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
48  * struct tpm_i2c_cr50_priv_data - Driver private data.
63  * tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
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.
92  * - 0:		Success.
93  * - -errno:	A POSIX error code.
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()
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.
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.
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.
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.
177  * @addr:	Register address to read from.
178  * @buffer:	Read destination, provided by caller.
179  * @len:	Number of bytes to read.
183  * bytes are read from TPM response into the provided 'buffer'.
186  * - 0:		Success.
187  * - -errno:	A POSIX error code.
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()
209 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);  in tpm_cr50_i2c_read()
218 	/* Read response data from the TPM */  in tpm_cr50_i2c_read()
219 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);  in tpm_cr50_i2c_read()
231  * tpm_cr50_i2c_write()- Write to TPM register.
242  * - 0:		Success.
243  * - -errno:	A POSIX error code.
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()
261 	priv->buf[0] = addr;  in tpm_cr50_i2c_write()
262 	memcpy(priv->buf + 1, buffer, len);  in tpm_cr50_i2c_write()
268 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);  in tpm_cr50_i2c_write()
285  * tpm_cr50_check_locality() - Verify if required TPM locality is active.
290  * - loc:	Success.
291  * - -errno:	A POSIX error code.
306 	return -EIO;  in tpm_cr50_check_locality()
310  * tpm_cr50_release_locality() - Release TPM locality.
315  * - 0:		Success.
316  * - -errno:	A POSIX error code.
320 	struct i2c_client *client = to_i2c_client(chip->dev.parent);  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.
346  * - loc:	Success.
347  * - -errno:	A POSIX error code.
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()
365 	stop = jiffies + chip->timeout_a;  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.
384  * cr50 requires all 4 bytes of status register to be read.
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.
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.
417  * @burst:	Return value for burst.
420  * cr50 uses bytes 3:2 of status register for burst count and
421  * all 4 bytes must be read.
424  * - 0:		Success.
425  * - -errno:	A POSIX error code.
428 					     size_t *burst, u32 *status)  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()
445 		*burst = le16_to_cpup((__le16 *)(buf + 1));  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.
462  * @buf_len:	Buffer length to read.
465  * - >= 0:	Number of read bytes.
466  * - -errno:	A POSIX error code.
473 	u8 addr = TPM_I2C_DATA_FIFO(chip->locality);  in tpm_cr50_i2c_tis_recv()
478 		return -EINVAL;  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()
492 	/* Read first chunk of burstcnt bytes */  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()
507 	/* Now read the rest of the data */  in tpm_cr50_i2c_tis_recv()
510 		/* Read updated burst count and check status */  in tpm_cr50_i2c_tis_recv()
515 		len = min_t(size_t, burstcnt, expected - cur);  in tpm_cr50_i2c_tis_recv()
518 			dev_err(&chip->dev, "Read failed\n");  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()
546  * tpm_cr50_i2c_tis_send() - TPM transmission callback.
552  * - 0:		Success.
553  * - -errno:	A POSIX error code.
564 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_tis_send()
567 			rc = -ETIMEDOUT;  in tpm_cr50_i2c_tis_send()
581 		/* Read burst count and check 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()
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()
630  * tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
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.
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()
723 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in tpm_cr50_i2c_probe()
724 		return -ENODEV;  in tpm_cr50_i2c_probe()
732 		return -ENOMEM;  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()
770 	/* Read four bytes from DID_VID register */  in tpm_cr50_i2c_probe()
773 		dev_err(dev, "Could not read vendor id\n");  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()
800  * tpm_cr50_i2c_remove() - Driver remove function.
804  * - 0:		Success.
805  * - -errno:	A POSIX error code.
810 	struct device *dev = &client->dev;  in tpm_cr50_i2c_remove()