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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP244 * Copyright (C) 2009 - 2016 STMicroelectronics5 */6 7#include <linux/module.h>8#include <linux/i2c.h>9#include <linux/of.h>10#include <linux/acpi.h>11#include <linux/tpm.h>12 13#include "../tpm.h"14#include "st33zp24.h"15 16#define TPM_DUMMY_BYTE 0xAA17 18struct st33zp24_i2c_phy {19 struct i2c_client *client;20 u8 buf[ST33ZP24_BUFSIZE + 1];21};22 23/*24 * write8_reg25 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.26 * @param: tpm_register, the tpm tis register where the data should be written27 * @param: tpm_data, the tpm_data to write inside the tpm_register28 * @param: tpm_size, The length of the data29 * @return: Returns negative errno, or else the number of bytes written.30 */31static int write8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size)32{33 struct st33zp24_i2c_phy *phy = phy_id;34 35 phy->buf[0] = tpm_register;36 memcpy(phy->buf + 1, tpm_data, tpm_size);37 return i2c_master_send(phy->client, phy->buf, tpm_size + 1);38} /* write8_reg() */39 40/*41 * read8_reg42 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.43 * @param: tpm_register, the tpm tis register where the data should be read44 * @param: tpm_data, the TPM response45 * @param: tpm_size, tpm TPM response size to read.46 * @return: number of byte read successfully: should be one if success.47 */48static int read8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size)49{50 struct st33zp24_i2c_phy *phy = phy_id;51 u8 status = 0;52 u8 data;53 54 data = TPM_DUMMY_BYTE;55 status = write8_reg(phy, tpm_register, &data, 1);56 if (status == 2)57 status = i2c_master_recv(phy->client, tpm_data, tpm_size);58 return status;59} /* read8_reg() */60 61/*62 * st33zp24_i2c_send63 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.64 * @param: phy_id, the phy description65 * @param: tpm_register, the tpm tis register where the data should be written66 * @param: tpm_data, the tpm_data to write inside the tpm_register67 * @param: tpm_size, the length of the data68 * @return: number of byte written successfully: should be one if success.69 */70static int st33zp24_i2c_send(void *phy_id, u8 tpm_register, u8 *tpm_data,71 int tpm_size)72{73 return write8_reg(phy_id, tpm_register | TPM_WRITE_DIRECTION, tpm_data,74 tpm_size);75}76 77/*78 * st33zp24_i2c_recv79 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.80 * @param: phy_id, the phy description81 * @param: tpm_register, the tpm tis register where the data should be read82 * @param: tpm_data, the TPM response83 * @param: tpm_size, tpm TPM response size to read.84 * @return: number of byte read successfully: should be one if success.85 */86static int st33zp24_i2c_recv(void *phy_id, u8 tpm_register, u8 *tpm_data,87 int tpm_size)88{89 return read8_reg(phy_id, tpm_register, tpm_data, tpm_size);90}91 92static const struct st33zp24_phy_ops i2c_phy_ops = {93 .send = st33zp24_i2c_send,94 .recv = st33zp24_i2c_recv,95};96 97/*98 * st33zp24_i2c_probe initialize the TPM device99 * @param: client, the i2c_client description (TPM I2C description).100 * @param: id, the i2c_device_id struct.101 * @return: 0 in case of success.102 * -1 in other case.103 */104static int st33zp24_i2c_probe(struct i2c_client *client)105{106 struct st33zp24_i2c_phy *phy;107 108 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {109 dev_info(&client->dev, "client not i2c capable\n");110 return -ENODEV;111 }112 113 phy = devm_kzalloc(&client->dev, sizeof(struct st33zp24_i2c_phy),114 GFP_KERNEL);115 if (!phy)116 return -ENOMEM;117 118 phy->client = client;119 120 return st33zp24_probe(phy, &i2c_phy_ops, &client->dev, client->irq);121}122 123/*124 * st33zp24_i2c_remove remove the TPM device125 * @param: client, the i2c_client description (TPM I2C description).126 * @return: 0 in case of success.127 */128static void st33zp24_i2c_remove(struct i2c_client *client)129{130 struct tpm_chip *chip = i2c_get_clientdata(client);131 132 st33zp24_remove(chip);133}134 135static const struct i2c_device_id st33zp24_i2c_id[] = {136 { TPM_ST33_I2C },137 {}138};139MODULE_DEVICE_TABLE(i2c, st33zp24_i2c_id);140 141static const struct of_device_id of_st33zp24_i2c_match[] __maybe_unused = {142 { .compatible = "st,st33zp24-i2c", },143 {}144};145MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match);146 147static const struct acpi_device_id st33zp24_i2c_acpi_match[] __maybe_unused = {148 {"SMO3324"},149 {}150};151MODULE_DEVICE_TABLE(acpi, st33zp24_i2c_acpi_match);152 153static SIMPLE_DEV_PM_OPS(st33zp24_i2c_ops, st33zp24_pm_suspend,154 st33zp24_pm_resume);155 156static struct i2c_driver st33zp24_i2c_driver = {157 .driver = {158 .name = TPM_ST33_I2C,159 .pm = &st33zp24_i2c_ops,160 .of_match_table = of_match_ptr(of_st33zp24_i2c_match),161 .acpi_match_table = ACPI_PTR(st33zp24_i2c_acpi_match),162 },163 .probe = st33zp24_i2c_probe,164 .remove = st33zp24_i2c_remove,165 .id_table = st33zp24_i2c_id166};167 168module_i2c_driver(st33zp24_i2c_driver);169 170MODULE_AUTHOR("TPM support <TPMsupport@list.st.com>");171MODULE_DESCRIPTION("STM TPM 1.2 I2C ST33 Driver");172MODULE_VERSION("1.3.0");173MODULE_LICENSE("GPL");174