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
45  * struct tpm_i2c_cr50_priv_data - Driver private data.
47  *		If irq <= 0, then a fixed timeout is used instead of waiting for irq.
60  * tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
66  * processing but is instead used to avoid fixed delays.
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.
85  * Wait for completion interrupt if available, otherwise use a fixed
89  * - 0:		Success.
90  * - -errno:	A POSIX error code.
94 	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);  in tpm_cr50_i2c_wait_tpm_ready()
96 	/* Use a safe fixed delay if interrupt is not supported */  in tpm_cr50_i2c_wait_tpm_ready()
97 	if (priv->irq <= 0) {  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.
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.
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.
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.
183  * - 0:		Success.
184  * - -errno:	A POSIX error code.
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()
208 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);  in tpm_cr50_i2c_read()
218 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);  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.
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()
264 	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);  in tpm_cr50_i2c_write()
270 	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);  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.
292  * - 0:		Success.
293  * - -errno:	A POSIX error code.
308 	return -EIO;  in tpm_cr50_check_locality()
312  * tpm_cr50_release_locality() - Release TPM locality.
332  * tpm_cr50_request_locality() - Request TPM locality 0.
336  * - 0:		Success.
337  * - -errno:	A POSIX error code.
352 	stop = jiffies + chip->timeout_a;  in tpm_cr50_request_locality()
360 	return -ETIMEDOUT;  in tpm_cr50_request_locality()
364  * tpm_cr50_i2c_tis_status() - Read cr50 tis status.
383  * tpm_cr50_i2c_tis_set_ready() - Set status register to ready.
397  * tpm_cr50_i2c_get_burst_and_status() - Get burst count and status.
400  * @burst:	Return value for burst.
403  * cr50 uses bytes 3:2 of status register for burst count and
407  * - 0:		Success.
408  * - -errno:	A POSIX error code.
411 					     size_t *burst, u32 *status)  in tpm_cr50_i2c_get_burst_and_status()  argument
419 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_get_burst_and_status()
428 		*burst = le16_to_cpup((__le16 *)(buf + 1));  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.
448  * - >= 0:	Number of read bytes.
449  * - -errno:	A POSIX error code.
461 		return -EINVAL;  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()
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()
493 		/* Read updated burst count and check status */  in tpm_cr50_i2c_tis_recv()
498 		len = min_t(size_t, burstcnt, expected - cur);  in tpm_cr50_i2c_tis_recv()
501 			dev_err(&chip->dev, "Read failed\n");  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()
531  * tpm_cr50_i2c_tis_send() - TPM transmission callback.
537  * - 0:		Success.
538  * - -errno:	A POSIX error code.
553 	stop = jiffies + chip->timeout_b;  in tpm_cr50_i2c_tis_send()
556 			rc = -ETIMEDOUT;  in tpm_cr50_i2c_tis_send()
570 		/* Read burst count and check 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()
582 			dev_err(&chip->dev, "Write failed\n");  in tpm_cr50_i2c_tis_send()
587 		len -= limit;  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()
604 		dev_err(&chip->dev, "Start command failed\n");  in tpm_cr50_i2c_tis_send()
619  * tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
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()
688 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in tpm_cr50_i2c_probe()
689 		return -ENODEV;  in tpm_cr50_i2c_probe()
697 		return -ENOMEM;  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()
747 		return -ENODEV;  in tpm_cr50_i2c_probe()
752 		 client->addr, client->irq, vendor >> 16);  in tpm_cr50_i2c_probe()
757  * tpm_cr50_i2c_remove() - Driver remove function.
761  * - 0:		Success.
762  * - -errno:	A POSIX error code.
767 	struct device *dev = &client->dev;  in tpm_cr50_i2c_remove()