1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * STMicroelectronics TPM SPI Linux driver for TPM ST33ZP24
4  * Copyright (C) 2009 - 2016 STMicroelectronics
8 #include <linux/spi/spi.h>
14 #include "st33zp24.h"
42  * usually on st33zp24 2 are enough).
77 		return -EPROTO;  in st33zp24_status_to_errno()
80 		return -EMSGSIZE;  in st33zp24_status_to_errno()
82 		return -ENOSYS;  in st33zp24_status_to_errno()
89  * Send byte to the TIS register according to the ST33ZP24 SPI protocol.
101 	struct spi_device *dev = phy->spi_device;  in st33zp24_spi_send()
103 		.tx_buf = phy->tx_buf,  in st33zp24_spi_send()
104 		.rx_buf = phy->rx_buf,  in st33zp24_spi_send()
107 	/* Pre-Header */  in st33zp24_spi_send()
108 	phy->tx_buf[total_length++] = TPM_WRITE_DIRECTION | LOCALITY0;  in st33zp24_spi_send()
109 	phy->tx_buf[total_length++] = tpm_register;  in st33zp24_spi_send()
112 		phy->tx_buf[total_length++] = tpm_size >> 8;  in st33zp24_spi_send()
113 		phy->tx_buf[total_length++] = tpm_size;  in st33zp24_spi_send()
116 	memcpy(&phy->tx_buf[total_length], tpm_data, tpm_size);  in st33zp24_spi_send()
119 	memset(&phy->tx_buf[total_length], TPM_DUMMY_BYTE, phy->latency);  in st33zp24_spi_send()
121 	spi_xfer.len = total_length + phy->latency;  in st33zp24_spi_send()
125 		ret = phy->rx_buf[total_length + phy->latency - 1];  in st33zp24_spi_send()
132  * Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
144 	struct spi_device *dev = phy->spi_device;  in st33zp24_spi_read8_reg()
146 		.tx_buf = phy->tx_buf,  in st33zp24_spi_read8_reg()
147 		.rx_buf = phy->rx_buf,  in st33zp24_spi_read8_reg()
150 	/* Pre-Header */  in st33zp24_spi_read8_reg()
151 	phy->tx_buf[total_length++] = LOCALITY0;  in st33zp24_spi_read8_reg()
152 	phy->tx_buf[total_length++] = tpm_register;  in st33zp24_spi_read8_reg()
154 	memset(&phy->tx_buf[total_length], TPM_DUMMY_BYTE,  in st33zp24_spi_read8_reg()
155 	       phy->latency + tpm_size);  in st33zp24_spi_read8_reg()
157 	spi_xfer.len = total_length + phy->latency + tpm_size;  in st33zp24_spi_read8_reg()
162 		ret = phy->rx_buf[total_length + phy->latency - 1];  in st33zp24_spi_read8_reg()
164 		memcpy(tpm_data, phy->rx_buf + total_length + phy->latency,  in st33zp24_spi_read8_reg()
173  * Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
198 		phy->latency = latency;  in st33zp24_spi_evaluate_latency()
206 		return -ENODEV;  in st33zp24_spi_evaluate_latency()
208 	return latency - 1;  in st33zp24_spi_evaluate_latency()
218  * @param: dev, the spi_device description (TPM SPI description).
226 	phy = devm_kzalloc(&dev->dev, sizeof(struct st33zp24_spi_phy),  in st33zp24_spi_probe()
229 		return -ENOMEM;  in st33zp24_spi_probe()
231 	phy->spi_device = dev;  in st33zp24_spi_probe()
233 	phy->latency = st33zp24_spi_evaluate_latency(phy);  in st33zp24_spi_probe()
234 	if (phy->latency <= 0)  in st33zp24_spi_probe()
235 		return -ENODEV;  in st33zp24_spi_probe()
237 	return st33zp24_probe(phy, &spi_phy_ops, &dev->dev, dev->irq);  in st33zp24_spi_probe()
242  * @param: client, the spi_device description (TPM SPI description).
256 MODULE_DEVICE_TABLE(spi, st33zp24_spi_id);
259 	{ .compatible = "st,st33zp24-spi", },
275 		.name = "st33zp24-spi",
288 MODULE_DESCRIPTION("STM TPM 1.2 SPI ST33 Driver");