument
188 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  in tpm_cr50_i2c_read()
190 		.addr = client->addr,  in tpm_cr50_i2c_read()
195 		.addr = client->addr,  in tpm_cr50_i2c_read()
202 	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_i2c_read()
205 	tpm_cr50_i2c_enable_tpm_irq(chip);  in tpm_cr50_i2c_read()
207 	/* Send the register address byte to the TPM */  in tpm_cr50_i2c_read()
208 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);  in tpm_cr50_i2c_read()
212 	/* Wait for TPM to be ready with response data */  in tpm_cr50_i2c_read()
213 	rc = tpm_cr50_i2c_wait_tpm_ready(chip);  in tpm_cr50_i2c_read()
218 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);  in tpm_cr50_i2c_read()
221 	tpm_cr50_i2c_disable_tpm_irq(chip);  in tpm_cr50_i2c_read()
222 	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);  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()
264 	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_i2c_write()
267 	tpm_cr50_i2c_enable_tpm_irq(chip);  in tpm_cr50_i2c_write()
270 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);  in tpm_cr50_i2c_write()
274 	/* Wait for TPM to be ready, ignore timeout */  in tpm_cr50_i2c_write()
275 	tpm_cr50_i2c_wait_tpm_ready(chip);  in tpm_cr50_i2c_write()
278 	tpm_cr50_i2c_disable_tpm_irq(chip);  in tpm_cr50_i2c_write()
279 	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_i2c_write()
288  * tpm_cr50_check_locality() - Verify TPM locality 0 is active.
289  * @chip: A TPM chip.
292  * - 0:		Success.
293  * - -errno:	A POSIX error code.
295 static int tpm_cr50_check_locality(struct tpm_chip *chip)  in tpm_cr50_check_locality()  argument
301 	rc = tpm_cr50_i2c_read(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));  in tpm_cr50_check_locality()
308 	return -EIO;  in tpm_cr50_check_locality()
312  * tpm_cr50_release_locality() - Release TPM locality.
313  * @chip:	A TPM chip.
314  * @force:	Flag to force release if set.
316 static void tpm_cr50_release_locality(struct tpm_chip *chip, bool force)  in tpm_cr50_release_locality()  argument
322 	if (tpm_cr50_i2c_read(chip, addr, &buf, sizeof(buf)) < 0)  in tpm_cr50_release_locality()
327 		tpm_cr50_i2c_write(chip, addr, &buf, sizeof(buf));  in tpm_cr50_release_locality()
332  * tpm_cr50_request_locality() - Request TPM locality 0.
333  * @chip: A TPM chip.
336  * - 0:		Success.
337  * - -errno:	A POSIX error code.
339 static int tpm_cr50_request_locality(struct tpm_chip *chip)  in tpm_cr50_request_locality()  argument
345 	if (!tpm_cr50_check_locality(chip))  in tpm_cr50_request_locality()
348 	rc = tpm_cr50_i2c_write(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));  in tpm_cr50_request_locality()
352 	stop = jiffies + chip->timeout_a;  in tpm_cr50_request_locality()
354 		if (!tpm_cr50_check_locality(chip))  in tpm_cr50_request_locality()
360 	return -ETIMEDOUT;  in tpm_cr50_request_locality()
364  * tpm_cr50_i2c_tis_status() - Read cr50 tis status.
365  * @chip: A TPM chip.
367  * cr50 requires all 4 bytes of status register to be read.
372 static u8 tpm_cr50_i2c_tis_status(struct tpm_chip *chip)  in tpm_cr50_i2c_tis_status()  argument
376 	if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0)  in tpm_cr50_i2c_tis_status()
383  * tpm_cr50_i2c_tis_set_ready() - Set status register to ready.
384  * @chip: A TPM chip.
386  * cr50 requires all 4 bytes of status register to be written.
388 static void tpm_cr50_i2c_tis_set_ready(struct tpm_chip *chip)  in tpm_cr50_i2c_tis_set_ready()  argument
392 	tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), buf, sizeof(buf));  in tpm_cr50_i2c_tis_set_ready()
397  * tpm_cr50_i2c_get_burst_and_status() - Get burst count and status.
398  * @chip:	A TPM chip.
407  * - 0:		Success.
408  * - -errno:	A POSIX error code.
410 static int tpm_cr50_i2c_get_burst_and_status(struct tpm_chip *chip, u8 mask,  in tpm_cr50_i2c_get_burst_and_status()  argument
419 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_get_burst_and_status()
422 		if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0) {  in tpm_cr50_i2c_get_burst_and_status()
431 		    *burst > 0 && *burst <= TPM_CR50_MAX_BUFSIZE - 1)  in tpm_cr50_i2c_get_burst_and_status()
437 	dev_err(&chip->dev, "Timeout reading burst and status\n");  in tpm_cr50_i2c_get_burst_and_status()
438 	return -ETIMEDOUT;  in tpm_cr50_i2c_get_burst_and_status()
442  * tpm_cr50_i2c_tis_recv() - TPM reception callback.
443  * @chip:	A TPM chip.
445  * @buf_len:	Buffer length to read.
448  * - >= 0:	Number of read bytes.
449  * - -errno:	A POSIX error code.
451 static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)  in tpm_cr50_i2c_tis_recv()  argument
461 		return -EINVAL;  in tpm_cr50_i2c_tis_recv()
463 	rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
468 		dev_err(&chip->dev,  in tpm_cr50_i2c_tis_recv()
471 		rc = -EIO;  in tpm_cr50_i2c_tis_recv()
476 	rc = tpm_cr50_i2c_read(chip, addr, buf, burstcnt);  in tpm_cr50_i2c_tis_recv()
478 		dev_err(&chip->dev, "Read of first chunk failed\n");  in tpm_cr50_i2c_tis_recv()
485 		dev_err(&chip->dev, "Buffer too small to receive i2c data\n");  in tpm_cr50_i2c_tis_recv()
486 		rc = -E2BIG;  in tpm_cr50_i2c_tis_recv()
494 		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
498 		len = min_t(size_t, burstcnt, expected - cur);  in tpm_cr50_i2c_tis_recv()
499 		rc = tpm_cr50_i2c_read(chip, addr, buf + cur, len);  in tpm_cr50_i2c_tis_recv()
501 			dev_err(&chip->dev, "Read failed\n");  in tpm_cr50_i2c_tis_recv()
509 	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);  in tpm_cr50_i2c_tis_recv()
513 		dev_err(&chip->dev, "Data still available\n");  in tpm_cr50_i2c_tis_recv()
514 		rc = -EIO;  in tpm_cr50_i2c_tis_recv()
518 	tpm_cr50_release_locality(chip, false);  in tpm_cr50_i2c_tis_recv()
523 	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)  in tpm_cr50_i2c_tis_recv()
524 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_recv()
526 	tpm_cr50_release_locality(chip, false);  in tpm_cr50_i2c_tis_recv()
531  * tpm_cr50_i2c_tis_send() - TPM transmission callback.
532  * @chip:	A TPM chip.
533  * @buf:	Buffer to send.
537  * - 0:		Success.
538  * - -errno:	A POSIX error code.
540 static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)  in tpm_cr50_i2c_tis_send()  argument
548 	rc = tpm_cr50_request_locality(chip);  in tpm_cr50_i2c_tis_send()
553 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_tis_send()
554 	while (!(tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)) {  in tpm_cr50_i2c_tis_send()
556 			rc = -ETIMEDOUT;  in tpm_cr50_i2c_tis_send()
560 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_send()
571 		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);  in tpm_cr50_i2c_tis_send()
576 		 * Use burstcnt - 1 to account for the address byte  in tpm_cr50_i2c_tis_send()
579 		limit = min_t(size_t, burstcnt - 1, len);  in tpm_cr50_i2c_tis_send()
580 		rc = tpm_cr50_i2c_write(chip, TPM_I2C_DATA_FIFO(0), &buf[sent], limit);  in tpm_cr50_i2c_tis_send()
582 			dev_err(&chip->dev, "Write failed\n");  in tpm_cr50_i2c_tis_send()
587 		len -= limit;  in tpm_cr50_i2c_tis_send()
591 	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);  in tpm_cr50_i2c_tis_send()
595 		dev_err(&chip->dev, "Data still expected\n");  in tpm_cr50_i2c_tis_send()
596 		rc = -EIO;  in tpm_cr50_i2c_tis_send()
601 	rc = tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), tpm_go,  in tpm_cr50_i2c_tis_send()
604 		dev_err(&chip->dev, "Start command failed\n");  in tpm_cr50_i2c_tis_send()
611 	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)  in tpm_cr50_i2c_tis_send()
612 		tpm_cr50_i2c_tis_set_ready(chip);  in tpm_cr50_i2c_tis_send()
614 	tpm_cr50_release_locality(chip, false);  in tpm_cr50_i2c_tis_send()
619  * tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
620  * @chip:	A TPM chip.
626 static bool tpm_cr50_i2c_req_canceled(struct tpm_chip *chip, u8 status)  in tpm_cr50_i2c_req_canceled()  argument
637 	ret = device_property_read_u8(dev, "firmware-power-managed", &val);  in tpm_cr50_i2c_is_firmware_power_managed()
672  * tpm_cr50_i2c_probe() - Driver probe function.
676  * - 0:		Success.
677  * - -errno:	A POSIX error code.
682 	struct device *dev = &client->dev;  in tpm_cr50_i2c_probe()
683 	struct tpm_chip *chip;  in tpm_cr50_i2c_probe()  local
688 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in tpm_cr50_i2c_probe()
689 		return -ENODEV;  in tpm_cr50_i2c_probe()
691 	chip = tpmm_chip_alloc(dev, &cr50_i2c);  in tpm_cr50_i2c_probe()
692 	if (IS_ERR(chip))  in tpm_cr50_i2c_probe()
693 		return PTR_ERR(chip);  in tpm_cr50_i2c_probe()
697 		return -ENOMEM;  in tpm_cr50_i2c_probe()
699 	/* cr50 is a TPM 2.0 chip */  in tpm_cr50_i2c_probe()
700 	chip->flags |= TPM_CHIP_FLAG_TPM2;  in tpm_cr50_i2c_probe()
702 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED;  in tpm_cr50_i2c_probe()
705 	chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
706 	chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);  in tpm_cr50_i2c_probe()
707 	chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
708 	chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);  in tpm_cr50_i2c_probe()
710 	dev_set_drvdata(&chip->dev, priv);  in tpm_cr50_i2c_probe()
711 	init_completion(&priv->tpm_ready);  in tpm_cr50_i2c_probe()
713 	if (client->irq > 0) {  in tpm_cr50_i2c_probe()
714 		rc = devm_request_irq(dev, client->irq, tpm_cr50_i2c_int_handler,  in tpm_cr50_i2c_probe()
717 				      dev->driver->name, chip);  in tpm_cr50_i2c_probe()
719 			dev_err(dev, "Failed to probe IRQ %d\n", client->irq);  in tpm_cr50_i2c_probe()
723 		priv->irq = client->irq;  in tpm_cr50_i2c_probe()
729 	rc = tpm_cr50_request_locality(chip);  in tpm_cr50_i2c_probe()
736 	rc = tpm_cr50_i2c_read(chip, TPM_I2C_DID_VID(0), buf, sizeof(buf));  in tpm_cr50_i2c_probe()
739 		tpm_cr50_release_locality(chip, true);  in tpm_cr50_i2c_probe()
746 		tpm_cr50_release_locality(chip, true);  in tpm_cr50_i2c_probe()
747 		return -ENODEV;  in tpm_cr50_i2c_probe()
752 		 client->addr, client->irq, vendor >> 16);  in tpm_cr50_i2c_probe()
753 	return tpm_chip_register(chip);  in tpm_cr50_i2c_probe()
757  * tpm_cr50_i2c_remove() - Driver remove function.
761  * - 0:		Success.
762  * - -errno:	A POSIX error code.
766 	struct tpm_chip *chip = i2c_get_clientdata(client);  in tpm_cr50_i2c_remove()  local
767 	struct device *dev = &client->dev;  in tpm_cr50_i2c_remove()
769 	if (!chip) {  in tpm_cr50_i2c_remove()
774 	tpm_chip_unregister(chip);  in tpm_cr50_i2c_remove()
775 	tpm_cr50_release_locality(chip, true);  in tpm_cr50_i2c_remove()